Enhancing the performance and economics of anion exchange membrane electrolysis for renewable hydrogen production

Intermittency and variability of renewable energy sources pose substantial challenges to maintaining grid reliability during the global transition to carbon neutrality. Anion exchange membrane (AEM) electrolysis, which combines the advantages of alkaline electrolysis and proton exchange membrane (PEM) electrolysis, is attracting increasing commercial interest for the conversion of curtailed electricity into storable green hydrogen. However, data supporting the long-term reliability and durability of AEM electrolysis are limited. Accordingly, this study quantitatively assesses the commercialization potential of AEM electrolysis through enhancements determined via single-cell experiments coupled with techno-economic analysis. Developed AEM electrolysis employed a low-cost membrane and nickel-based catalyst. Optimized electrode, catalyst, and ionomer compositions and operating conditions increased efficiency from 74 to 93%. Consequently, capital expenditure was reduced by 12% at an advanced technology level in grid-coupled simulations of photovoltaic, wind turbine, and hybrid power operations on Jeju Island, South Korea. Nevertheless, a relatively high degradation rate (0.0013%/h) increased the levelized cost of hydrogen (LCOH) to 7.25–9.03 USD/kg during long-term operation. Conversely, when the efficiency reached 93%, the degradation rate decreased to levels comparable to those in the case of PEM electrolysis (0.00013%/h) and LCOH reduced to 4–5 USD/kg. Findings of this study underscore that in addition to enhancing efficiency, improving stack durability and ensuring long-term operational stability are essential for the commercialization of AEM electrolysis, which would enable cost-effective green hydrogen production for a sustainable future.