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 similar to 7 x 10(-4) S/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.