The effect of defects for the ion transport of Li3ScCl6 and Li3InCl6 with the interface of lithium metal anode: A first-principles study

Abstract

Li3ScCl6 and Li3InCl6 have good ionic conductivity and a wide stable chemical window, which showing great potential in many inorganic solid-state electrolytes. Due to the disordered occupancy phenomenon of the lattice sites between the framework lithium ions and the transported ions. The concentration nonuniformity of lithium ions causes the blocking of mobile ions in the transition metal lithium halide solid electrolyte. However, vacancy defects can cause changes in the charge balance of nonstoichiometric systems, which reducing blocking effects during ion diffusion. In addition, lithium dendrites still exist at the interface between the inorganic solid electrolyte and the lithium metal anode. It can effectively improve the occurrence of interface side reaction because LiF has high interface energy. The effect of vacancy defects for lithium ion migration parameters of Li3ScCl6 and Li3InCl6 at different temperatures are simulated by the first principle. The results showing that lithium ions had better migration and diffusion ability in the structure containing lithium site defects of Li3InCl6. A dual-halide electrolyte interface model was constructed to suppress the growth of Li dendrites on the surface of a Li metal anode. The Li3ScCl6-LiF heterostructure interface can stably control ion transport on the surface of a lithium metal anode.