Ambient-air-stable Li 3InCl 6 halide solid electrolyte, with high ionic conductivity of 1.49 × 10 −3 S cm −1 at 25 °C, delivers essential advantages over commercial sulfide-based solid electrolyte.
Most inorganic solid-state electrolytes (SSEs) suffer from incompatibility with oxide cathode materials and instability in ambient air, presenting major barriers for their application in high performance all-solid-state batteries (ASSLBs). Herein, we report a rationally designed halide-based Li 3InCl 6 SSE with a high ionic conductivity of 1.49 × 10 −3 S cm −1 (25 °C). The Li 3InCl 6 SSE is stable towards oxide cathode materials ( e.g., LiCoO 2) without any interfacial treatment. By applying the Li 3InCl 6 SSEs, significantly enhanced electrochemical performances are achieved in terms of capacity and durability. Experimental investigations reveal that the Li 3InCl 6 can avoid side reactions between the SSEs and the oxide cathode materials and thus effectively improve the Li + migration across the interface. Moreover, Li 3InCl 6 is highly stable in ambient air and possesses good ionic conductivity retention after a reheating process, further making it an attractive electrolyte for next-generation ASSLBs.