磷酸铁锂电池充放电过程中的热性能

Thermal performance of LiFePO_4 cell during charge-discharge process

采用电化学-量热法对磷酸铁锂电池在30℃不同倍率下充放电过程中的电参数、热流进行精确测量,研究其热性能。结果表明:电池0.2充电和放电初始阶段的热流缓慢增大,而0.5和1充放电初始阶段的热流快速增大;电池充电和放电过程中的热流、产热量随着充放电倍率的升高而增大。根据电池0.2,0.5,1充放电过程中的电流、热流和时间数据计算得到电池充放电过程的产热量、电极反应物质的量,从而计算出电池0.2充电和放电过程电极反应的驻r m分别为-7.074和7.266 J/mo·lK。

The electrical parameter and heat flow of LiFePO4/Li cell during the charge-discharge process at different rates and 30 ℃ were measured precisely by electrochemical-calorimetric method. Then the thermal performance of cell was investigated. The results show that the heat flow of cell increases slowly in the initial stage of charging and discharging at 0.2 C, while increases rapidly in the initial stage of charging and discharging at 0.5 C and 1 C. The heat flow and heat output of cell during the charge-discharge progress increase as the increase of charge-discharge rate. The heat output, quantity of electrode reaction mass for cell during the charge-discharge process at 0.2 C, 0.5 C, 1 C were calculated according to the current, heat flow and time, and the △rSm of electrode reaction for cell during charge-discharge at 0.2 C was calculated as -7.074 and 7.266 J/mol. K respectively on the basis of work above.