Simulation of membrane chemical degradation in a proton exchange membrane fuel cell by computational fluid dynamics

Membrane chemical degradation is a major contributor to the still limited lifetime of proton exchange membrane (PEM) fuel cells. In the present work, this phenomenon is simulated by computational fluid dynamics (CFD). The main advantage of the CFD model is that it can provide the degradation profile across the cell active area. Results reveal that degradation accelerates when voltage, temperature and pressure are increased and when reactants humidity and membrane thickness are decreased. Moreover, membrane deterioration is found to be more severe where oxygen pressure is higher, and more heterogeneous when oxygen distribution is less uniform. Generally, conditions that increase current production and thus oxygen depletion along the cell increase degradation heterogeneity. The flow field design is also found to influence the membrane degradation spatial profile. The modeling strategy here applied, the incorporation of a degradation sub-model into a general-purpose CFD code, can be used to include other degradation mechanisms.