Impedance Study of Alternative (La,Sr)FeO[sub 3−δ] and (La,Sr)(Co,Fe)O[sub 3−δ] MIEC Cathode Compositions

In this study, two mixed electronic ionic conducting (MIEC) cathode materials, and , are characterized by electrochemical impedance spectroscopy. The chemical surface and diffusion coefficients of both cathode materials are obtained directly from impedance measurements performed on full anode-supported solid oxide fuel cells. This is done by a combined distribution of relaxation times and an equivalent circuit impedance analysis method, which allows a high resolved identification and deconvolution of each single polarization mechanisms contributing to the overall loss of the cell.