Zhao Enyue, Li Qinghao, Meng Fanqi, Liu Jue, Wang Junyang, He Lunhua, Jiang Zheng, Zhang Qinghua, Yu Xiqian, Gu Lin, Yang Wanli, Li Hong, Wang Fangwei, Huang Xuejie
Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
School of physical sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
Angew Chem Int Ed Engl. 2019 Mar 22;58(13):4323-4327. doi: 10.1002/anie.201900444. Epub 2019 Feb 19.
Lattice-oxygen redox (l-OR) has become an essential companion to the traditional transition-metal (TM) redox charge compensation to achieve high capacity in Li-rich cathode oxides. However, the understanding of l-OR chemistry remains elusive, and a critical question is the structural effect on the stability of l-OR reactions. Herein, the coupling between l-OR and structure dimensionality is studied. We reveal that the evolution of the oxygen-lattice structure upon l-OR in Li-rich TM oxides which have a three-dimensional (3D)-disordered cation framework is relatively stable, which is in direct contrast to the clearly distorted oxygen-lattice framework in Li-rich oxides which have a two-dimensional (2D)/3D-ordered cation structure. Our results highlight the role of structure dimensionality in stabilizing the oxygen lattice in reversible l-OR, which broadens the horizon for designing high-energy-density Li-rich cathode oxides with stable l-OR chemistry.
晶格氧氧化还原（l-OR）已成为传统过渡金属（TM）氧化还原电荷补偿的重要补充，以实现富锂正极氧化物的高容量。然而，对l-OR化学的理解仍然难以捉摸，一个关键问题是结构对l-OR反应稳定性的影响。在此，研究了l-OR与结构维度之间的耦合。我们发现，在具有三维（3D）无序阳离子框架的富锂TM氧化物中，l-OR作用下氧晶格结构的演变相对稳定，这与具有二维（2D）/3D有序阳离子结构的富锂氧化物中明显扭曲的氧晶格框架形成直接对比。我们的结果突出了结构维度在稳定可逆l-OR中氧晶格方面的作用，这为设计具有稳定l-OR化学性质的高能量密度富锂正极氧化物拓宽了视野。
