Modelling of the operation of Polymer Exchange Membrane Fuel Cells in the presence of electrodes flooding

This paper presents a simple pseudo-2D model of Polymer Exchange Membrane Fuel Cell including mass transport limitation due to flooding. The gas channels are assumed parallel to the membrane and the changes in gas composition due to the electro-chemical reactions are taken into account. The overpotentials at anode and cathode are evaluated by a Tafel law while a simple reasoning about heat transfer shows that at the highest intensities, liquid water appears at the cathode-backing layers interface. It is assumed that the appearance of liquid defines the local value of the limiting current density. The results of this model differ from those obtained with a conventional 1D approach when there is a high difference in water inlet concentration between hydrogen and air channels. Furthermore, the pseudo-2D model proposes a credible representation of the high-intensity range of the polarization curve, and allows to determine the limiting current in the whole cell, as a function of gases hydration.