Cap assembly and secondary battery including the same

Abstract

The present disclosure relates to a cap assembly and a secondary battery including the same, and is directed to providing a cap assembly in which a safety vent can be deformed at a low operating pressure and a secondary battery including the same. To this end, the present disclosure provides a cap assembly including an upper cap having a first opening, a lower cap disposed at a lower side of the upper cap and having a second opening communicating with the first opening, and a safety vent disposed between the upper cap and the lower cap and having a vent plate coupled to the lower cap, a coupling portion spaced apart from the vent plate and in contact with the upper cap, and a rotation shaft portion connected between the coupling portion and the vent plate and deformable by an operating pressure.

Description

Technical Field

[0001] This disclosure relates to a cover assembly and a secondary battery including the cover assembly. Background Technology

[0002] Unlike non-rechargeable primary batteries, secondary batteries are rechargeable and dischargeable batteries. Low-capacity secondary batteries are used in portable small electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motors in hybrid vehicles, electric vehicles, etc., and as energy storage batteries. Such secondary batteries include electrode assemblies consisting of positive and negative electrodes, a housing of the electrode assemblies, and electrode terminals connected to the electrode assemblies.

[0003] The information disclosed above, which serves as the background art of this invention, is only intended to improve the understanding of the background of this invention, and therefore may include information that does not constitute related art. Summary of the Invention

[0004] [Technical Issues]

[0005] The present invention aims to provide a cover assembly for a safety vent that can deform under low operating pressure, and a secondary battery including the cover assembly.

[0006] However, the objectives of the present invention are not limited to those mentioned above, and those skilled in the art should clearly understand from the following description of the invention that is not mentioned.

[0007] [Technical Solution]

[0008] One embodiment of the present invention for achieving the above objective provides a cover assembly, comprising: an upper cover having a first opening; a lower cover disposed below the upper cover and having a second opening communicating with the first opening; and a safety venting member disposed between the upper cover and the lower cover and having a venting plate connected to the lower cover, a connecting portion spaced apart from the venting plate and in contact with the upper cover, and a rotating shaft portion connected between the connecting portion and the venting plate and deformable by operating pressure.

[0009] The shaft section can be bent and deformed by operating pressure to allow for the deformation of the exhaust plate.

[0010] The top cover may include: an inner body; an outer body spaced apart from the inner body and in contact with the connecting portion; and a bridging portion connecting the inner body and the outer body.

[0011] The pivot section can be located between the inner body and the outer body.

[0012] The distance between the end of the pivot section and the central axis of the inner body can be less than or equal to the distance between the inner circumferential surface of the outer body and the central axis of the inner body.

[0013] The pivot section can be positioned between the first opening and the second opening.

[0014] The thickness of the rotating shaft can be less than the thickness of the connecting part.

[0015] The thickness of the rotating shaft can be 33% to 67% of the thickness of the connecting part.

[0016] The thickness of the rotating shaft can be less than the thickness of the exhaust plate.

[0017] The thickness of the rotating shaft can be 33% to 67% of the thickness of the exhaust plate.

[0018] The thickness of the rotating shaft can be in the range of 0.1 mm to 0.2 mm.

[0019] The length of the rotating shaft can be in the range of 0.25 mm to 0.45 mm.

[0020] The cover assembly may further include an inclined portion that extends at an angle from the pivot portion and is connected to the connecting portion.

[0021] The distance between the end of the inclined portion and the central axis of the inner body can be less than or equal to the distance between the inner circumferential surface of the outer body and the central axis of the inner body.

[0022] The cover assembly may further include a bent portion extending from the connecting portion and surrounding the outer body.

[0023] The bent portion may include: a first bent portion that contacts a first surface of the outer body; a second bent portion that is spaced apart from the first bent portion and contacts a second surface of the outer body; and a connecting portion that connects the first bent portion and the second bent portion.

[0024] The cover assembly may further include a first insulating member disposed between the safety vent and the lower cover.

[0025] One embodiment of the present invention provides a secondary battery, comprising: a can having an opening; an electrode assembly housed within the can; and a cover assembly covering the opening, wherein the cover assembly comprises: an upper cover; a lower cover disposed below the upper cover; a safety vent disposed between the upper and lower covers and having a pivot portion deformable by operating pressure; and a bending portion extending from the safety vent and surrounding an edge of the upper cover.

[0026] The can may include a crimped portion surrounding the bent portion.

[0027] The secondary battery may further include a second insulating member disposed between the bent portion and the crimped portion.

[0028] [Beneficial Effects]

[0029] According to the present invention, since the shaft portion is bent and deformed under low operating pressure and the safety vent is allowed to deform, the safety vent can deform under low operating pressure.

[0030] However, the beneficial effects that can be obtained by the present invention are not limited to those mentioned above, and those skilled in the art should clearly understand other beneficial effects not mentioned from the description of the present invention given above. Attached Figure Description

[0031] The following figures, which are attached to this document, illustrate preferred embodiments of the invention by way of example and, together with the detailed description of the invention given below, are intended to enable a further understanding of the technical concept of the invention. Therefore, the invention should not be interpreted solely based on the matters shown in these figures.

[0032] Figure 1 A perspective view illustrating the structure of a secondary battery according to a first embodiment of the present invention.

[0033] Figure 2 A cross-sectional view illustrating the structure of a secondary battery according to a first embodiment of the present invention.

[0034] Figure 3 A partial cross-sectional view illustrating the structure of a secondary battery according to a first embodiment of the present invention.

[0035] Figure 4 A cross-sectional view illustrating the construction of the cover assembly according to a first embodiment of the present invention.

[0036] Figure 5 A partial cross-sectional view illustrating the construction of the cover assembly according to a first embodiment of the present invention.

[0037] Figure 6 A partial cross-sectional view illustrating the deformation state of the safety vent in a secondary battery according to a first embodiment of the present invention.

[0038] Figure 7 A partial cross-sectional view illustrating the state of deformation of the pivot portion in the cover assembly according to a first embodiment of the present invention.

[0039] Figure 8 and Figure 9 A partial cross-sectional view illustrating the construction of the cover assembly according to a second embodiment of the present invention.

[0040] Figure 10A cross-sectional view illustrating the structure of a secondary battery according to a third embodiment of the present invention.

[0041] Figure 11 A partial cross-sectional view illustrating the structure of a secondary battery according to a third embodiment of the present invention.

[0042] Figure 12 A cross-sectional view illustrating the construction of the cover assembly according to a third embodiment of the present invention.

[0043] Figure 13 A partial cross-sectional view illustrating the construction of the cover assembly according to a third embodiment of the present invention.

[0044] Figure 14 A partial cross-sectional view illustrating the deformation state of the safety vent in a secondary battery according to a third embodiment of the present invention.

[0045] Figure 15 A partial cross-sectional view illustrating the state of deformation of the pivot portion in the cover assembly according to a third embodiment of the present invention.

[0046] Figure 16 and Figure 17 A partial cross-sectional view illustrating the construction of the cover assembly according to a fourth embodiment of the present invention. Detailed Implementation

[0047] Preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings. Prior to this, it should be noted that the terms or words used in this specification and claims should not be construed as limited to their general or dictionary meanings, but rather should be interpreted as having meanings and concepts consistent with the technical spirit of the invention, based on the principle that the inventor can be their own lexicographer to appropriately define the concepts of the terms in order to best interpret their invention. Therefore, the embodiments described in this specification and the constructions shown in the drawings are merely some of the most preferred embodiments of the invention and do not represent all the technical ideas of the invention. It should be understood that various equivalents and modifications may exist that can replace the embodiments described herein at the time of filing this application.

[0048] Furthermore, when used in this specification, the terms “comprise,” “include,” “comprising,” and / or “including” indicate the presence of the described shapes, quantities, steps, operations, components, elements, and / or groups thereof, but do not exclude the presence or addition of one or more other shapes, quantities, operations, components, elements, and / or groups thereof.

[0049] Additionally, the use of "can" or "may" when describing embodiments of the invention may refer to "one or more embodiments of the invention." Furthermore, to better understand the invention, the accompanying drawings may not be drawn to scale, and the dimensions of some components may be enlarged. Also, the same reference numerals may be assigned to the same components in different embodiments.

[0050] Referring to two comparable objects as "identical" means that they are "approximately identical." Therefore, the phrase "approximately identical" can include cases with deviations considered low in the art, such as deviations less than or equal to 5%. Additionally, stating that a parameter is uniform within a predetermined region can mean that the parameter is uniform in terms of its average value.

[0051] Although the terms “first,” “second,” etc., may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another, and unless otherwise specifically stated, the first component may be referred to as the second component.

[0052] Throughout the instruction manual, unless otherwise specifically stated, each component may be singular or plural.

[0053] Arranging any structure "above (or below)" or "on (or below)" a component can mean that the arbitrary structure is configured to contact the upper (or lower) surface of the component, or it can mean that another structure is inserted between the component and the arbitrary structure disposed on (or below) the component.

[0054] Furthermore, it should be understood that when a component is referred to as being "connected to," "linked to," or "attached to" another component, these components can be directly connected or linked to each other, but the other component can be "inserted" between these components, or the components can also be "connected," "linked," or "attached" through another component. Further, when a part is referred to as being electrically connected to another part, this includes not only the case where the part is directly connected to the other part, but also the case where the part is connected to the other part with another element placed between the part and the other part.

[0055] Throughout the instruction manual, when “A and / or B” is mentioned, unless otherwise specifically stated, it means A, B, or A and B. That is, the term “and / or” includes any and all combinations of the listed items. When “C~D” is mentioned, unless otherwise specifically stated, it means greater than or equal to C and less than or equal to D.

[0056] Figure 1 A perspective view illustrating the structure of a secondary battery according to a first embodiment of the present invention. Figure 2A cross-sectional view illustrating the structure of a secondary battery according to a first embodiment of the present invention is shown. Figure 3 A partial cross-sectional view illustrating the structure of a secondary battery according to a first embodiment of the present invention.

[0057] refer to Figures 1 to 3 According to the first embodiment of the present invention, the secondary battery 1 may include a can 100, an electrode assembly 200, and a cover assembly 300.

[0058] The can 100 may be formed into a hollow cylindrical shape. The can 100 may include a bottom portion 110 having a generally circular shape and a side wall portion 120 extending upward from the bottom portion 110 for a predetermined length. The can 100 may be made of steel, steel alloy, nickel-plated steel, nickel-plated steel alloy, aluminum, or aluminum alloy.

[0059] The upper portion of the can 100 may be open during the manufacturing process of the secondary battery 1 according to the first embodiment of the present invention. That is, an opening 100a may be provided at the upper surface of the can 100. The opening 100a may be formed to extend through the upper surface of the can 100 in the vertical direction.

[0060] The electrode assembly 200 can be housed in the tank 100. The electrode assembly 200 can be integrated as a single structure and can be inserted into the tank 100 during the assembly process of the secondary battery 1 according to the first embodiment of the present invention. Then, electrolyte can be additionally injected into the tank 100.

[0061] A rolled portion 130 recessed toward the central axis C of the can 100 may be formed in the upper part of the can 100 to prevent the electrode assembly 200 from falling out of the can 100 through the opening 100a.

[0062] The coiled portion 130 may be located on the underside of the cover assembly 300. The crimped portion 140, which is bent to surround the bend portion 340 of the cover assembly 300, may be formed on the upper portion of the coiled portion 130.

[0063] Electrode assembly 200 may include an electrode, an electrode assembly, or a core, or may be referred to as an “electrode,” an “electrode assembly,” or a “core.” 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., transition metal oxides (LiCoO2, LiNiO2, LiMn2O4, etc.)), and a separator 230 located between the negative electrode plate 210 and the positive electrode plate 220 to prevent short circuits and allow only lithium ion movement.

[0064] The negative electrode plate 210, the positive electrode plate 220, and the diaphragm 230 can be wound into a generally cylindrical shape. The negative electrode plate 210 can be copper (Cu) foil, the positive electrode plate 220 can be aluminum (Al) foil, and the diaphragm 230 can be polyethylene (PE) or polypropylene (PP).

[0065] The negative electrode tab 240 can be soldered to the negative electrode plate 210. The negative electrode tab 240 can extend to protrude downward from the electrode assembly 200 by a predetermined length. The positive electrode tab 250 can be soldered to the positive electrode plate 220.

[0066] The positive electrode terminal 250 may extend to protrude upward from the electrode assembly 200 by a predetermined length. The negative electrode terminal 240 may be copper (Cu) or nickel (Ni), and the positive electrode terminal 250 may be aluminum (Al).

[0067] The negative electrode connector 240 can be soldered to the bottom portion 110 of the can 100. Therefore, the can 100 can be used as a negative electrode. The negative electrode connector 240 can be ultrasonically welded or laser welded to the bottom portion 110 of the can 100. Conversely, the positive electrode connector 250 can be soldered to the bottom portion 110 of the can 100, and in this case, the can 100 can be used as a positive electrode.

[0068] The electrode assembly 200 may further include a center pin 260. The center pin 260 is in the form of a hollow cylindrical tube and can be generally connected to the center of the electrode assembly 200. The center pin 260 may be made of steel, stainless steel, aluminum, aluminum alloy or polybutylene terephthalate, but the material of the center pin 260 is not limited to these.

[0069] The center pin 260 can suppress deformation of the electrode assembly 200 during charging and discharging. The center pin 260 can also serve as a channel for the movement of gas generated within the electrode assembly 200. In some cases, the center pin 260 can be omitted.

[0070] The cap assembly 300 can be attached to the can 100 and can cover the opening 100a. The cap assembly 300 can be secured to the can 100 by a crimping part 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 can protect the electrode assembly 200 from external environmental influences.

[0071] When the internal pressure of the canister 100 rises above a predetermined pressure due to thermal runaway or fire of the electrode assembly 200, the cover assembly 300 can break, and the gas in the canister 100 can be released to the outside. The cover assembly 300 can be used as a positive electrode terminal.

[0072] Figure 4A cross-sectional view illustrating the construction of the cover assembly according to a first embodiment of the present invention is shown. Figure 5 A partial cross-sectional view illustrating the construction of the cover assembly according to a first embodiment of the present invention.

[0073] refer to Figures 1 to 5 According to a first embodiment of the present invention, the cover assembly 300 may include an upper cover 310, a safety vent 320, a lower cover 330, and a bent portion 340.

[0074] The top cover 310 can be used as a terminal for electrical connection to an external device. The top cover 310 can be used as a positive electrode terminal.

[0075] *A first opening 310a may be provided in the top cover 310. When abnormal internal pressure occurs in the can 100 due to overcharging or other reasons, the first opening 310a can be used to allow internal gases to escape to the outside. The top cover 310 may be made of aluminum or an aluminum alloy.

[0076] The top cover 310 may include an inner body 311, an outer body 312, and a bridging portion 313.

[0077] The inner body 311 can form the appearance of the central portion of the top cover 310. The inner body 311 can be formed to have a generally disc-shaped form. The inner body 311 can be configured so that its central axis C is aligned with the central axis C of the can 100.

[0078] The outer body 312 can form the appearance of the edge of the upper cover 310. The outer body 312 can contact the safety vent 320. The outer body 312 can be formed into a generally hollow annular shape. The diameter of the outer body 312 can be formed to be larger than the diameter of the inner body 311.

[0079] The outer body 312 can be configured to be coaxial with the inner body 311. That is, the central axis C of the outer body 312 can be configured to coincide with the central axis C of the inner body 311 and the central axis C of the tank 100.

[0080] The inner body 311 and the outer body 312 can be configured to be vertically spaced apart. The outer body 312 can be disposed below the inner body 311. Alternatively, the inner body 311 and the outer body 312 can be configured to be coplanar.

[0081] The bridging portion 313 can be disposed between the inner body 311 and the outer body 312, and can support the inner body 311 relative to the outer body 312. The bridging portion 313 can be formed in the shape of a rod whose two ends connect the outer circumferential surface of the inner body 311 and the inner circumferential surface of the outer body 312.

[0082] The bridging portion 313 can be provided as a plurality of bridging portions 313. The plurality of bridging portions 313 can be arranged to be spaced apart in the circumferential direction of the can 100 about the central axis C of the can 100. The spacing between adjacent bridging portions 313 can be equal, but the invention is not limited thereto.

[0083] The first opening 310a can be formed as a hole passing through the upper cover 310. The first opening 310a can also be formed as a hole passing through the region between the inner body 311 and the outer body 312.

[0084] The first opening 310a can be provided as a plurality of first openings 310a. The plurality of first openings 310a can each be disposed between different pairs of adjacent bridging portions 313. The number of first openings 310a is not limited to this. Figure 1 The quantity is given in the example, and can be changed to various other quantities.

[0085] The safety vent 320 can be disposed between the upper cover 310 and the lower cover 330. The safety vent 320 can be in close contact, contact, connected or linked to the lower part of the upper cover 310.

[0086] The safety vent 320 can be in close contact, engage, or connect with the edge of the cover 310, excluding the central portion (i.e., the inner body 311) that protrudes upward from the cover 310. The safety vent 320 can be made of aluminum or an aluminum alloy.

[0087] The safety venting component 320 may include an vent plate 321, a connecting portion 322, and a rotating shaft portion 323.

[0088] The exhaust plate 321 can be disposed between the upper cover 310 and the lower cover 330. The exhaust plate 321 can be connected to the lower cover 330. The lower surface of the central portion of the exhaust plate 321 can be in close contact, contact, connect or link with the upper surface of the central portion of the lower cover 330.

[0089] Cutout 321a may be provided at the exhaust plate 321. Cutout 321a may be provided as a plurality of cutouts 321a at the exhaust plate 321. Cutout 321a may be formed recessed to a predetermined depth from the outer or inner surface of the exhaust plate 321, but the invention is not limited thereto.

[0090] When the internal pressure of canister 100 rises to a level higher than or equal to the reference pressure (or the rupture pressure of safety vent 320) due to thermal runaway or fire of electrode assembly 200, the cut 321a may rupture, and the effluent generated in canister 100 may be discharged to the outside through the second opening 330a of lower cover 330, the cut 321a, and the first opening 310a of upper cover 310 in sequence. Here, the effluent discharged from the first opening 310a may include at least any one of flame, gas, and smoke.

[0091] The connecting portion 322 can be provided on the radially outer side of the exhaust plate 321, can be spaced apart from the exhaust 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, contact, connect, or link.

[0092] Figure 6 A partial cross-sectional view illustrating the deformation state of the safety vent in a secondary battery according to a first embodiment of the present invention, and Figure 7 A partial cross-sectional view illustrating the state of deformation of the pivot portion in the cover assembly according to a first embodiment of the present invention.

[0093] refer to Figures 1 to 7 According to the first embodiment of the present invention, the pivot portion 323 can be connected between the exhaust plate 321 and the connecting portion 322. The pivot portion 323 can extend from the outer circumferential surface of the exhaust plate 321 in the radial direction of the tank 100, or can extend from one end of the connecting portion 322 toward the central axis C of the tank 100, to connect between the exhaust plate 321 and the connecting portion 322.

[0094] The end 323a of the pivot portion 323 connected to the connecting portion 322 and the connecting portion 322 can be connected in a stepped shape.

[0095] The rotating shaft portion 323 can be deformed by operating pressure. Here, operating pressure is the minimum pressure required for the deformation of the safety vent 320.

[0096] Operating pressure is the minimum pressure at which the safety vent 320 is compressed by the exhaust of substances such as flames, gases and smoke generated in the tank 100 due to the increased internal pressure caused by thermal runaway or fire of the electrode assembly 200, resulting in deformation of the safety vent 320.

[0097] The rotating shaft portion 323 can be bent and deformed toward the upper part of the tank 100 due to operating pressure, and can allow for deformation of the exhaust plate 321. The exhaust plate 321 can deform toward the upper part of the tank 100 due to the bending and deformation of the rotating shaft portion 323.

[0098] The pivot portion 323 can be located between the inner body 311 and the outer body 312. The pivot portion 323 can be located between the inner circumferential surface 312a of the outer body 312 and the outer circumferential surface 311a of the inner body 311.

[0099] The pivot portion 323 may be located between the first opening 310a and the second opening 330a. The pivot portion 323 may be located between the first opening 310a formed in the upper cover 310 and the second opening 330a formed in the lower cover 330.

[0100] The thickness T of the pivot portion 323 can be less than the thickness of the connecting portion 322. The thickness T of the pivot portion 323 can be 33% to 67% of the thickness T of the connecting portion 322. When the thickness T of the pivot portion 323 is less than 33% of the thickness of the connecting portion 322, the pivot portion 323 can be bent and deformed under an operating pressure below 9.5 kgf. When the thickness of the pivot portion 323 exceeds 67% of the thickness T of the connecting portion 322, the pivot portion 323 can be bent and deformed without bending under low operating pressure, and can be bent and deformed under high operating pressure of 12 kgf or higher.

[0101] The thickness T of the pivot portion 323 can be in the range of 0.1 mm to 0.2 mm. When the thickness T of the pivot portion 323 is less than 0.1 mm, the pivot portion 323 can bend and deform under an operating pressure below 9.5 kgf, and may form cracks. When the thickness T of the pivot portion 323 exceeds 0.2 mm, the pivot portion 323 can remain unbent and deform under low operating pressure, but can bend and deform under high operating pressure of 12 kgf or higher.

[0102] The length L of the rotating shaft portion 323 can be in the range of 0.25 mm to 0.45 mm. When the length L of the rotating shaft portion 323 is less than 0.25 mm, the rotating shaft portion 323 can bend without bending under low operating pressure, but can bend under high operating pressure of 12 kgf or higher. Here, the low operating pressure can be in the range of 9.5 kgf to 12 kgf. When the length L of the rotating shaft portion 323 exceeds 0.45 mm, the rotating shaft portion 323 can bend under operating pressure of less than 9.5 kgf.

[0103] When the thickness T of the connecting part 322 is 0.3 mm, the thickness of the rotating shaft part 323 is 0.1 mm (33% of the thickness T of the connecting part 322), and the length L of the rotating shaft part 323 is 0.45 mm, the rotating shaft part 323 can be bent and deformed under an operating pressure of 9.5 kgf.

[0104] The thickness T of the rotating shaft portion 323 can be less than the thickness T of the exhaust plate 321. The thickness T of the rotating shaft portion 323 can be 33% to 67% of the thickness T of the exhaust plate 321. When the thickness T of the rotating shaft portion 323 is less than 33% of the thickness T of the exhaust plate 321, the rotating shaft portion 323 can be bent and deformed under an operating pressure below 9.5 kgf. When the thickness T of the rotating shaft portion 323 exceeds 67% of the thickness T of the exhaust plate 321, the rotating shaft portion 323 can remain unbent and deformed under low operating pressures, and can be bent and deformed under high operating pressures of 12 kgf or higher.

[0105] The thickness T of the pivot portion 323 can be in the range of 0.1 mm to 0.2 mm. When the thickness T of the pivot portion 323 is less than 0.1 mm, the pivot portion 323 can bend and deform under an operating pressure below 9.5 kgf, and may form cracks. When the thickness T of the pivot portion 323 exceeds 0.2 mm, the pivot portion 323 can remain unbent and deform under low operating pressure, but can bend and deform under high operating pressure of 12 kgf or higher.

[0106] When the thickness T of the exhaust plate 321 is 0.3 mm, the thickness of the shaft portion 323 is 0.1 mm (33% of the thickness T of the exhaust plate 321), and the length L of the shaft portion 323 is 0.45 mm, the shaft portion 323 can be bent and deformed under an operating pressure of 9.5 kgf.

[0107] The length L of the rotating shaft portion 323 can be in the range of 0.25 mm to 0.45 mm. When the length L of the rotating shaft portion 323 is less than 0.25 mm, the rotating shaft portion 323 can bend without deformation under low operating pressure and can bend under high operating pressure of 12 kgf or higher. When the length L of the rotating shaft portion 323 exceeds 0.45 mm, the rotating shaft portion 323 can bend under operating pressure of less than 9.5 kgf.

[0108] The bent portion 340 may extend from the safety vent 320 and may surround the outer body 312. The bent portion 340 may extend from the connecting portion 322 in the radial direction of the tank 100 and may surround the outer body 312. The bent portion 340 may extend to bend upward from the connecting portion 322 to surround the outer body 312.

[0109] The bent portion 340 may include a first bent portion 341, a second bent portion 342, and a connecting portion 343.

[0110] The first bent portion 341 can be formed to contact the first surface A of the outer body 312. Here, the first surface A can be the lower surface of the outer body 312 oriented toward the location of the tank 100. The upper surface of the first bent portion 341 and the lower surface of the outer body 312 can be in close contact, touching, joined, or connected.

[0111] The second bent portion 342 can be provided to contact the second surface B of the outer body 312. Here, the second surface B can be the upper surface of the outer body 312. The lower surface of the second bent portion 342 can be in close contact with the upper surface of the outer body 312.

[0112] The connecting portion 343 can be connected between the first bent portion 341 and the second bent portion 342. The connecting portion 343 can be provided to contact the free end of the outer body 312, and can connect one side of the first bent portion 341 and one side of the second bent portion 342.

[0113] The lower cover 330 may be disposed below the upper cover 310. The lower cover 330 may be located below the safety vent 320. The lower cover 330 may be connected to the safety vent 320. A second opening 330a may be provided in the lower cover 330. The second opening 330a may be in the form of a hole formed through the lower cover 330.

[0114] When abnormal internal pressure occurs in tank 100 due to overcharging or other reasons, the second opening 330a can be used to allow internal gas to be discharged to the outside. When the safety vent 320 ruptures, the second opening 330a can communicate with the first opening 310a. The first opening 310a and the second opening 330a can be configured to be vertically spaced apart.

[0115] The upper surface of the central portion of the lower cover 330 can be in close contact, contact, connect, or link with the lower surface of the central portion of the exhaust plate 321. The lower cover 330 can be electrically connected to the electrode assembly 200 via the positive electrode terminal 250. The lower cover 330 can be electrically connected to the safety exhaust element 320 and the upper cover 310.

[0116] The positive electrode terminal 250 of the electrode assembly 200 can be welded to the lower surface of the lower cover 330. The lower surface of the lower cover 330 can be ultrasonically welded and / or laser welded to the positive electrode terminal 250. The lower cover 330 can be made of aluminum or aluminum alloy.

[0117] In the event of thermal runaway or fire in the electrode assembly 200, the safety vent 320 may deform due to the internal pressure of the tank 100, and the lower cover 330 and the safety vent 320 may be electrically separated.

[0118] The first insulating member 350 can be installed between the safety vent 320 and the lower cover 330. The first insulating member 350 can be located between the edge of the lower cover 330 and the connecting portion 322.

[0119] When the safety vent 320 deforms due to the gas in the canister 100, the first insulating member 350 can be used to insulate the lower cover 330 from the safety vent 320. The first insulating member 350 can be formed of a resin material such as polyethylene (PE), polypropylene (PP) or polyethylene terephthalate (PET), but the material of the first insulating member 350 is not limited to these.

[0120] The second insulating member 400 can be installed on the upper part of the can 100. The second insulating member 400 can be installed between the crimped portion 140 and the bent portion 340 of the outer body 312 surrounding the upper cover 310.

[0121] The second insulating member 400 can be in close contact with the outer surface of the bent portion 340 and the inner surface of the crimped portion 140. The end of the second insulating member 400 can be in close contact with the inner surface of the rolled portion 130.

[0122] The second insulating member 400 can be used to insulate the can 100 from the lid assembly 300. The second insulating member 400 can be formed of a resin material such as polyethylene (PE), polypropylene (PP) or polyethylene terephthalate (PET), but the material of the second insulating member 400 is not limited to these.

[0123] Figure 8 and Figure 9 A partial cross-sectional view illustrating the construction of the cover assembly according to a second embodiment of the present invention.

[0124] refer to Figure 8 and Figure 9 According to the second embodiment of the present invention, the distance L1 between the end 323a of the pivot portion 323 and the central axis C of the inner body 311 can be less than or equal to the distance L2 between the inner circumferential surface 312a of the outer body 312 and the central axis C of the inner body 311.

[0125] The distance L1 between the end 323a of the pivot portion 323 connected to the connecting portion 322 and the central axis C of the inner body 311, and the distance between the inner circumferential surface 312a of the outer body 312 and the central axis C of the inner body 311, can be equal. The end 323a of the pivot portion 323 and the inner circumferential surface 312a of the outer body 312 can be positioned collinearly. The inner circumferential surface 312a of the outer body 312 and the end 323a of the pivot portion 323 can be located on a reference line oriented in a direction parallel to the central axis C of the inner body 311.

[0126] Figure 10 A cross-sectional view illustrating the structure of a secondary battery according to a third embodiment of the present invention is provided. Figure 11 A partial cross-sectional view illustrating the structure of a secondary battery according to a third embodiment of the present invention is shown below. Figure 12 A cross-sectional view illustrating the structure of the cover assembly according to a third embodiment of the present invention is provided. Figure 13 A partial cross-sectional view illustrating the structure of the cover assembly according to a third embodiment of the present invention is shown. Figure 14 A partial cross-sectional view illustrating the deformation state of the safety vent in a secondary battery according to a third embodiment of the present invention, and Figure 15 A partial cross-sectional view illustrating the state of deformation of the pivot portion in the cover assembly according to a third embodiment of the present invention.

[0127] refer to Figures 10 to 15 According to a third embodiment of the present invention, the secondary battery 1 may include a canister 100, an electrode assembly 200, and a cover assembly 300.

[0128] In describing the secondary battery 1 according to the third embodiment of the present invention, another embodiment of the cover assembly 300 described above with respect to the secondary battery 1 according to the first embodiment of the present invention will be described.

[0129] The above description of the secondary battery 1 according to the first embodiment of the present invention can be applied as is to the remaining construction of the secondary battery 1 according to the third embodiment of the present invention.

[0130] The cover assembly 300 may include an upper cover 310, a safety vent 320, a lower cover 330, and a bent portion 340.

[0131] A first opening 310a can be provided in the top cover 310. When abnormal internal pressure occurs in the tank 100 due to overcharging or other reasons, the first opening 310a can be used to allow internal gas to be discharged to the outside.

[0132] The top cover 310 may include an inner body 311, an outer body 312, and a bridging portion 313.

[0133] The inner body 311 can form the appearance of the central portion of the top cover 310. The inner body 311 can be formed to have a generally disc-shaped form. The inner body 311 can be configured so that its central axis C is aligned with the central axis C of the can 100.

[0134] The outer body 312 can form the appearance of the edge of the upper cover 310. The outer body 312 can contact the safety vent 320. The outer body 312 can be formed into a generally hollow annular shape. The diameter of the outer body 312 can be formed to be larger than the diameter of the inner body 311.

[0135] The outer body 312 can be configured to be coaxial with the inner body 311. That is, the central axis C of the outer body 312 can be configured to coincide with the central axis C of the inner body 311 and the central axis C of the tank 100.

[0136] The inner body 311 and the outer body 312 can be configured to be vertically spaced apart. The outer body 312 can be disposed below the inner body 311. Alternatively, the inner body 311 and the outer body 312 can be configured to be coplanar.

[0137] The bridging portion 313 can be disposed between the inner body 311 and the outer body 312, and can support the inner body 311 relative to the outer body 312. The bridging portion 313 can be formed in the shape of a rod whose two ends connect the outer circumferential surface of the inner body 311 and the inner circumferential surface of the outer body 312.

[0138] The bridging portion 313 can be provided as a plurality of bridging portions 313. The plurality of bridging portions 313 can be arranged to be spaced apart in the circumferential direction of the can 100 about the central axis C of the can 100. The spacing between adjacent bridging portions 313 can be equal, but the invention is not limited thereto.

[0139] The first opening 310a can be formed as a hole passing through the upper cover 310. The first opening 310a can also be formed as a hole passing through the region between the inner body 311 and the outer body 312.

[0140] The first opening 310a can be provided as a plurality of first openings 310a. The plurality of first openings 310a can each be disposed between different pairs of adjacent bridging portions 313. The number of first openings 310a can be varied.

[0141] The safety vent 320 can be disposed between the upper cover 310 and the lower cover 330. The safety vent 320 can be in close contact, contact, connected or linked to the lower part of the upper cover 310.

[0142] The safety vent 320 can be in close contact, contact, join or connect with the edge of the cover 310 other than the central portion (i.e., the inner body 311) that protrudes upward from the cover 310 (i.e., the outer body 312).

[0143] The safety venting component 320 may include an vent plate 321, a connecting portion 322, a rotating shaft portion 323, and an inclined portion 324.

[0144] The exhaust plate 321 can be disposed between the upper cover 310 and the lower cover 330. The exhaust plate 321 can be connected to the lower cover 330. The lower surface of the central portion of the exhaust plate 321 can be in close contact, contact, connect or link with the upper surface of the central portion of the lower cover 330.

[0145] A cutout 321a may be provided at the exhaust plate 321. The cutout 321a may be provided as a plurality of cutouts 321a at the exhaust plate 321. The cutout 321a may be recessed to a predetermined depth from the outer or inner surface of the exhaust plate 321, but the invention is not limited thereto.

[0146] When the internal pressure of the canister 100 rises to a level higher than or equal to the reference pressure (or the rupture pressure of the safety vent 320) due to thermal runaway or fire of the electrode assembly 200, the cut 321a may rupture, and the discharge generated in the canister 100 may be discharged to the outside through the second opening 330a of the lower cover 330, the cut 321a, and the first opening 310a of the upper cover 310 in sequence.

[0147] The connecting portion 322 can be provided on the radially outer side of the exhaust plate 321, can be spaced apart from the exhaust 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, contact, connect, or link.

[0148] The rotating shaft portion 323 can be disposed between the exhaust plate 321 and the connecting portion 322. The rotating shaft portion 323 can extend from the outer circumferential surface of the exhaust plate 321 in the radial direction of the tank 100.

[0149] The rotating shaft portion 323 can deform under operating pressure. The rotating shaft portion 323 can bend and deform towards the upper part of the tank 100 due to operating pressure, and can also allow deformation of the exhaust plate 321. The exhaust plate 321 can deform towards the upper part of the tank 100 due to the bending deformation of the rotating shaft portion 323.

[0150] The pivot portion 323 can be located between the inner body 311 and the outer body 312. The pivot portion 323 can be located between the inner circumferential surface 312a of the outer body 312 and the outer circumferential surface 311a of the inner body 311.

[0151] The pivot portion 323 may be located between the first opening 310a and the second opening 330a. The pivot portion 323 may be located between the first opening 310a formed in the upper cover 310 and the second opening 330a formed in the lower cover 330.

[0152] The inclined portion 324 can extend from the pivot portion 323 in an inclined manner and can be connected to the connecting portion 322. The inclined portion 324 can be connected between the pivot portion 323 and the connecting portion 322. The end 324a of the inclined portion 324 can be connected to the connecting portion 322.

[0153] The inclined portion 324 can extend upward in the radial direction of the tank 100 from the end of the pivot portion 323, or it can extend downward in the direction toward the central axis C of the tank 100 from one side end of the connecting portion 322, so as to connect the pivot portion 323 and the connecting portion 322.

[0154] 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 circumferential surface 312a of the outer body 312 and the outer circumferential surface 311a of the inner body 311.

[0155] The inclined portion 324 may be located between the first opening 310a and the second opening 330a. The inclined portion 324 may be located between the first opening 310a formed in the upper cover 310 and the second opening 330a formed in the lower cover 330.

[0156] Due to the inclined portion 324, the rotating shaft portion 323 can avoid interference with the outer body 312 when it is bent and deformed. The inclined portion 324 can deform together with the rotating shaft portion 323. Due to operating pressure, the inclined portion 324 can bend and deform together with the rotating shaft portion 323 toward the upper part of the tank 100.

[0157] The bent portion 340 may extend from the safety vent 320 and may surround the outer body 312. The bent portion 340 may extend from the connecting portion 322 in the radial direction of the tank 100 and may surround the outer body 312. The bent portion 340 may extend from the connecting portion 322 to bend upward to surround the outer body 312.

[0158] The bent portion 340 may include a first bent portion 341, a second bent portion 342, and a connecting portion 343.

[0159] The first bent portion 341 can be formed to contact the first surface A of the outer body 312. The upper surface of the first bent portion 341 and the lower surface of the outer body 312 can be in close contact, contact, join or connect.

[0160] The second bent portion 342 can be provided to contact the second surface B of the outer body 312. The lower surface of the second bent portion 342 can be in close contact with the upper surface of the outer body 312.

[0161] The connecting portion 343 can be connected between the first bent portion 341 and the second bent portion 342. The connecting portion 343 can be provided to contact the free end of the outer body 312, and can connect one side of the first bent portion 341 and one side of the second bent portion 342.

[0162] The lower cover 330 may be disposed below the upper cover 310. The lower cover 330 may be located below the safety vent 320. The lower cover 330 may be connected to the safety vent 320. A second opening 330a may be provided in the lower cover 330. The second opening 330a may be in the form of a hole formed through the lower cover 330.

[0163] When the safety vent 320 ruptures, the second opening 330a can communicate with the first opening 310a. The first opening 310a and the second opening 330a can be configured to be vertically spaced apart.

[0164] The upper surface of the central portion of the lower cover 330 can be in close contact, contact, connect, or link with the lower surface of the central portion of the exhaust plate 321. The lower cover 330 can be electrically connected to the electrode assembly 200 via the positive electrode terminal 250. The lower cover 330 can be electrically connected to the safety exhaust element 320 and the upper cover 310.

[0165] The positive electrode terminal 250 of the electrode assembly 200 can be welded to the lower surface of the lower cover 330. In the event of thermal runaway or fire of the electrode assembly 200, the safety vent 320 can be deformed due to the internal pressure of the tank 100, and the lower cover 330 and the safety vent 320 can be electrically separated.

[0166] Figure 16 and Figure 17 A partial cross-sectional view illustrating the construction of the cover assembly according to a fourth embodiment of the present invention.

[0167] refer to Figure 16 and Figure 17 According to the fourth embodiment of the present invention, the distance L1 between the end 324a of the inclined portion 324 and the central axis C of the inner body 311 can be less than or equal to the distance L2 between the inner circumferential surface 312a of the outer body 312 and the central axis C of the inner body 311.

[0168] The distance L1 between the end 324a of the inclined portion 324 connected to the connecting portion 322 and the central axis C of the inner body 311, and the distance between the inner circumferential surface 312a of the outer body 312 and the central axis C of the inner body 311, can be equal. The end 324a of the inclined portion 324 and the inner circumferential surface 312a of the outer body 312 can be positioned collinear. The inner circumferential surface 312a of the outer body 312 and the end 324a of the inclined portion 324 can be located on a reference line oriented in a direction parallel to the central axis C of the inner body 311.

[0169] The invention has been described above with reference to the embodiments illustrated in the accompanying drawings. However, the embodiments are merely illustrative, and those skilled in the art will understand that various modifications and other equivalent embodiments are possible.

[0170] Therefore, the scope of protection of this invention should be defined by the appended claims.

Claims

1. A cover assembly, comprising: The top cover has a first opening; The lower cover is disposed on the lower side of the upper cover and has a second opening communicating with the first opening; as well as A safety venting device is disposed between the upper cover and the lower cover and has an venting plate connected to the lower cover, a connecting portion spaced apart from the venting plate and in contact with the upper cover, and a rotating shaft portion connected between the connecting portion and the venting plate and deformable by operating pressure.

2. The cover assembly of claim 1, wherein the pivot portion is bent and deformed by the operating pressure to allow deformation of the exhaust plate.

3. The cover assembly according to claim 1, wherein the upper cover comprises: inner subject; The outer body is spaced apart from the inner body and contacts the connecting portion; as well as A bridging section connects the inner body and the outer body.

4. The cover assembly according to claim 3, wherein the pivot portion is disposed between the inner body and the outer body.

5. The cover assembly according to claim 4, wherein the distance between the end of the pivot portion and the central axis of the inner body is less than or equal to the distance between the inner circumferential surface of the outer body and the central axis of the inner body.

6. The cover assembly of claim 3, wherein the pivot portion is disposed between the first opening and the second opening.

7. The cover assembly according to claim 3, wherein the thickness of the pivot portion is less than the thickness of the connecting portion.

8. The cover assembly of claim 7, wherein the thickness of the pivot portion is 33% to 67% of the thickness of the connecting portion.

9. The cover assembly according to claim 3, wherein the thickness of the pivot portion is less than the thickness of the exhaust plate.

10. The cover assembly of claim 9, wherein the thickness of the pivot portion is 33% to 67% of the thickness of the exhaust plate.

11. The cover assembly of claim 7, wherein the thickness of the pivot portion is in the range of 0.1 mm to 0.2 mm.

12. The cover assembly according to claim 7, wherein the length of the pivot portion is in the range of 0.25 mm to 0.45 mm.

13. The cover assembly of claim 3, further comprising an inclined portion extending at an angle from the pivot portion and connected to the connecting portion.

14. The cover assembly of claim 13, wherein 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 circumferential surface of the outer body and the central axis of the inner body.

15. The cover assembly of claim 3, further comprising a bent portion extending from the connecting portion and surrounding the outer body.

16. The cover assembly of claim 15, wherein the bent portion comprises: The first bent portion contacts the first surface of the outer body; The second bend portion is spaced apart from the first bend portion and contacts the second surface of the outer body; as well as The connecting portion is connected between the first bent portion and the second bent portion.

17. The cover assembly of claim 1, further comprising a first insulating member disposed between the safety vent and the lower cover.

18. A secondary battery, comprising: A can with an opening; Electrode assembly, housed in the can; as well as Cover assembly, covering the opening, The cover assembly includes: Top cover; The lower cover is located on the lower side of the upper cover; A safety vent, disposed between the upper cover and the lower cover, and having a rotating shaft portion deformable by operating pressure; and The bent portion extends from the safety vent and surrounds the edge of the top cover.

19. The secondary battery of claim 18, wherein the can includes a crimped portion surrounding the bent portion.

20. The secondary battery according to claim 19, further comprising a second insulating member disposed between the bent portion and the crimped portion.

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