Investigation on mechanical bending caused thermal runaway of lithium-ion cell

Lithium-ion batteries are widely used in electronics, and are susceptible to thermal runaway from mechanical abuse, which poses a threat to consumer safety and the development of new batteries. This work conducts both experimental and numerical simulation to study thermal runaway caused by varying degrees of mechanical bending of commercial mobile phone batteries. The results show that batteries with greater degrees of deformation have a higher thermal runaway maximum temperature with quick temperature rise rate. Simulated results provide in-depth analysis towards correlation between temperature and heat generation, it is found that the two significant increases in temperature rise rate are attributed to the heat generated by SEI decomposition and the heat released by the cathode and electrolyte reaction. In order to effectively reduce or even eliminate the hazards of thermal runaway, it is necessary to lengthen the interval between the two heat releases or to reduce the amount of heat released. This study further develops a theoretical framework for battery bending abuse and provides guidance to prevent thermal runaway.