Comprehensively Investigating the Impact of High-Temperature Cyclic Aging on Thermal Runaway Characteristics for Lithium-Ion Batteries

Battery safety issues have severely limited the rapid development and popularization of electric vehicles. Harsh conditions such as high temperature accelerate the degradation of battery safety. To address this issue, a comprehensive analysis of the impact of high-temperature cyclic aging on lithium-ion battery safety is carried out. In the Accelerating Rate Calorimeter, lithium-ion batteries are performed on adiabatic thermal runaway tests and overcharge tests. Regardless of the fully-charged state or half-charged state, in the adiabatic thermal runaway process, high-temperature cyclic aging reduces the characteristic temperature, and the activation energy from the self-heating temperature to thermal runaway triggering temperature decreases. During the overcharge process, high-temperature cyclic aging increases the voltage plateau and the crest voltage before thermal runaway, and their corresponding charging temperature decreases. Besides, the decrease in thermal runaway triggering temperature is also caused by high-temperature cyclic aging during the overcharge process. In short, high-temperature cyclic aging reduces the safety and tolerance of lithium-ion batteries. The results provide a reference for the optimal design of the battery safety management system.