화학공학소재연구정보센터
Chinese Journal of Chemical Engineering, Vol.24, No.3, 427-432, 2016
Influence of synthesis parameters on the properties of LiFePO4/C cathode material
The influence of sintering temperature, carbon content and dispersive agent in ball-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 of crystallinity of LiFePO4, formation of Fe2P and maintenance of carbon in LiFePO4/C. Carbon maintenance is favored by low sintering temperature, and 700 degrees C 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 degrees C by using acetone as the dispersive agent in ball-milling exhibits an excellent rate capability and capacity retention without any fade at 0.1C, 1C and 2C, with corresponding average discharge capacities of 153.8, 128.3 and 121.0 mA . h . g(-1), respectively, in the first 50 cycles. (c) 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.