Film for a separator of electrochemical apparatus, and production method and use thereof

• US 6,096,456 A
• Filed: 09/22/1997
• Issued: 08/01/2000
• Est. Priority Date: 09/29/1995
• Status: Expired due to Term

• Current Assignee: Showa Denko KK
• Original Assignee: Showa Denko KK
• Inventors: Naijo, Shuichi, Ohkubo, Takashi, Takeuchi, Masataka
• Primary Examiner(s): Nuzzolillo, Maria
• Assistant Examiner(s): DOVE, TRACY MAE
• Application Number:
  US08/934,902
• Time in Patent Office: 1,044 Days
• Field of Search: 429/249, 429/252, 429/320
• US Class Current: 429/249
• CPC Class Codes: H01G 9/02 Diaphragms; Separators
• 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 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 50/42 Acrylic resins
• CPC Class Codes: H01M 50/449 having a layered structure
• CPC Class Codes: H01M 50/46 Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: H01M 6/188 Processes of manufacture
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

This invention provides a film comprising a cross-linked polymer having an oxyalkylene group or a cross-linked polymer having an oxyalkylene group through a urethane bond, as a constituent component, a production method of the film, and an electrochemical apparatus using the film as a separator.

The film for separator of an electrochemical apparatus can be easily and uniformly processed, can include an electrolytic solution, exhibits good film thickness and ensures excellent safety and reliability. The electrochemical apparatus is free of leakage of the solution.

Claims

1. A film for a separator of an electrochemical apparatus comprising, as a constituent component, an acryloyl-based cross-linked or an alkyl-substituted acryloyl-based cross-linked polymer having an oxyalkylene group, said film having been formed by electromagnetic wave polymerization and said film having a uniform film thickness of from 1 to 30 μ

m with a fluctuation of film thickness of within ±

10%, an ion conductivity greater than 1×

10^-4 S/cm and a film strength sufficient to be a free-standing film.

3. A film for a separator of an electrochemical apparatus as claimed in claim 1 or 2, wherein said polymer is a polymer of an acryloyl-based or methacryloyl-based compound having a structure containing a unit represented by formula (1) and/or a copolymer comprising said compound as a copolymer component:

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO--R.sup.2 -- (1)

wherein R¹ represents hydrogen or an alkyl group;

R² represents a divalent organic group containing an oxyalkylene group and said organic group may be linear, branched or cyclic, or may contain one or more elements other than carbon, hydrogen and oxygen;

x and y each represents 0 or an integer of from 1 to 5 and z represents a numerical value of from 1 to 10, provided that when x=0 and y=0, z=0; and

the moiety (CH₂) and the moiety (CH(CH₃)) may be configured irregularly;

provided that when the unit represented by formula (1) is present in plurality in the same molecule, the R¹ or R² groups or the values represented by x, y or z are independent from each other and need not be the same.

4. A film for a separator of an electrochemical apparatus as claimed in claim 1 or 2, wherein said polymer is a polymer of an acryloyl-based or methacryloyl-based compound having a structure containing a unit represented by formula (2) and/or a copolymer comprising said compound as a copolymer component:

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH (CH.sub.3)).sub.y ].sub.z NHCOO(R.sup.3 O).sub.n -- (2)

wherein R¹ represents hydrogen or an alkyl group, R³ represents --(CH₂)₂ -- or --CH(CH₃)CH₂ --, n represents an integer of 1 or greater, and x, y and z each has the same meaning as defined in formula (1).

5. A film for a separator of an electrochemical apparatus as claimed in claims 1 or 2, wherein said film contains an electrolyte and/or a solvent.

6. A film for a separator of an electrochemical apparatus as claimed in claim 5, wherein at least one of the electrolyte is an alkali metal salt, a quaternary ammonium salt or a quaternary phosphonium salt.

7. A film for a separator of an electrochemical apparatus as claimed in claim 5, wherein said solvent is a carbonate-base compound.

8. A film for a separator of an electrochemical apparatus as claimed in claims 1 or 2, wherein said film is a film having a support.

9. A film for a separator of an electrochemical apparatus as claimed in claims 1 or 2, wherein said film is a film having a porous support.

10. A film for a separator of an electrochemical apparatus as claimed in claim 8, wherein said support is a granular support.

11. A film for a separator of an electrochemical apparatus as claimed in claim 8, wherein said support is an agglomerate of primary particles.

12. A film for a separator of an electrochemical apparatus as claimed in claim 8, wherein said support has a BET specific surface area of not smaller than 10 m² /g.

13. A separator of an electrochemical apparatus comprising a film claimed in claim 8.

14. A separator of an electrochemical apparatus as claimed in claim 13, wherein said separator is a separator compounded with a support.

15. A separator of an electrochemical apparatus as claimed in claim 13, wherein said separator contains a solvent and an electrolyte in the total amount of 100 to 1,000% based on the total weight of said separator.

16. A battery using the film described in claims 1 or 2 as a separator.

17. A battery as claimed in claim 16, wherein the negative electrode of the battery comprises an electrode containing lithium, a lithium alloy or a material capable of occluding and releasing lithium ions.

18. A method for producing a battery using the film of claims 1 or 2, comprising

laminating a positive electrode, a separator comprising the film described in claims 1 or 2 and a negative electrode in any order to form a positive electrode/separator/negative electrode laminate with the separator being interposed between the positive electrode and the negative electrode as a battery-constituting structure,

filling the battery-constituting structure with a polymerizable monomer-containing material containing, as essential constituent components, at least one electrolyte and at least one acryloyl-based or methacryloyl-based compound having a structure containing a unit represented by formula (1) or (2):

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO--R.sup.2 -- (1)

wherein R¹ represents hydrogen or an alkyl group;

R² represents a divalent organic group containing an oxyalkylene group and said organic group may be linear, branched or cyclic, or may contain one or more elements other than, carbon, hydrogen and oxygen;

x and y each represents 0 or an integer of from 1 to 5 and z represents a numerical value of from 1 to 10, provided that when x=0 and y=0, z=0; and

the moiety (CH₂) and the moiety (CH(CH₃)) may be configured irregularly;

provided that when the unit represented by formula (1) is present in plurality in the same molecule, the R¹ or R² groups or the values represented by x, y or z are independent from each other and need not be the same;

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (C(CH.sub.3)).sub.y ].sub.z NHCOO(R.sup.3 O).sub.n -- (2)

wherein R¹ represents hydrogen or an alkyl group, R¹ represents --(CH₂)₂ -- or --CH(CHA)CH₂ --, n represents an integer of 1 or greater, and x, y and z which has the same meaning as defined in formula (1), and

polymerizing said polymerizable monomer-containing material.

19. A method for producing a battery using the film of claims 1 or 2, comprising

forming a positive electrode/separator laminate and/or a negative electrode/separator laminate by laminating a separator comprising a film described in claims 1 or 2 on at least one of a positive electrode and a negative electrode,

using the positive electrode/separator laminate and/or the negative electrode/separator laminate to form a positive electrode/separator/negative electrode laminate with the separator being interposed between the positive electrode and the negative electrode as a battery-constituting structure and

filling the battery-constituting structure with a liquid material containing at least one electrolyte as an essential constituent component.

20. A method for producing a battery using the film of claims 1 or 2, comprising

forming a positive electrode/separator laminate and/or a negative electrode/separator laminate by laminating a separator comprising a film described in claims 1 or 2 on at least one of a positive electrode and a negative electrode,

using the positive electrode/separator laminate and/or the negative electrode/separator laminate to form a positive electrode/separator/negative electrode laminate with the separator being interposed between the positive electrode and the negative electrode as a battery-constituting structure and

filling the battery-constituting structure with a polymerizable monomer-containing material containing, as essential constituent components, at least one electrolyte and at least one acryloyl-based or methacryloyl-based compound having a structure containing a unit represented by formula (1) or (2):

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO--R.sup.2 -- (1)

wherein R¹ represents hydrogen or an alkyl group;

R² represents a divalent organic group containing an oxyalkylene group and said organic group may be linear, branched or cyclic or may contain one or more elements other than carbon, hydrogen and oxygen;

x and y each represents 0 or an integer of from 1 to 5 and z represents a numerical value of from 1 to 10, provided that when x=0 and y=0 z=0; and

the moiety (CH₂) and the moiety (CH(CH₃)) may be configured irregularly;

provided that when the unit represented by formula (1) is present in plurality in the same molecule, the R¹ or R² groups or the values represented by x, y or z sire independent from each other and need not be the same;

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO(R.sup.3 O).sub.n -- (2)

wherein R¹ represents hydrogen or an alkyl group, R³ represents --(CH₂)₂ -- or --CH(CH₃)CH₂ --, n represents an integer of 1 or greater, and x, y and z each has the same meaning as defined in formula (1), and

polymerizing said polymerizable monomer-containing material.

21. A method for producing a battery using the film of claims 1 or 2, having a separator comprising the film described in claims 1 or 2, which comprises

forming a positive electrode/porous support/negative electrode laminate with the porous support being interposed between the positive electrode and the negative electrode as a battery-constituting structure using a positive electrode/porous support laminate and/or a negative electrode/porous support laminate obtained by, laminating a porous support on at least one of the positive electrode said the negative electrode,

filling the battery-constituting structure with a polymerizable monomer-containing material containing, as essential constituent components, at least one electrolyte and at least one acryloyl-based or methacryloyl based compound having a structure containing a unit represented by formula (1) or (2):

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO--R.sup.2 -- (1)

wherein R¹ represents hydrogen or an alkyl group;

R² represents a divalent organic grout containing an oxyalkylene group and said organic group may be linear, branched or cyclic, or may contain one or more elements other than carbon, hydrogen and oxygen;

x and v each represents 0 or an integer of from 1 to 5 and z represents a numerical value of from 1 to 10, provided that when x=0 and y=0, z=0; and

the moiety (CH₂) and the moiety (CH(CH₃)) may be configured irregularly;

provided that when the unit represented by formula (1) is present in plurality in the same molecule, the R¹ or R² groups or the values represented by x, y or z are independent from each other and need not be the same;

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.2)).sub.y ].sub.z NHCOO(R.sup.3 O).sub.n -- (2)

wherein R¹ represents hydrogen or an alkyl group, R³ represents --(CH₂)₂ -- or --CH(CH₃)CH₂ --, n represents an integer of 1 or greater, and x, y and z each has the same meaning as defined in formula (1), and

polymerizing said polymerizable monomer-containing material.

22. A method for producing a battery using the film of claims 1 or 2, comprising

impregnating and/or coating at least one of a positive electrode and a negative electrode with a polymerizable monomer-containing material containing, as a constituent component, at least one acryloyl-based or methacryloyl-based compound having a structure containing a unit represented by formula (1) or (2):

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO--R.sup.2 -- (1)

wherein R¹ represents hydrogen or an alkyl group;

R² represents a divalent organic group contain an oxyalkylene group and said organic group may be linear, branched or cyclic, or may contain one or more elements other than carbon, hydrogen and oxygen;

x and y each represents 0 or an integer of from 1 to 5 and z represents a numerical value of from 1 to 10, provided that when x=0 and v=0, z=0; and

the moiety (CH₂) and the moiety (CH(CH₃)) may be configured irregularly;

provided that when the unit represented by formula (1) is present in plurality in the same molecule, the R¹ or R² groups or the values represented by x, y or z are independent from each other and need not be the same;

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO(R.sup.3 O).sub.n -- (2)

wherein R¹ represents hydrogen or an alkyl group, R³ represents --(CH₂)₂ -- or --CH(CH₃)CH₂ --, n represents an integer of 1 or greater, and x, y and z each has the same meaning as defined in formula (1);

forming a positive electrode/separator/negative electrode laminate with the separator being interposed between the positive electrode and the negative electrode as a battery-constituting structure using a positive electrode, a negative electrode and a separator comprising a film described in claims 1 or 2, and

polymerizing said polymerizable monomer-containing material.

23. A method for producing a battery as claimed in claim 22, wherein said polymerizable monomer-containing material is a polymerizable monomer-containing material containing, as essential constituent components, at least, one electrolyte and at least one acryloyl-based or methacryloyl-based compound having a structure containing a unit represented by formula (1) or (2):

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO--R.sup.2 -- (1)

wherein R¹ represents hydrogen or an alkyl group;

R² represents a divalent organic group containing an oxyalkylene group and said organic group may be linear, branched or cyclic, or may contain one or more elements other than carbon, hydrogen and oxygen;

x and v each represents 0 or an integer of from 1 to 5 and z represents a numerical value of from 1 to 10, provided that when x=0 and y=0, z=0; and

the moiety (CH₂) and the moiety (CH(CH₃)) may be configured irregularly;

provided that when the unit represented by formula (1) is present in plurality in the same molecule, the R¹ or R² groups or the values represented by x, y or z are independent from each other and need not be the same,

space="preserve" listing-type="equation">CH.sub.2 ═

C(R.sup.1)CO[O(CH.sub.2).sub.x (CH(CH.sub.3)).sub.y ].sub.z NHCOO(R.sup.3 O).sub.n -- (2)

wherein R¹ represents hydrogen or an alkyl group, R³ represents --(CH₂)₂ -- or --CH(CH₃)CH₂ --, n represents an integer of 1 or greater, and x, y and z each has the same meaning as defined in formula (1).

24. A film for a separator of an electrochemical apparatus as claimed in claim 9, wherein said support is a granular support.

25. A film for a separator of an electrochemical apparatus as claimed in claim 9, wherein said support is an agglomerate of primary particles.

26. A film for a separator of an electrochemical apparatus as claimed in claim 9, wherein said support has a BET specific surface area of not smaller than 10 m² /g.

27. A film for a separator of an electrochemical apparatus as claimed in claim 1 or 2, wherein said tensile strength is more than 3 kg/cm² and a modulus of elasticity is more than 10⁶ dyn/cm².

2. A film for a separator of an electrochemical apparatus comprising, as a constituent component, an acryloyl-based cross-linked polymer having a urethane bond and an oxyalkylene group, said film having a uniform film thickness of from 1 to 30 μ

m with a fluctuation of film thickness of within ±

10% and an ion conductivity greater than 1×

10^-4 S/cm.