This paper reports on the electrochemical performance of an SOFC cathode for potential use in intermediate-temperature solid oxide fuel cells (IT-SOFCs) using the oxygen non-stoichiometric misfit-layered cobaltite Ca3Co4O9+delta or composites of Ca3Co4O9+delta with Ce0.9Gd0.1O1.95 (CGO/Ca3Co4O9+delta). Electrochemical impedance spectroscopy revealed that symmetric cells with an electrode of pure Ca3Co4O9+delta exhibit a cathode polarization resistance (R-p) of 12.4 Omega cm(2), at 600 degrees C in air. Strikingly, R-p of the composite CGO/Ca3Co4O9+delta with 50 vol.% CGO was reduced by a factor of 19 (i.e. R-p = 0.64 Omega cm(2)), the lowest value reported so far for the Ca3Co4O9 family of compounds. These findings together with the reported thermal expansion coefficient, good compatibility with CGO and chemical durability of this material suggest that it is a promising candidate cathode for IT-SOFCs. (C) 2011 Elsevier B.V. All rights reserved.