EP-4742330-A1 - ELECTRODE CURRENT COLLECTOR, ELECTRODE ASSEMBLY COMPRISING ELECTRODE CURRENT COLLECTOR, AND METHOD FOR MANUFACTURING ELECTRODE CURRENT COLLECTOR

Abstract

The present disclosure relates to an electrode current collector, an electrode assembly including the electrode current collector, and a method for manufacturing the electrode current collector, and an electrode current collector according to the present disclosure is an electrode current collector including an electrode tab extending at an end, and includes a polymer layer and a first metal layer and a second metal layer laminated on both surfaces of the polymer layer, wherein in the electrode tab, a concave portion recessed toward the polymer layer is formed in at least one of the first metal layer or the second metal layer.

Inventors

• KANG, GYUNG SOO
• MAENG, HAN SOL

Assignees

• LG Energy Solution, Ltd.

Dates

Publication Date

20260513

Application Date

20240816

Claims (20)

1. An electrode current collector comprising an electrode tab extending at an end, the electrode current collector comprising: a polymer layer and a first metal layer and a second metal layer laminated on both surfaces of the polymer layer, wherein in the electrode tab, a concave portion recessed toward the polymer layer is formed in at least one of the first metal layer or the second metal layer.
2. The electrode current collector according to claim 1, wherein the concave portion comprises a first concave portion formed in the first metal layer; and a second concave portion formed in the second metal layer.
3. The electrode current collector according to claim 2, wherein the first concave portion and the second concave portion are formed to face each other in the stacking direction.
4. The electrode current collector according to claim 3, wherein the first concave portion and the second concave portion are provided at positions spaced apart from each other by a regular interval.
5. The electrode current collector according to claim 4, wherein the mutually facing spacing between the first metal layer portion where the first concave portion is formed and the second metal layer portion where the second concave portion is formed is 2 to 8 um.
6. The electrode current collector according to claim 2, wherein the first concave portion and the second concave portion are formed in multiples in the first metal layer and the second metal layer, respectively.
7. The electrode current collector according to claim 1, wherein the depth in the stacking direction of the concave portion is formed to be 1 to 4 um.
8. The electrode current collector according to any one of claims 1 to 7, wherein the thickness of the polymer layer is 4 to 14 um, and the thicknesses of the first metal layer and the second metal layer are formed to be 0.2 to 2 um.
9. The electrode current collector according to claim 1, wherein the concave portion is formed in the first metal layer, and the electrode current collector further comprises an additional metal layer laminated on the outer surface of the first metal layer.
10. The electrode current collector according to claim 9, wherein the thicknesses of the first metal layer and the second metal layer are formed to be 0.2 to 2 um, and the thickness of the additional metal layer is formed to be 0.2 to 2 um.
11. The electrode current collector according to claim 9, wherein the concave portion and the second metal layer are provided at positions spaced apart from each other by a regular interval.
12. The electrode current collector according to claim 11, wherein the mutually facing spacing between the portion where the concave portion is formed in the first metal layer and the second metal layer is 2 to 10 um.
13. The electrode current collector according to claim 9, wherein the additional metal layer is located on the electrode tab.
14. The electrode current collector according to claim 9, wherein the additional metal layer further comprises a protrusion that protrudes corresponding to the concave portion.
15. The electrode current collector according to claim 14, wherein the height of the protrusion in the stacking direction is formed to be 1 to 4 um.
16. An electrode current collector comprising an electrode tab extending at an end, the electrode current collector comprising: a polymer layer and a first metal layer and a second metal layer laminated on both surfaces of the polymer layer, wherein some sections of the first metal layer and the second metal layer in the electrode tab form a narrow section in which the mutual spacing is narrowed, and the mutual spacing between the first metal layer and the second metal layer in the narrow section is 72% or less with respect to the thickness of the polymer layer other than the narrow section.
17. The electrode current collector according to claim 16, wherein the mutual spacing between the first metal layer and the second metal layer in the narrow section is 2 to 10 um.
18. The electrode current collector according to claim 16, wherein in the narrow section, a concave portion recessed toward the polymer layer is formed in at least one of the first metal layer or the second metal layer so that the mutual spacing between the first metal layer and the second metal layer is narrowed.
19. The electrode current collector according to claim 16, wherein in the narrow section, at least one of the first metal layer or the second metal layer comprises metal wedges inserted into the polymer layer so that the mutual spacing between the first metal layer and the second metal layer is narrowed.
20. The electrode current collector according to claim 16, wherein in the narrow section, the second metal layer comprises metal ribs extending to the polymer layer so that the mutual spacing between the first metal layer and the second metal layer is narrowed.

Description

TECHNICAL FIELD CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to Korean Patent Application No. 10-2023-0107879 filed on August 17, 2023, Korean Patent Application No. 10-2023-0107801 filed on August 17, 2023, Korean Patent Application No. 10-2023-0107719 filed on August 17, 2023, and Korean Patent Application No. 10-2024-0108652 filed on August 13, 2024 in the Republic of Korea, the disclosures of which are incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to an electrode current collector, an electrode assembly including the electrode current collector, and a method for manufacturing the electrode current collector. BACKGROUND ART Secondary batteries are rechargeable unlike primary batteries, and have been heavily researched and developed in recent years due to their potential for miniaturization and large capacity. As the technology development and demand for electric vehicles, energy storage systems (ESSs), mobile devices, and the like increase, the demand for secondary batteries as an energy source is rapidly increasing. However, the safety of secondary batteries is not keeping up with the pace of technological advancement. To solve this problem, there is a method for improving safety by creating an electrical short before the abnormal behavior of secondary batteries to drain energy or by short-circuiting the electrical connection. Secondary batteries are classified into coin type batteries, cylindrical batteries, prismatic batteries, and pouch type batteries depending on the shape of a battery case. In a secondary battery, the electrode assembly mounted inside the battery case is a power generating element that can be charged and discharged with a stacked structure of electrodes and separators. The electrode assembly may be roughly classified into a jelly-roll type in which a sheet-like positive electrode and negative electrode where an active material is applied to a current collector having a separator interposed therebetween are wound, a stack type in which multiple positive electrodes and negative electrodes are sequentially stacked with a separator interposed therebetween, and a stack/folding type in which the stack-type unit cells are wound with a long separation film. SUMMARY TECHNICAL PROBLEM The present disclosure is designed to providing an electrode current collector having improved weldability, an electrode assembly including the electrode current collector, and a method for manufacturing the electrode current collector. TECHNICAL SOLUTION An electrode current collector according to an embodiment of the present disclosure is an electrode current collector including an electrode tab extending at an end, and may include a polymer layer and a first metal layer and a second metal layer laminated on both surfaces of the polymer layer, wherein in the electrode tab, a concave portion recessed toward the polymer layer may be formed in at least one of the first metal layer or the second metal layer. Meanwhile, an electrode current collector according to an embodiment of the present disclosure is an electrode current collector including an electrode tab extending at an end, and may include a polymer layer and a first metal layer and a second metal layer laminated on both surfaces of the polymer layer, wherein some sections of the first metal layer and the second metal layer in the electrode tab may form a narrow section in which the mutual spacing is narrowed, and the mutual spacing between the first metal layer and the second metal layer in the narrow section may be 72% or less with respect to the thickness of the polymer layer other than the narrow section. Additionally, an electrode assembly according to an embodiment of the present disclosure is an electrode assembly in which electrodes and separators are alternately stacked, wherein the electrode may include an electrode current collector including an electrode tab extending at an end, and the electrode current collector may include a polymer layer and a first metal layer and a second metal layer laminated on both surfaces of the polymer layer in the stacking direction, wherein in the electrode tab, a concave portion recessed toward the polymer layer may be formed in at least one of the first metal layer or the second metal layer. In addition, a method for manufacturing the electrode current collector according to an embodiment of the present disclosure may include a lamination process for laminating a first metal layer and a second metal layer on both surfaces of a polymer layer to form a stack; a tab formation process for forming an electrode tab by notching an end portion of the stack; and a concave portion formation process for forming a concave portion recessed toward the polymer layer in at least one of the first metal layer and the second metal layer in the electrode tab. ADVANTAGEOUS EFFECTS According to the present disclosure, in an electrode current collector in which met