Experimental Study of the Key Thermal-safety Parameters of LiFePO4 Pouch Cell used for Energy Storage System

The thermal safety performance of lithium-ion battery itself is importance to the battery energy storage system. A LiFePO4 pouch cell was used to study the effects of ambient temperature on the electro-thermal characteristic of the battery and to correlate the heat generation rate with the state of charge of battery via experiment. Meanwhile, the thermal runaway is carried out to determine the temperature threshold of thermal safety, moreover, the gas composition obtained from the thermal runaway. The results show that the battery can obtain well performs when its working temperature is in a proper temperature range: 25~40°C. It is found that the heat generation is decline with the ambient temperature increased. Meanwhile, the higher temperature distribution is located at the positive tab, the monitoring point can be place at this zone for the thermal management system. In the thermal runaway process, the selfheating temperature is 102.66 °C, and the volume fraction of hydrogen (H
2
) is largest in all the gases released. There is a serious swelling phenomenon accompanied by the overcharge process in short time, the strain gauge is necessary for the battery safety management system. The obtained results provide fundamental data support for thermal-safety management of battery energy storage system.