Performances of YBaCo1.4Cu0.6O5+δ–Ce0.8Sm0.2O1.9 composite cathodes for intermediate-temperature solid oxide fuel cells

Abstract

The electrochemical properties of YBaCo1.4Cu0.6O5+δ–xCe0.8Sm0.2O1.9 (YBCC–xSDC, x=20, 30, 40, 50wt%) have been investigated for the potential application in intermediate-temperature solid oxide fuel cells (IT-SOFCs). No chemical reactions between YBCC cathode and SDC electrolyte, and YBCC and La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) occur. The thermal expansion coefficient (TEC) of YBCC cathode decreases with SDC addition. The TEC of YBCC–30SDC cathode is 13.60×10–6K−1 from 30 to 850°C in air and it exhibits the best electrochemical performance among the YBCC–xSDC cathodes. The polarization resistance (Rp) of YBCC–30SDC is 0.027Ωcm2 at 850°C, 0.044Ωcm2 at 800°C and 0.075Ωcm2 at 750°C. The maximum power density value of electrolyte-based cell with YBCC–30SDC cathode is 662, 483 and 319mWcm−2 at 850, 800 and 750°C, respectively. Preliminary results indicate that YBCC–30SDC is especially promising as a cathode for IT-SOFCs.