In situ formation of a solid oxide fuel cell (SOFC) cermet anode by NiWO sub(4) reduction

• Published in: Journal of power sources 2013-09, Vol.237, p.33-40
• Main Authors: Sabolsky, E M, Gansor, P, Ciftyuerek, E, Sabolsky, K, Xu, C, Zondlo, J W
• Format: Article
• Language: English
• ISSN: 0378-7753

The presented work describes a process for producing a mixed-conducting SOFC cermet anode through the in situ reduction of a ternary oxide. A porous nickel tungstenate (NiWO sub(4)) was screen-printed and bonded onto an yttrium-stabilized zirconia (YSZ) electrolyte-supported SOFC by treatment at 1000 degree C for 1 h. An (La,Sr)MnO sub(3)/Ce sub(0.9)Gd sub(0.1)O sub(2)(LSM/GDC) was utilized as the cathode with the NiWO4 acting as the anode for the SOFC. The similar to 1-cm diameter fuel cell with a similar to 100- mu m thick YSZ electrolyte was tested in H sub(2) fuel at 800 degree C. During the insertion of the H sub(2) fuel, the NiWO sub(4) was reduced to form a Ni/WO sub(x) cermet composite that consisted of a fine mixture of Ni-nanoparticles dispersed over the porous WO sub(x) support structure. A maximum power density of similar to 104 mW cm super(-2) was attained for the reduced NiWO sub(4) anode, even with an un-optimized and dense microstructure, on an electrolyte-supported cell. The power density was increased to similar to 165 mW cm super(-2) with the incorporation of GDC powder into the NiWO sub(4) anode. The same NiWO sub(4)/GDC composite was tested within a fuel stream of H sub(2) containing 10 ppm PH sub(3). The cell's degradation rate was 0.006 V h super(-1) for 5 h at 750 degree C, which is similar to that observed for conventional Ni/YSZ cermets.