Influence of Carbon Dioxide and Humidity on the Stability of (La0.6Sr0.4)(0.99)Co1-xTixO3-delta Cathode

(La0.6Sr0.4)(0.99)CoO3-delta is a very promising cathode material due to its excellent electronic and ionic conductivity. However, non-artificial air from the ambient atmosphere contains impurities such as H2O and CO2, which cause degradation and performance loss of the cathode. Introduction of Ti into the B-site of (La0.6Sr0.4)(0.99)CoO3-delta improves the chemical stability of the material. (La0.6Sr0.4)(0.99)Co1-xTixO3-delta (0 <= x >= 0.1) electrodes prepared in this work were analyzed using X-ray diffraction method (XRD), X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS). Studied (La0.6Sr0.4)(0.99)CoO3-delta materials with Ti in B-site showed reversible degradation under gas mixture with carbon dioxide addition. Improved stability was observed for (La0.6Sr0.4)(0.99)Co1-xTixO3-delta materials with Ti in B-site compared to unmodified (La0.6Sr0.4)(0.99)CoO3-delta in gas mixture containing water vapour.