Rivet fixing structure and secondary battery including same

Abstract

The present disclosure provides a rivet fixing structure and a secondary battery comprising same. The rivet fixing structure may comprise: a case having a bottom unit of which one side is opened and the other side has a through-hole; a rivet unit arranged to penetrate the through-hole; and a gasket arranged between the rivet unit and the through-hole such that the surface area facing the inside of the case is formed to be larger than the sectional area between the rivet unit and the through-hole.

Description

Rivet fixing structure and secondary battery including the same

[0001] The present disclosure relates to a rivet fixing structure and a secondary battery including the same.

[0002]

[0003] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for driving motors or actuators and as energy storage batteries for hybrid cars, electric vehicles, electric propulsion vessels, and Urban Air Mobility (UAM). Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a case housing the assembly, and electrode terminals connected to the electrode assembly.

[0004] Electrolyte is injected into the case of a secondary battery for a chemical reaction between the positive and negative electrodes, and the case is sealed with a sealing member to prevent leakage of the electrolyte. However, when the internal pressure of the case increases, the sealing member undergoes compressive deformation, causing a gap to form and potentially leading to leakage of the electrolyte to the outside.

[0005] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art.

[0006]

[0007] The present disclosure provides a rivet fixing structure for solving the above-mentioned problems and a secondary battery including the same.

[0008] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below.

[0009]

[0010] A rivet fixing structure according to one embodiment of the present invention for solving the above technical problem may include a case having a bottom portion having one side open and a through hole formed on the other side, a rivet portion disposed through the through hole, and a gasket disposed between the rivet portion and the through hole, wherein the surface area facing the interior of the case is formed to be larger than the cross-sectional area between the rivet portion and the through hole.

[0011] According to one embodiment of the present invention, the gasket may include a main body portion through which a rivet portion is disposed, an extension portion protruding radially from one end of the main body portion, and an extension portion formed at the end of the extension portion, with at least one surface facing the interior of the case.

[0012] According to one embodiment of the present invention, the extension may be formed such that the surface area facing the interior of the case is larger than the cross-sectional area in the thickness direction of the extension.

[0013] According to one embodiment of the present invention, the rivet portion may include a base portion disposed on the inner side of the bottom portion, a fastening portion protruding from the base portion and disposed through a through hole, and a flange portion formed to extend radially from the base portion so as to protrude to the outer side of the fastening portion.

[0014] According to one embodiment of the present invention, the extension may include a first surface that is in contact with the radial outer circumference of the flange portion, a second surface that is in contact with the bottom portion, a third surface that extends radially outward from the first surface, and a fourth surface that connects the second surface and the third surface and is formed to be inclined toward the radial outward.

[0015] According to one embodiment of the present invention, the extension may include a first surface that is in contact with the radial outer circumference of the flange portion, a second surface that is in contact with the bottom portion, and a third surface that connects the first surface and the second surface and is formed to be inclined toward the radial outer side.

[0016] According to one embodiment of the present invention, the extension may include a first surface that is in contact with the radial outer circumference of the flange portion, a second surface that is in contact with the bottom portion, a third surface that extends radially outward from the first surface, and a fourth surface formed in a vertical direction connecting the second surface and the third surface.

[0017] According to one embodiment of the present invention, the main body is inserted into a through hole and is in close contact with the outer surface of the fastening part, and the extension part may be positioned between the flange part and the inner surface of the bottom part.

[0018] According to one embodiment of the present invention, the extension may include a fastening groove into which a fastening projection formed protruding from the flange portion is inserted.

[0019] According to one embodiment of the present invention, the gasket may include a main body portion through which a rivet portion is disposed, and an extension portion that extends radially from one end of the main body portion, becomes thicker toward the end, and has an outer surface facing the interior of the case.

[0020] According to one embodiment of the present invention, the rivet portion may include a base portion disposed on the inner side of the bottom portion, a fastening portion protruding from the base portion and disposed through a through hole, and a flange portion that extends radially from the base portion to protrude outward from the fastening portion and becomes thinner toward the end.

[0021] According to one embodiment of the present invention, the extension may include a first surface formed at an angle and in close contact with the flange portion, a second surface formed in close contact with the bottom portion, and a third surface formed in a vertical direction connecting the first surface and the second surface.

[0022] According to one embodiment of the present invention, the extension may include a first surface formed at an angle and in close contact with the flange portion, a second surface formed at an angle and in close contact with the bottom portion, and a third surface formed at an angle toward the radial outer side and connecting the first surface and the second surface.

[0023] According to one embodiment of the present invention, the gasket may include an extended portion that extends radially from the extended portion and is formed to surround the outer surface of the flange portion.

[0024] According to one embodiment of the present invention, the extended portion may include a first surface that is in contact with the radial outer circumference of the flange portion, a second surface that is in contact with the bottom portion, a third surface that extends radially outward from the first surface, and a fourth surface formed in a vertical direction connecting the second surface and the third surface.

[0025] According to one embodiment of the present invention, the extended portion may include a first surface that is in contact with the radial outer circumference of the flange portion, a second surface that is in contact with the bottom portion, a third surface that extends radially outward from the first surface, and a fourth surface that connects the second surface and the third surface and is formed to be inclined toward the radial outward.

[0026] According to one embodiment of the present invention, the extended portion may include a first surface that is in contact with the radial outer circumference of the flange portion, a second surface that is in contact with the bottom portion, and a third surface that connects the first surface and the second surface and is formed to be inclined toward the radial outer side.

[0027] According to one embodiment of the present invention, the extension portion may include a fastening groove into which a fastening projection formed protruding from the flange portion is inserted.

[0028] A secondary battery according to one embodiment of the present invention for solving a technical problem may include an electrode assembly comprising a first electrode, a second electrode, and a separator; a case having a bottom portion having one side open and a through hole formed on the other side, in which the electrode assembly is received and electrically connected to the second electrode; a vent plate fastened to the open side of the case; a rivet portion disposed through the through hole and electrically connected to the first electrode; and a gasket disposed between the rivet portion and the through hole, wherein the surface area facing the interior of the case is formed to be larger than the cross-sectional area between the rivet portion and the through hole.

[0029] According to one embodiment of the present invention, the device may include an electrode terminal disposed on the outer side of a case and fastened to a rivet portion, and an external insulator disposed between the outer surface of a bottom portion and the electrode terminal, with its inner surface in close contact with a gasket.

[0030]

[0031] According to some embodiments of the present invention, by optimizing the shape of the gasket provided between the rivet portion and the case, it is possible to prevent the sealing force from decreasing even when the pressure inside the case increases.

[0032] 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.

[0033]

[0034] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0035] FIG. 1 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure.

[0036] Figure 2 is a cross-sectional view showing a comparative example of a rivet fastening structure.

[0037] FIG. 3 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure.

[0038] Figure 4 is an enlarged view showing an example of area A of Figure 3.

[0039] FIG. 5 is a partial cross-sectional view showing an example of a rivet portion according to the embodiment of FIG. 3.

[0040] FIG. 6 is a partial cross-sectional view showing an example of a gasket according to the embodiment of FIG. 3.

[0041] FIGS. 7 and FIGS. 8 are partial cross-sectional views showing other examples of a gasket according to the embodiment of FIG. 3.

[0042] FIG. 9 is a cross-sectional view showing an example of a rivet fixing structure according to another embodiment of the present disclosure.

[0043] FIG. 10 is a partial cross-sectional view showing an example of a rivet portion according to the embodiment of FIG. 9.

[0044] FIG. 11 is a partial cross-sectional view showing an example of a gasket according to the embodiment of FIG. 9.

[0045] FIG. 12 is a partial cross-sectional view showing another example of a gasket according to the embodiment of FIG. 9.

[0046] FIG. 13 is a cross-sectional view showing an example of a rivet fixing structure according to another embodiment of the present disclosure.

[0047] FIG. 14 is a partial cross-sectional view showing an example of a gasket according to the embodiment of FIG. 13.

[0048] FIGS. 15 and FIGS. 16 are partial cross-sectional views showing other examples of a gasket according to the embodiment of FIG. 13.

[0049]

[0050] Preferred embodiments of the present invention will be described in detail below 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. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0051] Additionally, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups.

[0052] 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.

[0053] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0054] 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.

[0055] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0056] The fact 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.

[0057] Furthermore, where it is stated that one component is "connected," "coupled," or "connected" to another component, it should be understood that while said components may be directly connected or connected to each other, another component may be "interposed" between each component, or that each component may be "connected," "coupled," or "connected" through another component. Additionally, when it is stated that a part is electrically coupled with another part, this includes not only cases where they are directly connected but also cases where they are connected with another component in between.

[0058] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise. That is, "and / or" includes any combination or any combination of the enumerated items. "C to D" means C or more and D or less, unless specifically stated otherwise.

[0059] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0060] FIG. 1 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure.

[0061] Referring to FIG. 1, a secondary battery (10) according to one embodiment of the present disclosure may include an electrode assembly (40), a case (20) in which the electrode assembly (40) is received on one side that is open, and a vent plate (51) that is fastened to one side that is open of the case (20).

[0062] The electrode assembly (40) may include a first electrode (41) and a second electrode (42) positioned with respect to a separator (43), and may be wound in the form of a jelly roll.

[0063] The first electrode (41) may include a first substrate and a first active material layer coated on both sides of the first substrate. It may include a first uncoated portion (41a) in the first substrate, which is an area where the first active material layer is not coated. The second electrode (42) may include a second substrate and a second active material layer coated on both sides of the second substrate. It may include a second uncoated portion (42a) in the second substrate, which is an area where the second active material layer is not coated. Here, the first uncoated portion (41a) and the second uncoated portion (42a) may be arranged in opposite directions.

[0064] The first electrode (41) can function as an anode. In this case, the first substrate may be composed of, for example, aluminum foil, and the first active material layer may include, for example, a transition metal oxide. The second electrode (42) can function as a cathode. In this case, the second substrate may be composed of, for example, copper foil or nickel foil, and the second active material layer may include, for example, graphite.

[0065] The separator (43) functions to prevent a short circuit between the first electrode (41) and the second electrode (42) while allowing the movement of lithium ions. The separator (43) may be composed of, for example, a polyethylene film, a polypropylene film, a polyethylene-polypropylene film, etc.

[0066] The case (20) accommodates the electrode assembly (40) and the electrolyte, and together with the vent plate (51), can form the outer shape of the secondary battery (10). The case (20) may have a bottom portion (21) with one side open and a through hole formed on the other side. The case (20) may be made of a metal such as aluminum, aluminum alloy, or nickel-plated steel.

[0067] Inside the case (20), a first current collector plate (31) and a second current collector plate (32) that are electrically connected to the electrode assembly (40) may be provided. The first current collector plate (31) may be electrically connected by contacting the first non-contact portion (41a) of the first electrode (41). The second current collector plate (32) may be electrically connected by contacting the second non-contact portion (42a) of the second electrode (42).

[0068] A rivet portion (61) is provided in a through hole formed in the bottom portion (21) of the case (20) so as to be electrically connected to the first current collector plate (31). An electrode terminal (63) provided on the outer side of the bottom portion (21) of the case (20) can be fastened to the rivet portion (61). Accordingly, the electrode terminal (63) provided on the outer side of the case (20) can be electrically connected to the first electrode (41) through the rivet portion (61) and the first current collector plate (31). Here, an insulating gasket (62) is provided in the through hole so as to electrically insulate the case (20) from the rivet portion (61).

[0069] A vent plate (51) may be attached to an open side of the case (20). In one embodiment, the vent plate (51) may be attached to one end of the case (20) through a clamping process. At this time, a sealing member (52) may be provided between the vent plate (51) and the case (20) to electrically insulate the vent plate (51) and the case (20).

[0070] Additionally, the second current collector plate (32) can be electrically connected to the case (20) during the process of clamping the vent plate (51). In one embodiment, a sealing member (52) is provided between the vent plate (51) and the case (20), and an end of the second current collector plate (32) can be positioned between the sealing member (52) and the case (20). Through this, the case (20) can be electrically connected to the second electrode (42) through the second current collector plate (32) while being insulated from the vent plate (51) through the sealing member (52).

[0071] A secondary battery according to one embodiment of the present disclosure may further include, although not illustrated in FIG. 1, an electrode terminal disposed on the outer side of a case and fastened to a rivet portion, an external insulator disposed between the outer surface of a bottom portion and the electrode terminal, and an internal insulator disposed on the inner surface of a bottom portion. Here, the internal insulator may not be provided as necessary. A form in which the electrode terminal, the external insulator, and the internal insulator are provided will be described below with reference to the drawings.

[0072] In addition, various embodiments of a rivet fixing structure including a rivet portion (61) disposed in a through hole (22) formed in the bottom portion (21) of a case (20) in a secondary battery (10) according to one embodiment of the present disclosure, and a gasket (62) disposed between the rivet portion (61) and the through hole (22) to electrically insulate the rivet portion (61) are described in more detail below.

[0073] Figure 2 is a cross-sectional view showing a comparative example of a rivet fastening structure.

[0074] Referring to FIG. 2, the rivet fixing structure may include a rivet portion (110) placed in a through hole (22) formed in the bottom portion (21) of the case (20), and a gasket (201) placed between the rivet portion (110) and the through hole (22) to provide electrical insulation. The gasket (201) may be made of an insulating material to electrically insulate the rivet portion (110) and the bottom portion (21) of the case (20).

[0075] Additionally, it may include an electrode terminal (63) positioned on the outside of the case (20) and fastened to the rivet portion (110), an outer insulator (65) positioned between the outer surface of the bottom portion (21) and the electrode terminal (63) with its inner surface in close contact with the gasket (201), and an inner insulator (64) that is in close contact with the inner surface of the bottom portion (21), with its inner surface in close contact with the gasket (201) and fastened to the rivet portion (110).

[0076] In one embodiment, the gasket (201) may include a main body (202) through which a rivet portion (110) is disposed, and an extension portion (203) protruding radially from one end of the main body portion (202). Additionally, the rivet portion (110) may include a base portion (111) disposed inside the bottom portion (21), a fastening portion (112) protruding from the base portion (111) and disposed through a through hole (22), and a flange portion (113) formed by extending radially from the base portion (111) so as to protrude outward from the fastening portion (112).

[0077] With this configuration, when a gasket (201) is inserted into a through hole (22) inside the case (20), the main body (202) is positioned through the through hole (22), and the extension (203) can be in close contact with the inner surface of the bottom part (21). Then, an internal insulator (64) can be positioned on the inner surface of the bottom part (21), and a rivet part (110) can be inserted into the main body (202). At this time, the inner surface of the internal insulator (64) can be fixed by the flange part (113) while in close contact with the outer surface of the extension (203).

[0078] Then, the outer insulator (65) is placed on the outer surface of the bottom part (21) so that the main body part (202) is inserted into the outer insulator (65) from the outside of the case (20), and the electrode terminal (63) is placed on the outer insulator (65) so that the fastening part (112) is inserted into the electrode terminal (63), and then the rivet part (110) is punched to fasten all components to the bottom part (21). At this time, the inner surface of the outer insulator (65) is in close contact with the outer surface of the main body part (202), and the electrode terminal (63) can be fastened with its inner surface in close contact with the outer surface of the fastening part (112) while the electrode terminal (63) is placed on the upper side of the main body part (202) and the outer insulator (65). Accordingly, the rivet portion (110) can be assembled to be electrically connected to the electrode terminal (63) and electrically insulated from the case (20) by means of a gasket (201), an internal insulator (64), and an external insulator (65).

[0079] With this configuration, when pressure increases inside the case (20), the internal insulator (64) may be compressed in the axial direction of the rivet portion (110), the extension portion (203) of the gasket (201) may be compressed in the axial direction, and the main body portion (202) may be compressed in the radial direction. At this time, a gap may occur between the rivet portion (110) and the gasket (201), or a gap may occur between the gasket (201) and the through hole (22), causing the electrolyte to leak out.

[0080] Accordingly, the present invention discloses a rivet fixing structure capable of preventing a gap from forming between a gasket and other components even when pressure rises inside a case (20). Hereinafter, with reference to FIGS. 3 to 17, examples of rivet fixing structures according to various embodiments of the present disclosure will be described in detail.

[0081] FIG. 3 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure, and FIG. 4 is an enlarged view showing an example of area A of FIG. 3. FIG. 5 is a partial cross-sectional view showing an example of a rivet part according to the embodiment of FIG. 3, and FIG. 6 is a partial cross-sectional view showing an example of a gasket according to the embodiment of FIG. 3.

[0082] Referring to FIGS. 3 to 6, a rivet fixing structure according to one embodiment of the present disclosure may include a case (20) having a bottom portion (21) having one side open and a through hole (22) formed on the other side, a rivet portion (110) disposed through the through hole (22), and a gasket (210) disposed between the rivet portion (110) and the through hole (22) to provide electrical insulation. The gasket (210) may be made of an insulating material to electrically insulate the rivet portion (110) and the bottom portion (21) of the case (20).

[0083] In one embodiment, the gasket (210) may include a main body (211) through which a rivet portion (110) is positioned, an extension portion (212) protruding radially from one end of the main body portion (211), and an extension portion (213) formed at the end of the extension portion (212) with at least one surface facing the interior of the case (20). The main body portion (211), the extension portion (212), and the extension portion (213) of the gasket (210) may be formed integrally.

[0084] The rivet portion (110) may include a base portion (111) disposed on the inner side of the bottom portion (21), a fastening portion (112) protruding from the base portion (111) and disposed through a through hole (22), and a flange portion (113) formed by extending radially from the base portion (111) so as to protrude outward from the fastening portion (112).

[0085] With this configuration, the main body (211) of the gasket (210) is inserted into the through hole (22) and adheres to the outer surface of the fastening part (112), and the extension part (212) of the gasket (210) can be positioned between the flange part (113) and the inner surface of the bottom part (21). Additionally, a fastening groove (212a) can be formed in the extension part (212) into which a fastening projection (113a) protruding from the flange part (113) is inserted.

[0086] Additionally, the outer insulator (65) may be positioned on the outer surface of the bottom portion (21) so that the main body portion (211) of the gasket (210) is inserted into the outer insulator (65). The electrode terminal (63) may be positioned on the upper side of the outer insulator (65) and the main body portion (211) of the gasket (210) so that the fastening portion (112) is inserted into the electrode terminal (63). The inner insulator (64) may be positioned in close contact with the inner surface of the bottom portion (21), but the inner insulator may not be provided.

[0087] The gasket (210) may be formed such that the surface area facing the interior of the case (20) (or the electrode assembly housed inside the case (20)) is larger than the cross-sectional area of ​​the portion interposed between the rivet portion (110) and the through hole (22). For example, as shown in FIG. 4, the surface area (A1) of the extension portion (213) facing the interior of the case (20) must be formed to be larger than the cross-sectional area (A2) in the thickness direction of the extension portion (212). When pressure rises inside the case (20), the surface area (A1) facing the interior of the case (20) is formed to be relatively large, so it can receive a large pressure. In this case, the extension portion (212) can be more closely attached to the rivet portion (110) and the bottom portion (21). Additionally, when the extension (212) is compressed under pressure, the gasket (210), made of an elastic material, can reflexively expand in the extension (212), which is another area not subjected to pressure. Thus, the extension (212) can be more closely attached to the rivet (110) and the bottom (21), preventing a gap from forming.

[0088] In one embodiment, referring to FIG. 6, the gasket (210) may include a main body (211) through which a rivet portion is positioned, an extension portion (212) protruding radially from one end of the main body (211), and an extension portion (213) formed at the end of the extension portion (212). Here, the extension portion (213) may be configured in a roughly trapezoidal shape.

[0089] More specifically, the extension portion (213) may include a first surface (213a) that extends axially from the extension portion (212) and adheres to the radial outer surface of the flange portion (113), a second surface (213b) that adheres to the bottom portion (21), a third surface (213c) that extends radially outward from the first surface (213a), and a fourth surface (213d) that connects the second surface (213b) and the third surface (213c) and is formed inclined toward the radial outward. Here, the sum of the area of ​​the third surface (213c) and the area of ​​the fourth surface (213d) may correspond to the surface area facing the interior of the case (20).

[0090] FIGS. 7 and FIGS. 8 are partial cross-sectional views showing other examples of a gasket according to the embodiment of FIG. 3.

[0091] Referring to FIG. 7, the gasket (220) may include a main body (221) through which a rivet portion is positioned, an extension portion (222) protruding radially from one end of the main body (221), and an extension portion (223) formed at the end of the extension portion (222). Here, the main body (221) and the extension portion (222) may have the same configuration as the main body (211) and the extension portion (212) described with reference to FIG. 3 to 6. Also, the extension portion (223) may be configured in a roughly triangular shape.

[0092] More specifically, the extension portion (223) may include a first surface (223a) in contact with the radial outer circumference of the flange portion (113), a second surface (223b) in contact with the bottom portion (21), and a third surface (223c) formed to connect the first surface (223a) and the second surface (223b) and inclined toward the radial outer side. Here, the area of ​​the third surface (223c) may correspond to the surface area facing the interior of the case (20).

[0093] In another embodiment, referring to FIG. 8, the gasket (230) may include a main body (231) through which a rivet portion is positioned, an extension portion (232) protruding radially from one end of the main body (231), and an extension portion (233) formed at the end of the extension portion (232). Here, the main body (231) and the extension portion (232) may have the same configuration as the main body (211) and the extension portion (212) described with reference to FIG. 3 to 6. Also, the extension portion (233) may be configured in a roughly rectangular shape.

[0094] More specifically, the extension portion (233) may include a first surface (233a) that extends axially from the extension portion (232) and adheres to the radial outer surface of the flange portion (113), a second surface (233b) that adheres to the bottom portion (21), a third surface (233c) that extends radially outward from the first surface (233a), and a fourth surface (233d) formed in a vertical direction connecting the second surface (233b) and the third surface (233c). Here, the sum of the area of ​​the third surface (233c) and the area of ​​the fourth surface (233d) may correspond to the surface area facing the interior of the case (20).

[0095] FIG. 9 is a cross-sectional view showing an example of a rivet fixing structure according to another embodiment of the present disclosure, FIG. 10 is a partial cross-sectional view showing an example of a rivet portion according to the embodiment of FIG. 9, and FIG. 11 is a partial cross-sectional view showing an example of a gasket according to the embodiment of FIG. 9. FIG. 12 is a partial cross-sectional view showing another example of a gasket according to the embodiment of FIG. 9.

[0096] Referring to FIGS. 9 to 12, a rivet fixing structure according to one embodiment of the present disclosure may include a case (20) having a bottom portion (21) having one side open and a through hole (22) formed on the other side, a rivet portion (120) disposed through the through hole (22), and a gasket (240) disposed between the rivet portion (120) and the through hole (22) to provide electrical insulation. The gasket (240) may be made of an insulating material to electrically insulate the rivet portion (120) and the bottom portion (21) of the case (20).

[0097] In one embodiment, the gasket (240) may include a main body (241) through which a rivet portion (120) is positioned, and an extension portion (242) that extends radially from one end of the main body (241), becomes thicker toward the end, and has an outer surface facing the interior of the case (20).

[0098] The rivet portion (120) may include a base portion (121) disposed on the inner side of the bottom portion (21), a fastening portion (122) protruding from the base portion (121) and disposed through the through hole (22), and a flange portion (123) that extends radially from the base portion (121) to protrude outward from the fastening portion (122) and becomes thinner toward the end.

[0099] With this configuration, the main body (241) of the gasket (240) is inserted into the through hole (22) and comes into close contact with the outer surface of the fastening part (122), and the extension part (242) of the gasket (240) can be positioned between the flange part (123) and the inner surface of the bottom part (21). Additionally, a fastening groove (242aa) into which a fastening projection (123a) protruding from the flange part (123) is inserted can be formed in the extension part (242).

[0100] Additionally, the outer insulator (65) may be positioned on the outer surface of the bottom portion (21) so that the main body portion (241) of the gasket (240) is inserted into the outer insulator (65). The electrode terminal (63) may be positioned on the upper side of the outer insulator (65) and the main body portion (241) of the gasket (240) so that the fastening portion (122) is inserted into the electrode terminal (63). The inner insulator (64) may be positioned in close contact with the inner surface of the bottom portion (21), but the inner insulator may not be provided.

[0101] The gasket (240) may be formed such that the surface area facing the interior of the case (20) is larger than the cross-sectional area between the rivet portion (120) and the through hole (22). For example, as shown in FIG. 9, the surface area (A1) of the extension portion (242) facing the interior of the case (20) must be formed to be larger than the cross-sectional area (A2) in the thickness direction of the main body portion (241).

[0102] In one embodiment, referring to FIG. 11, the gasket (240) may include a main body (241) through which a rivet portion is positioned, and an extension portion (242) that extends radially from one end of the main body (241), becomes thicker toward the end, and has an outer surface facing the interior of the case (20). Here, the extension portion (242) may be configured in a roughly trapezoidal shape.

[0103] More specifically, the extension portion (242) may include a first surface (242a) formed at an angle and in close contact with the flange portion (123), a second surface (242b) formed in close contact with the bottom portion (21), and a third surface (242c) formed in a vertical direction connecting the first surface (242a) and the second surface (242b). Here, the area of ​​the third surface (242c) may correspond to the surface area facing the interior of the case (20).

[0104] In another embodiment, referring to FIG. 12, the gasket (250) may include a main body (251) through which a rivet portion is positioned, and an extension portion (252) that extends radially from one end of the main body (251), has a thickness that increases in at least one region toward the end, and whose outer surface faces the interior of the case (20). Here, the main body (251) may have the same configuration as the main body (241) described with reference to FIG. 9 to FIG. 11. Also, the extension portion (252) may be configured in a roughly trapezoidal shape.

[0105] More specifically, the extension portion (252) may include a first surface (252a) formed at an angle and in close contact with the flange portion (123), a second surface (252b) formed at an angle and in close contact with the bottom portion (21), and a third surface (252c) formed at an angle toward the radial outer side and connecting the first surface (252a) and the second surface (252b). Here, the area of ​​the third surface (252c) may correspond to the surface area facing the interior of the case (20).

[0106] FIG. 13 is a cross-sectional view showing an example of a rivet fixing structure according to another embodiment of the present disclosure, and FIG. 14 is a partial cross-sectional view showing an example of a gasket according to the embodiment of FIG. 13. FIG. 15 and FIG. 16 are partial cross-sectional views showing other examples of a gasket according to the embodiment of FIG. 13.

[0107] Referring to FIGS. 13 to 16, a rivet fixing structure according to another embodiment of the present disclosure may include a case (20) having a bottom portion (21) having one side open and a through hole (22) formed on the other side, a rivet portion (120) disposed through the through hole (22), and a gasket (260) disposed between the rivet portion (120) and the through hole (22) to provide electrical insulation. The gasket (260) may be made of an insulating material to electrically insulate the rivet portion (120) and the bottom portion (21) of the case (20). Here, the rivet portion (120) may have the same configuration as the rivet portion (120) described with reference to FIGS. 9 and 10.

[0108] The gasket (260) may be formed such that the surface area facing the interior of the case (20) is larger than the cross-sectional area between the rivet portion (120) and the through hole (22). For example, as shown in FIG. 13, the surface area (A1) of the extended portion (263) facing the interior of the case (20) must be formed to be larger than the cross-sectional area (A2) in the thickness direction of the main body portion (261).

[0109] In one embodiment, referring to FIG. 14, the gasket (260) may include a main body (261) through which a rivet portion is positioned, an extension portion (262) that extends radially from one end of the main body (261) and becomes thicker toward the end, and an extended extension portion (263) that extends radially from the extension portion (262) and protrudes axially to surround the outer surface of the flange portion (123). Here, the main body (261) and the extension portion (262) may have the same configuration as the main body (241) and the extension portion (242) described with reference to FIG. 9 to 11. Also, the extended extension portion (263) may be configured in an approximately rectangular shape.

[0110] More specifically, the extended portion (263) may include a first surface (263a) that protrudes axially from the extended portion (262) and is in contact with the radial outer surface of the flange portion (123), a second surface (263b) that is in contact with the bottom portion, a third surface (263c) that extends radially outward from the first surface (263a), and a fourth surface (263d) formed in a vertical direction connecting the second surface (263b) and the third surface (263c). Here, the sum of the area of ​​the third surface (263c) and the area of ​​the fourth surface (263d) may correspond to the surface area facing the interior of the case (20).

[0111] In another embodiment, referring to FIG. 15, the gasket (270) may include a main body (271) through which a rivet portion is positioned, an extension portion (272) that extends radially from one end of the main body (271) and becomes thicker toward the end, and an extended extension portion (273) that extends radially from the extension portion (272) and protrudes axially to surround the outer surface of the flange portion (123). Here, the main body (271) and the extension portion (272) may have the same configuration as the main body (241) and the extension portion (242) described with reference to FIG. 9 to 11. Also, the extended extension portion (273) may be configured in a roughly trapezoidal shape.

[0112] More specifically, the extended portion (273) may include a first surface (273a) that protrudes axially from the extended portion (272) and is in contact with the radial outer surface of the flange portion (123), a second surface (273b) that is in contact with the bottom portion (21), a third surface (273c) that extends radially outward from the first surface (273a), and a fourth surface (273d) that connects the second surface (273b) and the third surface (273c) and is formed inclined toward the radial outward. Here, the sum of the area of ​​the third surface (2733c) and the area of ​​the fourth surface (273d) may correspond to the surface area facing the interior of the case (20).

[0113] In another embodiment, referring to FIG. 16, the gasket (280) may include a main body (281) through which a rivet portion is positioned, an extension portion (282) that extends radially from one end of the main body (281) and becomes thicker toward the end, and an extended extension portion (283) that extends radially from the extension portion (282) and protrudes axially to surround the outer surface of the flange portion (123). Here, the main body (281) and the extension portion (282) may have the same configuration as the main body (241) and the extension portion (242) described with reference to FIG. 9 to 11. Also, the extended extension portion (283) may be configured in a roughly triangular shape.

[0114] More specifically, the extended portion (283) may include a first surface (283a) that protrudes axially from the extended portion (282) and is in contact with the radial outer surface of the flange portion (123), a second surface (283b) that is in contact with the bottom portion (21), and a third surface (283c) that connects the first surface (283a) and the second surface (283b) and is formed to be inclined toward the radial outer side. Here, the area of ​​the third surface (283c) may correspond to the surface area facing the interior of the case (20).

[0115] Although the present invention has been described above 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.

Claims

1. A case having a bottom portion that is open on one side and has a through hole formed on the other side; A rivet portion disposed through the above-mentioned through hole; and A gasket disposed between the rivet portion and the through hole, wherein the surface area facing the interior of the case is formed to be larger than the cross-sectional area between the rivet portion and the through hole. A rivet-fastened structure including 2. In Paragraph 1, The above gasket is, A main body portion through which the above-mentioned rivet portion is positioned; An extension portion protruding radially from one end of the main body portion; and An extension formed at the end of the extension portion, with at least one surface facing the interior of the case. A rivet-fastened structure including 3. In Paragraph 2, The above extension is, A rivet fixing structure in which the surface area facing the interior of the above case is formed to be larger than the cross-sectional area in the thickness direction of the extension.

4. In Paragraph 2, The above rivet part is, A base portion disposed on the inner side of the above-mentioned bottom portion; A fastening part protruding from the base part and positioned through the through hole; and A flange portion formed by extending radially from the base portion to protrude outwardly from the fastening portion. A rivet-fastened structure including 5. In Paragraph 4, The above extension is, A first surface that is in close contact with the radial outer circumference of the flange portion; A second surface in close contact with the bottom portion above; A third surface extending radially outward from the first surface; and A fourth surface connecting the second surface and the third surface, formed at an angle toward the radial outer side. A rivet-fastened structure including 6. In Paragraph 4, The above extension is, A first surface that is in close contact with the radial outer circumference of the flange portion; A second surface in close contact with the above-mentioned bottom portion; and A third surface connecting the first surface and the second surface and formed inclined toward the radial outer side. A rivet-fastened structure including 7. In Paragraph 4, The above extension is, A first surface that is in close contact with the radial outer circumference of the flange portion; A second surface in close contact with the above-mentioned bottom portion; A third surface extending radially outward from the first surface; and A fourth surface formed in a vertical direction connecting the second surface and the third surface. A rivet-fastened structure including 8. In Paragraph 4, The above main body is inserted into the through hole and adheres to the outer surface of the fastening part, and The above extension is a rivet-fastened structure positioned between the flange portion and the inner surface of the bottom portion.

9. In Paragraph 8, The above extension part is, A fastening groove into which a fastening projection formed protruding from the above flange portion is inserted. A rivet-fastened structure including 10. In Paragraph 1, The above gasket is, A main body portion through which the above-mentioned rivet portion is positioned; and An extension portion extending radially from one end of the main body, becoming thicker toward the end, and having an outer surface facing the interior of the case. A rivet-fastened structure including 11. In Paragraph 10, The above rivet part is, A base portion disposed on the inner side of the above-mentioned bottom portion; A fastening part protruding from the base part and positioned through the through hole; and A flange portion that extends radially from the base portion to protrude outwardly from the fastening portion, and becomes thinner toward the end. A rivet-fastened structure including 12. In Paragraph 11, The above extension is, A first surface formed at an angle and in close contact with the above-mentioned flange portion; A second surface in close contact with the above-mentioned bottom portion; and A third surface formed in a vertical direction connecting the first surface and the second surface. A rivet-fastened structure including 13. In Paragraph 11, The above extension is, A first surface formed at an angle and in close contact with the above-mentioned flange portion; A second surface in close contact with the above-mentioned bottom portion; and A third surface connecting the first surface and the second surface and formed inclined toward the radial outer side. A rivet-fastened structure including 14. In Paragraph 11, The above gasket is, An extended extension portion that extends radially from the above extension portion and is formed to surround the outer surface of the above flange portion. A rivet-fastened structure including 15. In Paragraph 14, The above-mentioned extension part is, A first surface that is in close contact with the radial outer circumference of the flange portion; A second surface in close contact with the above-mentioned bottom portion; A third surface extending radially outward from the first surface; and A fourth surface formed in a vertical direction connecting the second surface and the third surface. A rivet-fastened structure including 16. In Paragraph 14, The above-mentioned extension part is, A first surface that is in close contact with the radial outer circumference of the flange portion; A second surface in close contact with the above-mentioned bottom portion; A third surface extending radially outward from the first surface; and A fourth surface connecting the second surface and the third surface, formed at an angle toward the radial outer side. A rivet-fastened structure including 17. In Paragraph 14, The above-mentioned extension part is, A first surface that is in close contact with the radial outer circumference of the flange portion; A second surface in close contact with the above-mentioned bottom portion; and A third surface connecting the first surface and the second surface and formed inclined toward the radial outer side. A rivet-fastened structure including 18. In Paragraph 14, The above extension is, A fastening groove into which a fastening projection formed protruding from the above flange portion is inserted. A rivet-fastened structure including 19. An electrode assembly comprising a first electrode, a second electrode, and a separator; A case having a bottom portion with one side open and a through hole formed on the other side, in which the electrode assembly is accommodated and electrically connected to the second electrode; A vent plate fastened to one open side of the above case; A rivet portion disposed through the above-mentioned through-hole and electrically connected to the first electrode; and A gasket disposed between the rivet portion and the through hole, wherein the surface area facing the interior of the case is formed to be larger than the cross-sectional area between the rivet portion and the through hole. A secondary battery including 20. In Paragraph 19, An electrode terminal disposed on the outer side of the above case and fastened to the rivet portion; and An external insulator disposed between the outer surface of the bottom portion and the electrode terminal, with its inner surface in close contact with the gasket. An interest battery containing

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