Separator for a non-aqueous secondary battery and non-aqueous secondary battery

Patent metadata

Field	Value
Publication number	US-10115948-B2
Application number	US-201214352851-A
Country	US
Kind code	B2
Filing date	Oct 19, 2012
Priority date	Oct 21, 2011
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

The present invention provides a separator for a non-aqueous secondary battery including a porous substrate, and an adhesive porous layer that is formed at one or both sides of the porous substrate, that contains polyvinylidene fluoride resin A and polyvinylidene fluoride resin B, and that has a porosity of from 30% to 60% and an average pore size of from 20 nm to 100 nm.

First claim

The invention claimed is:

1. A separator for a non-aqueous secondary battery, comprising:
a porous substrate, and
an adhesive porous layer that is coated on one side or both sides of the porous substrate, contains (1) the following polyvinylidene fluoride resin A and (2) the following polyvinylidene fluoride resin B, and has a porosity of from 30% to 52% and an average pore size of from 36 nm to 100 nm:
(1) polyvinylidene fluoride resin A selected from the group consisting of vinylidene fluoride homopolymers, and vinylidene fluoride copolymers containing structural units derived from vinylidene fluoride and structural units derived from hexafluoropropylene, a total content of structural unit derived from hexafluoropropylene in each of the vinylidene fluoride copolymers being 1.5 mol % or less of a total content of structural unit in each of the vinylidene fluoride copolymers; and
(2) polyvinylidene fluoride resin B selected from the group consisting of vinylidene fluoride copolymers containing a structural unit derived from vinylidene fluoride and a structural unit derived from hexafluoropropylene, a total content of structural unit derived from hexafluoropropylene in each of the vinylidene fluoride copolymers being greater than 1.5 mol % of a total content of structural unit in each of the vinylidene fluoride copolymers,
wherein, in the adhesive porous layer, a content of the polyvinylidene fluoride resin A is from 15 parts by mass to 40 parts by mass, and a content of the polyvinylidene fluoride resin B from 60 parts by mass to 85 parts by mass, when a total amount of the polyvinylidene fluoride resin A and the polyvinylidene fluoride resin B is taken as 100 parts by mass.

2. The separator for a non-aqueous secondary battery according to claim 1 , wherein the adhesive porous layer has an average pore size of from 36 nm to 70 nm.

3. The separator for a non-aqueous secondary battery according to claim 1 , wherein an amount per unit area of the adhesive porous layer at one side of the porous substrate is from 0.5 g/m 2 to 1.5 g/m 2 .

4. The separator for a non-aqueous secondary battery according to claim 1 , wherein the value obtained by subtracting the Gurley value of the porous substrate from the Gurley value of the separator provided with an adhesive porous layer is 300 sec/100 cc or less.

5. The separator for a non-aqueous secondary battery according to claim 1 , wherein the polyvinylidene fluoride resin A consists of structural units derived from vinylidene fluoride and structural units derived from hexafluoropropylene, and the polyvinylidene fluoride resin B consists of a structural unit derived from vinylidene fluoride and a structural unit derived from hexafluoropropylene.

6. The separator for a non-aqueous secondary battery according to claim 1 , wherein
the polyvinylidene fluoride resin A and the polyvinylidene fluoride resin B are bound together to form a porous structure by being dissolved and blended together in a state in which the polyvinylidene fluoride resin A and the polyvinylidene fluoride resin B are in a solvent.

7. A non-aqueous secondary battery comprising a positive electrode, a negative electrode, and the separator for a non-aqueous secondary battery according to claim 1 , the separator being disposed between the positive electrode and the negative electrode, wherein, in the non-aqueous secondary battery, electromotive force is obtained by lithium doping/dedoping.

Assignees

• Teijin Ltd

Inventors

• Nishikawa Satoshi
• Yoshitomi Takashi
• Otsuka Atsuhiro
• Iwai Ayumi

Classifications

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/426 Primary

  Fluorocarbon polymers · CPC title

• H01M50/491

  Porosity · CPC title