Ionic covalent organic frameworks with tailored anionic redox chemistry and selective ion transport for high-performance Na-ion cathodes

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Zhongqiu Tong
  • Hui Wang
  • Zhiqiang Guan
  • Fan Zhang
  • Yongbing Tang

Detail(s)

Original languageEnglish
Pages (from-to)441-447
Journal / PublicationJournal of Energy Chemistry
Volume75
Online published3 Jun 2022
Publication statusOnline published - 3 Jun 2022

Abstract

Employing cathode materials with multiple redox couples and electrolytes with efficient cation transport kinetics are two effective approaches to improving the electrochemical performance of batteries. In this work, for the first time, we present a design strategy of simultaneously realizing reversible cationic and anionic redox chemistries as well as selective anion/cation transport in the viologen-based COFs (BAV-COF:X, coordinated anions of X = Cl-, Br-, I-, and ClO4-) for high-performance Na-ion cathodes. Besides the cationic redox of viologen segments, the different redox activities of anions effectively tune the total capacities of the COFs. Meanwhile, electrochemical analysis and ab-initial molecular dynamics (AIMD) calculation illustrate that the anion/cation transport kinetics of electrolytes caged in the COFs’ channels can be selectively tuned by the coordinated anions. As a result, combining high-potential Br-/Br2 redox couple, cationic redox of viologen segments, and enhanced Na+ transport kinetics, the BAVCOF:Br- demonstrates stable performance with energy densities of 358.7 and 145.2 Wh kg-1 at power densities of 116.5 and 2124.1 W kg-1, respectively. This study offers new insight into the fabrication of organic cathodes with anionic redox and the advantages of COFs electrode materials in anion/cation transport selectivity for energy storage applications.

Research Area(s)

  • Cationic and anionic redox chemistries, Selective anion/cation transport, Ionic COFs, Organic cathode, Na-ion battery

Citation Format(s)

Ionic covalent organic frameworks with tailored anionic redox chemistry and selective ion transport for high-performance Na-ion cathodes. / Tong, Zhongqiu; Wang, Hui; Kang, Tianxing; Wu, Yan; Guan, Zhiqiang; Zhang, Fan; Tang, Yongbing; Lee, Chun-Sing.

In: Journal of Energy Chemistry, Vol. 75, 12.2022, p. 441-447.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review