Synthesis of lithium iron phospho-olivines by aqueous precipitation and carbothermal reduction

LiFePO_4 was prepared by carbothermal reduction of FePO_4 which was synthesized by aqueous precipitation from FeSO_4·7H_2O and NH_4H_2PO_4 and hydrogen peroxide as the oxidizing agents.Samples were characterized by XRD and SEM.It is shown that the pure and homogenous LiFePO_4 was successfully synthesized at 560,600,700 and 800℃,with average particle sizes about 0.30.4μm for the material synthesized at 560℃ and 0.60.7μm at 800℃.The residual carbon during processing was coated on LiFePO_4,resulting in the enhancement of the material's electronic properties.The discharge capacity of the material synthesized at 560℃ is 151mA·h/g at 0.1C rate and 129mA·h/g at 1C rate.