| Thermally Conversion (Cu,Fe)3O4 Spinel Coating on Solid Oxide Fuel Cell Interconnect Steel Shujiang Geng1; Fuhui Wang1; 1NORTHEASTERN UNIVERSITY, Shenyang, China; PAPER: 206/Corrosion/Regular (Oral) SCHEDULED: 11:55/Tue. 29 Nov. 2022/Andaman 2 ABSTRACT: Ferritic stainless steels have been widely employed as solid oxide fuel cell (SOFC) interconnects owing to their low cost, coefficient of thermal expansion match with other SOFC components, and good oxidation resistance and acceptable electrical conductivity of Cr2O3. However, they are confronted with several problems during operation in SOFC cathode working condition such as the evaporation of Cr2O3 which results in cathode Cr-poisoning and subsequent degradation of cell performance [1-5]. Therefore, it is necessary to develop electrically conductive coating on them in order to block Cr2O3 evaporation. So far, CuFe2O4 spinel coating is a promising coating to improve the electrical conductivity of the surface oxide scale thermally formed on the steel. In present paper, CuFe alloy layer has been deposited on ferritic stainless steel (SUS 430) by magnetron sputtering method. The coated steels were evaluated in air at 800C corresponding to SOFC cathode environment. It was found that the coated steel initially experienced a large mass gain, followed by slight increase with time. The CuFe alloy layer was mainly converted into CuFe2O4 spinel layer beneath which a Cr-rich layer was grown from the steel substrate upon thermal exposure. The Cr-free outer layer not only suppressed Cr migration outward but also reduced the surface oxide scale area specific resistance (ASR) of the coated steel. <br />Keywords: (CuFe)3O4 coating, Solid oxide fuel cell interconnect, Oxidation, Electrical property References: 1. H. Falk-Windisch, J. E. Svensson, J. Froitzheim. Effect of temperature on chromium vaporization and oxide scale growth on interconnect steels for Solid Oxide Fuel Cells. Journal of Power Sources.287,25 (2015).<br />2. M. Stanislowski, E. Wessel, K. Hilpert, T. Markus, L. Singheiser. Chromium Vaporization from High-Temperature Alloys. Journal of The Electrochemical Society.154,A295 (2007).<br />3. S. P. Jiang, X. Chen. Chromium deposition and poisoning of cathodes of solid oxide fuel cells – A review. International Journal of Hydrogen Energy.39,505 (2014).<br />4. Z. Xu, W. Xu, E. Stephens, B. Koeppel. Mechanical reliability and life prediction of coated metallic interconnects within solid oxide fuel cells. Renewable Energy.;113,1472 (2017).<br />5. W. N. Liu, X. Sun, E. Stephens, M. A. Khaleel. Life prediction of coated and uncoated metallic interconnect for solid oxide fuel cell applications. Journal of Power Sources.189,1044 (2009). |
