Protective multilayer laminate for covering an electrochemical device

• US 5,445,856 A
• Filed: 11/10/1993
• Issued: 08/29/1995
• Est. Priority Date: 11/10/1993
• Status: Expired due to Fees

• Current Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Original Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Inventors: Chaloner-Gill, Benjamin
• Primary Examiner(s): Thibodeau, Paul J.
• Assistant Examiner(s): Sand, Stephen
• Application Number:
  US08/150,634
• Time in Patent Office: 657 Days
• Field of Search: 428/34.1, 428/35.7, 428/35.9, 428/36.6, 428/323, 428/327, 428/328, 428/329, 428/331, 428/332, 428/347, 428/402, 428/457, 428/472.2, 428/913, 428/404, 428/407 , 428/461, 428/194, 428/122, 428/124, 523/200, 524/202, 524/204, 524/512, 524/513, 429/162, 429/163, 429/171, 429/174, 429/175, 429/176, 429/177, 429/185, 429/192, 429/213
• US Class Current: 428/35.9
• 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 2307/206 Insulating
• CPC Class Codes: B32B 2307/31 Heat sealable
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/7244 Oxygen barrier
• CPC Class Codes: B32B 2311/24 Aluminium
• CPC Class Codes: B32B 2323/04 Polyethylene
• CPC Class Codes: B32B 2439/00 Containers; Receptacles
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 7/02 Physical, chemical or physicochemical properties
• CPC Class Codes: H01G 9/08 Housing; Encapsulation
• CPC Class Codes: H01M 50/119 Metals
• CPC Class Codes: H01M 50/121 Organic material
• CPC Class Codes: H01M 50/129 with two or more layers of only organic material
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 428/1359 Three or more layers [continuous layer]
• CPC Class Codes: Y10T 428/24215 Acute or reverse fold of exterior component
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/257 : Iron oxide or aluminum oxide
• CPC Class Codes: Y10T 428/259 : Silicic material
• CPC Class Codes: Y10T 428/2817 : Heat sealable
• CPC Class Codes: Y10T 428/2982 : Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/31692 : Next to addition polymer from unsaturated monomers

Abstract

A laminate is provided for use as a protective covering for inhibiting penetration of oxygen or oxygen and water therethrough and is particularly suitable for protecting components of an electrochemical cell such as a lithium battery. The laminate comprises an ionomeric polymeric layer for heat sealing layers of the laminate to one another and at least two flexible polymeric layers, one of which may comprise the ionomeric layer; and an oxygen scavenging agent incorporated in one of the flexible polymeric layers or disposed between any two of the flexible polymeric layers. It is preferred that the laminate be insulating as well for inhibiting transport of electricity as well as oxygen and water through the laminate and comprises two or more polymeric layers having, when combined, the characteristics of flexibility, electrical insulation, adhesiveness, and stability to water.

Claims

1. A laminate, for use as a protective, insulating covering or wrap for an electrochemical battery or cell, the laminate capable of inhibiting transport of electricity, oxygen, and water therethrough which comprises:

a. a first layer which is a polymeric metal-containing ionomeric cross-linked ethylene-acrylic copolymer, said layer forming a heat seal when two portions of the laminate are heat sealed together to form said covering or wrap;

b. a second layer which is a metal foil layer;

c. a third layer which is a polymeric layer of a polymeric amide or a polyester;

d. a fourth layer which is a polymeric adhesive polyethylene layer between the metal foil layer and the third layer;

e. each of said polymeric layers being essentially devoid of hydroxide pendent groups;

f. an oxygen scavenger incorporated in one of said polymeric layers or disposed between layers of the laminate; and

g. said first layer being on one side of said second layer and said third layer being on the other side of said second layer.

2. The laminate according to claim 1 wherein the oxygen scavenger comprises a metal compound having a reducing property.

3. The laminate according to claim 1 wherein the oxygen scavenger comprises particles of copper oxide mixed with particles of alumina.

4. The laminate according to claim 1 wherein the oxygen scavenger is incorporated into one of the polymeric layers by mixing together pellets of the polymeric material forming said one of said polymeric layers and particles of a metal compound having a reducing property and then extruding such mixture to form a sheet thereof.

5. The laminate according to claim 1 wherein the oxygen scavenger is selected from the group consisting of metal oxides, metal carbides, metal carbonates, metal sulfites, metal carbonyls, metal silicides, and mixtures thereof.

6. The laminate according to claim 5 wherein the oxygen scavenger further comprises one selected from the group consisting of non-metal carbonates, sulfates, carbon, alumina, clay, and mixtures thereof.

7. The laminate according to claim 1 wherein the oxygen scavenger is between the first layer and the metal foil layer.

8. The laminate according to claim 1 which is in the form of a single sheet, folded over onto itself with the heat sealable layer sealed to itself on three sides.

9. An article comprising tow superimposed laminates according to claim 1 which have been heat sealed together along four edges.

10. A laminate, for use as a protective, insulating covering or wrap for an electrochemical battery or cell, the laminate capable of inhibiting transport of electricity, oxygen, and water therethrough which comprises:

a. a first layer which is a metal-containing ionomeric cross-linked ethylene acrylic copolymer, said layer forming a heat seal when two panels of the laminate are heat sealed together to form said covering or wrap;

b. a second layer which is low density polyethylene layer;

c. a third layer which is a nylon layer;

d. a fourth layer which is a second low density polyethylene;

e. a fifth layer which is an aluminum foil layer;

f. a sixth layer which is a third low density polyethylene layer;

g. a seventh layer which is a second nylon layer;

h. each of said polymeric layers being essentially devoid of hydroxide pendent groups;

i. an oxygen scavenger incorporated in one of said polymeric layers or disposed between layers of said laminate; and

wherein

j. said second layer is between said first and third layers;

said third layer is between said second and fourth layers;

said fourth layer is between said third and fifth layers;

said fifth layer is between said fourth and sixth layers; and

said sixth layer is between said fifth and seventh layers.

11. The laminate according to claim 10 wherein the oxygen scavenger comprises a metal compound having a reducing property.

12. The laminate according to claim 10 wherein the oxygen scavenger comprises fine particles of copper oxide mixed with particles of alumina.

13. The laminate according to claim 10 wherein the oxygen scavenger is incorporated into one of the polymeric layers by mixing together pellets of polymeric material and particles of a metal compound having a reducing property and then extruding such mixture to form a sheet thereof.

14. The laminate according to claim 10 wherein the oxygen scavenger is selected from the group consisting of metal oxides, metal carbides, metal carbonates, metal sulfites, metal carbonyls, metal silicides, and mixtures thereof.

15. The laminate according to claim 14 wherein the oxygen scavenger further comprises one selected from the group consisting of non-metal carbonate, sulfates, carbon, alumina, clay, and mixtures thereof.

16. The laminate according to claim 10 wherein the oxygen scavenger is between the first-layer and the metal foil layer.

17. The laminate according to claim 10 which is in the form of a single sheet, folded over onto itself with the heat sealable layer sealed to itself on three sides.

18. An article comprising two superimposed laminates according to claim 10 which have been heat sealed together along four edges.