Performance of Membrane-Electrode Assembly in the PEMFC under the Constant Voltage Procedure

The present study aims at obtaining a better understanding on the changes that the membrane electrode assembly (MEA) of a proton exchange membrane fuel cell (PEMFC) experiences along time under voltage control procedure. Constant voltage 0.6 V was set-up at 55 oC. After every hour, the electrochemical characterization was performed using polarization curves, and electrochemical impedance spectroscopy (EIS). Polarization curves showed an effective increase of the MEA performance along time, with the maximum power density increasing from 1141 mW to 1481 mW. From the impedance experiments it was observed that the proton exchange membrane (PEM) and the charge transfer resistances decrease with time.