中文摘要：

通过低温溶剂热法和高温热处理技术合成了橄榄石结构的LiFePOdcarbon（C-LiFePO4）纳米材料．在此基础上，通过溶液共混法制备了一种新型的聚三苯胺（PTPAn）修饰包覆的C—LiFePO4复合锂离子电池正极材料（C—LiFeP04，PTPAn）．利用X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）、电化学阻抗谱（EIS）以及恒电流充放电等测试方法，考察PTPAn包覆量对C-LiFePO4／PTPAn复合正极材料性能的影响．结果表明：通过溶液共混法PTPAn能够致密地包覆在C-LiFePO4表面，形成一个有效的电子，离子传输通道从而有效提高C-LiFePO4基复合材料的电化学活性．所有样品中C-LiFePc）4／10％（州PTPAn作为正极材料呈现出最佳的电化学性能，在O．1C倍率恒流充放电下材料首次放电比容量为154．5mAh·g^-1，在10C高倍率恒流充放电下材料的放电比容量达到114．2mAh·g^-1．当C-LiFePO4，PTPAn复合材料表面包覆的PTPAn含量进一步增加，复合材料的电化学性能出现下降的趋势．电化学阻抗测试表明PTPAn包覆层明显减小了C—LiFePO4电极的电荷转移电阻．

英文摘要：

An olivine LiFePOJcarbon （C-LiFePO,） nanocrystalline material was prepared using a low-temperature solvothermal method, followed by a high-temperature post-annealing process. Then polytriphenylamine （PTPAn）- modified C-LiFePO4 （C-LiFePOJPTPAn） was prepared, as a composite for novel cathodes for lithium-ion batteries, by solution blending of the C.-LiFePO4 nanocrystalline material and the electroactive conducting polymer PTPAn. The effects of PTPAn coating of the C,-LiFePOJPTPAn samples were investigated using X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, electrochemical impedance spectroscopy （EIS）, and galvanostatic charge-discharge testing. The results indicated that the solution blending method produced a compact PTPAn coating on the C-LiFePO,, providing an effective electronic/ionic conducting pathway and enhancing the electrochemical activities of C-LiFePO4-based composites. The C-LiFePOJ10% （w） PTPAn electrode displayed an improved initial discharge capacity of 154.5 mAh. g-I at 0.1C, a superior high-rate performance discharge capacity of 114.2 mAh.g^-1 at 10C, and excellent cycling stability. With further increases in the PTPAn content of the coating on the C-LiFePO4/PTPAn composite, the electrochemical properties of the composite decreased. Electrochemical impedance measurements also demonstrated that the PTPAn coating significantly decreased the charge-transfer resistance of the C-LiFePO4 electrode.