含FEC电解液的锂离子电池低温性能研究

Low-Temperature Performance of Li-Ion Battery with Fluoroethylene Carbonate Electrolyte

研究含FEC溶剂电解液(FEC+EMC,EC,PC)的低温性能及其与磷酸铁锂正极或中间相碳微球(MCMB)负极的匹配.该电解液具有较高的低温电导率,FEC可在1.6 V与负极反应成膜,有效地提高负极稳定性.红外测试发现,FEC可抑制其它电解液溶剂在负极成膜过程中的分解,在常温(20℃)和低温(-20℃)下形成的SEI膜阻抗均较低.电化学测试表明,以该电解液装配的锂离子电池(电极)具有较高的低温放电容量和倍率性能.

The low temperature performance of electrolytes containing FEC including FEC＋EMC,EC and PC,as well as the compatibility of electrolytes with LiFePO4 anode and with MCMB cathode were investigated.The electrolyte exhibits a high value of ionic conductivity at low temperature.The stability of cathode was enhanced by the formation of SEI film at 1.6 V as a result of FEC reaction.The infrared spectra showed that FEC can suppress decomposition of other solvents during SEI formation,and lower the resistance of SEI on MCMB cathode.The electrochemistry test indicates that Li-ion batteries with FEC electrolyte display high capacity at low temperature and better rate performance.