Inhibition of oxygen dimerization by local symmetry tuning in Li-rich layered oxides for improved stability

Fanghua Ning; Biao Li; Jin Song; Yuxuan Zuo; Huaifang Shang; Zimeng Zhao; Zhen Yu; Wangsheng Chu; Kun Zhang; Guang Feng; Xiayan Wang; Dingguo Xia

doi:10.1038/s41467-020-18423-7

Inhibition of oxygen dimerization by local symmetry tuning in Li-rich layered oxides for improved stability

Nat Commun. 2020 Oct 2;11(1):4973. doi: 10.1038/s41467-020-18423-7.

Authors

Fanghua Ning¹, Biao Li¹, Jin Song¹, Yuxuan Zuo¹, Huaifang Shang¹, Zimeng Zhao², Zhen Yu³, Wangsheng Chu⁴, Kun Zhang¹, Guang Feng¹, Xiayan Wang⁵, Dingguo Xia^{6

7}

Affiliations

¹ Beijing Key Laboratory of Theory and Technology for Advanced Batteries Materials, College of Engineering, Peking University, Beijing, 100871, People's Republic of China.
² Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing, 100124, People's Republic of China.
³ National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China.
⁴ National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China. chuws@ustc.edu.cn.
⁵ Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing, 100124, People's Republic of China. xiayanwang@bjut.edu.cn.
⁶ Beijing Key Laboratory of Theory and Technology for Advanced Batteries Materials, College of Engineering, Peking University, Beijing, 100871, People's Republic of China. dgxia@pku.edu.cn.
⁷ Beijing Innovation Center for Engineering Science and Advanced Technology, Peking University, Beijing, 100871, People's Republic of China. dgxia@pku.edu.cn.

Abstract

Li-rich layered oxide cathode materials show high capacities in lithium-ion batteries owing to the contribution of the oxygen redox reaction. However, structural accommodation of this reaction usually results in O-O dimerization, leading to oxygen release and poor electrochemical performance. In this study, we propose a new structural response mechanism inhibiting O-O dimerization for the oxygen redox reaction by tuning the local symmetry around the oxygen ions. Compared with regular Li₂RuO₃, the structural response of the as-prepared local-symmetry-tuned Li₂RuO₃ to the oxygen redox reaction involves the telescopic O-Ru-O configuration rather than O-O dimerization, which inhibits oxygen release, enabling significantly enhanced cycling stability and negligible voltage decay. This discovery of the new structural response mechanism for the oxygen redox reaction will provide a new scope for the strategy of enhancing the anionic redox stability, paving unexplored pathways toward further development of high capacity Li-rich layered oxides.