Heterogeneous through-plane distributions of polytetrafluoroethylene in polymer electrolyte membrane fuel cell gas diffusion layers

• Published in: Journal of power sources 2012-03, Vol.201, p.219-225
• Main Authors: Rofaiel, A., Ellis, J.S., Challa, P.R., Bazylak, A.
• Format: Article
• Language: English
• Subjects: Applied sciences; 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; Fuel cells; Gas diffusion layer; Heterogeneous; Polymer electrolyte membrane fuel cell; Polytetrafluoroethylene (PTFE); Wettability distribution
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2011.11.005

► Scanning Electron Microscopy (SEM) Energy Dispersive X-ray Spectrometry imaging. ► Heterogeneous Polytetrafluoroethylene (PTFE) distributions of gas diffusion layers. ► PTFE distributions for paper, felt, and cloth gas diffusion layers (GDLs). ► SEM Backscatter Electron Imaging (SEI) of morphological features of the GDL. Polytetrafluoroethylene (PTFE) has been widely employed as a hydrophobic coating for the polymer electrolyte membrane fuel cell (PEMFC) gas diffusion layer (GDL). Despite a number of application techniques available, a method of quantifying the distribution of PTFE in the through-plane direction of the GDL has not been well established. In this work, we present a novel method for measuring heterogeneous through-plane PTFE distributions within the bulk of the GDL using scanning electron microscopy (SEM) energy dispersive X-ray spectrometry (EDS) imaging. To the authors’ best knowledge, this work represents the first direct experimental investigation of the through-plane distributions of PTFE for various commercially available GDLs. SEM EDS imaging of typical PTFE distributions for paper, felt, and cloth GDLs are presented and discussed. SEM backscatter electron images (SEI) are also provided to enable the comparison of PTFE distributions with the morphological features of the GDL. This work has the potential to be employed to tune PTFE distributions for optimal water management in the GDL for improving the overall design and performance of PEMFCs.