Joseph D. Fairweather

Effect of Hydrophilic Treatment of Microporous Layer on Fuel Cell Performance

The gas diffusion layer in a polymer electrolyte fuel cell is the component primarily responsible for effective water management under a wide variety of conditions. The incorporation of hydrophilic alumosilicate fibers in the microporous layer leads to an improvement in the fuel cell performance associated with a decrease in the mass transport resistance especially under high RH operation. This improvement in performance is obtained without sacrificing performance under low RH conditions. The alumosilicate fibers create domains that wick liquid water away from the catalyst layer. The improved mass transport performance is corroborated by AC impedance and neutron radiography analysis and is consistent with an increase in the average pore diameter inside the microporous layer.

In Situ and Ex Situ Characterization of Carbon Corrosion in PEMFCs

Carbon corrosion is an important degradation mechanism that impairs PEMFC performance through destruction of catalyst connectivity, collapse of pore structure, and loss of hydrophobic character. In this study, carbon corrosion was quantified in situ by measurement of carbon dioxide in fuel cell exhaust gases through non-dispersive infrared spectroscopy (NDIR). Performance degradation was also studied by a DOE protocol for catalyst support accelerated stress testing. Finally, changes in gas diffusion layer and microporous layer carbon surfaces were observed through an ex situ aging procedure.