Abstract
The effect of the amount of cobalt in (Gd0.6Sr0.4)0.99Fe1-xCoxO3-δ solid oxide fuel cell (SOFC) cathodes (x = 0.00,
0.05, 0.10, 0.15, 0.20 and 0.25) was studied by powder X-ray
diffraction (XRD), scanning electron microscopy (SEM), dilatometry,
four-point DC conductivity measurements, cone-shaped electrodes, and
electrochemical impedance spectroscopy (EIS). XRD and scanning electron
microscopy revealed two phases: a cubic phase and an orthorhombic phase.
One phase has a small particle size (cubic phase), and the other phase
(orthorhombic) has a larger particle size. Dilatometry indicated that
the thermal expansion coefficient increased with increasing Co content.
The electrical conductivity maximum for the Co-rich compound was found
to have a value of 82 S cm−1 at approximately 300 °C. It was
shown that the activity of the cathodes was strongly dependent on the
amount of cobalt. The highest activity was found for the cobalt-rich
compound (Gd0.6Sr0.4)0.99Fe0.75Co0.25O3-δ with an area-specific resistance of 0.9 Ωcm2 at 600 °C, measured on a cone-shaped electrode in air.
Original language | English |
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Journal | Journal of Solid State Electrochemistry |
Volume | 23 |
Issue number | 3 |
Pages (from-to) | 965-970 |
Number of pages | 6 |
ISSN | 1432-8488 |
DOIs | |
Publication status | Published - 2019 |