Preparation and Performance of SrCo1-xGaxO3-δ Cathode Materials for Interme-diate Temperature Solid Oxide Fuel Cells

Cathode materials of SrCo1-xGaxO3-δ (x=0, 0.1, 0.2, 0.3, 0.4) for intermediate temperature solid oxide fuel cells (IT-SOFC) were synthesized by an Ethylene Diamine Tetraacetie Acid (EDTA)-citrate complexing method. The obtained samples were characterized by X-ray diffraction, thermal expansion measurement, X-ray photoelec- tron spectroscopy and electrochemical impedance spectroscopy, and the effects of Ga-doping on performance and properties of materials were evaluated. The results show that all the samples have brownmillerite structure. The thermal expansion coefficient (TEC), electrical conductivity and the amount of adsorbed oxygen on the surface of the cathode materials gradually decrease with Ga content increasing. Among the as-abtained samples, SrCo0.8Ga0.2O3-δ shows the lowest area specific resistance (ASR) of 0.73 Ω•cm 2 at 600℃, the single-cell with it as