Ion‐Selective Microporous Polymer Membranes with Hydrogen‐Bond and Salt‐Bridge Networks for Aqueous Organic Redox Flow Batteries

• DOI: 10.1002/adma.202210098
• Publication Date: 2023-01-12T23:44:52Z
• Authors: Anqi Wang; Rui Tan; Dezhi Liu; Jiaxin Lu; Xiaochu Wei; Alberto Alvarez‐F...; Chunchun Ye; Charlotte Breakwell; Stefan Guldin; Anthony R. Kucernak; Kim E. Jelfs; Nigel P. Brandon; Neil B. McKeown; Qilei Song
• Keywords: energy storage; redox flow batteries; ion-conducting membranes; ion conducting membranes; microporous polymers

Redox flow batteries (RFBs) have great potential for long-duration grid-scale energy storage. Ion-conducting membranes are a crucial component in RFBs, allowing charge-carrying ions to transport while preventing the cross-mixing of redox couples. Commercial Nafion widely used but their unsatisfactory ionic and molecular selectivity, as well high costs, limit performance widespread deployment this technology. To extend longevity reduce cost RFB systems, inexpensive ion-selective that concurrently deliver low resistance selectivity toward redox-active species highly desired. Here, high-performance fabricated from blends carboxylate- amidoxime-functionalized polymers intrinsic microporosity, which exploit beneficial properties both polymers. The enthalpy-driven formation cohesive interchain interactions, including hydrogen bonds salt bridges, facilitates microscopic miscibility blends, ionizable functional groups within sub-nanometer pores allow optimization membrane ion-transport functions. resulting microporous demonstrate fast cation conduction with crossover species, enabling improved power ratings reduced capacity fade aqueous RFBs using anthraquinone ferrocyanide