Secondary battery, method of manufacturing the same, and battery pack including the same

Abstract

The invention relates to a secondary battery, a manufacturing method therefor, and a battery pack including the same. A secondary battery according to one aspect of the present invention comprises: an electrode assembly extending in one direction; an outer film encapsulating a portion of the electrode assembly; and a cap enclosing the remainder of the electrode assembly, in which the cap includes: a cover member for covering one side portion of the electrode assembly in an extension direction; a connecting member provided at an outer surface of the cover member to include a coupling member coupled to the outer film; and a terminal member having at least a portion thereof exposed to an outer side of the cover member and electrically connected to the electrode assembly.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of Korean Patent Application No. 10-2023-0153866, filed November 8, 2023; Korean Patent Application No. 10-2024-0071771, filed May 31, 2024; Korean Patent Application No. 10-2024-0086470, filed July 1, 2024; Korean Patent Application No. 10-2024-0104208, filed August 5, 2024; and Korean Patent Application Nos. 10-2024-0155665 and 10-2024-0155717, filed November 5, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The present invention relates to a secondary battery, a method for manufacturing the secondary battery, and a battery pack including the secondary battery. Background Technology

[0005] In recent years, the depletion of fossil fuels has led to rising energy prices and increased concern about environmental pollution. The demand for eco-friendly alternative energy sources is becoming an indispensable factor in future life. Therefore, research into various power generation technologies such as solar, wind, and tidal power is ongoing, and energy storage devices, such as batteries, for more efficient use of generated electricity are also receiving significant attention.

[0006] Furthermore, with technological advancements and the increasing demand for battery-powered electronic mobile devices and electric vehicles, the demand for batteries as energy sources is rapidly increasing. Therefore, extensive research has been conducted on batteries capable of meeting diverse needs.

[0007] Batteries that store electrical energy can generally be divided into primary batteries and secondary batteries. Primary batteries are disposable, consumable batteries. Secondary batteries, on the other hand, are rechargeable batteries made using materials capable of repeatedly undergoing oxidation and reduction processes with the interaction of current. That is, the battery is charged when a reduction reaction occurs with the material using current, and discharged when an oxidation reaction occurs with current. This repeated charge-discharge cycle generates electricity.

[0008] Secondary batteries can be classified into cylindrical batteries, pouch batteries, and prismatic batteries based on their shape. Among them, pouch batteries are manufactured by housing an electrode assembly in the form of a stack of positive electrodes, negative electrodes, separators, etc., inside a pouch, and then sealing the outer part of the pouch.

[0009] Secondary batteries can be classified into cylindrical batteries, pouch batteries, and prismatic batteries based on their shape. Among them, pouch batteries are manufactured by housing electrode assemblies in a stacked form, such as positive electrodes, negative electrodes, and separators, inside a pouch, and then sealing the outer part of the pouch.

[0010] According to related technologies, pouch batteries may have limitations in the molding process of the pouch film, which can lead to cracks, and many pouch films are discarded after the degassing process. Furthermore, the molding depth is limited by the material properties of the pouch film, thus limiting the increase in battery capacity. In addition, since existing pouch batteries are constructed by cup-molding the upper and lower shells using a pouch film and sealing the outer portions of the two shells together, there are limitations in controlling or predicting the direction of battery leakage in the event of increased internal pressure or explosion due to abnormal battery behavior.

[0011] Therefore, a secondary battery is needed that has a shape that can increase battery capacity while being less restricted in shape. In addition, a secondary battery is needed in which the direction of gas ejection is controlled when gas ejection and flame generation occur inside the battery. Summary of the Invention

[0012] Technical issues

[0013] The purpose of this invention is to provide a secondary battery in which the battery capacity is increased, while having relatively few shape restrictions, reducing the amount of moisture introduced from the outside, and improving structural stability.

[0014] The purpose of this invention is to provide a secondary battery that has improved safety by controlling the direction of the gas or flame generated inside the secondary battery.

[0015] Technical solution

[0016] A secondary battery according to one aspect of the invention includes: an electrode assembly extending in one direction; an outer membrane configured to surround a portion of the electrode assembly; and a cover configured to surround the remaining portion of the electrode assembly, wherein the cover includes: a covering member configured to cover one side of the electrode assembly in the direction of extension; a connecting member including a connecting portion disposed on an outer surface of the covering member and coupled to the outer membrane; and a terminal member at least a portion exposed outside the covering member and electrically connected to the electrode assembly.

[0017] Here, the terminal component can extend from the inside of the connecting component to the outside of the connecting component, and has a constant cross-sectional area in the longitudinal direction.

[0018] Here, the electrode assembly may include a stack of multiple electrodes and separators, and a portion of the terminal component exposed inside the connecting component may have a plane perpendicular to the stacking direction of the electrodes and separators.

[0019] Here, the terminal component may include: a body portion configured to pass through the connecting component and the cover portion; and an outer portion exposed to the outside of the connecting component, wherein the cross-sectional area of ​​the outer portion may be larger than the cross-sectional area of ​​the body portion, such that the movement of the outer portion toward the electrode assembly is restricted by the cover portion.

[0020] Here, the terminal component may include: a body portion configured to pass through the connecting component and the cover component; and an inner portion exposed inside the connecting component and having a cross-sectional area larger than that of the body portion.

[0021] Here, the secondary battery may also include a busbar disposed between the internal portion and the electrode assembly to connect one end of the internal portion and the electrode assembly.

[0022] Here, the busbar can be configured to hook onto the inner portion, such that the movement of the busbar toward the electrode assembly is restricted by the inner portion.

[0023] Here, the terminal component can be configured to pass through the busbar.

[0024] Here, the busbar may include: a first metal component in contact with the internal portion; and a second metal component extending from the first metal component toward the electrode assembly.

[0025] Here, the busbar may include: a first metal component in contact with the inner portion; a second metal component extending from the first metal component toward the electrode assembly; a third metal component extending from the second metal component toward the outer membrane; and a fourth metal component extending from the third metal component toward the electrode assembly and having one end connected to the electrode assembly.

[0026] Here, the electrode assembly may include multiple electrode tabs, each of the second, third, and fourth metal components may be arranged in pairs, and a portion and the remainder of the multiple electrode tabs may be respectively connected to the paired fourth metal components.

[0027] Here, the outer peripheral surface of the cover component can extend in the circumferential direction of the electrode assembly, and the connecting portion can be disposed on the outer peripheral surface of the cover component.

[0028] Here, the connecting part can have a ring shape.

[0029] Here, the covering component may include: a covering portion having an outward surface facing the outside of the electrode assembly; and an extension portion extending from the covering portion toward the electrode assembly, wherein a connecting portion is disposed on the outer surface of the extension portion.

[0030] Here, the extension may include: a first extension; and a second extension, the second extension extending parallel to the first extension at a predetermined distance.

[0031] Here, the extension may include: a third extension disposed between the first extension and the second extension; and a fourth extension extending parallel to the third extension at a predetermined distance.

[0032] Here, the first to fourth extensions can be connected to each other to have a ring shape.

[0033] Here, the covering portion can be plate-shaped, and the extension portion can extend from the edge of the covering portion.

[0034] Here, the covering portion can be set on the same surface as one of the surfaces of the connecting portion, or it can be set to be further outward than one of the surfaces of the connecting portion.

[0035] Here, the connecting component may include an external portion configured to cover the outward surface.

[0036] Here, the covering portion may include an inward surface opposite to the outward surface and facing the electrode assembly, and the connecting component may include an inner portion configured to cover the inward surface.

[0037] Here, the connecting component may include an extension portion—a side portion—that is disposed on an inner surface opposite to the outer surface of the extension portion.

[0038] Here, the connecting member may include an end-side portion disposed on one side of the end of the extension portion, the end-side portion being used to connect the extension portion-side portion to the connecting portion, wherein the extension portion may be embedded in the connecting member.

[0039] Here, the outer membrane can be flexible and bendable.

[0040] According to another aspect of the invention, a method for manufacturing a secondary battery includes: providing an electrode assembly comprising a positive electrode and a negative electrode and extending in one direction; surrounding a portion of the electrode assembly with an outer membrane; and covering the remaining portion of the electrode assembly with a cover, wherein the cover includes: a covering member configured to cover one side of the electrode assembly in the direction of extension; a connecting member including a connecting portion disposed on an outer surface of the covering member and coupled to the outer membrane; and a terminal member, at least a portion of which is exposed outside the covering member and is electrically connected to the electrode assembly.

[0041] According to another aspect of the invention, a battery pack includes: a secondary battery; and a package configured to house the secondary battery, wherein the secondary battery includes: an electrode assembly extending in one direction; an outer membrane configured to surround a portion of the electrode assembly; and a cover configured to surround the remaining portion of the electrode assembly, wherein the cover includes: a covering member configured to cover one side of the electrode assembly in the direction of extension; a connecting member including a connecting portion disposed on an outer surface of the covering member and coupled to the outer membrane; and a terminal member, at least a portion of which is exposed outside the covering member and is electrically connected to the electrode assembly.

[0042] Beneficial effects

[0043] In the secondary battery according to a preferred embodiment of the present invention, since there is no process for molding an outer film, there are few restrictions on the form in which the outer film accommodates the electrode assembly, and the possibility of defects such as cracks in the outer film can be reduced to improve battery capacity.

[0044] In addition, it can reduce the degree to which moisture seeps from the outside of the secondary battery into the secondary battery, thereby improving the safety of the secondary battery.

[0045] In addition, due to its excellent sealing strength, it can withstand the high level of internal pressure caused by the gas generated inside the secondary battery, thereby improving the durability of the secondary battery.

[0046] In addition, terminal components and busbars can be electrically connected to electrode assemblies in various forms.

[0047] In addition, the structural stability of the secondary battery can be improved by the connection relationship and arrangement of the connecting components and the cover components, and the problem of leakage to the cover part in the event of increased internal pressure explosion or flame explosion can be controlled.

[0048] In addition, the secondary battery can be effectively electrically connected to the outside through the terminal components that pass through the connecting components.

[0049] In addition, the outer part of the connecting component can protect the covered part of the covering component from external contamination or impact.

[0050] In addition, the external parts and the connecting parts can be connected to improve the connection between the connecting parts and the cover parts.

[0051] In addition, since the cover is covered by the external part, the insulation between the cover and other parts can be improved, and heat transfer can be suppressed in the event of thermal runaway.

[0052] In addition, since the cover is completely surrounded by the connecting parts, the cover can be easily manufactured using an injection molding process.

[0053] Furthermore, since the electrode assembly is sealed by an outer membrane and a cap, in the event of abnormal behavior inside the secondary battery, gas or flame emissions may be directed towards the outer membrane. Therefore, the stability of the secondary battery can be improved.

[0054] The effects of the present invention are not limited to those described above; therefore, many other effects are described in this specification. Attached Figure Description

[0055] Figure 1 This is a perspective view of a battery pack according to an embodiment of the present invention, as viewed from above. Here, the packaging is indicated by dashed lines, and the configuration seen through the packaging is indicated by solid lines.

[0056] Figure 2 This is a perspective view of a secondary battery according to a first embodiment of the present invention, as viewed from above.

[0057] Figure 3 yes Figure 2 An exploded 3D view of a secondary battery.

[0058] Figure 4 It's a diagram. Figure 3 An exploded perspective view showing the interconnected state of the connecting and covering components.

[0059] Figure 5 It is along Figure 2 A partial cross-sectional view taken from line A-A'.

[0060] Figure 6 It is along Figure 2 A partial cross-sectional view taken from line B-B'.

[0061] Figure 7 This is a perspective view of a secondary battery according to a second embodiment of the present invention, as viewed from above.

[0062] Figure 8 yes Figure 7An exploded 3D view of a secondary battery.

[0063] Figure 9 It is along Figure 7 A partial cross-sectional view taken from line C-C'.

[0064] Figure 10 It is along the third embodiment of the present invention Figure 7 A partial cross-sectional view taken from line C-C'.

[0065] Figure 11 It is along the fourth embodiment of the present invention Figure 7 A partial cross-sectional view of the secondary battery (first modified example of the connection part) cut by line C-C'.

[0066] Figure 12 It is along the fourth embodiment of the present invention Figure 7 A partial cross-sectional view of the secondary battery (second modified example of the connection part) cut by line C-C'.

[0067] Figure 13 It is along the fourth embodiment of the present invention Figure 7 A partial cross-sectional view of the secondary battery (third modified example of the connection part) cut by line C-C'. Detailed Implementation

[0068] Hereinafter, various aspects of the invention will be described in detail with reference to the accompanying drawings to enable those skilled in the art to readily practice the invention. However, the invention may be implemented in several different forms and is not limited to or construed as described below.

[0069] To clearly explain the invention, detailed descriptions of irrelevant parts or related known technologies that may unnecessarily obscure the spirit of the invention have been omitted, and reference numerals have been added to components in each figure. In this case, the same or similar reference numerals are assigned to the same or similar elements throughout the specification.

[0070] Furthermore, the terms or words used in this specification and claims should not be construed as having a general meaning or dictionary-based meaning, but should be interpreted as meanings and concepts that are within the scope of the invention, based on the principle that the inventor can appropriately define the concepts of the terms in order to best describe and interpret his or her invention.

[0071] Figure 1 This is a perspective view of a battery pack according to an embodiment of the present invention, as viewed from above. Here, the packaging is indicated by dashed lines, and the configuration seen through the packaging is indicated by solid lines.

[0072] exist Figure 1 The present invention discloses a battery pack according to an embodiment of the present invention. (See reference...) Figure 1 According to an embodiment of the present invention, the battery pack 1 can be a battery pack for charging and discharging electrical energy.

[0073] The battery pack 1 according to an embodiment of the present invention may include secondary batteries 3. Multiple secondary batteries 3 may be provided. The battery pack 1 may include a package 2 therein containing multiple secondary batteries 3. The package 2 may be configured to protect the secondary batteries 3 from external impacts or contamination.

[0074] In this embodiment, the packaging 2 can be provided as a box-shaped structure. The packaging 2 can be made of metal or plastic with a certain degree of rigidity. The packaging 2 can have a structure in which multiple plates are connected.

[0075] However, the shape or structure of the packaging 2 can be modified as needed. For example, at least a portion of the packaging 2 can have a curved shape. Additionally, the packaging 2 can include other components. For example, the packaging 2 can be provided with busbars electrically connected to multiple secondary batteries 3 and / or venting components connecting the interior and exterior of the packaging 2 to each other.

[0076] The following describes a secondary battery according to an embodiment of the present invention.

[0077] Implementation Method 1

[0078] Figure 2 This is a perspective view of a secondary battery according to a first embodiment of the present invention, as viewed from above. Figure 3 yes Figure 2 An exploded 3D view of a secondary battery. Figure 4 It's a diagram. Figure 3 An exploded perspective view showing the interconnected state of the connecting and covering components. Figure 5 It is along Figure 2 A partial cross-sectional view taken from line A-A'. Figure 6 It is along Figure 2 A partial cross-sectional view taken from line B-B'.

[0079] Reference Figures 2 to 6 According to Embodiment 1 of the present invention, the secondary battery 3 may include an electrode assembly 10, an outer membrane 20, and a cover 30. Each configuration of the secondary battery 3 will be described in more detail below. For reference, the content of Embodiment 1 can be applied equivalently to other embodiments described later, provided there is no conflict.

[0080] Electrode assembly

[0081] The electrode assembly 10 of the secondary battery 3 may include a positive electrode, a negative electrode, and a separator. Here, the separator may be disposed between the positive and negative electrodes to physically separate them. The electrode assembly 10 may be provided in the form of a stack of positive, negative, and separator components, or in the form of a wound assembly of positive, negative, and separator components. There are no particular limitations on the type or structure of the electrode assembly 10. The electrode assembly 10 may extend in one direction (X-axis direction) and have a predetermined length.

[0082] The electrode assembly 10 may include electrode contacts 11 connected to the electrodes. The electrode contacts 11 may be provided separately or may be incorporated as part of a current collector constituting the electrodes. For reference, if the electrode assembly 10 is an all-solid-state battery, a solid electrolyte may be provided instead of a separator.

[0083] external membrane

[0084] Reference Figures 1 to 6 The secondary battery 3 according to a first embodiment of the present invention may include an outer membrane 20. The outer membrane 20 of the secondary battery 3 may be configured to surround a portion of the electrode assembly 10. Specifically, the outer membrane 20 may be configured to surround a cover 30 and the electrode assembly 10, the cover 30 being described later. More specifically, the outer membrane 20 may be coupled to the cover 30 to define an internal space, and the electrode assembly 10 may be accommodated within this internal space.

[0085] As illustrated, in this embodiment, the outer membrane 20 may surround the electrode assembly 10 in the circumferential direction. Here, the circumferential direction may be a direction surrounding an axis (X-axis) parallel to the extension direction of the electrode assembly 10. The outer membrane 20 may be made of a material that can deform into a shape that can surround the electrode assembly 10. For example, the outer membrane 20 may have a predetermined flexibility so that it can be bent by an external force.

[0086] Additionally, the outer membrane 20 can be made of a non-elastic material. In related technologies, the pouch membrane is molded to define a space for accommodating the electrode assembly. However, since the outer membrane 20 does not need to be molded to deform its shape, it can be made of a non-elastic material. That is, the outer membrane 20 may not be elastic. Alternatively, the outer membrane 20 may have a certain degree of elasticity as needed.

[0087] The outer membrane 20 of the secondary battery 3 can have a shape in which a sheet or film is rolled up along the side surface of the electrode assembly 10. That is, the outer membrane 20 can be configured to surround a side portion of the electrode assembly 10. Here, one end and the other end of the outer membrane 20 can be configured to be connected to each other and surround the electrode assembly 10. Regarding the shape in which one end and the other end of the outer membrane 20 are connected to each other, one surface of one end and the other surface of the other end can be joined together to contact each other (see...). Figure 2This is just an example, and the form in which one end of the outer membrane 20 is joined to define a space for accommodating the electrode assembly 10 can vary.

[0088] Regarding the method of connecting one end and the other end of the outer membrane 20 to each other, one end and the other end of the outer membrane 20 can be connected to each other by heat sealing or heat and pressure sealing. That is, the outer membrane 20 may include a material that has sealing properties by heating.

[0089] As an example of the structure of the outer membrane 20, the outer membrane 20 can be provided in the form of a membrane. Specifically, the outer membrane 20 can be configured as multiple layers including a sealant layer, a barrier layer, and an insulating layer. More specifically, the outer membrane 20 can be disposed from the interior near the electrode assembly 10 in the order of sealant layer, barrier layer, and insulating layer.

[0090] The sealant layer may comprise a material that provides a seal by heating one end of the outer membrane 20 to the other. For example, the sealant layer of the outer membrane 20 may comprise at least one or more materials selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aromatic polyamide, nylon, polyester, poly(p-phenylenebenzobisoxazole), polyarylate, Teflon, and glass fiber. Primarily, polyolefin-based resins, such as polypropylene (PP) or polyethylene (PE), may be used. In particular, polypropylene (PP) may exhibit excellent mechanical properties such as tensile strength, rigidity, surface hardness, abrasion resistance, and heat resistance, as well as chemical properties such as corrosion resistance.

[0091] The barrier layer may include a metal. For example, the metal of the barrier layer may be made of one or more materials selected from the group consisting of Fe, C, Cr, Mn, Ni, and Al. For example, the barrier layer may include stainless steel (STS). Alternatively, the barrier layer may be made of an alloy, such as an aluminum alloy.

[0092] The insulating layer may include an insulating material. That is, the electrode assembly 10 can be insulated from the outside through the insulating layer. Therefore, the insulating layer can prevent short circuits in the external membrane 20. For example, the insulating layer may include at least one or more materials selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aromatic polyamide, nylon, polyester, poly(p-phenylenebenzobisoxazole), polyarylate, Teflon, and glass fiber. Primarily, polymers with abrasion resistance and heat resistance, such as nylon resin or polyethylene terephthalate (PET), can be used.

[0093] The outer membrane 20 may be configured to surround a portion of the electrode assembly 10, and the cover 30 may be configured to surround the remaining portion of the electrode assembly 10. Specifically, when the outer membrane 20 is configured to surround the electrode assembly 10 along its side surface (outer peripheral surface), an opening defined by an edge of the outer membrane 20 may be formed at each of the two ends of the electrode assembly 10. Here, the opening may be located on each side of the electrode assembly 10 in its extending direction (X-axis direction).

[0094] The cover 30 of the secondary battery 3 can be connected to the outer membrane 20 in the form of covering the openings on both sides of the electrode assembly 10. In addition, the electrode assembly 10 can be housed in the internal space defined by the outer membrane 20 and the cover 30.

[0095] The outer membrane 20 can be attached to the cover 30. As an example of a method of attaching the cover 30 to the outer membrane 20, the cover 30 and the outer membrane 20 can be attached to each other by welding. Specifically, the connecting member 40, described later, can include a metallic material, and the outer membrane 20 can include a metal layer that can be attached to the connecting member 40 by welding at the portion facing the connecting member 40.

[0096] As another example of a method for attaching the cover 30 to the outer membrane 20, the cover 30 and the outer membrane 20 can be joined together by sealing. Specifically, the connecting member 40 may include a resin material that has adhesive properties when heated, and the outer membrane 20 may include a resin layer at the portion facing the connecting member 40 that can be joined to the connecting member 40 by heating and pressurization. Here, the resin layer may include a material that has sealing properties when heated, as described above.

[0097] In the pouch cell according to the related art, a cup-shaped component housing the electrode assembly 10 can be molded by molding a sheet or film. During the molding process of the cup-shaped component, the depth that can be molded may be limited by the material properties of the sheet or film, and the capacity to accommodate the electrode assembly 10 may also be limited. In addition, when molding the sheet or film, the thickness at the corners is the thinnest, which often leads to defects such as cracks. Furthermore, the pouch cell according to the related art may require a gas collection component to collect gas during the degassing process to remove gas accumulated inside the pouch, and most of the gas collection components may be removed and discarded after the degassing process.

[0098] On the other hand, in the secondary battery 3 according to the first embodiment of the present invention, the outer membrane 20 can be used to match the volume of the electrode assembly 10, and therefore, there may be no limitation on the capacity of the electrode assembly 10. Furthermore, since there is no need to mold a cup-shaped component, defects such as cracks in the outer membrane 20 can be prevented, and the material and thickness of the outer membrane 20 can be selected relatively freely. Additionally, since the electrolyte injection and degassing processes are performed through the cover 30, the economic efficiency of the process can be improved because no discardable outer membrane 20 is generated.

[0099] build

[0100] Reference Figures 2 to 6 According to a first embodiment of the present invention, the cover 30 of the secondary battery 3 may include a connecting member 40, a covering member 50, and a terminal member 60. In this embodiment, the cover 30 can seal the electrode assembly 10 together with the outer membrane 20. Therefore, the emission of gas or flame due to abnormal internal behavior can be guided (or concentrated) towards the outer membrane 20, and thus, the stability of the secondary battery 3 can be improved.

[0101] The connecting member 40 of the cover 30 can be connected to the outer membrane 20. Additionally, the covering member 50 of the cover 30 can be connected to the connecting member 40 and can be partially exposed to the outside of the connecting member 40. Specifically, one surface of the covering member 50 can be exposed to the outside of the connecting member 40.

[0102] Here, the interior of the connecting member 40 may refer to a portion of the interior space defined by the cover 30 and the outer membrane 20, and the exterior of the connecting member 40 may refer to the exterior space of the cover 30 and the outer membrane 20.

[0103] Additionally, one surface of the cover member 50 exposed to the outside of the connecting member 40 may be an outward-facing surface 51a. The outward-facing surface 51a may be provided on the cover portion 51 of the cover member 50, which will be described later. The surface facing the outward-facing surface 51a of the cover portion 51 may be referred to as an inward-facing surface 51b. The inward-facing surface 51b may be a surface facing the electrode assembly 10.

[0104] Reference Figures 2 to 6 In this embodiment, the connecting member 40 may include a connecting portion 41. The connecting portion 41 may be the portion that directly connects the covering member 50 to the outer membrane 20, which will be described later. As needed, the connecting portion 41 may be configured as: a single layer containing one material, a single layer containing different materials from each other, multiple layers each containing different materials from each other, or multiple layers each containing different materials.

[0105] In this embodiment, the connecting portion 41 may be disposed on the outer surface 54a of the extension portion 54 in the cover member 50. Here, the outer surface 54a of the extension portion 54 may be an outward-facing surface (or an outer peripheral surface). The connecting portion 41 may be disposed between the extension portion 54 and the outer membrane 20 to connect the extension portion 54 to the outer membrane 20.

[0106] In this embodiment, the connecting portion 41 may be disposed along the outer surface 54a (or outer peripheral surface) of the extension portion 54. As will be described in detail later, in this embodiment, since the extension portion 54 has an annular shape, the connecting portion 41 may also have an annular shape corresponding to the extension portion 54. Here, the annular shape may be the shape viewed along the longitudinal direction (X-axis direction) of the electrode assembly 10. The shape of the connecting portion 41 may be appropriately modified according to the structure of the cover member 50.

[0107] Additionally, in this embodiment, the connecting member 40 may include an inner portion 43. The inner portion 43 may be disposed on the inner surface 51b of the covering portion 51. The inner portion 43 may cover the entire inner surface 51b. The inner portion 43 may be plate-shaped and have a predetermined thickness. Therefore, heat transfer or moisture penetration through the covering portion 51 can be effectively suppressed. A terminal hole 43a may be provided in the inner portion 43. The terminal hole 43a may be a hole through which the terminal member 60, described later, passes.

[0108] In this embodiment, the connecting member 40 may include an extension-side portion 44. The extension-side portion 44 may be disposed on the inner surface 54b (or inner peripheral surface) of the extension portion 54 in the cover member 50, which will be described later. Here, the inner surface 54b of the extension portion 54 may be a surface facing the outer surface 54a. The inner surface 54b may also be an inward-facing surface.

[0109] In this embodiment, the extension portion-side portion 44 may be provided along the inner surface 54b (or inner peripheral surface) of the extension portion 54. Since the extension portion 54 has an annular shape, the extension portion-side portion 44 may also have an annular shape corresponding to the extension portion 54. Here, the annular shape may be the shape viewed along the longitudinal direction (X-axis direction) of the electrode assembly 10. The shape of the extension portion-side portion 44 may be appropriately modified according to the structure of the cover member 50.

[0110] Here, the extension portion - side portion 44 and the inner portion 43 can be connected to each other. In other words, the extension portion - side portion 44 can extend from the inner portion 43. The extension portion - side portion 44 can extend from the edge portion of the inner portion 43. Therefore, the connecting member 40 can improve the following aspects: the rigidity of the cover 30 is enhanced, the water penetration is prevented, and the heat conduction is suppressed.

[0111] As an example of a configuration for electrical connection to the outside, the cover 30 of the secondary battery 3 according to a first embodiment of the present invention may include a terminal component 60. The terminal component 60 may pass through the connecting component 40 and the covering component 50, and is exposed to both the outside and the inside of the connecting component 40. The portion of the terminal component 60 exposed to the inside of the connecting component 40 may be electrically connected to the electrode assembly 10. Here, the electrical connection may include a direct connection between the terminal component 60 and the electrode assembly 10, and an indirect connection achieved through another conductive member. The portion of the terminal component 60 exposed to the outside of the connecting component 40 may be electrically connected to the outside.

[0112] For electrical connection between electrode assembly 10 and the outside, terminal component 60 may include conductive material. Terminal component 60 may be configured to protrude outward from connection component 40 (see [link to documentation]). Figure 2 Therefore, the secondary battery 3 can be electrically connected to the outside in more ways and can effectively provide electrical energy to the outside.

[0113] The configuration of the terminal component 60 will be described in more detail below. According to the first embodiment of the invention, the terminal component 60 of the cover 30 can extend from the interior to the exterior of the connecting component 40. Here, the terminal component 60 can be configured to have a constant cross-sectional area in the longitudinal direction. For example, the terminal component 60 can have a cylindrical shape or a cuboid shape. Here, a terminal component 60 with a cuboid shape will be described as an example. The terminal component 60 with a constant cross-sectional area in the longitudinal direction can be manufactured relatively easily.

[0114] Electrode assembly 10 may include parallel-stacked electrodes and spacers. Here, terminal member 60 may have one surface and another surface positioned at both ends of a portion exposed inside connecting member 40, and is flat based on the stacking direction of the electrodes and spacers. (Refer to...) Figure 4 One and the other surfaces located at the two ends of the terminal component 60 can be surfaces that contact the electrode contacts 11 of the electrode assembly 10. This shape allows the terminal component 60 to be connected to the electrode contacts 11 more efficiently.

[0115] Furthermore, when the secondary battery 3 includes multiple electrode assemblies 10, the electrode contacts 11 of the multiple electrode assemblies 10 can be electrically connected to one side and the other side of the terminal component 60, respectively. Therefore, the battery capacity of the secondary battery 3 can be effectively increased.

[0116] In addition to the shape described in the first embodiment of the invention, the terminal component 60 may have various shapes for effective electrical connection. Although not specifically shown in the drawings, a predetermined gasket may be provided on the outer peripheral portion of the terminal component 60. The gasket may be configured to prevent electrolyte leakage. The gasket may be inserted between the outer peripheral portion of the terminal component 60 and the cover component 50. The gasket may be made of a polymer material, such as plastic or rubber.

[0117] The structure of the cover component 50 will be described in more detail below.

[0118] As an example of a configuration that improves the structural stability of the cover 30, at least a portion of the covering member 50 of the cover 30 according to the first embodiment of the present invention can be embedded in the connecting member 40. In this respect, the covering member 50 of the cover 30 may include a covering portion 51 and an extension portion 54.

[0119] The covering portion 51 of the covering member 50 can be disposed on one side of the electrode assembly 10 in the longitudinal direction (X-axis direction). The covering portion 51 can cover one side of the electrode assembly 10. The covering portion 51 can have a square plate shape, but the shape of the covering portion 51 is not particularly limited, as long as it partially covers the electrode assembly 10.

[0120] The outward surface 51a of the cover portion 51 may be configured to expose the exterior of the connecting member 40. Here, the outward surface 51a may be the surface of the outer surface of the cover portion 51, facing the exterior of the electrode assembly 10. The outward surface 51a of the cover portion 51 may be located on the same surface as one surface of the connecting member 40. More specifically, the outward surface 51a may be located on the same surface as one surface of the connecting portion 41 of the connecting member 40, which will be described later. Alternatively, the outward surface 51a may be configured to be further outward than one surface of the connecting portion 41.

[0121] Due to this configuration, space utilization can be improved when multiple secondary batteries 3 are arranged. Here, based on... Figure 6 The outward surface 51a may refer to the surface facing forward (positive direction of the X-axis) from the covering portion 51, and a surface of the connecting portion 41 may refer to the end surface facing forward (positive direction of the X-axis).

[0122] The extension 54 of the cover member 50 can extend toward the electrode assembly 10. That is, the extension 54 can extend from the cover member 51 toward the electrode assembly 10. Specifically, the extension 54 can be configured such that the end surface 54c on the electrode assembly 10 side is exposed to the interior of the connecting member 40. Here, the extension 54 can extend from the edge of the cover member 51.

[0123] Reference Figure 5 and Figure 6 Multiple extensions 54 may be provided for the cover member 50. Here, at least one extension 54 may be configured such that the end surface 54c on one side of the electrode assembly 10 is exposed to the interior of the connecting member 40. Specifically, among the multiple extensions 54 extending from the cover member 51 toward the electrode assembly 10, a portion of the extension may be embedded in the connecting member 40, while another portion may be exposed to the interior of the connecting member 40.

[0124] However, in the first embodiment of the invention, an example is given in which all of the plurality of extension portions 54 are exposed inside the connecting member 40. Specifically, the plurality of extension portions 54 may include a first extension portion 55 to a fourth extension portion 58.

[0125] Reference Figure 5 and Figure 6 The first extension portion 55 and the second extension portion 56 can extend parallel to each other on both sides of the cover portion 51 in the width direction (Y-axis direction). The first extension portion 55 and the second extension portion 56 can be set at a predetermined distance in the width direction. Here, the width direction (Y-axis direction) can be a direction perpendicular to the direction of the electrode and separator stack (Z-axis direction). Each of the first extension portion 55 and the second extension portion 56 can have a separator wall (or plate) shape and a predetermined thickness.

[0126] The third extension portion 57 and the fourth extension portion 58 can extend parallel to each other from both sides in the height direction (Z-axis direction) of the cover portion 51. The third extension portion 57 and the fourth extension portion 58 can be set at a predetermined distance in the height direction. Here, the height direction (Z-axis direction) can be parallel to the direction of the electrode and separator stack (Z-axis direction). Each of the third extension portion 57 and the fourth extension portion 58 can have a separator wall (or plate) shape and a predetermined thickness.

[0127] Here, the first extension portion 55 to the fourth extension portion 58 can be connected to each other. Therefore, when viewed along the longitudinal direction (X-axis direction) of the electrode assembly 10, the first extension portion 55 to the fourth extension portion 58 can have an overall annular shape. In other words, each of the first extension portion 55 to the fourth extension portion 58 can have an annular shape along the circumferential direction of the electrode assembly 10. Here, the annular shape can be the shape viewed along the longitudinal direction (X-axis direction) of the electrode assembly 10.

[0128] Reference Figure 5 The end surface 54c of the extension 54 exposed inside the connecting member 40 can be positioned at a predetermined distance from the electrode assembly 10. Therefore, damage to the electrode assembly 10 by the extension 54 can be prevented.

[0129] In this embodiment, the extension portion 54 has been described as being composed of the first extension portion 55 to the fourth extension portion 58. However, if desired, the extension portion 54 may be configured to include only some of the extension portions of the first extension portion 55 to the fourth extension portion 58. For example, the extension portion 54 may be composed of the first extension portion 55 and the second extension portion 56, and configured to be open in the height direction (Z-axis direction).

[0130] Reference Figures 2 to 6 The extension 54 can be fitted into the connecting member 40 in the form of a recess defined in the connecting member 40. Some portions of the cover portion 51 and the extension 54 can be fitted into the connecting member 40, and thus, the connecting member 40 and the cover portion 50 can be connected to each other (see [link to documentation]). Figures 2 to 6 Here, the connecting member 40 and the extension portion 54 can be adhered to each other by heat sealing. Alternatively, the connecting member 40 and the extension portion 54 can be adhered to each other by applying an adhesive between them. Here, the type and application form of the adhesive used for adhesion between the connecting member 40 and the extension portion 54 can vary. The adhesive can be made of a material with relatively high hydrophobicity.

[0131] When the connecting member 40 and the extension portion 54 are joined together by a seal, the connecting member 40 may include a resin material that has adhesive properties due to heating. That is, the resin material of the connecting member 40 with adhesive properties can be melted by heating, and the connecting member 40 can be adhered to the extension portion 54 by applying pressure. Thus, the connecting member 40 and the covering member 50 can be joined together.

[0132] Although not described in detail in this invention, the cover 30 may also include an electrolyte injection port for injecting electrolyte or a gas discharge port for discharging gas during the degassing process.

[0133] In the cover 30 of the secondary battery 3 according to the first embodiment of the present invention, the connecting member 40 and the covering member 50, at least a portion of which is embedded in the connecting member 40, can cover the electrode assembly 10. Depending on the material of the connecting member 40, moisture outside the connecting member 40 can penetrate into the connecting member 40. Moisture penetration may lead to defects in the secondary battery 3.

[0134] In the cover 30 of the secondary battery 3 according to the first embodiment of the present invention, a covering member 50 comprising a material with excellent water resistance, such as metal, can cover the electrode assembly 10 together with the connecting member 40. Therefore, the area of ​​the connecting member 40 through which moisture permeates can be reduced. Furthermore, since at least a portion of the covering member 50 is configured to be embedded in the connecting member 40, moisture may have difficulty permeating between the covering member 50 and the connecting member 40. Therefore, the secondary battery 3 according to the first embodiment of the present invention can reduce the amount of moisture permeating into the secondary battery, thereby reducing performance limitations of the secondary battery 3.

[0135] Furthermore, the cover 30 of the secondary battery 3 according to the first embodiment of the present invention can be configured such that the extension portion 54 of the covering member 50 is embedded in the connecting member 40. Therefore, since the connecting member 40 restricts the movement of the covering member 50 to prevent the covering member 50 from separating, the structural stability of the secondary battery 3 can be improved.

[0136] Furthermore, since the cover 300 of the secondary battery 3 includes a terminal component 60, the cover 30 can be effectively electrically connected to the outside. In addition, the terminal component 60 can be connected to various types of electrode assemblies 10 by changing its shape and arrangement, and the terminal component 60 can be effectively connected to the electrode contacts 11 even when the number of electrode contacts 11 increases.

[0137] Although not described in detail in the first embodiment of the invention, the cover 30 may also include a gas venting member (not shown) for venting gas inside the secondary battery 3 or a venting member (not shown) for causing leakage in a particular direction.

[0138] Implementation Method 2

[0139] Figure 7 This is a perspective view of a secondary battery according to a second embodiment of the present invention, as viewed from above. Figure 8 yes Figure 7 An exploded 3D view of a secondary battery. Figure 9 It is along Figure 7 A partial cross-sectional view taken from line C-C'.

[0140] In the following text, the secondary battery 3 according to the first embodiment of the present invention will be omitted. Figure 2 The following is a detailed description of the same configuration as shown in the figure, and the differences between the first and second embodiments will be specifically described.

[0141] Reference Figures 7 to 9The secondary battery 103 according to the second embodiment of the present invention may differ from the secondary battery 3 according to the first embodiment in terms of the shape of the connecting member 140, the shape of the terminal member 160, the presence or absence of the busbar 170, and the connection method of the configuration. Figure 2 (As shown in the diagram). The secondary battery 103 according to the second embodiment of the present invention may include an electrode assembly 10, an outer membrane 20, and a cover 130.

[0142] Here, the outer membrane 20 of the secondary battery 103 can have a shape in which a sheet or film is wound along the side surface of the electrode assembly 10. That is, the outer membrane 20 can be configured to surround the side portion of the electrode assembly 10. Here, one end and the other end of the outer membrane 20 can be configured to be connected to each other and surround the electrode assembly 10. Regarding the form in which one end and the other end of the outer membrane 20 are connected to each other, a surface of one end and a surface of the other end can be joined together to contact each other (see...). Figure 7 This is just an example, and the form in which one end of the outer membrane 20 is joined to define the space for accommodating the electrode assembly 10 can vary.

[0143] Reference Figures 7 to 9 The cover 130 of the secondary battery 103 may include a connecting member 140, a covering member 50, and a terminal member 160. The connecting member 140 of the cover 130 may be coupled to the outer membrane 20, and the covering member 50 of the cover 130 may be coupled to the connecting member 140 such that a portion of the covering member 320 is exposed to the outside of the connecting member 140. The terminal member 160 of the cover 130 may be disposed through the connecting member 140 and the covering member 50. In addition, one end and the other end of the terminal member 160 may be exposed to the outside and inside of the connecting member 140, respectively.

[0144] Each configuration of the cover 130 will be described in more detail below.

[0145] In this embodiment, the cover member 50 can be constructed in the same manner as the cover member of the secondary battery according to the first embodiment. Specifically, the cover member 50 may include a cover portion 51 and an extension portion 54. One surface of the cover portion 51 may be configured to expose the exterior of the connecting member 140. Hereinafter, one surface is referred to as the outward surface 51a, and the surface opposite to the outward surface 51a is referred to as the inward surface 51b. The inward surface 51b may be the surface facing the electrode assembly 10.

[0146] In this embodiment, the extension portion 54 can be embedded in the connecting member 140. That is, one end of the extension portion 54 may not be exposed inside the connecting member 140. For this purpose, the connecting member 140 may include an end-side portion 145 disposed on one side of the end of the extension portion 54, the end-side portion 145 for connecting the extension portion-side portion 44 to the connecting portion 41. The end-side portion 145 may be a portion covering the end surface 54c of the extension portion 54.

[0147] This structure not only ensures the structural stability of the cover 30, but also the stability of the connecting portion 41 that seals the cover 30 and the outer membrane 20. In particular, the advantage of being able to control the direction of venting can be expected. If the extension portion 54 is fully embedded in the connecting member 140, and therefore there are no exposed parts inside it, the possibility of the connecting portion 41 separating from the extension portion 54 of the cover member 50 can be eliminated.

[0148] In other words, in the event of a rapid increase in internal pressure of the secondary battery 3 causing an explosive release of internal gas, or in the event of a fire causing flames to spread to the outside, since there are no cracks in the direction of the cover 30 through which flames or gas can escape, the venting can be controlled to prevent it from occurring in the direction of the cover 30. Therefore, the advantage is that it can solve the heat transfer phenomenon that may occur due to venting in the direction of the cover 30 when the battery pack is assembled.

[0149] In this embodiment, the end-side portion 145 may have an annular shape corresponding to the shape of the extension portion 54. Here, the annular shape may be the shape viewed along the extension direction (X-axis direction) of the electrode assembly 10.

[0150] In this embodiment, the end-side portion 145 can be connected to each of the connecting portion 41 and the extension-side portion 44. Therefore, the extension portion 54 can be fully embedded in the connecting member 140. Due to this configuration, moisture penetration into the space accommodating the electrode assembly 10 can be further suppressed. This is because a predetermined gap exists at the junction between the outer surface 54a of the extension portion 54 and the connecting portion 41, allowing moisture to penetrate, but this gap is blocked by the end-side portion 145.

[0151] Furthermore, due to the above configuration, in abnormal situations such as increased internal pressure or explosion, the emission of gas or flame may be directed towards the outer membrane 20. This is because the gap between the outer surface 54a of the extension 54 and the connecting portion 41 is blocked by the end-side portion 145, and thus the emission of gas or flame through the cover 130 is suppressed.

[0152] As described above, in the second embodiment of the invention, since the extension portion 54 is provided in a manner that is fully embedded in the connecting member 140, the structural stability of the cover 30 can be improved, and the exhaust direction of the gas or flame can also be effectively controlled. Furthermore, there is no protruding shape on the other surface of the connecting member 140 facing the electrode assembly. A portion of the busbar 170, which will be described later, can be provided on this portion.

[0153] Regarding the structure of the terminal component 160 of the cover 130, the terminal component 160 may include a body portion 161, an outer portion 162, and an inner portion 163. Specifically, the outer portion 162 may be connected to one end of the body portion 161, and the inner portion 163 may be connected to the other end.

[0154] The body portion 61 of the terminal component 160 can be configured to pass through the connecting component 140 and the cover component 50. That is, the outer peripheral surface of the body portion 161 can contact the connecting component 140 and the cover component 50. A predetermined gasket for preventing electrolyte leakage can be provided around the exterior of the body portion 161.

[0155] The outer portion 162 of the terminal component 160 may be exposed to the outside of the connecting component 140. Therefore, when the secondary battery 103 is electrically connected to the outside to provide electrical power, the outer portion 162 may be connected to the outside. The inner portion 163 of the terminal component 160 may be exposed to the inside of the connecting component 140. Therefore, the inner portion 163 may be electrically connected to the electrode assembly 10.

[0156] According to a second embodiment of the present invention, each of the outer portion 162 and the inner portion 163 of the terminal component 160 may have a cross-sectional area larger than that of the body portion 161. (Refer to...) Figure 9 Terminal component 160 can be fitted into connecting component 140 and cover component 50 via outer portion 162 and inner portion 163. Therefore, terminal component 160 can be prevented from separating, thereby improving the structural stability of cover 130.

[0157] Each of the body portion 161, outer portion 162, and inner portion 163 of the terminal component 160 according to the second embodiment of the present invention may have a generally cylindrical shape. That is, each of the body portion 161, outer portion 162, and inner portion 163 may have a generally circular cross-section. This is merely an example, and the body portion 161, outer portion 162, and inner portion 163 may have different cross-sections from each other.

[0158] As previously described, the internal portion 163 of the terminal component 160, extending into the interior of the connecting component 140, can be electrically connected to the electrode assembly 10. Here, the electrical connection can include a direct connection between the internal portion 163 and the electrode assembly 10, as well as an indirect connection between the internal portion 163 and the electrode assembly 10 via another conductive member.

[0159] When the internal portion 163 and the electrode assembly 10 are directly connected to each other, the electrode contacts 11 of the electrode assembly 10 can be connected to the internal portion 163. Alternatively, when the internal portion 163 and the electrode assembly 10 are indirectly connected to each other, the secondary battery 103 may include a busbar 170, which serves as an example of a conductive member acting as a medium.

[0160] Busbar 170 may be disposed between connecting member 140 and electrode assembly 10 to connect one end of internal portion 163 exposed inside connecting member 140 to electrode assembly 10. Busbar 170 may be made of conductive metal. In addition, busbar 170 may be configured in various shapes depending on the length of internal portion 163.

[0161] As an example of a configuration for efficient arrangement, the busbar 170 according to a second embodiment of the present invention may include a first metal component 171, a second metal component 172, a third metal component 173 and a fourth metal component 174.

[0162] Reference Figure 9 The first metal component 171 can contact the connecting component 140 and the inner portion 163. One surface of the first metal component 171 facing the connecting component 140 can be configured to contact the connecting component 140. Additionally, another surface of the first metal component 171 facing the inner portion 163 can be configured to contact the inner portion 163. In this respect, the first metal component 171 can have a generally plate-like shape and can define a hole at its center. The body portion 151 of the terminal component 160 can pass through the hole in the first metal component 171, and the other surface of the first metal component 171 facing the inner portion 163 can contact the inner portion 163. That is, the first metal component 171 of the busbar 170 can be configured to hook onto the inner portion 163, such that movement in the direction toward the electrode assembly 10 is restricted by the inner portion 163. Therefore, effective fixation of the busbar 170 is possible. The terminal component 160 can comprise a metallic material, and the inner portion 163 of the terminal component 160 and the first metal component 171 can be joined together by welding.

[0163] The second metal component 172 can extend from the first metal component 171 toward the electrode assembly 10. Here, the second metal component 172 can extend in a direction substantially perpendicular to the direction in which the first metal component 171 extends. In addition, a surface of the second metal component 172 facing the connecting component 140 can contact the connecting component 140.

[0164] The third metal component 173 can extend from the second metal component 172 toward the outer membrane 20. Here, the third metal component 173 can extend in a direction substantially perpendicular to the direction in which the second metal component 172 extends. Specifically, the third metal component 173 can extend in a direction away from the inner portion 163. In addition, a surface of the third metal component 173 facing the connecting component 140 can contact the connecting component 140.

[0165] The fourth metal component 174 can extend from the third metal component 173 toward the electrode assembly 10. In addition, one surface of the fourth metal component 174 facing the outer membrane 20 can contact the outer membrane 20.

[0166] One end of the fourth metal component 174 can be connected to the electrode assembly 10. Specifically, one end of the fourth metal component 174 can be connected to the electrode tab 11 of the electrode assembly 10. In this respect, each of the second metal component 172, the third metal component 173, and the fourth metal component 174 can be arranged in pairs. Here, each of the plurality of electrode tabs 11 of the electrode assembly 10 can be connected to the relatively close fourth metal component 174. Therefore, even if the secondary battery 103 includes a plurality of electrode assemblies 10 and the number of electrode tabs 11 increases, the fourth metal component 174 can be effectively connected to the electrode tabs 11.

[0167] According to the second embodiment of the present invention, the busbar 170 can be configured to contact the outer membrane 20 or the cover 130. Therefore, the structural stability of the secondary battery 103 can be improved. In addition, since the busbar 170 includes a first metal component 171, a second metal component 172, a third metal component 173, and a fourth metal component 174, the secondary battery 10 can have various shapes depending on the number, arrangement, and shape of the electrode assemblies 10.

[0168] The form of the busbar 170 described in this invention may only be a preferred example. Therefore, the shape and arrangement of the busbar 170 can vary.

[0169] Implementation Method 3

[0170] Figure 10 It is along the third embodiment of the present invention Figure 7 A partial cross-sectional view taken from line C-C'.

[0171] The electrode assembly, outer membrane, cover covering, terminal component, and busbar of the secondary battery 203 according to the third embodiment of the present invention can be used with the electrode assembly, outer membrane, cover covering, terminal component, and busbar of the secondary battery 103 according to the second embodiment of the present invention (e.g., Figures 7 to 9 It is constructed in the same way as shown in the diagram.

[0172] Reference Figure 10 In the secondary battery 203 according to the third embodiment of the present invention, the connecting member 240 of the cover 230 may further include an outer portion 242. The outer portion 242 may be configured to cover the outward surface 51a of the cover portion 51 facing the electrode assembly 10. Therefore, the cover portion 51 may have an outward surface 51a and an inward surface 51b covered by the outer portion 242 and the inner portion 43, respectively. That is, the cover portion 51 may be completely embedded in the connecting member 240.

[0173] In this embodiment, the outer portion 242 can have a plate shape that completely covers the outer surface 51a. Therefore, the covering member 50 can be protected from external impacts and contamination. However, the shape of the outer portion 242 is not particularly limited, as long as it covers the outer surface 51a.

[0174] In this embodiment, the edge portion of the outer portion 242 can be connected to the connecting portion 41. The outer portion 242 can be integral with the connecting portion 41. The outer portion 242 can be made of the same material as the connecting portion 41.

[0175] Therefore, the cover member 50 can be completely surrounded by the connecting member 240, and thus the connection between the connecting member 240 and the cover member 50 can be improved. In addition, since the gap between the connecting portion 41 and the outer surface 54a of the extension portion 54 is blocked by the outer portion 242, moisture penetration into the space accommodating the electrode assembly 10 can also be very effectively suppressed.

[0176] In this embodiment, the body portion 161 of the terminal component 160 can pass through the cover component 50 and the inner portion 43 and extend through the outer portion 242. The outer portion 162 of the terminal component 160 can be located at one end of the body portion 161. Here, the end of the body portion 161 can be the portion facing the outer portion 242.

[0177] Here, the outer portion 162 may have a cross-sectional area larger than that of the body portion 161. Therefore, one side of the outer portion 162 may hook onto the outer portion 242, thereby restricting the movement (or separation) of the terminal component 160.

[0178] As described above, in this embodiment, since the outer surface 51a of the covering member 50 is covered by the outer portion 242, not only are durability and connection characteristics improved, but the insulation characteristics between the terminal member 160 and other members are also improved. Furthermore, in the event of thermal runaway, the outer portion 242 can suppress heat transfer.

[0179] Furthermore, in this embodiment, since the cover member 50, made of metal material, is surrounded by the connecting member 240, the cover 230 can be easily manufactured using an injection molding process. Therefore, the productivity of secondary batteries can be improved, the manufacturing process can be simplified, and manufacturing costs can be reduced.

[0180] Implementation Method 4

[0181] Figure 11 It is along the fourth embodiment of the present invention Figure 7 A partial cross-sectional view taken along line C-C'. (Refer to...) Figure 11 According to the fourth embodiment of the present invention, the electrode assembly 10, outer membrane 20, covering member 50, terminal member 160 and bus bar 170 of the secondary battery 303 can be constructed in the same manner as the electrode assembly, outer membrane, covering member, terminal member and bus bar of the secondary battery according to the second embodiment.

[0182] Here, the connecting member 340 in the cover 330 of the secondary battery 303 according to the fourth embodiment of the present invention may include a connecting portion 41. In addition, the outward surface 51a and inward surface 51b of the covering portion 51, as well as the inner surface 54b and end surface 54c of the extension portion 54, may not be covered by the connecting member 340.

[0183] In other words, the outward surface 51a, the inward surface 51b, the inner surface 54b, and the end surface 54c can be exposed. Alternatively, if desired, the inward surface 51b, the inner surface 54b, and / or the end surface 54c can be at least partially covered by the busbar 170.

[0184] In this embodiment, the connecting member 340 may have an annular shape surrounding the outer surface 54a (or outer peripheral surface) of the extension portion 54. As described above, in this embodiment, the connecting member 340 can be simply and compactly constructed to have only the connecting portion 41. Therefore, the secondary battery 303 can be made lightweight, while rigidity is enhanced by the covering member 50.

[0185] Connection components 40, 140, 240, and 340 in embodiments 1 to 4

[0186] Examples of modifications to the connecting parts 40, 140, 240, and 340 according to embodiments 1 to 4 of the present invention will be described in more detail, for example, an example of a modification to the connecting portion 41 of the connecting part 40. The description of the modification examples can be applied to all embodiments 1 to 4 of the present invention and may include modifications that may be made by those skilled in the art. Hereinafter, embodiment 4 is described as a representative example.

[0187] First, refer to Figure 11 As a first modification example, the connecting portion 41 of the connecting member 340 according to the first embodiment of the present invention may include a first layer 41a, the first layer 41a having an outer surface including a first resin and allowing connection to the inner surface of the outer membrane 20 and an inner surface allowing connection to the outer surface of the covering member 50.

[0188] The first resin disposed in the first layer 41a can be readily applied to the bonding between the covering member 50 and the outer film 20. For example, the first resin may include a resin selected from the group consisting of: melting point (T) m The resin has a melting point of 135°C to 150°C, a melt flow rate (MFR) of 4 g / 10 min to 10 g / 10 min at 230°C, and a melting point (T). m The resin is a resin with a temperature range of 135°C to 150°C and a melt flow rate (MFR) of 4 g / 10 min to 10 g / 10 min at 230°C. When the first resin having the aforementioned physical properties is applied to the first layer 41a, the heat resistance can be excellent, such that even when hot-melting is performed at high temperatures, the first layer 41a can withstand the heat without changing its appearance, thus sufficiently ensuring excellent sealing strength, and exhibiting excellent durability against the increase in internal pressure caused by gases generated inside the secondary battery.

[0189] For example, the first resin may include a modified polyolefin resin. The first layer may include an amount of more than 50 wt%, preferably greater than or equal to 70 wt%, greater than or equal to 80 wt%, or greater than or equal to 90 wt% of the first resin. The first resin may be applied alone, and in the case of mixing the first resin, the residue may include a suitable resin, such as other polyolefin-based resins.

[0190] Modified polyolefin resins can be modified with acids or siloxanes, preferably with acids, and more preferably with copolymers of acrylic-containing monomers or post-treated polyolefins with acids. For example, modified polyolefin resins can be acid-modified polypropylene or acid-modified polyethylene, and plasma-treated polypropylene or polyethylene can be applied; more preferably, modified polyolefin resins can include acid-modified polypropylene. When using modified polyolefins, the functional groups introduced through modification can improve the adhesion to the metal surface, and thus facilitate the bonding between the metal and the resin. Considering that the metal is used as the material for the covering component 50, the resin, such as the resin described above, can be applied to the connecting component 40.

[0191] Reference Figure 12 As a second modification example, the connecting portion 41 of the connecting member 340 may include a first layer 41a and a second layer 41b. The first layer 41a includes a first resin and allows connection to the outer surface of the covering member 50. The second layer 41b includes a second resin, stacked on the outer surface of the first layer, and allows connection to the inner surface of the outer membrane 20.

[0192] For example, the first resin disposed in the first layer 41a can be as described above, and the second resin disposed in the second layer 41b can include a resin selected from the group consisting of: melting point (T) m The resins are those with a melting point (Tm) of 120°C to 145°C, those with a melt flow rate (MFR) of 5 g / 10 min to 18 g / 10 min at 230°C, and those with a melting point (Tm) of 120°C to 145°C and a melt flow rate (MFR) of 5 g / 10 min to 18 g / 10 min at 230°C.

[0193] As another example, the first resin and the second resin may be selected to satisfy at least one of the relations selected from Expression 1 below and Expression 2 below.

[0194] [Expression 1]

[0195] T m2 > T m1

[0196] In expression 1 above, T m1 It is the melting point of the first resin, T m2 This is the melting point of the second resin, expressed in °C.

[0197] [Expression 2]

[0198] MFR2 > MFR1

[0199] In Expression 2 above, MFR1 is the melt flow rate of the first resin and MFR2 is the melt flow rate of the second resin, in g / 10 min.

[0200] When the connecting member 340 is configured as a single layer, the bonding force with the covering member 50 and with the outer membrane 20 can be further improved when the connecting member 340 is configured as a double layer, and the sealing strength can be further improved. Specifically, when the second layer contains a resin having a higher melting point or lower melt flow rate than the first resin applied to the first layer, its physical properties can be more similar to those of the outer membrane 20, which can lead to improved not only seal processability but also increased bonding strength due to thermal fusion. Therefore, the sealing strength can be increased, and thus, the durability against increased internal pressure can be significantly improved.

[0201] For example, the first resin disposed in the first layer 41a can be the same as described above, and the second resin disposed in the second layer 41b can be, for example, a polyolefin-based resin. The polyolefin-based resin can differ from the first resin in terms of whether or not a modifying group is introduced. The second resin can be an unmodified polyolefin-based resin, which may include, for example, polypropylene or polyethylene, and can be a homopolymer thereof, or a random copolymer or block copolymer copolymerized with a small amount of comonomer. When the second resin is included in the second layer, the amount of the second resin can be the same as the amount of the first resin when the first resin is included in the first layer.

[0202] The polyolefin-based resin can be, for example, an unstretched polyolefin resin. Unstretched polyolefin resins can be manufactured by casting without being stretched in a particular direction during manufacturing or processing, and are more flexible than stretched polyolefin resins, do not have the problem of tearing in a particular direction, and are relatively easy to process. However, since the connecting part 40 can be manufactured by injection molding together with the cover part 50, and due to the characteristics of the cover 30, a certain or higher stiffness may be required, the unstretched and stretched polyolefin resins can be appropriately selected according to the required degree by taking into account the physical properties of each resin.

[0203] Reference Figure 13 As a third modification example, the connecting portion 41 of the connecting member 340 may include a first layer 41a, a second layer 41b and a third layer 41c. The first layer 41a includes a first resin and allows connection to the outer surface of the covering member 50. The second layer 41b includes a second resin and allows connection to the inner surface of the outer membrane 20. The third layer 41c includes a third resin and is disposed between the first layer 41a and the second layer 41b.

[0204] For example, the first and second resins can be as described above, and the third resin can include a resin selected from the group consisting of: melting point (T) m The resin has a temperature range of 145°C to 170°C, a melt flow rate (MFR) of 2 g / 10 min to 4 g / 10 min at 230°C, and a melting point (T). m The resin is a resin with a melt flow rate (MFR) of 2 g / 10 min to 4 g / 10 min at 145°C to 170°C and at 230°C.

[0205] As another example, the first resin, the second resin, and the third resin may be selected to satisfy at least one of the relations selected from Expression 3 below and Expression 4 below.

[0206] [Expression 3]

[0207] T m3 > T m2 > T m1

[0208] In expression 3 above, T m1 It is the melting point of the first resin, T m2 It is the melting point of the second resin, T m3 It is the melting point of the third resin, in °C.

[0209] [Expression 4]

[0210] MFR2 > MFR1 > MFR3

[0211] In expression 4 above, MFR1 is the melt flow rate of the first resin, MFR2 is the melt flow rate of the second resin, and MFR3 is the melt flow rate of the third resin, with units of g / 10 min.

[0212] When the connecting member 340 is configured as a three-layer structure, the third layer 41c, located between the first layer 41a and the second layer 41b, can be selected from layers having a higher melting point and a lower melt flow rate than the other layers. In this case, the deformation of the connecting member 40 due to heating can be minimized, thereby ensuring not only sealing strength but also insulation performance.

[0213] The third resin that can be applied to the third layer 41c can be, for example, a resin that meets the above-mentioned melting point and melt flow rate range within the same type of resin as the second resin, and for example, the third resin can be selected as a homopolymer olefin-based resin as a single polymer.

[0214] According to embodiments 1 to 4 of the present invention, connecting members 40, 140, 240 and 340 may be disposed on one surface of the covering member 50, and may include connecting portions 242, 43, 44 and 145. The connecting portions 242, 43, 44 and 145 are disposed on at least one surface of the covering member 50 other than the surface of the covering member 50 on which the connecting portion 41 is disposed (e.g., the outer surface 54a) (e.g., the inner surface 54b, the end surface 54c, the outward surface 51a and the inward surface 51b).

[0215] The connecting portions 242, 43, 44 and 145 of the connecting parts 40, 140, 240 and 340 may include a first layer comprising a first resin and having an inner surface that allows coupling to a surface of the cover part, similar to a first modified example of the connecting portion 41.

[0216] Additionally, the connecting portions 242, 43, 44, and 145 of the connecting components 40, 140, 240, and 340 may include a first layer and a second layer, the first layer comprising a first resin and allowing bonding to a surface of the cover component, and the second layer comprising a second resin and stacked on the outer surface of the first layer.

[0217] Additionally, the connecting portions 242, 43, 44, and 145 of the connecting components 40, 140, 240, and 340 may include a first layer, a second layer, and a third layer, wherein the first layer includes a first resin and allows bonding to a surface of the cover component, the second layer includes a second resin and is disposed on the outermost side, and the third layer includes a third resin and is disposed between the first layer and the second layer.

[0218] More specifically, in addition to the connecting portion 41, the connecting member 40 may also include a connecting portion that covers one side of the covering member 50, and as shown in the figure. Figure 5 In embodiment 1, the connecting portion may include an inner portion 43 disposed on the inward surface 51b of the covering portion 51 of the covering member 50, and an extension-side portion 44 disposed on the inner surface 54b (or inner peripheral surface) of the extension portion 54 of the covering member 50. The inner portion 43 and the extension-side portion 44 may be modified independently of the connecting portion 41, using the same or different modifications as the first to third modification examples of the connecting portion 41, and generally, the same modification example may be used because the cover 30 is manufactured by injection molding.

[0219] As another example, in addition to the connecting portion 41, the connecting member 40 may also include a connecting portion that covers one side of the covering member 50, and as... Figure 9In embodiment 2, the connecting portion may include an inner portion 43 disposed on the inward surface 51b of the covering portion 51 of the covering member 50, an extension-side portion 44 disposed on the inner surface 54b (or inner peripheral surface) of the extension portion 54 of the covering member 50, and an end-side portion 145 covering the end surface 54c of the extension portion 54 of the covering member 50. The inner portion 43, the extension-side portion 44, and the end-side portion 145 may be modified independently of the connecting portion 41, using the same or different modifications as the first to third modification examples of the connecting portion 41, and generally, the same modification example may be used because the cover 30 is manufactured by injection molding.

[0220] As another example, in addition to the connecting portion 41, the connecting member 40 may also include a connecting portion that covers one side of the covering member 50, and as... Figure 10 In embodiment 3, the connecting portion may include an inner portion 43 disposed on the inner surface 51b of the covering portion 51 of the covering member 50, an extension-side portion 44 disposed on the inner surface 54b (or inner peripheral surface) of the extension portion 54 of the covering member 50, an end-side portion 145 covering the end surface 54c of the extension portion 54 of the covering member 50, and an outer portion 242 on the outer surface of the covering portion 51 of the covering member 50 facing the outside of the electrode assembly 10. The inner portion 43, the extension-side portion 44, the end-side portion 145, and the outer portion 242 may be modified independently of the connecting portion 41, using the same or different modifications as the first to third modification examples of the connecting portion 41, and generally, the same modification example may be used because the cover 30 is manufactured by injection molding.

[0221] Evaluation Example

[0222] The following text describes in detail... Figures 11 to 13 The evaluation example of the connecting portion 41 of the connecting member 340 shown herein allows for easy evaluation by those skilled in the art. However, the invention may be implemented in different forms and should not be construed as limited to the evaluation example set forth herein.

[0223] Evaluation Example 1

[0224] An outer membrane with a polyethylene terephthalate (PET) film (266 mm wide, 50 m high, 12 μm thick) and a nylon film (266 mm wide, 50 m high, 25 μm thick) are stacked on one side of an aluminum alloy film (266 mm wide, 50 m high, 60 μm thick), and a polypropylene film (266 mm wide, 50 m high, 80 μm thick) is stacked on the other side of the aluminum alloy film to prepare an outer membrane with a structure of PET / nylon / aluminum alloy film / polypropylene film. Here, the PET and nylon films are substrate layers, the aluminum alloy film is a gas barrier layer, and the polypropylene film is a sealant layer.

[0225] Next, aluminum metal plates with a thickness of 1 mm and maleic anhydride-modified acid-modified polypropylene resin (T) with a thickness of 2 mm were used respectively. m (At 135 °C, MFR of 6 g / 10 min), prepared by embedding injection with... Figure 11 The connecting portions 41 and 41a of the cover member 50 and the connecting member 340 are of the same shape.

[0226] Electrode assemblies are fabricated by simulating the assembly of negative electrode, positive electrode, and porous polyethylene separator in a stacked manner. After encapsulating the electrode assemblies with an external film, a structure with [missing information - likely a specific feature] is manufactured by assembling covering and connecting components. Figure 2 The secondary battery shown is of the shape indicated. Here, the sealing of the outer membrane and connecting parts is performed for 5 seconds at 240°C and 0.3 MPa.

[0227] Evaluation Example 2

[0228] When the cover part 50 and the connecting part 340 are manufactured by injection molding, unstretched polypropylene resin (cPP, T) randomly copolymerized with ethylene is used. m (140℃, MFR 10 g / 10 min) and acid-modified polypropylene resin modified with maleic anhydride (PPa, T) m The material for the connecting component 340 was subjected to heterogeneous embedding injection at 135℃ (MFR of 6 g / 10 min), and therefore, as Figure 12 As shown, the secondary battery is manufactured using the same method as in Evaluation Example 1, except that an acid-modified polypropylene resin layer (first layer 41a, 1 mm) is formed at the location in contact with the cover member 50 and an ethylene copolymer polypropylene resin layer (second layer 41b, 1 mm) is formed at the location in contact with the inner surface of the outer membrane.

[0229] Experimental Example 1: Evaluation of Sealing Strength

[0230] For each secondary battery manufactured in the evaluation example, the sealing strength was evaluated using the following method.

[0231] After cutting the connecting portion of the connecting component and the outer membrane at 15 mm intervals, the connecting component is attached to the lower clamp of the UTM, and the outer membrane is attached to the upper clamp. Then, the low-speed seal strength is calculated by calculating the average value of the 8 mm portion starting from the point exceeding 4.5 kgf / 15 mm in the seal strength diagram, which is measured by stretching in a 180° direction at a speed of 5 mm / min at room temperature and 60°.

[0232] [Table 1]

[0233]

[0234] Referring to Table 1 above, in the case of evaluation example 1, the sealing strength of the connecting part of the connecting component manufactured according to the first modified example is evaluated, and when the room temperature sealing strength and the high temperature sealing strength are confirmed, it is confirmed that the required sealing strength level is exceeded. Therefore, it is confirmed that when the connecting part of the connecting component is made of a resin having the above-mentioned properties, the minimum sealing strength against internal pressure can be ensured.

[0235] Furthermore, in the case of evaluation example 3, the connecting part of the connecting component was manufactured according to the second modified example, and due to the strong sealing strength, it was observed that the connecting part of the connecting component did not peel off but the outer film was torn, thus confirming the excellent sealing strength. Moreover, when the structure is double-layered, it was confirmed that the sealing strength is similar to that at room temperature even at high temperature, demonstrating excellent performance.

[0236] Although embodiments of the invention have been described with reference to specific examples, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention as defined by the appended claims.

[0237] [Figure Labels]

[0238] 1: Battery pack 2: Packaging

[0239] 3, 103, 203, 303: Secondary battery; 10: Electrode assembly

[0240] 11: Electrode contacts 20: External film

[0241] 30, 130, 230, 330: Covers; 40, 140, 240: Connecting parts

[0242] 41: Connecting part 41a: First layer

[0243] 41b: Second layer; 41c: Third layer

[0244] 242: External Part

[0245] 43: Internal section 44: Extension section - Side section

[0246] 145: End-side portion; 50: Covering component

[0247] 51: Covering portion 51a: Outer surface

[0248] 51b: Inward surface 54: Extension portion

[0249] 54a: Outer surface; 54b: Inner surface

[0250] 54c: End surface; 55: First extension portion

[0251] 56: Second extension 57: Third extension

[0252] 58: Fourth extension portion; 60, 160: Terminal components

[0253] 161: Main body part 162: External part

[0254] 163: Internal section; 170: Busbar

[0255] 171: First metal component; 172: Second metal component

[0256] 173: Third metal component 174: Fourth metal component

Claims

1. A secondary battery, comprising: An electrode assembly that extends in one direction; An outer membrane, the outer membrane being configured to surround a portion of the electrode assembly; as well as A cover, configured to surround the remainder of the electrode assembly. The cover includes: A cover member configured to cover one side of the electrode assembly in the direction of extension; A connecting component, the connecting component including a connecting portion disposed on the outer surface of the covering component and coupled to the outer membrane; and A terminal component, at least a portion of which is exposed outside the cover component, and the terminal component is electrically connected to the electrode assembly.

2. The secondary battery according to claim 1, wherein, The terminal component extends from the interior of the connecting component to the exterior of the connecting component, and the terminal component has a constant cross-sectional area in the longitudinal direction.

3. The secondary battery according to claim 1, wherein, The electrode assembly includes multiple stacked electrodes and spacers, and A portion of the terminal component exposed inside the connecting component has a plane perpendicular to the stacking direction of the electrode and the separator.

4. The secondary battery according to claim 1, wherein, The terminal component includes: The body portion, which is configured to pass through the connecting member and the covering member; and The external portion, which is exposed to the outside of the connecting member, The cross-sectional area of ​​the outer portion is larger than that of the body portion, such that the movement of the outer portion toward the electrode assembly is restricted by the covering component.

5. The secondary battery according to claim 1, wherein, The terminal component includes: The body portion, which is configured to pass through the connecting member and the covering member; and An internal portion, which is exposed inside the connecting member and has a cross-sectional area larger than that of the body portion.

6. The secondary battery according to claim 5 further includes a busbar disposed between the internal portion and the electrode assembly for connecting one end of the internal portion and the electrode assembly.

7. The secondary battery according to claim 6, wherein, The busbar is configured to hook onto the internal portion, such that the movement of the busbar toward the electrode assembly is restricted by the internal portion.

8. The secondary battery according to claim 6, wherein, The terminal component is configured to pass through the busbar.

9. The secondary battery according to claim 6, wherein, The busbar includes: A first metal component, the first metal component being in contact with the internal portion; and A second metal component extends from the first metal component toward the electrode assembly.

10. The secondary battery according to claim 6, wherein, The busbar includes: A first metal component, the first metal component being in contact with the internal portion; A second metal component extends from the first metal component toward the electrode assembly; A third metal component, the third metal component extending from the second metal component toward the outer membrane; and A fourth metal component extends from the third metal component toward the electrode assembly, and one end of the fourth metal component is connected to the electrode assembly.

11. The secondary battery according to claim 10, wherein, The electrode assembly includes multiple electrode contacts. Each of the second, third, and fourth metal components is arranged in pairs, and A portion of the electrode contacts and the remaining portion of the electrode contacts are respectively connected to the pair of fourth metal components.

12. The secondary battery according to claim 1, wherein, The outer peripheral surface of the cover component extends in the circumferential direction of the electrode assembly, and The connecting portion is disposed on the outer peripheral surface of the cover component.

13. The secondary battery according to claim 12, wherein, The connecting portion has a ring shape.

14. The secondary battery according to claim 1, wherein, The covering component includes: The covering portion has an outwardly facing surface toward the outside of the electrode assembly; and The extension portion extends from the cover portion toward the electrode assembly. The connecting portion is disposed on the outer surface of the extension portion.

15. The secondary battery according to claim 14, wherein, The extension portion includes: First extension; and The second extension portion extends parallel to the first extension portion at a predetermined distance.

16. The secondary battery according to claim 15, wherein, The extension portion includes: A third extension portion, the third extension portion being disposed between the first extension portion and the second extension portion; and The fourth extension extends parallel to the third extension at a predetermined distance.

17. The secondary battery according to claim 16, wherein, The first extension portion to the fourth extension portion are connected to each other to have a ring shape.

18. The secondary battery according to claim 14, wherein, The covering portion has a plate shape, and The extension portion extends from the edge of the covered portion.

19. The secondary battery according to claim 14, wherein, The covering portion is disposed on the same surface as one of the surfaces of the connecting portion, or disposed outward compared to one of the surfaces of the connecting portion.

20. The secondary battery according to claim 14, wherein, The connecting component includes an outer portion configured to cover the outward surface.

21. The secondary battery according to claim 14, wherein, The covering portion includes an inward surface opposite to the outward surface and facing the electrode assembly, and The connecting component includes an internal portion configured to cover the inward surface.

22. The secondary battery according to claim 14, wherein, The connecting component includes an extension-side portion disposed on an inner surface opposite to the outer surface of the extension portion.

23. The secondary battery according to claim 22, wherein, The connecting component includes an end-side portion disposed on one side of the end of the extension portion, the end-side portion being used to connect the extension-side portion to the connecting portion. The extension portion is embedded in the connecting component.

24. The secondary battery according to claim 1, wherein, The outer membrane is flexible and can be bent.

25. A method for manufacturing a secondary battery, the method comprising the following steps: Provides an electrode assembly including a positive electrode and a negative electrode that extend in one direction; The outer membrane surrounds a portion of the electrode assembly; as well as Cover the remaining portion of the electrode assembly with the cap. The cover includes: A cover member configured to cover one side of the electrode assembly in the direction of extension; A connecting component, the connecting component including a connecting portion disposed on the outer surface of the covering component and coupled to the outer membrane; and A terminal component, at least a portion of which is exposed outside the cover component, and the terminal component is electrically connected to the electrode assembly.

26. A battery pack, comprising: Secondary batteries; as well as Packaging, the packaging being configured to house the secondary battery, The secondary battery includes: An electrode assembly that extends in one direction; An outer membrane, the outer membrane being configured to surround a portion of the electrode assembly; and A cover, configured to surround the remainder of the electrode assembly. The cover includes: A cover member configured to cover one side of the electrode assembly in the direction of extension; A connecting component, the connecting component including a connecting portion disposed on the outer surface of the covering component and coupled to the outer membrane; and A terminal component, at least a portion of which is exposed outside the cover component, and the terminal component is electrically connected to the electrode assembly.

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