From raincoats to coatings in pipelines - PFAS, i.e. perfluorinated alkyl compounds, are polymers commonly referred to as plastics that are used in a wide range of applications thanks to their extreme durability. Scientists have been warning about the dangers and possible effects of these carcinogenic substances on humans and the environment for decades. However, since the beginning of this year at the latest, when journalists revealed the extent of contamination in Europe in numerous European daily newspapers, PFAS have come under scrutiny: companies' efforts to replace PFAS have increased significantly, as the EU is currently examining a comprehensive ban on these substances.
PFAS also play a central role in hydrogen technologies because they are very durable, easy to process and highly efficient as membranes. However, efforts have been underway for some time to develop PFAS-free alternatives, and researchers at Hahn-Schickard have also been actively involved since 2018. The starting point was a German-Canadian collaboration with Simon Fraser University in Vancouver. There, in the "cradle of the fuel cell", alternative polymers have been developed for a long time with the promising prospect of making them technically superior to PFAS.
The new polymers are more gas-tight, which means that thinner membranes could significantly increase the efficiency of electrolysis. As electrolysis capacities are planned worldwide with an electricity demand that is more than 20 times the total German demand, enormous amounts of electricity could be saved. It is precisely with this motivation that Hahn-Schickard is developing PFAS-free alternatives for electrolysis applications in the "Fluorine-free MEA" project under the leadership of Dr. Carolin Klose. The project is part of the "H2Giga" hydrogen lead project. Hahn-Schickard is developing its own PFAS-free polymers for the first time together with a membrane manufacturer from Baden-Württemberg, which also has many years of expertise in this field. Hahn-Schickard has been able to recruit high-ranking experts for this complex field of polymer development, including Privatdozent Dr. Klaus-Dieter Kreuer and Professor Giorgi Titvinidze - both of whom have been researching polymers for fuel cells and electrolysis for over two decades and joined Hahn-Schickard in 2021. This makes Hahn-Schickard one of a handful of institutes worldwide that are driving forward this important polymer development for electrolysis and fuel cells.
PFAS alternatives also play an important role in fuel cells for emission-free mobility. In aviation, PFAS alternatives could even be the key to success: "With PFAS alternatives, fuel cells can be operated at higher temperatures. This is crucial for aviation, because higher temperatures mean major weight savings and therefore a longer range," explains Dr. Andreas Münchinger, Head of the Hahn-Schickard "Alternative Membranes" Group and Hahn-Schickard project manager in the "H2Sky" alliance, which is the central German project for the development of fuel cells for aviation with over 26 million euros.
ionysis GmbH, which was spun off in 2022, is proof of how far Hahn-Schickard's research has already come. This is because "ionysis GmbH" has also committed itself to PFAS-free electrolysis and fuel cells and, with around 20 employees, has now won its first orders from industry. If the cooperation with the University of Freiburg and the Fraunhofer Institute for Solar Energy Systems ISE is added to this, Freiburg could become a "science hub" for PFAS-free, green technologies.