Cylindrical secondary battery

Abstract

Disclosed is a cylindrical secondary battery. The cylindrical secondary battery includes: an electrode assembly; a cylindrical can accommodating the electrode assembly and having a terminal hole at a first end; and a terminal portion coupled to the first end of the can and electrically connected to the electrode assembly, and the can further includes a coupling groove and a coupling protrusion adjacent to the terminal hole on a portion through which the terminal hole passes. In a cylindrical secondary battery according to an embodiment of the present disclosure, a sealing force of the cylindrical secondary battery may be increased by providing a groove and a protrusion in a can that is a region to which a crimp terminal is bonded.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0074064 filed in the Korean Intellectual Property Office on June 9, 2023, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0002] Aspects of embodiments of the present disclosure relate to a cylindrical secondary battery. Background Art

[0003] Recently, the demand for secondary batteries in which both the positive electrode terminal and the negative electrode terminal are arranged on one side of the secondary battery is increasing. This type of secondary battery has the advantage of a simple electrical connection structure with the outside.

[0004] In the cylindrical secondary battery of the above type, the electrode assembly is housed inside a cylindrical can. The can is electrically connected to the negative electrode of the electrode assembly through a negative electrode collector plate. The positive electrode terminal is provided at the top end of the can. The positive electrode terminal is electrically connected to the positive electrode of the electrode assembly through a positive electrode collector plate. Here, the positive electrode terminal is insulated from the can by an insulator.

[0005] However, if there is a gap between the positive electrode terminal and the insulator, the problem of incomplete sealing of the secondary battery occurs. Therefore, electrolyte leakage occurs. In addition, the positive electrode terminal may rotate due to external force. Therefore, there is a need for a structure for improving the sealing force of the positive electrode terminal area and preventing or substantially preventing the rotation of the positive electrode terminal.

[0006] The above information disclosed in this Background section is provided to enhance understanding of the background of the invention and therefore it may contain information that does not constitute the prior art. Summary of the invention

[0007] According to an aspect of an embodiment of the present disclosure, a cylindrical secondary battery having improved safety is provided.

[0008] According to one or more embodiments of the present disclosure, a cylindrical secondary battery includes: an electrode assembly; a cylindrical can that accommodates the electrode assembly and has a terminal hole at a first end; and a terminal portion that is coupled to the first end of the can and is electrically connected to the electrode assembly, and the can also includes a coupling groove and a coupling protrusion that are adjacent to the terminal hole on a portion through which the terminal hole passes.

[0009] The depth of the coupling groove may be smaller than the thickness of the first end of the can where the coupling groove is formed.

[0010] The depth of the coupling groove may be 10% to 30% less than the thickness of the first end of the can where the coupling groove is formed.

[0011] The engaging protrusion may face the interior of the can.

[0012] The coupling protrusion may protrude to a height equal to or lower than an inner surface of the first end of the can where the coupling groove is formed.

[0013] The coupling protrusion may be positioned on the cut surface side of the terminal hole.

[0014] The engaging protrusion may face the exterior of the can.

[0015] The bonding groove may face the exterior of the can.

[0016] The terminal part may include a riveted terminal electrically connected to the electrode assembly, and an insulator (or at least one insulator) between the riveted terminal and the can to insulate the riveted terminal and the can from each other.

[0017] The diameter of the combining groove may be equal to or smaller than the diameter of the insulator.

[0018] The insulator may be arranged at a position corresponding to that of the coupling groove, and may include a coupling portion protruded to be shaped to correspond to the coupling groove.

[0019] According to one or more embodiments of the present disclosure, a cylindrical secondary battery includes: a can having an upper portion through which a terminal hole passes and a cylindrical side portion extending downward from the upper portion; an electrode assembly including a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate, the electrode assembly being wound in a cylindrical shape; a terminal portion including a riveted terminal inserted into the terminal hole and electrically connected to the first electrode plate and at least one insulator between the riveted terminal and the can to insulate the riveted terminal and the can from each other, wherein the can also includes a coupling groove and a coupling protrusion adjacent to the terminal hole.

[0020] The coupling groove may be concavely formed from a surface of the upper portion, and a depth of the coupling groove may be smaller than a thickness of the upper portion.

[0021] The depth of the coupling groove may be 10% to 30% less than the thickness of the upper portion.

[0022] The engaging protrusion may face the interior of the can.

[0023] The combining protrusion may protrude to a height equal to or lower than an inner surface of the upper portion.

[0024] The coupling protrusion may be positioned on the cut surface side of the terminal hole.

[0025] The engaging protrusion may face the exterior of the can.

[0026] The bonding groove may face the exterior of the can.

[0027] The insulator may include a first portion (eg, a circular first portion) positioned outside the upper portion, a second portion (eg, a circular second portion) positioned inside the upper portion, and a third portion connecting the first portion and the second portion.

[0028] The diameter of the coupling groove may be equal to or smaller than the diameter of the first portion or the second portion.

[0029] The insulator may be arranged at a position corresponding to that of the coupling groove, and may include a coupling portion protruding in a shape corresponding to that of the coupling groove.

[0030] The secondary battery may further include a first electrode collector plate between the riveted terminal and the electrode assembly and electrically connected to the first electrode plate; and a second electrode collector plate adjacent to one end of the side portion and electrically connected to the second electrode plate and the side portion.

[0031] The secondary battery may further include a cap assembly coupled to and insulated from the side portion.

[0032] The side portion may include a beading portion concavely formed at an upper portion of the cap assembly and a crimping portion formed by bending a lower end of the side portion inwardly, and the cap assembly may be disposed between the beading portion and the crimping portion.

[0033] The cover assembly may include a cover plate for sealing the side portion and a gasket between the cover plate and the side portion.

[0034] An edge of the second electrode current collector plate may be between the beaded portion and the gasket, and may be in contact with the beaded portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a perspective view of a cylindrical secondary battery according to an embodiment of the present disclosure.

[0036] Figure 2 is based on Figure 1 A cross-sectional view of a cylindrical secondary battery.

[0037] Figure 3 is based on Figure 1 An enlarged cross-sectional view of a portion of a can of a cylindrical secondary battery.

[0038] Figure 4 It shows that according to Figure 3 A cross-sectional view of a portion of the tank and the insulator.

[0039] Figures 5 to 7 is a cross-sectional view showing a portion of a tank and an insulator according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0040] Examples of the present disclosure are provided to more completely explain the present disclosure to those skilled in the art, and the following examples may be modified in various other forms. However, the present disclosure may be implemented in many different forms and should not be construed as being limited to the example embodiments set forth herein. On the contrary, these example embodiments are provided so that the present disclosure will be thorough and complete, and will convey aspects and features of the present disclosure to those skilled in the art.

[0041] In addition, in the accompanying drawings, the size or thickness of various components may be exaggerated for the sake of brevity and clarity. The same reference numerals always refer to the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items. In addition, it will be understood that when element A is referred to as being "connected to" element B, element A may be directly connected to element B, or one or more intervening elements C may be present between element A and element B so that element A and element B are indirectly connected to each other.

[0042] The terms used herein are for the purpose of describing specific embodiments and are not intended to limit the disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. It will also be understood that when the terms "comprise" or "include" and / or variations thereof are used in this specification, the stated features, quantities, steps, operations, elements and / or components are indicated, but the presence or addition of one or more other features, quantities, steps, operations, elements, components and / or groups thereof is not excluded.

[0043] It will be understood that, although the terms "first", "second", etc. may be used herein to describe various members, elements, regions, layers, and / or parts, these members, elements, regions, layers, and / or parts will not be limited by these terms. These terms are used to distinguish one member, element, region, layer, and / or part from another member, element, region, layer, and / or part. Thus, for example, the first member, first element, first region, first layer, and / or first part discussed below may be referred to as the second member, second element, second region, second layer, and / or second part without departing from the teachings of the present disclosure.

[0044] For ease of description, spatially relative terms such as "under", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature to another (or some) elements or features with reference to the figures. It will be understood that in addition to the orientations depicted in the figures, the spatially relative terms are also intended to cover different orientations of the device in use or operation. For example, if the elements or features in the figures are turned over, the elements described as "under" or "beneath" other elements or features will then be oriented as "on" or "above" the other elements or features. Therefore, the example term "under" can cover both above and below orientations.

[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concept belongs. It will also be understood that terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and not interpreted in an ideal or overly formal sense unless they are explicitly defined herein.

[0046] Here, a cylindrical secondary battery according to an embodiment of the present invention will be described in more detail with reference to the accompanying drawings (for convenience, based on Figure 1 and Figure 2 , the following description will be provided by defining the upper part as the upper direction and the lower part as the lower direction).

[0047] Figure 1 is a perspective view of a cylindrical secondary battery according to an embodiment of the present disclosure; and Figure 2 is based on Figure 1 A cross-sectional view of a cylindrical secondary battery.

[0048] like Figure 1 and Figure 2 As shown in the figure, a cylindrical secondary battery 10 according to an embodiment of the present disclosure may include a cylindrical can 100, an electrode assembly 200 accommodated inside the can 100, a first electrode collector plate 300, a second electrode collector plate 400, a terminal portion 500 disposed at a first side of the can 100, and a cap assembly 600 disposed at a second side of the can 100.

[0049] like Figure 1 and Figure 2 As shown in FIG. 1 , the can 100 may include a circular upper surface portion 110 and a cylindrical side portion 130 extending downward from the upper surface portion 110. Since the lower portion of the side portion 130 is open, the can 100 has a cylindrical shape with an open lower end.

[0050] Terminal hole 110a (see Figure 3) may be formed through the center of the upper surface portion 110. A portion of the terminal portion 500 may be exposed to the outside of the secondary battery 10 through the terminal hole 110a. A coupling groove and a coupling protrusion for improving the coupling strength with respect to the terminal portion 500 may be formed around the terminal hole 110a (to be described later).

[0051] In the side portion 130, its upper end is connected to the upper surface portion 110 to be formed integrally therewith. The lower end of the side portion 130 is open, and the cap assembly 600 is disposed at the open end. The curling portion 132 may be formed adjacent to the lower end of the side portion 130. The curling portion 132 may be formed concavely inwardly from the side portion 130. The end of the side portion 130 spaced apart from the curling portion 132 may be bent toward the inside of the can 100 to form a crimping portion 134. By the curling portion 132, the separation of the electrode assembly 200 may be prevented or substantially prevented. The cap assembly 600 may be disposed between the curling portion 132 and the crimping portion 134. The crimping portion 134 may fix the cap assembly 600 to seal the can 100.

[0052] The can 100 having the above structure may be made of steel, steel alloy, aluminum, aluminum alloy or equivalents thereof, but the embodiments of the present disclosure are not limited thereto. The electrode assembly 200, the first electrode collector plate 300 and the second electrode collector plate 400 are accommodated inside the can 100 together with the electrolyte.

[0053] like Figure 2 As shown in , the electrode assembly 200 may have a first electrode plate 210 wound in a cylindrical shape, a second electrode plate 220, and a separator 230 disposed between the first electrode plate 210 and the second electrode plate 220. In an embodiment, the first electrode plate 210 may be a positive electrode plate, and the second electrode plate 220 may be a negative electrode plate. However, it is also possible to configure in the opposite manner.

[0054] In the first electrode plate 210, the positive electrode active material layer may be formed on at least one surface of the aluminum (Al) foil by coating or the like. For example, the positive electrode active material layer may be a transition metal oxide (e.g., LiCoO2, LiNiO2, LiMn2O4, etc.). The first electrode plate 210 may include a first electrode uncoated portion in which the positive electrode active material layer is not formed. In an embodiment, a plurality of first electrode substrate tabs may be formed by cutting the first electrode uncoated portion into a specific shape by a notch or the like. In an embodiment, the first electrode substrate tab may be disposed to face the upper surface portion 110 of the can 100. In addition, the first electrode substrate tab protrudes upward from the separator 230 and may be electrically connected to the first electrode current collector plate 300.

[0055] In the second electrode plate 220, the negative electrode active material layer may be formed by coating at least one surface of a copper (Cu) foil or a nickel (Ni) foil. For example, the negative electrode active material layer may be graphite, carbon, etc. The second electrode plate 220 may include a second electrode uncoated portion on which a negative electrode active material layer is not formed. In an embodiment, a plurality of second electrode substrate tabs may be formed by cutting the second electrode uncoated portion into a specific shape by a notch, etc. In an embodiment, the second electrode substrate tab may be arranged to face the lower portion of the tank 100. In addition, the second electrode substrate tab may protrude downward from the separator 230 and may be electrically connected to the second electrode collector plate 400. A portion of the second electrode substrate tab may be welded and electrically connected to the curling portion 132 of the tank 100.

[0056] The separator 230 may be polyethylene (PE) or polypropylene (PP), but is not limited thereto. The separator 230 may prevent or substantially prevent an electrical short circuit between the first electrode plate 210 and the second electrode plate 220 and allow (eg, only allow) movement of lithium ions.

[0057] The electrode assembly 200 having the above-described structure is electrically connected to the first electrode collector plate 300 and the second electrode collector plate 400 to be electrically connected to the terminal part 500 and the can 100 , respectively.

[0058] like Figure 2 As shown in , the first electrode collector plate 300 has a disc shape and may be made of the same material as the first electrode plate 210. For example, the first electrode collector plate 300 may be made of aluminum or an aluminum alloy. The diameter of the first electrode collector plate 300 may be smaller than the diameter of the can 100, so that the first electrode collector plate 300 may be prevented or substantially prevented from being electrically connected to the can 100. The first electrode collector plate 300 may be welded in a state where its lower surface is in contact with the first electrode substrate tab of the first electrode plate 210. Therefore, the first electrode collector plate 300 and the first electrode plate 210 may be electrically connected. In addition, the upper surface of the first electrode collector plate 300 may be welded to the riveted terminal 510 of the terminal portion 500 to be described later. Therefore, the first electrode collector plate 300 and the riveted terminal 510 may be electrically connected. Therefore, the first electrode plate 210 and the riveted terminal 510 may be electrically connected through the first electrode collector plate 300. That is, the first electrode current collector plate 300 becomes a current flow path between the first electrode plate 210 and the rivet terminal 510 .

[0059] like Figure 2As shown in , the second electrode collector plate 400 may include a disc-shaped plate surface portion 410 and a contact portion 420 extending from the plate surface portion 410. The upper surface of the plate surface portion 410 may be welded in a state of contact with the second electrode substrate tab of the second electrode plate 220. Therefore, the second electrode collector plate 400 and the second electrode plate 220 may be electrically connected. In an embodiment, the second electrode collector plate 400 may be made of the same material as the second electrode plate 220. For example, the second electrode collector plate 400 may be made of copper. In an embodiment, the contact portion 420 may extend downward from the edge of the plate surface portion 410. The contact portion 420 may be in close contact with the inner surface of the curling portion 132. In an embodiment, the contact portion 420 may have a curve corresponding to the curve of the curling portion 132. For example, the contact portion 420 may be welded to the curling portion 132 to be electrically connected to the curling portion 132. However, the second electrode collector plate 400 is not electrically connected to the cap assembly 600.

[0060] like Figure 1 and Figure 2 As shown in , the terminal part 500 may include a rivet terminal 510 and at least one insulator 520 for insulating the rivet terminal 510 from the can 100 .

[0061] The riveted terminal 510 is inserted into the terminal hole 110a formed in the upper surface portion 110 of the can 100. The riveted terminal 510 is electrically connected to the first electrode plate 210 through the first electrode current collector plate 300. The riveted terminal 510 is a terminal that is bonded to the upper surface portion 110 of the can 100 by a riveting method. The riveted terminal 510 is inserted into the terminal hole 110a from the outside of the can 100 toward the inside. Here, one end of the riveted terminal 510 is disposed outside the can 100, and the other end is disposed inside the can 100. When the riveted terminal 510 is bonded, at least one insulator 520 is inserted between the riveted terminal 510 and the upper surface portion 110 of the can 100 to insulate the can 100 from the riveted terminal 510. In a state where the riveted terminal 510 is inserted into the terminal hole 110a, the inner end of the riveted terminal 510 is pressed and deformed by a process such as pressing or spinning. Therefore, the rivet terminal 510 may be closely combined with the upper surface portion 110 of the can 100 .

[0062] The insulator 520 may be made of an insulating material. The insulator 520 may have a cross-sectional shape of an "H" that is approximately horizontal or sideways. The insulator 520 may be used without limitation as long as the insulator 520 is made of an insulating material that is insoluble in the electrolyte. In addition, the insulator 520 may have appropriate elasticity to be tightly combined with the upper surface portion 110 of the tank 100 and the riveted terminal 510 by pressing. A more detailed structure of the insulator 520 will be described later.

[0063] like Figure 2As shown in FIG. 6 , the cap assembly 600 may include a cap plate 610 for sealing the can 100 and a gasket 620 for insulating the can 100 and the cap plate 610 from each other.

[0064] In an embodiment, the cap plate 610 may include a disc-shaped plane portion 612, an inclined surface 614 connected to the plane portion 612, and an extension surface 616 connected to the inclined surface 614. The plane portion 612 may be arranged approximately parallel to the second electrode current collector plate 400. The inclined surface 614 may extend obliquely downward from the edge of the plane portion 612. The extension surface 616 may extend from the edge of the inclined surface 614 and may be parallel to the plane portion 612. The extension surface 616 may be surrounded by a gasket 620 and arranged between the curling portion 132 and the crimping portion 134. In an embodiment, a notch 612a may be formed on the plane portion 612. When the pressure inside the secondary battery 10 is greater than a specific pressure, the notch 612a may rupture. When the notch 612a ruptures, the internal gas of the secondary battery 10 may be discharged. That is, the notch 612a serves as a vent.

[0065] The gasket 620 is disposed between the lower portion of the curling portion 132 and the crimping portion 134, and may cover the extended surface 616 of the cap plate 610. The gasket 620 may cover part or all of the extended surface 616. The side where the gasket 620 and the extended surface 616 contact each other may be defined as the inner side, and the side where the gasket 620 and the curling portion 132 contact each other may be defined as the outer side. Here, a portion of the contact portion 420 of the second electrode collector plate 400 may be inserted between the outer upper portion of the gasket 620 and the curling portion 132. Therefore, the contact portion 420 of the second electrode collector plate 400 and the extended surface 616 of the cap plate 610 do not contact each other due to the gasket 620. That is, the gasket 620 may insulate the cap plate 610 and the can 100 from each other, and may insulate the cap plate 610 and the second electrode collector plate 400 from each other.

[0066] Through the above structure, the rivet terminal 510 has a positive polarity, and the can 100 has a negative polarity.

[0067] In the secondary battery according to the above-described embodiment of the present disclosure, a structure for improving the sealing force and the bonding force between the can and the riveted terminal will be described in more detail.

[0068] Figure 3 is based on Figure 1 an enlarged cross-sectional view of a portion of a can of a cylindrical secondary battery; and Figure 4 It shows that according to Figure 3 A cross-sectional view of a portion of the tank and the insulator.

[0069] like Figure 3 and Figure 4As shown in FIG. 1 , the coupling groove 112 and the coupling protrusion 114 may be provided on an inner surface of the upper surface portion 110 of the can 100 adjacent to the terminal hole 110 a formed in the center.

[0070] In an embodiment, the coupling groove 112 may be formed by forging. The coupling groove 112 may be shaped as a circular ring having a width (e.g., a predetermined width) based on the center of the upper surface portion 110 of the can 100. The diameter of the terminal hole 110a may be defined as L1. Here, the outer diameter (or diameter) of the coupling groove 112 may be formed to be larger than the diameter of the terminal hole 110a. The outer diameter of the coupling groove 112 refers to the diameter based on the outer edge of the coupling groove 112 in a direction away from the center of the upper surface portion 110. 1 / 2 of the length obtained by subtracting the diameter L1 of the terminal hole 110a from the outer diameter of the coupling groove 112 is defined as the width of the coupling groove 112. In other words, referring to Figure 3 , the width of the coupling groove 112 may be understood as the diameter length of the groove recessed from the inner surface of the upper surface portion 110. In addition, the depth L3 of the coupling groove 112 may refer to the length of the inner surface of the upper surface portion 110 recessed in the direction of the thickness L2 of the upper surface portion 110. For more details, refer to Figure 3 , the depth L3 of the coupling groove 112 is the length from the inner surface of the upper surface portion 110 to the bottom surface of the coupling groove 112. In an embodiment, the coupling groove 112 is concavely machined or formed from the inner surface of the upper surface portion 110 by forging. Therefore, the depth L3 of the coupling groove 112 is formed to be smaller than the thickness L2 of the upper surface portion 110. In an embodiment, for example, the depth L3 of the coupling groove 112 may be 10% to 30% smaller than the thickness L2 of the upper surface portion 110.

[0071] When the coupling groove 112 is forged from the upper surface portion 110, the metal is pushed outward and protrudes a certain amount of processing. Here, the direction in which the metal is pushed is the direction of the cut surface (cut side) of the terminal hole 110a. In addition, the direction in which the metal is pushed and protrudes is the direction facing the electrode assembly 200. By machining the portion of the coupling groove 112 that is pushed to protrude, in an embodiment, the protrusion may have a triangular or substantially triangular cross-sectional shape. The protrusion thus formed corresponds to the coupling protrusion 114. The protruding height of the coupling protrusion 114 is equal to or less than the height of the inner surface of the upper surface portion 110 of the can 100 so as to prevent or substantially prevent interference with surrounding components due to the coupling protrusion 114.

[0072] The above-mentioned combining groove 112 and combining protrusion 114 improve the sealing force by increasing the combining force with the insulator 520. Therefore, the leakage of the electrolyte contained in the tank 100 can be prevented or substantially prevented. In addition, by combining the groove 112 and the combining protrusion 114, the friction between the insulator 520 and the upper surface portion 110 is increased. Therefore, the insulator 520 can be tightly (e.g., very tightly) combined with the upper surface portion 110. Therefore, even if the riveted terminal 510 moves, the insulator 520 does not move. Therefore, in order to rotate the riveted terminal 510, a very large rotation pressure must be applied. That is, compared with the existing terminal structure, the rotation pressure of the riveted terminal 510 can be increased. Therefore, the riveted terminal 510 will not rotate due to conventional external shocks or vibrations that occur in the use environment of the secondary battery. Therefore, the problem of the riveted terminal 510 rotating due to external force can be prevented or substantially prevented.

[0073] like Figure 4 As shown in FIG. 5 , a coupling portion 528 coupled to the coupling groove 112 may be provided on the insulator 520 . Figure 2 and Figure 4 As shown in , the insulator 520 may include a disk-shaped first portion (or first part) 522 disposed outside the upper surface portion 110, a disk-shaped second portion (or second part) 524 disposed inside the upper surface portion 110, and a cylindrical third portion (or third part) 526 connecting the first portion 522 and the second portion 524. A coupling portion 528 may be formed on the second portion 524. In an embodiment, the second portion 524 may have a length that fully extends outside the coupling groove 112 of the upper surface portion 110. In other words, the diameter of the coupling groove 112 may be equal to or less than the diameter of the insulator 520. For example, the length of the second portion 524 may be 2 to 3 times the length of the coupling groove 112. The first portion 522 to the third portion 526 may be formed integrally or separately to be coupled to the upper surface portion 110. In an embodiment, the description is based on an example in which the first portion 522 to the third portion 526 are integrally formed. The coupling portion 528 is formed based on Figure 2 The second portion 524 is protruded on the upper surface thereof and is formed based on Figure 4 The second portion 524 protrudes on the lower surface. The coupling portion 528 is formed to correspond to the position of the coupling groove 112, and the coupling portion 528 has a convex shape corresponding to the shape of the coupling groove 112. In an embodiment, when viewed in a plan view, the coupling groove 112 is a circular groove, and therefore, the coupling portion 528 may be a ring-shaped protrusion. Although not shown in the drawings, the insulator 520 may be additionally provided with a groove corresponding to the coupling protrusion 114. However, in an embodiment, the insulator 520 has elasticity and can be in close contact with the coupling protrusion 114, and a groove corresponding to the coupling protrusion 114 is not provided.

[0074] In the above-described embodiment, an embodiment has been described in which the second portion 524 of the insulator 520 has a length sufficient to cover the coupling groove 112. In addition, an embodiment has been described in which the coupling groove 112 and the coupling protrusion 114 are provided inside the upper surface portion 110 of the can 100. Here, some embodiments having a structure different from that of the above-described embodiment will be described.

[0075] Figures 5 to 7 is a cross-sectional view showing a portion of a tank and an insulator according to some embodiments of the present disclosure.

[0076] like Figure 5 As shown in FIG. 1 , the coupling groove 112 and the coupling protrusion 114 of the upper surface portion 110 can be Figure 4 The coupling groove 112 and the coupling protrusion 114 in the embodiment shown in FIG. 5 are the same. The first portion 522', the third portion 526' and the coupling portion 528' of the insulator 520' may be the same as Figure 4 The first portion 522, the third portion 526 and the joint 528 of the embodiment shown in FIG. 5 are the same. However, the length of the second portion 524′ may be longer than Figure 4 The length of the second portion 524 of the insulator 520 is shorter than Figure 4 The length of the second portion 524 of the embodiment is short, and the second portion 524' can also be formed to have a length that fully covers the coupling groove 112. Figure 4 As with the embodiment shown in , the sealing force of the terminal portion 500 can be maintained.

[0077] In an embodiment, Figure 6 As shown in , the coupling groove 112' may be provided at the inner or inner surface of the upper surface portion 110 of the can 100, and the coupling protrusion 114' may be provided at the outer or outer surface of the upper surface portion 110. In another embodiment, as Figure 7 As shown in , both the coupling groove 112 ″ and the coupling protrusion 114 ″ may be provided at the outer portion or outer surface of the upper surface portion 110 . Although not shown in the drawings, the position of the coupling portion of the insulator may also be changed to correspond to the position of the coupling grooves 112 ′, 112 ″.

[0078] As described above, even if the positions of the coupling groove and the coupling protrusion are changed, the sealing force remains the same. Figure 4 The sealing force of the embodiment shown in is the same and can prevent or substantially prevent rotation of the riveted terminal.

[0079] In a cylindrical secondary battery according to one or more embodiments of the present disclosure, the sealing force of the cylindrical secondary battery can be increased by providing forged grooves and protrusions in a can as an area to which a riveted terminal is coupled. Therefore, leakage of electrolyte inside the secondary battery can be prevented or substantially prevented. In addition, the rotation of the riveted terminal can be prevented or substantially prevented by increasing the rotation pressure of the riveted terminal.

[0080] Although some embodiments for carrying out the present disclosure have been described herein, the present disclosure is not limited to these embodiments, and those skilled in the art will understand that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as set forth in the following claims.

Claims

1. A cylindrical secondary battery, comprising: Electrode assembly; a cylindrical can accommodating the electrode assembly and having a terminal hole at a first end; as well as a terminal portion coupled to the first end of the can and electrically connected to the electrode assembly, Wherein, the can further includes a combining groove and a combining protrusion, and the combining groove and the combining protrusion are adjacent to the terminal hole at a portion through which the terminal hole passes.

2. The cylindrical secondary battery according to claim 1, wherein: The depth of the coupling groove is smaller than the thickness of the first end of the can where the coupling groove is formed.

3. The cylindrical secondary battery according to claim 2, wherein: The depth of the coupling groove is 10% to 30% less than the thickness of the first end of the can at which the coupling groove is formed.

4. The cylindrical secondary battery according to claim 1, wherein: The combining protrusion faces the interior of the can.

5. The cylindrical secondary battery according to claim 4, wherein: The coupling protrusion protrudes to a height equal to or lower than an inner surface of the first end of the can where the coupling groove is formed.

6. The cylindrical secondary battery according to claim 5, wherein: The coupling protrusion is positioned on a cut surface side of the terminal hole.

7. The cylindrical secondary battery according to claim 1, wherein: The combining protrusion faces the outside of the can.

8. The cylindrical secondary battery according to claim 7, wherein: The combining groove faces the exterior of the can.

9. The cylindrical secondary battery according to claim 1, wherein: The terminal part includes a rivet terminal electrically connected to the electrode assembly and an insulator between the rivet terminal and the can to insulate the rivet terminal and the can from each other.

10. The cylindrical secondary battery according to claim 9, wherein: A diameter of the combining groove is equal to or smaller than a diameter of the insulator.

11. The cylindrical secondary battery according to claim 10, wherein: The insulator is arranged at a position corresponding to that of the coupling groove, and includes a coupling portion protruding to be shaped to correspond to the coupling groove.

12. A cylindrical secondary battery, comprising: a can having an upper portion through which the terminal hole passes and a cylindrical side portion extending downwardly from the upper portion; an electrode assembly, comprising a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate, the electrode assembly being wound in a cylindrical shape; as well as a terminal portion including a riveted terminal inserted into the terminal hole and electrically connected to the first electrode plate and an insulator between the riveted terminal and the can to insulate the riveted terminal and the can from each other, Wherein, the can further includes a coupling groove and a coupling protrusion adjacent to the terminal hole.

13. The cylindrical secondary battery according to claim 12, wherein: The coupling groove is concavely formed from a surface of the upper portion, and a depth of the coupling groove is smaller than a thickness of the upper portion.

14. The cylindrical secondary battery according to claim 13, wherein: The depth of the combining groove is 10% to 30% less than the thickness of the upper portion.

15. The cylindrical secondary battery according to claim 12, wherein: The combining protrusion faces the interior of the can.

16. The cylindrical secondary battery according to claim 15, wherein: The combining protrusion protrudes to a height equal to or lower than an inner surface of the upper portion.

17. The cylindrical secondary battery according to claim 16, wherein: The coupling protrusion is positioned on a cut surface side of the terminal hole.

18. The cylindrical secondary battery according to claim 12, wherein: The combining protrusion faces the outside of the can.

19. The cylindrical secondary battery according to claim 18, wherein: The combining groove faces the exterior of the can.

20. The cylindrical secondary battery according to claim 12, wherein: The insulator includes a first portion disposed outside the upper portion, a second portion disposed inside the upper portion, and a third portion connecting the first portion and the second portion.

21. The cylindrical secondary battery according to claim 20, wherein: A diameter of the coupling groove is equal to or smaller than a diameter of the first portion or the second portion.

22. The cylindrical secondary battery according to claim 21, wherein The insulator is disposed at a position corresponding to that of the coupling groove, and includes a coupling portion protruding in a shape corresponding to that of the coupling groove.

23. The cylindrical secondary battery according to claim 12, further comprising: a first electrode current collector plate between the riveted terminal and the electrode assembly and electrically connected to the first electrode plate; as well as A second electrode current collector plate is adjacent to one end of the side portion and is electrically connected to the second electrode plate and the side portion. 24 . The cylindrical secondary battery according to claim 23 , further comprising a cap assembly coupled to and insulated from the side portion.

25. The cylindrical secondary battery according to claim 24, wherein: The side portion comprises: a bead portion concavely disposed at an upper portion of the cover assembly; and A crimping portion is formed by bending a lower end of the side portion inwardly, and the cap assembly is arranged between the curling portion and the crimping portion.

26. The cylindrical secondary battery according to claim 25, wherein: The cover assembly includes a cover plate for sealing the side portion and a gasket between the cover plate and the side portion.

27. The cylindrical secondary battery according to claim 26, wherein: An edge of the second electrode current collector plate is between the beaded portion and the gasket and in contact with the beaded portion.

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