How can we design anion-exchange membranes to achieve longer fuel cell lifetime?

The substantial advancements and availability of new cost-effective materials have drawn significant attention to the anion-exchange membrane fuel cell (AEMFC) technology. The anion exchange membrane (AEM) is a core component in AEMFCs, essential for conducting hydroxide ions and controlling water transport between the fuel cell electrodes. In this study, we apply a numerical model to investigate the relationship and sensitivity of AEMFC performance and its stability to key AEM properties. Our findings show that membrane maximum hydration level (λmax) has the most significant impact on AEMFC lifetime, followed by membrane ion-exchange capacity, water diffusivity, and membrane thickness. We also demonstrate the significance of improving the stability of the functional group to AEMFC lifetime, while AEM hydroxide conductivity shows a negligible effect on AEMFC lifetime. Finally, we provide a simple algebraic functional relationship between key dimensionless parameters as well as a machine learning-based analysis of the relationship between AEM parameters and AEMFC lifetime. Through these analyses, we calculate the lifetime of selected membranes from the literature and compare them to the measured operation time. This study summarizes and highlights important AEM property targets suggested to improve AEM design to boost the performance stability of AEMFCs.