CN-122025845-A - Electrode assembly and rechargeable battery having the same

Abstract

An electrode assembly and a rechargeable battery having the same are disclosed. The electrode assembly includes a separator, a positive electrode, and a negative electrode positioned such that the separator is between the positive electrode and the negative electrode and wound together with the separator. The negative electrode includes a negative electrode substrate, a first active material layer on a first surface of the negative electrode substrate, and a second active material layer on a second surface of the negative electrode substrate. A plurality of first grooves are formed in the first active material layer. The second grooves are formed in the second active material layer, and the first grooves have different patterns.

Inventors

• Min Zhongji
• Hong Daxuan
• Chi Jiongmin

Assignees

• 三星SDI株式会社

Dates

Publication Date

20260512

Application Date

20251029

Priority Date

20241108

Claims (20)

1. 1. An electrode assembly, the electrode assembly comprising: a diaphragm, and A positive electrode and a negative electrode positioned with the separator between the positive electrode and the negative electrode and wound together with the separator, Wherein the negative electrode includes a negative electrode substrate, a first active material layer on a first surface of the negative electrode substrate, and a second active material layer on a second surface of the negative electrode substrate, A plurality of first grooves formed in the first active material layer, and A plurality of second grooves are formed in the second active material layer, the plurality of second grooves having a different pattern than the plurality of first grooves.
2. 2. The electrode assembly of claim 1, wherein: the first surface faces the inside of the electrode assembly, and The plurality of first grooves are positioned in a dot pattern.
3. 3. The electrode assembly of claim 2, wherein: The plurality of first grooves are positioned in a dot pattern, and One or more of the plurality of first grooves has a width that becomes smaller as its distance from the negative electrode substrate decreases.
4. 4. The electrode assembly of claim 2, wherein: One or more of the plurality of first grooves has a width in the range of 20 μm to 60 μm, One or more of the plurality of first grooves has a depth in the range of 30 μm to 70 μm, and The first plurality of grooves has a density in the range of 100EA/mm 2 to 450EA/mm 2 .
5. 5. The electrode assembly of claim 1, wherein: the second surface faces the outside of the electrode assembly, and The plurality of second grooves are positioned in a line pattern.
6. 6. The electrode assembly according to claim 5, wherein the plurality of second grooves are positioned parallel to a width direction of the negative electrode and at a distance from each other in a length direction of the negative electrode.
7. 7. The electrode assembly of claim 5, wherein: one or more of the plurality of second grooves has a width greater than a depth thereof, and One or more of the plurality of second grooves has a constant width in a thickness direction of the negative electrode.
8. 8. The electrode assembly of claim 5, wherein: one or more of the plurality of second grooves has a width in the range of 40 μm to 70 μm, and One or more of the plurality of second grooves has a depth in the range of 10 μm to 30 μm.
9. 9. An electrode assembly, the electrode assembly comprising: a diaphragm, and A positive electrode and a negative electrode positioned with the separator between the positive electrode and the negative electrode and wound together with the separator, Wherein the negative electrode includes a negative electrode substrate, a first active material layer on an inner surface of the negative electrode substrate, and a second active material layer on an outer surface of the negative electrode substrate, A plurality of first grooves are formed in the first active material layer, A plurality of second grooves formed in the second active material layer, the plurality of second grooves having a different pattern from the plurality of first grooves, and The area of the surface area of the second active material layer exposed by the plurality of second grooves is greater than the area of the surface area of the first active material layer exposed by the plurality of first grooves.
10. 10. The electrode assembly of claim 9, wherein: the plurality of first grooves are positioned in a dot pattern, and The plurality of second grooves are positioned in a line pattern.
11. 11. The electrode assembly of claim 10, wherein: The plurality of first grooves are positioned in a dot pattern, and One or more of the plurality of first grooves has a width that becomes smaller as its distance from the negative electrode substrate decreases.
12. 12. The electrode assembly of claim 11, wherein: One or more of the plurality of first grooves has a width in the range of 20 μm to 60 μm, One or more of the plurality of first grooves has a depth in the range of 30 μm to 70 μm, and The first plurality of grooves has a density in the range of 100EA/mm 2 to 450EA/mm 2 .
13. 13. The electrode assembly according to claim 10, wherein the plurality of second grooves are positioned in the line pattern parallel to a width direction of the negative electrode and spaced apart from each other in a length direction of the negative electrode.
14. 14. The electrode assembly of claim 13, wherein: one or more of the plurality of second grooves has a width greater than a depth thereof, and One or more of the plurality of second grooves has a constant width in a thickness direction of the negative electrode.
15. 15. The electrode assembly of claim 14, wherein: one or more of the plurality of second grooves has a width in the range of 40 μm to 70 μm, and One or more of the plurality of second grooves has a depth in the range of 10 μm to 30 μm.
16. 16. The electrode assembly of claim 1, wherein: the negative electrode includes a flat portion and a curved portion, an The first plurality of grooves and the second plurality of grooves are positioned at least in the curved portion.
17. 17. The electrode assembly of claim 16, wherein the first and second pluralities of grooves are positioned throughout the planar portion and the curved portion.
18. 18. A rechargeable battery, the rechargeable battery comprising: The electrode assembly according to claim 1 or 9, and A case configured to accommodate and seal the electrode assembly and the electrolyte in the internal space.
19. 19. The rechargeable battery of claim 18, wherein: the electrode assembly is wound around two rotation axes and includes a center portion and a pair of bent portions located at both sides of the center portion, and The plurality of first grooves and the plurality of second grooves are located at least in the pair of curved portions.
20. 20. The rechargeable battery of claim 18, wherein: The electrode assembly is wound around a rotation axis, The plurality of first grooves are located in the whole first active material layer, and The plurality of second grooves is located throughout the second active material layer.

Description

Electrode assembly and rechargeable battery having the same Technical Field The present disclosure relates to a rechargeable battery, and to a rechargeable battery having a winding-type electrode assembly. Background Rechargeable batteries are used for a variety of purposes including as power sources for small electronic devices such as mobile phones and laptop computers, and as power sources for driving motors such as electric vehicles and hybrid vehicles. The rechargeable battery includes an electrode assembly and a case accommodating and sealing the electrode assembly and an electrolyte in an inner space. The electrode assembly includes two electrodes (positive and negative electrodes) and a separator. To increase the output and capacity of the rechargeable battery, it may be advantageous to increase the energy density and load level of the electrodes. However, electrodes developed in this way may have undesirable side effects that reduce the impregnability of the electrolyte. When the impregnation of the electrolyte in the electrode is reduced, precipitation may begin in a region where the impregnation of the electrolyte is insufficient, which may reduce the life characteristics of the rechargeable battery. Disclosure of Invention The present disclosure describes an electrode assembly and a rechargeable battery including the same capable of improving life characteristics by increasing energy density and load level of an electrode while improving impregnation of an electrolyte. The electrode assembly according to the example embodiment includes a separator, a positive electrode, and a negative electrode positioned such that the separator is between the positive electrode and the negative electrode and wound together with the separator. The negative electrode includes a negative electrode substrate, a first active material layer on a first surface of the negative electrode substrate, and a second active material layer on a second surface of the negative electrode substrate. A plurality of first grooves are formed in the first active material layer. A plurality of second grooves are formed in the second active material layer, the plurality of second grooves having a different pattern than the plurality of first grooves. The first surface may face the inside of the electrode assembly, and the plurality of first grooves may be disposed in a dot pattern. The plurality of first grooves may be disposed in a dot pattern, and each or one or more of the plurality of first grooves may have a width that becomes smaller as its distance from the negative electrode substrate decreases. The width of each or one or more of the plurality of first grooves may be in the range of approximately 20 μm to 60 μm. The depth of each or one or more of the plurality of first grooves may be in the range of approximately 30 μm to 70 μm. The density of the plurality of first grooves may be in a range of approximately 100EA/mm 2 to 450EA/mm 2. The second surface may face the outside of the electrode assembly, and the plurality of second grooves may be positioned in a line pattern. The plurality of second grooves may be positioned parallel to the width direction of the negative electrode and spaced apart from each other in the length direction of the negative electrode. The width of each or one or more of the plurality of second grooves may be greater than the depth of each or one or more of the plurality of second grooves. Each or one or more of the plurality of second grooves may have a constant width or a substantially constant width in the thickness direction of the negative electrode. The width of each or one or more of the plurality of second grooves may be in the range of approximately 40 μm to 70 μm. The depth of each or one or more of the plurality of second grooves may be in the range of approximately 10 μm to 30 μm. An electrode assembly according to another example embodiment includes a separator, and positive and negative electrodes positioned such that the separator is between the positive and negative electrodes and wound together with the separator. The negative electrode includes a negative electrode substrate, a first active material layer on an inner surface of the negative electrode substrate, and a second active material layer on an outer surface of the negative electrode substrate. A plurality of first grooves are formed in the first active material layer. A plurality of second grooves are formed in the second active material layer, the plurality of second grooves having a different pattern than the plurality of first grooves. The area of the surface area of the second active material layer exposed by the plurality of second grooves is greater than the area of the surface area of the first active material layer exposed by the plurality of first grooves. The plurality of first grooves may be positioned in a dot pattern and the plurality of second grooves may be positioned in a line pattern. The plurality of first gro