Abstract: 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 1.0×106 ?/cm or more and 1.0×1010 ?/cm or less.

Abstract: A positive electrode active material includes a primary particle represented by Compositional Formula (1): Li1+xNiyCozM1?x?y?zO2 ??(1), where x is a number satisfying a relation represented by an expression ?0.12?x?0.2; y is a number satisfying a relation represented by an expression 0.7?y?0.9; z is a number satisfying a relation represented by an expression 0.05?z?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.

Abstract: 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 Li?NixCoyM11?x?y?zM2zO2+? so 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° C. to 400° 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° C. to 800° 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° C. to 900° C. for 0.5 to 50 hours to obtain the lithium composite compound.

Abstract: A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li1+aNibMncCodTieMfO2+?, and has an atomic ratio Ti3+/Ti4+ between Ti3+ and Ti4+, 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 ? are numbers satisfying ?0.1?a?0.2, 0.7<b?0.9, 0?c<0.3, 0?d<0.3, 0<e?0.25, 0?f<0.3, b+c+d+e+f=1, and ?0.2???0.2.

Abstract: A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li1+aNibMncCodTieMfO2+?, and has an atomic ratio Ti3+/Ti4+ between Ti3+ and Ti4+, 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 ? are numbers satisfying ?0.1?a?0.2, 0.7<b?0.9, 0?c<0.3, 0?d<0.3, 0<e?0.25, 0?f<0.3, b+c+d+e+f=1, and ?0.2???0.2.

Abstract: 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: Li1+aM1O2+? (where M1 represents metal elements other than Li containing at least Ni, ?0.05?a?0.15, ?0.1???0.1). A content of Ni is 70 atom % or more, and a generating amount of oxygen gas in the range from 200° C. to 450° 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° C. or more and 900° C. or less.

Abstract: 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 1.0×106 ?/cm or more and 1.0×1010 ?/cm or less.

Abstract: Provided is a method for producing a cathode active material used for a lithium secondary battery, via efficiently firing a nickel-containing precursor in a short time. The method includes the steps of mixing lithium carbonate with a compound other than Li, and firing the precursor obtained through the mixing step thereby to obtain a lithium composite compound. The firing step includes a heat treating substep of heat-treating a precursor rotating in a furnace tube (10) of a firing furnace (1). The firing furnace (1) includes a first gas feeding system that injects an oxidative gas, and a second gas feeding system that makes an oxidative gas flow in the axis direction of the furnace tube (10). The heat treating substep includes spraying an oxidative gas onto the precursor, and simultaneously exhausting a carbon dioxide gas generated from the precursor by a gas flow.

Abstract: 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: Li1+?NixCoyM11-x-y-zM2zO2+?. When Pi is defined as porosity with respect to an opening diameter of 0.6 ?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.

Abstract: A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li1+aNibMncCodTieMfO2+?, and has an atomic ratio Ti3+/Ti4+ between Ti3+ and Ti4+, 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 ? are numbers satisfying ?0.1?a?0.2, 0.7<b?0.9, 0?c<0.3, 0?d<0.3, 0<e?0.25, 0?f<0.3, b+c+d+e+f=1, and ?0.2???0.2.

Abstract: An object of the present invention is to provide lithium ion secondary batteries having cycle characteristics as well as high energy density and rate characteristics during high-potential charging of a layered compound. The following is provided, a positive electrode active material for lithium ion secondary batteries, comprising particles each having: a core part comprising a lithium metal composite oxide; and a surface layer part comprising a lithium metal composite oxide having a composition differing from that in the core part, the surface layer part being formed on the surface of the core part, wherein both the core part and the surface layer part have a layered structure, the surface layer part contains Ni, Mn, and Li, and Ni/Mn mole ratio in the surface is less than 1.

Abstract: The objective of the present invention is to provide a lithium ion secondary battery, the charged state of which can be detected from the battery voltage with high accuracy, and which is able to achieve a high capacity in a high-potential range. This objective can be achieved by a cathode active material for lithium ion secondary batteries, which is composed of a lithium transition metal oxide containing Li and metal elements including at least Ni and Mn, and which is characterized in that: the atomic ratio of Li to the metal elements satisfies 1.15<Lil(metal elements)<1.5; the atomic ratio of Ni to Mn satisfies 0.334<Ni/Mn?1; and the atomic ratio of Ni and Mn to the metal elements satisfies 0.975?(Ni+Mn)/(metal elements)?1.

Abstract: Provided is a method for manufacturing a cathode electrode material, including the step of performing calcination of a mixture of lithium carbonate and a compound containing Ni, and capable of mass-producing a cathode electrode material including a lithium composite oxide with high Ni concentration industrially. The manufacturing method includes a mixture step of mixing lithium carbonate and a compound including Ni, and a calcination step of performing calcination of a mixture obtained in the mixture step under oxidizing atmosphere to obtain a lithium composite compound with high Ni concentration. The calcination step includes: a first heat treatment step to obtain a first precursor; a second heat treatment step of performing heat treatment of the first precursor to obtain a second precursor; and a third heat treatment step of performing heat treatment of the second precursor to obtain the lithium composite compound.

Abstract: 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: Li1+aM1O2+?wherein M1 represents a metal element or metal elements other than Li, and contains at least Ni, ?0.03?a?0.10, and ?0.1<?<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.

Abstract: A positive electrode active material includes a primary particle represented by Compositional Formula (1): Li1+xNiyCozM1?x?y?zO2 (1), where x is a number satisfying a relation represented by an expression ?0.12?x?0.2; y is a number satisfying a relation represented by an expression 0.7?y?0.9; z is a number satisfying a relation represented by an expression 0.05?z?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.

Abstract: A composite, soft-magnetic powder comprising soft-magnetic, iron-based core particles having an average particle size of 2-100 ?m, and boron nitride-based coating layers each covering at least part of each soft-magnetic, iron-based core particle, said coating layers being polycrystalline layers comprising fine boron nitride crystal grains having different crystal orientations and an average crystal grain size of 3-15 nm, the average thickness of said polycrystalline layers being 6.6% or less of the average particle size of said soft-magnetic, iron-based core particles, is produced by (1) mixing iron nitride powder having an average particle size of 2-100 ?m with boron powder having an average particle size of 0.1-10 ?m, (2) heat-treating the resultant mixed powder at a temperature of 600-850° C. in a nitrogen atmosphere, and (3) removing non-magnetic components.

Abstract: 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 ?GM-O>?GTiO2, wherein ?GM-O represents 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 ?m, and a variation coefficient (=standard deviation/average particle size) of 35% or less, which indicates a particle size distribution range.

Abstract: 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.

Abstract: 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.

Abstract: A method for producing coated, fine metal particles comprising the steps of mixing powder comprising TiC and TiN with powder of an oxide of a metal M meeting the relation of ?GM-O>?GTiO2, wherein ?GM-O represents the standard free energy of formation of metal M oxide, and 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, and coated, fine metal particles each comprising a metal core particle and a Ti oxide coating and having a carbon content of 0.2-1.4% by mass and a nitrogen content of 0.01-0.2% by mass.