Barium- and strontium-enriched (Ba0.5Sr0.5)1+xCo0.8Fe0.2O3−δ oxides as high-performance cathodes for intermediate-temperature solid-oxide fuel cells

✍ Scribed by Wei Zhou; Ran Ran; Zongping Shao; Wei Zhuang; Jing Jia; Hongxia Gu; Wanqin Jin; Nanping Xu

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 818 KB
• Volume: 56
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2008.02.002

✦ Synopsis

Ba 0.5 Sr 0.5 ) 1+x Co 0.8 Fe 0.2 O 3Àd , or BSCF(1 + x), (0 6 x 6 0.3) oxides were synthesized and investigated as cathodes for intermediatetemperature solid-oxide fuel cells. The A-site cation excess in BSCF(1 + x) resulted in a lattice expansion and the creation of more active sites for oxygen reduction reaction due to the lowered valence states of the B-site ions and the increased oxygen vacancy concentration, which improved the oxygen adsorption process. On the other hand, the A-site excess could also result in higher resistances for oxygen adsorption (due to the formation of BaO and/or SrO impurities), and oxygen-ion transfer (by facilitating the solid-phase reaction between the cathode and the electrolyte). By taking all these factors into account, we found BSCF1.03 to be the optimal composition, which lead to a peak power density of 1026.2 ± 12.7 mW cm À2 at 650 °C for a single cell.