La-doped Ba0.6Sr0.4Co0.6Fe0.4O3-delta perovskites were synthesized and investigated as new cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs). The structural characteristics, thermal expansion coefficient (TEC), electrical conductivity and electrochemical properties were characterized by X-ray diffraction (XRD), dilatometry, DC four-terminal method, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. The TEC of (Ba0.6Sr0.4)(0.9)La0.1Co0.4Fe0.6O3-delta (BSLCF) was 14.9 x 10(-6) K-1 at 30-800 degrees C, lower than Ba0.6Sr0.4Co0.4Fe0.6O3-delta (BSCF) of 15.6 x 10(-6) K-1. The electrical conductivity of BSCF was improved by La-doping, e.g. a value of 122 S cm-(1) for BSLCF vs. 52 S cm(-1) for BSCF at 500 degrees C, respectively. In addition, La-doping enhanced the electrochemical activity for oxygen reduction reaction. The polarization resistance of BSLCF was 0.18 Omega cm(2) at 700 degrees C, about a quarter lower than that of BSCF. The improved electrochemical performance of BSLCF should be ascribed to the higher conductivity as well as the improved oxygen adsorption/desorption and oxygen ions diffusion processes. (C) 2010 Elsevier Ltd. All rights reserved.