Achieving ultrahigh electrochemical performance by surface design and nanoconfined water manipulation

Haisheng Li; Kui Xu; Pohua Chen; Youyou Yuan; Yi Qiu; Ligang Wang; Liu Zhu; Xiaoge Wang; Guohong Cai; Liming Zheng; Chun Dai; Deng Zhou; Nian Zhang; Jixin Zhu; Jinglin Xie; Fuhui Liao; Hailin Peng; Yong Peng; Jing Ju; Zifeng Lin; Junliang Sun

doi:10.1093/nsr/nwac079

Achieving ultrahigh electrochemical performance by surface design and nanoconfined water manipulation

Natl Sci Rev. 2022 Apr 27;9(6):nwac079. doi: 10.1093/nsr/nwac079. eCollection 2022 Jun.

Authors

Haisheng Li¹, Kui Xu², Pohua Chen¹, Youyou Yuan¹, Yi Qiu¹, Ligang Wang¹, Liu Zhu³, Xiaoge Wang¹, Guohong Cai¹, Liming Zheng¹, Chun Dai¹, Deng Zhou⁴, Nian Zhang⁴, Jixin Zhu², Jinglin Xie¹, Fuhui Liao¹, Hailin Peng¹, Yong Peng⁵, Jing Ju¹, Zifeng Lin⁶, Junliang Sun¹

Affiliations

¹ College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.
² Key Laboratory of Flexible Electronics, and Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China.
³ Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou 730000, China.
⁴ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
⁵ School of Physical Science and Technology, Electron Microscopy Centre of Lanzhou University, and Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China.
⁶ College of Materials Science and Engineering, Sichuan University, Chengdu 610065, China.

Abstract

The effects of nanoconfined water and the charge storage mechanism are crucial to achieving the ultrahigh electrochemical performance of two-dimensional transition metal carbides (MXenes). We propose a facile method to manipulate nanoconfined water through surface chemistry modification. By introducing oxygen and nitrogen surface groups, more active sites were created for Ti₃C₂ MXene, and the interlayer spacing was significantly increased by accommodating three-layer nanoconfined water. Exceptionally high capacitance of 550 F g^-1 (2000 F cm^-3) was obtained with outstanding high-rate performance. The atomic scale elucidation of the layer-dependent properties of nanoconfined water and pseudocapacitive charge storage was deeply probed through a combination of 'computational and experimental microscopy'. We believe that an understanding of, and a manipulation strategy for, nanoconfined water will shed light on ways to improve the electrochemical performance of MXene and other two-dimensional materials.

Keywords: energy storage mechanism; nanoconfined water; supercapacitors; two-dimensional material, MXene.