The layered perovsldte PrBaxCo2O5+delta (PBxCO, x = 0.90-1.0) oxides have been synthesized by a solid-state reaction technique, and evaluated as the potential cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Room temperature X-ray diffraction patterns show the orthorhombic structures which double the lattice parameters from the perovskite cell parameter as a approximate to a(p), b approximate to a(p) and c approximate to 2a(p) (a(p) is the cell parameter of the primitive perovskite) in the Pmmm space group. There is a good chemical compatibility between the PBxCO cathode and the Ce0.9Gd0.1O1.95 (CGO) electrolyte at 1000 degrees C. The electrical conductivity and thermal expansion coefficient of PB CO are improved due to the increased amount of electronic holes originated from the Ba-deficiency. The results demonstrate the high electrochemical performance of PBxCO cathodes, as evidenced by the super low polarization resistances (R-p) over the intermediate temperature range. The lowest R-p value, 0.042 Omega cm(2), and the cathodic overpotential, -15 mV at a current density of -25 mA cm(-2), are obtained in the PrBa0.94Co2O5+delta cathode at 600 degrees C in air, which thus allow to be used as a highly promising cathode for IT-SOFCs. A CGO electrolyte fuel cell with the PrBa0.94CO2O5+delta cathode presents the attractive peak power density of similar to 1.0 W cm(-2) at 700 degrees C. Furthermore, the oxygen reduction kinetics of the PrBa0.94Co2O5+delta cathode is also studied, and the rate-limiting steps for oxygen reduction reaction are determined at different temperatures. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.