Thermal conductor for high-energy electrochemical cells

• US 6,117,584 A
• Filed: 07/25/1997
• Issued: 09/12/2000
• Est. Priority Date: 07/25/1997
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company), Avestor (Bolloré SE), Bathium Canada Inc. (Bolloré SE)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Domroese, Michael K., Hoffman, Joseph A., Trice, Jennifer L., Rouillard, Roger, Radewald, Vern E., Lindeman, David D.
• Primary Examiner(s): Nuzzolillo, Maria
• Assistant Examiner(s): Ruthkosky, Mark
• Application Number:
  US08/900,428
• Time in Patent Office: 1,145 Days
• Field of Search: 429/101, 429/152, 429/153, 429/162, 429/26, 429/66, 429/120, 429/121
• US Class Current: 429/120
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/647 Prismatic or flat cells, e.g. pouch cells
• CPC Class Codes: H01M 10/653 characterised by electrically insulating or thermally conductive materials
• CPC Class Codes: H01M 10/6553 Terminals or leads
• CPC Class Codes: H01M 10/6554 Rods or plates
• CPC Class Codes: H01M 10/6556 Solid parts with flow channel passages or pipes for heat exchange closed pipes H01M10/6552
• CPC Class Codes: H01M 2006/106 Elliptic wound cells
• CPC Class Codes: H01M 50/224 Metals
• CPC Class Codes: H01M 50/534 characterised by the material of the leads or tabs
• CPC Class Codes: H01M 50/536 characterised by the method of fixing the leads to the electrodes, e.g. by welding
• CPC Class Codes: H01M 50/538 Connection of several leads or tabs of wound or folded electrode stacks
• CPC Class Codes: H01M 6/10 with wound or folded electrodes
• CPC Class Codes: H01M 6/181 with polymeric electrolytes
• 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

Abstract

A thermal conductor for use with an electrochemical energy storage device is disclosed. The thermal conductor is attached to one or both of the anode and cathode contacts of an electrochemical cell. A resilient portion of the conductor varies in height or position to maintain contact between the conductor and an adjacent wall structure of a containment vessel in response to relative movement between the conductor and the wall structure. The thermal conductor conducts current into and out of the electrochemical cell and conducts thermal energy between the electrochemical cell and thermally conductive and electrically resistive material disposed between the conductor and the wall structure. The thermal conductor may be fabricated to include a resilient portion having one of a substantially C-shaped, double C-shaped, Z-shaped, V-shaped, O-shaped, S-shaped, or finger-shaped cross-section. An elastomeric spring element may be configured so as to be captured by the resilient conductor for purposes of enhancing the functionality of the thermal conductor. The spring element may include a protrusion that provides electrical insulation between the spring conductor and a spring conductor of an adjacently disposed electrochemical cell in the presence of relative movement between the cells and the wall structure. The thermal conductor may also be fabricated from a sheet of electrically conductive material and affixed to the contacts of a number of electrochemical cells.

Claims

1. An energy storage device, comprising:

a thin-film electrochemical cell having an anode contact and a cathode contact; and

a conductor coupled to the anode contact or the cathode contact and including a resilient portion for maintaining contact between the conductor and a wall structure disposed adjacent the conductor in the presence of relative movement between the conductor and the wall structure, the conductor conducting current into and out of the electrochemical cell and conducting thermal energy between the electrochemical cell and a thermally conductive and electrically resistive material disposed between the conductor and the wall structure.

2. The device of claim 1, wherein the conductor comprises a flexible lead that attaches to an external connection for conducting current into and out of the electrochemical cell.

3. The device of claim 1, wherein the conductor comprises a lead that attaches to an external connection and cooperates with the anode and cathode contacts to conduct current into and out of the electrochemical cell.

4. The device of claim 1, wherein the resilient portion of the conductor has one of a substantially C-shaped, double C-shaped, Z-shaped, O-shaped, S-shaped, V-shaped, L-shaped, single finger-shaped, or multiple finger-shaped cross-section.

5. The device of claim 1, wherein:

the electrochemical cell comprises laterally offset anode and cathode current collecting films coupled to the anode and cathode contacts, respectively; and

the resilient portion of the conductor comprises the laterally offset anode and cathode current collecting films.

6. The device of claim 1, further including a spring element that cooperates with the resilient portion of the conductor to maintain contact between the conductor and the wall structure.

7. The device of claim 6, wherein the spring element includes a stop that impedes collapsing of the resilient portion of the conductor when the resilient portion is subjected to a compressive force.

8. The device of claim 6, wherein the spring element includes a protrusion that provides electrical insulation between the conductor and a conductor of an adjacently disposed electrochemical cell in the presence of relative movement between the conductor and the wall structure.

9. The device of claim 6, wherein the spring element includes a first protrusion and a second protrusion, the first and second protrusions respectively providing electrical insulation between a conductor and one of the anode or cathode contacts of an adjacently disposed electrochemical cell in the presence of relative movement between the conductor and the wall structure.

10. The device of claim 1, further including a substantially cylindrical spring element captured by the resilient portion of the conductor that cooperates with the resilient portion to maintain contact between the conductor and the wall structure.

11. The device of claim 1, wherein the conductor is spot welded to the one of the anode or cathode contacts.

12. The device of claim 1, wherein the one of the anode contact or the cathode contacts comprises a copper contact layer, and the conductor is welded to the copper contact layer.

13. The device of claim 1, wherein the conductor has a length approximately coextensive with a length of the anode contact or the cathode contact.

14. The device of claim 1, wherein the thermally conductive and electrically resistive material comprises one of an anodized coating on the wall structure, a sheet of thermally conductive polymer material adjacent the wall structure, a thermal compound on the wall structure or a mineral-based sheet material adjacent the wall structure.

15. The device of claim 1, wherein the resilient portion of the conductor varies in position within a range of approximately 1 to 3 millimeters to maintain contact between the conductor and the wall structure in the presence of relative movement between the conductor and the wall structure.

28. The device of claim 1, wherein the thermally conductive and electrically resistive material comprises an anodized surface of the wall structure, the anodized surface comprising a conformal plastic coating.

29. The device of claim 1, wherein the wall structure is fabricated from stainless steel, and the thermally conductive and electrically resistive material comprises one of a sheet of plastic material or a mineral-based sheet material.

30. The device of claim 1, wherein:

the device comprises a plurality of the thin-film electrochemical cells; and

the conductor comprises a sheet of electrically conductive material that extends across the anode contact or the cathode contact of at least two of the electrochemical cells.

31. The device of claim 30, wherein the thermally conductive and electrically resistive material comprises one of an anodized coating on the wall structure, a sheet of thermally conductive polymer material adjacent the wall structure, a thermal compound on the wall structure or a mineral-based sheet material adjacent the wall structure.

32. The device of claim 1, wherein the conductor comprises a plurality of stacked conductors.

16. An energy storage device, comprising:

an enclosure including a first wall structure and a second wall structure;

a thermally conductive and electrically resistive material disposed on or adjacent to the first wall structure;

a thin-film electrochemical cell disposed between the first and second wall structures; and

a conductor, defining one of a positive contact or a negative contact for the electrochemical cell, that maintains engagement with the material disposed on the first wall structure in response to relative movement between the electrochemical cell and the first wall structure, the conductor defining a current path for conducting current between the electrochemical cell and a contact external to the electrochemical cell, and defining a thermal flux path for conducting thermal energy between the electrochemical cell and the thermally conductive and electrically resistive material disposed on the first wall structure.

17. The device of claim 16, wherein the conductor has one of a substantially C-shaped, double C-shaped, Z-shaped, O-shaped, S-shaped, V-shaped, L-shaped, single finger-shaped, or multiple finger-shaped cross-section.

18. The device of claim 16, further including a spring element captured by the conductor that cooperates with the conductor to maintain engagement between the conductor and the material disposed on the first wall structure in response to relative movement between the electrochemical cell and the first wall structure.

19. The device of claim 18, wherein the spring element includes a stop that impedes collapsing of the conductor when the conductor is subjected to a compressive force.

20. The device of claim 18, wherein the spring element includes a protrusion that provides electrical insulation between the conductor and a conductor of an adjacently disposed electrochemical cell in response to relative movement between the conductor and the first wall structure.

21. The device of claim 16, wherein the conductor has a length approximately coextensive with a length of the electrochemical cell.

22. The device of claim 16, wherein the thermally conductive and electrically resistive material comprises one of an anodized coating on the first wall structure, a polymer material adjacent the first wall structure, a thermal compound on the first wall structure or a sheet material disposed adjacent the first wall structure.

23. The device of claim 16, wherein the conductor varies in position within a range of approximately 1 to 3 millimeters to maintain engagement with the material disposed on the first wall structure in response to relative movement between the electrochemical cell and the first wall structure.

24. A method of transferring thermal energy and electrical current into and out of a thin-film electrochemical cell, comprising:

conducting current between the electrochemical cell and a contact external to the electrochemical cell using a resilient conductor defining one of a positive or a negative contact for the electrochemical cell;

conducting, using the resilient conductor, thermal energy between the electrochemical cell and thermally conductive and electrically resistive material disposed adjacent the resilient conductor; and

maintaining mechanical contact between the resilient conductor and the thermally conductive and electrically resistive material in response to variations in a separation distance between the electrochemical cell and the thermally conductive and electrically resistive material.

25. The method of claim 24, wherein maintaining mechanical contact between the resilient conductor and the thermally conductive and electrically resistive material comprises mechanically deforming the resilient conductor in response to variations in the separation distance between the electrochemical cell and the thermally conductive and electrically resistive material.

26. The method of claim 24, wherein maintaining mechanical contact between the resilient conductor and the thermally conductive and electrically resistive material comprises displacing a portion of the resilient conductor within a range of 1 to 3 millimeters in response to variations in the separation distance between the electrochemical cell and the thermally conductive and electrically resistive material.

27. The method of claim 24, wherein:

the electrochemical cell comprises laterally offset anode and cathode current collecting films; and

maintaining mechanical contact between the resilient conductor and the thermally conductive and electrically resistive material comprises flexing the laterally offset anode and cathode current collecting films in response to variations in the separation distance between the electrochemical cell and the thermally conductive and electrically resistive material.