Thin Reinforced Composite Membranes for Efficient Anion-Exchange Membrane Water Electrolysis

Recently, as the demand for hydrogen (H 2 ) used as a raw material or fuel in various industries increases, interest in environmentally friendly water electrolysis technology is increasing. In particular, anion-exchange membrane water electrolysis (AEMWE) is receiving great attention as it is considered a cost-effective and stable process compared to the traditional proton exchange membrane water electrolysis (PEMWE). In the AEMWE system, the anion-exchange membrane (AEM) is a core material that facilitates the movement of OH - ions and determines the reaction rates of OER and HER. The AEM must have high ionic conductivity for OH - ions and low gas permeability, and excellent physical and chemical stabilities are required for long-term operation in alkaline conditions. In this study, therefore, a reinforced composite AEMs with excellent mechanical strength even at a thin film thickness were fabricated using various porous supports and their properties were systematically analyzed. For preparing AEMs, a polymer backbone and ion exchange groups with an excellent stability under harsh alkaline conditions were introduced. Moreover, the membrane development was conducted to simultaneously increase the degree of crosslinking and ion exchange capacity. The properties of the prepared AEMs were confirmed through AEMWE experiments, and the excellent current density and long-term stability were confirmed in 1 M KOH solution conditions. This work was supported by NRF grants funded by the Government of Korea (MEST) (NRF-2022M3C1A3081178 and NRF-2022M3H4A4097521).