The goal of this research was to study the effect of organic precursors with functionalized aromatic anhydrides or aromatic diketones on the performance of the LiFePO4/C composite. A coprecipitation method was applied to prepare a series of LiFePO4/C materials by calcinating amorphous LiFePO4 with 5 wt % organic precursors at 750 degrees C. The materials were characterized by X-ray diffraction, scanning electron microscopy, particle size analysis, thermal analysis, Brunauer-Emmett-Teller specific surface area and electrochemical methods. The obtained LiFePO4/C composites showed a well-ordered olivine-type LiFePO4 structure with a minor Fe2P impurity. The occurrence of the Fe2P phase can be attributed to the relatively high temperature of 750 degrees C. The LiFePO4/C composites produced by pyrolysis of an aromatic diketone with a longer alkoxy branch exhibited a better capacity compared to other types of organic compounds. The longer alkoxy aromatic diketone showed a better performance because its decomposition temperature was close to the temperature of the LiFePO4 phase transformation resulting in a fine particle size and uniform carbon distribution on the composite surface. The performance of different organic precursors showed a strong relationship with its decomposition temperature, but was not in correlation with its weight loss. According to Raman spectral analysis, longer alkoxy aromatic diketones have a larger (D+G)/PO4 peak ratio indicating higher uniform and carbon content coating on LiFePO4/C particles. (c) 2007 The Electrochemical Society.