Transport phenomena and performance limits in polymeric electrolyte membrane fuel cells

In polymeric electrolyte fuel cells the hydration level of the perfluosulphonic membrane used as electrolyte is a very important parameter for proton conductivity. Only an accurate local description of the hydration condition of the membrane allows a reliable prediction of cell performance. In this work we refer to the development of a detailed model of a polymeric fuel cell that takes into account a local integration of mass and charge transport equations throughout the membrane and the mass, energy (gas and solid) and momentum balances on the plane of the cell. The calculation of all the voltage losses and the temperature and humidity conditions on both the cathodic and the anodic sides helps in understanding how to avoid undesirable working conditions. Of particular interest is the possibility of simulating different feeding systems (co-flow, counter-flow, cross-flow) as well as different flow fields (conventional, serpentine, interdigitated). The modelling results for polymeric fuel cells, fed by hydrogen or methanol, are presented in terms of characteristic curves for different flow geometries and operative parameters and are compared with literature data.