Associating and tuning sodium and oxygen mixed-ion conduction in niobium-based perovskites

Autor: Fabrice Mauvy, Thierry Le Mercier, Alain Demourgues, Guillaume Gouget, Sébastien Fourcade, Mathieu Duttine, U-Chan Chung, Marc-David Braida
Přispěvatelé: Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Solvay (France), This work was supported by Solvay and CNRS., Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Advanced Functional Materials
Advanced Functional Materials, Wiley, 2020, 30 (11), 1909254 (12 p.). ⟨10.1002/adfm.201909254⟩
ISSN: 1616-301X
1616-3028
Popis: International audience; Pure ionic conductors as solid‐state electrolytes are of high interest in electrochemical energy storage and conversion devices. They systematically involve only one ion as the charge carrier. The association of two mobile ionic species, one positively and the other negatively charged, in a specific network should strongly influence the total ion conduction. Nb5+‐ (4d0) and Ti4+‐based (3d0) derived‐perovskite frameworks containing Na+ and O2− as mobile species are investigated as mixed ion conductors by electrochemical impedance spectroscopy. The design of Na+ blocking layers via sandwiched pellet sintered by spark plasma sintering at high temperatures leads to quantified transport number of both ionic charge carriers tNa+ and tO2−. In the 350–700 °C temperature range, ionic conductivity can be tuned from major Na+ contribution (tNa+ = 88%) for NaNbO3 to pure O2− transport in NaNb0.9Ti0.1O2.95 phase. Such a Ti‐substitution is accompanied with a ≈100‐fold increase in the oxygen conductivity, approaching the best values for pure oxygen conductors in this temperature range. Besides the demonstration of tunable mixed ion conduction with quantifiable cationic and anionic contributions in a single solid‐state structure, a strategy is established from structural analysis to develop other architectures with improved mixed ionic conductivity.
Databáze: OpenAIRE
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