Thermal and Electrical Properties of New Cathode Material Ba[sub 0.5]Sr[sub 0.5]Co[sub 0.8]Fe[sub 0.2]O[sub 3−δ] for Solid Oxide Fuel Cells

A newly developed cathode material, Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3 − δ , was synthesized and characterized. X-ray diffraction results identified it as a cubic perovskite structure. Thermogravimetric results showed that lattice oxygen loss was about 2% in weight between 50 and 1000°C. Thermal expansion coefficient results in air and argon were extraordinarily high, with slope changes occurring at about 382 and 360°C, respectively. Electrical conductivity values were sufficient for cathode application with the maximum of about 28.1 S cm − 1 at 500°C in air and 17.3 S cm − 1 at 900°C in N 2 , correspondingly. Both thermal and electrical properties were closely associated with lattice oxygen behaviors and oxygen partial pressure.