Conditioning and testing of a medium-power alkaline electrolyzer stack at high current densities for green hydrogen production

Abstract

Although alkaline water electrolyzers are a mature technology (TRL 9), standardized electrochemical conditioning protocols are still lacking, particularly for medium-power systems, hindering reproducibility and scalability. This study investigates electrochemical conditioning processes in alkaline water electrolyzers at laboratory and medium-power scales to establish standardized protocols that enhance reproducibility and facilitate industrial scaling. A three-electrode cell was employed to examine redox processes on Ni-coated electrodes, and two Alkaline Water Electrolyzer stacks were tested with galvanostatic and potentiostatic conditioning protocols. Conditioning induces chemical modifications on Ni electrodes, forming hydrides and oxides that influence performance. Proper conditioning reduces measurement variability, improves polarization curve reproducibility, and enables more accurate system evaluation. Potentiostatic conditioning proved the most effective, ensuring stable hydrogen and oxygen evolution reactions. By replicating real operational conditions, conditioning enhances performance reliability, aiding the optimization and scaling of electrolyzers for hydrogen production. These findings contribute to bridge the gap between microscale studies and industrial-scale systems.