Panasonic Intellectual Property Management Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Panasonic Holdings Corporation

Sanyo Electric Co., Ltd.

Masanori Sugimori

Katsunori Yanagida

Nobuhiro Hirano

Yasunori Baba

Yusuke Fukumoto

Yuji Yokoyama

Yo Kato

Natsumi Goto

Yuki Morikawa

Masanobu Takeuchi

Kouhei Tuduki

Akihiko Takada

Provided is an electrode slurry carbon nanotube liquid dispersion which improves charge/discharge cycle characteristics. An electrode slurry carbon nanotube liquid dispersion which is one aspect of the present disclosure and contains 0.1-1.5 mass % of carbon nanotubes, a dispersion medium, and carboxymethyl cellulose, the viscosity of which at 100sin a 3% aqueous solution is 2-200 mPa·s, wherein: the carboxymethyl cellulose content constitutes 50-250 parts by mass relative to 100 parts by mass of carbon nanotubes; the viscosity at 100sis 50-200 mPa·s in a state in which the carbon nanotubes are dispersed; and the particle distribution according to the laser diffraction method exhibits a D10 of 0.3-1.0 μm, a D50 of 3-10 μm and a D90 of 60 μm or less in a state in which the carbon nanotubes are dispersed.

Electrode slurry carbon nanotube liquid dispersion, negative electrode slurry, non-aqueous electrolyte secondary battery, and method for producing electrode slurry carbon nanotube liquid dispersion

A negative electrode for a nonaqueous electrolyte secondary battery comprises a negative electrode core body, and a negative electrode mixture layer. When the range of 40% of the thickness of the negative electrode mixture layer from the surface of the negative electrode mixture layer on the side opposite to the negative electrode core body is defined as a first region and the range of 40% of the thickness of the negative electrode mixture layer from the interface between the negative electrode mixture layer and the negative electrode core body is defined as a second region, the BET specific surface area of the graphite included in the first region is smaller than the BET specific surface area of the graphite included in the second region.

Negative electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery

In a nonaqueous electrolyte secondary battery, a separator includes a substrate, a first filler layer disposed on one side of the substrate and containing phosphate salt particles, and a second filler layer disposed on the other side of the substrate and containing inorganic particles. The separator is disposed between a positive electrode and a negative electrode in such a manner that the side of the substrate which bears the first filler layer is directed to the positive electrode side.

Nonaqueous electrolyte secondary battery including separator with filler layers on opposite sides of substrate

A separator for use in a non-aqueous electrolyte secondary battery according to the present invention comprises a porous substrate and a filler layer disposed upon the substrate. The filler layer includes phosphate particles and a reticulated polyvinylidene fluoride resin. The filler layer has a polyvinylidene fluoride resin content of 15 mass % to 40 mass %, inclusive. The D10 particle size (D) of the phosphate particles on a volume basis is 0.02 μm to 0.5 μm, inclusive, and is smaller than the average pore size of the pores in the substrate. The BET specific surface area of the phosphate particlesis 5 m/g to 100 m/g, inclusive.

Non-aqueous electrolyte secondary battery

This non-aqueous electrolyte secondary battery comprises a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The separator includes; a porous base material; a first filler layer which contains phosphate particles as a primary component and is arranged on one surface of the base material; and a second filler layer which is arranged on the other surface of the base material and which contains at least one type of compound selected from the group consisting of an aromatic polyamide, an aromatic polyimide and an aromatic polyamideimide. The BET specific surface area of the phosphate particles is 5-100 m/g. The content of the aforementioned compounds in the second filler layeris 15 mass % or more.

In a nonaqueous electrolyte secondary battery a separator includes a porous substrate, a first filler layer, and a second filler layer. The first filler layer comprises phosphate particles having a BET specific surface area of 5 to 100 m/g and polyvinylidene fluoride and is formed on a first surface that faces the positive electrode side of the substrate and contacts the positive electrode. The second filler comprises inorganic particles which have a melting point higher than that of the phosphate particles and is formed on at least one of a second surface that faces the negative electrode side of the substrate and the area between the substrate and the first filler layer. The content of the polyvinylidene fluoride in the first filler layer is 10 to 50 mass % and is higher in a region on the positive electrode side than in a region on the substrate side.

Nonaqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The separator has a multilayer structure in which a first filler layer containing phosphate particles, a porous resin substrate, and a second filler layer containing inorganic particles having higher heat resistance than the phosphate particles are stacked in this order from the negative electrode side. The first filler layer is disposed on the porous resin substrate in such a manner that the surface of the first filler layer faces the surface of the negative electrode. The phosphate particles have a BET specific surface area in the range of 5 m/g or more and 100 m/g or less.

Non-aqueous electrolyte secondary battery having separator with multilayer structure

A negative electrode for a nonaqueous electrolyte secondary battery, which is an example of embodiments, comprises a negative electrode core body and a negative electrode mixture layer provided on the surface of the negative electrode core body. The negative electrode mixture layer includes graphite and fibrous carbon. The BET specific surface area of the graphite included in the first region is smaller than the BET specific surface area of the graphite included in the second region. In addition, the average length of the fibrous carbon included in the second region is longer than the average length of the fibrous carbon included in the first region.

A negative electrode for a nonaqueous electrolyte secondary battery, which is an example of embodiments, comprises a negative electrode core body and a negative electrode mixture layer provided on the surface of the negative electrode core body. The negative electrode mixture layer includes graphite and fibrous carbon. The BET specific surface area of the graphite included in the first region is smaller than the BET specific surface area of the graphite included in the second region. In addition, the average length of the fibrous carbon included in the first region is longer than the average length of the fibrous carbon included in the second region.

A negative electrode for a nonaqueous electrolyte secondary battery comprises a negative electrode core body and a negative electrode mixture layer provided. When the range of 40% of the thickness of the negative electrode mixture layer from the surface of the negative electrode mixture layer is defined as a first region and the range of 40% of the thickness of the negative electrode mixture layer from the surface of the negative electrode core body is defined as a second region, the BET specific surface area of the graphite included in the first region is smaller than that of the graphite included in the second region. The first region includes the multiwalled fibrous carbon more than the single wall fibrous carbon in terms of mass and the second region includes the single wall fibrous carbon more than the multiwalled fibrous carbon in terms of mass.

In a non-aqueous electrolyte secondary battery according to one exemplary embodiment, a separator includes a substrate, a first filler layer containing phosphate particles and formed on at least one surface of the substrate, and a second filler layer containing inorganic particles and formed on a surface of the first filler layer on the side of the at least one surface of the substrate. The phosphate particles have a BET specific surface area of 5 m/g or more and 100 m/g or less.

In a nonaqueous electrolyte secondary battery, a separator includes a substrate, a first filler layer containing phosphate salt particles, and a second filler layer interposed between the substrate and the first filler layer and containing inorganic particles. The separator is disposed between a positive electrode and a negative electrode in such a manner that the first filler layer and the second filler layer are directed to the positive electrode side. Further, a resin layer is disposed between the positive electrode and the first filler layer.

Nonaqueous electrolyte secondary battery including separator having substrate, phosphate salt layer, inorganic particle layer, and resin layer between separator and positive electrode

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode and a separator disposed between the positive electrode and the negative electrode, wherein the separator includes an inorganic filler layer which includes a first filler layer containing phosphate salt particles and a second filler layer disposed on the first filler layer and containing inorganic particles more heat resistant than the phosphate salt particles, and the BET specific surface area of the phosphate salt particles is in the range of not less than 5 m/g and not more than 100 m/g.

A negative electrode for nonaqueous electrolyte secondary batteries includes a negative electrode current collector and a negative electrode mixture layer disposed on the negative electrode current collector, and the negative electrode mixture layer contains a negative electrode active material containing lithium titanate, a binder, and a (meth)acrylic acid-based polymer. The amount of the (meth)acrylic acid-based polymer in the negative electrode mixture layer is 10 mass % or less relative to the total amount of the (meth)acrylic acid-based polymer and the binder. The amount of the (meth)acrylic acid-based polymer in a portion of the negative electrode mixture layer that extends from the surface to the middle of the negative electrode mixture layer in the thickness direction (upper region) is 60 mass % or more relative to the total amount of the (meth)acrylic acid-based polymer.

Negative electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery

The present invention provides a nonaqueous electrolyte secondary battery capable of suppressing the increase in IV resistance of a battery in a combination of a negative electrode containing a lithium-titanium composite oxide and a carbon material and a positive electrode containing a lithium transition metal oxide. A nonaqueous electrolyte secondary battery according to the present invention includes a positive electrode, a negative electrode, a separator placed between the positive electrode and the negative electrode, and a nonaqueous electrolyte. The positive electrode contains a lithium transition metal oxide in which Ni accounts for 30 mole percent or more of the total molar amount of metal elements excluding Li and also contains tungsten element. The negative electrode contains a lithium-titanium composite oxide and a carbon material. The nonaqueous electrolyte contains a substance reduced on the negative electrode at a potential of 0.5 V to 1.5 V (vs. Li/Li).

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Hyogo, Japan

Masanori Sugimori