An investigation on the performance of LiFePO4/C derived from various FePO4

LiFePO4/C composites were synthesized by carbothermal reduction method using commercial FePO4 and Tween#80-assisted synthesized nano-FePO4 as starting materials, glucose as reducing agent, and also carbon source. The FePO4 intermediates were characterized by X-ray diffraction and scanning electron microscopy. A suitable mole ratio of Li to Fe was investigated, and the performances of samples synthesized under different temperatures were studied. It seems that the residual carbon content, which determine the electrochemical polarization of the cathode composites, greatly depend on the synthesis temperature when carbothermal reduction method was used. The electrochemical measurements showed that the discharge capacity first increase and then decrease with the rise of temperature. The optimal sample synthesized at 600 A degrees C for 10 h using homemade FePO4 as iron source exhibit 142 mAh g(-1) at 0.2 C and a capacity retention rate of 98.8 % after 50 cycles.