Lithium-rich or Ni-rich layered oxides cathode materials have attracted great attentions owing to their high specific capacity for lithium-ion batteries. But the poor rate capability and voltage fade of lithium-rich layered oxides cathode materials have limited their practical applications. The degree of Li/Ni mixing not only affects the rate capability but also the structure stability and the cycling stability. In this experiment we propose to examine in detail the crystal structures of Ni-rich LiMn0.8Ni0.1Co0.1O2 and Li-rich Li1.2Mn0.6Ni0.2O2, in order to determine the degree of Li/Ni mixing of the materials, determine the occupations of the different sites by transition metal elements (Fe, Ni, Co, Mn, Zr) of similar mass weight, and give new insights about the structure-performance relationship and instruct the structure design and optimization for high performance electrode materials