Electrodeposition of ruthenium oxide on ferritic stainless steel bipolar plate for polymer electrolyte membrane fuel cells

Abstract

The effect of RuO2 electrodeposition on ferritic stainless steel as a bipolar plate is evaluated in terms of the surface morphology, interfacial contact resistance (ICR), potentiostatic polarization, contact angle, and X-ray photoelectron spectroscopy. The surface morphology of deposited RuO2 is greatly stabilized by addition of HNO3 in 10 mM RuCl3 center dot xH(2)O solution. The RuO2-deposition on stainless steel shows a high contact angle indicating the high surface energy and hydrophobic characteristics. The ICR measurement indicates that the deposition of conductive RuO2 on stainless steel is very effective in decreasing ICR value. Moreover, after potentiostatic polarization, the ICR value shows only 2.4 and 2.2 m Omega cm(2) at 150 N/cm(2) under air and H-2 purged environments, respectively. In electrochemical test, even though the current density of RuO2-deposited stainless steel is slightly higher than that of bare stainless steel, it is acceptable value for the relevant DOE 2015 target for metallic bipolar plates (less than 1 mu A/cm(2)). Because the RuO2-deposition on stainless steel shows a low ICR value and good corrosion resistance and high contact angle, the RuO2-deposition is a sufficiently feasible method for the bipolar plate material of PEMFC. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.