Electrochemical Cell With Improved Internal Contact

• US 20100068619A1
• Filed: 10/01/2009
• Published: 03/18/2010
• Est. Priority Date: 01/28/2005
• Status: Active Grant

• Current Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Original Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Inventors: Kaplin, David Aaron
• Granted Patent: US 8,283,066 B2
• Time in Patent Office: Days
• US Class Current: 429/174
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/058 Construction or manufacture
• CPC Class Codes: H01M 50/107 having curved cross-section, e.g. round or elliptic H01M50/103, H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 50/533 characterised by the shape of the leads or tabs
• CPC Class Codes: H01M 50/534 characterised by the material of the leads or tabs
• CPC Class Codes: H01M 50/538 Connection of several leads or tabs of wound or folded electrode stacks
• 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

Electrochemical battery cells with strip-like electrodes and having a pressure contact between a lead from one of the electrodes and a side wall of the cell container. An electrochemical cell having a spiral wound electrode assembly having an internal lead in direct pressure contact with a lithium foil negative electrode free of a separate current collector and in contact with an inner portion of the cell container, wherein specified contact between the lead and lithium foil provides current flow between the container and foil.

Claims

1. An electrochemical cell, comprising:

a substantially round, cylindrical container comprising a conductive material, said container having;

a closed end with a negative terminal, an open end sealed by an end assembly that is electrically insulated from the container and has a positive terminal and a sidewall extending between the closed end and the open end;

a nonaqueous, organic electrolyte;

a jellyroll electrode assembly comprising a positive electrode, a separator and a negative electrode consisting essentially of lithium or a lithium alloy of at least 90 wt. % lithium and having a length, a width and a cumulative surface area;

an internal lead connected to less than 0.7% of the cumulative surface area of the negative electrode at an edge of the negative electrode that is proximate to the closed end of the container;

wherein the lead extends a distance across the negative electrode measured along a longitudinal axis of the electrode assembly from the edge of the negative electrode that is greater than 10% and less than 88% of the width of the negative electrode;

wherein a portion of the lead is folded and extends upward to make electrical contact with the container sidewall by pressure only, said portion of the lead having an integrally formed groove to bias the lead against the sidewall.

2. An electrochemical cell according to claim 1, wherein the groove has a shape selected from the group consisting of:

a V-shape, an arc and a combination thereof.

3. An electrochemical cell according to claim 2, wherein the groove is disposed substantially parallel to a longitudinal axis of the jellyroll electrode assembly.

4. An electrochemical cell according to claim 1, wherein a maximum difference between the sidewall of the container is defined by one equation selected from the group consisting of:

5. An electrochemical cell, comprising:

a substantially round, cylindrical container comprising a conductive material having a closed end with a negative terminal, an open end sealed by an end assembly electrically insulated from the container and having a positive terminal, and a sidewall extending between the closed end and the open end;

a nonaqueous, organic electrolyte;

a jellyroll electrode assembly comprising a positive electrode, a separator and a negative electrode consisting essentially of lithium or a lithium alloy of at least 90 wt. % lithium and having a length, a width and a cumulative surface area; and

an internal lead oriented along a longitudinal axis of the jellyroll electrode assembly and folded so that a first terminal end of the lead is connected to the negative electrode and a second terminal end of the lead makes electrical contact with the container sidewall by pressure only; and

wherein a portion of the lead has a groove to bias the lead against the sidewall.

6. An electrochemical cell according to claim 5, wherein the groove has a shape selected from the group consisting of:

a V-shape, an arc and a combination thereof.

7. An electrochemical cell according to claim 5, wherein a maximum difference between the sidewall of the container is defined by one equation selected from the group consisting of:

8. An electrochemical cell according to claim 7, wherein the groove is disposed substantially parallel to a longitudinal axis of the jellyroll electrode assembly.

9. An electrochemical cell according to claim 5, wherein the internal lead connected to the negative electrode at an edge of the negative electrode that is proximate to the closed end of the container.

10. An electrochemical cell according to claim 5, wherein the internal lead is connected to less than 0.7% of the cumulative surface area of the negative electrode.

11. An electrochemical cell according to claim 10, wherein the internal lead is connected to at an edge of the negative electrode that is proximate to the closed end of the container.

12. The electrochemical cell according to claim 10, wherein the surface area is connected to 0.02% to 0.5% of the cumulative surface area.

13. The electrochemical cell according to claim 10, wherein the lead has an area of 5.0 mm² to less than 160 mm² in contact with the surface of the negative electrode and wherein the lead is nickel plated cold rolled steel, nickel, a nickel alloy, copper, a copper alloy, or stainless steel.

14. The electrochemical cell according to claim 13, wherein the lead has an area from 10.0 mm² to 92.6 mm² in contact with the surface of the negative electrode

15. An electrochemical cell according to claim 5, wherein the internal lead is connected to the negative electrode at an edge of the negative electrode that is proximate to the closed end of the container and extends a distance across the negative electrode measured along a longitudinal axis of the electrode assembly from the edge of the negative electrode that is greater than 10% and less than 88% of the width of the negative electrode;

16. The electrochemical cell according to claim 15, wherein the distance is between 10% to 60% of the width of the negative electrode.

17. The electrochemical cell according to claim 15, wherein the distance is between 10% to 50% of the width of the negative electrode.

18. The electrochemical cell according to claim 5, wherein there is no direct electrical contact between the sidewall of the container and either the negative electrode or the positive electrode contact.

19. An electrochemical cell, comprising:

a substantially round, cylindrical container comprising a conductive material having a closed end with a negative terminal, an open end sealed by an end assembly electrically insulated from the container and having a positive terminal, and a sidewall extending between the closed end and the open end;

a nonaqueous, organic electrolyte;

a jellyroll electrode assembly comprising a positive electrode, a separator and a negative electrode consisting essentially of lithium or a lithium alloy of at least 90 wt. % lithium and having a length, a width and a cumulative surface area;

an internal lead oriented along a longitudinal axis of the jellyroll electrode assembly and folded so that a first terminal end of the lead is connected to the negative electrode and a second terminal end of the lead makes electrical contact with the container side wall;

wherein the internal lead connected to less than 0.7% of the cumulative surface area of the negative electrode at an edge of the negative electrode that is proximate to the closed end of the container and extends a distance across the negative electrode measured along a longitudinal axis of the electrode assembly from the edge of the negative electrode that is greater than 10% and less than 88% of the width of the negative electrode.

20. The electrochemical cell according to claim 19, wherein the lead has a resistance of less than 15 mΩ

/cm length.

21. The electrochemical cell according to claim 20, wherein the resistance is less than 5 mΩ

/cm length.

22. The electrochemical cell according to claim 19, wherein there is no direct electrical contact between the sidewall of the container and either the negative electrode or the positive electrode contact.