Interfacial Water-Transport Effects in Proton-Exchange Membranes [electronic resource].
- Berkeley, Calif. : Lawrence Berkeley National Laboratory. Environmental Energy Technologies Division, 2009.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 33 : digital, PDF file
- Additional Creators:
- Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory. Environmental Energy Technologies Division
United States. Department of Energy. Office of Scientific and Technical Information
- It is well known that the proton-exchange membrane is perhaps the most critical component of a polymer-electrolyte fuel cell. Typical membranes, such as Nafion(R), require hydration to conduct efficiently and are instrumental in cell water management. Recently, evidence has been shown that these membranes might have different interfacial morphology and transport properties than in the bulk. In this paper, experimental data combined with theoretical simulations will be presented that explore the existence and impact of interfacial resistance on water transport for Nafion(R) 21x membranes. A mass-transfer coefficient for the interfacial resistance is calculated from experimental data using different permeation cells. This coefficient is shown to depend exponentially on relative humidity or water activity. The interfacial resistance does not seem to exist for liquid/membrane or membrane/membrane interfaces. The effect of the interfacial resistance is to flatten the water-content profiles within the membrane during operation. Under typical operating conditions, the resistance is on par with the water-transport resistance of the bulk membrane. Thus, the interfacial resistance can be dominant especially in thin, dry membranes and can affect overall fuel-cell performance.
- Published through SciTech Connect.
Journal of Fuel Cell Science and Technology ISSN 1550-624X FT
Weber, Adam; Kienitz, Brian; Yamada, Haruhiko; Nonoyama, Nobuaki.
- Funding Information:
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