Work

Analysis of anion exchange membrane water electrolyzer performance and its evolution over time

Year: 2025

Type: article

Abstract: Understanding water, evolved gas, and ionic transport in membrane-electrode-assemblies (MEAs) is essential for the development of high performance and durable anion exchange membrane water electrolyzers (AEMWEs). This study evaluates MEA conditioning process, operating conditions, and short-term stability in 1 M potassium hydroxide (KOH) electrolyte, focusing on the underlying transport phenomena. The MEA conditioning process is investigated, connecting cell performance to changes in ohmic, ionic, and charge transfer resistances. We observe a significant initial voltage loss in continuous cell operation which could be associated with gas bubbles accumulation, transport layer and flow field passivation and changes in the catalyst oxidation state. Further, we investigate the effects of materials and operational configurations, including the membrane type and thickness, and the electrolyte flowrate, including KOH being fed to both electrodes as well as to anode only (dry cathode). Furthermore, the effect of drying temperature on the AEM water uptake and swelling properties associated with in situ electrochemical performance is evaluated. Finally, we report 700 hours AEMWE operation at 1 A/cm2, discussing the performance changes over time due to changes within the MEA and to the surrounding test apparatus.

Source: iScience

DOI: 10.1016/j.isci.2025.114037