KR-102963792-B1 - Battery cell, Battery pack comprising the same and vehicle

KR102963792B1KR 102963792 B1KR102963792 B1KR 102963792B1KR-102963792-B1

Abstract

A battery module according to the present invention comprises: an electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound around a winding axis; a battery housing that accommodates the electrode assembly and is electrically connected to the second electrode and has a closed portion having a through hole formed therein; an electrode terminal that passes through the through hole and is electrically connected to the first electrode so as not to contact the inner wall of the through hole; and a terminal gasket interposed between the electrode terminal and the through hole, wherein the electrode terminal has a stepped portion on a contact interface facing the outer surface of the closed portion and in contact with the terminal gasket.

Inventors

임구민
김성녕
안성현
진의겸
황보광수

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260511
Application Date: 20241224

Claims (15)

An electrode assembly comprising a first electrode and a second electrode and a separator interposed between them, wound around a winding axis; A battery housing that accommodates the electrode assembly and is electrically connected to the second electrode, and has a closed portion having a through hole formed therein; An electrode terminal passing through the through hole so as not to come into contact with the inner wall of the through hole and electrically connected to the first electrode; and It includes a terminal gasket interposed between the electrode terminal and the through hole, The above electrode terminal is, A step portion is provided on the contact interface facing the outer surface of the above-mentioned closure portion and in contact with the above-mentioned terminal gasket, and A battery cell characterized in that the above-mentioned step portion is provided at a first position where a virtual line extending vertically from the end of the closure portion forming the inner wall of the through hole meets the contact interface, or at a position radially outward from the first position.
In paragraph 1, The above step portion is, A first layer extending parallel to the outer surface of the above-mentioned closure; and A battery cell characterized by including a second layer located radially inward from the first layer and having a shorter shortest distance to the outer surface of the closure than the first layer.
In paragraph 2, A battery cell characterized in that the terminal gasket has a minimum thickness between the outer surface of the second layer and the closure portion facing each other.
In paragraph 2, The above step portion is, A battery cell characterized by further including a projection protruding toward the outer surface of the closure portion in the second layer portion.
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In paragraph 1, A battery cell characterized in that the terminal gasket is made of an electrical insulating material of a different material having a relatively different melting point.
In paragraph 1, The above terminal gasket is, A lower layer in contact with the inner surface of the above-mentioned closure; and A battery cell characterized by including an upper layer having a lower melting point than the lower layer and contacting the outer surface of the closure and the end of the closure.
In paragraph 1, The above electrode terminal is, A body part inserted into the above-mentioned through hole; An outer flange portion extending radially from the first side of the body portion and pressing the terminal gasket against the outer surface of the closure portion; and A battery cell comprising an inner flange portion that extends radially from the second side of the body portion and presses the terminal gasket against the inner surface of the closure portion.
In paragraph 8, It includes a first current collector plate attached to one side of the electrode assembly to contact a first non-retaining portion extending from the first electrode, and A battery cell characterized in that the electrode terminal includes a flat surface provided to make face-to-face contact with the first current collector plate in the body portion.
In paragraph 8, The above terminal gasket is, An external gasket interposed between the outer flange portion and the outer surface of the closed portion of the battery housing; An internal gasket interposed between the inner flange portion and the inner surface of the closure portion of the battery housing; and A battery cell characterized by including an intermediate gasket interposed between the body portion and the through hole and connecting the outer gasket and the inner gasket.
In paragraph 1, The battery housing has a cylindrical shape and comprises: a side wall portion extending in the axial direction; a closing portion connected to one end of the side wall portion and extending in the radial direction; and an open end provided at the other end of the side wall portion. A battery cell characterized by including a housing lid that covers the open end of the battery housing.
In Paragraph 11, A battery cell characterized in that the electrode assembly is accommodated inside the battery housing such that a second non-existent portion extending from the second electrode faces the open end.
In Paragraph 12, It includes a second current collector plate disposed between the electrode assembly and the housing lead inside the battery housing and in contact with the second non-removable portion, A battery cell characterized in that at least one side of the second current collector plate is welded to the battery housing or the housing lead.
A battery pack characterized by including at least one battery cell described in any one of claims 1 to 4 and claims 6 to 13.
An automobile characterized by including a battery pack according to Clause 14.

Description

Battery cell, battery pack comprising the same and vehicle The present invention relates to a battery cell, and more specifically, to a battery cell capable of actively inducing an electrical short circuit when a thermal event, such as thermal runaway, occurs in the battery cell, a battery pack including the same, and an automobile. Secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, as they have the primary advantage of being able to drastically reduce the use of fossil fuels, as well as the advantage of not generating any by-products from the use of energy. Cylindrical, prismatic, and pouch-type battery cells are widely known as types of secondary batteries. In the case of a cylindrical battery cell, an insulating separator is placed between the positive and negative electrodes and wound to form a jellyroll-shaped electrode assembly, which is then inserted into a housing along with an electrolyte to constitute the battery. Additionally, strip-shaped electrode tabs can 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 the cap of the seal that seals the opening of the housing, and the negative electrode terminal is the housing. 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. For small cylindrical batteries with 1865 or 2170 form factors, resistance and heat generation are not major issues. However, if the form factor is increased to apply cylindrical batteries to electric vehicles, a problem may arise where the cylindrical battery catches fire as a large amount of heat is generated around the electrode tabs during fast charging. 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 collection plate to these non-parts. Meanwhile, a conventional tapless cylindrical battery cell, as disclosed in Korean Published Patent No. 10-2024-0059520, includes a battery can functioning as a first electrode and a bottom member of the battery can as a second electrode. A first electrode terminal is fitted into a hole provided in the bottom member of the battery can. The first electrode terminal is electrically insulated from the bottom member of the battery can by riveting it to the bottom member with a gasket interposed therebetween. The cylindrical battery cells can be connected in series and/or in parallel via a busbar to form a battery pack and used as a power source for electric vehicles, etc. When a problem such as a thermal event occurs in any one of the built-in battery cells in the battery pack, it has a thermal or electrical adverse effect on the other battery cells. Therefore, at this time, for example, it is advantageous to prevent or delay chain ignition between battery cells by causing an overcurrent to flow momentarily through the busbar connected to the battery cell where the thermal event occurred, thereby causing the busbar to fuse and interrupting the flow of current between the battery cells. However, in the case of a positive terminal with a riveting structure, when the battery cell explodes, the positive terminal and the battery can, which is the negative terminal, do not come into sufficient contact, making it difficult to induce an electrical short circuit of the battery cell. Consequently, there is an aspect where it is difficult to quickly fuse the busbar. The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a perspective view of a battery cell according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the main components of a battery cell according to an embodiment of the present invention. Figure 3 is a cutaway perspective view of the battery cell of Figure 1. Figure 4 is a cross-sectional view of the battery cell of Figure 1. Figure 5 is an enlarged view of the electrode terminal portion in Figure 3. FIGS. 6 and FIGS. 7 are process diagrams for exp