Showa Denko K.k.

Showa Denko Kabushiki Kaisha

Akihiko Shirakawa

Takao Noda

Isao Kabe

Akihisa Tonegawa

Fumiyoshi Ono

Joseph Gaze

Yoshiaki Yamauchi

Gaku Oriji

Koji Tokita

Chunfu Yu

Masahiro Suzuki

Tadatoshi Kurozumi

Yoshinori Shibuya

Hitoshi Yokouchi

Hideki Oohata

Ryuichi Mitsumoto

Hirofumi Fukunaga

The invention provides a method of producing a cathode active material for a lithium secondary battery, whereby it is possible to configure a lithium secondary battery in which the discharge capacity is improved and elution of lithium ions from the lithium metal phosphate is suppressed when washing the lithium metal phosphate after the same was synthesized. The method of producing a cathode active material for a lithium secondary battery includes synthesizing a lithium metal phosphate represented by a composition formula LiMPO, wherein the element M represents one or two or more of transition metals selected from among Fe, Mn, Co and Ni, and after the synthesis, washing the lithium metal phosphate with a washing liquid containing lithium ion.

Method of producing cathode active material for lithium secondary battery

Provided is a method for producing a lithium metal phosphate, and the method comprises initiating and allowing to proceed, in the presence of a polar solvent, a conversion reaction of a lithium ion (Li) source such as lithium hydroxide, a divalent transition metal ion (M) source such as a divalent transition metal sulfate, and a phosphate ion (PO) source such as phosphoric acid into a lithium metal phosphate at 150&#xb0; C. or higher. The conversion reaction is initiated and allowed to proceed by bringing solution A containing one of a lithium ion, a divalent transition metal ion, and a phosphate ion into contact with solution B containing the others of these ions at 150&#xb0; C. or higher, or by adjusting the pH of solution C that has a pH of lower than 4 and contains a lithium ion, a divalent transition metal ion, and a phosphate ion to 4 or higher.

Method for producing lithium metal phosphate

A method is employed for producing a positive electrode active material for a lithium secondary battery that comprises mixing lithium phosphate having a particle diameter Dof 100 &#x3bc;m or less, an M element-containing compound having a particle diameter Dof 100 &#x3bc;m or less (where, M is one type or two or more types of elements selected from the group consisting of Mg, Ca, Fe, Mn, Ni, Co, Zn, Ge, Cu, Cr, Ti, Sr, Ba, Sc, Y, Al, Ga, In, Si, B and rare earth elements) and water, adjusting the concentration of the M element with respect to water to 4 moles/L or more to obtain a raw material, and producing olivine-type LiMPOby carrying out hydrothermal synthesis using the raw material.

Production method of positive electrode active material for lithium secondary battery

A capacitor element is obtained by chemically converting an anode body comprising a niobium or niobium alloy in an electrolyte solution, which is obtained by dissolving an oxygen supply agent such as hydrogen peroxide, a freezing point depressant such as ethylene glycol, and an electrolyte such as phosphoric acid in water, at a solution temperature lower than the freezing point of a solution having the composition of the electrolyte solution excluding the freezing point depressant, for forming a dielectric layer in the surface of the anode body or repairing a dielectric layer formed in the surface of the anode body. An electrolytic capacitor is obtained by forming a cathode on the dielectric layer of the capacitor element, electrically connecting the anode body and the cathode respectively to external terminals, and then sealing them.

Method for manufacturing capacitor element

The invention relates to a method for a complex oxide film having a high relative dielectric constant formed on a substrate surface by wet-treatment method and a production process of the complex oxide film comprising a step of washing the complex oxide film with an acid solution of pH 5 or less to thereby reduce salts in the film. Further, the invention relates to a dielectric material and a piezoelectric material containing the complex oxide film, a capacitor and a piezoelectric element including the material, and a electronic device comprising the element.

Complex oxide film and method for producing same, dielectric material including complex oxide film, piezoelectric material, capacitor, piezoelectric element, and electronic device

A complex oxide film is provided having a high relative dielectric constant and capacitance having low temperature-dependency. The film thickness can be arbitrarily controlled. A manufacturing method thereof, a composite body comprising the complex oxide film and a manufacturing method thereof are provided. The complex oxide film containing titanium element and calcium element can be obtained by forming a metal oxide film containing titanium element on a substrate surface and then allowing a solution containing calcium ion to react with the metal oxide layer. A capacitor including the complex oxide film as dielectric material and a piezoelectric element including it as piezoelectric material can be produced.

Complex oxide film and method for producing same, composite body and method for producing same, dielectric material, piezoelectric material, capacitor and electronic device

The invention aims at providing a complex oxide film having a high relative dielectric constant and a high voltage resistance, whose film thickness can be arbitrarily controlled, and a manufacturing method thereof, a composite body comprising the complex oxide film and a manufacturing method thereof, a dielectric or piezoelectric material comprising the complex oxide film or composite body, a capacitor or piezoelectric element comprising the complex oxide film advantageous to improve voltage resistance, and an electronic device equipped with the same, without involving any complicated or large scale equipment. The complex oxide film can be obtained by forming a metal oxide film containing a titanium element on a substrate surface and then allowing a solution containing strontium ion to react with the metal oxide film. A capacitor including the complex oxide film as dielectric material and a piezoelectric element including it as piezoelectric material can be produced.

Complex oxide film and method for producing same, composite body and method for producing same, dielectric material, piezoelectric material, capacitor, piezoelectric element and electronic device

There is provided a method for producing a capacitor which is capable of producing a capacitor having a high withstand voltage and low leakage current,

Method for producing capacitor, capacitor, wiring board, electronic device, and IC card

The capacitor material of the present invention is comprised by laminating a titanium dioxide layer and a titanate compound layer having perovskite crystals.

Capacitor material, production method of the same, and capacitor, wiring board and electronic device containing that material

A barium calcium titanate of the present invention has a remarkable effect that a fine barium calcium titanate powder having excellent dispersibility, reduced impurities and high crystallinity and being solid-dissolved at an arbitrary ratio, and a production process thereof are provided. The barium calcium titanate represented by the compositional formula: (BaCa)TiO(wherein 0&#x3c;X&#x3c;0.2 and 0.98&#x2266;Y&#x2266;1.02), which contains 3 mol % or less (including 0 mol %) of an orthorhombic perovskite compound and in which the specific surface area D is from 1 to 100 m/g.

Barium calcium titanate, production process thereof and capacitor

The present invention relates to a capacitor having high capacitance, low ESR (equivalent series resistance) in a high-frequency region and low leakage current, including a composite oxide film obtained by reaction of an oxide film obtained by subjecting the surface of the substrate comprising valve-acting metal element to electrolytic oxidation with a solution in which metal ion and an organic base are dissolved and by subsequently sintering the reactant, a solid electrolyte formed on the composite oxide film and a conductor layer formed thereon; a method for producing the same and electronic devices using the same.

Capacitor and method for manufacturing same

The present invention provides a barium titanate having a small particle size, containing small amounts of unwanted impurities, and exhibiting excellent electric characteristics, which can be employed for forming a dielectric ceramic thin film required for a small-sized capacitor which enables production of a small-sized electronic apparatus; and a process for producing the barium titanate. When a titanium oxide sol is reacted with a barium compound in an alkaline solution containing a basic compound, the basic compound is removed in the form of gas after completion of reaction, and the resultant reaction mixture is fired, a barium titanate having a large BET specific surface area and a high tetragonality content is produced.

Barium titanate and production and process thereof

A cathode electroactive material for use in lithium ion secondary cells, process for producing the material, and lithium ion secondary cells using the cathode electroactive material, wherein the electroactive material predominantly comprises an Li&#x2014;Mn composite oxide particles with the spinel structure and particles of the electroactive material have an average porosity of 15% or less, the porosity being calculated by employing the following equation:Porosity (%)=()&#xd7;100(wherein A represents a total cross-section area of pores included in a cross-section of one secondary particle, and B represents the cross-section area of one secondary particle), a tapping density of 1.9 g/ml or more, a size of crystallites of 400 &#x212b;&#x2013;960 &#x212b;, a lattice constant of 8.240 &#x212b; or less. The cathode electroactive material of the present invention is formed of particles which are dense and spherical and exhibit excellent packing characteristics to an electrode, and exhibit high initial capacity and capacity retention percentage at high temperature.

Cathode electroactive material, production method therefor and secondary cell

A cathode electroactive material for use in lithium ion secondary cells, process for producing the material, and lithium ion secondary cells using the cathode electroactive material, wherein the electroactive material predominantly comprises an Li&#x2014;Mn composite oxide particles with the spinel structure and particles of the electroactive material have an average porosity of 15% or less, the porosity being calculated by employing the following equation:Porosity (%)=()&#xd7;100(wherein A represents a total cross-section area of pores included in a cross-section of one secondary particle, and B represents the cross-section area of one secondary particle), a tapping density of 1.9 g/ml or more, a size of crystallites of 400 &#x212b;-960 &#x212b;, a lattice constant of 8.240 &#x212b; or less. The cathode electroactive material of the present invention is formed of particles which are dense and spherical and exhibit excellent packing characteristics to an electrode, and exhibit high initial capacity and capacity retention percentage at high temperature.

Growing community of inventors

Chiba, Japan

Akihiko Shirakawa