Symmetry-breaking of LiMn_(6) hexatomic-ring in grain surface of Li_(2)MnO_(3)  

作　　者：Lihang Wang Shu Zhao Boya Wang Haijun Yu 

机构地区：[1]Institute of Advanced Battery Materials and Devices,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China [2]Key Laboratory of Advanced Functional Materials,Ministry of Education,Beijing University of Technology,Beijing 100124,China

出　　处：《Journal of Energy Chemistry》2023年第6期110-117,I0004,共9页能源化学（英文版）

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)。

摘　　要：LiMn_(6) hexatomic-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 LiMn_(6) hexatomic-ring is always broken,especially in the grain surface of LLOs,which will greatly affect its electrochemical performance.Herein,the symmetry-breaking of LiMn_(6) hexatomic-ring in the grain surface of Li_(2)MnO_(3) was 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 LiMn_(6) hexatomic-ring is higher than that of the unbroken LiMn_(6),and the former is more favorable for spinelization on the grain surface.Furthermore,the exposure proportion of crystallographic planes with different symmetry-broken LiMn_(6) hexatomic-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 LiMn_(6) hexatomic-ring will provide more targeted strategies for designing high-performance LLOs cathodes for lithium-ion batteries.

关 键 词：Li-rich layered oxides LiMn_(6)functional unit SYMMETRY-BREAKING Surface structure Density functional theory 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ131.11[化学工程—无机化工]