SmBaCoCuO5+x as cathode material based on GDC electrolyte for intermediate-temperature solid oxide fuel cells

The performance of SmBaCoCuO5+x (SBCCO) cathode has been investigated for their potential utilization in intermediate-temperature solid oxide fuel cells (IT-SOFCs). The powder X-ray diffraction (XRD), thermal expansion and electrochemical performance on Ce0.9Gd0.1O1.95 (GDC) electrolyte are evaluated. XRD results show that there is no chemical reaction between SBCCO cathode and GDC electrolyte when the temperature is below 950 °C. The thermal expansion coefficient (TEC) value of SBCCO is 15.53 × 10−6 K−1, which is ∼23% lower than the TEC of the SmBaCo2O5+x (SBCO) sample. The electrochemical impedance spectra reveals that SBCCO symmetrical half-cells by sintering at 950 °C has the best electrochemical performance and the area specific resistance (ASR) of SBCCO cathode is as low as 0.086 Ω cm2 at 800 °C. An electrolyte-supported fuel cell generates good performance with the maximum power density of 517 mW cm−2 at 800 °C in H2. Preliminary results indicate that SBCCO is promising as a cathode for IT-SOFCs.

Research highlights▶ We synthesize a new kind of layered perovskite SmBaCoCuO5+x (SBCCO) as a cathode material of a solid oxide fuel cell. ▶ There are some reports on the performance of cathodes in proton-conducting SOFCs based on BaCe0.8Sm0.2O3−δ electrolyte. ▶ However, to the best of our knowledge, the performance of SBCCO cathodes in oxygen-ion conducting SOFCs has not been reported to date. ▶ In this work, the ceramic powder SBCCO is examined as a cathode for IT-SOFCs based on Ce0.9Gd0.1O1.95 (GDC) electrolyte.