Jx Nippon Oil Energy Corporation

Toda Kogyo Corporation

Toda Kyogo Corp.

Noriyo Ishimaru

Takashi Suzuki

Takashi Oyama

Tamotsu Tano

Seiji Okazaki

Ippei Fujinaga

Wataru Oda

Tomoaki Urai

Katsuaki Kurata

Toshiyuki Oda

Toshiaki Hiramoto

Akino Sato

Takefumi Kono

This disclosure concerns graphite materials having lattice distortion for lithium-ion secondary battery negative electrode obtained by a manufacturing method comprising the steps of: pulverizing and classifying a raw coke composition obtained from a heavy-oil composition undergone coking by delayed coking process, the raw coke composition having a H/C atomic ratio that is a ratio of hydrogen atoms H and carbon atoms C of 0.30 to 0.50 and having a micro-strength of 7 to 17 mass % to obtain powder of the raw coke composition; giving compressive stress and shear stress to the powder of the raw coke composition so that average circularity is 0.91 to 0.97 to obtain round powder; heating the round powder to obtain a carbonized composition; and graphitizing the carbonized composition.

Graphite material with lattice distortion for use in lithium-ion secondary battery negative electrodes, and lithium-ion secondary battery

A method for producing an amorphous carbon material for a negative electrode of a lithium-ion secondary battery includes the steps of; pulverizing and classifying a raw coke composition obtained from a heavy-oil composition undergone coking by delayed coking process to obtain powder of the raw coke composition, the raw coke composition having a H/C atomic ratio that is a ratio of hydrogen atoms H and carbon atoms C of 0.30 to 0.50 and having a micro-strength of 7 to 17 mass %; giving compressive stress and shear stress to the powder of the raw coke composition to obtain a carbonized composition precursor; and heating the carbonized composition precursor under an inert atmosphere at a temperature from 900&#xb0; C. to 1,500&#xb0; C. so that a size of a crystallite Lc(002) is in a range of 2 nm to 8 nm, the size being calculated from a (002) diffraction line obtained by X-ray wide-angle diffractometry.

Method of producing amorphous carbon material for the negative electrode of lithium ION secondary battery, and lithium ION secondary battery

A graphite material for a negative electrode is provided which can suppress capacity degradation due to repeated charging and discharging cycles, storage in a charged state, and floating charging. A method of manufacturing a graphite material for a negative electrode of a lithium ion secondary battery is provided in which an atomic ratio H/C of hydrogen atoms H and carbon atoms C in the raw coke composition is in a range of 0.30 to 0.50 and a microstrength of the raw coke composition is in a range of 7 wt % to 17 wt %.

Graphite material for negative electrodes of lithium ion secondary battery, manufacturing method for said material, and lithium ion secondary battery using same

Provided is an amorphous carbon material for a negative electrode of a lithium ion secondary battery. The amorphous carbon material comprises a size of a crystallite Lc(002) in c-axis direction ranging from 2.0 to 8.0 nm, the size being calculated from a (002) diffraction line of the amorphous carbon material measured by powder X-ray diffractometry; a carbon-derived spectrum appearing in a range from 3,200 to 3,400 gauss (G) in an electron spin resonance measured using X band; a relative signal intensity ratio (I/I) of the spectrum ranging from 2.4 to 3.5, wherein the relative signal intensity ratio is a ratio of signal intensity (I) at temperature of 4.8 K to signal intensity (I) at temperature of 40K; and a line width (&#x394;Hpp) of the spectrum ranging from 70 to 180 gauss (G), wherein the line width is calculated from a first-order derivative spectrum at temperature of 4.8 K.

Amorphous carbon material for negative electrode of lithium ion secondary battery and nonaqueous secondary battery comprising same

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Kanagawa, Japan

Noriyo Ishimaru