Secondary battery

• US 5,714,277 A
• Filed: 03/28/1994
• Issued: 02/03/1998
• Est. Priority Date: 03/30/1993
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kawakami, Soichiro
• Primary Examiner(s): CHU, JOHN S Y
• Application Number:
  US08/218,638
• Time in Patent Office: 1,408 Days
• Field of Search: 429/129, 429/137, 429/131, 429/62, 429/189, 429/198, 429/199, 430/138
• US Class Current: 429/62
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 2200/00 Safety devices for primary or secondary batteries
• CPC Class Codes: H01M 2200/10 Temperature sensitive devices
• CPC Class Codes: H01M 2300/0034 Fluorinated solvents
• CPC Class Codes: H01M 50/451 comprising layers of only organic material and layers containing inorganic material
• CPC Class Codes: H01M 50/454 comprising a non-fibrous layer and a fibrous layer superimposed on one another
• CPC Class Codes: H01M 50/457 comprising three or more layers
• CPC Class Codes: H01M 50/46 Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: H01M 6/164 by the solvent
• CPC Class Codes: H01M 6/168 by additives
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A purpose of the present invention is to provide a secondary battery of high safety and high energy density.

The battery of the present invention is a secondary battery microcapsules containing lithium at least formed of negative electrode active material, a separator, positive electrode active material, electrolytic solution (electrolyte), a collector and a battery case, characterized in that microcapsules are dispersed within the electrolytic solution or separator, said microcapsules discharging the chemical substance having hydroxyl group or chemical substance which is polymerization initiator, when the temperature within battery rises.

Claims

1. A lithium secondary battery comprising a negative electrode having negative electrode active material, a positive electrode having positive electrode active material, a separator sandwiched between said negative electrode and said positive electrode, and an electrolyte solution between said negative electrode and said positive electrode, wherein said electrolyte solution includes a perfluorocarbon inert liquid as a flame retardant.

2. A lithium secondary battery according to claim 1, characterized in that the surface of said negative electrode opposed to the positive electrode is covered with a membrane capable of transmitting at least lithium ions.

3. A lithium secondary battery according to claim 1, characterized in that the surface of said positive electrode opposed to the negative electrode is covered with a membrane capable of transmitting at least lithium ions.

4. A lithium secondary battery according to claim 2, characterized in that said membrane is made of flame retardant or incombustible material.

5. A lithium secondary battery according to claim 1, wherein said negative electrode active material is lithium or lithium alloy.

6. A lithium secondary battery according to claim 1, characterized in that the mixture ratio by weight of perfluorocarbon in electrolyte solution is from 1 to 20 wt %.

7. A lithium secondary battery according to claim 1, characterized in that the boiling point of said perfluorocarbon is 50°

C. or above.

8. A secondary battery according to claim 3, wherein said membrane comprises a flame retarding material or an incombustible material.

9. A lithium secondary battery comprising a negative electrode having negative electrode active material, a positive electrode having positive electrode active material, a separator sandwiched between said negative electrode and said positive electrode, and an electrolyte solution between said negative electrode and said positive electrode, wherein said electrolyte solution includes tricresyl phosphate as a flame retardant.

10. A lithium secondary battery according to claim 9, characterized in that the surface of said negative electrode opposed to the positive electrode is covered with a membrane capable of transmitting at least lithium ions.

11. A lithium secondary battery according to claim 9, characterized in that the surface of said positive electrode opposed to the negative electrode is covered with a membrane capable of transmitting at least lithium ions.

12. A lithium secondary battery according to claim 10, characterized in that said membrane comprises a flame retardant or an incombustible material.

13. A lithium secondary battery according to claim 11, characterized in that said membrane comprises a flame retardant or an incombustible material.

14. A lithium secondary battery according to claim 9, wherein said negative electrode active material is lithium or lithium alloy.

15. A lithium secondary battery according to claim 9 characterized in that the mixture ratio by weight of the tricresyl phosphate in said electrolyte solution is from 1 to 20 wt %.

16. A secondary battery containing microcapsules comprising:

a negative electrode having negative electrode active material, a positive electrode having positive electrode active material with a separator sandwiched between said negative electrode and said positive electrode, and an electrolyte solution between said negative electrode and said positive electrode, characterized by comprising microcapsules containing a chemical substance having at least a compound having hydroxyl group in at least one of said separator and said electrolyte solution.

17. A secondary battery according to claim 16, wherein said chemical substance is alcohol.

18. A secondary battery according to claim 16, characterized in that the mixture amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.

19. A secondary battery according to claim 16, characterized in that said secondary battery is a lithium secondary battery.

20. A secondary battery according to claim 16, characterized in that said chemical substance has at least flame retardant.

21. A secondary battery according to claim 16, characterized in that the surface of the negative electrode opposed to the positive electrode is covered with a membrane capable of transmitting at least lithium ions.

22. A secondary battery according to claim 16, characterized in that the surface of the positive electrode opposed to the negative electrode is covered with a membrane capable of transmitting at least lithium ions.

23. A secondary battery according to claim 21 characterized in that said membrane is made of fire retarding material or incombustible material.

24. A secondary battery according to claim 16, wherein said negative electrode active material is lithium or lithium alloy.

25. A secondary battery according to claim 16, characterized in that the melting point of said microcapsules is from 70°

to 150°

C.

26. A secondary battery according to claim 16, characterized in that each said microcapsule is from 1 to 500 microns in size.

27. A secondary battery according to claim 16, characterized in that the amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.

28. A secondary battery according to claim 22, wherein said membrane comprises a flame retarding material or an incombustible material.

29. A secondary battery according to claim 16, wherein said chemical substance is alcohol.

30. A secondary battery according to claim 16, characterized in that the amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.

31. A secondary battery containing microcapsules comprising:

a negative electrode having negative electrode active material, a positive electrode having positive electrode active material with a separator sandwiched between said negative electrode and said positive electrode, and an electrolyte solution between said negative electrode and said positive electrode, characterized by comprising microcapsules containing a chemical substance having at least polymerization initiator or cross-linking agent in at least one of said separator and said electrolyte solution.

32. A secondary battery according to claim 31, characterized in that said secondary battery is a lithium secondary battery.

33. A secondary battery according to claim 31, characterized in that said microcapsules contain, ink addition to polymerization initiator or cross-linking agent, one kind or more selected from monomer, oligomer, and polymer.

34. A secondary battery according to claim 31, characterized in that said chemical substance has at least flame retardant.

35. A secondary battery according to claim 31, characterized in that the surface of the negative electrode opposed to the positive electrode is covered with a membrane capable of transmitting at least lithium ions.

36. A secondary battery according to claim 31, characterized in that the surface of the positive electrode opposed to the negative electrode is covered with a membrane capable of transmitting at least lithium ions.

37. A secondary battery according to claim 35 characterized in that said membrane is made of fire retarding material or incombustible material.

38. A secondary battery according to claim 31, wherein said negative electrode active material is lithium or lithium alloy.

39. A secondary battery according to claim 31, characterized in that the melting point of said microcapsules is from 70°

to 150°

C.

40. A secondary battery according to claim 31, characterized in that each said microcapsule is from 1 to 500 microns in size.

41. A secondary battery according to claim 31, characterized in that the amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.

42. A secondary battery according to claim 36, wherein said membrane comprises a flame retarding material or an incombustible material.

43. A secondary battery according to claim 31, characterized in that the amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.

44. A secondary battery containing microcapsules comprising:

a negative electrode having negative electrode active material, a positive electrode having positive electrode active material with a separator sandwiched between said negative electrode and said positive electrode, and an electrolyte solution between said negative electrode and said positive electrode, characterized by comprising microcapsules containing a chemical substance having at least acid in at least one of said separator and said electrolyte solution.

45. A secondary battery according to claim 44, characterized in that said secondary battery is a lithium secondary battery.

46. A secondary battery according to claim 44, characterized in that said chemical substance has at least flame retardant.

47. A secondary battery according to claim 44, characterized in that the surface of the negative electrode opposed to the positive electrode is covered with a membrane capable of transmitting at least lithium ions.

48. A secondary battery according to claim 44, characterized in that the surface of the positive electrode opposed to the negative electrode is covered with a membrane capable of transmitting at least lithium ions.

49. A secondary battery according to claim 47, characterized in that said membrane is made of fire retarding material or incombustible material.

50. A secondary battery according to claim 44, wherein said negative electrode active material is lithium or lithium alloy.

51. A secondary battery according to claim 44, characterized in that the melting point of said microcapsules is from 70°

to 150°

C.

52. A secondary battery according to claim 44, characterized in that each said microcapsule is from 1 to 500 microns in size.

53. A secondary battery according to claim 44, characterized in that the amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.

54. A secondary battery according to claim 48, wherein said membrane comprises a flame retarding material or an incombustible material.

55. A secondary battery according to claim 44, characterized in that the amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.

56. A secondary battery containing microcapsules comprising:

a negative electrode having negative electrode active material, a positive electrode having positive electrode active material with a separator sandwiched between said negative electrode and said positive electrode, and an electrolyte solution between said negative electrode and said positive electrode, characterized by comprising microcapsules containing a chemical substance in at least one of said separator and said electrolyte solution and a surface of the positive electrode opposed to the negative electrode is covered with a membrane capable of transmitting at least lithium ions.

57. A secondary battery according to claim 56, wherein said chemical substance has at least a compound having hydroxyl group.

58. A secondary battery according to claim 56, characterized in that said chemical substance has at least polymerization initiator or cross-linking agent.

59. A secondary battery according to claim 58, characterized in that said microcapsules contain, in addition to polymerization initiator or cross-linking agent, one kind of more selected from monomer, oligomer, and polymer.

60. A secondary battery according to claim 56, characterized in that said chemical substance has at least acid.

61. A secondary battery according to claim 56, characterized in that said chemical substance has at least flame retardant.

62. A secondary battery according to claim 56, characterized in that the surface of the negative electrode opposed to the positive electrode is covered with a membrane capable of transmitting at least lithium ions.

63. A second battery according to claim 56, characterized in that the surface of the positive electrode opposed to the negative electrode is covered with a membrane capable of transmitting at least lithium ions.

64. A secondary battery according to claim 62 characterized in that said membrane is made of fire retarding material or incombustible material.

65. A secondary battery according to claim 62, wherein said negative electrode active material is lithium or lithium alloy.

66. A secondary battery according to claim 62, characterized in that the melting point of said microcapsules is from 70°

to 150°

C.

67. A secondary battery according to claim 62, characterized in that each said microcapsule is from 1 to 500 microns in size.

68. A secondary battery according to claim 62, characterized in that the amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.

69. A secondary battery according to claim 63, wherein said membrane comprises a flame retarding material or an incombustible material.

70. A secondary battery according to claim 56, wherein said chemical substance is alcohol.

71. A secondary battery according to claim 56, characterized in that the amount of said microcapsules is from 1 to 20 wt % of said electrolyte solution.