Performance of composite LaCoO3-La2(Zr,Y)2O7 cathodes

Composite cathodes were prepared by high temperature reaction and screen printed onto a ceria-gadolinia electrolyte. Different depositions and/or firing conditions were used to change the electrode microstructures. A combination of steady state cathodic polarisation measurements and impedance spectroscopy was used to evaluate the performance of these cathodes and to investigate the effects of the most representative microstructural features. Both types of results suggest different mechanisms for relatively low and high cathodic polarisation. The results obtained for the best composite cathodes an comparable to results obtained for La1-xSrxCo1-yFeyO3-delta, and are much better than those obtained for La1-xSrxMnO3-delta. (C) 2000 Elsevier Science B.V. All rights reserved.