Overview of alkaline water electrolysis processes and recommendations for the implementation of a laboratory-scale AWE test rig

Alkaline water electrolysis (AWE) is a mature, scalable technology for renewable hydrogen production. Yet the buildup of reliable laboratory-scale systems remains a significant challenge. This paper provides a practical guide to the design, construction, and operation of a zero-gap AWE cell and its associated test rig. Fundamental principles governing AWE performance including thermodynamics, overpotentials, and bubble-related transport phenomena, are outlined to connect electrochemical theory with practical implementation. Detailed descriptions of key cell components are provided alongside discussions of electrode kinetics and degradation mechanisms, with an emphasis on industrial-standard nickel-based catalysts. Beyond cell architecture, this review consolidates critical considerations for testing infrastructure: electrolyte circulation strategies, gas–liquid separation, gas handling, safety systems, and the integration of sensors enabling reproducible, industrially relevant operation. Special attention is placed on aspects such as dissolved gas transport, bubble management, gas crossover, and contamination from stainless steel components which can strongly influence both performance and safety.