Flexible thin printed battery and device and method of manufacturing same

• US 20030165744A1
• Filed: 12/17/2002
• Published: 09/04/2003
• Est. Priority Date: 02/12/2002
• Status: Active Grant

• Current Assignee: Energizer Brands, LLC (Energizer Holdings, Inc.)
• Original Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Inventors: Langan, Richard A., Zhang, Jing, Schubert, Mark A., Tucholski, Gary R., Bailey, John C., Zheng, Guanghong, Webber, Andrew, Hilmi, Abdelkader, Feddrix, Frank H., Tudron, Frank B.
• Granted Patent: US 7,348,096 B2
• Time in Patent Office: Days
• US Class Current: 429/303
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 2004/028 Positive electrodes
• CPC Class Codes: H01M 2300/0002 Aqueous electrolytes
• CPC Class Codes: H01M 2300/0014 Alkaline electrolytes
• CPC Class Codes: H01M 2300/0085 Immobilising or gelification of electrolyte
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0414 by screen printing
• CPC Class Codes: H01M 4/06 Electrodes for primary cells
• CPC Class Codes: H01M 4/08 Processes of manufacture
• CPC Class Codes: H01M 4/244 Zinc electrodes
• CPC Class Codes: H01M 4/26 Processes of manufacture
• CPC Class Codes: H01M 4/50 of manganese
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/623 fluorinated polymers
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: H01M 4/663 containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
• CPC Class Codes: H01M 4/667 in the form of layers, e.g. coatings
• CPC Class Codes: H01M 50/121 Organic material
• CPC Class Codes: H01M 50/42 Acrylic resins
• CPC Class Codes: H01M 50/463 : Separators, membranes or diaphragms characterised by their shape
• CPC Class Codes: H01M 50/497 : Ionic conductivity
• CPC Class Codes: H01M 6/045 : characterised by aqueous electrolyte
• CPC Class Codes: H01M 6/12 : with flat electrodes
• CPC Class Codes: H01M 6/22 : Immobilising of electrolyte
• CPC Class Codes: H01M 6/40 : Printed batteries , e.g. thin film batteries
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49108 : Electric battery cell making
• CPC Class Codes: Y10T 29/4911 : including sealing
• CPC Class Codes: Y10T 29/49114 : including adhesively bonding
• CPC Class Codes: Y10T 29/49115 : including coating or impregnating

Abstract

A flat, flexible electrochemical cell is provided. The within invention describes various aspects of the flat, flexible electrochemical cell. A printed anode is provided that obviates the need for a discrete anode current collector, thereby reducing the size of the battery. An advantageous electrolyte is provided that enables the use of a metallic cathode current collector, thereby improving the performance of the battery. Printable gelled electrolytes and separators are provided, enabling the construction of both co-facial and co-planar batteries. Cell contacts are provided that reduce the potential for electrolyte creepage in the flat, flexible electrochemical cells of the within invention.

Claims

1. A carbon zinc battery comprising at least one printed electrode and a gelled material, said gelled material comprising a polyethylene glycol diacrylate dissolved in a zinc chloride solution.

2. The gelled material of claim 1, wherein said gelled material is printed onto said at least one printed electrode.

3. The gelled material of claim 2, wherein said polyethylene glycol diacrylate has a molecular weight of between 300 and 4500.

4. The gelled material of claim 3, wherein said polyethylene glycol diacrylate has a molecular weight of between 400 and 900.

5. The gelled material of claim 4, wherein said polyethylene glycol diacrylate has a molecular weight of between 700 and 800.

6. The gelled material of claim 3, further comprising a photoinitiator, a polymer viscosifier and an aqueous zinc chloride solution.

7. The gelled material of claim 6, wherein said gelled material has the following weight percent formulation:

5.0 to 25.0 percent polyethylene glycol diacrylate;

0.10 to 2.0 percent photoinitiator; and

1.0 to 10.0 percent polymer viscosifier.

8. The gelled material of claim 7, wherein said polymer viscosifier comprises a high molecular weight polyethylene oxide.

9. The gelled material of claim 8, wherein said polyethylene oxide has a molecular weight of about 600,000.

10. The gelled material of claim 3, further comprising a photoinitiator, a non-polymer viscosifier and an aqueous zinc chloride solution.

11. The gelled material of claim 10, wherein said gelled material has the following weight percent formulation:

3.0 to 25.0 percent polyethylene glycol diacrylate;

0.10 to 2.0 percent photoinitiator; and

1.0 to 10.0 percent non-polymer viscosifier.

12. The gelled material of claim 11, wherein said non-polymer viscosifier comprises fumed silica.

13. A method of forming a gelled material for a carbon zinc battery, said method comprising the steps of:

Providing a polyethylene glycol diacrylate (PEG) having a molecular weight of between 300 and 4500;

Providing a photoinitiator;

Providing a viscosifier;

Providing an aqueous zinc chloride solution;

Providing a printed electrode;

Mixing said PEG, photoinitiator, viscosifier and zinc chloride solution to a desired viscosity;

Printing said mixture onto said printed electrode; and

Curing said mixture.

14. The method of claim 13, wherein said PEG has a molecular weight of between 400 and 900.

15. The method of claim 14, wherein said PEG has a molecular weight of between 700 and 800.

16. The method of claim 15, wherein said viscosifier is a high molecular weight polymer binder.

17. The method of claim 16, wherein said polymer binder is polyethylene oxide.

18. The method of claim 15, wherein said viscosifier is a non-polymer binder.

19. The method of claim 18, wherein said non-polymer binder is fumed silica.

20. The method of claim 16, wherein said mixture has the following weight percent formulation:

5.0 to 25.0 percent polyethylene glycol diacrylate;

0.10 to 2.0 percent photoinitiator; and

1.0 to 10.0 percent polymer viscosifier.

21. The method of claim 18, wherein said mixture has the following weight percent formulation:

3.0 to 25.0 percent polyethylene glycol diacrylate;

0.10 to 2.0 percent photoinitiator; and

1.0 to 10.0 percent non-polymer viscosifier.

22. The method of claim 16, wherein said curing is performed by exposure to ultra-violet radiation with a black light in ambient air.

23. The method of claim 18, wherein said curing is performed by exposure to ultra-violet radiation with black light in ambient air.

24. A battery comprising an alkaline electrolyte, at least one printed electrode and a printed separator, said separator comprising a copolymer of acrylic or methacrylic acid and a styrene sulphonate.

25. The battery of claim 24, wherein said acrylic or methacrylic acid is acrylic acid and the styrene sulphonate is sodium styrene sulphonate.

26. The battery of claim 25, wherein said copolymer is in a 20:

80 molar ratio of acrylic acid and sodium styrene sulphonate.

27. The battery of claim 26, wherein said separator is formed of a gel in a 20:

80 weight percent of copolymer and water.

28. The battery of claim 27, wherein said at least one printed electrode comprises a printed anode and a printed cathode, said gel is printed directly onto said cathode to form a first separator surface, and is printed directly onto said anode to form a second separator surface, and is formed into a free-standing film positioned between the first separator surface and the second separator surfaces.

29. The battery of claim 28, wherein said alkaline electrolyte comprises an aqueous solution of potassium hydroxide.

30. The battery of claim 29, wherein said solution is a 34% to 42% solution based on the weight of potassium hydroxide to the weight of the solution.

31. A method for assembling an alkaline battery comprising a printed separator, said method comprising the steps of:

providing a printed anode and a printed cathode,

providing a gelled copolymer of acrylic or methacrylic acid and a styrene sulphonate,

printing said gel on a surface of said printed anode to form a first separator surface,

printing said gel on a surface of said printed cathode to form a second separator surface,

forming a free-standing film from said gel,

disposing of said film between said first and second separator surfaces.

32. The method of claim 31, wherein said copolymer comprises acrylic acid and sodium styrene sulphonate.

33. The method of claim 32, wherein said copolymer gel is in a 20:

80 molar ratio of acrylic acid and sodium styrene sulphonate.

34. The method of claim 33, wherein said copolymer gel is in a 20:

80 weight percent of copolymer and water.

35. A carbon zinc battery comprising a zinc anode printed directly onto a first section of flexible nonconductive substrate material and a gelled electrolyte comprising zinc chloride, water and a gelling agent.

36. The battery of claim 35, wherein said gelling agent comprises nonionic or anionic derivatives and natural guar gum.

37. The battery of claim 36, wherein said gelling agent is Galactasol.

38. A flat flexible battery comprising an electrode, at least one electrode internal current collector having first and second ends and at least one electrode external terminal having first and second ends, and a flexible nonconductive packaging material, said packaging material sealed together at at least one seal junction to form a seal area and a sealed housing surrounding said electrode, wherein said internal current collector and said external terminal are discrete structures, and wherein said internal current collector first end contacts said electrode, said internal current collector second end is positioned within said seal junction, said external terminal first end is positioned within said seal junction and said external terminal second end is positioned external said seal junction and external said housing.

39. The battery of claim 38 wherein said internal current collector and said external terminal are in physical contact within said seal junction.

40. The battery of claim 38 wherein said internal current collector and said external terminal are not in physical contact within said seal junction.

41. The battery of claim 38 wherein said battery is connected to a printed circuit and said printed circuit or said battery or both further comprise an adhesive surface.

42. A carbon zinc battery comprising a printed cathode and a printed current collector, wherein at least a portion of said cathode current collector is printed directly onto a flexible nonconductive substrate, and at least a portion of said cathode is printed directly onto said current collector.

43. The battery of claim 42 wherein said cathode current collector comprises a carbon ink.

44. The battery of claim 43, wherein said printed cathode is printed from a cathode ink comprising manganese dioxide, a binder, a solvent and graphite.

45. The battery of claim 44, wherein said manganese dioxide is jet-milled.

46. The battery of claim 45, wherein said manganese dioxide has a d(50) of between about 1.0 and 40.0 microns.

47. The battery of claim 46, wherein said cathode ink wet formulation comprises 1.0 to 2.0 weight percent PVDF binder, 4.0 to 45.0 weight percent graphite and 17.0 to 66.0 weight percent manganese dioxide and 28.0 to 37.0 weight percent NMP solvent.

48. The battery of claim 47, wherein said formulation comprises 1.0 to 2.0 weight percent PVDF binder, 12.0 to 31.0 weight percent graphite, 31.0 to 51.0 weight percent manganese dioxide and 34.0 to 35.0 weight percent NMP solvent.

49. The battery of claim 46, wherein said cathode ink wet formulation comprises 1.0 to 4.0 weight percent PVP binder, 6.0 to 25.0 weight percent graphite and 25.0 to 43.0 weight percent manganese dioxide, balanced with water.

50. The battery of claim 49, wherein said cathode ink wet formulation comprises 1.5 to 2.0 weight percent PVP binder, 11.0 to 16.0 weight percent graphite and 33.0 to 38.0 weight percent manganese dioxide, balanced with water.

51. A method for making a printed cathode and current collector, comprising the steps of:

providing a jet milled manganese dioxide;

providing a binder;

providing a conductive additive;

providing a solvent;

predissolving the binder in the solvent;

grinding the manganese dioxide and conductive additive together to form a solid mixture;

adding the solid mixture to the binder solution and combining them into a homogenous cathode mixture;

providing a current collector;

printing said homogenous cathode mixture onto a current collector;

curing said printed cathode mixture to drive off the solvent.

52. The method of claim 51, wherein said binder is PVP and said solvent is water.

53. The method of claim 51, wherein said binder is PVDF and said solvent is NMP.

54. The method of claim 51, further comprising the step of printing said current collector directly onto a flexible nonconductive substrate and drying said collector.

55. The method of claim 54, further comprising the steps of printing said cathode mixture directly onto said current collector.

56. A carbon zinc battery comprising a printed cathode current collector, wherein at least a portion of said printed cathode current collector is printed onto a flexible nonconductive substrate.

57. The battery of claim 56 wherein said printed cathode current collector comprises a metallic ink printed onto said flexible nonconductive substrate.

58. The battery of claim 57, wherein said printed cathode current collector further comprises a protective carbon ink printed onto said metallic ink and onto said flexible nonconductive substrate.

59. The battery of claim 58, wherein said metallic ink in selected from the group consisting of silver ink and aluminum ink.

60. The battery of claim 59, wherein said protective carbon ink comprises on a wet basis between 20 and 25 weight percent graphite, between 15 and 18 weight percent of a styrene-ethylene-butylene styrene block co-polymer binder and the remainder comprises toluene as a solvent.

61. The battery of claim 56, wherein said cathode current collector is a carbon ink printed directly onto said flexible nonconductive substrate and comprises on a wet basis 8 to 10 weight percent of a styrene-ethylene-butylene-styrene (SEBS) block copolymer, 34 to 38 weight percent graphite and the remainder comprises toluene or trichloroethylene solvent.

62. The battery of claim 61, wherein said remainder further comprises carbon black in an amount of 5 weight percent or less.

63. The battery of claim 56, wherein said cathode current collector comprises a protective carbon ink and a metallic substrate, wherein said protective carbon ink is printed directly onto a metallic substrate and directly onto a flexible nonconductive substrate.

64. The battery of claim 63, wherein said metallic substrate comprises silver foil or aluminum foil.

65. The battery of claim 64, wherein said protective carbon ink comprises between 20 and 25 weight percent graphite, between 15 and 18 weight percent of a styrene-ethylene-butylene styrene block co-polymer binder and the remainder comprising toluene as a solvent.

66. A non-alkaline battery comprising a zinc anode printed onto a flexible nonconductive substrate material and an electrolyte having a pH of about 7.0.

67. The battery of claim 66, wherein said electrolyte has a pH in the range of 6.5 to 7.0

68. The battery of claim 67, wherein said electrolyte comprises an acetate compound.

69. The battery of claim 68, wherein said acetate compound is a zinc acetate.

70. The battery of claim 68, wherein said acetate compound is ammonium acetate.

71. The battery of claim 69, wherein said battery further comprises a printed manganese dioxide cathode wherein said cathode ink comprises a nonaqueous solvent.

72. The battery of claim 71, wherein said cathode ink further comprises a polyvinylidene fluoride (PVDF) binder.

73. The battery of claim 72, wherein said nonaqueous solvent is N-methyl pyrrolidone (NMP).

74. The battery of claim 71, further comprising a printed cathode current collector printed directly onto a flexible non-conductive substrate, and said printed cathode is printed directly onto said current collector.

75. The battery of claim 74, wherein said current collector comprises a silver ink.

76. The battery of claim 74, wherein said zinc anode is printed directly onto a flexible non-conductive substrate without an intervening anode current collector.

77. The battery of claim 76, wherein said printed zinc anode has an ink formulation comprising zinc powder and a source of excess zinc ions.

78. The battery of claim 77, wherein said source of excess zinc ions is an aqueous zinc acetate solution.

79. A battery comprising a zinc anode printed directly onto a flexible nonconductive substrate without an intervening anode current collector.

80. The battery of claim 79 wherein said zinc anode is printed using a zinc ink formulation comprising a source of excess zinc +2 cations.

81. The battery of claim 80, wherein said source of excess zinc ions is an aqueous zinc acetate solution.

82. The battery of claim 81, wherein said formulation further comprises a binder and a co-solvent system.

83. The battery of claim 82, wherein said co-solvent system comprises water and N-methylpyrrolidone (NMP).

84. The battery of claim 83, wherein said binder comprises polyvinylpyrrolidone (PVP).

85. The battery of claim 84, wherein said battery comprises a zinc chloride electrolyte.

86. The battery of claim 85, said electrolyte further comprising cetyltrimethylammonium.