Synthesis of LiFePO_4/C cathode material by the sol and carbothermal reduction method and its performance

The lithium ion cathode material LiFePO4 is synthesized by sol and carbothermal reduction methods with cheap Fe(Ⅲ) salt as the Fe source.The structure,morphology and electrochemical performance of the samples are characterized by the XRD,SEM,AC impedance and galvanostatic charge-discharge methods.The results show that the cathode material is of olivine-type phase.Carbon coating can disperse particles of material and decrease the impedance of electrode reaction.The first discharge capacity of LiFePO4 at the 0.1 C rate is 103.3 mA·h/g.The first discharge capacity of LiFePO4/C at 0.1 C,0.2 C and 0.5 C rates is 147.9 mA·h/g,133.3 mA·h/g and 122.1 mA·h/g respectively.After 20 cycles,the capacity decrease rates are 3.0 %,2.7% and 2.4%.