On-Line PEM Fuel Cell Hydration Marker Based on Frequency Response Analysis

PEM fuel cell hydration monitoring is a key factor to keep a humid balance inside the proton exchange membrane. It is well known that, high humid level inside of the fuel cell can flooding the diffusion layer and decreasing the mass flow of reactant gases. On the other hand, a drying condition decreases the charge transfer between the cell anode and cathode. Both conditions cause irreversible damage in the proton exchange membrane and drop the fuel cell performance. In this study, the experimental data obtained from PEM fuel single-cell are analyzed by electrochemical impedance spectroscopy (EIS). These data are treated and analyzed to be modeled using a circuital model. Also, it is developed a method to predict the humid that the single-cell is experimenting when the EIS is on-line by injecting the perturbation current to fuel cell system operating in the field. The results obtained from the model against experimental data, they fit in 95%.