Matsushita Electric Industrial Co., Ltd.

Zenichiro Ito

Yoshiyuki Ozaki

Junichi Yamaura

Akiyoshi Morita

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.

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Hirakata, Japan

Zenichiro Ito