Polymer electrolyte membrane (PEM) electrolysis has demonstrated its potential to produce hydrogen and oxygen in a clean and safe way. Despite its numerous advantages over alkaline electrolysis, high capital costs have been preventing the technology’s wide use in hydrogen production. Use of expensive materials, high material usage, limited durability of the main PEM components and complex stack designs mainly account for the high costs. Eight European partners joined forces in the EU-funded project NOVEL (Novel materials and system designs for low cost, efficient and durable PEM electrolysers), developing high-performance electrolysers with efficiency of 75 % in producing hydrogen. Building on the success of a predecessor project, NOVEL developed and demonstrated novel materials and competitive PEM technology with lower membrane, electrode and bipolar plate costs, and also increased membrane electrode assembly (MEA) performance. The new materials also ensure longer lifetime of the most crucial PEM components as well as cost-efficient operation of the electrolyser at high pressures. Researchers extensively worked on identifying and enhancing understanding of the most important degradation mechanisms affecting PEMs. Single-cell degradation tests were performed to study the impact of temperature and current density. Results showed that membrane degradation takes place mainly at the cathode side. They also developed new membrane materials and electrocatalysts that should be included in the production of large-scale MEAs. The project team also produced new lower-cost coatings for bipolar plates and current collectors to replace titanium or noble metal materials that are expensive. Use of new materials suppresses the formation of high-contact resistance and increases resistance to corrosion. Proper selection of membrane materials is crucial to the performance, durability and cost of MEAs. Proton exchange membranes based on polymers that were synthesised by radiation grafting offer a cost-competitive option compared to state-of-the-art perfluorinated membranes.
Hydrogen production, polymer electrolyte membrane, NOVEL, PEM electrolysers, membrane electrode assembly