Proton conductivity of potassium doped barium zirconates

Journal Article · Fri Jan 15 04:00:00 EST 2010 · Journal of Solid State Chemistry

OSTI ID:21372453

Xiaoxiang, Xu ^[1]; Irvine, John T.S. ^[1]

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1. School of Chemistry, University of St. Andrews, Fife KY16 9ST (United Kingdom)

Potassium doped barium zirconates have been synthesized by solid state reactions. It was found that the solubility limit of potassium on A-sites is between 5% and 10%. Introducing extra potassium leads to the formation of second phase or YSZ impurities. The water uptake of barium zirconates was increased even with 5% doping of potassium at the A-site. The sintering conditions and conductivity can be improved significantly by adding 1 wt% ZnO during material synthesis. The maximum solubility for yttrium at B-sites is around 15 at% after introducing 1 wt% zinc. The conductivity of Ba{sub 0.95}K{sub 0.05}Zr{sub 0.85}Y{sub 0.11}Zn{sub 0.04}O{sub 3-{delta}} at 600 deg. C is 2.2x10{sup -3} S/cm in wet 5% H{sub 2}. The activation energies for bulk and grain boundary are 0.29(2), 0.79(2) eV in wet 5% H{sub 2} and 0.31(1), 0.74(3) eV in dry 5% H{sub 2}. A power density of 7.7 mW/cm{sup 2} at 718 deg. C was observed when a 1 mm thick Ba{sub 0.95}K{sub 0.05}Zr{sub 0.85}Y{sub 0.11}Zn{sub 0.04}O{sub 3-{delta}} pellet was used as electrolyte and platinum electrodes. - Graphical abstract: Potassium doped barium zirconates have been synthesized by solid state reactions. It was found that the solubility limit of potassium on A-sites is between 5% and 10 %. The sintering conditions and conductivity can be improved significantly by adding 1 wt% ZnO during material synthesis. Five percent doping of potassium at A-site can double the total conductivity.

• OSTI ID: 21372453
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 183; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
DIRECT ENERGY CONVERTERS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROCHEMICAL CELLS
ELEMENTS
ENERGY
FABRICATION
FUEL CELLS
GRAIN BOUNDARIES
HYDROGEN
IONIC CONDUCTIVITY
MATERIALS
METALS
MICROSTRUCTURE
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLATINUM
PLATINUM METALS
POTASSIUM COMPOUNDS
PROTON CONDUCTIVITY
SINTERING
SOLUBILITY
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
ZINC COMPOUNDS
ZINC OXIDES
ZIRCONATES
ZIRCONIUM COMPOUNDS