Effect of B2O3-Bi2O3-PbO frit on the performance of LaBaCo2O5+δ cathode for intermediate-temperature solid oxide fuel cells

The effects of B2O3-Bi2O3-PbO (BBP) flit on the electrochemical performance, electrical conductivity, and thermal expansion of LaBaCo2O5+delta (LBCO) cathode were investigated. BBP fit was found to be effective in lowering the sintering temperature of LBCO cathode by about 200 degrees C and in improving its electrochemical performance within the intermediate-temperature range of 600-800 degrees C. LBCO with 5 wt.% BBP frit cathode based on Sm0.2Ce0.8O1.9 electrolyte showed the best electrochemical performance, i.e., the lowest area-specific resistance (ASR) and cathodic overpotential. The ASR values were about 64.1%, 66.1%, and 74.5% lower than those of LBCO at 700, 750, and 800 degrees C, respectively. The cathodic overpotential decreased from 51.0 mV for LBCO to 8.2 mV at a current density of 0.2 A cm(-2) at 700 degrees C. The electrical conductivity of LBCO with 5 wt.% BBP frit was about 320 -330 S cm(-1) at 600-800 degrees C in air. Crown Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.