Influences of Lithium Content on Structure,Morphology and Electrochemical Behavior of Li_(1+x)[Ni_(0.5)Co_(0.2)Mn_(0.3)]_(1-x)O_2(x=0.091,0.115,0.138)

The spherical lithium-rich transition metal oxides were prepared by co-precipitation method.The samples of Li1-x[Ni0.5Co0.2Mn0.3]1-xO2(x =0.091,0.115,0.138)were characterized by XRD and SEM,and the influences of lithium content on structure and the morphology of lithium-rich transition metal oxides were studied.The results demonstrated that the structure of Li1-x[Ni0.5Co0.2Mn0.3]1-xO2(x= 0.091,0.115,0.138)was not altered with Li content.However,the size of primary particle increased with the increase of Li content.It has been found that the material has better electrochemical behavior when xis equal to 0.115,and the discharge capacity is as high as 230mAhg-1 when the material is activated at 0.1Cin the voltage range of 2.0～4.8V.The capacity retention of the material after 50cycles is 84% at 0.2Cin the voltage range of 2.0～4.6V.The discharge capacities of the material at 0.2C,1C,2Care 209.3mAhg-1,156.1mAhg-1,113.0mAhg-1,respectively.