Structural tuning and electrochemical behavior of indium halide solid-state electrolytes

Halide solid electrolytes have become the core enabling material for solid-state battery systems due to their excellent properties, leading the next generation of energy storage technology innovation. This system inherits the mechanical flexibility of sulfide electrolyte and the electrochemical stability of oxide electrolyte, and achieves a wide electrochemical window while breaking through the bottleneck of room temperature ionic conductivity of the polymer electrolytes. Despite the unique advantages demonstrated by halide electrolytes systems, there are still significant technical bottlenecks in their commercial application. Herein, we report a reasonably designed indium halide electrolyte material with high ionic conductivity and low ionic migration barrier of 1.53 × 10 −3 S cm −1 at 25°C. The symmetrical cells constructed based on this method can exhibit 250 h of long cycle stability at 0.4 mA cm −2 with 0.4 mA h cm −2 . Especially noteworthy is that the Li 3 InCl 6 shows high stability in air. These breakthrough characteristics make it an ideal electrolyte material candidate for constructing high energy density all-solid-state lithium batteries.