Abstract
The newly developed LiNi <sub>0.6</sub> Co <sub>0.4-x</sub> Mn <sub>x</sub> O <sub>2</sub> (0.1 < x < 0.3) cathode materials were synthesized by calcining the mixture of Ni <sub>x</sub> Co <sub>y</sub> Mni <sub>1-x-y</sub> (OH) <sub>2</sub> and Li <sub>2</sub> CO <sub>3</sub> at 900-940 °C for 15 hr in flowing O <sub>2</sub> atmosphere. The Ni <sub>x</sub> Co <sub>y</sub> Mni <sub>1-x-y</sub> (OH) <sub>2</sub> precursor was obtained by the chemical co-precipitation method at the pH value controlled by the concentration of NaOH, NH <sub>4</sub> OH and transition metal sulfate solution. The X-ray diffraction patterns indicated the pure layered hexagonal structure LiNi <sub>0.6</sub> Co <sub>0.4-x</sub> Mn <sub>x</sub> O <sub>2</sub> . The electrochemical behavior of LiNi <sub>x</sub> Co <sub>y</sub> Mn <sub>1-x-y</sub> O <sub>2</sub> powder was examined by using test cells cycled within the voltage range 3-4.3 V at the 0.1C rate for the first cycle and then at the 0.2C rate afterwards. LiNi <sub>x</sub> Co <sub>y</sub> Mn <sub>1-x-y</sub> O <sub>2</sub> cathode materials showed good initial discharge capacity (165-180 mAh/g) and cycling performance. The fading rate was less than 5 % after 20 cycling test. It is demonstrated that LiNi <sub>x</sub> Co <sub>y</sub> Mn <sub>1-x-y</sub> O <sub>2</sub> electrode should exhibit great potential for the future application in lithium-ion battery cathode material.