Impact of Solvent Treatment of the Superionic Argyrodite Li6PS5Cl on Solid‐State Battery Performance

With growing interest in solution‐based processing of electrolytes for all‐solid‐state batteries comes the need to more deeply understand potential detrimental effects of the solvent on electrolyte materials, as well as effects on the cell performance that may not have been evident by structural characterization alone. Herein, the superionic solid electrolyte Li6PS5Cl is treated with five organic solvents selected for a range of different physical and chemical properties. The electrolytes treated with solvents that do not lead to obvious degradation are used in cathode composites of solid‐state batteries In/LiIn│Li6PS5Cl│NCM‐622:Li6PS5Cl. After treatment in some solvents, the solid electrolyte remains seemingly unaffected, but a strong influence on the solid‐state battery performance is observed, revealing underlying effects that warrant deeper study.