▎ 摘　　要

Plain and cerium-doped LiNi0.5Co0.2Mn0.3O2 cathode materials were prepared via a combustion method, then graphene was coated onto the materials by a physical method. The results of x-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy confirmed the presence of a graphene coating layer on the LiNi0.497Ce0.003Co0.2Mn0.3O2 samples, the stratified structure and surface appearance of which were identical to those of LiNi0.5Co0.2Mn0.3O2. The 3 wt% graphene-coated LiNi0.497Ce0.003Co0.2Mn0.3O2 samples showed enhanced electrochemical performance with retention of 77.47% capacity over 50 cycles, compared with 72.02% for uncoated samples. Moreover, 3 wt% graphene-coated LiNi0.497Ce0.003Co0.2Mn0.3O2 sustained superior discharge-specific capacity and better stability at high current densities such as 2C. Cation disordering was decreased by inhibition of the side effects inherent in charge-discharge processes, which gave rise to more stable structures. These enhancements in the electrochemical performance of LiNi0.5Co0.2Mn0.3O2 can be attributed to cerium doping and graphene coating.