Influence of impurities on the bulk and grain-boundary conductivity of CaZrO3-based proton-conducting electrolyte: A distribution of relaxation time study
| Autor: | М.S. Plekhanov, A.V. Kuzmin, A.S. Lesnichyova |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
General Chemical Engineering Relaxation (NMR) Analytical chemistry 02 engineering and technology Electrolyte Conductivity 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Dielectric spectroscopy Grinding Impurity Electrode Electrochemistry Grain boundary 0210 nano-technology |
| Zdroj: | Electrochimica Acta. 348:136327 |
| ISSN: | 0013-4686 |
| DOI: | 10.1016/j.electacta.2020.136327 |
| Popis: | In the present work single-phase proton-conducting electrolyte CaZr0.95Sc0.05O3-δ (CZS) is synthesized by a conventional solid-state technique with different impurities content. Impurities are introduced by using different milling bodies during the synthesis. It is shown that milling by steel balls or grinding in a jasper mortar results in approximately 1 at.% of iron and silica respectively. Milling with ZrO2 balls does not lead to a noticeable increase in the level of impurities in CZS. The influence of impurities on the bulk and grain boundary conductivity is studied by means of electrochemical impedance spectroscopy. The measurements are performed on symmetric cells with different electrodes: Pt|CZS|Pt, (Pt + PrO2)|CZS|(Pt + PrO2) and Ag|CZS|Ag. The data analyzed by the conventional equivalent circuit and distribution of relaxation times (DRT) techniques. It is shown that impurities influence only the grain boundary conductivity which proves that the grain boundary segregation occurs. However, a large grain-boundary resistance could be an obstacle to determine the bulk resistance. |
| Databáze: | OpenAIRE |
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