Symmetry-breaking of LiMn6 hexatomic-ring in grain surface of Li2MnO3
作者机构：Institute of Advanced Battery Materials and Devices Faculty of Materials and Manufacturing Beijing University of Technology Key Laboratory of Advanced Functional Materials Ministry of Education Beijing University of Technology
出 版 物：《Journal of Energy Chemistry》 (能源化学(英文版))
年 卷 期：2023年第81卷第6期
页 面：110-117页
核心收录：
学科分类：081702[工学-化学工艺] 0808[工学-电气工程] 08[工学] 0817[工学-化学工程与技术] 0702[理学-物理学]
基 金：financially supported by the National Key R&D Program of China (2022YFB2404400) the National Natural Science Foundation of China (92263206, and 22002004) “The Youth Beijing Scholars program” (PXM2021＿014204＿000023)
主 题：Li-rich layered oxides LiMn6 functional unit Symmetry-breaking Surface structure Density functional theory
摘 要：LiMn6hexatomic-rings act as functional units in Li-rich layered oxides(LLOs), which determine the capacity, voltage, and structural stability of LLOs. However, the symmetry of the LiMn6hexatomic-ring is always broken, especially in the grain surface of LLOs, which will greatly affect its electrochemical performance. Herein, the symmetry-breaking of LiMn6hexatomic-ring in the grain surface of Li2MnO3was studied, and their effect on charge compensation mechanism and structure evolution behavior was thoroughly investigated. The results show that the electrochemical activity of the symmetry-broken LiMn6hexatomic-ring is higher than that of the unbroken LiMn6, and the former is more favorable for spinelization on the grain surface. Furthermore, the exposure proportion of crystallographic planes with different symmetry-broken LiMn6hexatomic-ring has also been discussed, which can be adjusted by changing the partial pressure of oxygen. The in-depth understanding of the symmetry-breaking of LiMn6hexatomic-ring will provide more targeted strategies for designing high-performance LLOs cathodes for lithium-ion batteries.
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