Nonaqueous electrolyte secondary battery and battery pack

Patent metadata

Field	Value
Publication number	US-10326141-B2
Application number	US-201715691935-A
Country	US
Kind code	B2
Filing date	Aug 31, 2017
Priority date	Sep 16, 2015
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

According to one embodiment, a nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The negative electrode includes a negative electrode current collector and a negative electrode mixed-material layer on the negative electrode current collector. The negative electrode mixed-material layer includes a titanium-containing metal oxide and a binder including an acrylic resin. The negative electrode satisfies α/β>1.36×10 −2 , where “α” is a peel strength (N/m) between the current collector and the negative electrode mixed-material layer, and “β” is a cutting strength (N/m) according to a surface and interfacial cutting method in the negative electrode mixed-material layer.

First claim

What is claimed is:

1. A nonaqueous electrolyte secondary battery comprising:
a positive electrode;
a negative electrode comprising a negative electrode current collector and a negative electrode mixed-material layer disposed on the negative electrode current collector, the negative electrode mixed-material layer comprising a titanium-containing metal oxide and a binder, the titanium-containing metal oxide having lithium ions inserted into and extracted from, the binder comprising an acrylic resin, and the negative electrode satisfying equation (I); and
a nonaqueous electrolyte:
α/β>1.36×10 −2   (I),

where “α” represents a peel strength (N/m) between the negative electrode current collector and the negative electrode mixed-material layer, and “β” represents a cutting strength (N/m) as measured according to a surface and interfacial cutting method in the negative electrode mixed-material layer.

2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode further satisfies equation (II):
α/β<4.9×10 −2   (II).

3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the peel strength α ranges from 2.5 N/m to 27 N/m.

4. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the acrylic resin includes a nitrile group.

5. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the acrylic resin includes a polymer of the acrylic resin, a copolymer of the acrylic resin, or both the polymer of the acrylic resin and the copolymer of the acrylic resin.

6. A battery pack comprising the nonaqueous electrolyte secondary battery according to claim 1 .

7. The battery pack according to claim 6 , further comprising:
an external power distribution terminal; and
a protective circuit.

8. The battery pack according to claim 6 , wherein the battery pack comprises a plural of the nonaqueous electrolyte secondary battery, the plural of nonaqueous electrolyte secondary battery being electrically connected in series, in parallel, or in a combination of in series and in parallel.

9. A vehicle comprising the battery pack according to claim 6 .

10. The vehicle according to claim 9 , wherein the battery pack is disposed in an engine compartment of the vehicle.

11. A negative electrode comprising:
a negative electrode current collector; and
a negative electrode mixed-material layer disposed on the negative electrode current collector, the negative electrode mixed-material layer comprising a titanium-containing metal oxide and a binder, the titanium-containing metal oxide having lithium ions inserted into and extracted from, and the binder comprising an acrylic resin, wherein
the negative electrode satisfies equation (I):
α/β>1.36×10 −2   (I),

where “α” represents a peel strength (N/m) between the negative electrode current collector and the negative electrode mixed-material layer, and “β” represents a cutting strength (N/m) as measured according to a surface and interfacial cutting method in the negative electrode mixed-material layer.

12. The negative electrode according to claim 11 , wherein the negative electrode further satisfies equation (II):
α/β<4.9×10 −2   (II).

13. The negative electrode according to claim 11 , wherein the peel strength α ranges from 2.5 N/m to 27 N/m.

14. The negative electrode according to claim 11 , wherein the acrylic resin includes a nitrile group.

15. The negative electrode according to claim 11 , wherein the acrylic resin includes a polymer of the acrylic resin, a copolymer of the acrylic resin, or both the polymer of the acrylic resin and the copolymer of the acrylic resin.

16. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode current collector further comprises an undercoat layer on a surface thereof.

17. The negative electrode according to claim 11 , wherein the negative electrode current collector further comprises an undercoat layer on a surface thereof.

18. The nonaqueous electrolyte secondary battery according to claim 16 , wherein the undercoat layer comprises a carbon material and a resin, and the resin is fluorine-based resin, polyacrylic acid, acrylic resin, polyolefin resin, polyimide, polyamide, or polyamidemide.

19. The negative electrode according to claim 17 , wherein the undercoat layer comprises a carbon material and a resin, and the resin is fluorine-based resin, polyacrylic acid, acrylic resin, polyolefin resin, polyimide, polyamide, or polyamidemide.

Assignees

• Toshiba Kk

Inventors

• Isozaki Yoshiyuki
• Takami Norio
• Hoshina Keigo
• Ishibashi Mitsuru
• Yamashita Yasunobu

Classifications

• H01M50/211

  adapted for pouch cells · CPC title

• H01M50/296

  characterised by terminals of battery packs (terminals of batteries H01M50/543) · CPC title

• C08K3/00

  Use of inorganic substances as compounding ingredients · CPC title

• C09D133/20

  Homopolymers or copolymers of acrylonitrile (C09D155/02 takes precedence) · CPC title

• H01M4/48

  of inorganic oxides or hydroxides · CPC title