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Modeling of two-phase behavior in the gas diffusion medium of PEFCs via full morphology approach

 
: Schulz, V.P.; Becker, J.; Wiegmann, A.; Mukherjee, P.P.; Wang, C.-Y.

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Journal of the Electrochemical Society 154 (2007), No.4, pp.B419-B426
ISSN: 0013-4651
English
Journal Article
Fraunhofer ITWM ()

Abstract
A full morphology (FM) model has been developed for studying the two-phase characteristics of the gas diffusion medium in a polymer electrolyte fuel cell (PEFC). The three-dimensional (3D) fibrous microstructure for the nonwoven gas diffusion layer (GDL) microstructure has been reconstructed using a stochastic technique for Toray090 and SGL10BA carbon papers. The FM model directly solves for the capillary pressure-saturation relations on the detailed morphology of the reconstructed GDL from drainage simulations. The estimated capillary pressure-saturation curves can be used as valuable inputs to macroscopic two-phase models. Additionally, 3D visualization of the water distribution in the gas diffusion medium suggests that only a small number of pores are occupied by liquid water at breakthrough. Based on a reduced compression model, the two-phase behavior of the GDL under mechanical load is also investigated and the capillary pressure-saturation relations are evaluated for different compression levels.

: http://publica.fraunhofer.de/documents/N-59394.html