Influence of Contact Pressure on Hydrogen Crossover and Polarization Behavior in AEM Water Electrolysis
Jan Witte, Patrick Trinke, Boris Bensmann, Maik Becker, Richard Hanke‐Rauschenbach, Thomas Turek
Abstract
Anion exchange membrane water electrolysis (AEMWE) holds the potential to become a key technology for future hydrogen production. In the present study, the influence of contact pressure on hydrogen crossover and polarization behavior is systematically investigated in a range from 0.5 MPa to 2.5 MPa in 0.5 MPa increments. The electrodes were prepared as catalyst-coated substrate (CCS), applying 3 mg cm −2 NiFe 2 O 4 on the anode substrate and 0.5 mg cm −2 Pt on the cathode substrate. It is demonstrated that an elevated contact pressure results in a decreased high frequency resistance ( R HF ), while simultaneously leading to a significantly increased hydrogen content on the anode side. At 3 A cm −2 the ohmic resistance decreases by approx. 30 mΩ cm 2 when increasing the contact pressure from 0.5 MPa to 2.5 MPa, whereas the anodic hydrogen content increased by approx. 1.5 vol.% respectively. Additionally, it can be observed that the selection of the gas diffusion layer (GDL) material has a strong effect on hydrogen crossover, while the influence on cell voltage is insignificant. Overall, these results show a promising starting point for further investigations on the interactions between cathode properties, cell compression and anodic gas contamination.