Secondary battery

Abstract

A secondary battery (10) includes an electrode assembly (100), a case (200) that accommodates the electrode assembly (100) and is open toward one side in a first direction, and a cover assembly (300) that covers an end portion of the case (200) on the one side in the first direction. The cover assembly (300) can include a cover plate (310) that includes a gas vent (312), and a plate-shaped gas vent member (320) that is disposed on opposite sides of the cover plate (310) in the first direction and has a plurality of cutout portions (N) each having a cutout, wherein the plurality of cutout portions (N) are capable of breaking when an internal pressure of the case (200) reaches or exceeds a first threshold. The plurality of cutout portions (N) are positioned along a circumferential direction around a first portion (322) of the gas vent member (320), and can be spaced apart from each other by a predetermined distance. Each cutout portion (N) can include a pair of side portions (N1) that extend outward from the first portion (322) and are spaced apart from each other, and an outer peripheral portion (N2) that connects outer ends of the pair of side portions (N1) and partially surrounds the first portion (322).

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2023-0191918 filed on December 26, 2023 and Korean Patent Application No. 10-2024-0192195 filed on December 20, 2024, the entire contents disclosed in the documents of the aforementioned patent applications are incorporated herein by reference.

[0002] This invention relates to a secondary battery in which internally generated gas or heat is rapidly and uniformly discharged, thereby improving safety and increasing battery capacity or reducing battery size. Background Technology

[0003] Secondary batteries are commonly used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. Types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries.

[0004] When a secondary battery is repeatedly charged and discharged, gas may be generated, which can increase the internal pressure. If this internal pressure is not managed, there is a risk of the secondary battery exploding. Therefore, secondary batteries have a venting structure. (See reference...) Figure 1 Describe the exhaust structure.

[0005] Figure 1 The venting structure of a conventional secondary battery is shown. (Refer to...) Figure 1 The secondary battery 1 may include an electrode assembly 2, a housing 3 that houses the electrode assembly 2, and a cover assembly 4 that covers the upper end of the housing 3.

[0006] The cover assembly 4 may include a cover plate 5, an exhaust member 7, and a current interruption device 8 (CID). The cover plate 5 may include exhaust ports 6. Multiple exhaust ports 6 may be disposed along the outer peripheral surface of the protruding cylindrical head of the cover plate 5. The cover plate 5 may be electrically connected via coupling to the exhaust member 7. The current interruption device 8 may be electrically connected between the electrode assembly 2 and the cover plate 5 via coupling to the electrode leads of the electrode assembly 2 and the exhaust member 7. Figure 1 (a) in the middle.

[0007] When the internal pressure of housing 3 increases, the exhaust component 7 may deform, and a portion of the current interruption device 8 may separate. As a result, the electrode assembly 2 and the cover plate 5 may disconnect. Figure 1 (b)). Furthermore, the exhaust component 7 can break, and the gas and heat inside the housing 3 may be discharged to the outside through the exhaust port 6. Figure 1 (c) of the text. The exhaust component 7 may include a cut that facilitates breakage.

[0008] In a conventional exhaust structure, the slits are asymmetrically formed in the exhaust member 7, allowing the exhaust member 7 to open only to one side and close to the other side. Figure 1 (c) Therefore, since the gas and heat are not fully discharged because they only pass through one side, there is a risk of explosion or fire. Furthermore, to rapidly discharge the gas and heat, the size of the exhaust port 6 on one side must be increased, which leads to a relative reduction in battery capacity. Additionally, since the exhaust component 7 only opens to one side, the size of the fractured piece caused by the cut is relatively large, which may hinder the discharge of gas and heat.

[0009] The relevant prior art is Korean Patent Application No. 10-2011-0095118. Summary of the Invention

[0010] Technical issues

[0011] To address the aforementioned problems, the present invention aims to provide a secondary battery in which generated gases or heat are rapidly and uniformly discharged, thereby improving safety.

[0012] The purpose of this invention is to provide a secondary battery with increased capacity or reduced size.

[0013] The object of the present invention is to provide a secondary battery in which the cut of the exhaust component is sufficiently and reliably broken.

[0014] The object of the present invention is to provide a secondary battery in which a combination of an exhaust component and a current interruption device is stably established.

[0015] The object of the present invention is to provide a secondary battery in which a fractured component formed by a fractured cut of an exhaust member is stably supported.

[0016] The technical problem to be solved by the present invention is not limited to the above-described objectives, and other objectives and advantages not described herein will be understood through the following description and will become clearer through examples of the invention. Furthermore, it is apparent that the objectives and advantages of the present invention can be embodied by the means and combinations thereof shown in the claims.

[0017] Technical solution

[0018] To address the aforementioned problems, the present invention provides a secondary battery comprising an electrode assembly 100, a housing 200, and a cover assembly 300.

[0019] The housing 200 can accommodate the electrode assembly 100 and is open to one side facing the first direction.

[0020] The cover assembly 300 can cover one end of the housing 200 in a first direction.

[0021] The cover assembly 300 may include a cover plate 310 and an exhaust member 320.

[0022] The cover plate 310 may include an exhaust port 312.

[0023] The exhaust component 320 can be disposed on the other side of the cover plate 310 in the first direction.

[0024] The exhaust component 320 may be provided with multiple cutouts N.

[0025] In each of the plurality of incision portions N, an incision can be formed.

[0026] When the internal pressure of the housing 200 exceeds the first threshold, the multiple cut sections N can break.

[0027] The exhaust component 320 can be plate-shaped.

[0028] Multiple cutouts N can be arranged along the circumferential direction surrounding the first portion 322 of the exhaust member 320.

[0029] Multiple cuts N can be spaced apart from each other at a predetermined distance.

[0030] Each cut portion N may include a pair of side portions N1 and a peripheral portion N2.

[0031] The opposite side N1 can extend outward from the first part 322.

[0032] The opposite sides N1 can be spaced apart from each other.

[0033] The outer peripheral part N2 can be connected to the outer ends of a pair of side parts N1.

[0034] The outer periphery N2 may partially surround the first part 322.

[0035] Each cutout N may be provided with a radially predetermined section S, wherein the distance between a pair of side portions N1 gradually increases as they move radially away from the center C of the first portion 322.

[0036] In one embodiment, the peripheral portion N2 of each of the plurality of cutout portions N may protrude outward away from the first portion 322.

[0037] In the implementation, the plurality of cutouts N may have corresponding sizes and shapes, and may be spaced apart at equal angles with the first portion 322 as the center.

[0038] In the implementation, each of the plurality of cutouts N has a fan-shaped shape centered on the first portion 322.

[0039] In the implementation, the plurality of cutouts N may have corresponding sizes and shapes.

[0040] Three to six cut sections N can be set.

[0041] In the implementation, the plurality of cutouts N may have corresponding sizes and shapes, and may be spaced apart at equal angles with the first portion 322 as the center.

[0042] The exhaust component 320 may include: a first part 322; a second part 324; and a plurality of third parts 326.

[0043] The second part 324 may surround the first part 322 and multiple cutouts N.

[0044] Multiple third parts 326 can be arranged between multiple cut sections N.

[0045] Multiple third parts 326 may extend along one or the other side in the radial direction.

[0046] Multiple third parts 326 can connect to the first part 322 and the second part 324.

[0047] Each of the plurality of third parts 326 may have a width W that is greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300.

[0048] In an implementation, the width W of each of the plurality of third portions 326 may be greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 3 / 20 of the diameter of the housing 200 or the cover assembly 300.

[0049] In one embodiment, the central portion of the exhaust member 320 may be configured to protrude toward the other side in the first direction.

[0050] Therefore, the other end of the first direction of the first part 322 may be located on the other side of the first direction relative to the other end of the outer periphery N2 of each of the plurality of cutouts N.

[0051] When the internal pressure of the housing 200 is greater than or equal to the second threshold, the central portion of the exhaust member 320 can be bent to protrude toward one side in the first direction.

[0052] Therefore, one end of the first part 322 in the first direction may be located on one side of the first direction relative to the outer peripheral part N2 of each of the plurality of cut portions N when they are not broken.

[0053] In an implementation, the second threshold may be different from the first threshold.

[0054] In an implementation, the second threshold may be greater than or equal to the first threshold.

[0055] In an implementation, the strength of the peripheral portion N2 in each of the plurality of cutouts N can be different from the strength of a pair of side portions N1.

[0056] In an implementation, in each of the plurality of cutouts N, the strength of the peripheral portion N2 may be less than the strength of a pair of side portions N1.

[0057] In an embodiment, the diameter R of the first portion 322 may be greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300.

[0058] In an embodiment, the diameter R of the first portion 322 may be greater than or equal to 3 / 40 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 1 / 8 of the diameter of the housing 200 or the cover assembly 300.

[0059] In one embodiment, the exhaust component 320 may be coupled to and electrically connected to the cover plate 310.

[0060] The cover assembly 300 may also include a current interruption device 340, which is coupled to the first part 322 to electrically connect the electrode assembly 100 and the cover plate 310.

[0061] Beneficial effects

[0062] According to an embodiment of the present invention, a secondary battery may include: an electrode assembly 100; a housing 200 that houses the electrode assembly 100 and is open to one side in a first direction; and a cover assembly 300 that covers the end of the housing 200 on one side in the first direction. The cover assembly 300 may include: a cover plate 310 having a vent 312; and a plate-shaped venting member 320 disposed on the other side of the cover plate 310 in the first direction and having a plurality of slits N, each having a slit therein. When the internal pressure of the housing 200 exceeds a first threshold, the plurality of slits N can break. The plurality of slits N may be arranged along a circumferential direction surrounding a first portion 322 of the venting member 320 and spaced apart from each other at a predetermined distance. Each of the plurality of slits N may include: a pair of side portions N1, the pair of side portions being spaced apart from each other and extending outward from the first portion 322; and an outer peripheral portion N2 connecting the outer ends of the pair of side portions N1 and partially surrounding the first portion 322. Each of the plurality of cutouts N may be provided with a radially predetermined section S, wherein the distance between a pair of side portions N1 gradually increases as they move radially away from the center C of the first portion 322.

[0063] Therefore, when the internal pressure of the secondary battery 10 increases, the plurality of cuts N around the first portion 322 of the venting member 320 can break, and not only the outer periphery N2 of each cut portion N but also a pair of side portions N1 can break, allowing the gas or heat generated inside the secondary battery 10 to be rapidly discharged in all directions. For example, when projected onto a plane perpendicular to the first direction, the gas or heat can be rapidly discharged from the first portion 322 in the radial direction. As a result, the risk of fire or explosion of the secondary battery 10 can be reduced, thereby improving the safety of the secondary battery 10.

[0064] Furthermore, the vents 312 of the cover 310 can be distributed in all directions to quickly discharge gas or heat passing through the broken venting member 320 in all directions, thereby reducing the size of the cover 310 (e.g., width / diameter or height). When the width / diameter of the cover 310 is reduced, short circuits between the cover 310 and the housing 200 can be prevented, thereby improving the safety of the secondary battery 10. When the height of the cover 310 (width / length in the first direction) is reduced, the width / length of the electrode assembly 100 in the first direction can be increased, thereby increasing the battery capacity or allowing the secondary battery to be manufactured smaller.

[0065] Furthermore, since not only the outer periphery N2 of each cut-out portion N but also the pair of side portions N1 can break, even when the size of each cut-out portion N is reduced, gas or heat can be discharged faster than when only the outer periphery N2 of each cut-out portion N breaks. When the size of each cut-out portion N is reduced, the size of each fractured piece L formed by the breakage of each cut-out portion N can also be reduced. Therefore, the size of the blank space provided between the cover plate 310 and the exhaust member 320 can be reduced, so that multiple fractured pieces L can be bent to form an opening H in the exhaust member 320. As a result, the size of the cover plate 310 (e.g., width / diameter or height) can be reduced, thereby improving the safety of the secondary battery 10, increasing the battery capacity, or miniaturizing the secondary battery 10.

[0066] Furthermore, since each cut N has a predetermined section S, the overall size of the multiple openings H formed by the fracture of the multiple cut N can be increased even when multiple cut N are positioned along the circumferential direction. Therefore, gas or heat can be rapidly released.

[0067] According to an embodiment of the present invention, the outer peripheral portion N2 of each of the plurality of cut portions N may protrude outward away from the first portion 322.

[0068] Therefore, the internal area (area of ​​the fractured part L) of each cut portion N can be increased. As a result, since each cut portion N can withstand sufficient pressure, each cut portion N can fracture sufficiently, thereby reducing the risk of fire or explosion of the secondary battery 10 and improving the safety of the secondary battery 10.

[0069] According to an embodiment of the present invention, the plurality of cutouts N may have corresponding sizes and shapes, and may be spaced apart at equal angles with the first portion 322 as the center.

[0070] Therefore, when the multiple cuts N of the exhaust component 320 break, gas or heat can be discharged uniformly and rapidly in all directions. As a result, the risk of fire or explosion of the secondary battery 10 can be reduced, thereby improving the safety of the secondary battery 10.

[0071] According to an embodiment of the present invention, each of the plurality of cutouts N has a fan-shaped shape centered on the first portion 322.

[0072] Therefore, the total size of the multiple openings H formed by the fracture of multiple cut sections N can be increased. Thus, gas or heat can be rapidly released.

[0073] Furthermore, when multiple cut sections N break, gas or heat can be released uniformly and rapidly in all directions. As a result, the risk of fire or explosion of the secondary battery 10 can be reduced, thereby improving the safety of the secondary battery 10.

[0074] According to an embodiment of the present invention, the plurality of cut portions N can have corresponding sizes and shapes. Three to six cut portions N can be provided.

[0075] Therefore, since the number of simple cut sections N is six or fewer, the internal area of ​​each cut section N (the area of ​​the fractured part L) can be large enough. As a result, each cut section N can fracture sufficiently when subjected to sufficient pressure.

[0076] Furthermore, since the number of cut portions N is three or more, the angle between the pair of sides N1 of each cut portion N can be sufficiently reduced to a predetermined angle (e.g., 120 degrees) or less. As a result, the length of the peripheral portion N2 is reduced, so that when the peripheral portion N2 and the pair of sides N1 are subjected to sufficient pressure, both the peripheral portion N2 and the pair of sides N1 can fracture sufficiently.

[0077] According to an embodiment of the invention, the plurality of slits N may have corresponding sizes and shapes, and may be spaced apart at equal angles with respect to a first portion 322 as the center. The venting member 320 may include: a first portion 322; a second portion 324 surrounding the first portion 322 and the plurality of slits N; and a plurality of third portions 326 disposed between the plurality of slits N, extending radially to one or the other side and connecting the first portion 322 and the second portion 324. The width W of each of the plurality of third portions 326 is greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300.

[0078] Therefore, since the width W of the third portion 326 is greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300, the width of the third portion 326 is large enough that it can stably support the first portion 322 that supports the multiple broken pieces L. As a result, the multiple broken pieces L can be stably supported. Furthermore, since the width W of the third portion 326 is less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300, the size of the opening H formed by the fracture of the multiple cut portions N can be large enough. Therefore, gas or heat can be rapidly discharged.

[0079] According to an embodiment of the invention, the width W of each of the plurality of third portions 326 may be greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 3 / 20 of the diameter of the housing 200 or the cover assembly 300.

[0080] Therefore, since the width W of the third portion 326 is greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300, the width of the third portion 326 is large enough that it can stably support the first portion 322 that supports the multiple broken pieces L. As a result, the multiple broken pieces L can be stably supported. Furthermore, since the width W of the third portion 326 is less than or equal to 3 / 20 of the diameter of the housing 200 or the cover assembly 300, the size of the opening H formed by the fracture of the multiple cut portions N can be large enough. Therefore, gas or heat can be released rapidly.

[0081] According to an embodiment of the present invention, the central portion of the exhaust member 320 may be formed to protrude toward the other side of the first direction. Therefore, the other end of the first portion 322 in the first direction may be located on the other side of the first direction relative to the other end of the outer peripheral portion N2 of each of the plurality of cutouts N. When the internal pressure of the housing 200 is equal to or greater than the second threshold, the central portion of the exhaust member 320 is bent to protrude toward the side of the first direction. Therefore, one end of the first portion 322 in the first direction may be located on the side of the first direction relative to the upper end of the outer peripheral portion N2 of each of the plurality of cutouts N when they are not broken.

[0082] Therefore, when the exhaust member 320 deforms (flips) such that the central portion of the exhaust member 320 protrudes from one side in the first direction to the other, forces such as compressive forces or tensions (e.g., towards one side or the other in the radial direction) can be concentrated and applied to the multiple slits N in the exhaust member 320 with relatively low intensity. As a result, when the exhaust member 320 deforms (flips), the multiple slits N can break sufficiently, thereby allowing gas or heat to be rapidly discharged.

[0083] Specifically, when the exhaust member 320 deforms (flips) and compressive or tensile forces are applied to one or the other side in the radial direction, the degree of deformation of the side N1, which has low stiffness due to the notch, may differ from the degree of deformation of the two sides of the side N1, which has high stiffness due to the absence of the notch. Due to this difference in the degree of deformation, the side N1 is subjected to significant pressure along its length extending to one or the other side in the radial direction, potentially causing it to fracture sufficiently. Therefore, gas or heat can be rapidly discharged.

[0084] According to an embodiment of the present invention, the second threshold may be different from the first threshold.

[0085] Therefore, since bending (overturning) and breakage of the exhaust component 320 may occur sequentially, multiple cuts N can be reliably broken.

[0086] According to an embodiment of the present invention, the second threshold may be greater than or equal to the first threshold.

[0087] Therefore, when the second threshold is greater than the first threshold, when the internal pressure of the housing 200 reaches the first threshold, the multiple cut portions N may fracture but not completely fracture due to the internal pressure. However, as the internal pressure increases due to insufficient fracture and reaches the second threshold, the exhaust member 320 deforms (flips), causing the multiple cut portions N to fracture completely. Furthermore, when the second threshold is equal to the first threshold, when the internal pressure reaches the first threshold, the multiple cut portions N may fracture completely due to the internal pressure of the housing 200 and the deformation of the exhaust member 320. Therefore, incomplete fracture of the multiple cut portions N can be prevented, thereby improving the safety of the secondary battery 10 by reducing the risk of fire or explosion.

[0088] According to an embodiment of the present invention, in each of the plurality of cutouts N, the strength of the outer peripheral portion N2 may be different from the strength of a pair of side portions N1.

[0089] Therefore, since the fractures of the peripheral portion N2 and the lateral portion N1 can occur sequentially, multiple cut portions N can be reliably fractured.

[0090] According to an embodiment of the present invention, in each of the plurality of cutouts N, the strength of the outer peripheral portion N2 may be less than the strength of a pair of side portions N1.

[0091] Therefore, the peripheral portion N2 may fracture before the pair of side portions N1. As a result, the fracture of the pair of side portions N1, which connect to both ends of the peripheral portion N2, may be caused by the first fracture of the peripheral portion N2. Thus, not only the peripheral portion N2 of each cut portion N but also the pair of side portions N1 may fracture sufficiently.

[0092] According to an embodiment of the present invention, the diameter R of the first part 322 may be greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300.

[0093] Therefore, since the diameter R of the first portion 322 is greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300, the width of the first portion 322 is large enough to stably support the multiple broken pieces L. Furthermore, when the first portion 322 is connected to the current interruption device 340, a stable connection (e.g., welding) can be established between the first portion 322 and the current interruption device 340. Additionally, since the diameter R of the first portion 322 is less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300, the size of the opening H formed by the fracture of the multiple cut portions N can be large enough. Therefore, gas or heat can be rapidly discharged.

[0094] According to an embodiment of the present invention, the diameter R of the first part 322 may be greater than or equal to 3 / 40 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 1 / 8 of the diameter of the housing 200 or the cover assembly 300.

[0095] Therefore, since the diameter R of the first portion 322 is greater than or equal to 3 / 40 of the diameter of the housing 200 or the cover assembly 300, the width of the first portion 322 is large enough to stably support the multiple broken pieces L. Furthermore, when the first portion 322 is connected to the current interruption device 340, a stable connection (e.g., welding) can be established between the first portion 322 and the current interruption device 340. Additionally, since the diameter R of the first portion 322 is less than or equal to 1 / 8 of the diameter of the housing 200 or the cover assembly 300, the size of the opening H formed by the fracture of the multiple cut portions N can be large enough. Therefore, gas or heat can be rapidly discharged.

[0096] According to an embodiment of the invention, the exhaust component 320 may be coupled to and electrically connected to the cover plate 310. The cover assembly 300 may also include a current interruption device 340 coupled to the first portion 322 to electrically connect the electrode assembly 100 and the cover plate 310.

[0097] Therefore, since the current interruption device 340 is connected to the first portion 322 where the notch N is not formed, the exhaust member 320 and the current interruption device 340 can be stably connected. Furthermore, when the notch N breaks, the first portion 322 can stably support the broken member L.

[0098] In addition to the aforementioned advantages, the specific effects of the invention will be further described while describing the specific details of the invention. Attached Figure Description

[0099] Figure 1 The exhaust structure of a conventional secondary battery is shown.

[0100] Figure 2 and Figure 3 This is a schematic cross-sectional view of a secondary battery according to an embodiment of the present invention.

[0101] Figures 4 to 6 It is shown Figure 2 and Figure 3 Plan view of three embodiments of the exhaust component.

[0102] Figure 7 It is shown schematically. Figure 4 A perspective view of the open exhaust components.

[0103] [Explanation of reference numerals in the attached figures]

[0104] 10: Secondary batteries

[0105] 100: Electrode assembly; 110: Electrode lead.

[0106] 200: Housing

[0107] 300: Cover component

[0108] 310: Cover plate; 312: Exhaust port

[0109] 320: Exhaust component; 322: First part

[0110] 324: Part Two; 326: Part Three

[0111] N: Incision N1: Side

[0112] N2: Outer perimeter; S: Planned section

[0113] L: Fractured component H: Opening

[0114] 330: Washer

[0115] 340: Current interruption device

[0116] 342: First connector; 344: Second connector Detailed Implementation

[0117] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art will be able to implement the technical ideas of the present invention. In describing the present invention, detailed descriptions of prior art related to the present invention will be omitted where it is determined that such detailed descriptions unnecessarily obscure the essential points of the present invention. Preferred embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. In the drawings, the same reference numerals are used to denote the same or similar parts.

[0118] Although terms such as "first" and "second" are used to describe various elements, these elements are certainly not limited by these terms. These terms are only used to distinguish one element from another, and unless otherwise specified, the first element can also be the second element.

[0119] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0120] In the following text, "arranging a component on top of (or below) a component" or "arranging a component on the top of (or bottom) a component" means not only "arranging a component to contact the upper (or lower) surface," but also "arranging a component above the upper (or lower) surface, with another component inserted between them."

[0121] Furthermore, when an element is described as being “connected to,” “linked to,” or “in contact with” another element, it should be understood that the element may be “directly connected to,” “directly linked to,” or “directly in contact with” the other element, or that the element may be “connected to,” “linked to,” or “in contact with” the other element by means of another element inserted therebetween or via another element.

[0122] Unless the context clearly indicates otherwise, the singular expressions used herein include the plural expressions. Terms such as “consisting of” or “comprising” as used herein should not be construed as necessarily including all elements or steps described in the specification, but should be construed as excluding some elements or steps, or including additional elements or steps.

[0123] Figure 1 The exhaust structure of a conventional secondary battery is shown. Figure 2 and Figure 3 This is a schematic cross-sectional view of a secondary battery according to an embodiment of the present invention. Figures 4 to 6 It is shown Figure 2 and Figure 3 Plan view of three embodiments of the exhaust component. Figure 7 It is shown schematically. Figure 4 A perspective view of the open exhaust components.

[0124] [Rechargeable Battery]

[0125] Reference Figure 2 and Figure 3 The secondary battery 10 according to the embodiment may include an electrode assembly 100, a housing 200 and a cover assembly 300.

[0126] Electrode assembly 100 may be a core-type assembly in which anode sheet, diaphragm sheet, and cathode sheet are laminated and wound. However, it is not limited thereto. Electrode assembly 100 may include electrode leads 110 protruding to one side (e.g., the upper side) along a first direction (e.g., the vertical direction).

[0127] The housing 200 can accommodate the electrode assembly 100. The housing 200 can be opened to one side facing the first direction.

[0128] The cover assembly 300 can cover one end of the housing 200 in a first direction.

[0129] The cover assembly 300 may include a cover plate 310 and a venting member 320. The cover assembly 300 may include a gasket 330. The cover assembly 300 may include a current interruption device (CID) 340.

[0130] The cover plate 310 may include an exhaust port 312. The exhaust port 312 may be disposed on the side surface or the top surface of the cover plate 310. One or more exhaust ports 312 may be disposed along a circumferential direction. Here, the circumferential direction may be the direction about an imaginary axis A that extends along a first direction and passes through the center of the first portion 322.

[0131] The cover plate 310 can be connected to the exhaust component 320. The cover plate 310 can be electrically connected to the exhaust component 320.

[0132] Gasket 330 can be disposed between cover plate 310 and venting member 320 and housing 200. Gasket 330 can insulate housing 200 from cover plate 310 and venting member 320.

[0133] The current interruption device 340 can be disposed on the opposite side of the exhaust member 320 in the first direction. The current interruption device 340 can electrically connect the electrode assembly 100 and the cover plate 310. To achieve this, the current interruption device 340 may include a first connector 342 and a second connector 344. The first connector 342 can be connected to the electrode lead 110 of the electrode assembly 100. The second connector 344 can be connected to the first portion 322 of the exhaust member 320, which is electrically connected to the cover plate 310.

[0134] The current interruption device 340 can electrically connect the electrode assembly 100 to the cover plate 310 and electrically disconnect the electrode assembly 100 from the cover plate 310 when the internal pressure of the housing 200 exceeds a predetermined value.

[0135] For example, the current interruption device 340 may include the first connector 342 and the second connector 344 as described above, and the venting member 320 deforms when the internal pressure of the housing 200 exceeds the second threshold, thus, as Figure 1 As shown, the second connector 344 connected to the exhaust component 320 can be separated from the first connector 342. As a result, the electrode assembly 100 and the cover plate 310 can be electrically disconnected.

[0136] The exhaust component 320 will be described below.

[0137] [Exhaust System]

[0138] The exhaust member 320 may be disposed on the opposite side (e.g., the underside) of the cover plate 310 in the first direction. The exhaust member 320 may be plate-shaped. The exhaust member 320 may include a material comprising metal (e.g., aluminum).

[0139] [incision]

[0140] Further reference Figures 4 to 7 According to the embodiment, the exhaust component 320 may be provided with a plurality of notched portions N.

[0141] Multiple cutouts N may be arranged along the circumferential direction surrounding the first portion 322 of the exhaust member 320.

[0142] Multiple cuts N can be spaced apart from each other at a predetermined distance. When the internal pressure of the housing 200 exceeds a first threshold, the multiple cuts N can break.

[0143] A cut can be formed in each of the plurality of cut portions N. The cuts can be arranged continuously or intermittently. When each of the plurality of cut portions N breaks, a fracture member L can be formed. One side of the fracture member L can be connected to the first portion 322. An opening H can be formed in the exhaust member 300 by bending or deforming the fracture member L. Figure 7 Gas and heat can be discharged to the outside through opening H and exhaust port 312.

[0144] Each cut portion N may include a pair of side portions N1 and a peripheral portion N2.

[0145] A pair of side portions N1 may extend outward from the first portion 322 (e.g., towards one side or the other in a radial direction). The pair of side portions N1 may be spaced apart from each other.

[0146] Here, the radial direction can be the direction of movement away from or towards the imaginary axis on a plane perpendicular to the imaginary axis that extends in the first direction and passes through the center C of the first part 322.

[0147] The outer peripheral portion N2 can connect to the outer ends of a pair of side portions N1. The outer peripheral portion N2 can partially surround the first portion 322.

[0148] Therefore, when the internal pressure of the secondary battery 10 increases, the plurality of cuts N around the first portion 322 of the venting member 320 can break, and not only the outer periphery N2 of each cut portion N but also a pair of side portions N1 can break, allowing the gas or heat generated inside the secondary battery 10 to be rapidly discharged in all directions. For example, when projected onto a plane perpendicular to the first direction, the gas or heat can be rapidly discharged from the first portion 322 in the radial direction. As a result, the risk of fire or explosion of the secondary battery 10 can be reduced, thereby improving the safety of the secondary battery 10.

[0149] Furthermore, the vents 312 of the cover 310 can be distributed in all directions to quickly discharge gas or heat passing through the broken venting member 320 in all directions, thereby reducing the size of the cover 310 (e.g., width / diameter or height). When the width / diameter of the cover 310 is reduced, short circuits between the cover 310 and the housing 200 can be prevented, thereby improving the safety of the secondary battery 10. When the height of the cover 310 (width / length in the first direction) is reduced, the width / length of the electrode assembly 100 in the first direction can be increased, thereby increasing the battery capacity or allowing the secondary battery to be manufactured smaller.

[0150] Furthermore, since not only the outer periphery N2 of each cut-out portion N but also the pair of side portions N1 can break, even when the size of each cut-out portion N is reduced, gas or heat may be released faster than when only the outer periphery N2 of each cut-out portion N breaks. When the size of each cut-out portion N is reduced, the size of each fractured piece L formed by the breakage of each cut-out portion N can also be reduced. Therefore, the size of the blank space provided between the cover plate 310 and the exhaust member 320 can be reduced, allowing multiple fractured pieces L to be bent to form an opening H in the exhaust member 320. As a result, the size of the cover plate 310 (e.g., width / diameter or height) can be reduced, thereby improving the safety of the secondary battery 10, increasing the battery capacity, or miniaturizing the secondary battery 10.

[0151] The peripheral portion N2 of each of the multiple cut portions N can protrude outward away from the first portion 322.

[0152] Therefore, the internal area (area of ​​the fractured component L) of each cut N can be increased. As a result, since each cut N can withstand sufficient pressure, each cut N can fracture sufficiently, thereby reducing the risk of fire or explosion of the secondary battery 10 and improving the safety of the secondary battery 10.

[0153] Each cutout N may be provided with a radially predetermined section S, wherein the distance between a pair of side portions N1 gradually increases as they move radially away from the center C of the first portion 322.

[0154] Therefore, since each cut N has a predetermined section S, the overall size of the multiple openings H formed by the fracture of the multiple cut N may increase even when the multiple cut N are positioned along the circumferential direction. Thus, gas or heat can be rapidly released.

[0155] In each of the multiple cutouts N, the strength of the peripheral portion N2 may differ from the strength of a pair of side portions N1.

[0156] Therefore, since the fractures of the peripheral portion N2 and the lateral portion N1 can occur sequentially, multiple cut portions N can be reliably fractured.

[0157] In each of the plurality of cut portions N, the strength of the peripheral portion N2 may be less than the strength of a pair of side portions N1.

[0158] Therefore, the peripheral portion N2 can fracture before the pair of side portions N1. As a result, the fracture of the pair of side portions N1, which connect to both ends of the peripheral portion N2, may be caused by the first fracture of the peripheral portion N2. Thus, not only the peripheral portion N2 of each cut portion N but also the pair of side portions N1 can fracture sufficiently.

[0159] Each of the multiple cutouts N has a fan-shaped shape centered on the first part 322.

[0160] Therefore, the total size of the multiple openings H formed by the fracture of multiple cut sections N can be increased. Thus, gas or heat can be rapidly released.

[0161] Furthermore, when multiple cut sections N break, gas or heat can be uniformly and rapidly discharged in all directions. As a result, the risk of fire or explosion of the secondary battery 10 can be reduced, thereby improving the safety of the secondary battery 10.

[0162] Multiple cutouts N can have corresponding sizes and shapes. Three to six cutouts N can be provided.

[0163] Therefore, since the number of notches N is six or fewer, the internal area of ​​each notch N (the area of ​​the fractured part L) can be large enough. As a result, each notch N can fracture sufficiently when subjected to sufficient pressure.

[0164] Furthermore, since the number of cut portions N is three or more, the angle between the pair of sides N1 of each cut portion N can be sufficiently reduced to a predetermined angle (e.g., 120 degrees) or less. As a result, the length of the peripheral portion N2 is reduced, so that when the peripheral portion N2 and the pair of sides N1 are subjected to sufficient pressure, both the peripheral portion N2 and the pair of sides N1 can fracture sufficiently.

[0165] Multiple cutouts N can have corresponding sizes and shapes, and can be spaced apart at equal angles with the first part 322 as the center.

[0166] Therefore, when the multiple cuts N of the exhaust component 320 break, gas or heat can be discharged uniformly and rapidly in all directions. As a result, the risk of fire or explosion of the secondary battery 10 can be reduced, thereby improving the safety of the secondary battery 10.

[0167] [Part One, Part Two, and Part Three]

[0168] The exhaust component 320 may include a first portion 322. The exhaust component 320 may also include a second portion 324 and a third portion 326.

[0169] The first part 322 may be the central part of the exhaust member 320. One side of the plurality of broken members L may be connected to the first part 322. Figure 7 ).

[0170] The diameter R of the first part 322 can be greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300. For example, the diameter R of the first part 322 can be greater than or equal to 1 mm and less than or equal to 5 mm. For example, when the diameter of the housing 200 or the cover assembly 300 is 21 mm, the diameter R of the first part 322 can be greater than or equal to 1 mm and less than or equal to 5 mm.

[0171] Therefore, since the diameter R of the first portion 322 is greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300, the width of the first portion 322 is large enough to stably support the multiple broken pieces L. Furthermore, when the first portion 322 is connected to the current interruption device 340, a stable connection (e.g., welding) can be established between the first portion 322 and the current interruption device 340. Additionally, since the diameter R of the first portion 322 is less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300, the size of the opening H formed by the fracture of the multiple cut portions N can be large enough. Therefore, gas or heat can be rapidly discharged.

[0172] Preferably, the diameter R of the first portion 322 can be greater than or equal to 3 / 40 of the diameter of the housing 200 or the cover assembly 300 and less than or equal to 1 / 8 of the diameter of the housing 200 or the cover assembly 300. For example, the diameter R of the first portion 322 can be greater than or equal to 1.5 mm and less than or equal to 2.5 mm. For example, when the diameter of the housing 200 or the cover assembly 300 is 21 mm, the diameter R of the first portion 322 can be greater than or equal to 1.5 mm and less than or equal to 2.5 mm.

[0173] Therefore, since the diameter R of the first portion 322 is greater than or equal to 3 / 40 of the diameter of the housing 200 or the cover assembly 300, the width of the first portion 322 is large enough to stably support the multiple broken pieces L. Furthermore, when the first portion 322 is connected to the current interruption device 340, a stable connection (e.g., welding) can be established between the first portion 322 and the current interruption device 340. Additionally, since the diameter R of the first portion 322 is less than or equal to 1 / 8 of the diameter of the housing 200 or the cover assembly 300, the size of the opening H formed by the fracture of the multiple cut portions N can be large enough. Therefore, gas or heat can be rapidly discharged.

[0174] The first part 322 can be connected to the aforementioned current interruption device 340. As a result, the current interruption device 340 can electrically connect the electrode assembly 100 to the cover plate 310 through the first part 322.

[0175] Therefore, since the current interruption device 340 is connected to the first portion 322 where the notch N is not formed, the exhaust member 320 and the current interruption device 340 can be stably connected. Furthermore, when the notch N breaks, the first portion 322 can stably support the broken member L.

[0176] The second part 324 may surround the first part 322 and multiple cutouts N.

[0177] Multiple third portions 326 can be provided. Multiple third portions 326 can be provided between multiple cutouts N. Multiple third portions 326 can extend to one side or the other in the radial direction. Multiple third portions 326 can connect to the first portion 322 and the second portion 324.

[0178] When multiple cutouts N have corresponding sizes and shapes and are positioned at equal angular intervals around the first portion 322, the width W of each third portion 326 can be greater than or equal to 1 / 25 of the diameter of the housing 200 or cover assembly 300 and less than or equal to 1 / 4 of the diameter of the housing 200 or cover assembly 300. For example, the width W of each third portion 326 can be 1 mm or greater and 5 mm or less. For example, when the diameter of the housing 200 or cover assembly 300 is 21 mm, the diameter R of the first portion 322 can be in the range of 1 mm to 5 mm.

[0179] Therefore, since the width W of the third portion 326 is greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300, the width of the third portion 326 is large enough that it can stably support the first portion 322 that supports the multiple broken pieces L. As a result, the multiple broken pieces L can be stably supported. Furthermore, since the width W of the third portion 326 is less than or equal to 1 / 4 of the diameter of the housing 200 or the cover assembly 300, the size of the opening H formed by the fracture of the multiple cut portions N can be large enough. Therefore, gas or heat can be rapidly discharged.

[0180] Preferably, the width W of each third portion 326 is greater than or equal to 1 / 25 of the diameter of the housing 200 or cover assembly 300 and less than or equal to 3 / 20 of the diameter of the housing 200 or cover assembly 300. For example, the diameter R of the first portion 322 can be 1 mm or greater and 3 mm or less. For example, when the diameter of the housing 200 or cover assembly 300 is 21 mm, the diameter R of the first portion 322 can be in the range of 1 mm to 3 mm.

[0181] Therefore, since the width W of the third portion 326 is greater than or equal to 1 / 25 of the diameter of the housing 200 or the cover assembly 300, the width of the third portion 326 is large enough that it can stably support the first portion 322 that supports the multiple broken pieces L. As a result, the multiple broken pieces L can be stably supported. Furthermore, since the width W of the third portion 326 is less than or equal to 3 / 20 of the diameter of the housing 200 or the cover assembly 300, the size of the opening H formed by the fracture of the multiple cut portions N can be large enough. Therefore, gas or heat can be released rapidly.

[0182] [Deformation of exhaust components]

[0183] The central portion of the exhaust member 320 may be formed to protrude toward the other side (e.g., the lower side) in the first direction. Therefore, the other end (e.g., the lower end) of the first portion 322 in the first direction may be located on the other side of the first direction relative to the other end of the outer periphery N2 of each of the plurality of cutouts N. Figure 2 ).

[0184] When the internal pressure of the housing 200 is greater than or equal to the second threshold, the central portion of the exhaust member 320 can be bent to protrude toward one side (e.g., the upper side) in the first direction. Therefore, one end (e.g., the upper end) of the first portion 322 in the first direction can be located on one side of the first direction relative to the outer peripheral portion N2 of each of the plurality of cuts N when they are not broken. Figure 3 (The dashed line in the image). Here, "when multiple cuts N are not broken" means that each cut N is not broken or is assumed to be not broken.

[0185] Therefore, when the exhaust member 320 deforms (flips) such that the central portion of the exhaust member 320 protrudes from one side in the first direction to the other, forces such as compressive forces or tensions (e.g., towards one side or the other in the radial direction) can be concentrated and applied to the multiple slits N in the exhaust member 320 with relatively low intensity. As a result, when the exhaust member 320 deforms (flips), the multiple slits N can break sufficiently, thereby allowing gas or heat to be rapidly discharged.

[0186] Specifically, when the exhaust member 320 deforms (flips) and compressive or tensile forces are applied to one or the other side in the radial direction, the degree of deformation of the side N1, which has low stiffness due to the notch, may differ from the degree of deformation of the two sides of the side N1, which has high stiffness due to the absence of the notch. Due to this difference in the degree of deformation, the side N1 is subjected to significant pressure along its length extending to one or the other side in the radial direction, allowing it to fracture sufficiently. Therefore, gas or heat can be rapidly released.

[0187] The second threshold can be different from the first threshold mentioned above.

[0188] Therefore, the bending (flipping) and breaking of the exhaust component 320 can be performed sequentially, so that the multiple cuts N can be reliably broken.

[0189] The second threshold can be greater than or equal to the first threshold mentioned above.

[0190] Therefore, when the second threshold is greater than the first threshold, when the internal pressure of the housing 200 reaches the first threshold, the multiple cut portions N may fracture but not completely fracture due to the internal pressure. However, as the internal pressure increases due to insufficient fracture and reaches the second threshold, the exhaust member 320 deforms (flips), causing the multiple cut portions N to fracture completely. Furthermore, when the second threshold is equal to the first threshold, when the internal pressure reaches the first threshold, the multiple cut portions N may fracture completely due to the internal pressure of the housing 200 and the deformation of the exhaust member 320. Therefore, incomplete fracture of the multiple cut portions N can be prevented, thereby improving the safety of the secondary battery by reducing the risk of fire or explosion of the secondary battery 10.

[0191] It should be understood that the described embodiments are illustrative in all respects and not restrictive, and the scope of the invention will be indicated by the following claims, not by the detailed description thereof. Furthermore, the meaning and scope of the claims described below, as well as all variations and modifications derived from equivalent concepts, should be interpreted as being included within the scope of the invention.

[0192] Although the present invention has been described with reference to exemplary figures, it should be understood that the invention is not limited to the embodiments and figures disclosed in this specification, and those skilled in the art will understand that various modifications can be made without departing from the scope and concept of the invention. Furthermore, although the operational effects of the configuration according to the invention are not explicitly described in the description of embodiments of the invention, it should be understood that predictable effects can also be identified through this configuration.

Claims

1. A secondary battery, the secondary battery comprising: Electrode assembly (100); A housing (200) that houses the electrode assembly (100) and is open to one side in a first direction; as well as A cover assembly (300) that covers the end of the housing (200) on one side in the first direction. The cover assembly (300) includes: a cover plate (310) having an exhaust port (312); and a plate-shaped exhaust member (320) disposed on the other side of the cover plate (310) in the first direction and having a plurality of cuts (N) each having a cut therein. Specifically, when the internal pressure of the housing (200) exceeds a first threshold, the plurality of cuts (N) can break. The plurality of cutouts (N) are arranged circumferentially around the first portion (322) of the exhaust member (320) and spaced apart from each other at a predetermined distance. Each of the plurality of cut portions (N) includes: a pair of side portions (N1) spaced apart from each other and extending outward from the first portion (322); and a peripheral portion (N2) connecting the outer ends of the pair of side portions (N1) and partially surrounding the first portion (322), and each of the plurality of cut portions (N) is provided with a radially predetermined segment (S), wherein the distance between the pair of side portions (N1) gradually increases as it moves away from the center (C) of the first portion (322) in the radial direction.

2. The secondary battery according to claim 1, wherein, The peripheral portion (N2) of each of the plurality of cut portions (N) protrudes outward away from the first portion (322).

3. The secondary battery according to claim 1 or 2, wherein, The plurality of cuts (N) have corresponding sizes and shapes and are spaced apart at equal angles with the first portion (322) as the center.

4. The secondary battery according to any one of claims 1 to 3, wherein, Each of the plurality of cuts (N) has a fan-shaped shape centered on the first portion (322).

5. The secondary battery according to claim 4, wherein, The plurality of cuts (N) have corresponding sizes and shapes, and Set three to six incisions (N).

6. The secondary battery according to claim 4, wherein, The plurality of cuts (N) have corresponding sizes and shapes, and are spaced apart at equal angles with the first portion (322) as the center. The exhaust component (320) includes: a first portion (322); a second portion (324) surrounding the first portion (322) and the plurality of cutouts (N); and a plurality of third portions (326) disposed between the plurality of cutouts (N), extending radially to one or the other side and connecting the first portion (322) and the second portion (324), the width W of each of the plurality of third portions (326) being greater than or equal to 1 / 25 of the diameter of the housing (200) or the cover assembly (300) and less than or equal to 1 / 4 of the diameter of the housing (200) or the cover assembly (300).

7. The secondary battery according to claim 6, wherein, The width W of each of the plurality of third parts (326) is greater than or equal to 1 / 25 of the diameter of the housing (200) or the cover assembly (300) and less than or equal to 3 / 20 of the diameter of the housing (200) or the cover assembly (300).

8. The secondary battery according to any one of claims 1 to 7, wherein, The central portion of the exhaust member (320) is formed to protrude toward the other side in the first direction, such that the other end of the first portion (322) in the first direction is located on the other side in the first direction relative to the other end of the outer peripheral portion (N2) in the first direction of each of the plurality of cutouts (N), and When the internal pressure of the housing (200) is greater than or equal to the second threshold, the central portion of the exhaust member (320) is bent to protrude toward the side in the first direction, such that the end of the first portion (322) in the first direction is located on the side in the first direction relative to the end of the outer peripheral portion (N2) of each of the plurality of cuts (N) when they are not broken.

9. The secondary battery according to claim 8, wherein, The second threshold is different from the first threshold.

10. The secondary battery according to claim 8, wherein, The second threshold is greater than or equal to the first threshold.

11. The secondary battery according to any one of claims 1 to 10, wherein, In each of the plurality of cuts (N), the strength of the outer peripheral portion (N2) is different from the strength of the pair of side portions (N1).

12. The secondary battery according to claim 11, wherein, In each of the plurality of cuts (N), the strength of the outer peripheral portion (N2) is less than the strength of the pair of side portions (N1).

13. The secondary battery according to any one of claims 1 to 12, wherein, The diameter (R) of the first portion (322) is greater than or equal to 1 / 25 of the diameter of the housing (200) or the cover assembly (300) and less than or equal to 1 / 4 of the diameter of the housing (200) or the cover assembly (300).

14. The secondary battery according to claim 13, wherein, The diameter (R) of the first portion (322) is greater than or equal to 3 / 40 of the diameter of the housing (200) or the cover assembly (300) and less than or equal to 1 / 8 of the diameter of the housing (200) or the cover assembly (300).

15. The secondary battery according to any one of claims 1 to 14, wherein, The exhaust component (320) is connected to and electrically connected to the cover plate (310), and The cover assembly (300) also includes a current interruption device (340) coupled to the first part (322) to electrically connect the electrode assembly (100) and the cover plate (310).

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