Accelerated stress testing in proton exchange membrane water electrolysis - critical review

Proton exchange membrane water electrolysis is a promising technology for the production of green hydrogen because of its ideal coupling with renewable energies. However, the reduction of noble materials and the improvement of efficiency and lifetime are challenges to be overcome in order to make this type of hydrogen cost-effective. This paper proposes an in-depth analysis of the electrolyzer operating conditions: power supply, temperature and water flow rate, associating the degradation phenomena identified at each operating point. A cause–effect map of the electrolyzer degradation allows to identify the stress variables and the operating points of interest according to the failure and the component concerned. A comprehensive literature review of the electrolyzer materials degradation is presented in the first part. Accelerated stress protocols proposed in the literature are also presented under a critical approach. The review of degradation and accelerated protocols thus represents an important conceptual framework for the analysis of stress conditions and the guided design of accelerated protocols, presented in the last part of the paper. •A review of PEMWE degradation based on real operating conditions is reported.•A definition of AST is given based on its review for electrolysis.•Stress variables are provided, as is degradation analysis at each operation stage.