Anode-Electrolyte Interlayering in Solid-State Batteries via Dry-Processing

The interlayer consists of lithiophilic metallic or metal-containing nanoparticles supported on holey graphene, a special carbon material perforated by small holes that enables dry processing. The composite interlayer guides uniform lithium deposition and maintain stability during cycling. The result is a thin, film-like material that can be integrated (via dry processes) into battery cells as standalone interlayers or combined with solid electrolyte and cathode powders to form bi- and tri-layer structures, separating anodes and electrolytes while encouraging efficient ionic movement and long cell lifecycles. Tests found that battery cells incorporating this dry-processed interlayer achieved ultrahigh current density and low overpotential, indicating that the interlayer prevents rough patches, resists dendrite formation, and supports efficient charge and discharge over time. The interlayer has demonstrated a high lithium-ion flux (i.e., a high critical current density of ~25 mA/cm²) and has shown that full battery cells incorporating the protective layer can be successfully cycled (with an areal capacity of 7 mAh/cm²). This innovation contributes to both the SABERS (LEW-TOPS-167) and SABERS 2.0 (LEW-TOPS-188) portfolios, improving the state of the art for solid state batteries. The anode interlayer is currently at a TRL 4 and is available to license independently or as part of the larger SABERS solid-state battery suite. NASA’s SABERS (Solid-state Architecture Batteries for Enhanced Rechargeability and Safety) project aims to advance battery efficiency, power, and safety. Solid-state batteries promise higher energy density and safety compared to conventional lithium-ion batteries due to their use of solid, stable electrolytes. However, when lithium metal serves as the anode, repeated plating and stripping during charge/discharge cycles can cause surface roughness, inactive lithium debris, and dendritic growth from uneven ionic activity, all of which degrade performance and risk short circuits. Current mitigation strategies add interlayers between the anode and electrolyte, enabling ion transport while preventing direct contact. These interlayers, often graphite or silver-carbon composites, are fabricated using costly, solvent-based processes that require long preparation and drying times. Dry processing reduces cost and complexity, but no dry-processable interlayer techniques exist, leaving a gap for scalable, solvent-free manufacturing. Innovators at NASA’s Langley Research Center developed a fully dry method for creating an anode interlayer without the use of solvents. Using a perforated nanomaterial and lithophilic compounds, this technique is faster, less costly, and improves solid-state battery life and stability.