A high performance composite cathode with enhanced CO2 resistance for low and intermediate-temperature solid oxide fuel cells

CO2-resistant perovskite cathode has a significant role in solid oxide fuel cell (SOFC) application particularly for operation in an air atmosphere contains higher than normal amount of CO2 such as in single-chamber SOFC (SC-SOFC). This work features a systematic study of the electrochemical performance of SrCo(0.8)Nb(0.1)Tac(0.1)O(3-delta) (SCNT)-Ce0.9Gd0.1O2-delta (GDC) composite cathode under CO2 exposure for SOFC operation in low-temperature (LT, 500 degrees C and below) and intermediate-temperature (IT, 500-700 degrees C) ranges. The complementary results from powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, in situ high temperature XRD, electrochemical impedance spectroscopy, and the single cell test show that SCNT-GDC cathode exhibit slightly lower electrochemical performance but higher CO2 resistance than SCNT, which enables practical SOFC application. At 550 degrees C, SCNT-GDC-based single cell has a peak power density of 630 mW cm(-2) and reduces to a stable power density of 525 mW cm(-2) after exposure to air containing 1 vol% CO2 for 2 h. The collective characterization and electrochemical data presented here highlight the potential of SCNT-GDC composite cathode for use in SC-SOFC and to enhance the performance stability in LT and IT-SOFCs.