Preparation of an Ionic Liquid Gel Polymer Electrolyte and Its Compatibility with a LiFePO4 Cathode

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 1.650x10(-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.