Electrochemical performance comparison of LiFePO4 supported by various carbon materials

In the present work, various LiFePO4/carbon composites were prepared through a facile solvothermal route followed by heat treatment. These as-prepared LiFePO4/carbon composites, including LiFePO4/acetylene black (95:5 wt.%), LiFePO4/carbon nanotube (95:5 wt.%) and LiFePO4/graphene (95:5 wt.%), were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Their electrochemical performances were also investigated and compared in detail. The achieved results indicate that both particle-size and electrochemical performance of LiFePO4 much depend on the carbon supporter. When acetylene black and carbon nanotube were used as carbon supporter, the prepared LiFePO4 particles were agglomerate together to form large-size second particles which cannot well connect with carbon supporter. In the LiFePO4/graphene composite, ∼50 nm LiFePO4 particles uniformly loaded on the two-dimensional carbon supporter, and thus display much better rate ability. This result suggests that graphene should be a promising carbon supporter for LiFePO4.