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 degrees C. The thermal expansion coefficient (TEC) value of SBCCO is 15.53 x 10(-6) K-1, which is similar to 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 degrees C has the best electrochemical performance and the area specific resistance (ASR) of SBCCO cathode is as low as 0.086 Omega cm(2) at 800 degrees C. An electrolyte-supported fuel cell generates good performance with the maximum power density of 517 mW cm(-2) at 800 degrees C in H-2. Preliminary results indicate that SBCCO is promising as a cathode for IT-SOFCs. (C) 2010 Elsevier B.V. All rights reserved.