Characterization of electrical properties of GDC doped A-site deficient LSCF based composite cathode using impedance spectroscopy

The composite cathode consisting of A-site deficient perosvkite material La0.58Sr0.4Co0.2Fe0.8O3−δ (L58SCF) and Ce0.8Gd0.2O2−δ (GDC) on YSZ electrolyte is studied for potential applications in intermediate/low-temperature solid oxide fuel cells (SOFCs). Impedance spectroscopy measurements are performed in air over the temperature range of 600–800 °C under open circuit potential. The results show that the addition of 40 wt.% GDC to L58SCF (L58SCF–GDC40) results in the lower polarization resistance (0.07 Ω cm2 at 800 °C, 0.11 Ω cm2 at 750 °C and 0.22 Ω cm2 at 700 °C) than other composite cathodes and its activation energy values calculated for the low- and high-frequency arcs are 0.86 and 1.10 eV, respectively. The composite cathode exhibit high exchange current density and low charge-transfer resistance.