Fabrication and Rate Performance of Spherical LiFePO4 Nanoparticles for High–power Lithium Ion Battery
The spherical LiFePO4/C nanoparticles are synthesized by modified carbothermal reduction method. XRD patterns show that the LiFePO4 compound is orthorhombic crystal structure. SEM and TEM results indicate that the LiFePO4 composite had a spherical morphology with carbon coated and the particle size is nanoscale. Charge/discharge tests and CV curves show that as-prepared sample exhibits discharge capacity of 153 mAh g-1at 0.2 C rate with high electrode reaction reversibility. The discharge capacities of the material are 150, 132, 119, 111, 103 and 96 mAh g-1 at 1 C, 5 C, 10 C, 15 C, 20 C and 25 C rate and high voltage plateaus are achieved. The good rate performance of the composite is due to its nano particle size and spherical morphology, which reduced the diffusion path of lithium ions and electrons, increased the conductive specific surface and improved the processability of the LiFePO4 cathode.
lithium-ion batteries, cathode materials, LiFePO4, rate performance
This work was supported by Doctoral Fund of Shandong Province (BS2009NJ001), the Project of Higher Educational Science and Technology Program of Shandong Province (J10LB56) and the Research Fund of Binzhou University (2008ZDL04).
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