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

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. (SBSCO) electrode was sintered onto gadolinia-doped ceria ( , CGO91) at to form symmetrical cells and exhibited an ASR value of at . The lowest ASR value was observed when the composite cathode of of SBSCO and of CGO91 (SBSCO50) was used in conjunction with an interlayer of CGO91 applied between the electrode and stabilized electrolyte. These were at and at , respectively. The coefficient of thermal expansion (CTE) of SBSCO was at . However, the CTE of the composite cathode of SBSCO50 was shown to be at , this being more compatable with the other components within the cell.