Korea’s research team has developed the key technology of the next-generation anion exchange membrane water electrolyzers (AEMWEs), which effectively lower the cost of producing green hydrogen with no carbon emissions. Professor Lee Young-moo, Department of Energy Engineering, and his team conducted co-research with Dr. Lee So-young  and her team from the Hydrogen-Fuel Cell Research Center of the Korea Institute of Science and Technology (KIST), and they developed a membrane electrode assembly (MEA) for AEMWEs. This technology is expected to be used to replace the costly proton exchange membrane water electrolyzers (PEMWEs).

Hydrogen is attracting attention as a clean energy source replacing fossil fuels, and active efforts are being made to develop water electrolysis technology that can produce green hydrogen without carbon emissions. In recent years, many companies have been working on relevant research and commercialization, but the existing PEMWE technology has disadvantages in that its core material technology is largely concentrated in some developed countries and the cost of manufacturing the system is high as it uses expensive precious metal catalysts and perfluorocarbon-based proton exchange membranes.

As an alternative to the existing system, the AEMWEs, which use anion exchange membranes and electrode binders, are the result of a next-generation water electrolysis technology, which enables the safe production of hydrogen with high purity at low cost by using non-precious metal catalysts and replacing the titanium separator plates of the water electrolysis cell with steel ones.

When considering only the prices of catalysts and separator plate materials, an AEMWE is about 3,000 times cheaper than a PEMWE. But AEMWEs have not been commercially used due to their lower performance compared to PEMWEs and a durability problem with an operation time of less than 100 hours.

The team developed poly(fluorenyl-co-aryl piperidinium) (PFAP)-based anion exchange materials (electrolyte membranes and electrode binders) with high ion conductivity and alkali durability by increasing the specific surface area of the polymer structure, and then based on this technology, developed a membrane electrode assembly. The developed material has far superior durability of more than 1,000 hours and shows the world’s best cell performance of 7.68A/cm2, which is six times the performance of the existing anion exchange materials and about 1.2 times that of an expensive commercial PEMWE technology (6A/cm2).
The team has resolved the low performance and durability issues of the core materials, pointed out as limitations in AEMWEs, and enhanced the technology to such an extent that Korean technology can replace the PEMWE technology. Supported by Korea’s Ministry of Trade, Industry and Energy, the team is also working hard to enable the commercialization of the anion exchange membrane materials by applying technologies to increase their capacity and scale.

Dr. Lee So-young said, “We developed the materials and high-efficiency technology that surpass the limitations of the next-generation AEMWEs, paving the way for a generation shift of the water electrolysis technology that can significantly reduce the cost of producing green hydrogen.”

Professor Lee Young-moo said, “The materials we developed have the potential to be used as core materials not only for water electrolyzers, but also for hydrogen fuel cells, and the next-generation hydrogen projects including carbon capture, utilization and storage technologies and direct ammonia fuel cells.”

Supported by the Ministry of Science and ICT, the research was conducted as a material parts technology development project by the KIST, National Research Foundation of Korea, and Korea Evaluation Institute of Industrial Technology and the results were published in the latest issue of Energy & Environmental Science (IF=38.532, JCR top 0.182%).

*(Paper title) High-performance anion exchange membrane water electrolyzers with a current density of 7.68 Acm-2 and durability of 1000h
    - (Lead author) post-doctoral researcher Chen Nan-jun, Hanyang University
    - (Lead author) researcher Paek Sae-yane, the KIST
    - (Corresponding author) senior researcher Lee So-young, KIST
    - (Corresponding author) Professor Lee Young-moo, Hanyang University