▎ 摘　　要

LiFePO4 was prepared by spray drying technique, and then graphene coated LiFePO4 nanocomposites were synthesized by microwave hydrothermal method at low temperature. The morphology, structural properties and particle size distribution of the samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and dynamic laser scattering (DLS). For the samples as cathode materials for Li-ion batteries, the electrochemical performance and dynamic characteristics of electrode process were investigated by constant-current charge-discharge techniques, cyclic voltammetric (CV) and electrochemical impedance spectra (EIS). Compared with LiFePO4 electrode, graphene coated LiFePO4 exhibits superior rate capability (125.4 mAh.g(-1) at 5 C) and endurable cycle life (about 95% capacitance retained after 100 cycles at 1 C). The optimum performances of graphene coated LiFePO4 are attributed to its typical nanocomposite structure, which not only remarkably enhances the electrochemical reversibility but also obviously reduces the charge transfer resistance. The results of this study may pave an effective strategy to improve the electrochemical performance of LiFePO4 electrode for batteries.