JP-2026514365-A - Battery cells, and battery packs including said battery cells and automobiles

Abstract

A battery cell according to one embodiment of the present invention includes an electrode assembly comprising a first electrode having a first blank portion, a second electrode having a second blank portion, and a separator interposed between them; a battery housing configured to house the electrode assembly through an opening provided on one side; and a first current collector provided on the opening side and configured to electrically connect the first blank portion and the battery housing, wherein the first current collector may be configured such that at least a portion of it separates from the battery housing when the internal pressure rises above a reference value.

Inventors

• ホン－ジェ・キム
• サン－ジン・パク
• ジョン－フン・パク
• ジェ－ユン・ウ
• ジュン－ス・イ
• サン－ハク・チェ
• ウ－リ・ハン

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

20241014

Priority Date

20231012

Claims (19)

1. An electrode assembly comprising a first electrode having a first blank portion, a second electrode having a second blank portion, and a separator interposed between them, A battery housing configured to accommodate the electrode assembly through an opening provided on one side, A first current collector is provided on the opening side and configured to electrically connect the first blank portion and the battery housing, Includes, The first current collector is configured such that at least a portion of it separates from the battery housing when the internal pressure rises above a reference value, in a battery cell.
2. A welded portion is formed between the first current collector and the inner surface of the battery housing, and at least a portion of the first current collector is welded to the inner surface of the battery housing, as described in claim 1.
3. The first current collector is A first blank portion connecting portion is positioned on the upper part of the electrode assembly and connected to the first blank portion, Multiple housing coupling portions are arranged on the inner surface of the battery housing, Includes, The battery cell according to claim 2, wherein at least one welded portion is provided between at least one of the plurality of housing joints and the inner surface of the battery housing.
4. The first current collector is The electrode assembly further includes a support portion positioned on the upper part of the electrode assembly, The battery cell according to claim 3, wherein the first plain portion connecting portion and the plurality of housing connecting portions are formed extending from the support portion.
5. Each of the aforementioned multiple housing joints is, A contact portion welded to the inner surface of the battery housing, A connecting portion that connects the support portion and the contact portion, The battery cell according to claim 4, including the battery cell described in claim 4.
6. The battery cell according to claim 5, wherein the contact portions are provided spaced apart from each other along the circumferential direction of the electrode assembly.
7. The battery cell according to claim 3, wherein the welded portion is provided for each of the plurality of housing joint portions.
8. The battery cell according to claim 7, wherein the welded portion includes a weak portion with low welding strength.
9. The battery cell according to claim 8, wherein the welding strength of the weak portion is approximately 10 kgf/ cm² or less.
10. The battery cell according to claim 7, wherein multiple welded portions are formed within the same housing joint, between the inner surface of the battery housing and the plurality of housing joints.
11. The battery cell according to claim 10, wherein the number of welded portions formed within one housing joint is configured to differ for each of the multiple housing joints.
12. The battery housing includes a beading portion formed at the end adjacent to the opening and press-fitted inward, The battery cell according to claim 7, wherein the welded portion is provided between the beading portion and the plurality of housing joint portions.
13. The beading portion has a flat section parallel to the bottom surface of the battery housing in at least a portion of the area. The battery cell according to claim 12, wherein the radial width of the welded portion is set to be 20% or less of the length of the flat section.
14. The battery cell according to claim 3, wherein the welded portion is provided only on a portion of the plurality of housing joint portions.
15. The battery cell according to claim 1, further comprising a housing cover configured to seal the opening and having a vent portion.
16. The battery cell according to claim 1, further comprising a terminal electrically connected to the second blank portion, passing through the battery housing on the opposite side of the opening.
17. The present invention further includes a second current collector located between the electrode assembly and the terminal, The second current collector is The second plain section joining section is joined to the second plain section, A terminal coupling portion connected to the aforementioned terminal, The battery cell according to claim 16, including the battery cell according to claim 16.
18. A battery pack comprising a plurality of battery cells as described in any one of claims 1 to 17.
19. An automobile comprising the battery pack described in claim 18.

Description

This invention relates to a battery cell, a battery pack containing the battery cell, and an automobile. This application claims priority under Korean Patent Application No. 10-2023-0135959, filed on October 12, 2023, and all information disclosed in the specification and drawings of said application is incorporated herein by reference. Secondary battery cells, with their high applicability across product lines and electrical characteristics such as high energy density, are universally applied not only to portable devices but also to electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electrical drive sources. Such secondary battery cells offer not only the primary advantage of dramatically reducing the use of fossil fuels, but also the advantage of producing no by-products associated with energy use. Therefore, they are attracting attention as a new energy source that improves environmental friendliness and energy efficiency. Depending on the charge and discharge capacity required by electric vehicles (EVs) or hybrid electric vehicles (HEVs), battery packs may be configured by connecting multiple battery cells in series or parallel. In this case, it is common practice to first configure a battery module containing at least one battery cell, and then add other components to this module to form a battery pack or battery rack. Furthermore, in recent years, cell-to-pack (CELL-TO-PACK) battery packs, where multiple battery cells are directly housed in a pack housing or similar without being modularized, have also been manufactured. However, in the case of battery packs containing multiple lithium secondary battery cells, the damage caused by fire and explosion is even more severe. Fires in battery packs begin due to abnormal temperature increases and internal gas generation in the battery cells due to overcharging, etc. Consequently, when the internal pressure of the battery cells rises above a certain level, venting occurs, and high-temperature sparks containing high-temperature gas, electrode active materials, and aluminum particles are ejected outwards from the battery cells. On the other hand, conventional cylindrical battery cells have a beading portion formed by press-fitting inward at the end adjacent to the opening of the battery housing, in order to prevent vertical movement of the electrode assembly inside the battery housing. At this time, if a thermal event such as thermal runaway occurs inside the cylindrical battery cell, high temperature and pressure are applied to the sides of the battery housing, such as the beading area. This prevents the flame from being released towards the opening, resulting in a side rupture phenomenon where the flame is ejected while destroying the sides of the battery housing, such as the beading area. When a side rupture occurs, the ejected flame can directly target other adjacent cylindrical battery cells, potentially causing a chain reaction of thermal runaway. Therefore, there is a need to develop battery cells that can minimize the high temperature and pressure applied to the sides of the battery housing, such as the beading area, during thermal events, thereby suppressing the occurrence of side rupture. In particular, there is a need to develop battery cells that can guide the flame towards the opening of the battery housing during thermal events, thereby suppressing the occurrence of side rupture. This is an overall perspective view of a battery cell according to one embodiment of the present invention.This is a perspective view of an electrode assembly included in a battery cell according to one embodiment of the present invention.This is a cross-sectional view of a battery cell relating to Entity Model 1.This is a schematic cross-sectional view showing the state in which the first current collector included in a battery cell according to one embodiment of the present invention is separated from the battery housing when a thermal event occurs.This is a perspective view of a first current collector included in a battery cell according to one embodiment of the present invention.This is a plan view showing the internal structure of a battery cell according to one embodiment of the present invention.This is an enlarged view of portion A in Figure 3, and is a diagram illustrating a welded portion included in a battery cell according to one embodiment of the present invention.This is a cross-sectional view showing the state in which a first current collector included in a battery cell according to one embodiment of the present invention is separated from the battery housing when a thermal event occurs.This is a plan view of a battery cell according to another embodiment of the present invention.This is a cross-sectional view showing a state in which a part of the first current collector included in a battery cell according to one embodiment of the present invention is coupled to the battery housing.This is a cross-sectional view showing a state in wh