Structure and Electrochemical Properties of the Cathode/Electrolyte Interface in the Planar SOFC

The electrochemical behaviour of the cathode/electrolyte interface which is formed between screen printed La0.8Sr0.2MnO3-cathode and ZrO2+8%Y2O3 electrolyte was investigated. The impedance of the cathode/electrolyte interface was calculated as a function of (I) the oxygen exchange velocity between cathode material and atmosphere, (II) interface microstructure and (III) the oxygen vacancies diffusion coefficient. A very good agreement between calculated and measured impedancee spectra was achieved. The influence of the porosity of the cathode on the impedance is discussed.