SmBaCoCuO 5+ x as cathode material based on GDC electrolyte for intermediate-temperature solid oxide fuel cells

Abstract

The performance of SmBaCoCuO 5+ 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 Ce 0.9Gd 0.1O 1.95 (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 SmBaCo 2O 5+ 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 cm 2 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 H 2. Preliminary results indicate that SBCCO is promising as a cathode for IT-SOFCs.