(480c) Innovations in Proton Exchange Membrane Fuel Cell Cathode Materials and Architectures for High Power Density, and Durability

This talk will highlight our group’s recent research on advancing PGM cathode performance and durability, including the development of novel diagnostics, imaging methods, and simulation tools. The talk will highlight three key areas of innovation for PGM cathodes: 1) highly accessible catalyst supports, 2) high oxygen permeability ionomer for electrodes, and 3) ionomer-free cathodes. First, the talk will highlight the analysis of transport, reaction, and degradation in highly accessible catalysts, including image-based modeling of the coupled transport and reaction in catalyst aggregates that yields new insights into transport resistances in the support as well as Pt particle size effects due to electrokinetic phenomena. The analysis also includes evaluating the redistribution of Pt at the aggregate-scale during voltage cycling with high surface area carbon supports. The talk will further highlight the use of the nano-scale resolution X-ray CT (nano-CT) at Carnegie Mellon for imaging the redistribution of Pt at the MEA scale. Second, the talk will cover our progress on integrating high oxygen permeability ionomer (HOPI) into cathodes for higher performance and durability as part of the Carnegie Mellon-led project in the DOE’s Million Mile Fuel Cell Truck (M2FCT) program. The talk will present our studies on optimizing HOPI inks and coatings, as well as highlighting our experimental and modeling results that unveil the mechanisms behind the higher apparent mass activity and improved durability with HOPI. We will also introduce our approach to evaluating the durability of new electrode ionomers via a simple electrode-specific AST. Finally, the talk will highlight our recent work on ionomer-free cathodes that use novel catalysts to eliminate the need for ionomer and alleviate its negative impacts of reduced ORR activity and high oxygen mass transport.