Solution-processed Li-Containing Chalcogenide for Solid Electrolyte Applications

Abstract

In an effort to derive Li-containing chalcogenide through a solution process for potential use in solid electrolyte applications, sulfide materials with compositions of Li-Ge-S or Li-Ga-Ge-S were fabricated, and their structural changes were investigated in terms of processing conditions. It was experimentally verified that, as for the Li-Ge-S system, GeS2 begins to dominate as the major crystalline phase after heat treatment above 320 degrees C at the expense of GeS and S-8 phases, both of which are predominant in the as-dried samples. In the Li-Ga-Ge-S system, the resulting powder materials become more amorphized with increasing amounts of Ga. The prepared solution-processed quaternary samples then exhibited an ionic conductivity of similar to 2x10(-4) S.cm(-1) at room temperature, which is expected to further increase after optimization of the processing conditions as well as compositions.