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 range of physical properties. Therefore several perovskite materials, based on lanthanum chromite and strontium titanate were synthesised and investigated with regard to their application as anodes in solid oxide fuel cells. The perovskite powders were studied by thermogravimetric and differential thermal analysis (TG/DTA) and X-ray diffraction (XRD). Conductivity data in the range of 100–900°C and the thermal expansion behaviour were measured both in air and Ar–4%H2. The electrochemical properties of a screen-printed electrode were studied preliminary as function of the hydrogen partial pressure using impedance spectroscopy. In this group of materials high electronic conductivity of up to 60 S/cm at 900°C was observed. However, none of the materials investigated so far showed a combination of the advantageous properties and is therefore superior to the state-of-the-art Ni–YSZ anode.