Secondary battery and sealing block for sealing secondary battery

Abstract

The present invention relates to a rechargeable secondary battery and a sealing block for sealing the secondary battery by applying pressure to the secondary battery. A secondary battery according to the present invention comprises: an electrode assembly; a pouch-type outer material having an inner space accommodating the electrode assembly and an outer material opening allowing communication between the inner space and the outside; and a cap member inserted into the outer material opening, in which a portion of an inner surface of the outer material facing the cap member may include a sealing surface coupled to the cap member to seal an interior of the outer material and a separation surface separated from the cap member. The sealing block according to the present invention seals a secondary battery, the secondary battery comprising: an electrode assembly; a pouch-type outer material having an inner space accommodating the electrode assembly; and a cover member inserted into an external material opening allowing communication between the internal space and the outside, and the sealing block may include a pressing body pressing the external material and the cover member, thereby fusing the external material and the cover member to each other and forming a sealing portion for sealing the internal space.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2023-0147085, filed with the Korean Intellectual Property Office on October 30, 2023, and Korean Patent Application No. 10-2024-0149726, filed with the Korean Intellectual Property Office on October 29, 2024, the disclosures of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a secondary battery and a sealing block for sealing the secondary battery, and more specifically, to a secondary battery that can be charged and discharged and a sealing block for sealing the secondary battery by applying pressure to the secondary battery. Background Technology

[0004] Unlike primary batteries, which cannot be recharged, secondary batteries (rechargeable batteries) are batteries that can be charged and discharged. Small secondary batteries are used in portable electronic devices such as mobile phones, laptops, and camcorders, while medium or large secondary batteries are widely used as power sources for motors in hybrid vehicles and similar applications.

[0005] Such secondary batteries can be classified in various ways according to the type of external material that houses the electrode assembly. For example, secondary batteries can be classified as: prismatic secondary batteries, in which the electrode assembly is housed in a prismatic metal can; cylindrical secondary batteries, in which the electrode assembly is housed in a cylindrical metal can; and pouch-type secondary batteries, in which the electrode assembly is housed in a pouch made of laminated sheets.

[0006] In addition, pouch-type secondary batteries can be manufactured by housing the electrode assembly in a cup-shaped portion inside a pouch and then sealing the pouch. However, due to the material properties of the pouch, the molding depth of such a cup-shaped portion is limited, which results in the problem that the cup-shaped portion cannot be molded deep enough to increase the capacity of the secondary battery.

[0007] To address this issue, pouch-type secondary batteries are typically manufactured by placing the electrode assembly within the pouch-shaped outer material, folding or rolling up the outer material to form an internal space for housing the electrode assembly, inserting a cover member into an opening area communicating with the internal space, and then sealing the outer material and the cover member.

[0008] Figure 1 This is a diagram showing an example of a conventional pouch-type secondary battery, and Figure 1This is a schematic diagram of a conventional pouch-type secondary battery viewed from the front. The pouch-type secondary battery 1 includes a pouch-shaped outer material 3 in which electrode assemblies are housed, a cover member 2 inserted into an opening region of the outer material 3, and a sealing portion 4 formed by connecting the cover member 2 and the outer material 3 to seal the inner region of the outer material 3.

[0009] The outer material 3 consists of a metal substrate layer and resin layers formed on both surfaces of the metal substrate layer, and the sealing portion 4 can be formed by thermally fusing the inner resin layer and the cover member formed on the inner surface 2 of the outer material 3. Here, a process of pressing the cover member 2 and the outer material 3 with a high-temperature sealing block should be performed to thermally fuse the inner resin layer of the outer material 3 and the cover member 2.

[0010] Figure 2 It is used to describe Figure 1 The image shows a crack appearing in the sealed part of the pouch-type secondary battery, and... Figure 2 It is shown in accordance with Figure 1 A crack forms in the middle region 4a of one surface of the sealing part 4. Figure 2 In this process, all areas of the inner surface of the outer material 3 facing the cover member 2 are thermally fused to the cover member 2 to form the sealing portion 4. That is, the sealing portion 4 is formed in all areas of the inner surface of the outer material 3 and the cover member 2 facing each other, and the sealing portion 4 is formed as wide as possible.

[0011] When the sealing portion 4 is formed in this way and is relatively wide, heat and pressure cannot be adequately transferred to the side region 4b of the sealing portion 4, thus causing a problem of deterioration in the sealing performance of the side region 4b of the sealing portion 4.

[0012] In addition, when the sealing part 4 is heated and pressed for a long time to improve the sealing performance of the side area 4b of the sealing part 4, there is a problem that the middle area 4a of the sealing part 4 is over-sealed and cracks appear in the middle area 4a. Summary of the Invention

[0013] Technical issues

[0014] This disclosure is designed to solve problems in related technologies, and therefore relates to providing a secondary battery and a sealing block for sealing such a secondary battery, the secondary battery preventing cracks in the sealing portion and having improved sealing performance of the sealing portion.

[0015] Technical solution

[0016] The secondary battery according to this disclosure may include: an electrode assembly; a pouch-shaped outer material having an internal space for accommodating the electrode assembly and an external material opening that allows communication between the internal space and the outside; and a cover member inserted into the external material opening, wherein a portion of the inner surface of the outer material facing the cover member may include a sealing surface and a separating surface, the sealing surface being coupled to the cover member to seal the interior of the outer material, and the separating surface being separated from the cover member.

[0017] The outer material can be formed by rolling or folding the outer material sheet such that one end of the outer material sheet, which includes a metal layer and a resin layer formed on two surfaces of the metal layer, intersects with each other.

[0018] One end of the outer material sheet can be joined or fused together with the other end.

[0019] The sealing surface can be attached to the cover component by adhesion or fusion.

[0020] The cover component can have a cuboid shape.

[0021] On each surface of the inner surface of the cover member facing the external material, a sealing area connected by the sealing surface and a separation area facing the separation surface can be formed.

[0022] The sealing area may include a first sealing area in a straight line shape extending along the edge of the inner surface of the outer material; a second sealing area extending from one end of the first sealing area toward the interior space; and a third sealing area extending from the other end of the first sealing area toward the interior space.

[0023] The second sealing area and the third sealing area may extend along one side edge and the other side edge of the cover member, respectively.

[0024] A through hole can be formed in the cover member, into which electrode leads electrically connected to the electrode assembly are inserted.

[0025] An electrolyte injection port can be formed in the cover member for injecting electrolyte into the internal space of the receiving electrode assembly of the external material.

[0026] Parts of the cover structure may be exposed to the exterior of the external material.

[0027] The thickness of the first sealing region may be greater than or equal to the thickness of each of the second and third sealing regions.

[0028] The thickness of the first sealing area can be 3mm to 10mm, and the thicknesses of the second and third sealing areas can be 3mm to 7mm respectively.

[0029] Additionally, according to the sealing block of this disclosure, the secondary battery includes: an electrode assembly; a pouch-shaped outer material forming an internal space to accommodate the electrode assembly; and a cover member inserted into an opening in the outer material, the opening allowing communication between the internal space and the outside. The sealing block may include a pressing body that presses the outer material and the cover member, thereby allowing the outer material and the cover member to fuse together to form a sealing portion for sealing the internal space.

[0030] The pressing body may include: a first body in the shape of a cuboid block extending in a straight line; a second body extending from one end of the first body in a direction perpendicular to the direction in which the first body extends; and a third body extending from the other end of the first body in a direction parallel to the direction in which the second body extends.

[0031] The sealing block according to the invention may further include a heating element that heats the pressing body.

[0032] Beneficial effects

[0033] The secondary battery according to this disclosure has a sealing surface formed only in the portion of the area where the outer material and the cover member face each other, so that the area for transferring heat and pressure is formed relatively narrow, thereby preventing cracks due to over-sealing.

[0034] The sealing block according to this disclosure includes a pressing body that presses only the edge portion of the area where the cover member and the outer material of the secondary battery face each other, which can prevent the area where the cover member and the outer material of the secondary battery face each other from being over-sealed. Attached Figure Description

[0035] Figure 1 This is a diagram showing an example of a pouch-type secondary battery.

[0036] Figure 2 It is used to describe Figure 1 The image shows a crack appearing in the sealed part of a pouch-type secondary battery.

[0037] Figure 3 This is a perspective view of a secondary battery based on this disclosure.

[0038] Figure 4 This is an exploded perspective view of a secondary battery according to this disclosure.

[0039] Figure 5 It is along Figure 3 A cross-sectional view taken along the AA' direction.

[0040] Figure 6 This is a schematic diagram showing the state in which the external materials and cover components of a secondary battery according to the present disclosure are connected to each other.

[0041] Figure 7 This is a schematic diagram showing the state in which the cover member of the secondary battery according to the present disclosure is inserted into the external material.

[0042] Figure 8 This is a development diagram used to specifically describe the external materials of the sealing surface and the separating surface in the secondary battery according to this disclosure.

[0043] Figure 9 It is a diagram used to describe the parameters of the upper sealing surface in a secondary battery according to this disclosure.

[0044] Figure 10 It is a diagram used to describe the parameters of the right sealing surface in a secondary battery according to this disclosure.

[0045] Figure 11 This is a perspective view showing the cover component of a secondary battery according to the present disclosure.

[0046] Figure 12 It is a perspective view of the sealing block according to this disclosure.

[0047] Figure 13 It is along Figure 12 A cross-sectional view taken along the BB' direction. Detailed Implementation

[0048] In the following description, preferred embodiments of the present disclosure will be described in sufficient detail with reference to the accompanying drawings to enable those skilled in the art to readily implement the present disclosure. However, the present disclosure may be embodied in many different forms and is not limited to or constrained by the following embodiments.

[0049] In order to clearly describe this disclosure, irrelevant or detailed descriptions of related known techniques that may unnecessarily obscure the main points of this disclosure have been omitted, and throughout this disclosure, the same or similar reference numerals are attached to the same or similar elements when attaching reference numerals to elements in each figure.

[0050] Furthermore, it should be understood that the terms or words used in this disclosure and the appended claims should not be construed as limited to their general or dictionary meanings, but rather as being interpreted based on the principle that inventors are allowed to appropriately define terms for best interpretation, and based on the meanings and concepts corresponding to the technical aspects of this disclosure.

[0051] In the following description, a secondary battery according to the present disclosure and a sealing block for sealing the secondary battery will be described with reference to the accompanying drawings.

[0052] Secondary batteries

[0053] Figure 3It is a perspective view of the secondary battery 10 according to this disclosure, and Figure 4 This is an exploded perspective view of the secondary battery 10 according to this disclosure. Figure 5 It is along Figure 3 A cross-sectional view taken along the AA' direction.

[0054] Reference Figures 3 to 5 The secondary battery 10 according to this disclosure may include: an electrode assembly 100; a pouch-shaped outer material 200 having an internal space 220 for accommodating the electrode assembly 100 and an outer material opening 210 allowing communication between the internal space 220 and the outside; and a cover member 300 inserted into the outer material opening 210. Here, the portion of the cover member 300 inserted into the outer material 200 may be coupled to the outer material 200 to form a sealed portion S1 that seals the internal space 220, and the remaining portion of the cover member 300 inserted into the outer material 200 may form a non-sealed portion S2 that is separate from the outer material 200.

[0055] The electrode assembly 100 is a stack comprising a positive electrode, a negative electrode, and a separator, and may have various structures. For example, the electrode assembly may be a stacked electrode assembly in which the positive electrode, negative electrode, and separator are stacked in one direction, or a stack-folded electrode assembly in which the positive electrode, negative electrode, and separator are stacked in one direction and then folded.

[0056] Here, the positive electrode may include a positive current collector and a positive active material coated on the positive current collector, and the negative electrode may include a negative current collector and a negative active material coated on the negative current collector. The separator is an insulating material membrane inserted between the positive and negative electrodes to prevent contact between them, and multiple pores may be formed in the separator to allow positive ions to pass through.

[0057] The outer material 200 is formed by winding an outer material sheet 200a in one direction, and an internal space 220 for accommodating the electrode assembly 100 can be formed inside the wound outer material sheet 200a. In addition, the two sides of the internal space 220 can communicate with the outside.

[0058] Specifically, the outer material sheet 200a is a sheet having one end 201a and another end 202a spaced apart from the one end 201a in a predetermined direction, and the outer material 200a is formed by rolling or folding the outer material sheet 200a so that one end 201a and the other end 202a intersect. One end 201a and the other end 202a of the outer material sheet 200a can be joined to each other in various ways. For example, one end 201a and the other end 202a can be bonded with an adhesive, or one end 201a and the other end 202a can be thermally fused to each other by receiving heat and pressure.

[0059] One end 201a of the outer material sheet 200a can be connected to the inner or outer surface of the other end 202a. For example... Figure 4 As shown, the outer surface of one end 201a of the outer material sheet 200a can be connected to the inner surface of the other end 202a. Additionally, the inner surface of one end 201a of the outer material sheet 200a can be connected to the inner surface of the other end 202a.

[0060] Alternatively, the outer material sheet 200a can be a laminate comprising a metal layer such as aluminum or stainless steel. In this case, a resin layer can be formed on each of the outer and inner surfaces of the metal layer.

[0061] The metal layer can serve as a substrate to maintain mechanical strength and a barrier layer to prevent the penetration of moisture and oxygen. The metal layer can be made of aluminum or aluminum alloys to not only prevent the inflow or leakage of foreign substances such as gases and moisture, but also to improve the strength of the battery casing. Aluminum alloys can include alloy numbers 8079, 1N30, 8021, 3003, 3004, 3005, 3104, 3105, etc., which can be used alone or in combination of two or more.

[0062] The first resin layer coated on the outer surface of the metal layer should have excellent resistance to the external environment to protect the electrode assembly from external influences. Therefore, the first resin layer is required to have excellent tensile strength and durability relative to its thickness. Materials used for the first resin layer may include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene and polypropylene, etc.

[0063] A second resin layer coated on the inner surface of the metal layer can be attached to the cover member 300, described later, to seal the interior space 220, and the second resin layer can be made of a polyolefin resin. For example, materials used for the second resin layer may include cast polypropylene (CPP), chlorinated polypropylene, polyethylene, ethylene propylene copolymer, polyethylene and acrylic acid copolymer, polypropylene and acrylic acid copolymer, etc.

[0064] Typically, pouch-type secondary batteries are manufactured by molding a cup-shaped portion onto a pouch membrane, inserting electrode assemblies into the cup-shaped portion, and then sealing the pouch membrane. The cup-shaped portion is molded together with another pouch membrane. However, due to the material properties of the pouch membrane, the molding depth of the cup-shaped portion is limited, making it impossible to mold the cup-shaped portion deeply to increase the capacity of the secondary battery. Furthermore, there is a problem that the pouch membrane becomes thinner during the molding process of the cup-shaped portion, leading to defects such as cracks in the pouch membrane.

[0065] On the other hand, since the outer material 200 of the secondary battery 10 according to this disclosure is prepared by rolling or folding the outer material sheet 200a, the electrode assembly 100 can be housed within the internal space 220 of the outer material 200 without molding a separate cup-shaped portion. In this case, the conventional limitations resulting from forming a cup-shaped portion in the outer material do not apply, making it easy to increase the capacity of the secondary battery 10 by increasing the size of the internal space 220. Furthermore, since the outer material 200 prepared by rolling or folding the outer material sheet 200a does not form a portion with reduced thickness, defects such as cracks in the outer material 200 can be prevented.

[0066] For reference, the secondary battery 10 according to this disclosure can be formed by placing the electrode assembly 100 in an unfolded state on the upper surface of the outer material sheet 200a, and then rolling or folding the outer material sheet 200a. Alternatively, the secondary battery 10 according to this disclosure can be formed by rolling or folding the outer material sheet 200a to form an internal space 220 and an external material opening 210, and then inserting the electrode assembly 100 into the external material opening 210. In both cases, the electrode assembly 100 can be housed within the outer material 200 without molding a separate cup-shaped portion.

[0067] Additionally, refer to Figures 3 to 5 The cover member 300 may be a member connected to the outer material 200 and blocking the outer material opening 210. The internal space 220 of the outer material 200 accommodating the electrode assembly 100 may be filled with electrolyte, and the cover member 300 may seal the internal space 220 to prevent electrolyte leakage from the internal space 220. Specifically, the cover member 300, inserted into the outer material opening 210 that allows communication between the internal space 220 and the outside, may be connected to the inner surface 230 of the outer material 200 to seal the internal space 220. Here, the inner surface 230 of the outer material 200 may be the aforementioned second resin layer.

[0068] The length of the portion of the cover member 300 inserted into the outer material 200 can be formed in various ways. For example, as... Figure 3 and Figure 5As shown, only a portion of the cover member 300 can be inserted into the outer material 200, and the remaining portion of the cover member 300 can be exposed to the outside of the outer material 200. Alternatively, the entire cover member 300 can be inserted into the outer material 200.

[0069] The cover member 300 may be made of a material that is not easily permeable to moisture so as to attach to the inner surface 230 of the outer material 200 and seal the interior space 220 of the outer material 200. For example, the cover member 300 may be obtained from metal or resin, or from a laminate in which a resin layer is formed on both surfaces of a metal layer.

[0070] Additionally, the cover member 300 can have various shapes. For example, the cover member 300 may include a body 300a and a gasket 300b to block the internal space 220 of the external material 200. Specifically, a through-hole through which the gas lead 120 passes may be formed in the body 300a. The gasket 300b is a member surrounding the body 300a and can prevent electrolyte leakage between the external material 200 and the body 300a. In this case, the gasket 300b may also be a medium for a strong connection between the external material 200 and the body 300a.

[0071] The pad 300b can have various shapes. For example, the pad 300b can have a frame shape with a side surface surrounding the outer surface of the body 300a. Alternatively, the pad 300b can be formed to surround both the inner and outer surfaces of the body 300a.

[0072] Alternatively, the cover member 300 may have a cuboid box shape. In this case, the four side surfaces of the cover member 300 inserted into the external material opening 210 face the inner surface 230 of the external material 200, and all four side surfaces of the cover member 300 are formed as flat planes, so that the four side surfaces of the cover member 300 can be firmly connected to the inner surface 230 of the external material 200, thereby effectively sealing the internal space 220 of the external material 200.

[0073] The cover member 300 can be thermally bonded to the inner surface 230 of the outer material 200 to seal the internal space 220 of the outer material 200. Specifically, the cover member 300 and the outer material 200 can be pressed together by a sealing block at high temperature, or they can be thermally fused together by the sealing block simultaneously receiving heat and pressure. Here, the sealing block can press the edges of the four flat side surfaces of the cover member 300 and the portions where they intersect with the outer material 200 to form a sealing portion S1 in which the outer material 200 and the cover member 300 are thermally fused.

[0074] Here, there are no protruding or recessed portions in each of the four regions where the sealing block presses against the outer material 200 and the cover member 300, so the sealing block can transmit pressure evenly to the body 300a of the cover member 300 and the outer material 200 it presses against. In this case, the inner surface 230 of the outer material 200 can be uniformly thermally fused to the edge portion of each of the four surfaces of the cover member 300 to form four sealing portions S1.

[0075] Alternatively, the sealing portion S1 may be an adhesive layer formed between the outer material 200 and the cover member 300. Specifically, an adhesive layer of tape or cured adhesive may be formed between the edge portion of each of the four surfaces of the cover member 300 and the outer material 200, and this may be the sealing portion S1 that seals the internal space 220.

[0076] The cover member 300 may include a body 300a and a gasket 300b surrounding the side surface of the body 300a, so the sealing portion S1 may be an adhesive layer formed between the gasket 300b and the outer material 200.

[0077] Figure 6 This is a schematic diagram showing the connection between the outer material 200 and the cover member 300. Figure 6 A surface of a cover member 300 inserted into an outer material 200 is shown, and the portion of the cover member 300 and the outer material 200 facing each other can be divided into a sealed portion S1 and a non-sealed portion S2.

[0078] Here, the non-sealed portion S2 is the portion not pressed by the sealing block, and the outer material 200 and the cover member 300 are separated from each other in the non-sealed portion S2. That is, the portion where the outer material 200 and the cover member 300 face each other may include the sealed portion S1 where the outer material 200 and the cover member 300 are connected to each other, and the non-sealed portion S2 where the outer material 200 and the cover member 300 are separated from each other.

[0079] Figure 7 This diagram schematically illustrates the state in which the cover member 300 is inserted into the outer material 200. After the cover member 300 is inserted into the outer material 200, the portion of one surface of the cover member 300 facing the outer material 200 can be divided into a sealing region 310 and a separating region 320. The sealing region 310 may be the region that seals with the inner surface 230 of the outer material 200 to seal the internal space 220, and the separating region 320 may be the region that is separated from and not connected to the inner surface of the outer material 200.

[0080] Specifically, the sealing region 310 can be formed on the surface of the gasket 300b of the cover member 300. The gasket 300b surrounds the side surface of the body 300a, so the sealing region 310 can be formed on the outer surface of the gasket 300b. Here, the separation region 320, which is separate from and not connected to the inner surface of the outer material 200, can also be formed on the outer surface of the gasket 300b.

[0081] Additionally, the portion of the inner surface 230 of the outer material 200 facing the cover member 300 can be divided into a sealing surface 231 and a separating surface 232. The sealing surface 231 is attached to the cover member 300 to seal the internal space 220, and the separating surface 232 can be separated from the cover member 300 without being attached to it. Specifically, the sealing surface 231 can be attached to the gasket 300b of the cover member 300. Furthermore, the separating surface 232 faces the gasket 300b, but can be separated from the gasket 300b without being attached to it.

[0082] Furthermore, when the cover member 300 is inserted into the outer material 200, the sealing surface 231 and the sealing region 310 can correspond to each other, and the separating surface 232 and the separating region 320 can correspond to each other. That is, on each surface of the inner surface 230 of the cover member 300 facing the outer material, a sealing region 310 to which the sealing surface 231 is connected and a separating region 320 facing the separating surface 232 can be formed. In this case, the sealing surface 231 is connected to the sealing region 310 to form a sealed portion S1 that seals the internal space 220 of the outer material 200, and the separating surface 232 and the separating region 320 can be separated from each other to form a non-sealed portion S2.

[0083] The sealing surface 231 can be thermally bonded to the sealing region 310 to seal the internal space 220. Specifically, the cover member 300 and the outer material 200 can be pressed by the sealing block at high temperature, or they can be thermally fused together by the sealing block simultaneously receiving heat and pressure. In this case, the sealing surface 231 and the sealing region 310 can be pressed by the sealing block, and the separating surface 232 and the separating region 320 can be left unpressed by the sealing block.

[0084] Here, the sealing surface 231 and the sealing region 310 can be thermally fused together to form a sealed portion S1, and the separating surface 232 and the separating region 320 can remain separated from each other to form a non-sealing portion S2. The sealing regions 310 formed on each of the four side surfaces of the cover member 300 can be thermally fused to the sealing surface 231 formed on the outer material 200 to form four sealed portions S1, and the separating regions 310 formed on each of the four surfaces of the cover member 300 can be separated from the separating surface 232 formed on the outer material 200 to form four non-sealing portions S2.

[0085] Furthermore, in conventional pouch-type secondary batteries, a sealing portion is formed on the inner surface of the outer material and the entire portion where the cover member faces each other. If the sealing portion is formed too wide in this way, heat and pressure cannot be effectively transferred to the edges of the sealing portion, resulting in a weak sealing force at the edges. Additionally, when the entire sealing portion is pressed down for an extended period to improve the sealing force at the edges, the sealing portion can be damaged, such as by cracks appearing in the middle portion of the sealing portion due to over-sealing.

[0086] In this respect, in the secondary battery 10 according to the present disclosure, the inner surface 230 of the outer material 200 and the portion of the cover member 300 facing each other are divided into a sealed portion S1 and a non-sealed portion S2, such that the sealed portion S1 is formed relatively narrow, and conventional problems caused by the wide formation of the sealed portion can be solved.

[0087] For reference, the sealing portion S1 may be an adhesive layer formed between the sealing surface 231 and the sealing area 310. Specifically, an adhesive layer of tape or cured adhesive may be formed between the sealing area 310 formed on each of the four surfaces of the cover member 300 and the sealing surface 231 formed on the outer material 200, and this may be the sealing portion S1 that seals the interior space 220 of the outer material 200.

[0088] In addition, such as Figure 6 and Figure 7 As shown, the sealing region 310, which is connected to the sealing surface 231 to form the sealing portion S1, may include a first sealing region 311 formed in a straight line along the edge of the inner surface 230 of the outer material 200. The first sealing region 311 may be connected to the edge portion of the inner surface 230 of the outer material 200 to prevent the internal space 220 of the outer material 200 from communicating with the outside.

[0089] The sealing region 310 may include a second sealing region 312 extending from one end of the first sealing region 311 toward the interior of the outer material 200 and a third sealing region 313 extending from the other end of the first sealing region 311 toward the interior of the outer material 200. The second sealing region 312 and the third sealing region 313 may extend along one edge and the other edge of the cover member 300, respectively.

[0090] The edge portion of the cover member 300 is bent at a predetermined angle, and therefore, even when attached to the outer material 200, it can easily separate from the outer material 200 after a certain period of time. However, when the second sealing region 312 and the third sealing region 313 are formed along the edge of the cover member 300, the connection force of the edge portion of the cover member 300 is improved, and therefore the edge portion of the cover member 300 can be prevented from separating from the outer material 200 after a certain period of time.

[0091] Figure 8 This is a development drawing of the external material 200 used to specifically describe the sealing surface 231 and the separating surface 232. (Reference) Figure 8 The inner surface 230 of the outer material 200 may be composed of first to fifth inner surfaces 230a, 230b, 230c, 230d, and 230e. The first to fourth sealing surfaces 231a, 231b, 231c, and 231d may be formed on one end and the other end of the first to fourth inner surfaces 230a, 230b, 230c, and 230d, respectively. Furthermore, the first to fourth separating surfaces 232a, 232b, 232c, and 232d may be formed on one end and the other end of the first to fourth inner surfaces 230a, 230b, 230c, and 230d, respectively.

[0092] The outer material 200 can be rolled up or folded to form an internal space 220 for accommodating the electrode assembly 100, and external material openings 210 that allow the internal space 220 to communicate with the outside can be formed on both sides of the internal space 220. The cover member 300 can be inserted into the external material openings 210, and the first to fourth inner surfaces 230a, 230b, 230c, and 230d can respectively face the four side surfaces of the inserted cover member 300.

[0093] At this time, the first to fourth sealing surfaces 231a, 231b, 231c, and 231d formed on each of the first to fourth inner surfaces 230a, 230b, 230c, and 230d can be thermally fused or adhesively connected to the sealing regions 310 formed on each of the four side surfaces of the cover member 300 to form four sealing portions S1. Additionally, the first to fourth separating surfaces 232a, 232b, 232c, and 232d formed on each of the first to fourth inner surfaces 230a, 230b, 230c, and 230d can, together with the separating regions 320 formed on each of the four side surfaces of the cover member 300, form four non-sealing portions S2.

[0094] Figure 9 It is a diagram used to describe the parameters of the upper sealing surface in a secondary battery according to this disclosure. Figure 9 The first sealing surface 231a and the first separating surface 232a described above are shown.

[0095] Here, the width a1 of the leg of the first sealing surface 231a should be formed to be thick enough to fully seal the cover member 300 and the outer material 200. However, if the width a1 of the leg of the first sealing surface 231a is formed to be too thick, the cover member 300 and the outer material 200 may be over-fused, thereby damaging the secondary battery 10. Therefore, the width a1 of the leg of the first sealing surface 231a should not be formed to be too thick.

[0096] In other words, the width a1 of the leg of the first sealing surface 231a should have an appropriate length. Specifically, the width a1 of the leg of the first sealing surface 231a should have a length of 3 mm or more. When the width a1 of the leg of the first sealing surface 231a is less than 3 mm, the cover member 300 and the outer material 200 may not be adequately sealed. On the other hand, when the width a1 of the leg of the first sealing surface 231a is 3 mm or more, the cover member 300 and the outer material 200 can be adequately sealed.

[0097] Additionally, the width a1 of the leg of the first sealing surface 231a can be 7 mm or less. When the width a1 of the leg of the first sealing surface 231a exceeds 7 mm, the cover member 300 and the outer material 200 may become over-fused. When the width a1 of the leg of the first sealing surface 231a is 7 mm or less, over-fusion of the cover member 300 and the outer material 200 can be prevented.

[0098] Furthermore, the width a2 of the platform-shaped portion of the first sealing surface 231a should be formed to be thick enough to adequately seal the cover member 300 and the external material 200. However, if the width a2 of the platform-shaped portion of the first sealing surface 231a is formed to be too thick, the cover member 300 and the external material 200 may be over-fused, thereby damaging the secondary battery 10. Therefore, the width a2 of the platform-shaped portion of the first sealing surface 231a should not be formed to be too thick.

[0099] In other words, the width a2 of the platform-shaped portion of the first sealing surface 231a should have an appropriate length. Specifically, the width a2 of the platform-shaped portion of the first sealing surface 231a should have a length of 3 mm or more. When the width a2 of the platform-shaped portion of the first sealing surface 231a is less than 3 mm, the cover member 300 and the outer material 200 may not be adequately sealed. On the other hand, when the width a2 of the platform-shaped portion of the first sealing surface 231a is 3 mm or more, the cover member 300 and the outer material 200 can be adequately sealed.

[0100] Furthermore, the width a2 of the platform-shaped portion of the first sealing surface 231a can be 10 mm or less in length. When the width a2 of the platform-shaped portion of the first sealing surface 231a exceeds 10 mm, there is a possibility of excessive fusion between the cover member 300 and the outer material 200. When the width a2 of the platform-shaped portion of the first sealing surface 231a is 10 mm or less in length, excessive fusion between the cover member 300 and the outer material 200 can be prevented.

[0101] Figure 10 It is a diagram used to describe the parameters of the right sealing surface in a secondary battery according to this disclosure. Figure 10 The second sealing surface 231b and the second separating surface 232b described above are shown.

[0102] In the case of the second sealing surface 231b, as in the case of the first sealing surface 231a, it is important that the legs and the platform-shaped portion have appropriate thickness. The width b1 of the legs of the second sealing surface 231b can be 3 mm or more and the length can be 7 mm or less. In addition, the width b2 of the platform-shaped portion of the second sealing surface 231b can be 3 mm or more and the length can be 10 mm or less.

[0103] When the width b1 of the leg portion and the width b2 of the platform portion of the second sealing surface 231b are formed as described above, the cover member 300 and the outer material 200 can be sufficiently sealed, while preventing the cover member 300 and the outer material 200 from becoming over-fused.

[0104] In other words, the width a1 of the leg of the first sealing surface 231a and the width b1 of the leg of the second sealing surface 231b can both have a length of 3 mm or more and 7 mm or less. In addition, the width a2 of the platform-shaped portion of the first sealing surface 231a and the width b2 of the platform-shaped portion of the second sealing surface 231b can both have a length of 3 mm or more and 10 mm or less.

[0105] At this time, the first sealing region 311 can correspond to the platform-shaped portion of the sealing surfaces 231a, 231b, 231c, and 231d, and the second sealing region 312 and the third sealing region 313 can correspond to the legs of the sealing surfaces 231a, 231b, 231c, and 231d.

[0106] Therefore, the thickness of the first sealing region 311 corresponds to the width a2 of the platform-shaped portion of the first sealing surface 231a and the width b2 of the platform-shaped portion of the second sealing surface 231b, such that the thickness of the first sealing region 311 can have a length of 3 mm or more and 10 mm or less. Furthermore, the thicknesses of the second sealing region 312 and the third sealing region 313 correspond to the width a1 of the leg of the first sealing surface 231a and the width b1 of the leg of the second sealing surface 231b, such that the thicknesses of the second sealing region 312 and the third sealing region 313 can have a length of 3 mm or more and 7 mm or less. In this case, the thickness of the first sealing region 311 can be greater than or equal to the thickness of each of the second sealing region 312 and the third sealing region 313.

[0107] Figure 11 This is a perspective view showing the cover component 300. (Reference) Figure 11 Sealing regions 310b and 310c and separating regions 320b and 320c can be formed on each of the upper and right surfaces of the cover member 300. The sealing region 310b formed on the upper surface of the cover member 300 can be connected to the second sealing surface 231b, and the separating region 320b formed on the upper surface of the cover member 300 can be separated from the second separating surface 232b. Similarly, the sealing region 310c formed on the right surface of the cover member 300 can be connected to the third sealing surface 231c, and the separating region 320c formed on the right surface of the cover member 300 can be separated from the third separating surface 232c.

[0108] In addition, such as Figure 3 and Figure 4 As shown, an electrolyte injection port can be formed in the cover member 300 for injecting electrolyte into the internal space 220 of the outer member 200 that houses the electrode assembly 100. The electrolyte injection port can be a through hole penetrating the cover member 300.

[0109] An electrolyte injection process for injecting electrolyte into the internal space 220 can be performed through the electrolyte injection port. For example, with the secondary battery 10 installed, the user can inject electrolyte into the internal space 220 of the external material 200 through the electrolyte injection port, such that the cover member 300 with the electrolyte injection port faces upward.

[0110] Additionally, a degassing process can be performed through the electrolyte injection port to release gases generated during the activation of the secondary battery 10 to the outside. For example, the user can open the electrolyte injection port to cause the gas in the internal space 220 to be released.

[0111] After the electrolyte injection or degassing process, the electrolyte injection port can be sealed or welded to seal the internal space 220. Alternatively, by installing a valve that can open and close the electrolyte injection port, it can be opened only when necessary.

[0112] On the other hand, conventional pouch-type secondary batteries have an air pocket formed by rolling up a portion of the external material, and the air pocket is removed from the external material after capturing the internal gas, which usually results in the repeated disposal of a portion of the external material. In this regard, the secondary battery 10 according to this disclosure includes an electrolyte injection port formed in the cover member 300, and the user can inject electrolyte into the internal space 220 and discharge gas from the internal space 220 to the outside through this electrolyte injection port, thereby solving the conventional problem of repeated disposal of a portion of the external material.

[0113] In addition, such as Figures 3 to 5 and Figure 11 As shown, a through-hole 330 can be formed in the cover member 300, and an electrode lead 120 electrically connected to the electrode assembly 100 is inserted into the through-hole 330. The electrode lead 120 is connected to an electrode connector 110, which is connected to the uncoated portion of each electrode stacked in the electrode assembly 100. A portion of the electrode lead 120 can be exposed to the outside of the secondary battery 10. Here, the through-hole 330 can be formed in the body 300a of the cover member 300, and the through-hole 330 can have a shape corresponding to the shape of the inserted electrode lead 120.

[0114] Alternatively, a sealing member such as an O-ring can be inserted between the through-hole 330 and the electrode lead 120, or a sealant layer made of thermoplastic resin can be formed. In this case, leakage of electrolyte injected into the internal space 220 through the through-hole 330 can be prevented.

[0115] sealing block

[0116] The sealing block 500 according to this disclosure is a sealing block for sealing the aforementioned secondary battery 10, and may include a pressing body 510 that presses the portions of the outer material 200 and the cover member 300 of the secondary battery 10 that face each other. Specifically, the pressing body 510 presses the outer material 200 and the cover member 300 such that the outer material 200 and the cover member 300 fuse together to seal the internal space 220.

[0117] The pressing body 510 thermally fuses the inner surfaces 230 of the cover member 300 and the outer material 200, and can press one surface of the cover member 300 and the outer material 200 while the cover member 300 is inserted into the opening 210 of the outer material. In this case, a sealant layer can be formed between one surface of the cover member 300 and the inner surface 230 of the outer material 200, the sealant layer having a shape corresponding to the shape of the pressing surface pressed by the pressing body 510.

[0118] When the sealant layer is formed between the inner surface 230 of the outer material 200 and the cover member 300, the internal space 220 of the outer material 200 is sealed, thus preventing leakage of electrolyte injected into the internal space 220.

[0119] Additionally, the pressing body 510 can press the outer material 200 and the cover member 300 at high temperatures to thermally fuse them. Furthermore, when the heating member 520, which will be described later, is installed in the pressing body 510, the pressing body 510 can simultaneously transfer heat and pressure to the outer material 200 and the cover member 300 to thermally fuse them.

[0120] Figure 12 It is a perspective view of the sealing block 500 according to this disclosure. Figure 12 The specific shape of the pressing body 510 constituting the sealing block 500 is shown. (Refer to...) Figure 12 The pressing body 510 may include a first body 511 that is rectangular in shape and extends along a straight line, a second body 512 that extends from one end of the first body 511 in a direction perpendicular to the direction in which the first body 511 extends, and a third body 513 that extends from the other end of the first body 511 in a direction parallel to the direction in which the second body 512 extends.

[0121] In this way, since the pressing body 510 has first to third bodies 511, 512, and 513, the sealing region 310 having the aforementioned first to third sealing regions 311, 312, and 313 can be formed in the cover member 300. That is, the pressing body 510 can form a first sealing region 311 facing the edge portion of the external material 200, and a second sealing region 312 and a third sealing region 313 that contact the edge of the cover member 300 when it is inserted into the external material 200.

[0122] In this case, the communication between the internal space 220 of the external material 200 and the outside can be blocked by the first sealing area 311 formed by the pressing body 510. In addition, the connection force of the edge portion of the cover member 300 is improved by the second sealing area 312 and the third sealing area 313 formed by the pressing body 510, so that the edge portion of the cover member 300 can be prevented from separating from the external material 200 after a certain period of time.

[0123] Figure 13 It is along Figure 12 A cross-sectional view taken along the BB' direction. (Reference) Figure 13 A heating element 520 for heating the pressing body 510 can be installed inside the pressing body 510. The heating element 520 heats the pressing body 510 to keep it at a high temperature and can be configured in various ways. For example, the heating element 520 can be a heating wire mounted adjacent to the pressing surface of the pressing body 510, at which the pressing body 510 presses the outer material 200 and the cover member 300.

[0124] When the heating element 520 is installed inside the pressing body 510, the temperature of the pressing body 510 can be maintained at a high level while the outer material 200 and the cover member 300 are pressed. Therefore, the pressing body 510 can simultaneously transfer heat and pressure to the outer material 200 and the cover member 300, allowing the outer material 200 and the cover member 300 to be thermally fused together without the need for a preheating step that brings the outer material 200 and the cover member 300 to a high temperature before pressing.

[0125] The present disclosure has been described above with respect to a limited number of embodiments and accompanying drawings, but the present disclosure is not limited thereto, and those skilled in the art who are within the scope of the technical aspects of the present disclosure and the appended claims and their equivalents may embody the present disclosure in different forms.

[0126] [List of reference numerals]

[0127] 10: Secondary battery; 100: Electrode assembly

[0128] 110: Electrode connector; 120: Electrode lead

[0129] 200: External material 200a: External material sheet

[0130] 201a: One end of the outer material sheet; 202a: The other end of the outer material sheet.

[0131] 210: External material opening; 220: Internal space

[0132] 230: Inner surface of external material; 231: Sealing surface

[0133] 232: Separation surface 300: Cover component

[0134] 310: Sealing area; 311: First sealing area

[0135] 312: Second sealing area; 313: Third sealing area

[0136] 320: Separation area; 330: Through hole

[0137] 500: Sealing block; 510: Pressing body

[0138] 511: First subject 512: Second subject

[0139] 513: Third main body; 520: Heating component

[0140] S1: Sealed section; S2: Non-sealed section

Claims

1. A secondary battery, the secondary battery comprising: Electrode assembly; A bag-shaped outer material having an internal space for accommodating the electrode assembly and an external material opening allowing communication between the internal space and the outside; as well as A cover member, which is inserted into the opening in the external material. The portion of the inner surface of the outer material facing the cover member includes: A sealing surface, the sealing surface being coupled to the cover member to seal the interior of the external material; and A separation surface, which is separated from the cover member.

2. The secondary battery according to claim 1, in, The outer material is formed by rolling or folding an outer material sheet such that one end and the other end of the outer material sheet, which includes a metal layer and a resin layer formed on two surfaces of the metal layer, intersect each other.

3. The secondary battery according to claim 2, in, One end of the outer material sheet is joined or fused together with the other end.

4. The secondary battery according to claim 1, in, The sealing surface is attached to the cover member by adhesion or fusion.

5. The secondary battery according to claim 1, in, The cover component has a rectangular block shape.

6. The secondary battery according to claim 5, in, On each of the inner surfaces of the cover member facing the external material, a sealing region to which the sealing surface is connected and a separation region facing the separation surface are formed.

7. The secondary battery according to claim 6, in, The sealed area includes: A first sealing region extends in a straight line along the edge of the inner surface of the outer material; A second sealing region extends from one end of the first sealing region toward the internal space; and A third sealing region extends from the other end of the first sealing region toward the interior space.

8. The secondary battery according to claim 7, in, The second sealing region and the third sealing region extend along one side edge and the other side edge of the cover member, respectively.

9. The secondary battery according to claim 1, in, A through hole is formed in the cover member, and an electrode lead electrically connected to the electrode assembly is inserted into the through hole.

10. The secondary battery according to claim 1, in, An electrolyte injection port for injecting electrolyte into the internal space containing the electrode assembly of the external material is formed in the cover member.

11. The secondary battery according to claim 1, in, A portion of the cover member is exposed to the outside of the external material.

12. The secondary battery according to claim 8, in, The thickness of the first sealing region is greater than or equal to the thickness of each of the second and third sealing regions.

13. The secondary battery according to claim 8, in, The thickness of the first sealing area is 3mm to 10mm, and The thicknesses of the second sealing region and the third sealing region are 3 mm to 7 mm, respectively.

14. A sealing block for sealing a secondary battery, the secondary battery comprising: Electrode assembly; A bag-shaped outer material that forms an internal space to accommodate the electrode assembly; and a cover member, said cover member being inserted into an external material opening allowing communication between said internal space and the outside, said sealing block comprising: The pressing body presses against the outer material and the cover member, thereby allowing the outer material and the cover member to fuse together to form a sealing portion for sealing the interior space.

15. The sealing block according to claim 14, in, The pressing body includes: A first main body in the shape of a cuboid block, the first main body extending in a straight line; The second body extends from one end of the first body in a direction perpendicular to the direction in which the first body extends; and The third body extends from the other end of the first body in a direction parallel to the direction in which the second body extends.

16. The sealing block according to claim 14, further comprising: A heating element that heats the pressing body.

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