Ion-Conducting Membranes for Long-Duration Energy Storage

Abstract

Redox flow batteries (RFBs) have emerged as a promising candidate for large-scale energy storage, particularly in the integration of intermittent renewable energy sources and enhancement of grid stability. As one of the critical components of RFBs, the ion-conducting membrane facilitates ion conduction and prevents redox-active species from crossing over, thereby significantly influencing the efficiencies and lifespan of RFBs. Designing highly selective membranes based on different transport behaviors of ions in ion transport channels benefits redox flow batteries for long-duration grid-scale energy storage applications. Herein, we introduce the ion transport mechanism, discuss design strategies of highly selective ion-conducting membranes, and present the challenges and perspectives for their application in redox flow battery applications. This review provides insights into the design of a highly selective ion-conducting membrane tailored for long-duration grid-scale redox flow battery applications.