Abstract:The bare LiFePO4 and LiFePO4/C composites with network structure were prepared by solid-state reaction. The crystalline structures, morphologies and specific surface areas of the materials were investigated by X-ray diffractometry(XRD), scanning electron microscopy(SEM) and multi-point brunauer emmett and teller(BET) method. The results show that the LiFePO4/C composite with the best network structure is obtained by adding 10% phenolic resin carbon. Its electronic conductivity increases to 2.86×10−2 S/cm. It possesses the highest specific surface area of 115.65 m2/g, which exhibits the highest discharge specific capacity of 164.33 mA∙h/g at C/10 rate and 149.12 mA∙h/g at 1 C rate. The discharge capacity is completely recovered when C/10 rate is applied again.

Key words: LiFePO4/C composite; lithium ion batteries; electrochemical properties; network structure