Abstract
La2-xCoTiO6-delta/Ce0.9Gd0.1O2-delta composites are presented as promising new cathodes for solid oxide fuel cells. The B-site ordering characteristic of double perovskites is present in the whole series. Additionally, increasing amounts of La-vacancies give rise to ordering of alternating La-rich and square-rich (square = vacancy) Layers perpendicular to the c-axis. The introduction of La vacancies produces both oxidation of Co2+ to Co3+ and oxygen vacancies inducing a change of both electrical and electrochemical properties. The best electrochemical performances are obtained for Low x due to a compromise between sufficiently high amount of defects to provide electronic and ionic conductivities, but not so high to induce defect clustering. The material with x = 0.05 exhibits the best performances of the series. Symmetrical cells made of composites of this material and Ce0.9Gd0.1O2-delta deposited on pellets of this electrolyte show a polarization resistance of 0.39 Omega cm(2) at 1073 K.
Original language | English |
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Journal | Journal of Materials Chemistry A |
Volume | 4 |
Issue number | 9 |
Pages (from-to) | 3386-3397 |
Number of pages | 12 |
ISSN | 2050-7488 |
DOIs | |
Publication status | Published - 2016 |