Hitachi Chemical Company, Ltd.

Hitachi Maxell, Limited

Hidetoshi Honbou

Yoshito Ishii

Akihide Tanaka

Norio Iwayasu

Yuki Okuda

Yuriko Ida

Nobushige Nakamura

Keiji Okabe

An anode material for a lithium ion secondary battery that includes a carbon material having an average interlayer spacing das determined by X-ray diffraction of from 0.335 nm to 0.340 nm, a volume average particle diameter (50% D) of from 1 &#x3bc;m to 40 &#x3bc;m, a maximum particle diameter Dof 74 &#x3bc;m or less, and at least two exothermic peaks within a temperature range of from 300&#xb0; C. to 1000&#xb0; C. in a differential thermal analysis in an air stream.

Anode material for lithium ion secondary battery, anode for lithium ion secondary battery, and lithium ion secondary battery

Provided is a lithium ion rechargeable battery less suffering from swelling even when stored at high temperatures. Disclosed are a cathode active material, a cathode for a lithium ion rechargeable battery using the cathode active material, and a lithium ion rechargeable battery using the cathode. The cathode active material includes particles, each of the particles including a cathode material capable of intercalating and deintercalating lithium ions, and a film formed on at least part of surfaces of the particles. The film includes a compound represented by Chemical Formula (1). Examples of the compound represented by Chemical Formula (1) include lithium squarate and dilithium squarate. Preferably, the lithium ion rechargeable battery is a prismatic battery.

Cathode active material and lithium ion rechargeable battery using the material

The present invention is to provide a lithium ion secondary battery that realizes to raise an initial charge and discharge efficiency without deteriorating its charge and discharge characteristic in comparison with the conventional technology. A carbon material and a lithium ion secondary battery using the carbon material as the anode material, wherein the face interval dof the carbon material determined by an X ray diffraction apparatus is not less than 0.340 nm and not more than 0.370 nm, and further, V/Vrepresenting a ratio of a volume Vof pores having diameters from not less than 1 nm to less than 10 nm in the carbon material with respect to a volume Vof pores having diameters from not less than 10 nm to less than 100 nm therein is not more than 0.2.

Anode material for lithium secondary batteries and lithium secondary batteries

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Hitachinaka, Japan

Hidetoshi Honbou