Dual Thermal Stabilization Toward Highly Safe and Durable All-Solid-State Lithium Metal Batteries Based on Sulfide...

The practical deployment of all-solid-state lithium (Li) metal batteries (ASSLMBs) based on sulfide electrolytes is constrained by the thermal-electrochemical coupled failure and safety issues under abusive conditions. Here, a dual thermal-stabilization strategy is identified and rationalized as the optimal choice to tailor above issues. A fluorinated graphene (FG)-interlayer is introduced to effectively enhance heat dissipation and deflect Li dendrite propagation inside the ASSLMBs, while an oxygen-vacancy-rich copper oxide (CuO_1-x) additive is applied to efficiently capture reactive oxygen species released from charged cathodes and thus mitigate the electrolyte oxidation. As a demonstration model, the as-modified Li₆PS₅Cl (LPSC)-based full cells achieve stable cycling over 2000 cycles at 1 C with 96% capacity retention, and well retain the room-temperature capacity even at 90°C. Accelerated rate calorimetry (ARC) tests on pouch cells further demonstrate enhanced thermal stability. This dual-thermal-stabilization paradigm can be extended to sulfide/chlorinated oxide bilayer electrolyte systems.