Electrochemical investigation of Pr2CuO4-based composite cathode for intermediate-temperature solid oxide fuel cells

Abstract

Pr2CuO4-xCe0.9Gd0.1O1.95 (PCO-xCGO, x = 0, 10, 20, 30, 40, 50 wt%) composite cathodes were investigated for potential application in intermediate-temperature solid oxide fuel cells (IT-SOFCs). The effect of different sintering temperature on the microstructure and electrochemical performance of the composite cathode was observed. The oxygen reduction reaction (ORR) mechanism was analyzed by the electrochemical impedance spectroscopy. It was found that the addition of CGO in PCO cathode significantly reduced the polarization resistance (Rp). The lowest Rp of 0.12 Ω cm2 for PCO-40CGO composite cathode at 700 °C in air. Oxygen partial pressure dependence study indicates that the charge transfer process is rate-limiting step for ORR on the electrode. The maximum exchange current density i0 of the PCO-40CGO composite cathode was 15.10 mA cm2 at 700 °C. All above properties indicate that the PCO-40CGO composite is a promising cathode material for IT-SOFCs.