中文摘要：

用共沉淀法制备了固溶体正极材料Li[Li0．2Mn0．54Co0．13Ni0．13]O2，并用偏铝酸锂（α-LiAlO2）进行包覆改性。XRD和场发射扫描电子显微镜（FEsEM）测试表明：包覆前后的材料均属于α-NaFeO2六方层状结构，R3m空间群；包覆后的样品颗粒表面形成了一层不均匀絮状包覆物α-LiAlO2。包覆量为3％的样品性能较好：以低电流（0．05c）在2．0～4．8v循环，首次放电比容量达273．0mAh／g；当电流提高到1．00C时，放电比容量为173．2mAh／g。倍率性能的提高，得益于包覆样品具有的较低的界面电阻与反应电阻，电化学阻抗谱（EIS）测试结果证明了这一点。

英文摘要：

Co-precipitation method was used to synthesize the solid solution cathode material Li [ Li0.2Mn0. 54Co0.13Ni0. 13 ] O2 and the performance of this material coated with lithium aluminate （α-LiAlO2） was studied. XRD and field-emission scanning electron microscopy （FESEM） test showed that beth the materials before and after coating belonged to α-NaFeO2 hexagonal layered struc- ture with R3m space group, the thick inhomogeneous floceus layers were coated on the surface of particle. The better performance was achieved by sample with coating amount of 3 % ： when cycled in 2.0 - 4.8 V at a low current （0.05 C）, the specific discharge capacity was 273.0 mAh/g, when the current increased to 1.00 C, the specific discharge capacity reached to 173.2 mAh/g. The rate capability was benefitted from the lower surface impedance and reaction impedance as indicated by the electrochemical impedance spectroscopy（EIS） test result.