Pore-scale liquid water visualization for understanding water transport in operating fuel cells

July 03, 2019

Pranay Shrestha (1), ChungHyuk Lee (1), Kieran F. Fahy (1), Manojkumar Balakrishnan (1), Nan Ge (1), Aimy Bazylak (1)
ECS Transactions, 92, Issue 8, July 2019: 61-69. DOI: 10.1149/09208.0061ecst


To implement successful water management strategies in polymerelectrolyte membrane (PEM) fuel cells, we need to understand how the complex heterogenous nature of the gas diffusion layer (GDL) impacts the pore-scale transport of liquid water. Here, we investigated the 3-D pore-scale liquid water distribution within the cathode GDL via in operando synchrotron X-ray tomography during low current density fuel cell operation to capture the early appearance of liquid water pathways. We found that the invasion of liquid water into the GDL only partially filled certain GDL pores. Liquid water wicked along some GDL fibers, which was attributed to the hydrophilic nature of carbon fiber and the presence of pore-scale mixed wettability within the GDLs. Mixed wettability and partial pore filling should be considered in the pore-scale modeling and design of next-generation GDLs.

How Our Software Was Used

Dragonfly was used to visualize liquid water distribution in 3-D and obtain isometric views

Author Affiliation

(1) Thermofluids for Energy and Advanced Materials Laboratory, Department of Mechanical & Industrial Engineering, Institute for Sustainable Energy, Faculty of Applied Science and Engineering, University of Toronto, Toronto, Ontario, Canada.