Negative electrode material for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery using the same

• US 8,920,977 B2
• Filed: 09/23/2011
• Issued: 12/30/2014
• Est. Priority Date: 03/27/2009
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: Kameda, Takashi, Sato, Hideharu
• Primary Examiner(s): Takeuchi, Yoshitoshi
• Application Number:
  US13/241,384
• Publication Number:
  US 20120052393A1
• Time in Patent Office: 1,194 Days
• Field of Search: None
• US Class Current: 429/231.8
• CPC Class Codes: C01B 32/21 After-treatment
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/82 by IR- or Raman-data
• CPC Class Codes: C01P 2004/32 Spheres
• CPC Class Codes: C01P 2006/11 Powder tap density
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A negative electrode material for a nonaqueous electrolyte secondary battery, where the negative electrode contains a carbon material A and a carbon material B. Carbon material A is a multilayer-structure carbon material containing a graphitic particle having an amorphous carbon surface covering, where the interplaner spacing of 002 planes, by wide-angle XRD, is 3.37 Å or less, Lc is 900 Å or more, the tap density is 0.8 g/cm³ or more, and the Raman R value is from 0.25 to 0.6. Carbon material B is a graphitic particle where the interplanar spacing of 002 planes, by wide-angle XRD, is 3.37 Å or less, Lc is 900 Å or more, the tap density is 0.8 g/cm³ or more, the Raman R value is from 0.2 to 0.5, and the average degree of circularity, determined by a flow-type particle analyzer, is 0.9 or more.

Claims

1. A negative electrode material for nonaqueous electrolyte secondary battery, comprising a carbon material (A) and a carbon material (B),

wherein the carbon material (A) is a multilayer-structure carbon material comprising a graphitic particle and an amorphous carbon covering the surface of the graphitic particle, and wherein the carbon material (A) has:

an interplanar spacing (d002) of 002 planes by the wide-angle X-ray diffraction method of 3.37 Å

or less;

a crystallite size (Lc) of 900 Å

or more;

a tap density of 0.8 g/cm³ or more; and

a Raman R value, as a ratio of a peak intensity near 1,360 cm<sup>−

1</sup> to a peak intensity near 1,580 cm<sup>−

1</sup> in the argon ion laser Raman spectrum, from 0.25 to 0.6, and

wherein the carbon material (B), which is not a multilayer-structure carbon material, comprises a graphitic particle, and wherein the carbon material (B) has;

an interplanar spacing (d002) of 002 planes by the wide-angle X-ray diffraction method of 3.37 Å

or less;

a crystallite size (Lc) of 900 Å

or more;

a tap density of 0.8 g/cm³ or more;

a Raman R value, as a ratio of a peak intensity near 1,360 cm<sup>−

1</sup> to a peak intensity near 1,580 cm<sup>−

1</sup> in the argon ion laser Raman spectrum, from 0.2 to 0.5; and

an average degree of circularity, as determined by a flow-type particle analyzer, of 0.9 or more.

2. The negative electrode material of claim 1, wherein a ratio in the average particle diameter between the carbon material (A) and the carbon material (B) (average particle diameter of carbon material (A)/average particle diameter of carbon material (B)) is from 0.7 to 1.3.

3. The negative electrode material of claim 1, wherein a ratio of the carbon material (B) is from 30 to 70 wt %, based on a total amount of the carbon material (A) and the carbon material (B).

4. The negative electrode material of claim 1, wherein in the graphitic particle employed for the carbon material (A) has:

an interplanar spacing (d002) of 002 planes by the wide-angle X-ray diffraction method of 3.37 Å

or less;

a crystallite size (Lc) of 900 Å

or more;

a tap density of 0.8 g/cm³ or more; and

a Raman R value, as a ratio of a peak intensity near 1,360 cm<sup>−

1</sup> to a peak intensity near 1,580 cm<sup>−

1</sup> in the argon ion laser Raman spectrum, from 0.2 to 0.5.

5. The negative electrode material of claim 1, having a tap density of 0.8 g/cm³ or more.

6. The negative electrode material of claim 1, wherein the carbon material (B) has a true density of 2.21 g/cm³ or more.

7. The negative electrode material of claim 1, wherein a specific surface area of the carbon material (A) is from 0.5 to 8 m²/g.

8. The negative electrode material of claim 1, wherein the average degree of circularity of the graphitic particle employed for the carbon material (A), as determined by a flow-type particle analyzer, is 0.88 or more.

9. The negative electrode material of claim 1, wherein the pore volumes in the range of 10 to 100,000 nm of the carbon material (A) and the carbon material (B), as measured by the mercury intrusion method, are 0.4 ml/g or more.

10. The negative electrode material of claim 1, wherein an average particle diameter of the carbon material (A) is from 2 to 30 μ

m.

11. A negative electrode for nonaqueous electrolyte secondary battery, comprising:

a current collector; and

a negative electrode layer disposed on the current collector,

wherein the negative electrode layer comprises the negative electrode material of claim 1 and a binder resin.

12. A nonaqueous electrolyte secondary battery, comprising:

the negative electrode of claim 11;

a positive electrode, which stores and releases lithium ion; and

a nonaqueous electrolytic solution.

13. The negative electrode material of claim 1, wherein a ratio of the carbon material (B) is from 10 to 90 wt %, based on a total amount of the carbon material (A) and the carbon material (B).

14. The negative electrode material of claim 1, wherein the ratio in the average particle diameter between the carbon material (A) and the carbon material (B) is from 0.8 to 1.2.

15. The negative electrode material of claim 1, wherein a ratio of the carbon material (B) is from 30 to 50 wt %, based on a total amount of the carbon material (A) and the carbon material (B).

16. The negative electrode material of claim 1, wherein in the graphitic particle employed for the carbon material (A) has:

an interplanar spacing (d002) of 002 planes by the wide-angle X-ray diffraction method of 3.36 Å

or less;

a crystallite size (Lc) of 950 Å

or more;

a tap density of 0.85 g/cm³ or more; and

a Raman R value, as a ratio of a peak intensity near 1,360 cm<sup>−

1</sup> to a peak intensity near 1,580 cm<sup>−

1</sup> in the argon ion laser Raman spectrum, from 0.25 to 0.5.

17. The negative electrode material of claim 5, having a tap density of 0.85 g/cm³ or more.

18. The negative electrode material of claim 6, wherein the true density of the carbon material (B) is 2.23 g/cm³ or more.

19. The negative electrode material of claim 7, wherein the specific surface area of the carbon material (A) is from 1 to 6 m²/g.

20. The negative electrode material of claim 9, wherein the pore volumes in the range of 10 to 100,000 nm of the carbon material (A) and the carbon material (B), as measured by the mercury intrusion method, are 0.5 ml/g or more.