离子液体/凝胶聚合物电解质的制备及其与LiFePO_4的相容性

Preparation of an Ionic Liquid Gel Polymer Electrolyte and Its Compatibility with a LiFePO_4 Cathode

以1-甲基-3-乙基咪唑六氟磷酸盐(EMIPF6)、聚偏氟乙烯-六氟丙烯(P(VDF-HFP))和六氟磷酸锂(LiPF6)为原料,采用溶液浇铸法制备了离子液体/凝胶聚合物电解质(ILGPE).通过循环伏安(CV)、计时电流法、恒流充放电、电化学阻抗法(EIS)研究了该电解质的离子传输特性以及与锂离子电池正极材料LiFePO4的相容性.结果表明,离子液体/凝胶聚合物电解质的室温电导率为1.650×10-3S·cm-1,电化学稳定窗口达到5.0V.在充放电循环过程中,电极表面形成的钝化膜改善了锂离子脱、嵌可逆性和电极/电解质的界面性质.

An ionic liquid gel polymer electrolyte（ILGPE） based on 1-ethyl-3-methyl-imidazolium hexafluorophosphate（EMIPF6）,poly（vinylidenefluoride-hexafluoropropylene）（P（VDF-HFP） and LiPF6 was prepared by a solution casting method.Its ion transport characteristics and compatibility with LiFePO4 were investigated by cyclic voltammetry（CV）,chronoamperometry,galvanostatic charge-discharge and electrochemical impedance spectroscopy（EIS）.The results show that the ionic conductivity and electrochemical window at room temperature are 1.650×10-3 S·cm-1 and 5.0 V,respectively.The lithiation/delithiation reversibility was improved because of the formation of a passivation layer on the surface of the electrode during the charge-discharge cycles.