Connector from the tab of an electrode current collector to the terminal pin of a feedthrough in an electrochemical cell

Patent metadata

Field	Value
Publication number	US-10205151-B2
Application number	US-201615289392-A
Country	US
Kind code	B2
Filing date	Oct 10, 2016
Priority date	Apr 20, 2012
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

A process for creating a laser braze weld joint between a current collector and a terminal pin in the construction of electrochemical cells is described. The laser braze welding process utilizes a laser weld instrument to create a braze-like joint between two work pieces. The weld joint is created by controlling the amount of laser heat and energy imparted to the work pieces through proper control and positioning of the laser beam with respect to the work pieces. Preferably, the method is used to bond the terminal pin to the cathode current collector. This method of attachment is suitable for either primary or secondary cells, particularly those powering implantable biomedical devices.

First claim

What is claimed is:

1. An electrochemical cell, comprising:
a) a casing;
b) an electrode assembly contained within the casing, the electrode assembly comprising:
i) an anode composed of an anode active material contacted to an anode current collector;
ii) a cathode composed of a cathode active material contacted to a cathode current collector; and
iii) an intermediate separator preventing direct physical contact between the anode and the cathode while permitting ionic flow therebetween;

c) a glass-to-metal seal supported in an opening in the casing, the glass-to-metal seal comprising a terminal pin in a non-conductive relationship with the casing, wherein a distal pin portion resides outside the casing and a proximal pin portion is inside the casing;
d) a coupler comprising an annular sidewall having a height extending to and meeting with an upper face wall and a lower face, wherein a recess extends from the lower face wall part-way through the coupler height toward, but not in communication with, the upper face wall, wherein the terminal pin is supported by the coupler with the proximal pin portion residing in the recess,
e) wherein a first weld connects the coupler to the proximal pin portion in the recess and a second weld connects the annular sidewall of the coupler to a tab for one of the anode current collector and the cathode current collector,
f) wherein the other of the anode current collector and the cathode current collector not joined to the coupler is electrically connected to a second terminal for the cell; and
g) an electrolyte contained inside the casing to activate the electrode assembly.

2. The electrochemical cell of claim 1 wherein the lower face wall of the coupler contacts the tab of the current collector with the second weld connecting the coupler to the tab surrounding the first weld connecting the coupler to the proximal terminal pin portion.

3. The electrochemical cell of claim 1 wherein a width of the coupler extending from the annular sidewall to the recess at the lower face wall contacts the tab of the current collector with the second weld connecting the coupler to the tab surrounding the first weld connecting the coupler to the proximal terminal pin portion.

4. The electrochemical cell of claim 1 wherein the one of the anode current collector and the cathode current collector connected to the coupler is of a first metal having a first melting temperature and the terminal pin is of a second metal having a second melting temperature, and the first melting temperature and the second melting temperature differ by at least about 500° C.

5. The electrochemical cell of claim 4 wherein the first metal of the one of the anode current collector and the cathode current collector is selected from the group consisting of aluminum, titanium, nickel, steel, stainless steel, niobium, copper, gold, silver, platinum, palladium, and combinations thereof.

6. The electrochemical cell of claim 4 wherein the second metal of the terminal pin is selected from the group consisting of molybdenum, tantalum, tungsten, and combinations thereof.

7. The electrochemical cell of claim 4 wherein the coupler is of a third metal selected from the group consisting of aluminum, titanium, nickel and stainless steel.

8. The electrochemical cell of claim 4 wherein the third melting temperature of the coupler is at least about 125° C. less than the second melting temperature of the terminal pin.

9. The electrochemical cell of claim 1 wherein at least one of the first and second welds is devoid of an intermetallic bond.

10. The electrochemical cell of claim 1 wherein at least one of the first and second welds comprises a boundary line that delineates the respective coupler from the proximal pin portion and the coupler from the tab of the one of the anode current collector and the cathode current collector of the first metal.

11. The electrochemical cell of claim 1 wherein at least one of the first and second welds is characterized as having been formed using a laser beam.

12. The electrochemical cell of claim 1 wherein the anode active material is selected from the group consisting of lithium, lithium alloys, lithium silver, lithium aluminum, lithium boron, lithium silver boron, carbon, and combinations thereof.

13. The electrochemical cell of claim 1 wherein the cathode active material is selected from the group consisting of silver vanadium oxide, copper silver vanadium oxide, manganese dioxide, cobalt nickel, nickel oxide, copper oxide, copper sulfide, iron disulfide, titanium disulfide, copper vanadium oxide, lithium nickel oxide, lithium manganese oxide, lithium cobalt oxide, lithium cobalt tin oxide, lithium cobalt nickel oxide, and mixtures thereof.

14. The electrochemical cell of claim 1 wherein the electrolyte comprises a nonaqueous solvent having an ionically conductive salt dissolved therein.

15. The electrochemical cell of claim 1 wherein an insulator is intermediate the glass-to-metal seal and the coupler.

16. An electrochemical cell, comprising:
a) a casing;
b) an electrode assembly contained within the casing, the electrode assembly comprising:
i) an anode composed of an anode active material contacted to an anode current collector;
ii) a cathode composed of a cathode active material contacted to a cathode current collector; and
iii) an intermediate separator preventing direct physical contact between the anode and the cathode while permitting ionic flow therebetween,
iv) wherein one of the anode current collector and the cathode current collector is composed of a first metal selected from the group consisting of aluminum, titanium, nickel, steel, stainless steel, niobium, copper, gold, silver, platinum, palladium, and combinations thereof, the first metal having a first melting temperature;

c) a glass-to-metal seal supported in an opening in the casing, the glass-to-metal seal comprising a terminal pin in a non-conductive relationship with the casing, wherein a distal pin portion resides outside the casing and a proximal pin portion is inside the casing, and wherein the terminal pin is of second metal selected from the group consisting of molybdenum, tantalum, tungsten, and combinations thereof;
d) a coupler comprising an annular sidewall having a height extending to and meeting with an upper face wall and a lower face, wherein a recess extends from the lower face wall part-way through the height toward, but not in communication with, the upper face wall, wherein the terminal pin is supported by the coupler with the proximal pin portion residing in the recess, and wherein the coupler is of a third metal selected from the group consisting of aluminum, titanium, nickel and stainless steel, the third metal having a third melting temperature that is less than the second melting temperature of the terminal pin,
e) wherein a first weld connects the coupler to the proximal pin portion in the recess and a second weld connects the annular sidewall of the coupler to a tab for one of the anode current collector and the cathode current collector,
f) wherein the other of the anode current collector and the cathode current collector not joined to the coupler is electrically connected to a second terminal for the cell; and
g) an electrolyte contained within the casing to activate the electrode assembly.

17. The electrochemical cell of claim 16 wherein the lower face wall of the coupler contacts the tab of the current collector with the second weld connecting the coupler to the tab surrounding the first weld connecting the coupler to the proximal terminal pin

Assignees

• Greatbatch Ltd

Inventors

• Dai Xiangyang
• Roy Mark J

Classifications

• B23K26/20 Primary

  Bonding (soldering by means of radiant energy B23K1/005) · CPC title

• H01M50/566

  by welding, soldering or brazing · CPC title

• H01M50/176

  for prismatic or rectangular cells (H01M50/181 takes precedence) · CPC title

• H01M50/562

  characterised by the material · CPC title

• H01M50/533

  characterised by the shape of the leads or tabs · CPC title