Battery cell, and battery pack and vehicle comprising same

Abstract

The present invention relates to a battery cell in which smooth venting is possible under abnormal conditions such as an increase in internal pressure, and a battery pack and a vehicle including same, the battery cell comprising: an electrode assembly in which a first electrode, a second electrode, and a separator disposed therebetween are wound around a winding shaft; a battery can that accommodates the electrode assembly via an opening formed on one side, has a closed portion formed on the other side, and is electrically connected to the second electrode; an electrode terminal that is electrically connected to the first electrode via a through-hole formed in the closed portion of the battery can; and a cap covering the opening of the battery can, wherein the closed portion of the battery can has a vent notch having a fracture structure.

Description

Battery cells, battery packs including the same, and automobiles

[0001] The present invention relates to a battery cell, a battery pack including the same, and an automobile, and more specifically, to a battery cell capable of smooth venting within the battery cell under abnormal conditions such as increased internal pressure, a battery pack including the same, and an automobile.

[0002] This application is a priority claim application for Korean Patent Application No. 10-2024-0141948 filed on October 17, 2024, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0003] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product groups, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. These secondary batteries are attracting attention as a new energy source for enhancing eco-friendliness and energy efficiency, not only for the primary advantage of drastically reducing the use of fossil fuels but also because they generate no by-products from energy use.

[0004] 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 unit secondary battery cells, or unit battery cells, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Additionally, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Accordingly, the number of battery cells included in the battery pack can be varied depending on the required output voltage or charge / discharge capacity.

[0005] Meanwhile, the application areas of secondary batteries are very diverse. Among these, battery packs used in devices such as electric vehicles require high capacity and high output. In such cases, if a problem occurs inside the secondary battery and the internal pressure rises, the pressure is typically reduced through a vent structure that releases internal gas to the outside. As a result, the internal gas of the problematic secondary battery is smoothly vented, thereby preventing accidents such as explosions caused by a continuous rise in internal pressure.

[0006] However, if abnormal chemical reactions occur within the battery due to overcharging, over-discharging, internal short circuits, or external impact, venting may not function properly, leading to thermal runaway where heat generated inside the secondary battery increases rapidly and uncontrollably. Once thermal runaway begins, the battery temperature rises uncontrollably fast, causing the internal materials to continue decomposing and generating more gas, initiating a vicious cycle. This increases the risk of the battery spontaneously igniting or exploding.

[0007] To prevent this, various safety devices are applied to secondary batteries. For example, structures such as pressure valves or rupture notches prevent battery explosions by rupturing and releasing the gas when the internal gas pressure rises above a certain level.

[0008] However, if a structure is located near a pressure valve or a fracture notch, there is a risk that the structure may obstruct smooth venting, and the fracture of the notch may cause deformation in the surrounding area, potentially leading to unexpected accidents.

[0009] Therefore, it is necessary to develop a secondary battery having a structure that allows for the smooth discharge of internal gas through foreseeable rupture in the event of an increase in internal pressure caused by a malfunction.

[0010] Accordingly, the technical problem to be solved by the present invention is to provide a battery cell having a structure capable of smooth venting, a battery pack including the same, and an automobile.

[0011] In addition, the invention provides a battery cell, a battery pack including the same, and an automobile for reducing or preventing deformation of the surrounding area when a part of the battery cell component is fractured for gas emission.

[0012] In addition, the invention provides a battery cell capable of reducing the internal pressure of the battery cell using a bottom cooling method, a battery pack including the same, and an automobile.

[0013] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below.

[0014] To solve the above objective, the present invention comprises, as a battery cell, 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 can that accommodates the electrode assembly through an opening formed on one side and has a closed portion formed on the other side and is electrically connected to the second electrode; an electrode terminal that is electrically connected to the first electrode through a through hole formed in the closed portion of the battery can; and a cap that covers the opening of the battery can, wherein the closed portion of the battery can has a vent notch formed therein having a fracture structure.

[0015] The opening of the battery can can be welded together with the edge of the cap.

[0016] For example, the closure of the battery can may be positioned at the top of the battery can, and the opening of the battery can may be formed at the bottom of the battery can.

[0017] The above cap can be inserted from the opening of the battery can inward in the longitudinal direction of the battery can and welded together with the side of the battery can.

[0018] The closing portion of the battery can comprises a first surface positioned toward the outside of the battery can and a second surface positioned toward the inside of the battery can, and the vent notch may include at least one of an upper notch formed concavely by being sunken inward in the thickness direction of the closing portion of the battery can from the first surface and a lower notch formed concavely by being sunken inward in the thickness direction of the closing portion of the battery can from the second surface.

[0019] The above vent notch includes the above upper notch and the above lower notch, and the depth of indentation from each surface of the closing portion of the battery can between the upper notch and the lower notch may be different.

[0020] The closed portion of the battery can includes a plating layer on at least a second surface, and the thickness of the plating layer may be greater than the recessed depth of the lower notch.

[0021] The closed portion of the battery can includes a plating layer on at least a second surface, and the thickness of the plating layer may be greater than the recessed depth of the lower notch.

[0022] The above-mentioned vent notch is recessed to have a stepped structure inwardly in the thickness direction of the closing portion of the battery can, and the size of the recessed area exposed to the outside along the depth direction of the recessed structure may gradually decrease.

[0023] The above vent notch may be provided in a closed loop shape.

[0024] The above vent notches may be formed in multiple locations radially outward from the center of the opening of the battery can.

[0025] The above multiple vent notches may each have different depths or patterns.

[0026] The above-mentioned vent notch may include a plurality of curved portions formed along at least a portion of the circumference of the electrode terminal and a plurality of linear portions each connected to the plurality of curved portions and formed radially from the center of the opening of the battery can.

[0027] The above vent notch may be equipped with a protective member.

[0028] In addition, the present invention provides a battery pack comprising at least one of the battery cells described above.

[0029] In the above battery pack, a cooling pad may be placed on the opposite side of the portion where the vent notch of the battery cell is located.

[0030] For example, a cooling pad may be positioned toward the bottom of the battery cell.

[0031] In addition, the present invention provides a vehicle comprising at least one of the battery packs described above.

[0032] A battery cell according to various embodiments of the present invention, a battery pack including the same, and an automobile have the effect of reducing deformation of the battery cell's components and surrounding parts.

[0033] In addition, the battery cell according to various embodiments, the battery pack including the same, and the automobile have the effect of being able to smoothly vent internal gas using a bottom cooling method.

[0034] In addition, the battery cell according to various embodiments, the battery pack including the same, and the automobile have the effect of extending the lifespan of the battery cell by ensuring the stability and durability of the battery cell.

[0035] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0036] FIG. 1 is a schematic diagram showing a battery cell according to one embodiment of the present invention.

[0037] Figure 2 is a schematic diagram showing the electrode assembly of the battery cell of Figure 1.

[0038] Figure 3 is a drawing for explaining the configuration of the electrode assembly according to Figure 2.

[0039] Figure 4 is a schematic diagram showing the cross-sectional view of the battery cell of Figure 1.

[0040] Figure 5 is a drawing for explaining the welded portion of the cap of the battery cell of Figure 1.

[0041] FIG. 6 is a drawing for explaining another embodiment of the welded part of the cap of FIG. 5.

[0042] FIG. 7 is a drawing for explaining a vent notch formed in the closed portion of a battery can of a battery cell according to one embodiment of the present invention.

[0043] FIGS. 8 to 10 are drawings for explaining other embodiments of the vent notch of FIG. 7.

[0044] FIG. 11 is a top view schematically showing the vent notch of FIG. 7.

[0045] FIG. 12 is a top view schematically showing another embodiment of the vent notch of FIG. 7.

[0046] FIG. 13 is a drawing for explaining a vent notch formed in the closed portion of a battery can of a battery cell according to another embodiment of the present invention.

[0047] FIG. 14 is a top view schematically showing the vent notch of FIG. 13.

[0048] FIG. 15 is a drawing illustrating a vent notch formed in the closed portion of a battery can of a battery cell according to another embodiment of the present invention.

[0049] FIG. 16 is a top view schematically showing the vent notch of FIG. 15.

[0050] Figure 17 is a drawing illustrating the fractured state of the vent notch of Figure 15.

[0051] FIG. 18 is a schematic diagram showing a protective member for a vent notch of a battery can of a battery cell according to one embodiment of the present invention.

[0052] FIG. 19 is a schematic diagram showing a battery pack including a battery cell according to one embodiment of the present invention.

[0053] Figure 20 is a diagram illustrating the battery cell cooling method of the battery pack of Figure 19.

[0054] FIG. 21 is a schematic diagram showing a car including the battery pack of FIG. 19.

[0055] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0056] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0057] In addition, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar configurations are omitted, and the focus is on the differences.

[0058] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0059] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0060] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0061] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0062] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0063] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0064] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back may be used in this specification, these terms are used merely for convenience of explanation and may vary depending on the position or arrangement, rotation, or position of the observer, as is obvious to those skilled in the art of this invention.

[0065] The present invention may be implemented in the following embodiments, each independently. Furthermore, the present invention may be implemented in combination of two or more of the following embodiments. Each of the following embodiments may not only be implemented independently but may also be freely combined with one another.

[0066] For convenience of explanation, in this specification, the direction following the length direction of the winding axis of an electrode assembly wound in a jelly roll shape is referred to as the winding axis direction (Z). The direction surrounding the winding axis is referred to as the circumferential direction, and the direction in which the electrode assembly is wound along the winding axis is referred to as the winding direction (X). Furthermore, the direction approaching or moving away from the winding axis is referred to as the radial direction.

[0067]

[0068] FIG. 1 is a schematic diagram showing a battery cell (1) according to one embodiment of the present invention.

[0069] Hereinafter, a battery cell (1) according to various embodiments of the present invention will be described in detail.

[0070] First, the battery cell (1) may be a cylindrical battery cell. For example, the battery cell (1) may be a cylindrical battery cell in which the ratio of the form factor (defined as the ratio of the diameter of the cylindrical battery cell to the height, i.e., the ratio of the diameter (Φ) to the height (H)) is approximately greater than 0.4.

[0071] Here, the form factor may refer to a value representing the diameter and height of a cylindrical battery cell. The cylindrical battery cell may be a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell by applying the numerical value representing the form factor. Here, the first two digits represent the diameter of the cell, the next two digits represent the height of the cell, and the last digit 0 indicates that the cross-section of the cell is circular.

[0072] Additionally, the battery cell (1) may be a cylindrical battery cell, for example, having a form factor ratio (ratio of diameter in the radial direction to height in the core axis direction) greater than approximately 0.4. For example, the diameter of the battery cell (1) may be 40 mm to 50 mm, and the height may be 60 mm to 130 mm. The form factor of the battery cell (1) may be, for example, 46110, 4875, 48110, 4880, or 4680.

[0073] However, the shape of the battery cell (1) according to the present invention is not limited by the above and can be applied to batteries of other shapes. For example, it can be applied to prismatic batteries.

[0074]

[0075] FIG. 2 schematically shows the electrode assembly (20) of the battery cell (1) of FIG. 1, FIG. 3 explains the configuration of the electrode assembly (20) according to FIG. 2, and FIG. 4 schematically shows the cross-sectional view of the battery cell (1) of FIG. 1.

[0076] Referring to FIGS. 1 to 4, a battery cell (1) according to one embodiment comprises, mainly, a battery can (10), an electrode assembly (20), an electrode terminal (30), and a cap (60).

[0077] The above battery can (10) may be a cylindrical structure for the above cylindrical battery cell. In this case, a side wall member (11) may form the side of the cylinder of the battery can (10), and a bottom member (12) may be connected to the side wall member (11) to form one end of the cylinder. That is, the bottom member (12) may be a closed part of the battery can (10), and the other end of the battery can (10) facing the bottom member (12) may be open to become an opening.

[0078] The bottom member (12) may be in the shape of a disc with a through hole (H) formed in the center, and the side wall member (11) may be in the shape of a cylinder having a constant radius along the circumferential direction surrounding the bottom member (12).

[0079] The battery can (10) including the bottom member (12) and the side wall member (11) may be a member formed by a deep drawing process of a metal sheet having nickel plated on the surface of steel. Of course, the material of the bottom member (12) and the side wall member (11) is not limited to this.

[0080] An electrode terminal (30) can be fitted into the through hole (H) of the bottom member (12). The electrode terminal (30) can be fixed by riveting to the bottom member (12) with a gasket (70) interposed therebetween. The gasket (70) is interposed between the electrode terminal (30) and the bottom member (12) to seal the inside of the battery can (10) to prevent leakage of the electrolyte and to electrically insulate the electrode terminal (30) from the bottom member (12).

[0081] However, the method of connecting the electrode terminal (30) and the bottom member (12) is not limited to this. For example, if there is a structure that can seal the space between the electrode terminal (30) and the bottom member (12) and electrically insulate the electrode terminal (30) and the bottom member (12), various other fixing methods, such as a bolt-nut connection method, a glass seal method, or a chrome coating & PP-MAH heat bonding method, can also be applied.

[0082] Thus, the electrode terminal (30) can be electrically connected to the first electrode (21) described later to have a first polarity, and the battery can (10) can be electrically connected to the second electrode (22) described later to have a second polarity. That is, both the bottom member (12) and the side wall member (11) connected thereto can have a second polarity. Accordingly, the bottom member (12) can have both the electrode terminal (30) having a first polarity and the closed part having a second polarity. Thus, the electrode terminal (30) can have a positive polarity, and the closed part can have a negative polarity. Of course, the opposite may also be true.

[0083]

[0084] The above battery cell (1) can accommodate an electrode assembly (20) inside the battery can (10) through the opening of the battery can (10).

[0085] The above electrode assembly (20) may be configured such that the first electrode (21) and the second electrode (22) and the separator (28) interposed between them are wound around a winding axis.

[0086] The electrode assembly (20) after the completion of winding may be in the form of a jelly-roll. When viewed from the top or bottom of the electrode assembly (20) in the XY plane, the outer shape of the electrode assembly (20) along the circumferential direction is circular. The structure of the electrode assembly (20) is not limited by the embodiment and may have a winding structure well known in the art. The first electrode (21), the second electrode (22), and the separator (28) may each be formed to have a predetermined width along the winding axis direction (Z) and to extend a predetermined length along the winding direction (X). The first electrode (21) may be an anode plate, and the second electrode (22) may be a cathode plate. Of course, the opposite may also be true.

[0087] The first electrode (21) and the second electrode (22) may be manufactured in the form of a sheet. The first electrode (21) and the second electrode (22) may be configured such that an active material layer is applied to at least a portion of the surface of a metal foil (23). The first electrode (21) and the second electrode (22) may have a retaining portion (24) where the active material layer is applied and a non-retaining portion (26) where the active material layer is not applied.

[0088] The above-mentioned uncoated portion (26) can be exposed to the outside of the separator (28) while forming a plurality of winding turns based on the winding axis of the electrode assembly (20), and can be used as an electrode tab itself. That is, the positive plate and the negative plate may each include an uncoated portion (26) in which an active material is not coated at the long side end in the winding axis direction (Z). In addition, the uncoated portions (26) of the first electrode (21) and the second electrode (22) may be configured to face opposite directions in the winding axis direction (Z). The uncoated portion (26) of the first electrode (21) may be housed inside the battery can (10) such that it is located at one end in the winding axis direction (Z), and the uncoated portion (26) of the second electrode (22) is located at the other end in the winding axis direction (Z). Here, the positive active material coated on the positive plate and the negative active material coated on the negative plate may be used without limitation as long as they are active materials known in the art.

[0089] Also, the separator (28) may be a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., used alone or in a laminated form. As another example, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0090] At least one surface of the above-mentioned separator (28) may include a coating layer of inorganic particles. Additionally, it is possible for the separator (28) itself to be composed of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure combined with a binder such that interstitial volume exists between adjacent particles.

[0091] The above-mentioned blank portion (26) can itself function as an electrode tab.

[0092] The above-mentioned blank portion (26) may form multiple flag-shaped notching tabs (27) by forming notches at predetermined intervals along the winding direction (X). The multiple notching tabs (27) may be in the shape of an isosceles trapezoid arranged along the winding direction (X). However, they are not limited thereto and may be in various shapes such as semicircles, semi-ellipses, triangles, rectangles, parallelograms, etc.

[0093] Additionally, the plurality of notching tabs (27) may have the same width along the winding direction (X). However, the width of the plurality of notching tabs (27) may gradually or stepwise widen along the winding direction (X), from the winding center side, where the winding of the electrode assembly (20) begins, to the outermost point after winding, the outer circumference side.

[0094] Additionally, the plurality of notching tabs (27) may be formed such that the height of the notching tabs (27) increases stepwise along the winding axis direction (Z) from the core side to the outer side. However, the height of the plurality of notching tabs (27) may be constant or gradually decrease.

[0095] Additionally, the plurality of notching tabs (27) may be flattened by being bent radially in the electrode assembly (20). Additionally, the notching tabs (27) may be bent radially inward or outward in the electrode assembly (20).

[0096] Additionally, the plurality of notching tabs (27) may be bent one by one during the process of forming the electrode assembly (20) in the form of a jelly-roll. Alternatively, the notching tabs (27) may be bent all at once after forming the electrode assembly (20) in the form of a jelly-roll.

[0097] In this way, the notching tabs (27) of the first electrode (21) and the notching tabs (27) of the second electrode (22), which are bent and overlapped in the radial direction, can each provide a plane that is substantially perpendicular to the axial direction at both axial ends of the electrode assembly (20).

[0098] At least one end of the above electrode assembly (20) in the winding axis direction (Z) can be electrically connected to a current collector plate (40, 50). At this time, the electrode terminal (30) can be connected to a first current collector plate (40) that is electrically connected to the first electrode (21).

[0099] The first current collector plate (40) and the second current collector plate (50) may each be bonded to a substantially flat surface provided by the notching tab (27) exposed at both ends of the winding axis direction (Z) of the electrode assembly (20) by being bent. The first current collector plate (40) may be an anode current collector plate made of aluminum, and the second current collector plate (50) may be a negative current collector plate made of copper. However, the material of the current collector plates (40, 50) does not need to be limited thereto. In addition, the current collector plates (40, 50) may be manufactured by punching, trimming, piercing, and bending a metal sheet, and the manufacturing method is not limited thereto.

[0100] The cap (60) may be configured to cover the opening of the battery can (10).

[0101] That is, the cap (60) may be configured as a cover structure that effectively seals the opening of the battery can (10). By doing so, the battery cell (1) is sealed, the internal electrolyte and electrode assembly (20) are protected from the external environment, and the long-term performance of the battery cell (1) can be maintained. The joint point between the opening of the battery can (10) and the cap (60) can be joined by welding. For example, the cap (60) can be joined to the battery can (10) using butt welding. Thus, the battery cell (1) can have a larger internal capacity than a battery cell using beading and crimping methods with the same external shape. Thus, the energy density of the battery cell (1) can be increased. However, the battery can (10) and the cap (60) can be joined by other joining methods other than welding, and the joining method is not limited to this.

[0102] The above cap (60) may be made of a metallic material for electrical connection with the second current collector plate (50). Therefore, the cap (60) may be conductive. For example, the cap (60) may include aluminum material.

[0103] The thickness of the cap (60) may be approximately 0.5 mm or more and 2 mm or less. For example, the thickness of the cap (60) may be approximately 1 mm.

[0104] The cap (60) may be disc-shaped so as to be fixed to the opening of the battery can (10) or to seal the opening of the can, but its shape is not limited thereto. Additionally, the thickness of the cap (60) may be designed to provide sufficient strength to prevent deformation in high temperature or high pressure environments and to ensure durability to prevent leakage of the internal electrolyte.

[0105]

[0106] However, the above-mentioned battery cell (1) is a high-output battery or a high-density energy battery, and excessive heat may be generated during use. This may cause abnormal chemical reactions within the battery cell (1), thereby abnormally increasing internal pressure. In other words, if this heat is not properly managed, it may lead to cell performance degradation, shortened lifespan, and even safety issues.

[0107] Accordingly, the battery cell (1) may be equipped with a cooling structure to be described later. This cooling structure can play an important role in maintaining overall performance and lifespan by effectively dissipating heat generated inside the battery cell (1).

[0108] The cooling structure of the battery cell (1) can be designed in various locations, such as the top, side, and bottom, and the thermal management method may vary depending on each location. Among these, the bottom cooling structure may be a method of placing a cooling channel or a heat exchanger at the bottom of the battery cell (1), that is, at the bottom portion where the battery cells (1) are stacked or arranged.

[0109] This bottom cooling structure can improve overall performance and safety while maximizing the thermal management efficiency of the battery cell (1). Since heat generated during use naturally has a downward conduction characteristic, by placing the cooling structure at the bottom of the battery cell (1), the internal heat removal path is minimized, and faster and more efficient heat dissipation can be achieved.

[0110] In addition, in the design of a battery utilizing a bottom cooling structure for efficient heat dissipation from the bottom of the cell, it is desirable to design an internal gas exhaust path at the top of the battery cell (1) to prevent thermal runaway of the battery cell (1) and to control the internal pressure in terms of ensuring safety.

[0111] Accordingly, as illustrated in FIG. 4, a battery cell (1) according to one embodiment of the present invention is configured such that a vent notch (121) is formed in a closed portion where the electrode terminal (30) is positioned on the upper part of the battery can (10). That is, the vent notch (121) can be designed on the upper part of the battery cell (1) together with a rivet structure riveted into a through hole (H) of the closed portion of the battery can (10).

[0112] The above-mentioned vent notch (121) is configured to open at a set pressure along a designed fracture structure. Thus, when the internal pressure of the battery can (10) exceeds the fracture pressure, the vent notch (121) fractures to release internal gas upward, thereby preventing the battery cell (1) from exploding.

[0113] Accordingly, in a battery cell (1) according to one embodiment of the present invention, the vent notch (121) is formed on the battery can (10) rather than on the cap (60) of the battery cell (1), thereby allowing the use of a lower cooling structure. As a result, the battery cell (1) can optimize thermal management at the bottom of the battery cell (1), and when abnormal conditions occur due to excessive internal pressure inside the battery can (10), the vent notch (121) is broken in the upward direction of the battery cell (1), allowing for smooth venting of internal gas. Through this, the internal pressure can be controlled to prevent thermal runaway while maintaining the temperature distribution within the battery cell (1) more quickly and efficiently.

[0114]

[0115] FIG. 5 is a drawing for explaining the weld (W) of the cap (60) of the battery cell (1) of FIG. 1, and FIG. 6 is a drawing for explaining another embodiment of the weld (W) of the cap of FIG. 5.

[0116] Referring to FIG. 5, the opening of the battery can (10) is formed at the bottom of the battery can (10) and can be welded together with the edge of the cap (60). The cap (60) can be provided to be in contact with the end of the opening of the battery can (10). That is, the diameter of the cap (60) in the circumferential direction can be substantially the same as the diameter of the outer surface of the battery can (10).

[0117] Thus, by welding along the perimeter of the part where the edge of the cap (60) and the battery can (10) meet, the weld (W) can be located on the side along the circumference rather than on the bottom of the battery cell (1). As a result, the part where the lower cooling device of the battery cell (1) meets the battery cell (1) can remain substantially flat, while protecting the interior of the battery cell (1) and maintaining isolation from the external environment.

[0118] Additionally, referring to FIG. 6, the cap (60) can be inserted inward from the opening of the battery can (10) toward the upper winding axis direction (Z). For example, the cap (60) can be inserted inward by a certain length (d) from the opening of the battery can (10) toward the upper winding axis direction (Z). To this end, the diameter of the cap (60) along the circumferential direction may be substantially the same as or slightly larger than the diameter of the inner circumferential surface of the battery can (10). Thus, the cap (60) is press-fitted into the opening of the battery can and welded together with the side of the battery can (10), so that the weld (W) is located inside the battery can (10) rather than at the bottom of the battery cell (1). As a result, the battery cell (1) can maintain a substantially flat surface at the point where it contacts the lower cooling device, while protecting the interior of the battery cell (1) and maintaining isolation from the external environment.

[0119]

[0120] Below, we examine various embodiments of the vent notch (121) of the present invention for preventing thermal runaway within the battery cell (1) under abnormal conditions such as increased internal pressure.

[0121] FIG. 7 is a drawing for explaining a vent notch (121) formed in a closed portion of a battery cell (1) according to one embodiment of the present invention.

[0122] Referring to FIG. 7, the vent notch (121) may be formed in a closure portion positioned on the upper part of the battery can (10). The closure portion of the battery can (10) is provided in the bottom member (12) of the battery can (10) as described above. Accordingly, the closure portion of the battery can (10) may be substantially disc-shaped and may include a first surface (12a) which is an upper surface and a second surface (12b) which is a lower surface, based on the winding axis direction (Z).

[0123] The first surface (12a) is positioned facing the outside of the battery can (10), and the second surface (12b) can be positioned facing the inside of the battery can (10) as a lower surface with respect to the first surface (12a) and the winding axis direction (Z).

[0124] The above-mentioned vent notch (121) is configured such that the closed portion of the battery can (10) is partially indented along the winding axis direction (Z) to reduce its thickness, but is not completely removed and maintains a predetermined thickness. At this time, the thin portion remaining after processing has strength capable of withstanding an increase in the internal pressure of the battery can (10), and can be designed so that when the internal pressure reaches a critical value, gradual rupture begins from the thinnest portion of the vent notch (121). Such rupture leads to gradual separation rather than a sudden explosion, and can undergo a process of stably discharging the internal gas of the battery cell (1) to the outside.

[0125] The shape of the above-mentioned vent notch (121) can be designed in various ways to enable precise pressure control. Although the drawing illustrated in the present invention is exemplified as having a triangular cross-section, for example, a fine groove in the shape of a semicircle or U-shape can be formed, or a polygonal pattern can be configured to induce predictable fracture. This shape can be modified during the processing process according to the material and thickness of the battery can (10), and can be applied differently to suit the intended use and required safety.

[0126] Additionally, the depth of the recess of the vent notch (121) formed along the winding axis direction (Z) can be designed by considering the thermal stress distribution in the area to minimize metal deformation that may occur during the process of forming the vent notch (121) in the closed part of the battery can (10). For example, a rivet structure in which the electrode terminal (30) is riveted is provided in the through hole (H) formed in the closed part of the battery can (10), and the rivet structure and the first current collector plate (40) can be joined by welding. Such a welded area may be sensitive to thermal stress. To this end, the depth of the recess of the vent notch (121) can be optimized so that the welded area is not subjected to excessive stress.

[0127] The above-mentioned vent notch (121) may include at least one of an upper notch (1211) and a lower notch (1212). The upper notch (1211) and the lower notch (1212) may be formed to induce fracture of the secondary battery and to be recessed with a constant thickness along the winding axis direction (Z) from the first surface (12a) or the second surface (12b) of the closed portion of the battery can (10).

[0128] The upper notch (1211) may be formed concavely by being sunken inward in the thickness direction of the closed portion of the battery can (10) from the first surface (12a). Additionally, the lower notch (1212) may be formed concavely by being sunken inward in the thickness direction of the closed portion of the battery can (10) from the second surface (12b).

[0129] A battery cell (1) according to one embodiment may have both the upper notch (1211) and the lower notch (1212) in the closed portion of the battery can (10).

[0130] Thus, the notch structure, which is recessed along the winding axis direction (Z) from both surfaces (12a, 12b) of the closure of the battery can (10), can be fractured in a more precise and predictable manner. Unlike traditional notch structures that are recessed from only a single surface, this method allows for more precise control of the fracture pressure because the vent notch (121) is recessed from both surfaces (12a, 12b).

[0131] Accordingly, the battery cell (1) according to one embodiment of the present invention is recessed along the winding axis direction (Z) from both surfaces (12a, 12b) of the closed portion of the battery can (10), and thus the notch press depth for forming the vent notch (121) can be reduced compared to a notch structure recessed from a single surface, thereby reducing or preventing deformation of the vent notch (121) or its surrounding area. In addition, by designing the battery can (10) to cause fracture while dispersing force from both the inside and outside, the strength and stability of the battery can (10) can be maintained, and fracture can be induced quickly when a specific pressure is reached.

[0132] At this time, the upper notch (1211) and the lower notch (1212) can be formed with the same depth (a1, a2) in the winding axis direction (Z), respectively. Thus, due to the structure in which the two surfaces (12a, 12b) of the closing part of the battery can (10) are indented to the same depth, the thickness (a3) ​​of the closing part of the battery can (10) is uniformly thinned inward in the thickness direction, allowing the breaking to proceed in a more uniform and predictable manner. In addition, since the stress is symmetrically distributed along the winding axis direction (Z), the durability of the battery can (10) is maintained until it breaks, and the impact during the breaking process can be minimized.

[0133]

[0134] FIGS. 8 to 10 are drawings for explaining other embodiments of the vent notch (121) of FIG. 7. Referring to FIGS. 8 to 10, in a battery cell (1) according to another embodiment of the present invention, the recessed depths of the upper notch (1211) and the lower notch (1212) may differ from each other.

[0135] First, as shown in FIG. 8, the closed portion of the battery can (10) may include a plating layer (122) on at least one of the first surface (12a) and the second surface (12b).

[0136] The battery can (10) is primarily made of a metal material, and by forming the plating layer (122) on the surface of this metal, the battery cell (1) can be protected from the external environment and the reaction with the electrolyte inside the battery can (10) can be minimized. Thus, the plating layer (122) contributes significantly to the corrosion resistance, electrical performance, and mechanical strength of the battery cell (1), and in particular, can play a role in suppressing reactivity with the electrolyte. If the inner surface of the battery can (10) is directly exposed to the electrolyte, corrosion may occur due to a chemical reaction between the metal and the electrolyte, but the plating layer (122) can block this reaction, thereby extending the lifespan of the battery cell (1). For example, the metal may be steel, and the plating layer (122) may be a nickel layer.

[0137] Accordingly, the battery cell (1) according to the present embodiment may be configured such that the vent notch (121) for preventing thermal runaway is formed in the closed portion of the battery can (10), and the plating layer (122) capable of minimizing reaction with the electrolyte inside the battery can (10) is not removed or damaged.

[0138] For example, the plating layer (122) is included on at least the second surface (12b) of the closed portion of the battery can (10), and so that the plating layer (122) is not removed or damaged, the lower notch (1212) can be formed with a depth (b2) shallower than the thickness (b4) of the plating layer (122) along the winding axis direction (Z). That is, the thickness of the plating layer (122) can be greater than the depth of the lower notch (1212) and smaller than the depth of the upper notch (1211) (b1). Thus, while minimizing the reaction between the closed portion of the battery can (10) and the internal electrolyte of the battery can (10), in the event of an abnormal condition of the battery cell (1), the resulting increase in internal pressure can push out the portion formed with a thin thickness (b3) of the vent notch (121), causing it to break.

[0139] Accordingly, the battery cell (1) according to the present embodiment improves corrosion resistance, electrical contact characteristics, mechanical strength, etc. due to the plating layer (122), and enables smooth venting due to the vent notch (121).

[0140] In addition, as another example, as illustrated in FIG. 9, the battery cell (1) according to the present embodiment may have a recessed depth (c1) of the upper notch (1211) along the winding axis direction (Z) that is smaller than the recessed depth (c2) of the lower notch (1212). As a result, stress is concentrated on the lower notch (1212), which is formed relatively large due to internal pressure, and thus fracture may occur easily. Accordingly, if the thickness (c3) between the upper notch (1211) and the lower notch (1212) is processed to be sufficiently thin, fracture occurs locally at the vent notch (121) of the battery can (10), thereby preventing deformation of the surrounding area and minimizing damage to the battery cell (1).

[0141] Accordingly, the battery cell (1) according to the present embodiment can be configured to break more easily at a specific point to ensure a smooth discharge path for the internal gas (G) when a structure is located around the pressure valve or the vent notch (121). By doing so, damage to other parts of the battery can (10) can be minimized, and the design allows for predictable venting, thereby providing the effect of improving overall safety.

[0142] In addition, as another example, as illustrated in FIG. 10, the battery cell (1) according to the present embodiment may have a stepped structure formed such that the vent notch (121) is recessed inward in the thickness direction along the winding axis direction (Z) from the surface of the closed portion of the battery can (10). At this time, the stepped structure may be configured such that the area of ​​the recessed region exposed to the outside from the top surface of the battery can (10) gradually decreases at the depth of recessation along the winding axis direction (Z) from the surface.

[0143] Thus, by effectively distributing stress over several stages, the fracture of the vent notch (121) can be controlled, thereby preventing sudden deformation of the surrounding area. The vent notch (121) of such a multi-stage structure is designed so that fracture occurs in stages when internal pressure increases, allowing the internal pressure to be gradually relieved through each stage of the vent notch (121).

[0144] The above-mentioned vent notch (121) may have at least one of the upper notch (1211) and lower notch (1212) having a stepped structure as described above. For example, the above-mentioned vent notch (121) may be recessed by a predetermined depth (d1) along the winding axis direction (Z) from the first surface (12a) to form a primary recessed portion having a large recessed area exposed to the outside. From there, it may be recessed by a predetermined depth (d2) along the winding axis direction (Z) to form a secondary recessed portion having a relatively narrow recessed area, thereby providing an upper notch (1211) having a secondary multi-stage structure. At this time, it may further include lower notches (1212) of various shapes recessed by a predetermined depth (d3) along the winding axis direction (Z) from the second surface (12b). By doing so, the processing depth of the upper notch (1211) along the winding axis direction (Z) is reduced, thereby forming a fracture portion of a predetermined thickness (d4), which further prevents deformation of the area around the vent notch (121).

[0145] Accordingly, the battery cell (1) according to the present embodiment enables gradual pressure relief over several stages rather than pressure relief occurring all at once when the vent notch (121) is broken, thereby efficiently discharging internal gas. In addition, the stepped structure can provide the effect of improving overall strength by dispersing the energy generated upon breaking in stages and at different times, thereby minimizing damage to other parts of the battery can (10).

[0146]

[0147] FIG. 11 is a top view schematically showing the vent notch (121) of FIG. 7, and FIG. 12 is a top view schematically showing another embodiment of the vent notch (121) of FIG. 7.

[0148] Referring to FIGS. 11 and 12, the vent notch (121) may be formed to have a ring shape along the circumferential direction, spaced apart from the center of the electrode terminal (30) connected to the through hole (H) formed in the closed portion of the battery can (10). That is, the ring-shaped vent notch (121) is formed continuously along the circumference of the closed portion of the battery can (10), so that when internal pressure rises, the fracture is not concentrated at one point but is evenly distributed.

[0149] As a result, stress concentration at specific points is reduced, and fracture occurs in a more predictable and stable manner. In addition, fracture proceeds more quickly and smoothly, allowing internal gases to be rapidly released to the outside.

[0150] Additionally, the vent notch (121) may be provided in an arbitrary closed loop shape along the circumferential direction, even if it is not a ring shape with a constant radius. As a result, the vent notch (121) can be broken as intended in the design, thereby simultaneously improving the durability and stability of the battery cell (1).

[0151]

[0152] FIG. 13 is a drawing for explaining a vent notch (121) formed in the closed portion of a battery can (10) of a battery cell (1) according to another embodiment of the present invention, and FIG. 14 is a top view schematically showing the vent notch (121) of FIG. 13.

[0153] Referring to FIGS. 13 and 14, the battery cell (1) according to the present embodiment may have a plurality of vent notches (121, 121a) formed radially outward from the center of the opening of the battery can (10). By doing so, stress caused by abnormal pressure inside the battery can (10) is concentrated in one vent notch (121), thereby preventing excessive deformation or fracture at a specific point. That is, the plurality of vent notches (121, 121a) formed at various locations react independently to uniformly distribute pressure at the fracture site, thereby reducing the fragility of the battery cell (1) and improving structural strength.

[0154] The plurality of vent notches (121, 121a) may be formed to have various shapes or patterns, and are not limited to the shapes of the vent notches (121, 121a) as shown in FIGS. 7 to 13. That is, each of the plurality of vent notches (121, 121a) may have various depths or patterns along the winding axis direction (Z).

[0155] For example, one vent notch (121) may have an upper notch (1211) and a lower notch (1212) in a closed-loop shape, while another vent notch (121a) may be formed only of the upper notch (1211) in a closed-loop shape. Multiple vent notches (121, 121a) having different depths and patterns along the winding axis direction (Z) can cause stress to be distributed in various ways when internal pressure rises, thereby inducing the battery can (10) to break first at a specific location. As a result, internal gas is gradually discharged to the outside, and pressure can be safely relieved without sudden breakage or explosion of the battery can (10). In addition, the independent structure of each vent notch (121, 121a) can reduce the vulnerability of the battery cell (1) and improve overall durability, thereby further increasing the safety of the battery cell (1).

[0156] Accordingly, the battery cell (1) according to the present embodiment can prevent excessive deformation or fracture in a specific area by having a plurality of vent notches (121, 121a). In addition, by having a plurality of vent notches (121, 121a) having different depths and patterns along the winding axis direction (Z), the order or degree of fracture can be controlled when abnormal conditions occur, which can play an important role in maximizing the safety of the battery cell (1) and preventing unexpected explosions.

[0157]

[0158] FIG. 15 is a drawing for explaining a vent notch (121) formed in the closed portion of a battery can (10) of a battery cell (1) according to another embodiment of the present invention, FIG. 16 is a top view schematically showing the vent notch (121) of FIG. 15, and FIG. 17 is a drawing for explaining the state in which the vent notch (121) of FIG. 15 is broken.

[0159] Referring to FIGS. 15 to 17, the battery cell (1) according to the present embodiment may have the vent notch (121) include a plurality of curved portions (1213) and a plurality of linear portions (1214).

[0160] The curved portion (1213) forms part of a vent notch (121) formed near the through hole (H) of the closed portion of the battery can (10) and can be designed to selectively break in response to abnormal pressure occurring inside the battery cell (1). The curved portion (1213) can be arranged to surround the outer circumference or near the outer circumference of the electrode terminal (30) along the circumferential direction, and can be formed continuously or discontinuously along at least a portion of the circumference of the electrode terminal (30). By doing so, when the internal pressure of the battery cell (1) rises, stress can be concentrated locally to induce breakage at a specific location.

[0161] The linear portion (1214) can be interconnected with each of the curved portions (1213) and can be arranged radially along the circumferential direction with respect to the center of the electrode terminal (30). Such a radial structure can be uniformly formed on the closed portion of the battery can (10). Thus, when the internal pressure of the battery cell (1) exceeds a certain threshold value, the vent notch (121) can be configured to break along the radial structure. This radial arrangement ensures that stress is evenly distributed upon breakage, thereby guaranteeing uniform breakage of the closed portion of the battery can (10) and enabling rapid relief of abnormal pressure.

[0162] As a result, even under abnormal pressure conditions inside the battery cell (1), at least a portion of the closure of the battery can (10) can be safely broken, thereby minimizing secondary damage. Additionally, the structure allows at least a portion of the closure of the battery can (10) to be broken radially and folded outward without the broken member being completely removed, thus maintaining a smooth gas discharge path.

[0163] In addition, the vent notch (121) according to the present embodiment described with reference to FIGS. 15 to 17 may also have various shapes, patterns, and depths of depression, similar to the vent notch (121) according to the embodiment described above with reference to FIGS. 7 to 14, and redundant descriptions are omitted below.

[0164] Accordingly, the battery cell (1) according to the present embodiment can maximize the flexibility of fracture control and the efficiency of pressure relief, and also optimize the flow of discharged gas to accelerate the process of reducing internal pressure and enable the battery cell (1) to operate safely without performance degradation.

[0165]

[0166] FIG. 18 schematically shows a protective member (123) of a vent notch (121) of a battery can (10) of a battery cell (1) according to one embodiment of the present invention.

[0167] The above-mentioned vent notch (121) is a fracture portion configured to be fractured by abnormal internal pressure of the battery cell (1), and may additionally be provided with a protective member (123) to increase its functional reliability.

[0168] The protective member (123) may be positioned to cover or wrap around the area of ​​the vent notch (121) or its vicinity, and may perform a protective function to selectively break the vent notch (121) only under abnormal pressure conditions. This prevents the vent notch (121) or its surrounding area from being unnecessarily broken or deformed due to external impact or environmental factors.

[0169] The protective member (123) may be manufactured from a durable material such as a polymer material and may provide strength and heat resistance suitable for the internal and external environment of the battery can (10). Additionally, the protective member (123) may be designed so that the vent notch (121) breaks normally when the internal pressure of the battery cell (1) reaches a specific threshold, so as not to impair the fracture characteristics of the vent notch (121). For example, the protective member (123) may not hinder the deformation of the vent notch (121) upon fracture and may allow the stress concentrated around the vent notch (121) to be effectively transferred to the expected fracture site.

[0170] In addition, the protective member (123) can also perform the role of preventing the scattering of foreign substances that may occur upon fracture. By controlling the discharge of foreign substances, such as fragments, to the outside when the vent notch (121) fractures, damage to surrounding components can be minimized. This protective member (123) improves the long-term stability and reliability of the battery cell (1) and can enhance safety within the battery system.

[0171]

[0172] FIG. 19 is a schematic diagram showing a battery pack (P) equipped with a battery cell (1) according to an embodiment of the present invention, FIG. 20 is a diagram explaining a method of cooling the battery cell (1) of the battery pack (P) of FIG. 19, and FIG. 21 is a schematic diagram showing a vehicle (V) equipped with a battery pack (P) according to an embodiment of the present invention.

[0173] A battery pack (P) according to one embodiment of the present invention may further include various other components of a battery pack known at the time of filing the present invention. For example, a battery pack (P) according to one embodiment of the present invention may further include components such as a current sensor, a fuse, and a service plug.

[0174] Referring to FIGS. 19 and 20, the battery pack (P) may include a pack housing (200) configured to accommodate at least one of the aforementioned battery cells (1) and a cooling pad (100) configured to release heat from the battery cells (1) within the pack housing (200).

[0175] As described above, the battery cell (1) may be designed to utilize a bottom cooling structure for efficient heat dissipation downwards. Accordingly, the battery pack (P) may be provided with the cooling pad (100) at the bottom portion where the battery cells (1) are placed, that is, on the side of the cap (60). By doing so, heat generated from the battery cell (1) can be dissipated downwards, thereby preventing overheating inside the battery cell (1).

[0176] The battery pack (P) can be designed to be in close contact with the bottom of the battery cell (1) using a material that has high thermal conductivity and flexibility. As a result, heat generated from the battery cell (1) is rapidly transferred through the cooling pad (100), and the heat is dispersed, thereby maximizing the thermal management efficiency of the battery pack (P).

[0177] Additionally, the cooling pad (100) can be connected to a cooling channel so that a cooling fluid circulates along the heat transfer surface of the cooling pad (100), thereby enabling more efficient heat dissipation. This structure can maintain the stability of the battery pack (P) even in high-power or high-temperature environments and contribute to optimizing the thermal characteristics of the battery cell (1). Furthermore, since the thickness and material selection of the cooling pad (100) can affect the total weight of the battery pack (P), it can be designed to provide effective cooling performance while minimizing weight through a lightweight structure.

[0178] Accordingly, the battery pack (P) according to the present embodiment can establish an efficient heat dissipation system for the battery cell (1) by utilizing a cooling pad (100) disposed at the bottom of the battery cell (1). In addition, in the battery pack (P), the cooling pad (100) is disposed on the opposite side of the portion where the vent notch (121) of the battery cell (1) is located. Therefore, the battery pack (P) can stably secure an internal gas (G) discharge path to prevent thermal runaway of the battery cell (1) by utilizing the vent notch (121) formed at the top of the battery cell (1). In this way, while maximizing cooling performance by using a bottom cooling method, the discharge of gas (G) from the vent notch (121) is not blocked by the cooling pad (100), allowing for smooth venting, thereby effectively reducing the internal pressure of the battery cell (1).

[0179] Additionally, referring to FIG. 21, a vehicle (V) according to one embodiment of the present invention may include one or more battery packs (P) according to the present invention. Furthermore, a vehicle (V) according to one embodiment of the present invention may include various other components included in the vehicle in addition to the battery packs (P). For example, a vehicle (V) according to one embodiment of the present invention may include, in addition to the battery packs (P) according to one embodiment of the present invention, a vehicle body, a motor, an electronic control unit (ECU), or other control devices.

[0180] In addition, the battery pack (P) according to one embodiment of the present invention can be applied to various types of energy storage devices or power sources, and it is also possible to equip it in other devices, mechanisms, and facilities, such as an energy storage system using a secondary battery, in addition to the vehicle (V).

[0181]

[0182] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0183]

[0184] [Explanation of the symbol]

[0185] 1: Battery cell

[0186] 10: Battery can

[0187] 11: Sidewall member

[0188] 12: Floor member (closed part)

[0189] 12a: First surface

[0190] 12b: Second surface

[0191] 121, 121a: Vent notch

[0192] 1211: Upper notch

[0193] 1212: Bottom notch

[0194] 1213: Curved section

[0195] 1214: Linear part

[0196] 122: Plating layer

[0197] 123: Absence of protection

[0198] 20: Electrode assembly

[0199] 21: First electrode

[0200] 22: Second electrode

[0201] 23: Metal foil

[0202] 24: Maintenance Department

[0203] 26: Mujibu

[0204] 27: Notching Tab

[0205] 28: Separator

[0206] 30: Electrode terminal

[0207] 40: First ceremonial tablet

[0208] 50: Second tribunal

[0209] 60: Cap

[0210] 70: Gasket

[0211] 100: Cooling pad

[0212] 200: Pack Housing

[0213] H: Through hole

[0214] W: Welded part

[0215] G: Gas

[0216] P: Battery pack

[0217] V: Car

Claims

As a battery cell, An electrode assembly comprising a first electrode and a second electrode and a separator interposed between them, wound around a winding axis; A battery can that accommodates the electrode assembly through an opening formed on one side, has a closed portion formed on the other side, and is electrically connected to the second electrode; An electrode terminal electrically connected to the first electrode through a through hole formed in the closed portion of the battery can; and It includes a cap that covers the opening of the battery can, and The closure of the battery can above is, A battery cell characterized by having a bent notch formed with a fracture structure. In Article 1, The opening of the battery can above is, A battery cell characterized by being welded together with the edge of the above-mentioned cap. In Article 1, The above cap is, A battery cell characterized by being inserted into the longitudinal inner side of the battery can from the opening of the battery can and welded together with the side of the battery can. In Article 1, The closure of the battery can above is, A first surface positioned toward the outside of the battery can; and It includes a second surface positioned toward the interior of the battery can, and The above vent notch is, A battery cell characterized by including an upper notch formed concavely by being sunken inward in the thickness direction of the closing portion of the battery can from the first surface, and a lower notch formed concavely by being sunken inward in the thickness direction of the closing portion of the battery can from the second surface. In Paragraph 4, The above vent notch is, A battery cell characterized by the fact that the recessed depths of the upper notch and the lower notch are different from each other. In Paragraph 4, The closure of the battery can above is, It includes a plating layer on at least a second surface, A battery cell characterized by the thickness of the plating layer being greater than the recessed depth of the lower notch. In Article 1, The above vent notch is, The closing portion of the battery can is recessed inwardly in the thickness direction to have a stepped structure, and The above step structure is, A battery cell characterized by the size of the externally exposed depression area gradually decreasing along the direction of the depression depth. In Article 1, The above vent notch is, A battery cell characterized by being provided in a closed loop shape. In Article 8, The above vent notch is, A battery cell characterized by having a plurality of openings formed radially outward from the center of the battery can. In Article 9, Multiple above-mentioned vent notches, A battery cell characterized by having different depths or patterns. In Article 1, The above vent notch is, A plurality of curved portions formed along at least a portion of the circumference of the electrode terminal; and A battery cell characterized by including a plurality of linear sections that are each connected to the plurality of curved sections and formed radially from the center of the opening of the battery can. In Article 1, The above vent notch is, A battery cell characterized by having a protective member. A battery pack characterized by including a battery cell according to any one of claims 1 to 12. In Article 13, A battery pack characterized by having a cooling pad positioned on the opposite side of the portion where the vent notch of the battery cell is located. A vehicle equipped with at least one battery pack according to Article 14.

Images