Porous SOFC Anodes Prepared by Sublimation of an Immiscible Metal Oxide during Sintering

Abstract

Nanostructured composite powder, consisting of 20 wt % SnO 2 , 50 wt % NiO, and 30 wt % Gd 0.1 Ce 0.9 O 2 (GDC), was prepared using a combustion chemical vapor deposition process from a single solution containing all precursors. Bilayer solid oxide fuel cells (SOFC) anodes of different porosity were fabricated by copressing of NiO-GDC powder and SnO 2 -NiO-GDC composite powder. Porosity variation in the anodes was achieved by the removal of the SnO 2 -phase during firing and subsequent cell testing. Anode-supported SOFC single cells were constructed and tested for electrochemical performance. Interfacial polarization resistances of a cell with the bilayer anode were 1.20, 0.49, 0.22, and 0.1 Ω cm 2 at 500, 550, 600, and 650°C, respectively, demonstrating peak power densities of 171, 301, 441, and 544 mW/cm 2 , respectively.