Li₇P₂S₈I solid electrolytes synthesized by liquid-phase synthesis with improved heat treatment process

Abstract

Liquid-phase synthesis is a promising method for the production of Li₇P₂S₈I solid electrolytes. To improve the ionic conductivity of electrolytes developed via this method, this study focused on the separation of drying and crystallization processes for the precise control of crystallization at low temperatures. The pelletized samples exhibited a high ionic conductivity of approximately 1.0 mS cm⁻¹ when they were dried at temperatures below 90 °C under vacuum and crystallized at 110 °C. The separation of the drying and crystallization processes and pelletization before crystallization are crucial for achieving high ionic conductivities, comparable to those of materials obtained via solid-phase synthesis, at low temperatures.