In situ observation of thermal runaway propagation in lithium-ion battery electrodes triggered by high-frequency induction heating
Changyong Jin, Yuedong Sun, Yuejiu Zheng, Jian Yao, Yu Wang, Xin Lai, Chengshan Xu, Huaibin Wang, Fangshu Zhang, Huafeng Li, Jianfeng Hua, Xuning Feng, Minggao Ouyang
Abstract
Lithium-ion batteries (LIBs) are instrumental for electric vehicles, but safety is a concern due to thermal runaway (TR) events. In this study, an in situ observation method for TR and its propagation (TRP) in LIB electrodes is presented, employing high-frequency induction heating as the TR triggering method. The non-contact, rapid heating technique facilitates direct trigger of TRP in a self-made tempered glass observer. Experiments reveal that venting occurs in all samples, and dendritic burn patterns appear on separators upon TRP. The heat-induced shrinkage of separators is more pronounced on the anode side. Phenomena observed during tests include gas flow paths, drifting sparks, short-circuit propagation, and electrolyte boiling. This method may contribute to a better understanding of LIB TRP behavior, facilitating strategies to improve safety and TR characteristics.