Evaluation of short circuit safety of NCM/C Li-ion power battery under different state of health 2020-01-0454
With the increasing frequency of fire incidents of electric vehicles, the safety of power batteries has attracted more and more attention. At present, the research on the safety of power batteries is mainly focused on fresh batteries. As the state of health of batteries deepens, how the safety of the battery evolves is not clear enough so far. This paper analyzes the short circuit safety of a NCM/C rectangular battery under different cycle numbers. The results show that with the increase of the cycle numbers, the maximum short-circuit current of the battery increases slightly. When the cycle number is less than 800, the maximum temperature of the battery is below 130 °C. The main failure feature of the battery is bulging in volume or opening of the explosion-proof valve. However, when the cycle number reaches 1000, the battery goes into thermal runaway. The explosion-proof valve opens, and a large amount of smoke is sprayed, and the surface temperature of the battery reaches 350 °C.
Lei Liu, Chunjing Lin, Peixia Yang, Fang Wang, Bin Fan
Harbin Institute of Technology, CATARC