Parameters estimation of a PEM fuel cell polarization curve and analysis of their behavior with temperature

The paper shows and discusses a procedure of parameter estimation applied to the evaluation of some operating parameters of a proton-exchange membrane fuel cell (PEMFC). First, a brief literature review about the main parameters (exchange current density, cell resistance, internal current density and limiting current density) has been done. Then the analytical model adopted to describe the polarization curve has been discussed. Based on this model, a parameter analysis has been done, and it has been shown that three parameters of the cell polarization curve model can be simultaneously estimated: the cathode exchange current density, the cell resistance and the internal current density. To evaluate these parameters both a set of our measurements on a PEM single cell (active area of 25 cm2 and Nafion 115 membrane) and data from other authors has been considered. The cell has been fed with pure hydrogen and air, the cell temperature has been varied from 50 °C to 80 °C, and accordingly the reactants have been introduced in the cell humidified at the same temperature. The parameters have been estimated in each operating conditions of the cell, and their behavior, as a function of the cell operating temperature, has been discussed.