Synthesis Conditions of LGPS Solid Electrolytes with High Ionic Conductivity by Liquid-Phase Method

Li10GeP2S12 solid electrolytes, which exhibit ionic conductivity comparable to that of organic electrolytes, have attracted attention. An excess sulfur solution method for short-time synthesis of Li10GeP2S12 has been proposed, and it has been revealed that the heat treatment process using a titanium boat improves ionic conductivity compared to other combustion boats, such as quartz boats. To elucidate the mechanism, analysis including X-ray diffraction and Raman spectroscopy were conducted, and they revealed the formation of lattice distortion related to the enhanced ionic conductivity. Furthermore, applying a Ge-rich composition precursor successfully achieved the liquid-phase synthesis of Li10GeP2S12 solid electrolyte with high ionic conductivity.