Measuring the current distribution with sub-millimeter resolution in PEFCs: II. impact of operating parameters

Mathias Reum*, Stefan A. Freunberger, Alexander Wokaun, Felix N. Büchi

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

In the first paper of this series, an experimental technique for measuring the current-density distribution with a resolution better than the sub-millimeter scale of the channel and rib structures in the flow-field plates of polymer electrolyte fuel cells (PEFCs) was introduced. This method is extended to the determination of local membrane resistance with the same spatial resolution in the present paper. The combined measurement of current and resistance allows for investigating the interaction of mass- and charge-transport processes, which determine the local rate distribution across the domain of channels and ribs. Therewith, the influence of relevant operating parameters such as reactant composition, dew points, and cell compression on local current generation is investigated. The results show that the distribution of water and oxidant across the channel and rib are the main reasons for significant current gradients on a scale smaller than a millimeter. Humidity variation mainly affects the membrane resistance under the channel, while reactant concentration predominantly influences current generation under the rib-covered cell area.

Original languageEnglish
Pages (from-to)B301-B310
JournalJournal of the Electrochemical Society
Volume156
Issue number3
DOIs
Publication statusPublished - 9 Feb 2009
Externally publishedYes

ASJC Scopus subject areas

  • Electrochemistry
  • Electronic, Optical and Magnetic Materials
  • Materials Chemistry
  • Surfaces, Coatings and Films
  • Renewable Energy, Sustainability and the Environment
  • Condensed Matter Physics

Fields of Expertise

  • Advanced Materials Science

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