16 Ω were measured for LSCF/LSGMC composite cathode on LSGM substrate at 800ºC in air. Low-frequency secondary arcs in the impedance spectra of LSCF/LSGMC cathode coupled with low current density and low cathode porosity suggested possible mass transfer limitations. The LSCF/LSGMC composite electrode performed best at 800ºC (0.11 A/cm 2 at 0.045 V overpotential) while the BSCF/LSGMC performed best at the lowest temperature investigated (0.1 A/cm 2 at 700ºC and 0.04 V overpotential).