Development of high-performance roll-to-roll-coated gas-diffusion-electrode-based fuel cells

This study focuses on determining fabrication conditions to create high-performance roll-to-roll-coated (R2Rcoated) gas-diffusion electrodes (GDEs) for proton-exchange-membrane fuel cells (PEMFCs). Here, we examine how process conditions influence the distribution of ionomer in the electrode, which is shown to be critical for high performance. Using a combination of Kelvin probe, X-ray photoelectron spectroscopy, and nano-scale X-ray computed tomography we show that formation of an ionomer-rich surface is promoted by using a higher drying rate. We show that R2R-coated GDEs have higher surface ionomer concentration than spray-coated GDEs, which enables these R2R-coated GDEs to not need an additional ionomer overlayer, as is typically the case for spraycoated GDEs. This will reduce the number of processing steps and lower material costs in a manufacturing setting. This work shows that with the appropriate selection of materials, ink formulation, and processing conditions, direct-coated GDEs are a viable pathway for fuel cell manufacturing.

Automated summary

This study focuses on determining fabrication conditions to create high-performance roll-to-roll-coated gas-diffusion electrodes for proton-exchange-membrane fuel cells. It was found that using a higher drying rate can promote the formation of an ionomer-rich surface in the electrode. The R2R-coated GDEs have a higher surface ionomer concentration than spray-coated GDEs, eliminating the need for an additional ionomer overlayer and reducing processing steps and manufacturing costs.