In the recent few years, PEMWE’s R&D has inched towards; operating conditions; such as increased operating temperature and cathode-anode high differential pressure operation, flow field design, stack development, and modeling. In this work the effect of clamping pressure on the PEMWE cell performance is studied. A 50 cm2 active area PEMWE cell with double serpentine flow field channels for the anode and cathode side is used. The standard electrochemical technique to characterize the performance of electrochemical cells is the polarization curve. Thus, the IV curves are measured at different clamping pressures. Also, the electrochemical impedance spectroscopy (EIS) is used as a non-invasive technique to characterize the electrochemical processes at different clamping pressures. All these measurements are conducted at constant cell temperature (70°C) and atmospheric pressure. Furthermore, to ensure a high confidence level in the obtained data, experiments are repeated few times.
Early results for polarization curve predict that the PEMWE cell performance increases with increasing the clamping pressure at fixed temperature and current density. This can be elucidated by the EIS measurements which predict an increment in ohmic and activation resistance at lower clamping pressure values for the same temperature and current density.