Influence of Power Fluctuation on Ni-Based Electrode Degradation and Hydrogen Evolution Reaction Performance in Alkaline Water Splitting: Probing the Effect of Renewable Energy on Water Electrolysis

HighlightsWhat are the main findings?Square-wave power has the greatest influence on Ni cathode HER compared to step- and triangle-power.Increasing the amplitude of square-wave power enhances coated cathode’s degradation.What is the implication of the main finding?Guidance for industrializing hydrogen production via renewable energy-coupled electrolytic water.Evaluation theory of cathode materials in electrolytic water.AbstractThe combination of water electrolysis and renewable energy to produce hydrogen is a promising way to solve the climate and energy crisis. However, the fluctuating characteristics of renewable energy not only present a significant challenge to the use of water electrolysis electrodes, but also limit the development of the hydrogen production industry. In this study, the effects of three different types of waveforms (square, step, and triangle, which were used to simulate the power input of renewable energy) on the electrochemical catalysis behavior of Ni plate cathodes for HER was investigated. During the test, the HER performance of the Ni cathode increased at first and then slightly decreased. The fluctuating power led to the degradation of the Ni cathode surface, which enhanced the catalysis effect by increasing the catalytic area and the active sites. However, prolonged operation under power fluctuations could have damaged the morphology of the electrode surface and the substances comprising this surface, potentially resulting in a decline in catalytic efficiency. In addition, the electrochemical catalysis behavior of the prepared FeNiMo-LDH@NiMo/SS cathode when subjected to square-wave potential with different fluctuation amplitudes was also extensively studied. A larger amplitude of fluctuating power led to a change in the overpotential and stability of the LDH electrode, which accelerated the degradation of the cathode. This research provides a technological basis for the coupling of water electrolysis and fluctuating renewable energy and thus offers assistance to the development of the “green hydrogen” industry.