Li−Ag alloy anode with interfacial silver layer for all−solid−state lithium metal batteries utilizing Li₃InCl₆ halide solid electrolyte

Halide solid state electrolyte with Li₃InCl₆ structure has attracted growing attention due to its good deformability, high ionic conductivity, and good compatibility with high-voltage cathode. However, Li₃InCl₆ undergoes intense interface side reaction with Li metal anode. To this end, a silver interface layer is introduced between Li and Li₃InCl₆ through a simple cold pressing method to form a Li−Ag anode. The Ag buffer layer prevents the direct contact between Li and Li₃InCl₆, thus suppresses the interfacial side reaction and the formation of voids and Li dendrites. The Li diffusion kinetics has also been improved due to the formation of Li-Ag alloy phase. Li−Ag/Li₃InCl₆/Li−Ag symmetric cell exhibits a high critical current density of 1.3 mA cm⁻² and a long life-span of 500 h at 0.1 mA cm⁻². This work provides a simple and economical solution for stabilizing the interface between Li₃InCl₆ halide solid electrolyte and Li metal anode.