Preparation and characterization of PrBaCo1.9Ni0.1O5 + δ–Ce0.8Sm0.2O1.9 composite cathodes for intermediate temperature solid oxide fuel cells

• PrBaCo1.9Ni0.1O5 + δ (PBCNO)–xSDC composite is evaluated as cathode for IT-SOFC.
• The TECs of PBCNO cathode decrease greatly with SDC addition.
• The addition of SDC to PBCNO cathode reduces the polarization resistance.
• The fuel cell PBCNO–40SDC/SDC/NiO–SDC shows the highest power density at 800 °C.

PrBaCo1.9Ni0.1O5 + δ (PBCNO)–xCe0.8Sm0.2O1.9 (SDC) (x = 0, 10, 20, 30, 40, and 50 wt%) composites are investigated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). XRD results show that PBCNO is chemically compatible with the SDC electrolyte at 1000 °C. The thermal expansion coefficient (TEC) decreases with the increase of SDC content. The average TEC at the temperature range of 35–900 °C decreases from 22.6 × 10− 6 K- 1 for pure PBCNO cathode to 15.2 × 10− 6 K− 1 for PBCNO–50SDC composite cathode. The addition of SDC reduces the polarization resistance. The lowest polarization resistance of 0.012 Ω cm2 is achieved at 800 °C for the PBCNO–40SDC composite cathode. In the temperature range of 600–800 °C, the PBCNO–40SDC composite cathode delivers the power density of 483 mW cm− 2 at 800 °C. These results indicate that PBCNO–40SDC is a promising cathode material for IT-SOFCs.