The lifetime of fuel cells is the main obstacle to their large-scale deployment, especially in the transportation sector. Scientists have shown that some localized defects in the electrodes can propagate to the fuel cell membrane. Published in the Journal of Power Sources, this work is based in particular on ultra-sophisticated cells that allow the electrochemical state of fuel cells to be monitored in detail, combined with fine analysis of the materials.
Capable of producing energy from hydrogen and oxygen from the air, fuel cells are valuable tools for the energy transition. Ideally, they would be used in heavy-duty transportation applications, such as trains and trucks, but this would require commercial fuel cell systems to have a lifetime of at least 20,000 hours, which is not yet the case. One way to improve this parameter is to better understand the defects that can occur in the main core elements of a fuel cell, which are often made of brittle materials that are complicated to shape. The thickness of the ionomer membrane, which separates the electrodes and acts as an electrolyte, is less than 20 µm, or one-fifth the thickness of a human hair, while the electrodes take the form of platinum nanoparticles deposited on submicrometer carbon particles.