ZrO2包覆对正极材料LiNi0.5Mn1.5O4电化学性能的改进

Coating ZrO2 enhancing the electrochemical properties of LiNi0.5Mn1.5O4 cathode material

采用ZrO2对正极材料LiNi0.5Mn1.5O4进行包覆以提高材料的电化学性能,通过X射线衍射(XRD)、扫描电子显微镜(SEM)等测试手段表征ZrO2包覆后材料的结构和形貌,通过电化学测试手段对包覆后的正极材料进行电化学性能分析,将测试结果与原相正极材料LiNi0.5Mn1.5O4进行对比得到:ZrO2包覆量为1.5%(质量分数)的样品表现出更高的放电比容量、更好的倍率性能以及更好的放电比容量保持率,在0.2 C放电倍率下材料的放电比容量首次表现可达129.5mAh/g,在0.5 C放电倍率下经过50次循环后材料的容量保持率仍然高达95.4%;电化学循环伏安测试结果显示不同ZrO2包覆量所制备的材料均具有4.7和4.0 V两个放电平台,材料属于Fd-3m空间群尖晶石结构。

ZrO2-coating is attempted to improve the performance of LiNi0.5Mn1.5O4 cathode material.XRD and SEM are used for studying the structure and the morphology of the materials.The electrochemical properties of coated cathode materials are analysed by electrochemical testing.Compared with the bare LiNi0.5Mn1.5O4,sample coated with1.5%ZrO2(mass percentage)exhibits a higher discharge specific capacity,better rate performance and rate capability.Its first discharge specific capacity at 0.2 C is 129.5 mAh/g,the capacity retention of which after 50 cycles at 0.5 C reaches 95.4%.The electrochemical cyclic voltammetry(ECV)test shows that the materials prepared with different ZrO2 coating amount have two discharge platforms of 4.7 V and 4.0 V,and the materials belonged to the spinel structure of Fd-3m space group.