High oxide-ion conductivity through the interstitial oxygen site in Ba7Nb4MoO20-based hexagonal perovskite related oxides
Open Access
- 25 January 2021
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature Communications
- Vol. 12 (1), 1-7
- https://doi.org/10.1038/s41467-020-20859-w
Abstract
Oxide-ion conductors are important in various applications such as solid-oxide fuel cells. Although zirconia-based materials are widely utilized, there remains a strong motivation to discover electrolyte materials with higher conductivity that lowers the working temperature of fuel cells, reducing cost. Oxide-ion conductors with hexagonal perovskite related structures are rare. Herein, we report oxide-ion conductors based on a hexagonal perovskite-related oxide Ba7Nb4MoO20. Ba7Nb3.9Mo1.1O20.05 shows a wide stability range and predominantly oxide-ion conduction in an oxygen partial pressure range from 2 × 10−26 to 1 atm at 600 °C. Surprisingly, bulk conductivity of Ba7Nb3.9Mo1.1O20.05, 5.8 × 10−4 S cm−1, is remarkably high at 310 °C, and higher than Bi2O3- and zirconia-based materials. The high conductivity of Ba7Nb3.9Mo1.1O20.05 is attributable to the interstitial-O5 oxygen site, providing two-dimensional oxide-ion O1−O5 interstitialcy diffusion through lattice-O1 and interstitial-O5 sites in the oxygen-deficient layer, and low activation energy for oxide-ion conductivity. Present findings demonstrate the ability of hexagonal perovskite related oxides as superior oxide-ion conductors.Keywords
Funding Information
- MEXT | Japan Society for the Promotion of Science (JP15H02291, JP16H00884, JP16H06293, JP16H06440, P16H06441, JP16H06438, JP16K21724, JP17K17717, JP17H06222, JP19H00821, Core-to-Core Program, A. Advanced Research Networks (Solid Oxide Interfaces for Faster Ion Transport)
This publication has 48 references indexed in Scilit:
- Ionic conduction in substituted scheelite-type oxidesSolid State Ionics, 2000
- Oxygen diffusion and surface exchange in La2−xSrxNiO4+δSolid State Ionics, 2000
- Fast oxygen transport in acceptor doped oxidesSolid State Ionics, 2000
- Designing fast oxide-ion conductors based on La2Mo2O9Nature, 2000
- Electrical properties of new type high oxide ionic conductor RE10Si6O27 (RE = La, Pr, Nd, Sm, Gd, Dy)Journal of the European Ceramic Society, 1998
- Synthesis and Electrical Properties of Dense Ce0.9Gd0.1O1.95 CeramicsJournal of the American Ceramic Society, 1998
- Ionic conductivity of lanthanoid silicates, Ln10(SiO4)6O3(Ln = La, Nd, Sm, Gd, Dy, Y, Ho, Er and Yb)Journal of Materials Chemistry, 1995
- Doped LaGaO3 Perovskite Type Oxide as a New Oxide Ionic ConductorJournal of the American Chemical Society, 1994
- Oxide-ion conduction in Ba2In2O5 and Ba3In2MO8 (M=Ce, Hf, or Zr)Solid State Ionics, 1990
- The bimevox series: A new family of high performances oxide ion conductorsSolid State Ionics, 1990