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LiFePO4/polymer/natural graphite: low cost Li-ion batteries

2004; Elsevier BV; Volume: 50; Issue: 2-3 Linguagem: Inglês

10.1016/j.electacta.2004.02.073

1873-3859

Karim Zaghib, Kathryn A. Striebel, Abdelbast Guerfi, Joongpyo Shim, Michel Armand, M. Gauthier,

Advanced Battery Materials and Technologies

Abstract The aging and performance of natural graphite/PEO-based gel electrolyte/LiFePO4 cells are reported. The gel polymer electrolytes were produced by electron-beam irradiation and then soaked in a liquid electrolyte. The natural graphite anode in gel electrolyte containing LiBF4-EC/GBL exhibited high reversible capacity (345 mAh/g) and high coulombic efficiency (91%). The LiFePO4 cathode in the same gel-polymer exhibited a reversible capacity of 160 mAh/g and 93% coulombic efficiency. Better performance was obtained at high-rate discharge with 6% carbon additive in the cathode, however the graphite anode performance suffers at high rate. The Li-ion gel polymer battery shows a capacity fade of 13% after 180 cycles and has poor performance at low temperature due to low diffusion of the lithium to the graphite in the GBL system. The LiFePO4/gel/Li system has an excellent rate capacity. LiFePO4 cathode material is suitable for HEV application.