Durability of Water Electrolysis Cells Against the Long-Term Voltage Fluctuation Simulating Wind Power

Long-term durability equivalent to 320 days was evaluated using the potential fluctuation protocol with upper potential of 2.3 V. The current density drastically decreased during the accelerated potential fluctuations, but mostly recovered by providing the sufficient rest time, suggesting that the stagnation of the generated gas causes the reversible current loss. Besides the reversible current loss, a small portion of irreversible current losses were found. From detailed evaluation of the anode structure, a partial delamination of the anode and increased pore diameter within the anode after accelerated potential fluctuation test were observed, which was not observed in our shorter potential fluctuation test. A possible reason for this difference was found to be related to the initial anode structure. The dense anode structure most likely makes produced oxygen gases hard to escape from pores, leading to increase in the pressure within the pores and finally the destruction of the anode.