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

Abstract

The electrochemical behaviour of the cathode/electrolyte interface which is formed between screen printed Lao_0.8Sr_0.2MNO₃-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 impedance spectra was achieved. The influence of the porosity of the cathode on the impedance is discussed.