Structural and Electrochemical Characterization of LiFePO4 Synthesized by Hydrothermal Method

Phospho-olivine cathode materials were prepared by hydrothermal reaction. Carbon black was added to enhance the electrical conductivity of LiFePO4 . The structural and morphological performance of and LiFePO4-C powders were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). LiFePO4/Li and LiFePO4-C/Li cells were characterized electrochemically by cyclic voltammogram (CV), charge/discharge experiments and ac impedance spectroscopy. The results showed that the discharge capacity of LiFePO4/Li cell was 147 mAh/g at the first cycle and 118 mAh/g after 30 cycles, respectively. The discharge capacity of LiFePO4-C/Li cell with 5 wt% carbon black was the largest among LiFePO4-C/Li cells, 133 mAh/g at the first cycle and 128 mAh/g after 30 cycles, respectively. It was demonstrated that cycling performance of LiFePO4-C/Li cell with 5 wt% carbon black was better than that of LiFePO4/Li cell.