Preparation And Characterization Of Lithium Battery Cathode Materials LiNi_0.5Mn_1.5O₄ And LiNi_0.5Mn_0.5O₂

With the arrival of the 3G era, people's requirements are higher for a new generation of battery. This makes the battery industry has been greatly developed, and the lithium ion battery as one of the representatives is the focus of people's research.The cathode material is always the focus of the research in the lithium ion battery. After understanding the principle of lithium ion battery operation, we have carried out a detailed study on the LiNi_0.5Mn_1.5O₄ cathode material for Li ion battery. In this thesis, co- precipitation method and sol-gel method were used to prepare cathode material LiNi_0.5Mn_1.5O₄, and used the battery testing system for test the electrochemical properties, the structure and morphology of the samples were characterized by SEM and XRD. The test results show that the LiNi_0.5Mn_1.5O₄ possessed high voltage discharge platform with 4.7V, and discharge capacity retention rate is as high as 84.7% after 25 times of circulation in 0.1C ratio.Finally, study the modification of LiNi_0.5Mn_1.5O₄ with doping of F and coating of TiO₂.The research of F doped shows that: the rate of the lithium ion battery is obviously improved, this is because the intercalation of lithium ions becomes easier after doped of F, reduce the resistance of lithium ion intercalation, the electrochemical activity is enhanced of LiNi_0.5Mn_1.5O₄ cathode material. The research of TiO₂ coated shows that: the cycle performance of the battery increased significantly, because educe to the dissolution of HF on manganese in LiNi_0.5Mn_1.5O₄ with the existence of TiO₂, improve the performance of the battery.