Secondary battery and battery pack including same

Abstract

The present disclosure relates to a secondary battery and a battery pack capable of improving operational convenience and safety of the battery. To this end, the present disclosure provides a secondary battery comprising: an electrode assembly; a cell case configured to accommodate the electrode assembly and having a vent hole formed therein; a movable member installed so as to be reciprocally movable in a direction parallel to the first direction inside the cell case; and a plurality of exhaust members disposed at the movable member and configured to rupture as an internal pressure of the cell case increases, in which each of the exhaust members selectively faces the exhaust hole in association with movement of the movable member. According to the present disclosure, since the bursting pressure of the exhaust member can be changed by the linear reciprocating movement of the movable member, it is possible to flexibly cope with changes in the type and production purpose of the battery and the application environment thereof.

Description

Technical Field

[0001] Aspects of embodiments of the present disclosure relate to a secondary battery and a battery pack including the secondary battery. Background Art

[0002] Generally, as the demand for portable electronic products such as laptop computers, video cameras, and mobile phones has increased sharply and the full commercialization of robots, electric vehicles, etc. has occurred, research on battery packs capable of repeated charging and discharging has been actively conducted.

[0003] A typical battery has a structure including an electrode assembly (not shown) configured to charge and discharge current and a case that houses the electrode assembly. The electrode assembly is housed in the case through an opening of the case, and a lid assembly is coupled to the opening of the case and seals the opening of the case. An exhaust device is installed at the lid assembly, and the exhaust device breaks under gas pressure to discharge high-pressure gas in the case to the outside.

[0004] The above information disclosed in the technology forming the background of the present disclosure is only intended to improve the understanding of the background of the present disclosure, and thus may include information that does not constitute the prior art. Summary of the Utility Model

[0005] One aspect of embodiments of the present disclosure relates to a secondary battery and a battery pack including the secondary battery that can improve the operation convenience and safety of the battery.

[0006] These and other aspects and features of the present disclosure will be described in the following description of some embodiments of the present disclosure or will become apparent from the following description of some embodiments of the present disclosure.

[0007] According to one aspect of the present disclosure, a secondary battery includes: an electrode assembly; a single cell case configured to house the electrode assembly and having an exhaust hole formed therein; a movable member installed to be reciprocally movable in a direction parallel to a first direction inside the single cell case; and a plurality of exhaust members provided at the movable member and configured to break as the internal pressure of the single cell case increases, wherein each of the exhaust members selectively faces the exhaust hole in association with the movement of the movable member.

[0008] The plurality of exhaust members may be arranged in the first direction.

[0009] The thickness of the exhaust member may be less than the thickness of the movable member.

[0010] Each of the exhaust members may have a different breaking pressure.

[0011] Each of the exhaust members may have a different thickness.

[0012] A plurality of exhaust members may be arranged in a first direction, and the thickness of the exhaust members may sequentially increase or decrease in the first direction.

[0013] The secondary battery may further include a gasket disposed between the single cell case and the movable member and configured to seal between the single cell case and the movable member.

[0014] The gasket may be fixed to the movable member and in slidable contact with the single cell case.

[0015] The secondary battery may further include a support member configured to movably support the movable member relative to the single cell case.

[0016] The support member may include: a support body fixed to the single cell case; and a pressing rod configured to extend from the support body and press the movable member toward the single cell case.

[0017] The pressing rod may extend parallel to the first direction, and the pressing rod and the exhaust member may be spaced apart in a direction intersecting the first direction.

[0018] The pressing rod may be provided as a pair of pressing rods, and the pair of pressing rods may contact both sides of the movable member.

[0019] The pressing rod may be provided to be elastically deformable.

[0020] The secondary battery may further include a groove recessed in the movable member and provided to face the exhaust hole.

[0021] The groove may include: a first groove extending in the first direction; and a plurality of second grooves extending from the first groove in a direction intersecting the first direction and arranged in the first direction.

[0022] The secondary battery may further include a guide rail recessed in the single cell case and configured to guide the movement of the movable member.

[0023] The length of the guide rail parallel to the first direction may be greater than the length of the movable member parallel to the first direction.

[0024] The secondary battery may further include: a rod connected to the movable member and configured to protrude to the outside of the single cell case; and a rod rail formed to pass through the single cell case and configured to guide the movement of the rod.

[0025] The secondary battery may further include a rod plate configured to extend from the movable member and support the rod relative to the movable member, and the rod plate may be provided to face the rod rail and may contact the single cell case.

[0026] According to another aspect of the present disclosure, a battery pack includes a housing and one or more secondary batteries disposed in the housing. The secondary battery includes: an electrode assembly; a single cell case configured to accommodate the electrode assembly and having an exhaust hole formed therein; a movable member mounted to be reciprocally movable in a direction parallel to a first direction inside the single cell case; and a plurality of exhaust hole members disposed at the movable member and configured to rupture as the internal pressure of the single cell case increases, wherein each of the exhaust hole members selectively faces the exhaust hole in association with the movement of the movable member. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings of the present specification illustrate some embodiments of the present disclosure and further describe aspects and features of the present disclosure together with the detailed description of the present disclosure. However, the present disclosure should not be construed as being limited to the drawings.

[0028] Figure 1 is a perspective view schematically showing the configuration of a battery pack according to an embodiment of the present disclosure.

[0029] Figure 2 is a perspective view schematically showing the configuration of a secondary battery according to an embodiment of the present disclosure.

[0030] Figure 3 is a plan view schematically showing the configuration of a secondary battery according to an embodiment of the present disclosure.

[0031] Figure 4 is a cross-sectional view schematically showing the configuration of a secondary battery according to an embodiment of the present disclosure.

[0032] Figure 5 is a perspective view schematically showing the installation state of a movable member and an exhaust member according to an embodiment of the present disclosure.

[0033] Figure 6 is Figure 5 an exploded perspective view of

[0034] Figure 7 is a bottom perspective view schematically showing the installation state of a movable member and an exhaust member according to an embodiment of the present disclosure.

[0035] Figure 8 is Figure 7 an exploded perspective view of

[0036] Figure 9 is a side view schematically showing the installation state of a movable member and an exhaust member according to an embodiment of the present disclosure.

[0037] Figure 10is a plan view schematically showing the configurations of a movable member and an exhaust member according to an embodiment of the present disclosure.

[0038] Figure 11 is a cross-sectional view schematically showing the configurations of a movable member and an exhaust member according to an embodiment of the present disclosure.

[0039] Figure 12 is a cross-sectional view schematically showing the configurations of a movable member and an exhaust member according to an embodiment of the present disclosure.

[0040] Figure 13 is an enlarged view schematically showing the configuration of a groove according to an embodiment of the present disclosure.

[0041] Figure 14 is a view schematically showing a state in which a movable member is moved by using a groove.

[0042] Figure 15 is a bottom perspective view schematically showing the configuration of a secondary battery according to another embodiment of the present disclosure.

[0043] Figure 16 is a plan view schematically showing the configuration of a secondary battery according to another embodiment of the present disclosure.

[0044] Figure 17 is a perspective view schematically showing the configuration of a secondary battery according to still another embodiment of the present disclosure.

[0045] Figure 18 is an enlarged view schematically showing the configuration of a secondary battery according to still another embodiment of the present disclosure.

[0046] Figure 19 is an exploded perspective view schematically showing the configuration of a secondary battery according to still another embodiment of the present disclosure.

[0047] Figure 20 and Figure 21 is a view schematically showing a process of moving a movable member by using a rod and a rod rail. Detailed Description

[0048] Here, some embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Terms or words used in this specification and claims should not be construed as limited to common meanings or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical concept of the present disclosure based on the principle that the inventor can be his / her own lexicographer to appropriately define terms.

[0049] The embodiments described in this specification and the configurations shown in the drawings are provided as some example embodiments of the present disclosure and do not represent all technical concepts, aspects, and features of the present disclosure. Therefore, it will be understood that various equivalents and modifications that can replace or modify the embodiments described herein may exist at the time of filing this application.

[0050] It will be understood that when an element or layer is referred to as being "on", "connected to", or "coupled to" another element or layer, it can be directly on, directly connected to, or directly coupled to the other element or layer, or there may also be one or more intervening elements or layers. When an element or layer is referred to as being "directly on", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers. For example, when a first element is described as being "coupled" or "connected" to a second element, the first element can be directly coupled to or directly connected to the second element, or the first element can be indirectly coupled to or indirectly connected to the second element via one or more intervening elements.

[0051] In the figures, for clarity of illustration, the dimensions of various elements, layers, etc. may be exaggerated. The same reference numerals denote the same or similar elements. As used herein, the term "and / or" includes any combination and all combinations of one or more of the associated listed items. Further, when describing embodiments of the present disclosure, the use of "may" relates to "one or more embodiments of the present disclosure". Expressions such as "at least one of..." and "any one of..." modify the entire list of elements after a list of elements and do not modify individual elements in the list. When a phrase such as "at least one of A, B, and C", "at least one of A, B, or C", "at least one of the group consisting of A, B, and C", or "at least one of A, B, and C" is used to specify a list of elements A, B, and C, the phrase can refer to any suitable combination or subset of A, B, and C and all suitable combinations or subsets, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the terms "use" and its variants can be considered to be synonymous with the terms "utilize" and its variants, respectively. As used herein, the terms "substantially", "about", and similar terms are used as approximate terms and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by a person of ordinary skill in the art.

[0052] It will be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, the first element, component, region, layer or section discussed below may be referred to as the second element, component, region, layer or section without departing from the teachings of the exemplary embodiments.

[0053] For ease of description, spatial relative terms such as "beneath", "below", "lower", "above", "upper", etc. may be used herein to describe the relationship of one element or feature to another (other) element or feature as shown in the figures. It will be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, an element described as "beneath" or "below" another element or feature will then be oriented "above" or "over" the other element or feature. Thus, the term "beneath" can encompass both an upper and a lower orientation. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and the spatial relative descriptors used herein should be interpreted accordingly.

[0054] The terms used herein are for the purpose of describing embodiments of the present disclosure and are not intended to limit the present disclosure. As used herein, the singular forms "a" and "an" are also intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that when the terms "comprises", "comprising", and / or their variants are used in this specification, it is specified that there are the stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0055] In addition, any numerical range disclosed and / or recited herein is intended to include all sub-ranges having the same numerical precision as contained within the recited range. For example, a range of "1.0 to 10.0" is intended to include all sub-ranges between the recited minimum value of 1.0 and the recited maximum value of 10.0 (and including the recited minimum value of 1.0 and the recited maximum value of 10.0), i.e., having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit recited herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit recited in this specification is intended to include all higher numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification as well as the claims to expressly recite any sub-ranges that are included within the ranges expressly recited herein.

[0056] Referring to two compared elements, features, etc. as "the same" may mean that they are "substantially the same". Thus, the phrase "substantially the same" may include cases having a deviation considered to be low in the art, e.g., a deviation of 5% or less. Additionally, when a certain parameter is said to be uniform in a given region, this may mean that it is uniform in terms of the average value.

[0057] Throughout the specification, unless otherwise stated, each element may be singular or plural.

[0058] When any element is said to be disposed "above (or below)" or "on (or beneath)" a component, this may mean that any element is positioned in contact with the upper (or lower) surface of the said component, and may also mean that another element may be disposed between the said component and any arbitrary element disposed "above (or below)" the said component.

[0059] In addition, it will be understood that when an element is said to be "coupled", "linked", or "connected" to another element, the elements may be directly "coupled", directly "linked", or directly "connected" to each other, or one or more intermediate elements may be present between them, and the elements may be "coupled", "linked", or "connected" to another element through the said intermediate elements. Additionally, when a component is said to be "electrically coupled" to another component, the component may be directly electrically connected to the said other component, or one or more intermediate components may be present between them such that the component and the said other component are indirectly electrically connected to each other.

[0060] Throughout the specification, unless otherwise stated, when stating "A and / or B", it means A, B, or A and B. That is, "and / or" includes any combination or all combinations of the listed items. When stating "C to D", unless otherwise specified, it means C or greater and D or less.

[0061] The terms used in this specification are for the purpose of describing embodiments of the present disclosure and are not intended to limit the present disclosure.

[0062] Figure 1 is a perspective view schematically showing the configuration of a battery pack according to an embodiment of the present disclosure.

[0063] Referring to Figure 1 , the battery pack 1 includes a housing 10 and a secondary battery 20.

[0064] The housing 10 can serve as a component that supports the secondary battery 20 and protects the secondary battery 20 from external impacts and foreign substances.

[0065] The longitudinal direction of the housing 10 described below may indicate a direction based on Figure 1 parallel to the X-axis, and the width direction of the housing 10 may indicate a direction based on Figure 1 parallel to the Y-axis.

[0066] The housing 10 may include a housing body 11 and a housing cover 12.

[0067] The housing body 11 may provide a space inside for accommodating the secondary battery 20. The housing body 11 according to the present embodiment may be formed in the shape of a box having a hollow and an open side. For example, based on Figure 1 , the open side of the housing body 11 may be set to face upward. The cross-sectional shape of the housing body 11 is not limited to Figure 1 the quadrilateral shape shown in, and may be changed to various other shapes such as a polygonal shape, a circular shape, and an elliptical shape.

[0068] The housing cover 12 may be coupled to the housing body 11 and close the internal space of the housing body 11. The housing cover 12 according to the present embodiment may be formed in a substantially plate shape. The housing cover 12 may be set to face the open side of the housing body 11, for example, the upper surface of the housing body 11. The housing cover 12 may be fixed to the housing body 11 by various types of coupling methods such as bolt connection, welding, and fitting (assembly).

[0069] The secondary battery 20 may serve as a unit structure for storing and supplying electric power in the battery pack. The secondary battery 20 may be disposed in the housing 10.

[0070] The secondary battery 20 may be provided as one or more secondary batteries 20. Hereinafter, as an example, the case where a plurality of secondary batteries 20 are provided as shown in Figure 1 will be described, but the secondary battery 20 is not limited thereto, and may also be provided as a single secondary battery 20.

[0071] A plurality of secondary batteries 20 can be arranged in multiple rows in the housing 10. For example, the plurality of secondary batteries 20 can be arranged in multiple rows in the length direction of the housing 10. However, the arrangement form of the plurality of secondary batteries 20 is not limited thereto, and the plurality of secondary batteries 20 can also be arranged in multiple rows in the width direction of the housing 10, or arranged in multiple rows in both the length direction and the width direction of the housing 10.

[0072] The plurality of secondary batteries 20 can be electrically connected in series or in parallel through bus bars (not shown).

[0073] Figure 2 is a perspective view schematically showing the structure of a secondary battery according to an embodiment of the present disclosure, Figure 3 is a plan view schematically showing the structure of a secondary battery according to an embodiment of the present disclosure, Figure 4 is a cross-sectional view schematically showing the structure of a secondary battery according to an embodiment of the present disclosure.

[0074] Hereinafter, an example in which the secondary battery 20 is a lithium-ion secondary battery having a prismatic shape will be described. However, the present disclosure is not limited thereto, and the secondary battery 20 can also be a lithium polymer battery or a cylindrical battery.

[0075] Referring to Figure 1 and Figure 2 , the secondary battery 20 according to the present embodiment includes an electrode assembly 100, a single cell housing 200, a movable member 300, and an exhaust member 400.

[0076] The electrode assembly 100 may include a positive electrode 110, a negative electrode 120, and a separator 130 disposed between the positive electrode 110 and the negative electrode 120.

[0077] Both the positive electrode 110 and the negative electrode 120 may include a coated portion as an area where an active material is coated on a current collector formed of a thin metal foil, and may respectively include flat portions 110a and 120a as areas where the active material is not coated.

[0078] The electrode assembly 100 may be wound into the form of a pole core after the separator 130, which is an insulator, is disposed between the positive electrode 110 and the negative electrode 120. However, the electrode assembly 100 is not limited to this form, and may also be formed into a stacked structure in which the positive electrode 110 and the negative electrode 120 formed of a plurality of sheets are alternately stacked with the separator 130 disposed therebetween.

[0079] The electrode assembly 100 may be formed as a single electrode assembly 100 or provided as a plurality of electrode assemblies 100.

[0080] The single cell case 200 may form the overall outer shape of the secondary battery 20. The single cell case 200 may accommodate the electrode assembly 100 therein. The single cell case 200 may include a conductive metal material such as aluminum, aluminum alloy, or nickel-plated steel.

[0081] The single cell case 200 according to the present embodiment may include a case body 210 and a cover plate 220.

[0082] The case body 210 may be formed in a rectangular parallelepiped shape having an open surface. The open surface of the case body 210 may be set to face upward in the outer case 10 and set to face the outer case cover 12 vertically.

[0083] The cover plate 220 may be coupled to the case body 210 and seal the single cell case 200. For example, the cover plate 220 may be formed in a flat plate shape. The cover plate 220 may be set to cover the open side of the case body 210 from above the case body 210. The cover plate 220 may be coupled to the case body 210 by various types of coupling methods such as welding, bolting, and fitting.

[0084] The single cell case 200 may further include single cell terminals 230.

[0085] The single cell terminals 230 may be installed to pass through the cover plate 220 and protrude to the outside of the cover plate 220. The outer circumferential surface of the upper column of the single cell terminals 230 may be threaded and fixed to the cover plate 220 by a nut. However, the present disclosure is not limited thereto, and the single cell terminals 230 may be formed of a riveting structure and may be riveted to the cover plate 220, or may be welded and coupled to the cover plate 220.

[0086] The single cell terminals 230 protruding to the outside of the cover plate 220 may be formed as a pair of single cell terminals 230. The pair of single cell terminals 230 may be respectively connected to the positive electrode 110 and the negative electrode 120 of the electrode assembly 100. Accordingly, the pair of single cell terminals 230 may be used as the positive electrode terminal and the negative electrode terminal of the secondary battery 20.

[0087] For example, the single cell terminals 230 may be electrically connected to a first current collector 240 and a second current collector 250, which are respectively joined to the flat portion 110a of the positive electrode and the flat portion 120a of the negative electrode by welding. The first current collector 240 and the second current collector 250 may be respectively used as the positive electrode current collector and the negative electrode current collector of the secondary battery 20. More specifically, the pair of single cell terminals 230 may be coupled to the first current collector 240 and the second current collector 250 by welding. However, the present disclosure is not limited thereto, and the single cell terminals 230, the first current collector 240, and the second current collector 250 may be formed by integrally coupling.

[0088] The single cell case 200 may further include an exhaust hole 221.

[0089] The exhaust hole 221 may be formed in a shape of a hole vertically passing through two surfaces of the cover plate 220. The exhaust hole 221 may be used as a component providing a path for discharging flames, gases, smokes, etc. formed in the single cell case 200 from the secondary battery 20 during thermal runaway of the secondary battery 20. The lower side of the exhaust hole 221 may be connected to the internal space of the case body 210. The upper side of the exhaust hole 221 may be connected to the external space of the cover plate 220. The cross-sectional shape of the exhaust hole 221 may be changed into various shapes such as an oval shape, a circular shape, and a polygonal shape.

[0090] Although an example in which the exhaust hole 221 is formed in the cover plate 220 is shown in Figures 2 to 4 , the exhaust hole 221 is not limited thereto and may also be formed in the case body 210.

[0091] The single cell case 200 may further include an electrolyte inlet 222 formed to pass through the cover plate 220, and a sealing stopper may be installed on the electrolyte inlet 222.

[0092] An insulating member may be installed between the electrode assembly 100 and the cover plate 220. The insulating member may include a first lower insulating member 260 and a second lower insulating member 270. Each of the first lower insulating member 260 and the second lower insulating member 270 may be installed between the electrode assembly 100 and the cover plate 220.

[0093] One end of a separation member that may be installed opposite to one side surface of the electrode assembly 100 may be installed between the insulating member and the single cell terminal 230.

[0094] The separation member may include a first separation member 280 and a second separation member 290.

[0095] One end of the first separation member 280 that may be installed opposite to one side surface of the electrode assembly 100 may be installed between the first lower insulating member 260 and one of the pair of single cell terminals 230, and one end of the second separation member 290 that may be installed opposite to one side surface of the electrode assembly 100 may be installed between the second lower insulating member 270 and the other single cell terminal of the pair of single cell terminals 230.

[0096] One of the pair of single - cell terminals 230 that is welded and coupled to the first current collector 240 may be coupled to one end of the first separation member 280 and the first lower insulating member 260, and the other single - cell terminal 230 that is welded and coupled to the second current collector 250 of the pair of single - cell terminals 230 may be coupled to one end of the second separation member 290 and the second lower insulating member 270.

[0097] The movable member 300 may be installed to be reciprocally movable in a direction parallel to the first direction within the single - cell housing 200. The first direction described below may indicate a direction from right to left based on Figure 4 a direction parallel to the Y - axis direction. However, the first direction is not limited thereto and may be changed in various ways depending on the position of the exhaust hole 221, the mounting angle of the secondary battery 20, etc.

[0098] Figure 5 is a perspective view schematically showing the installation state of the movable member and the exhaust member according to an embodiment of the present disclosure, Figure 6 is Figure 5 an exploded perspective view of Figure 7 is a bottom perspective view schematically showing the installation state of the movable member and the exhaust member according to an embodiment of the present disclosure, Figure 8 is Figure 7 an exploded perspective view of Figure 9 is a side view schematically showing the installation state of the movable member and the exhaust member according to an embodiment of the present disclosure, Figure 10 is a plan view schematically showing the configuration of the movable member and the exhaust member according to an embodiment of the present disclosure, Figure 11 is a cross - sectional view schematically showing the configuration of the movable member and the exhaust member according to an embodiment of the present disclosure, and Figure 12 is a cross - sectional view schematically showing the configuration of the movable member and the exhaust member according to an embodiment of the present disclosure.

[0099] Referring to Figures 5 to 12 , the movable member 300 according to the present embodiment may be formed in the shape of a plate having a first surface 301 and a second surface 302 facing each other. The first surface 301 of the movable member 300 may be disposed toward the inner surface of the cover plate 220, and the second surface 302 may be disposed toward the inner space of the housing body 210. The first surface 301 of the movable member 300 may be disposed to vertically face the exhaust hole 221.

[0100] The movable member 300 may be disposed such that its longitudinal direction is parallel to the first direction. The movable member 300 may be disposed such that its width direction is parallel to the second direction. Here, the second direction is a direction perpendicular to the first direction and may indicate based on Figure 2Any direction parallel to the X-axis. The length of the movable member 300 in the first direction may be greater than its width in the second direction. For example, the movable member 300 may be formed in an oval planar shape having its length in the first direction greater than its width in the second direction. When the movable member 300 reciprocates in a direction parallel to the first direction, a partial area of the first surface 301 may always face the exhaust hole 221.

[0101] A gasket 310 configured to seal the space between the movable member 300 and the single body housing 200 may be installed between the movable member 300 and the single body housing 200.

[0102] The gasket 310 according to the present embodiment may be provided between the first surface 301 of the movable member 300 and the inner surface of the cover plate 220.

[0103] The upper surface and the lower surface of the gasket 310 may be in contact with the inner surface of the cover plate 220 and the first surface 301 of the movable member 300, respectively. More specifically, the lower surface of the gasket 310 facing the first surface 301 of the movable member 300 may be fixed to the first surface 301. For example, the lower surface of the gasket 310 may be fixed to the first surface 301 of the movable member 300 by various types of bonding methods such as using an adhesive and performing fusion. The upper surface of the gasket 310 facing the inner surface of the cover plate 220 may be in slidable contact with the inner surface of the cover plate 220. For example, the upper surface of the gasket 310 may simply be in contact with the inner surface of the cover plate 220 without a separate adhesive. When the movable member 300 moves, the gasket 310 may move relative to the cover plate 220 together with the movable member 300. Therefore, the gasket 310 may cause smooth movement of the movable member 300 while ensuring airtightness between the movable member 300 and the cover plate 220.

[0104] The gasket 310 may have an annular shape having a hollow portion formed at the center portion. The lower surface of the gasket 310 may be provided to face the edge region of the first surface 301. Therefore, interference of the gasket 310 with the exhaust member 400 to be described below can be prevented.

[0105] The gasket 310 may be formed of an elastically deformable material such as rubber or (poly)siloxane. Therefore, the gasket 310 may be in close contact with the first surface 301 of the movable member 300 and the inner surface of the cover plate 220 by the elastic restoring force of the gasket 310 itself, and moisture or foreign matter can be more effectively prevented from entering between the movable member 300 and the cover plate 220.

[0106] Although an example in which the gasket 310 is installed between the movable member 300 and the cover plate 220 of the single unit housing 200 has been described above, the movable member 300 is not limited thereto, and may also be configured such that the first surface 301 directly contacts the inner surface of the cover plate 220.

[0107] The movable member 300 may be supported by a support member 320 so as to be reciprocally movable relative to the single unit housing 200 in a direction parallel to the first direction.

[0108] The support member 320 may include a support body 321 and a pressing rod 322.

[0109] The support body 321 may form the outer shape of one side of the support member 320 and may be fixed to the single unit housing 200.

[0110] The support body 321 according to the present embodiment may be fixed to the inner surface of the cover plate 220 by various types of bonding methods such as welding, bolt connection, and fitting. The support body 321 may be spaced apart from the movable member 300 in a direction opposite to the first direction. The support body 321 may be formed to have a substantially U-shaped cross section. The support body 321 may be provided such that its concave side faces one end of the movable member 300. Both ends of the support body 321 may extend in the first direction. The gap between both ends of the support body 321 may be smaller than the width of the movable member 300.

[0111] The pressing rod 322 may extend from the support body 321 and press the movable member 300 toward the cover plate 220 of the single unit housing 200. Accordingly, the movable member 300 may maintain close contact with the gasket 310 or the cover plate 220 of the single unit housing 200.

[0112] The pressing rod 322 may slidably support the movable member 300. For example, the pressing rod 322 may simply contact the second surface 302 of the movable member 300. Accordingly, when an external force greater than the sum of the frictional force between the pressing rod 322 and the second surface 302 and the frictional force between the gasket 310 and the inner surface of the cover plate 220 is applied to the movable member 300 in a direction parallel to the first direction, the movable member 300 may smoothly slide in a direction parallel to the first direction.

[0113] The pressing rod 322 may be provided to be elastically deformable. Accordingly, the pressing rod 322 may always apply a pressing force to the movable member 300 by the elastic restoring force of the pressing rod 322 itself.

[0114] The pressing rod 322 can be configured as a pair of pressing rods 322. The pair of pressing rods 322 can be respectively connected to both ends of the support 321. The pair of pressing rods 322 can contact both sides of the movable member 300. For example, the pair of pressing rods 322 can extend from both ends of the support 321 in the first direction. The pair of pressing rods 322 can be spaced apart from each other in a direction parallel to the second direction. The pair of pressing rods 322 can contact the edge regions at both sides of the second surface 302, and the edge regions are spaced apart from the central portion of the movable member 300 in the second direction. Therefore, it is possible to prevent the pressing rod 322 from interfering with the exhaust member 400 to be described below, and a uniform pressing force can be applied to the movable member 300.

[0115] The pressing rod 322 according to the present embodiment can include a first extension portion 322a, a second extension portion 322b, and a contact portion 322c.

[0116] The first extension portion 322a can be connected to the support 321, and can form the outer shape of one end of the pressing rod 322. The first extension portion 322a can extend obliquely away from the second surface 302 at a predetermined angle from one end of the support 321, that is, based on Figure 12 extend downward.

[0117] The second extension portion 322b can be connected to the first extension portion 322a, and can form the outer shape of the central portion of the pressing rod 322. The second extension portion 322b can extend obliquely toward the second surface 302 at a predetermined angle from one end of the first extension portion 322a, that is, based on Figure 12 extend upward. Therefore, the first extension portion 322a and the second extension portion 322b can relatively reduce the contact area of the pressing rod 322 with the movable member 300 due to the contact portion 322c to be described below, and thus can reduce the magnitude of the frictional force applied to the movable member 300.

[0118] The contact portion 322c can be connected to the second extension portion 322b, and can form the outer shape of the other end of the pressing rod 322. The contact portion 322c can extend from one end of the second extension portion 322b in a direction parallel to the first direction. The upper surface of the contact portion 322c can contact the edge region of the second surface 302 of the movable member 300. The upper surface of the contact portion 322c can simply contact the second surface 302 of the movable member 300 without a fixing member such as a separate adhesive. The contact portion 322c can press the movable member 300 toward the cover plate 220 through the elastic restoring force transmitted via the first extension portion 322a and the second extension portion 322b.

[0119] Although the example in which the movable member 300 is supported by the support member 320 to be movable relative to the cover plate 220 has been described above, the movable member 300 is not limited thereto, and may also be movably provided in the cover plate 220 or supported by a separate support member to be movable relative to the cover plate 220.

[0120] The exhaust member 400 may be provided at the movable member 300 and may be opened and closed in association with a change in the internal pressure of the single cell housing 200. That is, during normal operation of the secondary battery 20, the exhaust member 400 may remain closed and seal the exhaust hole 221. When the internal pressure of the single cell housing 200 increases to a predetermined level or more due to overcharging of the secondary battery 20, the occurrence of a fire thereof, etc., the exhaust member 400 may rupture and allow communication between the internal space of the single cell housing 200 and the exhaust hole 221. Accordingly, flames, gases, smoke, etc. formed in the single cell housing 200 may be discharged to the outside of the single cell housing 200 through the rupture area of the exhaust member 400.

[0121] The exhaust member 400 may be integrally formed with the movable member 300. That is, within the entire area of the movable member 300, the exhaust member 400 may be a partial area of the movable member 300 provided to directly face the exhaust hole 221. During the rupture operation, the exhaust member 400 may open a partial area of the movable member 300 provided to block the communication between the internal space of the single cell housing 200 and the exhaust hole 221. For example, the exhaust member 400 may be formed by reducing the thickness of a partial area of the movable member 300 through machining such as forging or pressing. However, the exhaust member 400 is not limited thereto, and may also be coupled to the movable member 300 after being separately manufactured from the movable member 300.

[0122] The area of the exhaust member 400 may be smaller than the area of the exhaust hole 221. However, the area of the exhaust member 400 is not limited thereto, and may also be larger than the area of the exhaust hole 221. The cross-sectional shape of the exhaust member 400 is not limited to Figures 6 to 10 the circular shape shown in, and may be changed to various other shapes such as a polygonal shape and an elliptical shape.

[0123] The thickness of the exhaust member 400 may be smaller than the thickness of the movable member 300. Here, the thickness of the exhaust member 400 may indicate the thickness in a direction parallel to the Z-axis direction. Accordingly, when the internal pressure of the single cell housing 200 increases, the exhaust member 400 may rupture before the movable member 300, thereby ensuring smooth exhaust performance. Figures 5 to 8

[0124] ​The exhaust member 400 may be provided as a plurality of exhaust members 400. The plurality of exhaust members 400 may be arranged on the movable member 300 in a direction parallel to the first direction. When the movable member 300 reciprocates in the direction parallel to the first direction, each of the exhaust members 400 may be provided to selectively face the exhaust hole 221. Accordingly, when any one of the exhaust members 400 is damaged, the user may move the movable member 300 to prevent loss of the exhaust performance of the secondary battery 20 or any leakage of gas or the like from the single cell case 200.

[0125] Hereinafter, an example in which five exhaust members 400 are formed will be described, but the number of the exhaust members 400 is not limited thereto and may be changed to various other numbers of two or more, for example, three, four, or six.

[0126] The exhaust member 400 according to the present embodiment may include a first exhaust member 410, a second exhaust member 420, a third exhaust member 430, a fourth exhaust member 440, and a fifth exhaust member 450.

[0127] The first exhaust member 410, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 may be spaced apart from a pair of pressing rods 322 in a direction parallel to the second direction. The first exhaust member 410, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 may be provided in a central region of the movable member 300 located between the pair of pressing rods 322. The first exhaust member 410, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 may be sequentially arranged in a direction parallel to the first direction. The central axes of the first exhaust member 410, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 may be collinear with each other in a direction parallel to the first direction. The first exhaust member 410, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 may be spaced apart at equal intervals or different intervals.

[0128] When the movable member 300 is positioned at the initial position, the exhaust hole 221 can be set to face the first exhaust member 410. When the movable member 300 moves in the first direction from the initial position, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 can be set to sequentially face the exhaust hole 221. When the movable member 300 moves in the direction opposite to the first direction after moving a predetermined distance in the first direction, the first exhaust member 410, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 can be set to sequentially face the exhaust hole 221 in the reverse order.

[0129] Each of the exhaust members 400 in the exhaust member 400 can have a different bursting pressure. Therefore, the user can change the exhaust member 400 facing the exhaust hole 221 according to the type and production purpose of the secondary battery 20, so as to freely set the exhaust operation time, pressure, etc. of the secondary battery 20.

[0130] The bursting pressure of each of the exhaust members 400 in the exhaust member 400 can be determined by a method of forming the exhaust members 400 with different thicknesses from each other.

[0131] For example, as Figure 11 shown, the first exhaust member 410 can have a first thickness t1, the second exhaust member 420 can have a second thickness t2, the third exhaust member 430 can have a third thickness t3, the fourth exhaust member 440 can have a fourth thickness t4, and the fifth exhaust member 450 can have a fifth thickness t5. The sizes of the first thickness t1, the second thickness t2, the third thickness t3, the fourth thickness t4, and the fifth thickness t5 can be changed to various values as long as the values are different from each other.

[0132] The thickness of the exhaust member 400 can increase or decrease sequentially in the first direction. Therefore, the user can linearly adjust the bursting pressure of the exhaust member 400 in the direction in which the movable member 300 moves.

[0133] For example, the size of the first thickness t1 can be smaller than the size of the fifth thickness t5, and the sizes of the second thickness t2, the third thickness t3, and the fourth thickness t4 can gradually increase between the value of the first thickness t1 and the value of the fifth thickness t5. Therefore, the bursting pressure of the first exhaust member 410, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 can be the smallest at the first exhaust member 410 and can gradually increase toward the fifth exhaust member 450.

[0134] However, the thicknesses of the first exhaust member 410, the second exhaust member 420, the third exhaust member 430, the fourth exhaust member 440, and the fifth exhaust member 450 are not limited thereto, and the size of the first thickness t1 may be greater than the size of the fifth thickness t5, and the sizes of the second thickness t2, the third thickness t3, and the fourth thickness t4 may gradually decrease between the value of the first thickness t1 and the value of the fifth thickness t5.

[0135] Examples of determining the bursting pressure of the exhaust member 400 by forming exhaust members 400 having different thicknesses from each other have been described above, but the present disclosure is not limited thereto, and the bursting pressures of the exhaust members 400 may also be configured to be different from each other by forming exhaust members 400 having different shapes, areas, etc. from each other.

[0136] The secondary battery 20 according to the present embodiment may further include a groove 500.

[0137] The groove 500 may be used as a component that provides a structure for fastening an operating member or the like that is allowed to enter through the exhaust hole 221 to the movable member 300. Accordingly, while the operating member is fastened to the groove 500, the user may move the movable member 300 by applying an external force. Examples of the operating member may include various types of tools such as a driving member and a pin.

[0138] For example, the groove 500 may be formed in a shape of a groove that is recessed in the first surface 301 of the movable member 300. The groove 500 may be provided to face the exhaust hole 221 to easily fasten to a tool or the like that enters from the outside of the exhaust hole 221.

[0139] Figure 13 is an enlarged view schematically showing the configuration of a groove according to an embodiment of the present disclosure.

[0140] Referring to Figure 13 the groove 500 may include a first groove 510 and a second groove 520.

[0141] The first groove 510 may be provided on the first surface 301 of the movable member 300 and may have a longitudinal direction extending in a first direction. The first groove 510 may be formed in a linear shape that intersects the central axes of all of the plurality of exhaust members 400. The length of the first groove 510 may be greater than the distance between a pair of exhaust members 400 (e.g., the first exhaust member 410 and the fifth exhaust member 450) provided at both ends among the plurality of exhaust members 400. Accordingly, during the movement of the movable member 300, the first groove 510 may always maintain a state in which a partial section is provided to face the exhaust hole 221.

[0142] The second groove 520 may extend from the first groove 510 in a direction intersecting the first direction (e.g., a direction parallel to the second direction). That is, the second groove 520 may be arranged to intersect the first groove 510. The internal space of the second groove 520 may communicate with the internal space of the first groove 510. Each end of the second groove 520 may protrude to one side of the first groove 510. Therefore, the second groove 520 can cause the external force applied by the user to be smoothly transmitted to the movable member 300, and can prevent the operating member from detaching from the groove 500 during the movement of the movable member 300.

[0143] The second groove 520 may be provided as a plurality of second grooves 520. The plurality of second grooves 520 may be arranged at a predetermined interval in the first direction. The number of the second grooves 520 may be changed to various numbers according to the length of the first groove 510 and the like.

[0144] Figure 14 is a view schematically showing a state in which a movable member is moved by using a groove.

[0145] Referring to Figure 14 , when the user wants to adjust the exhaust pressure of the secondary battery 20 in a state where the second exhaust member 420 is set to face the exhaust hole 221, the user can insert the operating member into the groove 500 through the exhaust hole 221.

[0146] When the operating member is inserted into the groove 500, at least a partial area of the operating member may be disposed in any one of the second grooves 520.

[0147] In this state, the user can apply an external force to the operating member in a direction parallel to the first direction, and the external force applied to the operating member can be transmitted to the movable member 300 through the second groove 520.

[0148] The movable member 300 may linearly move in a direction parallel to the first direction due to the received external force, and the exhaust member 400 facing the exhaust hole 221 may be changed from the second exhaust member 420 to the first exhaust member 410 or the third exhaust member 430.

[0149] The battery pack may further include a battery management system (BMS) for managing the plurality of secondary batteries 20. The BMS may include a detection device, a balancing device, and a control device.

[0150] The detection device can detect the state (voltage, current, temperature, etc.) of the secondary battery 20 and detect the state information indicating the state of the secondary battery 20. The detection device can detect the voltage of each secondary battery 20 that constitutes the battery pack. The detection device can also detect the current of each secondary battery 20 that constitutes the battery pack. The detection device can further detect the temperature of the secondary battery 20 or the ambient temperature at at least one point of the battery pack.

[0151] The balancing device can perform a balancing operation on the secondary batteries 20 that constitute the battery pack.

[0152] The control device can receive the state information (voltage, current, temperature, etc.) of the secondary battery 20 from the detection device. The control device can monitor and calculate the state (voltage, current, temperature, state of charge (SOC), state of health (SOH), etc.) of the secondary battery 20 based on the state information received from the detection device. In addition, the control device can perform control functions (e.g., temperature control, balancing control, charge / discharge control, etc.), protection functions (e.g., preventing over-discharge, over-charge, and over-current, short-circuit protection, flame-retardant function, etc.), etc. based on the state monitoring results. In addition, the control device can also communicate wired or wirelessly with external devices of the battery pack (e.g., an upper-level controller, a vehicle, a charger, a power conversion system (PCS), etc.).

[0153] The control device can also control the charge / discharge operation and protection operation of the battery.

[0154] The detection device, the balancing device, and the control device can include a processor and a memory.

[0155] The processor can be implemented as a central processing unit (CPU) or a system on chip (SoC), can run an operating system or an application to control multiple hardware or software components connected to the processor, and can perform various data processing and arithmetic operations. The processor can be configured to execute at least one instruction stored in the memory and store the execution result data in the memory.

[0156] The memory can store at least one instruction executed by the processor. The memory can be implemented as a volatile storage medium and / or a non-volatile storage medium, e.g., implemented as a read-only memory (ROM) and / or a random access memory (RAM).

[0157] Hereinafter, a battery pack according to another embodiment of the present disclosure will be described.

[0158] The battery pack according to the present embodiment can be configured such that only the detailed structure of the secondary battery 20 is different from the battery pack described above with reference to Figures 1 to 14 described battery pack.

[0159] Therefore, when describing the battery pack according to the present embodiment, a detailed configuration of the secondary battery 20 different from the battery pack described above with reference to Figures 1 to 14 will be described.

[0160] The description of the battery pack given above with reference to Figures 1 to 14 can be applied without change to the remaining configuration of the battery pack according to the present embodiment.

[0161] Figure 15 is a bottom perspective view schematically showing a configuration of a secondary battery according to another embodiment of the present disclosure, and Figure 16 is a plan view schematically showing a configuration of a secondary battery according to another embodiment of the present disclosure.

[0162] Referring to Figure 15 and Figure 16 , the secondary battery 20 according to the present embodiment may further include a guide rail 600.

[0163] The guide rail 600 may serve as a component for guiding the movable member 300.

[0164] The guide rail 600 according to the present embodiment may be formed in a shape having a groove that is recessed from the single cell case 200 (more specifically, the inner surface of the cover plate 220). The guide rail 600 may have a length direction extending in a direction parallel to the first direction.

[0165] The movable member 300 may be inserted into the guide rail 600. When the gasket 310 is installed between the movable member 300 and the cover plate 220, the gasket 310 may be inserted into the guide rail 600 together with the movable member 300.

[0166] The length of the guide rail 600 parallel to the first direction may be greater than the length of the movable member parallel to the first direction. Accordingly, the movable member 300 may freely reciprocate in the direction parallel to the first direction within the guide rail 600. The length of the guide rail 600 may be changed to various values within a range in which each of the plurality of exhaust members 400 may be arranged to face the exhaust hole 221.

[0167] The outer peripheral surface of the movable member 300 perpendicular to the second direction may be in slidable contact with the inner peripheral surface of the guide rail 600 perpendicular to the second direction. Accordingly, the movement of the movable member 300 in the second direction is restricted, and thus it is possible to prevent the exhaust member 400 and the exhaust hole 221 from being misaligned with each other.

[0168] Hereinafter, a battery pack according to still another embodiment of the present disclosure will be described.

[0169] The battery pack according to the present embodiment may be configured such that only the detailed configuration of the secondary battery 20 is different from the battery pack described above with reference to Figures 1 to 14 or the battery pack described above with reference to Figure 15 and Figure 16 described battery packs.

[0170] Therefore, when describing the battery pack according to the present embodiment, the detailed configuration of the secondary battery 20 that is different from the battery pack described above with reference to Figures 1 to 14 or the battery pack described above with reference to Figure 15 and Figure 16 described battery packs will be described.

[0171] The description of the battery pack given above with reference to Figures 1 to 14 or the description of the battery pack given above with reference to Figure 15 and Figure 16 can be applied without change to the remaining configuration of the battery pack according to the present embodiment.

[0172] Figure 17 is a perspective view schematically showing the configuration of a secondary battery according to another embodiment of the present disclosure, Figure 18 is an enlarged view schematically showing the configuration of a secondary battery according to another embodiment of the present disclosure, Figure 19 is an exploded perspective view schematically showing the configuration of a secondary battery according to another embodiment of the present disclosure.

[0173] Although an example in which the secondary battery 20 includes a groove 500 is shown in Figures 17 to 19 , the present embodiment is not limited thereto, and the secondary battery 20 may also be configured not to include the groove 500.

[0174] Referring to Figures 17 to 19 , the secondary battery 20 according to the present embodiment may further include a rod 700 and a rod rail 800.

[0175] The rod 700 may be connected to the movable member 300, and when the movable member 300 moves, the rod 700 may move together with the movable member 300 in a direction parallel to the first direction. The rod 700 may protrude to the outside of the single cell case 200. The upper end of the rod 700 protruding to the outside of the single cell case 200 may be formed in various shapes that can be grasped by a user.

[0176] The rod 700 may be connected to the movable member 300 through a rod plate 330 extending from the movable member 300. For example, the rod plate 330 may support the rod 700 with respect to the movable member 300.

[0177] The rod plate 330 according to the present embodiment may be formed in a shape of a flat plate extending in a direction parallel to the second direction from the edge side of the movable member 300. The upper surface of the rod plate 330 may be provided to be parallel to and face the inner surface of the cover plate 220.

[0178] The rod 700 may vertically extend from the upper surface of the rod plate 330 toward the inner surface of the cover plate 220. The upper end of the rod 700 may pass through the cover plate 220 through a rod rail 800 described below, and protrude to the upper side of the cover plate 220.

[0179] The rod rail 800 may serve as a component for guiding the movement of the rod 700.

[0180] The rod rail 800 according to the present embodiment may be formed in a shape of a hole vertically passing through the single body case 200 (more specifically, the cover plate 220). The rod rail 800 may have a longitudinal direction extending parallel to the first direction. The rod 700 may be inserted into the rod rail 800, and may reciprocate in the first direction or in a direction opposite to the first direction in the longitudinal direction of the rod rail 800. The length of the rod rail 800 may be formed to be greater than the movement range of the movable member 300.

[0181] The rod plate 330 may be provided to face the rod rail 800. The rod plate 330 may be in direct contact with the single body case 200 (more specifically, the inner surface of the cover plate 220). Accordingly, during normal operation of the secondary battery 20, the rod plate 330 may prevent the electrolyte, gas, etc. from leaking from the inside of the single body case 200 through the rod rail 800.

[0182] Figure 20 and Figure 21 are views schematically showing a process of moving a movable member using a rod and a rod rail.

[0183] Referring to Figure 20 and Figure 21 , when a user wants to adjust the exhaust pressure of the secondary battery 20 in a state where the first exhaust member 410 is set to face the exhaust hole 221, the user may grasp the rod 700 protruding to the outside of the single body case 200 and apply an external force to the rod 700 in the first direction.

[0184] The external force applied to the rod 700 may be transmitted to the movable member 300 through the rod plate 330, and the movable member 300 may linearly move in the first direction.

[0185] When the movable member 300 moves a predetermined distance or more in the first direction, the exhaust member 400 facing the exhaust hole 221 may change from the first exhaust member 410 to the second exhaust member 420.

[0186] According to the present disclosure, since the bursting pressure of the exhaust member can be changed by the linear reciprocating movement of the movable member, it is possible to flexibly cope with changes in the type of battery, production purpose, and its application environment.

[0187] According to the present disclosure, during the movement of the movable member, it is possible to prevent any leakage of electrolyte, gas, etc. from inside the single cell housing.

[0188] According to the present disclosure, by preventing the movable member from moving in a direction other than the first direction, smooth exhaust performance of the secondary battery can be ensured.

[0189] However, the effects obtainable by the present disclosure are not limited to the above effects, and those skilled in the art will clearly understand other technical effects not mentioned through the appended description of the present disclosure.

[0190] The present disclosure has been described with reference to the embodiments shown in the drawings, but these embodiments are merely illustrative, and it should be understood that those skilled in the art can derive various variations and other equivalent embodiments based on the embodiments.

[0191] Therefore, the technical scope of the present disclosure should be defined by the appended claims.

Claims

1. A secondary battery, characterized in that, The secondary battery includes: an electrode assembly; a single cell case configured to accommodate the electrode assembly, and having an exhaust hole formed therein; a movable member installed to be reciprocally movable in a direction parallel to a first direction inside the single cell case; and a plurality of exhaust members provided at the movable member and configured to rupture as the internal pressure of the single cell case increases, wherein each of the plurality of exhaust members selectively faces the exhaust hole in association with the movement of the movable member.

2. The secondary battery according to claim 1, wherein The plurality of exhaust members are arranged in the first direction.

3. The secondary battery according to claim 1, characterized in that, The thickness of the exhaust member is less than the thickness of the movable member.

4. The secondary battery according to claim 1, characterized in that, Each of the plurality of exhaust members has a different rupture pressure.

5. The secondary battery according to claim 4, characterized in that, Each of the plurality of exhaust members has a different thickness.

6. The secondary battery according to claim 5, wherein: the plurality of exhaust members are arranged in the first direction; and the thicknesses of the plurality of exhaust members sequentially increase or decrease in the first direction.

7. The secondary battery according to claim 1, characterized in that, The secondary battery further includes a gasket provided between the single cell case and the movable member and configured to seal between the single cell case and the movable member.

8. The secondary battery according to claim 7, characterized in that, The gasket is fixed to the movable member and is in slidable contact with the single cell case.

9. The secondary battery according to claim 1, wherein The secondary battery further includes a support member configured to movably support the movable member relative to the single cell case.

10. The secondary battery according to claim 9, wherein The support member includes: a support body fixed to the single cell case; and a pressing rod configured to extend from the support body and press the movable member toward the single cell case.

11. The secondary battery according to claim 10, wherein: the pressing rod extends parallel to the first direction; and the pressing rod and the exhaust member are spaced apart in a direction crossing the first direction.

12. The secondary battery according to claim 10, wherein The pressing rod is provided as a pair of pressing rods, and the pair of pressing rods contact both sides of the movable member.

13. The secondary battery according to claim 10, wherein The pressing rod is provided to be elastically deformable.

14. The secondary battery according to claim 1, wherein The secondary battery further includes a groove recessedly formed in the movable member and provided to face the exhaust hole.

15. The secondary battery according to claim 14, wherein The groove includes: a first groove extending in the first direction; and a plurality of second grooves extending from the first groove in a direction crossing the first direction and arranged in the first direction.

16. The secondary battery according to claim 1, characterized in that, The secondary battery further includes a guide rail recessedly formed in the single cell case and configured to guide the movement of the movable member.

17. The secondary battery according to claim 16, characterized in that, The length of the guide rail parallel to the first direction is greater than the length of the movable member parallel to the first direction.

18. The secondary battery according to claim 1, characterized in that, The secondary battery further includes: a rod connected to the movable member and configured to protrude to the outside of the single cell case; and a rod rail formed to pass through the single cell case and configured to guide the movement of the rod.

19. The secondary battery according to claim 18, characterized in that, The secondary battery further includes a rod plate configured to extend from the movable member and support the rod relative to the movable member, Wherein, the rod plate is arranged to face the rod rail and contact the single cell housing.

20. A battery pack, characterized in that, The battery pack includes: a housing; and one or more secondary batteries disposed in the housing, Wherein, the secondary battery includes: an electrode assembly; a single cell housing configured to accommodate the electrode assembly, and an exhaust hole is formed in the single cell housing; a movable member mounted to reciprocate in a direction parallel to a first direction inside the single cell housing; and a plurality of exhaust members disposed at the movable member and configured to rupture as the internal pressure of the single cell housing increases, Wherein, each of the plurality of exhaust members selectively faces the exhaust hole in association with the movement of the movable member.

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