Secondary battery and battery pack including the same

Abstract

This disclosure relates to a secondary battery and a battery pack including the secondary battery. The secondary battery includes: a housing having an open side, the housing including a plurality of walls defining an internal space; an electrode assembly housed in the internal space; a cover plate configured to close the open side of the housing; a first terminal disposed on the cover plate; a first plate disposed in the internal space between one of the plurality of walls and the electrode assembly, the first plate including a first current collector connection portion; and a first current collector including a first terminal connection portion and a first plate connection portion, the first terminal connection portion being electrically connected to the first terminal, the first plate connection portion being connected to the first terminal connection portion, and including a first welding surface facing away from one of the plurality of walls, the first welding surface being welded to the first current collector connection portion.

Description

Technical Field

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

[0002] A lithium secondary battery includes any one of a positive electrode and a negative electrode comprising active materials capable of inserting and deintercalating lithium ions, and an electrolyte, and generates electrical energy through a redox reaction when lithium ions are inserted into or deintercalated from the positive and negative electrodes.

[0003] Because of the risk of explosion and fire caused by thermal runaway when the internal temperature of a lithium secondary battery rises rapidly and an explosion occurs, there is a need to develop structural methods to suppress thermal runaway.

[0004] This background section is intended to provide a general understanding of the background of this disclosure and may therefore contain information that does not constitute related (or prior art). Summary of the Invention

[0005] This disclosure relates to a secondary battery that prevents thermal runaway within the secondary battery due to external impact. This disclosure also relates to a battery pack including a secondary battery.

[0006] Embodiments of this disclosure provide a secondary battery, comprising: a housing having an open side and a plurality of walls defining an internal space; an electrode assembly housed in the internal space; a cover plate closing one open side of the housing; a first terminal mounted on the cover plate; a first plate located in the internal space between one of the plurality of walls and the electrode assembly and having a first current collector connection portion; and a first current collector including a first terminal connection portion electrically connected to the first terminal and a first plate connection portion, the first plate connection portion being electrically connected to the first terminal connection portion and having a first welding surface facing away from the wall and welded to the first current collector connection portion.

[0007] Embodiments of this disclosure provide a secondary battery, comprising: a housing having an open side, the housing including a plurality of walls defining an internal space; an electrode assembly housed in the internal space; a cover plate configured to close one open side of the housing; a first terminal disposed on the cover plate; a first plate disposed in the internal space between one of the plurality of walls and the electrode assembly, the first plate including a first current collector connection portion; and a first current collector including a first terminal connection portion and a first plate connection portion, the first terminal connection portion being electrically connected to the first terminal, the first plate connection portion being connected to the first terminal connection portion and including a first welding surface facing away from one of the plurality of walls, the first welding surface being welded to the first current collector connection portion.

[0008] In some embodiments, the first plate connection portion may further include a first stop surface that blocks the first current collector connection portion and intersects with the first welding surface.

[0009] In some embodiments, the first plate connection portion may further include: a first thick portion having a first stop surface and being thicker than the first current collector connection portion; and a first thin portion having a first welding surface and being thinner than the first thick portion.

[0010] In some embodiments, the first plate connection portion further includes: a first thick portion including a first stop surface, the first thick portion having a thickness greater than the thickness of the first current collector connection portion; and a first thin portion including a first welding surface, the first thin portion having a thickness less than the thickness of the first thick portion.

[0011] In some embodiments, when an external force is applied to the first plate connection portion, the first thin portion can be cut.

[0012] In some embodiments, the first thin portion is configured to be cut when an external force is applied to the first plate connection portion.

[0013] In some embodiments, the first plate connection portion may further include a first end thick portion, which is spaced apart from a first thick portion, bends at a first thin portion, and protrudes toward a wall.

[0014] In some embodiments, the first plate connection portion further includes being spaced apart from the first thick portion, bent at the first thin portion, and protruding toward a wall.

[0015] In some embodiments, the first plate connection portion may further include a first through hole extending through the first thin portion in the width direction of the first plate connection portion.

[0016] In some embodiments, the first plate connection portion further includes a first through hole that passes through the first thin portion in the lateral direction of the first plate connection portion.

[0017] In some embodiments, the first plate may further include: a first terminal block connection portion electrically connected to a first terminal block member provided on one side of the electrode assembly; and a first step portion connecting the first terminal block connection portion and the first current collector connection portion in a stepped manner.

[0018] In some embodiments, the first plate further includes: a first terminal block connection portion electrically connected to a first terminal block member disposed on one side of the electrode assembly; and a first step portion connecting the first terminal block connection portion and the first current collector connection portion in a step configuration.

[0019] In some embodiments, the first plate may further include a first bending-inducing cut that is recessed in the first connector portion such that it is thinner than the surrounding area and extends in the width direction of the first plate.

[0020] In some embodiments, the first plate further includes a first bending-inducing cut that is recessed in the first connector portion such that the thickness of the first bending-inducing cut is less than the thickness of the surrounding area, and the first bending-inducing cut extends in the lateral direction of the first plate.

[0021] In some embodiments, the first bending-inducing cut may be formed in an area of ​​the first tab connection portion that does not overlap with the first tab of the electrode assembly.

[0022] In some embodiments, a first bending-inducing cut is formed in a region of the first tab connection portion that does not overlap with the first tab of the electrode assembly.

[0023] In some embodiments, the first terminal may be mounted on one side of the cover plate, and the secondary battery may include: a second terminal mounted on the other side of the cover plate; a second plate located in the interior space between the electrode assembly and another wall of a plurality of walls facing one wall, and having a second current collector connection portion on one side thereon; and a second current collector including a second terminal connection portion and a second plate connection portion, the second terminal connection portion being electrically connected to the second terminal, the second plate connection portion being connected to the second terminal connection portion and having a second welding surface facing away from the other wall and welded to the second current collector connection portion.

[0024] In some embodiments, a first terminal is disposed on one side of a cover plate, and wherein the secondary battery further includes: a second terminal disposed on the other side of the cover plate; a second plate disposed in an internal space between an electrode assembly and another wall of a plurality of walls facing one of the walls, the second plate including a second current collector connection portion; and a second current collector including a second terminal connection portion and a second plate connection portion, the second terminal connection portion being electrically connected to the second terminal, the second plate connection portion being connected to the second terminal connection portion and including a second welding surface facing away from the other wall of the plurality of walls and welded to the second current collector connection portion.

[0025] In some embodiments, the second plate connection portion may further include a second stop surface that blocks the second current collector connection portion and intersects with the second welding surface.

[0026] In some embodiments, the second plate connection portion may further include: a second thick portion having a second stop surface and being thicker than the second current collector connection portion; and a second thin portion having a second welding surface and being thinner than the second thick portion.

[0027] In some embodiments, the second plate connection portion further includes: a second thick portion including a second stop surface, the second thick portion having a thickness greater than the thickness of the second current collector connection portion; and a second thin portion including a second welding surface, the second thin portion having a thickness less than the thickness of the second thick portion.

[0028] In some embodiments, the second thin portion can be cut when an external force is applied to the second plate connection portion.

[0029] In some embodiments, the second thin portion is configured to be cut when an external force is applied to the second plate connection portion.

[0030] In some embodiments, the second plate connection portion may further include a second end thick portion that is spaced apart from the second thick portion, bends at the second thin portion, and protrudes toward the other wall.

[0031] In some embodiments, the second plate connection portion further includes being spaced apart from the second thick portion, bent at the second thin portion, and protruding toward another wall of the plurality of walls.

[0032] In some embodiments, the second plate connection portion may further include a second through hole that passes through the second thin portion in the width direction of the second plate connection portion.

[0033] In some embodiments, the second plate connection portion further includes a second through hole that passes through the second thin portion in the lateral direction of the second plate connection portion.

[0034] In some embodiments, the second plate may further include: a second terminal block connection portion electrically connected to a second terminal block member provided on the other side of the electrode assembly; and a second step portion connecting the second terminal block connection portion and the second current collector connection portion in a stepped manner.

[0035] In some embodiments, the second plate further includes: a second terminal block connection portion electrically connected to a second terminal block member disposed on the other side of the electrode assembly; and a second step portion connected to the second terminal block connection portion and the second current collector connection portion in a step configuration.

[0036] In some embodiments, the second plate may further include a second bending-inducing cut that is recessed in the second connector portion such that it is thinner than the surrounding area and extends in the width direction of the second plate.

[0037] In some embodiments, the second plate further includes a second bending-inducing cut that is recessed in the second connector portion such that the thickness of the second bending-inducing cut is less than the thickness of the surrounding area, and the second bending-inducing cut extends in the lateral direction of the second plate.

[0038] In some embodiments, the second bending-inducing cut may be formed in a region of the second tab connection portion that does not overlap with the second tab of the electrode assembly.

[0039] In some embodiments, the second bending-inducing cut is formed in the area of ​​the second tab connection portion that does not overlap with the second tab of the electrode assembly.

[0040] In some embodiments, the housing may have a cuboid shape, one wall may be a first sidewall located on one side in the longitudinal direction of the housing, and the other wall may be a second sidewall located on the other side in the longitudinal direction of the housing. The first plate may extend while facing the first sidewall, and the second plate may extend while facing the second sidewall.

[0041] In some embodiments, the housing has a cuboid geometry, wherein one of the plurality of walls is a first sidewall located on one side in the longitudinal direction of the housing, and another of the plurality of walls is a second sidewall located on the other side in the longitudinal direction of the housing, wherein a first plate extends while facing the first sidewall, and a second plate extends while facing the second sidewall.

[0042] Embodiments of this disclosure provide a battery pack, including: a housing and a plurality of secondary batteries disposed inside the housing, wherein each of the secondary batteries includes: the housing having an open side and a plurality of walls defining an internal space; an electrode assembly housed in the internal space; a cover plate closing one open side of the housing; a first terminal mounted on the cover plate; a first plate located in the internal space between one of the plurality of walls and the electrode assembly and having a first current collector connection portion; and a first current collector including a first terminal connection portion and a first plate connection portion, the first terminal connection portion being electrically connected to the first terminal, the first plate connection portion being connected to the first terminal connection portion and having a first welding surface facing away from a wall and welded to the first current collector connection portion.

[0043] Embodiments of this disclosure provide a battery pack, including: a housing; and a plurality of secondary batteries disposed inside the housing, wherein each of the plurality of secondary batteries includes: the housing having an open side, the housing including a plurality of walls defining an internal space; an electrode assembly housed in the internal space; a cover plate configured to close one open side of the housing; a first terminal disposed on the cover plate; a first plate disposed between one of the walls and the electrode assembly in the internal space, the first plate including a first current collector connection portion; and a first current collector including a first terminal connection portion and a first plate connection portion, the first terminal connection portion being electrically connected to the first terminal, the first plate connection portion being electrically connected to the first terminal connection portion and including a first welding surface opposing one of the walls, the first welding surface being welded to the first current collector connection portion. Attached Figure Description

[0044] The accompanying drawings illustrate embodiments of the present disclosure, and together with the detailed description thereof, further describe aspects and features of the present disclosure. Therefore, the present disclosure should not be construed as limited to the drawings:

[0045] Figure 1 A perspective view of a battery pack according to an embodiment of the present disclosure is shown for illustrative purposes.

[0046] Figure 2 A perspective view of a secondary battery according to an embodiment of the present disclosure is shown for illustrative purposes.

[0047] Figure 3 An exploded perspective view of a secondary battery according to an embodiment of the present disclosure is shown for illustrative purposes.

[0048] Figure 4 According to the embodiments of this disclosure Figure 2 A cross-sectional view taken from line S1-S1 in the diagram;

[0049] Figure 5 A view of an electrode assembly according to an embodiment of the present disclosure is shown for illustrative purposes.

[0050] Figure 6 According to embodiments of this disclosure Figure 4 A magnified view of part A;

[0051] Figure 7 According to embodiments of this disclosure Figure 4 A magnified view of part B;

[0052] Figure 8 Examples based on embodiments of this disclosure Figure 4 A view of a modified example of part A;

[0053] Figure 9 Examples based on embodiments of this disclosure Figure 4A view of a modified example of part B;

[0054] Figure 10 Examples based on embodiments of this disclosure Figure 4 The view of the modified example of part A; and

[0055] Figure 11 Examples based on embodiments of this disclosure Figure 4 The view showing the modified example of part B. Detailed Implementation

[0056] In this document, some embodiments of the present disclosure will be described in further detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as limited to their general or dictionary meanings, and should be interpreted as consistent with the technical ideas of the present disclosure, based on the principle that the inventor can be his / her own lexicographer to appropriately define the terms and concepts.

[0057] The embodiments described in this specification and the configurations shown in the accompanying drawings are provided as some embodiments of this disclosure and do not represent all technical ideas, aspects, and features of this disclosure. Accordingly, it will be understood that various equivalents and modifications may exist to replace or modify the embodiments described herein at the time of filing this application.

[0058] It will be understood that when an element or layer is referred to as being "on" another element or layer, "connected to," or "linked to" another element or layer, it may be directly on, connected to, or linked to the other element or layer, or one or more intermediary elements or layers may be present. When an element or layer is referred to as being "directly on" another element or layer, "directly connected to," or "directly linked to" another element or layer, no intermediary element or layer is present. For example, when a first element is described as being "linked" or "connected" to a second element, the first element may be directly linked to or connected to the second element, or the first element may be indirectly linked to or connected to the second element via one or more intermediary elements.

[0059] In the accompanying drawings, the dimensions of various elements, layers, etc., may be enlarged for clarity. The same reference numerals denote the same or similar elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated enumerated items. Furthermore, the use of "may" in describing embodiments of this disclosure refers to "one or more embodiments of this disclosure." Expressions such as "at least one of..." and "any one of..." modify the entire list of elements, not individual elements, when preceding / following a list of elements. When phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from the group of A, B, and C," or "at least one selected from A, B, and C" are used to denote a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the term "use" may be considered synonymous with the term "utilize." As used herein, the terms “substantially,” “about,” and similar terms are used as approximations rather than terms of degree and are intended to describe the inherent variations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art.

[0060] 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 segments, these elements, components, regions, layers, or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0061] For ease of description, spatial relative terms, such as “below,” “under,” “down,” “above,” and “above,” are used herein to describe the relationship of one element or feature to another element or feature illustrated in the figures. It will be understood that, in addition to the orientation depicted in the figures, spatial relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features will be oriented “above” or “above” other elements or features. Thus, the term “below” can cover both above and below orientations. The device may be oriented in other ways (e.g., rotated 90 degrees or otherwise), and the spatial relative descriptors used herein should be interpreted accordingly.

[0062] The terminology used herein is for describing embodiments of this disclosure and is not intended to limit this disclosure. As used herein, unless the context clearly indicates otherwise, the singular form “a” is intended to include the plural form as well. It will be further understood that the term “comprising,” when used in this specification, indicates the presence of said features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0063] Furthermore, any numerical range disclosed and / or set forth herein is intended to include all subranges with the same numerical precision contained within the set forth range. For example, the range “1.0 to 10.0” is intended to include all subranges between the stated minimum value of 1.0 and the stated maximum value of 10.0 (and including both the stated minimum value of 1.0 and the stated maximum value of 10.0), i.e., 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 set forth herein is intended to include all lower numerical limits contained herein, and any minimum numerical limit set forth in this specification is intended to include all higher numerical limits contained herein. Accordingly, the applicant reserves the right to amend this specification (including the claims) to expressly set forth any subranges contained within the range expressly set forth herein.

[0064] Referring to two compared elements, features, etc., as "identical" can mean that they are "substantially identical." Therefore, the phrase "substantially identical" can include situations in the art where the deviation is considered low, for example, a deviation of 5% or less. Additionally, when a parameter is described as uniform in a given region, this can mean that it is uniform in terms of average value.

[0065] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0066] When any element is referred to as being arranged (or placed or positioned) "above (or below)" a component, it may mean that the element is placed to contact the upper (or lower) surface of the component, and may also mean that another component may be inserted between the component and any element arranged (or placed or positioned) on (or below) the component.

[0067] Furthermore, it should be understood that when a component is referred to as "connected," "linked," or "attached" to another component, the components may be directly "connected," "linked," or "attached" to each other, or one or more intermediary components may exist therein, through which the component may be "connected," "linked," or "attached" to another component. Additionally, when a component is referred to as "electrically connected" to another component, the component may be directly electrically connected to the other component, or one or more intermediary components may exist therein, allowing the component and the other component to be indirectly electrically connected to each other.

[0068] When “C~D” is used, it means above C and below D, unless otherwise indicated.

[0069] The terminology used in this specification is for describing embodiments of this disclosure and is not intended to limit this disclosure.

[0070] Figure 1 A perspective view illustrating the configuration of the battery pack. Figure 2 A perspective view illustrating the configuration of a secondary battery. Figure 3 An exploded perspective view illustrating the configuration of a secondary battery. Figure 4 For along Figure 2 The cross-sectional view taken by line S1-S1 in the diagram. Figure 5 A view illustrating the configuration of the electrode assembly. Figure 6 for Figure 4 A magnified view of part A, and Figure 7 for Figure 4 A magnified view of part B.

[0071] refer to Figure 1 The battery pack 1 may include a housing 10, a secondary battery 2, and a busbar 3.

[0072] The housing 10 can form the general exterior of the battery pack 1 and provide space to accommodate the secondary battery 2.

[0073] The housing 10 may include a housing body 11 and a cover 12.

[0074] The outer casing 11 may have a box-like geometry, with a hollow interior and an open side. The cross-sectional geometry of the outer casing 11 is not limited to... Figure 1 The example shown is a quadrilateral geometry, and it can be designed to be various geometric shapes, such as polygons, circles, ellipses or other geometric shapes.

[0075] The cover 12 can be attached to the housing body 11 and can close the internal space of the housing body 11. The cover 12 can have a substantially planar geometry and can face the open side of the housing body 11. The cover 12 can be fixed to the housing body 11 by various connection methods such as bolting, welding, mating, etc.

[0076] The secondary battery 2 can be used as a unit structure in the battery pack 1 for storing and supplying power. The secondary battery 2 can be disposed inside the housing 10.

[0077] Multiple secondary batteries 2 can be provided. The multiple secondary batteries 2 can be arranged in the longitudinal direction of the housing 10 (based on...). Figure 1 (X-axis direction) and lateral direction (based on) Figure 1 Arranged in two or more rows in at least one of the directions of the Y-axis. Figure 1 For example, multiple secondary batteries 2 are arranged in twelve rows along the longitudinal direction of the housing 10, but the arrangement of the multiple secondary batteries 2 is not limited to this, and can be designed in various arrangements. The multiple secondary batteries 2 can be arranged in parallel. The number of secondary batteries 2 can be designed in various ways depending on the size, shape, etc. of the housing 10.

[0078] Multiple secondary batteries 2 can be electrically connected via busbar 3.

[0079] Busbar 3 can be disposed between cover 12 and secondary battery 2. Multiple busbars 3 can be provided. Each busbar 3 can connect a pair of adjacent secondary batteries 2 in series or in parallel.

[0080] The first terminal 420 of one of the adjacent secondary batteries 2 and the second terminal 430 of the other adjacent secondary battery 2 may face each other in the longitudinal direction of the housing 10. That is, the front wall 120 of any one of the adjacent secondary batteries 2 may be configured to face the rear wall 130 of the other secondary battery 2.

[0081] Busbar 3 can be connected to the first terminal 420 of one of a pair of adjacent secondary batteries 2 and the second terminal 430 of the other. Accordingly, multiple secondary batteries 2 can be connected in series with each other via busbar 3.

[0082] However, the busbar 3 is not limited to this configuration and can be connected to each of the first terminals 420 of one of a pair of adjacent secondary batteries 2 and the first terminals 420 of the other secondary battery 2, or to each of the second terminals 430 of one of a pair of adjacent secondary batteries 2 and the second terminals 430 of the other secondary battery 2.

[0083] Busbar 3 may include conductive materials such as copper, aluminum, nickel, etc. The specific shape of busbar 3 is not limited to... Figure 1 As shown in the figure, and can have various geometries that enable electrical connection of adjacent secondary batteries 2.

[0084] Multiple busbars 3 can be supported in the housing 10 by busbar brackets H.

[0085] The busbar bracket H can be formed with a planar geometry. The busbar bracket H can be disposed between the cover 12 and the secondary battery 2. The busbar 3 can be fixed to the busbar bracket H by various connection methods such as mating, bolting, injection molding, etc. The busbar bracket H can be configured to include an electrically insulating polymer composite material.

[0086] refer to Figures 2 to 7 The secondary battery 2 includes a casing 100, an electrode assembly 200, a cover plate 410, a first terminal 420, a first plate 800A, and a first current collector 600A.

[0087] The secondary battery 2 is shown as a prismatic lithium-ion secondary battery. However, the invention is not limited thereto, and the secondary battery 2 may be a lithium polymer battery or a cylindrical battery.

[0088] The housing 100 forms the general exterior of the secondary battery 2 and houses the electrode assembly 200.

[0089] The housing 100 may include a plurality of walls 110, 120, 130, 140 and 150 defining an internal space 101. The plurality of walls 110, 120, 130, 140 and 150 may include a bottom wall 110, a front wall 120, a rear wall 130, a first side wall 140 and a second side wall 150.

[0090] The bottom wall 110 may form the lower exterior of the shell 100 (see...) Figure 3 The bottom wall 110 may have a rectangular planar geometry. The bottom wall 110 may be mounted on the bottom surface of the outer casing 11.

[0091] The front wall 120, the rear wall 130, the first side wall 140, and the second side wall 150 can form the outer periphery of the housing 100.

[0092] The front wall 120, rear wall 130, first side wall 140, and second side wall 150 may have a planar geometry extending upward from the edge of the bottom wall 110 (see...). Figure 3 The front wall 120, rear wall 130, first side wall 140, and second side wall 150 may surround the space above the bottom wall 110. The front wall 120, rear wall 130, first side wall 140, and second side wall 150 may form a rectangular cross-sectional geometry.

[0093] The front wall 120 and the rear wall 130 may be arranged to face each other in the transverse direction of the housing 100. The front wall 120 and the rear wall 130 may be arranged to be parallel to each other. The areas of the front wall 120 and the rear wall 130 may be substantially the same.

[0094] The first sidewall 140 and the second sidewall 150 may face each other in the longitudinal direction of the housing 100. The first sidewall 140 may be located on one side of the housing 100 in the longitudinal direction, and the second sidewall 150 may be located on the other side of the housing 100 in the longitudinal direction.

[0095] The first sidewall 140 and the second sidewall 150 may be configured to be parallel to each other. The areas of the first sidewall 140 and the second sidewall 150 may be substantially the same. The areas of the first sidewall 140 and the second sidewall 150 may be smaller than the areas of the front wall 120 and the rear wall 130.

[0096] The housing 100 may include an opening 160. The opening 160 may refer to the space defined by the upper portions of the front wall 120, the rear wall 130, the first side wall 140, and the second side wall 150. The opening 160 allows the internal space 101 of the housing 100 to be interconnected with the external space.

[0097] Accordingly, the housing 100 according to this embodiment may have a rectangular geometry with an open top.

[0098] The first direction described below can refer to the direction parallel to the Y-axis and based on... Figures 2 to 4 The direction from the second sidewall 150 toward the first sidewall 140. The second direction can refer to a direction parallel to the X-axis and based on... Figures 2 to 4 The direction from the front wall 120 towards the rear wall 130. The third direction can refer to a direction parallel to the Z-axis and based on... Figures 2 to 4 From the opening 160 toward the bottom wall 110.

[0099] The electrode assembly 200 can be used as a unit structure to perform charging and discharging operations of electricity in a secondary battery. The electrode assembly 200 can be stored in the internal space 101 of the housing 100.

[0100] The electrode assembly 200 may include a first electrode 210, a second electrode 220, and a diaphragm 230 disposed between the first electrode 210 and the second electrode 220. Multiple first electrodes 210, diaphragms 230, and second electrodes 220 may be provided.

[0101] The electrode assembly 200 is shown in a stacked configuration, wherein a plurality of first electrodes 210, diaphragms 230, and second electrodes 220 are sequentially stacked in a second direction. However, the form of the electrode assembly 200 is not limited to this, and it may also have a configuration in which the first electrodes 210, diaphragms 230, and second electrodes 220 are stacked around a winding axis in a clockwise or counterclockwise direction.

[0102] The first electrode 210 can be used as the positive electrode or the negative electrode of the electrode assembly 200. The first electrode 210 is shown as the positive electrode of the electrode assembly 200. However, the first electrode 210 is not limited thereto and can also be used as the negative electrode of the electrode assembly 200.

[0103] The first electrode 210 can have a geometry including a metal foil such as aluminum or an aluminum alloy. As long as the first electrode 210 has conductivity and does not cause harmful chemical changes to the secondary battery 2, the type, size, shape, etc. of the first electrode 210 are not particularly limited. The cross-sectional geometry of the first electrode 210 can have various shapes other than the Figure 5 rectangular geometry shown in.

[0104] Multiple first electrodes 210 can be provided. The multiple first electrodes 210 can be arranged between the front wall 120 and the rear wall 130 of the housing 100 in the second direction. The number of the first electrodes 210 can vary according to the charging capacity of the secondary battery 2, etc.

[0105] The first active material layer 211 can be coated on at least a part of the first electrode 210. The first active material layer 211 can be coated on both surfaces of the first electrode 210, or alternatively, can be coated on only one surface of the first electrode 210.

[0106] Since the first electrode 210 is used as the positive electrode in this embodiment, the first active material layer 211 can include a positive electrode active material.

[0107] The positive electrode active material can be a compound for reversible insertion / extraction of lithium (i.e., a lithiated insertion compound). The positive electrode active material can include a composite oxide of a metal containing cobalt, manganese, nickel, iron, or a combination thereof. Lithium can be used as the positive electrode active material.

[0108] For example, the positive electrode active material can include lithium-iron-phosphorus oxide (LiFePO4, LFP), lithium-manganese-iron-phosphorus oxide (LiMnFePO4, LMFP), or lithium-nickel-cobalt-manganese oxide (LiNi x Co y Mn z O2, LNCM). Where, 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1.

[0109] The positive electrode active material can only include lithium-iron-phosphorus oxide (LiFePO4, LFP), lithium-manganese-iron-phosphorus oxide (LiMnFePO4, LMFP), and lithium-nickel-cobalt-manganese oxide (LiNi x Co y Mn zOne of the following (O2, LNCM). Positive electrode active materials may also include lithium-iron-phosphorus oxide (LiFePO4, LFP), lithium-manganese-iron-phosphorus oxide (LiMnFePO4, LMFP), and lithium-nickel-cobalt-manganese oxide (LiNi). x Co y Mn z Two or all of O2 (LNCM).

[0110] The first active material layer 211 may include a positive electrode conductive material.

[0111] The positive electrode conductive material ensures the conductivity of the positive electrode active material layer. Any material that does not cause harmful chemical changes and is capable of conducting electrons can be used as the positive electrode conductive material.

[0112] Non-limiting examples of positive electrode conductive materials may include: carbon-based materials, such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, carbon nanotube; metallic materials, in the form of metal powder or metal fiber containing copper, nickel, aluminum, silver, etc.; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0113] The first active material layer 211 may include a positive electrode binder.

[0114] The positive electrode binder can bind the particles constituting the positive electrode active material together. The positive electrode binder can attach the positive electrode active material to the first electrode 210.

[0115] Non-limiting examples of non-aqueous adhesives, aqueous adhesives, dry adhesives, or combinations thereof may be used as positive electrode adhesives.

[0116] Non-aqueous adhesives may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0117] Waterborne adhesives may include styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, poly(meth)acrylonitrile, ethylene-propylene-diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, or combinations thereof.

[0118] When an aqueous binder is used as the positive electrode binder, the first active material layer 211 may include a cellulose compound that provides viscosity. One or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts may be mixed and used as the cellulose compound. Na, K, or Li may be used as the alkali metal.

[0119] The dry adhesive is a fibrous polymer material and may include polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0120] The first electrode 210 may include a first uncoated portion 212 thereon to which the first active material layer 211 is not coated. The first uncoated portion 212 may be disposed in an end region of the first electrode 210 facing the first sidewall 140 in the housing 100. However, the configuration of the first uncoated portion 212 is not limited thereto, and the first uncoated portion 212 may be formed over the entire edge region of the first electrode 210.

[0121] The second electrode 220 can be used as another of the positive and negative electrodes of the electrode assembly 200. The second electrode 220 is shown as the negative electrode of the electrode assembly 200. However, the second electrode 220 is not limited thereto, and can also be used as the positive electrode of the electrode assembly 200.

[0122] Multiple second electrodes 220 may be provided. These second electrodes 220 may be arranged in a second direction between the front wall 120 and the rear wall 130 of the housing 100. The first electrode 210 and the second electrode 220 may be alternately arranged in the second direction. The second electrode 220 may be spaced apart from the first electrode 210 in the second direction by a predetermined interval.

[0123] The second electrode 220 may have a metal foil geometry, including copper, copper alloys, nickel, or nickel alloys. The type, size, shape, etc., of the second electrode 220 are not particularly limited, as long as its conductivity does not cause harmful chemical changes to the secondary battery 2. The cross-sectional geometry of the second electrode 220 can be, except... Figure 5 Various geometric shapes other than the rectangular geometry shown.

[0124] The second active material layer 221 may be applied to at least a portion of the second electrode 220. The second active material layer 221 may be applied to both surfaces of the second electrode 220, or alternatively, may be applied to only one surface of the second electrode 220.

[0125] Since the second electrode 220 is used as a negative electrode, the second active material layer 221 may include the negative electrode active material.

[0126] The negative electrode active material may include materials in which lithium ions can be reversibly inserted and / or reversibly extracted. The negative electrode active material may include lithium metal, lithium metal alloys, materials that can be doped / dedoped with lithium, or transition metal oxides.

[0127] Materials in which lithium ions can be reversibly inserted and / or extracted may include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, or combinations thereof. Non-limiting examples of crystalline carbon may include graphite, such as natural or synthetic graphite, in amorphous, tabular, flake, spherical, or fibrous forms. Non-limiting examples of amorphous carbon may include soft or hard carbon, mesophase pitch carbides, calcined coke, etc.

[0128] Lithium metal alloys may include Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, or Sn.

[0129] Materials that can be doped / dedoped with lithium can include Si-based or Sn-based negative electrode active materials. Si-based negative electrode active materials can include silicon, silicon-carbon composites, and SiO₂. x (x=1 or 2), Si-Q alloy (Q is selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements (excluding Si), Group 15 elements, Group 16 elements, transition metals, rare earth elements and combinations thereof) or combinations thereof. Sn-type negative electrode active materials may include Sn, SnO2, Sn-type alloys or combinations thereof.

[0130] Silicon-carbon composites may include composites of silicon and amorphous carbon. Silicon-carbon composites may include silicon particles coated with amorphous carbon. For example, a silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous carbon coating (shell) on the surface of the secondary particles.

[0131] Amorphous carbon may be located between the primary silicon particles, such that the primary silicon particles are coated with amorphous carbon. Secondary particles may be dispersed and present in the amorphous carbon matrix.

[0132] Silicon-carbon composites may include crystalline carbon. For example, a silicon-carbon composite may include a core comprising crystalline carbon and silicon particles, and an amorphous carbon coating on the surface of the core.

[0133] Si-based or Sn-based negative electrode active materials can be used in combination with carbon-based negative electrode active materials.

[0134] The second active material layer 221 may include a negative electrode conductive material and a negative electrode binder.

[0135] The negative electrode conductive material ensures the conductivity of the second active material layer 221. Any material that does not cause harmful chemical changes and is capable of conducting electricity may be used. Non-limiting examples of negative electrode conductive materials may include: carbon-based materials, such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metallic materials, in the form of metal powders or metal fibers containing copper, nickel, aluminum, silver, etc.; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0136] The negative electrode binder can attach the particles constituting the negative electrode active material to each other. The negative electrode binder attaches the negative electrode active material to the second electrode 220.

[0137] Non-limiting examples of non-aqueous adhesives, aqueous adhesives, dry adhesives, or combinations thereof that can be used as negative electrode adhesives.

[0138] Non-aqueous adhesives may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0139] Waterborne adhesives may include styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, poly(meth)acrylonitrile, ethylene-propylene-diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, or combinations thereof.

[0140] When an aqueous binder is used as the negative electrode binder, the second active material layer 212 may include a cellulose compound that provides viscosity. One or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts may be mixed and used as the cellulose compound. Na, K, or Li may be used as the alkali metal.

[0141] Dry adhesives are fibrous polymeric materials and may include polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0142] The second electrode 220 may include a second uncoated portion 222 thereon to which the second active material layer 221 is not coated. The second uncoated portion 222 may be disposed in another end region of the second electrode 220 facing the second sidewall 150 in the housing 100. However, the configuration of the second uncoated portion 222 is not limited thereto, and the second uncoated portion 222 may be formed throughout the entire edge region of the second electrode 220.

[0143] A diaphragm 230 may be disposed between the first electrode 210 and the second electrode 220. The diaphragm 230 can prevent short circuits between the first electrode 210 and the second electrode 220 while allowing lithium ions to migrate between the first electrode 210 and the second electrode 220.

[0144] The diaphragm 230 can completely cover the surface area of ​​the electrode assembly 200. Accordingly, the diaphragm 230 can prevent the first electrode 210 and the second electrode 220 from being directly exposed to the outside of the electrode assembly 200.

[0145] The diaphragm 230 may include polyethylene, polypropylene, polyvinylidene fluoride, or two or more multilayer membranes. The diaphragm 230 may include mixed multilayer membranes, such as polyethylene / polypropylene double-layer membranes, polyethylene / polypropylene / polypropylene triple-layer membranes, polypropylene / polypropylene / polypropylene triple-layer membranes, etc.

[0146] The diaphragm 230 may include a porous substrate and a coating on one or both surfaces of the porous substrate. The diaphragm 230 may include organic materials, inorganic materials, or a combination thereof.

[0147] Porous substrates may include polymer films of polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyimide amide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, polytetrafluoroethylene (e.g., Teflon), or copolymers or mixtures thereof.

[0148] Organic materials may include polymers such as polyvinylidene fluoride or (meth)acrylic acid polymers.

[0149] Inorganic materials may include, but are not limited to, particles of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, or combinations thereof.

[0150] Organic and inorganic materials can exist in a coating as a mixture. Organic and inorganic materials can also exist as a coating that includes organic materials and a stack of coatings that include inorganic materials.

[0151] The first connecting piece 301 can be electrically connected to the first electrode 210. Since the first electrode 210 is shown as a positive electrode, the first connecting piece 301 can be used as a positive electrode connecting piece of the secondary battery 2. However, the first connecting piece 301 is not limited to this, and when the first electrode 210 is a negative electrode, the first connecting piece 301 can be used as a negative electrode connecting piece of the secondary battery 2.

[0152] The first connector member 301 may extend from the electrode assembly 200 in a first direction. The first connector member 301 may extend from the electrode assembly 200 toward the first sidewall 140 inside the housing 100.

[0153] Multiple first connector components 301 may be provided. The multiple first connector components 301 may be arranged in a third direction. A pair of first connector components 301 may be formed, and the pair of first connector components 301 may be spaced apart at a predetermined distance along a third direction.

[0154] The first connector component 301 may include a plurality of first connectors 310.

[0155] The first terminal block 310 may have a foil geometry extending from the first uncoated portion 212 of the first electrode 210 in a first direction. The first terminal block 310 may have a substantially rectangular geometry. However, the geometry of the first terminal block 310 is not limited to this and may be various geometries.

[0156] The first connecting piece 310 may be formed as a single piece together with the first electrode 210. For example, the first connecting piece 310 may be the remaining area of ​​the first uncoated portion 212, which is left after a portion of the first uncoated portion 212 has been cut or removed by a grooving process or the like. Alternatively, the first connecting piece 310 may be manufactured separately from the first electrode 210 and then connected to the first uncoated portion 212 by welding or the like. The material of the first connecting piece 310 may be substantially the same as the material of the first electrode 210.

[0157] The number of first tabs 310 may be substantially the same as the number of first electrodes 210. Each of the first tabs 310 may extend from a first uncoated portion 212 of a different first electrode 210. Adjacent first tabs 310 may be arranged facing each other in a second direction. That is, a plurality of first tabs 310 may be arranged in the second direction. Adjacent first tabs 310 may be arranged parallel to each other. Accordingly, the first tab member 301 may be an assembly of a plurality of first tabs 310 arranged in the second direction. Adjacent first tabs 310 may contact each other and may also be spaced apart from each other by the thickness of the diaphragm 230.

[0158] The secondary battery 2 may include a second connecting piece component 302.

[0159] The second terminal member 302 can be electrically connected to the second electrode 220. Since the second electrode 220 is shown as a negative electrode, the second terminal member 302 can be used as a negative electrode terminal of the secondary battery 2. However, the second terminal member 302 is not limited to this, and when the second electrode 220 is a positive electrode, the second terminal member 302 can be used as a positive electrode terminal of the secondary battery 2.

[0160] The second contact member 302 may extend from the electrode assembly 200 in a direction opposite to the first direction. The second contact member 302 may extend from the electrode assembly 200 toward the second sidewall 150 inside the housing 100. That is, the first contact member 301 and the second contact member 302 may extend from the electrode assembly 200 in directions opposite to each other.

[0161] Multiple second connector components 302 may be provided. The multiple second connector components 302 may be arranged in a third direction. A pair of second connector components 302 may be formed, and the pair of second connector components 302 may be spaced apart at a predetermined distance in a third direction.

[0162] The second connector component 302 may include a plurality of second connectors 320.

[0163] The second terminal block 320 may have a foil geometry extending from the second uncoated portion 222 of the second electrode 220 in a direction opposite to the first direction. The second terminal block 320 may have a substantially rectangular geometry. However, the shape of the second terminal block 320 is not limited to this and may have various geometries.

[0164] The second connector 320 may be formed as a single piece together with the second electrode 220. For example, the second connector 320 may be the remaining area of ​​the second uncoated portion 222, which is left after a portion of the second uncoated portion 222 has been cut or removed by a grooving process or the like. Alternatively, the second connector 320 may be manufactured separately from the second electrode 220 and then connected to the second uncoated portion 222 by welding or the like. The material of the second connector 320 may be substantially the same as the material of the second electrode 220.

[0165] The number of second tabs 320 may be substantially the same as the number of second electrodes 220. Each of the second tabs 320 may extend from a second uncoated portion 222 of a different second electrode 220. Adjacent second tabs 320 may be arranged facing each other in a second direction. That is, a plurality of second tabs 320 may be arranged in the second direction. Adjacent second tabs 320 may be arranged parallel to each other. Accordingly, the second tab member 302 may be an assembly of a plurality of second tabs 320 arranged in the second direction. Adjacent second tabs 320 may contact each other and may also be spaced apart from each other by the thickness of the diaphragm 230.

[0166] Cover plate 410 can be attached to housing 100 to close the open side of housing 100. Cover plate 410 closes opening 160. First terminal 420 is mounted on cover plate 410.

[0167] Cover plate 410 and first terminal 420 may be included in cover assembly 400. Cover assembly 400 may include second terminal 430. First terminal 420 may be mounted longitudinally on one side of cover plate 410, and second terminal 430 may be mounted longitudinally on the other side of cover plate 410. First terminal 420 may be positioned closer to first sidewall 140 than to second sidewall 150, and second terminal 430 may be positioned closer to second sidewall 150 than to first sidewall 140.

[0168] The cover plate 410 can be arranged to face the electrode assembly 200 in a third-party direction. That is, the cover plate 410 can be arranged in a third-party direction at a predetermined distance from the electrode assembly 200. The cover plate 410 can be configured to be parallel to the bottom wall 110 of the housing 100.

[0169] The cover plate 410 can be mounted on the upper portion of the housing 100, more specifically, on the upper portions of the front wall 120, rear wall 130, first side wall 140, and second side wall 150. The cover plate 410 can be connected to the housing 100 by various types of connection methods such as welding, screwing, and mating.

[0170] The first terminal 420 may protrude outward from the cover plate 410. The first terminal 420 may be electrically connected to the first electrode 210. Since the first electrode 210 is shown as serving as a positive electrode, the first terminal 420 may be exemplified as the positive electrode terminal of the secondary battery 2.

[0171] The first terminal 420 can be inserted into the cover plate 410. The upper part of the first terminal 420 can protrude outward from the cover plate 410. Figure 3An example is shown in which the first terminal 420 has a rectangular cross-sectional geometry, but the cross-sectional geometry of the first terminal 420 is not limited to this and can be various geometries such as circular geometry, elliptical geometry, polygonal geometry, etc. The first terminal 420 may include a conductive material such as aluminum, nickel, copper, etc.

[0172] The first gasket 421 can be installed between the cover plate 410 and the first terminal 420. The first gasket 421 can electrically insulate the cover plate 410 from the first terminal 420 and prevent moisture or foreign substances from entering between the cover plate 410 and the first terminal 420.

[0173] The first gasket 421 may include insulating materials such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET) rubber, etc. The first gasket 421 may be fixed between the cover plate 410 and the first terminal 420 by pressing, injection, adhesion, etc.

[0174] The second terminal 430 may protrude outward from the cover plate 410 at a position spaced apart from the first terminal 420. The second terminal 430 may be electrically connected to the second electrode 220. Since the second electrode 220 is shown as serving as a negative electrode, the second terminal 430 may be the negative electrode terminal of the secondary battery 2.

[0175] The second terminal 430 can be inserted into the cover plate 410. The upper part of the second terminal 430 can protrude to the outside of the cover plate 410. Figure 3 An example is shown in which the second terminal 430 has a rectangular cross-sectional geometry, but the cross-sectional geometry of the second terminal 430 is not limited to this and can be various geometries such as circular geometry, elliptical geometry, polygonal geometry, etc. The second terminal 430 may include a conductive material such as aluminum, nickel, copper, etc.

[0176] The second gasket 431 can be installed between the cover plate 410 and the second terminal 430. The second gasket 431 can electrically insulate the cover plate 410 and the second terminal 430 and prevent moisture or foreign substances from entering between the cover plate 410 and the second terminal 430.

[0177] The second gasket 431 may include insulating materials such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET) rubber, etc. The second gasket 431 may be fixed between the cover plate 410 and the second terminal 430 by pressing, injection, adhesion, etc.

[0178] The cover assembly 400 may include an exhaust port 440 and a single exhaust element 450.

[0179] The vent 440 may have a hole geometry that extends vertically through both sides of the cover plate 410 in a third-order upward direction. The vent 440 provides a path through which flames, gases, smoke, etc., generated in the housing 100 can be discharged to the outside of the housing 100 in the event of thermal runaway of the secondary battery 2 due to overcurrent or other reasons. The vent 440 may be located between the first terminal 420 and the second terminal 430. The cross-sectional geometry of the vent 440 can be various shapes, such as elliptical, circular, or polygonal.

[0180] A single vent 450 is installed in the vent 440 and can be opened and closed in response to changes in the internal pressure of the housing 100. During normal operation of the secondary battery 2, the single vent 450 can prevent electrolyte or other substances from leaking from the housing 100 to the outside of the housing 100 or prevent moisture or external substances from entering the housing 100 by closing the vent 440. In the event of thermal runaway of the secondary battery 2, the single vent 450 can open the vent 440 to guide flames, gases, smoke, etc., generated within the housing 100 to the outside of the housing 100.

[0181] The individual exhaust component 450 can be formed into a substantially planar geometry. The individual exhaust component 450 can be fixed to the cover plate 410 by various connection methods such as welding, screwing, and mating. The individual exhaust component 450 can be disposed in the exhaust hole 440, or disposed on the upper or lower side of the cover plate 410 opposite the exhaust hole 440.

[0182] The thickness of the individual exhaust element 450 parallel to a third direction may be less than the thickness of the cover plate 410. Accordingly, the individual exhaust element 450 may rupture or break when the internal pressure of the housing 100 increases. The individual exhaust element 450 may include a cut recessed towards the inside of the individual exhaust element 450 to preferentially break when the internal pressure of the housing 100 increases.

[0183] The cover assembly 400 may include an electrolyte inlet 460 formed through the cover plate 410 and in which a sealing plug may be installed. The electrolyte inlet 460 may be positioned at a predetermined distance from the vent 440. The electrolyte inlet 460 may be located between the first terminal 420 and the second terminal 430.

[0184] The cover assembly 400 may include an inner insulating member 470.

[0185] An inner insulating member 470 may be disposed between the cover plate 410 and the electrode assembly 200. The inner insulating member 470 prevents direct contact between the cover plate 410 and the electrode assembly 200, thereby insulating the cover plate 410 and the electrode assembly 200.

[0186] The inner insulating member 470 may face the electrode assembly 200 in the housing 100 in a third-party orientation. That is, the cover plate 410, the inner insulating member 470, and the electrode assembly 200 may be arranged sequentially in the third-party orientation.

[0187] The inner insulation member 470 may include a first current collector insulating plate 480 inserted between the first terminal connection portion 601 of the first current collector 600A and the electrode assembly 200, and a second current collector insulating plate 490 inserted between the second terminal connection portion 701 of the second current collector 700A and the electrode assembly 200. The inner insulation member 470 may include insulating materials such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET) rubber, etc.

[0188] A first plate 800A is located in the internal space 101 between a first sidewall 140 and an electrode assembly 200. The first plate 800A may face the first sidewall 140 and may extend parallel to the longitudinal direction of the first sidewall 140. The first plate 800A may include a pair of first contact plate connection portions 802 and a first central rib portion 801 between the pair of first contact plate connection portions 802.

[0189] The first central rib portion 801 may have a stepped configuration starting from the pair of first tab connection portions 802 and may protrude near the first sidewall 140. The first tab connection portions 802 may be electrically connected to the first tab member 301 of the electrode assembly 200. The pair of first tab connection portions 802 may extend upward in a third direction.

[0190] The secondary battery 2 may include a pair of first sub-plates 890. A pair of first terminal block connection portions 802 may be in electrical contact with the pair of first sub-plates 890.

[0191] Each of the first sub-boards 890 can be inserted between the corresponding first terminal block member 301 and the corresponding first terminal block connection portion 802, and can make electrical contact with the corresponding first terminal block member 301 and the corresponding first terminal block connection portion 802. The first sub-board 890 provides electrical connection between the first terminal block member 301 and the first board 800A by limiting the relative movement of the plurality of first terminals 310 constituting the first terminal block member 301. Accordingly, the first sub-board 890 can prevent some of the first terminals 310 from losing electrical connection due to the relative movement of the first terminals 310.

[0192] The first plate 800A includes a first current collector connection portion 807. The first current collector connection portion 807 is provided on one side of the first plate 800A. For example, the first current collector connection portion 807 may be provided at the end portion of the first plate 800A in the positive Z-axis direction (+).

[0193] The first plate 800A may include a first stepped portion 804 that connects the first contact plate connection portion 802 and the first current collector connection portion 807 in a stepped manner or configuration. The first stepped portion 804 may be provided between the first contact plate connection portion 802 and the first current collector connection portion 807 of the pair of first contact plate connection portions 802 near the cover plate 410.

[0194] Due to the first step portion 804, in the first direction, the distance between the first current collector connection portion 807 and the electrode assembly 200 can be less than the distance between the first terminal block connection portion 802 and the electrode assembly 200.

[0195] The first current collector 600A includes a first terminal connection portion 601 and a first plate connection portion 610. The first terminal connection portion 601 is electrically connected to a first terminal 420. The first plate connection portion 610 is connected to the first terminal connection portion 601. The first plate connection portion 610 includes a first welding surface 611, which is a surface facing away from the first sidewall 140, and is welded to the first current collector connection portion 807.

[0196] The first plate connection portion 610 may include a first stop surface 613 that blocks the first current collector connection portion 807 and intersects with the first welding surface 611. The end edge of the first current collector connection portion 807 may be positioned to face the first stop surface 613.

[0197] The side surface of the first current collector connection portion 807 welded to the first welding surface 611 may be a side surface facing the first welding surface 611 and away from the electrode assembly 200.

[0198] The first plate connection portion 610 may include a first thick portion 620 and a first thin portion 622. The first thick portion 620 may include a first stop surface 613. The thickness of the first thick portion 620 in a first direction may be greater than the thickness of the first current collector connection portion 807. The first plate connection portion 610 may further include a first through hole passing through the first thin portion 622 in the lateral direction of the first plate connection portion 610.

[0199] The first thin portion 622 may include a first welding surface 611. The thickness of the first thin portion 622 in the first direction may be less than the thickness of the first thick portion 620.

[0200] When an impact is applied to the casing 100 of the secondary battery 2 in the first direction or the third direction upward, the first welded surface 611 can separate from the first current collector connection portion 807, or the first current collector connection portion 807 and the first terminal block connection portion 802 can be bent or broken. Therefore, the first plate 800A can be easily separated from the first plate connection portion 610 of the first current collector 600A. Accordingly, the first plate connection portion 610 will not apply a large impact to the electrode assembly 200, and can suppress the short circuit between the first current collector 600A and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0201] The secondary battery 2 may include a second plate 900A and a second current collector 700A.

[0202] The second plate 900A is located in the internal space 101 between the second sidewall 150 and the electrode assembly 200. The second plate 900A may face the second sidewall 150 and may extend parallel to the longitudinal direction of the second sidewall 150. The second plate 900A may include a pair of second contact connection portions 902 and a second central rib portion 901 between the pair of second contact connection portions 902.

[0203] The second central rib portion 901 may be stepped from the pair of second tab connection portions 902 and may protrude near the second sidewall 150. The second tab connection portion 902 may be electrically connected to the second tab member 302 of the electrode assembly 200. The pair of second tab connection portions 902 may extend upward in a third direction.

[0204] The secondary battery 2 may include a pair of second sub-plates 990. A pair of second terminal block connection portions 902 may make electrical contact with the pair of second sub-plates 990.

[0205] Each of the second sub-boards 990 can be inserted between the corresponding second terminal block member 302 and the corresponding second terminal block connection portion 902, and can make electrical contact with the corresponding second terminal block member 302 and the corresponding second terminal block connection portion 902. The second sub-board 990 provides electrical connection between the second terminal block member 302 and the second board 900A by limiting the relative movement of the plurality of second terminals 320 constituting the second terminal block member 302. Accordingly, the second sub-board 990 can prevent some of the second terminals 320 from losing electrical connection due to the relative movement of the second terminals 320.

[0206] The second plate 900A includes a second current collector connection portion 907. The second current collector connection portion 907 is provided on one side of the second plate 900A. For example, the second current collector connection portion 907 may be provided at the end portion of the second plate 900A in the positive Z-axis direction (+).

[0207] The second plate 900A may include a second stepped portion 904 that connects the second connector portion 902 and the second manifold connection portion 907 in a stepped manner or configuration. The second stepped portion 904 may be provided between the second connector portion 902 and the second manifold connection portion 907 near the cover plate 410 in a pair of second connector portions 902.

[0208] Due to the second step portion 904, in the first direction, the distance between the second current collector connection portion 907 and the electrode assembly 200 can be less than the distance between the second terminal block connection portion 902 and the electrode assembly 200.

[0209] The second current collector 700A includes a second terminal connection portion 701 and a second plate connection portion 710. The second terminal connection portion 701 is electrically connected to the second terminal 430. The second plate connection portion 710 is connected to the second terminal connection portion 701. The second plate connection portion 710 includes a second welding surface 711, which is a surface facing away from the second sidewall 150, and is welded to the second current collector connection portion 907.

[0210] The second plate connection portion 710 may include a second stop surface 713 that blocks the second current collector connection portion 907 and intersects with the second welding surface 711. The end edge of the second current collector connection portion 907 may be positioned to face the second stop surface 713.

[0211] The side surface of the second current collector connection portion 907 welded to the second welding surface 711 may be a side surface facing the second welding surface 711 and away from the electrode assembly 200.

[0212] The second plate connection portion 710 may include a second thick portion 720 and a second thin portion 722. The second thick portion 720 may include a second stop surface 713. The thickness of the second thick portion 720 in the first direction may be greater than the thickness of the second current collector connection portion 907. The second plate connection portion 710 may further include a second through hole passing through the second thin portion 722 in the lateral direction of the second plate connection portion 710.

[0213] The second thin portion 722 may include a second welding surface 711. The thickness of the second thin portion 722 in the first direction may be less than the thickness of the second thick portion 720.

[0214] When an impact is applied to the casing 100 of the secondary battery 2 in the first direction or the third direction upward, the second welded surface 711 can separate from the second current collector connection portion 907, or the second current collector connection portion 907 and the second terminal block connection portion 902 can be bent or broken. Therefore, the second plate 900A can be easily separated from the second plate connection portion 710 of the second current collector 700A. Accordingly, the second plate connection portion 710 will not apply large impacts to the electrode assembly 200, and can suppress short circuits between the second current collector 700A and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0215] Figure 8 For example Figure 4 The view of the modified example of part A, and Figure 9 For example Figure 4 A view showing a modified example of part B. (Reference) Figure 8 and Figure 9 The secondary battery 2 of the present invention may include Figure 8 and Figure 9 The first current collector 600B, the second current collector 700B, the first plate 800B, and the second plate 900B illustrated herein are used to replace Figures 3 to 7 The first current collector 600A, the second current collector 700A, the first plate 800A, and the second plate 900A are illustrated in the figure.

[0216] A first plate 800B is located in the internal space 101 between a first sidewall 140 and an electrode assembly 200. The first plate 800B may face the first sidewall 140 and may extend parallel to the longitudinal direction of the first sidewall 140. The first plate 800B may include a pair of first contact tab connection portions 802 and a first central rib portion 801 between the pair of first contact tab connection portions 802. The first plate 800B further includes a first current collector connection portion 815. The first current collector connection portion 815 is provided on one side of the first plate 800B. For example, the first current collector connection portion 815 may be provided at the end portion of the first plate 800B in the positive Z-axis direction (+).

[0217] The first plate 800B may further include a first stepped portion 812 that connects the first contact plate connection portion 802 and the first current collector connection portion 815 in a stepped manner or configuration. The first stepped portion 812 may be provided between the first contact plate connection portion 802 and the first current collector connection portion 815 of the pair of first contact plate connection portions 802 near the cover plate 410.

[0218] Due to the first step portion 812, in the first direction, the distance between the first current collector connection portion 815 and the electrode assembly 200 can be less than the distance between the first terminal block connection portion 802 and the electrode assembly 200.

[0219] The first current collector 600B includes a first terminal connection portion 601 and a first plate connection portion 630. The first terminal connection portion 601 is electrically connected to a first terminal 420. The first plate connection portion 630 is connected to the first terminal connection portion 601. The first plate connection portion 630 includes a first welding surface 631, which is a surface facing away from the first sidewall 140, and is welded to the first current collector connection portion 815.

[0220] The first plate connection portion 630 may include a first stop surface 633 that blocks the first current collector connection portion 815 and intersects with the first welding surface 631. The end edge of the first current collector connection portion 815 may be positioned to face the first stop surface 633.

[0221] The side surface of the first current collector connection portion 815 welded to the first welding surface 631 may be a side surface facing the first welding surface 631 and away from the electrode assembly 200.

[0222] The first plate connection portion 630 may include a first thick portion 640, a first thin portion 642, a first end-thick portion 644, and a first groove portion 646. The thickness of the first thick portion 640 in the first direction may be greater than the thickness of the first current collector connection portion 815.

[0223] The thickness of the first thin portion 642 in the first direction may be less than the thickness of the first thick portion 640. The first end-thick portion 644 may be spaced apart from the first thick portion 640, may be bent at the first thin portion 642, and may protrude toward the first sidewall 140. The thickness of the first end-thick portion 644 in the first direction may be greater than the thickness of the first thin portion 642.

[0224] The first groove portion 646 may be a recessed portion between the first thick portion 640 and the first end thick portion 644, so as to move away from the first sidewall 140 in the first direction.

[0225] When an impact is applied to the casing 100 of the secondary battery 2 in the first direction or the third direction upward, the first welded surface 631 can separate from the first current collector connection portion 815, or the first current collector connection portion 815 and the first terminal block connection portion 802 can be bent or broken. Therefore, the first plate 800B can be easily separated from the first plate connection portion 630 of the first current collector 600B. Accordingly, the first plate connection portion 630 will not apply large impacts to the electrode assembly 200, and can suppress short circuits between the first current collector 600B and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0226] When the first plate connection portion 630 is cut, the first thin portion 642 with the thinnest thickness can be cut along the virtual cutting line CU1.

[0227] Furthermore, when an impact is applied to the casing 100 of the secondary battery 2 in the third-direction upward direction, the first plate connection portion 630 can be plastically deformed to increase or decrease the gap of the first groove portion 646 in the third-direction upward direction to absorb the impact. Accordingly, the first plate connection portion 630 will not apply large impacts to the electrode assembly 200, and can reliably suppress short circuits between the first current collector 600B and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0228] The second plate 900B is located within the internal space 101 between the second sidewall 150 and the electrode assembly 200. The second plate 900B may face the second sidewall 150 and may extend parallel to the longitudinal direction of the second sidewall 150. The second plate 900B may include a pair of second contact connection portions 902 and a second central rib portion 901 between the pair of second contact connection portions 902. The second plate 900B further includes a second current collector connection portion 915. The second current collector connection portion 915 is provided on one side of the second plate 900B. For example, the second current collector connection portion 915 may be provided at the end portion of the second plate 900B in the positive Z-axis direction (+).

[0229] The second plate 900B may include a second stepped portion 912 that connects the second contact connection portion 902 and the second current collector connection portion 915 in a stepped manner or configuration. The second stepped portion 912 may be provided between the second contact connection portion 902 and the second current collector connection portion 915 near the cover plate 410 in a pair of second contact connection portions 902.

[0230] Due to the second step portion 912, in the first direction, the distance between the second current collector connection portion 915 and the electrode assembly 200 can be less than the distance between the second terminal block connection portion 902 and the electrode assembly 200.

[0231] The second current collector 700B includes a second terminal connection portion 701 and a second plate connection portion 730. The second terminal connection portion 701 is electrically connected to the second terminal 430. The second plate connection portion 730 is connected to the second terminal connection portion 701. The second plate connection portion 730 includes a second welding surface 731, which is a surface facing away from the second sidewall 150, and is welded to the second current collector connection portion 915.

[0232] The second plate connection portion 730 may include a second stop surface 733 that blocks the second current collector connection portion 915 and intersects with the second welding surface 731. The end edge of the second current collector connection portion 915 may be positioned to face the second stop surface 733.

[0233] The side surface of the second current collector connection portion 915 welded to the second welding surface 731 may be a side surface facing the second welding surface 731 and away from the electrode assembly 200.

[0234] The second plate connection portion 730 may include a second thick portion 740, a second thin portion 742, a second end thick portion 744, and a second groove portion 746. The thickness of the second thick portion 740 in the first direction may be greater than the thickness of the second current collector connection portion 915.

[0235] The thickness of the second thin portion 742 in the first direction may be less than the thickness of the second thick portion 740. The second end-thick portion 744 may be spaced apart from the second thick portion 740, may be bent at the second thin portion 742, and may protrude toward the second sidewall 150. The thickness of the second end-thick portion 744 in the first direction may be greater than the thickness of the second thin portion 742.

[0236] The second groove portion 746 may be a recessed portion between the second thick portion 740 and the second end thick portion 744, so as to move away from the second sidewall 150 in the first direction.

[0237] When an impact is applied to the casing 100 of the secondary battery 2 in the first direction or the third direction upward, the second welded surface 731 can separate from the second current collector connection portion 915, or the second current collector connection portion 915 and the second terminal block connection portion 902 can be bent or broken. Therefore, the second plate 900B can be easily separated from the second plate connection portion 730 of the second current collector 700B. Accordingly, the second plate connection portion 730 will not apply large impacts to the electrode assembly 200, and can suppress short circuits between the second current collector 700B and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0238] When the second plate connecting portion 730 is cut, the second thin portion 742 with the thinnest thickness can be cut along the virtual cutting line CU2.

[0239] Furthermore, when an impact is applied to the casing 100 of the secondary battery 2 in the third-direction upward direction, the second plate connection portion 730 can be plastically deformed to increase or decrease the gap of the second groove portion 746 in the third-direction upward direction to absorb the impact. Accordingly, the second plate connection portion 730 will not apply large impacts to the electrode assembly 200, and can reliably suppress short circuits between the second current collector 700B and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0240] Figure 10 For example Figure 4 The view of the modified example of part A, and Figure 11 For example Figure 4 A view showing a modified example of part B. (Reference) Figure 10and Figure 11 The secondary battery 2 may include Figure 10 and Figure 11 The first current collector 600C, the second current collector 700C, the first plate 800C, and the second plate 900C illustrated are used to replace Figures 3 to 7 The first current collector 600A, the second current collector 700A, the first plate 800A, and the second plate 900A are illustrated in the figure.

[0241] A first plate 800C is located in the internal space 101 between a first sidewall 140 and an electrode assembly 200. The first plate 800C may face the first sidewall 140 and may extend parallel to the longitudinal direction of the first sidewall 140. The first plate 800C may include a pair of first contact patch portions 802 and a first central rib portion 801 between the pair of first contact patch portions 802. The first plate 800C includes a first current collector connection portion 825. The first current collector connection portion 825 is provided on one side of the first plate 800C. For example, the first current collector connection portion 825 may be provided at the end portion of the first plate 800C in the positive Z-axis direction (+). The thickness of the first current collector connection portion 825 in the first direction may be greater than the thickness of the first contact patch portions 802.

[0242] The first plate 800C may include a first stepped portion 822 that connects the first contact plate connection portion 802 and the first current collector connection portion 825 in a stepped manner. The first stepped portion 822 may be provided between the first contact plate connection portion 802 and the first current collector connection portion 825 near the cover plate 410 in a pair of first contact plate connection portions 802.

[0243] Due to the first step portion 822, in the first direction, the distance between the first current collector connection portion 825 and the electrode assembly 200 can be less than the distance between the first terminal block connection portion 802 and the electrode assembly 200.

[0244] The first plate 800C may include a first bending-inducing cutout 830 in the first connector portion 802. The first bending-inducing cutout 830 may be recessed such that its thickness is thinner than the surrounding area, and may extend in the lateral or width direction of the first connector portion 802.

[0245] For example, the first bending induction cut 830 may be recessed in a first direction and extend in a second direction from the surface of the first tab connection portion 802 facing the electrode assembly 200.

[0246] The first bending-inducing cut 830 may be formed in the region of the first contact portion 802 that does not overlap with the first contact 310 and the first contact member 301 of the electrode assembly 200. For example, the cross-sectional geometry of the first bending-inducing cut 830 may be semi-circular or curved.

[0247] The first current collector 600C includes a first terminal connection portion 601 and a first plate connection portion 650. The first terminal connection portion 601 is electrically connected to a first terminal 420. The first plate connection portion 650 is connected to the first terminal connection portion 601. The first plate connection portion 650 includes a first welding surface 651, which is a surface facing away from the first sidewall 140, and is welded to the first current collector connection portion 825.

[0248] The first plate connection portion 650 may include a first stop surface 653 that blocks the first current collector connection portion 825 and intersects with the first welding surface 651. The end edge of the first current collector connection portion 825 may be positioned to face the first stop surface 653.

[0249] The side surface of the first current collector connection portion 825 welded to the first welding surface 651 may be a side surface facing the first welding surface 651 and away from the electrode assembly 200.

[0250] The first plate connection portion 650 may include a first thick portion 660, a first thin portion 662, a first end-thick portion 664, a first groove portion 666, and a first through hole 668. The thickness of the first thick portion 660 in the first direction may be greater than the thickness of the first current collector connection portion 825.

[0251] The thickness of the first thin portion 662 in the first direction may be less than the thickness of the first thick portion 660. The first end-thick portion 664 may be spaced apart from the first thick portion 660, may be bent at the first thin portion 662, and may protrude toward the first sidewall 140. The thickness of the first end-thick portion 664 in the first direction may be greater than the thickness of the first thin portion 662.

[0252] The first groove portion 666 may be a recessed portion between the first thick portion 660 and the first end thick portion 664, so as to move away from the first sidewall 140 in the first direction.

[0253] A first through-hole 668 may be formed in the first thin portion 662 to pass through the first thin portion 662 in the lateral or width direction of the first plate connection portion 650. Due to the first through-hole 668, the first thin portion 662 can be more easily bent or cut.

[0254] When an impact is applied to the casing 100 of the secondary battery 2 in the first direction or the third direction upward, the first welded surface 651 can separate from the first current collector connection portion 825, or the first current collector connection portion 825 and the first terminal block connection portion 802 can be bent or broken. Therefore, the first plate 800C can be easily separated from the first plate connection portion 650 of the first current collector 600C. Accordingly, the first plate connection portion 650 will not apply large impacts to the electrode assembly 200, and can suppress short circuits between the first current collector 600C and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0255] In this case, the first thin portion 662, which has the thinnest thickness among the first thick portion 660, the first thin portion 662, and the first end thick portion 664, can be cut or bent first. Because the first through hole 668 is formed in the first thin portion 662, the first thin portion 662 can be cut or bent more easily.

[0256] In addition, depending on the location where the external force is applied to the first current collector 600C and the first plate 800C, the location where the first bending induced cut 830 is formed can be easily broken, cut, or bent.

[0257] Simultaneously, when an impact is applied to the casing 100 of the secondary battery 2 in the third-direction upward direction, the first plate connection portion 650 can be plastically deformed to increase or decrease the gap of the first groove portion 666 in the third-direction upward direction to absorb the impact. Accordingly, the first plate connection portion 650 will not apply large impacts to the electrode assembly 200, and can reliably suppress short circuits between the first current collector 600C and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0258] The second plate 900C is located in the internal space 101 between the second sidewall 150 and the electrode assembly 200. The second plate 900C may face the second sidewall 150 and may extend parallel to the longitudinal direction of the second sidewall 150. The second plate 900C may include a pair of second contact connection portions 902 and a second central rib portion 901 between the pair of second contact connection portions 902.

[0259] The second plate 900C further includes a second manifold connection portion 925. The second manifold connection portion 925 is provided on one side of the second plate 900C. For example, the second manifold connection portion 925 may be provided at the end portion of the second plate 900C in the positive Z-axis direction (+).

[0260] The second plate 900C may include a second stepped portion 922 that connects the second contact plate connection portion 902 and the second current collector connection portion 925 in a stepped manner. The second stepped portion 922 may be provided between the second contact plate connection portion 902 and the second current collector connection portion 925 near the cover plate 410 in a pair of second contact plate connection portions 902.

[0261] Due to the second step portion 922, in the first direction, the distance between the second current collector connection portion 925 and the electrode assembly 200 can be less than the distance between the second terminal block connection portion 902 and the electrode assembly 200.

[0262] The second plate 900C may include a second bending-inducing cutout 930 in the second connector portion 902. The second bending-inducing cutout 930 may be recessed such that its thickness is thinner than the surrounding area, and may extend in the lateral or width direction of the second connector portion 902.

[0263] For example, the second bending induction cut 930 may be recessed in a first direction and extend in a second direction from the surface of the second terminal block connection portion 902 facing the electrode assembly 200.

[0264] The second bending induction cut 930 may be formed in the second contact connection portion 902 in a region that does not overlap with the second contact 320 and the second contact member 302 of the electrode assembly 200. For example, the cross-sectional shape of the second bending induction cut 930 may be semi-circular or curved.

[0265] The second current collector 700C includes a second terminal connection portion 701 and a second plate connection portion 750. The second terminal connection portion 701 is electrically connected to the second terminal 430. The second plate connection portion 750 is connected to the second terminal connection portion 701. The second plate connection portion 750 includes a second welding surface 751, which is a surface facing away from the second sidewall 150, and is welded to the second current collector connection portion 925.

[0266] The second plate connection portion 750 may include a second stop surface 753 that blocks the second current collector connection portion 925 and intersects with the second welding surface 751. The end edge of the second current collector connection portion 925 may be positioned to face the second stop surface 753.

[0267] The side surface of the second current collector connection portion 925 welded to the second welding surface 751 may be a side surface facing the second welding surface 751 and away from the electrode assembly 200.

[0268] The second plate connection portion 750 may include a second thick portion 760, a second thin portion 762, a second end-thick portion 764, a second groove portion 766, and a second through hole 768. The thickness of the second thick portion 760 in the first direction may be greater than the thickness of the second current collector connection portion 925.

[0269] The thickness of the second thin portion 762 in the first direction may be less than the thickness of the second thick portion 760. The second end-thick portion 764 may be spaced apart from the second thick portion 760, may be bent at the second thin portion 762, and may protrude toward the second sidewall 150. The thickness of the second end-thick portion 764 in the first direction may be greater than the thickness of the second thin portion 762.

[0270] The second groove portion 766 may be a recessed portion between the second thick portion 760 and the second end thick portion 764, so as to move away from the second sidewall 150 in the first direction.

[0271] A second through hole 768 may be formed in the second thin portion 762 to pass through the second thin portion 762 in the lateral or width direction of the second plate connection portion 750. Due to the second through hole 768, the second thin portion 762 can be more easily bent or cut.

[0272] When an impact is applied to the casing 100 of the secondary battery 2 in the first direction or the third direction upward, the second welded surface 751 can separate from the second current collector connection portion 925, or the second current collector connection portion 925 and the second terminal block connection portion 902 can be bent or broken. Therefore, the second plate 900C can be easily separated from the second plate connection portion 750 of the second current collector 700C. Accordingly, the second plate connection portion 750 will not apply large impacts to the electrode assembly 200, and can suppress short circuits between the second current collector 700C and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0273] In this case, the second thin portion 762, which has the thinnest thickness among the second thick portion 760, the second thin portion 762, and the second end thick portion 764, can be cut or bent first. Because the second through hole 768 is formed in the second thin portion 762, the second thin portion 762 can be cut or bent more easily.

[0274] In addition, depending on the location where the external force is applied to the second current collector 700C and the second plate 900C, the location where the second bending induced cut 930 is formed can be easily broken, cut, or bent.

[0275] Simultaneously, when an impact is applied to the casing 100 of the secondary battery 2 in the third-direction upward direction, the second plate connection portion 750 can be plastically deformed to increase or decrease the gap of the second groove portion 766 in the third-direction upward direction to absorb the impact. Accordingly, the second plate connection portion 750 will not apply large impacts to the electrode assembly 200, and can reliably suppress short circuits between the second current collector 700C and the electrode assembly 200 and the resulting thermal runaway of the secondary battery 2.

[0276] When an impact is applied to the secondary battery casing, the plate electrically connected to the electrode assembly's terminals separates from the current collector, and the current collector does not transfer the impact to the electrode assembly. Accordingly, short circuits between the current collector and the electrode assembly, and the resulting thermal runaway of the secondary battery, can be suppressed.

[0277] However, the aspects and features of the present invention are not limited to those described above, and those skilled in the art will clearly understand from the detailed description given above that other aspects and features not mentioned will be apparent.

[0278] Although the invention has been described with reference to some embodiments and the accompanying drawings illustrating aspects thereof, the invention is not limited thereto. Various modifications and variations can be made by those skilled in the art within the spirit and scope of the invention.

Claims

1. A secondary battery, comprising: A housing having an open side, the housing including a plurality of walls defining an internal space; Electrode assembly, housed within the internal space; A cover plate is configured to close one of the open sides of the housing; The first terminal is disposed on the cover plate; A first plate is disposed in the internal space between one of the plurality of walls and the electrode assembly, the first plate including a first current collector connection portion; as well as The first current collector includes a first terminal connection portion and a first plate connection portion, the first terminal connection portion being electrically connected to the first terminal, the first plate connection portion being connected to the first terminal connection portion and including a first welding surface facing away from one of the plurality of walls, the first welding surface being welded to the first current collector connection portion.

2. The secondary battery according to claim 1, wherein the first plate connection portion further includes a first stop surface, the first stop surface blocking the first current collector connection portion and intersecting with the first welding surface.

3. The secondary battery according to claim 2, wherein the first plate connection portion further comprises: The first thick portion includes the first stop surface, and the thickness of the first thick portion is greater than the thickness of the first current collector connection portion; as well as The first thin portion includes the first welding surface, and the thickness of the first thin portion is less than the thickness of the first thick portion.

4. The secondary battery of claim 3, wherein the first thin portion is configured to be cut when an external force is applied to the first plate connection portion.

5. The secondary battery of claim 3, wherein the first plate connection portion further includes a first end thick portion spaced apart from the first thick portion, bent at the first thin portion and protruding toward one of the plurality of walls.

6. The secondary battery according to claim 3 or 5, wherein the first plate connection portion further includes a first through hole passing through the first thin portion in the lateral direction of the first plate connection portion.

7. The secondary battery according to claim 1, wherein the first plate further comprises: The first connecting piece is electrically connected to a first connecting piece member disposed on one side of the electrode assembly; as well as The first step portion connects the first terminal block connection portion and the first current collector connection portion in a stepped configuration.

8. The secondary battery according to claim 7, wherein the first plate further includes a first bending-inducing cut, the first bending-inducing cut being recessed in the first terminal block connection portion such that the thickness of the first bending-inducing cut is less than the thickness of the surrounding area, and the first bending-inducing cut extending in the lateral direction of the first plate.

9. The secondary battery of claim 8, wherein the first bending-inducing cut is formed in a region of the first terminal block connection portion that does not overlap with the first terminal block of the electrode assembly.

10. The secondary battery according to claim 1, wherein the first terminal is disposed on one side of the cover plate, and wherein the secondary battery further comprises: The second terminal is located on the other side of the cover plate; A second plate is disposed in the internal space between the electrode assembly and another wall of the plurality of walls facing one of the plurality of walls, the second plate including a second current collector connection portion; as well as The second current collector includes a second terminal connection portion and a second plate connection portion. The second terminal connection portion is electrically connected to the second terminal. The second plate connection portion is connected to the second terminal connection portion and includes a second welding surface. The second welding surface is opposite to the other wall of the plurality of walls and is welded to the second current collector connection portion.

11. The secondary battery of claim 10, wherein the second plate connection portion further includes a second stop surface, the second stop surface blocking the second current collector connection portion and intersecting with the second welding surface.

12. The secondary battery according to claim 11, wherein the second plate connection portion further comprises: The second thick portion includes the second stop surface, and the thickness of the second thick portion is greater than the thickness of the second current collector connection portion; as well as The second thin portion includes the second welding surface, and the thickness of the second thin portion is less than the thickness of the second thick portion.

13. The secondary battery of claim 12, wherein the second thin portion is configured to be cut when an external force is applied to the second plate connection portion.

14. The secondary battery of claim 12, wherein the second plate connection portion further includes a second end thick portion that is spaced apart from the second thick portion, bends at the second thin portion, and protrudes toward the other wall of the plurality of walls.

15. The secondary battery according to claim 12 or 14, wherein the second plate connection portion further includes a second through hole passing through the second thin portion in the lateral direction of the second plate connection portion.

16. The secondary battery according to claim 10, wherein the second plate further comprises: The second connector portion is electrically connected to the second connector member disposed on the other side of the electrode assembly; as well as The second step portion connects the second terminal block connection portion and the second current collector connection portion in a stepped configuration.

17. The secondary battery of claim 16, wherein the second plate further includes a second bending-inducing cut, the second bending-inducing cut being recessed in the second terminal block connection portion such that the thickness of the second bending-inducing cut is less than the thickness of the surrounding area, the second bending-inducing cut extending in the lateral direction of the second plate.

18. The secondary battery of claim 17, wherein the second bending-inducing cut is formed in a region of the second terminal block connection portion that does not overlap with the second terminal block of the electrode assembly.

19. The secondary battery of claim 10, wherein the housing has a cuboid geometry, wherein one of the plurality of walls is a first sidewall located on one side in the longitudinal direction of the housing, and the other of the plurality of walls is a second sidewall located on the other side in the longitudinal direction of the housing, and wherein the first plate extends while facing the first sidewall, and the second plate extends while facing the second sidewall.

20. A battery pack, comprising: shell; as well as Multiple secondary batteries are disposed inside the casing. Each of the plurality of secondary batteries is a secondary battery according to any one of claims 1 to 19.

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