Abstract
Gas diffusion medium (GDM) is a crucial component in proton exchange membrane fuel cells (PEMFCs). Being composed of a gas diffusion layer (GDL) with a micro-porous layer (MPL) coated onto it, it ensures a proper water management due to the highly hydrophobic materials employed in cell assembly. In current commercial applications, the desired water repellent behaviour is usually obtained by using polytetrafluoroethylene (PTFE). In this work, Fluorolink® P56 (Solvay Specialty Polymers, Milan, Italy), a commercially available, anionic, segmented high molecular weight polyfluorourethane with perfluoropolyether groups was extensively evaluated as an alternative to PTFE for micro-porous layer hydrophobization. A change in polymer used is desirable in order to simplify the production process, both in terms of ink formulation and thermal treatment, as well as to get a higher hydrophobicity and, consequently, more efficient water management. Innovative prepared samples were compared to a PTFE-based GDM, in order to assess differences both from morphological and from an electrochemical point of view.
Highlights
From the past few decades to worldwide energy demand has been reported to be continuously rising, and this trend is expected for the medium-term future
The use of the new polymer was allowed to work at a lower temperature during the heat treatment step, and it did not affect hydrophobic properties, both before and after cell testing
Electrochemical Impedance Spectroscopy (EIS) analysis and polarization curves showed an improvement in performance using Fluorolink® P56 and a lower polymer concentration with respect to PTFE
Summary
From the past few decades to worldwide energy demand has been reported to be continuously rising, and this trend is expected for the medium-term future. Quite apart from the fact that common fossil energy sources are not renewable, they are the most remarkable cause of greenhouse gas emissions. Several worldwide organizations are focused on this problem and, among them, the European Union has set several guidelines in order to reduce greenhouse gas emissions. Changes in energy production are needed and, in this respect, proton exchange membrane fuel cells (PEMFCs) are considered very promising due to their zero-emission energy production process. They show many advantages in terms of low operating temperature, compactness, fast response to load change and high efficiency [3,4,5,6,7]. The electrolyte used in the device is a polymer-based membrane and is usually composed by fluorinated compounds; Nafion®, which was developed by Dupont in the late 1960s, is a very common polymer for that kind of application [8]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
