Original scientific paper
https://doi.org/10.5599/jese.503
Evaluation of strontium substituted lanthanum manganite- -based solid oxide fuel cell cathodes using cone-shaped electrodes and electrochemical impedance spectroscopy
Kent Kammer Hansen
orcid.org/0000-0002-1349-958X
; Department of Energy Conversion and Storage, Technical University of Denmark, DK-4000 Roskilde, Denmark
Abstract
Five La1-xSrxMnO3+−based perovskites (x = 0, 0.05, 0.15, 0.25 and 0.50) were synthesized and investigated by powder XRD, dilatometry and electrochemical impedance spectroscopy measurements and cone-shaped electrode techniques. The thermal expansion coefficient increased with increasing strontium content. It was shown that the total polarization resistance was the lowest for the intermediate compound, La0.95Sr0.05MnO3+. Two arcs were found in the impedance spectra. These arcs were attributed to two one-electron processes. The results indicate that either Mn(III) is the catalytically active species or that the redox capacity is important for the activity of the compounds towards the reduction of oxygen in a solid oxide fuel cell. At higher temperatures, the oxide ionic conductivity may also play a role.
Keywords
LSM; EIS; Oxygen; SOFC; Cathode
Hrčak ID:
201119
URI
Publication date:
17.5.2018.
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