Title： | Suppressing the Dynamic Oxygen Evolution of Sodium Layered Cathodes through Synergistic Surface Dielectric Polarization and Bulk Site-Selective Co-doping |
Authors： | Xiao Xia1, Tong Liu2, Chen Cheng1, Hongtai Li1, Tianran Yan1, Haolv Hu1, Yihao Shen1, Huanxin Ju3, Ting-Shan Chan4, Zhenwei Wu5, Yuefeng Su2,6, Yu Zhao7*, Duanyun Cao2,6*, and Liang Zhang1,8* |
Institutions： | 1Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China 2Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China 3PHI China Analytical Laboratory, Core Tech Integrated Limited, Nanjing 211111, China 4National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan 5Institute of Nonequilibrium Systems, School of Systems Science, Beijing Normal University, Beijing 100875, China 6Beijing Institute of Technology Chongqing Innovation Center, Chongqing 401120, China 7College of Material, Chemistry, and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, China 8Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, China |
Abstract： | Utilizing anionic redox activity within layered oxide cathode materials represents a transformational avenue for enabling high-energy-density rechargeable batteries. However, the anionic oxygen redox reaction is often accompanied with irreversible dynamic oxygen evolution, leading to unfavorable structural distortion and thus severe voltage decay and rapid capacity fading. Herein, it is proposed and validated that the dynamic oxygen evolution can be effectively suppressed through the synergistic surface CaTiO3 dielectric coating and bulk site-selective Ca/Ti co-doping for layered Na2/3Ni1/3Mn2/3O2. The surface dielectric coating layer not only suppresses the surface oxygen release but more importantly inhibits the bulk oxygen migration by creating a reverse electric field through dielectric polarization. Meanwhile, the site-selective doping of oxygen-affinity Ca into Na layers and Ti into transition metal layers effectively stabilizes the bulk oxygen through modulating the O 2p band center and the oxygen migration barrier. Such a strategy also leads to a reversible structural evolution with a low volume change because of the enhanced structural integrality and improved oxygen rigidity. Because of these synergistic advantages, the designed electrode exhibits greatly suppressed voltage decay and capacity fading upon long-term cycling. This study affords a promising strategy for regulating the dynamic oxygen evolution to achieve high-capacity layered cathode materials. |
IF： | 32.086 |
Link： | https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202209556 |
Editor: Guo Jia