La0.6Sr0.4Co0.8Fe0.2O3-delta (LSCF) cathodes have been deposited by conventional spray pyrolysis on Ce0.8Gd0.2O1.9 (CGO) electrolytes at different temperatures between 250 and 450 degrees C, obtaining electrodes with different microstructure and porosity. Highly porous and macroporous electrodes are obtained at deposition temperatures of 250 degrees C and 450 degrees C, respectively, with an average grain size of 30-50 nm. The influence of the post-annealing treatment on the microstructure and on the electrochemical properties is investigated by scanning electron microscopy and impedance spectroscopy in air and as a function of the oxygen partial pressure to identify the different contributions to the polarization. Samples annealed at 650 degrees C show similar values of area specific resistance 0.04-0.06 Omega cm(2) at a measured temperature of 650 degrees C. However, after annealing the samples at 850 degrees C, the ASR values increase up to 0.1-0.6 Omega cm(2) with the lowest value corresponding to the film deposited at 250 degrees C due to the large porosity and surface area of this film. The performance degradation upon annealing is attributed to decreasing reaction sites induced by grain growth and densification. (C) 2014 Elsevier B.V. All rights reserved.