Abstract: Provided is a complex oxide that has a high hydrogen content, contains almost no impurity phase, and is suitable for proton conductivity. The complex oxide is represented by a chemical formula Li7-xHxLa3M2O12 (M represents Zr and/or Hf, and 3.2<x?7) and is a single phase of a garnet type structure belonging to a cubic system. A method for producing the complex oxide includes an exchange step of bringing a raw material complex oxide represented by a chemical formula Li7-xHxLa3M2O12 (M represents Zr and/or Hf, and 0?x?3.2) and a compound having a hydroxy group or a carboxyl group into contact with each other to exchange at least some of lithium of the raw material complex oxide and hydrogen of the compound having a hydroxy group or a carboxyl group.

Abstract: Provided is a complex oxide that has a space group I-43d, has a high hydrogen content, contains almost no impurity phase, exhibits almost no aluminum substitution in the structure thereof, and is suitable for proton conductivity. This complex oxide is represented by a chemical formula Li7-x-yHxLa3Zr2-yMyO12 (M represents Ta and/or Nb, 3.2<x?7-y, and 0.25<y<2) and is a single phase of a garnet type structure belonging to a cubic system, and the crystal structure thereof is a space group I-43d.

Abstract: A composite oxide which includes lithium, at least one of calcium and magnesium, and nickel and manganese, and has a lithium-excess layered rock-salt structure, and a cathode active material and a lithium secondary battery which contain the composite oxide.

Abstract: Provided are: an alkali metal titanium oxide having a uniform composition and that is such that there are no residual by-products having a different composition or unreacted starting materials; and a method for producing a titanium oxide and proton exchange body obtained by processing the alkali metal titanium oxide. The method produces an alkali metal titanium oxide by firing the result of impregnating the surface and inside of pores of porous titanium compound particles with an aqueous solution of an alkali metal-containing component. The alkali metal titanium oxide is subjected to proton exchange, and with the proton exchange body of the alkali metal titanium oxide as the starting material, the titanium oxide is produced through a heat processing step.

Abstract: Provided are a sodium ion secondary battery and a lithium ion secondary battery capable of undergoing a reversible large-capacity charge/discharge reaction. The sodium and lithium ion secondary batteries each have a positive electrode, a negative electrode, and an electrolyte. The active substance of the positive or negative electrode of these secondary batteries is a single-phase polycrystal represented by the following chemical formula: NaxTi4O9 (2?x?3), preferably Na2Ti4O9, having a one-dimensional tunnel type structure, and belonging to a monoclinic crystal system. This polycrystal is obtained by filling a container made of molybdenum or the like with a raw material containing a sodium compound and at least one of a titanium compound and metal titanium, and firing at 800° C. or more but 1600° C. or less.

Abstract: There are provided a lithium-containing garnet crystal high in density and ionic conductivity, and an all-solid-state lithium ion secondary battery using the lithium-containing garnet crystal. The lithium-containing garnet crystal has a chemical composition represented by Li7-xLa3Zr2-xTaxO12 (0.2?x?1), and has a relative density of 99% or higher, belongs to a cubic system, and has a garnet-related structure. The lithium-containing garnet crystal has a lithium ion conductivity of 1.0×10?3 S/cm or higher. Further, this solid electrolyte material has a lattice constant a of 1.28 nm?a?1.30 nm, and lithium ions occupy 96h-sites in the crystal structure. The all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode and a solid electrolyte, and the solid electrolyte is constituted of the lithium-containing garnet crystal according to the present invention.

Abstract: To provide a lithium ion conductive crystal body having a high density and a large length and an all-solid state lithium ion secondary battery containing the lithium ion conductive crystal body. A Li5La3Ta2O12 crystal body, which is one example of the lithium ion conductive crystal body, has a relative density of 99% or more, belongs to a cubic system, has a garnet-related type structure, and has a length of 2 cm or more. The Li5La3Ta2O12 crystal body is grown by a melting method employing a Li5La3Ta2O12 polycrystal body as a raw material. With the growing method, a Li5La3Ta2O12 crystal body having a relative density of 100% can also be obtained. In addition, the all-solid state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, in which the solid electrolyte contains the lithium ion conductive crystal body.

Abstract: Provided is a high-density lithium-containing garnet crystal body. The lithium-containing garnet crystal body has a relative density of 99% or more, belongs to a tetragonal system, and has a garnet-related type structure. A method of producing a Li7La3Zr2O12 crystal, which is one example of this lithium-containing garnet crystal body, includes melting a portion of a rod-like raw material composed of polycrystalline Li7La3Zr2O12 belonging to a tetragonal system while rotating it on a plane perpendicular to the longer direction and moving the melted portion in the longer direction. The moving rate of the melted portion is preferably 8 mm/h or more but not more than 19 mm/h. The rotational speed of the raw material is preferably 30 rpm or more but not more than 60 rpm. By increasing the moving rate of the melted portion, decomposition of the raw material due to evaporation of lithium can be prevented and by increasing the rotational speed of the raw material, air bubbles can be removed.

Abstract: Provided is a titanate compound capable of further increasing the capacity of a power storage device when used as an electrode active material thereof. The titanate compound according to the present invention includes at least 60%, based on the number thereof, of particles having an anisotropic shape and a specific surface area of 10-30 m2/g as measured by a nitrogen adsorption BET one-point method, and having a long-axis diameter (L) in the range of 0.1<L?0.9 ?m as measured by electron microscopy.

Abstract: Provided are: an alkali metal titanium oxide having a uniform composition and that is such that there are no residual by-products having a different composition or unreacted starting materials; and a method for producing a titanium oxide and proton exchange body obtained by processing the alkali metal titanium oxide. The method produces an alkali metal titanium oxide by firing the result of impregnating the surface and inside of pores of porous titanium compound particles with an aqueous solution of an alkali metal-containing component. The alkali metal titanium oxide is subjected to proton exchange, and with the proton exchange body of the alkali metal titanium oxide as the starting material, the titanium oxide is produced through a heat processing step.

Abstract: Provided are an alkali metal titanium oxide and titanium oxide that have a novel form and are industrially advantageous. The alkali metal titanium oxide is obtained by firing the result of impregnating the surface and interior of pores of porous titanium compound particles with an aqueous solution of an alkali metal-containing component, and has the form of secondary particles resulting from the aggregation of primary particles having an anisotropic structure. The titanium oxide is obtained using the alkali metal titanium oxide as a starting material. The secondary particles can further assume a clumped structure, have a suitable size, and are easily handled, and so are industrially advantageous. In particular, the H2Ti12O25 of the present invention is an electrode material that is for a lithium secondary battery, has a high capacity and a superior initial charging/discharging rate and cycling characteristics, and has an extremely high practical value.

Abstract: A method of producing a titanium oxide, including the steps of: ion-exchanging a sodium titanium oxide Na2Ti6O13, to synthesize Li2Ti6O13; subjecting Li2Ti6O13 to proton exchange, to give H2Ti6O13; and subjecting H2Ti6O13, as a starting material, to a heat treatment.

Abstract: The present invention relates to a novel compound characterized by having a one-dimensional tunnel structure and being represented by the chemical formula H2Ti12O25, a method for manufacturing the same, and a lithium secondary battery containing, as a constituent thereof, an electrode produced by using the novel titanium oxide as an active material, and expected to demonstrate superior charge/discharge cycle characteristics over a long period of time as well as high capacity.

Abstract: A method of producing a titanium oxide, including the steps of: ion-exchanging a sodium titanium oxide Na2Ti6O13, to synthesize Li2Ti6O13; subjecting Li2Ti6O13 to proton exchange, to give H2Ti6O13; and subjecting H2Ti6O13, as a starting material, to a heat treatment.

Abstract: The present invention relates to a novel compound characterized by having a one-dimensional tunnel structure and being represented by the chemical formula H2Ti12O25, a method for manufacturing the same, and a lithium secondary battery containing, as a constituent thereof, an electrode produced by using the novel titanium oxide as an active material, and expected to demonstrate superior charge/discharge cycle characteristics over a long period of time as well as high capacity.