Synthesis and characterization of a Ni/Ba2In0.6Ti1.4O5.7▭0.3 cermet for SOFC application

Ni-based cermets were prepared and reduced from mixtures of NiO and Ba2In0.6Ti1.4O5.7 square(0.3). A cermet containing 18.7 vol.% of Ni exhibits promising characteristics: 40% of open porosity and a lower DC resistivity than a Ni/YSZ cermet with a larger Ni content (30 vol.%). Its thermal expansion coefficient is 11.4 x 10(-6) K-1 whereas that measured for Ba2In0.6Ti0.4O5.7 square(0.3) is 9.9 x 10(-6) K-1. Electrical measurements vs. the Ni content have shown that the percolation threshold corresponds to 15.7 vol.% of Ni. By using saccharose as a pore former, the porosity of the electrode can be tuned. It is shown that the pore size is controlled by the particle size distribution of the pore former. (c) 2006 Elsevier B.V. All rights reserved.