A review on the degradation of hydrogen evolution electrodes under fluctuating renewable electricity

As the global energy system transitions toward cleaner and low-carbon pathways, the development of efficient and durable water electrolysis technologies for hydrogen production has become increasingly crucial. The rapid expansion of renewable energy sources such as solar and wind provides abundant, clean electricity for green hydrogen production; however, their inherent intermittency and volatility often force electrolyzers to deviate from steady-state operation, resulting in efficiency losses and accelerated electrode degradation. A comprehensive understanding of degradation mechanisms under fluctuating power input is therefore essential for achieving large-scale and stable hydrogen production. This review summarizes the characteristic fluctuation patterns of renewable energy and their impacts on the operational stability of electrolytic systems. It further provides a systematic discussion of electrode degradation behaviors and dominant mechanisms under various operating conditions, including over-power, low-power, no-power, start–stop cycling, and dynamic fluctuation scenarios. Finally, key future research priorities are highlighted, emphasizing the development of multiscale degradation models, dynamic evaluation and lifetime prediction frameworks, and highly stable, adaptive electrode materials. These advances will provide critical theoretical and technological foundations for efficient, durable water electrolysis systems powered by renewable energy.