Itoh T.,AGC Seimi Chemical Co. |
Nakayama M.,Nagoya Institute of Technology
Journal of Solid State Chemistry | Year: 2012
To study the local structure and oxygen ion conduction mechanism in (La 0.6Sr 0.4)(Co 0.2Fe 0.8)O 3-δ (LSCF) as a function of the oxygen partial pressure (P(O 2)), in situ the Co and Fe K-edge X-ray absorption spectroscopy (XAS) was measured at elevated temperatures of 900 and 1000 K. The reduction of the Co and Fe valence, i.e., the oxygen content (3-δ) in LSCF, followed the change of P(O 2) from 1 to 10 -4 atm during∼4000 s. The quantitative analysis of the X-ray absorption near edge structure (XANES) and the extended X-ray absorption fine structure (EXAFS) indicated that the Fe valence was higher than the Co valence at oxidative condition (δ≈0) in LSCF. Whereas the Co valence decreased more than the Fe valence after reduction of P(O 2) at both 900 and 1000 K. From the relaxation plots of the valence and the oxygen content (3-δ) for Co and Fe after changing P(O 2), we successfully determined D chem and E a of an oxygen ion migration around Co and Fe in LSCF. A structural model with and without oxygen vacancies and an oxygen ion conduction mechanism for LSCF are proposed based on these results. © 2012 Elsevier Inc. All rights reserved.
AGC Seimi Chemical Co. | Date: 2011-08-03
To provide a surface modified lithium-containing composite oxide having excellent discharge capacity, volume capacity density, safety, durability for charge and discharge cycles, and high rate property. A surface modified lithium-containing composite oxide, comprising particles of a lithium-containing composite oxide having a predetermined composition and a lithium titanium composite oxide containing lithium, titanium and element Q (wherein Q is at least one element selected from the group consisting of B, Al, Sc, Y and In) contained in the surface layer of the particles, wherein the lithium titanium composite oxide is contained in the surface layer of the particles in a proportion of the total amount of titanium and element Q in the lithium titanium composite oxide contained in the surface layer to the lithium-containing composite oxide particles is from 0.01 to 2 mol %, and the lithium titanium composite oxide has a peak at a diffraction angle 2 within a range of 43.80.5 in powder X-ray diffraction measurement in which CuK rays are used.
Agc Seimi Chemical Co. | Date: 2013-02-20
To provide an air electrode material powder for a solid oxide fuel cell, comprising a novel LSCF powder having a highly uniform composition suitable as an air electrode material for a solid oxide fuel cell, and its production process. A composite oxide having a perovskite structure and containing lanthanum, strontium, cobalt, iron and oxide, wherein the dispersion point determined by the peak intensity [La] of the L1 characteristic X-ray of lanthanum and the peak intensity [Sr] of the L1 characteristic X-ray of strontium as obtained by EPMA measurement, is present within a range of the formula (1) and the dispersion point determined by the peak intensity [Co] of the K1 characteristic X-ray of cobalt and the peak intensity [Fe] of the K1 characteristic X-ray of iron is present within a range of the formula (2): wherein 0.2a1.0 and 0.1b4.0.
Agc Seimi Chemical Co. | Date: 2015-01-28
To provide an NiO-GDC composite powder or NiO-SDC composite powder having a uniform composition, which is suitable as an anode material for a solid oxide fuel cell. A process for producing an anode material for a solid oxide fuel cell, made of a composite powder comprising a composite oxide containing cerium element and gadolinium or samarium element, and oxygen element, and an oxide containing nickel element and oxygen element, which comprises a dissolving step of mixing raw material compounds containing metal elements constituting the above composite powder, at least one organic acid selected from the group consisting of maleic acid, lactic acid and malic acid, and a solvent to obtain a metal elements-containing solution, and a drying/sintering step of drying and sintering the metal elements-containing solution.
Agc Seimi Chemical Co. | Date: 2014-07-22
To provide a composite oxide powder for a solid oxide fuel cell containing lanthanum, strontium and/or calcium, manganese and oxygen and having a highly uniform composition, and its production method. A composite oxide powder containing lanthanum, strontium and/or calcium, manganese and oxygen, wherein the coefficient of variation () of lanthanum is at most 6.0% and the coefficient of variation () of manganese is at most 13.0%, as calculated from the peak area ratio of the L ray of lanthanum and the K ray of manganese measured by an energy dispersive X-ray spectrometer attached to a scanning electron microscope.