Synthesis and properties of Ni-SDC cermets for IT-SOFC anode by co-precipitation

Ni-Samaria-doped ceria (SDC) cermets have been prepared using a chemical co-precipitation process with Ni(NO3)(2), Sro(NO3)(3) and kCe(NO3)(3) as precursors and (NH4)(2)CO3 as mineralizer. The co-precipitates were fired at 600, 700 and 800 degreesC for 2 h, respectively, resulting in powders, which consist of two phases, the cubic NiO and fluorite structure ceria as confirmed with X-ray diffraction identification. The powder was observed with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The powders were fine with surface area of 23-51 m(2)/g, and an average agglomerate particle size of 0.23-0.36 mum. The powder was sintered to porous NiO-SDC cermets, which were subsequently reduced to Ni-SDC cermets with porosity of about 30-40%. The Ni-SDC cermets exhibit metallic behavior over the temperature from 500 to 800 degreesC, as measured with a DC four-probe technique in H,. The Ni-SDC cermets with high electrical conductivity appear to be compatible with the electrolyte (SDC) for intermediate temperature solid oxide fuel cell (IT-SOFC) application. (C) 2004 Elsevier B.V. All rights reserved