Electrochemical performance of La2Cu1−xCoxO4 cathode materials for intermediate-temperature SOFCs

K2NiF4-type structure oxides La2Cu1−xCoxO4 (x = 0.1, 0.2, 0.3) are synthesized and evaluated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). The materials are characterized by XRD, SEM and electrochemical impedance spectrum (EIS), respectively. The results show that no reaction occurs between La2Cu1−xCoxO4 electrode and Ce0.9Gd0.1O1.95 (CGO) electrolyte at 1000 °C. The electrode forms good contact with the electrolyte after sintering at 800 °C for 4 h in air. The electrode properties of La2Cu1−xCoxO4 are studied under various temperatures and oxygen partial pressures. The optimum composition of La2Cu0.8Co0.2O4 results in 0.51 Ω cm2 polarization resistance (Rp) at 700 °C in air. The rate limiting step for oxygen reduction reaction (ORR) is the charge transfer process. La2Cu0.8Co0.2O4 cathode exhibits the lowest overpotential of about 50 mV at a current density of 48 mA cm−2 at 700 °C in air.

► La2Cu1−xCoxO4 cathode materials are studied for applications in IT-SOFCs. ► Cathode material gave the lowest polarization resistance of 0.51 Ω cm2 at 700 °C. ► The rate limiting step for oxygen reduction reaction is the charge transfer process.