Detailed Characterization of Anode Supported SOFCs by Impedance Spectroscopy

Anode supported thin electrolyte cells are studied by electrochemical impedance spectroscopy (EIS). A model consisting of an inductance, a serial resistance (Rs) and 5 arcs to describe the polarization resistance is suggested. The model is applied on a good performing cell with ASR = 0.15 Ωcm 2 at 850°C and a poor performing cell with ASR = 0.29 Ωcm 2 made following the same procedure. The EIS-analysis suggests that the electrochemical difference originates from microstructural differences in the cathode. Large differences in the cathode composite microstructure were observed by SEM post-test analysis consistent with the results of the electrical characterization.