Open AccessX‐ray tomography of morphological changes after freeze/thaw in gas diffusion layers
Author(s) -
Je Junho,
Kim Jongrok,
Kaviany Massoud,
Son Sang Young,
Kim MooHwan
Publication year - 2011
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049511023156
Subject(s) - electrolyte , capillary action , materials science , polymer , membrane , diffusion , gaseous diffusion , fuel cells , tomography , proton exchange membrane fuel cell , chemical engineering , analytical chemistry (journal) , chemistry , composite material , chromatography , electrode , optics , thermodynamics , physics , biochemistry , engineering
Liquid water produced in a polymer electrolyte membrane fuel cell experiences a freeze/thaw cycle when the cell is switched off and on while operating at ambient temperatures below freezing. This freeze/thaw cycle permanently deforms the polymer electrolyte membrane fuel cell capillary structures and reduces both the cell life and its ability to generate electric power. The X‐ray tomography facility at the Pohang Accelerator Laboratory was used to observe the freeze/thaw effects on the gas diffusion layer (GDL), which is the thickest capillary layer in the cell. Morphological changes in the GDL under a water freeze/thaw cycle were observed. A scenario in which freeze/thaw cycles affect fuel cell performance is suggested based on images from X‐ray tomography.