JP-2026514397-A - Current collector plate and cylindrical battery cell containing it, battery pack containing the cylindrical battery cell and automobile

Abstract

A current collector plate and a cylindrical battery cell including the same, a battery pack including the cylindrical battery cell and an automobile are disclosed. A current collector plate according to one embodiment of the present invention is a current collector plate that electrically connects an electrode assembly housed inside a cylindrical battery cell, and includes a peripheral portion that defines the periphery, a central portion that is separated from the peripheral portion and connects with the electrode assembly, and a connecting portion that connects the peripheral portion and the central portion, wherein the width of the connecting portion is formed to vary.

Inventors

• ソン－ミン・イム
• ビュン－グ・イ
• ジョン－スン・ナ
• ド－ユン・キム
• ソ－ヨン・イ

Assignees

• エルジー エナジー ソリューション リミテッド

Dates

Publication Date

20260511

Application Date

20240802

Priority Date

20230803

Claims (17)

1. A current collector plate that electrically connects electrode assemblies housed inside a cylindrical battery cell, The peripheral part that defines the periphery, It is separated from the aforementioned peripheral portion and has a central part that connects to the electrode assembly, A current collector plate comprising a connecting portion that connects the peripheral portion and the central portion, characterized in that the width of the connecting portion is formed to vary.
2. The current collector plate according to claim 1, characterized in that the peripheral portion has the form of a rim in which at least a portion of the inner region is open.
3. The current collector plate according to claim 1, characterized in that the connecting portion includes a first portion connected to the central part and a second portion connected to the peripheral part, and the width of the first portion is narrower than the width of the second portion.
4. The current collector plate according to claim 3, characterized in that the first connecting portion between the first and second parts is formed at an inclination.
5. The current collector plate according to claim 4, characterized in that the first connecting portion includes a first inclined portion on one side and a second inclined portion on the other side, and the first inclined portion and the second inclined portion are formed symmetrically to each other.
6. The current collector plate according to claim 4, characterized in that the first connecting portion is formed inclined to expand from the first portion toward the second portion and is connected to the second portion.
7. The end of the second part is located outside the end of the first part, and is further from the center than the end of the first part. The current collector plate according to claim 6, characterized in that the first connecting portion connects the end of the first part and the end of the second part from the end of the first part toward the second part.
8. The current collector plate according to claim 4, characterized in that the first connecting portion is formed inclined to expand from the first portion toward the central part and is connected to the second portion.
9. The end of the second part is located outside the end of the first part, and is closer to the center than the end of the first part. The current collector plate according to claim 8, characterized in that the first connecting portion connects the end of the second portion toward the central part from the end of the first portion.
10. The current collector plate according to claim 3, characterized in that the first part and the second part are connected perpendicularly to each other by a first connecting portion.
11. The end of the second part is located outward from the end of the first part. The end of the second part and the end of the first part are located at the same distance from the center. The current collector plate according to claim 10, characterized in that the first connecting portion connects the end of the first part and the end of the second part.
12. The current collector plate according to claim 3, characterized in that the second connecting portion between the second part and the peripheral portion is formed at an inclination.
13. The current collector plate according to claim 12, characterized in that the second connecting portion includes a third inclined portion on one side and a fourth inclined portion on the other side, and the third inclined portion and the fourth inclined portion are formed symmetrically to each other.
14. The current collector plate according to claim 13, characterized in that a through hole is formed between the third inclined portion and the fourth inclined portion.
15. A cylindrical battery cell comprising at least one current collector plate as described in any one of claims 1 to 14.
16. A battery pack comprising at least one cylindrical battery cell as described in claim 15.
17. An automobile comprising at least one cylindrical battery cell as described in claim 15.

Description

This application claims priority under Korean Patent Application No. 10-2023-0101813, filed on August 3, 2023, and Korean Patent Application No. 10-2024-0037365, filed on March 18, 2024. All information disclosed in the specifications and drawings of those applications is incorporated herein. This invention relates to a current collector plate and a cylindrical battery cell containing the same, a battery pack containing the cylindrical battery cell, and an automobile; more specifically, to a current collector plate and a cylindrical battery cell containing the same, in which the connecting portion breaks when a short-circuit current is applied without increasing the internal resistance of the battery cell; and to a battery pack containing the cylindrical battery cell and an automobile. Rechargeable batteries, which are easily adaptable to different product groups and possess high energy density and other electrical characteristics, are universally applied not only to portable devices but also to electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electrical sources. Such secondary batteries are attracting attention not only for their primary advantage of dramatically reducing the use of fossil fuels, but also because they produce no by-products associated with energy use, making them environmentally friendly and a promising new energy source for improving energy efficiency. Currently, widely used types of rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these individual rechargeable battery cells is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells can be connected in series to form a battery module or battery pack. Alternatively, multiple battery cells can be connected in parallel to form a battery module or battery pack depending on the required charge/discharge capacity. Thus, the number of battery cells and the electrical connection configuration included in a battery module or battery pack can be configured in various ways depending on at least one of the required output voltage and charge/discharge capacity. Furthermore, cylindrical, prismatic, and pouch-type battery cells are known types of secondary battery cells. In the case of cylindrical battery cells, an insulating separator membrane is interposed between the positive and negative electrodes, and this is wound up to form a jelly roll-shaped electrode assembly, which is then placed in a battery case along with the electrolyte to constitute the battery. For cylindrical battery cells, current collector plates may be used to electrically connect the positive and negative electrode plates, respectively. On the other hand, with the recent application of cylindrical battery cells to electric vehicles, the form factor of cylindrical battery cells is increasing. Specifically, the diameter and height of cylindrical battery cells are increasing compared to conventional cylindrical battery cells with form factors such as 18650 and 21700. This increase in form factor leads to increased energy density, greater safety against thermal runaway, and improved cooling efficiency. As the form factor increases, the need to protect cylindrical battery cells from short-circuit currents and other factors is also increasing. For example, a fuse section (e.g., a notched groove) can be formed on the current collector plate. However, simply forming a fuse section on the current collector plate does not easily cause the connection portion of the current collector plate to break smoothly without increasing the internal resistance of the battery cell when a short-circuit current is applied. Normally, when the internal resistance of a battery cell increases, this resistance obstructs the flow of current, preventing the current collector plate from breaking when a short-circuit current is applied. This allows the current to continue flowing, ultimately leading to the battery cell igniting or exploding. Therefore, a structure is required in which the current collector plate easily breaks when a short-circuit current is applied, without increasing the internal resistance of the battery cell. This diagram shows a current collector plate according to one embodiment of the present invention.This is an enlarged view of part A in Figure 1.This figure shows a current collector plate according to a modified embodiment of Figure 1.This is an enlarged view of section B in Figure 3.This figure shows a current collector plate according to another modified embodiment of Figure 1.This is an enlarged view of section C in Figure 5.This figure shows the test conditions for the current collector plate.Figures 8(a) to 8(c) are graphs showing the test results under the test conditions shown in Figure 7.This figure shows how fusing occurred during a test of the current collector plate accord