SrCo1-yTiyO3-δ as potential cathode materials for intermediate-temperature solid oxide fuel cells

The perovskites SrCo1-yTiyO3-delta (SCTy, y = 0.00-0.20) are synthesized and assessed as potential cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs) based on the La0.9Sr0.1Ga0.8O3-delta (LSGM) electrolyte. Say composites with y >= 0.05 adopt a cubic perovskite structure with thermal stability between 30 degrees C and 1000 degrees C in air. Substitution of Ti significantly enhances the electrical conductivity of the SCTy composites relative to the undoped SrCoO3-delta. The highest electrical conductivity of the sample with y = 0.05 varied from 430 S cm(-1) to 160 S cm(-1) between 300 degrees C to 800 degrees C in air. The area-specific resistances of the SCTy cathodes on the LSGM electrolyte gradually increase from 0.084 Omega cm(2) at y = 0.05 to 0.091 Omega cm(2) at y = 0.20 with increasing Ti content at 750 degrees C. Single-cells that used SCTy cathodes with y = 0.05, 0.10, 0.15, and 0.20 on a 300 mu m-thick LSGM electrolyte achieve peak power densities of 793, 608, 525, and 425 mW cm(-2) at 800 degrees C, respectively. These novel SCTy cubic perovskites demonstrate considerable potential for application in IT-SOFC cathodes. (C) 2011 Elsevier B.V. All rights reserved.