Novel Amorphous Nitride‐Halide Solid Electrolytes with Enhanced Performance for All‐Solid‐State Batteries

Solid electrolytes (SEs) in all-solid-state batteries (ASSBs) are garnering considerable attention for their potential applications in next-generation energy storage systems. Amorphous SEs with dual-anion hold great promise for achieving favorable performance, such as high ionic conductivity and good compatibility with electrodes within ASSBs. Here, we discover a family of amorphous nitride-halide SEs, Li3xMClyNx (M=Ta or La, 1≤3x≤1.4, y=5 or 3), which can achieve ionic conductivities up to 7.34 mS cm-1 at 30 °C. The amorphous properties and local structures are investigated using powder X-ray diffraction, cryogenic transmission electron microscopy, and atomic pair distribution function analysis. Impressively, ASSBs employing amorphous Li3xTaCl5Nx have demonstrated good performance at high rates and charging voltages, as well as at low temperature.