National Institute of Advanced Industrial Science and Technology

Ishihara Sangyo Kaisha, Ltd.

Kunimitsu Kataoka

Junji Akimoto

Naoki Hamao

Hiroshi Hayakawa

Hideaki Nagai

Tomoyuki Sotokawa

Haruo Ishizaki

Yoshimasa Kumashiro

Nobuharu Koshiba

Akemi Kawashima

Chika Takamori

Yuso Ishida

Tomoki Ariga

The lithium composite oxide single crystal has a chemical composition represented by LiGaLaZrTaNbO(0.02≤x<0.5, 0≤W≤1.0, 0≤V≤1.0, and 0.05≤W+V≤1.0), which belongs to a space group I-43d in a cubic system and has a garnet structure.

Lithium composite oxide single crystal, lithium composite oxide polycrystal, lithium composite oxide material, solid electrolyte material, all- solid-state lithium-ion secondary battery, and method for producing solid electrolyte material

Provided is a novel solid electrolyte material of high density and high ionic conductivity, and an all-solid-state lithium ion secondary battery that utilizes the solid electrolyte material. The solid electrolyte material has a chemical composition represented by LiGaLaZrO(0.08≤x<0.5), has a relative density of 99% or higher, belongs to space group I-, in the cubic system, and has a garnet-type structure. The lithium ion conductivity of the solid electrolyte material is 2.0×10S/cm or higher. The solid electrolyte material has a lattice constant a such that 1.29 nm≤a≤1.30 nm, and lithium ions occupy thesite, thesite and two types ofsite, and gallium occupies thesite and thesite, in the crystal structure. The all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte. The solid electrolyte is made up of the solid electrolyte material of the present invention.

Gallium-substituted solid electrolyte material, and all-solid-state lithium ion secondary battery

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 LiLaTaOcrystal 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 LiLaTaOcrystal body is grown by a melting method employing a LiLaTaOpolycrystal body as a raw material. With the growing method, a LiLaTaOcrystal 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.

Lithium ion conductive crystal body and all-solid state lithium ion secondary battery

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 LiHLaZrMO(M represents Ta and/or Nb, 3.2&#x3c;x&#x2264;7&#x2212;y, and 0.25&#x3c;y&#x3c;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.

Proton-conductive complex oxide and fuel cell using same as electrolyte

A solid electrolyte material having high ion conductivity and a all-solid-state lithium-ion secondary battery using this solid electrolyte material are provided. The solid electrolyte material has a garnet-related structure crystal represented by the chemical composition LiLaZrTaNbO(0.05&#x2264;x+y&#x2264;0.2, x&#x2265;0, y&#x2265;0), which belongs to an orthorhombic system and a space group belonging to Ibca. The solid electrolyte material has lithium-ion conductivity at 25&#xb0; C. of at least 1.0&#xd7;10S/cm. Also, in this solid electrolyte material, the lattice constants are 1.29 nm&#x2264;a&#x2264;1.32 nm, 1.26 nm&#x2264;b&#x2264;1.29 nm, and 1.29 nm&#x2264;c&#x2264;1.32 nm, and three 16f sites and one 8d site in the crystal structure are occupied by lithium-ions. The all-solid-state lithium-ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, the solid electrolyte comprising this solid electrolyte material.

Solid electrolyte with low-symmetry garnet-related structure and lithium-ion secondary battery

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 LiLaZrOcrystal, which is one example of this lithium-containing garnet crystal body, includes melting a portion of a rod-like raw material composed of polycrystalline LiLaZrObelonging 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.

Lithium-containing garnet crystal body, method for producing same, and all-solid-state lithium ion secondary battery

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 LiHLaMO(M represents Zr and/or Hf, and 3.2&#x3c;x&#x2264;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 LiHLaMO(M represents Zr and/or Hf, and 0&#x2264;x&#x2264;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.

There are provided a solid electrolyte material having high density and ion conductivity, and an all solid lithium ion secondary battery using the solid electrolyte material. The solid electrolyte material has a garnet-related structure which has a chemical composition represented by LiLaZrTaNbO(0&#x2264;x&#x2264;0.8, 0.2&#x2264;y&#x2264;1, and 0.2&#x2264;x+y&#x2264;1) and relative density of 99% or greater, and belongs to a cubic system. The solid electrolyte material has lithium ion conductivity which is equal to or greater than 1.0&#xd7;10S/cm. The solid electrolyte material has a lattice constant a which satisfies 1.28 nm&#x2264;a&#x2264;1.30 nm, and has a lithium ion which occupies only two or more 96h sites in a crystal structure. The all solid lithium ion secondary battery includes a positive electrode, a negative electrode, and a solid electrolyte. The solid electrolyte includes the solid electrolyte material.

Solid electrolyte material and all solid lithium ion secondary battery

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: NaTiO(2&#x2264;x&#x2264;3), preferably NaTiO, 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&#xb0; C. or more but 1600&#xb0; C. or less.

Polycrystalline material and production method therefor

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 LiLaZrTaO(0.2&#x2264;x&#x2264;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&#xd7;10S/cm or higher. Further, this solid electrolyte material has a lattice constant a of 1.28 nm&#x2264;a&#x2264;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.

Lithium lanthanum zirconium tantalum oxide garnet crystal and all-solid-state lithium ion secondary battery

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.

Method for producing titanium oxide using porous titanium compound impregnated with solution

A method of producing a titanium oxide, including the steps of: ion-exchanging a sodium titanium oxide NaTiO, to synthesize LiTiO; subjecting LiTiOto proton exchange, to give HTiO; and subjecting HTiO, as a starting material, to a heat treatment.

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Tsukuba, Japan

Kunimitsu Kataoka