Power Output and Durability of Electrospun Fuel Cell Fiber Cathodes with PVDF and Nafion/PVDF Binders. Issue 5 (1st January 2016)

• Record Type: Journal Article
• Authors: Brodt, Matthew; Wycisk, Ryszard; Dale, Nilesh; Pintauro, Peter
• Is Part Of: Journal of the Electrochemical Society. Volume 163:Issue 5(2016)
• Page Start: F401
• Page End: F410
• Publication Date: 2016-01-01
• Subjects: carbon corrosion -- cathode binders -- durability -- electrospinning -- fuel cells -- membreane-electrode-assemblies -- nanofibers; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0711605jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Membrane-electrode-assemblies (MEAs) with electrospun nanofiber mat electrodes (0.10 mg/cm 2 Pt loading) and a Nafion 211 membrane were prepared and tested in a H2 /air fuel cell at 100% and 40% relative humidity. The cathode binder was either neat poly(vinylidene fluoride) (PVDF) or a Nafion/PVDF blend (20 to 80 wt% Nafion) and the anode binder was Nafion with poly(acrylic acid). Polarization curves were recorded at 80°C and ambient pressure before, intermittently, and after a carbon corrosion voltage cycling experiment. The Nafion/PVDF cathode MEA with the smallest amount of PVDF (80/20 Nafion/PVDF weight ratio) produced the highest maximum power at beginning-of-life (BoL), 545 mW/cm 2 at 100% RH, which was 35% greater than that for a conventional MEA with a neat Nafion binder. Carbon corrosion scaled inversely with cathode PVDF content, with a 33/67 Nafion/PVDF cathode binder MEA producing the highest end-of-life (EoL) power (330 mW/cm 2 ). MEAs with < 50 wt% PVDF in the cathode binder exhibited a power density decline during carbon corrosion, whereas the power increased during/after carbon corrosion for nanofiber cathodes with binders containing > 50 wt% PVDF due to favorable increases in the hydrophilicity of the carbon support and Pt mass activity, coupled with a lower carbon loss.