(358b) Understanding the Effects of Electrode Design, Cell Assembly, and Operating Conditions on AEM Electrolyzer Performance

Hydrogen is emerging as a key energy carrier in the transition towards renewable energy, providing a pathway to achieve a zero-carbon energy landscape. While traditional technologies like the alkaline water electrolyzer (AWE) and proton exchange membrane water electrolyzer (PEMWE) dominate the commercial scene, recent developments focus on combining their benefits, leading to the creation of the anion exchange membrane water electrolyzer (AEMWE). Operating under high pH conditions, the AEMWE allows for more affordable materials and non-precious metal electrocatalysts to be used and differential pressure operation while taking advantage of an efficient zero-gap design that facilitates high-performance. Hence, the AEMWE represents a significant advancement in low-temperature water electrolysis, though further development is needed.

Anion exchange membranes, ionomers, and catalysts – as the "active" components in AEMWE systems – have been extensively researched, with a number of materials being suggested and discussed in the literature. Yet, material selection represents only one piece of the overall puzzle when it comes to the design, operation, performance and durability of AEMWEs. Testing a zero-gap cell design in an actual electrolyzer, in contrast to half-cell or three-electrode setups, highlights how phenomena such as bubble formation, interactions among components, and mass transport shape the overall performance of the cell. Numerous factors related to electrode design, cell assembly, and operation significantly influence the performance of an electrolyzer cell.

Therefore, the primary aim of this research was to study a range of operational factors for AEMWEs and to understand how these variables influence both polarization performance and galvanostatic durability. A high-quality set of commercially available active materials including Aemion+â„¢ anion-exchange membrane and ionomers, PtNi/C as the cathode catalyst, and either IrOx or NiFeOx as the anode catalyst, has been used in this study. Then, different electrode configurations were made by altering ionomer-to-catalyst ratios and varying the types of porous transport layers used. Furthermore, several key variables related to cell assembly were changed including the type of membrane, membrane thickness, electrode pre-treatment method, gasket thickness, and cell hardware. Finally, the operating conditions were adjusted by changing the cell break-in, temperature, heating mode, and current density.