Hitachi Chemical Company, Ltd.

Showa Denko Materials Co., Ltd.

Sanyo Electric Co., Ltd.

Tatsuya Nishida

Yoshito Ishii

Kazuo Yamada

Atsushi Fujita

Akira Yasuda

Hideyuki Tsuchiya

Masayuki Kouzu

Yoshie Oosaki

Yoshie Ohsaki

Katsutomo Ohzeki

Souichirou Suda

Masayuki Terasaka

Hideyuki Inomata

Yoshihiro Shoji

Kouichi Takei

Hiroshi Nakagawa

Kiyoshi Suzuki

Katsuya Imai

A negative electrode material for a lithium ion secondary battery including carbon over a part or a whole of a surface of an oxide of silicon, in which the content of the carbon is from 0.5 mass-% to less than 5 mass-%.

Negative electrode material for lithium ion secondary battery, negative electrode for lithium ion secondary battery, and lithium ion secondary battery

A negative electrode active material for a lithium ion secondary battery includes silicon oxide particles, each of which has carbon on at least a portion of its surface, in which: a ratio (P/P) of an intensity of an X-ray diffraction peak at 2&#x3b8; of from 27&#xb0; to 29&#xb0;, which is derived from Si, to an intensity of an X-ray diffraction peak at 2&#x3b8; of from 20&#xb0; to 25&#xb0;, which is derived from SiO, is within a range of from 1.0 to 2.6, when CuK&#x3b1; radiation having a wavelength of 0.15406 nm is used as a radiation source; and a ratio (S/S) of a specific surface area calculated from moisture adsorption at 298 K to a specific surface area calculated from nitrogen adsorption at 77 K is 0.60 or less.

Negative electrode active material for lithium ion secondary battery, negative electrode for lithium ion secondary battery, and lithium ion secondary battery

A negative electrode active material for a lithium ion secondary battery includes silicon oxide particles, each of which has carbon on at least a portion of its surface, in which: a ratio (P/P) of an intensity of an X-ray diffraction peak at 2&#x3b8; of from 27&#xb0; to 29&#xb0;, which is derived from Si, to an intensity of an X-ray diffraction peak at 2&#x3b8; of from 20&#xb0; to 25&#xb0;, which is derived from SiO, is within a range of from 1.0 to 2.6, when CuK&#x3b1; radiation having a wavelength of 0.15406 nm is used as a radiation source; and a specific surface area calculated from carbon dioxide adsorption at 273 K is 8.5 m/g or less.

A negative electrode active material for a lithium ion secondary battery, the negative electrode active material includes silicon oxide particles, each of which has carbon on at least a portion of its surface, in which: a ratio (P/P) of an intensity of an X-ray diffraction peak at 2&#x3b8; of from 27&#xb0; to 29&#xb0;, which is derived from Si, to an intensity of an X-ray diffraction peak at 2&#x3b8; of from 20&#xb0; to 25&#xb0;, which is derived from SiO, is within a range of from 1.0 to 2.6, when CuK&#x3b1; radiation having a wavelength of 0.15406 nm is used as a radiation source; and a specific surface area calculated from moisture adsorption at 298 K is 6.5 m/g or less.

A negative electrode material for a lithium ion secondary battery includes a silicon oxide and having a diffraction peak attributable to Si (111) in an X-ray diffraction spectrum, in which a size of a silicon crystallite calculated from the diffraction peak is from 2.0 nm to 8.0 nm.

A negative electrode for a lithium secondary battery includes a layer of a mixture containing graphite powder and an organic binder on a current collector, wherein a diffraction intensity ratio (002)/(110) measured by X-ray diffractometry of the layer of a mixture is 500 or less. A lithium secondary battery includes the negative electrode for a lithium secondary battery, and a positive electrode that includes a lithium compound. This results in less deterioration in the rapid charge and discharge characteristics and the cycle characteristics when the density of the negative electrode is made higher, thereby providing a high capacity lithium secondary battery having the improved energy density per unit volume of the secondary battery.

Negative electrode for lithium secondary battery and lithium secondary battery

A method for forming a negative electrode for a lithium secondary battery, includes providing a paste comprising graphite particulates comprise assembled or bound graphite particles in each of which a plurality of flat-shaped particles are assembled or bound together so that the planes of orientation are not parallel to one another, and the mixture including 3 to 10 parts by weight of the organic binder per 100 parts by weight of the graphite particulates, a binder and a solvent, coating the paste on a current collector, drying the paste coated on the current collector to form a mixture of the graphite particulates and the binder, and integrating the mixture with the current collector by pressing to provide a density of the mixture of graphite particulates and organic binder of 1.5 to 1.9 g/cm.

Graphite particles and lithium secondary battery using the same as negative

Graphite particles and lithium secondary battery using the same as negative electrode

A graphite particle obtained by assembling or binding together a plurality of flat-shaped particles so that the planes of orientation are not parallel to one another, or a graphite particle in which aspect ratio is 5 or less or specific surface area is 8 m/g or less or the size of crystallite in the direction of c-axis of the crystal is 500 &#x212b; or more and the size of crystallite in the direction of plane is 1,000 &#x212b; or less as measured by X ray broad angle diffraction, or a graphite particle in which pore volume of the pores having a size falling in a range of 10to 10&#x212b; is 0.4 to 2.0 cc/g per weight of graphite particle or pore volume of the pores having a size falling in a range of 1&#xd7;10to 2&#xd7;10&#x212b; is 0.08 to 0.4 cc/g per weight of graphite particle is suitable for production of negative electrode of lithium secondary battery, and a lithium secondary battery obtained therefrom is excellent in rapid charge-discharge characteristics, cycle characteristics, etc.

In order to provide a nonaqueous electrolyte secondary battery negative electrode material that has an excellent discharging capacity, the charge/discharge efficiency and the charge load characteristics, a manufacturing method thereof, a nonaqueous electrolyte secondary battery negative electrode with the negative electrode material and a nonaqueous electrolyte secondary battery, the invention provides a nonaqueous electrolyte secondary battery negative electrode material including graphite particles that have a block-like structure where a plurality of flat graphite fine particles assembles or bonds non-parallel with each other, the aspect ratio of 5 or less and a volume of fine pores in the range of 10 to 10nm in a volume of 400 to 2000 cm/kg; and a layer of carbon formed on a surface of the graphite particle, wherein a ratio (by weight ratio) of the layer of carbon to the graphite particle is in the range of 0.001 to 0.01, a manufacturing method thereof, a nonaqueous electrolyte secondary battery negative electrode with the negative electrode material and a nonaqueous electrolyte secondary battery.

Non-aqueous electrolyte secondary battery-use cathode material, production method therefor, non-aqueous electrolyte secondary battery-use cathode and non-aqueous electrolyte secondary battery using the cathode material

A negative electrode for a lithium secondary battery, comprising a layer of a mixture containing graphite powder and an organic binder on a current collector, wherein a diffraction intensity ratio (002)/(110) measured by X-ray diffractometry of the layer of a mixture is 500 or less,

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Hitachi, Japan

Tatsuya Nishida