# US 5,344,724 A · Non-aqueous electrolyte secondary cell

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- Number: US 5,344,724 A
- Document ID: US5344724A
- Status: Granted
- Kind: A
- Application number: 08/042,794
- Filed: 1993-04-06
- Granted: 1994-09-06
- Earliest claimed: 1992-04-10
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Yoshiyuki Ozaki; Akiyoshi Morita; Junichi Yamaura; Zenichiro Ito
- Web page: https://patentgrep.com/patent/US5344724A

## CPC

- H01M 4/587: for inserting or intercalating light metals
- H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 6/10: with wound or folded electrodes
- H01M 6/164: {by the solvent}
- H01M 10/0585: of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
- H01M 10/0587: of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
- H01M 50/103: prismatic or rectangular (H01M50/109, H01M50/11 take precedence)
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## 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.

## Claims

### Claim 1

A non-aqueous electrolyte secondary cell comprising a sheet type positive electrode plate with a lithium-containing metal oxide as a major positive electrode active material, a sheet type negative electrode plate with graphitic particles as a major negative electrode coating agent, a separator and a non-aqueous electrolyte, wherein;
said negative electrode plate is produced by adding to the graphitic particles as a major component a binder to produce a paste, coating the paste on both sides of a metal foil collector, pressing the coated collector to produce a sheet type electrode plate, said coating layer having a porosity of 25% to 40%; and
said graphitic particles are produced by heat-treating a pitch in the molten state to produce carbonaceous mesophase particles, extracting and separating the particles as precursor, carbonizing the mesophase particles and then heat-treating the carbonized particles through graphitization at 2500.degree. C. to 2900.degree. C.

### Claim 2 (depends on 1)

The non-aqueous electrolyte secondary cell according to claim 1, wherein said graphitic particles have an average particle size of 3 .mu.m to 25 .mu.m.

### Claim 3 (depends on 1)

The non-aqueous electrolyte secondary cell according to claim 1, wherein said graphitic particles 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.

### Claim 4 (depends on 1)

The non-aqueous electrolyte secondary cell according to claim 1, wherein said graphitic particles are spherical particles of mesocarbon microbeads.

### Claim 5

A non-aqueous electrolyte secondary cell comprising a sheet type positive electrode plate with a lithium-containing metal oxide as a major positive electrode active material, a sheet type negative electrode plate with graphitic particles as a major negative electrode coating agent, a separator and a non-aqueous electrolyte, wherein;
said negative electrode plate is produced by adding to the graphitic particles as a major component a binder to produce a paste, coating the paste on both sides of a metal foil collector, pressing the coated collector to produce a sheet type electrode plate, said coating layer having a porosity of 25% to 40%;
said graphitic particles are produced by heat-treating a pitch in the molten state to produce carbonaceous mesophase particles, extracting and separating the particles as precursor, carbonizing the mesophase particles and then heat-treating the carbonized particles through graphitization at 2500.degree. C. to 2900.degree. C.; and characterized by:
having an average particle size of 3 .mu.m to 25 .mu.m,
b) having a lattice plane spacing (d002) of 3.36 .ANG. to 3.39 .ANG., as determined by X-ray diffraction analysis, and
c) having 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.

### Claim 6 (depends on 5)

The non-aqueous electrolyte secondary cell according to claim 5, wherein said positive electrode plate and said negative electrode plate have a thickness of 120 .mu.m to 350 .mu.m, respectively.

### Claim 7 (depends on 6)

The non-aqueous electrolyte secondary cell according to claim 6, wherein said cell is a cylindrical cell containing an electrode plate assembly which is produced by rolling a rectangular positive electrode plate and a rectangular negative electrode plate in the spiral form with a separator being interposed therebetween.

### Claim 8 (depends on 6)

The non-aqueous electrolyte secondary cell according to claim 6, wherein said cell is a prismatic type cell containing an electrode plate assembly which is produced by rolling a rectangular positive electrode plate and a rectangular negative electrode plate in the spiral form with a separator being interposed therebetween and then compressing the roll into an ellipse form.

### Claim 9 (depends on 6)

The non-aqueous electrolyte secondary cell according to claim 6, wherein said cell is a prismatic type cell containing an electrode plate assembly which is produced by stacking a plurality of positive and negative electrode plates in a laminate form.