TP3 : Investigation of electrical and corrosion properties of mextallic bipolar plates made of monel alloy and stain less steel coated by TiN used for PEM fuel cells
Thesis > Central Library of Shahrood University > Chemical and Materials Engineering > MSc > 2016
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Abstarct: Proton Exchange Membrane (PEM) fuel cells are electrochemical devices that convert chemical energy of a fuel directly into electrical energy. Bipolar plate is the key components in PEM fuel cells. mextallic bipolar plate is one of the good choices using as BPs in PEM fuel cells. The most important disadvantage of BPs is the low corrosion resistance and formation of oxide laxyers in their surface that cause to increase interfacial contact resistance and consequently decrease in PEM fuel cells efficiency. In this study, Monel alloy and SS 316L is chosen to investigate corrosion and electrical properties as BPs. X-ray fluorescence, X-ray Diffraction, Scanning electron Microscope to investigate the morphology, Interfacial contact resistance and Corrosion resistance by potentiodynamic polarization method was conducted to investigate BPs Properties. Substrate was conducted in different temperature to investigate of oxidation properties. Results of oxidation show that contact resistance of both alloys will be increased. So, titanium nitride coating is used to avoid of oxide laxyer formation and increase corrosion resistance. The coating is implemented by R.F magnetron sputtering and cathodic arc evaporation-PVD methods. In this study, roughness effect of substrate surface and coating thickness is investigated on the contact resistance of coating. Titanium nitride coting by sputtering method increases the substrate contact resistance and also due to its poor adhesion to substrate, it decreases the corrosion resistance. Coating by CAE-PVD shows improvement in contact resistance and increase in corrosion resistance with compare to sputtering method. Result of CAE-PVD shows that best candidate of monel alloy for making BPs is the sample with 600 nm coating thickness and substrate roughness 200 that contain 7 mΩ.cm2 ICR and corrosion current density of 0.836 µA.cm-2. Also for the stainless steel the best candidate is the sample with 600 nm thickness and Substrate roughness 200 that contain 8.74 mΩ.cm2 ICR and 0.130 µA.cm-2 corrosion current density.
Keywords:
#PEM Fuel Cells #Bipolar plate #Monel alloy #Stainless steel 316L #TiN #R.F magnetron sputtering #Cathodic arc evaporation-PVD #Contact resistance #Corrosion resistance Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
Visitor: