Effect of reactant phase form on the properties of LiFePO4 synthesized by carbothermal reduction method

Pure olivine LiFePO4/C composite compounds are synthesized by carbothermal reduction (CTR) method using trigonal anhydrous FePO4 raw material. The physical and electrochemical properties of the prepared samples are investigated in comparison with those of a sample obtained from incompletely crystallized hydrous FePO4·2H2O. The olivine LiFePO4/C prepared with trigonal anhydrous FePO4 has a high discharge capacity of 142 mAh g− 1 at 0.1 C. The composite also displays a better rate capability, a higher discharge capacity and a more stable cycle-life than that synthesized with incompletely crystallized hydrous FePO4·2H2O. The improved electrochemical performance of trigonal anhydrous FePO4 synthesis samples originates mainly from the single-phase structure and small particle size.