Design and Testing of an Experimental Model to Measure Interfacial Permeability in a Polymer Electrolyte Fuel Cell

Open Access
Comerford, John Jeffrey
Area of Honors:
Mechanical Engineering
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Matthew M Mench, Thesis Supervisor
  • Mary I Frecker, Faculty Reader
  • Matthew M Mench, Honors Advisor
  • polymer electrolyte fuel cell
  • interfacial permeability
The interface of the microporous layer (MPL) and catalyst layer (CL) in a polymer electrolyte fuel cell (PEFC) plays an important role in reactant transport and cathode water management. It is believed that there may be a connection between the in-plane permeability of fluids at this interface and cathode mass transport losses that limit PEFC performance. Experimental work, however, is needed to validate and confirm this hypothesis. The goal of this project was to design, construct, and validate a test device to study the effects of MPL and CL selection, operating temperature, and permeating fluid on interfacial permeability. A radial flow device was designed and constructed to measure the pressure drop and flow rate across a compressed MPL|CL interface using both water and air as the impregnating fluid. Initial testing was performed on an MPL|CL sample, and the results were compared to a permeability model for radial, incompressible flow. The results of the air experiments were in strong agreement with the linear relationship between the pressure gradient and flow rate given by the model. A non-linear trend, however, was observed when testing with water as the impregnating liquid, indicating the need for improvements to the experiment or a lack of complete physical description in the theoretical model. Future work should include adding temperature and compression controls and extensive testing on a variety of MPL and CL combinations in order to better evaluate the correlation between interfacial permeability and mass transport losses.