Investigation of Electrochemical Impedance Spectroscopy Response of Membrane-Electrode Assembly with Time in the PEMFCs

The main objective of this study is to understand comprehensively of the impedance behavior of the polymer electrolyte membrane fuel cell (PEMFC) with time under a standard membrane-electrode assembly (MEA) procedure. A procedure was developed by US fuel cell council (USFCC) which contain a combination of constant current and voltage control and cyclic potential processes. The impedance response of MEA was evaluated by the electrical model. Based on the impedance spectra, charge transfer resistance (Rct), mass transfer resistance (Rmt) and solution resistance (Rs) were extracted using expanded Randle's analogous circuits. Results indicated that the proton conductivity of the PEM, catalyst area and activity and transportation of reactants to the catalyst surface increase with time.