No easy task: reducing hydrogen permeation in silicone seals is technologically demanding. In addition to the impermeability to hydrogen, the secure and permanent adhesion of the coating to the silicone surface is a major challenge for the researchers. This is particularly tricky due to the low surface energy of silicone.
Complex tests
To evaluate the newly developed coatings, coated and uncoated test specimens are examined on a specially developed permeation test stand and the permeation rates are determined. In order to be able to assess the mechanical stability and sealing effect of the coated materials in practice, the scientists are also adapting methods for measuring the compression set (DVR). In addition, the project partners are developing test protocols to validate the coated seals later under real operating conditions in fuel cells.
In the H2Coat project, the partners are pooling their expertise in materials technology and fuel cell development. Rhenotherm Mini Parts develops and investigates suitable coating systems, evaluates their adhesion and barrier effect and later transfers the process to real fuel cell components. The ZBT provides test specimens and bipolar plates with seals, carries out permeation and DVR measurements and tests the coated seals in fuel cells under real operating conditions. The results are compared with reference stacks in order to evaluate the effect of the coating on performance and ageing.
With the development of the H2Coat special coating, the project partners are making an important contribution to the economic and safe use of hydrogen in fuel cell technology. The significant reduction of hydrogen losses through silicone seals will increase the efficiency of fuel cells and create the basis for a broader industrial application – a step towards greater sustainability, safety and competitiveness in fuel cell technology.
