REBaCo 2 O 5+δ (RE = Pr, Nd, and Gd) as promising oxygen electrodes for intermediate-temperature solid oxide electrolysis cells
Double-perovskite REBaCo 2 O 5+δ (RE = Pr, Nd, and Gd) oxides were synthesized and evaluated as oxygen electrodes for intermediate-temperature solid oxide electrolysis cells (IT-SOECs). The crystal structures, thermal stability properties, electrical conductivities, and electrochemical performances...
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Veröffentlicht in: | RSC advances 2017, Vol.7 (27), p.16332-16340 |
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Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
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Zusammenfassung: | Double-perovskite REBaCo
2
O
5+δ
(RE = Pr, Nd, and Gd) oxides were synthesized and evaluated as oxygen electrodes for intermediate-temperature solid oxide electrolysis cells (IT-SOECs). The crystal structures, thermal stability properties, electrical conductivities, and electrochemical performances of the REBaCo
2
O
5+δ
materials were investigated systematically. Among the three oxides, PrBaCo
2
O
5+δ
(PBCO) has the highest electrical conductivity of 645 S cm
−1
at 600 °C. The electrical conductivity decreases as the ionic radius of the RE decreases, which is related to the increase in oxygen vacancy concentration. NdBaCo
2
O
5+δ
(NBCO) has the lowest polarization resistance of 0.95 Ω cm
2
among the three oxides at 650 °C, which is mainly because NBCO has a better balance between thermal expansion compatibility and conductivity than PBCO and GdBaCo
2
O
5+δ
(GBCO). For electrochemical performance in SOECs, NBCO has the smallest current/voltage loss; at a voltage of 1.2 V, the power density of NBCO is 1.58 W cm
−2
at 800 °C. Even at 700 °C, a maximum power density of 0.857 W cm
−2
can still be achieved by NBCO. These results suggest that NBCO is a novel and promising candidate oxygen electrode material for IT-SOECs. |
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ISSN: | 2046-2069 2046-2069 |
DOI: | 10.1039/C6RA28005F |