Electrolytes

Kilner, John A.; Druce, J.; Ishihara, T.

doi:10.1016/b978-0-12-410453-2.00004-x

Cited by 8 publications

(6 citation statements)

References 177 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ion conductors have a wide range of applications such as solid oxide fuel cells (SOFCs), gas sensors, batteries, and oxygen separation membranes. − The development of SOFCs and high-performance oxygen separation membranes requires new materials with high oxide-ion conductivity. − Improved ion conductivity necessitates a deep understanding of the mechanisms of oxide-ion conduction at an atomic level. ,,− The structural disorder is of vital importance for the ion conduction and various material properties. For example, AgI, β-alumina, stabilized zirconia, LAMOX, fluorite-type bismuth oxide Bi 2 O 3 , and copper iodide CuI exhibit high ion conductivity due to the presence of the structural disorder and ion-diffusion pathways. ,− …”

Section: Introductionmentioning

confidence: 99%

Oxide-Ion Occupational Disorder, Diffusion Path, and Conductivity in Hexagonal Perovskite Derivatives Ba₃WNbO_8.5 and Ba₃MoNbO_8.5

et al. 2022

View full text Add to dashboard Cite

Hexagonal perovskite derivatives Ba 3 MNbO 8.5 (M: W and Mo) are attracting much interest due to high oxide-ion conductivity and potential use for many applications. This work shows the electrical conductivities of Ba 3 WNbO 8.5 (3.7 × 10 −2 S cm −1 ) and Ba 3 MoNbO 8.5 (8.8 × 10 −2 S cm −1 ) at 900 °C and confirms higher activation energy for conductivity of Ba 3 WNbO 8.5 than that of Ba 3 MoNbO 8.5 . Key factors governing the conductivity and activation energy are the ratio of tetrahedral O3 to octahedral O2 oxide ions and diffusion pathways in Ba 3 MNbO 8.5 . However, the O2/O3 disorders and oxide-ion diffusion paths are unresolved important issues in Ba 3 MNbO 8.5 . Here, Rietveld and maximumentropy method (MEM) analyses of in situ neutron-diffraction data up to 800 °C were performed to obtain the crystal structure and neutron scattering length densities (NSLDs) of Ba 3 WNbO 8.5 . MEM NSLDs show two-dimensional oxide-ion migration through the octahedral O2 and tetrahedral O3 sites in the intrinsically oxygen-deficient layer. Numbers of the interstitial O3 and lattice O2 atoms n(O3) and n(O2) increase and decrease, respectively, with increasing temperature, which indicates that the O2/O3 disorder is more prominent at high temperatures. The O2/O3 disordering makes the minimum NSLD on the O2−O3 path higher, which enhances oxide-ion conductivity, leading to higher activation energies of Ba 3 WNbO 8.5 compared with Ba 3 MoNbO 8.5 .

show abstract

Section: Introductionmentioning

confidence: 99%

Oxide-Ion Occupational Disorder, Diffusion Path, and Conductivity in Hexagonal Perovskite Derivatives Ba₃WNbO_8.5 and Ba₃MoNbO_8.5

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Since the discovery of enhanced ionic conductivity for the La 2 Mo 2 O 9 compound by Lacorre in 2000 [ 1 ], the efforts of application [ 2 ] for this system in different electrochemical devices have continuously increased [ 3 ]. Oxygen pumps, sensors, and solid oxide fuel cells (SOFCs) [ 4 , 5 , 6 , 7 ] are only a few types of equipment where lanthanum molybdenum oxide can be successfully applied. Despite a reversible phase transformation [ 8 , 9 ] above 540 °C from a low-temperature form α-La 2 Mo 2 O 9 [ 10 ] to a high-temperature form β-La 2 Mo 2 O 9 [ 11 ], its chemical stability [ 12 ] under air atmosphere in the range of temperature from 600 °C to 1000 °C creates the conditions for using this compound as a solid electrolyte of oxygen ions [ 13 ].…”

Section: Introductionmentioning

confidence: 99%

Thermoanalytical and X-ray Diffraction Studies on the Phase Transition of the Calcium-Substituted La2Mo2O9 System

Žalga

Gaidamavičienė

2023

Materials

View full text Add to dashboard Cite

An aqueous sol-gel preparation technique was applied for the synthesis of calcium-substituted lanthanum molybdate with the initial composition of La2–xCaxMo2O9–x/2. The influence of the substitution effect, which plays a crucial role in the formation of final ceramics, was investigated. The thermal behavior tendencies of phase transition at elevated temperatures from the monoclinic crystal phase to cubic as well as reversible transformation were identified and discussed in detail. It was proved that the phase transformation in the obtained mixture significantly depends only on the impurities’ amount, while the partial substitution by calcium atoms above the value of x = 0.05 does not create a homogeneous multicomponent system for La2–xCaxMo2O9–x/2 composition.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Solid oxide ion conductors play a significant role in electricity conversion devices (solid oxide fuel cells (SOFCs)) as an alternative energy [1]. SOFC is an electrochemical device which requires high temperature (>1000 K) for its operation [1]. The recent surge in the energy demand comes from the domestic sector where high temperature devices are generally restricted, this makes SOFC out of contest as a popular choice of portable alternative energy sources.…”

Section: Introductionmentioning

confidence: 99%

“…Low * Authors to whom any correspondence should be addressed. temperature (working between 500 and 800 K) fast oxide ion conductors (FOICs) can solve this problem [1,2]. The ionic conductivity of the high temperature FOICs generally decreases sharply with decrease in the temperature [2] hence such FOICs cannot be used in low temperature SOFC (IT and LT-SOFC).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Overlapping large polaron tunnelling in lanthanum silicate oxyapatite

Yadav¹,

Jha²,

Jha³

et al. 2022

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Amongst the various fast ion conductors, lanthanum excess lanthanum silicate oxyapatite ( La_{10-\alpha}(SiO_{4})_{6}O_{2+\delta} ) has shown higher oxide ion conductivity with lower activation energy. On the other hand, the activation energy increases with La vacancies (La at 4f site). In the present work, La site is altered with Ca to form (La_{1-x}Ca_{x})_{9.67}(SiO_{4})_{6}O_{2+\delta} (x = 0.0, 0.05, 0.10 and 0.15) with minimum oxygen non-stoichiometry and studied the hopping/tunnelling mechanism with the Ca substitution. The elemental content obtained from Rietveld refinement of the X-ray diffractograms suggests La deficiency with minimum oxygen deficiency. Further, XPS and TGA studies confirm the formation of La deficient samples. Temperature and frequency dependent ac conductivity in the temperature range (548 K – 973 K) suggests that the conduction takes place via overlapping large polaron tunnelling. Further, the tunnelling distance and polaron radii as a function of temperature and frequency are observed to be altered with Ca and affecting the ion conducting channel through the elongation of La(6h) triangles. Our study suggests the phononic contribution play a pivotal role in ionic transport.

show abstract

Electrolytes

Cited by 8 publications

References 177 publications

Oxide-Ion Occupational Disorder, Diffusion Path, and Conductivity in Hexagonal Perovskite Derivatives Ba₃WNbO_8.5 and Ba₃MoNbO_8.5

Oxide-Ion Occupational Disorder, Diffusion Path, and Conductivity in Hexagonal Perovskite Derivatives Ba₃WNbO_8.5 and Ba₃MoNbO_8.5

Thermoanalytical and X-ray Diffraction Studies on the Phase Transition of the Calcium-Substituted La2Mo2O9 System

Overlapping large polaron tunnelling in lanthanum silicate oxyapatite

Contact Info

Product

Resources

About

Electrolytes

Cited by 8 publications

References 177 publications

Oxide-Ion Occupational Disorder, Diffusion Path, and Conductivity in Hexagonal Perovskite Derivatives Ba3WNbO8.5 and Ba3MoNbO8.5

Oxide-Ion Occupational Disorder, Diffusion Path, and Conductivity in Hexagonal Perovskite Derivatives Ba3WNbO8.5 and Ba3MoNbO8.5

Thermoanalytical and X-ray Diffraction Studies on the Phase Transition of the Calcium-Substituted La2Mo2O9 System

Overlapping large polaron tunnelling in lanthanum silicate oxyapatite

Contact Info

Product

Resources

About

Oxide-Ion Occupational Disorder, Diffusion Path, and Conductivity in Hexagonal Perovskite Derivatives Ba₃WNbO_8.5 and Ba₃MoNbO_8.5

Oxide-Ion Occupational Disorder, Diffusion Path, and Conductivity in Hexagonal Perovskite Derivatives Ba₃WNbO_8.5 and Ba₃MoNbO_8.5