publications

2025

1. Microstructural Control by Freeze-Casting of CaO Architectures for Improved and Stable Thermochemical Energy Storage Performance

   N. Amghar, J. Ivorra-Martínez, A. Perejón, D. Henry Hanaor, A. Gurlo, J. Ramírez-Rico, L.A. Pérez-Maqueda, and P.E. Sánchez-Jiménez

   Journal of Energy Storage, 2025

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   This study investigates the development of porous calcium-based monoliths via freeze-casting (FC) as a novel approach for thermochemical energy storage, particularly within the Calcium Looping (CaL) process. The freeze-casting technique enabled the fabrication of scaffolds with controlled porosity using polyvinyl alcohol (PVA) as a binder. Experimental results demonstrated that freeze-cast monoliths exhibited superior multicycle performance under various carbonation and calcination conditions. The FC-CaCO3 monolith achieved the highest residual conversion of 68.1 % under mild vacuum calcination conditions (780 °C, 0.1 bar CO2), significantly surpassing other configurations. Tests conducted in an inert atmosphere also yielded favorable results, with a conversion of 56.1 %, outperforming equivalent raw powder samples. The enhanced performance is attributed to improved CO2 interaction with the porous structure, mitigating sintering effects and preserving active surface area. Morphological observations by X-ray tomography and SEM confirmed limited particle sintering after multiple cycles, maintaining a reactive surface that supported consistent conversion rates. The pore size distribution of the material evolves upon cycling resulting in an increased microporosity, while the pore network maintains a low tortuosity (τ ~ 1.5–2.0). The addition of dopants such as ZrO2 and SiO2 did not enhance performance, as the monoliths’ inherent structure provided sufficient stability. These findings highlight freeze-casting as a promising method for creating advanced porous materials suitable for energy storage applications. © 2025 The Authors

2. Porous Cu Thin Films Prepared by Magnetron Sputtering Using Helium as Depositing Gas

   G.M. Arzac, J. López-Viejobueno, M.E. Calvo, F.J. Ferrer-Fernandez, V. Godinho, D. Hufschmidt, M.C.J. de Haro, J. Ramírez-Rico, F. Varela, and A. Fernández

   Surface and Coatings Technology, 2025

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   In this work, porous copper thin films were prepared by magnetron sputtering (MS) deposition using helium as the process gas. Electron microscopy techniques were used to study the shape, size, amount and distribution of the pores. Working under direct current (DC) or radiofrequency (RF) conditions, enabled to achieve respectively a dense porous or an open porous columnar microstructure. At the nanoscopic level a characteristic solid-gas nanocomposite structure was also produced in both films. Spherical and faceted nano-bubbles filled with helium, with a size range of 1–22 nm and a uniform distribution across the entire thickness were visualized. RF conditions allowed higher gas loading, achieving up to 6.2 at.% He preferentially occluded in smaller pores. Characterization revealed that the RF-deposited copper (Cu) film is oxidised to a greater depth than the DC-deposited film, forming a thicker copper oxide(s) layer. This phenomenon can be attributed to the open porous nanostructure of the former. The results presented herein improve our understanding of MS deposition of copper with helium as process gas and pave the way for designing a wide range of materials with applications in the field of fusion reactors, (electro)catalysis, photocatalysis, fuel cells, electronics and the fabrication of negative crystals. © 2025 The Authors

3. Development and Characterization of Laboratory-Scale Sodium-Ion Battery Full Cell Containing Low Fluorinated Electrolyte

   M.N. Aslam, Y. Lu, S. Zhang, M. Gaško, M. Zarrabeitia, L.F. Pfeiffer, T. Werner, P. Axmann, C. Leibing, and A. Balducci

   Journal of Power Sources, 2025

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   Sodium-ion batteries (NIBs) are increasingly recognized as a viable and complementary technology to the Li-ion batteries (LIBs), with progress towards commercialization. However, the performance, stability and safety of these devices need to be further improved. State-of-the-art electrolytes, containing high fluorine content such as sodium hexafluorophosphate (NaPF6), guarantee satisfactory performance with improved SEI stability, but they pose serious environmental and safety concerns. Therefore, the development of less-fluorinated electrolytes that offer safe, sustainable, and promising performance is immensely important. This study investigates a sustainable, low-fluorinated electrolyte, comprising sodium bis(fluorosulfonyl)imide (NaFSI) and sodium difluoro(oxalato)borate (NaDFOB) in propylene carbonate (PC) solvent, for NIBs. The findings underscore that the use of this electrolyte in a laboratory-scale NIB full cell containing hard carbon (HC) and P2-Na2/3Al1/9Fe1/9Mn2/3Ni1/9O2(P2-AFMNO) cathode, allows the realization of devices which display high performance and stability, i.e., achieving 80 % capacity retention within a wider voltage range of 1.5–4.3 V vs Na+/Na, after 200 cycles. An X-ray photoelectron spectroscopy (XPS) analysis revealed the formation of inorganic-rich, robust and stable interfaces on both electrodes, contributing to enhanced stability and lifetime of the NIB demonstrator. © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license. http://creativecommons.org/licenses/by/4.0/

4. In Situ TEM and Synchrotron SAXS/WAXS Study on the Impact of Different Iron Salts on Iron-Catalysed Graphitization of Cellulose

   Emily C. Hayward, Masaki Takeguchi, Harry J. Lloyd, Joshua M. Stratford, Andrew J. Smith, Tim Snow, Joaquin Ramírez-Rico, and Zoe Schnepp

   Journal of Materials Chemistry A, 2025

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5. Special Issue on Sustainable Development of Printed Electronics: From Materials Processing to Devices Implementation

   E. Carlos, M. Ozório, N. Alves, and J. Coelho

   ACS Applied Electronic Materials, 2025

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6. 3D-printed Mineral Limestone Structures for Calcium Looping Thermochemical Energy Storage: Reactivity and Performance across Cycles

   A. Castro-Chincho, J. Ivorra-Martínez, A. Perejón, P.E. Sánchez-Jiménez, D. Lascano, J. Ramírez-Rico, and L.A. Pérez-Maqueda

   Journal of Energy Storage, 2025

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   This work presents a proof of concept for the use of 3D-printed CaCO₃ structures, prepared from low-cost and widely available mineral limestone, as an innovative approach for thermochemical energy storage (TCES) via the calcium looping (CaL) process in a fixed-bed reactor. These structures offer significant advantages in terms of reaction efficiency, gas flow control, structural stability, and maintenance. These factors are critical for achieving uniform reaction surface distribution and effective thermal management. The 3D structures were fabricated by robocasting and subjected to various debinding and calcination conditions. They maintained their structural integrity and exhibited high reactivity over multiple carbonation-calcination cycles. Under scheme 1 conditions (calcinations in nitrogen), the printed structures retained a CaO conversion of 0.44 after 50 cycles, corresponding to an energy density of 1.39 MJ kg−1 CaO, outperforming the powdered sample, which reached a conversion of 0.32. Advanced characterization techniques, including thermography, scanning electron microscopy, and X-ray computed tomography, highlight the internal structural advantages of the 3D structures. Overall, this study demonstrates the potential of 3D-printed CaCO₃ structures as scalable and efficient TCES materials, offering a promising route toward improving the performance and practical deployment of solid-state thermochemical energy storage systems. © 2025 The Authors

7. Polymer Electrolytes for Potassium Batteries: Incorporating Ionic Liquids to Enhance the Room Temperature Ionic Conductivity

   J. Chen, S. Ebrahimi-Koodehi, B. Iliev, Y. Steinberg, M. Leskes, T.J.S. Schubert, E. Castillo-Martínez, D. Bresser, and M. Zarrabeitia

   Journal of Materials Chemistry A, 2025

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   Exploring the next generation of batteries based on sustainable materials is crucial for transitioning to a post-lithium-technology era. Potassium-based technology is one of the candidates that could fulfil the sustainability criteria. The electrolyte plays a crucial role in battery performance, being responsible for ionic transport, cycling performance, working temperature, and safety. Polyethylene oxide (PEO)-based solid polymer electrolytes (SPEs) have been extensively studied. However, one of the drawbacks of SPEs is their poor ionic conductivity at room temperature (RT). Quasi-solid and solvent-free polymer electrolytes are a promising solution to this issue, combining the benefits of a liquid phase and SPEs. This work focuses on the development of cross-linked PEO, fluorinated K salt, and ionic liquid (IL)-based solvent-free SPEs for potassium batteries. The designed cross-linked ternary solvent-free SPEs are thoroughly characterized both physicochemically and electrochemically, achieving ionic conductivities of up to 1.6 × 10−3 S cm−1 at 20 °C. The solvent-free SPEs were tested in K cells at 20 °C, using a Prussian white (PW) cathode as a proof-of-concept. The effects that different fluorinated anions, such as bis(fluoromethanesulfonyl) imide (FSI−) and bis(trifluoromethanesulfonyl) imide (TFSI−), have on the electrochemical performance were analysed by investigating the solid electrolyte interphase (SEI) formed on the K metal surface through electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and magic-angle spinning solid-state nuclear magnetic resonance spectroscopy (MAS-ssNMR). © 2025 The Royal Society of Chemistry.

8. Interlayer Spacing Control of MoS2with Covalent Thiol Functionalization: Understanding Structure and Electrochemistry from Experiments and Simulation

   J. Choi, K. Nam, Y.T. Malik, R. Leiter, M. Zarrabeitia, C. Scheurer, and S. Fleischmann

   ACS Nano, 2025

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   Molybdenum disulfide (MoS2) is an increasingly investigated two-dimensional electrode material for electrochemical energy storage and conversion. Strategies to increase its interlayer spacing are emerging and have been shown to improve ion intercalation capacity and kinetics. This work explores covalent thiol functionalization for controlling MoS2interlayer spacing. Using a hydrothermal bottom-up synthesis, dithiolated molecules can be directly incorporated into the MoS2lattice to act as pillars. Using a comprehensive combination of experiments and simulation, we investigate the influence of dithiol pillar loading on the emerging structure, pillar–host interactions, and electrochemistry. Our results reveal clustering of pillars at low loading, leading to an inhomogeneous interlayer expansion. At high pillar loading, the formation of defective bonding configurations with excess sulfur is observed. Interlayer expansion leads to an increased electrochemical Li+storage capacity with a maximum of 1.43 Li+per MoS2. However, dithiols occupy storage sites and impede Li+transport within the interlayer space, leading to unfavorable performance at high pillar loading. This underlines the importance of carefully adjusting the density of nanoconfined pillar molecules within the interlayer space. Overall, the work comprehensively analyzes covalent dithiol functionalization of transition metal dichalcogenide-based electrode materials, offering valuable insights for the design of advanced energy materials. © 2025 The Authors. Published by American Chemical Society

9. Elucidating the Modes of Incorporation of the Ferulic Acid Amides Feruloyltyramine and Feruloyloctopamine into the Lignin-Suberin Fraction of Potato Periderms

   J.C. del Río, J. Ralph, J.J. Benítez, S. Guzman-Puyol, J.A. Heredia-Guerrero, and J. Rencoret

   International Journal of Biological Macromolecules, 2025

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   Ferulic acid amides are naturally present in the cell walls of potato (Solanum tuberosum) periderms. In this study, we investigated their modes of incorporation into the periderm cell wall polymers. A lignin/suberin-enriched fraction was isolated and analyzed by GPC, DFRC, and 2D-NMR. The analyses revealed that the lignin domain of this fraction was predominantly composed of G-lignin units, with an H:G:S ratio of 2:70:28 (S/G ratio of 0.40). More importantly, the data also indicated the presence of two ferulic acid amides, feruloyltyramine and feruloyloctopamine, that are incorporated into the lignin/suberin structure of potato periderms through a variety of linkages, including 8−O−4′ and 4−O−β’ ether linkages, as well as 8–5′ linkages forming a phenylcoumaran structure involving the ferulate moiety. Although the phenolic groups of the tyramine and octopamine moieties could theoretically undergo oxidation, potentially creating additional sites for radical coupling, our research indicates that these groups remain predominantly as free phenolic entities that do not participate in radical coupling. On the other hand, all the phenolic groups of the ferulate moieties are bound through ether linkages reinforcing the conclusion that the feruloyltyramine and feruloyloctopamine moieties are linked to lignin/suberin within the cell wall via radical coupling reactions. © 2025 The Authors

10. Triphenyl Acetic Glyceroate as a Sustainable Multifunctional Additive for Developing Transparent, Biodegradable, and Flexible Polylactide Green Alternative to Polyethylene-Based Films for Food Packaging

    Martina Ferri, Luca Lenzi, Micaela Degli Esposti, Laura Martellosio, José J. Benítez, Jesús Hierrezuelo, Montserrat Grifé-Ruiz, Diego Romero, Susana Guzmán-Puyol, José A. Heredia-Guerrero, Davide Morselli, and Paola Fabbri

    Chemical Engineering Journal, 2025

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    Polylactide-based materials represent a promising bio-based alternative to traditional food packaging polymers. However, their widespread use is still limited due to significant drawbacks, such as brittleness, high gas permeability, and biodegradability only under specific conditions. This work introduces fully bio-based Triphenyl Acetic Glyceroate (TPAG), synthesized through a solvent-free and mild conditions valorization of glycerol and phenylacetic acid, as a polylactide (PLA) plasticizer and multiple property-enhancer for extending foodstuff shelf-life. After optimizing TPAG synthesis and confirming its structure through FT-IR and NMR, PLA-based films are prepared at different TPAG contents (0, 5, 10, and 20 phr). Detailed investigations of the films’ thermal, mechanical, optical, hydrodynamic, barrier, antioxidant, antibacterial, migration, and biodegradation characteristics are carried out. TPAG shows a significant plasticizing effect while maintaining high transparency and improving PLA’s antioxidant, antibacterial and UV-blocking activities. Moreover, a notable lowering in oxygen and water vapor transmission rate is detected, revealing water vapor barrier properties closer to LDPE. Migration tests verify the material’s compliance with European regulations up to 10 phr, and BOD assessments in seawater indicate improved biodegradability. Fresh food preservation is evaluated on pear slices, showing limited variation of color, acidity, antioxidant power, and weight loss comparable to LDPE-based commercial packaging.

11. Plasticized Cellulose Bioplastics with Beeswax for the Fabrication of Multifunctional, Biodegradable Active Food Packaging

    P. Florido-Moreno, J.J. Benítez, J. González-Buesa, J.M. Porras-Vázquez, J. Hierrezuelo-León, M. Grifé-Ruiz, D. Romero, A. Athanassiou, J.A. Heredia-Guerrero, and S. Guzman-Puyol

    Food Hydrocolloids, 2025

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    Plasticized cellulose bioplastics with antioxidant and antimicrobial properties were prepared by blending cellulose and glycerol in a mixture of trifluoroacetic acid and trifluoroacetic anhydride, adding a solution of beeswax in chloroform, and subsequent drop-casting. Optical, chemical, structural, mechanical, thermal, and hydrodynamic properties were fully characterized. In addition, the biodegradability in seawater was investigated by determination of the biological oxygen demand. The incorporation of beeswax ruled out the transparency and UV blocking, modified the main mechanical parameters, and improved the thermal stability and the antioxidant capacity, as well as the hydrodynamic and barrier properties. In general, these features were comparable to those of common petroleum-based food packaging plastics. Such changes were explained by the incorporation of beeswax into the polymer matrix, as determined by infrared spectroscopy and X-ray diffraction. These cellulose-beeswax bioplastics were evaluated as viable food packaging materials by determination of the overall migration by using Tenax® as a dry food simulant, oxygen permeability at different relative humidities, measurement of antimicrobial activity against Escherichia coli and Bacillus cereus, and through preservation of fresh-cut pear slices, showing results similar to those obtained by using low-density polyethylene. © 2024 The Authors

12. Elucidating ‘Transfer-Lithiation’ from Graphite to Si within Composite Anodes during Pre-Lithiation and Regular Charging

    L. Frankenstein, P. Jan Glomb, M. Mohrhardt, S. Böckmann, L. Focks, A. Gómez-Martín, T. Placke, M. Hansen, M. Winter, and J. Kasnatscheew

    ChemSusChem, 2025

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    Si-based anodes can increase specific energy and energy density of Li ion batteries. However, the volume-induced material stress and capacity loss necessitates only a partial Si utilization within composite anodes, typically with state-of-the-art graphite, so called Si/Gr composites. In this work, various Si nanowires (SiNWs), a promising Si architecture for these composites, are investigated and modified via pre-lithiation. Though, charged pre-lithiated anodes show potentials below 0 V vs. Li|Li+ in the initial cycles, they do not show indications for metallic Li, which is likely a hint for a triggered surface Li depletion in course of a continuous “transfer-lithiation” from lithiated Gr to Si, which is indicated by decreasing LiC6 and increasing LixSiy signals via nuclear magnetic resonance (NMR), X-ray diffraction (XRD) as well as shifts in capacities of respective voltage plateaus during discharge after storage. A relevant contribution of self-discharge is unlikely as shown by a stable open-circuit-voltage during storage in charged state and similar subsequent discharge capacities, being consequently a hint for an intra-electrode capacity shift. The process of transfer lithiation is finally validated via solid-state 7Li NMR for varied Si morphology, i. e., amorphous and crystalline, as well as during pre-lithiation with passivated lithium metal powder (PLMP). © 2024 The Author(s). ChemSusChem published by Wiley-VCH GmbH.

13. Cellulose and Xylan Nanofiber Mats via Electrospinning: Lignin-enhanced Properties in Wood-Inspired Biocomposites

    M. García-Rollán, R. Ruiz-Rosas, J.M. Rosas, J. Rodríguez-Mirasol, J.M. Porras-Vázquez, J.J. Benítez, A. Athanassiou, J.A. Heredia-Guerrero, and S. Guzman-Puyol

    Carbohydrate Polymer Technologies and Applications, 2025

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    Nanofiber mats were fabricated by combining cellulose, xylan, and organosolv lignin. The biopolymers, and a small amount (15 wt. %) of polyethylene oxide, were dissolved in a mixture of trifluoroacetic acid and trifluoroacetic anhydride, then blended in various ratios (keeping cellulose as the main component and changing the proportions of lignin and hemicellulose) and processed via electrospinning. The resulting nanofiber mats were systematically characterized for their CIELAB color parameters, morphology, chemical composition, mechanical strength, thermal stability, hydrodynamic behavior, antioxidant capacity, and wettability. The incorporation of organosolv lignin significantly altered the color of the nanofiber mats, making them more brownish, with luminosity values from 90 for L-0 to 58 for L-50. It also disrupted the hydrogen bonding network, as evidenced by the chemical shift of the ATR-FTIR spectra. Additionally, organosolv lignin affected key mechanical properties with mechanical values similar to other polymer nanofibers, while thermogravimetric analysis revealed an enhancement of about 10 °C in the heat resistant index, thereby broadening the potential applications of the nanofiber mats. Finally, the presence of organosolv lignin improved antioxidant capacity to values of 100 % of RSA, reduced water uptake, and increased water contact angle to values of 110° for L-50. © 2025 The Author(s)

14. Enhancing Sodium-Ion Battery Performance: The Role of Glyoxylic Acetal-Based Electrolytes in Solid Electrolyte Interphase Formation and Stability

    M. Gaško, C. Leibing, L. Fridolin Pfeiffer, P. Axmann, A. Balducci, and M. Zarrabeitia

    ChemElectroChem, 2025

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    This study systematically investigates the feasibility of replacing conventional sodium hexafluorophosphate (NaPF6) in carbonate-based electrolytes with sodium bis(fluorosulfonyl)imide (NaFSI) and sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) in a 1,1,2,2-tetraethoxyglyoxal (TEG):propylene carbonate (PC) solvent system tested with hard carbon (HC) anode materials for sodium-ion batteries (SIBs). The influence of electrolyte composition and cycling conditions on the evolution of the solid electrolyte interphase (SEI) and overall electrochemical performance of the HC is comprehensively evaluated by means of electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy. The SEI chemical composition, transport properties, and stability are thoroughly characterized. The results demonstrate that the HC tested in NaFSI/TEG:PC electrolyte exhibits superior performance compared to both the conventional NaPF6/ethylene carbonate (EC):PC system and the NaTFSI/TEG:PC-based alternative, achieving higher initial coulombic efficiencies (ICEs), lower interfacial resistance, and enhanced Na+ transport properties. The improved electrochemical stability of the HC in NaFSI/TEG:PC electrolyte is attributed to the formation of a bilayered SEI, comprising an inorganic-rich inner layer and an organic-rich outer layer. These findings underscore the pivotal role of electrolyte formulation in enhancing the HC SEI characteristics and cycling performance, thereby positioning NaFSI in TEG:PC chemistry as a promising electrolyte candidate for next-generation SIBs. © 2025 The Author(s). ChemElectroChem published by Wiley-VCH GmbH.

15. Editorial - Preserving Food and the Planet: Sustainable Packaging for a Circular Food Economy

    S. Guzman-Puyol, J.J. Benítez, and J.A. Heredia-Guerrero

    Future Foods, 2025

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16. Plant Cuticles Exhibit Significant Mid-Infrared Emissivity in the Atmospheric Windows †

    A. Heredia, A. González Moreno, J.J. Benítez, and E. Domínguez

    International Journal of Molecular Sciences, 2025

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    As sessile organisms, plants have developed strategies to cope with exposure to high radiation. The plant cuticle is located at the interface between the plant and the surrounding environment, thus acting as a first barrier that protects plants against environmental conditions, including solar radiation. The isolated cuticles displayed notable absorptance in the infrared spectral range which, according to Kirchhoff’s law of thermal radiation, equals the emission dissipation ability. Comparison among the different cuticles showed that a significant range of their reflectance, transmittance, and absorbance spectra match the spectral regions known as atmospheric windows, between 3–4 and 8–13 microns, located within the mid-infrared region (MIR). They allow energy to pass through into the outer space. These optical parameters varied between cuticles from different plant species and they were not a simple function of the cuticle’s thickness but the product of its specific composition in combination with its molecular arrangement. © 2025 by the authors.

17. Characterization of Coffee Waste-Based Biopolymer Composite Blends for Packaging Development

    G. Hernández-López, L.L. Barrera-Necha, S. Bautista-Baños, M. Hernández-López, O. Pérez-Camacho, J.J. Benítez, J.L. Acosta-Rodriguez, and Z.N. Correa-Pacheco

    Foods, 2025

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    In recent years, coffee waste by-products have been incorporated into polymer blends to reduce environmental pollution. In this study, coffee parchment (CP) was incorporated into biodegradable polylactic acid (PLA) and poly (butylene adipate-co-terephthalate) (PBAT) polymer blends to prepare ribbons through the extrusion process. Extracted green coffee bean oil (CO) was used as a plasticizer, and CP was used as a filler with and without functionalization. A solution of chitosan nanoparticles (ChNp) as a coating was applied to the ribbons. For the raw material, proximal analysis of the CP showed cellulose and lignin contents of 53.09 ± 3.42% and 23.60 ± 1.74%, respectively. The morphology of the blends was observed via scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) showed an increase in the ribbons’ thermal stability with the functionalization. The results of differential scanning calorimetry (DSC) revealed better miscibility for the functionalized samples. The mechanical properties showed that with CP incorporation into the blends and with the ChNp coating, the Young’s modulus and the tensile strength decreased with no significant changes in the elongation at break. This work highlights the potential of reusing different by-products from the coffee industry, such as coffee oil from green beans and coffee parchment as a filler, and incorporating them into PLA PBAT biodegradable polymer blend ribbons with a nanostructured antimicrobial coating based on chitosan for future applications in food packaging. © 2025 by the authors.

18. Nanoconfinement Geometry of Pillared V2O5Determines Electrochemical Ion Intercalation Mechanisms, Storage Sites, and Diffusion Pathways

    J. Karol, C.O. Ogolla, M. Sotoudeh, M. Dillenz, M. Tobis, E. Vollmer, Y.T. Malik, M. Zarrabeitia, A. Gross, B. Butz, and S. Fleischmann

    ACS Nano, 2025

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    Improving the electrochemical ion intercalation capacity and kinetics in layered host materials is a critical challenge to further develop lithium-ion batteries, as well as emerging cell chemistries based on ions beyond lithium. Modification of the nanoconfining interlayer space within host materials by synthetic pillaring approaches has emerged as a promising strategy; however, the resulting structural properties of host materials, host–pillar interactions as well as associated electrochemical mechanisms remain poorly understood. Herein, we systematically study a series of bilayered V2O5host materials pillared with alkyldiamines of different lengths, resulting in tunable nanoconfinement geometries with interlayer spacings in the range of 1.0–1.9 nm. The electrochemical Li+intercalation capacity is increased from approximately 1.0 to 1.5 Li+per V2O5in expanded host materials due to the stabilization of new storage sites. The intercalation kinetics improve with expansion due to a transition in Li+diffusion pathways from 1D to 2D diffusional networks. Operando X-ray diffraction reveals a transition of the intercalation mechanism from solid-solution Li+intercalation in V2O5hosts with small and medium interlayer spacings to solvent cointercalation in V2O5with the largest interlayer spacing. The work systematically demonstrates the impact of nanoconfinement geometry within bilayered V2O5on the resulting Li+intercalation metrics and mechanisms, providing insights into both the microstructure and associated electrochemistry of pillared materials. © 2025 The Authors. Published by American Chemical Society

19. The Impact of Dual-Salt Electrolyte with Low Fluorine Content on the Performance of Layered Transition Metal Oxides for Sodium-Ion Batteries

    Y. Lu, M.N. Aslam, C. Leibing, M. Zarrabeitia, L. Roselli, L.F. Pfeiffer, P. Axmann, J. Geisler, P. Adelhelm, and A. Balducci

    Small, 2025

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    In this work, the characterization of novel electrolytes based on the combination of propylene carbonate (PC) solvent with sodium bis(fluorosulfonyl)imide (NaFSI) and sodium difluoro(oxalato)borate (NaDFOB), as well as their application in sodium-ion batteries (SIBs) is presented. The results show that dual-salt electrolytes have a wide electrochemical stability window, excellent transport properties, and mostly suppress anodic dissolution. When combined with P2-Na2/3Al1/9Fe1/9Mn2/3Ni1/9O2(P2-AFMNO) cathode electrode for SIBs operating at 4.3 V vs Na+/Na, they enable high performance and stability. XPS investigation revealed that this performance is related to the formation of a thin and homogeneous cathode electrolyte interphase (CEI) at the electrode surface. © 2025 The Author(s). Small published by Wiley-VCH GmbH.

20. Graphene Exfoliation in Cyrene for the Sustainable Production of Microsupercapacitors

    P. Moreira, D. Carvalho, R. Abreu, M.D. Alba, J. Ramírez-Rico, E. Fortunato, R. Martins, J.V. Pinto, E. Carlos, and J. Coelho

    JPhys Energy, 2025

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    Graphene and its composites have attracted much attention for applications in energy storage systems. However, the toxic solvents required for the exfoliation process have hampered the exploitation of its properties. In this work, graphene dispersions are obtained via liquid phase exfoliation (LPE) of graphite in cyrene, an environmentally friendly solvent with solubility parameters like those of N-methyl-2-pirrolidone. The obtained dispersions with a concentration of 0.2 mg ml−1 comprised multilayered graphene sheets with lateral sizes in the hundreds of nanometers, as confirmed by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. Mixing the obtained dispersions with ethanol made it possible to collect the graphene, which was redispersed in 2-Propanol. This active material was used to fabricate supercapacitor electrodes using a scalable spray deposition method on carbon nanotube (CNT) current collectors with the aid of vinyl masks. The device, tested with a PVA/LiCl gel electrolyte, achieved a specific capacitance of 3.4 mF cm−2 (0.015 mA cm−2). In addition, the devices show excellent cycling stability (>10 000 cycles at 0.5 mA cm−2) and good mechanical properties, losing less than 10% of initial capacitance after 1000 bending cycles. This work demonstrates the adaptability of liquid-phase exfoliation to produce graphene sustainably, providing the proof-of-concept for further 2D materials processing and green microsupercapacitor (MSC) fabrication. © 2025 The Author(s). Published by IOP Publishing Ltd.

21. Green Exfoliation of 2D Nanomaterials Using Cyrene as a Solvent

    P. Moreira, J. Mendes, T. Calmeiro, D. Nunes, D. Carvalho, A. Kelly, H. Águas, E. Fortunato, R. Martins, J. Vaz Pinto, J. Coelho, and E. Carlos

    Nanoscale Advances, 2025

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    Liquid-phase exfoliation (LPE) is a versatile and scalable method for producing high-quality two-dimensional materials (2DMs). However, commonly used solvents such as dimethylformamide (DMF) or N-methyl-2-pyrrolidone (NMP) are highly toxic, limiting their potential for large-scale industrial applications. In this study, we address this challenge using Cyrene (dihydrolevoglucosenone), a nontoxic and biodegradable solvent, for the exfoliation of several materials, including graphene, MoS2, WS2, MoO3, V2O5, and hBN (hexagonal boron nitride). Exfoliation was carried out using low-powered bath sonication, a cost effective and energy efficient method and optimization was conducted to maximize the final concentration of exfoliated material. To assess the potential of Cyrene for LPE, extensive characterization and comparison of the produced 2DMs with their precursors was performed. The highest ink concentrations were observed for MoS2 (2.6 mg mL−1), followed by hBN (2.3 mg mL−1) and V2O5 (1.9 mg mL−1), demonstrating the ability of Cyrene to effectively stabilize a variety of 2D materials in dispersion. Structural and morphological properties of the exfoliated materials were characterized using X-ray diffraction (XRD), Raman spectroscopy, UV-vis spectroscopy, scanning electron microscopy (SEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). XRD patterns mainly showed only one reflection revealing the oriented nature of the materials, with significant broadening of the full width at half maximum (FWHM) compared to the original materials. Also, Raman spectroscopy spectra for graphene showed ratios characteristic of multi-layered structures and SEM imaging revealed a broad distribution of flake sizes. This work highlights the potential of Cyrene as a sustainable and efficient solvent for LPE of diverse 2D materials. The systematic optimization method presented here achieves high dispersion concentrations in a repeatable manner using low-power and ecofriendly means. These findings establish a foundation for the scalable production of 2D inks, enabling their use in advanced applications such as electrode, dielectric and semiconductor layers of electronic devices. This journal is © The Royal Society of Chemistry, 2025

22. Multicomponent Heavy Metals Adsorption on Functionalized Swelling Micas: Mechanistic Insights and Structural Evolution

    Francisco J. Osuna, Javier R. Chaparro, Esperanza Pavón, and María D. Alba

    Surfaces and Interfaces, 2025

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    Heavy metal contamination is a critical environmental issue, often involving complex multicomponent systems. Swelling brittle micas, a family of designer sorbents, have demonstrated exceptional heavy metal removal capabilities, yet their behabior in competitive adsorption systems remains largely unexplored. This study systematically investigates the simultaneous uptake of Pb²⁺, Cd²⁺, and Hg²⁺ on both as-synthesized brittle mica and its thiol-functionalized counterpart. Using X-ray diffraction (XRD) and nuclear magnetic resonance (NMR), we reveal critical structural transformations occurring at both short- and long-range scales during adsorption. Our findings demonstrate that competitive adsorption governs metal uptake, leading to a reduction in total adsorption capacity compared to single-metal systems. However, selectivity toward specific metal cations remains unchanged, irrespective of competing species or surface functionalization. Overall, this study not only improves our understanding of heavy metal adsorption but also paves the way for more effective and sustainable sorbent design in environmental remediation.

23. Poly(Ionic) Liquid-Enhanced Ion Dynamics in Cellulose-Derived Gel Polymer Electrolytes

    T.G. Paiva, M. Dos Santos Klem, S.L. Silvestre, J. Coelho, N. Alves, E. Fortunato, E.J. Cabrita, and M.C. Corvo

    ChemSusChem, 2025

    Abs DOI

    Gel polymer electrolytes (GPEs) are regarded as a promising alternative to conventional electrolytes, combining the advantages of solid and liquid electrolytes. Leveraging the abundance and eco-friendliness of cellulose-based materials, GPEs were produced using methyl cellulose and incorporating various doping agents, either an ionic liquid (1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [Pyr14][TFSI]), its polymeric ionic liquid analogue (Poly(diallyldimethylammonium bis(trifluoromethylsulfonyl)imide) [PDADMA][TFSI]), or an anionically charged backbone polymeric ionic liquid (lithium poly[(4-styrenesulfonyl)(trifluoromethyl(S-trifluoromethylsulfonylimino) sulfonyl) imide] LiP[STFSI]). The ion dynamics and molecular interactions within the GPEs were thoroughly analyzed using Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR), Heteronuclear Overhauser Enhancement Spectroscopy (HOESY), and Pulsed-Field Gradient Nuclear Magnetic Resonance Diffusion (PFG-NMR). Li+ transference numbers (tLi+) were successfully calculated. Our study found that by combining slow-diffusing polymeric ionic liquids (PILs) with fast-diffusing lithium salt, we were able to achieve transference numbers comparable to those of liquid electrolytes, especially with the anionic PIL, LiP[STFSI]. This research highlights the influence of the polymer′s nature on lithium-ion transport within GPEs. Additionally, micro supercapacitor (MSC) devices assembled with these GPEs exhibited capacitive behavior. These findings suggest that further optimization of GPE composition could significantly improve their performance, thereby positioning them for application in sustainable and efficient energy storage systems. © 2024 The Author(s). ChemSusChem published by Wiley-VCH GmbH.

24. Revisiting Intercalation Anode Materials for Potassium-Ion Batteries

    M.J. Piernas-Muñoz and M. Zarrabeitia

    Materials, 2025

    Abs DOI

    Potassium-ion batteries (KIBs) have attracted significant attention in recent years as a result of the urgent necessity to develop sustainable, low-cost batteries based on non-critical raw materials that are competitive with market-available lithium-ion batteries. KIBs are excellent candidates, as they offer the possibility of providing high power and energy densities due to their faster K+ diffusion and very close reduction potential compared with Li+/Li. However, research on KIBs is still in its infancy, and hence, more investigation is required both at the materials level and at the device level. In this work, we focus on recent strategies to enhance the electrochemical properties of intercalation anode materials, i.e., carbon-, titanium-, and vanadium-based compounds. Hitherto, the most promising anode materials are those carbon-based, such as graphite, soft, or hard carbon, each with its advantages and disadvantages. Although a wide variety of strategies have been reported with excellent results, there is still a need to improve the standardization of the best carbon properties, electrode formulation, and electrolyte composition, given the impossibility of a direct comparison. Therefore, additional effort should be made to understand what are the crucial carbon parameters to develop a reference electrode and electrolyte formulation to further boost their performance and move a step forward in the commercialization of KIBs. © 2025 by the authors.

25. Comprehensive Profiling of Extractable Lipophilic Constituents in Potato Peel Waste: A Basis for Future Biorefinery Applications

    J. Rencoret, S. Guzman-Puyol, J.J. Benítez, J.A. Heredia-Guerrero, and J.C. del Río

    Industrial Crops and Products, 2025

    Abs DOI

    The dichloromethane-soluble lipophilic fraction of potato peel waste, representing 2.8 % of its dry weight, was comprehensively analyzed using gas chromatography–mass spectrometry (GC-MS). This fraction was found to be rich in bioactive constituents, including n-fatty acids (7600 mg/kg), n-fatty alcohols (5870 mg/kg), n-alkyl ferulates (5760 mg/kg), n-alkanes (2970 mg/kg), high-molecular-weight esters (2800 mg/kg), monoglycerides (123 mg/kg), and steroid compounds (2120 mg/kg). The latter comprised several distinct classes, including steroid hydrocarbons (36 mg/kg), steroid ketones (164 mg/kg), free sterols (390 mg/kg), and sterol glycosides (1530 mg/kg). These lipophilic molecules are of considerable interest to the pharmaceutical, nutraceutical, cosmetic, and chemical industries due to their functional properties. Their presence in potato peel waste highlights the value of this agro-industrial byproduct as a sustainable and economically viable source of bioactive ingredients. This study provides an important basis for the development of biorefinery strategies aimed at recovering and valorizing these valuable compounds from this underutilized waste stream. © 2025 The Authors

26. Laser-Induced Graphene: A Promising Conductive Platform for Cell Culture

    H. Vazão de Almeida, J.M. Inácio, C. Pereira, T. Pinheiro, T. Calmeiro, R. Correia, J. Coelho, J.V. Pinto, J.A. Belo, R. Martins, and E. Fortunato

    Advanced Healthcare Materials, 2025

    Abs DOI

    Cardiovascular mortality remains a major health challenge. Cardiomyocyte (CM)-based tissue engineering (TE) offers promising alternatives for developing therapies via in vitro models. However, the immature phenotype of CM in engineered tissues hampers progress. Recent studies introduce conductive materials like graphene to enhance CM maturation, but conventional graphene synthesis suffers from complexity, toxicity, and low yield. Laser-induced graphene (LIG) provides a sustainable, cost-effective, eco-friendly solution with efficient conductivity and biocompatibility. A LIG-based substrate is bioengineered in this study, hypothesizing that its conductive, anisotropic properties promote CM maturation and mimic the native cardiac niche. LIG is fabricated using a CO2 laser with Parylene-C as a precursor. Stem cells (SCs) and SC-derived embryoid bodies (EBs) are cultured on LIG substrates, and their viability, metabolic activity, morphology, and protein expression are evaluated through immunofluorescence and electron microscopy. Both SCs and EBs maintain viability and activity throughout the culture. Moreover, EB-derived CM exhibit spontaneous contraction and express cardiac-specific proteins, confirming functional differentiation on LIG matrices. This first report demonstrates that LIG substrates support SC culture and differentiation, highlighting their potential in developing refined in vitro cardiac models and advancing regenerative therapeutic strategies. The findings support LIG as a transformative advancement in TE. © 2025 Wiley-VCH GmbH.

27. Understanding the Component-Driven Influence on the Electrochemical Properties in Single-Ion Polymer Electrolytes for Sodium-Based Batteries

    C. Wunder, L. Graeber, D. Bresser, M. Zarrabeitia, and S. Passerini

    ACS Applied Polymer Materials, 2025

    Abs DOI

    Research on polymer electrolytes has attracted growing attention in recent years as they offer increased mechanical and thermal stability compared to liquid electrolytes, making them excellent candidates for metal batteries. Their properties can be fine-tuned depending on the need, allowing, for example, the creation of single-ion polymer electrolytes (SIPEs) that could suppress dendrite formation and charge gradient buildups. This work describes the optimization of a Na-SIPE consisting of sodium salt monomer (SSM), pentaerythritol tetraacrylate (PETA4), pentaerythritol tetrakis(3-mercaptopropionate) (PETMP), and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), by varying the composition ratio of the SIPE components. In addition, the influence on ionic conductivity and overall performance in Na-based cells of three different anionic centers of SSM is reported. The best electrochemical performance is achieved with a content of 17 mol% SSM, 18 mol% PVDF-HFP, 40 mol% PETMP, and 25 mol% PET4A due to the highest ionic conductivity. The optimal SSM is found to be (4-styrenesulfonyl)(dicyano)methanide (NaSDCM), enabling the NaSDCM-based SIPE to achieve a conductivity of 2.9 × 10-4 S cm-1 at 90 °C and 4.2 × 10-5 S cm-1 at 20 °C, thermal stability up to 300 °C, and electrochemical stability window up to 5 V vs Na+/Na. This SIPE with 50 wt% molecular transporter enables the realization of Na∥SIPE∥Prussian White (PW) cells, delivering a specific capacity of 102 mAh g-1 after 200 cycles at 0.1C and 40 °C. © 2025 The Authors. Published by American Chemical Society.

2024

1. Direct Laser Writing of MnOx Decorated Laser-Induced Graphene on Paper for Sustainable Microsupercapacitor Fabrication

   R. Abreu, M. Dos Santos Klem, T. Pinheiro, J.V. Pinto, N. Alves, R. Martins, E. Carlos, and J. Coelho

   FlatChem, 2024

   Abs DOI

   Laser-induced graphene (LIG) on paper is a popular choice for fabricating flexible micro-supercapacitors (MSCs) as it is a simple and sustainable process. However, carbon-based MSC electrodes have limited energy densities. To address this challenge, this study presents a highly reproducible and cost-effective method for decorating manganese oxide (MnOx) on interdigital LIG MSC electrodes, fabricated via a single-step direct laser writing (DLW) process on paper substrates. The paper fibers embedded with MnOx precursors are transformed into graphene through laser processing while reducing the salt, resulting in the formation of MnOx-LIG. The resulting MnOx-LIG-MSC exhibits a specific capacitance of 12.30 mF cm−2 (0.05 mA cm−2) with a 60 % retention at 1000 bending cycles (30°), due to the pseudocapacitive contribution of MnOx. Furthermore, the devices exhibit high electrochemical stability, retaining 190 % of the initial specific capacitance after 10,000 cycles, and a high energy density of 2.6 μWh cm−2 (at a power of 0.109 mW cm−2). The study demonstrates that manganese oxide-based LIG-MSCs have the potential to be used as energy storage devices for portable, low-cost, and flexible paper electronics. © 2024 The Author(s)

2. Enhanced Extraction of Bioactive Compounds from Tea Waste for Sustainable Polylactide-Based Bioplastic Applications in Active Food Packaging

   M.A. Acquavia, J.J. Benítez, S. Guzman-Puyol, J.M. Porras-Vázquez, J. Hierrezuelo-León, M. Grifé-Ruiz, D. Romero, A. Di Capua, R. Bochicchio, S. Laurenza, G. Bianco, and J.A. Heredia-Guerrero

   Food Packaging and Shelf Life, 2024

   Abs DOI

   Active and sustainable food packaging materials were prepared through solvent casting, by blending tea waste (TW) extract rich in bioactive molecules with a neat polylactide (PLA) polymeric matrix. The optimization of tea waste extraction using a response surface methodology allowed achieving efficient yield and high phenolic content, which significantly enhanced the antioxidant properties of the resulting bioplastics. TW extract incorporation into PLA films increased UV-blocking capability, while keeping the oxygen permeability performance. Mechanical testing revealed improved ductility and toughness in TW extract-containing films compared to pure polylactide film, ascribed to the plasticizing effect of TW polyphenols. Food packaging assays showed effective moisture retention, comparable to low-density polyethylene (LDPE) plastics, antioxidant activity, and excellent bacteria barrier properties allowing the use for food packaging applications. Moreover, migration tests and detection of non-intentionally added substances (NIAS) allowed to establish the safety and regulatory compliance of these bioplastics. © 2024 The Authors

3. Transparent, Plasticized Cellulose-Glycerol Bioplastics for Food Packaging Applications

   J.J. Benítez, P. Florido-Moreno, J.M. Porras-Vázquez, G. Tedeschi, A. Athanassiou, J.A. Heredia-Guerrero, and S. Guzman-Puyol

   International Journal of Biological Macromolecules, 2024

   Abs DOI

   Free-standing films have been obtained by drop-casting cellulose-glycerol mixtures (up to 50 wt% glycerol) dissolved in trifluoroacetic acid and trifluoroacetic anhydride (TFA:TFAA, 2:1, v:v). A comprehensive examination of the optical, structural, mechanical, thermal, hydrodynamic, barrier, migration, greaseproof, and biodegradation characteristics of the films was conducted. The resulting cellulose-glycerol blends exhibited an amorphous molecular structure and a reinforced H-bond network, as evidenced by X-ray diffraction analysis and infrared spectroscopy, respectively. The inclusion of glycerol exerted a plasticizing influence on the mechanical properties of the films, while keeping their transparency. Hydrodynamic and barrier properties were assessed through water uptake and water vapor/oxygen transmission rates, respectively, and obtained values were consistent with those of other cellulose-based materials. Furthermore, overall migration levels were below European regulation limits, as stated by using Tenax® as a dry food simulant. In addition, these bioplastics demonstrated good greaseproof performance, particularly at high glycerol content, and potential as packaging materials for bakery products. Biodegradability assessments were carried out by measuring the biological oxygen demand in seawater and high biodegradation rates induced by glycerol were observed. © 2024 The Authors

4. MoS2 Decorated Carbon Fiber Yarn Hybrids for the Development of Freestanding Flexible Supercapacitors

   J.T. Carvalho, A. Correia, N.J.A. Cordeiro, J. Coelho, S.A. Lourenço, E. Fortunato, R. Martins, and L. Pereira

   npj 2D Materials and Applications, 2024

   Abs DOI

   Academic and industrial efforts have focused on developing energy storage devices for wearable and portable electronics using low-cost, scalable, and sustainable materials and approaches. In this work, commercially available stretch-broken carbon fiber yarns (SBCFYs) were hybridized with mixed phases of 1 T and 2H MoS2 nanosheets via conventional and microwave-assisted heating (CAH, MAH) without the use of binders to fabricate symmetric freestanding 1D fiber-shaped supercapacitors (FSCs). Electrochemical characterization performed in a three-electrode configuration showed promising results with specific capacitance values of 184.41 and 180.02 F·g−1, at 1 mV·s−1 for CAH and MAH, respectively. Furthermore, after performing 3000 CV cycles at 100 mV·s−1, the capacitance retention was 79.5% and 95.7%, respectively. Using these results as a reference, symmetric 1D FSCs were fabricated by pairing hybridized SBCFYs with MoS2 by MAH. The devices exhibited specific capacitances of approximately 58.60 ± 3.06 F·g−1 at 1 mV·s−1 and 54.81 ± 7.34 F·g−1 at 0.2 A·g−1 with the highest power density achieved being 15.17 W·g−1 and energy density of 5.06×10–4Wh·g−1. In addition, five 1D FSCs were hand-stitched and connected in series onto a cotton fabric. These supercapacitors could power a temperature and humidity sensor for up to six minutes, demonstrating the practicality and versatility of the prepared 1D FSCs for powering future electronic systems. © The Author(s) 2024.

5. Fluoroethylene Carbonate: Bis(2,2,2,) Trifluoroethyl Carbonate as High Performance Electrolyte Solvent Blend for High Voltage Application in NMC811|| Silicon Oxide-Graphite Lithium Ion Cells

   F. Demelash, A. Gómez-Martín, B. Heidrich, E. Adhitama, P. Harte, A. Javed, A. Arifiadi, M.M. Bela, P. Yan, D. Diddens, M. Winter, and P. Niehoff

   Small Structures, 2024

   Abs DOI

   LiNixMnyCozO2 cathode materials combined with Si-based anode materials are current state-of-the-art high energy density chemistries for lithium ion batteries. Increasing the upper cut-off voltage is an intriguing approach to achieve even higher energy density in lithium ion batteries. However, poor oxidation stability of the state-of-the-art electrolytes leads to transition metal dissolution (TMD), migration, and deposition (TMDMD) on the negative electrode, followed by sudden and rapid capacity fade. Furthermore, the chemical instability of the lithium hexafluorophosphate causes hydro-fluoric acid to develop, which targets the native SiOx layers on silicon anodes and breaks the chemical bond to the carboxymethylcellulose sodium salt binder. Herein, a fluorine-rich electrolyte formulation consisting of lithium-bis(fluorsulfonyl)imide with fluoroethylene carbonate (FEC): bis(2,2,2,) trifluoroethyl carbonate (BFEC) was applied in NMC811||10%SiOx-90%graphite cells to achieve high oxidation stability and prevent TMD and deposition. Up-to-date, this is the premier electrochemical performance reported in literature with a capacity retention of 94.5% and 92.2% with 0.5 °C and 4.5 V upper cut-off voltage cycling at 20 and 40 °C after 100 cycles, respectively. The post mortem analysis showed that stabilization is achieved by forming inorganic- and salt-rich interphases that protect the electrolyte versus decomposition at the electrode. © 2024 The Authors. Small Structures published by Wiley-VCH GmbH.

6. Minimizing Solvated Water via Synergistic Effect of Salt Anion and Cosolvent Enables Stable Zn Metal Anodes in Low-Cost Acetate Electrolyte

   H. Fei, F. Yang, J.A. Yuwono, M. Zarrabeitia, S. Passerini, and A. Varzi

   Chemical Engineering Journal, 2024

   Abs DOI

   Aqueous zinc metal batteries (ZMBs) have attracted increasing attention in the past decades owing to their potentially low cost and non-flammability. However, the poor Coulombic efficiency (CE) and short lifespan caused by side reactions (e.g., H2 evolution) and dendrite growth limit the practical applications of ZMBs. Given that H2 evolution is primarily originated from solvated water, here, a low-cost acetate-based electrolyte constituted by 1 m ZnAc2 and 5 m KAc in an 80:20 water:trimethyl phosphate (TMP) (v/v) mixture is proposed to minimize solvated water and boost the electrochemical performance of aqueous ZMBs without compromising intrinsic advantages of the aqueous electrolyte. The relatively high abundance of Ac− enables preferential coordination with Zn2+, meanwhile, the addition of TMP not only further replaces water molecules in the inner solvation shell, but also significantly interrupts the H-bond network of water. Improved electrochemical performance are demonstrated in Zn||Zn and Zn||Cu half-cells and Zn||I2 full cells. © 2024 The Author(s)

7. Optimising Anode Supported BaZr1-xYxO3-δ Electrolytes for Solid Oxide Fuel Cells: Microstructure, Phase Evolution and Residual Stresses Analysis

   S. Fernandez-Muñoz, R. Chacartegui, M.D. Alba, and J. Ramírez-Rico

   Journal of Power Sources, 2024

   Abs DOI

   Yttrium-doped BaZrO3 is a promising electrolyte for intermediate-temperature protonic ceramic fuel cells. In the anode-supported configuration, a slurry containing the electrolyte is deposited on the surface of a calcined porous anode and sintered. Differences in sintering behaviour and thermal expansion coefficients for the anode and electrolyte result in elastic residual stresses that can impact the long-term stability of the cell during cyclic operation. Half-cells using BaZr0.8Y0.2O3-δ as the electrolyte were fabricated using the solid-state reaction sintering method under various sintering conditions. Comprehensive microstructure and residual stress analyses as a function of processing parameters were performed using two-dimensional X-ray diffraction, Rietveld refinement, and scanning electron microscopy, before and after the half-cells were reduced under hydrogen, giving a complete picture of phase, microstructure, and stress evolution under thermal and reduction cycles like the actual operation of the cell. Our results reveal that a temperature of 1400 °C and shorter soaking times might be advantageous for obtaining phase-pure and thin yttrium-doped BaZrO3 electrolytes with improved microstructure and the presence of compressive residual stress. These findings offer valuable insights into optimising the fabrication process of BaZrO3-based electrolytes, leading to enhanced performance and long-term stability of anode-supported protonic ceramic fuel cells operating at intermediate temperatures. © 2024 The Authors

8. Experimental Considerations of the Chemical Prelithiation Process via Lithium Arene Complex Solutions on the Example of Si-Based Anodes for Lithium-Ion Batteries

   L. Frankenstein, M. Mohrhardt, C. Peschel, L. Stolz, A. Gómez-Martín, T. Placke, H. Hur, M. Winter, and J. Kasnatscheew

   Advanced Energy and Sustainability Research, 2024

   Abs DOI

   Losses of Li inventory in lithium-ion batteries lead to losses in capacity and can be compensated by electrode prelithiation before cell assembly or before cell formation. The approach of chemical prelithiation, for example, via Li arene complex (LAC)-based solutions is technically an apparently simple and promising approach. Nevertheless, as shown herein on the example of Si-based anodes and LAC solutions based on 4,4′-dimethylbiphenyl (4,4′-DMBP), several practical challenges need to be considered. Given their reactivity, the LAC solution can not only decompose itself within a range of a few hours, as seen by discoloration and confirmed via mass spectrometry, but can also decompose its solvent and binder of added composite electrodes. Effective prelithiation requires an excess in capacity of the LAC solution (relative to anode capacity) and optimized system characteristic conditions (time, temperature, etc.) as exemplarily shown by comparing Si-based nanoparticles with nanowires. It is worth noting that the prelithiation degree alone does not determine the boost in cycle life, but relevantly depends on previously applied prelithiation conditions (e.g., temperature), as well. © 2023 The Authors. Advanced Energy and Sustainability Research published by Wiley-VCH GmbH.

9. Materials for 3D Printed Metal and Metal-Ion Batteries

   T. García Rodríguez, J.I. Medina Santos, J. Coelho, and S. Pinilla

   ChemElectroChem, 2024

   Abs DOI

   The review provides an overview of the latest innovations, trends, and challenges in the field of 3D-printed metal and metal-ion batteries. It focuses on the materials used in the printing of batteries, including electrodes, electrolytes, and other electroactive components. Compared to other high-quality reviews on the topic, this review provides a broader selection of materials that are expected to gain attention in the next few years, such as redox-active polymers and metal-organic frameworks. This work gives an overview and insight into the latest trends in printing techniques as well as a statistical review of their uses and strengths. We have also gathered the latest works done for each of the material types, and we have taken the opportunity to put them in context and use them to exemplify in which direction is the field going. The review concludes with a critical view of the challenges ahead and a discussion of the direction that the field is taking as well as the external factors that might help to define its future. © 2024 The Authors. ChemElectroChem published by Wiley-VCH GmbH.

10. Direct Recycling at the Material Level: Unravelling Challenges and Opportunities through a Case Study on Spent Ni-Rich Layered Oxide-Based Cathodes

    M.M. Gnutzmann, A. Makvandi, B. Ying, J. Buchmann, M.J. Lüther, B. Helm, P. Nagel, M. Peterlechner, G. Wilde, A. Gómez-Martín, K. Kleiner, M. Winter, and J. Kasnatscheew

    Advanced Energy Materials, 2024

    Abs DOI

    Direct recycling is a key technology for enabling a circular economy of spent lithium ion batteries (LIBs). For cathode active materials (CAMs), it is regarded as the tightest closed-loop and most efficient approach among current recycling techniques as it simply proceeds via re-lithiation and reconstruction of aged CAMs instead of separating them into elemental components. In this work, spent, i.e., morphologically and structurally decomposed CAM based on LiNi0.83Co0.12Mn0.05O2 (NCM-831205) is restored by mimicking conditions of original CAM synthesis. After evaluating and optimizing the high-temperature duration for CAM restoration and subsequent washing procedure, the recycled CAM is shown to maintain poly-crystallinity and tap density, successfully recover specific surface area, lithium content, crystal structure in surface and bulk, while, however, only partly the original secondary particle size and shape. Though, comparable in initial 100 charge/discharge cycles with pristine CAM in lithium ion-cells, the subsequent increase in resistance and capacity fading remains a challenge. High temperature during recycling can be regarded as a key challenge on material level, as it not only promotes detrimental surface carbonate species from residual carbon black but also enhances cation disorder and micro-/nanoscopic porosity through oxygen release, likely in de-lithiated, thus less thermally stable regions of cycled NCM. © 2024 The Author(s). Advanced Energy Materials published by Wiley-VCH GmbH.

11. Ultrahigh Ni-Rich (90%) Layered Oxide-Based Cathode Active Materials: The Advantages of Tungsten (W) Incorporation in the Precursor Cathode Active Material

    M. Heidbuchel, A. Gómez-Martín, L. Frankenstein, A. Makvandi, M. Peterlechner, G. Wilde, M. Winter, and J. Kasnatscheew

    Small Science, 2024

    Abs DOI

    Minor amounts of tungsten (W) are well known to improve Ni-rich layered oxide-based cathode active materials (CAMs) for Li ion batteries. Herein, W impacts are validated and compared for varied concentrations and incorporation routes in aqueous media for LiNi0.90Co0.06Mn0.04O2 (NCM90-6-4), either via modification of a precursor NixCoyMnz(OH)2 (pCAM) within a sol–gel reaction or directly during synthesis, i.e., either via an W-based educt or during co-precipitation in a continuously operated Couette–Taylor reactor. In particular, the sol–gel modification is shown to be beneficial and reveals >500 cycles for ≈80% state-of-health NCM90-6-4||graphite cells. It can be related to homogeneously W-modified surface as well as smaller and elongated primary particles, whereas the latter are suggested to better compensate anisotropic lattice stress and decrease amount of microcracks, consequently minimizing further rise in surface area and the accompanied failure cascades (e.g., phase changes, metal dissolution, and crosstalk). Moreover, the different incorporation routes are shown to reveal different outcomes and demonstrate the complexity and sensitivity of W incorporation. © 2024 The Author(s). Small Science published by Wiley-VCH GmbH.

12. Revisiting Plant Cuticle Biophysics

    A. Heredia, J.J. Benítez, A. González Moreno, and E. Domínguez

    New Phytologist, 2024

    Abs DOI

    The plant cuticle is located at the interface of the plant with the environment, thus acting as a protective barrier against biotic and abiotic external stress factors, and regulating water loss. Additionally, it modulates mechanical stresses derived from internal tissues and also from the environment. Recent advances in the understanding of the hydric, mechanical, thermal, and, to a lower extent, optical and electric properties of the cuticle, as well as their phenomenological connections and relationships are reviewed. An equilibrium based on the interaction among the different biophysical properties is essential to ensure plant growth and development. The notable variability reported in cuticle geometry, surface topography, and microchemistry affects the analysis of some biophysical properties of the cuticle. This review aimed to provide an updated view of the plant cuticle, understood as a modification of the cell wall, in order to establish the state-of-the-art biophysics of the plant cuticle, and to serve as an inspiration for future research in the field. © 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.

13. Elucidating the Mechanism of Iron-Catalyzed Graphitization: The First Observation of Homogeneous Solid-State Catalysis

    Robert D. Hunter, Masaki Takeguchi, Ayako Hashimoto, Kannan M. Ridings, Shaun C. Hendy, Dmitri Zakharov, Nils Warnken, Jack Isaacs, Sol Fernandez-Muñoz, Joaquín Ramirez-Rico, and Zoe Schnepp

    Advanced Materials, 2024

    Abs DOI

    Carbon is a critical material for existing and emerging energy applications and there is considerable global effort in generating sustainable carbons. A particularly promising area is iron-catalyzed graphitization, which is the conversion of organic matter to graphitic carbon nanostructures by an iron catalyst. In this paper, it is reported that iron-catalyzed graphitization occurs via a new type of mechanism that is called homogeneous solid-state catalysis. Dark field in situ transmission electron microscopy is used to demonstrate that crystalline iron nanoparticles “burrow” through amorphous carbon to generate multiwalled graphitic nanotubes. The process is remarkably fast, particularly given the solid phase of the catalyst, and in situ synchrotron X-ray diffraction is used to demonstrate that graphitization is complete within a few minutes.

14. Electrochemical Deposition of Manganese Oxide on Paper-Based Laser-Induced Graphene for the Fabrication of Sustainable High-Energy-Density Supercapacitors

    Maykel dos Santos Klem, Rodrigo Abreu, Tomás Pinheiro, João Coelho, Neri Alves, and Rodrigo Martins

    Advanced Sustainable Systems, 2024

    Abs DOI

    Laser-induced graphene (LIG) is widely used to fabricate microsupercapacitors (MSCs) on various sustainable substrates, such as wood, cork, and lignin. However, the fabrication of MSCs, especially high energy density devices on paper, has rarely been reported. In this work, LIG electrodes are fabricated on wax-coated paper, followed by electrochemical deposition of manganese oxide (MnO2). The obtained LIG/MnO2 supercapacitors exhibit a maximum areal capacitance of 86.9 mF cm−2, while a device with pristine LIG electrodes exhibit a capacitance of 9.1 mF cm−2, both measured at a current density of 0.1 mA cm−2. In addition, the supercapacitor exhibits good cycling stability, retaining 80% of its initial capacitance after 1000 charge/discharge cycles at a current density of 1 mA cm−2. Notably, the LIG/MnO2 supercapacitor exhibits an exceptionally high energy density of 7.3 µWh cm−2 at a power density of 38.8 µW cm−2. In summary, a simple, fast, scalable, reproducible, and energy-efficient fabrication method is represented using electrochemical deposition of manganese oxide on paper-based laser-induced graphene, which are natural, abundant, and sustainable materials, paving the way for large-scale production of environmentally friendly supercapacitors.

15. Effect of Different Charge Rates on the Active Material Lithiation of Gr/SiOx Blend Anodes in Lithium-Ion Cells

    J. Knorr, A. Gómez-Martín, H.-C. Hsiao, A. Adam, B. Rödl, and M.A. Danzer

    Journal of Energy Storage, 2024

    Abs DOI

    Anodes with blended active materials, containing SiOx as a secondary material in addition to graphite, gain interest in research and commercial applications to increase the capacity of lithium-ion batteries. SiOx has the advantage of significantly higher specific capacity than graphite but the disadvantage of a reduced cycling and structural stability. To understand the processes involved for this type of blend anode, a detailed investigation of its electrochemical behavior is required. This work provides a non-destructive method for understanding the interaction between blend materials in cells containing silicon-based active material. This method helps to identify internal battery conditions and thereby optimize the battery performance. A cylindrical cell containing approximately 10 wt% of SiOx is used for electrochemical testing. By analyzing the voltage hysteresis, differences in the graphite lithiation are observable, which allows conclusions to be drawn about the SiOx lithiation. An increase in the charge rate leads to a decrease in graphite lithiation and consequently to an increase in SiOx lithiation. This effect is explained by the analysis of the pure material anode potentials. Validation of the effect is given by X-ray diffraction analysis to identify the state of graphite lithiation. © 2024 Elsevier Ltd

16. Influence of the Chemical Activation with KOH/KNO3 on the CO2 Adsorption Capacity of Activated Carbons from Pyrolysis of Cellulose

    Irene Lamata-Bermejo, María D. Alba, and Joaquín Ramírez-Rico

    Journal of Environmental Chemical Engineering, 2024

    Abs DOI

    Plant biomass is an attractive precursor to prepare activated carbons with high surface area for CO2 adsorption due to its low-cost and easy regeneration. Despite this interest, there are still remaining questions regarding the optimal processing conditions and the choice of activating agent. Moreover, since plant biomass shows a highly variable proportion of different biopolymers (cellulose, hemicellulose, lignin), it is important to understand the activation effect on each constituent. In this work, carbons obtained from pyrolysis of cellulose were activated using two potassium salts, using two different activation temperatures. The samples were characterized to elucidate the influence of the activation conditions on their CO2 adsorption capacity. In general, all the carbons activated at higher temperature showed higher adsorption capacity. These results are comparable with other carbons derived from biomass described in the bibliography. Among the activated carbons studied, the carbon activated only with KOH exhibits the highest CO2 adsorption capacity at 1 bar meanwhile the highest adsorption capacity at saturation pressure belongs to the carbon activated with larger ratio of KNO3.

17. Reversible K-ion Intercalation in CrSe2 Cathodes for Potassium-Ion Batteries: Combined Operando PXRD and DFT Studies

    W. Li, J. Döhn, J. Chen, M. Dillenz, M. Sotoudeh, D.M. Pickup, S. Luo, R. Parmenter, J. Arbiol, M. Alfredsson, A.V. Chadwick, A. Gross, M. Zarrabeitia, and A.Y. Ganin

    Journal of Materials Chemistry A, 2024

    Abs DOI

    In the pursuit of more affordable battery technologies, potassium-ion batteries (KIBs) have emerged as a promising alternative to lithium-ion systems, owing to the abundance and wide distribution of potassium resources. While chalcogenides are uncommon as intercalation cathodes in KIBs, this study’s electrochemical tests on CrSe2 revealed a reversible K+ intercalation/deintercalation process. The CrSe2 cathode achieved a KIB battery capacity of 125 mA h g−1 at a 0.1C rate within a practical 1-3.5 V vs. K+/K operation range, nearly matching the theoretical capacity of 127.7 mA h g−1. Notably, the battery retained 85% of its initial capacity at a high 1C rate, suggesting that CrSe2 is competitive for high-power applications with many current state-of-the-art cathodes. In-operando PXRD studies uncovered the nature of the intercalation behavior, revealing an initial biphasic region followed by a solid-solution formation during the potassium intercalation process. DFT calculations helped with the possible assignment of intermediate phase structures across the entire CrSe2-K1.0CrSe2 composition range, providing insights into the experimentally observed phase transformations. The results of this work underscore CrSe2’s potential as a high-performance cathode material for KIBs, offering valuable insights into the intercalation mechanisms of layered transition metal chalcogenides and paving the way for future advancements in optimizing KIB cathodes. © 2024 The Royal Society of Chemistry.

18. Life Cycle Assessment of Bio-Based Hard Carbon for Sodium-Ion Batteries across Different Production Scales

    H. Liu, M. Baumann, H. Moon, X. Zhang, X. Dou, M. Zarrabeitia, E. Crenna, R. Hischier, S. Passerini, N.V.D. von der Assen, and M. Weil

    Chemical Engineering Journal, 2024

    Abs DOI

    This paper aims to address research gaps surrounding the environmental impact of Hard Carbon (HC) production by conducting a Life Cycle Assessment (LCA) based on data from two laboratories with differing backgrounds and scenarios. HC is commonly used as anode material for sodium-ion batteries, a potentially sustainable and cost-efficient alternative for lithium-ion batteries. The study identifies environmentally sustainable routes for HC synthesis by comparing various biomass and synthesis pathways. The study reveals that the energy consumption of the pyrolysis process is the primary contributor to the environmental footprint of lab-scale HC production. A prospective LCA is performed by upscaling the laboratory processes to pilot- and industrial scale based on expert judgement and assumptions on energy and material balance. The results show that the environmental profile of HC can be significantly improved when the production scale is expanded. At large production scales, HC shows great potential to be used as a counterpart to graphite in future battery systems. However, direct emissions, such as methane, and the depletion of materials, such as argon and acid, become more critical to the environmental footprint, highlighting the need for energy recovery, emission treatment strategies, and more efficient use of materials. This work provides a framework for future LCA studies of HC, highlighting the limitations of simplified upscaling. It also provides a foundation for developing sustainable energy storage systems, thereby contributing to more informed decision-making in HC industrial production. © 2024 The Authors

19. Systematic “Apple-to-Apple” Comparison of Single-Crystal and Polycrystalline Ni-Rich Cathode Active Materials: From Comparable Synthesis to Comparable Electrochemical Conditions

    M.J. Lüther, S.-K. Jiang, M.A. Lange, J. Buchmann, A. Gómez-Martín, R. Schmuch, T. Placke, B.J. Hwang, M. Winter, and J. Kasnatscheew

    Small Structures, 2024

    Abs DOI

    State-of-the-art ternary layered oxide cathode active materials in Li-ion batteries (LIBs) consist of polycrystalline (PC), i.e., micron-sized secondary particles, which in turn consist of numerous nanosized primary particles. Recent approaches to develop single crystals (SCs), i.e., single and separated micron-sized primary particles, appear promising in terms of cycle life given their mechanical stability. However, a direct and systematic (“fair”) comparison of SC with PC in LIB cell application remains a challenge due to both differences on material level and state-of-charge (SoC), as SCs typically have slightly lower delithiation capacities/Li+ extraction ratios. In this work, PC and SC Li[Ni0.8Mn0.1Co0.1]O2 (NMC811) are synthesized with comparable bulk and surface characteristics from identical self-synthesized precursors. Indeed, the cycle life of SCs is not only superior, when conventionally charged to equal upper cutoff voltage (UCV), as shown in NMC||Li and NMC||graphite cells, but also after adjusting UCVs to similar SoCs, where bigger SCs counterintuitively have even a better rate performance and cycle life. © 2024 The Author(s). Small Structures published by Wiley-VCH GmbH.

20. Tuning the Reconstruction of Metal-Organic Frameworks during the Oxygen Evolution Reaction

    X. Ma, L. Schröck, G. Gao, Q. Ai, M. Zarrabeitia, C. Liang, M.Z. Hussain, R. Khare, K.-T. Song, D.J. Zheng, M. Koch, I.E.L. Stephens, S. Hou, Y. Shao-Horn, J. Warnan, A.S. Bandarenka, and R.A. Fischer

    ACS Catalysis, 2024

    Abs DOI

    Recently, there has been growing interest in the conversion of metal-organic frameworks (MOFs) into metal-hydroxide catalysts for alkaline oxygen evolution reactions (OERs). While studies have shown that the initial OER performance of MOF-derived intermediates surpasses that of traditional metal-hydroxide catalysts, ongoing debates persist regarding these catalysts’ durability and electrochemical stability. Moreover, the inevitable reorganization (aging) of MOF-derived catalysts from disordered to ordered phases, particularly those primarily composed of nickel oxyhydroxides, remains a topic of discussion. To address these issues, we propose a straightforward approach to mitigating MOF reconstruction and modulating aging in harsh alkaline environments by introducing additional organic carboxylate linkers into electrolytes. Specifically, we focus on two examples: Ni-BPDC-MOFs and NiFe-BPDC-MOFs, of formula [M2(OH)2BPDC] (M: Ni and Fe; BPDC = 4,4′-biphenyldicarboxylate). Experimental results indicate that alkaline electrolytes containing additional BPDC linkers exhibit enhanced OER activity and a prolonged electrochemical lifespan. Complemented by in situ Raman spectroscopy, our findings suggest that manipulating the coordination equilibrium of the organic linker involved in Ni-MOF formation (linker assembly) and reconstruction (linker leaching) leads to the formation of more disordered nickel oxyhydroxide phases as the active catalyst material, which shows enhanced OER performance. © 2024 The Authors. Published by American Chemical Society.

21. Flexible Devices Based on Metal Oxides: Achievements and Prospects

    D. Nunes, A. Pimentel, P. Barquinha, M. Mendes, J. Coelho, H. Almeida, E. Fortunato, and R. Martins

    2024

    Abs DOI

    Flexible devices based on metal oxides: Achievements and prospects focuses on the integration of flexibility in electronic circuitry, sensing applications, energy conversion and storage, and environmental remediation. Flexibility in these applications offers great potential, especially in the areas of wearable sensors, solar cells, transistors, electronic skin, and human body monitoring. The book investigates flexible and wearable devices based on metal oxide nanostructures or thin films that are capable of bending, rolling, compression, and folding, all while maintaining their performance. Metal oxide nanomaterials display exceptional properties that include mechanical stress tolerance, high optical transparency, high carrier mobilities, wide band gap, high dielectric constant, and superconductivity, amongst others. In some cases, they are also earth abundant, environmentally benign, cost-effective, chemically stable, and compatible with low-cost wet-chemical synthesis routes. The focus of the book is on wearables manufactured using sustainable manufacturing methods and integrated into substrates that are flexible, inexpensive, recyclable, abundant, and lightweight, including polymer, textile, cellulose and cork substrates. ©2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

22. From Structure to Electrochemistry: The Influence of Transition Metal Ordering on Na+/Vacancy Orderings in P2-type NaxMO2 Cathode Materials for Sodium-Ion Batteries

    L.F. Pfeiffer, M. Dillenz, N. Burgard, P. Beran, D. Roscher, M. Zarrabeitia, P. Drews, C. Hervoches, D. Mikhailova, A. Omar, V. Baran, N. Paul, M. Sotoudeh, M. Busch, M. Wohlfahrt-Mehrens, A. Gross, S. Passerini, and P. Axmann

    Journal of Materials Chemistry A, 2024

    Abs DOI

    P2-type layered oxides are attractive cathode active materials for sodium-ion batteries, however, these materials typically suffer from detrimental Na+/vacancy orderings. In this work, we investigate the origin as well as the influence of the transition metal ratio on Na+/vacancy orderings in P2-type cathode materials. A combination of X-ray diffraction (XRD), neutron diffraction, advanced electrochemical methods, operando XRD and DFT calculations is applied to study Na+/vacancy orderings in P2-NaxNi1/3Mn2/3O2 and P2-NaxMn3/4Ni1/4O2. In P2-NaxNi1/3Mn2/3O2, a honeycomb Ni/Mn superstructure leads to charge ordering within the transition metal slab and pronounced Na+/vacancy orderings, causing distinct voltage jumps at specific sodium contents (x = 2/3, 1/2 and 1/3). For P2-Na0.60Mn3/4Ni1/4O2, the Ni/Mn superstructure is disrupted, resulting in more complex charge orderings within the transition metal slab, partially suppressed Na+/vacancy orderings and an overall smoother potential profile. Based on our findings, guidelines to suppress Na+/vacancy orderings in P2-type cathode materials for sodium-ion batteries are postulated and discussed with respect to electrochemical measurements of various transition metal compositions. These guidelines can serve to predict the tendency towards Na+/vacancy orderings for a given cathode composition or to design new cathode compositions for enhanced cycle life based on the absence of Na+/vacancy orderings. © 2025 The Royal Society of Chemistry.

23. Direct Laser Writing: From Materials Synthesis and Conversion to Electronic Device Processing

    T. Pinheiro, M. Morais, S.L. Silvestre, E. Carlos, J. Coelho, H.V. Almeida, P. Barquinha, E. Fortunato, and R. Martins

    Advanced Materials, 2024

    Abs DOI

    Direct Laser Writing (DLW) has been increasingly selected as a microfabrication route for efficient, cost-effective, high-resolution material synthesis and conversion. Concurrently, lasers participate in the patterning and assembly of functional geometries in several fields of application, of which electronics stand out. In this review, recent advances and strategies based on DLW for electronics microfabrication are surveyed and outlined, based on laser material growth strategies. First, the main DLW parameters influencing material synthesis and transformation mechanisms are summarized, aimed at selective, tailored writing of conductive and semiconducting materials. Additive and transformative DLW processing mechanisms are discussed, to open space to explore several categories of materials directly synthesized or transformed for electronics microfabrication. These include metallic conductors, metal oxides, transition metal chalcogenides and carbides, laser-induced graphene, and their mixtures. By accessing a wide range of material types, DLW-based electronic applications are explored, including processing components, energy harvesting and storage, sensing, and bioelectronics. The expanded capability of lasers to participate in multiple fabrication steps at different implementation levels, from material engineering to device processing, indicates their future applicability to next-generation electronics, where more accessible, green microfabrication approaches integrate lasers as comprehensive tools. © 2024 The Authors. Advanced Materials published by Wiley-VCH GmbH.

24. Revalorization of Yerba Mate Residues: Biopolymers-Based Films of Dual Wettability as Potential Mulching Materials

    L.M. Sanchez, J. de Haro-Niza, E. Domínguez, A. Rodríguez, A. Heredia, and J.J. Benítez

    Polymers, 2024

    Abs DOI

    Biodegradable mulching films are a very attractive solution to agronomical practices intended to achieve more successful crop results. And, in this context, the employment of agricultural and industrial food residues as starting material for their production is an alternative with economic and environmental advantages. This work reports the preparation of bilayer films having two different wettability characteristics from three bio-derived biopolymers: TEMPO-oxidized cellulose nanofibers isolated from infused Yerba Mate residues, Chitosan and Polylactic acid. The infused Yerba Mate residues, the isolated and oxidized cellulose nanofibers, and the films were characterized. Nanofibrillation yield, optical transmittance, cationic demand, carboxyl content, intrinsic viscosity, degree of polymerization, specific surface area and length were studied for the (ligno)cellulose nanofibers. Textural and chemical analysis, thermal and mechanical properties studies, as well as water and light interactions were included in the characterization of the films. The bilayer films are promising materials to be used as mulching films. © 2024 by the authors.

25. Green Fabrication of Stackable Laser-Induced Graphene Micro-Supercapacitors under Ambient Conditions: Toward the Design of Truly Sustainable Technological Platforms

    Sara L. Silvestre, Maria Morais, Raquel R. A. Soares, Zachary T. Johnson, Eric Benson, Elisabeth Ainsley, Veronica Pham, Jonathan C. Claussen, Carmen L. Gomes, Rodrigo Martins, Elvira Fortunato, Luis Pereira, and João Coelho

    Advanced Materials Technologies, 2024

    Abs DOI

    Extensive research into green technologies is driven by the worldwide push for eco-friendly materials and energy solutions. The focus is on synergies that prioritize sustainability and environmental benefits. This study explores the potential of abundant, non-toxic, and sustainable resources such as paper, lignin-enriched paper, and cork for producing laser-induced graphene (LIG) supercapacitor electrodes with improved capacitance. A single-step methodology using a CO2 laser system is developed for fabricating these electrodes under ambient conditions, providing an environmentally friendly alternative to conventional carbon sources. The resulting green micro-supercapacitors (MSCs) achieve impressive areal capacitance (≈7–10 mF cm−2) and power and energy densities (≈4 μW cm-2 and ≈0.77 µWh cm−2 at 0.01 mA cm−2). Stability tests conducted over 5000 charge–discharge cycles demonstrate a capacitance retention of ≈80–85%, highlighting the device durability. These LIG-based devices offer versatility, allowing voltage output adjustment through stacked and sandwich MSCs configurations (parallel or series), suitable for various large-scale applications. This study demonstrates that it is possible to create high-quality energy storage devices based on biodegradable materials. This development can lead to progress in renewable energy and off-grid technology, as well as a reduction in electronic waste.

26. A Zirconia/Tantalum Biocermet: In Vitro and in Vivo Evaluation for Biomedical Implant Applications

    A. Smirnov, F. Guitián, J. Ramírez-Rico, and J.F. Bartolomé

    Journal of Materials Chemistry B, 2024

    Abs DOI

    A biocermet made of zirconia/20 vol% tantalum (3Y-TZP/Ta) is a new composite with exceptional capabilities due to a combination of properties that are rarely achieved in conventional materials (high strength and toughness, cyclic fatigue resistance and flaw tolerance, wear resistance, corrosion resistance, electrical conductivity, etc.). In this study, for the first time, the biomedical performance of a 3Y-TZP/Ta biocermet was evaluated in detail. Its in vitro biocompatibility was assessed using mesenchymal stem cell culture. The effectiveness of in vivo osteointegration of the biocermet was confirmed 6 months after implantation into the proximal tibiae of New Zealand white rabbits. In addition, the possibility of using magnetic resonance imaging (MRI) for medical analysis of the considered biocermet material was studied. The 3Y-TZP/Ta composite showed no injurious effect on cell morphology, extracellular matrix production or cell proliferation. Moreover, the implanted biocermet appeared to be capable of promoting bone growth without adverse reactions. On the other hand, this biocermet demonstrates artefact-free performance in MRI biomedical image analysis studies, making it more suitable for implant applications. These findings open up possibilities for a wide range of applications of these materials in orthopedics, dentistry and other areas such as replacement of hard tissues. © 2024 The Royal Society of Chemistry.

27. Electrolyte Motion Induced Salt Inhomogeneity - a Novel Aging Mechanism in Large-Format Lithium-Ion Cells

    S. Solchenbach, C. Tacconis, A. Gómez-Martín, V. Peters, L. Wallisch, A. Stanke, J. Hofer, D. Renz, B. Lewerich, G. Bauer, M. Wichmann, D. Goldbach, A. Adam, M. Spielbauer, P. Lamp, and J. Wandt

    Energy and Environmental Science, 2024

    Abs DOI

    The electrification of the transport sector places ever-increasing demands on the energy density, fast-charging performance, and lifetime of lithium-ion cells. In this study, we investigate fast-charging of high energy density (∼ 800 W h L−1) prototype cylindrical 4695 lithium-ion cells with two different (“low” and “high”) electrolyte amounts. Using pore volume calculations, computer tomography and moment of inertia measurements, we find that the volume change of the active material causes electrolyte motion into and out of the jelly roll upon cycling in the high electrolyte cells, while no electrolyte motion occurs in the low electrolyte cells. At the same time, the high electrolyte cells show a significantly worse capacity retention during fast charge cycling compared to the low electrolyte cells (24% vs. 5% capacity loss after 130 cycles). We demonstrate that a coupling of in-plane electrolyte motion with the through-plane LiPF6 concentration gradient rapidly causes a strong LiPF6 concentration gradient along the jelly roll height (= in-plane) on a cm-scale: after only 18 cycles, LiPF6 concentrations at the jelly roll edges and center (as determined by ion-chromatography) deviate by more than ± 50% in comparison to the initial average value. We term this hitherto unknown effect “electrolyte motion induced salt inhomogeneity” (EMSI). This long-scale salt concentration gradient causes a loss of cell capacity, an increase in resistance, and eventually highly localized lithium plating. Finally, we discuss the far-reaching implications of the EMSI effect on cell design and testing, not only for cylindrical cells but any large-format lithium-ion cell under high compression. © 2024 The Royal Society of Chemistry.

28. Sodium 4-Styrenesulfonyl(Trifluoromethanesulfonyl)Imide-Based Single-Ion Conducting Polymer Electrolyte Incorporating Molecular Transporters for Quasi-Solid-State Sodium Batteries

    C. Wunder, T.-L. Lai, E. Šić, T. Gutmann, E. de Vito, G. Buntkowsky, M. Zarrabeitia, and S. Passerini

    Journal of Materials Chemistry A, 2024

    Abs DOI

    Sodium batteries are an attractive alternative for future energy storage as they can be produced with abundant and low-cost materials. Nonetheless, sodium-ion batteries (SIBs) are often composed of flammable and volatile carbonate-based liquid electrolytes. Polymer electrolytes have attracted significant attention as safer alternatives. Among polymer electrolytes, single-ion conductive polymer electrolytes (SIPEs) are considered particularly interesting because they can suppress dendrite growth, enabling high-performance (quasi)-solid-state sodium-(metal) batteries. In this work, a self-standing, flexible, quasi-solid-state SIPE is investigated, which is composed of sodium 4-styrene sulfonyl (trifluoromethanesulfonyl) imide (NaSTFSI), pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) and pentaerythritol tetraacrylate (PET4A) blended with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). The SIPE membrane, including 50 wt% of molecular transporter, exhibits ionic conductivity of 1.4 × 10−5 S cm−1 and 1.3 × 10−4 S cm−1 at 20 °C and 90 °C, respectively, thermal stability up to 280 °C, electrochemical stability window up to 4.5 V vs. Na/Na+, and Na plating/stripping reversibility in symmetric Na‖Na cells. The manufactured SIPE implemented in Prussian White (PW)‖Na cells enables the delivery of 147 mA h g−1 of PW at 15 mA g−1 with a Coulombic efficiency of over 99%, which is comparable with the PW‖Na cells using liquid carbonate electrolyte, confirming the suitability of the designed SIPE for sodium-(metal) batteries. © 2024 The Royal Society of Chemistry.

29. Battery Types – Sodium Batteries – Low-Temperature Sodium Batteries | Cathode Active Materials

    M. Zarrabeitia, W. Zuo, and S. Passerini

    In Encyclopedia of Electrochemical Power Sources: Volume 1-7, Second Edition, 2024

    Abs DOI

    Sodium-ion batteries (SIBs), which commercialization may start already in 2023, as highlighted, are postulated as the most attractive economical and sustainable alternatives to lithium-ion batteries (LIBs) for light electromobility and large-scale stationary applications. However, the electrochemical performance of SIBs must be further improved through specific strategies that optimize the cathode active materials in terms of energy density and long-term cycling in line with maintaining their environmental competitiveness. This chapter highlights the most recent developments and pertinent strategies to enhance sodium cathode active materials. © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

30. Stabilization of P2 Layered Oxide Electrodes in Sodium-Ion Batteries through Sodium Evaporation

    M. Zarrabeitia, I. Salazar, B. Acebedo, and M.Á. Muñoz-Márquez

    Communications Materials, 2024

    Abs DOI

    Sodium-ion batteries are well positioned to become, in the near future, the energy storage system for stationary applications and light electromobility. However, two main drawbacks feed their underperformance, namely the irreversible sodium consumption during solid electrolyte interphase formation and the low sodiation degree of one of the most promising cathode materials: the P2-type layered oxides. Here, we show a scalable and low-cost sodiation process based on sodium thermal evaporation. This method tackles the poor sodiation degree of P2-type sodium layered oxides, thus overcoming the first irreversible capacity as demonstrated by manufacturing and testing all solid-state Na doped-Na~1Mn0.8Fe0.1Ti0.1O2 ǀǀ PEO-based polymer electrolyte ǀǀ Na full cells. The proposed sodium physical vapor deposition method opens the door for an easily scalable and low-cost strategy to incorporate any metal deficiency in the battery materials, further pushing the battery development. (Figure presented.) © The Author(s) 2024.

2023

1. Sustainable Integration of Zinc Oxide Nanoparticles: Enhancing Properties of Poly(ε-Caprolactone) Electrospun Nanofibers and Cast Films

   J.A.A. Abdullah, J.J. Benítez, A. Guerrero, and A. Romero García

   Coatings, 2023

   Abs DOI

   This study investigated the impact of adding zinc oxide nanoparticles (ZnO-NPs) to electrospun membranes and cast films made of poly(ε-caprolactone) (PCL). The physicochemical, mechanical, and morphological properties of the samples were analyzed. Physicochemical parameters included water contact angle (WCA), water vapor transmission rate (WVTR), permeance, water vapor permeability (WVP), light transmission (T600), and transparency (T). Mechanical properties, such as maximum stress (Ϭmax), elongation (εmax), and Young’s modulus (MPa), were also evaluated. Morphological properties were analyzed in terms of thickness, dispersion, and surface roughness (measured by the arithmetic (Ra) and quadratic (Rq) averages). The crystallinity and melting point, as well as the functional DPPH• scavenging percentage (SP%), were also studied. The results showed that adding 1 wt% ZnO-NPs improved the water barrier properties of PCL membranes and films, increasing WCA by 1%–6% and decreasing WVTR by 11%–19%, permeance by 34%–20%, and WVP by 4%–11%, respectively. The T600 values of PCL/ZnO-NPs membranes and films were 2–3 times lower than those of neat PCL samples, indicating improved optical properties. The mechanical properties of the composite membranes and films also improved, with Ϭmax increasing by 56%–32% and Young’s modulus increasing by 91%–95%, while εmax decreased by 79%–57%. The incorporation of ZnO-NPs also increased the thickness and surface roughness of the samples. The SP% of PCL/ZnO-NPs increased by almost 69%, demonstrating the beneficial effects of ZnO-NPs on the system. These findings suggest that incorporating ZnO-NPs into PCL membranes and films can enhance their properties, making them well suited for various applications, such as those within the realm of materials science and nanotechnology. © 2023 by the authors.

2. Incorporation of Bioactive Compounds from Avocado By-Products to Ethyl Cellulose-Reinforced Paper for Food Packaging Applications

   M.A. Acquavia, J.J. Benítez, G. Bianco, M.A. Crescenzi, J. Hierrezuelo-León, M. Grifé-Ruiz, D. Romero, S. Guzman-Puyol, and J.A. Heredia-Guerrero

   Food Chemistry, 2023

   Abs DOI

   Reinforced films were fabricated by impregnating paper in ethyl cellulose solutions. After solvent evaporation, the infused ethyl cellulose acted as binder of the paper microfibres and occupied the pores and cavities, thus improving the mechanical and barrier properties. To prepare active films, avocado by-products from guacamole industrial production were extracted in ethyl acetate. Then, the extract (optimized to be rich in phenolic compounds and flavonoids and mainly composed by lipids) was incorporated to the paper reinforced with the highest content of ethyl cellulose. In general, the addition of the avocado by-products extract decreased the water uptake and permeability, improved the wettability, and increased the biodegradability in seawater and the antioxidant capacity. In addition, these films acted as barriers and retainers for Escherichia coli and Bacillus cereus. The potentiality of these materials for food packaging was demonstrated by low overall migrations and a similar food preservation to common low-density polyethylene. © 2023 The Author(s)

3. On the Practical Applicability of the Li Metal-Based Thermal Evaporation Prelithiation Technique on Si Anodes for Lithium Ion Batteries

   E. Adhitama, M.M. Bela, F. Demelash, M.C. Stan, M. Winter, A. Gómez-Martín, and T. Placke

   Advanced Energy Materials, 2023

   Abs DOI

   Lithium ion batteries (LIBs) using silicon as anode material are endowed with much higher energy density than state-of-the-art graphite-based LIBs. However, challenges of volume expansion and related dynamic surfaces lead to continuous (re-)formation of the solid electrolyte interphase, active lithium losses, and rapid capacity fading. Cell failure can be further accelerated when Si is paired with high-capacity, but also rather reactive Ni-rich cathodes, such as LiNi0.8Co0.1Mn0.1O2 (NCM-811). Here, the practical applicability of thermal evaporation of Li metal is evaluated as a prelithiation technique on micrometer-sized Si (µ-Si) electrodes in addressing such challenges. NCM-811 || “prelithiated µ-Si” full-cells (25% degree of prelithiation) can attain a higher initial discharge capacity of ≈192 mAh gNCM-811−1 than the cells without prelithiation with only ≈160 mAh gNCM-811−1. This study deeply discusses significant consequences of electrode capacity balancing (N:P ratio) with regard to prelithiation on the performance of full-cells. The trade-off between cell lifetime and energy density is also highlighted. It is essential to point out that the phenomena discussed here can further guide the direction of research in using the thermal evaporation of Li metal as a prelithiation technique toward its practical application on Si-based LIBs. © 2022 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH.

4. Bio-Based Lacquers from Industrially Processed Tomato Pomace for Sustainable Metal Food Packaging

   J.J. Benítez, M.C. Ramírez-Pozo, M.M. Durán-Barrantes, A. Heredia, G. Tedeschi, L. Ceseracciu, S. Guzman-Puyol, D. Marrero-López, A. Becci, A. Amato, and J.A. Heredia-Guerrero

   Journal of Cleaner Production, 2023

   Abs DOI

   Bio-based lacquers prepared from an underutilized tomato processing residue such as pomace have been investigated as sustainable alternatives to bisphenol A (BPA)-based coatings for metal food packaging. The fabrication methodology consisted of a two-step process: spray-coating of a paste of the lipid fraction of tomato pomace with a mixture ethanol:H2O (3:1, v:v) on common metal substrates, used for food canning, such as aluminum (Al), chromium-coated tin-free steel (TFS), and electrochemically tin-plated steel (ETP), followed by the self melt-polycondensation of such lipid fraction. The polymerization reaction was conducted at 200 °C for different times (10, 20, 30, 40, 50, and 60 min) and was monitored by specular infrared spectroscopy, resulting in maximum degrees of esterification of ∼92% for Al and ∼85% for TFS and ETP substrates. The anticorrosion performance of the coatings was studied by electrochemical impedance spectroscopy at different immersion times (time intervals of 2–5 h during an overall stability test up to 170 h) in an aqueous solution of 1 wt% NaCl. The degree of polymerization and the physical properties of the coatings showed a strong dependence on the metal substrate used. In general, the best results were found for tomato pomace-based lacquers applied on aluminum, achieving higher mechanical strength (critical load of 1739 ± 198 mN for Al, 1078 ± 31 mN for ETP, and 852 ± 206 mN for TFS), hydrophobicity (water contact angle ∼95° for Al, ∼91° for ETP, and ∼88° for TFS), and improved anticorrosion performance (coating resistance of 0.7 MΩcm2 after 170 h of immersion for Al, 0.7 MΩcm2 after 70 h of immersion for TFS, and negligible coating resistance for ETP). In view of the technical innovation proposed in the present paper, the estimation of the environmental sustainability of the process has been considered relevant to fit the circular economy target. For this purpose, a life cycle analysis (LCA) was applied to the overall process, revealing multiple advantages for both the environment and human health. © 2022 The Authors

5. Ultrathin Single-Ion Conducting Polymer Enabling a Stable Li|Li1.3Al0.3Ti1.7(PO4)3 Interface

   Z. Chen, H.-P. Liang, Z. Lyu, N. Paul, G. Ceccio, R. Gilles, M. Zarrabeitia, A. Innocenti, M. Jasarevic, G.-T. Kim, S. Passerini, and D. Bresser

   Chemical Engineering Journal, 2023

   Abs DOI

   NASICON-type Li1+xAlxTi2−x(PO4)3 (LATP) solid electrolytes have attracted great attention because of their high ionic conductivity, wide electrochemical stability window, pronounced chemical resistance, and low cost. However, the chemical instability of LATP against metallic lithium (Li0) poses a major challenge and hinders its application in solid-state lithium batteries. Herein, an ultrathin polysiloxane-based single-ion conductor (PSiO) serves as multifunctional protection interlayer to enhance the interfacial stability between LATP and Li0. PSiO effectively blocks the direct contact between Li0 and LATP, regulates the homogeneous Li+ flux at the Li|electrolyte interface, promotes the intimate contact between PSiO and Li0 by forming Si − O − Li bonds, and generates an LiF-enriched Li|electrolyte interphase. As a result, it enables more than 2,000 h of stable cycling in symmetric PSIO@Li‖PSIO@Li cells and superior rate capability and cycling stability in high-energy PSIO@Li‖LiNi0.88Co0.09Mn0.03O2 cells. The realization of well performing 2-layer bipolar stacked cells eventually demonstrates the great potential of this approach. © 2023 Elsevier B.V.

6. Paper-Based Laser-Induced Graphene for Sustainable and Flexible Microsupercapacitor Applications

   J. Coelho, R. Correia, S.L. Silvestre, T. Pinheiro, A.C. Marques, M.R.P. Correia, J.V. Pinto, E. Fortunato, and R. Martins

   Microchimica Acta, 2023

   Abs DOI

   Laser-induced graphene (LIG) is as a promising material for flexible microsupercapacitors (MSCs) due to its simple and cost-effective processing. However, LIG-MSC research and production has been centered on non-sustainable polymeric substrates, such as polyimide. In this work, it is presented a cost-effective, reproducible, and robust approach for the preparation of LIG structures via a one-step laser direct writing on chromatography paper. The developed strategy relies on soaking the paper in a 0.1 M sodium tetraborate solution (borax) prior to the laser processing. Borax acts as a fire-retardant agent, thus allowing the laser processing of sensitive substrates that other way would be easily destroyed under the high-energy beam. LIG on paper exhibiting low sheet resistance (30 Ω sq−1) and improved electrode/electrolyte interface was obtained by the proposed method. When used as microsupercapacitor electrodes, this laser-induced graphene resulted in specific capacitances of 4.6 mF cm−2 (0.015 mA cm−2). Furthermore, the devices exhibit excellent cycling stability (> 10,000 cycles at 0.5 mA cm−2) and good mechanical properties. By connecting the devices in series and parallel, it was also possible to control the voltage and energy delivered by the system. Thus, paper-based LIG-MSC can be used as energy storage devices for flexible, low-cost, and portable electronics. Additionally, due to their flexible design and architecture, they can be easily adapted to other circuits and applications with different power requirements. Graphical Abstract: [Figure not available: see fulltext.] © 2022, The Author(s).

7. Biodegradability Assessment of Prickly Pear Waste–Polymer Fibers under Soil Composting

   Z.N. Correa-Pacheco, S. Bautista-Baños, J.J. Benítez, P. Ortega-Gudiño, E.O. Cisneros-López, and M. Hernández-López

   Polymers, 2023

   Abs DOI

   Nowadays, solving the problems associated with environmental pollution is of special interest. Therefore, in this work, the morphology and thermal and mechanical properties of extruded fibers based on polylactic acid (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) added to prickly pear flour (PPF) under composting for 3 and 6 months were evaluated. The highest weight loss percentage (92 ± 7%) was obtained after 6-month degradation of the PLA/PBAT/PPF/CO/AA blend, in which PPF, canola oil (CO), and adipic acid (AA) were added. Optical and scanning electron microscopy (SEM) revealed structural changes in the fibers as composting time increased. The main changes in the absorption bands observed by Fourier transform infrared spectroscopy (FTIR) were related to the decrease in -C=O (1740 cm−1) and -C-O (1100 cm−1) groups and at 1269 cm−1, associated with hemicellulose in the blends with PPF. Differential scanning calorimetry (DSC) showed an increase in the cold crystallization and melting point with degradation time, being more evident in the fibers with PPF, as well as a decrease in the mechanical properties, especially Young’s modulus. The obtained results suggest that PPF residues could promote the biodegradability of PLA/PBAT-based fiber composites. © 2023 by the authors.

8. LiNi0.5Mn1.5O4 Thin Films Grown by Magnetron Sputtering under Inert Gas Flow Mixtures as High-Voltage Cathode Materials for Lithium-Ion Batteries

   H. Darjazi, I. Madinabeitia, M. Zarrabeitia, E. Gonzalo, B. Acebedo, S. Rezvani, F.J. Fernández-Carretero, F. Nobili, A. García-Luis, and M.Á. Muñoz-Márquez

   ChemElectroChem, 2023

   Abs DOI

   Delivering a commercial high-voltage spinel LiNi0.5Mn1.5O4 (LNMO) cathode electrode for Li-ion batteries would result in a significant step forward in terms of energy density. However, the structural ordering of the spinel and particle size have considerable effects on the cathode material’s cyclability and rate capability, which are crucial challenges to address. Here, a novel mid-frequency alternating current dual magnetron sputtering method was presented, using different Ar-N2 gas mixtures ratios for the process gas to prepare various LNMO thin films with highly controlled morphology and particle size; as determined from X-ray diffraction, Raman spectroscopy and electron microscopy. It resulted in enhanced cycling and rate performance. This processing method delivered N-containing LNMO thin film electrodes with up to 15 % increased discharge capacity at 1 C (120 mAh g−1) with respect to standard LNMO (grown under only Ar gas flow) thin film electrodes, along with outstanding rate performance up to 10 C (99 mAh g−1) in the operating voltage window 3.5–4.85 V vs. Li+/Li. Besides, electrochemical impedance spectroscopy results showed that the intricate phase transitions present in standard LNMO electrodes were almost suppressed in N-containing LNMO thin films grown under different Ar-N2 gas flow mixtures. © 2022 The Authors. ChemElectroChem published by Wiley-VCH GmbH.

9. Mechanistic Understanding of Microstructure Formation during Synthesis of Metal Oxide/Carbon Nanocomposites

   M. Elmanzalawy, A. Innocenti, M. Zarrabeitia, N.J. Peter, S. Passerini, V. Augustyn, and S. Fleischmann

   Journal of Materials Chemistry A, 2023

   Abs DOI

   Nanocomposite materials consisting of metal oxide and carbon are of interest as electrode materials for both high rate intercalation-type and high capacity conversion-type charge storage processes. Facile synthesis processes like the pyrolysis of an organic carbon-source can yield a well-dispersed carbon phase within the metal oxide structure. Detailed understanding of the carbon formation process is required to tailor the resulting material microstructure. Herein, both the formation and the final microstructure of a molybdenum oxide/carbon nanocomposite are studied in detail. Octylamine assembled in the interlayer space of layered MoO3 serves as a carbon source. The structural changes during pyrolysis are characterized using a combination of in situ heating X-ray diffraction with simultaneous FTIR- and mass spectroscopy-coupled thermogravimetric analysis experiments. These reveal mobility and partial desorption of octylamine and interlayer water at low temperatures, octylamine decomposition and loss of long-range order at intermediate temperatures, and carbothermic reduction of molybdenum oxide at high temperatures during pyrolysis. The resulting nanocomposite mainly contains nanocrystalline MoO2 domains surrounded by a well-dispersed carbon phase, as observed with scanning transmission electron microscopy of focus-ion beam prepared cross-sectional lamellae. The electrochemical behavior is evaluated in organic, lithium-containing electrolyte for both intercalation and conversion-type reactions, showing good intercalation kinetics and a high first cycle efficiency for the conversion-type reaction. © 2023 The Royal Society of Chemistry.

10. Adaptive Multi-Site Gradient Adsorption of Siloxane-Based Protective Layers Enable High Performance Lithium-Metal Batteries

    S. Fang, F. Wu, S. Zhao, M. Zarrabeitia, G.-T. Kim, J.-K. Kim, N. Zhou, and S. Passerini

    Advanced Energy Materials, 2023

    Abs DOI

    Low Coulombic efficiency and significant capacity decay resulting from an unstable solid electrolyte interphase (SEI) and dendritic growth pose challenges to the practical application of lithium-metal batteries. In this study, a highly efficient protection layer induced by octaphenylsilsesquioxane (OPS) with LiFSI salt is investigated. The OPS exhibits a strong adsorption energy with lithium, its multi-site gradient adsorption ability enables the simultaneous capture of 8 Li+ and the uniform regulation of Li ion flux. Moreover, the mechanical strength and electronic insulation of the OPS layer induces Li deposition under the protection layer and effectively inhibits lithium dendrite growth. Such a protection layer contributes to the stable and dendrite-free performance of a lithium-metal battery employing LiNi0.8Co0.1Mn0.1O2 (NCM811) as a cathode and an ultrathin OPS-protected lithium foil (20 µm) as the anode. A remarkable capacity retention of 91.4% is achieved after 300 cycles at 1C. The OPS-protected Li anodes and NCM811 are also tested in combination with a Li1.5Al0.5Ge1.5(PO4)3 solid electrolyte, showing extended cyclability up to 300 cycles with an average Coulombic efficiency of 99.58% and capacity retention of 85.7%. © 2023 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH.

11. Revealing the Impact of Different Iron-Based Precursors on the ‘Catalytic’ Graphitization for Synthesis of Anode Materials for Lithium Ion Batteries

    L. Frankenstein, P. Glomb, J. Ramírez-Rico, M. Winter, T.J. Placke, and A. Gómez-Martín

    ChemElectroChem, 2023

    Abs DOI

    Low cost and environmentally friendly production of graphite anodes from naturally available biomass resources is of great importance to satisfy the increasing material demand for lithium ion batteries. Herein, graphitization of coffee ground was performed using four different iron-based activating additives, including iron (III) chloride, iron (III) nitrate, iron (III) oxide and pure iron, following either a wet or a dry mixing approach. The structural development regarding the type of activator used and the impact on the corresponding electrochemical performance are systematically investigated. A maximum degree of graphitization between 55 and 74 % (as determined by Raman spectroscopy) is attained using iron (III) chloride and iron powder, respectively. The graphitic anode material synthesized using iron powder reached a maximum reversible capacity of ≈320 mAh g−1 at a rate of 0.1 C. This study provides significant insights into the impact of activators on the design of synthetic graphite from renewable sources. © 2023 The Authors. ChemElectroChem published by Wiley-VCH GmbH.

12. A Comparative Study of Mixed Phosphate-Pyrophosphate Materials for Aqueous and Non-Aqueous Na-ion Batteries

    G. Gečė, M. Zarrabeitia, J. Pilipavičius, S. Passerini, and L. Vilčiauskas

    ChemistrySelect, 2023

    Abs DOI

    Na-ion batteries based on abundant and sustainable materials might become one of the leading alternative technologies especially suitable for large-scale stationary storage. Various (mixed)phosphate framework materials are attracting much interest mainly due to their high structural stability and diversity. In this study, we report on the successful synthesis of mixed phosphate-pyrophosphate Na7V4(PO4)(P2O7)4, Na4Fe3(PO4)2P2O7, and Na4Mn3(PO4)2P2O7. The electrochemical properties of these materials are comprehensively characterized in different organic and aqueous electrolytes. The findings reveal that Na7V4(PO4)(P2O7)4 and Na4Fe3(PO4)2P2O7 exhibit very good cycling performance and rate capability in organic solvent-based electrolytes. However, their performance deteriorates significantly even in ‘water-in-salt’ aqueous electrolytes due to the rapid electrochemical degradation. Na4Mn3(PO4)2P2O7 demonstrates limited electrochemical activity in organic electrolytes and virtually no activity in ‘water-in-salt’ electrolytes, likely due to degradation processes resulting in blocking interphasial layers on electrode particles. These results underscore the need for further research to optimize the performance of these materials and identify potential strategies for enhancing their stability and activity in different electrolytes. © 2023 Wiley-VCH GmbH.

13. Effective SEI Formation via Phosphazene-Based Electrolyte Additives for Stabilizing Silicon-Based Lithium-Ion Batteries

    A. Ghaur, C. Peschel, I. Dienwiebel, L. Haneke, L. Du, L. Profanter, A. Gómez-Martín, M. Winter, S. Nowak, and T. Placke

    Advanced Energy Materials, 2023

    Abs DOI

    Silicon, as potential next-generation anode material for high-energy lithium-ion batteries (LIBs), suffers from substantial volume changes during (dis)charging, resulting in continuous breakage and (re-)formation of the solid electrolyte interphase (SEI), as well as from consumption of electrolyte and active lithium, which negatively impacts long-term performance and prevents silicon-rich anodes from practical application. In this work, fluorinated phosphazene compounds are investigated as electrolyte additives concerning their SEI-forming ability for boosting the performance of silicon oxide (SiOx)-based LIB cells. In detail, the electrochemical performance of NCM523 || SiOx/C pouch cells is studied, in combination with analyses regarding gas evolution properties, post-mortem morphological changes of the anode electrode and the SEI, as well as possible electrolyte degradation. Introducing the dual-additive approach in state-of-the-art electrolytes leads to synergistic effects between fluoroethylene carbonate and hexafluorocyclotriphosphazene-derivatives (HFPN), as well as enhanced electrochemical performance. The formation of a more effective SEI and increased electrolyte stabilization improves lifetime and results in an overall lower cell impedance. Furthermore, gas chromatography-mass spectrometry measurements of the aged electrolyte with HFPN-derivatives as an additive compound show suppressed ethylene carbonate and ethyl methyl carbonate decomposition, as well as reduced trans-esterification and oligomerization products in the aged electrolyte. © 2023 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH.

14. Enabling Aqueous Processing of Ni-Rich Layered Oxide Cathode Materials by Addition of Lithium Sulfate

    M. Heidbuchel, T. Schultz, T. Placke, M. Winter, N. Koch, R. Schmuch, and A. Gómez-Martín

    ChemSusChem, 2023

    Abs DOI

    Aqueous processing of Ni-rich layered oxide cathode materials is a promising approach to simultaneously decrease electrode manufacturing costs, while bringing environmental benefits by substituting the state-of-the-art (often toxic and costly) organic processing solvents. However, an aqueous environment remains challenging due to the high reactivity of Ni-rich layered oxides towards moisture, leading to lithium leaching and Al current collector corrosion because of the resulting high pH value of the aqueous electrode paste. Herein, a facile method was developed to enable aqueous processing of LiNi0.8Co0.1Mn0.1O2 (NCM811) by the addition of lithium sulfate (Li2SO4) during electrode paste dispersion. The aqueously processed electrodes retained 80 % of their initial capacity after 400 cycles in NCM811||graphite full cells, while electrodes processed without the addition of Li2SO4 reached 80 % of their capacity after only 200 cycles. Furthermore, with regard to electrochemical performance, aqueously processed electrodes using carbon-coated Al current collector outperformed reference electrodes based on state-of-the-art production processes involving N-methyl-2-pyrrolidone as processing solvent and fluorinated binders. The positive impact on cycle life by the addition of Li2SO4 stemmed from a formed sulfate coating as well as different surface species, protecting the NCM811 surface against degradation. Results reported herein open a new avenue for the processing of Ni-rich NCM electrodes using more sustainable aqueous routes. © 2022 The Authors. ChemSusChem published by Wiley-VCH GmbH.

15. Plasticized, Greaseproof Chitin Bioplastics with High Transparency and Biodegradability

    J.A. Heredia-Guerrero, J.J. Benítez, J.M. Porras-Vázquez, G. Tedeschi, Y. Morales, D. Fernández-Ortuño, A. Athanassiou, and S. Guzman-Puyol

    Food Hydrocolloids, 2023

    Abs DOI

    A mixture of trifluoroacetic acid:trifluoroacetic anhydride (TFA:TFAA) was used to dissolve chitin from shrimp shells. Free-standing films were prepared by blending the chitin solution and glycerol at different percentages, followed by drop-casting, and the complete evaporation of the solvents. After this process, the chitin matrix showed an amorphous molecular structure, as determined by X-ray diffraction. Optical, mechanical, thermal, and antioxidant properties were also thoroughly investigated. The incorporation of glycerol induced a plasticizing effect on the mechanical response of films and improved their transparency. In addition, hydrodynamic and barrier properties were determined by contact angle and water vapor/oxygen transmission rates, respectively, and revealed typical values of other polysaccharides. These bioplastics also presented an excellent greaseproof behavior with the highest degree of oil repellency as determined by the Kit test. Moreover, the overall migration was evaluated by using Tenax® as a dry food simulant and levels were compliant with European regulations. Their antifungal properties were tested using Botrytis cinerea as a model. Biodegradability was also determined by measuring the biological oxygen demand in seawater. Degradation rates were high and similar to those of other fully-degradable materials. © 2023 The Authors

16. Stable Cycling of Si Nanowire Electrodes in Fluorine-Free Cyano-Based Ionic Liquid Electrolytes Enabled by Vinylene Carbonate as SEI-forming Additive

    N. Karimi, M. Zarrabeitia, H. Geaney, K.M. Ryan, B. Iliev, T.J.S. Schubert, A. Varzi, and S. Passerini

    Journal of Power Sources, 2023

    Abs DOI

    Herein, the mixture of the fluorine-free cyano-based ionic liquid N-butyl-N-methylpyrrolidinium tricyanomethanide (Pyr14TCM), lithium dicyanamide (LiDCA) (1:9 salt:IL mole ratio) and 5 wt% vinylene carbonate (VC) is proposed as an electrolyte for the stable electrochemical alloying of silicon nanowire (Si NW) anodes. Detailed electrochemical characterization of the electrolyte (long-term galvanostatic cycling and impedance tests of Si NW-Li half-cells) demonstrates a remarkable cycling performance of the Si anode delivering 1500 mAhg−1 after 500 cycles with 99.5% Coulombic efficiency. The electrode/electrolyte interface is thoroughly investigated via scanning electron microscopy (SEM), energy dispersive X-ray (EDX) mapping, and X-ray photoelectron spectroscopy (XPS). The postmortem analysis reveals the key role of VC in controlling the IL decomposition, resulting in a bilayer solid electrolyte interphase (SEI) formation. The inner layer is mostly composed of graphitic carbon serving as a conductive coating for Si, and inorganic compounds such as Li3N providing high Li-ion conductivity. The outer-layer, is rich in polymeric species ensuring the good mechanical stability and flexibility to withstand the extreme volume change of Si during de-/alloying process, thus explaining the observed prolonged cycling performance. © 2022 Elsevier B.V.

17. Bio-Waste-Derived Hard Carbon Anodes Through a Sustainable and Cost-Effective Synthesis Process for Sodium-Ion Batteries

    H. Moon, A. Innocenti, H. Liu, H. Zhang, M. Weil, M. Zarrabeitia, and S. Passerini

    ChemSusChem, 2023

    Abs DOI

    Sodium-ion batteries (SIBs) are postulated as sustainable energy storage devices for light electromobility and stationary applications. The anode of choice in SIBs is hard carbon (HC) due to its electrochemical performance. Among different HC precursors, bio-waste resources have attracted significant attention due to their low-cost, abundance, and sustainability. Many bio-waste materials have been used as HC precursors, but they often require strong acids/bases for pre-/post-treatment for HC development. Here, the morphology, microstructure, and electrochemical performance of HCs synthesized from hazelnut shells subjected to different pre-treatments (i. e., no pre-treatment, acid treatment, and water washing) were compared. The impact on the electrochemical performance of sodium-ion cells and the cost-effectiveness were also investigated. The results revealed that hazelnut shell-derived HCs produced via simple water washing outperformed those obtained via other processing methods in terms of electrochemical performance and cost–ecological effectiveness of a sodium-ion battery pack. © 2022 The Authors. ChemSusChem published by Wiley-VCH GmbH.

18. Improved Stability of Design Clay Minerals at High Temperature: A Comparison Study with Natural Ones

    Francisco J. Osuna, Javier R. Chaparro, Esperanza Pavon, and Maria D. Alba

    Ceramics International, 2023

    Abs DOI

    Clay minerals are ceramics materials that are involved in a wide range of economic uses. But, their structure and composition are modified by heating and, consequently, compromise their final applications. The actual temperatures at which changes occur vary greatly from one group to another group and even for different specimens within a given group. The aim of this research has been to evaluate the thermal behaviour of a set of design swelling micas, Na-Mica-n (Mn) and compare them with a set of natural smectites. All samples were heated in the range 200 °C to 1000 °C; afterwards, they were rehydrated thorough water suspension (0.4% wt). The results have shown that swelling micas have better property of hydration/dehydration than natural clay minerals and those with higher layer charge exhibited higher rehydration ability and dehydration temperature.

19. Mechanical Treatments on Design Powder Ceramic Materials: Insight into the Textural and Structural Changes

    F.J. Osuna, M. Fernández, E. Pavón, R.M. Torres, and M.D. Alba

    Advanced Powder Technology, 2023

    Abs DOI

    Mechanical treatment of porous ceramics, such as porous clay minerals, is a crucial step in ceramic processing. Among clay minerals, design swelling brittle micas have shown exceptional properties for further applications, although they exhibit low surface area and porosity. But, their mechanical activation could improve their textural properties and deserves to be investigated. Thus, the aim of this work was to evaluate the effects of gradual grinding in their surface and framework. At short grinding times, the surface area increases and mesoporous and microporous are generated. Long grinding time provokes particle agglomeration with the consequent change in their colloidal stability. At bulk level, framework defects are observed in both tetrahedral and octahedral sheets and increase with the total layer charge. © 2023 The Society of Powder Technology Japan

20. A Technological Approach Based on Engineered Nanoclay Composites for Cesium and Iodine Retention.

    Francisco J. Osuna, Esperanza Pavón, and María D. Alba

    Chemosphere, 2023

    Abs DOI

    The development of effective and environmentally friendly methods for separating hazardous radionuclides from waste poses a significant technological challenge. 137Cs and 131I are among the most important radionuclides discharged into the environment by nuclear power plants. One of the best ways to eliminate them involves adsorption on clay minerals. In this regard, studies have demonstrated that organofunctionalized clay minerals are effective adsorbents. Thus, this study investigates the capability of organofunctionalized synthetic design clay minerals to jointly eliminate cesium and iodine. The adsorbents studied are a range of organofunctionalized clay minerals with alkylammonium cations of different alkyl chain lengths (2, 3 and 18) and some physical mixtures of raw clay minerals and octadecylammonium compounds. Organofunctionalized synthetic swelling highly charged micas are effective adsorbents for the simultaneous adsorption of cesium and iodine. In addition, the optimal system is a mixture of Na-M4 with octadecylammonium (50% w/w).

21. Influence of CO2 Laser Beam Modelling on Electronic and Electrochemical Properties of Paper-Based Laser-Induced Graphene for Disposable pH Electrochemical Sensors

    T. Pinheiro, A. Rosa, C. Ornelas, J. Coelho, E. Fortunato, A.C. Marques, and R. Martins

    Carbon Trends, 2023

    Abs DOI

    Laser-induced graphene (LIG) allows for the fabrication of cost-effective, flexible electrodes on a multitude of recyclable and sustainable substrates, for implementation within electrochemical biosensors. This work expands on current LIG research, by experimentally modeling the effects of several CO2 laser irradiation variables towards resulting conductive and electrochemical properties of paper-derived LIG. Instead of relying on the established paradigm of manipulating power and scan speed of the laser irradiation process for optimized outcomes, modeling of underlying laser operation principles for pulse modulation, regarding pulse repetition frequencies, pulse duration and defocus are presented as the key aspects dominating graphitization processes of materials. This approach shows that graphitization is dominated by appropriate pulse durations, dictating the time the substrate is exposed to each laser pulse, with laser fluence and irradiation defocus influencing the resulting conductive properties, with sheet resistances as low as 14 Ω sq−1. Similarly, fabrication settings controlled by these parameters have a direct influence on the properties of LIG-based electrochemical three-electrode cells, with optimized fabrication settings reaching electrochemically active surface area as high as 35 mm2 and heterogeneous electron transfer rates of 3.4 × 10−3 cm.s−1. As a proof-of-concept, the production of environmentally friendly, accessible, and biocompatible pH sensors is demonstrated, using two modification approaches, employing riboflavin and polyaniline as pH-sensitive elements. © 2023

22. A Unique Polymer-Inorganic Cathode-Electrolyte-Interphase (CEI) Boosts High-Performance Na3V2(PO4)2F3 Batteries in Ether Electrolytes

    B. Qin, M. Zarrabeitia, A. Hoefling, Z. Jusys, X. Liu, J. Tübke, R.J. Behm, G. Cui, A. Varzi, and S. Passerini

    Journal of Power Sources, 2023

    Abs DOI

    The practical utilization of ether electrolytes has long been restricted due to the concern on its electrochemical oxidation stability. Recently, it has been demonstrated that ethers are compatible with a series of polyanionic cathodes for sodium batteries. However, the specific cathode-electrolyte interface is still poorly understood. In this work, via the use of highly complementary surface and interfacial characterization techniques, we identify that the use of an 1 M NaPF6-diglyme solution allows the formation of a unique polymer-inorganic cathode-electrolyte-interphase (CEI) on high-voltage Na3V2(PO4)2F3 polyanionic cathodes, contributing to excellent cyclability (capacity retention of 96.2% after 300 cycles at 0.5C, 1C = 128 mAh g−1) and outstanding rate capability (124, 120 and 112 mAh g−1, at 5C, 10C and 20C, respectively). The peculiar interfacial chemistry disclosed here may open up new opportunities for building high performance sodium batteries. © 2023 Elsevier B.V.

23. The Role of Protective Surface Coatings on the Thermal Stability of Delithiated Ni-Rich Layered Oxide Cathode Materials

    F. Reissig, J. Ramírez-Rico, T.J. Placke, M. Winter, R. Schmuch, and A. Gómez-Martín

    Batteries, 2023

    Abs DOI

    To achieve a broader public acceptance for electric vehicles based on lithium-ion battery (LIB) technology, long driving ranges, low cost, and high safety are needed. A promising pathway to address these key parameters lies in the further improvement of Ni-rich cathode materials for LIB cells. Despite the higher achieved capacities and thus energy densities, there are major drawbacks in terms of capacity retention and thermal stability (of the charged cathode) which are crucial for customer acceptance and can be mitigated by protecting cathode particles. We studied the impact of surface modifications on cycle life and thermal stability of LiNi0.90Co0.05Mn0.05O2 layered oxide cathodes with WO3 by a simple sol–gel coating process. Several advanced analytical techniques such as low-energy ion scattering, differential scanning calorimetry, and high-temperature synchrotron X-ray powder diffraction of delithiated cathode materials, as well as charge/discharge cycling give significant insights into the impact of surface coverage of the coatings on mitigating degradation mechanisms. The results show that successful surface modifications of WO3 with a surface coverage of only 20% can prolong the cycle life of an LIB cell and play a crucial role in improving the thermal stability and, hence, the safety of LIBs. © 2023 by the authors.

24. Solvent-Free Ternary Polymer Electrolytes with High Ionic Conductivity for Stable Sodium-based Batteries at Room Temperature

    D. Roscher, Y. Kim, D. Stępień, M. Zarrabeitia, and S. Passerini

    Batteries and Supercaps, 2023

    Abs DOI

    Transitioning to solid-state batteries using polymer electrolytes results in inherently safer devices and can facilitate the use of sodium metal anodes enabling higher energy densities. In this work, solvent-free ternary polymer electrolytes based on cross-linked polyethylene oxide (PEO), sodium bis(fluorosulfonyl) imide (NaFSI) or sodium bis(trifluoromethanesulfonyl) imide (NaTFSI) and N-butyl-N-methyl-pyrrolidinium-based ionic liquids (ILs, Pyr14FSI or Pyr14TFSI) are developed. Synthesized polymer membranes are thoroughly characterized, verifying their good thermal and electrochemical stability, as well as a low glass transition and crystallinity, thus high segmental mobility of the polymer matrix. The latter results in good ionic conductivities around 1×10−3 S cm−1 at 20 °C. The polymer electrolytes are successfully employed in sodium-metal battery (SMB) cells operating at room temperature (RT) and using P2-Na2/3Ni1/3Mn2/3O2 layered oxide as cathode. The electrochemical performance strongly depends on the choice of anion in the conducting sodium salt and plasticizing IL. Furthermore, this solid-state SMB approach mitigates capacity fading drivers for the P2-Na2/3Ni1/3Mn2/3O2, resulting in high Coulombic efficiency (99.91 %) and high capacity retention (99 % after 100 cycles) with good specific capacity (140 mAh g−1). © 2023 The Authors. Batteries & Supercaps published by Wiley-VCH GmbH.

25. Effect of Mo and W Interlayers on Microstructure and Mechanical Properties of Si3N4–Nickel-Base Superalloy Joints

    M. Singh, J.M. Martínez-Fernández, R. Asthana, J. Ramírez-Rico, and F.M. Valera-Feria

    International Journal of Applied Ceramic Technology, 2023

    Abs DOI

    Si3N4/nickel-base superalloy (Inconel-625) and Si3N4/Si3N4 joints with refractory metal (W and Mo) interlayers were vacuum brazed using a Ti-active braze Cu-ABA (92.75Cu–3Si–2Al–2.25Ti) at 1317 K for 30 min with the following interlayered arrangements: Si3N4/Mo/W/Inconel and Si3N4/Mo/W/Si3N4. The joints exhibited Ti segregation at the Si3N4/Cu-ABA interface, elemental interdiffusion across the joint interfaces, and sound metallurgical bonding. Knoop microhardness profiles revealed hardness gradients across the joints that mimicked the interlayered arrangement. The compressive shear strength of Si3N4/Si3N4 joints both with and without W and Mo layers was ∼142 MPa but the strength of Si3N4/Inconel joints increased from ∼9 MPa for directly bonded joints without interlayers to 53.5 MPa for joints with Mo and W interlayers. © 2022 The American Ceramic Society.

26. Three-Dimensional Nitrogen-Doped Carbonaceous Networks Anchored with Cobalt as Separator Modification Layers for Low-Polarization and Long-Lifespan Aluminum-Sulfur Batteries

    C. Xu, M. Zarrabeitia, Y. Li, J. Biskupek, U. Kaiser, X. Liu, and S. Passerini

    ACS Nano, 2023

    Abs DOI

    Aluminum-sulfur (Al-S) batteries have attracted extensive interest due to their high theoretical energy density, inherent safety, and low cost. However, severe polarization and poor cycling performance significantly limit the development of Al-S batteries. Herein, three-dimensional (3D) nitrogen-doped carbonaceous networks anchored with cobalt (Co@CMel-ZIF) is proposed as a separator modification layer to mitigate these issues, prepared via carbonizations of a mixture of ZIF-7, melamine, and CoCl2. It exhibits a 3D network structure with a moderate surface area and high average pore diameter, which is demonstrated to be effective in adsorbing the aluminum polysulfides and hindering the mobility of polysulfides across the separator for enhanced cyclic stability of Al-S batteries. Meanwhile, Co@CMel-ZIF are characterized by abundant catalytic pyridinic-N and Co-Nx active sites that effectively eliminate the barrier of sulfides’ conversion and thereby facilitate the polarization reduction. As a result, Al-S cells based on the separator modified with Co@CMel-ZIF exhibit a low voltage polarization of 0.47 V under the current density of 50 mA g-1 at 20 °C and a high discharge specific capacity of 503 mAh g-1 after 150 cycles. In contrast, the cell employing a bare separator exhibits a polarization of 1.01 V and a discharge capacity of 300 mAh g-1 after 70 cycles under the same conditions. This work demonstrates that modifying the separators is a promising strategy to mitigate the high polarization and poor cyclability of Al-S batteries. © 2023 American Chemical Society.

27. Could Potassium-Ion Batteries Become a Competitive Technology?

    Maider Zarrabeitia, Javier Carretero-González, Michal Leskes, Henry Adenusi, Boyan Iliev, Thomas J. S. Schubert, Stefano Passerini, and Elizabeth Castillo-Martinez

    Energy Materials, 2023

    Abs DOI

    Potassium-ion batteries (PIBs) have attracted significant attention as a complement to lithium-ion and sodium-ion batteries (SIBs). PIBs can theoretically provide higher specific energy and power density than SIBs due to lower standard electrode potential of K/K+ and faster K+ ion diffusion, maintaining the benefits of low-cost and sustainability. However, research on PIBs is in its infancy; therefore, further efforts are necessary to enhance their performance and position them as a competitive technology. In this perspective, the remaining challenges and possible strategies to advance the development of PIBs are presented.

28. Layered Oxide Cathodes for Sodium-Ion Batteries: Storage Mechanism, Electrochemistry, and Techno-economics

    W. Zuo, A. Innocenti, M. Zarrabeitia, D. Bresser, Y. Yang, and S. Passerini

    Accounts of Chemical Research, 2023

    Abs DOI

    Conspectus Lithium-ion batteries (LIBs) are ubiquitous in all modern portable electronic devices such as mobile phones and laptops as well as for powering hybrid electric vehicles and other large-scale devices. Sodium-ion batteries (NIBs), which possess a similar cell configuration and working mechanism, have already been proven as ideal alternatives for large-scale energy storage systems. The advantages of NIBs are as follows. First, sodium resources are abundantly distributed in the earth’s crust. Second, high-performance NIB cathode materials can be fabricated by using solely inexpensive and noncritical transition metals such as manganese and iron, which further reduces the cost of the required raw materials. Recently, the unprecedented demand for lithium and other critical minerals has driven the cost of these primary raw materials (which are utilized in LIBs) to a historic high and thus triggered the commercialization of NIBs. Sodium layered transition metal oxides (NaxTMO2, TM = transition metal/s), such as Mn-based sodium layered oxides, represent an important family of cathode materials with the potential to reduce costs, increase energy density and cycling stability, and improve the safety of NIBs for large-scale energy storage. However, these layered oxides face several key challenges, including irreversible phase transformations during cycling, poor air stability, complex charge-compensation mechanisms, and relatively high cost of the full cell compared to LiFePO4-based LIBs. Our work has focused on the techno-economic analysis, the degradation mechanism of NaxTMO2 upon cycling and air exposure, and the development of effective strategies to improve their electrochemical performances and air stability. Correlating structure-performance relationships and establishing general design strategies of NaxTMO2 must be considered for the commercialization of NIBs. In this Account, we discuss the recent progress in the development of air-stable, electrochemically stable, and cost-effective NaxTMO2. The favorable redox-active cations for NaxTMO2 are emphasized in terms of abundance, cost, supply, and energy density. Different working mechanisms related to NaxTMO2 are summarized, including the electrochemical reversibility, the main structural transformations during the charge and discharge processes, and the charge-compensation mechanisms that accompany the (de)intercalation of Na+ ions, followed by discussions to improve the stability toward ambient air and upon cycling. Then the techno-economics are presented, with an emphasis on cathodes with different chemical compositions, cost breakdown of battery packs, and Na deficiency, factors that are critical to the large-scale implementation. Finally, this Account concludes with an overview of the remaining challenges and new opportunities concerning the practical applications of NaxTMO2, with an emphasis on the cost, large-scale fabrication capability, and electrochemical performance. © 2023 The Authors. Published by American Chemical Society.

2022

1. Biopolymer-Based Films Reinforced with FexOy-Nanoparticles

   J.A.A. Abdullah, M. Jiménez-Rosado, J.J. Benítez, A. Guerrero, and A. Romero García

   Polymers, 2022

   Abs DOI

   Nowadays, natural polymer-based films are considered potentially environmentally friendly alternatives to conventional plastic films, due to many advantageous properties, including their easy processability, high flexibility, non-toxicity, low cost, high availability, and environmental safety. However, they are limited in their application by a number of shortcomings, including their high water solubility and vapor permeability as well as their poor opacity and low mechanical resistance. Thus, nanoparticles, such as green FexOy-NPs, can be used to overcome the drawbacks associated with these materials. Therefore, the aim of this study was to develop three different polymer-based films (gelatin-based, cellulose acetate-based and chitosan-based films) containing green synthesized FexOy-NPs (1.0% w/w of the initial polymer weight) as an additive to improve film properties. This was accomplished by preparing the different films using the casting method and examining their physicochemical, mechanical, microstructural, and functional characteristics. The results show that the incorporation of FexOy-NPs into the different films significantly enhanced their physicochemical, mechanical, and morphological properties as well as their antioxidant characteristics. Consequently, it was possible to produce suitable natural polymer-based films with potential applications across a wide range of industries, including functional packaging for food, antioxidants, and antimicrobial additives for pharmaceutical and biomedical materials as well as pesticides for agriculture. © 2022 by the authors.

2. Pre-Lithiation of Silicon Anodes by Thermal Evaporation of Lithium for Boosting the Energy Density of Lithium Ion Cells

   E. Adhitama, F. Dias Brandao, I. Dienwiebel, M.M. Bela, A. Javed, L. Haneke, M.C. Stan, M. Winter, A. Gómez-Martín, and T. Placke

   Advanced Functional Materials, 2022

   Abs DOI

   Silicon (Si) is one of the most promising anode candidates to further push the energy density of lithium ion batteries. However, its practical usage is still hindered by parasitic side reactions including electrolyte decomposition and continuous breakage and (re-)formation of the solid electrolyte interphase (SEI), leading to consumption of active lithium. Pre-lithiation is considered a highly appealing technique to compensate for active lithium losses. A critical parameter for a successful pre-lithiation strategy by means of Li metal is to achieve lithiation of the active material/composite anode at the most uniform lateral and in-depth distribution possible. Despite extensive exploration of various pre-lithiation techniques, controlling the lithium amount precisely while keeping a homogeneous lithium distribution remains challenging. Here, the thermal evaporation of Li metal as a novel pre-lithiation technique for pure Si anodes that allows both, that is, precise control of the degree of pre-lithiation and a homogeneous Li deposition at the surface is reported. Li nucleation, mechanical cracking, and the ongoing phase changes are thoroughly evaluated. The terms dry-state and wet-state pre-lithiation (without/with electrolyte) are revisited. Finally, a series of electrochemical methods are performed to allow a direct correlation of pre-SEI formation with the electrochemical performance of pre-lithiated Si. © 2022 The Authors. Advanced Functional Materials published by Wiley-VCH GmbH.

3. Revealing the Role, Mechanism, and Impact of AlF3 Coatings on the Interphase of Silicon Thin Film Anodes

   E. Adhitama, S. van Wickeren, K. Neuhaus, L. Frankenstein, F. Demelash, A. Javed, L. Haneke, S. Nowak, M. Winter, A. Gómez-Martín, and T. Placke

   Advanced Energy Materials, 2022

   Abs DOI

   Silicon (Si) holds great promise as an anode material for high energy density lithium ion batteries owing to its theoretical capacity of up to 3579 mAh g−1. However, this potential comes at the expense of major challenges, because the solid electrolyte interphase (SEI) at Si anodes hardly provides long-term protection due to severe volume expansion. Yet, when it comes to the SEI, the formation mechanism is not thoroughly understood. Here, thin AlF3 coatings are deposited on Si thin film to stabilize the SEI. To evaluate the SEI, systematic observation utilizing X-ray photoelectron spectroscopy is performed at different (de-)lithiation states, allowing stage-by-stage analysis to reveal the role, mechanism, and impact of AlF3 coating. Results show that the capacity retention is significantly improved for 90% after 100 cycles. The transformation of AlF3 into Li-Al-F compounds, as confirmed by ion chromatography, is responsible for an enhanced performance due to its high ionic conductivity. Moreover, the SEI of coated Si thin films is rich in inorganic species (i.e., LiF) which is beneficial to prevent electrons to pass through. This work will deepen the understanding of SEI on Si anodes with respect to the coating approach, suggesting future directions to improve coating layers on Si. © 2022 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH.

4. Elucidating the Role of Microstructure in Thiophosphate Electrolytes – a Combined Experimental and Theoretical Study of β-Li3PS4

   T. Ates, A. Neumann, T. Danner, A. Latz, M. Zarrabeitia, D. Stępień, A. Varzi, and S. Passerini

   Advanced Science, 2022

   Abs DOI

   Solid-state batteries (SSBs) are promising candidates to significantly exceed the energy densities of today’s state-of-the-art technology, lithium-ion batteries (LIBs). To enable this advancement, optimizing the solid electrolyte (SE) is the key. β-Li3PS4 (β-LPS) is the most studied member of the Li2S-P2S5 family, offering promising properties for implementation in electric vehicles. In this work, the microstructure of this SE and how it influences the electrochemical performance are systematically investigated. To figure this out, four batches of β-LPS electrolyte with different particle size, shape, and porosity are investigated in detail. It is found that differences in pellet porosities mostly originate from single-particle intrinsic features and less from interparticle voids. Surprisingly, the β-LPS electrolyte pellets with the highest porosity and larger particle size not only show the highest ionic conductivity (up to 0.049 mS cm–1 at RT), but also the most stable cycling performance in symmetrical Li cells. This behavior is traced back to the grain boundary resistance. Larger SE particles seem to be more attractive, as their grain boundary contribution is lower than that of denser pellets prepared using smaller β-LPS particles. © 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.

5. The Response of Tomato Fruit Cuticle Membranes Against Heat and Light

   J.J. Benítez, A. González Moreno, S. Guzman-Puyol, J.A. Heredia-Guerrero, A. Heredia, and E. Domínguez

   Frontiers in Plant Science, 2022

   Abs DOI

   Two important biophysical properties, the thermal and UV-Vis screening capacity, of isolated tomato fruit cuticle membranes (CM) have been studied by differential scanning calorimetry (DSC) and UV-Vis spectrometry, respectively. A first order melting, corresponding to waxes, and a second order glass transition (Tg) thermal events have been observed. The glass transition was less defined and displaced toward higher temperatures along the fruit ripening. In immature and mature green fruits, the CM was always in the viscous and more fluid state but, in ripe fruits, daily and seasonal temperature fluctuations may cause the transition between the glassy and viscous states altering the mass transfer between the epidermal plant cells and the environment. CM dewaxing reduced the Tg value, as derived from the role of waxes as fillers. Tg reduction was more intense after polysaccharide removal due to their highly interwoven distribution within the cutin matrix that restricts the chain mobility. Such effect was amplified by the presence of phenolic compounds in ripe cuticle membranes. The structural rigidity induced by phenolics in tomato CMs was directly reflected in their mechanical elastic modulus. The heat capacity (Cprev) of cuticle membranes was found to depend on the developmental stage of the fruits and was higher in immature and green stages. The average Cprev value was above the one of air, which confers heat regulation capacity to CM. Cuticle membranes screened the UV-B light by 99% irrespectively the developmental stage of the fruit. As intra and epicuticular waxes contributed very little to the UV screening, this protection capacity is attributed to the absorption by cinnamic acid derivatives. However, the blocking capacity toward UV-A is mainly due to the CM thickness increment during growth and to the absorption by flavone chalconaringenin accumulated during ripening. The build-up of phenolic compounds was found to be an efficient mechanism to regulate both the thermal and UV screening properties of cuticle membranes. © © 2022 Benítez, González Moreno, Guzmán-Puyol, Heredia-Guerrero, Heredia and Domínguez.

6. Practical Implementation of Magnetite-Based Conversion-Type Negative Electrodes via Electrochemical Prelithiation

   B.B. Bulut Kopuklu, E. Esen, A. Gómez-Martín, M. Winter, T. Placke, R. Schmuch, S.A. Alkan Gürsel, and A. Yürüm

   ACS Applied Materials and Interfaces, 2022

   Abs DOI

   We report the performance of a conversion-type magnetite-decorated partially reduced graphene oxide (Fe3O4@PrGO) negative electrode material in full-cell configuration with LiNi0.8Co0.15Al0.05O2(NCA) positive electrodes. To enable practical implementation of the conversion-type negative electrodes in full cells, the beneficial impact of electrochemical prelithiation on mitigating active lithium losses and improving cycle life is shown here for the first time in the literature. The initial Coulombic efficiency (ICE) of the full cells is improved from 70.8 to 91.2% by prelithiation of the negative electrode to 35% of its specific delithiation capacity. The prelithiation is shown to improve the surface passivation of the Fe3O4@PrGO electrodes, leading to less electrolyte reduction on their surface which is prominent from the significantly lowered accumulated Coulombic inefficiency values, lower polarization growth, and doubled capacity retention by the 100th cycle. The reduced surface reactions of the negative electrode by prelithiation also aids in reducing the extent of aging of the NCA positive electrode. Overall, the prelithiation leads to a longer cycle life, where a retained capacity of 60.4% was achieved for the prelithiated cells by the end of long-term cycling, which is 3 times higher than the capacity retention of the non-prelithiated cells. Results reported herein indicate for the first time that the electrochemical prelithiation of the Fe3O4@PrGO electrode is a promising approach for making conversion negative electrode materials more applicable in lithium-ion batteries. © 2022 American Chemical Society. All rights reserved.

7. High Temperature Mechanical Properties of Polycrystalline Y2SiO5

   R. Cabezas-Rodríguez, D. Ciria, J.M. Martínez-Fernández, G. Dezanneau, F. Karolak, and J. Ramírez-Rico

   Boletin de la Sociedad Espanola de Ceramica y Vidrio, 2022

   Abs DOI

   The high temperature mechanical properties of polycrystalline Y2SiO5 were studied in compression at temperatures in the range of 1200–1400 °C, both in constant strain rate and constant stress experiments. To examine the effect of grain size on the plastic deformation, two routes were used for the synthesis and sintering of Y2SiO5: one of solid state reaction followed by conventional sintering in air, and one of sol–gel synthesis followed by spark-plasma sintering, resulting in starting grain sizes of 2.2 and 0.9 μm, respectively. Ceramics obtained by these routes exhibited different high-temperature compression behavior: while the conventionally processed ceramic exhibited grain growth during mechanical testing and a stress exponent close to one, compatible with diffusional creep, the spark-plasma sintered ceramic showed no grain growth but significant cavitation, a stress exponent close to two and partially superplastic behavior. These results have implications for the design and lifetime assessment of rare earth silicate-based environmental barrier coatings. © 2021 SECV

8. Carbon-Yarn-Based Supercapacitors with in Situ Regenerated Cellulose Hydrogel for Sustainable Wearable Electronics

   J.T. Carvalho, I. Cunha, J. Coelho, E. Fortunato, R. Martins, and L. Pereira

   ACS Applied Energy Materials, 2022

   Abs DOI

   Developing sustainable options for energy storage in textiles is needed to power future wearable "Internet of Things" (IoT) electronics. This process must consider disruptive alternatives that address questions of sustainability, reuse, repair, or even a second life application. Herein, we pair stretch-broken carbon fiber yarns (SBCFYs), as current collectors, and an in situ regenerated cellulose-based ionic hydrogel (RCIH), as an electrolyte, to fabricate 1D fiber-shaped supercapacitors (FSCs). The areal specific capacitance reaches 433.02 μF·cm-2at 5 μA·cm-2, while the specific energy density is 1.73 × 10-2μWh·cm-2. The maximum achieved specific power density is 5.33 × 10-1mW·cm-2at 1 mA·cm-2. The 1D FSCs possess a long-life cycle and 92% capacitance retention after 10 »000 consecutive voltammetry cycles, higher than similar ones using the reference PVA/H3PO4gel electrolyte. Additionally, the feasibility and reproducibility of the produced devices were demonstrated by connecting three devices in series and parallel, showing a small variation of the current density in flat and bent positions. An environmentally responsible approach was implemented by recovering the active materials from the 1D FSCs and reusing or recycling them without compromising the electrochemical performance, thus ensuring a circular economy path. © 2022 American Chemical Society. All rights reserved.

9. Flame Confinement in Biomass Combustion Systems for Particles Abatement

   D. Ciria, M.P. Orihuela, P. Moreno-Naranjo, R. Chacartegui, J. Ramírez-Rico, and J.A. Becerra

   Energy Conversion and Management, 2022

   Abs DOI

   This work explores the use of open-pore, inert ceramic foams with different pore sizes as particle abatement systems in small biomass combustion systems. Porous foams made of silicon carbide with pore sizes 10 to 60 pores-per-inch were installed in an in-house designed combustion unit operated with wood pellets. Their effects on the temperature distribution inside the chamber, particulate and gases emissions were studied using different airflow rates in the reaction-limited regime (low equivalence ratio) to minimise stoichiometric factors. The influence of pore size, foam position with respect to the flame and space velocity were assessed. The confinement of the flame with inert foams was found to substantially modify the temperature distribution in the combustion chamber, improve the air-fuel mixture, and favour the thermal decomposition of the pellet, leading to a reduction in particulate emissions when compared to free-flame combustion at the same experimental conditions. In general, the amount of particulate matter was found to decrease by up to one order of magnitude as the pore size of the foam was reduced, while the temperature gradient in the combustion chamber was increased. Nitrogen oxides and carbon dioxide emissions were essentially unchanged, irrespectively of the pore size of the foam. It is expected that these values will be improved with longer residence times, as happens in operations with reduced excess air ratios. These results suggest that it is possible to control pollutants derived from domestic heating within the most restrictive current regulations on particulate emissions by integrating flame confinement designs with better operating practices and efficient abatement systems. © 2022 The Author(s)

10. Sustainable Carbon Sources for Green Laser-Induced Graphene: A Perspective on Fundamental Principles, Applications, and Challenges

    P.I. Claro, T. Pinheiro, S.L. Silvestre, A.C. Marques, J. Coelho, J.M. Marconcini, E. Fortunato, L.H. C Mattoso, and R. Martins

    Applied Physics Reviews, 2022

    Abs DOI

    Since the discovery of laser-induced graphene (LIG), significant advances have been made to obtain green LIG (gLIG) from abundant, eco-friendly, natural, and organic renewable bio-based carbon sources. Recently, some sustainable and cost-effective electronic devices have been designed with gLIG, resulting in diverse solutions to the environmental impact caused by electronic waste (e-waste). However, there are still several challenges that must be addressed regarding the widespread market implementation of gLIG-based products, from synthesis to practical applications. In this review, we focus on sustainable precursor sources, their conversion mechanisms, physical and chemical properties and applications, along with the challenges related to its implementation, showing the future opportunities and perspectives related to this promising new material. Various systems based on gLIG for energy storage, electrocatalysis, water treatment, and sensors have been reported in the literature. Additionally, gLIG has been proposed for ink formulation or incorporation into polymer matrices, to further expand its use to non-carbon-based substrates or applications for which pristine LIG cannot be directly used. In this way, it is possible to apply gLIG on diverse substrates, aiming at emerging wearable and edible electronics. Thus, this review will bring an overview of gLIG developments, in accordance with the European Green Deal, the United Nations Sustainable Development Goals and the new era of internet-of-things, which demands cost-effective electronic components based on the principles of energy efficiency and sustainable production methods. © 2022 Author(s).

11. Biocompatible Parylene-C Laser-Induced Graphene Electrodes for Microsupercapacitor Applications

    R. Correia, J. Deuermeier, M.R.P. Correia, J.V. Pinto, J. Coelho, E. Fortunato, and R. Martins

    ACS Applied Materials and Interfaces, 2022

    Abs DOI

    Laser irradiation of polymeric materials has drawn great attention as a fast, simple, and cost-effective method for the formation of porous graphene films that can be subsequently fabricated into low-cost and flexible electronic and energy-storage devices. In this work, we report a systematic study of the formation of laser-induced graphene (LIG) with sheet resistances as low as 9.4 ω/sq on parylene-C ultrathin membranes under a CO2 infrared laser. Raman analysis proved the formation of the multilayered graphenic material, with ID/IG and I2D/IG peak ratios of 0.42 and 0.65, respectively. As a proof of concept, parylene-C LIG was used as the electrode material for the fabrication of ultrathin, solid-state microsupercapacitors (MSCs) via a one-step, scalable, and cost-effective approach, aiming at future flexible and wearable applications. The produced LIG-MSC on parylene-C exhibited good electrochemical behavior, with a specific capacitance of 1.66 mF/cm2 and an excellent cycling stability of 96% after 10 000 cycles (0.5 mA/cm2). This work allows one to further extend the knowledge in LIG processes, widening the group of precursor materials as well as promoting future applications. Furthermore, it reinforces the potential of parylene-C as a key material for next-generation biocompatible and flexible electronic devices. © 2022 The Authors. Published by American Chemical Society.

12. Iron-Catalyzed Graphitization for the Synthesis of Nanostructured Graphitic Carbons

    R. D. Hunter, J. Ramírez-Rico, and Z. Schnepp

    Journal of Materials Chemistry A, 2022

    DOI
13. Improving High-Voltage Cycling Performance of Nickel-Rich NMC Layered Oxide Cathodes for Rechargeable Lithium–Ion Batteries by Mg and Zr Co-Doping

    H. Darjazi, E. Gonzalo, B. Acebedo, R. Cid Barreno, M. Zarrabeitia, F. Bonilla, M.Á. Muñoz-Márquez, and F. Nobili

    Materials Today Sustainability, 2022

    Abs DOI

    Regarding the cost and safety concerns arising together with the increasing demands on lithium–ion batteries, high energy density Ni-rich LiNi0.8Co0.1Mn0.1O2 (NMC811) materials are of substantial interest as cathode materials for the next-generation commercial lithium–ion batteries. However, their low cycling stability hinders their use in large-scale applications (Schipper et al., 2018) [1]. In this work, we report two NMC811 materials, pristine and Mg/Zr co-doped, both synthesized through a facile sol-gel method followed by a stepwise calcination process. The doped cathode presents enhanced structural stability and shows a specific capacity of 232 mAh/g, at 0.1C and high charge cut-off voltage of 4.8 V vs. Li+/Li, and significant good cycling stability after 100 cycles; better than pristine NMC811. To unravel the origin of the enhancement, we have investigated the ionic and electronic transport properties by means of electrochemical impedance spectroscopy measurements, as well as the behavior of the electrode–electrolyte interphase layer. © 2022 Elsevier Ltd

14. Enhancing the Interfacial Stability of High-Energy Si/Graphite||LiNi0.88Co0.09Mn0.03O2 Batteries Employing a Dual-Anion Ionic Liquid-based Electrolyte

    S. Fang, F. Wu, M. Zarrabeitia, M. Kuenzel, D. Roscher, X. Gao, J.-K. Kim, G.-T. Kim, and S. Passerini

    Batteries and Supercaps, 2022

    Abs DOI

    The poorly flammable room-temperature ionic liquid-based electrolyte composed of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and N-butyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (Pyr14FSI) with fluoroethylene carbonate (FEC) as an additive is investigated towards its compatibility with the LiNi0.88Co0.09Mn0.03O2 (NCM88) cathode and a high-capacity Si/graphite (SiG) anode, revealing a remarkably stable performance in lithium-ion cells. Interestingly, this dual-anion electrolyte with FEC additive forms a stable electrode-electrolyte interphase on both sides, which suppresses the morphological degradation of the electrode materials and continuous electrolyte decomposition. Consequently, lithium-ion cells using such dual-anion ionic liquid-based electrolyte display significantly improved cycling stability compared to conventional carbonate ester-based electrolyte, achieving a high specific energy of 385 Wh kg−1 (based on both cathode and anode active materials weight) with a capacity retention of 74 % after 200 cycles at 0.2 C, demonstrating the possibility to realize safe and high energy density LIBs. © 2022 The Authors. Batteries & Supercaps published by Wiley-VCH GmbH.

15. Magnesium Substitution in Ni-Rich NMC Layered Cathodes for High-Energy Lithium Ion Batteries

    A. Gómez-Martín, F. Reissig, L. Frankenstein, M. Heidbuchel, M. Winter, T. Placke, and R. Schmuch

    Advanced Energy Materials, 2022

    Abs DOI

    Ni-rich LiNi1−x−yMnxCoyO2 (NMC) layered oxides are promising cathode materials for high-energy density lithium ion batteries but suffer from severe capacity fading upon cycling. Elemental substitution (= doping) with Mg has repeatedly attracted attention in NMC materials to overcome instability problems at reasonable cost, yet rational compositional tuning is needed to guarantee sufficient cycle life without compromising energy density on the material level. Herein, a series of Mg-substituted NMC materials with 90 mol% Ni are investigated regarding key performance metrics in NMC || graphite full-cells benchmarked against LiNi0.80Mn0.10Co0.10O2 and LiNi0.90Mn0.05Co0.05O2 synthetized using the same co-precipitation route. A linear correlation between cycle life and attainable gravimetric capacities is demonstrated, which are directly influenced by the degree of Mg substitution and the amount of Li+ cycled upon (de-)lithiation processes. A Mg content <2 mol% should be considered to take notable benefit from the increase in Ni content from 80 to 90 mol% to achieve a higher energy density. The present study highlights the importance of evaluating the true implications of elemental substitution on cell performance and is expected to be an insightful guideline for the future development of NMC-type cathode materials in particular with high Ni and low Co content. © 2022 The Authors.

16. Opportunities and Challenges of Li2C4O4 as Pre-Lithiation Additive for the Positive Electrode in NMC622||Silicon/Graphite Lithium Ion Cells

    A. Gómez-Martín, M.M. Gnutzmann, E. Adhitama, L. Frankenstein, B. Heidrich, M. Winter, and T. Placke

    Advanced Science, 2022

    Abs DOI

    Silicon (Si)-based negative electrodes have attracted much attention to increase the energy density of lithium ion batteries (LIBs) but suffer from severe volume changes, leading to continuous re-formation of the solid electrolyte interphase and consumption of active lithium. The pre-lithiation approach with the help of positive electrode additives has emerged as a highly appealing strategy to decrease the loss of active lithium in Si-based LIB full-cells and enable their practical implementation. Here, the use of lithium squarate (Li2C4O4) as low-cost and air-stable pre-lithiation additive for a LiNi0.6Mn0.2Co0.2O2 (NMC622)-based positive electrode is investigated. The effect of additive oxidation on the electrode morphology and cell electrochemical properties is systematically evaluated. An increase in cycle life of NMC622||Si/graphite full-cells is reported, which grows linearly with the initial amount of Li2C4O4, due to the extra Li+ ions provided by the additive in the first charge. Post mortem investigations of the cathode electrolyte interphase also reveal significant compositional changes and an increased occurrence of carbonates and oxidized carbon species. This study not only demonstrates the advantages of this pre-lithiation approach but also features potential limitations for its practical application arising from the emerging porosity and gas development during decomposition of the pre-lithiation additive. © 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.

17. Structural Analysis of Mixed α- and β-Amyrin Samples

    L.D.M. Gómez-Pulido, R.C. González-Cano, J.J. Benítez, E. Domínguez, and A. Heredia

    Royal Society Open Science, 2022

    Abs DOI

    Little is known about the structure and molecular arrangement of α- and β-amyrin, a class of triterpenoids found within the cuticle of higher plants. Blends of both amyrin isomers with different ratios have been studied taking into consideration a combined methodology of density functional theory (DFT) calculations with experimental data from scanning electron microscopy, differential scanning calorimetry and Raman vibrational spectroscopy. Results indicate that trigonal trimeric aggregations of isomer mixtures are more stable, especially in the 1: 2 (α: β) ratio. A combination of Raman spectroscopy and DFT calculations has allowed to develop an equation to determine the amount of β-amyrin in a mixed sample. © 2022 The Authors

18. Greaseproof, Hydrophobic, and Biodegradable Food Packaging Bioplastics from C6-fluorinated Cellulose Esters

    S. Guzman-Puyol, G. Tedeschi, L. Goldoni, J.J. Benítez, L. Ceseracciu, A. Koschella, T. Heinze, A. Athanassiou, and J.A. Heredia-Guerrero

    Food Hydrocolloids, 2022

    Abs DOI

    Tridecafluorononanoic acid (TFNA), a C6-fluorinated carboxylic acid, was esterified with cellulose at different molar ratios (0:1, 1:1, 2:1, and 3:1) in a trifluoroacetic acid (TFA):trifluoroacetic anhydride (TFAA):CHCl3 (2:1:1, vv) solvent mixture. Free-standing films were obtained for all formulations and are presented as alternatives to composites and blends of paper with fluorinated molecules. Mechanical properties were investigated by tensile tests, and a plasticizer effect of fluorinated chains was observed. Interestingly, the wettability of these new cellulose derivatives was similar or even better than other common cellulose derivatives and fluorinated polymers employed in food packaging. Hydrodynamic properties were also improved by addition of TFNA, resulting in materials with water vapor permeability values comparable to other cellulose-based food packaging materials. In addition, films with the higher amounts of TFNA showed the required oil resistance for papers used in food packaging applications, as determined by the Kit Test. Finally, the biodegradation of these C6-fluorinated cellulose esters, assessed by biological oxygen demand (BOD) in seawater, was higher than typical bio-based polymers used in food packaging. The bioplastic synthesized at a molar ratio 1:1 (TFNA:cellulose) showed excellent performances in terms of greaseproof, hydrophobicity, ductility, and biodegradability, representing a sustainable alternative to typical plastics used in food packaging. © 2022 The Authors

19. Sustainable Bio-Based Polymers: Towards a Circular Bioeconomy

    S. Guzman-Puyol, J.J. Benítez, and J.A. Heredia-Guerrero

    Polymers, 2022

    DOI
20. Transparency of Polymeric Food Packaging Materials

    S. Guzman-Puyol, J.J. Benítez, and J.A. Heredia-Guerrero

    Food Research International, 2022

    Abs DOI

    Transparency is a very important technical parameter to evaluate and validate certain food packaging materials. In the recent scientific literature, several methods (i.e. transmittance, opacity, haze, and absorbance) have been used and such variety hinders a direct comparison of results from different authors. In this Review, we describe and discuss the most widely employed methods to measure transparency, with special emphasis on two main parameters: transmittance and opacity. Moreover, a comparison of the different techniques is addressed and the typical values of transmittance and opacity of common transparent food packaging materials are provided. Our current opinion is that transparency should be expressed as transmittance in the visible range due to both the quickness and easiness of the measurement and the standardization of data. This information should be accompanied by the thickness value and a graphical image of the analysed samples for a useful and complete characterization. © 2022 The Authors

21. Transparent, UV-blocking, and High Barrier Cellulose-Based Bioplastics with Naringin as Active Food Packaging Materials

    S. Guzman-Puyol, J. Hierrezuelo-León, J.J. Benítez, G. Tedeschi, J.M. Porras-Vázquez, A. Heredia, A. Athanassiou, D. Romero, and J.A. Heredia-Guerrero

    International Journal of Biological Macromolecules, 2022

    Abs DOI

    Free-standing, robust, and transparent bioplastics were obtained by blending cellulose and naringin at different proportions. Optical, thermal, mechanical, antioxidant, and antimicrobial properties were systematically investigated. In general, the incorporation of naringin produced important UV blocking and plasticizer effects and good antioxidant and antibacterial properties. Moreover, the barrier properties were characterized by determination of their water and oxygen transmission rates, finding that both parameters decreased by increasing the naringin content and reaching values similar to other petroleum-based plastics and cellulose derivatives used for food packaging applications. Finally, the biodegradability of these films was determined by measurement of the biological oxygen demand (BOD) in seawater, demonstrating an excellent decomposition in such conditions. © 2022 The Authors

22. Concentrated Electrolytes Enabling Stable Aqueous Ammonium-Ion Batteries

    J. Han, M. Zarrabeitia, A. Mariani, M. Kuenzel, A. Mullaliu, A. Varzi, and S. Passerini

    Advanced Materials, 2022

    Abs DOI

    Rechargeable aqueous batteries are promising devices for large-scale energy-storage applications because of their low-cost, inherent safety, and environmental friendliness. Among them, aqueous ammonium-ion (NH4+) batteries (AAIB) are currently emerging owing to the fast diffusion kinetics of NH4+. Nevertheless, it is still a challenge to obtain stable AAIB with relatively high output potential, considering the instability of many electrode materials in an aqueous environment. Herein, a cell based on a concentrated (5.8 m) aqueous (NH4)2SO4 electrolyte, ammonium copper hexacyanoferrate (N-CuHCF) as the positive electrode (cathode), and 3,4,9,10-perylene-bis(dicarboximide) (PTCDI) as the negative electrode (anode) is reported. The solvation structure, electrochemical properties, as well as the electrode–electrolyte interface and interphase are systematically investigated by the combination of theoretical and experimental methods. The results indicate a remarkable cycling performance of the low-cost rocking-chair AAIB, which offers a capacity retention of ≈72% after 1000 cycles and an average output potential of ≈1.0 V. © 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH.

23. Insights into the Impact of Activators on the ‘Catalytic’ Graphitization to Design Anode Materials for Lithium Ion Batteries

    V. Hanhart, L. Frankenstein, J. Ramírez-Rico, V. Siozios, M. Winter, A. Gómez-Martín, and T.J. Placke

    ChemElectroChem, 2022

    Abs DOI

    In this work, we systematically investigate the ‘catalytic’ graphitization of a biomass precursor (coffee ground) using 10–60 wt. % of the activator iron (III) chloride hexahydrate in a temperature range of 1000 °C – 2400 °C. Special focus is put on the correlation of synthesis conditions, e. g., heat treatment temperature and mass fraction of iron chloride, with the electrochemical performance in carbon||Li metal cells. The structural investigations of the materials reveal a positive impact of an increasing heat treatment temperature and/or mass fraction of inserted activator on the degree of graphitization and the delithiation capacity. However, a saturation point regarding the maximum degree of graphitization at 2000 °C and reversible capacity by the ‘catalytic’ graphitization approach using iron (III) chloride has been found. A maximum degree of graphitization of ≈69 % could be reached by applying 2000 °C and 40 wt. % FeCl3 ⋅ 6H2O, resulting in a reversible capacity of 235 mAh g−1. © 2022 The Authors. ChemElectroChem published by Wiley-VCH GmbH.

24. Zinc-Ion Hybrid Supercapacitors Employing Acetate-Based Water-in-Salt Electrolytes

    J. Han, A. Mariani, M. Zarrabeitia, Z. Jusys, R.J. Behm, A. Varzi, and S. Passerini

    Small, 2022

    Abs DOI

    Halide-free, water-in-salt electrolytes (WiSEs) composed of potassium acetate (KAc) and zinc acetate (ZnAc2) are investigated as electrolytes in zinc-ion hybrid supercapacitors (ZHSs). Molecular dynamics simulations demonstrate that water molecules are mostly non-interacting with each other in the highly concentrated WiSEs, while “bulk-like water” regions are present in the dilute electrolyte. Among the various concentrated electrolytes investigated, the 30 m KAc and 1 m ZnAc2 electrolyte (30K1Zn) grants the best performance in terms of reversibility and stability of Zn plating/stripping while the less concentrated electrolyte cannot suppress corrosion of Zn and hydrogen evolution. The ZHSs utilizing 30K1Zn, in combination with a commercial activated carbon (AC) positive electrode and Zn as the negative electrode, deliver a capacity of 65 mAh g−1 (based on the AC weight) at a current density of 5 A g−1. They also offer an excellent capacity retention over 10 000 cycles and an impressive coulombic efficiency (≈100%). © 2022 The Authors. Small published by Wiley-VCH GmbH.

25. Investigation of a Fluorine-Free Phosphonium-Based Ionic Liquid Electrolyte and Its Compatibility with Lithium Metal

    N. Karimi, M. Zarrabeitia, M. Hosseini, T. Ates, B. Iliev, T.J.S. Schubert, A. Varzi, and S. Passerini

    ACS Applied Materials and Interfaces, 2022

    Abs DOI

    A novel fluorine-free ionic liquid electrolyte comprising lithium dicyanamide (LiDCA) and trimethyl(isobutyl)phosphonium tricyanomethanide (P111i4TCM) in a 1:9 molar ratio is studied as an electrolyte for lithium metal batteries. At room temperature, it demonstrates high ionic conductivity and viscosity of about 4.5 mS cm-1 and 64.9 mPa s, respectively, as well as a 4 V electrochemical stability window (ESW). Li stripping/plating tests prove the excellent electrolyte compatibility with Li metal, evidenced by the remarkable cycling stability over 800 cycles. The evolution of the Li-electrolyte interface upon cycling was investigated via electrochemical impedance spectroscopy, displaying a relatively low impedance increase after the initial formation cycles. Finally, the solid electrolyte interphase (SEI) formed on Li metal appeared to have a bilayer structure mostly consisting of DCA and TCM reduction products. Additionally, decomposition products of the phosphonium cation were also detected, despite prior studies reporting its stability against Li metal. © 2022 The Authors. Published by American Chemical Society.

26. Polysiloxane-Based Single-Ion Conducting Polymer Blend Electrolyte Comprising Small-Molecule Organic Carbonates for High-Energy and High-Power Lithium-Metal Batteries

    H.-P. Liang, M. Zarrabeitia, Z. Chen, S. Jovanovic, S. Merz, J. Granwehr, S. Passerini, and D. Bresser

    Advanced Energy Materials, 2022

    Abs DOI

    Single-ion conducting polymer electrolytes are considered particularly attractive for realizing high-performance solid-state lithium-metal batteries. Herein, a polysiloxane-based single-ion conductor (PSiO) is investigated. The synthesis is performed via a simple thiol-ene reaction, yielding flexible and self-standing polymer electrolyte membranes (PSiOM) when blended with poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP). When incorporating 57 wt% of organic carbonates, these polymer membranes provide a Li+ conductivity of >0.4 mS cm−1 at 20 °C and a wide electrochemical stability window of more than 4.8 V. This excellent electrochemical stability allows for the highly reversible cycling of symmetric Li||Li cells as well as high-energy Li||LiNi0.6Mn0.2Co0.2O2 (NMC622) and Li||LiNi0.8Mn0.1Co0.1O2 (NMC811) cells for several hundred cycles at relatively high discharge and charge rates. Remarkably, Li||NMC811 cells with high mass loading cathodes provide more than 76% capacity retention at a high current density of 1.44 mA cm−2, thus rendering this polymer electrolyte suitable for high-performance battery applications. © 2022 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH.

27. Metal–Organic Framework Derived Copper Chalcogenides-Carbon Composites as High-Rate and Stable Storage Materials for Na Ions

    H. Li, H. Zhang, M. Zarrabeitia, H.-P. Liang, D. Geiger, U. Kaiser, A. Varzi, and S. Passerini

    Advanced Sustainable Systems, 2022

    Abs DOI

    Transition metal chalcogenides have been regarded as promising storage materials for sodium ions owing to their high theoretical capacity. Herein, copper-based metal–organic frameworks (Cu-BTC) are reported as precursors to fabrica copper chalcogenides-carbon composites, namely Cu1.8S@C and Cu2-xSe@C. The materials exhibit excellent electrochemical performance with high specific capacities (504 mAh g–1 for Cu1.8S@C and 317 mAh g–1 for Cu2-xSe@C at 0.1 A g–1) and long-term cycling stability when used as anode materials in cells employing carbon-coated Na3V2(PO4)3 (NVP/C) positive electrodes. The Cu2-xSe@C||NVP/C cell delivers a specific capacity of 73 mAh g–1 at 1.2 A g–1 (based on cathode mass) and excellent cycling stability (capacity retention of 85% after 500 cycles at 0.12 A g–1) with Coulombic efficiency of ≈99.9%. Moreover, the Cu2-xSe@C composite performs well as positive electrode storage material in a sodium-metal cell, offering a high reversible capacity of 216 mAh (per gram of Cu2-xSe@C) after 1800 cycles at 2 A g–1 and enabling high specific energy and power. © 2022 The Authors. Advanced Sustainable Systems published by Wiley-VCH GmbH.

28. Sodiophilic Current Collectors Based on MOF-Derived Nanocomposites for Anode-Less Na-Metal Batteries

    H. Li, H. Zhang, F. Wu, M. Zarrabeitia, D. Geiger, U. Kaiser, A. Varzi, and S. Passerini

    Advanced Energy Materials, 2022

    Abs DOI

    “Anode-less” sodium metal batteries (SMBs) with high energy may become the next-generation batteries due to the abundant resources. However, their cycling performance is still insufficient for practical uses. Herein, a metal organic frameworks (MOF)-derived copper-carbon (Cu@C) composite is developed as a sodiophilic layer to improve the Coulombic efficiency (CE) and cycle life. The Cu particles can provide abundant nucleation sites to spatially guide Na deposition and the carbon framework offer void volume to avoid volume changes during the plating/stripping process. As a result, Cu@C-coated copper and aluminum foils (denoted as Cu-Cu@C and Al-Cu@C foil) can be used as efficient current collectors for sodium plating/stripping, achieving, nearly 1600 and 240 h operation upon cycling at 0.5 mA cm−2 and 1 mA h cm−2, respectively. In situ dilatometry measurements demonstrate that Cu@C promotes the formation of dense Na deposits, thereby inhibiting side reactions, dendrite growth, and accumulation of dead Na. Such current collectors are employed in Na metal cells using carbon-coated Na3V2(PO4)3 (NVP/C) and copper selenides (Cu2-xSe@C) cathodes, achieving outstanding rate capability and improved cycling performance. Most noticeably, “anode-less” Na batteries using Al-Cu@C as anode and NVP/C as cathode demonstrate promising CE as high as 99.5%, and long-term cycling life. © 2022 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH.

29. Effect of Organic Cations in Locally Concentrated Ionic Liquid Electrolytes on the Electrochemical Performance of Lithium Metal Batteries

    X. Liu, A. Mariani, M. Zarrabeitia, M.E. Di Pietro, X. Dong, G.A. Elia, A. Mele, and S. Passerini

    Energy Storage Materials, 2022

    Abs DOI

    Organic cations are essential components of locally concentrated ionic liquid electrolytes (LCILEs), but receive little attention. Herein, we demonstrate their significant influence on the electrochemical performance of lithium metal batteries via a comparison study of two LCILEs employing either 1‑butyl‑1-methylpyrrolidinium cation (Pyr14+) or 1-ethyl-3-methylimidazolium cation (Emim+). It is demonstrated that the structure of the organic cation in LCILEs has only a limited effect on the Li+- bis(fluorosulfonyl)imide anion (FSI−) coordination. Nonetheless, the coordination of FSI− with the organic cations is different. The less coordination of FSI− to Emim+ than to Pyr14+ results in the lower viscosity and faster Li+ transport in the Emim+-based electrolyte (EmiBE) than the Pyr14+-based electrolyte (PyrBE). Additionally, the chemical composition of the solid-electrolyte interphase (SEI) formed on lithium metal is affected by the organic cations. A more stable SEI growing in the presence of Emim+ leads to a higher lithium plating/stripping Coulombic efficiency (99.2%). As a result, Li/EmiBE/LiNi0.8Mn0.1Co0.1O2 cells exhibit a capacity of 185 mAh g−1 at 1C discharge (2 mA cm−2) and capacity retention of 96% after 200 cycles. Under the same conditions, PyrBE-based cells show only 34 mAh g−1 capacity with 39.6% retention. © 2021 Elsevier B.V.

30. Exploring the Local Environment of the Engineered Nanoclay Mica-4 under Hydrothermal Conditions Using Eu3+ as a Luminescent Probe

    R. Martín-Rodríguez, F. Aguado, M.D. Alba, R. Valiente, E. Pavón, and A.C. Perdigon-Aller

    Journal of Alloys and Compounds, 2022

    Abs DOI

    High charge mica Na4Al4Si4Mg6O20F4, Mica-4, is a promising candidate as a filling material to immobilize high-level radioactive waste in deep geological repositories due to its extraordinary adsorption capacity. In contrast to traditional clay materials, the structural composition of this mica, with a high content of aluminum in the tetrahedral sheet, enhances its chemical reactivity, favoring the formation of new crystalline phases under mild hydrothermal conditions, and thus providing a definitive isolation of the radionuclides in the engineered barrier. Moreover, this synthetic clay has some features that allow its use as an optical sensor by doping with luminescent rare earth cations such as Eu3+. In this paper we discuss the local structure of the nanoclay Mica-4 using Eu3+ as a local probe to track the physical and chemical modifications under hydrothermal conditions. For that purpose, a set of hydrothermal experiments has been carried out heating Mica-4 and an aqueous Eu(NO3)3 solution in a stainless steel reactor at different temperatures and times. Optical properties of the as-treated samples were characterized by spectroscopic measurements. The fine peak structure of emission and the relative intensity of different Eu3+ transitions as well as the luminescence lifetime have been correlated with the structure and composition of this nanoclay, and the interaction mechanisms between the lanthanide ions and the clay mineral at different temperatures and times. Special attention has been paid to understanding the role of the aluminum content, which may act as either an aggregating or dispersing agent, in the optical features and reactivity of the system. © 2022 The Authors

31. Structure, Composition, Transport Properties, and Electrochemical Performance of the Electrode-Electrolyte Interphase in Non-Aqueous Na-Ion Batteries

    M.Á. Muñoz-Márquez, M. Zarrabeitia, S. Passerini, and T. Rojo

    Advanced Materials Interfaces, 2022

    Abs DOI

    Rechargeable Li-ion battery technology has progressed due to the development of a suitable combination of electroactive materials, binders, electrolytes, additives, and electrochemical cycling protocols that resulted in the formation of a stable electrode-electrolyte interphase. It is expected that Na-ion technology will attain a position comparable to Li-ion batteries dependent on advancements in establishing a stable electrode-electrolyte interphase. However, Li and Na are both alkali metals with similar characteristics, yet the physicochemical properties of these systems differ. For this reason, a detailed study on the electrode-electrolyte interphase properties, composition, and structure is required to understand the factors that influence the battery’s behavior. Herein, the research that has been performed on the electrode-electrolyte interphase for both anode and cathode in the most important families of electrode materials, including carbonate ester-based and advanced electrolytes such as ether-based carbonates and ionic liquids is presented. © 2022 The Authors. Advanced Materials Interfaces published by Wiley-VCH GmbH

32. Insight into the Role of Temperature, Time and pH in the Effective Zirconium Retention Using Clay Minerals

    Esperanza Pavón and María D. Alba

    Journal of Environmental Management, 2022

    Abs DOI

    The use of zirconium in chemical industries generates a potential risk of Zr contamination in the environment, with particular concern for the decommissioning of uranium-graphite reactors. Among the natural adsorbents employed for the treatment of nuclear waste, clay minerals showed a very high affinity adsorption for radionuclides, but the influence of the chemical composition, pressure, temperature and time reaction have not yet been analysed on deep. Thus, the objective of this research is to explore several experimental conditions for an actual prediction of the behaviour of zirconium immobilization by clay minerals. The results have shown that factors such as zirconium cation nature (Zr4+ or ZrO2+), temperature, time and pH influence the extent of zirconium immobilization by clay minerals and the zirconium phases generated. At moderate conditions, zirconium tectosilicates are formed and evolve to zircon at high temperature and a longer time reaction.

33. Water Peel-Off Transfer of Electronically Enhanced, Paper-Based Laser-Induced Graphene for Wearable Electronics

    T. Pinheiro, R. Correia, M. Morais, J. Coelho, E. Fortunato, M.G.F. Ferreira Sales, A.C. Marques, and R. Martins

    ACS Nano, 2022

    Abs DOI

    Laser-induced graphene (LIG) has gained preponderance in recent years, as a very attractive material for the fabrication and patterning of graphitic structures and electrodes, for multiple applications in electronics. Typically, polymeric substrates, such as polyimide, have been used as precursor materials, but other organic, more sustainable, and accessible precursor materials have emerged as viable alternatives, including cellulose substrates. However, these substrates have lacked the conductive and chemical properties achieved by conventional LIG precursor substrates and have not been translated into fully flexible, wearable scenarios. In this work, we expand the conductive properties of paper-based LIG, by boosting the graphitization potential of paper, through the introduction of external aromatic moieties and meticulous control of laser fluence. Colored wax printing over the paper substrates introduces aromatic chemical structures, allowing for the synthesis of LIG chemical structures with sheet resistances as low as 5 ω·sq-1, translating to an apparent conductivity as high as 28.2 S·cm-1. Regarding chemical properties, ID/IG ratios of 0.28 showcase low defect densities of LIG chemical structures and improve on previous reports on paper-based LIG, where sheet resistance has been limited to values around 30 ω·sq-1, with more defect dense and less crystalline chemical structures. With these improved properties, a simple transfer methodology was developed, based on a water-induced peel-off process that efficiently separates patterned LIG structures from the native paper substrates to conformable, flexible substrates, harnessing the multifunctional capabilities of LIG toward multiple applications in wearable electronics. Proof-of concept electrodes for electrochemical sensors, strain sensors, and in-plane microsupercapacitors were patterned, transferred, and characterized, using paper as a high-value LIG precursor for multiples scenarios in wearable technologies, for improved sustainability and accessibility of such applications. © 2022 American Chemical Society.

34. Two-Dimensional Material Inks

    S. Pinilla, J. Coelho, K. Li, J. Liu, and V. Nicolosi

    Nature Reviews Materials, 2022

    Abs DOI

    The development of new and more accurate fabrication technologies has, in the past few years, boosted interest in advanced device manufacturing. 2D materials, thanks to their diverse properties and dispersibility in liquid carriers, constitute a rich toolbox for ink-based applications. However, the lack of standardized production methods offering a good compromise between performance and affordability has so far been a limiting factor for the application of 2D inks. In this Review, we provide a comprehensive description of the steps involved in device fabrication for different applications, from material selection and ink formulation to printing strategies and device assembly. We conclude with a critical overview of the main scientific and technical limitations currently faced by 2D inks and the related printing technologies, and discuss their market penetration and implementation stage. © 2022, Springer Nature Limited.

35. Investigation of Lithium Polyacrylate Binders for Aqueous Processing of Ni-Rich Lithium Layered Oxide Cathodes for Lithium-Ion Batteries

    F. Reissig, S. Puls, T. Placke, M. Winter, R. Schmuch, and A. Gómez-Martín

    ChemSusChem, 2022

    Abs DOI

    Ni-rich layered oxide cathodes are promising candidates to satisfy the increasing energy demand of lithium-ion batteries for automotive applications. Aqueous processing of such materials, although desirable to reduce costs and improve sustainability, remains challenging due to the Li+/H+ exchange upon contact with water, resulting in a pH increase and corrosion of the aluminum current collector. Herein, an example was given for tuning the properties of aqueous LiNi0.83Co0.12Mn0.05O2 electrode pastes using a lithium polyacrylate-based binder to find the “sweet spot” for processing parameters and electrochemical performance. Polyacrylic acid was partially neutralized to balance high initial capacity, good cycling stability, and the prevention of aluminum corrosion. Optimized LiOH/polyacrylic acid ratios in water were identified, showing comparable cycling performance to electrodes processed with polyvinylidene difluoride requiring toxic N-methyl-2-pyrrolidone as solvent. This work gives an exemplary study for tuning aqueous electrode pastes properties aiming towards a more environmentally friendly processing of Ni-rich cathodes. © 2022 The Authors. ChemSusChem published by Wiley-VCH GmbH.

36. Synergistic Effects of Surface Coating and Bulk Doping in Ni-Rich Lithium Nickel Cobalt Manganese Oxide Cathode Materials for High-Energy Lithium Ion Batteries

    F. Reissig, M.A. Lange, L. Haneke, T. Placke, W.G. Zeier, M. Winter, R. Schmuch, and A. Gómez-Martín

    ChemSusChem, 2022

    Abs DOI

    Ni-rich layered oxide cathodes are promising candidates to satisfy the increasing energy demand of lithium-ion batteries for automotive applications. Thermal and cycling stability issues originating from increasing Ni contents are addressed by mitigation strategies such as elemental bulk substitution (“doping”) and surface coating. Although both approaches separately benefit the cycling stability, there are only few reports investigating the combination of two of such approaches. Herein, the combination of Zr as common dopant in commercial materials with effective Li2WO4 and WO3 coatings was investigated with special focus on the impact of different material processing conditions on structural parameters and electrochemical performance in nickel-cobalt-manganese (NCM) || graphite cells. Results indicated that the Zr4+ dopant diffusing to the surface during annealing improved the electrochemical performance compared to samples without additional coatings. This work emphasizes the importance to not only investigate the effect of individual dopants or coatings but also the influences between both. © 2021 The Authors. ChemSusChem published by Wiley-VCH GmbH

37. Cork Derived Laser-Induced Graphene for Sustainable Green Electronics

    S.L. Silvestre, T. Pinheiro, A.C. Marques, J. Deuermeier, J. Coelho, R. Martins, L. Pereira, and E. Fortunato

    Flexible and Printed Electronics, 2022

    Abs DOI

    The demand for smart, wearable devices has been dictating our daily life with the evolution of integrated miniaturized electronics. With technological innovations, comes the impactful human footprint left on the planet’s ecosystems. Therefore, it is necessary to explore renewable materials and sustainable methodologies for industrial processes. Here, an eco-friendly approach to producing flexible electrodes based on a single-step direct laser writing is reported. A 1.06 µm wavelength fiber laser was used for the first time to produce porous three-dimensional laser-induced graphene (LIG) on an agglomerated cork substrates. The obtained material exhibits the typical Raman spectra, along with an exceptionally low sheet resistance between 7.5 and 10 ohm sq−1. LIG on cork high electrical conductivity and the friendliness of the used production method, makes it an interesting material for future technological applications. To show its applicability, the production of planar micro-supercapacitors was demonstrated, as a proof of concept. Electrochemical performance studies demonstrate that LIG interdigitated electrodes, using PVA-H2SO4 electrolyte, achieve an area capacitance of 1.35 mF cm−2 (103.63 mF cm−3) at 5 mV s−1 and 1.43 mF cm−2 (109.62 mF cm−3) at 0.1 mA cm−2. In addition, devices tested under bending conditions exhibit a capacitance of 2.20 mF cm−2 (169.22 mF cm−3) at 0.1 mA cm−2. Here, showing that these electrodes can be implemented in energy storage devices, also successfully demonstrating LIG promising application on innovative, green, and self-sustaining platforms. © 2022 The Author(s). Published by IOP Publishing Ltd.

38. Strength and Thermal Shock Resistance of Fiber-Bonded Si-Al-C-O and Si-Ti-C-O Ceramics

    M.C. Vera, J.M. Martínez-Fernández, M. Singh, and J. Ramírez-Rico

    International Journal of Applied Ceramic Technology, 2022

    Abs DOI

    Silicon carbide-based fiber-bonded ceramics, obtained from hot pressing of woven silicon carbide fibers, are a cost-effective alternative to ceramic-matrix composites due to their ease of fabrication, involving few processing steps, and competitive thermomechanical properties. In this work, we studied the high-temperature strength and thermal shock resistance of Si-Al-C-O and Si-Ti-C-O fiber-bonded SiC ceramics obtained from hot pressing of two types of ceramic fibers, by mechanical testing in four-point bending. The bending strength of Si-Al-C-O-based fiber-bonded ceramics at room temperature is ∼250–260 MPa and remains constant with temperature, while the bending strength of Si-Ti-C-O increases slightly from the initial 220 to ∼250 MPa for the highest temperature. Both materials retain up to 90% of their room temperature strength after thermal shocks of 1400°C and show no reduction in elastic moduli. After thermal shock, failure mode is the same as in the case of as-received materials. © 2021 The Authors. International Journal of Applied Ceramic Technology published by Wiley Periodicals LLC on behalf of American Ceramics Society

39. Improved Capacity Retention for a Disordered Rocksalt Cathode via Solvate Ionic Liquid Electrolytes

    L. Wichmann, J.-P. Brinkmann, M. Luo, Y. Yang, M. Winter, R. Schmuch, T. Placke, and A. Gómez-Martín

    Batteries and Supercaps, 2022

    Abs DOI

    Lithium-rich disordered rocksalts (DRX) are a promising class of cathode materials for high-energy lithium ion batteries (LIBs) and lithium metal batteries (LMBs) due to the high initial specific capacities (>200 mAh g−1) as well as flexible chemical composition. However, challenges concerning severe capacity fade and voltage decay upon cycling at high cut-off voltages are still to be overcome. Moreover, state-of-the-art carbonate-based electrolytes can be decomposed by reactive oxygen species released by DRX materials during cycling. In this work, the electrochemical performance of Li1.25Fe0.5Nb0.25O2 (LFNO) || Li LMB and LFNO || graphite LIB cells is compared for a conventional, carbonate-based electrolyte and the solvate ionic liquid (SIL) [Li(G3)][TFSI] (G3: triethyleneglycoldimethylether). Cycle life is notably improved by the chemically more stable ionic liquid electrolyte, as the anionic redox activity of LFNO is prolonged compared to the carbonate-based cells. This work represents an important step toward an improved cycle life of DRX cathodes. © 2022 The Authors. Batteries & Supercaps published by Wiley-VCH GmbH.

40. Effect of Phosphoric Acid as Slurry Additive on Li4Ti5O12 Lithium-Ion Anodes

    Y. Xu, A. Mullaliu, S.D. Lin, Y. Ma, J. Asenbauer, M. Zarrabeitia, S. Passerini, and D. Bresser

    Electrochimica Acta, 2022

    Abs DOI

    The aqueous processing of lithium-containing electrode materials is challenged by the reactivity of such materials towards water, resulting in lithium leaching, slurry pH increase, and consequent corrosion of the aluminum current collector. The addition of (mild) acids to the aqueous electrode slurry has been reported as a viable method to suppress the corrosion issue. Herein, we present a comprehensive investigation of the addition of phosphoric acid (PA) to an aqueous electrode slurry containing Li4Ti5O12 as the active material. Following an initial evaluation of the slurry pH evolution as a function of the PA content, a comparative investigation of the PA-free electrodes and the “corrosion-free” electrodes was performed. The latter clearly outperform the PA-free electrodes in terms of their electrochemical performance. Interestingly, this is not only resulting from the buffered pH, but the phosphate anion also plays a decisive role. © 2022 Elsevier Ltd

41. Important Impact of the Slurry Mixing Speed on Water-Processed Li4Ti5O12Lithium-Ion Anodes in the Presence of H3PO4as the Processing Additive

    Y. Xu, S. Fang, M. Zarrabeitia, M. Kuenzel, D. Geiger, U. Kaiser, S. Passerini, and D. Bresser

    ACS Applied Materials and Interfaces, 2022

    Abs DOI

    The aqueous processing of lithium transition metal oxides into battery electrodes is attracting a lot of attention as it would allow for avoiding the use of harmful N-methyl-2-pyrrolidone (NMP) from the cell fabrication process and, thus, render it more sustainable. The addition of slurry additives, for instance phosphoric acid (PA), has been proven to be highly effective for overcoming the corresponding challenges such as aluminum current collector corrosion and stabilization of the active material particle. Herein, a comprehensive investigation of the effect of the ball-milling speed on the effectiveness of PA as a slurry additive is reported using Li4Ti5O12 (LTO) as an exemplary lithium transition metal oxide. Interestingly, at elevated ball-milling speeds, rod-shaped lithium phosphate particles are formed, which remain absent at lower ball-milling speeds. A detailed surface characterization by means of SEM, EDX, HRTEM, STEM-EDX, XPS, and EIS revealed that in the latter case, a thin protective phosphate layer is formed on the LTO particles, leading to an improved electrochemical performance. As a result, the corresponding lithium-ion cells comprising LTO anodes and LiNi0.5Mn0.3Co0.2O2 (NMC532) cathodes reveal greater long-term cycling stability and higher capacity retention after more than 800 cycles. This superior performance originates from the less resistive electrode-electrolyte interphase evolving upon cycling, owing to the interface-stabilizing effect of the lithium phosphate coating formed during electrode preparation. The results highlight the importance of commonly neglected─frequently not even reported─electrode preparation parameters. © 2022 American Chemical Society.

42. Influence of the Current Density on the Interfacial Reactivity of Layered Oxide Cathodes for Sodium-Ion Batteries

    M. Zarrabeitia, T. Rojo, S. Passerini, and M.Á. Muñoz-Márquez

    Energy Technology, 2022

    Abs DOI

    The full commercialization of sodium-ion batteries (SIBs) is still hindered by their lower electrochemical performance and higher cost ( W−1 h−1) with respect to lithium-ion batteries. Understanding the electrode–electrolyte interphase formation in both electrodes (anode and cathode) is crucial to increase the cell performance and, ultimately, reduce the cost. Herein, a step forward regarding the study of the cathode–electrolyte interphase (CEI) by means of X-ray photoelectron spectroscopy (XPS) has been carried out by correlating the formation of the CEI on the P2-Na0.67Mn0.8Ti0.2O2$ layered oxide cathode with the cycling rate. The results reveal that the applied current density affects the concentration of the formed interphase species, as well as the thickness of CEI, but not its chemistry, indicating that the electrode–electrolyte interfacial reactivity is mainly driven by thermodynamic factors. © 2022 The Authors. Energy Technology published by Wiley-VCH GmbH.

43. Role of the Voltage Window on the Capacity Retention of P2-Na2/3[Fe1/2Mn1/2]O2 Cathode Material for Rechargeable Sodium-Ion Batteries

    M. Zarrabeitia, F. Nobili, O. Lakuntza, J. Carrasco, T. Rojo, M. Casas-Cabanas, and M.Á. Muñoz-Márquez

    Communications Chemistry, 2022

    Abs DOI

    P2-Na2/3[Fe1/2Mn1/2]O2 layered oxide is a promising high energy density cathode material for sodium-ion batteries. However, one of its drawbacks is the poor long-term stability in the operating voltage window of 1.5–4.25 V vs Na+/Na that prevents its commercialization. In this work, additional light is shed on the origin of capacity fading, which has been analyzed using a combination of experimental techniques and theoretical methods. Electrochemical impedance spectroscopy has been performed on P2-Na2/3[Fe1/2Mn1/2]O2 half-cells operating in two different working voltage windows, one allowing and one preventing the high voltage phase transition occurring in P2-Na2/3[Fe1/2Mn1/2]O2 above 4.0 V vs Na+/Na; so as to unveil the transport properties at different states of charge and correlate them with the existing phases in P2-Na2/3[Fe1/2Mn1/2]O2. Supporting X-ray photoelectron spectroscopy experiments to elucidate the surface properties along with theoretical calculations have concluded that the formed electrode-electrolyte interphase is very thin and stable, mainly composed by inorganic species, and reveal that the structural phase transition at high voltage from P2- to “Z”/OP4-oxygen stacking is associated with a drastic increased in the bulk electronic resistance of P2-Na2/3[Fe1/2Mn1/2]O2 electrodes which is one of the causes of the observed capacity fading. © 2022, The Author(s).

44. Guidelines for Air-Stable Lithium/Sodium Layered Oxide Cathodes

    W. Zuo, Z. Xiao, M. Zarrabeitia, X. Xue, Y. Yang, and S. Passerini

    ACS Materials Letters, 2022

    Abs DOI

    The rational design of intercalation materials plays an indispensable role in continuously improving the performance of rechargeable batteries. The capability of some very promising layered oxide materials for positive electrodes (cathodes), such as sodium layered oxides and Ni-rich lithium layered oxides, are limited by several key challenges. Air stability is one of the issues that should be tackled appropriately. In this Perspective, we present the reaction mechanisms of layered oxides when exposed to moist atmospheres, the critical factors that affect the air stability of layered oxides, and the practical strategies toward air-stable electrodes. Based on the above understandings, we highlighted several pivotal research directions for further investigations of air stability of layered oxides. We expect that continued exploration in understanding the air stability of layered oxides will help to advance the design and lower the expense of cost-effective and high-energy cathodes for Li- and Na-ion battery technologies. © 2022 ACS Materials Letters. All right reserved.

2021

1. Mechanical Performances of Isolated Cuticles Along Tomato Fruit Growth and Ripening

   J.J. Benítez, S. Guzman-Puyol, F. Vilaplana, J.A. Heredia-Guerrero, E. Domínguez, and A. Heredia

   Frontiers in Plant Science, 2021

   Abs DOI

   The cuticle is the most external layer that protects fruits from the environment and constitutes the first shield against physical impacts. The preservation of its mechanical integrity is essential to avoid the access to epidermal cell walls and to prevent mass loss and damage that affect the commercial quality of fruits. The rheology of the cuticle is also very important to respond to the size modification along fruit growth and to regulate the diffusion of molecules from and toward the atmosphere. The mechanical performance of cuticles is regulated by the amount and assembly of its components (mainly cutin, polysaccharides, and waxes). In tomato fruit cuticles, phenolics, a minor cuticle component, have been found to have a strong influence on their mechanical behavior. To fully characterize the biomechanics of tomato fruit cuticle, transient creep, uniaxial tests, and multi strain dynamic mechanical analysis (DMA) measurements have been carried out. Two well-differentiated stages have been identified. At early stages of growth, characterized by a low phenolic content, the cuticle displays a soft elastic behavior. Upon increased phenolic accumulation during ripening, a progressive stiffening is observed. The increment of viscoelasticity in ripe fruit cuticles has also been associated with the presence of these compounds. The transition from the soft elastic to the more rigid viscoelastic regime can be explained by the cooperative association of phenolics with both the cutin and the polysaccharide fractions. © © 2021 Benítez, Guzmán-Puyol, Vilaplana, Heredia-Guerrero, Domínguez and Heredia.

2. Computational Design of Cutin Derivative Bio-Materials from Fatty Acids

   O.V.M. Bueno, J.J. Benítez, and M.A. San-Miguel

   In Green Chemistry and Computational Chemistry: Shared Lessons in Sustainability, 2021

   Abs DOI

   In recent decades, awareness for the preservation of the environment, promoted by government policies and international organizations, has intervened, amid other things, to encourage the use and massive development of green materials. Polyesters are one of the main groups among green materials, and synthetic products have been prepared using bio-reactors. On the other hand, biopolyesters such as cutin and suberin are abundantly and ubiquitously present in nature as tissues in higher plants. Cutin-inspired polymers and composites have been proven to be promising bio-materials, and some efforts have been employed both experimentally and theoretically to rationalize the physical-chemical principles underlying the self-assembly mechanisms that control the formation of such polymers in vivo. They have already been used to develop bio-materials with high biodegradability, biocompatibility, and non-toxicity. In particular, thin films have been synthetized to be applied in the can coating and packaging technology in the food industry. Other applications include tissue scaffolding, therapeutic uses, and molecular biomimetic recognition. Molecular simulation has become a valuable tool to gain insights at the atomistic level into the fundamental processes occurring in the synthesis of these bio-materials. This chapter reports the latest advances combining atomistic simulations and atomic force microscopy (AFM) techniques to provide meaningful pieces of evidence on key features that control the self-assembly processes of different pure and mixtures polyhydroxy acids forming cutin. © 2022 Elsevier Inc. All rights reserved.

3. Improved Lithium-Ion Transport Within the LiNi0.8Co0.15Al0.05O2 Secondary Cathode Particles Through a Template-Assisted Synthesis Route

   B.B. Bulut Kopuklu, A. Gómez-Martín, M. Winter, T. Placke, R. Schmuch, S.A. Alkan Gürsel, and A. Yürüm

   ACS Sustainable Chemistry and Engineering, 2021

   Abs DOI

   Herein, we report a sacrificial carbon fiber (CF) template-assisted synthesis of LiNi0.8Co0.15Al0.05O2 (C-NCA) by the Pechini method. An anisotropic primary particle morphology with an interconnected microstructure is obtained, originating from local overheating and oxygen-deficient zones induced by combustion of the CFs during high-temperature lithiation. Moreover, the particles assembled around the CFs demonstrated denser packing compared to the reference bare NCA (B-NCA) synthetized in the absence of the CF template. The anisotropic surfaces facilitate ion transport and stabilize the structure for high voltage and temperature operation. C-NCA||Li metal cells exhibit a reversible capacity of 106 mA h g-1 at 10 C and are able to retain 96% of their initial capacity as the C-rate is reverted to 0.1 C. The state of health of C-NCA||graphite full cells remains at 70% after 200 cycles at 0.33 C within 2.8-4.3 V. The results outperform the B-NCA cell, exhibiting a significant loss over 66 cycles while delivering only 50% of its initial capacity. The synthesis method allows for a straightforward route for tailoring the particle size, shape, and crystallinity, enabling the development of stable nickel-rich cathode materials, even at an upper cutoff voltage of 4.5 V or an operating temperature of 60 °C. © 2021 American Chemical Society.

4. Highly Stable Quasi-Solid-State Lithium Metal Batteries: Reinforced Li1.3Al0.3Ti1.7(PO4)3/Li Interface by a Protection Interlayer

   Z. Chen, G.-T. Kim, J.-K. Kim, M. Zarrabeitia, M. Kuenzel, H.-P. Liang, D. Geiger, U. Kaiser, and S. Passerini

   Advanced Energy Materials, 2021

   Abs DOI

   NASICON-type Li1+xAlxTi2−x(PO4)3 (LATP) solid electrolytes have developed as a promising candidate for solid-state lithium batteries. However, the brittle and stiff LATP suffers from poor physical contact with electrodes and chemical/electrochemical instability at electrode|electrolyte interfaces. Herein, a thin and flexible hybrid electrolyte comprised of LATP and poly(vinylidene fluoride-trifluorethylene) (PVDF-TrFE) incorporated with highly concentrated ionic liquid electrolyte (ILE) is prepared to resolve these prominent limitations. To further protect the LATP|Li interface, an ultrathin poly[2,3-bis(2,2,6,6-tetramethylpiperidine-N-oxycarbonyl)-norbornene] (PTNB) polymer is coated on Li, acting as an additional protective layer. Consequently, the lithium stripping-plating lifetime is prolonged from 128 to 792 h, with no dendritic lithium observed. The PTNB@Li||LiNi0.8Co0.1Mn0.1O2 (PTNB@Li||NCM811) cells achieve significantly improved rate capability and cycling stability, predominantly resulting from the drastically decreased interfacial resistances, prohibited dendritic lithium generation, mitigated cathode material phase evolution, and prevention of internal microcrack formation. The thinner interphases formed on NCM811 and PTNB@Li electrodes also play a key role. The quasi-solid-state batteries allow for the fabrication of multi-layer bipolar cells with stable cycling. Even under some exertive circumstances, (limited lithium source, low temperature, e.g., 0 °C), the impressive electrochemical performance achieved highlights the importance of such quasi-solid-state lithium batteries as a viable solution for the next-generation high-performance lithium batteries. © 2021 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH

5. Lithium Phosphonate Functionalized Polymer Coating for High-Energy Li[Ni0.8Co0.1Mn0.1]O2 with Superior Performance at Ambient and Elevated Temperatures

   Z. Chen, H.-D. Nguyen, M. Zarrabeitia, H.-P. Liang, D. Geiger, J.-K. Kim, U. Kaiser, S. Passerini, C. Iojoiu, and D. Bresser

   Advanced Functional Materials, 2021

   Abs DOI

   High-energy Ni-rich lithium transition metal oxides such as Li[Ni0.8Co0.1Mn0.1]O2 (NCM811) are appealing positive electrode materials for next-generation lithium batteries. However, the high sensitivity toward moist air during storage and the high reactivity with common organic electrolytes, especially at elevated temperatures, are hindering their commercial use. Herein, an effective strategy is reported to overcome these issues by coating the NCM811 particles with a lithium phosphonate functionalized poly(aryl ether sulfone). The application of this coating allows for a substantial reduction of lithium-based surface impurities (e.g., LiOH, Li2CO3) and, generally, the suppression of detrimental side reactions upon both storage and cycling. As a result, the coated NCM811-based cathodes reveal superior Coulombic efficiency and cycling stability at ambient and, particularly, at elevated temperatures up to 60 °C (a temperature at which the non-coated NCM811 electrodes rapidly fail) owing to the formation of a stable cathode electrolyte interphase with enhanced Li+ transport kinetics and the well-retained layered crystal structure. These results render the herein presented coating strategy generally applicable for high-performance lithium battery cathodes. © 2021 The Authors. Advanced Functional Materials published by Wiley-VCH GmbH

6. Impact of Flame Confinement with Inert Ceramic Foams on the Particulate Emissions of Domestic Heating Systems

   D. Ciria, M.P. Orihuela, J.A. Becerra, R. Chacartegui, and J. Ramírez-Rico

   Fuel, 2021

   Abs DOI

   Small solid biomass combustion systems are among the main contributors to the global particulate emissions share, and cheap, efficient abatement systems are not yet available for them. The placement of inert porous material to confine the combustion region is being recently explored as a possible mitigation system for this kind of pollution. However, given the complexity of biomass thermochemical decomposition processes, it is challenging to justify the performance of these systems on the basis of a physicochemical understanding. A foundational experiment-based study is carried out in this work to understand how combustion confinement affects the particulate emissions production mechanisms. A combustion unit was designed and built to systematically test ceramic foams with different porosities: keeping constant airflow and fuel feed rates. A comprehensive characterisation study was carried out on the solid biomass fuel, the temperature profile, the particulate emissions, and the remaining solid residue. The results evidenced that the use of foams has a substantial impact on the temperature distribution in the combustion chamber. The higher the cell density of the foam, the higher and more homogeneous are the temperatures reached in the combustion bed. This fact improved the thermal decomposition process of the pellets due to a better air-fuel mixture, leading to a reduction of the solid particulate matter emissions by more than 70%. These findings suggest that the use of an inert porous material above the combustion region might be a feasible solution for particulate emission control in small-size biomass combustion technology. © 2021 Elsevier Ltd

7. Improved Sodiation Additive and Its Nuances in the Performance Enhancement of Sodium-Ion Batteries

   A.J. Fernández-Ropero, M. Zarrabeitia, G. Baraldi, M. Echeverría, T. Rojo, M. Armand, and D. Devaraj

   ACS Applied Materials and Interfaces, 2021

   Abs DOI

   The abundance of the available sodium sources has led to rapid progress in sodium-ion batteries (SIBs), making them potential candidates for immediate replacement of lithium-ion batteries (LIBs). However, commercialization of SIBs has been hampered by their fading efficiency due to the sodium consumed in the formation of solid-electrolyte interphase (SEI) when using hard carbon (HC) anodes. Herein, Na2C3O5 sodium salt is introduced as a highly efficient, cost-effective, and safe cathode sodiation additive. This sustainable sodium salt has an oxidation potential of μ4.0 V vs Na+/Na°, so it could be practically implemented into SIBs. Moreover, for the first time, we have also revealed by X-ray photoelectron spectroscopy (XPS) that in addition to the compensating Na+ ions spent in the SEI layer, the high specific capacity and capacity retention observed from electrochemical measurements are due to the formation of a thinner and more stable cathode-electrolyte interphase (CEI) on the P2-Na2/3Mn0.8Fe0.1Ti0.1O2 while using such a cathode sodiation additive. Half-cell studies with P2-Na2/3Mn0.8Fe0.1Ti0.1O2 cathodes show a 27% increase in the specific capacity (164 mAh gP2-1) with cathode sodiation additives. Full-cell studies with the HC anode show a 4 times increase in the specific capacity of P2-Na2/3Mn0.8Fe0.1Ti0.1O2. This work provides notable insights into and avenues toward the development of SIBs. © 2021 American Chemical Society.

8. Iron Catalysis in Metal-Ion Batteries

   A. Gómez-Martín and J. Ramírez-Rico

   In Catalytic Science Series, 2021

   Abs DOI

   Metal-ion batteries are an essential link in the reliable implementation of renewable energies and in the development of electric vehicles to reduce our dependence on fossil fuels and green-house emissions. The manufacturing of the state-of-the-art graphite anode for lithium-ion batteries (LIBs) requires high-temperature treatments and long processing times resulting in high costs and energy consumption. The prior addition of an iron catalyst to a non-graphitizing carbon precursor has been shown to promote in situ graphitization during heat treatment at moderate temperatures (below 1,000 °C), resulting in considerable energy savings for graphite synthesis. This chapter reviews on the use of iron as catalyst for inducing the graphitization of carbon materials for application as anodes for metal-ion battery. The phenomena of catalytic graphitization of carbon materials by an Fe catalyst and main parameters influencing final graphitic structure are reviewed. Then, the chapter discusses about the electrochemical investigations of these materials as anodes for metal-ion batteries and how synthesis features affect the lithium-ion intercalation compared to state-of-the-art electrodes. © 2021 World Scientific Publishing Europe Ltd.

9. Structural Evolution in Iron-Catalyzed Graphitization of Hard Carbons

   Aurora Gomez-Martin, Zoe Schnepp, and Joaquin Ramirez-Rico

   Chemistry of Materials, 2021

   Abs DOI

   Despite the recent interest in catalytic graphitization to obtain graphite-like materials from hard-carbon sources, many aspects of its mechanism are still poorly unknown. We performed a series of in situ experiments to study phase transformations during graphitization of a hard-carbon precursor using an iron catalyst at temperatures up to 1100 °C and ex situ total scattering experiments up to 2000 °C to study the structural evolution of the resulting graphitized carbon. Our results show that upon heating and cooling, iron undergoes a series of reductions to form hematite, magnetite, and wüstite before forming a carbide that later decomposes into metallic iron and additional graphite and that the graphitization fraction increases with increasing peak temperature. Structural development with temperature results in decreasing sheet curvature and increased stacking, along with a decrease in turbostratic disorder up to 1600 °C. Higher graphitization temperatures result in larger graphitic domains without further ordering of the graphene sheets. Our results have implications for the synthesis of novel biomass-derived carbon materials with enhanced crystallinity.

10. Pectin-Cellulose Nanocrystal Biocomposites: Tuning of Physical Properties and Biodegradability

    A. González Moreno, S. Guzman-Puyol, E. Domínguez, J.J. Benítez, P. Mora Segado, S. Lauciello, L. Ceseracciu, J.M. Porras-Vázquez, L. Leõn-Reina, A. Heredia, and J.A. Heredia-Guerrero

    International Journal of Biological Macromolecules, 2021

    Abs DOI

    The fabrication of pectin-cellulose nanocrystal (CNC) biocomposites has been systematically investigated by blending both polysaccharides at different relative concentrations. Circular free-standing films with a diameter of 9 cm were prepared by simple solution of these carbohydrates in water followed by drop-casting and solvent evaporation. The addition of pectin allows to finely tune the properties of the biocomposites. Textural characterization by AFM showed fibrous morphology and an increase in fiber diameter with pectin content. XRD analysis demonstrated that pectin incorporation also reduced the degree of crystallinity though no specific interaction between both polysaccharides was detected, by ATR-FTIR spectroscopy. The optical properties of these biocomposites were characterized for the first time and it was found that pectin in the blend reduced the reflectance of visible light and increased UV absorbance. Thermal stability, analyzed by TGA, was improved with the incorporation of pectin. Finally, pectin-cellulose nanocrystal biocomposites showed a good biodegradability in seawater, comparable to other common bioplastics such as cellulose and low-molecular weight polylactide, among others. © 2021 Elsevier B.V.

11. Sodium Manganese-Rich Layered Oxides: Potential Candidates as Positive Electrode for Sodium-ion Batteries

    E. Gonzalo, M. Zarrabeitia, N.E. Drewett, J.M. López del Amo, and T. Rojo

    Energy Storage Materials, 2021

    Abs DOI

    Sodium-ion batteries (SIBs) are amongst the most attractive alternatives for stationary applications and light electromobility due to potentially substantial cost reductions resulting from the availability, wide distribution, and easily accessible nature its constituents. However, commercialization is hindered - especially by lack of high-performance negative electrodes, little development of advanced electrolytes with suitable electrochemical stability windows (ESW) and electrode-electrolyte interphases (EEI), and the necessity of ongoing optimization of the most promising positive electrodes. Sodium layered oxides (SLOs) are considered one of the best positive electrodes for SIBs, due to relatively facile synthesis, flexibility, versatility, high specific capacity and fast structural Na+ ion diffusion (which potentially enables work at high current densities). Amongst SLOs, sodium manganese-rich layered oxides (SMRLOs) - with general formula NaxMnyTM1-yO2 (y ≥ 0.67; where TM = one or more metal/s) - are the most promising candidates in terms of low-cost, environmental friendliness and cyclability. Advances in research have exploited a wide range of investigative approaches and characterization techniques (e.g. solid-state nuclear magnetic resonance (ssNMR), in situ and ex situ Synchrotron XRD (SXRD), ab initio calculations, etc.) and subsequently established a good understanding of the physicochemical properties of SMRLOs, particularly with respect to their effect on electrochemical performance. The goal of this review is, therefore, to highlight and contextualize the most recent improvements relating to SMRLOs, so as to make available a good understanding of the potential challenges facing commercialization. Conclusions regarding strategies for future SIB commercialization, especially the use of SMRLOs as positive electrodes, are proposed. © 2020 Elsevier B.V.

12. Cutin-Inspired Polymers and Plant Cuticle-like Composites as Sustainable Food Packaging Materials

    S. Guzman-Puyol, A. Heredia, J.A. Heredia-Guerrero, and J.J. Benítez

    In Sustainable Food Packaging Technology, 2021

    Abs DOI

    This chapter deals with the use of plant cuticle-like and cutin-inspired polymer materials as sustainable, biodegradable, and functional food packaging. The main characteristics of petroleum-based plastics are introduced, while bio-based, biodegradable polymers are shown as their realistic alternatives. In this scenario, the chemical composition, structure, and properties of plant cuticle and cutin are described. Cutin is compared to several bio-based, biodegradable polymers in terms of mechanical and thermal properties, wettability, and biodegradability. In addition, tomato pomace is presented as the main and most sustainable cutin resource and the current scalable techniques for the industrial fabrication of cutin-inspired commodities are discussed. Later, the properties of these biomimetic polymers are contextualized by comparison to reference polymers made of fatty hydroxyacids with a specific number and position of hydroxyl groups. In addition, the effect of the atmosphere (air/nitrogen) during polycondensation and the oxidation of the surface are reported. Finally, the fabrication of cutin-inspired coatings and plant cuticle-like composites is reviewed. © 2021 WILEY-VCH GmbH, Boschstr. 12, 69469 Weinheim, Germany.

13. Solvent Engineered Synthesis of Layered SnO for High-Performance Anodes

    S. Jaśkaniec, S.R. Kavanagh, J. Coelho, S. Ryan, C. Hobbs, A. Walsh, D.O. Scanlon, and V. Nicolosi

    npj 2D Materials and Applications, 2021

    Abs DOI

    Batteries are the most abundant form of electrochemical energy storage. Lithium and sodium ion batteries account for a significant portion of the battery market, but high-performance electrochemically active materials still need to be discovered and optimized for these technologies. Recently, tin(II) oxide (SnO) has emerged as a highly promising battery electrode. In this work, we present a facile synthesis method to produce SnO microparticles whose size and shape can be tailored by changing the solvent nature. We study the complex relationship between wet-chemistry synthesis conditions and resulting layered nanoparticle morphology. Furthermore, high-level electronic structure theory, including dispersion corrections to account for van der Waals forces, is employed to enhance our understanding of the underlying chemical mechanisms. The electronic vacuum alignment and surface energies are determined, allowing the prediction of the thermodynamically favoured crystal shape (Wulff construction) and surface-weighted work function. Finally, the synthesized nanomaterials were tested as Li-ion battery anodes, demonstrating significantly enhanced electrochemical performance for morphologies obtained from specific synthesis conditions. © 2021, The Author(s).

14. Nonfluorinated Ionic Liquid Electrolytes for Lithium Metal Batteries: Ionic Conduction, Electrochemistry, and Interphase Formation

    N. Karimi, M. Zarrabeitia, A. Mariani, D. Gatti, A. Varzi, and S. Passerini

    Advanced Energy Materials, 2021

    Abs DOI

    Cyano-based ionic liquids (ILs) are prime candidates for the manufacturing of cheaper and safer batteries due to their inherently low-volatility and absence of expensive fluorinated species. In this work, N-methyl-N-butylpyrrolidinium (Pyr14)-based ILs featuring two different cyano-based anions, i.e., dicyanamide (DCA) and tricyanomethanide (TCM), and their mixture with the respective Li salts (1:9 salt:IL mole ratio), alongside their combination (DCA–TCM), are evaluated as potential electrolytes for lithium metal batteries (LMBs). The electrolytes display significant ionic conductivity at room temperature (5 mS cm−1) alongside an electrochemical stability window up to 4 V, suitable for low-voltage LMBs such as Li–sulfur, as well as promising cycling stability. In addition to the detailed physicochemical (viscosity, conductivity) and electrochemical (electrochemical stability window, stripping/plating, and impedance test in symmetrical Li cells) characterization, the solid electrolyte interphase (SEI) formed in this class of ionic liquids is studied for the first time. X-ray photoelectron spectroscopy (XPS) provides evidence for an SEI dominated by a polymer-rich layer including carbon–nitrogen single, double, and triple bonds, which provides high ionic conductivity and mechanical stability, leading to the aforementioned cycling stability. Finally, a molecular insight is achieved by density functional theory (DFT) and classic molecular dynamics simulations both supporting the experimental evidence. © 2020 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH

15. Enhanced Li+ Transport in Ionic Liquid-Based Electrolytes Aided by Fluorinated Ethers for Highly Efficient Lithium Metal Batteries with Improved Rate Capability

    X. Liu, M. Zarrabeitia, A. Mariani, X. Gao, H.M. Schütz, S. Fang, T. Bizien, G.A. Elia, and S. Passerini

    Small Methods, 2021

    Abs DOI

    FSI−-based ionic liquids (ILs) are promising electrolyte candidates for long-life and safe lithium metal batteries (LMBs). However, their practical application is hindered by sluggish Li+ transport at room temperature. Herein, it is shown that additions of bis(2,2,2-trifluoroethyl) ether (BTFE) to LiFSI-Pyr14FSI ILs can effectively mitigate this shortcoming, while maintaining ILs′ high compatibility with lithium metal. Raman spectroscopy and small-angle X-ray scattering indicate that the promoted Li+ transport in the optimized electrolyte, [LiFSI]3[Pyr14FSI]4[BTFE]4 (Li3Py4BT4), originates from the reduced solution viscosity and increased formation of Li+-FSI− complexes, which are associated with the low viscosity and non-coordinating character of BTFE. As a result, Li/LiFePO4 (LFP) cells using Li3Py4BT4 electrolyte reach 150 mAh g−1 at 1 C rate (1 mA cm−2) and a capacity retention of 94.6% after 400 cycles, revealing better characteristics with respect to the cells employing the LiFSI-Pyr14FSI (operate only a few cycles) and commercial carbonate (80% retention after only 218 cycles) electrolytes. A wide operating temperature (from −10 to 40 °C) of the Li/Li3Py4BT4/LFP cells and a good compatibility of Li3Py4BT4 with LiNi0.5Mn0.3Co0.2O2 (NMC532) are demonstrated also. The insight into the enhanced Li+ transport and solid electrolyte interphase characteristics suggests valuable information to develop IL-based electrolytes for LMBs. © 2021 The Authors. Small Methods published by Wiley-VCH GmbH

16. Zirconium Retention for Minimizing Environmental Risk: Role of Counterion and Clay Mineral

    L. Montes, E. Pavón, and A. Cota

    Chemosphere, 2021

    Abs DOI

    Zr(IV) together with U(IV) are the major components of high-level radionuclide waste (HLRW) and spent nuclear fuel (SNF) from nuclear power plants. Thus, their retention in the waste disposal is of great importance for the environmental risk control. Here, the influence of clay minerals on the retention of Zr(IV), as component of the nuclear waste and as chemical analogues of U(IV), has been evaluated. Three clay minerals, two bentonites and one saponite, were hydrothermally treated with three zirconium salts. A structural study at long-range order by X-ray diffraction and short-range order by NMR was performed to evaluate the generation of new zirconium phases and degradation of the clay minerals. Three immobilization mechanisms were observed: i) cation exchange of ZrO2+ or Zr4+ by clay minerals, ii) the precipitation/crystallization of ZrO2, and, iii) the chemical interaction of zirconium with the clay minerals, with the formation of zirconium silicates. © 2020 Elsevier Ltd

17. Assessing the Reactivity of Hard Carbon Anodes: Linking Material Properties with Electrochemical Response Upon Sodium- and Lithium-Ion Storage

    H. Moon, M. Zarrabeitia, E. Frank, O. Böse, M. Enterría, D. Saurel, I. Hasa, and S. Passerini

    Batteries and Supercaps, 2021

    Abs DOI

    Hard carbon (HC) is the negative electrode (anode) material of choice for sodium-ion batteries (SIBs). Despite its advantages in terms of cost and sustainability, a comprehensive understanding of its microstructure is not complete yet, thus hindering a rational design of high-performance HC electrodes. In this study, rather than investigating how the precursor and synthesis method influence on the electrochemical properties of HC anodes, we examine the microstructure and surface chemistry of three optimized HC anodes obtained from different precursors by using different synthesis routes. The main goal is to evaluate the influence of the final materials properties (in their optimized state) on the electrochemical reactivity in lithium and sodium cells after a comprehensive structural characterization performed by means of X-ray photoelectron spectroscopy (XPS), wide-angle X-ray scattering (WAXS), Raman spectroscopy, scanning electron microscopy (SEM), and gas sorption measurements. The different electrochemical performance observed in terms of cycling stability and rate capability, and the stability of the solid electrolyte interphase (SEI) formed on the various HCs have been comprehensively investigated. A correlation of the material properties with their electrochemical response upon sodium and lithium uptake and release is clarified. By comparing the Na- and Li-ion storage behavior, a structure-function relation is identified. © 2021 The Authors. Batteries & Supercaps published by Wiley-VCH GmbH

18. Zinc Polyaleuritate Ionomer Coatings as a Sustainable, Alternative Technology for Bisphenol A-Free Metal Packaging

    D. Morselli, P. Cataldi, U.C. Paul, L. Ceseracciu, J.J. Benítez, A. Scarpellini, S. Guzman-Puyol, A. Heredia, P. Valentini, P.P. Pompa, D. Marrero-López, A. Athanassiou, and J.A. Heredia-Guerrero

    ACS Sustainable Chemistry and Engineering, 2021

    Abs DOI

    Sustainable coatings for metal food packaging were prepared from ZnO nanoparticles (obtained by the thermal decomposition of zinc acetate) and a naturally occurring polyhydroxylated fatty acid named aleuritic (or 9,10,16-trihydroxyhexadecanoic) acid. Both components reacted, originating under specific conditions zinc polyaleuritate ionomers. The polymerization of aleuritic acid into polyaleuritate by a solvent-free, melt polycondensation reaction was investigated at different times (15, 30, 45, and 60 min), temperatures (140, 160, 180, and 200 °C), and proportions of zinc oxide and aleuritic acid (0:100, 5:95, 10:90, and 50:50, w/w). Kinetic rate constants calculated by infrared spectroscopy decreased with the amount of Zn due to the consumption of reactive carboxyl groups, while the activation energy of the polymerization decreased as a consequence of the catalyst effect of the metal. The adhesion and hardness of coatings were determined from scratch tests, obtaining values similar to robust polymers with high adherence. Water contact angles were typical of hydrophobic materials with values ≥94°. Both mechanical properties and wettability were better than those of bisphenol A (BPA)-based resins and most likely are related to the low migration values determined using a hydrophilic food simulant. The presence of zinc provided a certain degree of antibacterial properties. The performance of the coatings against corrosion was studied by electrochemical impedance spectroscopy at different immersion times in an aqueous solution of NaCl. Considering the features of these biobased lacquers, they can be potential materials for bisphenol A-free metal packaging. © 2021 The Authors. Published by American Chemical Society.

19. By-Products Revaluation in the Production of Design Micaceous Materials

    A. Mouchet, F. Raffin, A. Cota, F.J. Osuna, E. Pavón, and M.D. Alba

    Applied Clay Science, 2021

    Abs DOI

    One of the main objectives of a sustainable development and circular economy is the recycling of by-products generated in industrial and agricultural production processes. One of the possible solution is the use of such by-product materials in the synthesis of environmental adsorbents. In the current research, we present the synthesis of a high charge swelling mica with enhance adsorbent properties from blast furnace slag and rice husk ash. Moreover, to ensure the sustainable synthesis a natural bentoniteis used as Si and Al source. Thus, the current study investigated the fabrication of swelling high charged micas, Na-Mn (n (layer charge) = 2 or 4), from FEBEX bentonite, blast furnace slag and rice husk ash thorough the NaCl melt method. The reaction yield, cation framework distribution and structural characteristic of micas have been studied thorough X-ray Diffraction and Solid State Nuclear Magnetic Resonance. The yields of Na-Mn synthesis and degree of purity of the mica depends on the nature of these precursors. Thus, a sustainable, non-expensive and environmental friendly process has been evaluated. © 2021

20. Ceria-Based Catalytic Coatings on Biomorphic Silicon Carbide: A System for Soot Oxidation with Enhanced Properties

    M.P. Orihuela, P. Miceli, J. Ramírez-Rico, D. Fino, and R. Chacartegui

    Chemical Engineering Journal, 2021

    Abs DOI

    In order to be efficient, catalysts require an adequate substrate with tailored porosity, specific surface area and pore size distribution. This work reports on the use of biomorphic silicon carbide, a wood-derived ceramic material, to fabricate a wall-flow filter onto which ceria-based catalytic coatings are synthesised in-situ with two different morphologies. Based on laboratory tests performed emulating realistic conditions, it is shown that the deposition of a ceria washcoat on the substrate reduces the temperature needed to regenerate the filter by 14 °C to 110 °C. The use of a ceria morphology that enhances the soot/catalyst contact conditions strengthens this effect. The influence of the substrate arrangement on the regeneration performance and the oxidative capacity of the catalytic coating is analysed. These results extend the possibilities of further reducing the soot oxidation temperature by combining the synergistic effects of an engineered ceria morphology and an optimum substrate arrangement. © 2021 Elsevier B.V.

21. Designed Organomicaceous Materials for Efficient Adsorption of Iodine

    F.J. Osuna, E. Pavón, M.C. Pazos, and M.D. Alba

    Journal of Environmental Chemical Engineering, 2021

    Abs DOI

    The anionic iodine 129I has a significant contribution to overall long-term dose resulting from the nuclear waste storage and its immobilization by clay barrier is crucial. Organoclays have been tested as ideal adsorption materials, being the clay layer charge and the length and type of organic molecules the most relevant parameters affecting the adsorption. In this work, a family of designed organomicas are explored in term of iodine adsorption capacity. Their adsorption capacities were always higher than that of the traditional clays and organoclays. C18-M4 shows a maximum monolayer adsorption capacity one order of magnitude higher than natural organoclays, with a free energy typical of physical adsorption and adsorption sites of high affinity. However, its surface is not homogeneous in terms of stability constant according to the Scatchard adsorption parameters. Hence, this study can provide a guidance for the design and construction of ultrahigh-capacity iodine adsorbents. © 2021 The Authors

22. Pb2+, Cd2+ and Hg2+ Removal by Designed Functionalized Swelling High-Charged Micas

    F.J. Osuna, E. Pavón, and M.D. Alba

    Science of the Total Environment, 2021

    Abs DOI

    The increasing accumulation of toxic heavy metals in the environment has generated the need of efficient removal systems, being the adsorption method the most popular one applied in aqueous solutions. Of particular concern is the case of Pb2+, Cd2+ and Hg2+ due to their high potential hazard. In this paper, we describe the feasibility of a new family of nanomaterials, swelling high charge micas, in the removal of these cations from aqueous solutions. Batch adsorption experiments were carried out in the as-made micas, Na[sbnd]Mn, and after functionalization with ethylammonium, EA-Mn, and mercaptoethylammonium, MEA-Mn. The results have demonstrated that all of them are efficient heavy metal adsorbents, being Na-M2 the best adsorbent for Pb2+ and Cd2+, and, MEA-M2 for Hg2+. © 2020 Elsevier B.V.

23. New Trends in Nanoclay-Modified Sensors

    E. Pavón, R. Martín-Rodríguez, A.C. Perdigon-Aller, and M.D. Alba

    Inorganics, 2021

    Abs DOI

    Nanoclays are widespread materials characterized by a layered structure in the nano-scale range. They have multiple applications in diverse scientific and industrial areas, mainly due to their swelling capacity, cation exchange capacity, and plasticity. Due to the cation exchange capacity, nanoclays can serve as host matrices for the stabilization of several molecules and, thus, they can be used as sensors by incorporating electroactive ions, biomolecules as enzymes, or fluorescence probes. In this review, the most recent applications as bioanalyte sensors are addressed, focusing on two main detection systems: electrochemical and optical methods. Particularly, the application of electrochemical sensors with clay-modified electrodes (CLME) for pesticide detection is described. Moreover, recent advances of both electrochemical and optical sensors based on nanoclays for diverse bioanalytes’ detection such as glucose, H2 O2, organic acids, proteins, or bacteria are also discussed. As it can be seen from this review, nanoclays can become a key factor in sensors’ development, creating an emerging technology for the detection of bioanalytes, with application in both environmental and biomedical fields. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

24. Swelling Layered Minerals Applications: A Solid State NMR Overview

    E. Pavón and M.D. Alba

    Progress in Nuclear Magnetic Resonance Spectroscopy, 2021

    Abs DOI

    Swelling layered clay minerals form an important sub-group of the phyllosilicate family. They are characterized by their ability to expand or contract in the presence or absence of water. This property makes them useful for a variety of applications, ranging from environmental technologies to heterogeneous catalysis, and including pharmaceutical and industrial applications. Solid State Nuclear Magnetic Resonance (SS-NMR) has been extensively applied in the characterization of these materials, providing useful information on their dynamics and structure that is inaccessible using other characterization methods such as X-ray diffraction. In this review, we present the key contributions of SS-NMR to the understanding of the mechanisms that govern some of the main applications associated to swelling clay minerals. The article is divided in two parts. The first part presents SS-NMR conventional applications to layered clay minerals, while the second part comprises an in-depth review of the information that SS-NMR can provide about the different properties of swelling layered clay minerals. © 2021 The Authors

25. Laser-Induced Graphene on Paper toward Efficient Fabrication of Flexible, Planar Electrodes for Electrochemical Sensing

    T. Pinheiro, S.L. Silvestre, J. Coelho, A.C. Marques, R. Martins, M.G.F. Ferreira Sales, and E. Fortunato

    Advanced Materials Interfaces, 2021

    Abs DOI

    Laser irradiation to induce networks of graphene-based structures toward cost-effective, flexible device fabrication is a highly pursued area, with applications in various polymeric substrates. This work reports the application of this approach toward commonly available, eco-friendly, low-cost substrates, namely, chromatographic and office papers. Through an appropriate chemical treatment with sodium tetraborate as a fire-retardant agent, photothermal conversion to porous laser-induced graphene (LIG) on paper is achieved. Raman peaks are identified, with I2D/IG and ID/IG peak ratios of 0.616 ± 0.095 and 1.281 ± 0.173, showing the formation of multilayered graphenic material, exhibiting sheet resistances as low as 56.0 Ω sq–1. Coplanar, LIG-based, three-electrode systems (working, counter and reference electrodes) are produced and characterized, showing high current Faradaic oxidation and reduction peaks, translating in high electrochemical active area, doubling the geometric area. Good electron transfer kinetics performed exclusively with on-chip measurements are reached, with k0 values as high as 7.15 × 10–4 cm s–1. Proof-of-concept, amperometric, enzymatic glucose biosensors are developed, exhibiting good analytical performance in physiologically relevant glucose levels, with results pointing to the applicability of paper-based LIG toward efficient, disposable electrochemical sensor development, increasing their sustainability and accessibility, while simplifying their production and reducing their cost. © 2021 Wiley-VCH GmbH

26. Inclusion of 2d Transition Metal Dichalcogenides in Perovskite Inks and Their Influence on Solar Cell Performance

    N. Taurisano, G. Bravetti, S. Carallo, M. Liang, O. Ronan, D. Spurling, J. Coelho, V. Nicolosi, S. Colella, G. Gigli, A. Listorti, and A. Rizzo

    Nanomaterials, 2021

    Abs DOI

    Organic–inorganic hybrid perovskite materials have raised great interest in recent years due to their excellent optoelectronic properties, which promise stunning improvements in photovoltaic technologies. Moreover, two-dimensional layered materials such as graphene, its derivatives, and transition metal dichalcogenides have been extensively investigated for a wide range of electronic and optoelectronic applications and have recently shown a synergistic effect in combination with hybrid perovskite materials. Here, we report on the inclusion of liquid-phase exfoliated molybdenum disulfide nanosheets into different perovskite precursor solutions, exploring their influence on final device performance. We compared the effect of such additives upon the growth of diverse perovskites, namely CH3NH3PbI3 (MAPbI3 ) and triple-cation with mixed halides Csx (MA0.17FA0.83 )(1−x)Pb (I0.83Br0.17 )3 perovskite. We show how for the referential MAPbI3 materials the addition of the MoS2 additive leads to the formation of larger, highly crystalline grains, which result in a remarkable 15% relative improvement in power conversion efficiency. On the other hand, for the mixed cation– halide perovskite no improvements were observed, confirming that the nucleation process for the two materials is differently influenced by the presence of MoS2 . © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

27. Waterproof-Breathable Films from Multi-Branched Fluorinated Cellulose Esters

    G. Tedeschi, S. Guzman-Puyol, L. Ceseracciu, J.J. Benítez, L. Goldoni, A. Koschella, T. Heinze, G. Cavallo, V. Dichiarante, G. Terraneo, A. Athanassiou, P. Metrangolo, and J.A. Heredia-Guerrero

    Carbohydrate Polymers, 2021

    Abs DOI

    Cellulose ester films were prepared by esterification of cellulose with a multibranched fluorinated carboxylic acid, “BRFA” (BRanched Fluorinated Acid), at different anhydroglucose unit:BRFA molar ratios (i.e., 1:0, 10:1, 5:1, and 1:1). Morphological and optical analyses showed that cellulose-BRFA materials at molar ratios 10:1 and 5:1 formed flat and transparent films, while the one at 1:1 M ratio formed rough and translucent films. Degrees of substitution (DS) of 0.06, 0.09, and 0.23 were calculated by NMR for the samples at molar ratios 10:1, 5:1, and 1:1, respectively. ATR-FTIR spectroscopy confirmed the esterification. DSC thermograms showed a single glass transition, typical of amorphous polymers, at −11 °C. The presence of BRFA groups shifted the mechanical behavior from rigid to ductile and soft with increasing DS. Wettability was similar to standard fluoropolymers such as PTFE and PVDF. Finally, breathability and water uptake were characterized and found comparable to materials typically used in textiles. © 2021 Elsevier Ltd

28. Liquid Exfoliated SnP3 Nanosheets for Very High Areal Capacity Lithium-Ion Batteries

    R. Tian, A. Griffin, M. McCrystall, M. Breshears, A. Harvey, C. Gabbett, D.V. Horvath, C. Backes, Y. Jing, T. Heine, S.-H. Park, J. Coelho, V. Nicolosi, M. Nentwig, C. Benndorf, O. Oeckler, and J.N. Coleman

    Advanced Energy Materials, 2021

    Abs DOI

    Increasing the energy density of lithium-ion batteries requires the discovery of new electrode materials capable of achieving very high areal capacity. Here, liquid phase exfoliation is used to produce nanosheets of SnP3, a 2D material with extremely high theoretical capacity of 1670 mAh g−1. These nanosheets can be fabricated into solution-processed thin films for use as lithium storing anodes. To maximize their performance, carbon nanotubes are incorporated into the electrodes to simultaneously enhance conductivity and toughness. As a result, electrodes of thickness >300 µm can be produced, which display active-mass-normalized capacities (≈1657 mAh g−1Active) very close to the theoretical value. These materials show maximum specific (≈1250 mAh g−1Electrode) and areal (>20 mAh cm−2) capacities, which are at the state-of-the-art for 2D-based electrodes, coupled with good rate performance and stability. In combination with commercial cathode materials, full-cells are fabricated with areal capacities of ≈29 mAh cm−2 and near-record energy densities approaching 1000 Wh L−1. © 2020 Wiley-VCH GmbH

29. Postsynthetic Treatment of Nickel–Iron Layered Double Hydroxides for the Optimum Catalysis of the Oxygen Evolution Reaction

    D. Tyndall, S. Jaśkaniec, B. Shortall, A. Roy, L. Gannon, K. O’Neill, M.P. Browne, J. Coelho, C. McGuinness, G.S. Duesberg, and V. Nicolosi

    npj 2D Materials and Applications, 2021

    Abs DOI

    Nickel–iron-layered double hydroxide (NiFe LDH) platelets with high morphological regularity and submicrometre lateral dimensions were synthesized using a homogeneous precipitation technique for highly efficient catalysis of the oxygen evolution reaction (OER). Considering edge sites are the point of activity, efforts were made to control platelet size within the synthesized dispersions. The goal is to controllably isolate and characterize size-reduced NiFe LDH particles. Synthetic approaches for size control of NiFe LDH platelets have not been transferable based on published work with other LDH materials and for that reason, we instead use postsynthetic treatment techniques to improve edge-site density. In the end, size-reduced NiFe LDH/single-wall carbon nanotube (SWCNT) composites allowed to further reduce the OER overpotential to 237 ± 7 mV ( = 0.16 ± 0.01 μm, 20 wt% SWCNT), which is one of the best values reported to date. This approach as well improved the long-term activity of the catalyst in operating conditions. © 2021, The Author(s).</p> </div> </div> </div> </li>

30. Organophilization of Acid and Thermal Treated Sepiolite for Its Application in BTEX Adsorption from Aqueous Solutions

    C.F. Varela, M.C. Pazos, and M.D. Alba

    Journal of Water Process Engineering, 2021

    Abs DOI

    Acid and thermal treated sepiolite was organophilized by cationic exchange with several alkylammonium cations (octylammonium, hexadecylammonium, tetradecyltrimethylammonium, and hexadecyltrimethylammonium). The adsorption capacity of BTEX from aqueous solutions was evaluated through the adsorption isotherms performed in batch. The results were analysed using three isotherm models: Freundlich, Langmuir and Dubinin-Radushkevich (D-R model). The behaviour of adsorption isotherm suggested the multilayer coverage on a heterogeneous surface, which is according to the Freundlich isotherm model. The thermodynamic analyse using the D-R model show that physical mechanisms govern the process. The maximum adsorption capacity of BTEX on the obtained materials was in the range values of 81.19 mg g−1- 1448.42 mg g−1, which are higher than those reported up to now. The organo-sepiolite materials exhibit a high potential in the adsorption of BTEX compounds from aqueous solutions. © 2021 Elsevier Ltd

31. Understanding the Electrode – Electrolyte Interphase of High Voltage Positive Electrode Na4Co3(PO4)2P2O7 for Rechargeable Sodium-Ion Batteries

    M. Zarrabeitia, M. Casas-Cabanas, and M.Á. Muñoz-Márquez

    Electrochimica Acta, 2021

    Abs DOI

    Sodium-ion batteries (SIBs) have been postulated as a potential solution for large-scale stationary applications and light electromobility. Among positive electrode materials for SIBs, Na4Co3(PO4)2P2O7 attracted significant attention due to its high voltage and good specific capacity even at very high current densities. However, details of the formed electrode – electrolyte interphase (EEI) are still uncertain, being this of extreme importance considering that the high operating voltage of this electrode material is around the stability edge of most of the conventional electrolytes which, in some cases, already display side reactions above 3.0 V vs. Na/Na+. In this work, the EEI of Na4Co3(PO4)2P2O7 is analyzed in half-cell configuration using 1 M NaPF6 in EC:DEC as electrolyte. Conventional and high energy X-ray photoelectron spectroscopy (XPS) has been used so as to understand the stability and the chemical composition of the EEI. The results reveal that a bilayer EEI is formed at full Na+ extracted state of charge (SOC - 4.7 V vs. Na/Na+), with semi-organic-rich species found in the subsurface region close to the electrode while more organic species are formed in the outermost surface region close to the electrolyte. Meanwhile, after full Na+ insertion (SOC - 3.0 V vs. Na/Na+) an additional outermost inorganic overlayer is formed which is composed of sodium carbonate and sodium fluorophosphate. Additionally, this inorganic-rich EEI is dissolving upon oxidation / charge process - affecting the outermost ~10 nm of the EEI. Despite this dynamic behavior of the EEI, the Na4Co3(PO4)2P2O7 positive electrode delivers excellent cyclability (94% capacity retention after 100 cycles at 0.2C), proving that it can be a good candidate as positive electrode material for SIBs. © 2021 Elsevier Ltd

</ol>

2020

1. Bio-Based Coatings for Food Metal Packaging Inspired in Biopolyester Plant Cutin

   J.J. Benítez, S. Osbild, S. Guzman-Puyol, A. Heredia, and J.A. Heredia-Guerrero

   Polymers, 2020

   Abs DOI

   Metals used for food canning such as aluminum (Al), chromium-coated tin-free steel (TFS) and electrochemically tin-plated steel (ETP) were coated with a 2-3-gm-thick layer of polyaleuritate, the polyester resulting from the self-esterification of naturally-occurring 9,10,16-trihydroxyhexadecanoic (aleuritic) acid. The kinetic of the esterification was studied by FTIR spectroscopy; additionally, the catalytic activity of the surface layer of chromium oxide on TFS and, in particular, of tin oxide on ETP, was established. The texture, gloss and wettability of coatings were characterized by AFM, UV-Vis total reflectance and static water contact angle (WCA) measurements. The resistance of the coatings to solvents was also determined and related to the fraction of unreacted polyhydroxyacid. The occurrence of an oxidative diol cleavage reaction upon preparation in air induced a structural modification of the polyaleuritate layer and conferred upon it thermal stability and resistance to solvents. The promoting effect of the tin oxide layer in such an oxidative cleavage process fosters the potential of this methodology for the design of effective long-chain polyhydroxyester coatings on ETP. © 2020 by the authors.

2. Elucidating Esterification Reaction during Deposition of Cutin Monomers from Classical Molecular Dynamics Simulations

   O.V.M. Bueno, J.J. Benítez, and M.A. San-Miguel

   Journal of Molecular Modeling, 2020

   Abs DOI

   The structural behavior of some cutin monomers, when deposited on mica support, was extensively investigated by our research group. However, other events, such as esterification reaction (ER), are still a way to explore. In this paper, we explore possible ER that could occur when these monomers adsorb on support. Although classical molecular dynamics simulations are not able to capture reactive effects, here, we show that they become valuable strategies to analyze the initial structural configurations to predict the most favorable reaction routes. Thus, when depositing aleuritic acid (ALE), it is observed that the loss of capacity to form self-assembled (SA) systems favors different routes to occur ER. In pure ALE bilayers systems, an ER is given exclusively through the –COOH and primary –OH groups. In pure ALE monolayers systems, the ER does not happen when the system is self-assembled. However, for disorganized systems, it is able to occur by two possible routes: –COOH and primary –OH (route 1) and –COOH and secondary –OH (route 2). When palmitic acid (PAL) is added in small quantities, ALE SAMs can now form an ER. In this case, ER occurs mostly through the –COOH and secondary –OH groups. However, when the presence of PAL is dominant, ER can occur with either of both possibilities, that is, routes 1 and 2. [Figure not available: see fulltext.]. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.

3. An Outlook on Printed Microsupercapacitors: Technology Status, Remaining Challenges, and Opportunities

   J. Coelho, M.P. Kremer, S. Pinilla, and V. Nicolosi

   Current Opinion in Electrochemistry, 2020

   Abs DOI

   The concept of the Internet of Things is dramatically changing the way society interacts with physical spaces and portable technologies. For the last couple of years, intensive research has been devoted on the design of several flexible and even wearable devices, such as displays and health-care sensors. Further developments on these new technologies are heavily conditioned by the lack of compatible energy storage/conversion units. Contrary to lithium-ion batteries, supercapacitors can be easily miniaturized and integrated on flexible/wearable technologies without losing their electrochemical performance. In this review, some of the most recent developments on the design and printing of light, flexible, and thin microsupercapcitors along with promising and further practical applications are presented. © 2020 Elsevier B.V.

4. Preparation and Characterization of Bio-Based PLA/PBAT and Cinnamon Essential Oil Polymer Fibers and Life-Cycle Assessment from Hydrolytic Degradation

   Z.N. Correa-Pacheco, J.D. Black-Solis, P. Ortega-Gudiño, M.A. Sabino, J.J. Benítez, A. Barajas-Cervantes, S. Bautista-Baños, and L.B. Hurtado-Colmenares

   Polymers, 2020

   Abs DOI

   Nowadays, the need to reduce the dependence on fuel products and to achieve a sustainable development is of special importance due to environmental concerns. Therefore, new alternatives must be sought. In this work, extruded fibers from poly (lactic acid) (PLA) and poly (butylenes adipate-co-terephthalate) (PBAT) added with cinnamon essential oil (CEO) were prepared and characterized, and the hydrolytic degradation was assessed. A two-phase system was observed with spherical particles of PBAT embedded in the PLA matrix. The thermal analysis showed partial miscibility between PLA and PBAT. Mechanically, Young’s modulus decreased and the elongation at break increased with the incorporation of PBAT and CEO into the blends. The variation in weight loss for the fibers was below 5% during the period of hydrolytic degradation studied with the most important changes at 37 °C and pH 8.50. From microscopy, the formation of cracks in the fiber surface was evidenced, especially for PLA fibers in alkaline medium at 37 °C. This study shows the importance of the variables that influence the performance of polyester-cinnamon essential oil-based fibers in agro-industrial applications for horticultural product preservation. © 2019 by the authors.

5. Novel Procedure for Laboratory Scale Production of Composite Functional Filaments for Additive Manufacturing

   Á. Díaz-García, J.Y. Law, A. Cota, A. Bellido-Correa, J. Ramírez-Rico, R. Schäfer, and V. Franco

   Materials Today Communications, 2020

   Abs DOI

   Successful 3D printing by material extrusion of functional parts for new devices requires high quality filaments. Uniform homogeneity and good dispersion of particles embedded in filaments typically takes several cycles of extrusion or well-prepared feedstock by injection molding, industrial kneaders or twin-screw compounding. These methods need specific production devices that are not available in many laboratories non-specialized in polymer research, such as those working on different material science and technology topics that try to connect with additive manufacturing. Therefore, laboratory studies are usually limited to compositions and filler concentrations provided by commercial companies. Here, we present an original laboratory scale methodology to custom-prepare the feedstock for extruding magnetic composite filaments for fused filament fabrication (FFF), which is attainable by a desktop single-screw extruder. It consists in encapsulating the fillers in custom made capsules that are used as feedstock and reach the melting area of the extruder maintaining the same concentration of fillers. Results have shown that our approach can create smooth and continuous composite filaments with good homogeneity and printability with fine level of dimensional control. We further show the good dispersion of the particles in the composite filament using X-Ray Tomography, which enabled a 3D reconstruction of the spacial distribution of the embedded magnetic particles. The major advantage of this new way of preparing the composite feedstock is that it avoids the hassle of multiple extrusion runs and industrial machinery, yet providing uniform filaments of well controlled filler concentration, which is predictable and reproducible. The proposed methodology is suitable for different polymer matrices and applicable to other functional particle types, not just limited to magnetic ones. This opens an avenue for further laboratory scale development of novel functional composite filaments, useful for any community. This democratization of complex filament preparation, including consumers preparing their own desired uniform novel filaments, will facilitate to unify efforts nearing 3D printing of new functional devices. © 2020 Elsevier Ltd

6. Vegetable Hierarchical Structures as Template for Bone Regeneration: New Bio-Ceramization Process for the Development of a Bone Scaffold Applied to an Experimental Sheep Model

   G. Filardo, A. Roffi, T. Fey, M. Fini, G. Giavaresi, M. Marcacci, J.M. Martínez-Fernández, L. Martini, J. Ramírez-Rico, F. Salamanna, M. Sandri, S. Sprio, A. Tampieri, and E. Kon

   Journal of Biomedical Materials Research - Part B Applied Biomaterials, 2020

   Abs DOI

   Long bone defects still represent a major clinical challenge in orthopedics, with the inherent loss of function considerably impairing the quality of life of the affected patients. Thus, the purpose of this study was to assess the safety and potential of bone regeneration offered by a load-bearing scaffold characterized by unique hierarchical architecture and high strength, with active surface facilitating new bone penetration and osseointegration in critical size bone defects. The results of this study showed the potential of bio-ceramization processes applied to vegetable hierarchical structures for the production of new wood-derived bone scaffolds, further improved by surface functionalization, with good biological and mechanical properties leading to successful treatment of critical size bone defects in the sheep model. Future studies are needed to evaluate if these scaffolds prototypes, as either biomaterial alone or in combination with augmentation strategies, may represent an optimal solution to enhance bone regeneration in humans. © 2019 Wiley Periodicals, Inc.

7. Binder-Free Supercapacitor Electrodes: Optimization of Monolithic Graphitized Carbons by Reflux Acid Treatment

   A. Gómez-Martín, A. Gutiérrez-Pardo, J.M. Martínez-Fernández, and J. Ramírez-Rico

   Fuel Processing Technology, 2020

   Abs DOI

   The rational design of electrodes mimicking the cellular structure of natural bio-resources has been a matter of increasing interest for applications in energy storage. Due to their anisotropic and hierarchical porosity, monolithic carbon materials from natural wood precursors are appealing as electrodes for supercapacitor applications due to their interconnected channels, relatively low cost and environmentally friendly synthesis process. In this work, a liquid-phase oxidative treatment with refluxing nitric acid at 100 °C for 8 h was performed to enhance the surface properties of beech-derived graphitized carbons treated with an iron catalyst. Microstructural, textural and surface investigations revealed that this strategy was successful in removing amorphous carbon and in functionalizing their surfaces. The crystallinity, accessible surface area, micropore volume and surface functionality of beech-derived carbons were increased upon the reflux treatment. The resulting porous carbon materials were evaluated as binderless monolithic electrodes for supercapacitors applications in aqueous KOH electrolyte. A maximum specific capacitance of 179 F·g−1 and a volumetric capacitance of 89 F·cm−3 in galvanostatic charge/discharge experiments were reached. Monolithic electrodes exhibited good cycling stability, with a capacitance retention over 95% after 10,000 cycles. © 2019 Elsevier B.V.

8. An Electrochemical Evaluation of Nitrogen-Doped Carbons as Anodes for Lithium Ion Batteries

   A. Gómez-Martín, J.M. Martínez-Fernández, M. Ruttert, M. Winter, T.J. Placke, and J. Ramírez-Rico

   Carbon, 2020

   Abs DOI

   New anode materials beyond graphite are needed to improve the performance of lithium ion batteries (LIBs). Chemical doping with nitrogen has emerged as a simple strategy for enhancing lithium storage in carbon-based anodes. While specific capacity and rate capability are improved by doping, little is known about other key electrochemical properties relevant to practical applications. This work presents a systematic evaluation of electrochemical characteristics of nitrogen-doped carbons derived from a biomass source and urea powder as anodes in LIB half- and full-cells. Results show that doped carbons suffer from a continuous loss in capacity upon cycling that is more severe for higher nitrogen contents. Nitrogen negatively impacts the voltage and energy efficiencies at low charge/discharge current densities. However, as the charge/discharge rate increases, the voltage and energy efficiencies of the doped carbons outperform the non-doped ones. We provide insights towards a fundamental understanding of the requirements needed for practical applications and reveal drawbacks to be overcome by novel doped carbon-based anode materials in LIB applications. With this work, we also want to encourage other researchers to evaluate electrochemical characteristics besides capacity and cycling stability which are mandatory to assess the practicality of novel materials. © 2020 Elsevier Ltd

9. Gelified Acetate-Based Water-in-Salt Electrolyte Stabilizing Hexacyanoferrate Cathode for Aqueous Potassium-Ion Batteries

   J. Han, A. Mariani, H. Zhang, M. Zarrabeitia, X. Gao, D.V. Carvalho, A. Varzi, and S. Passerini

   Energy Storage Materials, 2020

   Abs DOI

   Potassium acetate (KAc)-based “Water-in-salt” electrolytes (WiSE) are herein studied by Raman and classical Molecular Dynamics (MD), evidencing the notably suppressed water activity of these WiSEs since water can be effectively coordinated by both the acetate anion and the potassium cation. The overall molecular arrangement is found to approach the “sponge-like” structure observed in certain ionic liquids. With properly tuned composition, such WiSE can also be compatible with Al current collectors, as demonstrated by extensive electrochemical, scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis. The use of low-cost potassium manganese hexacyanoferrate (KMHCF) in conjunction with these electrolytes, however, is affected by poor cycling performance due to the limited stability of the cathode material in the alkaline environment. Promisingly though, the stability of KMHCF is found to improve substantially when the electrolyte is gelified by adding a small amount (2 \hspace0ptwt%) of carboxymethyl cellulose (CMC), as testified by the enhanced capacity retention as well as the higher Coulombic efficiency (>99.3%). In particular, Mn and Fe dissolution are suppressed and, as suggested by MD simulations, K cations diffusion may be promoted in the gel electrolyte compared to the liquid system. © 2020 Elsevier B.V.

10. Halide-Free Water-in-Salt Electrolytes for Stable Aqueous Sodium-Ion Batteries

    J. Han, M. Zarrabeitia, A. Mariani, Z. Jusys, M. Hekmatfar, H. Zhang, D. Geiger, U. Kaiser, R.J. Behm, A. Varzi, and S. Passerini

    Nano Energy, 2020

    Abs DOI

    The extensive investigation via classical Molecular Dynamics (MD) simulations of the halide-free “water-in-salt” electrolyte (WiSE) consisting of sodium acetate (8 m) and potassium acetate (32 m), unveils the interactions between cations, anions and water molecules. The WiSE’s application as electrolyte in symmetric aqueous sodium-ion batteries, featuring NASICON-type Na2VTi(PO4)3/C (NVTP/C) as active material at both the positive and the negative electrode, is also reported. In situ X-ray diffraction (XRD) measurements resolve the structural evolution of NVTP/C during the highly reversible sodium de/intercalation. Differential Electrochemical Mass Spectrometry (DEMS) confirms the remarkable stability of the highly concentrated electrolyte. Symmetric cells employing two NVTP/C electrodes and a green 32K8N electrolyte show an average discharge voltage of 1.13 V with stable cycling performance and a coulombic efficiency above 99.1% at 1C and 99.9% at 10C over 500 cycles. Compared to the fluorinated 9.2 m NaOTF, the 32K8N electrolyte has substantially lower cost, environmental impact and superior coulombic efficiency in symmetric cells. © 2020 Elsevier Ltd

11. Quantifying the Dependence of Battery Rate Performance on Electrode Thickness

    D.V. Horvath, J. Coelho, R. Tian, V. Nicolosi, and J.N. Coleman

    ACS Applied Energy Materials, 2020

    Abs DOI

    Simultaneous optimization of capacity and rate performance in battery electrodes would be much simplified by access to a simple equation relating rate performance to electrode thickness. Although a number of equations have been proposed, data on the effect of electrode thickness on rate performance are not extensive enough to identify the most appropriate model for thickness dependence. Here, using LiNi0.815Co0.15Al0.035O2 as a model system, we use chronoamperometry as a procedure to rapidly generate capacity-rate curves for >50 different electrode thicknesses. Using a semiempirical fitting equation, we extract the characteristic time (τ) associated with charge/discharge for each thickness (LE). We find the resultant τ-LE curve to be inconsistent with minimal models based on liquidor solid-phase diffusion alone but to be in excellent agreement with a relatively simple rate model which includes liquid- and solidphase-diffusion effects as well as electrical and electrochemical limitations. Thickness-dependent impedance measurements show that the magnitudes of the electrochemical and solid-state diffusion contributions are perfectly in line with the outputs of the rate model. © 2020 American Chemical Society.

12. Crystal Engineering of TMPOx-coated LiNi0.5Mn1.5O4 Cathodes for High-Performance Lithium-Ion Batteries

    M. Kuenzel, G.-T. Kim, M. Zarrabeitia, S.D. Lin, A.R. Schuer, D. Geiger, U. Kaiser, D. Bresser, and S. Passerini

    Materials Today, 2020

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    The use of cobalt-free LiNi0.5Mn1.5O4 (LNMO) would provide a great leap forward towards the realization of sustainable lithium-ion batteries. However, the high operating voltage remains to be a great challenge for the cathode/electrolyte stability. Herein, we report a rational material design to address these challenges by carefully tuning the synthesis parameters in order to engineer LNMO crystals with tailored surface facets, providing an exceptional rate capability and improved interfacial stability. The additional introduction of protective TMPOx coatings further enhances the long-term cycling stability, in particular, at elevated cut-off potentials up to 4.95 V, increased temperature of 40 °C, and high dis-/charge rates. As a result of the careful design of the LNMO active material particles, lithium-ion cells employing this material together with Li4Ti5O12 anodes provide an excellent rate capability with 80% of the low-rate capacity at fast dis-/charge rates of 10C combined with highly stable cycling at such high rate, as highlighted by a capacity fading of less than 5% after 1000 cycles. © 2020 Elsevier Ltd

13. 3D MXene Architectures for Efficient Energy Storage and Conversion

    K. Li, M. Liang, H. Wang, X. Wang, Y. Huang, J. Coelho, S. Pinilla, Y. Zhang, F. Qi, V. Nicolosi, and Y. Xu

    Advanced Functional Materials, 2020

    Abs DOI

    2D transition metal carbides and/or nitrides (MXenes), by virtue of high electrical conductivity, abundant surface functional groups and excellent dispersion in various solvents, are attracting increasing attention and showing competitive performance in energy storage and conversion applications. However, like other 2D materials, MXene nanosheets incline to stack together via van der Waals interactions, which lead to limited number of active sites, sluggish ionic kinetics, and finally ordinary performance of MXene materials/devices. Constructing 2D MXene nanosheets into 3D architectures has been proven to be an effective strategy to reduce restacking, thus providing larger specific surface area, higher porosity, and shorter ion and mass transport distance over normal 1D and 2D structures. In this review, the commonly used strategies for manufacturing 3D MXene architectures (3D MXenes and 3D MXene-based composites) are summarized, such as template, assembly, 3D printing, and other methods. Special attention is also given to the structure–property relationships of 3D MXene architectures and their applications in electrochemical energy storage and conversion, including supercapacitors, rechargeable batteries, and electrocatalysis. Finally, the authors propose a brief perspective on future opportunities and challenges for 3D MXene architectures/devices. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

14. Cathode-Electrolyte Interphase in a LiTFSI/Tetraglyme Electrolyte Promoting the Cyclability of V2O5

    X. Liu, M. Zarrabeitia, B. Qin, G.A. Elia, and S. Passerini

    ACS Applied Materials and Interfaces, 2020

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    V2O5, one of the earliest intercalation-type cathode materials investigated as a Li+ host, is characterized by an extremely high theoretical capacity (441 mAh g-1). However, the fast capacity fading upon cycling in conventional carbonate-based electrolytes is an unresolved issue. Herein, we show that using a LiTFSI/tetraglyme (1:1 in mole ratio) electrolyte yields a highly enhanced cycling ability of V2O5 (from 20% capacity retention to 80% after 100 cycles at 50 mA g-1 within 1.5-4.0 V vs Li+/Li). The improved performance mostly originates from the V2O5 electrode itself, since refreshing the electrolyte and the lithium electrode of the cycled cells does not help in restoring the V2O5 electrode capacity. Electrochemical impedance spectroscopy (EIS), post-mortem scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS) have been employed to investigate the origin of the improved electrochemical behavior. The results demonstrate that the enhanced cyclability is a consequence of a thinner but more stable cathode-electrolyte interphase (CEI) layer formed in LiTFSI/tetraglyme with respect to the one occurring in 1 M LiPF6 in EC/DMC (1:1 in weight ratio, LP30). These results show that the cyclability of V2O5 can be effectively improved by simple electrolyte engineering. At the same time, the uncovered mechanism further reveals the vital role of the CEI on the cyclability of V2O5, which can be helpful for the performance optimization of vanadium-oxide-based batteries. ©

15. Operando pH Measurements Decipher H+/Zn2+intercalation Chemistry in High-Performance Aqueous Zn/δ-V2O5batteries

    X. Liu, H. Euchner, M. Zarrabeitia, X. Gao, G.A. Elia, A. Gross, and S. Passerini

    ACS Energy Letters, 2020

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    Vanadium oxides have been recognized to be among the most promising positive electrode materials for aqueous zinc metal batteries (AZMBs). However, their underlying intercalation mechanisms are still vigorously debated. To shed light on the intercalation mechanisms, high-performance δ-V2O5 is investigated as a model compound. Its structural and electrochemical behaviors in the designed cells with three different electrolytes, i.e., 3 m Zn(CF3SO3)2/water, 0.01 M H2SO4/water, and 1 M Zn(CF3SO3)2/acetonitrile, demonstrate that the conventional structural and elemental characterization methods cannot adequately clarify the separate roles of H+ and Zn2+ intercalations in the Zn(CF3SO3)2/water electrolyte. Thus, an operando pH determination method is developed and used toward Zn/δ-V2O5 AZMBs. This method indicates the intercalation of both H+ and Zn2+ into δ-V2O5 and uncovers an unusual H+/Zn2+-exchange intercalation-deintercalation mechanism. Density functional theory calculations further reveal that the H+/Zn2+ intercalation chemistry is a consequence of the variation of the electrochemical potential of Zn2+ and H+ during the electrochemical intercalation/release. © © 2020 American Chemical Society.

16. Performance Trends in Wall-Flow Diesel Particulate Filters: Comparative Analysis of Their Filtration Efficiency and Pressure Drop

    M.P. Orihuela, R. Chacartegui, A. Gómez-Martín, J. Ramírez-Rico, and J.A. Becerra

    Journal of Cleaner Production, 2020

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    Soot and particulate emissions from the transport sector are a major concern worldwide, given their harmful effects on public health and the environment. On-road vehicles are the main contributing source to this kind of pollution. They are strictly regulated in many countries, with limitations on the number and concentration of released particles, and they must be equipped with particle abatement systems. Wall-flow particulate filters are the most popular and effective devices to reduce particulate emissions from diesel and gasoline vehicles. Diesel Particulate Filters (DPFs) have been a recurrent research topic since the last century. There are different research studies analysing different aspects of these systems, at different levels, using different methodologies and different approaches. Their results are not always comparable. This work analyses the latest advances and trends in this technology by comparing two relevant performance parameters: their filtration efficiency and pressure drop. The findings of this study suggest that, in order to be competitive, upcoming DPFs should have filtration efficiencies above 80%, and pressure drops below 10 kPa, for space velocities of 1.5·105 h−1 or more at the clean state. They should reach ∼100% efficiency after a short operation period, before the soot load reaches 0.2 g/L. Later, they should keep a low pressure drop for a longer time, with a reference of no more than 13 kPa for 6 g/L of soot load. Based on this analysis, this work proposes some test criteria and suggestions for the main parameters. © 2020 Elsevier Ltd

17. An Insight on the Design of Mercapto Functionalized Swelling Brittle Micas

    F.J. Osuna, E. Pavón, and M.D. Alba

    Journal of Colloid and Interface Science, 2020

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    Surface modification of natural clay minerals with reagents containing metal chelating groups has great environmental value. The functionalization by adsorption or grafting guarantees a durable immobilization of the reactive organic groups, preventing their leaching when they are used in liquid media. The aim of this research was the designed mercapto functionalization of swelling brittle micas, Na-Mn, thorough both chemical and physical mechanisms. Na-Mn were functionalized with 2-mercaptoethylammonium (MEA), 2,3-dimercapto-1-propanol (BAL) and (3-mercaptopropyl)trimethoxysilane (MPTMS). The thiol concentration on swelling brittle micas is higher than the observed value for others adsorbents. The cation exchange reaction with MEA and one-step grafting with MPTMS in acid medium are the most efficient mercapto functionalization mechanism. © 2019 Elsevier Inc.

18. Multiple Pollutants Removal by Functionalized Heterostructures Based on Na-2-Mica

    M.C. Pazos, L.R. Bravo, S.E. Ramos, F.J. Osuna, E. Pavón, and M.D. Alba

    Applied Clay Science, 2020

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    Organomica, C8–2-Mica, was obtained from a high charged synthetic mica, Na-2-Mica, by cation exchange reaction with octylammonium cations and these were used to host other bulky guest species such as polyhydroxy aluminium cations, Al1320. The hydrolization of 3-mercaptopropyltrimethoxysilane (MPTMS) allowed the covalent attachment with hydroxyl groups of the oligomeric cation, providing thiol groups that create specific adsorption sites, Al1320/SH. The structure of the adsorbents was analysed by XRD and Infrared spectroscopy and these were tested as an adsorbent for the removal of zinc and herbicide MCPA from aqueous solutions. C8–2-Mica was the best adsorbent for MCPA and thiol groups favoured the adsorption of Zn2+. Moreover, Al1320/SH showed excellent adsorptive properties for the simultaneous adsorption of MCPA and Zn2+. © 2020 Elsevier B.V.

19. Sustainable, High-Barrier Polyaleuritate/Nanocellulose Biocomposites

    G. Tedeschi, S. Guzman-Puyol, L. Ceseracciu, J.J. Benítez, P. Cataldi, M. Bissett, A. Heredia, A. Athanassiou, and J.A. Heredia-Guerrero

    ACS Sustainable Chemistry and Engineering, 2020

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    Free-standing and flexible biocomposite films formed by a polyaleuritate matrix and nanocellulose fillers (i.e., cellulose nanofibrils) have been fabricated by a sustainable process. For this, 9,10,16-trihydroxyhexadecanoic (aleuritic) acid from shellac and nanocellulose were blended at different ratios in water through a sonication process. Polymerization of the polyhydroxylated fatty acid into polyaleuritate was induced by a solvent-free, melting polycondensation reaction in the oven. These biocomposites were characterized to evaluate their chemical (by ATR-FTIR spectroscopy) and physical (e.g., density, thermal stability, rigidity, gas permeability, surface energy, etc.) properties. The compatibility between the polyester matrix and the polysaccharide fillers was excellent due to the interaction by H bonds of the polar groups of both components. The addition of nanocellulose increased all determined mechanical parameters as well as the wettability and the barrier properties, while the thermal stability and the water uptake were determined by the polyaleuritate matrix. The physical properties of these biocomposites were compared to those of petroleum-based plastics and bio-based polymers, indicating that the developed materials can represent a sustainable alternative for different applications such as packaging. © © 2020 American Chemical Society.

20. Quantifying the Effect of Electronic Conductivity on the Rate Performance of Nanocomposite Battery Electrodes

    R. Tian, N. Alcala, S.J.K. O’Neill, D.V. Horvath, J. Coelho, A. Griffin, Y. Zhang, V. Nicolosi, C. O’Dwyer, and J.N. Coleman

    ACS Applied Energy Materials, 2020

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    While it is well-known that the electronic conductivity of electrodes has a critical impact on rate performance in batteries, this relationship has been quantified only by computer simulations. Here we investigate the relationship between electrode electronic conductivity and rate performance in a model cathode system of lithium-nickel-manganese-cobalt-oxide (NMC) filled with various quantities of carbon black, single-walled carbon nanotubes, and graphene. We find extreme conductivity anisotropy and significant differences in the dependence of conductivity on mass fraction among the different fillers. Fitting capacity versus rate curves yielded the characteristic time associated with charge/discharge. This parameter increased linearly with the inverse of the out-of-plane electronic conductivity, with all data points falling on the same master curve. Using a simple mechanistic model for the characteristic time, we develop an equation that matches the experimental data almost perfectly with no adjustable parameters. This implies that increasing the electrode conductivity improves the rate performance by decreasing the RC charging time of the electrode and shows rate performance to be optimized for any electrode once σOOP > 1 S/m, a condition achieved by including <1 wt % single-walled carbon nanotubes in the electrode. © 2020 American Chemical Society.

21. Using Chronoamperometry to Rapidly Measure and Quantitatively Analyse Rate-Performance in Battery Electrodes

    R. Tian, P.J. King, J. Coelho, S.-H. Park, D.V. Horvath, V. Nicolosi, C. O’Dwyer, and J.N. Coleman

    Journal of Power Sources, 2020

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    For battery electrodes, measured capacity decays as charge/discharge current is increased. Such rate-performance is usually characterised via galvanostatic charge-discharge measurements, experiments which are very slow, limiting the speed at which rate experiments can be completed. This is particularly limiting during mechanistic studies where many rate measurements are needed. Building on work by Heubner at al., we demonstrate chronoamperometry (CA) as a fast method for measuring capacity-rate curves with hundreds of data points down to C-rates below 0.01C. While Heubner et al. reported equations to convert current transients to capacity vs. C-rate curves, we modify these equations to give capacity as a function of charge/discharge rate, R. We use these expressions to obtain simple equations which can accurately fit data for both capacity vs. C-rate and capacity vs. R at normal rates. Interestingly, at high-rates, the curves obtained from CA deviate from the normal behaviour showing a new, previously unobserved, decay feature. We associate this feature with the very early part of the current transient where electronic motion dominates the current. Using a simple model, we show that the dependence of the high-rate time constant on electrode thickness can be linked to electrode conductivity. © 2020 Elsevier B.V.

22. Microstructure and Thermal Conductivity of Si-Al-C-O Fiber Bonded Ceramics Joined to Refractory Metals

    M.C. Vera, J.M. Martínez-Fernández, M. Singh, V. Casalegno, C. Balagna, and J. Ramírez-Rico

    Materials Letters, 2020

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    We explore joining Si-Al-C-O fiber-bonded ceramics to Cu-clad-Mo using an Ag-Ti-Cu brazing alloy. A temperature of 900 °C and times in the range of 10–20 min are required to obtain sound joints irrespectively of the fiber orientation. The reaction layer is 1–2 μm thick and free of pores and defects. The thermal conductivity of the joined samples is well described considering that the metal and the ceramic are in series for thermal resistance. This implies that the joint is highly conductive and forms an almost perfect thermal interface between the two materials, confirming the quality of the obtained brazing layer. © 2020 Elsevier B.V.

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