磷酸铁锂动力电池电解液改善及过程参数优化

Improvement of electrolyte and process parameter optimization of LiFePO_4 power battery

为探究电解液组成和预化成工艺参数对20 Ah高压实密度磷酸铁锂动力电池用电极性能的影响,对电解液溶剂配比和预化成条件进行调整,用改变制成工艺后生产的负极极片组装电池,测试其满电状态、容量、首次库仑效率、内阻和极片厚度。结果表明:降低EC、PC含量可以有效改善极片状态,促进电解液在高压实负极体系中的浸润性,电池容量从19.15 Ah提升至20.41 Ah。同时配合小电流长时间的预化成工艺,可以明显提升电池的容量和首次库仑效率,改善高能量密度锂电池的电性能。

This paper studied the electrolyte composition and the influence of process parameters on the electrode performance of 20 Ah LiFePO4 power battery. By adjusting the ratio of electrolyte solvent and process parameters,the battery was assembled by the negative electrode which is produced by the adjusting process. The battery was tested and got the capacity, coulomb efficiency, battery internal resistance and thickness. The experimental results show that the lower content of EC and PC can effectively improve the state of cathode morphology and wettability.The capacity is increased from 19.15 Ah up to 20.41 Ah. At the same time, cooperating with small current for a long time process, it can significantly improve the capacity of the battery, coulomb efficiency and the other electrochemical property.