Single-Layer Oxyhalide-Nitride Solid-State Electrolyte Membrane for High-Energy-Density All-Solid-State Lithium Batteries

Abstract Simultaneous compatibility of solid-state electrolytes (SSEs) with high-voltage cathodes and low-voltage anodes is crucial for high-energy-density all-solid-state lithium batteries (ASSLBs). However, deformable SSEs that integrate readily into ASSLBs rarely satisfy both requirements. Multilayer SSE membranes, such as halide SSEs paired with cathodes and sulfide SSEs with anodes, are therefore widely used but reduce energy density. Here, the low-cost, deformable oxyhalide-nitride SSEs, Li1.75+3xZrCl4.75O0.5Nx (0.1 ≤ x ≤ 0.3), are developed through dual-anion doping with O and N. The O and N incorporation preserves stability against the high-voltage LiCoO2 cathode while promoting a stable interface with the low-voltage Li13Si4 anode. A Li13Si4 | Li2.2ZrCl4.75O0.5N0.15 | Li13Si4 symmetric cell sustains stable plating/stripping for 2000 h with low overpotential. A Li13Si4 | Li2.2ZrCl4.75O0.5N0.15 | LiCoO2 cell using the oxyhalide-nitride SSE as a single membrane layer shows an initial specific discharge capacity of 134.72 mAh g–1 with 92.38% Coulombic efficiency and remains stable for 100 cycles.