Carbon Nanotube and Nanofiber Film-based Membrane Electrode Assemblies
The present invention describes a carbon-materials-based membrane electrode assembly (MEA) for a fuel cell comprising a catalyst layer.
The catalyst layer can include a plurality of catalyst nanoparticles, e.g., platinum, disposed on buckypaper. A particular feature of the MEA, according to the invention, is that the buckypaper film is fabricated with carbon nanotubes, nanofibers, or a mixture thereof, with little or no binder. The buckypaper additionally can be treated with high temperature for improving electrical and/or mechanical properties of the structure. The microstructure of the buckypaper can be tailored by adjusting the starting materials and nanotubes dispersion so as to achieve a desired porosity, pore size, surface area, and electrical conductivity for use as the catalyst layer of the MEA. The catalyst nanoparticles are preferably deposited directly at the most efficient sites of the buckypaper to thereby maximize the three-phase reaction coefficient.
The MEA so fabricated can have a higher catalyst utilization rate at the electrodes, can provide higher power output, and can have enhanced oxidation resistance, and well as a longer service life, as compared to conventionally-fabricated fuel cells.