Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-9780343-B2
Application number	US-201514599095-A
Country	US
Kind code	B2
Filing date	Jan 16, 2015
Priority date	Jan 21, 2014
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

Provided is a nonaqueous electrolyte secondary battery including a bottomed cylindrical positive electrode casing, and a negative electrode casing which is fixed to an opening of the positive electrode casing through a gasket. The opening of the positive electrode casing is caulked to the negative electrode casing side to seal an accommodation space. A caulking tip end in the opening of the positive electrode casing is disposed in an inward direction of the negative electrode casing than a tip end of the negative electrode casing. A diameter d of the nonaqueous electrolyte secondary battery is in a range of 4 mm to 12 mm, a height h 1 of the nonaqueous electrolyte secondary battery is in a range of 1 mm to 3 mm, a side surface portion of the positive electrode casing is formed in a curved surface shape, a radius of curvature R is set in a range of 0.8 mm to 1.1 mm, and a height h 2 of the positive electrode casing is in a range of 65% to 90% with respect to the height h 1 of the nonaqueous electrolyte secondary battery.

First claim

What is claimed is:

1. A nonaqueous electrolyte secondary battery, comprising:
a bottomed cylindrical positive electrode casing; and
a negative electrode casing which is fixed to an opening of the positive electrode casing through a gasket, and forms an accommodation space between the positive electrode casing and the negative electrode casing,
wherein the opening of the positive electrode casing is caulked to the negative electrode casing side to seal the accommodation space,
the caulking is performed in such a manner that a caulking tip end in the opening of the positive electrode casing is disposed in an inward direction of the negative electrode casing than a tip end of the negative electrode casing, and
a diameter d of the nonaqueous electrolyte secondary battery is in a range of 4 mm to 12 mm, a height h 1 of the nonaqueous electrolyte secondary battery is in a range of 1 mm to 3 mm, at least a part of a side surface portion of the positive electrode casing on an opening side is formed in a curved surface shape, a radius of curvature R of the curved surface is set in a range of 0.8 mm to 1.1 mm, and a height h 2 of the positive electrode casing is in a range of 65% to 90% with respect to the height h 1 of the nonaqueous electrolyte secondary battery, wherein the radius of curvature defines a center of curvature that is located closer to a center of the battery in a diameter direction than a peripheral side wall of a side surface portion of the negative electrode casing such that the positive electrode casing presses an upper portion and the side surface portion of the negative electrode case.

2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the gasket is formed from any one of a polypropylene resin, polyphenyl sulfide (PPS), and a polyether ether ketone (PEEK) resin.

3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein a positive electrode which is provided on the positive electrode casing side and includes a lithium compound as a positive electrode active material, a negative electrode which is provided on the negative electrode casing side and includes SiO x (0≦X<2) as a negative electrode active material, a separator which is disposed between the positive electrode and the negative electrode, and an electrolytic solution which fills the accommodation space and includes at least an organic solvent and a supporting salt are accommodated in the accommodation space.

4. The nonaqueous electrolyte secondary battery according to claim 3 , wherein the positive electrode active material includes a lithium manganese oxide or a lithium titanate.

5. The nonaqueous electrolyte secondary battery according to claim 3 , wherein capacity balance (negative electrode capacity (mAh)/positive electrode capacity (mAh)), which is expressed by capacity of the negative electrode and capacity of the positive electrode, is in a range of 1.56 to 2.51.

6. The nonaqueous electrolyte secondary battery according to claim 3 , wherein the negative electrode active material includes lithium (Li) and SiO x (0≦X<2), and a molar ratio (Li/SiO x ) between lithium and SiO x is in a range of 3.9 to 4.9.

7. The nonaqueous electrolyte secondary battery according to claim 3 , wherein in the electrolytic solution, the organic solvent is a mixed solvent which contains propylene carbonate (PC) that is a cyclic carbonate solvent, ethylene carbonate (EC) that is a cyclic carbonate solvent, and dimethoxy ethane (DME) that is a chain ether solvent.

8. The nonaqueous electrolyte secondary battery according to claim 7 , wherein in the organic solvent, a mixing ratio between the propylene carbonate (PC), the ethylene carbonate (EC), and the dimethoxy ethane (DME) is (PC:EC:DME)=0.5 to 1.5:0.5 to 1.5:1 to 3 in terms of a volume ratio.

9. The nonaqueous electrolyte secondary battery according to claim 3 , wherein in the electrolytic solution, the supporting salt is lithium bis(trifluoromethane) sulfonimide (Li(CF 3 SO 2 ) 2 N).

10. The nonaqueous electrolyte secondary battery according to claim 3 , wherein the separator is formed from glass fiber.

Assignees

• Seiko Instr Inc

Inventors

• Sawayama Takumi
• Suzuki Tadahito

Classifications

• H01M50/186

  characterised by the disposition of the sealing members · CPC title

• H01M50/193

  Organic material · CPC title

• H01M2300/004

  Three solvents · CPC title

• H01M10/0427

  Button cells · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title