Anion Exchange Membrane in Water Electrolysis: From Material Research to Integrated Component Operation

ABSTRACT Anion exchange membrane water electrolysis (AEM‐WE) has attracted increasing interest because it combines the compact device architecture of membrane‐based electrolyzers with the potential to utilize platinum‐group‐metal‐free catalysts. Despite rapid advances in anion exchange membrane (AEM) hydroxide conductivity and alkaline stability, with some AEMs demonstrating over 8000 h stability and conductivities approaching 300 mS cm −1 , these material‐level advances have not translated proportionally into device operation. Consequently, long‐term electrolyzer lifetimes remain far below those of proton‐exchange membrane systems. In this perspective, we argue that the AEM should be considered not merely as a hydroxide‐conducting separator, but as a functional component of the membrane electrode assembly, influencing water transport, interfacial compatibility, gas crossover, and failure mechanisms. We first discuss why the conductivity and alkaline‐soaking stability of AEM alone are insufficient predictors of practical performance. We then examine coupled challenges including interfacial effects, oxidative degradation near the anode, chemical‐mechanical degradation, and the limitations of current evaluation methods. Finally, we outline how future progress may depend on integrating membrane chemistry with scalable fabrication, greener synthesis, and more consistent benchmarking protocols. We hope this perspective helps situate current membrane research within a broader device‐level context and highlights key questions for the next stage of AEM‐WE development.