Electrochemical properties of lithium iron phosphatecathodematerial using polymer electrolyte
Abstract.Carbon-coated lithium iron phosphate (LiFePO4/C) cathodematerial was synthesized by mechano-chemical activation method. Theperformance of LiFePO4/C in lithium battery was testedwith an electrospun polymer-based electrolyte. Liquid electrolyteof 1M lithium hexafluorophosphate (LiPF6) in ethylenecarbonate/dimethyl carbonate (EC/DMC) (1 : 1vol) was incorporatedin electrospun poly(vinylidene fluoride-co-hexafluoropropylene)(P(VdF-HFP)) microfibrous membrane to prepare the polymerelectrolyte (PE). The cell based on Li|PE|Li FePO4/Cexhibited an initial discharge capacity of 142 mAh g−1at 0.1 C-rate at room temperature. Good cycling performance evenunder the high current density of 2 C could be obtained. Impedancespectroscopy was applied to investigate the material behaviorduring 0.1 C-rate charge–discharge cycling. When the fresh cell andthe cell after different cycles were compared, impedance resistancewas found to decrease with cycling. Impedance study indicated goodcycle life for the cell when tested at room temperature.