(湘潭大学 化学学院 环境友好化学与应用教育部重点实验室，湘潭 411105)
摘 要: 采用高温固相法合成Ni2+、Mn2+共掺杂的LiFe0.95Ni0.02Mn0.03PO4/C正极材料。通过X射线衍射(XRD)、扫描电镜(SEM)、电化学阻抗谱(EIS)和电化学测试技术等研究材料的结构、形貌和电化学性能。结果表明：Ni2+和Mn2+共掺杂后的LiFe0.95Ni0.02Mn0.03PO4/C材料仍然具有LiFePO4/C橄榄石型晶体结构，且掺杂后材料的放电比容量和循环性能都得到显著改善。在0.1C和1C下放电时，未掺杂LiFePO4/C的首次放电比容量仅分别为153和140 mA∙h/g，而Ni2+、Mn2+共掺杂的LiFe0.95Ni0.02Mn0.03PO4/C材料首次放电比容量分别为165和145 mA∙h/g，且在1C下循环100次后容量保持率仍然为97.6%。
关键字: 锂离子电池；正极材料；金属离子共掺杂；电化学性性能
（School of Chemistry, Key Laboratory of Environmentally Friendly Chemistry and Applications,
Ministry of Education, Xiangtan University, Xiangtan 411105, China）
Abstract:LiFe0.95Ni0.02Mn0.03PO4/C cathode material co-doped by Ni2+ and Mn2+ ions, was prepared by high temperature solid phase method. The structure, morphology and electrochemical properties of the as-prepared material were characterized by XRD, SEM, EIS and charge-discharge methods. The results show that the as-prepared LiFe0.95Ni0.02Mn0.03PO4/C keeps the olivine structure of LiFePO4/C, and the discharge specific capacity and cyclic stability are obviously enhanced. The initial discharge capacities of LiFePO4/C without doping are only 153 and 140 mA∙h/g at 0.1C and 1C, respectively. While the initial discharge capacities of LiFe0.95Ni0.02Mn0.03PO4/C co-doped with Ni2+ and Mn2+ are 160 and 145 mA∙h/g at 0.1C and 1C, respectively. Besides, the capacity retention still has 97.6% after 100 cycles.
Key words: lithium-ion battery; cathode material; metal ions co-doping; electrochemical properties
