3D microstructure modeling of compressed fiber-based materials

• Published in: Journal of power sources Vol. 257; pp. 52 - 64
• Main Authors: Gaiselmann, Gerd, Tötzke, Christian, Manke, Ingo, Lehnert, Werner, Schmidt, Volker
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2014; Elsevier
• Subjects: Applied sciences; Compressed; Compressing; Compression model; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fiber-based materials; Fibers; Fuel cells; Gas-diffusion layer; Mathematical models; Microstructure; PEMFC; Simulated annealing; Stochastic modeling; Three dimensional; Three dimensional models; Fiber-based materials; PEMFC; Stochastic modeling; Compression model; Gas-diffusion layer; Simulated annealing; Stochastic model; Compression; Polymer electrolytes; Polymer solid electrolyte; Diffusion layer; Modeling; Microstructure; Proton exchange membrane fuel cells
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2014.01.095

A novel parametrized model that describes the 3D microstructure of compressed fiber-based materials is introduced. It allows to virtually generate the microstructure of realistically compressed gas-diffusion layers (GDL). Given the input of a 3D microstructure of some fiber-based material, the model compresses the system of fibers in a uniaxial direction for arbitrary compression rates. The basic idea is to translate the fibers in the direction of compression according to a vector field which depends on the rate of compression and on the locations of fibers within the material. In order to apply the model to experimental 3D image data of fiber-based materials given for several compression states, an optimal vector field is estimated by simulated annealing. The model is applied to 3D image data of non-woven GDL in PEMFC gained by synchrotron tomography for different compression rates. The compression model is validated by comparing structural characteristics computed for experimentally compressed and virtually compressed microstructures, where two kinds of compression – using a flat stamp and a stamp with a flow-field profile – are applied. For both stamps types, a good agreement is found. Furthermore, the compression model is combined with a stochastic 3D microstructure model for uncompressed fiber-based materials. This allows to efficiently generate compressed fiber-based microstructures in arbitrary volumes. •Introduction of model describing uniaxially compressed fiber-based materials.•It allows to virtually generate realistically compressed gas-diffusion layers (GDL).•Compression model is combined with a model for uncompressed non-woven GDL.•This allows to efficiently generate compressed GDL in arbitrary 3D volumes.