(354b) Improving Performance and Durability of Polymer Electrolyte Fuel Cell Cathodes with High Oxygen Permeability Ionomer

This talk will cover recent advances in the understanding of the impact of the polymer electrolyte binder (i.e., ionomer) on the performance and durability of polymer electrolyte fuel cells for medium and heavy-duty vehicles. Ionomer is critical for proton current conduction through the porous catalyst layers as well as providing an acidic environment at the catalyst interface. However, there are several negative impacts of the thin ionomer coatings on platinum and platinum-alloy catalysts, including greater oxygen transport resistance and poisoning by the ionomer. The increased oxygen transport resistance due to the ionomer will be covered, including the effects of diffusion, solubility, and polymer chain densification at the catalyst surface. The second half of the presentation will focus on recent advances in the development and application of high oxygen permeability ionomer (HOPI) for cathodes. The talk will cover recent characterization, fabrication, testing, and modeling work, highlighting demonstrated reductions in the oxygen transport resistance as well as significant increases in efficiency, power density, and durability.

This work was partially supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy under grant DE-0008822.