论文部分内容阅读
采用溶胶凝胶水解法在LiNi0.4Co0.2Mn0.4O2(NCM)表面包覆了0.5 wt%Al2O3.透射电镜(TEM)表明在NCM表面形成了均匀的Al2O3包覆层;分别采用恒电位极化及热重分析(TG)研究了包覆前后NCM的析氧特性;采用X射线吸收近边结构谱(XANES)研究了包覆前后O的电子结构.结果表明,包覆后的NCM析氧量更少;Al2O3包覆使得NCM表面层中与金属3d轨道杂化的O比例减少,而更稳定的、与金属4sp轨道杂化的O比例增加.这些因素导致Al2O3包覆后的NCM更加稳定、安全性更高.
The surface of LiNi0.4Co0.2Mn0.4O2 (NCM) was coated with 0.5 wt% Al2O3 by sol-gel hydrolysis method. Transmission electron microscopy (TEM) showed that uniform Al2O3 coating was formed on the surface of NCM. And thermogravimetric analysis (TG) were used to study the oxygen evolution characteristics of NCM before and after coating. The electronic structure of O before and after coating was studied by X-ray absorption near edge structure spectroscopy (XANES) Less, the proportion of O in the NCM surface layer with the metal 3d orbital hybridization decreases, while the more stable ratio of O to the metal 4sp orbit hybrid increases.These factors lead to the more stable NCMO after the Al2O3 coating, More secure.