Air-stable Li3InCl6 electrolyte with high voltage compatibility for all-solid-state batteries

Abstract

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 Li₃InCl₆ SSE with a high ionic conductivity of 1.49 × 10⁻³ S cm⁻¹ (25 °C). The Li₃InCl₆ SSE is stable towards oxide cathode materials (e.g., LiCoO₂) without any interfacial treatment. By applying the Li₃InCl₆ SSEs, significantly enhanced electrochemical performances are achieved in terms of capacity and durability. Experimental investigations reveal that the Li₃InCl₆ can avoid side reactions between the SSEs and the oxide cathode materials and thus effectively improve the Li⁺ migration across the interface. Moreover, Li₃InCl₆ 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.