LITHIUM ION BATTERY EXTERIOR MATERIAL

• US 20130209868A1
• Filed: 10/14/2011
• Published: 08/15/2013
• Est. Priority Date: 10/14/2010
• Status: Active Grant

• Current Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Original Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Inventors: Suzuta, Masayoshi, Echizen, Hidenori, Jikumaru, Takashi
• Granted Patent: US 9,123,922 B2
• Time in Patent Office: Days
• US Class Current: 429/176
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2250/05 5 or more layers
• CPC Class Codes: B32B 2255/06 on metal layer
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 2255/26 Polymeric coating
• CPC Class Codes: B32B 2307/206 Insulating
• CPC Class Codes: B32B 2307/42 Polarizing, birefringent, filtering
• CPC Class Codes: B32B 2307/51 Elastic
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 2307/702 Amorphous
• CPC Class Codes: B32B 2307/704 Crystalline
• CPC Class Codes: B32B 2307/714 Inert, i.e. inert to chemical degradation, corrosion
• CPC Class Codes: B32B 2307/734 Dimensional stability
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 2457/10 Batteries
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/306 comprising vinyl acetate or vinyl alcohol (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 27/36 : comprising polyesters
• CPC Class Codes: B32B 7/12 : using interposed adhesives or interposed materials with bonding properties
• 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 50/105 : Pouches or flexible bags
• CPC Class Codes: H01M 50/119 : Metals
• CPC Class Codes: H01M 50/121 : Organic material
• CPC Class Codes: H01M 50/124 : having a layered structure
• CPC Class Codes: H01M 50/126 : comprising three or more layers
• CPC Class Codes: H01M 50/138 : adapted for specific cells, e.g. electrochemical cells operating at high temperature
• CPC Class Codes: H01M 50/141 : for protecting against humidity
• CPC Class Codes: H01M 50/145 : for protecting against corrosion
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries

Abstract

A lithium ion battery exterior material, includes: a base material layer, and a sequentially laminated adhesive layer, aluminum foil layer provided with a corrosion prevention treated layer, and an adhesive resin layer on one surface of the base material layer; wherein, the adhesive resin layer contains an acid-modified polyolefin resin and a miscible elastomer dispersed in the acid-modified polyolefin at a dispersed phase size of 1 nm to less than 1 μm.

Claims

1. A lithium ion battery exterior material, comprising:

a base material layer, and an adhesive layer, an aluminum foil layer provided with a corrosion prevention treated layer, and an adhesive resin layer being sequentially laminated on one surface of the base material layer, the adhesive resin layer containing an acid-modified polyolefin resin and a miscible elastomer dispersed in the acid-modified polyolefin at a dispersed phase size of 1 nm to less than 1 μ

m, wherein the acid-modified polyolefin resin is a resin that has been graft-modified with one or more compounds of unsaturated carboxylic acid derivative components selected from the group consisting of unsaturated carboxylic acids, acid anhydrides of unsaturated carboxylic acids and esters of unsaturated carboxylic acids.

2. The lithium ion battery exterior material according to claim 1, wherein the adhesive resin layer contains an immiscible elastomer dispersed in the acid-modified polyolefin resin at a dispersed phase size of 1 μ

m to less than 1000 μ

m.

4. The lithium ion battery exterior material according to claim 1, wherein an absolute value of birefringence following a heat treatment of a thermoplastic resin layer is 0.002 or less and a degree of crystallization is 60% or less, the thermoplastic resin layer being composed of the adhesive resin layer and a sealant layer provided on an opposite surface of the adhesive resin layer from the base material layer.

5. The lithium ion battery exterior material according to claim 1, wherein a withstand voltage of the adhesive resin layer as measured according to the “

Testing Methods for Electric Strength of Solid Insulating Materials”

defined in JIS-C2110 is 0.04 kV/μ

m or more.

6. The lithium ion battery exterior material according to claim 1, wherein a laminated portion of the adhesive resin layer and a sealant layer provided on an opposite surface of the adhesive resin layer from the base material layer satisfies the following conditions (1) and (2):

(1) a heat of fusion Δ

H as measured by differential scanning calorimetry is 15 J/g to 80 J/g and a melting temperature Tm is 130°

C. to 170°

C.; and

,

(2) a melt viscosity η

at a shear velocity of 1×

10-2/second and temperature 30°

C. higher than the melting temperature Tm of a laminated portion of the sealant layer and the adhesive resin layer is 1000 Pa·

s to 7000 Pa·

s.

7. The lithium ion battery exterior material according to claim 1, wherein a luminosity difference Δ

L* of an aluminum laminate obtained by sequentially laminating the base material layer, the adhesive layer, the aluminum foil layer and the adhesive resin layer before and after drawing the adhesive resin layer surface of the aluminum laminate is 25 or less when a test piece of the aluminum laminate having a width of 15 mm is drawn by 150%, and when the luminosity before drawing is defined as L*1 and the luminosity after drawing is defined as L*2, the luminosity difference Δ

L* is L*2-L*1.

9. The lithium ion battery exterior material according to claim 1, wherein the content of the miscible elastomer is 1% by weight to 50% by weight based on 100% by weight of the adhesive resin layer, and the miscible elastomer is one or more compounds selected from the group consisting of styrene-based thermoplastic elastomers, hydrogenated styrene-based thermoplastic elastomers and propylene-α

-olefin copolymer elastomers, and is dispersed at a dispersed phase size of 1 nm to 200 nm.

10. The lithium ion battery exterior material according to claim 1, wherein a sealant layer provided on an opposite surface of the adhesive resin layer from the base material from the base material is composed of a polyolefin-based resin, and

the polyolefin-based resin and the acid-modified polyolefin-based resin contain one or more compounds selected from the group consisting of random polypropylene, homopolypropylene and block polypropylene.

13. The lithium ion battery exterior material according to claim 1, wherein the base material layer has at least one of a biaxially oriented polyester film and a biaxially oriented polyamide film.

14. The lithium ion battery exterior material according to claim 1, further comprising a molding improvement layer between the base material layer and the aluminum foil layer, wherein the base material layer has a protective layer on an opposite surface from the surface on which the aluminum foil layer is laminated.

17. The lithium ion battery exterior material according to claim 1, wherein the corrosion prevention treated layer is provided at least on the surface of the aluminum foil layer that contacts the adhesive resin layer.

18. The lithium ion battery exterior material according to claim 1, wherein the miscible elastomer is a polyolefin-based elastomer composed of a crystalline polyolefin segment and an amorphous polyolefin segment and having a microphase-separated structure, a content of the polyolefin-based elastomer is 5% by weight to 50% by weight, and the miscible elastomer is a propylene-based elastomer.

19. The lithium ion battery exterior material according to claim 1, wherein

the miscible elastomer is a styrene-based elastomer or a hydrogenated styrene-based elastomer, a content of the styrene-based elastomer or the hydrogenated styrene-based elastomer is 5% by weight to 30% by weight, and

a hydrogenation product of a block copolymer composed of styrene and butadiene, or a hydrogenation product of a block copolymer composed of styrene and isoprene.

23. The lithium ion battery exterior material according to claim 1, wherein

a polymer x having a functional group capable of reacting with a graft-modified unsaturated carboxylic acid derivative component is contained in the acid-modified polyolefin resin in the corrosion prevented treated layer,

the polymer x is a cationic polymer, and

the cationic polymer is one or more compounds selected from the group consisting of polyethyleneimine, an ion-polymer complex composed of polyethyleneimine and a polymer having carboxylic acid, a primary amine-grafted acrylic resin obtained by grafting a primary amine to an acrylic main backbone, a polyallylamine or derivative thereof, and aminophenol.

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