Multi-scale pore morphologies of a compressed gas diffusion layer for polymer electrolyte fuel cells

• Published in: International journal of heat and mass transfer Vol. 152; p. 119537
• Main Authors: Yoshimune, Wataru, Kato, Satoru, Yamaguchi, Satoshi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-05-2020; Elsevier BV
• Subjects: Compressed gas; Compression; Diffusion layers; Electrolytes; Electrolytic cells; Fuel cells; Gas diffusion layer; Gaseous diffusion; Mathematical analysis; Mercury intrusion porosimetry; Micro-porous layer; Morphology; Oxygen; Performance enhancement; Polymer electrolyte fuel cell; Polymers; Porosity; Proton exchange membrane fuel cells; Substrates; Synchrotron radiation; Synchrotrons; X ray microtomography; X-ray computed micro-tomography; Mercury intrusion porosimetry; Compression; X-ray computed micro-tomography; Gas diffusion layer; Micro-porous layer; Polymer electrolyte fuel cell
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2020.119537

•A higher compressed gas diffusion layer showed the lower cell performance especially at high current densities.•The effect of compression on a gas diffusion layer was investigated using mercury intrusion porosimetry and synchrotron X-ray computed micro-tomography.•The pore diameter of micro-pores within a micro-porous layer was invariant applying compression pressure.
Understanding the pore morphologies of a compressed gas diffusion layer is critical to improve the performance of polymer electrolyte fuel cells. In this study, the effect of compression on the cell performance was investigated. Increasing the gas diffusion layer compression increases oxygen transport resistance. Moreover, the pore morphologies of the compressed gas diffusion layer were investigated using mercury intrusion porosimetry with a simple compression device and synchrotron X-ray computed micro-tomography. The average pore diameter of the fibrous substrate reduced applying compression pressure, whereas that of the micro-porous layer remained unchanged even at high compression (38.6%). In addition, the oxygen transport resistance calculated from the structural parameters of a compressed gas diffusion layer, where porosity and pore diameter are explanatory factors, was in good agreement with the oxygen transport resistance obtained by fuel cell testing.
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