On the Experimental Investigation of the Clamping Pressure Effects on the Proton Exchange Membrane Water Electrolyser Cell Performance

The intermittent renewable and power energy sources can be effectively utilized usinghydrogen energy storage technology. Hydrogen has the highest energy capacity per unitweight of any known other fuel. Also it is considered as a promising energy carrier and a futurereplacement for fossil fuel energy sources. The proton exchange membrane water electrolyser(PEMWE) is the most candidate technology to produce hydrogen from renewable energysources. PEMWE cell splits water into hydrogen and oxygen when an electric current is passedthrough it. Electrical current forces the positively charged ions to migrate to negatively chargedcathode, where hydrogen is reduced. Meanwhile, oxygen is produced at the anode sideelectrode and escape as a gas with the circulating water.

In the recent few years, PEMWE’s R&D has inched towards; operating conditions; such asincreased operating temperature and cathode-anode high differential pressure operation, flowfield design, stack development, and modeling. In this work the effect of clamping pressure onthe PEMWE cell performance is studied. A 50 cm² active area PEMWE cell with doubleserpentine flow field channels for the anode and cathode side is used. The standardelectrochemical technique to characterize the performance of electrochemical cells is thepolarization curve. Thus, the IV curves are measured at different clamping pressures. Also, the electrochemical impedance spectroscopy (EIS) is used as a non-invasive technique tocharacterize the electrochemical processes at different clamping pressures. All thesemeasurements are conducted at constant cell temperature (70°C) and atmospheric pressure.Furthermore, to ensure a high confidence level in the obtained data, experiments are repeatedfew times.

Early results for polarization curve predict that the PEMWE cell performance increases withincreasing the clamping pressure at fixed temperature and current density. This can beelucidated by the EIS measurements which predict an increment in ohmic and activation