A simple solvothermal route to synthesize graphene-modified LiFePO4 cathode for high power lithium ion batteries

摘要

To improve the rate performance and cycling stability of LiFePO4, graphene-modified UFePO4 composite has been developed as Li-ion battery cathode material. The composite is successfully prepared via a novel solvothermal route. C-LiFePO4/graphene, with structure of C-LiFePO4 nanoparticles embedded in graphene matrix, exhibits excellent electrochemical properties, including superior high-rate capability and favorable charge-discharge cycle performance under relative high current density. The size of UFePO4 nanoparticles can be controlled below 30 nm with good reproducibility through this route and due to the synergism of thin carbon film and graphene matrix, the dual coatings exert a significant impact on the electronic conductivity. This novel composite presents excellent electrochemical properties: with reversible capacity of 90mAhg~(-1) at 10C and 42mAhg~(-1) at 40C achieved.