Hitachi Metals, Ltd.

Proterial, Ltd.

Hisato Tokoro

Akira Gunji

Shuichi Takano

Shin Takahashi

Takashi Nakabayashi

Tatsuya Toyama

Shigeo Fujii

Genei Nakajima

Yasushi Kaneko

Kimio Uchida

Hiroshi Haruna

Daiko Takamatsu

Akihiko Noie

Xiaoliang Feng

Kazuo Oda

Tatsuya Tooyama

Tsukasa Mikamoto

Sho Furutsuki

Nobuhiko Fujimori

Akio Takeuchi

Mariko Adachi

Takeo Oku

The present invention is to provide a cathode active material used for a lithium ion secondary battery which has a large charge-discharge capacity, and excels in charge-discharge cycle properties, output properties and productivity, and, a lithium ion secondary battery using the same. The cathode active material used for a lithium ion secondary battery comprises a lithium transition metal composite oxide represented by the following Formula (1); LiNiCoMnMO, where, in the formula (1), M is at least one metal element other than Li, Ni, Co, and Mn; and a, b, c, d, e, and α satisfy the following conditions: −0.04≤a≤0.04, 0.80≤b<1.00, 0≤c≤0.04, 0<d<0.20, b+c+d+e=1, −0.2<α<0.2, and c and d in the Formula (1) satisfy c/d≤0.75.

Cathode active material used for lithium ion secondary battery and lithium ion secondary battery

Making a positive electrode active material for lithium ion secondary batteries includes: weighting and mixing lithium carbonate and a compound containing respective metallic elements other than Li in a composition formula LiNiCoM2M2Oso as to have a metallic constituent ratio of the formula to obtain a mixture, and firing the mixture to obtain a lithium composite compound. Performing, on the mixture, a first heat treatment at 200&#xb0; C. to 400&#xb0; C. for 0.5 to 5 hours to obtain a first precursor. A step of performing a heat treatment on the first precursor under an oxidizing atmosphere at 450&#xb0; C. to 800&#xb0; C. for 0.5 to 50 hours, and reacting 92 mass % or more of the lithium carbonate to obtain a second precursor, and a finishing step of performing a heat treatment on the second precursor under an oxidizing atmosphere at 755&#xb0; C. to 900&#xb0; C. for 0.5 to 50 hours to obtain the lithium composite compound.

Method for producing positive electrode active material for lithium ion secondary batteries

A method for manufacturing a cathode active material for a lithium ion secondary battery comprises mixing lithium carbonate and a compound containing a metal element other than Li, and a firing step. The firing step includes at last two stages of controlling firing to different temperatures. The at least two stages include controlling a firing temperature to a lower temperature and controlling a firing temperature to a higher temperature. The firing is controlled is such that the former stage has a lower oxygen concentration in an atmosphere than the latter stage. The firing apparatus comprises at least two firing furnaces of controlling firing temperatures to different temperatures. The at least two firing furnaces include controlling a firing temperature to a lower temperature and controlling firing temperature to a higher temperature. The latter firing furnace has a gas outlet being in communication with the former firing furnace.

Method and firing apparatus for manufacturing cathode active material for lithium ion secondary battery

Provided is a cathode active material for a lithium ion secondary battery in which the secondary particles constituting the powder have a high breaking strength and a good coatability, and a method for manufacturing same. The cathode active material for a lithium ion secondary battery includes a primary particle of a lithium composite compound; and secondary particles formed by an aggregation of primary particles, wherein a ratio between an average particle size of the primary particles and an average particle size of the secondary particles is 0.006 or more and 0.25 or less, an amount of lithium carbonate is 0.4% by mass or less, and a breaking strength of the secondary particles is 30 MPa or more.

Cathode active material for lithium ion secondary battery, method for manufacturing cathode active material for lithium ion secondary battery, and lithium ion secondary

The present invention is to provide a cathode active material used for a lithium ion secondary battery which has a large charge-discharge capacity, and excels in charge-discharge cycle properties, output properties and productivity, and, a lithium ion secondary battery using the same. The cathode active material used for a lithium ion secondary battery comprises a lithium-transition metal composite oxide having an &#x3b1;-NaFeOtype crystal structure and represented by the following formula (1); LiNiCoMO, where, in the formula (1), M is at least one metal element other than Li, Ni and Co; and a, b, c, d and a are respectively numbers satisfying &#x2212;0.04&#x2264;a&#x2264;0.04, 0.80&#x2264;b&#x2264;1.0, 0&#x2264;c&#x2264;0.06, b+c+d=1, and &#x2212;0.2&#x3c;&#x3b1;&#x3c;0.2, and an a-axis lattice constant of the crystal structure is 2.878&#xd7;10m or more.

A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: LiNiMnCoTiMO, and has an atomic ratio Ti/Tibetween Tiand Ti, as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20. In the formula, M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and a are numbers satisfying &#x2212;0.1&#x2264;a&#x2264;0.2, 0.7&#x3c;b&#x2264;0.9, 0&#x2264;c&#x3c;0.3, 0&#x2264;d&#x3c;0.3, 0&#x3c;e&#x2264;0.25, 0&#x2264;f&#x3c;0.3, b+c+d+e+f=1, and &#x2212;0.2&#x2264;&#x3b1;&#x2264;0.2.

Positive-electrode material for lithium ion secondary battery, method for producing the same, and lithium ion secondary battery

A compound having a layered structure that is used for a positive electrode active material for a lithium ion secondary battery achieves both a high energy density and a high cyclability. The positive electrode active material for a lithium ion secondary battery contains a compound having a layered structure belonging to a space group R-3m, in which the compound having a layered structure is represented by a compositional formula: LiM1Owherein M1 represents a metal element or metal elements other than Li, and contains at least Ni, &#x2212;0.03&#x2264;a&#x2264;0.10, and &#x2212;0.1&#x3c;&#x3b1;&#x3c;0.1, a proportion of Ni in M1 is larger than 70 atom %, and a site occupancy of a transition metal or transition metals at a 3a site obtained by structural analysis by a Rietveld method is less than 2%, and a content of residual lithium hydroxide in the positive electrode active material is 1 mass % or less.

Positive electrode active material for lithium ion secondary battery, manufacturing method thereof, and lithium ion secondary battery

Provided are a cathode active material used for a lithium ion secondary battery having a high discharge capacity, and a small increase in internal resistance caused following charge/discharge cycles; a method for producing the same; and a lithium ion secondary battery. The cathode active material has a layered structure assigned to a space group of R-3m represented by the formula: LiM1O(where M1 represents metal elements other than Li containing at least Ni, &#x2212;0.05&#x2264;a&#x2264;0.15, &#x2212;0.1&#x2264;&#x3b1;&#x2264;0.1). A content of Ni is 70 atom % or more, and a generating amount of oxygen gas in the range from 200&#xb0; C. to 450&#xb0; C. is 30 mass ppm or less. The method comprises the steps of grinding and mixing a lithium raw material, and firing the resultant mixture in the range of 650&#xb0; C. or more and 900&#xb0; C. or less.

Cathode active material used for lithium ion secondary battery, method for producing same, and lithium ion secondary battery

A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: LiNiMnCoTiMO, and has an atomic ratio Ti/Tibetween Tiand Ti, as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20. In the formula, M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and &#x3b1; are numbers satisfying &#x2212;0.1&#x2264;a&#x2264;0.2, 0.7&#x3c;b&#x2264;0.9, 0&#x2264;c&#x3c;0.3, 0&#x2264;d&#x3c;0.3, 0&#x3c;e&#x2264;0.25, 0&#x2264;f&#x3c;0.3, b+c+d+e+f=1, and &#x2212;0.2&#x2264;&#x3b1;&#x2264;0.2.

Provided are a cathode active substance used for a lithium ion secondary battery capable of suppressing an increase in an internal resistance inside the battery caused following charge/discharge cycles, a cathode including the cathode active substance, and a lithium ion secondary battery provided with the cathode. The cathode active substance includes a lithium composite compound represented by Formula: LiNiCoMMO. When Pi is defined as porosity with respect to an opening diameter of 0.6 &#x3bc;m or less and measured by subjecting the active substance to a mercury press-in method, and Pp is defined as porosity with respect to the same diameter and measured by filling the active substance in a mold with an inner diameter of 10 mm, pressing the filled substance by a load of 40 MPa, and subjecting the pressed substance to the same method, a value of Pp/Pi is 1.5 or less.

Cathode active substance used for lithium ion secondary battery, cathode including same, and lithium ion secondary battery provided with cathode

Provided are a cathode active material used for a lithium ion secondary battery capable of sufficiently realizing both high charge/discharge capacities and excellent cycle properties, and a lithium ion secondary battery using the cathode active material. The cathode active material contains a plurality of secondary particles formed via agglomeration of a plurality of primary particles of a lithium transition metal composite oxide. Spreading resistance distributions of the secondary particles respectively observed in cross-sections at optional three positions of the cathode active material are measured so as to afford average values of spreading resistance of the secondary particles in the respective cross-sections. The average values of spreading resistance of the secondary particles are further averaged. The resultant averaged value of spreading resistance is made to enter the range of 1.0&#xd7;10&#x3a9;/cm or more and 1.0&#xd7;10&#x3a9;/cm or less.

Cathode active material used for lithium ion secondary battery and lithium ion secondary battery using same

A positive electrode active material includes a primary particle represented by Compositional Formula (1):NiCoMO&#x2003;&#x2003;(1),where x is a number satisfying a relation represented by an expression &#x2212;0.12&#x2264;x&#x2264;0.2; y is a number satisfying a relation represented by an expression 0.7&#x2264;y&#x2264;0.9; z is a number satisfying a relation represented by an expression 0.05&#x2264;z&#x2264;0.3; and M is at least one element selected from the group consisting of Mg, Al, Ti, Mn, Zr, Mo, and Nb; or a secondary particle into which the primary particle aggregates. The primary particle or the secondary particle includes a free lithium compound in a weight proportion of 0.1% or more and 2.0% or less, and the weight of lithium hydroxide in the free lithium compound is 60% or less of the weight of lithium carbonate in the free lithium compound.

Positive electrode active material for lithium ion secondary battery, and positive electrode for lithium ion secondary battery and lithium ion secondary battery comprising the same

Positive-electrode material for lithium ion secondary battery, method and producing the same, and lithium ion secondary battery

A method for producing coated, fine metal particles each having a Ti oxide coating and a silicon oxide coating formed in this order on a metal core particle by mixing powder comprising TiC and TiN with oxide powder of a metal M meeting the relation of &#x394;G&#x3e;&#x394;G, wherein &#x394;Grepresents the standard free energy of forming an oxide of the metal M; heat-treating the resultant mixed powder in a non-oxidizing atmosphere to reduce the oxide of the metal M with the powder comprising TiC and TiN, while coating the resultant metal M particles with Ti oxide; coating the Ti-oxide-coated surface with silicon oxide; and classifying the resultant particles such that they have a median diameter d50 of 0.4-0.7 &#x3bc;m, and a variation coefficient (=standard deviation/average particle size) of 35% or less, which indicates a particle size distribution range. Coated, fine metal particles each having a Ti oxide coating and a silicon oxide coating formed in this order on a metal core particle, which has a median diameter d50 of 0.4-0.7 &#x3bc;m, and a variation coefficient (=standard deviation/average particle size) of 35% or less, which indicates a particle size distribution range.

Coated, fine metal particles comprising titanium oxide and silicon oxide coating, and their production method

Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.

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Tokyo, Japan

Hisato Tokoro