Microstructural evolution of solution-processed Li-Ge-Ga-S chalcogenide powders for Li+ ion battery applications

Abstract

Sulfur-based chalcogenide Li?Ge?Ga?S powders for use in solid electrolyte of Li+ ion batteries have been successfully synthesized via a low-temperature solution-based process. Their Li+ ion conductivity turns out to be ~7×10?4S/cm at room temperature which is quite comparable with that of melt-quenched or mechanically-alloyed analogues. It is revealed that their microstructure becomes amorphized appropriately at a specific Ga/Ge ratio where the ionic conductivity is maximized. A structural model is proposed, which emphasizes correlations between gallium and lithium inside the amorphous structures.