Separator for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery utilizing same, and manufacturing methods of same

Patent metadata

Field	Value
Publication number	US-9825268-B2
Application number	US-201314382883-A
Country	US
Kind code	B2
Filing date	Jan 25, 2013
Priority date	Mar 6, 2012
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

The separator of a nonaqueous electrolyte secondary battery is characterized by having a composite nanofiber fiber which is a nanosize fiber that contains two or more kinds of aqueous resins whose melting points are different.

First claim

The invention claimed is:

1. A separator for a nonaqueous electrolyte secondary battery, wherein
the separator has a configuration such that first nanosize fibers and second nanosize fibers cross each other,
the first nanosize fibers only contain a first aqueous resin and has a structure with a three-dimensional crossing,
the second nanosize fibers contain the first aqueous resin and a second aqueous resin that has a melting point lower than a melting point of the first aqueous resin, and
the second aqueous resin is a resin which melts at a shutdown temperature of the separator or more, and the first aqueous resin is a resin which retains fiber structure even at the shutdown temperature or more.

2. The separator for a nonaqueous electrolyte secondary battery according to claim 1 , wherein
the nanosize fiber is configured such that the second aqueous resin is shaped like islands to be distributed within the first aqueous resin.

3. The separator for a nonaqueous electrolyte secondary battery according to claim 1 , wherein
the second nanosize fiber is configured such that all or part of a surface of the first aqueous resin is coated with the second aqueous resin.

4. The separator for a nonaqueous electrolyte secondary battery according to claim 1 , wherein
a volume ratio of the second aqueous resin is 40% or more and 80% or less on such a premise that total volume of the first aqueous resin and the second aqueous resin is 100%.

5. The separator for a nonaqueous electrolyte secondary battery according to claim 4 , wherein
the volume ratio of the second aqueous resin is 50% or more.

6. A nonaqueous electrolyte secondary battery, comprising:
a separator for a nonaqueous electrolyte secondary battery according to claim 1 ;
a positive electrode; and
a negative electrode.

7. A manufacturing method of a separator for a nonaqueous electrolyte secondary battery, wherein
nanosize fibers are formed by utilizing a liquid solution, which contains a first aqueous resin and a second aqueous resin that has a melting point lower than a melting point of the first aqueous resin, by utilizing an electrospinning method, and the separator is produced by crossing the nanosize fibers.

8. A manufacturing method of a nonaqueous electrolyte secondary battery, wherein
a separator for a nonaqueous electrolyte secondary battery which is manufactured with the manufacturing method according to claim 7 , a positive electrode and a negative electrode are combined so that the nonaqueous electrolyte secondary battery is manufactured.

Assignees

• Panasonic Corp
• Panasonic Ip Man Co Ltd

Inventors

• Mikami Masateru
• Nagino Toshifumi
• Kuromiya Takao

Classifications

• H01M50/417

  Polyolefins · CPC title

• H01M50/429

  Natural polymers · CPC title

• D01D5/36

  Matrix structure; Spinnerette packs therefor · CPC title

• D01F6/46

  of polyolefins · CPC title

• H01M2/162 Primary

  Electricity · mapped topic