Advanced Electrochemical Properties of LnBa[sub 0.5]Sr[sub 0.5]Co[sub 2]O[sub 5+δ] (Ln=Pr, Sm, and Gd) as Cathode Materials for IT-SOFC

Abstract

Excellent area-specific-resistance (ASR) values have been exhibited by cathode materials with a Sr-doped layer perovskite type structure and therefore show themselves to be possible candidates for intermediate-temperature-operating solid oxide fuel cell (IT-SOFC, 600–800°C) applications. SmnormalBa0.5normalSr0.5normalCo2normalO5+δ (SBSCO) electrode was sintered onto 10mol% gadolinia-doped ceria ( normalCe0.9normalGd0.1normalO2 , CGO91) at 1000°C to form symmetrical cells and exhibited an ASR value of 0.092Ωcm2 at 700°C . The lowest ASR value was observed when the composite cathode of 50wt% of SBSCO and 50wt% of CGO91 (SBSCO50) was used in conjunction with an interlayer of CGO91 applied between the electrode and 8mol% normalY2normalO3 stabilized ZrnormalO2 electrolyte. These were 0.12Ωcm2 at 600°C and 0.019Ωcm2 at 700°C , respectively. The coefficient of thermal expansion (CTE) of SBSCO was 21.9×10−6normalK−1 at 700°C . However, the CTE of the composite cathode of SBSCO50 was shown to be 13.6×10−6normalK−1 at 700°C , this being more compatable with the other components within the cell.

Electrochemical properties and durability of in-situ composite cathodes with SmBa0.5Sr0.5Co2O5+δ for metal supported solid oxide fuel cells

“…This implies that Sr substituted layered perovskites can be used as potential cathode materials for Solid Oxide Fuel Cells (SOFCs). Based on these results, our group has reported excellent ASRs of composite cathodes of SmBaCo2O5+δ 5 (SBCO) [7] and SmBa0.5Sr0.5Co2O5+δ (SBSCO) [8]. The ASR of SBCO on Ce0.9Gd0.1O2-δ (CGO91) is 0.13 Ω cm 2 [1].…”

“…Previous and on-going IT-SOFC cathode studies by our group have shown that Sr doped layered perovskite materials are promising cathode materials for application in SOFCs at temperatures between 500 o C and 700 o C [6][7][8]. Our research has been applied to layered perovskite compounds with the chemical formula YBaCo2O5, a material first synthesized and investigated in 1993 [6].…”

“…The ASR of SBCO on Ce0.9Gd0.1O2-δ (CGO91) is 0.13 Ω cm 2 [1]. The new composite cathode, SBSCO:50, shows lower ASR results than those of both conventional cathodes and layered perovskite cathodes for ITSOFCs [8].…”

“…Based on the ASR results for SBSCO:50 [8], a composite cathode comprised of 50 wt% SBSCO and 50 wt% CGO91, was chosen for further tests relevant to cathode materials in metal supported solid oxide fuel cells (MS-SOFCs) because MS-SOFCs 6…”

Novel layered perovskite GdBaCuFeO5+x as a potential cathode for proton-conducting solid oxide fuel cells

“…1, the as-prepared powder of layered GdBaCuFeO 5+x (GBCuF) exhibits a layered perovskite phase structure without any peaks attributable to impurities [12,16]. Figure 1 (part b) shows the X-ray diffraction (XRD) pattern of the chemical compatibility of the GBCuF cathode with BaZr 0.1 Ce 0.7 Y 0.2 O 3−δ (BZCY) electrolyte, which was investigated by mixing thoroughly with a 1:1 weight ratio and then sintered at 1,000°C for 10 h. Pure GBCuF contains a layered perovskite phase structure, while BZCY contains a perovskite-type structure; they are different structures.…”