Nippon Mining & Metals Co., Ltd.

Nippon Mining Co., Ltd.

Jx Nippon Mining Metals Corporation

Japan Energy Corporation

Nikko Materials Company, Limited

Hiroshi Tasaki

Eiji Nishimura

Yoshio Kajiya

Yasunori Yamamoto

Ryuichi Nagase

Chikara Tominaga

Yusaku Masuda

This invention provides a lithium nickel manganese cobalt composite oxide having a composition of LiaNixMnyCozO(x+y+z=1, 1.05&#x3c;a&#x3c;1.3), wherein, in the data obtained by measuring a Raman spectrum of the composite oxide, the peak intensity of an Eg oscillation mode of a hexagonal crystal structure located at 480 to 495 cmand the peak intensity of an F2g oscillation mode of a spinel structure located at 500 to 530 cmin relation to the peak intensity of an A1g oscillation mode having a hexagonal crystal structure in which the main peak is located at 590 to 610 cmare respectively 15% or higher and 40% or lower than the peak intensity of the A1g oscillation mode of a hexagonal crystal structure as the main peak. Thereby, the Raman spectrum can be used for the identification of the crystal structure to clarify the characteristics of a positive electrode precursor composed of lithium nickel manganese cobalt composite oxide. In particular, it is possible to obtain lithium nickel manganese cobalt composite oxide and a lithium rechargeable battery superior in rate characteristics and cycle characteristics.

Lithium nickel manganese cobalt composite oxide and lithium rechargeable battery

Provided is a cathode material for a lithium secondary battery composed of an aggregate of Li-A-O composite oxide particles (wherein A represents one or more metal elements selected from Mn, Fe, Co and Ni), wherein the lithium composite oxide contains 20 to 100 ppm (by mass) of P, and the total content of impurity elements excluding essential components is 2000 ppm or less. Also provided is a manufacturing method of such a cathode material for a lithium secondary battery including the steps of suspending lithium carbonate in water and thereafter introducing a metallic salt solution of one or more metal elements selected from Mn, Fe, Co and Ni in the lithium carbonate suspension, adding a small amount of phosphoric acid so that the P content in the Li-A-O composite oxide particles will be 20 to 100 ppm (by mass), and forming an aggregate of Li-A-O composite oxide particles containing 20 to 100 ppm (by mass) of P by filtering, cleansing, drying and thereafter oxidizing the obtained carbonate. This cathode material for a lithium secondary battery and its manufacturing method realize improved sinterability and battery characteristics.

Cathode material for lithium secondary battery and manufacturing method thereof

A lithium-containing complex oxide exhibits a high performance as a cathode active material of a lithium secondary cell or the like and having a high tap density. A granular lithium-containing complex oxide, such as lithium manganese complex oxide, is made up of 'complex oxide grains produced by integrating lithium-rich material grains abnormally grown during a firing reaction with the surfaces of the base grains by sintering.' The number of complex oxide grains is not more than 50 per gram of the complex grains. A metal oxide such as manganese oxide and lithium carbonate not more than 5 &#x3bc;m in average grain size are mixed by means of a mixer which grinds and mixes particles by using a shearing force and heated and fired at a warming rate of not more than 50&#xb0; C./h., thus producing the lithium-containing complex oxide.

Lithium-containing complex oxide and method of producing same

A Zn--Ni alloy having a high Ni content is used for supplying Ni.sup.2+ and Zn.sup.2+ ions into an acidic plating bath and for supplying Ni and Zn into a hot dip galvanizing bath. This alloy is characterized by being produced by using a flux consisting of a fused-salt former, which forms a salt having a melting temperature of 700.degree. C. or less, and Na.sub.2 B.sub.4 O.sub.7 and occasionaly additionally Na.sub.2 CO.sub.3. By using the inventive alloy, the bath can be quickly prepared, and Zn and Ni can be supplied to the bath without leaving the undissolved residue.

Method for producing a ZN-Ni alloy by melting in the presence of a flux

A Zn-Ni alloy having a high Ni content is used for supplying Ni.sup.2+ and Zn.sup.2+ ions into an acidic plating bath and for supplying Ni and Zn into a hot dip galvanizing bath. This alloy is characterized by being produced by using a flux consisting of a fused-salt former, which forms a salt having a melting temperature of 700.degree. C. or less, and Na.sub.2 B.sub.4 O.sub.7 and occasionaly additionally Na.sub.2 CO.sub.3. By using the inventive alloy, the bath can be quickly prepared, and Zn and Ni can be supplied to the bath without leaving the undissolved residue.

Method for preparation for a Zn-Ni electroplating or hot-dip galvanizing

A method for producing a brown coated article, wherein an iron substrate is dipped at a temperature of from 430.degree. to 600.degree. C. in a molten Zn plating bath containing from 0.05 to 1% by weight of Mn, so as to zinc hot-dip galvanize the same, a heat treatment is carried out to convert the Zn-Mn phase formed by the zinc hot-dip galvanizing to a Zn-Mn-Fe phase, and subsequently the zinc hot-dip galvanizing layer is brought into contact with an acidic aqueous solution containing an oxidizing agent.

Method for producing a color-coated article

Method for preparation of a Zn-Ni electroplating or hot-dip galvanizing

A brown coated article which exhibits stable color is provided by the composition and structure of a zinc hot-dip galvanizing layer. The zinc hot-dip galvanizing layer consists essentially of from 1 to 15% by weight of Fe and from 0.05 to 1% by weight of Mn, and balance of Zn. A brown Zn-Mn-Fe oxide layer is present on the surface of the zinc hot-dip galvanizing layer.

Color-coated article and method for producing the same

Zinc powder, which contains a coloring element, e.g., Ti, Mn, or V, is heated to a temperature of from 350.degree. to 700.degree. C. so as to oxidize the surface of the powder and hence to develop such colors as brown, navy blue, blue, greenish-brown, green, and coffee brown. The colored zinc powder is sprayed onto a steel, aluminum, or ceramic article to produce a colored article. The colored zinc powder is also used as a pigment.

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Saitama, Japan

Hiroshi Tasaki