Hitachi Metals, Ltd.

Hitachi, Ltd.

Proterial, Ltd.

Takashi Nakabayashi

Shin Takahashi

Hisato Tokoro

Shuichi Takano

Akira Gunji

Tatsuya Toyama

Xiaoliang Feng

Hiroshi Haruna

Daiko Takamatsu

Shigeo Fujii

Tatsuya Tooyama

Sho Furutsuki

Mitsuru Kobayashi

Yoshihito Yoshizawa

Motoki Ohta

Toyotaka Yuasa

Yasushi Kaneko

Kan Kitagawa

Mariko Adachi

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 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

Provided are a cathode material for lithium ion secondary battery having excellent rate characteristics and cycle characteristics while a cathode active substance has high density, and a lithium ion secondary battery cathode and a lithium ion secondary battery that use the above cathode material. The cathode material for lithium ion secondary battery (), represented by LiM1M2O[where &#x2212;0.1&#x2264;x&#x2264;0.3, 0&#x2264;y&#x2264;0.1; M1 is Ni, Co, Mn; and M2 is Mg, Al, Ti, Zr, Mo, Nb, Fe, B], is an agglomerate including secondary particles () both formed via aggregation of lithium metal composite oxide primary particles () having a layered structure. A mean porosity of the secondary particles having a particle size of more than 10 &#x3bc;m and equal to 50 &#x3bc;m or less is higher than that of the secondary particles having a particle size of 0.5 &#x3bc;m to 10 &#x3bc;m.

Lithium ion secondary battery cathode material, lithium ion secondary battery cathode and lithium ion secondary battery that use same, and method for manufacturing lithium ion secondary battery cathode material

A positive electrode active material for a non-aqueous secondary battery having high capacity and high rate characteristics is intended to be provided. Further, a positive electrode for a non-aqueous secondary battery and a non-aqueous secondary battery are intended to be provided by using the positive electrode active material. The positive electrode active material for the non-aqueous secondary battery contains a lithium composite oxide having an olivine structure represented by the chemical formula: LiMnM(PO)in which A&#x3e;0, B&#x3e;0, M represents a metal element, M in the chemical formula is one or more metal elements selected from Fe, Ni, Co, Ti, Cu, Zn, Mg, V, and Zr, the ratio A/B in the chemical formula is within a range of: 2&#x3c;A/B&#x2266;7, and the value of X is within a range of: 0.3&#x2266;X&#x3c;1.

Positive electrode active material for non-aqueous secondary battery and manufacturing method thereof, as well as non-aqueous secondary battery using positive electrode active material

The object of the present invention is to inhibit occurrence of structural collapse caused by volumetric change of primary particles of negative electrode active material and to improve adhesion between negative electrode active material and electrically conductive agent and between negative electrode mix layer and collector, whereby improvement of life is attained in negative electrode for non-aqueous secondary battery and non-aqueous secondary battery. In the negative electrode for non-aqueous secondary battery of the present invention, the negative electrode active material comprises silicon and/or tin, and at least one element selected from elements which do not react with lithium and has pores in both of the inner core portion and the outer peripheral portion of primary particles and a material which cures by a heat treatment is used as a binder.

Negative electrode for non-aqueous secondary battery and non-aqueous secondary battery

It is an objective of the present invention to provide a lithium-ion rechargeable battery anode which can control the volume change of a primary particle of a negative-electrode active material other than a carbon-based material and that can prevent cracks due to stress caused by the volume change from occurring and extending. There is provided an anode for a lithium-ion rechargeable battery including a primary particle of a negative-electrode active material, a conductive material, and a binder, the negative-electrode active material including at least one of silicon and tin, and at least one element selected from elements that do not chemically react with lithium, in which holes are present both in an inner core region in the central region of the primary particle of the negative-electrode active material and in a periphery region that covers the inner core region.

Anode for lithium-ion rechargeable battery and lithium-ion rechargeable battery including same

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

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 &#x394;G&#x3e;&#x394;G, wherein &#x394;Grepresents 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.

Growing community of inventors

Tokyo, Japan

Takashi Nakabayashi