Influence of synthesis parameters on the properties of LiF eP O4/C cathode material

The influence of sintering temperature,carbon content and dispersive agent in ball-milling was investigated on the properties of Li Fe PO4/C prepared using Fe2O3,NH4H2PO4,Li2CO3and glucose via solid state reaction.X-ray powder diffraction,scanning electron microscopy and charge–discharge test were applied to the characterization of the Li Fe PO4/C samples synthesized under different conditions.Sintering temperature affects the crystallite/particle size and degree of crystallinity of LiF eP O4,formation of Fe2P and maintenance of carbon in LiF e PO4/C.Carbon maintenance is favored by low sintering temperature,and 700 °C is optimum for synthesis of LiF eP O4/C with superior electrochemical performance.A higher carbon content in the range of 4.48%–11.03% results in a better rate capability for Li Fe PO4/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 at700 °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 153.8,128.3and 121.0 m A·h·g-1,respectively,in the first 50 cycles.