SEPARATOR FOR NON-AQUEOUS SECONDARY BATTERY AND NON-AQUEOUS SECONDARY BATTERY

• US 20150263325A1
• Filed: 10/25/2013
• Published: 09/17/2015
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: Semcorp Global Holdings KFT, Teijin Limited
• Original Assignee: Teijin Limited
• Inventors: Honda, Susumu, Yoshitomi, Takashi, Nishikawa, Satoshi
• Granted Patent: US 10,074,840 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 50/414 Synthetic resins, e.g. thermoplastics or thermosetting resins
• CPC Class Codes: H01M 50/434 Ceramics
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/446 Composite material consisting of a mixture of organic and inorganic materials
• CPC Class Codes: H01M 50/451 comprising layers of only organic material and layers containing inorganic material
• CPC Class Codes: H01M 50/457 comprising three or more layers
• CPC Class Codes: H01M 50/489 Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Provided is a separator for a non-aqueous secondary battery, including: a porous substrate, and a heat resistant porous layer that is provided on one side or both sides of the porous substrate, that is an aggregate of resin particles and an inorganic filler, and that satisfies the following expression (1). In expression (1), Vf is a volume proportion (% by volume) of the inorganic filler in the heat resistant porous layer, and CPVC is a critical pigment volume concentration (% by volume) of the inorganic filler. Also provided is a separator for a non-aqueous secondary battery, including: a porous substrate, a heat resistant porous layer that is provided on one side or both sides of the porous substrate, that includes a resin and an filler, and that satisfies the following expression (2), and an adhesive porous layer that is provided on both sides of a stacked body of the porous substrate and the heat resistant porous layer, and that includes an adhesive resin. In expression (2), Vf is a volume proportion (% by volume) of the filler in the heat resistant porous layer, and CPVC is a critical pigment volume concentration (% by volume) of the filler.

0.65≦Vf/CPVC≦0.99  expression (1)

0.40≦Vf/CPVC≦0.99  expression (2)

Claims

1. A separator for a non-aqueous secondary battery, comprising:

a porous substrate, and

a heat resistant porous layer that is provided on one side or both sides of the porous substrate, that is an aggregate of resin particles and an inorganic filler, and that satisfies the following expression (1);

0.65≦

Vf/CPVC≦

0.99 

 

expression (1)

wherein, in expression (1), Vf is a volume proportion (% by volume) of the inorganic filler in the heat resistant porous layer, and CPVC is a critical pigment volume concentration (% by volume) of the inorganic filler.

2. The separator for a non-aqueous secondary battery according to claim 1, wherein the heat resistant porous layer has a porosity of from 40% to 70%.

3. The separator for a non-aqueous secondary battery according to claim 2, wherein a product, of the porosity of the heat resistant porous layer and Vf/CPVC, is from 40% to 60%.

4. The separator for a non-aqueous secondary battery according to claim 1, wherein a content of the inorganic filler in the heat resistant porous layer is from 2.0 g/m² to 20.0 g/m².

5. The separator for a non-aqueous secondary battery according to claim 1, wherein the critical pigment volume concentration of the inorganic filler is from 20% by volume to 70% by volume.

6. The separator for a non-aqueous secondary battery according to claim 1, wherein:

the porous substrate includes a thermoplastic resin, and

in a case in which the separator for a non-aqueous secondary battery is heated at a rate of temperature increase of 5°

C./min. to a flow elongation deformation temperature of the thermoplastic resin, the separator for a non-aqueous secondary battery exhibits a thermal dimensional change ratio in a longitudinal direction of 3% or less and a thermal dimensional change ratio in a width direction of 3% or less.

7. The separator for a non-aqueous secondary battery according to claim 1, wherein, in a case in which the separator for a non-aqueous secondary battery is subjected to a heat treatment at 150°

C. for 30 minutes, the separator for a non-aqueous secondary battery exhibits a thermal shrinkage ratio in a longitudinal direction of 3% or less and a thermal shrinkage ratio in a width direction of 3% or less.

8. The separator for a non-aqueous secondary battery according to claim 1, wherein the resin particles include a polyvinylidene fluoride resin.

9. The separator for a non-aqueous secondary battery according to claim 1, wherein the inorganic filler is magnesium hydroxide or magnesium oxide.

17. The separator for a non-aqueous secondary battery according to claim 1, wherein the heat resistant porous layer further comprises a thickener.

18. 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, which is disposed between the positive electrode and the negative electrode,

wherein, in the non-aqueous secondary battery, an electromotive force is obtained by lithium doping/dedoping.

10. A separator for a non-aqueous secondary battery, comprising:

a porous substrate,

a heat resistant porous layer that is provided on one side or both sides of the porous substrate, that includes a resin and a filler, and that satisfies the following expression (2), and

an adhesive porous layer that is provided on both sides of a stacked body of the porous substrate and the heat resistant porous layer, and that includes an adhesive resin;

0.40≦

Vf/CPVC≦

0.99 

 

expression (2)

wherein, in expression (2), Vf is a volume proportion (% by volume) of the filler in the heat resistant porous layer, and CPVC is a critical pigment volume concentration (% by volume) of the filler.

11. The separator for a non-aqueous secondary battery according to claim 10, wherein an average of a porosity of the heat resistant porous layer and a porosity of the adhesive porous layer is from 30% to 70%.

12. The separator for a non-aqueous secondary battery according to claim 10, wherein, in the heat resistant porous layer, a proportion of the filler with respect to a total amount of the resin and the filler is from 50% by mass to 98% by mass.

13. The separator for a non-aqueous secondary battery according to claim 10, wherein the critical pigment volume concentration of the filler is from 20% by volume to 80% by volume.

14. The separator for a non-aqueous secondary battery according to claim 10, wherein a peel strength between the heat resistant porous layer and the adhesive porous layer is 0.05 N/cm or more.

15. The separator for a non-aqueous secondary battery according to claim 10, wherein:

the resin includes a polyvinylidene fluoride resin,

the filler is an inorganic filler, and

the heat resistant porous layer is an aggregate of the resin particles and the inorganic filler.

16. The separator for a non-aqueous secondary battery according to claim 10, wherein the filler is magnesium hydroxide or magnesium oxide.

19. The separator for a non-aqueous secondary battery according to claim 10, wherein the heat resistant porous layer further comprises a thickener.

20. A non-aqueous secondary battery comprising:

a positive electrode,

a negative electrode, and

the separator for a non-aqueous secondary battery according to claim 10, which is disposed between the positive electrode and the negative electrode,

wherein, in the non-aqueous secondary battery, an electromotive force is obtained by lithium doping/dedoping.