文献类型：期刊文献

英文题名：Freestanding covalent organic framework membranes with enhanced proton perm-selectivity for flow batteries

作者：Wu, Jun[1];Wang, Yixing[2];Wu, Yulin[1];Xu, Weiyi[1];Wang, Jiaqi[1];Li, Siyao[1];Xu, Zhi[1]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, State Key Lab Chem Engn, Shanghai, Peoples R China;[2]Suzhou Lab, Suzhou, Peoples R China

年份：2023

卷号：687

外文期刊名：JOURNAL OF MEMBRANE SCIENCE

收录：;EI(收录号：20233814746699);WOS:【SCI-EXPANDED(收录号:WOS:001080012700001)】；

基金：The authors gratefully acknowledge the research funding provided by National Key R&D Program of China (Grant Nos. 2021YFB3801301) and National Natural Science Foundation of China (Grant Nos. 22075076) .

语种：英文

外文关键词：Freestanding membranes; Covalent organic frameworks; Macromolecular suturing; Flow battery

摘要：Aqueous organic redox flow batteries (AORFBs) are attractive for energy storage applications, benefiting from the high safety and low cost. Covalent organic frameworks (COFs) with uniformly arranged rigid nanochannels are suitable for fabricating membranes implemented into AORFBs. However, most freestanding COF membranes are challenging to apply directly to flow batteries due to their insufficient mechanical strength. This work proposes a mechanochemistry-based method for fabricating freestanding COF membranes and a corresponding macromolecular suturing strategy to prepare membranes with excellent mechanical properties and enhanced proton conductivity. Through the steric hindrance effect of the introduced sulfonic acid group (-SO3H) functionalized chains, the ability of the membrane to block the crossover of redox couples is strengthened. Mean-while, the -SO3H groups provide additional active sites, constructing a more continuous proton pathway. The optimized membrane exhibits a high voltage efficiency of 79.06% at 40 mA cm-2 and retains nearly 100% of its discharge capacity even after 100 cycles at 80 mA cm-2, outperforming the TpAzo membrane. This work offers a novel strategy to promote the utilization of COF membranes in flow battery applications.