Modeling Overpotentials Related to Mass Transport through Porous Transport Layers of PEM Water Electrolysis Cells

verfasst von: Gergely Schmidt, Michel Suermann, Boris Bensmann, Richard Hanke-Rauschenbach, Insa Neuweiler
Abstract: Porous transport layers (PTL) are key components of proton exchange membrane water electrolysis (PEMWE) cells controlling species transport. Further optimization requires better understanding of how PTLs influence overpotentials. In this work, the data from an electrochemical overpotential breakdown is compared to a state-of-the-art model, which includes a Nernstian overpotential description, two-phase Darcian flow and advective-diffusive mass transport. Model parameters are derived from X-ray tomographic measurements, pore-scale calculations, standard models for porous materials and by transferring ex situ measurements from other materials. If the parameter set is available, model results and experimental data match well concerning PTL-related overpotentials at different current densities and operating pressures. Both experimental and modeling results suggest that mass transport through PTLs does not affect a considerable, pressure-independent share of mass transport overpotentials. Both model results and experimental findings conclude that mass transport through the cathode PTL causes overpotentials more than twice as high as through its anode counterpart. Further research opportunities regarding the relationship between PTL bulk properties and experimentally determined mass transport overpotentials are identified.
Organisationseinheit(en): Institut für Strömungsmechanik und Umweltphysik im Bauwesen
Fachgebiet Elektrische Energiespeichersysteme
Typ: Artikel
Journal: Journal of the Electrochemical Society
Band: 167
ISSN: 0013-4651
Publikationsdatum: 24.07.2020
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Elektronische, optische und magnetische Materialien, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Oberflächen, Beschichtungen und Folien, Elektrochemie, Werkstoffchemie
Ziele für nachhaltige Entwicklung: SDG 7 – Erschwingliche und saubere Energie
Elektronische Version(en): https://doi.org/10.1149/1945-7111/aba5d4 (Zugang: Offen)