The effect of NiO as graphitization catalyst on the structure and electrochemical performance of LiFePO4/C cathode materials

• NiO doped LiFePO4/C was synthesized by a facile solid state method.
• NiO doping can increase the graphitization of carbon in LiFePO4/C materials.
• The as-prepared materials exhibit excellent capacity and cycle ability at high rate.

The NiO doped LiFePO4/C composite was synthesized by a simple solid state method. The structure and morphology of synthesized particles were characterized by XRD, Raman spectrum, SEM, TEM and EDS. Electrochemical performance of the pristine and nickel oxide modified samples was evaluated by galvanostatic charge-discharge test, CV, and EIS. The results indicate that NiO doped LiFePO4/Li type coin cell exhibits improved specific capacity and cycle stability, especially at high rates. Among all the modified samples, the 5.0%wt NiO doped sample shows the best electrochemical performance, which achieves a specific capacity of 129 mA h g−1 at 1 C current rate due to the modest graphitization of carbon layer on the surface of LiFePO4 particles. The results indicate that nickel oxide modification is an effective way to improve the electrochemical performance of LiFePO4/C cathode materials for lithium ion batteries.