CN-122000492-A - Electrode assembly and secondary battery including the same

Abstract

The present disclosure relates to an electrode assembly and a secondary battery including the same. The electrode assembly according to the present disclosure includes a first electrode connected to a first electrode tab, a second electrode connected to a second electrode tab, and a separator between the first electrode and the second electrode. The first electrode, the separator, and the second electrode are sequentially stacked and wound about a winding axis such that the electrode assembly includes a core portion having a central hole formed therein and an outer portion connected to the core portion. The length of the core portion in the direction of the winding axis is different from the length of the outer portion in the direction of the winding axis.

Inventors

• ZHAO CHENGMIN

Assignees

• 三星SDI株式会社

Dates

Publication Date

20260508

Application Date

20250928

Priority Date

20241106

Claims (20)

1. 1. An electrode assembly, comprising: a first electrode connected to the first electrode tab; a second electrode connected to the second electrode tab, and A separator between the first electrode and the second electrode, Wherein the first electrode, the separator, and the second electrode are sequentially stacked and wound around a winding axis such that the electrode assembly includes a core portion having a central hole formed therein and an outer portion connected to the core portion, and Wherein the length of the core portion in the direction of the winding axis is different from the length of the outer portion in the direction of the winding axis.
2. 2. The electrode assembly of claim 1, wherein the outer portion comprises a first outer portion connected to the core portion and a second outer portion connected to the first outer portion, Wherein the length of the first outer portion in the direction of the winding axis is shorter than the length of the core portion in the direction of the winding axis, and Wherein the length of the second outer portion in the direction of the winding axis is shorter than the length of the first outer portion in the direction of the winding axis.
3. 3. The electrode assembly of claim 2, wherein the first and second electrode tabs protrude from the first outer portion.
4. 4. The electrode assembly of claim 2, wherein the electrode assembly has: A first outer surface formed by the core portion; a second outer surface formed by the first outer portion, and A third outer surface formed by the second outer portion.
5. 5. The electrode assembly of claim 4, wherein the top of the core portion, the top of the first outer portion, and the top of the second outer portion extend along lines parallel to each other, Wherein the first outer surface is perpendicular to the top of the core portion and the top of the first outer portion, and Wherein the second outer surface is perpendicular to the top of the first outer portion and the top of the second outer portion.
6. 6. The electrode assembly according to claim 4, wherein the top of the core portion, the top of the first outer portion, and the top of the second outer portion extend along lines parallel to each other, and Wherein the first and second outer surfaces are inclined radially outwardly from the core portion and the first outer portion, respectively.
7. 7. A secondary battery, comprising: An electrode assembly; A cylindrical case accommodating the electrode assembly; a cover plate sealing the opening of the cylindrical housing, and A gasket between the cover plate and the cylindrical housing, Wherein the electrode assembly comprises: a first electrode connected to the first electrode tab; a second electrode connected to the second electrode tab, and A separator interposed between the first electrode and the second electrode, Wherein the first electrode, the separator, and the second electrode are sequentially stacked and wound around a winding axis to form the electrode assembly, and the electrode assembly includes a core portion having a central hole formed therein and an outer portion connected to the core portion, and Wherein the length of the core portion in the direction of the winding axis is longer than the length of the outer portion in the direction of the winding axis.
8. 8. The secondary battery according to claim 7, wherein the cap plate comprises: a first flat portion located at a center of the cap plate and protruding in a direction away from the electrode assembly accommodated in the cylindrical case; A second flat portion located outside the first flat portion, and And a connection portion located between the first flat portion and the second flat portion.
9. 9. The secondary battery according to claim 8, wherein the connection portion is inclined radially outward from the first flat portion.
10. 10. The secondary battery according to claim 8, wherein a recess is formed in a lower surface of the second flat portion of the cap plate.
11. 11. The secondary battery according to claim 8, wherein the outer portion includes: A first outer portion connected to the core portion, and A second outer portion connected to the first outer portion, Wherein the length of the first outer portion in the direction of the winding axis is shorter than the length of the core portion in the direction of the winding axis, and Wherein the length of the second outer portion in the direction of the winding axis is shorter than the length of the first outer portion in the direction of the winding axis.
12. 12. The secondary battery according to claim 11, wherein the first electrode tab protrudes from the first outer portion and is connected to the second flat portion of the cap plate.
13. 13. The secondary battery according to claim 11, wherein the second electrode tab protrudes from the first outer portion and is connected to a bottom portion of the cylindrical case.
14. 14. The secondary battery according to claim 7, further comprising an insulating member interposed between the cap plate and the electrode assembly.
15. 15. The secondary battery according to claim 11, wherein the electrode assembly has: A first outer surface formed by the core portion; a second outer surface formed by the first outer portion, and A third outer surface formed by the second outer portion.
16. 16. The secondary battery according to claim 15, wherein the top of the core portion, the top of the first outer portion, and the top of the second outer portion extend along lines parallel to each other, Wherein the first outer surface is perpendicular to the top of the core portion and the top of the first outer portion, and Wherein the second outer surface is perpendicular to the top of the first outer portion and the top of the second outer portion.
17. 17. The secondary battery according to claim 15, wherein the top of the core portion, the top of the first outer portion, and the top of the second outer portion extend along lines parallel to each other, Wherein the first and second outer surfaces are inclined radially outwardly from the core portion and the first outer portion, respectively.
18. 18. The secondary battery according to any one of claims 11 to 17, wherein the top of the core portion is higher than a bottom of the second flat portion of the cap plate in the direction of the winding axis.
19. 19. The secondary battery according to any one of claims 11 to 17, wherein the top of the first outer portion is higher than the bottom of the gasket in the direction of the winding axis.
20. 20. The secondary battery according to any one of claims 11 to 17, wherein a longest diameter of the first outer portion is shorter than a diameter of a circle formed by an inner surface of the gasket.

Description

Electrode assembly and secondary battery including the same Technical Field The present disclosure relates to an electrode assembly and a secondary battery including the same. Background Unlike primary batteries, which are not designed to be (re) charged, secondary (or rechargeable) batteries are batteries that are designed to be discharged and re-charged. Low-capacity secondary batteries are used in portable small-sized electronic devices such as smart phones, function phones, notebook computers, digital cameras, and camcorders, and large-capacity secondary batteries are widely used as power sources for driving motors in hybrid vehicles and electric vehicles and for storing electric power (e.g., home-and/or utility-scale electric power storage). The secondary battery generally includes an electrode assembly including a positive electrode and a negative electrode, a case accommodating the electrode assembly, and an electrode terminal connected to the electrode assembly. In a secondary battery, the energy density is the amount of energy that can be stored per unit volume. The high energy density secondary battery provides increased operation time in the portable device and increased driving range in the electric vehicle. Accordingly, the energy density of the secondary battery is considered to be one of important factors determining the performance of the secondary battery, and various efforts have been made to increase the energy density of the secondary battery. The above information disclosed in this background section is for enhancement of understanding of the background of the disclosure and, therefore, may include information that does not form a related (or prior) art. Disclosure of Invention One aspect of the present disclosure provides an electrode assembly and a secondary battery including the same. These and other aspects and features of the present disclosure will be described in, or will be apparent from, the following description of the embodiments of the present disclosure. According to one embodiment of the present disclosure, there is provided an electrode assembly including a first electrode connected to a first electrode tab, a second electrode connected to a second electrode tab, and a separator between the first electrode and the second electrode, wherein the first electrode, the separator, and the second electrode are sequentially stacked and wound around a winding axis such that the electrode assembly includes a core portion and an outer portion connected to the core portion, the core portion having a central hole formed therein, and a length of the core portion in a direction of the winding axis is different from a length of the outer portion in the direction of the winding axis. According to one embodiment, the outer portion may comprise a first outer portion connected to the core portion and a second outer portion connected to the first outer portion, a length of the first outer portion in the direction of the winding axis may be shorter than the length of the core portion in the direction of the winding axis, and a length of the second outer portion in the direction of the winding axis may be shorter than the length of the first outer portion in the direction of the winding axis. According to one embodiment, the first electrode tab and the second electrode tab may protrude from the first outer portion. According to one embodiment, the electrode assembly may have a first outer surface formed by the core portion, a second outer surface formed by the first outer portion, and a third outer surface formed by the second outer portion. According to one embodiment, the top of the core portion, the top of the first outer portion and the top of the second outer portion may extend along lines parallel to each other, the first outer surface may be perpendicular to the top of the core portion and the top of the first outer portion, and the second outer surface may be perpendicular to the top of the first outer portion and the top of the second outer portion. According to one embodiment, the top of the core portion, the top of the first outer portion and the top of the second outer portion may extend along lines parallel to each other, and the first outer surface and the second outer surface may be inclined radially outwardly from the core portion and the first outer portion, respectively. According to one embodiment of the present invention for solving the technical problem, there is provided a secondary battery including an electrode assembly, a cylindrical case accommodating the electrode assembly, a cap plate sealing an opening of the cylindrical case, and a gasket interposed between the cap plate and the cylindrical case, wherein the electrode assembly includes a first electrode connected to a first electrode tab, a second electrode connected to a second electrode tab, and a separator interposed between the first electrode and the second electrode, wherein the first electrode, the separator