La0.6Sr0.4Co0.2Fe08O3 (LSCF) and LSCF-Ce0.8Gd0.2O3 (GDC) composite cathodes on YSZ electrolytes were studied for potential applications in low-temperature solid oxide fuel cells (SOFCs). Impedance spectroscopy measurements were performed in oxygen partial pressures ranging from 10(-3) to 1 atm over a temperature range from 500 to 750degreesC. The LSCF electrodes yielded low-current interfacial resistance values that were a factor of 10 lower than for (La,Sr)MnO3 cathodes. The addition of 50 vol.% GDC to LSCF resulted in an additional factor of approximate to 10 decrease in the polarization resistance, Polarization resistance values for the LSCF-GDC cathodes were as low as 0.01 Omega cm(2) at 750degreesC and 0.33 Omega cm(2) at 600degreesC.