Research Progress on Thermal Runaway Mechanisms of All-Solid-State Lithium Batteries

Despite their various advantages, all-solid-state lithium batteries (ASSLBs) remain vulnerable to thermal runaway (TR), and the mechanisms are covered in fog. Safety theories and methods applicable to liquid-state lithium-ion batteries (LSLIBs) cannot be transferred to ASSLBs directly. Therefore, this review discusses the distinction and connection between fire and TR of batteries and their definitions. The structures, components, and materials of the two batteries are then compared. Furthermore, the temperature nodes, reactions, and driving forces of TR from overcharged LSLIBs are interpreted. Based on the above content, this paper dissects the principles, areas, and laws of TR of ASSLBs, followed by discussing similarities and differences between the LSLIB and ASSLB regarding TR. In the final part, future development directions and research ideas for improving the safety of ASSLBs are proposed. This review provides a fundamental understanding of TR issues hidden in ASSLBs and accelerates this new battery’s interdisciplinary research.