Electrochemical performance of LiVPO4F synthesized by ball-milling assisted sol-gel method

Lithium vanadium fluorophosphate, a cathode material for lithium-ion batteries, was synthesized by a ball-milling assisted sol-gel method. The micro structure, surface morphology and electrochemical performance of LiVPO4F were investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and electrochemical tests. The results show that the sample synthesized at 550°C for 4 h was pure phase, possessed good crystallinity and uniform particle size distribution. At 0.1 C rate, the LiVPO4F sample demonstrated charge and discharge capacity of about 153.2 and 125.7 mA h g−1 at the first cycle respectively, the coulombic efficiency was 82%. The initial discharge capacity was 121.9 mA h g−1 at the rate of 0.3 C, and it became 118.7 mA h g−1 after 50 cycles.