The influence of sintering temperature, carbon content and dispersive agent in bail-milling was investigated on the properties of LiFePO4/C prepared using Fe2O3, NH4H2PO4, Li2CO3 and glucose via solid state reaction. ...The influence of sintering temperature, carbon content and dispersive agent in bail-milling was investigated on the properties of LiFePO4/C prepared using Fe2O3, NH4H2PO4, Li2CO3 and glucose via solid state reaction. X-ray powder diffraction, scanning electron microscopy and charge-discharge test were applied to the characterization of the LiFePO4/C samples synthesized under different conditions. Sintering temperature affects the crystallite/ particle size and degree ofcrystallinity of LiFePO4, formation of Fe2P and maintenance of carbon in LiFePO4/C. Car- bon maintenance is favored by low sintering temperature, and 700 ℃ is optimum for synthesis of LiFePO4/C with superior electrochemical performance. A higher carbon content in the range of 4.48%-11.03% results in a better rate capability for LiFePO4/C. The dispersive agent used in ball-milling impacts the existent state of carbon in the final product which subsequently determines its charge-discharge behavior. The sample prepared at 700 ℃ by using acetone as the dispersive agent in ball-milling exhibits an excellent rate capability and capacity retention without any fade at 0.1 C, 1C and 2C, with corresponding average discharge capacities of 153.8, 128.3 and 121.0 mA·h·g-1. rest2ectivelv, in the first 50 cvcles.展开更多
基金Supported by the Natural Science Foundation of Yunnan Province(2010ZC051)the Analysis and Testing Foundation(20140439)the Starting Research Fund from Kunming University of Science and Technology(14118245)
文摘The influence of sintering temperature, carbon content and dispersive agent in bail-milling was investigated on the properties of LiFePO4/C prepared using Fe2O3, NH4H2PO4, Li2CO3 and glucose via solid state reaction. X-ray powder diffraction, scanning electron microscopy and charge-discharge test were applied to the characterization of the LiFePO4/C samples synthesized under different conditions. Sintering temperature affects the crystallite/ particle size and degree ofcrystallinity of LiFePO4, formation of Fe2P and maintenance of carbon in LiFePO4/C. Car- bon maintenance is favored by low sintering temperature, and 700 ℃ is optimum for synthesis of LiFePO4/C with superior electrochemical performance. A higher carbon content in the range of 4.48%-11.03% results in a better rate capability for LiFePO4/C. The dispersive agent used in ball-milling impacts the existent state of carbon in the final product which subsequently determines its charge-discharge behavior. The sample prepared at 700 ℃ by using acetone as the dispersive agent in ball-milling exhibits an excellent rate capability and capacity retention without any fade at 0.1 C, 1C and 2C, with corresponding average discharge capacities of 153.8, 128.3 and 121.0 mA·h·g-1. rest2ectivelv, in the first 50 cvcles.
