Superior electrode performance of LiFePO4/C composite prepared by an in situ polymerization restriction method

The LiFePO4/C composite is prepared by heating the mixture of resorcinol-formaldehyde gel and FePO4, synthesized by an in situ polymerization restriction method, and lithium acetate dihydrate in the atmosphere of nitrogen. The physical and electrochemical properties of the LiFePO4/C composite are investigated by X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy and electrochemical measurements. The discharge capacity of LiFePO4 is as high as 155.6 mA h g(-1) in the first cycle at 0.5C, and it could remain 144.0 mA h g(-1) after 50 cycles. Even at the high rates of 10C, 20C and 50C, the initial discharge capacities of the electrodes exhibit 115.6 mA h g(-1), 84.5 mA h g(-1) and 67.8 mA h g(-1), and the electrodes deliver capacity retention of 89.5%, 90.9% and 85.7% after 1000 cycles, respectively. The outstanding electrochemical performance could be attributed to the small particle size and good electronic conductivity of the composite. (c) 2013 Elsevier B.V. All rights reserved.