| Proton Exchange Membrane Fuel Cells (PEMFCs) and PEM Electrolyzer were characterized using Electrochemical Impedance Spectroscopy (EIS). Faradaic resistance (RO), kinetic and mass transfer parameters such as charge transfer resistance, double layer capacitance and diffusion coefficient from Warburg's theory were obtained. The PEM electrolyzer and PEM fuel cell use perfluorocarbon sulfonic acid (PFSA ) ionomer (Nafion(TM)) as the electrolyte. The PEMFC showed more performance losses than the PEM Electrolyzer, these losses were corroborated with Warburg's theory. The PEMFC exhibited performance losses related with mass transfer. Two PEMFCs with different catalyst loading, 0.1 and 0.3mgPt/cm2, were compared respectively, and the memory effects were analyzed. The PEMFC with 0.3mgPt/cm2 presented better properties and less performances losses than the PEMFC with 0.1mgPt/cm 2. The memory effects of both PEMFCs were found to be related to the water content and management in the cells. This phenomenon was more evident at low applied potentials. |
