Cap gasket of cylindrical secondary battery, and cylindrical secondary battery using same

Abstract

Provided are: a cap gasket for maintaining sealing power without being excessively deformed even if crimping is performed; and a battery cell using same. The cap gasket includes a first gasket, and a second gasket fastened to the axial outer side of the first gasket. The first gasket includes a first radial extension portion, an axial extension portion extending axially outward from the radial outer end portion thereof, and at least one first fastening portion provided at the axial outer end portion thereof. The second gasket includes a second radial extension portion, and at least one second fastening portion which is provided on the axial inner side of the radial outer end portion thereof and is fastened to the first fastening portion in the axial direction. The first fastening portion and the second fastening portion include a first catching portion and a second catching portion fastened to each other, respectively, in the radial direction.

Description

Cap gasket for cylindrical secondary batteries and cylindrical secondary batteries using the same

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0165808, dated November 24, 2023, and Korean Patent Application No. 10-2024-0139346, dated October 14, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a cap gasket for a cylindrical secondary battery and a cylindrical secondary battery using the same, and more particularly, to a cap gasket that can maintain sealing force without being excessively deformed even when crimping is performed, and to a cylindrical secondary battery using the same.

[0003] The process of manufacturing a battery cell using a cylindrical can includes the steps of deep drawing a metal sheet to form a circular bottom portion and a circular tubular side wall member connected thereto, accommodating an electrode assembly therein, and then closing the open end of the side wall member with a cap.

[0004] A representative method of finishing the open end of the above side wall member by covering it with a cap is to form a beading portion on the side wall member, interpose a cap gasket on the axial outer surface of the beading portion, and form a crimping portion that compresses the edge of the cap.

[0005] Referring to FIG. 1, a conventional cap gasket (17) has an inner radial extension portion (172) arranged axially inward, an axial extension portion (173) extending axially outward from the inner radial extension portion (172), and a deformable sealing portion (179) that further extends axially from an axially outer end of the axial extension portion (173) and is bent radially inward by a crimping portion.

[0006] The edge of the cap (16) is positioned so as to be in contact with the inner radial extension (172) and the axial extension (173), and the cap gasket (17) and the cap (16) are inserted into the beading portion (116) provided at the open end of the can, and the edge of the can is crimped radially inward to form a crimping portion (117).

[0007] Then, as shown in FIG. 2, the inner surface of the cap gasket (17) is pressed against the axial outer surface provided on the axial outer side of the edge of the cap (16), the radial outer surface provided on the radial outer side, and the axial inner surface provided on the axial inner side, and the outer surface of the cap gasket (17) is pressed against the axial inner surface of the crimping portion (117) and the axial outer surface of the beading portion (116), so that the open end of the can is sealed.

[0008] However, in the conventional cap gasket (17), when the deformation sealing portion (179) is bent radially inward by crimping, due to its structure, the radially inner end (A) of the boundary portion between the axial extension portion (173) and the deformation sealing portion (179) is greatly compressed as it comes into contact with the corner portion of the radial outer surface and the axial outer surface provided at the upper end of the edge of the cap (16), and the outer periphery (B) of the deformation sealing portion (179) adjacent to the boundary portion between the axial extension portion (173) and the deformation sealing portion (179) cannot help but be greatly stretched in the axial direction.

[0009] If the inner end (A) is bent to an extreme degree in this way, as shown in Fig. 2, a phenomenon may occur in which the upper corner of the edge of the cap (16) and the cap gasket (17) do not come into close contact and float.

[0010] In addition, during the process of plastic processing of the crimping portion (117) of the can, there is a risk that the upper edge of the edge of the cap (16) may strongly scratch the inner wall of the cap gasket (17), causing the coating material applied to the cap gasket (17) for sealing to peel off, thereby weakening the sealing force.

[0011] In addition, if the outer circumference (B) of the deformation sealing portion (179) is excessively stretched in the direction of the arrow shown in FIG. 2, a shape in which the outer circumference of the cap gasket (17) is not in close contact with the inner circumference of the crimping portion (117) and floats may occur, as shown in FIG. 2.

[0012] Damaged areas of the coating material, gaps between the cap gasket (17) and the cap (16), or gaps between the cap gasket (17) and the can may become leakage paths for the electrolyte.

[0013] The present invention has been devised to solve the above-described problem, and provides a cap gasket structure capable of preventing the coating material of the cap gasket from being scratched by the cap during the process of crimping the open end of the side wall member of the can to seal the open end of the can with the cap, and a cylindrical secondary battery structure using the same.

[0014] In addition, the present invention aims to provide a cap gasket structure capable of preventing the cap gasket from being lifted from the surface of a cap or can due to excessive tension or compression applied to the cap gasket during a crimping process, and a cylindrical secondary battery structure using the same.

[0015] The technical objectives of the present invention are not limited to the purposes mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0016] The present invention can be applied to a battery cell including an electrode assembly and a housing that accommodates the electrode assembly.

[0017] The above electrode assembly may be in the form of a jelly-roll in which the first electrode and the second electrode are wound in layers around a predetermined core axis with a separator interposed therebetween.

[0018] The current collector of the first electrode may protrude axially outwardly so that its surface is exposed. The current collector of the second electrode may protrude axially outwardly so that its surface is exposed.

[0019] The current collector of the first electrode and the current collector of the second electrode may protrude axially outward from the first and second axial ends, respectively.

[0020] The portion of the above-mentioned collector exposed to the outside at the axial end of the electrode assembly can constitute an electrode tab of the electrode.

[0021] The above electrode tabs can be bent radially. Preferably, the electrode tabs can be bent radially inward and covered axially.

[0022] The electrode tab of the first electrode may be electrically connected to a first electrode terminal provided in the housing, and the electrode tab of the second electrode may be electrically connected to a second electrode terminal provided in the housing.

[0023] The electrode tab of the first electrode is connected to a first collector plate, and the first collector plate can be connected to the first electrode terminal. The first collector plate can electrically connect the first electrode and the first electrode terminal.

[0024] The electrode tab of the second electrode is bonded to a second collector plate, and the second collector plate can be electrically connected to the second electrode terminal. The second collector plate can electrically connect the second electrode and the second electrode terminal.

[0025] The above housing may be a can made of metal.

[0026] The above housing may be cylindrical.

[0027] The can may include a side wall member extending in the axial direction and surrounding an axially extending internal space, and an open end provided at one axial end of the side wall member.

[0028] The above battery cell may include a cap covering the open end.

[0029] A floor member is connected to the other axial end of the side wall member, and thus the other axial end of the side wall member can form a closed end.

[0030] The first electrode terminal may be installed on the above-mentioned floor member with a gasket interposed therebetween. The gasket may seal a gap between the first electrode terminal and the floor member and electrically insulate the first electrode terminal from the floor member.

[0031] The above second electrode terminal may be formed by the above floor member.

[0032] The cap can be fixed to the side wall member of the can by being pressed by a beading portion and a crimping portion formed at the open end of the can at the edge thereof.

[0033] A cap gasket may be interposed between the edge of the cap and the side wall member.

[0034] The edge of the cap is pressed by the beading portion and the crimping portion while the cap gasket is interposed, thereby sealing the connection portion between the cap and the can.

[0035] To solve the above-described problem, the present invention provides a loop-shaped cap gasket including a first gasket and a second gasket connected to the first gasket on an axial outer side of the first gasket.

[0036] The above loop shape may be a ring shape.

[0037] The above loop shape may be a closed loop.

[0038] The first gasket includes a first radial extension portion extending radially, and an axial extension portion extending axially outward from a radial outer end of the first radial extension portion.

[0039] The second gasket includes a second radial extension portion extending in a radial direction.

[0040] The second gasket is axially laminated to the first gasket on the axial outer side of the first gasket.

[0041] The above first gasket includes a first fastening portion provided at an axial outer end of the axial extension portion. One or two or more first fastening portions may be provided.

[0042] The second gasket includes a second fastening portion provided on the axial inner side of the radially outer end of the second radially extended portion and axially fastened to the first fastening portion. One or two or more second fastening portions may be provided. Two or more first fastening portions and two or more second fastening portions may be axially fastened to each other.

[0043] Accordingly, when the cap gasket is compressed and deformed by forming the crimping portion of the can, the direction in which the cap gasket is deformed corresponds to the direction in which the sealing force should be applied between the cap gasket and the can and the direction in which the sealing force should be applied between the cap gasket and the cap. Therefore, by minimizing the deformation of the cap gasket unrelated to the sealing force, the sealing performance of the gap gasket can be further enhanced.

[0044] In one example, the first fastening portion and the second fastening portion fastened thereto may be radially spaced apart from the radially inner and outer ends of the axially extended portion. At least one pair of the first fastening portion and the second fastening portion may be radially spaced apart from the radially inner and outer ends of the axially extended portion in the radial direction.

[0045] In one example, the first fastening portion and the second fastening portion connected thereto may be arranged at positions corresponding to the radially inner end of the axially extending portion in the radial direction. At least one pair of the first fastening portion and the second fastening portion may be arranged at positions corresponding to the radially inner end of the axially extending portion in the radial direction.

[0046] In one example, the first fastening portion and the second fastening portion connected thereto may be arranged at positions corresponding to the radially outer ends of the axially extended portions in the radial direction. At least one pair of the first fastening portion and the second fastening portion may be arranged at positions corresponding to the radially outer ends of the axially extended portions in the radial direction.

[0047] In one example, the first fastening portion and the second fastening portion connected thereto may extend along the circumferential direction of the first gasket and the second gasket, respectively.

[0048] Preferably, the pair of first and second fastening portions may each have a loop shape. The loop shape may be a closed loop.

[0049] Preferably, the plurality of first fastening portions may be arranged along a radial direction, and the plurality of second fastening portions may be arranged along a radial direction to correspond to the plurality of first fastening portions.

[0050] Preferably, at least two first fastening portions are arranged to be radially connected, and at least two second fastening portions corresponding to the at least two first fastening portions may also be arranged to be radially connected.

[0051] In one example, one of the first fastening portion and the second fastening portion and the other may each have an axially sunken fastening groove and a fastening projection extending axially to be inserted axially into the fastening groove.

[0052] For example, the first fastening portion may include a fastening groove that is recessed axially inward from the axial outer surface of the axial extension portion, and the second fastening portion may include a fastening projection that protrudes axially inward from the radial outer end of the second radial extension portion.

[0053] For example, the first fastening portion may include a fastening projection protruding axially outward from the axial outer surface of the axially extended portion, and the second fastening portion may include a fastening groove recessed axially outward from the axial inner surface of the radially outer end of the second radially extended portion.

[0054] One and the other of the plurality of first fastening portions may each have a fastening groove and a fastening projection, and the second fastening portions corresponding to one and the other of the plurality of second fastening portions may each have a fastening projection and a fastening groove.

[0055] Preferably, the first fastening portion and the other first fastening portion may be arranged to be radially connected, and the second fastening portions corresponding to the first fastening portion and the other first fastening portion may be arranged to be radially connected.

[0056] Accordingly, the inward bend formed during the crimping process applies pressure axially inwardly to the second radial extension portion of the second gasket, thereby receiving an insertion force that causes the fastening projection to be more strongly inserted axially into the fastening groove, thereby securing a higher fastening force. Accordingly, the second gasket can be more reliably prevented from being pushed radially inward by the inward bend formed during the crimping process.

[0057] In one example, the fastening projection may have a hook protruding radially from an extended end of the fastening projection, and the fastening groove corresponding to the fastening projection may have a hook groove sunken radially from a sunken end of the fastening groove so as to receive the hook in the radial direction.

[0058] Preferably, the hook may be provided on one side of the radially inner and outer sides of the fastening projection or on both sides, and the hook groove may be provided on one side of the radially inner and outer sides of the fastening groove or on both sides to correspond to the hook.

[0059] Accordingly, even before crimping processing, the first gasket and the second gasket are more firmly restrained in the axial direction by the hook groove and the hook hook structure, so that the first gasket and the second gasket can be temporarily integrated.

[0060] In one example, the radial inner surface of the axial extension portion of the first gasket may have a radial first inner surface radially facing the radial outer surface of the cap, and the axial inner surface of the second radial extension portion of the second gasket may have an axial first inner surface axially facing the edge of the axial outer surface of the cap facing the axial outer surface.

[0061] Preferably, the radial inner surface of the axial extension of the first gasket may further include a radial second inner surface that extends further axially outward than the radial outer surface of the cap.

[0062] Accordingly, since the first gasket can protrude axially further outward than the axial outer surface of the cap, the phenomenon of the second gasket being pushed radially inward by the protruding portion of the first gasket during the crimping process can be prevented.

[0063] Preferably, the axial inner surface of the second radial extension of the second gasket may further include an axial second inner surface that extends further axially outward than the radial outer surface of the cap.

[0064] Accordingly, since the cap gasket area corresponding to the corner portion of the radial outer surface and the axial outer surface of the cap can be prevented from being excessively folded and compressed during the crimping process, the phenomenon of the sealing force of the cap gasket being reduced can be prevented.

[0065] In one example, the second corner provided on the axial outer side of the radially outer end of the second radially extended portion may be rounded.

[0066] Accordingly, the second corner can be prevented from being excessively deformed or deformed in an unintended direction by the inward bending portion. In addition, the axial compression force and the radial compression force generated by the inward bending portion can be evenly applied to the second corner portion, so that the compression force by the inward bending portion can be fully applied to increase the fastening force of the first gasket and the second gasket and to improve the sealing force of the cap gasket.

[0067] In one example, the first corner provided on the axial inner side of the radially outer end of the first radially extended portion may be rounded.

[0068] Accordingly, when placing the first gasket on the axial outer surface of the beading portion, the outer surface of the first gasket can be naturally brought into close contact with the inner wall of the can.

[0069] Preferably, by setting the round radiation of the second corner to be smaller than the round radiation of the first corner, the compression force of the second corner portion and the fastening force of the first gasket and the second gasket can be stably secured.

[0070] In addition, in order to solve the above-described problem, the present invention provides a battery cell to which the above-described cap gasket is applied.

[0071] The above battery cell may be a cylindrical secondary battery.

[0072] The above battery cell has a can having a side wall member having an open end.

[0073] Near the open end of the above side wall member, a beading portion is provided by processing the side wall member in a radial inward direction.

[0074] The above side wall member further includes a crimping portion that is formed by bending an end of the side wall member radially inward from an axial outer side of the beading portion.

[0075] The above battery cell has a cap that seals the open end.

[0076] The edge of the cap is positioned axially between the beading portion and the crimping portion, and is pressed and fixed by the beading portion and the crimping portion.

[0077] The edge of the cap is press-sealed by the beading portion and the crimping portion while the cap gasket is interposed.

[0078] The above first gasket is arranged on the axial outer surface of the beading portion.

[0079] The axial inner surface of the second radial extension portion is in axial contact with the axial outer surface of the axial extension portion, and the second fastening portion of the second gasket is axially fastened to the first fastening portion of the first gasket.

[0080] The edge of the cap is in contact with the axial outer surface of the first radial extension portion of the first gasket, the radial inner surface of the axial extension portion, and the axial inner surface of the second radial extension portion of the second gasket.

[0081] Preferably, the axial outer corner of the edge of the cap may be aligned with the radial inner corner of the axial extension of the first gasket and the contact portion of the second radial extension of the second gasket.

[0082] Accordingly, the phenomenon of the edge portion of the cap scratching the cap gasket can be prevented and suppressed.

[0083] Preferably, the inwardly bent portion of the crimping portion may be positioned axially outside the joint surface of the first gasket and the second gasket.

[0084] Preferably, the inwardly bent portion of the crimping portion may be positioned radially outward from the cap.

[0085] Accordingly, the axial compression force and the radial compression force generated by the inward bending portion are evenly applied to the second corner portion, so that the compression force by the inward bending portion can be fully applied to increase the fastening force of the first gasket and the second gasket and to improve the sealing force of the cap gasket.

[0086] According to the present invention, in order to prevent excessive deformation of the cap gasket during the process of crimping the open end of the side wall member of the can to seal the open end of the can with the cap, the cap gasket is provided with a first radial extension portion, an axial extension portion, and a second radial extension portion. Accordingly, the phenomenon of the cap gasket being excessively compressed or excessively stretched at a specific point by the crimping process can be prevented, and thus the phenomenon of the cap gasket being lifted from the surface of the cap or the can can can be prevented.

[0087] According to the present invention, the cap gasket is manufactured by dividing it into a first gasket and a second gasket, and the second gasket is provided with a second radial extension, thereby facilitating the assembly process of the cap.

[0088] According to the present invention, since the axial outer corner of the edge of the cap is aligned with the radial inner corner of the axial extension of the first gasket and the contact portion of the second radial extension of the second gasket, the portion of the cap gasket that comes into contact with the corner portion of the cap does not move relative to the corner portion during the crimping process. Accordingly, the phenomenon of the coating material of the cap gasket being scratched by the cap can be prevented.

[0089] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0090] Fig. 1 is a partial cross-sectional perspective view of a conventional cap gasket.

[0091] Fig. 2 is a cross-sectional photograph showing a state in which the cap is sealed and fixed with a beading portion and a crimping portion by applying the cap gasket of Fig. 1.

[0092] Figure 3 is an exploded perspective view of a cap gasket of the first embodiment according to the present invention.

[0093] Figure 4 is a side cross-sectional view of the cap gasket of Figure 3.

[0094] Fig. 5 is a side cross-sectional view showing the cap gasket and cap of Fig. 3 placed on the open end of the can.

[0095] Figure 6 is an enlarged view of the box portion of Figure 5.

[0096] Figure 7 shows the can of Figure 6 in a crimped state.

[0097] Figure 8 is an enlarged cross-sectional view of the cap gasket of the second embodiment.

[0098] Figure 9 is an enlarged cross-sectional view of the cap gasket of the third embodiment.

[0099] Fig. 10 is an enlarged drawing of the fastening portion during the fastening process of the cap gasket of Fig. 9.

[0100] Fig. 11 is an enlarged cross-sectional view of the cap gasket of the fourth embodiment.

[0101] Fig. 12 is an enlarged drawing of the fastening portion during the fastening process of the cap gasket of Fig. 11.

[0102] Fig. 13 is an enlarged cross-sectional view of the cap gasket of the fifth embodiment.

[0103] Fig. 14 is an enlarged drawing of the fastening portion during the fastening process of the cap gasket of Fig. 13.

[0104] Fig. 15 is an enlarged cross-sectional view of the cap gasket of the sixth embodiment.

[0105] Fig. 16 is an enlarged drawing of the fastening portion during the fastening process of the cap gasket of Fig. 15.

[0106] Fig. 17 is an enlarged cross-sectional view of the cap gasket of the seventh embodiment.

[0107] Fig. 18 is an enlarged drawing of the fastening portion during the fastening process of the cap gasket of Fig. 17.

[0108] Fig. 19 is an enlarged cross-sectional view of the cap gasket of the eighth embodiment.

[0109] Fig. 20 is an enlarged drawing of the fastening portion during the fastening process of the cap gasket of Fig. 19.

[0110] Fig. 21 is an enlarged cross-sectional view of the cap gasket of the ninth embodiment.

[0111] Fig. 22 is an enlarged drawing of the fastening portion during the fastening process of the cap gasket of Fig. 21.

[0112] Fig. 23 is a side cross-sectional view of a battery cell to which the cap gasket of the first embodiment is applied.

[0113] [Explanation of symbols]

[0114] 10: Can (housing) 11: Side wall member 116: Beading portion 1161: Axial outer surface 117: Crimping portion 1171: Inward bend portion 12: Bottom member 13: First electrode terminal (positive terminal) 14: Gasket 15: Second electrode terminal 16: Cap 161: Radial outer surface 162: Axial inner surface 163: Axial outer surface 17: Cap gasket 171: First gasket (inner gasket) 172: First radial extension (inner radial extension) 1722: Axial outer surface C1: First corner 173: Axial extension 1730: Radial inner surface 1731: First radial inner surface 1732: Second radial inner surface 174: First fastening part (fastening groove, fastening projection) 1741: First catch part (hook groove, hook) 175: Second gasket (outer gasket) 176: Second radial extension part (outer radial extension part) 1760: Axial inner surface 1761: Axial first inner surface 1762: Axial second inner surface C2: Second corner 177: Second fastening part (fastening projection, fastening groove) 1771: Second catch part (hook, hook groove) 178: Fastening guide part 179: Deformable sealing part 19: Insulator 20: Electrode assembly 21: First electrode 22: Second electrode 27: Electrode tab 29: Core hollow part 31: First collector plate (positive collector plate) 32: Second collector plate (negative collector plate)

[0115] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0116] 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.

[0117] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0118] Hereinafter, the phrase "any configuration is placed on (or below)" a component or "on (or below)" a component may mean that any configuration is placed in contact with the upper surface (or lower surface) of said component, and that other configurations may be interposed between said component and any configuration placed on (or below) said component.

[0119] Additionally, when it is described that a component is "connected," "coupled," or "in contact with" another component, it should be understood that the components may be directly connected or in contact with each other, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "in contact with" another component.

[0120] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0121] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C to D", this means C or more and D or less, unless otherwise stated.

[0122] In describing the embodiment, the axial direction refers to the direction in which the axis forming the winding center of the jelly-roll type electrode assembly extends, the radial direction refers to the direction approaching (centripetal) or moving away (centrifugal) from the axis, and the circumferential direction refers to the direction surrounding the axis.

[0123] The battery cell to which the cap gasket (17) of the embodiment is applied may be, for example, a cylindrical battery cell having a form factor ratio (defined as the ratio of the diameter (Φ) to the height (H) of the cylindrical battery cell divided by the height) of approximately 0.4 or greater.

[0124] Here, the form factor refers to a value indicating the diameter and height of a cylindrical battery cell. The cylindrical battery cell may be, for example, a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell. In the numerical value indicating the form factor, the first two numbers indicate the diameter of the cell, the next two numbers indicate the height of the cell, and the last number 0 indicates that the cross-section of the cell is circular.

[0125] The above battery cell may be a cylindrical battery cell having a roughly cylindrical shape, a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0126] According to another embodiment, a battery cell may be a cylindrical battery cell having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0127] According to another embodiment, a battery cell may be a cylindrical battery cell having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0128] According to another embodiment, a battery cell may be a cylindrical battery cell having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0129] According to another embodiment, a battery cell may be a cylindrical battery cell having a generally cylindrical shape, a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0130] The present invention can of course also be applied to battery cells having a form factor ratio of approximately 0.4 or less, such as 18650 cells, 21700 cells, etc. For 18650 cells, the diameter is approximately 18 mm, the height is approximately 65 mm, and the form factor ratio is 0.277. For 21700 cells, the diameter is approximately 21 mm, the height is approximately 70 mm, and the form factor ratio is 0.300.

[0131] [Cap gasket]

[0132] <First Embodiment>

[0133] Referring to FIGS. 3 to 6, the cap gasket (17) of the first embodiment includes a first gasket (171) and a second gasket (175) connected to the first gasket (171) on the axial outer side of the first gasket.

[0134] The above second gasket (175) is manufactured in a pre-deformed form in a part where excessive deformation occurs when forming a crimping portion.

[0135] It is preferable that the above second gasket (175) be manufactured separately for the convenience of the assembly process of the cap and cap gasket.

[0136] The first gasket (171) includes a first radial extension portion (172) extending radially. The first radial extension portion (172) may include a portion interposed between the beading portion (116) of the can (10) and the inner surface of the shaft of the cap (16).

[0137] The first gasket (171) includes an axial extension portion (173) that extends axially outward from a radially outer end of the first radially extended portion (172). The axial extension portion (173) may include a portion interposed between a portion of the side wall member (11) positioned between the beading portion (116) and the crimping portion (117) of the can (10) and the radially outer surface (161) of the cap (16).

[0138] The second gasket (175) includes a second radial extension portion (176) extending radially. The second radial extension portion (176) may include a portion interposed between the crimping portion (117) of the can (10) and the axial outer surface of the cap (16).

[0139] The radial outer end of the second radial extension portion (176) is in contact with or connected to the axial outer end of the axial extension portion (173).

[0140] For the convenience of assembly, the first gasket (171) and the second gasket (175) are manufactured separately, and in order to firmly connect them, a first fastening portion (174) is provided on the axial outer surface of the axial extension portion (173) of the first gasket (171), and a second fastening portion (177) is provided on the axial inner side of the radial outer end of the second radial extension portion (176) of the second gasket (175).

[0141] The cap gasket (17) of the first embodiment is implemented in a form having one first fastening part (174) and one second fastening part (177).

[0142] The first fastening portion (174) and the second fastening portion (177) fastened thereto are arranged radially spaced apart from the two ends between the radially inner and outer ends of the axial extension portion (173).

[0143] The first fastening portion (174) and the second fastening portion (177) are fastened to each other in the axial direction.

[0144] Accordingly, the first fastening portion (174) and the second fastening portion (177) restrict the second gasket (175) from moving radially relative to the first gasket (171).

[0145] In the first embodiment, the first fastening portion (174) includes a fastening groove that is recessed axially inward from the axial outer surface of the axial extension portion (173). And the second fastening portion (177) includes a fastening projection that protrudes axially inward from the radially outer end of the second radial extension portion (176).

[0146] The first embodiment exemplifies a closed loop shape in which the fastening projection of the second fastening portion (177) and the fastening groove of the first fastening portion (174) are continuously formed along the circumferential direction.

[0147] The first corner (C1) provided on the axial inner side of the radially outer end of the first radially extended portion (172) is rounded. Then, when the first gasket (171) is placed on the beading portion (116) as illustrated in FIG. 6, the outer surface of the first gasket (171) and the inner surface of the beading portion (116) are in full contact, so that the first gasket (171) can be placed in the correct position.

[0148] Referring to FIGS. 5 to 7, the sealing structure of the can (10) using the cap gasket (17) is described.

[0149] The above cap gasket (17) is interposed between the cap (16) and the can (10) when sealing the open end of the battery can (10).

[0150] The above can (10) has a hollow cylindrical side wall member (11).

[0151] Near the open end of the side wall member (11), a beading portion (116) is provided in which the side wall member (11) is processed to be radially inward. Accordingly, on the radially inward side of the side wall member (11), the beading portion (116) has an axial outer surface (1161).

[0152] The above first gasket (171) is inserted so as to be placed on the axial outer surface (1161) of the beading portion (116).

[0153] The first corner (C1) of the first gasket (171) is rounded, so that it has a shape that corresponds to a curved shape of the connection portion between the side wall member (11) and the beading portion (116) to some extent. Accordingly, the first radial extension portion (172) can axially face and contact the axial outer surface (1161), and the axial extension portion (173) can radially face and contact the inner surface of the side wall member (11).

[0154] The edge of the cap (16) is placed on the first gasket (171) placed on the axial outer surface (1161) of the beading portion (116) within the side wall member (11). As the cap (16) is placed, the bottom surface of the cap (16) comes into contact with the axial outer surface of the first radial extension portion (172), and the outer peripheral surface of the cap (16) comes into contact with the inner peripheral surface of the axial extension portion (173). Accordingly, the position of the cap (16) relative to the first gasket (171) is possible.

[0155] The upper surface of the edge of the cap (16), i.e., the axial outer surface, and the upper surface of the axial extension (173) of the first gasket (171), i.e., the axial outer surface, can form a roughly flat surface.

[0156] The second gasket (175) is placed on the upper surface of the edge of the cap (16) and the upper surface of the axial extension portion (173) of the first gasket (171). Accordingly, the lower surface of the second radial extension portion (176) of the second gasket (175), i.e., the axial first inner surface provided on the radially inner portion of the axial inner surface, is in contact with the cap (16), and the axial second inner surface provided on the radially outer portion is in contact with the first gasket (171).

[0157] In addition, the axial outer corner of the edge of the cap (16), i.e., the corner of the radial outer surface and the side outer surface of the cap (16), is aligned with the radial inner corner of the axial extension (173) of the first gasket (171) and the contact portion of the second radial extension (176) of the second gasket (175) (see part A of FIG. 7).

[0158] According to the first embodiment, the radial inner surface of the axial extension portion (173) of the first gasket (171) has a radial first inner surface radially facing the radial outer surface of the cap (16), and the axial inner surface of the second radial extension portion (176) of the second gasket (175) has an axial first inner surface axially facing the edge of the axial outer surface of the cap (16) facing the axial outer surface, and an axial second inner surface extending axially further outward than the radial outer surface of the cap (16).

[0159] The second fastening portion (177) of the second gasket (175) and the first fastening portion (174) of the first gasket (171) are inserted and fastened in the axial direction. Accordingly, the positional alignment of the second gasket (175) with respect to the first gasket (171) and the cap (16) is possible, and in particular, the radial movement of the second gasket (175) with respect to the first gasket (171) and the cap (16) is restricted.

[0160] In this way, before forming the crimping portion (117), the second radial extension portion (176) of the cap gasket (17) is already bent radially inward and is in contact with the edge surface of the cap (16), i.e., the outer surface of the shaft (see Fig. 6).

[0161] Next, the end of the side wall member (11) on the axial outer side than the beading portion (116) is bent radially inwardly to form a crimping portion (117) as shown in Fig. 7. The crimping portion (117) is formed by plastically working the open end section of the side wall member (11) on the axial outer side than the edge of the cap (16) in the radial inward direction.

[0162] The crimping portion (117) is a plastically processed portion bent radially inward by the inwardly bent portion (1171) of the side wall member (11), and the inwardly bent portion (1171) and the crimping portion (117) axially press the first radially extended portion (172) and the second radially extended portion (176). The curved portion of the boundary between the beading portion (116) and the side wall member (11) presses the first radially extended portion (172) in the axially outward and radially inward directions, and the curved portion of the inwardly bent portion (1171) indicated by B in FIG. 7 presses the second radially extended portion (176) in the axially inward and radially inward directions.

[0163] Accordingly, the axial extension portion (173) of the cap gasket (17) is compressed in the radial direction, and the first radial extension portion and the second radial extension portion of the cap gasket (17) are compressed in the axial direction.

[0164] According to the first embodiment described above, the inwardly bent portion (1171) formed during the crimping process also presses the second radially extended portion (176) of the second gasket (175) located at the rear of the fastening projection of the second fastening portion (177) in the axial direction inward. Accordingly, the fastening projection of the second fastening portion (177) receives an insertion force that more strongly inserts it into the fastening groove of the first fastening portion (174) in the axial direction. Accordingly, the radial position of the second gasket (175) by the fastening structure can be more strongly regulated.

[0165] And even when pressure is applied radially inward to the second gasket (175) by the inward bending portion (1171), the radially outer lower portion of the second gasket (175) is clearly restricted from radially moving by the fastening structure.

[0166] <Second Embodiment>

[0167] In Fig. 8, a second embodiment is disclosed in which a portion of the cap gasket (17) of the first embodiment described above is modified, and a structure is disclosed in which the second corner (C2) provided on the axial outer side of the radial outer end of the second radial extension portion (176) is also rounded.

[0168] Preferably, the round radiation of the second corner (C2) can be set smaller than the round radiation of the first corner (C1).

[0169] According to the second embodiment, the second corner (C2) portion of the second gasket (175) is evenly compressed by the inwardly bent portion (1171) and strongly contacts the inwardly bent portion (1171). Accordingly, the second corner (C2) is not excessively deformed or deformed in an unintended direction by the inwardly bent portion (1171), and the axial compression force and the radial compression force generated by the inwardly bent portion (1171) are evenly applied to the second corner (C2) portion. Then, the compression force by the inwardly bent portion (1171) increases the fastening force between the first gasket (171) and the second gasket (175) and further improves the sealing force of the cap gasket (17).

[0170] <Third Embodiment>

[0171] In FIG. 9 and FIG. 10, a third embodiment of the cap gasket (17) of the first embodiment described above is disclosed, in which the fastening projection of the second fastening portion (177) is provided with a hook, which is a second engaging portion (1771) that protrudes radially from its extended end, and the fastening groove, which is the first fastening portion (174), is provided with a hook groove, which is a first engaging portion (1741) that is sunken in the radial direction from its sunken end.

[0172] The hook of the second hooking portion (1771) is provided on the radial outer side of the fastening projection of the second fastening portion (177), and the hook groove of the first hooking portion (1741) is provided on the radial outer side of the fastening groove of the first fastening portion (174) so ​​as to correspond to the hook of the second hooking portion (1771).

[0173] Referring to Fig. 10, first, a cap (16) is fitted to a first gasket (171). Accordingly, the axial outer surface (1722) of the first radial extension portion (172) of the first gasket (171) comes into contact with the axial inner surface (162) of the cap (16), and the radial first inner surface (1731) of the axial extension portion (173) of the first gasket (171) comes into contact with the radial outer surface (161) of the cap (16).

[0174] The axial inner surface (1760) of the second gasket (175) includes an axial first inner surface (1761) that contacts the axial outer surface (163) of the cap (16), and an axial second inner surface (1762) that extends radially further outward than the cap (16).

[0175] The fastening groove of the first fastening portion (174) of the first gasket (171) is spaced radially inward from the radially outer end of the axial extension portion (173). As illustrated in FIG. 10, a portion of the axial extension portion (173) that is radially inward from the fastening groove of the first fastening portion (174) is supported radially outward by the cap (16), whereas a portion of the axial extension portion (173) that is radially outward from the fastening groove of the first fastening portion (174) is not supported by a member.

[0176] Accordingly, while temporarily assembling the cap gasket (17) and the cap (16) by axially inserting the fastening projection of the second fastening portion (177) of the second gasket (175) into the fastening groove of the first fastening portion (174) of the first gasket (171), when the hook of the second catch portion (1771) presses a portion radially outward from the fastening groove of the first fastening portion (174) in the axial extension portion (173), the portion is easily elastically deformed, and the hook of the second catch portion (1771) can be easily inserted into the hook groove of the first catch portion (1741).

[0177] A fastening guide portion (178) is provided in the fastening projection of the second fastening portion (177) and the fastening groove of the first fastening portion (174) to ensure mutual alignment during the insertion process. The fastening guide portion (178) may be a chamfer shape provided near the extended end of the fastening projection of the second fastening portion (177) and / or the entrance of the fastening groove of the first fastening portion (174).

[0178] After the hook of the second catch (1771) is inserted into the hook groove of the first catch (1741), the second gasket (175) and the first gasket (171) are fastened together so that they do not move apart from each other in the axial direction by the hook of the second catch (1771) and the hook groove of the first catch (1741). In addition, in the process of inserting the cap (16) and the cap gasket (17) into the can (10) (see FIG. 6), the side wall member (11) supports the outer surface of the axial extension of the first gasket (171) radially inward, so that the fastening of the hook of the second catch (1771) and the hook groove of the first catch (1741) is strengthened. In addition, in the process of bending the side wall member (11) inward (see Fig. 7), the second gasket (175) is more strongly fastened to the first gasket (171) by the hook groove and hook, which are the first catch (1741) and the second catch (1771).

[0179] <Fourth Embodiment>

[0180] In Figs. 11 and 12, a fourth embodiment of a cap gasket (17) is disclosed. In contrast to the third embodiment, the cap gasket (17) of the fourth embodiment has the first fastening portion (174) of the first gasket (171) and the second fastening portion (177) of the second gasket (175) arranged at positions corresponding to the radially outer end of the axial extension portion (173).

[0181] The first fastening portion (174) has a fastening groove that is axially sunken, and the second fastening portion (177) has a fastening projection that protrudes axially. The fastening projection of the second fastening portion (177) has a hook that is a second engaging portion (1771) that protrudes radially inward from its extended end, and the fastening groove of the first fastening portion (174) has a hook groove that is a first engaging portion (1741) that is radially sunken inward.

[0182] In the above axial extension (173), the radially inner portion of the fastening groove of the first fastening portion (174) is supported radially outward by the cap (16). On the other hand, there is no member supporting the radially outer portion of the fastening projection of the second fastening portion (177).

[0183] Accordingly, while temporarily assembling the cap gasket (17) and the cap (16) by axially inserting the fastening projection of the second fastening portion (177) of the second gasket (175) into the fastening groove of the first fastening portion (174) of the first gasket (171), when the hook of the second engaging portion (1771) presses the radially inner portion of the fastening groove of the first fastening portion (174) at the axial extension portion (173), the fastening projection of the second fastening portion (177) is easily elastically deformed radially outward due to the reaction, and the hook of the second engaging portion (1771) can be easily inserted into the hook groove of the first engaging portion (1741).

[0184] A fastening guide portion (178) is provided in the fastening projection of the second fastening portion (177) and the fastening groove of the first fastening portion (174) to ensure mutual alignment during the insertion process. The fastening guide portion (178) may be a chamfer shape provided near the extended end of the fastening projection of the second fastening portion (177) and / or the entrance of the fastening groove of the first fastening portion (174).

[0185] After the hook of the second catch (1771) is inserted into the hook groove of the first catch (1741), the second gasket (175) and the first gasket (171) are fastened together by the hook of the second catch (1771) and the hook groove of the first catch (1741) so that they do not move apart from each other in the axial direction. In the process of inserting the cap (16) and the cap gasket (17) into the can (10) (see FIG. 6), the side wall member (11) supports the outer surface of the fastening projection of the second fastening portion (177) radially inward, so that the fastening between the hook of the second catch (1771) and the hook groove of the first catch (1741) is strengthened. In addition, in the process of bending the side wall member (11) inward (see Fig. 7), the second gasket (175) is more strongly fastened to the first gasket (171) by the hook groove and hook, which are the first catch (1741) and the second catch (1771).

[0186] <Example 5>

[0187] In Figs. 13 and 14, a fifth embodiment of a cap gasket (17) is disclosed. The cap gasket (17) of the fifth embodiment is provided with two first fastening portions (174) of a first gasket (171) and two second fastening portions (177) of a second gasket (175). The two first fastening portions (174) are arranged to be connected in a radial direction, and the two second fastening portions (177) are also arranged to be connected in a radial direction.

[0188] The cap gasket (17) of the fifth embodiment is implemented such that the two first fastening portions (174) have first fastening projections arranged radially inward and first fastening grooves arranged radially outward, and the two second fastening portions (177) have second fastening grooves arranged radially inward and second fastening projections arranged radially outward. In addition, the first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177) are mutually inserted in the axial direction, and the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) are mutually inserted in the axial direction.

[0189] The first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177) are arranged radially spaced apart from the radially inner and outer ends of the axial extension portion. In addition, the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) are arranged at positions corresponding to the radially outer ends of the axial extension portion in the radial direction.

[0190] A fastening guide portion (178) is provided in the first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177), and in the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) to induce mutual alignment during the insertion process. The fastening guide portion (178) may be a rounded fillet shape provided near the extended ends of the first fastening projection of the first fastening portion (174) and the second fastening projection of the second fastening portion (177) and / or the entrances of the first fastening groove of the first fastening portion (174) and the second fastening groove of the second fastening portion (177).

[0191] While temporarily assembling the cap gasket (17) and the cap (16) by inserting the two first fastening parts (174) and the second fastening part (177) in the axial direction, the second fastening projection of the second fastening part (177) of the second gasket (175) having a relatively small radial width is easily elastically deformed radially outward, so that the first fastening part (174) and the second fastening part (177) can be easily fastened.

[0192] According to the fifth embodiment described above, the inwardly bent portion (1171) formed during the crimping process also presses the second fastening groove of the second fastening portion (177) and the second radially extended portion (176) of the second gasket (175) located at the rear of the second fastening projection of the second fastening portion (177) axially inward. Accordingly, the first fastening projection of the first fastening portion (174) and the second fastening projection of the second fastening portion (177) receive an insertion force that more strongly inserts them into the second fastening groove of the second fastening portion (177) and the first fastening groove of the first fastening portion (174), respectively, in the axial direction. Accordingly, the radial position of the second gasket (175) by the fastening structure can be more strongly regulated.

[0193] And even when pressure is applied radially inward to the second gasket (175) by the inward bending portion (1171), the radially outer lower portion of the second gasket (175) is clearly restricted from radially moving by the fastening structure.

[0194] <Example 6>

[0195] In Fig. 15 and Fig. 16, a sixth embodiment of a cap gasket (17) is disclosed.

[0196] According to the sixth embodiment, the radial inner surface (1730) of the axial extension portion (173) of the first gasket (171) has a radial first inner surface (1731) radially facing the radial outer surface (161) of the cap (16) and a radial second inner surface (1732) extending axially further outward than the radial outer surface (161) of the cap (16), and the axial inner surface (1760) of the second radial extension portion (176) of the second gasket (175) has an axial first inner surface (1761) axially facing the edge of the axial outer surface (163) of the cap (16) facing the axial outer surface.

[0197] Accordingly, in a state where the cap (16) is temporarily fastened to the first gasket (171), the upper surface of the axial extension (173) of the first gasket (171) protrudes further upward than the upper surface of the edge of the cap (16), i.e., the axial outer surface (163).

[0198] The second radial extension portion (176) of the second gasket (175) is placed on the upper surface of the edge of the cap (16) and the upper surface of the axial extension portion (173) of the first gasket (171). Accordingly, the axial first inner surface (1761) of the second radial extension portion (176) of the second gasket (175) is in contact with the cap (16), and the corners of the radial outer surface (161) and the axial outer surface (163) of the cap (16) are aligned with the radial outer corners of the radial first inner surface (1731) of the second gasket (175).

[0199] At the radially inner end of the upper portion of the axial extension portion (173), a fastening guide portion (178) is provided to guide the insertion of the axial second inner surface (1762) of the second gasket (175).

[0200] The cap gasket (17) of the sixth embodiment is provided with two first fastening portions (174) of the first gasket (171) and two second fastening portions (177) of the second gasket (175). The two first fastening portions (174) are arranged to be connected in a radial direction, and the two second fastening portions (177) are also arranged to be connected in a radial direction. The two first fastening portions (174) have a first fastening projection arranged radially inward and a first fastening groove arranged radially outward, and the two second fastening portions (177) have a second fastening groove arranged radially inward and a second fastening projection arranged radially outward. In addition, the first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177) are mutually inserted in the axial direction, and the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) are mutually inserted in the axial direction.

[0201] The first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177) are arranged radially spaced apart from the radially inner and outer ends of the axial extension portion. In addition, the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) are arranged at positions corresponding to the radially outer ends of the axial extension portion in the radial direction.

[0202] A fastening guide portion (178) is provided in the first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177), and in the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) to induce mutual alignment during the insertion process. The fastening guide portion (178) may be a chamfered shape provided near the extended ends of the first fastening projection of the first fastening portion (174) and the second fastening projection of the second fastening portion (177) and / or the entrances of the first fastening groove of the first fastening portion (174) and the second fastening groove of the second fastening portion (177).

[0203] While temporarily assembling the cap gasket (17) and the cap (16) by inserting the two first fastening parts (174) and the second fastening part (177) in the axial direction, the second fastening projection of the second fastening part (177) of the second gasket (175) having a relatively small radial width is easily elastically deformed radially outward, so that the first fastening part (174) and the second fastening part (177) can be easily fastened.

[0204] According to the sixth embodiment described above, the inwardly bent portion (1171) formed during the crimping process also presses the second fastening groove of the second fastening portion (177) and the second radially extended portion (176) of the second gasket (175) located at the rear of the second fastening projection of the second fastening portion (177) in the axial direction. Accordingly, the first fastening projection of the first fastening portion (174) and the second fastening projection of the second fastening portion (177) receive an insertion force that more strongly inserts them into the second fastening groove of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) in the axial direction, respectively. Accordingly, the radial position of the second gasket (175) by the fastening structure can be more strongly regulated.

[0205] And even when pressure is applied radially inward to the second gasket (175) by the inward bending portion (1171), the radially outer lower portion of the second gasket (175) is clearly restricted from radially moving by the fastening structure.

[0206] <Seventh Embodiment>

[0207] In Fig. 17 and Fig. 18, a cap gasket (17) of the seventh embodiment is disclosed.

[0208] According to the seventh embodiment, the radial inner surface (1730) of the axial extension portion (173) of the first gasket (171) has a radial first inner surface (1731) radially facing the radial outer surface (161) of the cap (16) and a radial second inner surface (1732) extending axially further outward than the radial outer surface (161) of the cap (16), and the axial inner surface (1760) of the second radial extension portion (176) of the second gasket (175) has an axial first inner surface (1761) axially facing the edge of the axial outer surface (163) of the cap (16) facing the axial outer surface.

[0209] Accordingly, in a state where the cap (16) is temporarily fastened to the first gasket (171), the upper surface of the axial extension (173) of the first gasket (171) protrudes further upward than the upper surface of the edge of the cap (16), i.e., the axial outer surface (163).

[0210] The second radial extension portion (176) of the second gasket (175) is placed on the upper surface of the edge of the cap (16) and the upper surface of the axial extension portion (173) of the first gasket (171). Accordingly, the axial first inner surface (1761) of the second radial extension portion (176) of the second gasket (175) is in contact with the cap (16), and the corners of the radial outer surface (161) and the axial outer surface (163) of the cap (16) are aligned with the radial outer corners of the radial first inner surface (1731) of the second gasket (175).

[0211] The cap gasket (17) of the seventh embodiment is provided with two first fastening portions (174) of the first gasket (171) and two second fastening portions (177) of the second gasket (175). The two first fastening portions (174) are arranged to be connected in a radial direction, and the two second fastening portions (177) are also arranged to be connected in a radial direction. The two first fastening portions (174) have a first fastening projection arranged radially inward and a first fastening groove arranged radially outward, and the two second fastening portions (177) have a second fastening groove arranged radially inward and a second fastening projection arranged radially outward. In addition, the first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177) are mutually inserted in the axial direction, and the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) are mutually inserted in the axial direction.

[0212] The first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177) are arranged at positions corresponding to the radially inner end of the axial extension portion (173). In addition, the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) are arranged at positions corresponding to the radially outer end of the axial extension portion in the radial direction.

[0213] According to the seventh embodiment, the first fastening projection of the first fastening portion (174) has a hook, which is a first engaging portion (1741) protruding radially inward from its extended end, and the second fastening groove of the second fastening portion (177) has a hook groove, which is a second engaging portion (1771) recessed radially inward from its recessed end.

[0214] A fastening guide portion (178) is provided in the first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177), and in the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) to induce mutual alignment during the insertion process. The fastening guide portion (178) may be a chamfered shape provided near the extended ends of the first fastening projection of the first fastening portion (174) and the second fastening projection of the second fastening portion (177) and / or the entrances of the first fastening groove of the first fastening portion (174) and the second fastening groove of the second fastening portion (177).

[0215] While temporarily assembling the cap gasket (17) and the cap (16) by inserting the two first fastening portions (174) and the second fastening portion (177) in the axial direction, the second fastening projection of the second fastening portion (177) of the second gasket (175) having a relatively small radial width can be easily elastically deformed radially outward, so that the first fastening portion (174) and the second fastening portion (177) can be easily fastened. In addition, due to the fastening guide portion (178) provided long on the radially outer side of the first fastening projection of the first fastening portion (174) of the first gasket (171), the first fastening projection of the first fastening portion (174) can also be easily elastically deformed radially outward, so that the first fastening portion (174) and the second fastening portion (177) can be easily fastened.

[0216] The hook of the first hanging portion (1741) strengthens the temporary fastening force of the first gasket (171) and the second gasket (175).

[0217] According to the seventh embodiment described above, the inwardly bent portion (1171) formed during the crimping process also presses the second fastening groove of the second fastening portion (177) and the second radially extended portion (176) of the second gasket (175) located at the rear of the second fastening projection of the second fastening portion (177) in the axial direction. Accordingly, the first fastening projection of the first fastening portion (174) and the second fastening projection of the second fastening portion (177) receive an insertion force that more strongly inserts them into the second fastening groove of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) in the axial direction, respectively. Accordingly, the radial position of the second gasket (175) by the fastening structure can be more strongly regulated.

[0218] In addition, by means of the fastening guide portion (178) provided long on the radially outer side of the first fastening projection of the first fastening portion (174) of the first gasket (171) and the hook of the first catch portion (1741), the radially outer corner of the radially first inner surface (1731) of the second gasket (175) is brought into strong contact with the corner portion of the radially outer surface (161) and the shaft outer surface (163) of the cap (16), thereby further improving the sealing force.

[0219] <Embodiment 8>

[0220] Figures 19 and 20 disclose a cap gasket (17) of the eighth embodiment. This will be described with a focus on differences from the seventh embodiment.

[0221] According to the eighth embodiment, the first fastening projection of the first fastening portion (174) has a hook, which is a first engaging portion (1741) protruding from its extended end in both radial directions, and the second fastening groove of the second fastening portion (177) has a hook groove, which is a second engaging portion (1771) recessed from its recessed end in both radial directions.

[0222] While temporarily assembling the cap gasket (17) and the cap (16) by inserting the two first fastening portions (174) and the second fastening portion (177) in the axial direction, the second fastening projection of the second fastening portion (177) of the second gasket (175) is easily elastically deformed radially outward due to the portion where the radial width is relatively small and the radial thickness of the second fastening projection of the second fastening portion (177) is thinner, especially due to the hook groove of the second catch portion (1771), so that the first fastening portion (174) and the second fastening portion (177) can be easily fastened.

[0223] In addition, due to the fastening guide portion (178) provided long on the radially inner side of the first fastening projection of the first fastening portion (174) of the first gasket (171) and the hook groove of the second catch portion (1771) on the radially inner side of the second fastening groove of the second fastening portion (177), the corner portion of the axial first inner surface (1761) of the second gasket (175) can also be easily elastically deformed radially inward, so that the fastening of the first fastening portion (174) and the second fastening portion (177) can be easily accomplished.

[0224] In the eighth embodiment, the first engaging portion (1741) of the first engaging projection of the first engaging portion (174) and the second engaging portion (1771) of the second engaging groove of the second engaging portion (177) corresponding thereto are provided on both radial sides, thereby further strengthening the temporary engaging force of the first gasket (171) and the second gasket (175).

[0225] <Example 9>

[0226] In Fig. 21 and Fig. 22, a cap gasket (17) of the ninth embodiment is disclosed.

[0227] According to the ninth embodiment, the radial inner surface (1730) of the axial extension portion (173) of the first gasket (171) has a radial first inner surface (1731) radially facing the radial outer surface (161) of the cap (16), and the axial inner surface (1760) of the second radial extension portion (176) of the second gasket (175) has an axial first inner surface (1761) axially facing the edge of the axial outer surface (163) of the cap (16) facing the axial outer surface, and an axial second inner surface (1762) extending axially further outward than the radial outer surface (161) of the cap (16).

[0228] Accordingly, in a state where the cap (16) is temporarily fastened to the first gasket (171), the axial outer surface (163) of the cap (16) and the radial inner end of the upper surface of the axial extension (173) of the first gasket (171) can form an approximately flat surface. That is, the corner of the radial outer surface (161) and the axial outer surface (163) of the cap (16) is aligned with the corner of the radial first inner surface (1731) of the axial extension (173) of the first gasket (171).

[0229] The second gasket (175) is placed on the upper surface of the edge of the cap (16) and the upper surface of the axial extension portion (173) of the first gasket (171). Accordingly, the axial first inner surface (1761) of the second radial extension portion (176) of the second gasket (175) is in contact with the cap (16), and the axial second inner surface (1762) is in contact with the first gasket (171).

[0230] The cap gasket (17) of the ninth embodiment is provided with two first fastening portions (174) of the first gasket (171) and two second fastening portions (177) of the second gasket (175). The two first fastening portions (174) are arranged to be connected in a radial direction, and the two second fastening portions (177) are also arranged to be connected in a radial direction. The two first fastening portions (174) have a first fastening projection arranged radially inward and a first fastening groove arranged radially outward, and the two second fastening portions (177) have a second fastening groove arranged radially inward and a second fastening projection arranged radially outward. In addition, the first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177) are mutually inserted in the axial direction, and the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) are mutually inserted in the axial direction.

[0231] The first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177) are arranged at positions corresponding to the radially inner end of the axial extension portion (173). In addition, the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) are arranged at positions spaced apart from the radially inner end and the outer end of the axial extension portion (173) between the radially inner end and the outer end of the axial extension portion (173) in the radial direction.

[0232] According to the ninth embodiment, the first fastening projection of the first fastening portion (174) has a hook, which is a first engaging portion (1741) protruding radially inward from its extended end, and the second fastening groove of the second fastening portion (177) has a hook groove, which is a second engaging portion (1771) recessed radially inward from its recessed end.

[0233] A fastening guide portion (178) is provided in the first fastening projection of the first fastening portion (174) and the second fastening groove of the second fastening portion (177), and in the second fastening projection of the second fastening portion (177) and the first fastening groove of the first fastening portion (174) to induce mutual alignment during the insertion process. The fastening guide portion (178) may be a chamfered shape provided near the extended ends of the first fastening projection of the first fastening portion (174) and the second fastening projection of the second fastening portion (177) and / or the entrances of the first fastening groove of the first fastening portion (174) and the second fastening groove of the second fastening portion (177).

[0234] While temporarily assembling the cap gasket (17) and the cap (16) by inserting the two first fastening parts (174) and the second fastening part (177) in the axial direction, the second fastening projection of the second fastening part (177) of the second gasket (175) having a relatively small radial width is easily elastically deformed radially outward, so that the first fastening part (174) and the second fastening part (177) can be easily fastened.

[0235] In addition, due to the hook groove of the second catching portion (1771) on the radially inner side of the second fastening groove of the second fastening portion (177), the corner portion of the axial first inner surface (1761) of the second gasket (175) can also be easily elastically deformed radially inward, so that the first fastening portion (174) and the second fastening portion (177) can be easily fastened.

[0236] According to the ninth embodiment described above, the inwardly bent portion (1171) formed during the crimping process also presses the second fastening groove of the second fastening portion (177) and the second radially extended portion (176) of the second gasket (175) located at the rear of the second fastening projection of the second fastening portion (177) axially inward. Accordingly, the first fastening projection of the first fastening portion (174) and the second fastening projection of the second fastening portion (177) receive an insertion force that more strongly inserts them into the second fastening groove of the second fastening portion (177) and the first fastening groove of the first fastening portion (174), respectively, in the axial direction. Accordingly, the radial position of the second gasket (175) by the fastening structure can be more strongly regulated.

[0237] In addition, by the hook of the first hooking portion (1741) of the first fastening portion (174) of the first gasket (171), the radial outer corner of the radial first inner surface (1731) of the second gasket (175) is strongly pressed against the corner portion of the radial outer surface (161) and the shaft outer surface (163) of the cap (16), thereby further improving the sealing force.

[0238] [Battery Cell]

[0239] Figure 23 shows a battery cell to which the cap gasket (17) of the first embodiment is applied.

[0240] The battery cell of the embodiment includes an electrode assembly (20) and a housing (10) that accommodates the electrode assembly.

[0241] The above electrode assembly (20) is implemented in a jelly-roll shape in which a first electrode (21) and a second electrode (22) are laminated and wound around a predetermined core axis with a separator interposed therebetween. The electrode assembly (20) may have a cylindrical shape surrounding the core hollow portion (29). In an embodiment, the first electrode (21) is implemented as an anode, and the second electrode (22) is implemented as a cathode. However, the present invention is not limited thereto.

[0242] Referring to Fig. 23, the current collector of the first electrode (21) may protrude outward from the axial first end portion so that its surface is exposed, and the current collector of the second electrode (22) may protrude outward from the axial end portion so that its surface is exposed. The portion of the current collector exposed outward from the axial end portion of the electrode assembly constitutes an electrode tab (27) of the corresponding electrode. In the embodiment, the current collector of the first electrode (21) is implemented using aluminum foil, and the current collector of the second electrode (22) is implemented using copper foil. However, the present invention is not limited thereto.

[0243] The above electrode tab (27) is bent radially inward and covered in the axial direction.

[0244] The electrode tab of the first electrode (21) is bonded to the first collector plate (31), and the electrode tab of the second electrode (22) is bonded to the second collector plate (32). In the embodiment, the collector of the first electrode (21) is made of aluminum foil, and the collector of the second electrode (22) is made of copper foil. However, the present invention is not limited thereto.

[0245] The above housing (10) is implemented as a cylindrical can (10) made of metal. The can (10) has a side wall member (11) extending in the axial direction and surrounding an internal space extending in the axial direction, and a bottom member (12) connected to an axial first end of the side wall member (11). Accordingly, the axial first end of the side wall member (11) constitutes a closed end, and the axial second end of the side wall member (11) provided on the opposite side defines an open end.

[0246] The first electrode terminal (13) is installed through the central portion of the floor member (12) with a gasket (14) interposed therebetween. The gasket (14) seals the gap between the first electrode terminal (13) and the floor member (12) and electrically insulates the first electrode terminal (13) from the floor member (12).

[0247] With the electrode assembly (20) accommodated in the can (10), the first current collector (31) is connected to the first electrode terminal (13). Accordingly, the first electrode (21) and the first electrode terminal (13) are electrically connected.

[0248] An insulator (19) is interposed between the first collector plate (31) and the floor member (12). Accordingly, the first collector plate (31) is electrically insulated from the floor member (12).

[0249] With the above electrode assembly (20) housed in the can (10), the axial second end of the side wall member (11) is radially plastically deformed inward to form a beading portion (116).

[0250] The edge of the second collector plate (32) may be joined and fixed to the beading portion (116) by welding or the like. Accordingly, the can (10) is electrically connected to the second collector plate (32). The bottom member (12) of the can (10) may form a second electrode terminal of the battery cell. The second electrode (22) and the bottom member are electrically connected.

[0251] The battery cell includes a cap (16) covering the open end. The cap (16) is fixed to the side wall member (11) of the can (10) by being pressed by a beading portion (116) and a crimping portion (117) formed at the open end of the can (10) at its edge.

[0252] In order to seal the can (10) and the side wall member (11), the cap gasket (17) described above is interposed between the edge of the cap (16) and the side wall member (11). The edge of the cap (16) is pressed by the beading portion (116) and the crimping portion (117) while the cap gasket (17) is interposed, thereby sealing the connection portion between the cap (16) and the can (10).

[0253] It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be determined by the claims that follow, rather than by the detailed description set forth above. Furthermore, the meaning and scope of the claims that follow, as well as all possible modifications and variations derived from their equivalent concepts, should be construed as encompassing the scope of the present invention.

[0254] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. A loop-shaped cap gasket surrounding the radial outer end of a cap that extends radially to cover the axial end of the internal space defined by the housing of the battery cell, The above cap gasket includes a first gasket and a second gasket that is connected to the first gasket on the axial outer side of the first gasket, The above first gasket: A first radial extension extending in a radial direction; An axial extension extending axially outward from a radially outer end of the first radially extended portion; and Including one or more first fastening members provided on the axial outer end of the axial extension; The above second gasket; a second radial extension extending in a radial direction; and A cap gasket comprising: one or more second fastening portions provided on the axial inner side of the radially outer end of the second radially extended portion, and each of which is axially fastened with one or more first fastening portions; 2. A cap gasket according to claim 1, wherein the first fastening portion and the second fastening portion fastened thereto are spaced radially apart from the radially inner end and outer end of the axial extension portion.

3. A cap gasket according to claim 1, wherein the first fastening portion and the second fastening portion fastened thereto are arranged at positions corresponding to the radially inner end of the axially extended portion in the radial direction.

4. A cap gasket according to claim 1, wherein the first fastening portion and the second fastening portion fastened thereto are arranged at positions corresponding to the radially outer end of the axially extended portion in the radial direction.

5. In claim 1, the first fastening portion and the second fastening portion fastened thereto are cap gaskets that extend along the circumferential direction of the first gasket and the second gasket, respectively.

6. In claim 5, the plurality of first fastening portions are arranged along a radial direction, A cap gasket wherein the plurality of second fastening portions are arranged radially to correspond to the plurality of first fastening portions.

7. In claim 6, at least two first fastening members are arranged to be connected in a radial direction, A cap gasket, wherein at least two second fastening portions corresponding to the at least two first fastening portions are arranged to be radially connected.

8. A cap gasket according to claim 1, wherein one of the first fastening portion and the second fastening portion and the other have an axially sunken fastening groove and an axially extended fastening protrusion so as to be axially inserted into the fastening groove, respectively.

9. A cap gasket according to claim 8, wherein one and the other of the plurality of first fastening portions each have a fastening groove and a fastening projection, and the second fastening portions corresponding to one and the other of the plurality of second fastening portions each have a fastening projection and a fastening groove.

10. In claim 9, the first fastening portion and the other first fastening portion are arranged to be connected in a radial direction, A cap gasket, wherein the first fastening portion and the second fastening portion corresponding to the other first fastening portion are arranged to be radially connected.

11. In claim 8, the fastening projection has a hook protruding radially from an extended end of the fastening projection, A cap gasket, wherein the fastening groove corresponding to the fastening projection has a hook groove sunken in the radial direction at the sunken end of the fastening groove so as to receive the hook in the radial direction.

12. A cap gasket according to claim 11, wherein the hook is provided on one side of the radially inner and outer sides of the fastening projection or on both sides, and the hook groove is provided on one side of the radially inner and outer sides of the fastening groove or on both sides to correspond to the hook.

13. In claim 1, the radial inner surface of the axial extension of the first gasket has a radial first inner surface radially facing the radial outer surface of the cap, A cap gasket, wherein the axial inner surface of the second radial extension of the second gasket has an axial first inner surface that faces the edge of the axial outer surface of the cap in the axial direction facing the axial outer surface.

14. A cap gasket according to claim 13, wherein the radial inner surface of the axially extended portion of the first gasket further has a second radial inner surface that extends further axially outward than the radial outer surface of the cap.

15. A cap gasket according to claim 13, wherein the axial inner surface of the second radial extension portion of the second gasket further has an axial second inner surface that extends further axially outward than the radial outer surface of the cap.

16. A cap gasket according to claim 1, wherein the first corner provided on the axial inner side of the radial outer end of the first radial extension portion is rounded.

17. A cap gasket according to claim 1, wherein the second corner provided on the axial outer side of the radial outer end of the second radial extension portion is rounded.

18. In claim 17, the first corner provided on the axial inner side of the radial outer end of the first radial extension is rounded, A cap gasket, wherein the round radius of the second corner is smaller than the round radius of the first corner.

19. A cap gasket according to any one of claims 1 to 18; A can having a side wall member having an open end; A beading portion formed by radially inwardly recessing the side wall member near the open end; A crimping portion in which the end of the side wall member is caulked radially inward from the axial outer side of the beading portion; and A battery cell having a cap, the edge of which is positioned between the beading portion and the crimping portion in the axial direction and is press-fixed, with the cap gasket interposed therebetween; The above first gasket is arranged on the axial outer surface of the beading portion, The edge of the cap is in contact with the axial outer surface of the first radial extension portion of the first gasket and the radial inner surface of the axial extension portion, The axial inner surface of the second radial extension of the second gasket is in contact with the edge of the cap, A battery cell, wherein the second fastening portion of the second gasket is axially fastened to the first fastening portion of the first gasket.

20. A cylindrical secondary battery according to claim 19, wherein the axial outer corner of the edge of the cap is aligned with the radial inner surface of the axial extension portion of the first gasket and the axial inner surface of the second radial extension portion of the second gasket.

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