With the aim to characterize the impact of an interfacial layer of Ca3Co4O9+delta cathode material on the electrochemical performances of a symmetric cell made of a cerium gadolinium oxide (CGO) electrolyte and 50 wt.% Ca3Co4O9+delta - 50 wt.% CGO porous electrodes, conditions of thin film deposition by pulsed laser deposition were optimized. The beneficial impact of such an interfacial layer was confirmed by impedance spectroscopy which showed, for cells preparedin the same conditions, a division by a factor of two of the area specific resistance.when a thin layer of Ca3Co4O9+delta was introduced between the electrolyte and the electrodes. (C) 2014 Elsevier B.V. All rights reserved.