Synthesis of FePO_4·xH_2O for fabricating submicrometer structured LiFePO_C by a co-precipitation method

摘要

Amorphous hydrated iron (III) phosphate has been synthesized by a coordinate precipitation method from equimolecular Fe(NO_3)_3 and (NH_4)_2HPO_4 solutions at an elevated temperature. Hydrated iron (III) phosphate samples and the corresponding LiFePO_4/C products were characterized by XRD and SEM. The electrochemical behavior was studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The LiFePO_4/C fabricated from as-synthesized FePO_4 delivered discharge capacities of 162.5, 147.3,133.0, 114.7, 97.2,91.3 and 88.5 mAh g~(-1) at rates of 0.1C, 0.2C, 0.5C, 1C, 2C, 3C and AC with satisfactory capacity retention, respectively.