Prediction of Ground State Configurations and Electrochemical Properties of Li3InCl6 Doped with F, Br, and Ga

Abstract

Compared with conventional solid-state electrolytes, halide solid-state electrolytes have several advantages such as a wider electrochemical window, better compatibility with oxide cathode materials, improved air stability, and easier preparation conditions making them conductive to industrial production. We concentrate on a typical halide solid-state electrolyte, Li3InCl6, predict the most stable structure after doping with Br, F, and Ga by using the Alloy Theoretic Automated Toolkit based on first-principles calculations, and verify the accuracy of the prediction model. To investigate the potential of three equivalently doped ground state configurations of Li3InCl6 as solid-state electrolytes for all-solid-state lithium-ion batteries, their specific properties such as crystal structure, band gap, convex packing energy, electrochemical stability window, and lithium-ion conductivity are computationally analyzed using first-principles calculations. After a comprehensive evaluation, it is determined that the F-doped ground state configuration Li3InCl2.5F3.5 exhibits better thermal stability, wider electrochemical stability window, and better lithium ion conductivity (1.80 mS⋅cm−1 at room temperature). Therefore, Li3InCl2.5F3.5 has the potential to be used in the field of all-solid-state lithium-ion batteries as a new type of halide electrolyte.