Controllable Li3PS4–Li4SnS4 solid electrolytes with affordable conductor and high conductivity for solid-state battery

High ionic conductivity, low grain boundary impedance, and stable electrochemical property have become the focus for all-solid-state lithium–sulfur batteries (ASSLSB). One of the approaches is to promote the rapid diffusion of lithium ions by regulating the chemical bond interactions within the framework. The structure control of P 5+ substitution for Sn 4+ on lithium-ion transport was explored for a series of Li 3 PS 4 –Li 4 SnS 4 glass–ceramic electrolytes. Results showed that the grain boundary impedance of the glass electrolyte was reduced after heat treatments. The formation of LiSnPS microcrystals, a good superionic conductor, was detected by X-ray diffraction tests. Electrochemical experiments obtained the highest conductivity of 29.5 S cm −1 at 100°C and stable electrochemical window from –0.1 to 5 V at 25°C. In addition, the cell battery was assembled with prepared electrolyte, which is promoted as a candidate solid electrolyte material with improved performance for ASSLSB.