Investigation of carbon-decorated LiVPO4F nanoparticles as cathode for lithium-ion batteries with enhanced rate capability and cyclic performance

Abstract

Polyanion-type LiVPO4F has been regarded as a potential candidate of cathode material for lithium-ion batteries due to its high working voltage, excellent thermal stability and good safety. However, the pure LiVPO4F has a low electronic conductivity of 10−11 S cm−1, which greatly limits its application in high-power density batteries. In this research, the core-shell carbon-coated LiVPO4F composite is prepared using a facile sol-gel method followed by a solid-state reaction. Owing to the synergistic effects rendered by the LiVPO4F nanoparticles and conductive carbon coating, the as-prepared composite exhibits high reversible capacity (147.9 mAh g−1 at 0.1 C), excellent rate capability (121.2 mAh g−1 at 5 C) and stable cyclic performance (94% capacity retention after 200 cycles at 2 C). These results reveal that the carbon-coated LiVPO4F material is a promising cathode material for high-power lithium-ion batteries.