Self‐Standing Covalent Organic Polymer Membrane with High Stability and Enhanced Ion‐Sieving Effect for Flow Battery

作者：Yihan Zhen, Ziang Xu, Qingbin Cao, Maobin Pang, Qin Xu, Dongchen Lin, Jing Liu, Baoguo Wang · 发表于：Angewandte Chemie International Edition · 年份：2024 · DOI：10.1002/anie.202413046 · 被引用次数：48 · 研究领域：Advanced battery technologies research、Advanced Battery Materials and Technologies、Conducting polymers and applications

Abstract 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 −2 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.