退役LiFePO_4电池性能测评及储能应用

Testing of the performance and energy-storage applied for retired LiFePO_4 batteries

针对某电动公交车退役LiFePO_4动力电池,测试了电池的容量、直流内阻、常温下的储存性能,进而测试电池的倍率充放电性能、高低温特性和循环性能,分析了新旧电池相关参数的差异及变化规律;在此基础上,重组电池模组,测试其循环性能;最后集成了1MW·h梯次利用电池储能系统并参与风电平滑。结果显示,该动力电池容量衰退初始容量75%左右时,直流内阻只有小幅增加,电池常温下的储存性能、倍率性能、高低温性能下降不显著,电池单体和模块的循环性能良好,显示出该退役LiFePO_4电池具有较好的梯次利用价值。

The capacity, DC internal resistance and storage performance at room temperature have been tested for LiFePO4 batteries retired from electric bus. The charge/discharge rate performance, temperature performance, cycle performance have also been tested. The difference and change regulation of parameter between new batteries and retired batteries have also been analyzed. Then the batteries were recombined and the cycle performance of model have been tested. 1 MW·h secondary use batteried energy-storage system were integrated and participated in wind-power smoothing. The results show that DC internal resistance of battery increase a little, storage performance at room temperature, rate performance and temperature performance decrease slightly, the cycle performance of cell and model is still good, when the capacity of LiFePO4 battery decreased to about 75% of the initial capacity. These results show that the retired EV batteries has good reuse value.