A review on understanding and identifying degradation mechanisms in PEM water electrolysis cells: Insights for stack application, development, and research

This review, addressing developers, users, and researchers of PEM water electrolysis stacks, provides a detailed overview of the most important degradation mechanisms, the underlying influencing factors, and the resulting impact on system component degradation. By investigating the significance and the consequences of the degradation mechanisms on stack performance and life-time, it provides a comprehensive understanding of the challenges and impacts associated with PEM water electrolysis technology. Possible qualitative and quantitative statements based on observed degradation phenomena on stack and single cell level as well as from ex-situ examinations are evaluated. The most common diagnostic tools, based on electrochemical, imaging, and physical analysis methods, as well as elemental and structural analysis are described in an application-oriented manner regarding their advantages, possibilities, and limits.