磷酸铁锂正极材料与电解液的相容性研究

Study on compatibility of LiFePO_4 cathode material with electrolyte for lithium ion battery

在锂离子电池使用过程中磷酸铁锂正极材料会与电解液发生许多副反应,导致铁的溶解,造成正极材料与电解液相容性差。为了研究磷酸铁锂正极材料与电解液的相容性及其对电池搁置性能的影响,先利用电感耦合等离子发射光谱对不同磷酸铁锂正极材料在不同电解液中的溶铁量进行了表征,后又对制备的电池进行了常温及高温搁置性能测试。结果表明:磷酸铁锂正极材料对电解液具有选择性,并且正极材料在电解液中的溶铁量越大,其相容性越差,对锂离子电池性能影响越大。

LiFePO4 cathode material will react with electrolyte during the application of lithium ion battery, which will cause dissolution of Fe and further lead to poor compatibility of cathode material with electrolyte.To study the compatibility of cath- ode material with electrolyte and its impact on the storage performance of lithium ion battery,the Fe dissolutions of different LiFeP04 cathode materials in different electrolytes were characterized by the inductively coupled plasma atomic emission spectroscopy, and then the storage performances of lithium ion battery at normal-and high-temperatures were tested.Results showed that LiFePO4 cathode material had selectivity to electrolyte, and the larger the dissolved content of Fe, the worse the compatibility of cathode material with electrolyte, the greater the impact on the performance of lithium ion battery.