基于碳纳米管/氧化还原活性带电共聚物间的络合提高电化学电容器  

Concurrently Increasing Specific Energy and Suppressing Self-Discharge of Electrochemical Capacitors by Complexing Carbon Nanotubes with Redox Active Units-Containing Charged Copolymers

作　　者：莫光帅 葛康康 刘光明[1] Guang-shuai Mo;Kang-kang Ge;Guang-ming Liu(Hefei National Laboratory for Physical Sciences at the Microscale,Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes,Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学化学物理系,合肥微尺度物质科学国家研究中心,安徽省教育厅表界面化学与能源催化重点实验室,合肥230026

出　　处：《Chinese Journal of Chemical Physics》2023年第1期103-112,I0043-I0055,I0002,I0003,共25页化学物理学报（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(No.21873091,No.21622405,No.21574121,and No.52033001);the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.Y201769);the National Synchrotron Radiation Laboratory(No.UN2018LHJJ);the Fundamental Research Funds for the Central Universities(No.WK2480000007).

摘　　要：比能量和自放电是电化学电容器的两个重要性能.本文以2,2,6,6-四甲基哌啶-N-氧自由基和紫精作为氧化还原活性单元分别与阳离子单体共聚制备无规共聚物,并通过与羧基化多壁碳纳米管络合制备复合电极,实现两电极装置比能量的提高和自放电的抑制.由于析氢析氧速率慢于氧化还原活性单元的反应速率,从而提高了电解质的分解窗口,增加了两电极装置的比能量.另一方面,碳纳米管与共聚物间的络合抑制了氧化还原活性聚合物链的穿梭和交叉扩散,提升了两电极装置的自放电性能.基于碳纳米管/氧化还原活性带电共聚物间的络合,本工作为提高电化学电容器的比能量并抑制其自放电提供了一种简易通行的策略.Specific energy and self-discharge are two important performances of electrochemical capacitors.In this work,we have fabricated the composite electrodes by complexing the negatively charged carboxylated multi-walled carbon nanotubes(cMWCNT)with the redox active units-containing positively charged random copolymers.2,2,6,6-Tetramethylpiperidinyl-N-oxyl and viologen are employed as model redox active units to exemplify the strategy of the concurrent increase of specific energy and suppression of self-discharge of a two-electrode device.The slower hydrogen and oxygen evolution reactions compared with the reactions of the redox active units lead to an increased electrolyte decomposition window,thereby giving rise to an increase in specific energy.On the other hand,the complexation between the cMWCNT and the copolymers suppresses both the redox shuttling and the cross-diffusion of the redox active units-containing polymer chains,leading to an improved performance of self-discharge.Based on the complexation between carbon nanotubes and redox active units-containing charged copolymers,this work provides a convenient and universal strategy to concurrently increase specific energy and suppress self-discharge of electrochemical capacitors.

关 键 词：带电高分子 比能量 自放电 电解质分解窗口 络合 

分 类 号：O631.5[理学—高分子化学] TM53[理学—化学]