Enhanced properties of LiFePO4/C cathode materials co-doped with V and F ions via high-temperature ball milling route

Abstract

V and F ions co-doped LiFePO4/C (LFP-VF) cathode material is prepared via high-temperature ball milling route. Effects of V and F ions co-doped on the structure, morphology and electrochemical property of LiFePO4 are investigated in this work, and some analysis of X-ray diffraction, scanning electron microscope, transmission electron microscope, charge-discharge tests, electrochemical impedance spectroscopy and cyclic voltammetry are employed. The results confirm that prepared LFP-VF exhibits excellent electrochemical property. The specific capacities are 165.7 (0.1 C), 154.9 (1.0 C) and 124.9 (10 C) mAhg−1. Moreover, over 500 cycles at 1.0 C-rate, the discharge capacity is 148.2 mAhg−1 with a capacity retention rate of 95.7%. Experimental results indicate that the electrochemical performance of LiFePO4 can be greatly enhanced by co-doping with V and F ions.