Hydrogen fuel cells – especially the PEMFC (polymer electrolyte membrane fuel cell) variety – are already used in vehicles around the world and will play a vital role in bringing about low-carbon mobility. However, a large quantity of these PEM fuel cells (also known as proton-exchange membrane fuel cells) will have reached end-of-life by 2030, and, as yet, there is no satisfactory process for recycling these high-tech, composite assemblies.
This is the complex problem the Fraunhofer Research Institution for Materials Recycling and Resource Strategies (IWKS) have set out to untangle in the "BReCycle" project, with the help of four partners: Proton Motor Fuel Cell GmbH, MAIREC Edelmetallgesellschaft mbH, Electrocycling GmbH and KLEIN Anlagenbau AG.
Under the "Innovations for the Energy Transition" programme, funded by the BMWi, the consortium is developing a tailor-made, closed-loop recycling concept for PEMFCs, in order to recover valuable technological metals, including platinum and ruthenium, by the most sustainable means possible.
PEMFCs are typically recycled by pyrometallurgical means, but the process produces highly toxic gas compounds, which then have to be purified, and loses base materials like steel and aluminium. BReCycle will explore alternative “wet” methods: starting with pre-dismantling to remove the electrical components, then extracting the metals using electrohydraulic fragmentation, for example, where the dismantled parts are placed in a reactor filled with water and then bombarded with shock waves.
At the same time, researchers at the IWKS will be looking at how the design of PEMFCs can be adapted to ensure ease of recycling and full secondary use of recovered materials. After completion, the knowledge gained will be put to use by the participating industrial partners. It will also inform the design of future fuel cells towards a more circular economic model.