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

作　　者：Zhongqiu Tong Hui Wang Tianxing Kang Yan Wu Zhiqiang Guan Fan Zhang Yongbing Tang Chun-Sing Lee 

机构地区：[1]Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China [2]Department of Chemistry,City University of Hong Kong,Hong Kong 999077,China [3]Center of Super-Diamond and Advanced Films(COSDAF),City University of Hong Kong,Hong Kong 999077,China [4]Key Laboratory of Material Physics of Ministry of Education,School of Physics and Microelectronics,Zhengzhou University,Zhengzhou 450052,Henan,China [5]Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,Guangdong,China

出　　处：《Journal of Energy Chemistry》2022年第12期441-447,I0012,共8页能源化学（英文版）

基　　金：supported by the NSFC/RGC Joint Research Scheme 2020/21(Project No:N_City U104/20)。

摘　　要：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(BAVCOF:X,coordinated anions of X=Cl^(-),Br^(-),I^(-),and ClO_(4)^(-))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-/Br_(2)redox couple,cationic redox of viologen segments,and enhanced Na+transport kinetics,the BAV-COF:Brdemonstrates 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.

关 键 词：Cationic and anionic redox chemistries Selective anion/cation transport Ionic COFs Organic cathode Na-ion battery 

分 类 号：TM912[电气工程—电力电子与电力传动]