The present invention relates to a material of the formula SnTiO.sub.3 having a crystal structure comprised of layers, wherein the layers comprise Sn(II) ions, Ti(IV) ions and edge-sharing O.sub.6-octahedra, the edge-sharing O.sub.6-octahedra form a sub-layer, the Ti(IV) ions are located within ⅔ of the edge-sharing O.sub.6-octahedra, thus forming edge-sharing TiO.sub.6-octahedra, the edge-sharing TiO.sub.6-octahedra form a honeycomb structure within the sub-layer, the honeycomb structure comprising hexagons with Ti(IV)-vacancies within the hexagons, the Sn(II) ions are located above and below the Ti(IV)-vacancies with respect to the sub-layer, the Ti(IV) ions are optionally substituted with M, M is one or more elements selected from Group 4 and Group 14 elements, and the crystal structure satisfies at least one of the following features (i) and (ii): (i) the Sn(II) ions have a tetrahedral coordination sphere involving three O ions of the layer and the electron lone pair of the Sn(II) ions which is situated at an apical position relative to the three O ions of the layer, (ii) the layers are stacked so that each layer is translated relative to each adjacent layer by a stacking vector S1 or a stacking vector S2, the centers of adjacent hexagons form a parallelogram with a side having a length x and side having a length y, the stacking vector S1 is a combined translation along the side having the length x by ⅔ x and along the side having a lengthy by ⅓ y, the stacking vector S2 is a combined translation along the side having the length x by ⅓ x and along the side having a lengthy by ⅔ y, and the crystal structure comprises layers translated relative to adjacent layers by the stacking vector 1 and layers translated relative to adjacent layers by the stacking vector S2. The present invention is further directed to a material of the formula SnTiO.sub.3 having a tetragonal perovskite-type crystal structure, a method for the preparation of SnTiO.sub.3, a device comprising a ferroelectric material and a use of the material of the formula SnTiO.sub.3 in a ferroelectric element.

A process for improving the grade and optical quality of zircon, comprising: baking a mixture of a zircon feed and concentrated sulphuric acid at a baking temperature in the range of from 200 up to 400° C., and for a time to form water leachable sulphates with impurities therein including at least iron and titanium; leaching the baked mixture to dissolve the leachable sulphates; and separating the zircon from the leachate containing the leached sulphates, which separated zircon is thereby of improved grade and optical quality.

The present disclosure broadly relates to a process for recovering vanadium, iron, titanium and silica values from vanadiferous feedstocks. More specifically, but not exclusively, the present disclosure relates to a metallurgical process in which vanadium, iron, titanium and silica values are recovered from vanadiferous feedstocks such as vanadiferous titanomagnetite, iron ores, vanadium slags and industrial wastes and by-products containing vanadium. The process broadly comprises digesting the vanadiferous feedstocks into sulfuric acid thereby producing a sulfation cake; dissolving the sulfation cake and separating insoluble solids thereby producing a pregnant solution; reducing the pregnant solution thereby producing a reduced pregnant solution; and crystallizing ferrous sulfate hydrates from the reduced pregnant solution, producing an iron depleted reduced solution. The process further comprises removing titanium compounds from the iron depleted reduced solution thereby producing a vanadium-rich pregnant solution; concentrating vanadium and recovering vanadium products and/or a vanadium electrolyte.

A cathode configured to use oxygen as a cathode active material includes: a porous film including a metal oxide, where a porosity of the porous film is about 50 volume percent to about 95 volume percent, based on a total volume of the porous film, and an amount of an organic component in the porous film is 0 to about 2 weight percent, based on a total weight of the porous film.

A novel titanate aqueous solution is provided that is capable of easily preparing titanate compounds composed of alkali metals or alkaline earth metals, wherein the titanate aqueous solution contains titanate ions and quaternary ammonium cations in water, and the titanate aqueous solution is characterized in that 30 g of the titanate aqueous solution (25° C.) adjusted to a concentration containing 9% by mass of titanium in terms of TiO.sub.2 is added with 30 mL of a sodium hydroxide aqueous solution (25° C.) having a concentration of 2.2% by mass while stirring to form a precipitate composed of Na.sub.2Ti.sub.3O.sub.7 hydrate, or has a transmittance at a wavelength of 360 nm being 50% or less.

According to one embodiment, a lithium ion secondary battery is provided. The lithium ion secondary battery includes a negative electrode containing a negative electrode active material-containing layer, a positive electrode, and an electrolyte containing Li ions and Na ions. The negative electrode active material-containing layer contains a Na-containing titanium composite oxide. A ratio (W.sub.E/W.sub.A) of an Na amount W.sub.E (g/g) in the electrolyte to an Na amount W.sub.A (g/g) in the negative electrode active material-containing layer satisfies Formula (1) below:
1×10.sup.−1≤W.sub.E/W.sub.A≤1×10.sup.5  (1).

Provided are lithium ions for achieving a lithium-ion secondary battery which is less susceptible to rises in internal resistance even over repeated charge-discharge cycles and which has excellent durability with respect to charge-discharge cycles.

A lithium-ion secondary battery 1 is provided with: a positive electrode; a negative electrode 7; a separator 8; an electrolyte solution 9; and a container 10 that houses the positive electrode 4, the negative electrode 7, the separator 8, and the electrolyte solution 9. At least one of the positive electrode mixture layer 3 or the negative electrode mixture layer 6 contains high-dielectric oxide solids 13, and the positive electrode active material 11 or the negative electrode active material 12 has a surface with portions thereof in contact with the high-dielectric oxide solids 13 and portions thereof in contact with the electrolyte solution 9.

According to one embodiment, a negative electrode is provided. The negative electrode includes a negative electrode active material-containing layer including a niobium titanium composite oxide and a sulfur-containing coating. Spectral data obtained by X-ray photoelectron spectroscopy on the surface of the negative electrode active material-containing layer includes a first peak with a peak top existing in the range of 208 eV to 210 eV and a second peak with a peak top existing in the range of 160 eV to 165 eV. The ratio (P2/P1) of the peak height P2 of the second peak to the peak height P1 of the first peak falls within the range of 0.05 to 2.

An optical lens with an antireflective film includes: a lens substrate; and an antireflective film disposed on the lens substrate. The antireflective film is formed of layers each having a physical thickness of 140 nm or less. In order from an air side, the antireflective film has: a first layer formed as an MgF.sub.2 layer, a second layer, a fourth layer, a sixth layer, an eighth layer, and a tenth layer each having a refractive index of 2.0 or more and 2.3 or less, and a third layer, a fifth layer, a seventh layer, and a ninth layer each formed as an SiO.sub.2 layer.

A mixed conductor represented by Formula 1:
A.sub.4+xM.sub.5-yM′.sub.yO.sub.12-δ,  Formula 1
wherein, in Formula 1, A is a monovalent cation, M is at least one of a divalent cation, a trivalent cation, or a tetravalent cation, M′ is at least one of a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, or a hexavalent cation, M and M′ are different from each other, and 0.3≤x<3, 0.01<y<2, and 0≤δ≤1 are satisfied.