Journal
JOURNAL OF MATERIALS CHEMISTRY A
Volume 3, Issue 45, Pages 22614-22626Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/c5ta05815e
Keywords
-
Ask authors/readers for more resources
A novel Co-free cathode, La0.3Sr0.7Fe0.7Cr0.3O3-delta (LSFCr-3), exhibiting the desired combination of high electrical conductivity, physical and chemical stability, and electrocatalytic activity, was systematically investigated for SOFC applications. Its excellent performance is attributed primarily to the presence of Cr, which was found to be predominant in the 3+ and 4+ oxidation states in the LSFCr-3 bulk, thus likely maintaining a 6-fold coordination with oxygen anions. This, in turn, causes disorder in the oxygen vacancy sub-lattice, stabilized by the Fe ion-oxygen tetrahedra. However, on the surface of the LSFCr-3 oxide, Cr is primarily in the 6+ state, together with some Cr3+/Cr4+, even at 700 degrees C. Cr6+ can only be tetrahedrally coordinated by oxygen anions, resulting in a large concentration of oxygen vacancies on the LSFCr-3 surface, with a surface exchange coefficient and oxygen ionic conductivity of ca. 10 (5) cm s (1) and ca. 10(-2) S cm(-1), respectively, at 700- 800 degrees C. The use of LSFCr-3 as the cathode in a Ni-Ce0.8Sm0.2O2-delta (SDC) anode-supported single solid oxide fuel cell in 3% H2O-H-2/air gave a maximum power density of 0.81 W cm(2) at 750 degrees C, which is superior to that of similar cells in which La0.6Sr0.4Fe0.8Co0.2O3-delta, a previously well studied material, was used as the cathode.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available