表面积对功率型磷酸铁锂电芯性能的影响

Effect of Specific Surface Area on the Performance of Power LFP Cell

纳米磷酸铁锂是商业化超高功率锂离子电芯的首选正极材料,比表面积对电性能有重要影响。考察了磷酸铁锂比表面积对电芯内阻、倍率和循环性能的影响。结果表明,磷酸铁锂正极材料的比表面积增大,相应电芯的电荷转移阻抗降低,倍率性能提高。高比表面积会增加与电解液的反应,从而对循环寿命有一定影响,对正极表面处理后可提升循环寿命,为大容量功率电芯设计提供依据。

As the cathode material,preferred nano-LFP plays a vital role in commercialized ultra-high power lithium-ion cell.The specific surface area(SSA)has an important effect on the cells’electrical properties.Effects of SSA on internal resistance,rate and cycling performance of the cells were elucidated.Our results show that the resistance of charge transfer decreases and therefore improves the rate performance of the cell with the increase of the SSA.The adverse effect on cycling life can be improved by certain surface modification.This work sheds light on the design for large-format power cell.