Preparation and Electrochemical Performance of V2O3-C Dual-Layer Coated LiFePO4 by Carbothermic Reduction of V2O5

Abstract

The V2O3-C dual-layer coated LiFePO4 cathode materials with excellent rate capability and cycling stability were prepared by carbothermic reduction of V2O5. X-ray powder diffraction, elemental analyzer, high resolution transmission electron microscopy and Raman spectra revealed that the V2O3 phase co-existed with carbon in the coating layer of LiFePO4 particles and the carbon content reduced without graphitization degree changing after the carbothermic reduction of V2O5. The electrochemical measurement results indicated that small amounts of V2O3 improved rate capability and cycling stability at elevated temperature of LiFePO4/C cathode materials. The V2O3-C dual-layer coated LiFePO4 composite with 1wt% vanadium oxide delivered an initial specific capacity of 167 mAh/g at 0.2 C and 129 mAh/g at 5 C as well as excellent cycling stability. Even at elevated temperature of 55 °C, the specific capacity of 151 mAh/g was achieved at 1 C without capacity fading after 100 cycles.