Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5146830 | International Journal of Hydrogen Energy | 2017 | 12 Pages |
Abstract
BaxSr1âxCo0.9Sb0.1O3âδ (BSCSbx, x = 0.0-0.8) are investigated as cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs). BSCSbx oxides are crystallized in a tetragonal structure with s.g. P4/mmm. XPS analysis shows that Ba doping reduces valence state of Co ions: Co in SrCo0.9Sb0.1O3âδ is prone to Co4+, while Co in Ba doped SrCo0.9Sb0.1O3âδ becomes more prone to Co3+. Oxygen deficiency δ increases with Ba doping even at high temperatures. Conductivity is found to decrease with Ba doping. Thermal expansion coefficient (TEC) decreases from 20.6 Ã 10â6 Kâ1 for x = 0.0 to 18.4 Ã 10â6 Kâ1 for x = 0.6 at 30-1000 °C. With increasing x from 0.0 to 0.6, polarization resistance (Rp) decreases monotonously, and then increases with further increasing x. The lowest Rp of 0.081 Ω cm2 at 700 °C is obtained for BSCSb0.6 cathode. At 700-850 °C, the Rp of BSCSb0.6 is mainly contributed from electron charge transfer; however, below 700 °C, ion charge transfer plays a more important role in Rp. Maximum power densities of the cell with BSCSb0.6 cathode on 300-μm thick La0.9Sr0.1Ga0.8Mg0.2O3âδ (LSGM) electrolyte attain 306-944 mW cmâ2 at 700-850 °C. These results indicate that BSCSb0.6 is a promising cathode for application in IT-SOFC.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Yuee Chen, Lei Zhang, Bingbing Niu, Wen Long, Zhaoyuan Song, Leilei Zhang, Yanru Huang, Tianmin He,