Energy storage device

• US 5,867,363 A
• Filed: 03/30/1994
• Issued: 02/02/1999
• Est. Priority Date: 09/18/1992
• Status: Expired due to Fees

• Current Assignee: Ultracap Technologies Corp.
• Original Assignee: Pinnacle Research Institute, Inc.
• Inventors: Poplett, James M., Anderson, Ronald L., Tong, Robert R., Ahmad, Nazir, Nelson, James P., Goodwin, Mark L., Cromack, Douglas, Wu, Davy, Tsai, K. C., Mason, Gary E., McEwen, Alan B.
• Primary Examiner(s): Ledynh, Bot L.
• Application Number:
  US08/219,965
• Time in Patent Office: 1,770 Days
• Field of Search: 361/328-330, 361/502-503, 361/517-520, 361/522, 361/524, 361/528, 361/532-533, 361/535-537, 361/540-541, 429/34-39, 429/163-164, 29/25.03
• US Class Current: 361/502
• CPC Class Codes: H01G 11/52 Separators
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01G 11/58 Liquid electrolytes
• CPC Class Codes: H01G 11/80 Gaskets; Sealings
• CPC Class Codes: H01M 10/0418 with bipolar electrodes
• CPC Class Codes: H01M 4/00 Electrodes
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0409 by a doctor blade method, slip-casting or roller coating
• CPC Class Codes: H01M 4/0416 involving impregnation with a solution, dispersion, paste or dry powder H01M4/0438 takes precedence
• CPC Class Codes: H01M 4/0419 involving spraying
• CPC Class Codes: H01M 4/0428 Chemical vapour deposition
• CPC Class Codes: H01M 4/0438 by electrochemical processing electroless electrochemical plating C23C18/54
• CPC Class Codes: H01M 4/045 Electrochemical coating; Electrochemical impregnation
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/58 of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
• CPC Class Codes: H01M 50/184 characterised by their shape or structure
• CPC Class Codes: H01M 50/186 characterised by the disposition of the sealing members
• CPC Class Codes: H01M 50/46 Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: H01M 50/548 on opposite sides of the cell
• CPC Class Codes: H01M 50/557 : Plate-shaped terminals
• CPC Class Codes: H01M 50/627 : Filling ports
• CPC Class Codes: H01M 6/48 : with bipolar electrodes
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/13 : Energy storage using capacitors
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

A dry preunit (10), includes a plurality of cells (110, 112, 114) in a true bipolar configuration, which are stacked and bonded together, to impart to the device an integral and unitary construction. Each cell (114) includes two electrically conductive electrodes (111A, 111B) that are spaced apart by a predetermined distance. The cell (114) also includes two identical dielectric gaskets (121, 123) that are interposed, in registration with each other, between the electrodes (111A, 111B), for separating and electrically insulating these electrodes. When the electrodes (111A, 111B), and the gaskets (121, 123) are bonded together, at least one fill gap (130) is formed for each cell. Each cell (114) also includes a porous and conductive coating layer (119, 120) that is formed on one surface of each electrode. The coating layer (119) includes a set of closely spaced-apart peripheral microprotrusions (125), and a set of distally spaced-apart central microprotrusions (127). These microprotrusions (125, 127) impart structural support to the cells, and provide additional insulation between the electrodes. An energy storage device (10A) such as a capacitor, is created with the addition of an electrolyte to the gap (130) of the dry preunit (10) and subsequent sealing of the fill ports.

Claims

1. A dry preunit for an energy storage device comprising:

at least a first cell for storing energy, said first cell comprising, in combination;

a. a first electrically conductive electrode;

b. a second electrically conductive electrode, said first and second electrodes being spaced apart by a first predetermined distance;

c. first dielectric gasket means interposed between said first and second electrodes, for separating and electrically insulating said first and second electrodes;

d. a first high surface area electrically conducting coating layer formed on one surface of said first electrode, such that said first coating layer is interposed between said first electrode and said gasket means; and

e. a plurality of protrusions on said first coating layer,

whereby, when said first electrode, said second electrode and said first gasket means having a centrally located opening are bonded together to form said first cell, an air filled fill gap is formed therebetween.

2. The dry preunit according to claim 1, wherein said first cell further includes a first fill port formed by said gasket means, in order to allow an electrolyte to flow into said fill gap.

3. The dry preunit according to claim 2, wherein said first cell further includes a first cord which is inserted within said first fill port;

and

wherein when said first cord is removed, said first fill port is opened and said fill gap becomes accessible.

4. An energy storage device according to claim 2 further including an ionically conductive medium, within the cell gaps of the dry preunit, wherein the fill ports are sealed.

5. The dry preunit of claim 2, wherein said first and second electrically conductive electrodes are a metal or metal alloy having a thickness of between about 1 and 10 mil;

and

the first high surface area electrically conducting coating layer is a mixed metal oxide.

6. The dry preunit according to claim 1,

wherein said second electrode is a bipolar electrode.

7. The dry preunit according to claim 1, wherein said second electrode includes a second electrically conductive, high surface area, porous coating layer formed on one surface thereof, such that said second coating layer is interposed between said second electrode and said first gasket means.

8. The dry preunit according to claim 7, wherein said second electrode further includes a second electrically conductive, high surface area, porous coating layer formed on another surface thereof.

9. The dry preunit according to claim 7, wherein said first coating layer of said first electrode, and said first and second coating layers of said second electrode are selected from a group consisting of metal oxides, mixed metal oxides, metal nitrides, and polymers.

10. The dry preunit of claim 1 wherein a porous hydrophobic polymeric material is inserted within the fill gap of each cell during construction to mitigate an increase of hydrostatic pressure due to an increase in temperature.

11. The dry preunit of claim 10, wherein the porous hydrophobic polymeric material is polytetrafluoroethylene having water entrance pressures of between 760 and 7600 torr.

12. A dry preunit for an energy storage device comprising:

a. a first electrically conductive electrode;

b. a second electrically conductive electrode, said first and second electrodes being spaced apart by a first predetermined distance;

c. first dielectric gasket means interposed between said first and second electrodes, for separating and electrically insulating said first and second electrodes;

d. a first high surface area electrically conducting coating layer formed on one surface of said first electrode, such that said first coating layer is interposed between said first electrode and said gasket means;

e. a second electrically conducting high surface area coating layer formed on one surface of said second electrode, such that said second coating layer is interposed between said second electrode and said first gasket means; and

f. a plurality of protrusions on the first coating layer, the second coating layer, or combination thereof and said protrusions impart structural support to said first cell, and provide additional electrical insulation between said first and second electrodes

whereby, when said first electrode, said second electrode and said first gasket means having a centrally located opening are bonded together to form said first cell, an air filled fill gap is formed therebetween.

13. The dry preunit according to claim 12, further including at least a second cell, and wherein said first cell and said second cell are stacked and connected, in order to impart an integral unitary structure to the dry preunit.

14. The dry preunit according to claim 13, wherein said second electrically conductive electrode is a bipolar electrode, which is shared by said first and second cell;

and

wherein said second cell further includes a third electrically conductive electrode which is oppositely disposed relative to said second electrically conductive electrode; and

wherein said first and second electrically conductive electrodes are spaced apart, by a second predetermined distance.

15. The dry preunit according to claim 14, wherein a second gasket means is interposed between said second and third electrodes, for separating and electrically insulating said second and third electrodes,

wherein a third coating layer is formed on a second surface of said second electrode, such that said third coating layer is interposed between said second electrode and said second gasket means;

and

wherein said second cell includes a plurality of discrete protrusions located on either electrode surface.

16. The dry preunit according to claim 15, wherein said second cell further includes a high surface area and a fourth electrically conductive coating which is formed on one surface of said third electrode;

and

wherein said fourth coating layer is interposed between said third electrode and said second gasket means.

17. The dry preunit according to claim 16, wherein said second cell further includes a second fill port that is formed within said second gasket means.

18. The dry preunit according to claim 17, further including exterior tab means for connection to a power source.

19. The dry preunit according to claim 16, wherein each of said first and third coating layers includes an additional layer having a set of peripheral protrusions, and a set of central discrete protrusions that are disposed in an arrayed arrangement.

20. The dry preunit according to claim 19, wherein the diameter of each protrusion is about 6 mil;

wherein the center-to-center separation of said peripheral protrusions is about 20 mil;

wherein the center-to-center separation of said central protrusions is about 40 mil; and

wherein said peripheral and central protrusions have a dielectric composition.

21. The dry preunit according to claim 15, wherein each of said first and second gasket means includes two dielectric gaskets, which are disposed in registration with each other;

and

wherein said first cord is disposed between said gaskets to form said first fill port.

22. The dry preunit according to claim 14, wherein said first and second predetermined distances are equal.

23. The dry preunit according to claim 14, wherein said first, second and third electrodes are similarly and rectangularly shaped.

24. A capacitor preunit including at least a first cell, the capacitor comprising:

a. a first electrically conductive electrode;

b. a second electrically conductive electrode, said first and second electrodes being bonded together to form a first cell and being spaced apart by a first predetermined distance; and

c. first dielectric peripheral gasket means interposed between said first and second electrodes, for separating and electrically insulating said first and second electrodes;

a fill gap formed between said first and second electrodes; and

a first fill port formed by said gasket means in order to allow an electrolyte to flow into said fill gap.

25. The capacitor preunit according to claim 24, wherein the first cell further includes:

a. a first high surface area coating layer formed on one surface of said first electrode, such that said first coating layer is interposed between said first electrode and said gasket means; and

b. a second high surface area coating layer formed on one surface of said second electrode, with the proviso that said second coating layer is interposed between said second electrode and said first gasket means;

c. a layer having a plurality of discrete protrusions; and

wherein said protrusions impart structural support to the first cell, and provide additional insulation between said first and second electrodes.

26. The capacitor preunit according to claim 25, further including at least a second cell;

wherein the first and second cell are stacked and bonded, in order to impart an integral unitary structure to the capacitor;

wherein said second electrically conductive electrode is a bipolar electrode, which is shared by said first and second cell;

wherein said second cell further includes a third electrically conductive electrode which is oppositely disposed relative to said second electrically conductive electrode; and

wherein said first and second electrically conductive electrodes are spaced apart, by a second predetermined distance.