Unblocking Oxygen Charge Compensation for Stabilized High‐Voltage Structure in P2‐Type Sodium‐Ion Cathode

Advanced Science

Zhenpeng Yao¹  Longlong Fan²  Hekang Zhu³  Qi Liu³  Yalan Huang³  Yang Ren³  Jian Zhang³  He Zhu³  Lin Gu⁴  Cheng Chao Li⁵  Hui Xia⁶  Si Lan⁶  Yanan Chen⁷  Kamila M. Wiaderek⁸  Hua Zhou⁸  Cheng‐Jun Sun⁸ 

[1] Center of Hydrogen Science Shanghai Jiao Tong University Shanghai 200240 P. R. China;College of Physics and Materials Science Tianjin Normal University Tianjin 300387 P. R. China;Department of Physics City University of Hong Kong Hong Kong 999077 P. R. China;Institute of Physics Chinese Academy of Sciences Beijing 100190 P. R. China;School of Chemical Engineering and Light Industry Guangdong University of Technology Guangzhou 510006 P. R. China;School of Material Science and Engineering Nanjing University of Science and Technology Nanjing 210094 P. R. China;School of Materials Science and Engineering Tianjin University Tianjin 300072 P. R. China;X‐Ray Science Division Argonne National Laboratory Argonne IL 60439 USA;

关键词: high‐voltage structural stability;    in situ synchrotron characterizations;    layered transition‐metal oxide cathodes;    oxygen charge compensation;    sodium‐ion battery;   

DOI  :  10.1002/advs.202200498

来源: DOAJ

【 摘 要 】

Abstract Layered transition‐metal (TM) oxides are ideal hosts for Li+ charge carriers largely due to the occurrence of oxygen charge compensation that stabilizes the layered structure at high voltage. Hence, enabling charge compensation in sodium layered oxides is a fascinating task for extending the cycle life of sodium‐ion batteries. Herein a Ti/Mg co‐doping strategy for a model P2‐Na2/3Ni1/3Mn2/3O2 cathode material is put forward to activate charge compensation through highly hybridized O2pTM3d covalent bonds. In this way, the interlayer OO electrostatic repulsion is weakened upon deeply charging, which strongly affects the systematic total energy that transforms the striking P2–O2 interlayer contraction into a moderate solid‐solution‐type evolution. Accordingly, the cycling stability of the codoped cathode material is improved superiorly over the pristine sample. This study starts a perspective way of optimizing the sodium layered cathodes by rational structural design coupling electrochemical reactions, which can be extended to widespread battery researches.

【 授权许可】

Unknown