Synthesis of lifePOgraphene nanocomposite and its electrochemical properties as cathode material for Li-Ion batteries

Abstract

LiFePOgraphene nanocomposite was successfully synthesized by rheological phase method and its electrochemical properties as the cathode materials for lithium ion batteries were measured. As the iron source in the synthesis, FeOOH nanorods anchored on graphene were first synthesized. The FeOOH nanorods precursors and the final LiFePOgraphene nanocomposite products were characterized by XRD, SEM, and TEM. While the FeOOH precursors were nanorods with 5-10 nm in diameter and 10-50 nm in length, the LiFePOwere nanoparticles with 20-100 nm in size. Compared with the electrochemical properties of LiFePOparticles without graphene nanosheets, it is clear that the graphene nanosheets can improve the performances of LiFePOas the cathode material for lithium ion batteries. The as-synthesized LiFePOgraphene nanocomposite showed high capacities and good cyclabilities. When measured at room temperature and at the rate of 0.1C (1C = 170 mA g-1), the composite showed a discharge capacity of 156 mA h g-1 in the first cycle and a capacity retention of 96% after 15 cycles. The improved performances of the composite are believed to be the result of the three-dimensional conducting network formed by the flexible and planar graphene nanosheets.