Modified carbothermal reduction method for synthesis of LiFePO4/C composite
(1. College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007, China
2. Henan Engineering Research Center of Motive Power and Key Materials, Xinxiang 453007, China;
3. College of Physics and Information Engineering, Henan Normal University, Xinxiang 453007, China)
2. Henan Engineering Research Center of Motive Power and Key Materials, Xinxiang 453007, China;
3. College of Physics and Information Engineering, Henan Normal University, Xinxiang 453007, China)
Abstract: With LiAc·2H2O as Li precursor, pure olivine phase LiFePO4/C was synthesized at a relatively low temperature (650 °C) and short sintering period (4 h) by molten salt carbothermal reduction method. Scanning electron micrograph shows that particle size of the product is about 1µm, smaller than that of the sample synthesized with Li2CO3 as Li precursor. Electrochemical measurements prove that LiFePO4/C obtained from LiAc·2H2O shows high capacity. The initial discharge capacities are 148 mA·h/g at 0.5C rate and 115 mA·h/g at 5C rate, respectively. After 50 cycles, the capacity retention ratios are 93% and 89% at 0.5C rate and 5C rate, respectively.
Key words: LiFePO4/C composite; molten salt; carbothermal reduction; β-cyclodextrin