To provide hexagonal Ca3Co2O6 with better electrochemical performance as cathode material for solid-oxide fuel cell, Ca-doped LaCoO3 perovskite is introduced as the second phase to achieve hetero-structured (1-x)Ca3Co2O6/x(La0.6Ca0.4)(2)Co2O6 dual-phase composites. The composites are successfully synthesized via a simple one-pot method. They behave as thermal-activated semiconductors in the temperature range from 300 to 800 degrees C, and the electrical conductivity is progressively enhanced with increasing x. Electrochemical measurements indicate that the composite electrodes exhibit reduced area specific resistance, and the x = 0.5 composite cathode shows the lowest polarization behavior. A power density as high as 620 mW cm(-2) is attained at x = 0.5 measured at 800 degrees C on an electrolyte-supported single cell with pure H-2 as fuel. The improved performance in the dual-phase composite cathode can be ascribed to the enhanced conductivity and enlarged triple-phase boundary region for electrode reaction due to the presence of second phase. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.