Zhen Yihan, Xu Ziang, Cao Qingbin, Pang Maobin, Xu Qin, Lin Dongchen, Liu Jing, Wang Baoguo
Department of Chemical Engineering, Tsinghua University, Beijing, China.
Angew Chem Int Ed Engl. 2025 Jan 2;64(1):e202413046. doi: 10.1002/anie.202413046. Epub 2024 Oct 25.
Fabrication of ion-conducting membranes with continuous sub-nanometer channels holds fundamental importance for flow batteries in achieving safe integration of renewable energy into grids. Self-standing covalent organic polymer (COP) membranes provide feasibility due to their rapid and selective ion transport. However, the development of a scale-up possible, mechanically robust and chemically stable membranes remains a significant challenge. Herein, using irreversible strong secondary amine linkage, we propose a self-standing COP membrane with sub-nanometer pores ranging from 4.5 to 6.4 Å, by a simple and efficient in situ polymerization approach. This membrane exhibits enhanced selectivity for proton and vanadium ions, especially excellent electrochemical stability, delivering an energy efficiency of over 80 % at the current density of 200 mA cm over 1000 cycles for an all-vanadium redox flow battery (VFB). This study provides novel insights for COP-based ion-sieving membranes in sustainable energy fields.
制备具有连续亚纳米通道的离子传导膜对于液流电池将可再生能源安全整合到电网中至关重要。自立式共价有机聚合物（COP）膜因其快速且选择性的离子传输而具有可行性。然而，开发可扩大规模、机械坚固且化学稳定的膜仍然是一项重大挑战。在此，我们利用不可逆的强仲胺键，通过一种简单高效的原位聚合方法，提出了一种具有4.5至6.4 Å亚纳米孔的自立式COP膜。该膜对质子和钒离子表现出增强的选择性，尤其是出色的电化学稳定性，在全钒氧化还原液流电池（VFB）中，在200 mA cm的电流密度下经过1000次循环，能量效率超过80%。这项研究为可持续能源领域基于COP的离子筛分膜提供了新的见解。
