| , because of its high charge and discharge performance, stability, environmental protection, it widely apply as the cathode material of lithium-ion in electric vehicles and other high-power devices. Although the low electronic conductivity and low lithium-ion diffusion coefficient reduce its high rate charge and discharge performance, these shortcomings can be improved by reducing particle size and carbon coating in this study. In order to obtain excellent high rate charge and discharge performance, LiFePO4with different nanostructures like nanoparticles, one-dimensional and rod-like were synthesized by water/glycol solvothermal method. The influence of different proportions of water/glycol, solvothermal reaction temperature, and surface modifier on morphology and dispersion of LiFePO4were researched in this study. Further more, The influence of different carbon sources in coating modification on the electrochemical performance of LiFePO4was researched. It is found that ethylene glycol as solvent not only improve the dispersibility of LiFePO4, but also change the irregular agglomerate particles synthesized in hydrothermal to smaller particles. With the increase of the proportion of ethylene glycol, the size of LiFePO4particles were decreased. When pure ethylene glycol as the solvent, LiFePO4particles have a good monodispersity, and the particle size was approximately200nm. Using ascorbic acid, glucose, and graphene oxide as carbon sources, carbon were well coated on the surface of LiFePO4nanoparticles and then formed a core-shell structure of LiFePO4/C, only when using ascorbic acid as carbon sources, LiFePO4/C having a excellent high rate charge-discharge performance. When in a charge and discharge current density of30C, the discharge capacity was111.9mAh/g, and had a good charge-discharge cycle stability. |
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