Rivet fixing structure

Abstract

The present invention relates to a rivet fixing structure. The rivet fixing structure comprises: a case which is open on one side and has a bottom part on the other side having a through hole formed therein; a rivet part disposed so as to pass through the through hole; and a gasket interposed between the rivet part and the through hole. The gasket comprises: a ring-shaped main body part; a first extension part extending from one end of the main body part and extending along the outer surface of the bottom part; and a second extension part extending from the other end of the main body part and extending along the inner surface of the bottom part. At least a portion of the outer circumferential surface of the first extension part is tapered so that the radius gradually decreases as the distance from the one end of the main body part increases.

Description

Rivet fastening structure

[0001] The present disclosure relates to a rivet fixing structure of a secondary battery.

[0002]

[0003] Secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. Low-capacity secondary batteries are used in small, portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for motor drives and power storage in hybrid and electric vehicles. These secondary batteries include an electrode assembly comprising a positive and negative electrode, a case housing the electrode assembly, and electrode terminals connected to the electrode assembly.

[0004] The case of a secondary battery is filled with an electrolyte for the chemical reaction between the positive and negative electrodes, and the case is sealed to prevent leakage. However, the electrolyte can leak from the connection between the case and the electrode terminals during the battery's charge / discharge cycle, during a drop, or due to external impact.

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

[0006]

[0007] The present disclosure provides a rivet fixing structure to solve the above problems.

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

[0009]

[0010] According to one embodiment of the present disclosure for solving a technical problem, a rivet fixing structure includes 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 interposed between the rivet portion and the through hole, wherein the gasket includes a ring-shaped main body portion, a first extension portion extending from one end of the main body portion and extending along an outer surface of the bottom portion, and a second extension portion extending from the other end of the main body portion and extending along an inner surface of the bottom portion, and at least a portion of an outer circumferential surface of the first extension portion is tapered so that a radius gradually decreases as it moves away from the one end of the main body portion.

[0011] According to one embodiment of the present disclosure, the first extension portion includes a first surface extending in a direction parallel to the bottom portion so as to contact an outer surface of the bottom portion from one end of the main body portion, a second surface extending from the first surface in a direction perpendicular to the first surface, and a third surface extending from the second surface at an angle to the first surface.

[0012] According to one embodiment of the present disclosure, the length extended so that the first surface contacts the bottom portion is 0.05 to 0.2 mm.

[0013] According to one embodiment of the present disclosure, the length extended so that the first surface contacts the bottom portion is 10 to 40% of the thickness of the gasket.

[0014] According to one embodiment of the present disclosure, the angle formed by the first side and the third side is 20 degrees or more and 80 degrees or less.

[0015] According to one embodiment of the present disclosure, the first extension portion includes a first surface extending in a direction parallel to the bottom portion so as to contact an outer surface of the bottom portion from one end of the main body portion, and a second surface extending from the first surface at an angle to form a predetermined angle with the first surface.

[0016] According to one embodiment of the present disclosure, the length extended so that the first surface contacts the bottom portion is 0.05 to 0.2 mm.

[0017] According to one embodiment of the present disclosure, the length extended so that the first surface contacts the bottom portion is 10 to 40% of the thickness of the gasket.

[0018] According to one embodiment of the present disclosure, the angle formed by the first side and the second side is 20 degrees or more and 80 degrees or less.

[0019] According to one embodiment of the present disclosure, the rivet portion includes a base portion inserted so as to pass through the through hole, and a leg portion extending from the base portion along the inner surface of the bottom portion of the case.

[0020] According to one embodiment of the present disclosure, the leg portion includes a protrusion formed in a direction facing the inner surface of the bottom portion of the case, and the protrusion is in close contact with the second extension portion of the gasket.

[0021] According to one embodiment of the present disclosure, the gasket further comprises an inner insulator extending along an inner surface of the bottom portion and in contact with the second extension portion of the gasket.

[0022] According to one embodiment of the present disclosure, the contact location of the second extension portion and the inner insulator is disposed on the leg portion.

[0023] According to one embodiment of the present disclosure, the device further includes an electrode terminal connected to the base portion of the rivet portion and disposed on the outside of the case.

[0024] According to one embodiment of the present disclosure, the gasket further comprises an outer insulator extending along an outer surface of the bottom portion so as to be in contact with the first extension portion of the gasket and interposed between the bottom portion and the electrode terminal.

[0025] According to one embodiment of the present disclosure, at least a portion of the gasket is composed of a fluororesin material.

[0026] According to one embodiment of the present disclosure for solving the technical problem, a secondary battery includes an electrode assembly formed by winding a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode, a bottom portion having one side open and the other side having a through hole formed therein, a case for accommodating the electrode assembly, a rivet portion disposed penetrating the through hole, and a gasket interposed between the rivet portion and the through hole, wherein the gasket includes a ring-shaped main body portion, a first extension portion extending from one end of the main body portion and extending along an outer surface of the bottom portion, and a second extension portion extending from the other end of the main body portion and extending along an inner surface of the bottom portion, and at least a portion of an outer circumferential surface of the first extension portion is tapered so that a radius gradually decreases as it moves away from the one end of the main body portion.

[0027] According to one embodiment of the present disclosure, the first extension portion includes a first surface extending in a direction parallel to the bottom portion so as to contact an outer surface of the bottom portion from one end of the main body portion, and a second surface extending from the first surface at an angle to the first surface, wherein the angle formed by the first surface and the second surface is 20 degrees or more and less than 80 degrees.

[0028] According to one embodiment of the present disclosure, the length extended so that the first surface contacts the bottom portion is 0.05 to 0.2 mm.

[0029] According to one embodiment of the present disclosure, the length extended so that the first surface contacts the bottom portion is 10 to 40% of the thickness of the gasket.

[0030] According to one embodiment of the present invention for solving the above technical problem, a rivet fixing structure includes a case having a through hole in a first side and an open second side located in an opposite direction to the first side, a rivet portion disposed through the through hole, a gasket disposed between the rivet portion and the through hole and surrounding the case in an area adjacent to the through hole, and the rivet portion may include a base portion coupled to the case through the gasket, and a leg portion connected to the base portion and in contact with one surface of the gasket located inside the case.

[0031] According to one embodiment of the present invention, the bridge portion may include a plurality of notches configured to be broken by external pressure.

[0032] According to one embodiment of the present invention, the leg portion may be configured to apply pressure to the entire area of ​​the gasket that contacts the inner surface of the case when the notch is ruptured by external pressure.

[0033] According to one embodiment of the present invention, the leg portion may extend from a reference line where the side surface of the base portion and the side surface of the gasket are in contact in the radial direction of the case by 3.0 mm to 3.5 mm.

[0034] According to one embodiment of the present invention, the gasket may include a gasket inserted into a through hole, an outer insulator connected to an upper portion of the gasket and contacting at least a portion of an outer surface of the case in an area adjacent to the through hole, and an inner insulator connected to a lower portion of the gasket and contacting at least a portion of an inner surface of the case in an area adjacent to the through hole.

[0035] According to one embodiment of the present invention, the leg portion can contact at least a portion of the lower surface of the gasket and the lower surface of the inner insulator.

[0036] According to one embodiment of the present invention, the leg portion may extend from a reference line where the side surface of the base portion and the side surface of the gasket are in contact in the radial direction of the case by 3.0 mm to 3.5 mm.

[0037] According to one embodiment of the present invention, the leg portion may include a plurality of notches configured to be elongated by external pressure, and the gasket may include a gasket inserted into the through hole, an outer insulator connected to an upper portion of the gasket and contacting at least a portion of an outer surface of the case in an area adjacent to the through hole, and an inner insulator connected to a lower portion of the gasket and contacting at least a portion of an inner surface of the case in an area adjacent to the through hole.

[0038] According to one embodiment of the present invention, the leg portion can contact at least a portion of the lower surface of the gasket and the lower surface of the inner insulator.

[0039] According to one embodiment of the present invention for solving a technical problem, a secondary battery may include an electrode assembly including a first electrode, a second electrode, and a separator, a case in which the electrode assembly is accommodated therein and electrically connected to the second electrode and including a through hole on one side thereof, a rivet portion positioned to penetrate the through hole and seal the case and electrically connected to the first electrode, a gasket positioned between the rivet portion and the through hole and surrounding the case in an area adjacent to the through hole, and the rivet portion may include a base portion that penetrates the gasket and is coupled to the case, and a leg portion that is connected to the base portion and is in contact with one surface of the gasket located inside the case.

[0040] According to one embodiment of the present invention, the bridge portion may include a plurality of notches configured to be broken by external pressure.

[0041] According to one embodiment of the present invention, the leg portion may be configured to apply pressure to the entire area of ​​the gasket that contacts the inner surface of the case when the notch is ruptured by external pressure.

[0042] According to one embodiment of the present invention, the leg portion may extend from a reference line where the side surface of the base portion and the side surface of the gasket are in contact in the radial direction of the case by 3.0 mm to 3.5 mm.

[0043] According to one embodiment of the present invention, the gasket may include a gasket inserted into a through hole, an outer insulator connected to an upper portion of the gasket and contacting at least a portion of an outer surface of the case in an area adjacent to the through hole, and an inner insulator connected to a lower portion of the gasket and contacting at least a portion of an inner surface of the case in an area adjacent to the through hole.

[0044] According to one embodiment of the present invention, the leg portion can contact at least a portion of the lower surface of the gasket and the lower surface of the inner insulator.

[0045] According to one embodiment of the present invention, the leg portion may extend from a reference line where the side surface of the base portion and the side surface of the gasket are in contact in the radial direction of the case by 3.0 mm to 3.5 mm.

[0046] According to one embodiment of the present invention, the leg portion may include a plurality of notches configured to be elongated by external pressure, and the gasket may include a gasket inserted into the through hole, an outer insulator connected to an upper portion of the gasket and contacting at least a portion of an outer surface of the case in an area adjacent to the through hole, and an inner insulator connected to a lower portion of the gasket and contacting at least a portion of an inner surface of the case in an area adjacent to the through hole.

[0047] According to one embodiment of the present invention, the leg portion can contact at least a portion of the lower surface of the gasket and the lower surface of the inner insulator.

[0048] A method for manufacturing a secondary battery according to one embodiment of the present invention for solving a technical problem includes the steps of arranging a gasket to surround an area adjacent to a through hole formed on a first side of a case, the step of sealing the through hole by pressing the gasket and penetrating the through hole using a rivet portion, the step of inserting an electrode assembly through an opening formed on a second side of the case located in an opposite direction to the first side, and the step of closing the opening with a vent plate, wherein the rivet portion may include a base portion that is coupled to the case by penetrating the gasket and a leg portion that is connected to the base portion and is in contact with one surface of the gasket located inside the case.

[0049] According to one embodiment of the present invention, the step of sealing the through hole may include a step of breaking a notch formed in the leg portion by external pressure, thereby applying pressure to the entire area of ​​the gasket that contacts the inner surface of the case.

[0050] A rivet fixing structure according to one embodiment of the present invention for solving the above technical problem may include a case including a through hole in a first side and an open second side located in an opposite direction to the first side, a rivet portion disposed through the through hole, a gasket disposed between the rivet portion and the through hole and surrounding the case in an area adjacent to the through hole, and a heat dissipation layer disposed between an outer surface of the rivet portion and a side surface of the gasket.

[0051] According to one embodiment of the present invention, the rivet portion may include a base portion that penetrates the gasket and is coupled to the case, and an electrode terminal that is coupled to one end of the base portion and extends radially from one end of the base portion and contacts at least a portion of the upper surface of the gasket exposed to the outside of the case.

[0052] According to one embodiment of the present invention, the heat dissipation layer may extend to cover at least a portion of the gasket side and surround at least a portion of the outer surface of the base portion.

[0053] According to one embodiment of the present invention, the heat dissipation layer may include a plurality of heat dissipation pads arranged at a plurality of positions between the outer surface of the base portion and the side surface of the gasket.

[0054] According to one embodiment of the present invention, the heat dissipation layer can be attached to the outer surface of the base portion through an adhesive or heat fusion.

[0055] According to one embodiment of the present invention, the heat dissipation layer can be attached to the side of the gasket through an adhesive or heat sealing.

[0056] According to one embodiment of the present invention, the base portion may further include an insulating layer surrounding the inner surface.

[0057] According to one embodiment of the present invention, the insulation layer can surround at least a portion of the inner surface of the base portion.

[0058] According to one embodiment of the present invention, the insulation layer can be attached to the inner surface of the base portion through an adhesive or heat sealing.

[0059] According to one embodiment of the present invention for solving a technical problem, a secondary battery may include an electrode assembly including a first electrode, a second electrode, and a separator, a case in which the electrode assembly is accommodated therein and electrically connected to the second electrode and including a through hole on one side thereof, a rivet portion positioned to seal the case by penetrating the through hole and electrically connected to the first electrode, a gasket positioned between the rivet portion and the through hole and surrounding the case in a region adjacent to the through hole, and a heat dissipation layer positioned between an outer surface of the rivet portion and a side surface of the gasket.

[0060] According to one embodiment of the present invention, the rivet portion may include a base portion that penetrates the gasket and is coupled to the case, electrically connected to the first electrode, and an electrode terminal that is coupled to one end of the base portion and extends radially from the one end of the base portion and contacts at least a portion of the upper surface of the gasket exposed to the outside of the case.

[0061] According to one embodiment of the present invention, the heat dissipation layer may extend to cover at least a portion of the gasket side and surround at least a portion of the outer surface of the base portion.

[0062] According to one embodiment of the present invention, the heat dissipation layer may include a plurality of heat dissipation pads arranged at a plurality of positions between the outer surface of the base portion and the side surface of the gasket.

[0063] According to one embodiment of the present invention, the heat dissipation layer can be attached to the outer surface of the base portion through an adhesive or heat fusion.

[0064] According to one embodiment of the present invention, the heat dissipation layer can be attached to the side of the gasket through an adhesive or heat sealing.

[0065] According to one embodiment of the present invention, the base portion may further include an insulating layer surrounding the inner surface.

[0066] According to one embodiment of the present invention, the insulation layer can surround at least a portion of the inner surface of the base portion.

[0067] According to one embodiment of the present invention, the insulation layer can be attached to the inner surface of the base portion through an adhesive or heat sealing.

[0068] A method for manufacturing a secondary battery according to one embodiment of the present invention for solving a technical problem may include a step of arranging a gasket to surround an area adjacent to a through hole formed on a first side of a case, a step of sealing the through hole by penetrating the through hole while a heat dissipation layer is interposed between the gasket and the rivet using a rivet portion, a step of inserting an electrode assembly through an opening formed on a second side of the case located opposite the first side, and a step of closing the opening with a cap plate.

[0069] According to one embodiment of the present invention, the step of sealing the through hole may include the step of penetrating the rivet part into the through hole while arranging an insulating layer on the inner surface of the rivet part.

[0070] According to one embodiment of the present disclosure for solving a technical problem, a rivet fixing structure includes 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 interposed between the rivet portion and the through hole, wherein the gasket includes a ring-shaped main body portion, a first extension portion extending from one end of the main body portion and extending along an outer surface of the bottom portion, and a second extension portion extending from the other end of the main body portion and extending along an inner surface of the bottom portion, and at least a portion of an outer circumferential surface of the first extension portion may be tapered so that a radius gradually decreases as it moves away from the one end of the main body portion.

[0071] According to one embodiment of the present disclosure, the first extension portion may include a first surface extending in a direction parallel to the bottom portion so as to contact an outer surface of the bottom portion from one end of the main body portion, a second surface extending from the first surface in a direction perpendicular to the first surface, and a third surface extending from the second surface at an angle to the first surface.

[0072] According to one embodiment of the present disclosure, the length extended so that the first surface contacts the bottom portion may be 0.05 to 0.2 mm.

[0073] According to one embodiment of the present disclosure, the length extended so that the first surface contacts the bottom portion may be 10 to 40% of the thickness of the gasket.

[0074] According to one embodiment of the present disclosure, the angle formed by the first side and the third side may be 20 degrees or more and 80 degrees or less.

[0075] According to one embodiment of the present disclosure, the first extension portion may include a first surface extending in a direction parallel to the bottom portion so as to contact an outer surface of the bottom portion from one end of the main body portion, and a second surface extending from the first surface at an angle to the first surface.

[0076] According to one embodiment of the present disclosure, the rivet portion may include a base portion inserted so as to pass through the through hole and a leg portion extending from the base portion along an inner surface of the bottom portion of the case.

[0077] According to one embodiment of the present disclosure, the leg portion includes a protrusion formed in a direction opposite to the inner surface of the bottom portion of the case, and the protrusion can be brought into close contact with the second extension portion of the gasket.

[0078] According to one embodiment of the present disclosure, the rivet portion may include a base portion that penetrates the gasket and is coupled to the case, and a leg portion that is connected to the base portion and contacts one surface of the gasket located inside the case.

[0079] According to one embodiment of the present disclosure, the bridge portion may include a plurality of notches configured to be broken by external pressure.

[0080] According to one embodiment of the present disclosure, the bridge portion may be configured to apply pressure to the entire area of ​​the gasket that contacts the inner surface of the case when the notch is ruptured by external pressure.

[0081] According to one embodiment of the present disclosure, the leg portion may extend 3.0 mm to 3.5 mm in the radial direction of the case from a reference line where the side surface of the base portion and the side surface of the gasket meet.

[0082] According to one embodiment of the present disclosure, the device may further include an outer insulator connected to an upper portion of the gasket and contacting at least a portion of an outer surface of the case in an area adjacent to the through hole, and an inner insulator connected to a lower portion of the gasket and contacting at least a portion of an inner surface of the case in an area adjacent to the through hole.

[0083] According to one embodiment of the present disclosure, the leg portion can contact at least a portion of the lower surface of the gasket and the lower surface of the inner insulator.

[0084] According to one embodiment of the present disclosure, the leg portion may include a plurality of notches configured to be elongated by external pressure.

[0085] According to one embodiment of the present disclosure, a heat dissipation layer may further be disposed between the outer surface of the rivet portion and the side surface of the gasket.

[0086] According to one embodiment of the present disclosure, the rivet portion may include a base portion that penetrates the gasket and is coupled to the case, and may further include an electrode terminal that is coupled to one end of the base portion and extends radially from the one end of the base portion and contacts at least a portion of an upper surface of the gasket exposed to the outside of the case.

[0087] According to one embodiment of the present disclosure, the heat dissipation layer may extend to cover at least a portion of the gasket side and surround at least a portion of the outer surface of the base portion.

[0088] According to one embodiment of the present disclosure, the heat dissipation layer may include a plurality of heat dissipation pads arranged at a plurality of positions between the outer surface of the base portion and the side surface of the gasket.

[0089] According to one embodiment of the present disclosure, the base portion may further include an insulating layer surrounding the inner surface thereof.

[0090]

[0091] According to some embodiments of the present invention, in a secondary battery, the first extension portion of the gasket extends a predetermined length along the outer surface of the bottom portion of the case in which the through hole is formed, thereby extending the length of the leakage path of the electrolyte, thereby suppressing the leakage phenomenon of the electrolyte.

[0092] According to some embodiments of the present invention, a compression point is formed at a portion where the extended surface of the first extension of the gasket and the outer surface of the bottom portion of the case come into contact, so that the gasket and the bottom portion can be more firmly sealed.

[0093] According to some embodiments of the present invention, even if the first extension of the gasket protrudes beyond the through hole formed in the bottom of the case, the case and the gasket can be easily joined by the tapered shape of the outer surface of the first extension.

[0094] According to some embodiments of the present invention, a leg portion having a notch formed at the lower portion of a rivet portion that seals a through hole formed in a case of a secondary battery can be formed, thereby improving the sealing effect by compressing a gasket when the rivet portion is fastened to the case.

[0095] According to some embodiments of the present invention, when a rivet portion that seals a through hole formed in a case of a secondary battery is fastened to the case, the area or length of the leg portion of the rivet portion that presses a gasket arranged on the inner surface of the case increases, thereby further improving the sealing effect.

[0096] According to some embodiments of the present invention, by arranging a heat dissipation layer between the outer surface of a rivet portion that seals a through hole formed in a case of a secondary battery and the side surface of a gasket, when the rivet portion is welded to a positive electrode current collector, the gasket around the rivet portion is deformed due to welding heat, thereby preventing a problem in which a gap is formed and electrolyte leaks to the outside.

[0097] According to some embodiments of the present invention, by arranging an insulating layer on the outer surface of a rivet portion that seals a through hole formed in a case of a secondary battery, when the rivet portion is welded to a positive electrode collector plate, the welding heat is transmitted to the rivet portion or a gasket around it, and the gasket is deformed, thereby preventing a problem in which a gap is formed and electrolyte leaks to the outside.

[0098] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0099]

[0100] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0101] FIG. 1 is a cross-sectional view of a secondary battery according to one embodiment of the present disclosure.

[0102] Fig. 2 is a cross-sectional view showing a comparative example of a rivet fixing structure.

[0103] FIG. 3 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure.

[0104] FIG. 4 is a cross-sectional view showing an example of a rivet fixing structure according to the first embodiment of the present disclosure.

[0105] FIG. 5 is an enlarged cross-sectional view showing a portion of the gasket illustrated in FIG. 4 according to the first embodiment of the present disclosure.

[0106] FIG. 6 is a cross-sectional view showing an example of a rivet fixing structure according to a second embodiment of the present disclosure.

[0107] FIG. 7 is an enlarged cross-sectional view showing a portion of the gasket illustrated in FIG. 6 according to a second embodiment of the present disclosure.

[0108] FIG. 8 is a cross-sectional view showing an example of a rivet fixing structure according to a third embodiment of the present disclosure.

[0109] FIG. 9 is an enlarged cross-sectional view showing a portion of the gasket illustrated in FIG. 8 according to a third embodiment of the present disclosure.

[0110] FIGS. 10 to 14 are drawings for explaining an assembly method of a rivet fixing structure according to one embodiment of the present disclosure.

[0111] FIG. 15 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure, showing a state before a notch is broken.

[0112] FIG. 16 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure, showing a state after a notch is broken.

[0113] Fig. 17 is a cross-sectional view showing an example of a rivet fixing structure as a comparison example with Fig. 18.

[0114] FIG. 18 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure, and is a drawing showing the length of a leg extended from a reference line after a notch is broken.

[0115] FIG. 19 is a cross-sectional view showing a notch formed in a leg portion of a rivet portion according to one embodiment of the present disclosure.

[0116] FIG. 20 is a perspective view showing a notch formed in a leg portion of a rivet portion according to one embodiment of the present disclosure.

[0117] Fig. 21 is a plan view of a rivet fixing structure according to one embodiment of the present disclosure in which four notches are formed.

[0118] Fig. 22 is a plan view of a rivet fixing structure according to another embodiment of the present disclosure in which six notches are formed.

[0119] Fig. 23 is a plan view showing an example of a plane shape after the notch of the leg portion according to the embodiment of Fig. 22 is broken.

[0120] Fig. 24 is a plan view showing another example of a plane shape after the notch of the leg portion is broken according to the embodiment of Fig. 22, and is an example in which the notch is formed only in a part of the leg portion.

[0121] Fig. 25 is a plan view showing an example of a planar shape after the notch of the leg portion is extended according to the embodiment of Fig. 22.

[0122] FIG. 26 is a flowchart illustrating an example of a method for manufacturing a secondary battery according to one embodiment of the present disclosure.

[0123] Fig. 27 is a cross-sectional view of a rivet portion of a rivet fixing structure according to one embodiment of the present disclosure before being inserted into a through hole.

[0124] Fig. 28 is a cross-sectional view of a rivet portion of a rivet fixing structure according to one embodiment of the present disclosure after being inserted into a through hole.

[0125] FIG. 29 is a plan view and a cross-sectional view of a base portion of a rivet fixing structure according to one embodiment of the present disclosure, with a heat dissipation layer and an insulation layer attached thereto.

[0126] FIG. 30 is a plan view and a cross-sectional view of a case where a heat dissipation layer in a base portion of a rivet fixing structure according to one embodiment of the present disclosure includes two heat dissipation pads.

[0127] Fig. 31 is a cross-sectional view showing a rivet fixing structure in a case where there is no heat dissipation layer or insulation layer as a comparative example.

[0128] FIG. 32 is a cross-sectional view showing the movement of heat when a heat dissipation layer is attached to the outer surface of the base portion of a rivet fixing structure according to one embodiment of the present disclosure.

[0129] FIG. 33 is a cross-sectional view showing the movement of heat when a heat dissipation layer is attached to the outer and inner surfaces of the base portion of a rivet fixing structure according to one embodiment of the present disclosure.

[0130] FIG. 34 is a cross-sectional view showing the movement of heat when a heat dissipation layer is attached to the outer surface of the base portion of a rivet fixing structure according to one embodiment of the present disclosure and a heat insulating layer is attached to the inner surface.

[0131] FIG. 35 is a flowchart showing a method for manufacturing a secondary battery according to one embodiment of the present disclosure.

[0132] Fig. 36 is a cross-sectional view showing an example of a rivet fixing structure according to another embodiment of the present disclosure, showing a state before a notch is broken.

[0133] Fig. 37 is a cross-sectional view showing an example of a rivet fixing structure according to another embodiment of the present disclosure, showing a state after a notch is broken.

[0134]

[0135] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0136] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0137] Additionally, to facilitate understanding of the invention, the attached drawings may not be drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0138] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0139] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0140] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0141] Any configuration being placed "on (or under)" or "above (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0142] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component. Furthermore, when it is said that a part is electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where they are connected with another element in between.

[0143] When reference is made throughout the specification to "A and / or B," this means A, B, or A and B, unless otherwise stated. In other words, "and / or" includes all or any combination of the listed items. When reference is made to "C through D," this means C or more and D or less, unless otherwise stated.

[0144] The terminology used herein is for the purpose of describing embodiments of the invention and is not intended to limit the invention.

[0145] FIG. 1 is a cross-sectional view of a secondary battery according to an embodiment of the present disclosure. Referring to FIG. 1, the secondary battery according to an embodiment of the present disclosure includes an electrode assembly (110) that performs charging and discharging, a case (120) housing the electrode assembly (110), a first current collector plate (130) connected to the electrode assembly (110), a second current collector plate (150), an electrode terminal (141), a vent cap plate (142), and a sealing member (160). In FIG. 1, the vent cap plate (142) is illustrated as being disposed on the upper side of the secondary battery, and the electrode terminal (141) is disposed on the lower side of the secondary battery, but this is not limited thereto. Depending on the usage environment or requirements of the secondary battery, the vent cap plate (142) and the electrode terminal (141) may be changed to be disposed on the lower side and the upper side of the secondary battery, respectively.

[0146] An electrode assembly (110) is formed by winding a first electrode (111a, 111b), a separator (113), and a second electrode (112a, 112b) into a cylindrical jelly roll state with an empty core. The first electrode (111a, 111b) and the second electrode (112a, 112b) each include a coated portion (111a, 112a) in which an active material is applied to both sides of a substrate formed of a thin metal plate, and a non-coated portion (111b, 112b) in which the substrate is exposed because the active material is not applied.

[0147] The first electrode (111a, 111b) may be an electrode corresponding to a positive or negative electrode in a secondary battery. The second electrode (112a, 112b) may be an electrode corresponding to a pole opposite to the first electrode (111a, 111b). For example, if the first electrode (111a, 111b) is a positive electrode, the second electrode (112a, 112b) may be a negative electrode. Conversely, if the first electrode (111a, 111b) is a negative electrode, the second electrode (112a, 112b) may be a positive electrode.

[0148] As an example, the first electrode (111a, 111b) may be formed as a positive electrode by coating a positive electrode active material on an aluminum (Al) substrate, and the second electrode (112a, 112b) may be formed as a negative electrode by coating a negative electrode active material on a copper (Cu) substrate. The non-coated portion (111b) of the first electrode and the non-coated portion (112b) of the second electrode are respectively provided at opposite ends of the winding axis of the electrode assembly (110), but electrode terminals (141) and a case (120) having different polarities in the same direction are provided together. A vent cap plate (142) is positioned on the opposite side of the electrode terminal (141).

[0149] The case (120) is formed in a cylindrical shape to house the electrode assembly (110), and the electrode terminal (141) and the vent cap plate (142) are provided at each of the axial ends of the case (120) so as to face each other.

[0150] The electrode terminal (141) is connected to the first electrode (111a, 111b) through the first collector plate (130) via the rivet portion (143), and the case (120) is connected to the second electrode (112a, 112b) through the second collector plate (150). At this time, the vent cap plate (142) is electrically separated from the second collector plate (150) and the case (120) and has no polarity.

[0151] An electrode terminal (141) connected to a first electrode (111a, 111b) of an electrode assembly (110) inserted into a case (120) from the outside is installed on one side of the case. The case (120) has a partially open through hole (121) on one side.

[0152] For example, the electrode terminal (141) may be installed in a rivet structure in the through hole (121) of the case (120). For this purpose, the electrode terminal (141) may be connected to a rivet portion (143). One end of the rivet portion (143) is welded to the first collector plate (130) and is arranged to penetrate the through hole (121). The electrode terminal (141) is connected to the rivet portion (143) and is arranged on the outside of the case (120). The electrode terminal (141) may be formed to protrude beyond the outer surface of the case (120) around the through hole (121) and may be used as a positive electrode terminal. At this time, the first collector plate (130) becomes a positive electrode collector plate.

[0153] At this time, the first collector plate (130) is electrically connected to the uncoated portion (111b) of the first electrode through the rivet portion (143) and is electrically and mechanically connected to the electrode terminal (141). The first collector plate (130) is electrically connected to the electrode terminal (141) in a structure that reduces resistance by contacting most of the uncoated portion (111b) of the first electrode. The rivet portion (143) included in the electrode terminal (141) is installed in an electrically insulated state from the case (120) while forming a gasket (123) in the through hole (121) to form a gastight structure with respect to the electrolyte.

[0154] Here, the gasket (123) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0155] As another example, the gasket (123) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the gasket (123) is not limited to the materials listed above, and may include various materials with excellent plasticity and insulation properties depending on the selection.

[0156] In one embodiment, at least a portion of the case (120), the rivet portion (143), and the gasket (123) may constitute a rivet fixing structure of the secondary battery.

[0157] In one embodiment, the gasket (123) may include a ring-shaped main body portion, a first extension portion extending from one end of the main body portion and extending along an outer surface of the bottom portion, and a second extension portion extending from the other end of the main body portion and extending along an inner surface of the bottom portion. Here, at least a portion of the outer circumferential surface of the first extension portion may have a tapered shape such that the radius gradually decreases as it moves away from the one end of the main body portion.

[0158] In one embodiment, the first extension may include a first surface extending parallel to the bottom portion so as to contact an outer surface of the bottom portion from one end of the main body portion, a second surface extending from the first surface in a direction perpendicular to the first surface, and a third surface extending from the second surface at an angle to the first surface. For example, a length by which the first surface extends to contact the bottom portion may be about 0.05 to 0.2 mm. In addition, a length by which the first surface extends to contact the bottom portion may be about 10 to 40% of a thickness of the gasket (123). In addition, an angle formed by the first surface and the third surface may be about 20 degrees or more and 80 degrees or less.

[0159] In one embodiment, the first extension may include a first surface extending parallel to the bottom portion so as to contact an outer surface of the bottom portion from one end of the main body portion, and a second surface extending from the first surface at an angle to form a predetermined angle with the first surface.

[0160] In one embodiment, the rivet portion (143) may include a base portion inserted so as to pass through the through hole (121), and a leg portion extending from the base portion along the inner surface of the bottom portion of the case (120). Here, the leg portion includes a protrusion formed in a direction opposite to the inner surface of the bottom portion of the case (120), and the protrusion may be in close contact with the second extension portion of the gasket (123).

[0161] In one embodiment, the rivet portion (143) may include a base portion that penetrates the gasket and is coupled to the case (120), and a leg portion that is connected to the base portion and contacts one surface of the gasket located inside the case (120). For example, the leg portion may include a plurality of notches that are configured to be broken by external pressure. In addition, the leg portion may be configured to apply pressure to the entire area of ​​the gasket that contacts the inner surface of the case (120) when the notches are broken by the external pressure. In addition, the leg portion may extend from a reference line where a side surface of the base portion and a side surface of the gasket are in contact in a radial direction of the case (120) by about 3.0 mm to 3.5 mm. In another example, the leg portion may include a plurality of notches that are configured to be elongated by the external pressure.

[0162] In one embodiment, the rivet fastening structure may further include an outer insulator connected to an upper portion of the gasket (123) and contacting at least a portion of an outer surface of the case (120) in an area adjacent to the through hole (121), and an inner insulator connected to a lower portion of the gasket (123) and contacting at least a portion of an inner surface of the case (120) in an area adjacent to the through hole (121). In this case, the leg portion may contact at least a portion of a lower surface of the gasket (123) and a lower surface of the inner insulator.

[0163] In one embodiment, the rivet fastening structure may further include a heat dissipation layer disposed between the outer surface of the rivet portion (143) and the side surface of the gasket. In this case, the rivet portion (143) may include a base portion that penetrates the gasket and is coupled to the case (120), and may further include an electrode terminal (141) that is coupled to one end of the base portion and extends radially from the one end of the base portion to contact at least a portion of the upper surface of the gasket exposed to the outside of the case (120). In addition, the heat dissipation layer may extend to cover at least a portion of the side surface of the gasket and surround at least a portion of the outer surface of the base portion. In addition, the heat dissipation layer may include a plurality of heat dissipation pads that are disposed at a plurality of positions between the outer surface of the base portion and the side surface of the gasket. In this case, the rivet fastening structure may further include an insulating layer that surrounds the inner surface of the base portion.

[0164] In one embodiment, the first collector plate (130) may include a metal plate (131) including at least one bridge (132). For example, the first collector plate (130) may be formed of a conductive metal, specifically, a conductive metal such as nickel, aluminum, copper, silver, zinc, tin, stainless steel (e.g., SUS), nickel-plated steel, or a combination (alloy) thereof. In addition, the metal plate (131) and the bridge (132) constituting the first collector plate (130) may be made of the same material to form an integral body.

[0165] Here, the bridge (132) of the first collector plate (130) may be configured to be ruptured when a current exceeding a set value flows. For example, the bridge (132) normally operates as a part of a circuit through which current flows, but when an excessive amount of current flows, it may function as a fuse that melts due to the generated heat and blocks the circuit.

[0166] An insulating tape (145) may be attached to one side of the first collector plate (130). The insulating tape (145) may be interposed between the first collector plate (130) and the case (120) or between the non-conductive portion (111b) of the first electrode and the case (120), and may serve to electrically insulate each component. In one embodiment, the central portion of the insulating tape (145) may include a perforation (146) corresponding to the shape of the rivet portion (143) so that the rivet portion (143) may come into contact with the first collector plate (130). In addition, the insulating tape (145) may include a side wall (147) so as to surround a portion of the electrode assembly (110).

[0167] Additionally, the case (120) has a fully open opening (122) to allow the electrode assembly (110) to be inserted into the other side. The vent cap plate (142) seals the opening (122) after the electrode assembly (110) is inserted into the case (120) and is electrically isolated from the case (120).

[0168] At this time, the second collector plate (150) is electrically connected to the non-conductive portion (112b) of the second electrode and is electrically connected to the case (120). The second collector plate (150) is connected to the case (120) in a structure that reduces resistance by contacting most of the non-conductive portion (112b) of the second electrode.

[0169] The second collector plate (150) includes a bottom portion (151) welded to the non-conductive portion (112b) of the second electrode, and wing portions (152) formed adjacent to the bottom portion (151) and welded to the beading portion (129). The second collector plate (150) is formed by cutting and bending a circular plate, and each of the bottom portions (151) and wing portions (152) is provided in multiple numbers and arranged alternately along the circumferential direction. In one embodiment, the wing portions (152) can be repeatedly formed by bending the axial direction (upward) and radial direction (outer) of the electrode assembly (110).

[0170] In one embodiment, when the non-coated portion (112b) of the second electrode and the bottom portion (151) of the second collector plate (150) are welded, the bottom portion (151) can form a welding line in the radial direction of the second collector plate (150). Accordingly, the bottom portion (151) can be evenly connected along the circumferential direction in the area of ​​the non-coated portion (112b) of the second electrode, and the wing portion (152) can be evenly connected along the circumferential direction in the area of ​​the beaded portion (129). This can enable a uniform current flow along the circumferential direction in the entire area of ​​the beaded portion (129) of the case (120) from the non-coated portion (112b) of the second electrode.

[0171] In addition, since the second collector plate (150) has a hole (153) in the center, it can absorb and alleviate deformation caused by welding of the bottom portion (151) and the non-conductive portion (112b) of the second electrode, as well as vibration and shock that may be transmitted between the wing portion (152) and the bottom portion (151). The hole (153) can have a size that can absorb vibration and shock without increasing the current resistance between the wing portion (152) and the bottom portion (151).

[0172] The vent cap plate (142) is electrically isolated from the second collector plate (150) and is installed in the opening (122) of the case (120) through a crimping process. Alternatively, the vent cap plate (142) is installed in the opening (122) of the case (120) through a welding process. Due to the connection of the second collector plate (150), the case (120) can be used as a negative terminal. In this case, the second collector plate (150) becomes a negative collector plate.

[0173] The vent cap plate (142) may form a notch (144) on its inner surface. The notch (144) may be cut open to release internal pressure of the secondary battery to the outside when an abnormal event occurs in the secondary battery, thereby preventing a secondary explosion. Specifically, the notch (144) intensively receives internal pressure in the event of an abnormal event, thereby enabling easy cutting. The notch (144) may be formed over the entire circumferential area of ​​the vent plate (142), or may be formed in multiple pieces spaced apart at set intervals.

[0174] The sealing member (160) is interposed between the second collector plate (150) and the vent cap plate (142) and between the second collector plate (130) and the case (120) to seal the case by means of a beading portion (129) or a crimping process. In addition, the sealing member (160) can form a gas-tight structure with respect to the electrolyte between the second collector plate (130) and the opening (122) of the case (120).

[0175] For example, the sealing member (160) may include a polymer material or ceramic such as polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE or Teflon), polyethylene (PE), epoxy resin, silicone, polyvinylidene fluoride (PVDF), polypropylene (PP), polyacrylonitrile (PAN), or polyethylene oxide (PEO), but is not limited thereto, and may correspond to any one of the appropriate compounds used as an insulating material in the art.

[0176] A secondary battery according to one embodiment of the present invention can be applied to automobiles, mobile phones, and / or various types of electrical devices, but the present invention is not limited thereto.

[0177] Fig. 2 is a cross-sectional view illustrating a comparative example of a rivet fastening structure. The rivet fastening structure illustrated in Fig. 2 may be formed on one side of a case of a secondary battery. For example, at least a portion of the rivet fastening structure may correspond to a rivet portion (143) inserted into a through hole (121) formed on one side of a case (120) of a secondary battery illustrated in Fig. 1.

[0178] As illustrated, the rivet fixing structure according to the comparison may be configured to be inserted into a through hole (20) formed in a bottom portion (10) of a case of a secondary battery. The rivet fixing structure may include a rivet portion (30) disposed to penetrate the through hole (20), and a gasket (40) interposed between the rivet portion (30) and the through hole (20). An electrode terminal (50) may be disposed on the outside of the case to be connected to the rivet portion (30). An internal insulator (60) in contact with an inner surface of the bottom portion (10) and an external insulator (70) in contact with an outer surface of the bottom portion (10) may be disposed on the bottom portion (10).

[0179] According to the comparison, the gasket (40) may include a ring-shaped main body (42) that contacts along the outer surface of the rivet portion (30), and a first extension portion (44) and a second extension portion (46) that extend from each end of the main body portion (42). The first extension portion (44) may extend from one end of the main body portion (42) and protrude outward from the bottom portion (10). The second extension portion (46) may extend from the other end of the main body portion (42) and extend along the inner surface of the bottom portion (10).

[0180] According to the comparison, the gasket (40) can be placed in close contact with the inner insulator (60) and the outer insulator (70) to form a sealing structure to prevent electrolyte leakage near the through hole (20). Specifically, the outer insulator (70) can be placed in close contact with the first extension portion (44) of the gasket (40), and the inner insulator (60) can be placed in close contact with the second extension portion (46) of the gasket (40).

[0181] As illustrated, when the first extension portion (44) of the gasket (40) extends from one end of the main body portion (42) in the same direction as the insertion direction of the rivet portion (30), and the thickness of the first extension portion (44) and the thickness of the main body portion (42) are formed to be the same, a leakage phenomenon of the electrolyte may continuously occur near the through hole (20). Specifically, the leakage path of the electrolyte may be formed along the contact portion of the inner insulator (60) and the second extension portion (46), the contact portion of the through hole (20) and the main body portion (42), and the contact portion of the outer insulator (70) and the first extension portion (44).

[0182] This problem can be partially solved by artificially extending the leakage path of the electrolyte. For example, the first extension portion (44) of the gasket (40) can be further extended along the outer surface of the bottom portion (10), thereby extending the leakage path of the electrolyte near the contact area between the external insulator (70) and the first extension portion (44). However, when the first extension portion (44) is further extended along the outer surface of the bottom portion (10), the first extension portion (44) protrudes beyond the through hole (20) formed in the bottom portion (10), which may reduce the insertability of the case during the assembly process of the rivet fastening structure.

[0183] Below, a description is given of a rivet fixing structure according to several embodiments that can secure the insertability of a case during the assembly process of the rivet fixing structure while minimizing the leakage of electrolyte that may occur in the rivet fixing structure described above.

[0184] FIG. 3 is a cross-sectional view illustrating an example of a rivet fixing structure according to one embodiment of the present disclosure. The rivet fixing structure illustrated in FIG. 3 may be formed on one side of a case of a secondary battery. For example, at least a portion of the rivet fixing structure may correspond to a rivet portion (143) inserted into a through hole (121) formed on one side of a case (120) of a secondary battery illustrated in FIG. 1.

[0185] Referring to FIG. 3, the rivet fixing structure may include a case having a bottom portion (120) in which a through hole (110) is formed, a rivet portion (200) positioned penetrating the through hole (110), and a gasket (310) interposed between the rivet portion (200) and the through hole (110). An electrode terminal (400) may be positioned on the outside of the case so as to be connected to the rivet portion (200).

[0186] An internal insulator (330) may be placed on the inner surface of the bottom portion (120) of the case. The internal insulator (330) may extend along the inner surface of the bottom portion (120) and may be placed so as to be in contact with the inner surface of the bottom portion (120). Through this, the internal insulator (260) may electrically isolate the case and the electrode assembly housed within the case.

[0187] An external insulator (320) may be placed between the bottom portion (120) of the case and the electrode terminal (400). The external insulator (320) extends along the outer surface of the bottom portion (120) and is interposed between the outer surface of the bottom portion (120) and the electrode terminal (400), thereby electrically isolating the electrode terminal (400) and the case.

[0188] The rivet portion (200) may include a base portion (210) inserted to penetrate the through hole (110) and a leg portion (220) extending from the base portion (210). The leg portion (220) may extend along the inner surface of the bottom portion (120). The base portion (210) may be spaced apart from the through hole (110) provided in the bottom portion (120) so as not to come into contact with it. In addition, the leg portion (220) may be spaced apart from the inner surface of the bottom portion (120). A gasket (310) may be interposed in the spaced apart space between the rivet portion (200) and the bottom portion (120) so as to electrically isolate the rivet portion (200) from the case.

[0189] The gasket (310) can seal the space between the through hole (110) and the rivet portion (200). For example, the inner circumference of the gasket (240) can be in close contact with the base portion (210) of the rivet portion (200), and the outer circumference of the gasket (310) can be in close contact with the through hole (110) of the case.

[0190] The gasket (310) may include a ring-shaped main body (312) that contacts along the outer surface of the base portion (210), and a first extension portion (314) and a second extension portion (316) that extend from each end of the main body portion (312). The first extension portion (314) may extend from one end of the main body portion (312) and protrude outward from the bottom portion (120). The second extension portion (316) may extend from the other end of the main body portion (312) and extend along the inner surface of the bottom portion (120).

[0191] In one embodiment, the first extension portion (314) may extend along the outer surface of the bottom portion (120). Accordingly, the first extension portion (314) may protrude a predetermined length from the through hole (110) formed in the bottom portion (120) at a portion where it contacts the outer surface of the bottom portion (120).

[0192] Additionally, at least a portion of the outer surface of the first extension portion (314) may be tapered so that the radius gradually decreases as it moves away from one end of the main body portion (312). Accordingly, the radius of the outer surface of the first extension portion (314) may be larger than the radius of the through hole (110) at the portion where the first extension portion (314) contacts the main body portion (312), but at the end of the first extension portion (314), the radius of the outer surface of the first extension portion (314) may correspond to the radius of the through hole (110). For example, the radius of the outer surface of the first extension portion (314) at the end of the first extension portion (314) may be smaller than or equal to the radius of the through hole (110). Specific examples of the shape of the first extension portion (314) are described in detail below with reference to FIGS. 4 to 9.

[0193] The inner insulator (330) may be positioned so as to be in close contact with the outer surface of the second extension portion (316). As a specific example, the contact position of the inner insulator (330) and the second extension portion (316) may be positioned on the leg portion (220) of the rivet portion (200). In this case, the contact portion of the inner insulator (330) and the second extension portion (316) may be supported by the leg portion (220).

[0194] The external insulator (320) can be positioned so as to be in close contact with the outer surface of the first extension portion (314). As the electrode terminal (400) is connected to the rivet portion (200) and the external insulator (320) is pressed by the electrode terminal (400), the external insulator (320) can be in close contact with the tapered outer surface of the first extension portion (314) without any empty space.

[0195] A protrusion (230) may be formed on the leg portion (220) of the rivet portion (200) in a direction facing the inner surface of the bottom portion (120). The protrusion (230) may be in close contact with the gasket (310) and serve to fix the position of the gasket (310). In addition, as the gasket (310) is compressed by the protrusion (230), the sealing effect may be maximized.

[0196] In one embodiment, at least a portion of the gasket (310) may be composed of a fluororesin material. As a specific example, the gasket (310) may be composed of an elastic material such as PFA (perfluoroalkoxy) or PETE (polytelrafluoro ethylene), but is not limited thereto.

[0197] By this configuration, the first extension portion (314) of the gasket (310) extends a predetermined length along the outer surface of the bottom portion (120), thereby extending the length of the leakage path of the electrolyte and suppressing the phenomenon of electrolyte leakage. In addition, by forming a compression point at the point where the extended surface of the first extension portion (314) and the outer surface of the bottom portion (120) come into contact, the gasket (310) and the bottom portion (120) are firmly adhered to each other, thereby increasing the sealing property.

[0198] In addition, even if the first extension (314) extends along the outer surface of the bottom portion (120) and protrudes beyond the through hole (110) formed in the bottom portion (120), the case and the gasket can be easily joined due to the tapered shape of the outer surface of the first extension (314). An example of an assembly method of the rivet fixing structure is described in detail below in FIGS. 10 to 14.

[0199] FIG. 4 is a cross-sectional view showing an example of a rivet fixing structure according to the first embodiment of the present disclosure, and FIG. 5 is an enlarged cross-sectional view showing a portion of the gasket shown in FIG. 4 according to the first embodiment of the present disclosure.

[0200] Referring to FIG. 4, the rivet fixing structure may include a case having a bottom portion (120) in which a through hole (420) is formed, a rivet portion (200) disposed through the through hole, and a gasket (310) interposed between the rivet portion (200) and the through hole. An internal insulator (330) may be disposed on an inner surface of the bottom portion (120), and an external insulator (320) may be disposed on an outer surface of the bottom portion (120).

[0201] The gasket (310) may include a ring-shaped main body (312) that contacts along the outer surface of the rivet portion (200), and a first extension portion (314) and a second extension portion (316) that extend from each end of the main body portion (312). The first extension portion (314) may extend from one end of the main body portion (312) and protrude outward from the bottom portion (120). The second extension portion (316) may extend from the other end of the main body portion (312) and extend along the inner surface of the bottom portion (120).

[0202] The first extension portion (314) may extend along the outer surface of the bottom portion (120). Accordingly, the first extension portion (314) may protrude by a predetermined length (x) from the through hole formed in the bottom portion (120) at a portion where it contacts the outer surface of the bottom portion (120). In addition, at least a portion of the outer circumferential surface of the first extension portion (314) may be tapered so that the radius gradually decreases as it moves away from one end of the main body portion (312).

[0203] Referring to FIG. 5, the first extension portion (314) of the gasket (310) may include a first surface (314a_1), a second surface (314a_2), a third surface (314a_3), and a fourth surface (314a_4). The first surface (314a_1) may extend from one end of the main body portion (312) in a direction parallel to the bottom portion (120) and may contact an outer surface of the bottom portion (120). The second surface (314a_2) may extend from the first surface (314a_1) in a direction approximately perpendicular to the first surface (314a_1). The third surface (314a_3) may extend from the second surface (314a_2) at an angle to form a predetermined angle with the first surface (314a_1). The fourth side (314a_4) can extend from the third side (314a_3) in a direction parallel to the floor.

[0204] In one embodiment, the extended length (x) of the first surface (314a_1) may be 10% to 40% of the thickness of the main body (312). As a specific example, the thickness of the main body (312) may be formed to be about 0.5 mm, and the extended length (x) of the first extension (314) along the outer surface of the bottom may be formed to be 0.05 to 0.2 mm, but is not limited thereto. If the extended length (x) of the first surface (314a_1) exceeds 40% of the thickness of the main body (312), the insertability of the gasket into the through hole of the case may be reduced during the assembly process of the rivet fixing structure. In addition, if the extended length (x) of the first surface (314a_1) is less than 10% of the thickness of the main body (312), the sealing effect due to the compression point may be reduced at the portion where the first surface (314a_1) and the case come into contact.

[0205] In one embodiment, the angle formed by the first surface (314a_1) and the third surface (314a_3) may be greater than or equal to 20 degrees and less than or equal to 80 degrees. Preferably, the angle formed by the first surface (314a_1) and the third surface (314a_3) may be greater than or equal to 40 degrees and less than or equal to 60 degrees, but is not limited thereto.

[0206] In one embodiment, the fourth surface (314a_4) may be extended to contact the rivet portion. The extended length of the fourth surface (314a_4) may correspond to the thickness of the main body portion (312). For example, the extended length of the fourth surface (314a_4) may be less than or equal to the thickness of the main body portion (312). As a specific example, the extended length of the fourth surface (314a_4) may be formed to be approximately 0.5 mm, but is not limited thereto.

[0207] Fig. 6 is a cross-sectional view showing an example of a rivet fixing structure according to a second embodiment of the present disclosure, and Fig. 7 is an enlarged cross-sectional view showing a portion of a gasket illustrated in Fig. 6 according to the second embodiment of the present disclosure. In Figs. 6 and 7, components described or duplicated in Figs. 4 and 5 are omitted.

[0208] The gasket (310) may include a ring-shaped main body (312) that contacts along the outer surface of the rivet portion, and a first extension portion (314) and a second extension portion (316) that extend from each end of the main body portion (312). The first extension portion (314) may extend from one end of the main body portion (312) and protrude outward from the bottom portion (120). The second extension portion (316) may extend from the other end of the main body portion (312) and extend along the inner surface of the bottom portion (120).

[0209] The first extension portion (314) may extend along the outer surface of the bottom portion (120). Accordingly, the first extension portion (314) may protrude by a predetermined length (x) from the through hole formed in the bottom portion (120) at a portion where it contacts the outer surface of the bottom portion (120). In addition, the outer circumferential surface of the first extension portion (314) may be tapered overall so that the radius gradually decreases as it moves away from one end of the main body portion (312).

[0210] Referring to FIG. 7, the first extension portion (314) of the gasket (310) may include a first surface (314b_1), a second surface (314b_2), and a third surface (314b_3). The first surface (314b_1) may extend from one end of the main body portion (312) in a direction parallel to the bottom portion (120) and may contact an outer surface of the bottom portion (120). The second surface (314b_2) may extend from the first surface (314b_1) at an angle to form a predetermined angle with the first surface (314b_1). The third surface (314b_3) may extend from the second surface (314b_2) in a direction parallel to the bottom portion.

[0211] In one embodiment, the length (x) of the first surface (314b_1) may be 10 to 40% of the thickness of the main body (312). For example, the thickness of the main body (312) may be formed to be approximately 0.5 mm, and the length (x) of the first extension (314) extended along the outer surface of the bottom (120) may be formed to be 0.05 to 0.2 mm, but is not limited thereto.

[0212] In one embodiment, the angle formed by the first surface (314b_1) and the second surface (314b_2) may be greater than or equal to 20 degrees and less than or equal to 80 degrees. Preferably, the angle formed by the first surface (314b_1) and the second surface (314b_2) may be greater than or equal to 40 degrees and less than or equal to 60 degrees, but is not limited thereto.

[0213] In one embodiment, the third surface (314b_3) may be extended to contact the rivet portion. The extended length of the third surface (314b_3) may correspond to the thickness of the main body portion (312). For example, the extended length of the third surface (314b_3) may be less than or equal to the thickness of the main body portion (312). As a specific example, the extended length of the third surface (314b_3) may be formed to be approximately 0.5 mm, but is not limited thereto.

[0214] Fig. 8 is a cross-sectional view showing an example of a rivet fixing structure according to a third embodiment of the present disclosure, and Fig. 9 is an enlarged cross-sectional view showing a portion of a gasket (310) illustrated in Fig. 8 according to the third embodiment of the present disclosure. In Figs. 8 and 9, components described or duplicated in Figs. 4 and 5 are omitted.

[0215] The gasket (310) may include a ring-shaped main body (312) that contacts along the outer surface of the rivet portion, and a first extension portion (314) and a second extension portion (316) that extend from each end of the main body portion (312). The first extension portion (314) may extend from one end of the main body portion (312) and protrude outward from the bottom portion (120). The second extension portion (316) may extend from the other end of the main body portion (312) and extend along the inner surface of the bottom portion (120).

[0216] The first extension portion (314) may extend along the outer surface of the bottom portion (120). Accordingly, the first extension portion (314) may protrude by a predetermined length (x) from the through hole formed in the bottom portion (120) at a portion where it contacts the outer surface of the bottom portion (120). In addition, the outer circumferential surface of the first extension portion (314) may be tapered overall so that the radius gradually decreases as it moves away from one end of the main body portion (312).

[0217] Referring to FIG. 9, the first extension portion (314) of the gasket (310) may include a first surface (314c_1) and a second surface (314c_2). The first surface (314c_1) may extend from one end of the main body portion (312) in a direction parallel to the bottom portion (120) and may contact the outer surface of the bottom portion (120). The second surface (314c_2) may extend from the first surface (314c_1) at an angle to form a predetermined angle with the first surface (314c_1). The second surface (314c_2) may extend to contact the rivet portion.

[0218] In one embodiment, the length (x) of the first surface (314c_1) may be 10 to 40% of the thickness of the main body (312). For example, the thickness of the main body (312) may be formed to be approximately 0.5 mm, and the length (x) of the first extension (314) extended along the outer surface of the bottom (120) may be formed to be 0.05 to 0.2 mm, but is not limited thereto.

[0219] In one embodiment, the angle formed by the first surface (314c_1) and the second surface (314c_2) may be greater than or equal to 20 degrees and less than or equal to 80 degrees. Preferably, the angle formed by the first surface (314c_1) and the second surface (314c_2) may be greater than or equal to 40 degrees and less than or equal to 60 degrees, but is not limited thereto.

[0220] FIGS. 10 to 14 are drawings for explaining an assembly method of a rivet fastening structure according to one embodiment of the present disclosure. Referring to FIG. 10, the assembly method of the rivet fastening structure may be initiated by preparing a rivet portion (200). The rivet portion (200) may include a base portion (232) and a leg portion (234) extending from the base portion (232). The leg portion (234) may extend in a direction intersecting the base portion (232). A protrusion (236) may be formed on one surface of the leg portion (234) in the direction in which the base portion (232) extends.

[0221] Then, a gasket (310) may be placed. Referring to FIG. 11, the gasket (310) may be formed in a roughly ring shape. Accordingly, the rivet portion (200) and the gasket (310) may be joined in a manner in which the rivet portion (200) is inserted into the inner circumferential surface of the gasket (310).

[0222] According to one embodiment, the gasket may include a ring-shaped main body (312) that contacts along the outer surface of the rivet portion (200), and a first extension portion (314) and a second extension portion (316) that extend from both ends of the main body portion (312), respectively. The first extension portion (314) may extend from one end of the main body portion (312) in the same direction as the insertion direction of the rivet portion (200). At a portion where the first extension portion (314) and the main body portion (312) contact each other, a radius of the outer surface of the first extension portion (314) may be formed to be larger than a radius of the outer surface of the main body portion (312). In addition, the radius of the outer surface of the first extension portion (314) may be tapered so as to gradually decrease as it moves away from the main body portion (312).

[0223] The second extension portion (316) may extend from the other end of the main body portion and may extend along the leg portion of the rivet portion (200). The gasket (310) may be positioned so that the second extension portion (316) of the gasket (310) is in close contact with the protrusion formed on the leg portion of the rivet portion (200).

[0224] Then, the inner insulator (330) may be placed. For example, the inner insulator (330) may be in the shape of a disc with a through hole formed in the center, and the inner insulator (330) may be placed in such a way that the rivet portion (200) and the gasket (310) are inserted through the through hole of the inner insulator (330). The inner insulator (330) may be placed so as to be in contact with the outer surface of the second extension portion (316) of the gasket (310). The contact position of the inner insulator (330) and the gasket (310) may be placed on the leg portion of the rivet portion (200).

[0225] Then, the rivet part (200) and the gasket (310) can be combined with the case (100). Referring to FIG. 12, the case (100) can have a bottom portion in which a through hole is formed. Specifically, the rivet part (200) and the gasket (310) can be inserted through the through hole formed in the bottom portion of the case (100). At this time, since the outer surface of the first extension part (314) of the gasket (310) is formed to be tapered, the rivet part (200) and the gasket (310) can be easily inserted into the through hole of the case (100). The case (100) can be arranged so that the through hole of the case (100) is in contact with the outer surface of the main body part (312) of the gasket (310). In addition, the case (100) can be arranged so as to be in contact with the internal insulator (330).

[0226] Then, an external insulator (320) may be placed. Referring to FIG. 13, the external insulator (320) is in the shape of a disc with a through hole formed in the center, and the external insulator (330) may be placed in such a manner that the rivet portion (200) and the gasket (310) are inserted through the through hole of the external insulator (320). The external insulator (320) may be placed so as to be in contact with the outer surface of the first extension portion (314) of the gasket (310).

[0227] Then, the electrode terminal (400) can be placed. Referring to FIG. 14, the electrode terminal (400) can be connected to the rivet portion (200). The electrode terminal (400) can be placed on the external insulator (320) so as to be electrically insulated from the case (100). By the electrode terminal (400), the external insulator (320) and the gasket (310) are compressed, so that the external insulator (320) can be closely attached to the tapered outer surface of the first extension portion (314) without any empty space.

[0228] The assembly method of the rivet fastening structure illustrated in FIGS. 10 to 14 is merely an example and is not limited thereto. At least some of the components included in the illustrated rivet fastening structure may be omitted, new components not illustrated may be added, and the assembly order of the rivet fastening structure may also be changed.

[0229] Below in Fig. 15, various embodiments of a rivet fixing structure including a rivet portion (200) disposed in a through hole (110) formed in a case (100), and a gasket (310) disposed between the rivet portion (200) and the through hole (110) to electrically insulate the rivet portion (200) are described in more detail. The rivet portion (200) described below in Fig. 15 may correspond to the electrode terminal (141) and the rivet portion (143) in the secondary battery illustrated in Fig. 1, and the gasket (310) described below in Fig. 15 may correspond to the gasket (123) and / or the insulating tape (145) in the secondary battery illustrated in Fig. 1.

[0230] FIG. 15 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure, and is a view showing a state before a notch is broken, and FIG. 16 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure, and is a view showing a state after a notch is broken.

[0231] Referring to FIGS. 15 and 16, the rivet fixing structure may include a case (100) having a through hole (110) on a first side and an open second side located in an opposite direction to the first side, a rivet portion (200) disposed through the through hole (110), and a gasket (310) disposed between the rivet portion (200) and the through hole (110).

[0232] The case (100) may have a cylindrical shape including a through hole (110) on the first side and an open second side located opposite the first side. A vent cap plate (142) may be fastened to the open portion of the second side as illustrated in FIG. 1.

[0233] The rivet portion (200) may be positioned through the through hole (110). The rivet portion (200) may include a base portion (210) and a leg portion (220). The base portion (210) may be coupled to the case (100) by passing through the gasket (310). The leg portion (220) may be connected to the base portion (210) and may be in contact with one surface of the gasket (310) located inside the case (100). The leg portion (220) may be formed to extend radially from the lower end of the base portion (210).

[0234] The gasket (310) may be arranged between the rivet portion (200) and the through hole (110), and may be arranged to surround the case (100) in an area adjacent to the through hole (110). The gasket (310) may be made of an insulating material to electrically insulate the rivet portion (200) and the case (100). Here, the gasket (310) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0235] As another example, the gasket (310) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the gasket (310) is not limited to the materials listed above, and may include various materials with excellent plasticity and insulation properties depending on the selection.

[0236] In one embodiment, the leg portion (220) may include a plurality of notches (e.g., notches (221) of FIG. 19) configured to be broken by external pressure. The notches may be formed by recessing the outer surface along the longitudinal direction of the leg portion (220). The leg portion (220) may be configured to apply pressure to the entire area of ​​the gasket (310) that contacts the inner surface of the case (100) when the notches are broken by the external pressure. The leg portion (220) may apply pressure so that the gasket (310) is brought into closer contact with the inner surface of the case (100) when the notches are broken by the external pressure.

[0237] The gasket (310) can be inserted into the through hole (110). The gasket (310) can be inserted while contacting the inner surface of the through hole (110). The outer insulator (320) is connected to the upper portion of the gasket (310) and can contact at least a portion of the outer surface of the case (100) in the area adjacent to the through hole (110). The outer insulator (320) can be formed to be larger than the upper surface of the base portion (210) so as to electrically insulate the base portion (210) and the case (100). The inner insulator (330) is connected to the lower portion of the gasket (310) and can contact at least a portion of the inner surface of the case (100) in the area adjacent to the through hole (110).

[0238] In this configuration, the leg portion (220) can be in contact with the lower surface of the gasket (310) and at least a portion of the lower surface of the inner insulator (330). For example, when the notch is broken by external pressure, the leg portion (220) can be in contact with the entire lower surface of the gasket (310) and at least a portion of the lower surface of the inner insulator (330). When the notch of the leg portion (220) is broken by external pressure, the compressive force applied by the leg portion (220) to the edge of the gasket (310) that is in contact with the base portion (210) increases, thereby improving the sealing force of the gasket (310). Through this, it is possible to prevent a problem in which a gap is formed between the rivet portion (200) and the gasket (310) or a gap is formed between the gasket (310) and the through hole (110), thereby causing electrolyte to leak to the outside.

[0239] In another embodiment, the leg portion (220) may include a plurality of notches (e.g., the notches (221) of FIG. 19) configured to be elongated by external pressure. The plurality of notches formed in the leg portion (220) may be formed to be thinner than other portions of the leg portion (220) in adjacent areas and may be formed of an elongable metal material so as to be elongated when external pressure is applied. At this time, the leg portion (220) may be in contact with at least a portion of the lower surface of the gasket (310) and the lower surface of the inner insulator (330). When the notches are elongated by external pressure, the leg portion (220) may be in contact with the entire lower surface of the gasket (310) and at least a portion of the lower surface of the inner insulator (330). When the notch is extended by external pressure, the compressive force applied by the leg portion (220) to the edge of the gasket (310) that contacts the base portion (210) increases, thereby improving the sealing force of the gasket (310). Through this, it is possible to prevent a problem in which a gap occurs between the rivet portion (200) and the gasket (310) or a gap occurs between the gasket (310) and the through hole (110), thereby causing electrolyte to leak to the outside.

[0240] Fig. 17 is a cross-sectional view showing an example of a rivet fixing structure as a comparative example with Fig. 18, and Fig. 18 is a cross-sectional view showing an example of a rivet fixing structure according to one embodiment of the present disclosure, and is a drawing showing the length of a leg portion extended from a reference line after a notch is broken.

[0241] Referring to FIG. 18, in the rivet fixing structure according to one embodiment of the present disclosure, when the radius of the base portion (210) is 2.0 mm to 2.5 mm, the leg portion (220) may extend from a reference line (B) where the side surface of the base portion (210) and the side surface of the gasket (310) are in contact in the radial direction of the case (100) by 3.0 mm to 3.5 mm. In addition, the leg portion (220) may extend from a reference line (B) where the side surface of the base portion (210) and the side surface of the gasket (310) are in contact in the radial direction of the case (100) by 3.0 mm to 3.5 mm. Preferably, the leg portion (220) may extend from a reference line (B) where the side surface of the base portion (210) and the side surface of the gasket (310) are in contact in the radial direction of the case (100) by 3.3 mm.

[0242] As in the example described above, in the rivet fixing structure, the leg portion (220) can be set to extend longer in the radial direction of the base portion (210) from the reference line (B) compared to the length of the radius of the base portion (210).

[0243] In comparison, referring to FIG. 17, in a conventional rivet fixing structure, when the radius of the base of the rivet portion (2) is 2.0 mm to 2.5 mm, the inner flange portion of the rivet portion (20) can extend from the reference line (B) where the side surface of the rivet portion (2) and the side surface of the first gasket (3a) come into contact in the radial direction of the case (1) by 1 mm to 1.5 mm.

[0244] According to the rivet fixing structure according to one embodiment of the present disclosure of FIG. 18, the leg portion is extended by 2 mm more than the comparative example of FIG. 17, so that a greater compressive force can be applied to the corner of the gasket (310), and the sealing force can be prevented from decreasing in the gap between the gasket (310) and the internal insulator (330).

[0245] In addition, it is possible to prevent a gap from occurring between the gasket (310) and the inner insulator (330), thereby preventing a gap from occurring between the gasket (310) and the through hole (110). In addition, it is possible to prevent a decrease in sealing force in the gap between the gasket (310) and the outer insulator (320).

[0246] In addition, when the notch formed in the leg portion is broken or elongated by external pressure, the gasket (310) is compressed by the pressure, and the gasket (310) made of an elastic material can reflectively expand in another area, the inner insulator (330), which is not subject to pressure. Therefore, the inner insulator (330) can be brought into closer contact with the case (100), thereby preventing a gap from forming.

[0247] Fig. 19 is a cross-sectional view showing a notch formed in a leg portion of a rivet portion according to one embodiment of the present disclosure, and Fig. 20 is a perspective view showing a notch formed in a leg portion of a rivet portion according to one embodiment of the present disclosure. In addition, Fig. 21 is a plan view showing a case where four notches are formed in a rivet fastening structure according to one embodiment of the present disclosure, and Fig. 22 is a plan view showing a case where six notches are formed in a rivet fastening structure according to another embodiment of the present disclosure.

[0248] According to one embodiment, a plurality of notches may be formed in the leg portion (220) of the rivet fastening structure. A plurality of notches (221) may be formed at predetermined intervals on the outer circumference along the circumference direction of the leg portion (220).

[0249] For example, four notches (221) may be formed at equal intervals on the outer surface along the circumference of the leg portion (220). For another example, six notches (221) may be formed at equal intervals on the outer surface along the circumference of the leg portion (220).

[0250] The notch (221) may be formed in a recessed shape that is thinner than the thickness of the leg portion (220) where the notch (221) is not formed. For example, the cross-sectional shape of the notch (221) may have a semicircular or oval shape, a wedge shape that gradually narrows or becomes sharp, etc., but is not limited thereto. The notch (221) may be configured to be broken or elongated when external pressure is applied.

[0251] When external pressure is applied and the notch (221) is broken or elongated, the leg portion (220) may spread radially and come into contact with the lower surface of the gasket (310) and a portion of the lower surface of the inner insulator (330).

[0252] FIG. 23 is a plan view showing an example of a planar shape after a notch of a leg portion is broken according to the embodiment of FIG. 22, FIG. 24 is a plan view showing another example of a planar shape after a notch of a leg portion is broken according to the embodiment of FIG. 22, and is an example of a case where a notch is formed only in a part of a leg portion, and FIG. 25 is a plan view showing an example of a planar shape after a notch of a leg portion is extended according to the embodiment of FIG. 22.

[0253] FIG. 23 and FIG. 24 show a case where a leg portion (220) according to an embodiment of the present invention is broken when six notches (221) are formed, and FIG. 25 shows a case where a leg portion (220) according to an embodiment of the present invention is elongated when six notches (221) are formed.

[0254] For example, in the leg portion (220) of FIG. 23, six notches (221) are formed at regular intervals in the circumferential direction of the leg portion (220), and each notch (221) can be formed along the entire length of the leg portion (220). In this case, when external pressure is applied and the notches (221) are broken, the leg portion (220) can be spread out in a radial direction. When the leg portion (220) is spread out in a radial direction and comes into contact with a part of the lower surface of the gasket (310) and the lower surface of the internal insulator (330), the sealing length can be increased, so that the sealing force of the gasket (310) can be improved.

[0255] For another example, in the leg portion (220) of FIG. 24, six notches (221) are formed at regular intervals in the circumferential direction of the leg portion (220), and each notch (221) may be formed in a portion in the longitudinal direction. In this case, when external pressure is applied and the notches (221) are broken, the leg portion (220) may spread out in a radial direction. At this time, the pressure on the gasket (310) and the internal insulator (330) may be greater by the length of the leg portion (220) in which the notches (221) are not formed. Additionally, the area or length of the pressure region on the lower surface of the gasket (310) and the lower surface of the internal insulator (330) may be increased by the length of the leg portion (220) in which the notches (221) are formed, so that the sealing power of the gasket (310) may be further improved.

[0256] For another example, in the leg portion (220) of FIG. 25, extendable notches (221) are formed at regular intervals in the circumferential direction of the leg portion (220), and can be formed over the entire lengthwise area. In this case, when external pressure is applied to extend the notches (221), the leg portion (220) can spread out in a radial direction. When the notches (221) are extended and the leg portion (220) spreads out in a radial direction to come into contact with the lower surface of the gasket (310) and a portion of the lower surface of the internal insulator (330), the sealing length can be increased, thereby improving the sealing force of the gasket (310). Compared to the configuration of the leg portion (220) of FIG. 23, the configuration of the leg portion (220) of FIG. 25 can apply pressure to the gasket (310) even in the area of ​​the extended notches (221), so that the sealing force can be further improved.

[0257] FIG. 26 is a flowchart illustrating an example of a method for manufacturing a secondary battery according to one embodiment of the present disclosure.

[0258] Referring to FIG. 26, a method for manufacturing a secondary battery according to an embodiment of the present invention may include a step (S100) of arranging a gasket (310) to surround an area adjacent to a through hole (110) formed on a first side of a case (100), a step (S200) of sealing the through hole (110) by pressing the gasket (310) using a rivet portion (200) and penetrating the through hole (110), a step (S300) of inserting an electrode assembly through an opening formed on a second side of the case (100) located in an opposite direction to the first side, and a step (S400) of closing the opening with a vent plate ().

[0259] In the step (S100) of placing the gasket (310), the gasket (310) can be inserted into the through hole. After the gasket (310) is inserted while contacting the inner surface of the through hole (110), the outer insulator (320) is connected to the upper portion of the gasket (310) and can contact at least a portion of the outer surface of the case (100) in the area adjacent to the through hole (110). The inner insulator (330) is connected to the lower portion of the gasket (310) and can be placed so as to contact at least a portion of the inner surface of the case (100) in the area adjacent to the through hole (110).

[0260] The step (S200) of sealing the through hole (110) using the rivet portion (200) may include a step of applying pressure to the entire area of ​​the gasket (310) that contacts the inner surface of the case (100) by stretching or breaking the notch (221) formed in the leg portion (220) by external pressure. Here, the rivet portion (200) may include a base portion (210) that is coupled to the case (100) by penetrating the gasket (310) and a leg portion (220) that is connected to the base portion (210) and contacts one surface of the gasket (310) located inside the case (100).

[0261] The rivet portion (200) described below in FIG. 27 may correspond to the electrode terminal (141) and the rivet portion (143) in the secondary battery depicted in FIG. 1, and the gasket (310) described below in FIG. 27 may correspond to the gasket (123) and / or the insulating tape (145) in the secondary battery depicted in FIG. 1.

[0262] FIG. 27 is a cross-sectional view of a state before a rivet portion of a rivet fixing structure according to one embodiment of the present disclosure is inserted into a through hole, and FIG. 28 is a cross-sectional view of a state after a rivet portion of a rivet fixing structure according to one embodiment of the present disclosure is inserted into a through hole.

[0263] Referring to FIGS. 27 and 28, the rivet fixing structure may include a case (100) in which a through hole (110) is formed, a rivet portion (200) penetrating the through hole (110), and a gasket (310) disposed between the rivet portion (200) and the through hole (110).

[0264] The case (100) may include a through hole (110) on the first side, and may have an open second side located opposite the first side. A vent cap plate (142) may be fastened to the open portion of the second side, as illustrated in FIG. 1.

[0265] The rivet portion (200) may be arranged to penetrate the through hole (110). The rivet portion (200) may include a base portion (210) and an electrode terminal (400). The base portion (210) may be coupled to the case (100) by penetrating the gasket (310). The electrode terminal (400) may be coupled to one end of the base portion (210) and may be arranged to extend radially from one end of the base portion (210) and contact at least a portion of the upper surface of the gasket (310) exposed to the outside of the case (100).

[0266] The gasket (310) may be arranged between the rivet portion (200) and the through hole (110), and may be arranged to surround the case (100) in an area adjacent to the through hole (110). The gasket (310) may be made of an insulating material to electrically insulate the rivet portion (200) and the case (100). For example, the gasket (310) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0267] As another example, the gasket (310) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the gasket (310) is not limited to the materials listed above, and may include various materials with excellent plasticity and insulation properties depending on the selection.

[0268] The heat dissipation layer (500) may be disposed between the outer surface of the rivet portion (200) and the side surface of the gasket (310). The heat dissipation layer (500) may extend to cover at least a portion of the side surface of the gasket (310) and surround at least a portion of the outer surface of the base portion (210). In this case, the heat dissipation layer (500) may disperse heat, such as welding heat, generated when welding is performed to electrically connect the base portion (210) to the electrode plate or electrode tab of the electrode assembly accommodated inside the case (100), to the periphery of the gasket (310). The heat dissipation layer (500) may extend to cover the entire side surface of the gasket (310) and surround the entire outer surface of the base portion (210).

[0269] The heat dissipation layer (500) extends to cover at least a portion of the side surface of the gasket (310) so as to disperse heat transferred to the gasket (310) to the surroundings. The material of the heat dissipation layer (500) is not particularly limited as long as it is an appropriate material that allows heat to be dispersed to the surroundings while passing through the heat dissipation layer (500) when heat is transferred to the portion to which the heat dissipation layer (500) is attached. For example, the heat dissipation layer (500) may be implemented using a silicone heat dissipation sheet, a graphite heat dissipation sheet, or a combination of these materials.

[0270] The rivet fixing structure according to one embodiment of the present invention may further include an insulating layer (600) surrounding the inner surface of the base portion (210). The insulating layer (600) may surround at least a portion of the inner surface of the base portion (210). In this case, the insulating layer (600) may block heat from spreading to the outer surface of the base portion (210) when heat such as welding heat is applied to the central portion of the base portion (210). Through this, heat transferred to the gasket (310) through the outer surface of the base portion (210) may be reduced. The insulating layer (600) may extend to cover the entire inner surface of the base portion (210) and may surround the entire inner surface of the base portion (210). The material of the insulating layer (600) is not particularly limited as long as it is an appropriate material that can block at least a portion of the heat transferred to the portion to which the insulating layer (600) is attached. For example, the insulation layer (600) can be implemented as a silica insulation sheet.

[0271] FIG. 29 is a plan view and a cross-sectional view of a base portion of a rivet fixing structure according to one embodiment of the present disclosure in which a heat dissipation layer and an insulating layer are attached, and FIG. 30 is a plan view and a cross-sectional view of a base portion of a rivet fixing structure according to one embodiment of the present disclosure in which the heat dissipation layer includes two heat dissipation pads.

[0272] Referring to FIGS. 29 and 30, the heat dissipation layer (500) may be attached to the outer surface of the base portion (210) using an adhesive or heat fusion. In another embodiment, the heat dissipation layer (500) may be attached to the side surface of the gasket (310) using an adhesive or heat fusion.

[0273] Additionally, the insulation layer (600) may surround at least a portion of the inner surface of the base portion (210). The insulation layer (600) may be attached to the inner surface of the base portion (210) using an adhesive or heat fusion.

[0274] As illustrated in FIG. 30, the heat dissipation layer (500) may include a plurality of heat dissipation pads arranged at a plurality of locations between the outer surface of the base portion (210) and the side surface of the gasket (310). For example, the heat dissipation layer (500) may be formed by arranging or attaching a plurality of heat dissipation pads to surround the outer surface of the base portion (210).

[0275] Fig. 31 is a cross-sectional view showing a rivet fixing structure in a case where there is no heat dissipation layer or insulation layer as a comparative example.

[0276] Referring to Fig. 31, in a conventional rivet fixing structure, when performing welding to electrically connect the base portion (210) to an electrode plate or electrode tab of an electrode assembly housed inside a case (100), external heat (Q) for welding may be applied to the upper portion of the base portion (210). In this case, the heat is directly transferred to the gasket (310) through the base portion (210), and heat damage may occur on the side of the gasket (310) that is in contact with the base portion (210).

[0277] As described above, in the conventional rivet fixing structure, external heat (Q) is not distributed around the base portion (210) or the gasket (310), but is concentrated on the base portion (210), so that a large amount of heat may be transferred to the side of the gasket (310). In this case, the gasket (310) is deformed, causing a gap to form between the gasket (310) and the case (100), resulting in a problem of electrolyte leakage (L).

[0278] FIG. 32 is a cross-sectional view showing the movement of heat when a heat dissipation layer is attached to the outer surface of the base portion of a rivet fixing structure according to one embodiment of the present disclosure.

[0279] According to one embodiment, in a rivet fastening structure, a heat dissipation layer (500) may be attached to the outer surface of the base portion (210). In this structure, when external heat (Q) for welding is applied to the upper portion of the base portion (210), the heat (Q) may be distributed along the base portion (210) and to the surrounding area as well as to the gasket (310), which is another component therearound.

[0280] That is, when external heat (Q) for welding is applied to the upper portion of the base portion (210), the heat (Q) can pass through the heat dissipation layer (500) and be distributed downwards based on the heat dissipation layer (500). Accordingly, heat damage that may occur on the side of the gasket (310) can be reduced. In addition, since the possibility of the gasket (310) being deformed by the external heat (Q) is reduced, the sealing force between the gasket (310) and the case (100) can be maintained.

[0281] FIG. 33 is a cross-sectional view showing the movement of heat when a heat dissipation layer is attached to the outer and inner surfaces of the base portion of a rivet fixing structure according to one embodiment of the present disclosure.

[0282] According to one embodiment, a heat dissipation layer (500) may be attached to the outer and inner surfaces of the base portion (210). In this structure, when external heat (Q) for welding is applied to the upper portion of the base portion (210), the heat transmitted through the base portion (210) may be dispersed around it.

[0283] That is, when external heat (Q) for welding is applied to the upper portion of the base portion (210), the heat (Q) is primarily distributed to the surroundings due to the heat dissipation layer (500) attached to the inner surface of the base portion (210), and secondarily distributed to the surroundings due to the heat dissipation layer (500) attached to the outer surface of the base portion (210). Therefore, heat damage to the gasket (310) in contact with the outer surface of the base portion (210) can be prevented by the heat dissipation layer (500) attached to the outer and inner surfaces of the base portion (210).

[0284] FIG. 34 is a cross-sectional view showing the movement of heat when a heat dissipation layer is attached to the outer surface of the base portion of a rivet fixing structure according to one embodiment of the present disclosure and a heat insulating layer is attached to the inner surface.

[0285] According to one embodiment, a heat dissipation layer (500) may be attached to the outer surface of the base portion (210), and an insulation layer (600) may be attached to the inner surface of the base portion (210). In this structure, when external heat (Q) for welding is applied to the upper portion of the base portion (210), heat transmitted through the base portion (210) may be primarily blocked by the insulation layer (600) and secondarily dispersed by the heat dissipation layer (500).

[0286] For example, at least a portion of the external heat (Q) may not be transferred to the inner surface of the base portion (210) primarily due to the insulating layer (600) attached to the inner surface of the base portion (210). In addition, among the external heat (Q), the heat transferred to the inner surface of the base portion (210) may be secondarily dispersed to the surroundings due to the heat dissipation layer (500) attached to the outer surface of the base portion (210). Therefore, heat damage to the gasket (310) in contact with the outer surface of the base portion (210) may be prevented by the heat dissipation layer (500) attached to the outer surface of the base portion (210) and the insulation layer (600) attached to the inner surface of the base portion (210).

[0287] FIG. 35 is a flowchart showing a method for manufacturing a secondary battery according to one embodiment of the present disclosure.

[0288] Referring to FIG. 35, a method for manufacturing a secondary battery according to an embodiment of the present invention may include a step (S100) of arranging a gasket (310) to surround an area adjacent to a through hole (110) formed on a first side of a case (100), a step (S200) of sealing the through hole (110) by penetrating the through hole (110) while a heat dissipation layer (500) is interposed between the gasket (310) and the rivet part (200) using a rivet part (200), a step (S300) of inserting an electrode assembly through an opening formed on a second side of the case (100) located in an opposite direction to the first side, and a step (S400) of closing the opening with a vent plate.

[0289] In the step (S100) of placing the gasket (310), the gasket (310) may be placed between the rivet portion (200) and the through hole (110), and may be placed to surround the case (100) in the area adjacent to the through hole (110). For example, the gasket (310) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof. As another example, the gasket (310) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the gasket (310) is not limited to the materials listed above, and may include various materials with excellent plasticity and insulation properties depending on selection.

[0290] In the step (S200) of sealing the through hole (110) by penetrating the through hole (110) while interposing the heat dissipation layer (500) between the gasket (310) and the rivet portion (200), the heat dissipation layer (500) may be disposed between the outer surface of the rivet portion (200) and the side surface of the gasket (310). The heat dissipation layer (500) may extend to cover at least a portion of the side surface of the gasket (310) and may surround at least a portion of the outer surface of the base portion (210). In this case, the heat dissipation layer (500) may disperse heat, such as welding heat, generated when welding is performed to electrically connect the base portion (210) to the electrode plate or electrode tab of the electrode assembly accommodated inside the case (100), to the periphery of the gasket (310). The heat dissipation layer (500) may be extended to cover the entire side of the gasket (310) and may surround the entire outer surface of the base portion (210).

[0291] The heat dissipation layer (500) extends to cover at least a portion of the side surface of the gasket (310) so as to disperse heat transferred to the gasket (310) to the surroundings. The material of the heat dissipation layer (500) is not particularly limited as long as it is an appropriate material that allows heat to be dispersed to the surroundings while passing through the heat dissipation layer (500) when heat is transferred to the portion to which the heat dissipation layer (500) is attached. For example, the heat dissipation layer (500) may be implemented using a silicone heat dissipation sheet, a graphite heat dissipation sheet, or a combination of these materials.

[0292] The step (S200) of sealing the through hole (110) using the rivet part (200) may include a step of passing the rivet part (200) through the through hole (110) while arranging an insulating layer (600) on the inner surface of the rivet part (200). The insulating layer (600) may surround at least a portion of the inner surface of the base part (210). In this case, the insulating layer (600) may block heat from spreading to the outer surface of the base part (210) when heat such as welding heat is applied to the central portion of the base part (210). Through this, heat transferred to the gasket (310) through the outer surface of the base part (210) may be reduced. The insulating layer (600) may extend to cover the entire inner surface of the base part (210) and may surround the entire inner surface of the base part (210). The arrangement of the insulation layer (600) can be performed by attaching it to the inner surface of the base portion (210) using an adhesive or heat fusion. The material of the insulation layer (600) is not particularly limited as long as it is an appropriate material capable of blocking at least a portion of the heat transferred to the portion to which the insulation layer (600) is attached. For example, the insulation layer (600) can be implemented as a silica insulation sheet.

[0293] FIG. 36 is a cross-sectional view showing an example of a rivet fixing structure according to another embodiment of the present disclosure, showing a state before a notch is broken, and FIG. 37 is a cross-sectional view showing an example of a rivet fixing structure according to another embodiment of the present disclosure, showing a state after a notch is broken.

[0294] Referring to FIGS. 36 and 37, the rivet fixing structure may include a case (100) having a through hole (110) on a first side and an open second side located in an opposite direction to the first side, a rivet portion (200) disposed through the through hole (110), and a gasket (310) disposed between the rivet portion (200) and the through hole (110).

[0295] The case (100) may have a cylindrical shape including a through hole (110) on the first side and an open second side located opposite the first side. A vent cap plate (142) may be fastened to the open portion of the second side as illustrated in FIG. 1.

[0296] The rivet portion (200) may be positioned through the through hole (110). The rivet portion (200) may include a base portion (210) and a leg portion (220). The base portion (210) may be coupled to the case (100) by passing through the gasket (310). The leg portion (220) may be connected to the base portion (210) and may be in contact with one surface of the gasket (310) located inside the case (100). The leg portion (220) may be formed to extend radially from the lower end of the base portion (210).

[0297] The gasket (310) may be arranged between the rivet portion (200) and the through hole (110), and may be arranged to surround the case (100) in an area adjacent to the through hole (110). The gasket (310) may be made of an insulating material to electrically insulate the rivet portion (200) and the case (100). Here, the gasket (310) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0298] As another example, the gasket (310) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the gasket (310) is not limited to the materials listed above, and may include various materials with excellent plasticity and insulation properties depending on the selection.

[0299] The gasket (310) may include a ring-shaped main body (312) that contacts along the outer surface of the base portion (210), and a first extension portion (314) and a second extension portion (316) that extend from both ends of the main body portion (312), respectively. The first extension portion (314) may extend from one end of the main body portion (312) and protrude outward from the case (100). The second extension portion (316) may extend from the other end of the main body portion (312) and extend along the inner surface of the case (100).

[0300] In one embodiment, the first extension portion (314) may extend along the outer surface of the case (100). Accordingly, the first extension portion (314) may protrude a predetermined length from the through hole (110) formed in the case (100) at a portion where it contacts the outer surface of the case (100).

[0301] Additionally, at least a portion of the outer surface of the first extension portion (314) may be tapered so that the radius gradually decreases as it moves away from one end of the main body portion (312). Accordingly, at a portion where the first extension portion (314) contacts the main body portion (312), the radius of the outer surface of the first extension portion (314) may be larger than the radius of the through hole (110), but at an end of the first extension portion (314), the radius of the outer surface of the first extension portion (314) may correspond to the radius of the through hole (110). For example, the radius of the outer surface of the first extension portion (314) at the end of the first extension portion (314) may be smaller than or equal to the radius of the through hole (110).

[0302] In one embodiment, the leg portion (220) may include a plurality of notches (e.g., notches (221) of FIG. 19) configured to be broken by external pressure. The notches may be formed by recessing the outer surface along the longitudinal direction of the leg portion (220). The leg portion (220) may be configured to apply pressure to the entire area of ​​the gasket (310) that contacts the inner surface of the case (100) when the notches are broken by the external pressure. The leg portion (220) may apply pressure so that the gasket (310) is brought into closer contact with the inner surface of the case (100) when the notches are broken by the external pressure.

[0303] The gasket (310) can be inserted into the through hole (110). The gasket (310) can be inserted while contacting the inner surface of the through hole (110). The outer insulator (320) is connected to the upper portion of the gasket (310) and can contact at least a portion of the outer surface of the case (100) in the area adjacent to the through hole (110). The outer insulator (320) can be formed to be larger than the upper surface of the base portion (210) so as to electrically insulate the base portion (210) and the case (100). The inner insulator (330) is connected to the lower portion of the gasket (310) and can contact at least a portion of the inner surface of the case (100) in the area adjacent to the through hole (110).

[0304] In this configuration, the leg portion (220) can be in contact with the lower surface of the gasket (310) and at least a portion of the lower surface of the inner insulator (330). For example, when the notch is broken by external pressure, the leg portion (220) can be in contact with the entire lower surface of the gasket (310) and at least a portion of the lower surface of the inner insulator (330). When the notch of the leg portion (220) is broken by external pressure, the compressive force applied by the leg portion (220) to the edge of the gasket (310) that is in contact with the base portion (210) increases, thereby improving the sealing force of the gasket (310). Through this, it is possible to prevent a problem in which a gap is formed between the rivet portion (200) and the gasket (310) or a gap is formed between the gasket (310) and the through hole (110), thereby causing electrolyte to leak to the outside.

[0305] In another embodiment, the leg portion (220) may include a plurality of notches (e.g., the notches (221) of FIG. 19) configured to be elongated by external pressure. The plurality of notches formed in the leg portion (220) may be formed to be thinner than other portions of the leg portion (220) in adjacent areas and may be formed of an elongable metal material so as to be elongated when external pressure is applied. At this time, the leg portion (220) may be in contact with at least a portion of the lower surface of the gasket (310) and the lower surface of the inner insulator (330). When the notches are elongated by external pressure, the leg portion (220) may be in contact with the entire lower surface of the gasket (310) and at least a portion of the lower surface of the inner insulator (330). When the notch is extended by external pressure, the compressive force applied by the leg portion (220) to the edge of the gasket (310) that contacts the base portion (210) increases, thereby improving the sealing force of the gasket (310). Through this, it is possible to prevent a problem in which a gap occurs between the rivet portion (200) and the gasket (310) or a gap occurs between the gasket (310) and the through hole (110), thereby causing electrolyte to leak to the outside.

[0306] Although the present invention has been described above with reference to 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 idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. A case having a bottom part that is open on one side and has a through hole formed on the other side; A rivet portion positioned through the above through hole; and A gasket interposed between the above rivet portion and the above through hole Including, The gasket comprises a ring-shaped main body, a first extension extending from one end of the main body and extending along the outer surface of the bottom, and a second extension extending from the other end of the main body and extending along the inner surface of the bottom. Including, A rivet-fixed structure in which at least a portion of the outer surface of the first extension is tapered so that the radius gradually decreases as it moves away from one end of the main body.

2. In paragraph 1, The above first extension part is, A first surface extending in a direction parallel to the bottom portion so as to contact the outer surface of the bottom portion from one end of the main body portion; A second surface extending from the first surface in a direction perpendicular to the first surface; and A third surface extending from the second surface at an angle to the first surface A riveted fastening structure including:

3. In paragraph 2, A rivet fixing structure, wherein the length extended so that the first surface contacts the bottom portion is 0.05 to 0.2 mm.

4. In paragraph 2, A rivet fixing structure, wherein the length extended so that the first surface contacts the bottom portion is 10% to 40% of the thickness of the gasket.

5. In paragraph 2, A rivet fixing structure in which the angle formed by the first surface and the third surface is 20 degrees or more and 80 degrees or less.

6. In paragraph 1, The above first extension part is, A first surface extending in a direction parallel to the bottom portion so as to contact the outer surface of the bottom portion from one end of the main body portion; and A second surface extending from the first surface at an angle to form a predetermined angle with the first surface A riveted fastening structure including:

7. In paragraph 1, The above rivet part, A base portion inserted to pass through the above through hole; and A leg portion extending along the inner surface of the bottom of the case from the base portion A riveted fastening structure including:

8. In paragraph 7, The above leg portion includes a protrusion formed in a direction opposite to the inner surface of the bottom portion of the case, A rivet fixing structure in which the above protrusion is in close contact with the second extension of the above gasket.

9. In paragraph 1, The above rivet part, A base portion that penetrates the gasket and is joined to the case; and A rivet fixing structure comprising a leg portion connected to the base portion and in contact with one surface of the gasket located inside the case.

10. In paragraph 9, The above leg part, A riveting structure comprising a plurality of notches configured to be ruptured by external pressure.

11. In paragraph 10, The above leg part, A rivet fastening structure configured to apply pressure to the entire area of ​​the gasket in contact with the inner surface of the case when the notch is ruptured by external pressure.

12. In paragraph 9, The above leg part, A rivet fixing structure extending from a reference line where the side surface of the base portion and the side surface of the gasket meet in the radial direction of the case by 3.0 mm to 3.5 mm.

13. In paragraph 9, An external insulator connected to the upper portion of the gasket and in contact with at least a portion of the outer surface of the case in an area adjacent to the through hole; and A rivet fastening structure further comprising an internal insulator connected to the lower portion of the gasket and contacting at least a portion of the inner surface of the case in an area adjacent to the through hole.

14. In paragraph 13, The above leg part, A rivet fixing structure that contacts the lower surface of the above gasket and at least a portion of the lower surface of the above inner insulator.

15. In paragraph 9, The above leg part, A rivet fastening structure comprising a plurality of notches configured to be elongated by external pressure.

16. In paragraph 1, A rivet fixing structure further comprising a heat dissipation layer disposed between the outer surface of the rivet portion and the side surface of the gasket.

17. In paragraph 16, The above rivet part, It includes a base portion that penetrates the gasket and is coupled to the case, A rivet fixing structure further comprising an electrode terminal coupled to one end of the base portion and extending radially from one end of the base portion and contacting at least a portion of the upper surface of the gasket exposed to the outside of the case.

18. In paragraph 17, The above heat dissipation layer is, A rivet fastening structure extending to cover at least a portion of the gasket side and surrounding at least a portion of the outer surface of the base portion.

19. In paragraph 17, The above heat dissipation layer is, A rivet fixing structure comprising a plurality of heat dissipation pads arranged at a plurality of positions between the outer surface of the base portion and the side surface of the gasket.

20. In paragraph 17, A rivet fastening structure further comprising an insulating layer surrounding the inner surface of the base portion.

Images