Improving anion exchange membrane stability with hydrophilic polyethylene for advanced aqueous organic redox flow batteries

Abstract

Anion exchange membranes (AEMs) are a vital component of aqueous organic redox flow batteries (AORFBs). Conventional AEMs often suffer from high resistance and typically lack mechanical strength and durability, particularly when used over large areas. In this work, we report a high-performance combination membrane (CM) formed by the straightforward adhesion of a hydrophilic porous polyethylene (HPE) layer to an AEM. The exceptional hydrophilic stability of HPE in the electrolyte endows this CM with remarkable stability in single-cell operations. Furthermore, the CM effectively prevents electrolyte crossover while facilitating efficient anion transport, demonstrating long-term stability in a 52-stack battery, with each CM scaled up to an active area of 830 cm². This work presents a facile and scalable method for fabricating highly durable AEMs, offering significant advancements in the field of AORFBs.