The polarization resistance of La0.3Ba0.7CoO3-delta (LBC7) as cathode material was studied by impedance spectroscopy measurements in the temperature range of 450 <= T <= 750 degrees C, in air, on samples prepared by the solid state reaction (SSR) method and a wet chemical (WC) route, using symmetrical cells with single-layer and graded composition electrodes. While the LBC7 sample prepared by the SSR method and cooled at a rate of 10 degrees C/min turned out to be single phase with cubic symmetry, the sample prepared by the WC route is a mixture of the cubic phase and the 2H hexagonal phase. The lowest polarization resistance at 600 degrees C, Rp similar to 0.06 Omega cm(2), was obtained for the graded composition electrodes. Our results suggest that the electrode configuration is a key factor in order to reduce the polarization resistance of the LBC7 electrode material. (C) Copyright 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.