WEVO-CHEMIE GmbH has launched WEVOSIL 20000 A/B, a silicone sealant developed to withstand the demanding operating conditions of anion exchange membrane (AEM) electrolysers and flow batteries, including organic redox flow systems.
Designed for alkaline environments, the two-component material combines chemical resistance, mechanical stability and electrical insulation to deliver reliable sealing under sustained compression and elevated temperatures. It can also serve as an adhesive and supports manual, semi-automated and fully automated processing.
Wevo has also partnered with coating specialist Laufenberg GmbH to manufacture prefabricated flat gaskets using the new silicone formulation, offering manufacturers greater flexibility in gasket design and production.
WEVOSIL 20000 A/B can be applied in liquid form using standard twin-cartridge systems, with its 1:1 mixing ratio simplifying manual application and initial testing.
For series production, the sealant can be dispensed or screen-printed directly onto cell components, including bipolar plates, gas diffusion layers, flow frames and membrane electrode assemblies (MEAs). Its low viscosity allows it to flow into undercuts, while the application process supports sealing geometries with different widths and heights to suit component designs.
Curing at temperatures of 100 to 140°C, using a convection oven or an infrared heater, can further accelerate production. Under these conditions, the material cures to a tack-free state within one to two minutes, helping shorten cycle times.
Through its collaboration with Laufenberg, Wevo is extending the material's use beyond liquid-applied seals to prefabricated flat gaskets manufactured through a continuous roll-to-roll (R2R) coating process.
The silicone can be applied in layers approximately 50–500 µm thick to adhesive or non-adhesive carrier films. Adhesive films can be coated on both sides to achieve greater layer thicknesses, while non-adhesive films, including fluorine-based films, allow the cured silicone layer to be removed to create carrier-free gaskets.
Manufacturers can cut seals to the required dimensions from the prefabricated sheet material and install them directly into stacks. The approach is particularly suited to producing test cells and short stacks, while Laufenberg can also manufacture gaskets tailored to specific customer and component requirements.
The sealant's mechanical characteristics are designed to maintain sealing performance under the sustained compression found in electrolyser and flow-battery stacks.
WEVOSIL 20000 A/B has a hardness of approximately 50 Shore A and an elongation at break exceeding 100 per cent. Its compression set is 2 per cent at room temperature and below 10 per cent at 100°C, supporting resilience under demanding operating conditions.
Electrical insulation is another key feature. The material offers dielectric strength exceeding 20 kV/mm and volume and surface resistivity above 10¹⁴ Ω·cm. These properties help limit unwanted creep and shunt currents in electrochemical systems.
The formulation is also free from per- and polyfluoroalkyl substances (PFAS), addressing an additional material consideration for manufacturers developing next-generation energy technologies.
