The Swiss Federal Laboratories for Materials Science and Technology (Empa), together with French partners, is developing new materials for water electrolysis. The goal is to reduce the production costs of green hydrogen. The project is funded by the Swiss National Science Foundation (SNSF) and the French National Research Agency (ANR). Involved alongside Empa are the Institut de la Corrosion in Brest and the LEMTA research institute in Nancy.
The focus is on the technology of polymer electrolyte membrane water electrolysis (PEMWE). These electrolysers are considered efficient and compatible with fluctuating power supply from renewable sources. However, the environment inside is highly corrosive. Components for the supply and discharge of water and gases are therefore made of titanium, which must also be coated with platinum. Both drive up costs.
Titanium oxide replaces platinum, steel replaces titanium
Empa researcher Konstantin Egorov from the "Materials for Energy Conversion" lab relies on a special form of titanium oxide as a coating: highly crystalline oxygen-deficient rutile. According to Empa, the material lacks oxygen atoms at certain sites, giving it good conductivity.
The high crystallinity is intended to ensure corrosion resistance. Steel is to replace the more expensive titanium as the carrier material. "Steel is not only cheaper but also much easier to process. This enables new, advanced component designs that increase cell efficiency," explains Egorov. For the coating, the researchers use physical vapour deposition (PVD), a process widely used in industry. "It is important to us to develop something that the industry can actually use," emphasizes Egorov.
Bipolar plate passes first tests
According to Empa, the method has already worked for the first component, the bipolar plate. It has passed the corrosion tests of the project partners under laboratory conditions and in a functioning electrolyser.
Next, the researchers want to coat the porous transport layer. The challenge here is to coat the pores evenly without clogging them. The project runs until 2026. Subsequently, according to their own statements, the Empa researchers aim to find an industrial partner to further develop the technology towards commercialization.
