CN-122026015-A - Secondary battery and method for manufacturing the same

Abstract

The present disclosure relates to a secondary battery and a method for manufacturing the same. The secondary battery includes an electrode assembly including a plurality of electrode plates including a first tab and a second tab and each including a coating portion coated with an active material, and a plurality of separators between the plurality of electrode plates, a current collector electrically connected to the first tab and the second tab, and a case accommodating the electrode assembly, wherein the current collector includes a first section, the first tab is connected to the first section, and the first section includes a first sub-section and a second sub-section, a portion of the first tab is welded to the first sub-section in an initial bent state, and the remaining portion of the first tab is welded to the second sub-section in a secondary bent state.

Inventors

• Jin Menyou
• HUANG RENXUAN
• Song Duocheng

Assignees

• 三星SDI株式会社

Dates

Publication Date

20260512

Application Date

20250925

Priority Date

20241111

Claims (20)

1. 1. A secondary battery, comprising: An electrode assembly including a plurality of electrode plates including a first tab and a second tab, and a plurality of separators between the plurality of electrode plates, each of the plurality of electrode plates including a coating portion coated with an active material; a current collector electrically connected to the first and second tabs, and A case accommodating the electrode assembly, wherein: the current collector includes a first section, the first tab is connected to the first section, and The first section includes a first sub-section to which a portion of the first tab is welded in an initial bent state and a second sub-section to which the remaining portion of the first tab is welded in a secondary bent state.
2. 2. The secondary battery according to claim 1, wherein: The current collector further includes a second section, the second tab being welded to the second section, and The second section includes a third sub-section to which a portion of the second tab is welded in an initial bent state and a fourth sub-section to which the remaining portion of the second tab is welded in a secondary bent state.
3. 3. The secondary battery according to claim 2, wherein the first tab and the second tab are initially bent in opposite directions.
4. 4. The secondary battery according to claim 2, wherein the first and second tabs are secondarily bent in the same direction.
5. 5. The secondary battery according to claim 2, wherein: The current collector further comprises a central section, The first sub-section extends from the central section in a first direction, The third sub-section extends from the central section in a second direction, and The second direction is different from the first direction.
6. 6. The secondary battery according to claim 2, wherein: The portion of the first tab and the first subsection are welded to each other in a first plane, and the portion of the second tab and the third subsection are welded to each other in the first plane, The remaining portion of the first tab and the second subsection are welded to each other on a second plane different from the first plane, and The remaining portion of the second tab and the fourth subsection are welded to each other on a third plane different from the first plane and parallel to the second plane.
7. 7. The secondary battery according to claim 1, wherein a separation space is formed between the remaining portion of the first tab welded to the second subsection and an outermost coating portion of the coating portion adjacent to the second subsection.
8. 8. The secondary battery according to any one of claims 1 to 7, wherein: a first set of weld lines on the first subsection, and Each of the first set of bonding wires extends in a direction in which the first wire tab is initially bent.
9. 9. The secondary battery according to claim 8, wherein: a second set of weld lines on the second sub-section, and Each of the second set of bonding wires extends in a direction in which the first tab is secondarily bent.
10. 10. The secondary battery according to any one of claims 1 to 7, wherein the first tab is laser welded to the first section.
11. 11. The secondary battery according to any one of claims 1 to 7, wherein the case includes: a first long side wall and a second long side wall facing each other and spaced apart from each other, and The first and second short sidewalls facing each other and spaced apart from each other, wherein: The first and second short sidewalls have an area smaller than an area of the first and second long sidewalls, The first subsection facing the first short sidewall, and The second subsection faces the first long sidewall.
12. 12. A method for manufacturing a secondary battery, the method comprising: Preparing an electrode assembly including a plurality of electrode plates and a plurality of separators disposed between the plurality of electrode plates, wherein a first tab and a second tab are formed in the plurality of electrode plates, and each of the plurality of electrode plates includes a coating portion coated with an active material; preparing a current collector including a first section electrically connected to the first tab and a second section electrically connected to the second tab; Initially bending the first wiring lug; secondarily bending the first wiring lug; Welding a portion of the first tab in an initially bent state to a first sub-section of the first section; welding the remaining part of the first tab in the secondarily bent state to the second sub-section of the first section, and The electrode assembly coupled with the current collector is inserted into a case.
13. 13. The method for manufacturing a secondary battery according to claim 12, further comprising: initially bending the second wire connecting piece; secondarily bending the second wiring lug; Welding a portion of the second tab in an initially bent state to a third sub-section of the second section, and And welding the rest part of the second wire lug in the secondary bending state to a fourth subsection of the second section.
14. 14. The method for manufacturing a secondary battery according to claim 13, wherein the first tab and the second tab are initially bent in opposite directions.
15. 15. The method for manufacturing a secondary battery according to claim 13, wherein the first tab and the second tab are secondarily bent in the same direction.
16. 16. The method for manufacturing a secondary battery according to claim 13, wherein: performing welding between the portion of the first tab and the first subsection and welding between the portion of the second tab and the third subsection on a first plane, Performing welding between the remaining portion of the first tab and the second subsection on a second plane different from the first plane, and The welding between the remaining part of the second tab and the fourth subsection is performed on a third plane different from the first plane and parallel to the second plane.
17. 17. The method for manufacturing a secondary battery according to any one of claims 12 to 16, further comprising disposing a support plate on one surface of the electrode assembly before secondarily bending the first tab.
18. 18. The method for manufacturing a secondary battery according to claim 17, wherein the support plate is disposed between the remaining portion of the first tab and an outermost coating portion of the coating portion adjacent to the second sub-section.
19. 19. The method for manufacturing a secondary battery according to claim 17, further comprising removing the support plate after welding to the second subsection.
20. 20. The method for manufacturing a secondary battery according to claim 17, wherein the support plate comprises a ceramic material.

Description

Secondary battery and method for manufacturing the same Technical Field The present disclosure relates to a secondary battery and a method for manufacturing 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 for 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., electric power storage at home and/or utility scale). 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. The above information disclosed in this background section is for enhancement of understanding of the background of the present disclosure and, therefore, it may contain information that does not form a related (or prior) art. Disclosure of Invention An embodiment includes a secondary battery including an electrode assembly including a plurality of electrode plates and a plurality of separators between the plurality of electrode plates, wherein a first tab and a second tab are formed in the plurality of electrode plates, and each of the plurality of electrode plates includes a coating portion coated with an active material, a current collector electrically connected to the first tab and the second tab, and a case accommodating the electrode assembly, wherein the current collector includes a first section to which the first tab is connected, and the first section includes a first sub-section and a second sub-section to which a portion of the first tab is welded in an initial bent state, and the remaining portion of the first tab is welded in a secondary bent state. The current collector may further include a second section to which the second tab is welded, and the second section may include a third sub-section to which a portion of the second tab is welded in an initial bent state and a fourth sub-section to which the remaining portion of the second tab is welded in a secondary bent state. The first and second tabs may be initially bent in opposite directions. The first and second tabs may be secondarily bent in the same direction. The current collector may further include a central section, the first sub-section may extend from the central section in a first direction, the third sub-section may extend from the central section in a second direction, and the second direction may be different from the first direction. The welding between the portion of the first tab and the first subsection and the welding between the portion of the second tab and the third subsection may be performed on a first plane, the welding between the remaining portion of the first tab and the second subsection may be performed on a second plane different from the first plane, and the welding between the remaining portion of the second tab and the fourth subsection may be performed on a third plane different from the first plane and parallel to the second plane. A separation space may be formed between the remaining portion of the first tab welded to the second sub-section and an outermost coating portion of the coating portion adjacent to the second sub-section. A first set of weld lines may be on the first subsection, and each weld line of the first set of weld lines may extend in a direction in which the first tab is initially bent. A second set of weld lines may be on the second subsection, and each weld line of the second set of weld lines may extend in a direction of the second bend of the first tab. The first tab may be laser welded to the first section. The case may include first and second long sidewalls facing each other and spaced apart from each other, and first and second short sidewalls facing each other and spaced apart from each other, wherein the first and second short sidewalls may have an area smaller than that of the first and second long sidewalls, the first sub-section may face the first short sidewall, and the second sub-section may face the first long sidewall. Embodiments include a method for manufacturing a secondary battery including preparing an electrode assembly including a plurality of electrode plates and a plurality of separators disposed between the plurality of electrode plates, wherein a first tab and a second tab are formed in the plurality of electrode plates and each of the plurality of electrode plates includes a coating portion coated with an active material, preparing a current collector including a first section electrically connected to the first tab and a second section electrically connected to the second tab, initially bending