Method for fabricating self-aligning electrode

• US 7,851,238 B2
• Filed: 02/24/2009
• Issued: 12/14/2010
• Est. Priority Date: 10/20/2003
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Maxwell Technologies Incorporated (Tesla Inc.)
• Inventors: Mitchell, Porter, Xi, Xiaomei, Zhong, Linda, Zou, Bin
• Primary Examiner(s): Dang; Phuc T
• Application Number:
  US12/392,069
• Publication Number:
  US 20090223630A1
• Time in Patent Office: 658 Days
• Field of Search: 438/22, 438/88, 429/233, 429/235
• US Class Current: 438/22
• CPC Class Codes: H01G 11/22 Electrodes
• CPC Class Codes: H01G 11/28 arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
• CPC Class Codes: H01G 11/74 Terminals, e.g. extensions of current collectors
• CPC Class Codes: H01G 11/86 specially adapted for electrodes carbonisation or activation of carbon for the manufacture of electrodes H01G11/34
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10S 257/906 Dram with capacitor electrodes used for accessing, e.g. bit line is capacitor plate
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

Electrodes are constructed with pressure-bonding techniques that simplify alignment of various electrode components during lamination. In an exemplary embodiment, a current collector is made from aluminum foil that has been roughed or pitted on both surfaces. The surfaces of the current collector can be further treated to enhance adhesion properties of these surfaces. Layers of film that include active electrode material, such as activated carbon particles, are fabricated using non-lubricated techniques. Each film is coated on one side with an adhesive binder solution, such as a thermoplastic solution. The adhesive binder is dried, and the films are laminated to the current collector using a calender with heated rollers. The resulting electrode product is processed to shape electrodes, which can then be used in electrical energy storage devices, including double layer capacitors.

Claims

1. A method of manufacturing an electrode, the method comprising:

providing a first film of active electrode material comprising a first film surface;

coating the first film surface with a first layer of wet adhesive binder; and

drying the first layer of wet adhesive binder to obtain a first dry binder coating on the first film surface.

2. A method of manufacturing an electrode according to claim 1, wherein the step of providing a first film comprises providing the first film as an electrode material formed of dry fibrillized particles.

3. A method of manufacturing an electrode according to claim 1, further comprising

providing a current collector comprising a first current collector surface and a second current collector surface;

stacking the first film and the current collector so that the first current collector surface is in contact with the first dry binder coating; and

laminating the current collector and the first film by pressing the current collector and the first film to cause the first film to bond to the first current collector surface.

4. A method of manufacturing an electrode according to claim 3, further comprising:

providing a second film of active electrode material comprising a second film surface;

coating the second film surface with a second layer of wet adhesive binder;

drying the second layer of wet adhesive binder on the second film surface to obtain a second dry binder coating on the second film surface; and

stacking the second film and the current collector so that the second current collector surface is in contact with the second dry binder coating;

laminating the current collector and the second film by pressing the current collector and the second film to cause the second film to bond to the second current collector surface.

5. A method of manufacturing an electrode according to claim 4, wherein the step of laminating the current collector and the first film and the step of laminating the current collector and the second film are performed at the same time.

6. A method of manufacturing an electrode according to claim 5, wherein:

the step of providing a first film comprises providing the first film of active electrode material using a non-lubricated high-shear technique; and

the step of providing a second film comprises providing the second film of active electrode material using a non-lubricated high-shear technique.

7. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises spray coating the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises spray coating the second film surface with the second layer of wet adhesive binder.

8. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises gravure coating the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises gravure coating the second film surface with the second layer of wet adhesive binder.

9. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises using a slot die to coat the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises using a slot die to coat the second film surface with the second layer of wet adhesive binder.

10. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises using a doctor blade to coat the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises using a doctor blade to coat the second film surface with the second layer of wet adhesive binder.

11. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises reverse roll coating the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises reverse roll coating the second film surface with the second layer of wet adhesive binder.

12. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises knife over roll coating the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises knife over roll coating the second film surface with the second layer of wet adhesive binder.

13. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises metering rod coating the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises metering rod coating the second film surface with the second layer of wet adhesive binder.

14. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises curtain coating the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises curtain coating the second film surface with the second layer of wet adhesive binder.

15. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises air knife coating the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises air knife coating the second film surface with the second layer of wet adhesive binder.

16. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises immersion coating the first film surface with the first layer of wet adhesive binder; and

the step of coating the second film comprises immersion coating the second film surface with the second layer of wet adhesive binder.

17. A method of manufacturing an electrode according to claim 6, wherein:

the step of coating the first film comprises coating the first film surface with the first layer of wet adhesive binder having a thickness of between about 20 and about 30 microns; and

the step of coating the second film comprises coating the second film surface with the second layer of wet adhesive binder having a thickness of between about 20 and about 30 microns.

18. A method of manufacturing an electrode according to claim 6, wherein:

the first binder coating comprises a resin;

the second binder coating comprises a resin; and

the steps of laminating the current collector and the first and second films comprise heating the first and second dry binder layers to a temperature sufficient to soften the resin.

19. A method of manufacturing an electrode according to claim 6, wherein:

the first binder coating comprises a thermoplastic;

the second binder coating comprises the thermoplastic; and

the steps of laminating the current collector and the first and second films comprise heating the first and second dry binder layers to a temperature between 100 and 300 degrees Celsius.

20. A method of manufacturing an electrode according to claim 6, wherein the step of providing a current collector comprises providing aluminum foil.

21. A method of manufacturing an electrode according to claim 1, further comprising storing the coated first film on a roll.

22. A method of manufacturing an electrode according to claim 3, wherein the step of stacking requires only alignment to within the boundaries of the collector.

23. A method of manufacturing an electrode according to claim 6, wherein the first and the second layers of wet adhesive binder comprise EB-012.

24. A method of manufacturing an electrode, the method comprising:

making a first sheet from active electrode material using a non-lubricated high-shear technique, the active electrode material comprising activated carbon particles, the first sheet comprising a first sheet surface;

making a second sheet from the active electrode material using a non-lubricated high-shear technique, the second sheet comprising a second sheet surface;

coating the first sheet surface with a first layer of adhesive binder;

coating the second sheet surface with a second layer of adhesive binder;

providing a current collector comprising a first current collector surface and a second current collector surface;

stacking the first sheet, the second sheet, and the current collector so that the first current collector surface is in contact with the first layer of adhesive binder and the second current collector surface is in contact with the second layer of adhesive binder, thereby obtaining a stacked product; and

laminating the stacked product by pressing the current collector and the first and second sheets to cause the first sheet to bond to the first current collector surface and the second sheet to bond to the second current collector surface, thereby obtaining a laminated electrode product.

25. A method of manufacturing an electrode, the method comprising:

providing a first dry self supporting film of active electrode material formed from a dry powder material and comprising a first film surface;

coating the first film surface with a first layer of wet adhesive binder; and

drying the first layer of wet adhesive binder to obtain a first dry binder coating on the first film surface.