Cylindrical secondary battery comprising improved current collector plate, battery pack and vehicle including the same

Patent metadata

Field	Value
Publication number	US-12374762-B2
Application number	US-202218271796-A
Country	US
Kind code	B2
Filing date	Oct 28, 2022
Priority date	Oct 29, 2021
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A cylindrical secondary battery includes an electrode assembly having a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode, the positive electrode, the negative electrode, and the separator being wound in a winding direction, the positive electrode including a positive electrode uncoated portion exposed beyond the separator, the negative electrode including a negative electrode uncoated portion exposed beyond the separator, a positive electrode current collector plate coupled to the positive electrode uncoated portion by one or more positive electrode welding portions, and a negative electrode current collector plate coupled to the negative electrode uncoated portion by one or more negative electrode welding portions. A coupling area between the positive electrode uncoated portion and the positive electrode current collector plate is smaller than a coupling area between the negative electrode uncoated portion and the negative electrode current collector plate.

First claim

What is claimed is:

1. A cylindrical secondary battery comprising:
an electrode assembly having a positive electrode having a sheet shape, a negative electrode having a sheet shape, and a separator located between the positive electrode and the negative electrode, the positive electrode, the negative electrode, and the separator being wound in a winding direction, the positive electrode including a positive electrode uncoated portion exposed beyond the separator at a long side end, the negative electrode including a negative electrode uncoated portion exposed beyond the separator at a long side end;
a positive electrode current collector plate coupled to the positive electrode uncoated portion by one or more positive electrode welding portions; and
a negative electrode current collector plate coupled to the negative electrode uncoated portion by one or more negative electrode welding portions,
wherein a coupling area between the positive electrode uncoated portion and the positive electrode current collector plate is smaller than a coupling area between the negative electrode uncoated portion and the negative electrode current collector plate.

2. The cylindrical secondary battery according to claim 1 , wherein a number of the negative electrode welding portions is greater than a number of the positive electrode welding portions.

3. The cylindrical secondary battery according to claim 1 , wherein the positive electrode current collector plate covers a top of the electrode assembly, and
wherein the negative electrode current collector plate covers a bottom of the electrode assembly.

4. The cylindrical secondary battery according to claim 3 , wherein the positive electrode current collector plate includes one or more strips extending along a radial direction of the electrode assembly from a center of the positive electrode current collector plate, the one or more positive electrode welding portions being located on the one or more strips of the positive electrode current collector plate, and
wherein the negative electrode current collector plate includes one or more strips extending along the radial direction of the electrode assembly from a center of the negative electrode current collector plate, and the one or more negative electrode welding portions are located on the one or more strips of the negative electrode current collector plate.

5. The cylindrical secondary battery according to claim 4 , wherein the one or more strips of the positive electrode current collector plate includes two or more strips arranged at equal intervals, and
wherein the one or more strips of the negative electrode current collector plate includes two or more strips arranged at equal intervals.

6. The cylindrical secondary battery according to claim 4 , wherein a number of the strips of the negative electrode current collector plate is M, and a number of the strips of the positive electrode current collector plate is 1 to M−1 (M is a natural number equal to or greater than 2).

7. The cylindrical secondary battery according to claim 4 , wherein a number of the positive electrode welding portions is smaller than a number of the negative electrode welding portions.

8. The cylindrical secondary battery according to claim 1 , wherein a number of the positive electrode welding portions is equal to a number of the negative electrode welding portions, and
wherein an area of one positive electrode welding portion of the one or more positive electrode welding portions is smaller than an area of one negative electrode welding portion of the one or more negative electrode welding portions.

9. The cylindrical secondary battery according to claim 8 , wherein the one or more positive electrode welding portions and the one or more negative electrode welding portions extend along a radial direction of the electrode assembly.

10. The cylindrical secondary battery according to claim 3 , wherein the positive electrode current collector plate and the negative electrode current collector plate have a same outline shape as a top and bottom of the electrode assembly, respectively.

11. The cylindrical secondary battery according to claim 1 , further comprising:
a battery can configured to accommodate the electrode assembly therein, the battery can including an open portion and a partially closed portion opposite the open portion, the battery can being electrically connected to the negative electrode uncoated portion;
a cap plate configured to seal the open portion of the battery can; and
a rivet terminal at a center of the partially closed portion, the rivet being electrically connected to the positive electrode uncoated portion.

12. The cylindrical secondary battery according to claim 11 , wherein the cap plate is not connected to the electrode assembly so as to have no polarity.

13. The cylindrical secondary battery according to claim 11 , wherein the positive electrode current collector plate includes:
a rim portion;
one or more positive electrode tab coupling portions configured to extend inward from the rim portion, the one or more positive electrode tab coupling portion being coupled to the positive electrode uncoated portion by the one or more positive electrode welding portions; and
a terminal coupling portion spaced apart from the one or more positive electrode tab coupling portions, and
wherein the rivet terminal is coupled to the terminal coupling portion.

14. The cylindrical secondary battery according to claim 13 , wherein the rim portion defines a partially empty space.

15. The cylindrical secondary battery according to claim 13 , wherein the one or more positive electrode tab coupling portions and the terminal coupling portion are electrically connected by the rim portion.

16. The cylindrical secondary battery according to claim 13 , wherein the terminal coupling portion is located in a center portion of an inner space of the rim portion.

17. The cylindrical secondary battery according to claim 13 , wherein the one or more positive electrode tab coupling portions includes a plurality of the positive electrode tab coupling portions.

18. The cylindrical secondary battery according to claim 17 , wherein the plurality of positive electrode tab coupling portions are arranged at equal intervals along a circumferential direction of the rim.

19. The cylindrical secondary battery according to claim 17 , wherein each of the plurality of positive electrode tab coupling portions has a same extended length.

20. The cylindrical secondary battery according to claim 17 , wherein the terminal coupling portion is disposed to be surrounded by the plurality of positive electrode tab coupling portions.

21. The cylindrical secondary battery according to claim 13 , wherein the electrode assembly includes a cavity in a winding center portion thereof, and the terminal coupling portion is disposed at a location corresponding to the cavity.

22. The cylindrical secondary battery according to claim 13 , wherein the battery can includes a beading part at an end adjacent to the open portion, and
wherein the negative electrode current collector plate includes:
one or more negative electrode tab coupling portions coupled to the negative electrode uncoated portion by the one or more negative electrode welding portions; and
one or more can coupling portions electrically coupled to the beading part.

23. The cylindrical secondary battery according to claim 22 , wherein the one or more can coupling portions

Assignees

• Lg Energy Solution Ltd

Inventors

• Lee Byoung-Gu
• Ryu Duk-Hyun
• Lee Kwan-Hee

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M10/0587

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M50/536

  characterised by the method of fixing the leads to the electrodes, e.g. by welding · CPC title

• H01M50/545

  formed by the casing of the cells (cup shaped terminals adapted for cells having curved cross-section H01M50/56) · CPC title