采用高温固相合成法制备了碳包覆磷酸铁锂正极材料,使用不同有机碳源对LiFePO4进行碳包覆.通过热分析(TGDSC)、X-射线衍射光谱法(XRD)、热场发射透射电子显微镜(HRTEM)、显微激光拉曼光谱等分析方法对其相组成、化学结构和碳结构等进行分析,并对LiFePO4/C为正极材料的电池进行了测试.结果表明:酚醛树脂、蔗糖、聚乙二醇和柠檬酸为有机碳源所制备的LiFePO4材料,都为纯相的LiFePO4；碳包覆LiFePO4材料,具有较完整的碳包覆层,且都有石墨结构的有序碳生成,能改善材料的电导率；酚醛树脂为有机碳源得到的LiFePO4/C材料性能最好,在0.1C倍率下充放电,首次放电比容量达到148.6 mAh/g,1C倍率下充放电的比容量达到125.1 mAh/g.%LiFePO4/C cathode material was prepared by high temperature solid phase method, with different organic carbon sources as carbon coating. The phase composition, chemical structure and carbon structure of the LiFeP04/C were studied by the methods of TG-DSC, XRD, TEM and Raman. The battery with LiFePO4/C as cathode material was tested. It is shown that the LiFeP04/C synthesized with phenolic resin, sucrose, polyethylene glycol and citric acid as organic carbon sources were all single-phase materials. The carbon-coated LiFePO4 has a complete carbon coating where is generated ordered carbon with graphite structure, which can improve the conductivity of LiFePO4/C. The LiFePO4/C prepared with the organic carbon source of phenolic resin has the best electrical conductivity. The first discharge specific capacities of the samples were 148. 6 mAh/g at 0. 1C and 125. 1 mAh/g at 1C, respectively.
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