IP Library Granted Patent US 9,923,239
Granted Patent B2
US 9,923,239 · App. 14/118,288 · Granted Mar 20, 2018

Lithium ion battery

Inventor: Takeshi Azami (Kanagawa, JP)
Assignee: NEC ENERGY DEVICES, LTD.
H01M10/0567H01M4/133H01M4/587H01M4/621H01M4/625H01M10/0525H01M2004/021Y02T10/7011
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Quick Facts
Patent No.
US 9,923,239
App. No.
14/118,288
Granted
Mar 20, 2018
Kind
B2
Abstract

The purpose of the present invention is to provide a lithium-ion battery that exhibits excellent long-term life properties, does not suffer from rapid capacity degradation, and exhibits excellent charging/discharging characteristics in low-temperature environments. The present invention is directed to a lithium ion battery comprising: a negative electrode which comprises a negative electrode active material containing at least one of a graphite and an amorphous carbon, conductive additives containing a graphite, and a binder; a nonaqueous electrolyte solution; and a positive electrode containing a positive electrode active material capable of occluding and releasing lithium. The negative electrode active material has a spherical or massive shape, the conductive additives have a platy shape, and a part of an edge surface of the conductive additives contacts a surface of the negative electrode active material. The nonaqueous electrolyte solution contains a solvent, and an additive which reductively decomposes at a voltage lower than a reduction voltage of the solvent.

Claims (19)

1. A lithium ion battery comprising:

a negative electrode including a negative electrode active material containing at least one of a graphite and an amorphous carbon, a conductive additive, and a binder;

a nonaqueous electrolyte solution; and

a positive electrode including a positive electrode active material capable of occluding and releasing lithium,

wherein the negative electrode active material has a particulate shape;

the conductive additive comprises a platy graphite with a Raman peak intensity ratio I G /I D of 6-12, wherein the I G is an intensity of a peak in a G band near 1,580 cm −1 to 1,600 cm −1 corresponding to the in-plane vibration mode and the I D is an intensity of a peak in a D band near 1360 cm −1 derived from in-plane defects, and a thickness of 0.05 μm or larger and less than 0.1 μm,

at least a part of an edge surface of the conductive additive contacts with a surface of the negative electrode active material, and

the nonaqueous electrolyte solution contains a solvent, and an additive which reductively decomposes at a voltage lower than a reduction voltage of the solvent.

2. The lithium ion battery according to claim 1 , wherein the nonaqueous electrolyte solution comprises a cyclic sulfonate ester or a chain sulfonate ester including two sulfonyl groups, as the additive.

3. The lithium ion battery according to claim 1 , wherein the nonaqueous electrolyte solution comprises a cyclic sulfonate ester including two sulfonyl groups and being represented by the following formula (1), as the additive:

wherein in the formula (1), Q represents an oxygen atom, a methylene group or a single bond; A represents a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, a carbonyl group, a sulfinyl group, a substituted or unsubstituted fluoroalkylene group having 1 to 6 carbon atoms, or a divalent group having 2 to 6 carbon atoms to which an alkylene unit or a fluoroalkylene unit is bonded through an ether bond; and B represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted fluoroalkylene group or an oxygen atom.

4. The lithium ion battery according to claim 1 , wherein the nonaqueous electrolyte solution comprises a chain sulfonate ester including two sulfonyl groups and being represented by the following formula (2), as the additive:

wherein in the formula (2), X represents an alkylene group having 1 to 6 carbon atoms; and R represents an alkyl group having 1 to 6 carbon atoms, and two Rs may be the same group or different groups.

5. The lithium ion battery according to claim 1 , wherein D 50s /D 50a , being a ratio of an average particle diameter D 50s of the negative electrode active material to an average particle diameter D 50a of the conductive additive, is 3 or higher and 10 or lower.

6. The lithium ion battery according to claim 1 , wherein a content of the conductive additive in a negative electrode mixture of the negative electrode is 2.0 mass % or higher and 10 mass % or lower.

7. The lithium ion battery according to claim 4 , wherein the chain sulfonate represented by the formula (2) is represented by the following formula (3):

8. The lithium ion battery according to claim 1 , wherein a specific surface area of the conductive additive is 10 m 2 /g or larger and 40 m 2 /g or smaller.

9. The lithium ion battery according to claim 1 , wherein the positive electrode active material comprises manganese spinel (LiMn 2 O 4 ).

10. The lithium ion battery according to claim 1 , wherein the positive electrode active material comprises a carbon black.

Assignments (4)
RELEASE OF SECURITY INTEREST Recorded Oct 28, 2024
From: SUMITOMO MITSUI BANKING CORPORATION, AS SECURITY AGENT
To: ENVISION AESC JAPAN LTD.; ENVISION AESC ENERGY DEVICES LTD.
Reel/Frame 069461/0179 →
SECURITY AGREEMENT SUPPLEMENT Recorded Jul 2, 2019
From: ENVISION AESC ENERGY DEVICES, LTD.
To: SUMITOMO MITUSI BANKING CORPORATION, AS SECURITY AGENT
Reel/Frame 049649/0924 →
CHANGE OF NAME Recorded Jun 21, 2019
From: NEC ENERGY DEVICES, LTD.
To: ENVISION AESC ENERGY DEVICES, LTD.
Reel/Frame 049556/0123 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 18, 2013
From: AZAMI, TAKESHI
To: NEC ENERGY DEVICES, LTD.
Reel/Frame 031623/0461 →
Priority Claims (1)
JP 2011-155737 · Jul 14, 2011 · national
Continuity (1)
Related Publication 20140087249A1 · Mar 27, 2014