New Gasket Technology Boosts Performance and Lifespan of Key Sealing Components in Water Electrolysis Hydrogen Devices
A Korean research team has developed a technology that simultaneously enhances the safety and efficiency of gaskets, which directly impact the durability and explosion safety of ‘water electrolysis stacks’—the core modules of fuel cells and devices that produce hydrogen and oxygen by electrolyzing water. Gaskets are sealing components fitted between cells within the stack, serving to prevent the leakage or mixing of electrolytes, hydrogen, and oxygen.
The Korea Research Institute of Chemical Technology (KRICT) announced on the 2nd that a team led by Dr. Oh Keun-hwan has developed a nanocomposite technology that simultaneously enhances mechanical strength, hydrogen barrier performance, and chemical and thermal stability. This was achieved by functionalizing 2D ‘Boron Nitride Nanoflakes’ (BNNF) and applying them to silicone and EPDM (ethylene propylene diene monomer) rubber-based sealing gaskets. BNNF is a material made by slicing a substance where boron (B) and nitrogen (N) atoms are alternately arranged into thin layers.
In fuel cells and water electrolysis devices, fuel, oxygen, and coolant circulate within the cells. A decline in the performance of the internal sealing gaskets can lead to reduced system efficiency and serious safety accidents. Existing fluorinated and silicone gaskets, despite their excellent performance, face limitations due to high costs and environmental regulations on substances like PFAS (per- and polyfluoroalkyl substances). In contrast, while silicone and EPDM materials offer cost-effectiveness and processability, they are limited by insufficient hydrogen barrier properties and chemical resistance.
The research team chemically coated and bonded BNNF using ‘pyrenemethyl methacrylate’ (1-PMA), a type of polymer, to create a strong and dense 3D network within the polymer matrix.
By establishing a dense network structure within the material, the team maximized the ‘tortuous path effect,’ which effectively blocks the permeation of hydrogen molecules, and ensured structural stability even under high temperatures and in harsh environments. The team applied this developed structure to silicone and synthetic rubber (EPDM)-based sealing gaskets.
The team achieved significant performance improvements in terms of Young’s modulus and hydrogen permeability with the addition of just 0.5 weight percent (wt%) of BNNF. Young’s modulus is a mechanical property indicating how stiff and elastic a material is. A higher Young’s modulus value means the material is harder, allowing the gasket to maintain its shape under pressure, which serves as an indicator of improved sealing performance. Lower hydrogen permeability is an indicator of better gas leakage prevention.
With the BNNF addition, the EPDM composite showed a 32.1% increase in Young’s modulus and a 55.7% decrease in hydrogen permeability. The silicone composite demonstrated a 96.6% improvement in Young’s modulus and a 42.7% decrease in gas permeability, indicating enhanced sealing performance. In a chemical resistance evaluation, after 225 hours of exposure to acidic and alkaline conditions, the EPDM composite showed mass losses of only 6.6% and 3.8%, respectively, while the silicone composite showed losses of just 0.2% and 2.1%, proving excellent stability. In single-cell evaluations, it recorded a current density equal to or, under certain conditions, surpassing that of commercial gaskets.
Consequently, the developed technology goes beyond simply improving mechanical strength; it enhances barrier properties, chemical resistance, and electrochemical performance altogether, presenting the potential for non-fluorinated gaskets to replace existing ones across the entire hydrogen lifecycle, from production and storage to utilization.
The team is currently pursuing early-stage demonstration and technology transfer, and expects various field applications in the future, including hydrogen electric vehicles, power generation stacks, and large-scale water electrolysis facilities.
The research team stated,
Through this research, we have laid the foundation for domesticating silicone-based gaskets, for which we are highly dependent on imports.
KRICT President Lee Young-kook said:
By securing a non-fluorinated alternative material that can respond to environmental regulations, we will achieve both cost reduction and enhanced safety simultaneously
The research findings were published as a paper in the October issue of the international journal for materials and chemistry, ‘Advanced Composites and Hybrid Materials.’ In addition to principal investigator Dr. Oh Keun-hwan, Professor Kang Hong-suk of Inha University and Choi Won-jong, a student researcher at KRICT, participated as first authors.
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New Gasket Technology Boosts Performance and Lifespan of Key Sealing Components in Water Electrolysis Hydrogen Devices, source
