Andrew J. L. Steinbach

Influence of Anode GDL on PEMFC Ultra-Thin Electrode Water Management at Low Temperatures

In addition to meeting cost, durability, and rated performance targets, PEM fuel cell systems for automotive traction applications additionally need the capability to transiently attain relatively high current densities at low temperatures to provide drive-away power. Additionally, the system ideally would be robust towards atypical shutdown/restart events which may leave the fuel cell stack in a relatively flooded state.

A New Paradigm for PEMFC Ultra-Thin Electrode Water Management at Low Temperatures

In this paper, we provide initial results of a novel method which dramatically improved the performance of ultra-thin electrode polymer electrolyte membrane fuel cells under highly water-condensing operating conditions, realized via modification of the anode gas diffusion layer and utilization of reduced anode reactant pressures, including sub-atmospheric pressure down to 20kPa. Measurements indicated that the sub-atmospheric anode reactant acted to greatly reduce the water flux exiting out the cathode, likely reducing cathode water flooding and oxygen transport limitations.

Fine Tuning Highly Active Pt 3 Ni 7 Nanostructured Thin Films for Fuel Cell Cathodes

Polymer electrolyte membrane fuel cells (PEMFCs) are under intense research and development for transportation applications. It has been shown that a highly active, lower cost, oxygen reduction reaction (ORR) catalyst can be made by replacing a portion of the costly Pt catalyst with a transition metal, in this case Ni [1]. Further gains can be achieved through dealloying the PtNi alloy catalyst to create a Ptrich skin or shell, although spontaneous dealloying during fuel cell operation poses a significant durability issue [2]. While usually deployed in nanoparticle form, highly active Pt3Ni7 nanostructured thin films (NSTF) have also been demonstrated, and the substantial increase in both the specific activity and specific surface area has been attributed to a complex interplay between composition, grain size, lattice strain, and the catalyst nanoparticle morphology, e.g., Pt-skin, -shell or -skeleton structures [3].