Welding methods and apparatus for batteries

• US 20060222942A1
• Filed: 03/31/2005
• Published: 10/05/2006
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Casby, Kurt J., Zhao, Hailiang
• Granted Patent: US 7,544,220 B2
• Time in Patent Office: Days
• US Class Current: 429/180
• CPC Class Codes: H01M 10/0404 Machines for assembling batteries
• CPC Class Codes: H01M 10/0413 Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes
• CPC Class Codes: H01M 10/0431 Cells with wound or folded electrodes H01M10/045 takes precedence
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 50/147 Lids or covers
• CPC Class Codes: H01M 50/15 for prismatic or rectangular cells H01M50/153 takes precedence
• CPC Class Codes: H01M 50/50 Current conducting connections for cells or 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 29/49114 including adhesively bonding

Abstract

Embodiments of the invention provide an electrochemical cell including an electrode assembly having one or more of the electrodes being coupled to a feedthrough assembly. The one or more electrodes each include a connection tab. The connection tab extends a distance from separation material between the one or more electrodes (e.g., anode and cathode). The connection tab is provided to contact (e.g., electrically connected) a feedthrough pin of the feedthrough assembly by laser welding. The feedthrough pin with respect to the connection tab is oriented in at least one position lying within a 90 degree orientation on the connection tab. The feedthrough pin is coupled to the connection tab by laser welding.

Claims

1. An electrochemical cell of an implantable medical device, comprising:

a battery coil having an electrode assembly, the electrode assembly having one or more electrodes, each of the one or more electrodes having a tab extending therefrom; and

a battery header having a first feedthrough assembly, the first feedthrough assembly having a first feedthrough pin extending therefrom, the first feedthrough pin laser welded to a first tab extending from a first electrode of the one or more electrodes.

2. The electrochemical cell of claim 1, wherein the electrochemical cell is a lithium ion cell.

3. The electrochemical cell of claim 1, wherein the electrode assembly is a stacked plate assembly of the one or more electrodes.

4. The electrochemical cell of claim 1, wherein the first tab and first feedthrough pin are comprised of dissimilar materials.

5. The electrochemical cell of claim 1, wherein the first tab is of aluminum and the first feedthrough pin is of aluminum with titanium alloys.

6. The electrochemical cell of claim 1, wherein the first tab comprises at least one tab extending from the first electrode.

7. The electrochemical cell of claim 1, wherein the laser weld includes at least one point at which the first tab and the first feedthrough pin are coupled.

8. The electrochemical cell of claim 1, wherein the first feedthrough pin includes a connection portion that is oriented with respect to the first tab so that the connection portion of the first feedthrough pin is generally parallel with the upper edge of the first tab.

9. The electrochemical cell of claim 1, further comprising one of a coupling and a second feedthrough pin extending from the battery header, the one of the coupling and the second feedthrough pin coupled to a second tab extending from a second electrode of the one or more electrodes by laser welding thereof.

10. A method of manufacturing an electrochemical cell, comprising:

providing a battery coil having an electrode assembly, the electrode assembly having one or more electrodes, each of the one or more electrodes having a tab extending therefrom;

providing a battery header having a first feedthrough assembly, the first feedthrough assembly having a first feedthrough pin extending therefrom;

joining the battery coil with the battery header so as to form a joined unit whereby the first feedthrough pin of the battery header extends across a first tab of the battery coil; and

coupling the first feedthrough pin to the first tab by laser welding at a point where the first feedthrough pin contacts the first tab.

11. The method of claim 10, wherein the step of coupling the first feedthrough pin to the first tab further involves the step of manipulating the first feedthrough pin and the first tab, wherein such manipulation involves orienting only a connection portion of the feedthrough pin so that only the connection portion of the first feedthrough pin extends across the first tab.

12. The method of claim 10, wherein the step of coupling the first feedthrough pin to the first tab further involves orienting the first feedthrough pin so that the first feedthrough pin extends across the first tab in at least one position, wherein the at least one position lies within a 90 degree orientation on the first tab.

13. The method of claim 10, further comprising the step of providing a platform for positioning the joined unit prior to coupling the first feedthrough pin and first tab, wherein the platform has a plurality of securing mechanisms used to prevent movement of the joined unit during the laser welding.

14. The method of claim 13, wherein the step of providing the platform further includes providing at least one heat sink on the platform, wherein the joined unit is positioned on the platform so that the first tab contacts one of the at least one heat sink.

15. The method of claim 14, wherein the step of providing the platform further includes supporting the one heat sink with a linear actuator, wherein the linear actuator is located between the platform and the one heat sink so the one heat sink can deflect when contacted by the tab, and wherein the linear actuator is of a certain size in order to limit amount of deflection by the one heat sink to create contact between the first tab and the first feedthrough pin.

16. The method of claim 13, wherein the step of providing the platform further includes providing a shield used to protect the battery coil during laser welding of the first feedthrough pin and the first tab.

17. The method of claim 10, wherein the battery header further includes one of a coupling and a second feedthrough assembly having a second feedthrough pin extending therefrom, wherein the one of the coupling and the second feedthrough pin is coupled to a second tab of the battery coil.

18. The method of claim 17, wherein the battery header further includes at least one coupling, wherein the coupling is of nickel and the second tab is of aluminum.

19. A method of manufacturing an electrochemical cell, comprising:

providing an battery coil having an electrode assembly, the electrode assembly having one or more electrodes, each of the one or more electrodes having a tab extending therefrom;

providing a battery header having a first feedthrough assembly, the first feedthrough assembly having a feedthrough pin extending therefrom;

joining the battery coil with the battery header so as to form a joined unit whereby a first feedthrough pin of the battery header extends across a first tab of the battery coil and at least one of a coupling and a second feedthrough pin;

providing a platform for the joined unit, the platform having a plurality of securing members, a heat sink, and a shield;

positioning the joined unit on the platform so that the first tab contacts the heat sink;

securing the joined unit to the platform using one or more securing members;

positioning the shield so as to protect the battery coil during coupling of the first feedthrough pin and the first tab; and

coupling the first feedthrough pin to the first tab by laser welding at a point where the first feedthrough pin contacts the first tab.

20. The method of claim 19, wherein the step of securing the joined unit includes using the securing members to prevent vertical or horizontal movement of the joined unit.