Examining the mass transport resistance of porous transport layers at the rib/channel scale in polymer electrolyte membrane water electrolyzers: Modeling and design Articles uri icon

authors

  • GARCIA SALABERRI, PABLO ANGEL
  • Lang, Jack Todd
  • Chang, Hung Ming
  • Firas, Nausir
  • Shazhad, Hasan
  • Zenyuk, Iryna V.

publication date

  • July 2025

start page

  • 1

end page

  • 18

volume

  • 244

International Standard Serial Number (ISSN)

  • 0017-9310

Electronic International Standard Serial Number (EISSN)

  • 1879-2189

abstract

  • The porous transport layer (PTL) plays a relevant role in the efficiency of polymer electrolyte membrane water electrolyzers (PEMWE). Extraction of good design guidelines for this porous component is necessary for efficient water/oxygen transport. In this regard, numerical modeling provides a versatile tool to examine large parameter set and determine optimal PTL conditions to be verified experimentally. Here, a hybrid model is presented to analyze two-phase transport of oxygen and water in the anode PTL of a PEMWE. Oxygen capillary transport is modeled with a multi-cluster invasion-percolation algorithm, while water convective transport is modeled with a continuum formulation that incorporates the blockage of gas saturation. The model is validated against in-operando X-ray computed tomography data of the oxygen saturation distribution at the rib/channel scale. Subsequently, a comprehensive parametric analysis is presented, considering the following variables: (𝑖) PTL slenderness ratio, (𝑖𝑖) flow-field open area fraction, (𝑖𝑖𝑖) PTL isotropy, (𝑖𝑣) PTL average pore radius, and (𝑣) PTL pore-size heterogeneity. Among other conclusions, the results show that the water transport resistance under the rib can lead to non-negligible mass transport losses at high current density. Water transport from the channel to the catalyst layer can be promoted by: (𝑖) the use of PTLs with a slenderness ratio, defined as the PTL thickness to rib half-width ratio, around 0.5, (𝑖𝑖) the increase of the flow-field open area fraction, (𝑖𝑖𝑖) the design of highly anisotropic PTLs with a relatively large pore radius between 𝑟𝑝 ∼ 10 − 40 μm, and (𝑖𝑣) increasing the homogeneity of the PTL microstructure.

subjects

  • Chemistry
  • Industrial Engineering
  • Materials science and engineering

keywords

  • design; mass transport; modeling; pemwe; pore network; ptl