A review of mechanical abuse safety of lithium-ion batteries under different aging approaches

<p indent="0mm">With the rapid advancement of new energy vehicles, as the “core” component of pure electric vehicles (EVs), the safety of the entire lifecycle of lithium-ion batteries (LIBs) has drawn enormous research interest. The safety evaluation and design of LIBs are one of the technologies in the development process of EVs. During the driving process of EVs, battery aging is not only reflected in electrochemistry, such as the loss of materials inside the battery, but also includes changes in mechanical properties. These changes may cause the battery to be more prone to internal short circuit (ISC) and thermal runaway (TR) in the event of mechanical abuse, such as a collision. Even worse, it may cause serious hazards such as fire or explosion. These consequences not only pose a serious threat to the vehicle and occupants but also increase the difficulty of emergency management. Therefore, this review is intended to systematically analyze the safety issues of aged LIBs under mechanical abuse conditions, clarify the aging mechanism of LIBs, explore the variations in the electrochemical and mechanical properties of LIBs during the aging process, and elucidate the influence mechanism of different cycle aging conditions on the safety performance of LIBs under mechanical abuse conditions. This review also indicates the existing research limitations in this field at present, such as the incomplete theoretical system, the complexity of abuse conditions, and the deficiency of data-driven methods. Therefore, future research needs to further develop multi-physical field coupling models, conduct in-depth studies on the aging mechanism of batteries, and optimize the battery system design to enhance the safety and reliability of power batteries.