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.
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany.
C
C
Tötzke
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany.
I
I
Manke
Universität Ulm, 89069 Ulm, Germany.
G
G
Gaiselmann
Forschungszentrum Jülich, 52425 Jülich, Germany.
J
J
Bohner
BAM Bundesanstalt für Materialforschung und -Prüfung, 12200 Berlin, Germany.
B R
BR
Müller
BAM Bundesanstalt für Materialforschung und -Prüfung, 12200 Berlin, Germany.
A
A
Kupsch
BAM Bundesanstalt für Materialforschung und -Prüfung, 12200 Berlin, Germany.
M P
MP
Hentschel
Universität Ulm, 89069 Ulm, Germany.
V
V
Schmidt
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany.
J
J
Banhart
Forschungszentrum Jülich, 52425 Jülich, Germany.
W
W
Lehnert