高镍三元正极材料的容量衰减是其应用最大的障碍，也是导致其它问题如安全性的诱因。本项目拟采用NCA和NCM881为研究对象，分析其电化学性能与结构演化之间的关系，并研究晶面控制和改性对电化学性能的影响机理以验证该结构演化规律；进一步制作18650和软包叠片电池对材料进行全电池性能表征及性能分析，特别是结合X射线吸收技术并通过具有元素以及轨道选择性、化学与电子结构敏感性以及表面敏感的光电子显微技术（X-PEEM）和透射X-光扫描显微技术（STXM）研究相分离在实际多孔复合电极中的行为，将其与正极活性物质的尺寸效应、晶面调控、SRL的形成与演化以及表面钝化膜的相关性对应，从而深入理解固态电极中的相分离本质，全面剖析高镍三元正极的性能衰减机理并期望能从根本上解决该类材料本征上的稳定性缺陷。本项目的实施对厘清高镍三元正极材料的多因素影响规律，促进高镍三元正极材料的性能改进和电池性能提升具有重要意义。

The capacity degradation of Ni-rich cathode is the most serious problem for its application and the reasons for other problems such as safety problem. This item will analyze the relationship between the electrocheical performance and structural evolution and further prepare the single crystal morphology and Ni-rich materials coated with oxide and solid electrolyte etc. by atomic deposition technology. The 18650 and pouch battery are manufactured by these materials and their electrochemical performance and structural character are measured to establish the structural evolution process inside the battery. The X-ray photoemission electron microscopy (X-PEEM) and scanning transmission X-ray microscopy (STXM) are used to analyze the characterization inside the porous electrode to reveal the complexity of the interplays of surface morphology, chemistry and local conductivity of materials and the formation and evolution of SRL. This will be better understood the phase separation inside the solid electrode and the capacity degradation mechanism of the Ni-rich cathode, thus supply a possibility to solve the unstability defects of this kind of electrode materials. This item will distinguish the effect of the factors on the electrochemical performance of the Ni-rich cathode and promote its performance improvement of the materials and battery.