Cap assembly and secondary battery including same

Abstract

The present invention relates to a cap assembly and a secondary battery including same, and addresses the technical problem of providing a cap assembly in which a safety vent can be deformed by a low actuation pressure and a secondary battery including same. To this end, the present invention provides a cap assembly comprising: a cap-up including a first opening; a cap-down disposed below the cap-up and including a second opening that can communicate with the first opening; a vent plate disposed between the cap-up and the cap-down and coupled to the cap-down; a coupling part spaced apart from the vent plate and contacting the cap-up; and a hinge part connected between the coupling part and the vent plate and deformable by an actuation pressure.

Description

Cap assembly and secondary battery including the same

[0001] The present disclosure relates to a cap assembly and a secondary battery including the same.

[0002] 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.

[0003] 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.

[0004] The purpose of the present invention is to provide a cap assembly capable of deforming a safety vent with a low operating pressure and a secondary battery including the same.

[0005] 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.

[0006] According to one embodiment of the present invention for solving the above technical problem, a cap assembly includes: a cap up having a first opening, a cap down having a second opening that is disposed on a lower side of the cap up and is capable of communicating with the first opening, a vent plate that is disposed between the cap up and the cap down and is coupled to the cap down, a coupling portion that is spaced apart from the vent plate and comes into contact with the cap up, and a safety vent having a hinge portion that is connected between the coupling portion and the vent plate and is deformable by an operating pressure.

[0007] The above hinge portion can be bent by operating pressure to allow deformation of the vent plate.

[0008] The above cap up may include an inner body, an outer body spaced apart from the inner body and in contact with the joint, and a bridge connected between the inner body and the outer body.

[0009] The above hinge portion may be placed between the inner body and the outer body.

[0010] The distance between the end of the hinge portion and the central axis of the inner body may be less than or equal to the distance between the inner surface of the outer body and the central axis of the inner body.

[0011] The above hinge portion may be positioned between the first opening and the second opening.

[0012] The thickness of the above hinge portion may be smaller than the thickness of the above joining portion.

[0013] The thickness of the hinge portion may be 33% to 67% of the thickness of the joining portion.

[0014] The thickness of the above hinge portion may be smaller than the thickness of the above vent plate.

[0015] The thickness of the above hinge portion may be 33% to 67% of the thickness of the above vent plate.

[0016] The thickness of the above hinge portion may be 0.1 mm to 0.2 mm.

[0017] The length of the above hinge portion may be 0.25 mm to 0.45 mm.

[0018] It may further include an inclined portion extending obliquely from the hinge portion and connected to the connecting portion.

[0019] The distance between the end of the above-mentioned inclined portion and the central axis of the inner body may be less than or equal to the distance between the inner surface of the outer body and the central axis of the inner body.

[0020] It may further include a banding portion extending from the above-mentioned joint and wrapping the outer body.

[0021] The above banding portion may include a first banding portion that is in contact with the first surface of the outer body, a second banding portion that is spaced apart from the first banding portion and in contact with the second surface of the outer body, and a connecting portion that connects the first banding portion and the second banding portion.

[0022] It may further include a first insulating member disposed between the safety vent and the cap down.

[0023] According to one embodiment of the present invention, a secondary battery includes: a can having an opening, an electrode assembly accommodated in the can, and a cap assembly covering the opening, wherein the cap assembly may include a cap up, a cap down disposed below the cap up, a safety vent disposed between the cap up and the cap down and having a hinge portion deformable by operating pressure, and a banding portion extending from the safety vent and wrapping around a rim of the cap up.

[0024] The above can may include a crimping portion that surrounds the banding portion.

[0025] It may further include a second insulating member disposed between the banding portion and the crimping portion.

[0026] According to the present invention, the safety vent can be deformed by a low-pressure operating pressure by a hinge portion that allows deformation of the safety vent by being bent by a low-pressure operating pressure.

[0027] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0028] 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.

[0029] FIG. 1 is a perspective view schematically showing the configuration of a secondary battery according to a first embodiment of the present invention.

[0030] Figure 2 is a cross-sectional view schematically showing the configuration of a secondary battery according to the first embodiment of the present invention.

[0031] Figure 3 is a partial cross-sectional view schematically showing the configuration of a secondary battery according to the first embodiment of the present invention.

[0032] Fig. 4 is a cross-sectional view schematically showing the configuration of a cap assembly according to the first embodiment of the present invention.

[0033] Fig. 5 is a partial cross-sectional view schematically showing the configuration of a cap assembly according to the first embodiment of the present invention.

[0034] FIG. 6 is a partial cross-sectional view schematically showing a state in which a safety vent is deformed in a secondary battery according to the first embodiment of the present invention.

[0035] Fig. 7 is a partial cross-sectional view schematically showing a state in which a hinge portion is deformed in a cap assembly according to the first embodiment of the present invention.

[0036] FIGS. 8 and 9 are partial cross-sectional views schematically showing the configuration of a cap assembly according to a second embodiment of the present invention.

[0037] Fig. 10 is a cross-sectional view schematically showing the configuration of a secondary battery according to a third embodiment of the present invention.

[0038] Fig. 11 is a partial cross-sectional view schematically showing the configuration of a secondary battery according to a third embodiment of the present invention.

[0039] Fig. 12 is a cross-sectional view schematically showing the configuration of a cap assembly according to a third embodiment of the present invention.

[0040] Fig. 13 is a partial cross-sectional view schematically showing the configuration of a cap assembly according to a third embodiment of the present invention.

[0041] Fig. 14 is a partial cross-sectional view schematically showing a state in which a safety vent is deformed in a secondary battery according to a third embodiment of the present invention.

[0042] Fig. 15 is a partial cross-sectional view schematically showing a state in which a hinge portion is deformed in a cap assembly according to a third embodiment of the present invention.

[0043] FIG. 16 and FIG. 17 are partial cross-sectional views schematically showing the configuration of a cap assembly according to a fourth embodiment of the present invention.

[0044] 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.

[0045] 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.

[0046] In addition, when describing embodiments of the present invention, “may be”, “may be” may include “one or more embodiments of the present invention.” In addition, to help understanding of the invention, the attached drawings may not be drawn to scale, but the dimensions of some components may be exaggerated. In addition, the same reference numbers may be given to the same components in different embodiments.

[0047] 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.

[0048] 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.

[0049] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0050] 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.

[0051] 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 each other, 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.

[0052] 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.

[0053] FIG. 1 is a perspective view schematically showing the configuration of a secondary battery according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view schematically showing the configuration of a secondary battery according to a first embodiment of the present invention, and FIG. 3 is a partial cross-sectional view schematically showing the configuration of a secondary battery according to a first embodiment of the present invention.

[0054] Referring to FIGS. 1 to 3, a secondary battery (1) according to the first embodiment of the present invention may include a can (100), an electrode assembly (200), and a cap assembly (300).

[0055] The can (100) may be formed in a hollow cylindrical shape. The can (100) may include a generally circular bottom portion (110) and a side wall portion (120) extending upward from the bottom portion (110) by a set length. The can (100) may be made of steel, a steel alloy, nickel-plated steel, a nickel-plated steel alloy, aluminum, or an aluminum alloy.

[0056] During the manufacturing process of the secondary battery (1) according to the first embodiment of the present invention, the upper portion of the can (100) may be opened. That is, an opening (100a) may be provided on the upper surface of the can (100). The opening (100a) may be formed by penetrating the upper surface of the can (100) in the vertical direction.

[0057] The electrode assembly (200) can be accommodated inside the can (100). During the assembly process of the secondary battery (1) according to the first embodiment of the present invention, the electrode assembly (200) can be integrated into a single structure and inserted into the can (100). Thereafter, an electrolyte can be additionally injected into the can (100).

[0058] A beading part (130) recessed in the direction of the central axis (C) of the can (100) may be formed on the upper part of the can (100) to prevent the electrode assembly (200) from being separated from the outside of the can (100) through the opening (100a).

[0059] The beading part (130) may be located on the lower side of the cap assembly (300). A crimping part (140) bent to wrap around the banding part (340) of the cap assembly (300) may be formed on the upper part of the beading part (130).

[0060] The electrode assembly (200) may include or be referred to as an electrode, an electrode group, or a jelly roll. The electrode assembly (200) may include a negative electrode plate (210) coated with a negative electrode active material (e.g., graphite, carbon, etc.), a positive electrode plate (220) coated with a positive electrode active material (e.g., a transition metal oxide (LiCoO2, LiNiO2, LiMn2O4, etc.)), and a separator (230) positioned between the negative electrode plate (210) and the positive electrode plate (220) to prevent short circuiting and allow only the movement of lithium ions.

[0061] The negative electrode plate (210), the positive electrode plate (220), and the separator (230) can be wound in a roughly cylindrical shape. The negative electrode plate (210) can be a copper (Cu) foil, the positive electrode plate (220) can be an aluminum (Al) foil, and the separator (230) can be polyethylene (PE) or polypropylene (PP).

[0062] A negative electrode tab (240) may be welded to the negative electrode plate (210). The negative electrode tab (240) may protrude and extend to the lower portion of the electrode assembly (200) by a set length. A positive electrode tab (250) may be welded to the positive electrode plate (220).

[0063] The positive electrode tab (250) may be extended to protrude a set length from the top of the electrode assembly (200). The negative electrode tab (240) may be copper (Cu) or nickel (Ni), and the positive electrode tab (250) may be aluminum (Al).

[0064] The negative tab (240) can be welded to the bottom (110) of the can (100). Therefore, the can (100) can operate as a negative electrode. The negative tab (240) can be ultrasonically or laser welded to the bottom (110) of the can (100). Of course, conversely, the positive tab (250) can be welded to the bottom (110) of the can (100), in which case the can (100) can operate as a positive electrode.

[0065] The electrode assembly (200) may further include a center pin (260). The center pin (260) is in the form of a hollow circular pipe and may be coupled to approximately the center of the electrode assembly (200). The center pin (260) may be formed of steel, stainless steel, aluminum, an aluminum alloy, or polybutylene terepthalate, but the material is not limited thereto.

[0066] The center pin (260) can suppress deformation of the electrode assembly (200) during charging and discharging of the electrode assembly (200). The center pin (260) can function as a passage for gas generated in the electrode assembly (200). In some cases, the center pin (260) may be omitted.

[0067] The cap assembly (300) can be coupled to the can (100) to cover the opening (100a). The cap assembly (300) can be fixed to the can (100) by a crimping portion (140). The cap assembly (300) can be electrically connected to the electrode assembly (200). The cap assembly (300) can seal the opening (100a) of the can (100) and protect the electrode assembly (200) from the external environment.

[0068] When the internal pressure of the can (100) rises above the set pressure due to thermal runaway or ignition of the electrode assembly (200), the cap assembly (300) may rupture, releasing the internal gas of the can (100) to the outside. The cap assembly (300) may serve as a positive terminal.

[0069] FIG. 4 is a cross-sectional view schematically showing the configuration of a cap assembly according to the first embodiment of the present invention, and FIG. 5 is a partial cross-sectional view schematically showing the configuration of a cap assembly according to the first embodiment of the present invention.

[0070] Referring to FIGS. 1 to 5, a cap assembly (300) according to the first embodiment of the present invention may include a cap up (310), a safety vent (320), a cap down (330), and a banding portion (340).

[0071] The cap up (310) can serve as a terminal electrically connected to an external device. The cap up (310) can serve as a positive terminal.

[0072]

[0073] *The cap up (310) may be provided with a first opening (310a). The first opening (310a) may serve to discharge internal gas to the outside when an abnormal internal pressure occurs within the can (100) due to overfilling or other reasons. The cap up (310) may be manufactured from aluminum or an aluminum alloy.

[0074] The cap up (310) may include an inner body (311), an outer body (312), and a bridge (313).

[0075] The inner body (311) can form the central outer appearance of the cap up (310). The inner body (311) can be formed to have a roughly circular shape. The inner body (311) can be arranged so that its central axis (C) is aligned with the central axis (C) of the can (100).

[0076] The outer body (312) may form the outer edge of the cap up (310). The outer body (312) may be in contact with the safety vent (320). The outer body (312) may be formed to have a substantially hollow ring shape. The diameter of the outer body (312) may be formed to be larger than the diameter of the inner body (311).

[0077] The outer body (312) can be arranged coaxially with the inner body (311). That is, the central axis (C) of the outer body (312) can be arranged to coincide with the central axis (C) of the inner body (311) and the central axis (C) of the can (100).

[0078] The inner body (311) and the outer body (312) may be arranged to be spaced apart from each other vertically. The outer body (312) may be arranged on the lower side of the inner body (311). Alternatively, the inner body (311) and the outer body (312) may also be arranged on the same plane.

[0079] The bridge (313) is placed between the inner body (311) and the outer body (312) and can support the inner body (311) with respect to the outer body (312). The bridge (313) can be formed so that each end has a rod shape connecting the outer surface of the inner body (311) and the inner surface of the outer body (312).

[0080] A plurality of bridges (313) may be provided. The plurality of bridges (313) may be spaced apart from each other along the circumference of the can (100) with the central axis (C) of the can (100) as the center. The spacing between adjacent bridges (313) may be the same, but is not limited thereto.

[0081] The first opening (310a) may be formed to have the shape of a hole that penetrates the cap up (310). The first opening (310a) may be formed to have the shape of a hole that penetrates the area between the inner body (311) and the outer body (312).

[0082] The first opening (310a) may be provided in multiple numbers. The multiple first openings (310a) may be individually positioned between adjacent bridges (313). The number of first openings (310a) is not limited to that illustrated in FIG. 1, and the design may be changed to a variety of numbers.

[0083] The safety vent (320) may be positioned between the cap up (310) and the cap down (330). The safety vent (320) may be in close contact with, in contact with, coupled with, or connected to the lower portion of the cap up (310).

[0084] The safety vent (320) can be in close contact with, in contact with, coupled with or connected to the edge of the cap up (310) excluding the center portion protruding upward from the cap up (310), i.e., the inner body (311), i.e., the outer body (312). The safety vent (320) can be made of aluminum or an aluminum alloy.

[0085] The safety vent (320) may include a vent plate (321), a connecting portion (322), and a hinge portion (323).

[0086] The vent plate (321) can be placed between the cap up (310) and the cap down (330). The vent plate (321) can be combined with the cap down (330). The lower surface of the central portion of the vent plate (321) can be in close contact with, in contact with, combined with, or connected to the upper surface of the central portion of the cap down (330).

[0087] The vent plate (321) may be provided with a notch (321a). A plurality of notches (321a) may be provided on the vent plate (321). The notches (321a) may be formed concavely to a set depth from the outer surface or inner surface of the vent plate (321), but are not limited thereto.

[0088] As the internal pressure of the can (100) rises above the reference pressure (or the rupture pressure of the safety vent (320)) due to thermal runaway or ignition of the electrode assembly (200), the notch (321a) is ruptured, and the exhaust generated inside the can (100) can sequentially pass through the second opening (330a) of the cap down (330), the notch (321a), and the first opening (310a) of the cap up (310) and be discharged to the outside. Here, the exhaust discharged from the first opening (310a) may include at least one of flame, gas, and smoke.

[0089] The connecting portion (322) is provided on the radially outer side of the vent plate (321), is spaced apart from the vent plate (321), and can be connected to the outer body (312). The upper surface of the connecting portion (322) and the lower surface of the outer body (312) can be in close contact with, in contact with, connected to, or connected to each other.

[0090] FIG. 6 is a partial cross-sectional view schematically showing a state in which a safety vent is deformed in a secondary battery according to the first embodiment of the present invention, and FIG. 7 is a partial cross-sectional view schematically showing a state in which a hinge portion is deformed in a cap assembly according to the first embodiment of the present invention.

[0091] Referring to FIGS. 1 to 7, a hinge portion (323) according to the first embodiment of the present invention can be connected between a vent plate (321) and a connecting portion (322). The hinge portion (323) can extend from the outer circumferential surface of the vent plate (321) in the radial direction of the can (100), or can extend from one end of the connecting portion (322) in the direction of the central axis (C) of the can (100) to connect the vent plate (321) and the connecting portion (322).

[0092] The end (323a) of the hinge portion (323) connected to the joint portion (322) and the joint portion (322) can be connected in a stepwise manner.

[0093] The hinge portion (323) can be deformed by operating pressure. Here, the operating pressure means the minimum pressure for the safety vent (320) to be deformed.

[0094] The operating pressure is the minimum pressure at which the internal pressure of the can (100) increases due to thermal runaway or ignition of the electrode assembly (200), and emissions such as flames, gases, and smoke generated inside the can (100) pressurize the safety vent (320) and cause deformation of the safety vent (320).

[0095] The hinge portion (323) can be bent upwardly toward the can (100) by the operating pressure, thereby allowing deformation of the vent plate (321). Due to the bending deformation of the hinge portion (323), the vent plate (321) can be deformed upwardly toward the can (100).

[0096] The hinge portion (323) may be located between the inner body (311) and the outer body (312). The hinge portion (323) may be located between the inner surface (312a) of the outer body (312) and the outer surface (311a) of the inner body (311).

[0097] The hinge portion (323) may be positioned between the first opening (310a) and the second opening (330a). The hinge portion (323) may be positioned between the first opening (310a) formed in the cap up (310) and the second opening (330a) formed in the cap down (330).

[0098] The thickness (T) of the hinge portion (323) may be smaller than the thickness of the connecting portion (322). The thickness (T) of the hinge portion (323) may be 33% to 67% of the thickness (T) of the connecting portion (322). If the thickness (T) of the hinge portion (323) is less than 33% of the thickness of the connecting portion (322), the hinge portion (323) may be bent and deformed at an operating pressure of less than 9.5 kgf. If the thickness (T) of the hinge portion (323) is greater than 67% of the thickness (T) of the connecting portion (322), the hinge portion (323) may not be bent and deformed at a low operating pressure, but may be bent and deformed at a high operating pressure of 12 kgf or more.

[0099] The thickness (T) of the hinge portion (323) may be 0.1 mm to 0.2 mm. If the thickness (T) of the hinge portion (323) is less than 0.1 mm, the hinge portion (323) may be bent and deformed at an operating pressure of less than 9.5 kgf, and cracks may occur. If the thickness (T) of the hinge portion (323) exceeds 0.2 mm, the hinge portion (323) may not be bent and deformed at a low operating pressure, but may be bent and deformed at a high operating pressure of 12 kgf or more.

[0100] The length (L) of the hinge portion (323) may be 0.25 mm to 0.45 mm. If the length (L) of the hinge portion (323) is less than 0.25 mm, the hinge portion (323) is not subject to bending deformation under a low-pressure operating pressure, but may be subject to bending deformation under a high-pressure operating pressure of 12 kgf or more. Here, the low-pressure operating pressure may have a range of 9.5 kgf to 12 kgf. If the length (L) of the hinge portion (323) exceeds 0.45 mm, the hinge portion (323) may be subject to bending deformation under an operating pressure of less than 9.5 kgf.

[0101] If the thickness (T) of the joint portion (322) is 0.3 mm, the thickness of the hinge portion (323), which is 33% of the thickness (T) of the joint portion (322), is 0.1 mm, and the length (L) of the hinge portion (323) is 0.45 mm, the hinge portion (323) can be bent at an operating pressure of 9.5 kgf.

[0102] The thickness (T) of the hinge portion (323) may be smaller than the thickness (T) of the vent plate (321). The thickness (T) of the hinge portion (323) may be 33% to 67% of the thickness (T) of the vent plate (321). If the thickness (T) of the hinge portion (323) is less than 33% of the thickness (T) of the vent plate (321), the hinge portion (323) may be bent under an operating pressure of less than 9.5 kgf. If the thickness (T) of the hinge portion (323) is greater than 67% of the thickness (T) of the vent plate (321), the hinge portion (323) may not be bent under a low operating pressure, but may be bent under a high operating pressure of 12 kgf or more.

[0103] The thickness (T) of the hinge portion (323) may be 0.1 mm to 0.2 mm. If the thickness (T) of the hinge portion (323) is less than 0.1 mm, the hinge portion (323) may be bent and deformed at an operating pressure of less than 9.5 kgf, and cracks may occur. If the thickness (T) of the hinge portion (323) exceeds 0.2 mm, the hinge portion (323) may not be bent and deformed at a low operating pressure, but may be bent and deformed at a high operating pressure of 12 kgf or more.

[0104] If the thickness (T) of the vent plate (321) is 0.3 mm, the thickness (T) of the hinge portion (323), which is 33% of the thickness (T) of the vent plate (321), is 0.1 mm, and the length (L) of the hinge portion (323) is 0.45 mm, the hinge portion (323) can be bent at an operating pressure of 9.5 kgf.

[0105] The length (L) of the hinge portion (323) may be 0.25 mm to 0.45 mm. If the length (L) of the hinge portion (323) is less than 0.25 mm, the hinge portion (323) is not subject to bending deformation under a low operating pressure, but may be subject to bending deformation under a high operating pressure of 12 kgf or more. If the length (L) of the hinge portion (323) exceeds 0.45 mm, the hinge portion (323) may be subject to bending deformation under an operating pressure of less than 9.5 kgf.

[0106] The banding portion (340) extends from the safety vent (320) and can wrap around the outer body (312). The banding portion (340) can extend from the joining portion (322) in the radial direction of the can (100) to wrap around the outer body (312). The banding portion (340) can extend upwardly from the joining portion (322) in a curved manner to wrap around the outer body (312).

[0107] The banding portion (340) may include a first banding portion (341), a second banding portion (342), and a connecting portion (343).

[0108] The first banding portion (341) may be formed to be in contact with the first surface (A) of the outer body (312). Here, the first surface (A) may refer to the lower surface of the outer body (312) facing the direction in which the can (100) is positioned. The upper surface of the first banding portion (341) and the lower surface of the outer body (312) may be in close contact with, in contact with, coupled with, or connected to each other.

[0109] The second banding portion (342) may be provided to be in contact with the second surface (B) of the outer body (312). Here, the second surface (B) may refer to the upper surface of the outer body (312). The lower surface of the second banding portion (342) may be in close contact with the upper surface of the outer body (312).

[0110] The connecting portion (343) can connect between the first banding portion (341) and the second banding portion (342). The connecting portion (343) is provided to be in contact with the free end of the outer body (312) and can connect one end of the first banding portion (341) and one end of the second banding portion (342).

[0111] The cap down (330) may be positioned on the lower side of the cap up (310). The cap down (330) may be positioned on the lower side of the safety vent (320). The cap down (330) may be coupled to the safety vent (320). The cap down (330) may be provided with a second opening (330a). The second opening (330a) may be formed in the form of a hole formed by penetrating the cap down (330).

[0112] The second opening (330a) may serve to discharge internal gas to the outside when an abnormal internal pressure occurs inside the can (100) due to overcharging or other reasons. The second opening (330a) may communicate with the first opening (310a) when the safety vent (320) is ruptured. The first opening (310a) and the second opening (330a) may be arranged to be spaced apart from each other vertically.

[0113] The upper surface of the central portion of the cap down (330) may be in close contact with, in contact with, coupled with, or connected to the lower surface of the central portion of the vent plate (321). The cap down (330) may be electrically connected to the electrode assembly (200) via the positive electrode tab (250). The cap down (330) may be electrically connected to the safety vent (320) and the cap up (310).

[0114] The positive electrode tab (250) of the electrode assembly (200) may be welded to the lower surface of the cap down (330). The lower surface of the cap down (330) may be ultrasonically and / or laser welded to the positive electrode tab (250). The cap down (330) may be made of aluminum or an aluminum alloy.

[0115] In the event of thermal runaway or ignition of the electrode assembly (200), the safety vent (320) is deformed by the internal pressure of the can (100), and the cap down (330) and the safety vent (320) can be electrically separated.

[0116] A first insulating member (350) may be installed between the safety vent (320) and the cap down (330). The first insulating member (350) may be located between the edge of the cap down (330) and the joint (322).

[0117] The first insulating member (350) can serve to insulate between the cap down (330) and the safety vent (320) when the safety vent (320) is deformed by the internal gas of the can (100). The first insulating member (350) can be formed of a resin material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc., but the material is not limited thereto.

[0118] A second insulating member (400) may be installed on the upper part of the can (100). The second insulating member (400) may be installed between the banding member (340) and the crimping member (140) that wraps the outer body (312) of the cap up (310).

[0119] The second insulating member (400) can be in close contact with the outer surface of the banding portion (340) and the inner surface of the crimping portion (140). The end of the second insulating member (400) can be in close contact with the inner surface of the beading portion (130).

[0120] The second insulating member (400) may serve to insulate between the can (100) and the cap assembly (300). The second insulating member (400) may be formed of a resin material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc., but the material is not limited thereto.

[0121] FIGS. 8 and 9 are partial cross-sectional views schematically showing the configuration of a cap assembly according to a second embodiment of the present invention.

[0122] Referring to FIGS. 8 and 9, the distance (L1) between the end (323a) of the hinge portion (323) according to the second embodiment of the present invention and the central axis (C) of the inner body (311) may be less than or equal to the distance (L2) between the inner surface (312a) of the outer body (312) and the central axis (C) of the inner body (311).

[0123] The distance (L1) between the end (323a) of the hinge portion (323) connected to the connecting portion (322) and the central axis (C) of the inner body (311) and the distance between the inner surface (312a) of the outer body (312) and the central axis (C) of the inner body (311) may be the same. The end (323a) of the hinge portion (323) and the inner surface (312a) of the outer body (312) may be positioned on the same line. The inner surface (312a) of the outer body (312) and the end (323a) of the hinge portion (323) may be positioned on a reference line that faces in a direction parallel to the central axis (C) of the inner body (311).

[0124] FIG. 10 is a cross-sectional view schematically showing the configuration of a secondary battery according to a third embodiment of the present invention, FIG. 11 is a partial cross-sectional view schematically showing the configuration of a secondary battery according to a third embodiment of the present invention, FIG. 12 is a cross-sectional view schematically showing the configuration of a cap assembly according to a third embodiment of the present invention, FIG. 13 is a partial cross-sectional view schematically showing the configuration of a cap assembly according to a third embodiment of the present invention, FIG. 14 is a partial cross-sectional view schematically showing a state in which a safety vent is deformed in a secondary battery according to a third embodiment of the present invention, and FIG. 15 is a partial cross-sectional view schematically showing a state in which a hinge part is deformed in a cap assembly according to a third embodiment of the present invention.

[0125] Referring to FIGS. 10 to 15, a secondary battery (1) according to a third embodiment of the present invention may include a can (100), an electrode assembly (200), and a cap assembly (300).

[0126] In describing the secondary battery (1) according to the third embodiment of the present invention, another embodiment of the cap assembly (300) described in the secondary battery (1) according to the first embodiment of the present invention will be described.

[0127] The description of the secondary battery (1) according to the first embodiment of the present invention can be applied as is to the remaining configuration of the secondary battery (1) according to the third embodiment of the present invention.

[0128] The cap assembly (300) may include a cap up (310), a safety vent (320), a cap down (330), and a banding portion (340).

[0129] The cap up (310) may be provided with a first opening (310a). The first opening (310a) may serve to discharge internal gas to the outside when an abnormal internal pressure occurs inside the can (100) due to overcharging or other reasons.

[0130] The cap up (310) may include an inner body (311), an outer body (312), and a bridge (313).

[0131] The inner body (311) can form the central outer appearance of the cap up (310). The inner body (311) can be formed to have a roughly circular shape. The inner body (311) can be arranged so that its central axis (C) is aligned with the central axis (C) of the can (100).

[0132] The outer body (312) may form the outer edge of the cap up (310). The outer body (312) may be in contact with the safety vent (320). The outer body (312) may be formed to have a substantially hollow ring shape. The diameter of the outer body (312) may be formed to be larger than the diameter of the inner body (311).

[0133] The outer body (312) can be arranged coaxially with the inner body (311). That is, the central axis (C) of the outer body (312) can be arranged to coincide with the central axis (C) of the inner body (311) and the central axis (C) of the can (100).

[0134] The inner body (311) and the outer body (312) may be arranged to be spaced apart from each other vertically. The outer body (312) may be arranged on the lower side of the inner body (311). Alternatively, the inner body (311) and the outer body (312) may also be arranged on the same plane.

[0135] The bridge (313) is placed between the inner body (311) and the outer body (312) and can support the inner body (311) with respect to the outer body (312). The bridge (313) can be formed so that each end has a rod shape connecting the outer surface of the inner body (311) and the inner surface of the outer body (312).

[0136] A plurality of bridges (313) may be provided. The plurality of bridges (313) may be spaced apart from each other along the circumference of the can (100) with the central axis (C) of the can (100) as the center. The spacing between adjacent bridges (313) may be the same, but is not limited thereto.

[0137] The first opening (310a) may be formed to have the shape of a hole that penetrates the cap up (310). The first opening (310a) may be formed to have the shape of a hole that penetrates the area between the inner body (311) and the outer body (312).

[0138] The first opening (310a) may be provided in multiple numbers. The multiple first openings (310a) may be individually positioned between adjacent bridges (313). The number of first openings (310a) may be designed to vary.

[0139] The safety vent (320) may be positioned between the cap up (310) and the cap down (330). The safety vent (320) may be in close contact with, in contact with, coupled with, or connected to the lower portion of the cap up (310).

[0140] The safety vent (320) can be in close contact with, in contact with, coupled with or connected to the center portion protruding upward from the cap up (310), that is, the edge of the cap up (310) excluding the inner body (311), that is, the outer body (312).

[0141] The safety vent (320) may include a vent plate (321), a connecting portion (322), a hinge portion (323), and a slope portion (324).

[0142] The vent plate (321) can be placed between the cap up (310) and the cap down (330). The vent plate (321) can be combined with the cap down (330). The lower surface of the central portion of the vent plate (321) can be in close contact with, in contact with, combined with, or connected to the upper surface of the central portion of the cap down (330).

[0143] The vent plate (321) may be provided with a notch (321a). A plurality of notches (321a) may be provided on the vent plate (321). The notches (321a) may be formed concavely to a set depth from the outer surface or inner surface of the vent plate (321), but are not limited thereto.

[0144] As the internal pressure of the can (100) rises above the reference pressure (or the rupture pressure of the safety vent (320)) due to thermal runaway or ignition of the electrode assembly (200), the notch (321a) is ruptured, and the discharged matter generated inside the can (100) can sequentially pass through the second opening (330a) of the cap down (330), the notch (321a), and the first opening (310a) of the cap up (310) and be discharged to the outside.

[0145] The connecting portion (322) is provided on the radially outer side of the vent plate (321), is spaced apart from the vent plate (321), and can be connected to the outer body (312). The upper surface of the connecting portion (322) and the lower surface of the outer body (312) can be in close contact with, in contact with, connected to, or connected to each other.

[0146] The hinge portion (323) may be positioned between the vent plate (321) and the joining portion (322). The hinge portion (323) may extend from the outer circumferential surface of the vent plate (321) in the radial direction of the can (100).

[0147] The hinge portion (323) can be deformed by the operating pressure. The hinge portion (323) can be deformed in the upper direction of the can (100) by the operating pressure, thereby allowing the deformation of the vent plate (321). Due to the bending deformation of the hinge portion (323), the vent plate (321) can be deformed in the upper direction of the can (100).

[0148] The hinge portion (323) may be located between the inner body (311) and the outer body (312). The hinge portion (323) may be located between the inner surface (312a) of the outer body (312) and the outer surface (311a) of the inner body (311).

[0149] The hinge portion (323) may be positioned between the first opening (310a) and the second opening (330a). The hinge portion (323) may be positioned between the first opening (310a) formed in the cap up (310) and the second opening (330a) formed in the cap down (330).

[0150] The inclined portion (324) may extend obliquely from the hinge portion (323) and be connected to the connecting portion (322). The inclined portion (324) may be connected between the hinge portion (323) and the connecting portion (322). The end (324a) of the inclined portion (324) and the connecting portion (322) may be connected.

[0151] The inclined portion (324) may extend upwardly in a radial direction of the can (100) from an end of the hinge portion (323), or may extend downwardly in a radial direction of the can (100) from one end of the connecting portion (322) in a radial direction of the can (100) to connect the hinge portion (323) and the connecting portion (322).

[0152] The inclined portion (324) may be located between the inner body (311) and the outer body (312). The inclined portion (324) may be located between the inner surface (312a) of the outer body (312) and the outer surface (311a) of the inner body (311).

[0153] The inclined portion (324) may be positioned between the first opening (310a) and the second opening (330a). The inclined portion (324) may be positioned between the first opening (310a) formed in the cap up (310) and the second opening (330a) formed in the cap down (330).

[0154] By means of the inclined portion (324), the hinge portion (323) can avoid interference with the outer body (312) during bending deformation. The inclined portion (324) can be deformed together with the hinge portion (323). The inclined portion (324) can be bent together with the hinge portion (323) toward the upper direction of the can (100) by operating pressure.

[0155] The banding portion (340) extends from the safety vent (320) and can wrap around the outer body (312). The banding portion (340) can extend from the joining portion (322) in the radial direction of the can (100) to wrap around the outer body (312). The banding portion (340) can extend upwardly from the joining portion (322) in a curved manner to wrap around the outer body (312).

[0156] The banding portion (340) may include a first banding portion (341), a second banding portion (342), and a connecting portion (343).

[0157] The first banding portion (341) may be formed to be in contact with the first surface (A) of the outer body (312). The upper surface of the first banding portion (341) and the lower surface of the outer body (312) may be in close contact, in contact, combined, or connected.

[0158] The second banding portion (342) may be provided to be in contact with the second surface (B) of the outer body (312). The lower surface of the second banding portion (342) may be in close contact with the upper surface of the outer body (312).

[0159] The connecting portion (343) can connect between the first banding portion (341) and the second banding portion (342). The connecting portion (343) is provided to be in contact with the free end of the outer body (312) and can connect one end of the first banding portion (341) and one end of the second banding portion (342).

[0160] The cap down (330) may be positioned on the lower side of the cap up (310). The cap down (330) may be positioned on the lower side of the safety vent (320). The cap down (330) may be coupled to the safety vent (320). The cap down (330) may be provided with a second opening (330a). The second opening (330a) may be formed in the form of a hole formed by penetrating the cap down (330).

[0161] The second opening (330a) can communicate with the first opening (310a) when the safety vent (320) is broken. The first opening (310a) and the second opening (330a) can be arranged to be spaced apart from each other vertically.

[0162] The upper surface of the central portion of the cap down (330) may be in close contact with, in contact with, coupled with, or connected to the lower surface of the central portion of the vent plate (321). The cap down (330) may be electrically connected to the electrode assembly (200) via the positive electrode tab (250). The cap down (330) may be electrically connected to the safety vent (320) and the cap up (310).

[0163] The positive electrode tab (250) of the electrode assembly (200) can be welded to the lower surface of the cap down (330). In the event of thermal runaway or ignition of the electrode assembly (200), the safety vent (320) is deformed by the internal pressure of the can (100), and the cap down (330) and the safety vent (320) can be electrically separated.

[0164] FIG. 16 and FIG. 17 are partial cross-sectional views schematically showing the configuration of a cap assembly according to a fourth embodiment of the present invention.

[0165] Referring to FIGS. 16 and 17, the distance (L1) between the end (324a) of the inclined portion (324) according to the fourth embodiment of the present invention and the central axis (C) of the inner body (311) may be less than or equal to the distance (L2) between the inner surface (312a) of the outer body (312) and the central axis (C) of the inner body (311).

[0166] The distance (L1) between the end (324a) of the inclined portion (324) connected to the joint (322) and the central axis (C) of the inner body (311) and the distance between the inner surface (312a) of the outer body (312) and the central axis (C) of the inner body (311) may be the same. The end (324a) of the inclined portion (324) and the inner surface (312a) of the outer body (312) may be positioned on the same line. The inner surface (312a) of the outer body (312) and the end (324a) of the inclined portion (324) may be positioned on a reference line that faces in a direction parallel to the central axis (C) of the inner body (311).

[0167] Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

[0168] Therefore, the technical protection scope of the present invention should be defined by the following patent claims.

Claims

1. Cap up with first opening; A cap down disposed on the lower side of the cap up and having a second opening capable of communicating with the first opening; and A cap assembly characterized by comprising: a safety vent disposed between the cap up and the cap down, the safety vent having a vent plate coupled to the cap down, a coupling portion spaced apart from the vent plate and in contact with the cap up, and a hinge portion connected between the coupling portion and the vent plate and deformable by operating pressure.

2. In paragraph 1, A cap assembly characterized in that the hinge portion is bent by operating pressure to allow deformation of the vent plate.

3. In paragraph 1, The above cap up is, Inner body; An outer body disposed apart from the inner body and in contact with the connecting portion; and A cap assembly characterized by including a bridge connected between the inner body and the outer body.

4. In paragraph 3, A cap assembly characterized in that the hinge portion is positioned between the inner body and the outer body.

5. In paragraph 4, A cap assembly characterized in that the distance between the end of the hinge portion and the central axis of the inner body is less than or equal to the distance between the inner surface of the outer body and the central axis of the inner body.

6. In paragraph 3, A cap assembly characterized in that the hinge portion is positioned between the first opening and the second opening.

7. In paragraph 3, A cap assembly characterized in that the thickness of the hinge portion is smaller than the thickness of the connecting portion.

8. In paragraph 7, A cap assembly, characterized in that the thickness of the hinge portion is 33% to 67% of the thickness of the joining portion.

9. In paragraph 3, A cap assembly characterized in that the thickness of the hinge portion is smaller than the thickness of the vent plate.

10. In paragraph 9, A cap assembly characterized in that the thickness of the hinge portion is 33% to 67% of the thickness of the vent plate.

11. In paragraph 7, A cap assembly characterized in that the thickness of the hinge portion is 0.1 mm to 0.2 mm.

12. In paragraph 7, A cap assembly characterized in that the length of the hinge portion is 0.25 mm to 0.45 mm.

13. In paragraph 3, A cap assembly further comprising an inclined portion extending obliquely from the hinge portion and connected to the coupling portion.

14. In paragraph 13, A cap assembly characterized in that the distance between the end of the inclined portion and the central axis of the inner body is less than or equal to the distance between the inner surface of the outer body and the central axis of the inner body.

15. In paragraph 3, A cap assembly further comprising a banding portion extending from the above-described joint portion and wrapping the outer body.

16. In paragraph 15, The above banding part, A first banding portion in contact with the first surface of the outer body; A second banding portion spaced apart from the first banding portion and in contact with the second surface of the outer body; and A cap assembly characterized by including a connecting portion connecting the first banding portion and the second banding portion.

17. In paragraph 1, A cap assembly further comprising a first insulating member disposed between the safety vent and the cap down.

18. A can having an opening; An electrode assembly accommodated in the can; and A cap assembly covering the above opening; The above cap assembly, cap up; A cap down positioned on the lower side of the above cap up; A safety vent disposed between the cap up and the cap down and having a hinge portion that can be deformed by operating pressure; and A secondary battery characterized by including a banding portion extending from the safety vent and wrapping around the edge of the cap up.

19. In paragraph 18, A secondary battery characterized in that the can includes a crimping portion that wraps the banding portion.

20. In paragraph 19, A secondary battery further comprising a second insulating member disposed between the banding portion and the crimping portion.

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