Thin non-protonic electrolytic film, immobilized liquid-film conductor, and polymer cell

• US 6,235,432 B1
• Filed: 08/11/1998
• Issued: 05/22/2001
• Est. Priority Date: 12/11/1996
• Status: Expired due to Term

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Tonen Chemical Corp. (ENEOS Holdings, Inc.)
• Inventors: Kono, Koichi, Takita, Kotaro, Kaimai, Norimitsu
• Primary Examiner(s): Kalafut, Stephen
• Assistant Examiner(s): Martin, Angela J.
• Application Number:
  US09/117,994
• Time in Patent Office: 1,015 Days
• Field of Search: 429/300, 429/303, 429/304, 429/306, 429/322, 429/324, 429/249, 429/250, 429/231.95, 296/235
• US Class Current: 429/303
• CPC Class Codes: B66F 19/005 Lifting devices for manhole covers
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01G 11/54 Electrolytes
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01G 11/62 characterised by the solute, e.g. salts, anions or cations therein
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/054 Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 2300/0085 Immobilising or gelification of electrolyte
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

The thin film of non-protonic electrolyte comprises the microporous polyolefin film impregnated with an immobilized non-protonic electrolytic solution, where the film is treated to have improved affinity for the non-protonic solution by graft polymerization of the film with a monomer which can dissolve the non-protonic electrolytic solution, coating of the film with terminal-modified polypropylene which can dissolve the non-protonic electrolytic solution or coating of the film with wax which can dissolve the non-protonic electrolytic solution. The electrolyte-immobilized liquid-film conductor comprises the microporous polyolefin film impregnated with an immobilized non-protonic electrolytic solution, where the film contains an electron-conductive substance and is treated to have improved affinity for the non-protonic solution. The thin film of non-protonic electrolyte comprising the microporous polyolefin film gives a polymer battery, such as lithium battery, when combined with an anode and cathode. The polymer battery comprising the thin film of non-protonic electrolyte and the electrolyte-immobilized liquid-film conductor which is used at least one of the anode and cathode is advantageous over the conventional lithium battery of polymer electrolyte in various aspects, such as higher discharging function at low temperature, lesser self-discharge at high temperature, and higher charge/discharge characteristics over extended periods.

Claims

1. A thin film of non-protonic electrolyte, comprising a non-protonic electrolytic solution immobilized in a microporous polyolefin film having affinity for the non-protonic electrolytic solution, wherein the microporous polyolefin film comprises at least 1% by weight of a polyolefin having an average molecular weight of at least 5×

10⁵ and a molecular weight distribution of 10 to 300, wherein the molecular weight distribution is defined as weight average molecular weight/number average molecular weight.

3. The thin film of non-protonic electrolyte of claim 1 wherein said affinity of said microporous polyolefin film is introduced by graft polymerization of said microporous polyolefin film with a monomer selected from a group consisting of acrylic acid, methacrylic acid, esters thereof, and acrylamide and derivatives thereof.

4. The thin film of non-protonic electrolyte of claim 1 wherein affinity for the non-protonic electrolytic solution is introduced by adding terminal-modified polypropylene to said microporous polyolefin film.

5. The thin film of non-protonic electrolyte of claim 4 wherein affinity for the non-protonic electrolytic solution is introduced by coating said microporous polyolefin film with terminal-modified polypropylene.

6. The thin film of non-protonic electrolyte of claim 4 wherein said microporous polyolefin film in which affinity for the non-protonic electrolytic solution is introduced comprises a polyolefin composition containing terminal-modified polypropylene.

7. The thin film of non-protonic electrolyte of claim 4 wherein said terminal-modified polypropylene is living-polymerized to have functional groups at the terminals.

8. The thin film of non-protonic electrolyte of claim 4 wherein said microporous polyolefin film in which affinity for the non-protonic electrolytic solution is introduced contains terminal-modified polypropylene to 1 to 50% by weight of polyolefin.

9. The thin film of non-protonic electrolyte of claim 1 wherein affinity for the non-protonic electrolytic solution is introduced by adding wax having affinity for the non-protonic electrolytic solution to said microporous polyolefin film.

10. The thin film of non-protonic electrolyte of claim 9 wherein affinity for the non-protonic electrolytic solution is introduced by coating said microporous polyolefin film with wax having affinity for the non-protonic electrolytic solution.

11. The thin film of non-protonic electrolyte of claim 9 wherein said microporous polyolefin film in which affinity for the non-protonic electrolytic solution is introduced comprises a polyolefin composition containing wax.

16. A polymer battery, comprising the thin film of non-protonic electrolyte of claim 1, and an anode and cathode.

17. The polymer battery of claim 16, wherein at least one of said anode and said cathode comprises a non-protonic electrolytic solution immobilized in a microporous polyolefin film having an affinity for said non-protonic electrolytic solution and containing an electrically conductive substance.

2. A process for preparing a thin film of non-protonic electrolyte including steps for providing a microporous polyolefin film, introducing affinity for a non-protonic electrolytic solution in said microporous polyolefin film, and immobilizing said non-protonic electrolyte solution in said microporous polyolefin film, wherein the microporous polyolefin film comprises at least 1% by weight of a polyolefin having an average molecular weight of at least 5×

10⁵ and a molecular weight distribution of 10 to 300, wherein the molecular weight distribution is defined as weight average molecular weight/number average molecular weight.

18. The process for preparing a thin film of non-protonic electrolyte according to claim 2, wherein the affinity for the non-protonic electrolyte solution is introduced by adding terminal-modified polypropylene to said microporous polyolefin film.

19. The process for preparing a thin film of non-protonic electrolyte according to claim 2, wherein the affinity for the non-protonic electrolytic solution is introduced by coating said microporous polyolefin film with terminal-modified polypropylene.

20. The process for preparing a thin film of non-protonic electrolyte according to claim 2, wherein said microporous polyolefin film in which affinity for the non-protonic electrolytic solution is introduced comprises a polyolefin composition containing terminal-modified polypropylene.

21. The process for preparing a thin film of non-protonic electrolyte according to claim 2, wherein said terminal-modified polypropylene is living-polymerized to have functional groups at the terminals.

22. The process for preparing a thin film of non-protonic electrolyte according to claim 2, wherein said microporous polyolefin film in which affinity for the non-protonic electrolytic solution is introduced contains terminal-modified polypropylene to 1 to 50% by weight of polyolefin.

23. The process for preparing a thin film of non-protonic electrolyte according to claim 2, wherein affinity for the non-protonic electrolytic solution is introduced by adding wax having affinity for the non-protonic electrolytic solution to said microporous polyolefin film.

24. The process for preparing a thin film of non-protonic electrolyte according to claim 2, wherein affinity for the non-protonic electrolytic solution is introduced by coating said microporous polyolefin film with wax having affinity for the non-protonic electrolytic solution.

25. The process for preparing a thin film of non-protonic electrolyte according to claim 2, wherein said microporous polyolefin film in which affinity for the non-protonic electrolytic solution is introduced comprises a polyolefin composition containing wax.

12. An electrolyte-immobilized liquid-film conductor, comprising a non-protonic electrolytic solution immobilized in a microporous polyolefin film having affinity for the non-protonic electrolytic solution and containing an electrically conductive substance, wherein the microporous polyolefin film comprises at least 1% by weight of a polyolefin having an average molecular weight of at least 5×

10⁵ and a molecular weight distribution of 10 to 300, wherein the molecular weight distribution is defined as weight average molecular weight/number average molecular weight.

13. The electrolyte-immobilized liquid-film conductor of claim 12 wherein affinity for the non-protonic electrolytic solution is introduced by graft polymerization of said microporous polyolefin film containing an electrically conductive substance with a monomer which can dissolve said non-protonic electrolytic solution.

14. The electrolyte-immobilized liquid-film conductor of claim 12 wherein affinity for the non-protonic electrolytic solution is introduced by adding terminal-modified polypropylene to said microporous polyolefin film containing an electrically conductive substance.

15. The thin film of non-protonic electrolyte of claim 14 wherein said microporous polyolefin film in which affinity for the non-protonic electrolytic solution and electrical conductivity are introduced contains terminal-modified polypropylene to 1 to 50% by weight of polyolefin.