524 results found
Brugge RH, Kilner JA, Aguadero A, 2019, Germanium as a donor dopant in garnet electrolytes, Solid State Ionics, Vol: 337, Pages: 154-160, ISSN: 0167-2738
© 2019 Elsevier B.V. Cubic Li 7 La 3 Zr 2 O 12 (LLZO) garnet electrolytes continue to be viewed as an enabler of all-solid-state lithium battery technologies, or as protective membranes for next-generation lithium battery systems. Supervalent dopants at the lithium sublattice are commonly used to stabilise the conductive cubic phase, through the creation of lithium vacancies. The use of germanium (Ge 4+ ) as a higher valent dopant substituting for Li + was studied here and shown to stabilise the cubic LLZO phase through substitution of x = 0.10 mol of Ge (at the tetrahedral 24d Li sites of the space group Ia-3d, based on the neutron powder diffraction result). This substitution preference follows that of Al 3+ (having a similar ionic radius and reported to reside at 24d sites), but with a lower critical concentration for cubic phase stabilisation, in agreement with charge neutrality arguments to obtain the required Li content (ca. 6.4–6.6 per formula unit) for optimum conductivity. The x = 0.10 composition gave the highest bulk Li ion conductivity of 2.8 × 10 −4 S cm −1 at 25 °C, on the order of reported values for Al-doped LLZO. Surface chemical analysis using time of flight secondary ion mass spectrometry showed Ge homogeneously distributed within the grains as well as some Li-, O- and Ge- enrichment along the grain boundaries. Cyclic voltammetry of the cells containing Ge-doped LLZO showed a redox stability up to +5 V.
Manalastas W, Rikarte J, Chater RJ, et al., 2019, Mechanical failure of garnet electrolytes during Li electrodeposition observed by in-operando microscopy, JOURNAL OF POWER SOURCES, Vol: 412, Pages: 287-293, ISSN: 0378-7753
Akbay T, Kilner JA, Ishihara T, et al., 2019, Explicit Solution To Extract Self-Diffusion and Surface Exchange Coefficients from Isotope Back-Exchange Experiments, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 123, Pages: 258-264, ISSN: 1932-7447
Staykov A, Fukumori S, Yoshizawa K, et al., 2018, Interaction of SrO-terminated SrTiO3 surface with oxygen, carbon dioxide, and water, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 6, Pages: 22662-22672, ISSN: 2050-7488
Shen Z, Kilner JA, Skinner SJ, 2018, Mass Transport in (La0.8Sr0.2)(0.95)CrxFe1-xO3-delta-Scandia-Stabilized Zirconia Dual-Phase Composite as a Dense Layer in Oxygen Transport Membranes, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 122, Pages: 27135-27147, ISSN: 1932-7447
Saranya AM, Morata A, Pla D, et al., 2018, Unveiling the outstanding oxygen mass transport properties of Mn-rich perovskites in grain boundary-dominated La0.8Sr0.2(Mn1-xCox)(0.85)O-3 +/-delta nanostructures, Chemistry of Materials, Vol: 30, Pages: 5621-5629, ISSN: 0897-4756
Ion transport in solid-state devices is of great interest for current and future energy and information technologies. A superior enhancement of several orders of magnitude of the oxygen diffusivity has been recently reported for grain boundaries in lanthanum–strontium manganites. However, the significance and extent of this unique phenomenon are not yet established. Here, we fabricate a thin film continuous composition map of the La0.8Sr0.2(Mn1–xCox)0.85O3±δ family revealing a substantial enhancement of the grain boundary oxygen mass transport properties for the entire range of compositions. Through isotope-exchange depth profiling coupled with secondary ion mass spectroscopy, we show that this excellent performance is not directly linked to the bulk of the material but to the intrinsic nature of the grain boundary. In particular, the great increase of the oxygen diffusion in Mn-rich compositions unveils an unprecedented catalytic performance in the field of mixed ionic–electronic conductors. These results present grain boundaries engineering as a novel strategy for designing highly performing materials for solid-state ionics-based devices.
Niania M, Podor R, Ben Britton T, et al., 2018, In situ study of strontium segregation in La0.6Sr0.4Co0.2Fe0.8O3-delta in ambient atmospheres using high-temperature environmental scanning electron microscopy, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 6, Pages: 14120-14135, ISSN: 2050-7488
Shen Z, Kilner JA, Skinner SJ, 2018, Electrical conductivity and oxygen diffusion behaviour of the (La0.8Sr0.2)(0.95)CrxFe1-xO3-delta (x=0.3, 0.5 and 0.7) A-site deficient perovskites, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 20, Pages: 18279-18290, ISSN: 1463-9076
Wu J, Fujii K, Yashima M, et al., 2018, A systematic evaluation of the role of lanthanide elements in functional complex oxides; implications for energy conversion devices, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 6, Pages: 11819-11829, ISSN: 2050-7488
Brugge RH, Hekselman AKO, Cavallaro A, et al., 2018, Garnet Electrolytes for Solid State Batteries: Visualization of Moisture-Induced Chemical Degradation and Revealing Its Impact on the Li-Ion Dynamics, CHEMISTRY OF MATERIALS, Vol: 30, Pages: 3704-3713, ISSN: 0897-4756
Leonard K, Druce J, Thoreton V, et al., 2018, Exploring mixed proton/electron conducting air electrode materials in protonic electrolysis cell, SOLID STATE IONICS, Vol: 319, Pages: 218-222, ISSN: 0167-2738
Pergolesi D, Gilardi E, Fabbri E, et al., 2018, Interface effects on the ionic conductivity of doped ceria-yttria-stabilized zirconia heterostructures, ACS Appl Mater Interfaces, Vol: 10, Pages: 14160-14169, ISSN: 1944-8244
Multilayered heterostructures of Ce0.85Sm0.15O2-δ and Y0.16Zr0.92O2-δ of a high crystallographic quality were fabricated on (001)-oriented MgO single crystal substrates. Keeping the total thickness of the heterostructures constant, the number of ceria-zirconia bilayers was increased while reducing the thickness of each layer. At each interface Ce was found primarily in the reduced, 3+ oxidation state in a layer extending about 2 nm from the interface. Concurrently, the conductivity decreased as the thickness of the layers was reduced, suggesting a progressive confinement of the charge transport along the YSZ layers. The comparative analysis of the in-plane electrical characterization suggests that the contribution to the total electrical conductivity of these interfacial regions is negligible. For the smallest layer thickness of 2 nm the doped ceria layers are electrically insulating and the ionic transport only occurs through the zirconia layers. This is explained in terms of a reduced mobility of the oxygen vacancies in the highly reduced ceria.
Pramana SS, Cavallaro A, Li C, et al., 2018, Crystal structure and surface characteristics of Sr-doped GdBaCo2O6-delta double perovskites: oxygen evolution reaction and conductivity, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 6, Pages: 5335-5345, ISSN: 2050-7488
Cavallaro A, Pramana SS, Ruiz-Trejo E, et al., 2018, Amorphous-cathode-route towards low temperature SOFC, SUSTAINABLE ENERGY & FUELS, Vol: 2, Pages: 862-875, ISSN: 2398-4902
Staykov A, Tellez H, Druce J, et al., 2018, Electronic properties and surface reactivity of SrO terminated SrTiO3 and SrO-terminated iron-doped SrTiO3, SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, Vol: 19, Pages: 221-230, ISSN: 1468-6996
Harrington GF, Skinner SJ, Kilner JA, 2018, Can solute segregation in ceramic materials be reduced by lattice strain?, JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Vol: 101, Pages: 1310-1322, ISSN: 0002-7820
Lozano HT, Druce J, Cooper SJ, et al., 2017, Double perovskite cathodes for proton-conducting ceramic fuel cells: are they triple mixed ionic electronic conductors?, SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, Vol: 18, Pages: 977-986, ISSN: 1468-6996
Li C, Pramana SS, Ni N, et al., 2017, Surface Chemistry of La0.99Sr0.01NbO4-d and Its Implication for Proton Conduction, ACS APPLIED MATERIALS & INTERFACES, Vol: 9, Pages: 29633-29642, ISSN: 1944-8244
Harrington GF, Cavallaro A, McComb DW, et al., 2017, The effects of lattice strain, dislocations, and microstructure on the transport properties of YSZ films, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 19, Pages: 14319-14336, ISSN: 1463-9076
Wu K-T, Tellez H, Druce J, et al., 2017, Surface chemistry and restructuring in thin-film Lan+1NinO3n+1 (n=1, 2 and 3) Ruddlesden-Popper oxides, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 5, Pages: 9003-9013, ISSN: 2050-7488
Cooper SJ, Niania M, Hoffmann F, et al., 2017, Back-exchange: a novel approach to quantifying oxygen diffusion and surface exchange in ambient atmospheres, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 19, Pages: 12199-12205, ISSN: 1463-9076
Buannic L, Orayech B, Lopez Del Amo J-M, et al., 2017, Dual Substitution Strategy to Enhance Li+ Ionic Conductivity in Li7La3Zr2O12 Solid Electrolyte, CHEMISTRY OF MATERIALS, Vol: 29, Pages: 1769-1778, ISSN: 0897-4756
Aguesse F, Manalastas W, Buannic L, et al., 2017, Investigating the Dendritic Growth during Full Cell Cycling of Garnet Electrolyte in Direct Contact with Li Metal, ACS APPLIED MATERIALS & INTERFACES, Vol: 9, Pages: 3808-3816, ISSN: 1944-8244
Chater RJ, Cavallaro A, Bayliss RD, et al., 2017, Fast grain boundary oxygen ion diffusion in the alpha-phase of Bi2O3, SOLID STATE IONICS, Vol: 299, Pages: 89-92, ISSN: 0167-2738
Burriel M, Tellez H, Chater RJ, et al., 2016, Influence of Crystal Orientation and Annealing on the Oxygen Diffusion and Surface Exchange of La2NiO4+delta, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 120, Pages: 17927-17938, ISSN: 1932-7447
Druce J, Tellez H, Ishihara T, et al., 2016, Surface Composition and Oxygen Exchange Properties of Alkaline Earth-Free Perovskites; LaCo0.6Ni0.4O3, 229th Meeting of The-Electrochemical-Society / Symposium on Ionic and Mixed Conducting Ceramics, Publisher: ELECTROCHEMICAL SOC INC, Pages: 71-80, ISSN: 1938-5862
Akbay T, Staykov A, Druce J, et al., 2016, The interaction of molecular oxygen on LaO terminated surfaces of La2NiO4, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 4, Pages: 13113-13124, ISSN: 2050-7488
Tellez H, Druce J, Ishihara T, et al., 2016, Effects of Microstructure on Surface Segregation: Role of Grain Boundaries, 229th Meeting of The-Electrochemical-Society / Symposium on Ionic and Mixed Conducting Ceramics, Publisher: ELECTROCHEMICAL SOC INC, Pages: 57-69, ISSN: 1938-5862
Cooper SJ, Bertei A, Shearing PR, et al., 2016, TauFactor: An open-source application for calculating tortuosity factors from tomographic data, SoftwareX, Vol: 5, Pages: 203-210
© 2016 The Author(s) TauFactor is a MatLab application for efficiently calculating the tortuosity factor, as well as volume fractions, surface areas and triple phase boundary densities, from image based microstructural data. The tortuosity factor quantifies the apparent decrease in diffusive transport resulting from convolutions of the flow paths through porous media. TauFactor was originally developed to improve the understanding of electrode microstructures for batteries and fuel cells; however, the tortuosity factor has been of interest to a wide range of disciplines for over a century, including geoscience, biology and optics. It is still common practice to use correlations, such as that developed by Bruggeman, to approximate the tortuosity factor, but in recent years the increasing availability of 3D imaging techniques has spurred interest in calculating this quantity more directly. This tool provides a fast and accurate computational platform applicable to the big datasets (>108 voxels) typical of modern tomography, without requiring high computational power.
Limbeck A, Rupp GM, Kubicek M, et al., 2016, Dynamic etching of soluble surface layers with on-line inductively coupled plasma mass spectrometry detection - a novel approach for determination of complex metal oxide surface cation stoichiometry, JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, Vol: 31, Pages: 1638-1646, ISSN: 0267-9477
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