Alkaline-Stable Anion Conducting Ionomers for Anion Exchange Membrane Water Electrolyzers

Abstract

Water electrolysis is a process that uses renewable energy to decompose water into oxygen and hydrogen. It is one of the most promising alternatives to produce and store new energy from renewable energy resources. In this study, pore-filled anion exchange membranes (PFAEMs) were prepared by using quaternary ammonia groups along with various cross-linker groups with different chain lengths and using porous polyethylene substrates which were pretreated from hydrophobic into hydrophilic using surfactants. The conductivity of the anion exchange membranes was measured by the in-plane cell and through-plane at room temperature or 60 ℃. In addition, the characterizations of anion exchange membranes such as water uptake, swelling ratio, mechanical strength, contact angle and TGA were carried out. As a result, the PFAEM exhibited remarkably high ion conductivity at extremely low areal swelling ratio and excellent chemical stability in a NaOH solution for 500 h. As an essential component of anion exchange membrane water electrolyzers, catalyst layers prepared by the catalyst inks comprising of ionomer binder and electrocatalysts are sandwiched between the anion exchange membrane to form a membrane electrode assembly in order to evaluate its impedance and I-V polarization curves. Acknowledgment This research was supported in part by the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20213030040520) and by 2021 Green Convergence Professional Manpower Training Program of the Korea Environmental Industry and Technology Institute funded by the Ministry of Environment.