# US 2014/0154579 A1 · Lithium ion secondary battery

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- Number: US 2014/0154579 A1
- Document ID: US20140154579A1
- Status: Published application
- Kind: A1
- Application number: 14/234,748
- Filed: 2011-07-29
- Published: 2014-06-05
- Earliest claimed: 2011-07-29
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Inventors: Koji Takahata; Machiko Abe
- Web page: https://patentgrep.com/patent/US20140154579A1

## CPC

- H01M 4/583: Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/0404: {by coating on electrode collectors}
- H01M 4/1393: of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/366: {as layered products}
- H01M 4/587: for inserting or intercalating light metals
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- 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
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A lithium ion secondary battery 100A has negative electrode active material particles 710A which include graphite particles that are at least partially covered by an amorphous carbon film 750. The negative electrode, active material particles 710A have a TG weight-loss-on-heating onset temperature T1 which satisfies the condition 500° C.≦T1≦615° C. and a micro-Raman G-band half-width Gh which satisfies the condition 20≦Gh≦28. This configuration makes it possible to obtain a lithium ion secondary battery 100A in which the reaction resistance in a low-temperature environment can be kept low.

## Claims

### Claim 1

A lithium ion secondary battery, comprising:
negative electrode active material particles comprising graphite particles and being at least partially covered by an amorphous carbon film, wherein,
the negative electrode active material particles have a TG weight-loss-on-heating onset temperature T1 that satisfies the condition 500° C.≦T1≦615° C. and have a micro-Raman G-band half-width Gh that satisfies the condition 20≦Gh≦28.

### Claim 2 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein
the negative electrode active material particles have a linseed oil absorption F that satisfies the condition F≧50 mL/100 g.

### Claim 3 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein
the negative electrode active material particles have a linseed oil absorption F that satisfies the condition F≦64 mL/100 g.

### Claim 4

A method for manufacturing a lithium ion secondary battery, the method comprising:
step A of preparing negative electrode active material particles comprising graphite particles that are at least partially covered by an amorphous carbon film, having a TG weight-loss-on-heating onset temperature T1 that satisfies the condition 500° C.≦T1≦615° C., and having a micro-Raman G-band half-width Gh that satisfies the condition 20≦Gh≦28;
step B of forming a negative electrode mixture of the negative electrode active material particles and a binder mixed together in a solvent; and
step C of coating the negative electrode mixture onto at negative electrode current collector so as to form a negative electrode active material layer on the negative electrode current collector.

### Claim 5 (depends on 4)

The method according to claim 4, wherein the negative electrode active material particles have a linseed oil absorption F which satisfies the condition F≧50 mL/100 g.

### Claim 6 (depends on 4)

The method according to claim 4, wherein the negative electrode active material particles have a linseed oil absorption F which satisfies the condition F≦64 mL/100 g.

### Claim 7 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the amorphous carbon film in the negative electrode active material particles has a weight ratio X that satisfies the condition 0.01≦X≦0.10.

### Claim 8 (depends on 4)

The method according to claim 4, wherein the amorphous carbon film in the negative electrode active material particle has a weight ratio X that satisfies the condition 0.01≦X≦0.10.