Influence of cycling on the heat-release and thermal runaway of the lithium ion battery under adiabatic condition

With the development of lithium-ion batteries, the demand for safety is critical, and temperature has an important influence on the life and safety. LiCoO₂/C is taken as the object, and the heat generation and thermal runaway behavior at different cycle are studied under different current by using accelerating rate calorimeter. Comparing the heat generation of the batteries at different cycle, it is found that there is a strong correlation between the rate of capacity decay, DC resistance and the heat generation rate. According to the thermal runaway behavior, the self-heating temperature of the fresh battery is 105.4℃, followed by continuous self-heating. Until the temperature reaches 149.7℃, the battery is out of control, and an internal short circuit occurs, which finally leads to the battery thermal runaway. The initial temperature of self-heating and thermal runaway changes slightly, but the time of thermal runaway progress is shortened greatly.