Issue 28, 2025

Cation exchange membranes based on the Donnan exclusion effect for aqueous organic redox flow batteries

Abstract

Ion exchange membranes are a key parameter determining the energy efficiency of redox flow battery (RFB) systems as they facilitate the rapid transport of charge carrier ions while preventing the cross-diffusion of redox-active species. Cation exchange membranes (CEMs) possess higher chemical stability, more established fabrication processes, and lower manufacturing costs compared to anion exchange membranes (AEMs). However, a significant challenge arises with CEMs, such as Nafion, due to the Donnan effect, inhibiting compatibility with positively charged molecules. Here we use a simple strategy for modifying CEMs, utilising the Donnan effect produced by quaternary ammonium salt molecules. The modified CEMs enable performance comparable to that of AEMs, allowing for broader application in systems with cationic electrolytes. Using N1-ferrocenylmethyl-N1,N1,N2,N2,N2-pentamethyl-1,2-propanediamine dichloride (Fc-N2) as the catholyte, in conjunction with bis(3-trimethylammonio)propyl viologen tetrachloride (N2-Vi) as the anolyte, an impressive coulombic efficiency (CE) of approximately 99.7% was achieved at a current density of 40 mA cm−2, along with an energy efficiency (EE) of nearly 71.1%, which is comparable to the 75.75% observed with AEMs. This strategy demonstrates broad applicability across various positively charged reactive substances, confirming its universality and potential for improving RFB performance.

Graphical abstract: Cation exchange membranes based on the Donnan exclusion effect for aqueous organic redox flow batteries

Supplementary files

Article information

Article type
Paper
Submitted
08 Apr 2025
Accepted
22 May 2025
First published
18 Jun 2025

J. Mater. Chem. A, 2025,13, 22772-22782

Cation exchange membranes based on the Donnan exclusion effect for aqueous organic redox flow batteries

Z. Peng, K. Yang, J. Ning, Q. Li, S. Chen, A. Boota, S. Jiang, T. Zhang and B. Li, J. Mater. Chem. A, 2025, 13, 22772 DOI: 10.1039/D5TA02794B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements