In order to increase the industrial appeal of solid-state batteries (SSBs) based on garnet Li₇La₃Zr₂O₁₂ (LLZO), the possibility of manufacturing them using scalable production processes such as tape casting must be demonstrated. In particular, the scalable production of thick, high-capacity oxide-ceramic composite cathodes based on Ni-rich LiNi_xMn_yCo_zO₂ (NMC) remains a key challenge on the path to realizing ceramic SSBs with competitive energy densities. The limited thermal compatibility between NMC and LLZO during sintering requires the use of a sintering aid such as Li₃BO₃ (LBO), which, however, impairs the rheological stability of tape casting slurries. In this work, we have developed a new tape-casting process for thick oxide-ceramic composite cathodes by establishing a slurry formulation that is compatible with multiphase cathode compositions and enables the reproducible fabrication of composite NMC cathode tapes with high active material loading. Two cathode configurations are investigated: NMC-LLZO-LBO composite cathodes, where LLZO serves as the catholyte, and LLZO-free NMC-LBO cathodes. After cosintering, the residual porosity of the ceramic cathodes is infiltrated with a polymer electrolyte with and without conductive carbon additives to form hybrid polymer-ceramic SSBs. By systematically correlating cathode chemistry, secondary phase formation, and electrochemical performance, this study demonstrates how cathode chemistry and the balance between ionic and electronic transport pathways influence capacity utilization and cycle stability in thick, tape-cast NMC-based composite cathodes.

Next-generation rechargeable batteries require materials that offer enhanced electrochemical capabilities. Achieving these goals depends on understanding the fundamental principles governing these materials, which presents challenges associated to the complex interactions between composition, structural characteristics and electrochemical performance in battery materials. Despite intensive research, progress remains limited regarding effective strategies to mitigate the degradation of fragile alkali-metal-deficient frameworks arising from lattice stress and structural or chemo-mechanical instability upon cycling. In this Review, we explore the importance of chemical heterogeneity in rechargeable battery materials. We discuss how heterogeneity at atomic scale, nano-domains and up to phase-segregated levels within particles can enhance the electrochemical properties of battery materials beyond those of their homogeneous counterparts. Introducing chemical heterogeneity, principles and mechanisms can be unlocked to develop materials with improved structural stability, ion conductivity, redox activity, and phase transition characteristics, driving progress in battery technology. Finally, we outline the challenges and strategies for developing the future battery materials. (Figure presented.)

Silicon (Si) anodes promise high energy density for all-solid-state batteries (ASSBs), while avoiding Li-metal dendrites. However, one of the key limitations is the initial loss of active Li, reflected in a low initial Coulombic efficiency (ICE), arising from solid electrolyte (SE) decomposition, lithium trapping, and native oxide conversion. Here, we report an (electro)chemically guided interfacial-engineering strategy leveraging an irreducible SE to construct a dynamic nanoscale Si|SE interface that enhances ICE. The intrinsic stability of the SE down to the working potentials of Si anodes eliminates decomposition, whereas mechanochemical mixing activates interfacial reactions that realize in situ prelithiation. The engineered interface manifests efficient ion transport and replenishes Li inventory through redox reactions, while stabilizing electrochemical performance. Our approach delivers a record-high ICE approaching 100% in Si half-cells, together with >95% in high-loading LiCoO₂ full cells, demonstrating that precise interface control can unlock the full potential of Si anodes for high-energy ASSBs.

Solid–solid interfaces play a critical role in the performance of energy storage systems, catalysts, and electronic devices, yet their atomic-scale structure and behaviour remain challenging to probe experimentally. Explicit atomistic modelling provides a powerful approach for investigating interfaces by directly constructing and simulating contacting phases, enabling the calculation of interfacial energetics, electronic structure, charge transfer, stability, and transport processes. This Review summarises the methodology and applications of explicit interface modelling, including interface construction strategies, properties accessible from atomistic simulations, and recent advances enabled by machine-learned interatomic potentials that extend simulations to larger time and length scales. We also discuss how computational results can be interpreted and validated using experimental characterisation techniques, and highlight current challenges and emerging opportunities in predictive interface modelling and materials design.

All-solid-state batteries have great potential to outperform conventional lithium-ion batteries in both safety and energy density, as the solid electrolyte can potentially accommodate high-energy-density anodes such as metallic lithium or silicon more safely. However, the high-valence cations present in most highly conductive solid electrolytes facilitate reductive decomposition at low potentials, leading to significant irreversible lithium inventory loss. Preventing this requires the development of solid electrolytes that are thermodynamically stable at low operating potentials while providing high ionic conductivity and sufficient oxidative stability. To realize this, we explored a new family of Li-rich antifluorite irreducible solid electrolytes, Li2.65S0.35NxP0.65–x, the first reported nitrido-phosphido-sulfide, and investigated their application in all-solid-state batteries. The optimized composition Li2.65S0.35N0.15P0.5 possesses a remarkably high ionic conductivity of 1.05 mS cm–1, as well as a relatively high oxidative stability of 1.15 V vs Li+/Li for this class of materials. Ab initio molecular dynamics and density functional theory simulations reveal that enhanced Li diffusion is the result of enlarged diffusion bottleneck sizes. These are a consequence of (i) substitution with smaller anions or (ii) increased electrostatic repulsion from the substitution with high-valence anions. Importantly, the oxidative stability makes Li2.65S0.35N0.15P0.5 exhibit good compatibility with Si anodes, and in conjunction with the high ionic conductivity, this enables a high initial Coulombic efficiency of 94.2% as well as a stable cycle life of a full cell with a micron silicon–Li2.65S0.35N0.15P0.5 anode and a LiCoO2–Li3InCl6 cathode. This work highlights the potential of irreducible solid electrolytes for the design of all-solid-state batteries with low-potential and high-energy-density anodes.

The global transition to sustainable energy systems requires breakthroughs in electrochemical storage technologies that are not only safe but also resource efficient. Solid-state batteries (SSBs), which use superionic solid electrolytes (SEs) instead of flammable liquid electrolytes, are at the forefront of this transformation. In general, SEs promise increased safety, access to high-voltage cathode and metal anode chemistries, and new avenues for circular design and recyclability. However, to reach their full potential, intertwined challenges related to ion transport, (electro)chemical stability, manufacturing, processing, and cost must be overcome. This 2026 roadmap on next-generation SEs for battery applications outlines new directions that will contribute to research in the field of SSBs over the next decade. It provides an overview of the current state of the art in sulfide- and halide-based SEs for Li and Na systems, examines post-Li/Na chemistries (K, Mg, and others), and highlights advances in hydroborate, fully reduced (irreducible), and compositionally complex (high-entropy) electrolytes, as well as glass-ceramic electrolytes. Beyond material innovation, the paper emphasizes the critical role of redox activity in SEs, scalable processing, high-throughput synthesis, and machine learning, as well as operando analytics and nuclear magnetic resonance spectroscopy to accelerate discoveries and gain a better understanding of structure–property relationships. Finally, the growing importance of recycling and circular design for ensuring sustainability is highlighted. By combining insights from chemistry, materials science, data (computational) science, and manufacturing, this article assumes that future SEs will progressively evolve from passive components to active design elements in high-energy-density electrochemical systems. The integration of multidisciplinary innovations will be crucial to realizing the potential of SSBs in practical technologies that power a decarbonized world.

Molecular dynamics (MD) simulations have become essential for understanding diffusion mechanisms in solid-state materials such as ionic conductors, fuel cells, and gas sensors, yet most existing studies and software tools extract only standard metrics, leaving much of the information contained in the trajectories unused. Here we introduce GEMDAT, a user-friendly Python toolkit for site-resolved diffusion analysis of MD simulations of solid-state materials (https://github.com/GEMDAT-repos/GEMDAT). Beyond mean-squared displacements, radial distribution functions, and Arrhenius-based activation energies, GEMDAT provides jump rates, attempt frequencies, site-specific activation energies, rotational diffusion, and percolation. Our tool provides access to vibrational amplitudes, site geometries, and site occupancies—quantities that are also directly comparable to experimental diffraction data. Migration sites can be defined manually or identified automatically from the trajectory. A built-in caching approach, together with rapid visualization capabilities, makes the workflow fast and interactive. We demonstrate GEMDAT on a series of case studies involving crystalline Li- and Na-ion conductors, plastic crystals, amorphous structures, and surface configurations, showing how the code extracts atomic-level structural features and connects them to macroscopic transport properties, thereby guiding the optimization and development of solid-state materials.

Anode-free aqueous zinc metal batteries (AZMBs) offer significant potential for energy storage due to their low cost and environmental benefits. Ti₃C₂T_x MXene provides several advantages over traditional metallic current collectors like Cu and Ti, including better Zn plating affinity, lightweight, and flexibility. However, self-freestanding MXene current collectors in AZMBs remain underexplored, likely due to challenges with Zn deposition reversibility. This study investigates the combination of a Ti₃C₂T_x self-freestanding film with advanced electrolyte engineering, specifically examining the effects of Li-salt and propylene carbonate (PC) as additives on Zn plating reversibility. While using Li⁺ ions as an additive alone facilitates uniform Zn deposition on bulk metals through the electrostatic shielding effect, the addition of Li-salt negatively impacts Zn plating uniformity on Ti₃C₂T_x. Meanwhile, using PC additive alone forms an organic SEI layer on Ti₃C₂T_x and causes Zn agglomeration. The use of both additives together results in a ZnF₂-containing hybrid SEI layer with improved interfacial kinetics, promoting more uniform Zn deposition. This approach achieves an average Coulombic efficiency (CE) of 96.8% over 150 cycles (a maximum CE of 97.8%). The study highlights the strategic difference in electrolyte design, emphasizing the need for tailored approaches to optimize Zn deposition on MXenes, contrasting with traditional metallic current collectors.

All-solid-state batteries receive ample attention due to their promising safety characteristics and energy density. The latter holds true if they are compatible with next-generation high-capacity anodes, but most highly ion-conductive solid electrolytes decompose at low operating potentials, leading to lithium loss and increased cell resistances. Here the dynamic stability of solid electrolytes that can improve all-solid-state battery performance is demonstrated. Halide electrolytes Li₃YCl₃Br₃ and Li₂ZrCl₆, considered unstable at low potentials, are found to exhibit structurally reversible redox activity beyond their electrochemical stability windows, increasing compatibility with anodes and contributing to capacity without compromising ionic conductivity. The benefit of this dynamic stability window is demonstrated with cost-effective red phosphorus anodes, resulting in high reversible capacities (2,308 mAh g⁻¹), high rate capacity retention (1,024 mAh g⁻¹ at 7.75 mA cm⁻²) and extended cycle life (61% retention after 1,780 cycles). Furthermore, high areal capacity (7.65 mAh cm⁻²) and stability (70% retention after 1,000 cycles) are achieved for halide-based full cells with red phosphorous anodes. The beneficial redox activity of halide electrolytes greatly expands their application scenarios and suggests valuable battery design principles to enhance performance.

Fluorination of electrolytes has been a widely used strategy to enable stable cycling in lithium metal batteries. However, a move toward fluorine-free electrolytes is desirable given the safety and environmental concerns surrounding fluorinated materials. Designing these electrolytes requires a comprehensive understanding of bulk electrolyte and interfacial properties in the absence of fluorine, particularly the solvation structures surrounding Li⁺ and the solid electrolyte interface (SEI) composition. Among fluorine-free Li salts, lithium nitrate (LiNO₃) is often used to obtain highly ion-conductive SEI components. However, its poor ion dissociation and rapid consumption upon freshly plated lithium currently hinder its use as the main electrolyte salt. Herein, we show that the modification of Li⁺ inner solvation structures by employing lithium bis(oxalato)borate (LiBOB) as the secondary salt in LiNO₃/diglyme electrolytes synergistically improves both bulk Li⁺ transport and SEI properties. It significantly enhances ion dissociation, which increases the ionic conductivity of the electrolyte despite an increase in its viscosity. Furthermore, the presence of LiBOB-derived outer SEI components over the LiNO₃-derived ion-conductive inner SEI layer results in low-surface-area Li deposits and lower Li⁺/anion consumption during cycling. The dual-salt fluorine-free electrolyte enables stable, long-term cycling in Li/Cu cells for >700 cycles and shows promising capacity retention in Li/LFP full cells at ambient temperature. Our work highlights the importance of tuning the Li⁺ solvation structures for optimizing bulk and interface properties in fluorine-free electrolytes and presents a viable pathway toward the development of greener electrolytes for lithium metal batteries.