Optimized synthesis of Cu-doped LiFePO4/C cathode material by an ethylene glycol assisted co-precipitation method

Abstract LiFePO4/C and cupric ion doped LiFePO4/C cathode materials were synthesized via an ethylene glycol assisted co-precipitation method. We assessed the influence of different parameters on electrochemical performance including calcination conditions, the amount of cupric ions added, doping ways, and drying methods. The microstructure of the materials was characterized by XRD, SEM, TEM, and EA. The results indicated the optimized Cu-doped LiFePO4/C shows enhanced electrochemical performance with excellent high-rate capacity and cycle stability compared with LiFePO4/C. The optimized Cu-doped LiFePO4/C exhibited a high specific capacity of 148 mA h g−1 at 0.1 C. Even at a rate of 10 C, it still achieved a specific capacity of 111 mA h g−1 and its capacity retention ratio remained at 99.9% after 100 cycles at 1 C. These enhanced electrochemical properties were mainly due to a lesser extent of particle aggregation and more uniform carbon coating. Importantly, the synthesis process of this study is simple, fast, and economical thus it is promising to apply in industrialization.