Synthesis and characterization of Ni-cermet/proton conducting thin film electrolyte symmetrical assemblies

Cermet electrodes of Ni-BaCe0.9Y0.1O2.95 and assemblies of Ni-cermet/thin film electrolyte/Ni-cermet have been elaborated from a ceramic nanopowder synthesized by flash combustion. Anode/electrolyte/anode assemblies with a fully dense electrolyte of thickness ca. 20 mu m were fabricated by a co-pressing and co-sintering process followed by reduction of NiO to Ni metal. In the reduced state, the anode microstructures comprise a uniform and homogeneous distribution of Ni metal and ceramic phase with relatively high porosity and high conductivity. Impedance spectroscopy showed that there were two major rate-limiting processes for the electrode reaction and that cell performance is determined by the electrolyte resistance. A total specific resistance of 0.4 Omega cm(2) at 600 degrees C was obtained for optimized assemblies. (C) 2008 Elsevier B.V. All rights reserved.