Improved electrochemical performances of nanocrystalline LiFePO4/C composite cathode via V-doping and VO2(B) coating

► LiFePO4 with unique structure was prepared by an inorganic-based sol-gel route. ► The electrochemical performances of LiFePO4 are greatly enhanced by adding 9 mol% V. ► The bulk V-doping and VO2(B) coating co-exist in the LiFePO4 with 9 mol% V. ► The synergistic effect provides a promising way to optimize the capability of cathode.