Synthesis of LiFePO₄/C composite as a cathode material for lithium-ion battery by a novel two-step method

Abstract

In this study, LiFePO4/C is synthesized via a novel two-step method. The first step is the synthesis of nano-sized intermediate FePO4 by a modified sol–gel method. A fast and full combustion procedure is involved to remove carbon and control the size of the intermediate particles. The second step is to prepare LiFePO4/C by combining solid-state reaction with controllable carbon coating. This two-step method is facile to prepare nano-sized LiFePO4 and easy to optimize the carbon content for surface coating. X-ray diffraction shows that the LiFePO4/C composite possesses good crystallinity. Spherical morphology with a diameter of 30–150 nm is observed by scanning electron microscope and transmission electron microscope. Electrochemical measurements indicate that the LiFePO4/C composite exhibits discharge capacities of 162, 144, 126, and 106 mAh g−1 at 0.1, 1, 2, and 5C, respectively. No capacity fading is observed in 50 cycles.