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Title: A dedicated compression device for high resolution X-ray tomography of compressed gas diffusion layers

We present an experimental approach to study the three-dimensional microstructure of gas diffusion layer (GDL) materials under realistic compression conditions. A dedicated compression device was designed that allows for synchrotron-tomographic investigation of circular samples under well-defined compression conditions. The tomographic data provide the experimental basis for stochastic modeling of nonwoven GDL materials. A plain compression tool is used to study the fiber courses in the material at different compression stages. Transport relevant geometrical parameters, such as porosity, pore size, and tortuosity distributions, are exemplarily evaluated for a GDL sample in the uncompressed state and for a compression of 30 vol.%. To mimic the geometry of the flow-field, we employed a compression punch with an integrated channel-rib-profile. It turned out that the GDL material is homogeneously compressed under the ribs, however, much less compressed underneath the channel. GDL fibers extend far into the channel volume where they might interfere with the convective gas transport and the removal of liquid water from the cell.
Authors:
 [1] ;  [2] ; ;  [1] ; ;  [3] ;  [4] ; ; ;  [5] ;  [4] ;  [2]
  1. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany)
  2. (Germany)
  3. Universität Ulm, 89069 Ulm (Germany)
  4. Forschungszentrum Jülich, 52425 Jülich (Germany)
  5. BAM Bundesanstalt für Materialforschung und -Prüfung, 12200 Berlin (Germany)
Publication Date:
OSTI Identifier:
22392458
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 86; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; COMPRESSION; DIFFUSION; FIBERS; GEOMETRY; LAYERS; POROSITY; SYNCHROTRONS; TOMOGRAPHY; X RADIATION