中文摘要：

以价廉、低毒的无机盐为原料、去离子水为溶剂,通过简易可行的络合溶胶-凝胶法合成了LiFePO4/C复合正极材料。利用XRD、SEM、EIS及恒流充放电测试考察了聚乙烯吡咯烷酮（PVP）分子量对试样的形貌及电化学性能的影响。结果表明,以PVP-k30为表面活性剂所合成的试样颗粒均匀细小、形貌较规则且单分散性良好;该试样具有优良的电化学性能,0.1 C的放电比容量为155.7 mAh/g,3 C倍率下放电比容量依然能保持112.4 mAh/g,明显优于其它分子量PVP所制备的试样。

英文摘要：

LiFePO4/C composite cathode materials were synthesized via simple complexing sol-gel method,using cheap and low toxic inorganic salts as raw materials and deionized water as solvent. The effect of the molecular weight of polyvinylpylrrolidone（ PVP） on the morphologies and electrochemical performances of the samples were investigated by XRD,SEM,electrochemical impedance spectroscopy（ EIS） and galvanostatic charge/discharge tests. The results show that the sample prepared with PVP-k30 as surfactant possesses uniform and small particles which have rule morphology and good monodispersity,and the sample exhibits excellent electrochemical performances with a specific discharge capacity of 155.7 mAh /g at 0. 1 C and 112. 4 mAh /g at 3 C,which is much better than that of the samples prepared with PVP of other molecular mass.