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:
Sep. 06, 1994
Filed:
Apr. 06, 1993
Yoshiyuki Ozaki, Neyagawa, JP;
Akiyoshi Morita, Takaishi, JP;
Junichi Yamaura, Kobe, JP;
Zenichiro Ito, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A non-aqueous electrolyte secondary cell disclosed comprises a positive electrode sheet with a lithium-containing metal oxide as major positive electrode active material, a negative electrode sheet with graphitic particles as major negative electrode coating agent, a separator and a non-aqueous electrolyte, wherein the negative electrode sheet is produced by mixing the major graphitic particles, a binder and the like to produce a paste, coating the paste on both sides of a collector, pressing the coated collector, the coating layer having a porosity of 25% to 40%, and the graphitic particles have an average particle size of 3 .mu.m to 25 .mu.m which are produced by heat-treating a pitch in the molten state to produce carbonaceous mesophase particles, extracting the mesophase particles, carbonizing the mesophase particles and then heat-treating the carbonized particles through graphitization at 2500.degree. C. to 2900.degree. C. and which have a lattice plane spacing (d002) of 3.36 .ANG. to 3.39 .ANG., a crystal size in the direction of the C axis (Lc) of 200 .ANG. to 650 .ANG., as determined by X-ray diffraction analysis, and a ratio in intensity of the peak at 1360 cm.sup.-1 to that at 1580 cm.sup.-1 of 0.20 to 0.40 as determined by Argon laser-Raman spectrometry.