Comprehensive impedance investigation of low-cost anion exchange membrane electrolysis for large-scale hydrogen production

Anion exchange membrane (AEM) electrolysis is a promising solution for large-scale hydrogen production from renewable energy resources. However, the performance of AEM electrolysis is still lower than what can be achieved with conventional technologies. The performance of AEM electrolysis is limited by integral components of the membrane electrode assembly and the reaction kinetics, which can be measured by ohmic and charge transfer resistances. We here investigate and then quantify the contributions of the ohmic and charge transfer resistances, and the rate-determining steps, involved in AEM electrolysis by using electrochemical impedance spectroscopy analysis. The factors that have an effect on the performance, such as voltage, flow rate, temperature and concentration, were studied at 1.5 and 1.9 V. Increased voltage, flow rate, temperature and concentration of the electrolyte strongly enhanced the anodic activity. We observed that here the anodic reaction offered a greater contribution to the overpotential than the cathode did.

Automated summary

Anion exchange membrane (AEM) electrolysis is a promising method for large-scale hydrogen production from renewable energy resources, but its performance still lags behind conventional technologies. Through electrochemical impedance spectroscopy analysis, we investigated and quantified the contributions of ohmic and charge transfer resistances, as well as the impact of factors such as voltage, flow rate, temperature, and concentration on AEM electrolysis efficiency. It was found that increasing voltage, flow rate, temperature, and electrolyte concentration significantly enhanced the anodic activity.