Phospho-olivine LiFePO4 cathode materials were prepared by hydrothermal reaction at 150°C. Carbon black was added to enhance the electrical conductivity of LiFePO4. LiFePO4-C powders (0, 3, 5 and 10wt.%) were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). LiFePO4-C/solid polymer electrolyte (SPE)/Li cells were characterized electrochemically by charge/discharge experiments at a constant current density of 0.1mAcm−2 in a range between 2.5 and 4.3V vs. Li/Li+, cyclic voltammetry (CV) and ac impedance spectroscopy. The results showed that initial discharge capacity of LiFePO4 was 104mAhg−1. The discharge capacity of LiFePO4-C/SPE/Li cell with 5wt.% carbon black was 128mAhg−1 at the first cycle and 127mAhg−1 after 30 cycles, respectively. It was demonstrated that cycling performance of LiFePO4-C/SPE/Li cells was better than that of LiFePO4/SPE/Li cells.