An Alternative Synthesis Route of LiFePO4-Carbon Composites for Li-Ion Cathodes

Abstract

LiFePO4-Carbon (LFP/C) composites with high purity and good crystallinity were prepared by an improved environmentally benign and low-cost solvothermal method. Capping agent polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG-400) showed no significant dispersive effect during the synthesis. These capping agents were converted into networking carbons after annealing, which consequently improved the charge and discharge performance. It was able to deliver a high initial discharge specific capacity of 154.1 mAh g−1for sample prepared with PVP and 145.6 mAh g−1for sample prepared with PEG-400 while having great capacity retention. The rate capability and cycling performance of LFP/C samples prepared with PVP or PEG-400 at high current rates were significantly improved compared to the LFP/C sample prepared without a capping agent.