Electrochemical properties of La0.8Sr0.2FeO3-aEuroparts per thousandδ -La0.45Ce0.55O2-aEuroparts per thousandδ composite cathodes for intermediate temperature SOFC

The electrochemical properties of La0.8Sr0.2FeO3 -aEuro parts per thousand delta (LSF)-La0.45Ce0.55O2 -aEuro parts per thousand delta (LDC) composite cathodes coated on LSGM electrolyte were studied by electrochemical impedance spectroscopy and cathodic polarization technique. Results showed that the composite cathodes possessed superior electrochemical performance compared to that of pure LSF cathode. The cathodic overpotential of Cathode C was only 100 mV at 0.3 A cm(-2), and the charge transfer resistance and the gas phase diffusion resistance were decreased to 0.105 Omega cm(2) and 0.257 Omega cm(2), respectively at 800 A degrees C. The improvement of the electrochemical performance is contributed to the increase of the triple-phase boundary, enlargement of the effective area for electrode reaction, and increase of the porosity of the cathode by adding LDC to the cathode material.