Evidence for Micro-Porous Layer Degradation Under Accelerated stress test Conditions

Durability is important for high-volume fuel cell production and commercialization. Different fuel cell components are prone to various types of degradation. The ionomer inside the membrane and catalyst layer undergoes degradation chemically and/or mechanically and Pt may dissolve and coalesce resulting in a loss of active surface area. The carbon in the catalyst support and gas diffusion layer (GDL), meanwhile, may degrade through corrosion and/or erosion [13]. GDL degradation is mainly characterized by the changes in its properties. The micro-porous layer (MPL), which is the most recently added component of modern seven-layer membrane electrode assemblies (MEAs), has a soft and delicate structure comprising of carbon nanoparticles and PTFE that may also be susceptible to degradation. Although MPL is key for high fuel cell performance, particularly at high current densities where water management is a concern, there is no investigation in the literature to date that accounts for its possible degradation behavior during fuel cell operation.