大电流脉冲工况下磷酸铁锂电池衰降机理

Degradation mechanism of LFP lithium ion battery under high current pulse condition

随着插电混动型汽车、48 V轻混系统汽车的普及,对于功率型磷酸铁锂电池的需求也在快速增加。对磷酸铁锂电池在大电流脉冲工况下的衰降机理进行了分析,结果表明电池32%的容量衰降来自负极活性物质的损失,5%来自活性Li损失,电池内阻增加则主要来自石墨负极电荷交换阻抗的增加。

With the popularity of plug-in hybrid vehicles and 48 V light hybrid system vehicles,the demand for power type LFP lithium ion batteries is also increasing rapidly.In this paper,the degradation mechanism of LFP lithium ion battery under the condition of large current pulse is analyzed.The analysis results show that 32% of the capacity decreases of lithium ion battery comes from the loss of active substance,5% from the loss of active Li,and the increase of internal resistance mainly comes from the increase of charge exchange impedance of graphite anode.