Showa Denko K.k.

Yoshiyuki Nishimura

Akinori Sudoh

Shunsuke Yoshioka

Masataka Takeuchi

Yuuichi Kamijou

Takayuki Fukai

Ryusuke Miura

Yasuaki Wakizaka

Chiaki Sotowa

A method for producing a graphie material for an electrode material for lithium ion batteries, including a step for exothermically graphitizing a carbon material by directly passing an electric current therethrough. The carbon material has an compact powder resistivity of 0.4 &#x3a9;&#xb7;cm or less when compressed to a density of 1.4 g/cm, has an angle of repose in the range of 20&#xb0; to 50&#xb0; inclusive, and has a particle size (D90) in the volume-based particle size distribution measured using laser diffraction of 120 &#x3bc;m or less. The average surface interval (d002) of a surface (002) of the carbon material after graphitization, measured using x-ray diffraction, is in the range of 0.3354 nm-0.3450 nm inclusive.

Method for producing electrode material for lithium ion batteries

A graphite carbon composite material including a graphite material having diversity in the sizes of optical anisotropic structure and optical isotropic structure, the ratio thereof, and crystal direction, and a carbon material on the way to a graphitized structure of easily-graphitizable carbon. Also disclosed is a carbon material for a battery electrode, a past for an electrode, an electrode, a battery, a lithium ion secondary battery and a method of producing the graphite carbon composite material.

Graphite carbon composite material, carbon material for battery electrodes, and batteries

A graphite composite material obtained by mixing graphite materialhaving diversity in the sizes of optical anisotropic structure and optical isotropic structure, the ratio thereof, and crystal direction, and graphite material 2 having a rhombohedron structure, which is different from graphite material 1 and has an average interplanar spacing dof plane (002) of 0.3354 nm to 0.3370 nm measured by the powder X-ray diffraction method and Lc of 100 nm or more. Also disclosed is a carbon material for a battery electrode, a paste for an electrode, an electrode, a battery, a lithium ion secondary battery and a method of producing the graphite composite material.

Graphite material, carbon material for battery electrodes, and batteries

A method for producing a graphite material for lithium ion batteries, including a step for exothermically graphitizing a carbon material by directly applying an electric current therethrough. The carbon material is obtained by heating at a temperature in the range of 800&#xb0; C.-1500&#xb0; C. inclusive and subsequently pulverizing an organic carbon starting material, has a compact powder resistivity of 0.3 &#x3a9; cm or less when compressed to a density of 1.4 g/cm, has an angle of repose in the range of 20&#xb0; to 50&#xb0; inclusive, and has a particle size (D90) in the volume-based particle size distribution measured using laser diffraction of 120 &#x3bc;m or less. The average surface interval (d002) of a surface (002) of the carbon material after graphitization, measured using x-ray diffraction, is in the range of 0.3354 nm-0.3450 nm inclusive.

Provided are a graphite material suitable as an electrode material for nonaqueous electrolyte secondary batteries, a carbonaceous material for battery electrodes, and secondary batteries which exhibit excellent charge-discharge cycle characteristics and excellent severe-current-load characteristics. A graphite material which has specific sizes of optically anisotropic and isotropic structures, a specific content ratio between both structures, and various orientation of crystallization; and a carbonaceous material for battery electrodes which is made using the graphite material and which exhibits a large discharge capacity and a small irreversible capacity with the severe-current-load characteristics and cycle characteristics being kept at high levels.

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Tokyo, Japan

Yoshiyuki Nishimura