Abstract
In this study, electrochemical properties of layered perovskites having non-stoichiometric compositions (Sm1−xBaCo2O5+d, x = 0, 0. 01, 0.02, 0.03, 0.04, 0.05, 0.10, and 0.15) were analyzed for the direct application of cathode materials for Intermediate Temperature-operating Solid Oxide Fuel Cells (IT-SOFC). From the Sm1−xBaCo2O5+d oxide systems calcined at 1,100°C for 8 h, single phase (SmBaCo2O5+d, SBCO_1) was maintained only in the case of the x = 0 composition. In the compositions of x = 0.05–0.10, BaCoO2.6 was mixed with the pattern of SBCO. In addition, in the composition of x = 0.15, it was confirmed that BaCoO2.6 and CoO phases coexisted with SBCO. In the compositions of Sm1−xBaCo2O5+d, the overall Area Specific Resistance (ASR) values decreased as the removal amount of Sm increased from x = 0–0.10; then, the values increased for compositions from x = 0.15. For example, the ASRs of SBCO_1, Sm0.95BaCo2O5+d (SBCO_0.95), Sm0.90BaCo2O5+d (SBCO_0.90), and Sm0.85BaCo2O5+d (SBCO_0.85) measured at 600°C were 0.301, 0.147, 0.119, and 0.179 Ω cm2, respectively. In particular, SBCO_0.90 was found to have an excellent ASR property of about 0.035 Ω cm2 at 700°C. Typical properties of the metal–insulator transition (MIT) electrical conductivity were shown in all measured compositions. The temperature at which MIT occurred increased as the non-stoichiometric composition increased.
Highlights
As environmental problems such as global warming, caused by the indiscriminate use of fossil fuels since the beginning of the industrial revolution in the 19th century have recently emerged, interest in eco-friendly energy has been expanding (Wigley, 1998; Hoad, 2015)
The characteristic XRD patterns discovered in the vicinity of 23.4◦, 33.0o, 40.4o, 46.7o, 59.1o, 69.2o, 78.1o) indicate that the Sm1−xBaCo2O5+d oxide systems were synthesized as a single phase from the stoichiometric SmBaCo2O5+d (SBCO) composition in which Sm was not removed and the non-stoichiometric composition in which 0.01, 0.02, 0.03, and 0.04 mol% of Sm (SBCO_0.99, SBCO_0.98, SBCO_0.97, and SBCO_0.96) were partially removed
The electrochemical properties of materials having nonstoichiometric compositions in which Sm of the A/-site was partially removed in SmBaCo2O5+d oxide systems were studied for direct application of these materials as cathodes for IT-solid oxide fuel cells (SOFC)
Summary
As environmental problems such as global warming, caused by the indiscriminate use of fossil fuels since the beginning of the industrial revolution in the 19th century have recently emerged, interest in eco-friendly energy has been expanding (Wigley, 1998; Hoad, 2015). There is need for development of other energy methods that can replace these systems and mitigate their problems (Rodman and Meentemeyer, 2006; Kosnik, 2008; Ingole and Rakhonde, 2015). Fuel cells or fuel cell systems based on hydrogen energy have been emerging as alternative energy conversion methods to replace the energy generating from fossil fuel. An SOFC is an energy converting device that produces water and generates electricity via the chemical reaction of hydrogen and oxygen (Minh, 2004)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
