Enhanced low temperature electrochemical performances of LiFePO4/C by V3+ and F− co-doping

Abstract

V3+ and F− co-doped LiFePO4/C cathode materials are prepared via a facile wet milling-spray drying-carbothermal reduction (WSC) process. The obtained products have bowl-like morphologies with the diameters from 5 to 10 μm, which are composed of numerous nanoparticles smaller than 100 nm integrated by carbon network. The effects of ion doping are studied. V3+ and F− co-doped LiFePO4/C shows improved electrochemical performance, which delivers a discharge capacity of 136 mAh·g−1 (10 C) at 20 °C. At 0 °C, a capacity of 86 mAh·g−1 (10 C) can be obtained, which is 20 mAh·g−1 higher than LiFePO4/C. In addition, the V3+ and F− co-doped LiFePO4/C shows excellent cycle performances. The improved performance of V3+ and F− co-doped LiFePO4/C is due to the low charge transfer resistance, enhanced electrical conductivity and the holes on the surface of particles which can provide more ion transport channel.