A versatile method for preparing FePO4 and study on its electrode performance in lithium ion batteries

Iron phosphate(III) was prepared by thermal decomposition of organophosphonates Fe(III)OPO(OC6H4COO)2·0.5H2O and FePO4·1.5H2O in air atmosphere. The resulting materials were characterized by chemical analysis, TG/DTA, XRD, SEM and electrochemical characterization. The effect of preparing methods, sintering time and temperature on their crystalline structure, particle morphology and electrochemistry properties was investigated. The materials obtained from Fe(III) carboxy-phenyl phosphate annealed at 380 °C for 9 h showed the highest discharge capacity of about 146 mAh/g for the first cycle at the rate of 0.05 mA/cm2. Compared with homogeneous precipitation method, the coordinate precipitation method favors the synthesis of suitable cathode materials with low crystal structure, relatively small grain size and minor remains carbons that is beneficial for improving the electrochemical performance.