dc.description.abstract | In this study, the nanostructured perovskite La0.6Sr0.4Co0.8Fe0.2O3 (LSCF) and La0.6-xSr0.4BaxCo0.8Fe0.2O3 (note as x=0.13; LSB1CF, 0.26; LSB2CF, 0.39; LSB3CF) prepared by the glycine-nitrate combustion synthesis method were considered as a potential candidate for use as cathode in solid oxide fuel cells (SOFC) operated at intermediate-temperature. In the present work, combustion synthesis method was investigated by adjusting the pH of LSCF nitrate solution (pH=2, 3, 4, 5) and ratio between glycine and nitrate (G/N=0.50, 0.75, 1.00, 1.25). The crystal structure and morphology of the powders after calcining were analyzed and also its thermal properties and electrochemical characteristic were discussed. The optimal combustion synthesis parameters (pH and G/N) were used to synthesize the LSBxCF. Then the crystal structure and electrochemical properties were investigated. Finally, the feasibility for using as cathode in P-SOFC though combining LSCF as cathode backbone and LSBxCF as infiltrating material together by infiltration to fabricate a composite cathode was evaluated. The results of LSCF analysis showed that LSCF1.00/3, LSCF1.00/4, LSCF1.25/3 and LSCF1.25/4 were the optimal parameters for combustion synthesis whose crystal structure and morphology were the most suitable as cathode for SOFC. Among all, LSCF1.25/3 was analyzed that its average particle size around 300nm. For the measurement of thermal expansion coefficient (TMA), the coefficient of LSCF1.25/3 was about 11.8 × 10-6 K-1 which was the closest to that of electrolyte BCZY. In the results of four-probe DC conductivity measurement, LSCF1.00/4 had the highest conductivity near 3690 S/cm@550°C. For the thermosgravimetric analysis of LSBxCF, the results showed that the weight loss of La0.34Sr0.4Ba0.26Co0.8Fe0.2O3 (LSB2CF) was the biggest which indicated that LSB2CF provided the highest amount of oxygen vacancies in LSBxCF. Also, the resistance of electron conductivity and oxygen ion transfer for half-cell of LSB2CF was 0.24 ?cm2 and 0.30 ?cm2 respectively. Then, results of performance tests for the cell used LSCF as cathode backbone and LSB2CF as infiltrating material showed that the maximum power density of infiltrated cell was 39.5 mW/cm2 and pristine was 23.7 mW/cm2. The power density enhanced about 66.67 %. The polarization resistance of infiltrated cell was 1.06 ?cm2 and pristine was 3.21 ?cm2. The resistance reduced about 66.9 %. | en_US |