Analytical modeling of PEM fuel cell i–V curve

The performance of a fuel cell is characterized by its i–V curve. In this study, the performance of a bench scale fuel cell stack, run on hydrogen/air, is measured experimentally for different air flow rates and temperatures. The experimental data, obtained from the 40-W proton exchange membrane fuel cell (PEMFC), are used in estimating the parameters of a completely analytical model that describes the i–V curve. The analytical model consists of the three fundamental losses experienced by a fuel cell, namely: activation, ohmic, and concentration losses. The current loss is also considered in the model. While the Tafel constants, ohmic resistance, and the concentration loss constant are estimated through regression, the limiting current density and the current loss are obtained through measurements. The effect of temperature on the fuel cell performance, exchange current density, and current loss is also investigated. Both the exchange current density and the current loss are plotted against temperature on an Arrhenius-like plot and the related parameters are estimated. The theoretical equations derived in the literature, which model fuel cell performance, are found to reasonably fit the obtained experimental data.