Holzapfel: Surface coating for hydrogen electrolysis

The Holzapfel Group is successfully meeting the challenge that hydrogen applications pose for surface technology - for efficient and sustainable H2 electrolysis. Hydrogen is usually produced in electrolysers, which split water into its components hydrogen and oxygen on a large scale, using electrodes to transfer electricity. The Holzapfel Group has many years of experience with components for alkaline electrolysis (AEL). In this form of electrolysis, the electrolyte is typically a concentrated alkaline solution, such as potassium hydroxide solution. However, this alkaline solution attacks most base materials such as metals, dissolving them or causing corrosion damage. Full nickel electrodes can be used here, but these have cost disadvantages in terms of procurement. However, they can also be replaced by another base material such as steel.

This is where coating technology comes into play: If the base material itself is not alkali-resistant, the coating ensures that there is no contact between the electrolyte and the base material. The corresponding coatings must not only be alkali-resistant, but also non-porous and chemically resistant in order to protect the base material. The use of base materials such as steel and coating systems is more cost and resource efficient and therefore also more sustainable than the use of electrodes made from solid nickel. The Holzapfel Group has sufficient experience with coating processes that achieve these goals in the AEL. As well as with other components to be coated in an alkaline electrolyser. Holzapfel has compiled more information on this topic on the H2 Gamechanger website.