Review: Durability and Degradation Issues of PEM Fuel Cell Components

Besides cost reduction, durability is the most important issue to be solved before commercialisation of PEM Fuel Cells can be successful. For a fuel cell operating under constant load conditions, at a relative humidity close to 100% and at a temperature of maximum 75 °C, using optimal stack and flow design, the voltage degradation can be as low as 1–2 μV·h. However, the degradation rates can increase by orders of magnitude when conditions include some of the following, i.e. load cycling, start–stop cycles, low humidification or humidification cycling, temperatures of 90 °C or higher and fuel starvation. This review paper aims at assessing the degradation mechanisms of membranes, electrodes, bipolar plates and seals. By collecting long-term experiments as well, the relative importance of these degradation mechanisms and the operating conditions become apparent.