文献类型：期刊文献

英文题名：Sub-2-nm Channels within Covalent Triazine Framework Enable Fast Proton-Selective Transport in Flow Battery Membrane

作者：Xu, Weiyi[1];Wang, Yixing[1];Wu, Yulin[1];Xu, Fang[1];Dai, Liheng[1];Qu, Kai[1];Wang, Jiaqi[1];Wu, Jun[1];Lei, Linfeng[1];Li, Siyao[1];Xu, Zhi[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn Sch Chem Engn, Shanghai 200237, Peoples R China

年份：2023

卷号：33

期号：21

外文期刊名：ADVANCED FUNCTIONAL MATERIALS

收录：;EI(收录号：20230913650473);WOS:【SCI-EXPANDED(收录号:WOS:000939442900001)】；

基金：Acknowledgements The authors gratefully acknowledge the research funding provided by National Key R&D Program of China (2021YFB3801301), National Natural Science Foundation of China (22075076 and 22208092), and China Postdoctoral Science Foundation (2022M711142).

语种：英文

外文关键词：covalent triazine frameworks; flow battery; hybrid membranes; ion selectivity; sub-2-nm channels

摘要：Ion conductive membranes (ICMs) with robust sub-2-nm channels show high proton transport rate in flow battery, but it remains a great challenge to precisely control the ion sieving of the membranes. Herein, as a promising proton-selective carrier, sulfonated piperazine covalent triazine framework (s-pCTF) with the channel size of approximate to 1.5 nm and abundant fast proton hopping sites is introduced into sulfonated poly(ether ether ketone) (SPEEK) to fabricate advanced ICM for vanadium flow battery (VFB) application. The interior protoplasmic channels of s-pCTF demonstrate significant Donnan exclusion effect, resulting in a high proton/vanadium ion selectivity in theory (6.22 x 10(5)). Meanwhile, the nitrogen-rich sub-2-nm channels yield fast proton highway, and exterior-grafted sulfonic acid groups further facilitate the proton transfer. By regulating the ion sieving and proton conductivity, the optimal hybrid membrane exhibits synchronously improved battery performance with an enhanced energy efficiency (92.41% to 78.53% at 40-200 mA cm(-2)) and long-term stability for 900 cycles over 400 h (EE: 87.2-85% at 120 mA cm(-2)), outperforming pure SPEEK and Nafion212 membranes. This study validates the applicability of organic porous CTF with sub-2-nm channels and desired functionality in ICMs for high-performance VFB application.