Effects of the Electrode Supporter Structures for Achieving Optimum Hydrodynamic Performance for a Zero-gap Alkaline Water Electrolysis Cell

Abstract

Water electrolysis, a hydrogen energy production method, can generate pure hydrogen and oxygen without emitting carbon-based molecules; thus, it is an environmentally friendly technology. Zero-gap alkaline water electrolyzer (ZGAWE) can produce hydrogen economically and efficiently. Here, we developed a ZGAWE hydrodynamic model and investigated the changes in cell performance according to the input power and different electrode supporter structures, such as wavy mesh, foam, and serpentine, under actual operating conditions. Owing to its high hydrogen conversion rate and low operation costs, the wavy mesh supporter design had the highest efficiency. Additionally, as the system size increased, the operation costs decreased; thus, the wavy mesh supporter design was also applicable for large-scale ZGAWE systems. Foam supporter flow field design shows a very similar trend and can compete with the wavy mesh supporter. Conversely, different hydrodynamic performance and high operation costs of the serpentine flow field design made it unsuitable for the ZGAWE system, but it could be used for the proton/anion exchange membrane water electrolyzer. The results provide significant insights into the hydrodynamic effects to operate ZGAWEs at different cell voltages; additionally, the results can be used to develop high-performance water electrolyzer systems.