Electrochemical Characterization of Planar Anode Supported SOFC with Strontium-Doped Lanthanum Cobalt Oxide Cathodes

Abstract

The electrochemical performance of anode supported cells with screen-printed Sr-doped lanthanum cobalt oxide cathodes was studied using electrochemical impedance spectroscopy and polarization measurements. In order to obtain information on the resistance contribution from the cathode alone symmetrical cell measurements were carried out. Analysis of the symmetrical cell data in term of a distribution of relaxation times aided in the selection of an appropriate equivalent circuit for the cathode. Cell performance was dependent on the interdiffusion barrier layer and it was shown that the concentration polarization losses were strongly overlapped with the cathode losses, which complicates the deconvolution of the impedance spectra into individual process and / or electrode specific contributions.