Critical Elements are important for the economy, in particular for modern technologies, but their secure supply is at risk (for example, because they are sourced from a politically volatile region). For such elements, it is very important to develop closed recycling loops, in which waste components are processed to reclaim critical elements, that are subsequently reused. An example of such strategically important components, enabling the transition to renewable energy sources, are strong and lightweight Rare Earth Permanent Magnets (REPM), found in electric vehicles motors and off-shore wind turbines. Manufacturing of such magnets is reliant on rare earth elements, such as neodymium. 

Critical Elements are the elements that are important for the economy, in particular for modern technologies, but their secure supply is at risk (for example, because they are sourced from a politically volatile region). For such elements, it is very important to develop closed recycling loops, in which waste components are processed to reclaim critical elements, that are subsequently reused. An example of such strategically important components, enabling the transition to renewable energy sources, are Rare Earth Permanent Magnets, used in the motors of electric vehicles and wind turbines. Manufacturing of such magnets is reliant on rare earth elements, such as neodymium, dysprosium and terbium. 

Faced with climate change, renewable energy generation is increasingly rapidly, and so is the need for energy storage, given its intermittency. Fuel cells are important energy conversion devices to sustainably produce electricity from hydrogen, a fuel that is being produced more sustainably as the world decarbonises. Polymer electrolyte fuel cells (PEFC) are the most commercialised variant of this technology, with advantages including high power density, fast start-up, and manufacturing maturity. However, on top of high costs, current PEFC membranes show high gas crossover and restricted operation in dry conditions.