Air-stable Li ₃InCl ₆ electrolyte with high voltage compatibility for all-solid-state batteries

Abstract

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.

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 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.