Chris J. Lee, Yi-Hao Pai, Gong-Ru Lin, Fuh-Sheng Shieu

Teflon-Coated Carbon Fiber Core/Shell Structure Based Hydrophobic Gas-Diffusion Electrode for Proton Exchange Membrane Fuel Cells

Journal of the Electrochemical Society 157 (2010) B256-B259

Teflon-like film-covered carbon fiber fabricated using the CHF(3) plasma technology as a core/shell-like structure for the hydrophobic porous gas diffusion electrode (GDE) formation is successfully demonstrated for use in proton exchange membrane fuel cells (PEMFCs). The Teflon-like film, with thicknesses up to 1200 nm, produces an optimum water contact angle (WCA) of 131 degrees, which is attributed to the superior cross-linking density and greater number of -CF(2) functional groups. When compared with the film grown on a planar Si substrate, a similar WCA tendency was clearly observed; nevertheless, all of the obvious value was reduced in Delta WCA/WCA=23% due to the Lotus effect. The PEMFC measurements show that GDE with a Teflon-like film thickness of 1200 nm modules has the best performance with a maximum power density of 0.52 W/cm(2). However, cell performance tends to decline when the film thickness is increased to 2700 nm, a result which is ascribed to the great sheet resistance and Teflon-like film cracks of the GDE.

This article may also be available to you online

Cited Articles

1. Choukourov A., Pihosh Y., Stelmashuk V., Biederman H., Slavínská D., Kormunda M., Zajíčková L.,
   RF Sputtering of Composite SiOx/Plasma Polymer Films and Their Basic Properties,
   Surface and Coatings Technology 151 (2002) 214–217