The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 2010
Filed:
Jan. 24, 2003
Naoto Ohta, Kagawa, JP;
Katsuhide Nagaoka, Kagawa, JP;
Kazuhito Hoshi, Kagawa, JP;
Hidehiko Nozaki, Kagawa, JP;
Tetsuro Tojo, Kagawa, JP;
Toshiaki Sogabe, Kagawa, JP;
Naoto Ohta, Kagawa, JP;
Katsuhide Nagaoka, Kagawa, JP;
Kazuhito Hoshi, Kagawa, JP;
Hidehiko Nozaki, Kagawa, JP;
Tetsuro Tojo, Kagawa, JP;
Toshiaki Sogabe, Kagawa, JP;
Toyo Tanso Co., Ltd., Osaka-shi, JP;
Abstract
The invention provides an anode material for lithium ion secondary battery using a coated graphite powder as a raw material, which is coated thermoplastic resin of a carbonization yield of ≦20 wt % in a proportion of ≦10 parts by weight the carbonized material per 100 parts by weight graphite powder. Coating with thermoplastic resin increases the accumulative pore volume by ≦5%, relative to the uncoated powder, and results in pore sizes of 0.012-40 μm via mercury porosimeter method. Calculated with the BJH method as viewed from desorption isotherm, the coated graphite powder has a mesopore volume ≦0.01 cc/g or ≦60% of the pore volume of the uncoated graphite powder. This coated powder also has an average particle size ranging from 10-50 μm measured by a laser-scattering-particle-size-distribution measuring device, and a standard deviation to the average particle size (σ/D) ratio of ≦0.02.