Ex-situ evaluation of PTFE coated metals in a proton exchange membrane fuel cell environment

2.50
Hdl Handle:
http://hdl.handle.net/2436/620629
Title:
Ex-situ evaluation of PTFE coated metals in a proton exchange membrane fuel cell environment
Authors:
Baroutaji, A. ( 0000-0002-4717-1216 ) ; Carton, J.G.; Oladoye, A.M.; Stokes, J.; Twomey, B.; Olabi, A.G.
Abstract:
Metallic-based bipolar plates exhibit several advantages over graphite-based plates, including higher strength, lower manufacturing cost and better electrical conductivity. However, poor corrosion resistance and high interfacial contact resistance (ICR) are major challenges for metallic bipolar plates used in proton exchange membrane (PEM) fuel cells. Corrosion of metallic parts in PEM fuel cells not only increases the interfacial contact resistance but it can also decrease the proton conductivity of the Membrane Electrode Assembly (MEA), due to catalyst poisoning phenomena caused by corrosive products. In this paper, a composite coating of polytetrafluoroethylene (PTFE) was deposited on stainless steel alloys (SS304, SS316L) and Titanium (G-T2) via a CoBlast™ process. Corrosion resistance of the coated and uncoated metals in a simulated PEM fuel cell environment of 0.5 M H2SO4 + 2 ppm HF at 70 °C was evaluated using potentiodynamic polarisation. ICR between the selected metals and carbon paper was measured and used as an indicator of surface conductivity. Scanning Electron Microscopy (SEM), 3D microscopy, Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD), and contact angle measurements were used to characterise the samples. The results showed that the PTFE coating improved the hydrophobicity and corrosion resistance but increased the ICR of the coated metals due to the unconductive nature of such coating. Thus, it was concluded that it is not fully feasible to use the PTFE alone for coating metals for fuel cell applications and a hybrid coating consisting of PTFE and a conductive material is needed to improve surface conductivity.
Citation:
Ex-situ evaluation of PTFE coated metals in a proton exchange membrane fuel cell environment 2017, 323:10 Surface and Coatings Technology
Publisher:
Elsevier
Journal:
Surface and Coatings Technology
Issue Date:
Aug-2017
URI:
http://hdl.handle.net/2436/620629
DOI:
10.1016/j.surfcoat.2016.11.105
Additional Links:
http://linkinghub.elsevier.com/retrieve/pii/S0257897216312816
Type:
Article
Language:
en
ISSN:
0257-8972
Sponsors:
Enterprise Ireland
Appears in Collections:
Engineering and Technology

Full metadata record

DC FieldValue Language
dc.contributor.authorBaroutaji, A.en
dc.contributor.authorCarton, J.G.en
dc.contributor.authorOladoye, A.M.en
dc.contributor.authorStokes, J.en
dc.contributor.authorTwomey, B.en
dc.contributor.authorOlabi, A.G.en
dc.date.accessioned2017-08-30T11:22:43Z-
dc.date.available2017-08-30T11:22:43Z-
dc.date.issued2017-08-
dc.identifier.citationEx-situ evaluation of PTFE coated metals in a proton exchange membrane fuel cell environment 2017, 323:10 Surface and Coatings Technologyen
dc.identifier.issn0257-8972en
dc.identifier.doi10.1016/j.surfcoat.2016.11.105-
dc.identifier.urihttp://hdl.handle.net/2436/620629-
dc.description.abstractMetallic-based bipolar plates exhibit several advantages over graphite-based plates, including higher strength, lower manufacturing cost and better electrical conductivity. However, poor corrosion resistance and high interfacial contact resistance (ICR) are major challenges for metallic bipolar plates used in proton exchange membrane (PEM) fuel cells. Corrosion of metallic parts in PEM fuel cells not only increases the interfacial contact resistance but it can also decrease the proton conductivity of the Membrane Electrode Assembly (MEA), due to catalyst poisoning phenomena caused by corrosive products. In this paper, a composite coating of polytetrafluoroethylene (PTFE) was deposited on stainless steel alloys (SS304, SS316L) and Titanium (G-T2) via a CoBlast™ process. Corrosion resistance of the coated and uncoated metals in a simulated PEM fuel cell environment of 0.5 M H2SO4 + 2 ppm HF at 70 °C was evaluated using potentiodynamic polarisation. ICR between the selected metals and carbon paper was measured and used as an indicator of surface conductivity. Scanning Electron Microscopy (SEM), 3D microscopy, Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD), and contact angle measurements were used to characterise the samples. The results showed that the PTFE coating improved the hydrophobicity and corrosion resistance but increased the ICR of the coated metals due to the unconductive nature of such coating. Thus, it was concluded that it is not fully feasible to use the PTFE alone for coating metals for fuel cell applications and a hybrid coating consisting of PTFE and a conductive material is needed to improve surface conductivity.en
dc.description.sponsorshipEnterprise Irelanden
dc.language.isoenen
dc.publisherElsevieren
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S0257897216312816en
dc.rightsArchived with thanks to Surface and Coatings Technologyen
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/*
dc.subjectPEM fuel cellen
dc.subjectPTFE coatingsen
dc.subjectCoBlast™en
dc.subjectInterfacial contact resistanceen
dc.subjectFlow platesen
dc.subjectCorrosionen
dc.titleEx-situ evaluation of PTFE coated metals in a proton exchange membrane fuel cell environmenten
dc.typeArticleen
dc.identifier.journalSurface and Coatings Technologyen
dc.date.accepted2016-12-
rioxxterms.funderEnterprise Irelanden
rioxxterms.identifier.projectUoW300817ABen
rioxxterms.versionAMen
rioxxterms.licenseref.urihttps://creativecommons.org/CC BY-NC-ND 4.0en
rioxxterms.licenseref.startdate2018-08-25en
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