Communication—Contribution of Catalyst Layer Proton Transport Resistance to Voltage Loss in Polymer Electrolyte Water Electrolyzers

DOI:

10.1149/2.0031815jes

Authors:

Ugljesa Babic, Thomas J. Schmidt, Lorenz Gubler

Abstract:

Mass transport losses (η_mtx) play a significant role at high current densities in polymer electrolyte water electrolyzers (PEWEs). Previous work has shown that η_mtx depends on the porous transport layer (PTL) structure, although a clear correlation between the material morphology and η_mtx has not been established. In this work, we experimentally determine the overpotential η^H+_CLa associated with the proton transport in the anodic catalyst layer by measuring the ionic resistance in the catalyst layer using electrochemical impedance spectroscopy (EIS) and the transmission-line model. We found that overpotentials, including η^H+_CLa, depend on the PTL morphologic surface properties.