Cost-Effective PEM Electrolysis: The Quest to Achieve Superior Efficiencies with Reduced Investment

Hydrogen can directly replace fossil fuels in transport and industry when produced by water electrolysis with renewable energies such as solar or wind. The relevant technologies are either alkaline electrolysis or proton exchange membrane (PEM) water electrolysis. For PEM electrolysis in particular, key components that determine the stack cost are the bipolar plates (BPP), current collectors (CC), and membrane electrode assemblies (MEA). This paper discusses strategies for cost reduction by synthesizing highly active electrocatalysts with the aim of lowering the high Ir loading in the MEA. Additionally, we use vacuum plasma spraying (VPS) to apply either dense Ti coatings for corrosion protection of stainless steel components or build up Ti backing layers with defined porosity as contact elements with the MEA. The contact resistance of Ti can be reduced with the addition of Nb. The VPS coating and production procedure is adaptable to large-scale industrial production.