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) frit on the electrochemical performance, electrical conductivity, and thermal expansion of LaBaCo2O5+δ (LBCO) cathode were investigated. BBP frit was found to be effective in lowering the sintering temperature of LBCO cathode by about 200 °C and in improving its electrochemical performance within the intermediate-temperature range of 600–800 °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 °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 °C. The electrical conductivity of LBCO with 5 wt.% BBP frit was about 320–330 S cm−1 at 600–800 °C in air.

► B2O3–Bi2O3–PbO (BBP) frit is proven to be an effective sintering agent for cathode. ► The addition of 5 wt.% BBP reduces the sintering temperature of LaBaCo2O5+δ by 200 °C. ► BBP is effective for improving the performance of LaBaCo2O5+δ cathode for IT-SOFCs. ► The addition of 5 wt.% BBP to LaBaCo2O5+δ reduce the thermal expansion at 600–800 °C.