KR-102963793-B1 - Subassembly, and battery, battery pack and vehicle including the same

Abstract

The present invention relates to a battery comprising: a battery housing; an electrode assembly accommodated within the battery housing; a terminal gasket disposed within a through hole penetrating an end wall of the battery housing; an electrode terminal disposed within the terminal gasket and spaced apart from the end wall; and a shape-deforming member disposed between the end wall and the electrode terminal and applying force in the direction of the end wall. The battery housing has a first polarity, and the electrode terminal has a second polarity opposite to it. The bias member may be a spring washer in a compressed state and has a higher melting point than the terminal gasket. Therefore, when the terminal gasket melts during thermal runaway, the shape-deformed member returns to an undeformed state, and accordingly, the electrode terminal can electrically contact the battery housing to induce a short circuit.

Inventors

• 김성녕
• 오정섭
• 임구민
• 진의겸
• 허현준
• 황보광수

Assignees

• 주식회사 엘지에너지솔루션

Dates

Publication Date

20260512

Application Date

20250529

Priority Date

20241011

Claims (20)

1. As a subassembly of a battery, A battery housing having an internal space configured to accommodate at least a portion of an electrode assembly therein, extending in an axial direction, having an open end region on a first side along the axial direction and a closed end region on the opposite second side, wherein the closed end region is formed by an end wall having a through hole; Terminal gasket disposed within the above-mentioned through hole; An electrode terminal disposed within the terminal gasket, spaced apart from the end wall of the battery housing by the terminal gasket, and exposed to the outside of the battery housing; and A subassembly characterized by including a shape-deforming member disposed between the end wall and the electrode terminal, which applies force in the direction of the end wall to at least a portion of the electrode terminal.
2. In claim 1, The above electrode terminal is, A body portion disposed in the above-mentioned through hole; An outer flange portion extending radially outward from the outer end of the body portion; and A subassembly characterized by including an inner flange portion extending radially outward from the inner end of the body portion.
3. In claim 2, A subassembly characterized in that the body portion, the outer flange portion, and the inner flange portion are integrally formed as an integrated structure.
4. In claim 2, A subassembly characterized in that the inner surface of the inner flange portion defines a flat weld.
5. In claim 2, The above terminal gasket is, An external gasket interposed between the outer flange portion and the outer surface of the end wall of the battery housing; An internal gasket interposed between the inner flange portion and the inner surface of the end wall of the battery housing; and A subassembly characterized by including an intermediate gasket that extends between the body portion and the end wall of the battery housing and connects the outer gasket and the inner gasket.
6. In claim 5, A subassembly characterized in that the above-mentioned shape-deforming member is interposed between the above-mentioned outer flange portion and the above-mentioned outer gasket.
7. In claim 5, A subassembly characterized in that the above-described shape-deforming member is interposed between the outer surface of the end wall of the battery housing and the outer gasket.
8. In claim 1, A subassembly characterized in that the shape deformation member comprises an elastic bias member or a temperature-responsive deformation member.
9. In claim 1, The above-mentioned shape-deforming member includes an elastic bias member, and A subassembly characterized in that the above elastic bias member is a spring washer.
10. In claim 1, A subassembly characterized in that the battery housing is cylindrical in shape.
11. In claim 1, The above-mentioned shape-deforming member includes an elastic bias member, and A subassembly characterized in that the above elastic bias member is positioned in a compressed state biased to expand into a shape that is not deformed by a predetermined amount of displacement along the axial direction.
12. In claim 1, A subassembly characterized in that the above-mentioned shape-deforming member is positioned in a biased state to expand into a shape that is not deformed by a predetermined amount of displacement along the axial direction.
13. In claim 11, A subassembly characterized in that the above displacement amount is greater than or equal to the thickness of the terminal gasket.
14. In claim 13, A subassembly characterized in that the above displacement amount is greater than or equal to the total thickness of all parts of the terminal gasket along the axial direction.
15. In claim 1, A subassembly characterized in that the above-mentioned shape-deformed member is conductive.
16. In claim 1, A subassembly characterized in that the melting point of the shape-deformed member is higher than the melting point of the terminal gasket.
17. As a battery, A subassembly according to claim 1; and A battery characterized by comprising: an electrode assembly that is accommodated within the internal space of the battery housing, wherein a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode are wound together, and wherein the first electrode is electrically connected to the battery housing and the second electrode is electrically connected to an electrode terminal.
18. In claim 17, A battery characterized by further including a sealing body located on and sealing the open end region of the battery housing.
19. In claim 18, A battery characterized in that the battery housing further includes a crimping portion extending inwardly in radius to surround the edge of the seal.
20. A battery pack comprising a battery according to claim 17.

Description

Subassembly, and battery, battery pack and vehicle including the same The present invention relates to a battery subassembly and a battery, battery pack, and automobile including the same. Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product categories, are widely applied not only to portable devices but also to electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electric power sources. These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency because they drastically reduce the use of fossil fuels and have the advantage of not generating any by-products from energy use. Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these individual secondary batteries is generally about 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple batteries are connected in series to form a battery pack. Additionally, depending on the charge/discharge capacity required for the battery pack, multiple batteries are connected in parallel to form a battery pack. Accordingly, the number of batteries included in the battery pack and the electrical connection type can be set in various ways depending on the required output voltage and/or charge/discharge capacity. Meanwhile, cylindrical, prismatic, and pouch-type batteries are known as types of secondary batteries. In the case of cylindrical batteries, an insulating separator is interposed between the positive and negative electrodes, and this is wound to form a jellyroll-shaped electrode assembly; this assembly is then inserted into a battery housing along with an electrolyte to constitute the battery. Additionally, strip-shaped electrode tabs may be connected to the uninsulated portions of the positive and negative electrodes, and these electrode tabs electrically connect the electrode assembly with the externally exposed electrode terminals. For reference, the positive electrode terminal is generally a cap of a seal that seals the opening of the battery housing, and the negative electrode terminal is generally the battery housing itself. However, conventional cylindrical batteries having such a structure had the problem that current was concentrated in the strip-shaped electrode tabs connected to the positive electrode unoccupied part and/or the negative electrode unoccupied part, resulting in high resistance, excessive heat generation, and poor current collection efficiency. Small cylindrical batteries with form factors such as 1865 (diameter: 16mm, height: 65mm) or 2170 (diameter: 21mm, height: 70mm) are generally considered not to cause increased resistance or heat generation problems. However, if the form factor is increased to apply cylindrical batteries to electric vehicles, a lot of heat can be generated around the electrode tabs during rapid charging, which can lead to a fire in the cylindrical battery. To solve these problems, a cylindrical battery (so-called tab-less cylindrical battery) is proposed that has a structure with improved current collection efficiency by designing a positive electrode-free section and a negative electrode-free section to be located at the top and bottom, respectively, of a jellyroll-type electrode assembly, and welding a current collector to these non-free sections. FIGS. 1 to 3 illustrate the manufacturing process of a tapless cylindrical battery. Specifically, FIG. 1 illustrates the structure of an electrode unfolded into a planar state, FIG. 2 illustrates the winding direction in which a laminate of electrodes and a separator is wound to form an electrode assembly, and FIG. 3 illustrates the state in which the wound electrode assembly is arranged to be welded to a current collector. FIG. 4 is a cross-sectional view of a finished tapless cylindrical battery cut along the longitudinal direction (Y). Referring to FIGS. 1 to 4, the positive electrode (10) and the negative electrode (11) have a structure in which an active material (21) is coated on a sheet-shaped current collector (20), and a non-active portion (22) is formed along one long side of each electrode before being wound along the winding direction (X). The electrode assembly (A) is manufactured by sequentially stacking the positive electrode (10) and the negative electrode (11) together with two separator membranes (12) as shown in FIG. 2, and then winding them around an axis extending in the Y direction so that the wound portion proceeds in the X direction as shown in FIG. 2. At this time, the unwound portions of the positive electrode (10) and the negative electrode (11) are arranged in opposite directions along the Y direction. After the winding process, the unwound portion (10a) of the positive electrode (10) and the unwound portion (11a