(Invited) Towards Addressing Fundamental Manufacturing Questions for Polymer Electrolyte Fuel Cell Electrodes

As a result of the expansion of material handling, backup power, and now, automotive markets for low-temperature fuel cells, the need to understand and overcome challenges to high-volume electrode production has never been greater. OEMs and system integrators globally are addressing these challenges specific to their systems and materials. However, fundamental questions remain to be answered, to the benefit of the entire industry. The interactions between the supported catalyst, ionomer, and dispersing media in the electrode ink, the method of dispersion of the solid constituents of the ink, and the interaction of the ink with the substrate, strongly impact the morphology and ultimately performance of the electrode. The ink formulation must also be appropriate for the coating and drying processes, the physics and parameters of which also impact electrode morphology and performance. Research efforts to address these questions are complicated by multiple pathways to construct the membrane electrode assembly (MEA) – including decal-transfer, catalyst-coated membrane, and gas-diffusion electrode structures – as well as a great variety of coating processes that could be used. These different structures not only potentially affect the performance of the MEA – and differently under different operating conditions – but they affect cost. In this talk, manufacturing pathways and challenges for electrodes will be discussed, and an overview of activities at the National Renewable Energy Laboratory to address these fundamental questions will be given.