Emulsion Drying Preparation of LiFePO4/C Composite and Its Enhanced High-rate Performance at 50 °C

Abstract

Abstract LiFePO4/C composite was successfully synthesized by an emulsion drying method. As confirmed by X-ray diffraction and scanning transmission electron microscopic observation, the prepared particle size of LiFePO4 was of about 300 nm and the powder was modified by conductive carbon. Consequentially, the existence of carbon increased the electronic conductivity of LiFePO4/C composite to ca. 10-4 S cm−1 at 25 °C. Because of smaller particle size and enhanced conductivity, the composite showed higher capacity about 140 mA h g−1 (20 mA g−1), excellent cyclability and superior rate capability at 50 °C, i.e., over 90 mA h (g-phosphate)−1 at a current density of 1000 mA g−1.