▎ 摘　　要

Lithium iron phosphate LiFePO4 (LFP) nanoplatelets with crystals growth along the desired orientations were successfully coated onto the three-dimensional (3D) spherical graphene, through the electrostatic attraction, which can form the structure of 3D spherical graphene and the coating of nano-LFP particles at the same time. Various characterization techniques, including SEM, TEM, EDX, XRD, BET, galvanostatic charge-discharge, CV and EIS were applied to investigate the morphological structure, phase composition, carbon content, pore structure and electrochemical performance of the synthesized samples. Under optimized synthetic conditions the LFP nanoplatelets were tightly surrounded by 3D spherical graphene, which promises a good electronic contact between LFP and the 3D spherical graphene and effectively suppress the aggregation of the LFP crystals. Combined with the investigation results it can be concluded that the increase of introduced negatively charged graphene sheets and positively charged polystyrene spheres are responsible for both the improvement of conductivity and the formation of spherical porous structure of resultant samples. The good rate capability as well as the cycling stability of fabricated cathode material were ascribed to the well-crystallized nature and the desired crystal orientation of LFP as well as the bifunctional pathways for both Li+ and electron constructed by the 3D porous spherical graphene.