(Battery Student Slam 8 Award Winner) Enable Processing of Sulfide Solid Electrolytes in Humid Ambient Air

Sulfide solid-state electrolytes (SSEs) are promising candidates to realize all solid-state batteries (ASSBs) due to their superior ionic conductivity and excellent ductility. However, their hypersensitivity to moisture requires processing environments that are not compatible with today’s lithium-ion battery manufacturing infrastructure. Herein, we present a modification strategy that enables the processability of sulfide SSEs under humid ambient air. We demonstrate that compatible modification with the electrolyte with negligible impact on its ion conductivity. Importantly, the modification extends the amount of time that the sulfide SSE can be exposed to air with limited degradation of its structure while retaining the conductivity for days, a more than 100x improvement in protection time over competing approaches. Experimental and computational results reveal the interaction between modification to the SSE. The modified SSE maintains its function after exposure to ambient humidity when implemented in a Li0.5In/LiNi0.8Co0.1Mn0.1O2 ASSB. The proposed protection strategy represents a major step forward towards cost-competitive and energy-efficient sulfide SSE manufacturing for ASSB applications.