Correlation between microstructure and electrical conductivity in composite electrolytes containing Gd-doped ceria and Gd-doped barium cerate

Khandelwal, Mudrika; Venkatasubramanian, Anandram; Prasanna, T. R. S.; Gopalan, P.

doi:10.1016/j.jeurceramsoc.2010.10.027

Cited by 45 publications

(28 citation statements)

References 34 publications

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“…As it was reported for gadolinium and niobium-doped barium cerate, the specific grain boundary conductivity seems to be independent on the grain size [8,9]. Though, the activation energy of grain boundary conductivity shows significant changes with the microstructure [10]. For materials based on barium compounds sintered in the relatively high temperature, the change in the composition of grain boundaries caused by e.g.…”

Section: Introductionmentioning

confidence: 64%

Effect of microstructure on chemical stability and electrical properties of BaCe0.9Y0.1O3 − δ

Łącz

2016

Ionics

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Y-doped barium cerate BaCe 0.9 Y 0.1 O 3 − δ was synthesised by a solid-state reaction method. Materials with different average grain sizes and grain boundary surface areas were obtained. The effect of microstructure on the chemical stability in the CO 2 and H 2 O-containing atmosphere and electrical properties was analysed and discussed. To evaluate the chemical stability of BaCe 0.9 Y 0.1 O 3 − δ , the exposure test was performed. Samples were exposed to the carbon dioxide and water vapour-rich atmosphere at 25°C for 700 h. Thermogravimetry supplied by mass spectrometry was applied to analyse the samples before and after this comprehensive test. The mass loss for samples before and after the test and the amount of BaCO 3 formed during the test were directly treated as the measure of chemical instability of BaCe 0.9 Y 0.1 O 3 − δ in the atmosphere rich in carbon dioxide and water vapour. As it was observed, the BaCe 0.9 Y 0.1 O 3 − δ chemical stability towards CO 2 and H 2 O is not affected by the materials' microstructure. Electrical properties of BaCe 0.9 Y 0.1 O 3 − δ which differs with microstructure were determined using electrochemical impedance spectroscopy (EIS). It was found that the grain interior resistivity and activation energy of grain interior conductivity is microstructure independent. However, the effect on microstructure was seen on the EIS spectra in the range of grain boundary contribution. Therefore, the lowest activation energy and the highest conductivity were observed for a material with the lowest grain boundary surface area.

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Section: Introductionmentioning

confidence: 64%

Effect of microstructure on chemical stability and electrical properties of BaCe0.9Y0.1O3 − δ

Łącz

2016

Ionics

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“…Moreover, it is a common experimental fact 20 that, even for high values of δ (up to 0.2), this compound keeps the perovskite structure. Thus it can be viewed as a BCO compound in which some Ce have been substituted by Gd (dopants, with proportion δ) and oxygen atoms have been removed (oxygen vacancies, with proportion δ/2).…”

Section: Dry Compoundmentioning

confidence: 98%

Thermodynamics of hydration and oxidation in the proton conductor Gd-doped barium cerate from density functional theory calculations

et al. 2012

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Hydration and oxidation of gadolinium-doped barium cerate, a system with highly promising properties when used as electrolyte for protonic ceramic fuel cells, are investigated by means of density functional calculations. The energy landscape of oxygen vacancies and interstitial protons in this strongly distorted orthorhombic perovskite is computed. Although the most stable sites for protons are found in the close vicinity of the dopant, the picture of a very complex energy landscape emerges, in which some sites far away from Gd are found more stable than other ones in its close vicinity, due to the highly distorted geometry of the host materials. The fully hydrated phase can be approximated by a structure with 16 local minima. Both hydration (water incorporation) and oxidation (oxygen incorporation) are found to be exothermic processes with reaction enthalpies of −1.34 eV/H 2 O molecule and −0.70 eV/O atom, respectively. The hole polaron resulting from the exothermic incorporation of oxygen is found localized on oxygens around the dopant (small polaron) and carries a spin magnetic moment. Finally, the competition between hydration and oxidation is studied and discussed as a function of oxygen and water partial pressures.

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“…This is characteristic for grain interior and grain boundary conductivity, seeing as grain sizes of the materials studied in this dissertation are in the µm range (see Table II) and grain boundary thickness of ceramic materials is usually in the 1-10 nm range [23][24][25][26]. The capacitance values obtained in this paper contradict the results obtained in [27] for a BaCeO 3 -CeO 2 -based composite material. In that work, the IF capacitance values were more similar to those obtained for the HF arc, which suggests that the IF arc does not pertain to grain boundary conduction.…”

Section: Resultsmentioning

confidence: 67%

Electrical Properties of BaCeO₃-Based Electrolytes for use in Dual Protonic Ceramic-Solid Oxide Fuel Cells

Gaweł

Przybylski

2017

Acta Phys. Pol. A

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Bulk samples consisting of BaCe0.85Y0.15O 3−δ (BCY15) and Ce0.85Y0.15O 2−δ (YDC15) compounds, mixed together in different ratios, were studied as potential electrolytes in dual protonic ceramic-solid oxide fuel cells and compared with non-composite BCY15 and YDC15. The microstructures of the sintered materials indicate that BCY15 exhibits the largest grains, whereas composites have greater visible porosity than the non-composite samples. From X-ray diffraction studies it follows that BCY15 and YDC15 consist mainly of one phase, whereas the composites are two-phase materials. Electrochemical impedance spectroscopy studies at different temperatures show that the composite materials are capable of conduction the order of 10 −3 S/cm at temperatures above 500• C in a hydrogen-containing atmosphere. Furthermore, activation energy values of the conductivity determined for the composites in air atmosphere are between those obtained for BCY15 (Ea = 0.590 ± 0.017 eV) and YDC15 (Ea = 1.132±0.008 eV). From this it follows that both phases of the composites influence the electrical conductivity of the materials. In conclusion, BCY15 and the BCY15-YDC15 composites show promise for future use as electrolytes in dual protonic ceramic-solid oxide fuel cells.

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Correlation between microstructure and electrical conductivity in composite electrolytes containing Gd-doped ceria and Gd-doped barium cerate

Cited by 45 publications

References 34 publications

Effect of microstructure on chemical stability and electrical properties of BaCe0.9Y0.1O3 − δ

Effect of microstructure on chemical stability and electrical properties of BaCe0.9Y0.1O3 − δ

Thermodynamics of hydration and oxidation in the proton conductor Gd-doped barium cerate from density functional theory calculations

Electrical Properties of BaCeO₃-Based Electrolytes for use in Dual Protonic Ceramic-Solid Oxide Fuel Cells

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Correlation between microstructure and electrical conductivity in composite electrolytes containing Gd-doped ceria and Gd-doped barium cerate

Cited by 45 publications

References 34 publications

Effect of microstructure on chemical stability and electrical properties of BaCe0.9Y0.1O3 − δ

Effect of microstructure on chemical stability and electrical properties of BaCe0.9Y0.1O3 − δ

Thermodynamics of hydration and oxidation in the proton conductor Gd-doped barium cerate from density functional theory calculations

Electrical Properties of BaCeO3-Based Electrolytes for use in Dual Protonic Ceramic-Solid Oxide Fuel Cells

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Electrical Properties of BaCeO₃-Based Electrolytes for use in Dual Protonic Ceramic-Solid Oxide Fuel Cells