Toyota Jidosha Kabushiki Kaisha

Panasonic Holdings Corporation

Panasonic Corporation

Ryo Hanazaki

Takashi Ko

Natsumi Goto

Sho Tsuruta

Fumiharu Niina

Shinya Suzuki

Keiichi Takahashi

Kohei Kintsu

Yusuke Fukumoto

Yukihiro Okada

Harunari Shimamura

Akira Tsujiko

Naoyuki Wada

Akihiro Ochiai

Ryuta Morishima

Nobuo Matsui

Disclosed is a non-aqueous electrolyte secondary battery positive electrode that includes a positive electrode core and a positive electrode mixture layer disposed on the positive electrode core. The positive electrode mixture layer contains a positive electrode active material and carbon nanotubes. The positive electrode active material contains a lithium transition metal composite oxide (I) that either comprises secondary particles that are aggregates of primary particles having an average particle size of 1 μm or greater, or is substantially composed of single particles, the lithium transition metal composite oxide (I) having a volume-based median diameter of 0.6 μm to 6 μm, and a lithium transition metal composite oxide (II) that comprises secondary particles that are aggregates of primary particles having an average particle size of less than 1 μm, the lithium transition metal composite oxide (II) having a volume-based median diameter of 3 μm to 25 μm.

Non-aqueous electrolyte secondary battery positive electrode and non-aqueous electrolyte secondary battery

A positive electrode material consists of composite particles. Each of the composite particles includes a base material particle, a film, and a carbon nanotube. The film covers at least a part of a surface of the base material particle. The base material particle includes a positive electrode active material. The film includes a boron oxide. The carbon nanotube includes a first portion and a second portion. The first portion is buried in the film. The second portion is exposed on a surface of the film.

Positive electrode material, non-aqueous electrolyte secondary battery, and method of producing positive electrode material

A positive electrode active material for a non-aqueous electrolyte secondary battery according to a configuration includes a lithium-transition metal composite oxide containing nickel (Ni) in an amount of greater than or equal to 80 mol %, in which boron (B) is present at least on a particle surface of the lithium-transition metal composite oxide. In the lithium-transition metal composite oxide, when particles having a larger particle size than a volume-based 70% particle size (D70) are first particles and particles having a smaller particle size than a volume-based 30% particle size (D30) are second particles, a coverage ratio of B on surfaces of the second particle is larger than a coverage ratio of B on surfaces of the first particle by 5% or greater.

Positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

A positive electrode active material for a non-aqueous electrolyte secondary battery according to a configuration includes a lithium-transition metal composite oxide containing nickel (Ni) in an amount of greater than or equal to 80 mol %, in which boron (B) is present at least on a particle surface of the lithium-transition metal composite oxide. In the lithium-transition metal composite oxide, when particles having a larger particle size than a volume-based 70% particle size (D70) are first particles and particles having a smaller particle size than a volume-based 30% particle size (D30) are second particles, a coverage ratio of B on surfaces of the first particles is larger than a coverage ratio of B on surfaces of the second particles by 5% or greater.

An advantage is to provide a non-aqueous electrolyte secondary battery with improved heat resistance. A positive electrode active material contains a lithium-transition metal composite oxide containing 80 mol % or more of Ni and 0.1 mol % to 1.5 mol % of B on the basis of the total number of moles of metal elements excluding Li, and B and at least one element (M1) selected from Groups 4 to 6 are present on at least the surfaces of particles of the composite oxide. When particles having a volume-based particle size larger than 70% particle size (D70) are first particles, and particles having a volume-based particle size smaller than 30% particle size (D30) are second particles, the molar fraction of M1 on the basis of the total number of moles of metallic elements excluding Li on the surfaces of the second particles is greater than that of the first particles.

A non-aqueous electrolyte secondary battery includes at least an electrode composite material layer, an intermediate layer, and an electrode current collector. Intermediate layer is interposed between electrode composite material layer and electrode current collector. Intermediate layer contains at least insulating particles and conductive particles. Each insulating particle has an arc shape in a cross section of intermediate layer along a thickness direction. More conductive particles are present on an outer-circumference side of each arc shape than on an inner-circumference side of the arc shape.

Non-aqueous electrolyte secondary battery and method of producing the same

A lithium ion secondary battery includes at least a positive electrode, a negative electrode, and an electrolyte. The positive electrode contains at least a first positive electrode active material and a second positive electrode active material. The first positive electrode active material is expressed with a formula (I) LiNiCoMnOand the second positive electrode active material is expressed with a formula (II) LiNiCoMnO, where a, b, c, d, e, and f satisfy conditions of a&#x3e;d, 0.4&#x2264;a&#x2264;0.6, 0.2&#x2264;b&#x2264;0.5, 0.1&#x2264;c&#x2264;0.2, a+b+c=1.0, 0.2&#x2264;d&#x2264;0.5, 0.1&#x2264;e&#x2264;0.2, 0.4&#x2264;f&#x2264;0.6, and d+e+f=1.

Lithium ion secondary battery and method of manufacturing the same

A nonaqueous electrolyte secondary battery includes: a wound electrode body that is formed by laminating an elongated sheet-shaped positive electrode current collector foil, an elongated sheet-shaped negative electrode current collector foil, and an elongated sheet-shaped separator to obtain a laminate and winding the obtained laminate; a nonaqueous electrolytic solution; and a case that accommodates the wound electrode body and the nonaqueous electrolytic solution. A solid electrolyte interface film derived from an oxalato borate complex is formed on at least a surface of the negative electrode active material layer. The positive electrode current collector foil satisfies the following conditions of (a) 700%&#x2264;&#x3b1;&#x2264;760% and (b) 530%&#x2264;&#x3b2;&#x2264;590%, where &#x3b1; represents a 60-degree specular gloss in a direction parallel to a longitudinal direction of the positive electrode current collector foil, and &#x3b2; represents a 60-degree specular gloss in a width direction perpendicular to the longitudinal direction of the positive electrode current collector foil.

Nonaqueous electrolyte secondary battery and method of manufacturing the same

Provided is a method for producing a positive electrode for a nonaqueous electrolyte secondary battery having superior electrical conductivity with high productivity. The production method disclosed herein includes the following steps: a first kneading step (S) for kneading electrically conductive carbon fine particles and a hydrophobic binder that gels when contacted by water, in N-methyl-2-pyrrolidone (NMP); a second kneading step (S) for adding a positive electrode active material and water to a first kneaded product obtained in the first kneading step followed by additional kneading; and a step (S) for forming a positive electrode active material layer on the surface of a positive electrode current collector by coating a second kneaded product obtained in the second kneading step on the positive electrode current collector. The first kneaded product contains moisture, and the ratio of the mass of the moisture to the mass of the NMP is 0.002 or less in the first kneaded product, while in the second kneading step (S), the water is added at a mass ratio of 0.0022 to 0.0115 based on the mass of the NMP.

Positive electrode for nonaqueous electrolyte secondary battery and production method thereof

Provided is a nonaqueous electrolyte secondary cell in which heat generation is suppressed. The nonaqueous electrolyte secondary cell according to the invention has a positive electrode including positive electrode active material particles and a negative electrode including negative electrode active material particles. The negative electrode active material particles are carbon-black-adhered carbon-based negative electrode active material particles which are constituted by a carbon material having a graphite structure in at least part thereof and which have carbon black (CB) particles that have adhered to at least part of a surface portion. The positive electrode active material particles are of a hollow structure having a shell and a hollow portion. The average short diameter A of the CB particles in the carbon-black-adhered carbon-based negative electrode active material particles and an average inner diameter B of the hollow portions in the positive electrode active material particles fulfill the relationship: 1.2&#x2266;B/A&#x2266;260.

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Toyota, Japan

Ryo Hanazaki