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.

► LiFePO4/C composite was prepared by an in situ polymerization restriction method. ► The size of LiFePO4 in the composite is effectively restricted. ► The high-rate capability and cycling performance of LiFePO4 are enhanced greatly.