Secondary battery

Abstract

A secondary battery according to an embodiment of the present application can include an electrode assembly, an outer material formed of a sheet such that the outer material has an inner space for accommodating the electrode assembly and an outer material opening for communicating the inner space with the outside, and a cover for covering the outer material opening. The cover can include an outer portion coupled to the outer material, and a terminal portion disposed to cover the outer material opening together with the outer portion, exposed to the outside and the inside of the outer portion, and electrically connected to the electrode assembly at a portion exposed to the inside of the outer portion. The terminal portion can include a material having a lower moisture permeability than a material included in the outer portion. An area in which the terminal portion covers the outer material opening can be greater than or equal to 90% of an area in which the cover covers the outer material opening.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2024-0003706, filed in Korea on January 9, 2024, and Korean Patent Application No. 10-2025-0000526, filed in Korea on January 2, 2025, the disclosures of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to secondary batteries, and more specifically, to secondary batteries that can be charged and discharged. Background Technology

[0004] Recently, with rising energy prices due to the depletion of fossil fuels and increasing concerns about environmental pollution, the demand for eco-friendly alternative energy sources is an indispensable factor for future life. In this context, various energy production technologies such as solar, wind, and tidal power have been researched, and there is great interest in energy storage devices such as batteries for more efficient use of the generated electricity.

[0005] Furthermore, with technological advancements and the growing demand for battery-powered electronic mobile devices and electric vehicles, the demand for batteries as an energy source has increased dramatically, leading to numerous studies on batteries designed to meet diverse needs.

[0006] Batteries that store electrical energy can generally be divided into primary batteries and secondary batteries. Primary batteries are disposable batteries, while secondary batteries are rechargeable batteries made using materials that can repeatedly undergo oxidation and reduction reactions between the material and an electric current. That is, charging is performed when a reduction reaction occurs in the material through the passage of an electric current, and discharging is performed when an oxidation reaction occurs in the material, and this charging and discharging process is repeated to generate electricity.

[0007] Secondary batteries can be classified into cylindrical batteries, pouch batteries, and prismatic batteries based on their shape. Among them, pouch batteries can be manufactured by placing an electrode assembly, including positive and negative electrodes stacked on top of each other and separators, inside a pouch and sealing the sides of the pouch.

[0008] Conventional pouch cells suffer from membrane rupture during the membrane forming process, and most of the membrane is discarded after degassing. Furthermore, due to the material properties of the membrane, conventional pouch cells have a limited forming depth, thus restricting increases in battery capacity.

[0009] Therefore, there is a need for secondary batteries with fewer shape restrictions and higher battery capacity. Summary of the Invention

[0010] Technical issues

[0011] This disclosure aims to provide a secondary battery that has fewer shape constraints, increased battery capacity, and less water infiltration.

[0012] Technical solution

[0013] A secondary battery according to embodiments of the present disclosure may include: an electrode assembly; an outer packaging formed of a sheet such that the outer packaging has an internal space for receiving the electrode assembly and an opening configured to communicate the internal space with the outside; and a lid configured to cover the opening of the outer packaging. The lid may include: a covering portion coupled to the outer packaging; and a terminal portion configured to cover the opening of the outer packaging together with the covering portion, wherein the terminal portion is exposed to both the outside and the inside of the covering portion, and the portion of the terminal portion exposed to the inside of the covering portion is electrically connected to the electrode assembly. The material comprising the terminal portion may have a lower water vapor permeability than the material comprising the covering portion. The area of ​​the terminal portion covering the opening of the outer packaging may be equal to or greater than 90% of the area of ​​the lid covering the opening of the outer packaging.

[0014] The terminal portion may include: an exposed portion, one surface of which is exposed to the outside of the cover portion; and a support portion connected to the exposed portion and having a contact surface facing the cover portion, the contact surface being coupled to the inner surface of the cover portion.

[0015] The area of ​​the contact surface can be equal to or greater than 30% of the area of ​​the terminal portion covering the opening of the outer packaging.

[0016] The area of ​​the exposed portion covering the opening of the outer packaging can be equal to or greater than 50% of the area of ​​the lid covering the opening of the outer packaging.

[0017] The sum of the area of ​​the exposed portion of the terminal portion covering the opening of the outer packaging and the area of ​​the contact surface can be equal to or greater than 90% of the area of ​​the cover covering the opening of the outer packaging.

[0018] The exposed portion may include: an outer member having a shape consistent with the through-hole of the covered portion and exposed to the outside of the covered portion; and a through member extending from the periphery of the outer member in an inward direction along the covered portion and through the through-hole.

[0019] The supporting portion may include a first member that is vertically connected to the member. A contact surface may be included in the first member.

[0020] The width of the first component can be equal to or less than the width of the inner surface of the covered portion.

[0021] The covering portion may include a resin material that has adhesive properties when heated, and the first component may include a metallic material. The inner surface of the covering portion and the first component may be bonded together by heat and pressure.

[0022] The inner surface of the cover portion and the first component can be joined together by an adhesive applied between the cover portion and the first component.

[0023] The support portion may also include a second component that extends from the first component toward the electrode assembly and is electrically connected to the electrode assembly.

[0024] The second component can be attached to the inner surface of the outer packaging.

[0025] The covering portion may include: a first covering portion configured to cover the first member from the outside of the covering portion; and a second covering portion disposed between the second member and the outer packaging, connected to the outer packaging, and extending from the first covering portion toward the electrode assembly.

[0026] The surface of the first covering portion facing the first component can be connected to the contact surface.

[0027] Beneficial effects

[0028] The secondary battery according to the exemplary embodiments of this disclosure does not require a molding process for the outer packaging, and therefore has fewer restrictions on the shape of the outer packaging that houses the electrode assembly, a lower likelihood of defects such as cracks in the outer packaging, and improved battery capacity.

[0029] In addition, it can reduce water seepage into the secondary battery from the outside, thereby improving the safety of the secondary battery.

[0030] Specifically, it can prevent corrosion caused by water seepage as the secondary battery is used for a longer period of time, thereby maintaining the performance of the secondary battery.

[0031] In addition, the structural stability of the secondary battery can be improved by the connection relationship and arrangement of the terminal part and the cover part.

[0032] In addition, it can effectively maintain the sealing of the terminal parts and the cover parts.

[0033] The effects of this disclosure are not limited to the description disclosed, and these and other effects are included in the specification. Attached Figure Description

[0034] Figure 1 This is a schematic perspective view of a secondary battery according to Embodiment 1 of the present disclosure.

[0035] Figure 2An exploded perspective view of a secondary battery according to Embodiment 1 of this disclosure is shown schematically.

[0036] Figure 3 An exploded perspective view of the cover of a secondary battery according to Embodiment 1 of this disclosure is shown schematically.

[0037] Figure 4 It schematically shows along Figure 1 A cross-sectional view of a portion of the cross-section of the secondary battery according to Embodiment 1 of this disclosure, taken by line A-A'.

[0038] Figure 5 An exploded perspective view of a secondary battery according to Embodiment 2 of this disclosure is shown schematically.

[0039] Figure 6 An exploded perspective view of the cover of a secondary battery according to Embodiment 2 of this disclosure is shown schematically.

[0040] Figure 7 This is a schematic cross-sectional view of a portion of the cover and outer packaging of a secondary battery according to Embodiment 2 of this disclosure. Detailed Implementation

[0041] In the following, exemplary embodiments of the present disclosure will be described in full detail with reference to the accompanying drawings to enable those skilled in the art to readily implement the disclosure. However, the present disclosure may be implemented in many different forms and is not limited to or construed as described below.

[0042] In order to clearly describe this disclosure, irrelevant or detailed descriptions of related known technologies that may unnecessarily obscure the essential points of this disclosure have been omitted, and throughout the specification, the same or similar reference numerals are attached to the same or similar elements when reference numerals are attached to elements in each figure.

[0043] Furthermore, the terms or words used in the specification and appended claims should not be construed as limited to their general or dictionary meanings, but should be interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, in accordance with the principle that the inventors are permitted to appropriately define the terms for the best interpretation.

[0044] Implementation Method 1

[0045] Figure 1 A perspective view of a secondary battery 10 according to Embodiment 1 of this disclosure is shown schematically. Figure 2 An exploded perspective view of a secondary battery 10 according to Embodiment 1 of this disclosure is shown schematically.

[0046] The secondary battery 10 according to Embodiment 1 of this disclosure may include an electrode assembly 100, an outer packaging 200, and a cover 300. Each component of the secondary battery 10 will be described in more detail below. For reference, the description of Embodiment 1 can be applied equivalently to the following embodiments, provided that no conflicting descriptions exist.

[0047] The electrode assembly 100 of the secondary battery 10 may include a positive electrode, a negative electrode, and a separator. Here, the separator may be inserted between the positive and negative electrodes to physically separate them. The electrode assembly 100 may be a stacked type in which the positive electrode, negative electrode, and separator are stacked, or a wound type in which the positive electrode, negative electrode, and separator are wound.

[0048] Meanwhile, the electrode assembly 100 may have electrode contacts 110 connected to the electrodes. The electrode contacts 110 may be provided separately or may be incorporated into the current collector constituting the electrodes. For reference, when the electrode assembly 100 is an all-solid-state battery, the separator may be replaced with a solid electrolyte.

[0049] Reference Figure 2 The secondary battery 10 according to Embodiment 1 of this disclosure may include an outer packaging 200. The outer packaging 200 of the secondary battery 10 may be configured to cover a portion of the electrode assembly 100. Specifically, the outer packaging 200 may be configured to cover the electrode assembly 100 and a cover 300 as described below. More specifically, the outer packaging 200 may be coupled to the cover 300 to form an internal space, and the electrode assembly 100 may be accommodated in the internal space.

[0050] The outer packaging 200 of the secondary battery 10 may have a shape in which a sheet or film is wound along the side of the electrode assembly 100. That is, the outer packaging 200 may be disposed around the side of the electrode assembly 100. In this case, the outer packaging 200 may be disposed around the electrode assembly 100 such that one end and the other end are connected to each other.

[0051] Regarding the shape of the outer packaging 200 where one end and the other end are joined together, one surface of one end and the other surface of the other end can be joined in contact with each other (see...). Figure 2 ), and one surface at one end and one surface at the other end can be joined together in contact with each other (see Figure 5 This is provided as an example, and one end and the other end of the outer packaging 200 can be joined in various shapes to form a space for accommodating the electrode assembly 100.

[0052] Regarding the method of joining one end and the other end of the outer packaging 200, one end and the other end of the outer packaging 200 can be joined together by using a heat seal or by using a heat and pressure seal. That is, the outer packaging 200 may include a material that has sealing properties when heated. Specifically, the outer packaging 200 may include a material that has adhesive properties when it melts when heated. For example, the outer packaging 200 may include at least one material selected from the group consisting of: polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, poly(p-phenylenebenzobisoxazole), polyarylate, Teflon, and glass fiber. Typically, polyolefin-based resins such as polypropylene (PP) or polyethylene (PE) can be used. In particular, polypropylene (PP) can have good mechanical properties such as tensile strength, stiffness, surface hardness, abrasion resistance, and heat resistance, as well as good chemical properties such as corrosion resistance.

[0053] Simultaneously, the outer packaging 200 can cover a portion of the electrode assembly 100, and the cover 300 can cover the remaining portion of the electrode assembly 100. Specifically, when the outer packaging 200 is configured to surround the electrode assembly 100 along its sides, openings in the outer packaging can be formed at both ends of the electrode assembly 100. The cover 300 of the secondary battery 10 can be attached to the outer packaging 200 to cover the openings in the outer packaging at both ends of the electrode assembly 100, and the electrode assembly 100 can be accommodated within the internal space formed by the outer packaging 200 and the cover 300. That is, the cover 300 can be configured to cover the openings in the outer packaging.

[0054] As an example of the method of joining the cover 300 and the outer packaging 200, the cover 300 and the outer packaging 200 can be joined by welding. Specifically, the cover portion 310 may include a metal material, and the outer packaging 200 may include a metal layer that can be joined to the cover portion 310 by welding at the area in contact with the cover portion 310.

[0055] As another example of the method for joining the lid 300 and the outer packaging 200, the lid 300 and the outer packaging 200 can be joined by sealing. Specifically, the covering portion 310 may include a resin material that has adhesive properties when heated, and the outer packaging 200 may include a resin layer that can be bonded to the covering portion 310 in the area in contact with it by heat and pressure. Here, the resin layer may include the aforementioned material that has sealing properties when heated.

[0056] Conventional pouch cells have a cup-shaped portion for housing electrode assembly 100, which is formed by molding a sheet or film. During the molding process of the cup-shaped portion, the material properties of the sheet or film limit the molding depth and the capacity for housing the electrode assembly 100. Furthermore, when the sheet or film is molded, defects such as cracks often occur at the corners where the thickness reduction is greatest. In addition, conventional pouch cells require a gas collection section to collect gas during the degassing process to remove gas accumulated in the pouch; after the degassing process, the gas collection section is removed, thus many parts are discarded.

[0057] Conversely, the secondary battery 10 according to Embodiment 1 of this disclosure allows the outer packaging 200 to be adapted to the volume of the electrode assembly 100, thus potentially eliminating limitations on the capacity of the electrode assembly 100. Furthermore, the need to form a cup-shaped portion is eliminated, thereby preventing defects such as cracks in the outer packaging 200, and allowing for relatively free selection of the material and thickness of the outer packaging 200. Additionally, electrolyte injection and degassing can be performed via the cap 300, thereby reducing waste in the outer packaging 200 and improving the economic efficiency of the process.

[0058] Although not described in detail, cover 300 may also include an electrolyte solution inlet for injecting electrolyte solution or an exhaust port for releasing gas to the atmosphere during degassing.

[0059] Figure 3 An exploded perspective view of the cover 300 of the secondary battery 10 according to Embodiment 1 of this disclosure is shown schematically. Figure 4 It schematically shows along Figure 1 A cross-sectional view of a portion of the cross-section of the secondary battery 10 according to Embodiment 1 of this disclosure, taken by line A-A'.

[0060] Reference Figure 3 and Figure 4 According to Embodiment 1 of this disclosure, the cover 300 of the secondary battery 10 may include a cover portion 310 and a terminal portion 320.

[0061] The covering portion 310 of the cover 300 can be coupled to the outer packaging 200. Additionally, the terminal portion 320 of the cover 300 can be coupled to the covering portion 310 and exposed both inside and outside the covering portion 310. Here, the interior of the covering portion 310 can refer to a portion of the internal space formed by the cover 300 and the outer packaging 200, and the exterior of the covering portion 310 can refer to the space outside the cover 300 and the outer packaging 200. Simultaneously, the portion of the terminal portion 320 exposed inside the covering portion 310 can be electrically connected to the electrode assembly 100. In this case, the electrical connection can include a direct connection between the terminal portion 320 and the electrode assembly 100, as well as an indirect connection via a conductive member as an intermediate medium.

[0062] As an example of a configuration for improving the structural stability of the cover 300, the movement of the terminal portion 320 of the cover 300 according to Embodiment 1 of this disclosure in a direction away from the electrode assembly 100 can be restricted by the covering portion 310. Relatedly, the terminal portion 320 of the cover 300 may include an exposed portion 322 and a supporting portion 321.

[0063] The exposed portion 322 of the terminal portion 320 can be exposed to the outside of the cover portion 310. Therefore, the terminal portion 320 electrically connected to the electrode assembly 100 can make electrical contact with the outside through the exposed portion 322 exposed to the outside of the cover portion 310. That is, the secondary battery 10 can provide electrical energy to the outside through the exposed portion 322.

[0064] Reference Figure 4 The exposed portion 322 of the terminal portion 320 may include an external member 3221 and a through member 3222.

[0065] The outer component 3221 of the exposed portion 322 can be exposed to the outside of the covered portion 310. That is, one surface S1 of the exposed portion 322 can be exposed from one surface of the covered portion 310 in a direction away from the electrode assembly 100. Figure 4 (The upward direction) protrudes. Alternatively, one surface S1 of the exposed portion 322 may be located on the same plane as one surface of the covered portion 310. Here, one surface S1 of the exposed portion 322 may be the outermost surface of the exposed portion 322 facing the outside of the covered portion 310.

[0066] based on Figure 4 One surface S1 of the exposed portion 322 may be the upper surface of the exposed portion 322, and one surface of the covered portion 310 may be the upper surface of the covered portion 310.

[0067] Regarding the specific shape of the external member 3221, the cover portion 310 may have a through hole H for connection between the exposed portion 322 and the support portion 321.

[0068] The outer member 3221 can be formed to conform to the shape of the through hole H of the covering portion 310. Therefore, the outer member 3221 can protrude outward through the through hole H, or it can be disposed within the through hole H. That is, this shape allows the outer member 3221 to extend along a direction from the interior of the covering portion 310 to the exterior of the covering portion 310. Figure 4 Insert it into the through hole H in the upward direction.

[0069] The exposed portion 322 can pass through the member 3222 from the periphery of the outer member 3221 along the inward direction of the covering portion 310. Figure 4 It extends downwards and through a through hole. Preferably, the member 3222 can be formed along the periphery of the outer member 3221.

[0070] The peripheral edge of the exposed portion 322 can be defined by the member 3222. The outer peripheral edge of the member 3222 can contact or be adjacent to the inner peripheral edge of the through hole H. Therefore, the terminal portion 320 and the cover portion 310 can be securely connected to each other.

[0071] The support portion 321 of the terminal portion 320 can be connected to the exposed portion 322 and is supported by the cover portion 310 inside the cover portion 310 to prevent the exposed portion 322 from separating from the cover portion 310. Specifically, the contact surface S2 of the support portion 321 facing the cover portion 310 can be connected to the inner surface of the cover portion 310.

[0072] In the direction parallel to the penetration direction of the through hole H, the support portion 321 can overlap with the cover portion 310. Therefore, the support portion 321 can remain against the cover portion 310 to prevent the terminal portion 320 from separating from the cover portion 310. That is, the support portion 321 can be supported by the cover portion 310. In addition, the contact surface S2 of the support portion 321 can be connected to the inner surface of the cover portion 310. Therefore, the structural stability of the cover 300 can be improved. In addition, the sealing performance of the cover portion 310 and the terminal portion 320 can be improved.

[0073] As an example of a configuration for preventing water from seeping into the interior from the exterior of the cover 300, the ratio between the area of ​​the terminal portion 320 covering the outer packaging opening and the area of ​​the cover 300 covering the outer packaging opening according to Embodiment 1 of this disclosure can be determined. Here, the area of ​​the cover 300 covering the outer packaging opening can refer to the area of ​​the cover 300 protruding in the opening direction of the outer packaging 200. Similarly, the area of ​​the terminal portion 320 covering the outer packaging opening can refer to the area of ​​the terminal portion 320 protruding in the opening direction of the outer packaging 200. More specifically, the area of ​​the terminal portion 320 covering the outer packaging opening can refer to the sum of the area of ​​one surface S1 of the exposed portion 322 and the area of ​​the contact surface S2. Hereinafter, for ease of understanding, the area of ​​the terminal portion 320 covering the outer packaging opening is represented by "S1+S2".

[0074] The area S1+S2 of the terminal portion 320 covering the opening of the outer packaging can be equal to or greater than 90% of the area of ​​the cover 300 covering the opening of the outer packaging.

[0075] The method for calculating the area ratio of terminal portion 320 and cover 300 will be described in detail below.

[0076] Water vapor transmission rate (WVTR) can be calculated by dividing the amount of water permeated (g) by the area (m²). 2 The value is obtained by multiplying the water penetration rate (%) and the time (h). Hydrogen fluoride (HF) may be generated in the secondary battery 10 due to water penetration. HF can cause corrosion of the internal components of the secondary battery 10. When the concentration of HF generated in the secondary battery 10 after 10 years of use at room temperature is 10,000 ppm or higher, the internal components of the secondary battery 10 are at risk of corrosion. Therefore, the area of ​​the terminal portion 320 covering the outer packaging opening can be set such that the HF concentration is below 10,000 ppm. Since the amount of water penetration can be calculated from the HF concentration, the area of ​​the terminal portion 320 covering the outer packaging opening can be determined by the water vapor transmission rate. As a result of the calculation by this method, the area of ​​the terminal portion 320 covering the outer packaging opening can be equal to or greater than 90% of the area of ​​the cover 300 covering the outer packaging opening to prevent corrosion in the secondary battery 10.

[0077] The terminal portion 320 may include a material with a lower water vapor transmission rate than the material used to make the cover portion 310. Specifically, the terminal portion 320 may be made of a material with a lower water vapor transmission rate than the material used to make the cover portion 310. Therefore, when the cover portion 310 and the terminal portion 320 together cover the electrode assembly 100, the amount of water that seeps into the space containing the electrode assembly 100 can be reduced compared to when only the cover portion 310 covers the electrode assembly 100. Preferably, the terminal portion 320 may be made of metal.

[0078] Meanwhile, considering the prevention of water penetration and structural stability, the area of ​​the exposed portion 322 covering the opening of the outer packaging can be equal to or greater than 50% of the area of ​​the cover 300 covering the opening of the outer packaging. Specifically, the area of ​​one surface S1 of the exposed portion 322 can be equal to or greater than 50% of the area of ​​the cover 300 covering the opening of the outer packaging. That is to say, the area of ​​the outer component 3221 covering the opening of the outer packaging can be equal to or greater than 50% of the area of ​​the cover 300 covering the opening of the outer packaging.

[0079] In terms of the shape of the support portion 321 supported by the cover portion 310, the support portion 321 may include a first member 3211 and a second member 3212.

[0080] The first member 3211 of the support portion 321 can be extended from the through member 3222 along the extension direction of the through member 3222 ( Figure 4 The direction that is perpendicular to the vertical direction (in the middle) Figure 4 (Extending in the left and right direction). That is, the first member 3211 can be connected to the through member 3222 and formed perpendicular to the through member 3222.

[0081] In this configuration, the first member 3211 can remain abutting against the inner surface of the covering portion 310. Based on Figure 4 The inner surface of the covering portion 310 may refer to the lower surface of the covering portion 310.

[0082] Furthermore, the first member 3211 of the support portion 321 may include a contact surface S2. Specifically, one surface of the first member 3211 may be the contact surface S2. As described above, the contact surface S2 may be connected to the cover portion 310.

[0083] The area of ​​the contact surface S2 can be equal to or greater than 30% of the area S1+S2 of the terminal portion 320 covering the outer packaging opening. Therefore, sufficient sealing between the covering portion 310 and the terminal portion 320 can be ensured.

[0084] As an example of a configuration used to ensure a seal between the cover portion 310 and the terminal portion 320, a first member 3211 can extend from the member 3222 toward the outer packaging 200. Here, the width of the first member 3211 extending can be equal to or less than the width of the inner surface of the cover portion 310. That is, the widths T1 and T2 of the contact surfaces S2 can be equal to or less than the widths T3 and T4 of the inner surface of the cover portion 310 (see...). Figure 3 Therefore, the area of ​​the contact surface S2 can be equal to or less than the area of ​​the inner surface of the covering portion 310.

[0085] In this case, the extension width T1 of the first member 3211 connected to the second member 3212 and the extension width T2 of the first member 3211 not connected to the second member 3212 can be different. However, the extension widths T1 and T2 of the first member 3211 can be equal to or less than the widths T3 and T4 of the inner surface of the covering portion 310, respectively. For reference, Figure 4 The extension widths T1 and T2 of the first member 3211 are shown to be equal to the widths T3 and T4 of the inner surface of the covering portion 310.

[0086] Meanwhile, examples of the connection method between the cover portion 310 and the first member 3211 can include a sealed connection. The first member 3211 can include a metallic material, and the cover portion 310 can include a resin material that has adhesive properties when heated. Therefore, the resin material of the cover portion 310, which has adhesive properties when heated, can be pressure-bonded to the first member 3211 when it melts.

[0087] As another example of the connection method between the cover portion 310 and the first member 3211, the inner surface of the cover portion 310 and the first member 3211 can be connected to each other by an adhesive applied between the cover portion 310 and the first member 3211. Here, one surface of the first member 3211 connected to the inner surface of the cover portion 310 can be the contact surface S2.

[0088] A second member 3212 of the support portion 321 can extend from the first member 3211 toward the electrode assembly 100, and one end can be electrically connected to the electrode assembly 100. In this case, the second member 3212 may include a plurality of second members. That is, the support portion 321 can be electrically connected to the electrode assembly 100 at multiple locations. Therefore, when the secondary battery 10 includes a plurality of electrode assemblies 100, each of the plurality of electrode assemblies 100 can be electrically connected to each of the second members 3212 located nearby. Thus, the secondary battery 10 can effectively increase its battery capacity.

[0089] For example, the second member 3212 of the support portion 321 may include a pair of second members respectively connected to two opposite edges of the first member 3211 (see [link]). Figure 3 In other words, based on Figure 3 The second component 3212 can be connected to the upper and lower edges of the first component 3211. In this case, the second component 3212, extending from the top and bottom of the first component 3211, can be connected to two electrode contacts 110 located at the upper and lower positions, respectively.

[0090] However, this is provided as an example, and as another example, the second member 3212 of the support portion 321 may be formed along the periphery of the first member 3211. That is, the second member 3212 may be connected to all edges of the first member 3211.

[0091] Simultaneously, the second component 3212 can be connected to the outer packaging 200. More specifically, the second component 3212 can be connected to the inner surface of the outer packaging 200. Therefore, the water permeation path between the support portion 321 and the outer packaging 200 can be increased, and the amount of water permeation can be reduced.

[0092] Specifically, the second component 3212 may include a metallic material, and the outer packaging 200 may include a resin layer in the area in contact with the second component 3212, the resin layer having adhesive properties upon heating. Therefore, the second component 3212 and the outer packaging 200 can be joined using a heat and pressure seal.

[0093] According to Embodiment 1 of this disclosure, the cover 300 of the secondary battery 10 can cover the electrode assembly 100 with a covering portion 310 and a terminal portion 320. Depending on the material of the covering portion 310, water can permeate from the outside of the covering portion 310 into the covering portion 310. Water permeation may cause defects in the secondary battery 10. Since the cover 300 of the secondary battery 10 according to Embodiment 1 of this disclosure covers the electrode assembly 100 together with the terminal portion 320 made of metal and the covering portion 310, the area of ​​water permeation in the covering portion 310 can be reduced. In addition, since the support portion 321 is supported by the covering portion 310, the water permeation path between the support portion 321 and the covering portion 310 can be increased. Furthermore, since the support portion 321 is connected to the outer packaging 200, the water permeation path between the support portion 321 and the outer packaging 200 can be increased.

[0094] Therefore, the secondary battery 10 according to Embodiment 1 of this disclosure can reduce the performance problems of the secondary battery 10 by reducing the amount of water infiltration.

[0095] Implementation Method 2

[0096] Figure 5 An exploded perspective view of the secondary battery 10' according to Embodiment 2 of this disclosure is shown schematically. Figure 6 An exploded perspective view of the cover 300' of the secondary battery 10' according to Embodiment 2 of this disclosure is shown schematically. Additionally, Figure 7 The diagram schematically shows a portion of the cover 300' and outer packaging 200' of the secondary battery 10' according to Embodiment 2 of the present disclosure.

[0097] In the following text, detailed descriptions of components identical to those in Embodiment 1 of the present disclosure will be omitted, and the differences will be described in detail. The secondary battery 10' of Embodiment 2 of the present disclosure differs from the secondary battery 10 of Embodiment 1 in the shape of the outer packaging 200', the shape of the covering portion 310', the shape of the terminal portion 320', and the method for connecting the various components.

[0098] In the same manner as the secondary battery 10 according to Embodiment 1, the secondary battery 10' according to Embodiment 2 of this disclosure has a terminal portion 320' covering an area S1+S2 of the outer packaging opening, which is equal to or greater than 90% of the area covered by the cover 300' of the outer packaging opening.

[0099] Reference Figure 5 According to Embodiment 2 of this disclosure, the secondary battery 10' may include an electrode assembly 100, an outer packaging 200', and a cover 300'. The outer packaging 200' of the secondary battery 10' may be configured to cover a portion of the electrode assembly 100. Specifically, the outer packaging 200' may be configured to cover the cover 300' and the electrode assembly 100. More specifically, the outer packaging 200' may be coupled to the cover 300' to form an internal space, and the electrode assembly 100 may be accommodated in the internal space.

[0100] Regarding the shape of the outer packaging 200' where one end and the other end are joined together, one surface of one end and one surface of the other end can be joined in contact with each other (see...). Figure 5 ).

[0101] Reference Figure 6 The second member 3212' of the support portion 321' can be formed along the periphery of the first member 3211. That is, based on Figure 6 The second component 3212' can be connected to the periphery of the first component 3211. The shape of the second component 3212' can improve the structural stability between the cover portion 310' and the terminal portion 320'.

[0102] As an example of a configuration for improving the connection strength with the terminal portion 320', the cover portion 310' of the cover 300' according to Embodiment 2 of this disclosure may include a first cover portion 311 and a second cover portion 312.

[0103] Reference Figure 7 The first covering portion 311 can be configured to cover the first member 3211 from the outside of the covering portion 310'. That is, the first covering portion 311 can overlap the first member 311 in a direction parallel to the penetration direction of the through hole H.

[0104] Furthermore, a second cover portion 312 may extend from the first cover portion 311 in a direction toward the electrode assembly 100. Specifically, the second cover portion 312 may be disposed between the second member 3212' and the outer packaging 200'. More specifically, the second cover portion 312 may be formed along the periphery of the first cover portion 311.

[0105] The surface of the first covering portion 311 facing the first member 3211 can be connected to a surface of the first member 3211. More specifically, the surface of the first covering portion 311 facing the contact surface S2 can be connected to the contact surface S2. That is, the inner surface of the first covering portion 311 can be connected to the contact surface S2.

[0106] The second cover portion 312 can be disposed between the second member 3212' and the outer packaging 200' such that one surface of the second member 3212' can be attached to the support portion 321' of the second member 3212', and the other surface can be attached to the outer packaging 200'. In this case, adhesive 400 can be applied to the connection between the second cover portion 312 and other components. That is, adhesive 400 can be applied to one surface and the other surface of the second cover portion 312. The second cover portion 312 can be connected to the second member 3212' and the outer packaging 200' by adhesive 400. Preferably, adhesive 400 can be applied between the outer packaging 200' and the cover portion 310' to connect the outer packaging 200' to the cover portion 310', and adhesive 400 can be applied between the cover portion 310' and the terminal portion 320' to connect the cover portion 310' to the terminal portion 320'. Here, the type and coating pattern of the adhesive 400 used for connection can vary.

[0107] Furthermore, according to Embodiment 2 of this disclosure, the cover 300' can make one surface of the terminal portion 320' and one surface of the covering portion 310' coplanar. In this case, since no part of the terminal portion 320' protrudes outward from the covering portion 310', multiple secondary batteries 10' can be easily arranged.

[0108] Although this disclosure has been described above with reference to certain embodiments and accompanying drawings, this disclosure is not limited thereto, and it will be apparent to those skilled in the art to which this disclosure pertains that various modifications and alterations can be made to it within the scope of the technical aspects of this disclosure and the appended claims and their equivalents.

[0109] List of reference numerals

[0110] 10, 10': Secondary battery; 100: Electrode assembly

[0111] 110: Electrode contacts 200, 200': Outer packaging

[0112] 300, 300': Cover; 310, 310': Cover portion

[0113] 311: First coverage portion; 312: Second coverage portion

[0114] 320, 320': Terminal portion; 321, 321': Support portion

[0115] 322: Exposed parts; 400: Adhesive

[0116] 3211: First component; 3212, 3212': Second component

[0117] 3221: External component; 3222: Through component

Claims

1. A secondary battery, comprising: Electrode assembly; The outer packaging is formed of a sheet such that the outer packaging has an internal space for accommodating the electrode assembly and an opening configured to communicate the internal space with the outside. as well as A lid, the lid being configured to cover the opening of the outer packaging, The cover includes: The covering portion, which is attached to the outer packaging; and A terminal portion, configured to cover the outer packaging opening together with the cover portion, wherein the terminal portion is exposed both outside and inside the cover portion, and the portion of the terminal portion exposed inside the cover portion is electrically connected to the electrode assembly. The terminal portion comprises a material with a lower water vapor permeability than the material comprised in the covering portion, and Wherein, the area of ​​the terminal portion covering the opening of the outer packaging is equal to or greater than 90% of the area of ​​the cover covering the opening of the outer packaging.

2. The secondary battery according to claim 1, in, The terminal portion includes: An exposed portion, one surface of which is exposed to the outside of the covered portion; and A support portion, which is connected to the exposed portion and has a contact surface facing the covered portion, the contact surface being coupled to the inner surface of the covered portion.

3. The secondary battery according to claim 2, in, The area of ​​the contact surface is equal to or greater than 30% of the area of ​​the terminal portion covering the opening of the outer packaging.

4. The secondary battery according to claim 2, in, The area of ​​the exposed portion covering the opening of the outer packaging is equal to or greater than 50% of the area of ​​the cover covering the opening of the outer packaging.

5. The secondary battery according to claim 2, in, The sum of the area of ​​the exposed portion of the terminal portion covering the opening of the outer packaging and the area of ​​the contact surface is equal to or greater than 90% of the area of ​​the cover covering the opening of the outer packaging.

6. The secondary battery according to claim 2, in, The exposed portion includes: An external member having a shape consistent with the through-hole of the covering portion and exposed to the outside of the covering portion; and The through member extends from the periphery of the outer member in an inward direction along the covered portion and passes through the through hole.

7. The secondary battery according to claim 6, in, The support portion includes: A first component, the first component being perpendicularly connected to the through component, and The contact surface is included in the first component.

8. The secondary battery according to claim 7, in, The width of the first component is equal to or less than the width of the inner surface of the covering portion.

9. The secondary battery according to claim 7, in, The covering portion comprises a resin material that exhibits adhesive properties upon heating. The first component comprises a metallic material, and The inner surface of the covering portion and the first component are connected to each other by heat and pressure.

10. The secondary battery according to claim 7, in, The inner surface of the cover portion and the first component are joined together by an adhesive applied between the cover portion and the first component.

11. The secondary battery according to claim 7, in, The support portion also includes: A second component extends from the first component toward the electrode assembly and is electrically connected to the electrode assembly.

12. The secondary battery according to claim 11, in, The second component is attached to the inner surface of the outer packaging.

13. The secondary battery according to claim 11, in, The covered portion includes: A first covering portion, configured to cover the first member from the outside of the cover portion; and A second covering portion is disposed between the second component and the outer packaging, connected to the outer packaging, and extends from the first covering portion toward the electrode assembly.

14. The secondary battery according to claim 13, in, The surface of the first covering portion facing the first component is connected to the contact surface.

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