Effect of Nafion dispersion solvent on the interfacial properties between the membrane and the electrode of a polymer electrolyte membrane-based fuel cell

Abstract

A new Nation binder solution was prepared using a different organic solvent, dimethylacetamide (DMAc), and applied to a polymer electrolyte membrane-based fuel cell. Wide angle X-ray diffraction (WAXD), electrochemical impedance spectroscopy (EIS), and polarization of the fuel cell were carried out to determine the crystallinity of the Nation binder film, the cell resistance, and the fuel cell performance. This new Nation binder film, which was created using a homemade Nation solution containing DMAc, dissolved slower than a recast Nation film that was made using a commercial Nation solution in methanol (2 M). It was found that the slow dissolution of the homemade Nation binder film was due to a more highly developed crystalline morphology, which can lead to good structural integrity in the catalyst layer for long-term operation of the fuel cell. The micellar structure of Nation in the commercial Nation binder solution is broken by new organic solvent, which leads to higher physical chain entanglement between the Nation membrane and the Nation binder during preparation of the membrane/electrode assembly (MEA), thereby improving the interfacial stability between the membrane and the electrode and providing long-term stability of the fuel cell. (C) 2011 Elsevier B.V. All rights reserved.