Thermal, Electrical, and Environmental Safeties of Sulfide Electrolyte-Based All-Solid-State Li-Ion Batteries

[Image: see text] The next generation of all-solid-state lithium-ion batteries (ASLIBs) based on solid-state sulfide electrolytes (SSEs) is closest to commercialization. Understanding the overall safety behavior of SSE-ASLIBs is necessary for their product design and commercialization. However, their safety behavior in real-life situations, such as battery exposure to high temperature, overcharge, mechanical rupture, and air exposure, remains largely unknown. Herein, we report preliminary but needed evidence of (i) significantly improved resistance to electrical shorting at high temperatures, (ii) reduced heat generation when subjected to excessive heat, (iii) tolerable harmful gas generation when subjected to air exposure followed by high-temperature heating, and (iv) high-voltage charge stability when a battery is overcharged (5.5 V charge) in SSE-based ASLIBs compared to commercial liquid electrolyte-based LIBs (LE-LIBs). Furthermore, the result shows that SSEs can self-induce a fast and effective battery shut-down capability in ASLIBs and avoid thermal runaway upon mechanical damage and exposure to air.