Journal of Power Sources 191 (2009) 371–376 Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour High performance metal-supported solid oxide fuel cells fabricated by thermal spray Rob Hui a,∗ , Jörg Oberste Berghaus b,1 , Cyrille Decès-Petit a , Wei Qu a , Sing Yick a , Jean-Gabriel Legoux b , Christian Moreau b a National Research Council of Canada – Institute for Fuel Cell Innovation, 4250 Wesbrook Mall, Vancouver, BC, V6T 1W5 Canada b National Research Council of Canada – Industrial Materials Institute, 75 de Mortagne Boulevard, Boucherville, Quebec, J4B 6Y4 Canada article info Article history: Received 16 January 2009 Received in revised form 19 February 2009 Accepted 20 February 2009 Available online 6 March 2009 Keywords: Solid oxide fuel cells (SOFCs) Metal-supported Low temperature Thermal plasma spray High performance abstract Metal-supported solid oxide fuel cells (SOFCs) have been fabricated and characterized in this work. The cells consist of porous NiO–SDC as anode, thin SDC as electrolyte, and SSCo as cathode on porous stain- less steel substrate. The anode and electrolyte layers were consecutively deposited onto porous metal substrate by thermal spray, using standard industrial thermal spray equipment, operated in an open- air atmosphere. The cathode materials were applied to the as-sprayed half-cells by screen-printing and heat-treated at 800 ◦ C for 2 h. The cell components and performance were examined by scanning elec- tron microscopy (SEM), X-ray diffraction, leakage test, ac impedance and electrochemical polarization at temperatures between 500 and 700 ◦ C. The half-inch button cells exhibit a maximum power density in excess of 0.50 W cm -2 at 600 ◦ C and 0.92 W cm -2 at 700 ◦ C operated with humidified hydrogen fuel, respectively. The half-inch button cell was run at 0.5 A cm -2 at 603 ◦ C for 100 h. The cell voltage decreased from 0.701 to 0.698 V, giving a cell degradation rate of 4.3% kh -1 . Impedance analysis indicated that the cell degradation included 4.5% contribution from ohmic loss and 1.4% contribution from electrode polar- ization. The 5 cm × 5 cm cells were also fabricated under the same conditions and showed a maximum power density of 0.26 W cm -2 at 600 ◦ C and 0.56 W cm -2 at 700 ◦ C with dry hydrogen as fuel, respec- tively. The impedance analysis showed that the ohmic resistance of the cells was the major polarization loss for all the cells, while both ohmic and electrode polarizations were significantly increased when the operating temperature decreased from 700 to 500 ◦ C. This work demonstrated the feasibility for the fabrication of metal-supported SOFCs with relatively high performance using industrially available depo- sition techniques. Further optimization of the metal support, electrode materials and microstructure, and deposition process is ongoing. Crown Copyright © 2009 Published by Elsevier B.V. All rights reserved. 1. Introduction Metal-supported solid oxide fuel cells (SOFCs) have been rec- ognized as a promising alternative to conventional cermet- or ceramic-supported SOFCs. The metal-supported, such as stainless steel supported SOFCs exhibit high mechanical strength, good duc- tility, and matching thermal expansion coefficient with zirconia- and ceria-based electrolytes. Structural limitations arise not only from the thermal stress at rapid start-up and during temperature fluctuations; but also from the mechanical stress from assembly compaction and vibrations. Therefore, metal-supported SOFCs fulfil the requirements of structural robustness and thermal shock resis- ∗ Corresponding author. E-mail address: Rob.hui@nrc-cnrc.gc.ca (R. Hui). 1 Current address: Bekaert Advanced Coatings NV, E3-Laan 75-79, Deinze, 9800, Belgium. tance with low internal temperature and stress gradients. Stainless steels are available commercially in a wide range of composi- tions and microstructures. The unit price of steel is at least one order of magnitude lower than the ceramic components such as NiO and YSZ. Thus, the total material cost can be reduced signif- icantly. Metallic substrates can be easily fabricated into desired shapes, such as planar, circular tubular, and flat tubular by tradi- tional machining at low cost. The use of metallic substrates allows the use of conventional metal joining and forming techniques, and could significantly reduce the manufacturing costs of SOFC stacks. In comparison, glass–ceramic sealants used in electrolyte- and electrode-supported SOFCs need to provide adherence, elec- trical insulation, chemical stability and compatibility, as well as protection against mechanical degradation from stress during oper- ation. The structural instability resulting from start-up and thermal cycling is usually regarded as one of the main causes of cell breakage and stack failure [1]. Due to these potential merits of metal-supported SOFCs, significant technical progresses have been 0378-7753/$ – see front matter. Crown Copyright © 2009 Published by Elsevier B.V. All rights reserved. doi:10.1016/j.jpowsour.2009.02.067