Investigating Dry Room Compatibility of Chloride Solid-State Electrolytes for Scalable Manufacturing

Abstract

Solid-state electrolytes (SSEs) are receiving growing attention as they can replace conventional organic liquid electrolytes to alleviate flammability issues. The low Young’s modulus, decent ionic conductivity, and good oxidation stability make chloride SSEs promising candidates to be used as catholytes in all-solid-state batteries. To assess the scalability of chloride SSEs, their chemical stability in air and dry room environments needs to be evaluated. In this study, threechloride SSEs are investigated for their chemical stability under ambient air and dry room conditions: Li2ZrCl6 (LZC), Li3YCl6 (LYC), and Li3InCl6 (LIC). LZC undergo an irreversible hydrolysis reaction during air exposure and cannot be recovered by heat treatment. LYC decomposes into its hydrated precursors when exposed to ambient air, and further hydrolyzed during heat treatment and was thus not recoverable. LIC forms a stable hydrate and can be easily recovered by heating at 260 °C under vacuum. Finally, the electrochemical performance of dry room exposed chloride SSEs is evaluated where capacity loss was observed due to the lower SSE ionic conductivity due to the irreversible reactions.