Chromite/titanate based perovskites for application as anodes in solid oxide fuel cells

Perovskites containing lanthanides, partially substituted by alkaline-earth elements and transition metals like Cr, Ti, Fe or Co show a very broad ran ge of physical properties. Therefore several perovskite materials, based on lanthanum chromite and strontium titanate were synthesised and investigate d with regard to their application as anodes in solid oxide fuel cells. The perovskite powders were studied by thermogravimetric and differential ther mal analysis (TG/DTA) and X-ray diffraction (XRD), Conductivity data in the range of 100-900 degreesC and the thermal expansion behaviour were measure d both in air and Ar-4%H-2. The electrochemical properties of a screen-prin ted electrode were studied preliminary as function of the hydrogen partial pressure using impedance spectroscopy. In this group of materials high elec tronic conductivity of up to 60 S/cm at 900 degreesC was observed, However, none of the materials investigated so far showed a combination of the adva ntageous properties and is therefore superior to the state-of-the-art Ni-YS Z anode. (C) 2000 Elsevier Science B.V. All rights reserved.