Soft package battery cell of secondary battery and manufacturing method of soft package battery cell

Abstract

The method of manufacturing a pouch battery cell according to the present disclosure prevents the sealing quality of a pouch from becoming poor due to an electrolyte solution by reducing the amount of the electrolyte solution adhered to the sealing portion of the pouch, and provides a pouch battery cell in which gas inside the pouch can be effectively discharged to the outside of the pouch. The soft package battery cell of the present disclosure comprises: an electrode assembly; the electrode assembly is accommodated in the soft bag; and a gas discharge pipe disposed such that the gas discharge pipe extends from the inside to the outside of the soft package, in which gas inside the soft package can pass through the gas discharge pipe and be discharged to the outside of the soft package.

Description

Technical Field

[0001] Cross-reference to related applications This application is based on and claims priority to Korean Patent Application No. 10-2023-0083458, filed with the Korean Intellectual Property Office on June 28, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates to a pouch cell for a rechargeable and dischargeable secondary battery and a method for manufacturing the same. Background Technology

[0003] In recent years, due to the depletion of fossil fuels, rising energy prices, and increased concern about environmental pollution, the demand for environmentally friendly alternative energy sources has become an indispensable factor in future life. Consequently, research into various power generation technologies such as solar, wind, and tidal power is ongoing, which has also generated significant interest in energy storage devices such as batteries to more effectively utilize the electricity generated in this way.

[0004] Furthermore, with technological advancements and the increasing demand for battery-powered electronic mobile devices and electric vehicles, the demand for batteries as an energy source is rapidly increasing. Therefore, research has been conducted on batteries that can meet various needs.

[0005] 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, which are made by using materials that allow repeated oxidation and reduction processes between the material and an electric current. That is, the material is charged when an electric current causes a reduction reaction, and discharged when an electric current causes an oxidation reaction. As this charging and discharging process is repeated, electrical energy is generated.

[0006] For example, secondary batteries can be classified according to their shape into cylindrical battery cells, pouch battery cells, and prismatic battery cells. Among these battery cells, in the manufacture of pouch battery cells, for example, an electrode assembly in the form of a stack of cathode, anode, and separator can be housed inside the pouch, and then the outside of the pouch can be sealed. Summary of the Invention

[0007] Technical issues This disclosure provides a method for manufacturing a pouch cell that can prevent the sealing quality of the pouch from deteriorating due to the electrolyte solution by reducing the amount of electrolyte solution adhering to the sealing portion of the pouch, and a pouch cell that can effectively discharge gas inside the pouch to the outside of the pouch.

[0008] Technical solution The pouch cell according to this disclosure includes: an electrode assembly; a pouch containing the electrode assembly; and a gas discharge pipe configured to extend from the interior to the exterior of the pouch, wherein gas inside the pouch can pass through the gas discharge pipe and be discharged to the exterior of the pouch.

[0009] The gas discharge pipe may include: an inner layer and an outer layer, which are heat-sealable; and a permeable layer disposed between the inner and outer layers, which has higher permeability than either the inner or outer layer.

[0010] The inner and outer layers may contain polyolefin resins, and the permeable layer may contain polytetrafluoroethylene (PTFE).

[0011] The gas discharge pipe may further include a sealing portion that protrudes to the outside of the flexible housing and has an inner layer that is sealed by the seal.

[0012] The gas discharge pipe may also include a channel section that extends from the sealing section into the interior of the soft package and forms a space communicating with the interior of the soft package, through which gas flows out of the soft package.

[0013] The outer layer of the channel section can be sealed with a sealant and a soft padding.

[0014] The pouch cell may also include: electrode leads electrically connected to the electrode assembly and extending to the outside of the pouch, wherein a gas exhaust pipe may be provided with a gap between the gas exhaust pipe and the electrode leads.

[0015] The flexible package may include: a cup portion having space inside for mounting electrode assemblies; and a platform portion disposed at the edge of the cup portion and sealed, wherein a gas exhaust pipe may be inserted into the platform portion.

[0016] The gas discharge pipe may include: a first gas discharge pipe disposed at one end along the length of the flexible package; and a second gas discharge pipe disposed at the other end along the length of the flexible package.

[0017] The first gas exhaust pipe can be eccentrically positioned on one side of the width direction of the flexible package, and the second gas exhaust pipe can be eccentrically positioned on the other side of the width direction of the flexible package.

[0018] The method for manufacturing a pouch cell according to the present disclosure may include the following steps: (S1) arranging a gas discharge pipe at the edge of a pouch containing an electrode assembly; (S2) inserting an unsealed pipe configured to prevent the gas discharge pipe from being sealed into the gas discharge pipe; (S3) sealing the edge of the pouch; and (S4) injecting an electrolyte solution into the pouch through the gas discharge pipe.

[0019] The gas discharge pipe may include: a first gas discharge pipe disposed at one end of the length direction of the soft package; and a second gas discharge pipe disposed at the other end of the length direction of the soft package, wherein, in step (S4), the electrolyte solution can be injected into the soft package through the first gas discharge pipe, and the gas inside the soft package can be removed through the second gas discharge pipe.

[0020] The method for manufacturing a pouch cell according to the present disclosure may include the following steps: (S1') joining an unsealed tube to a gas discharge tube with the outer peripheral surface of the unsealed tube facing the inner peripheral surface of the gas discharge tube; (S2') arranging the gas discharge tube joined with the unsealed tube at the edge of a pouch containing an electrode assembly; (S3') sealing the edge of the pouch; and (S4') injecting an electrolyte solution into the pouch through the unsealed tube.

[0021] The method for manufacturing a pouch cell may further include the following steps: (S5) removing an unsealed tube after injecting an electrolyte solution into the pouch; and (S6) sealing one end of a gas emission tube.

[0022] Beneficial effects According to embodiments of this disclosure, the amount of electrolyte solution adhering to the sealing portion during the sealing process of the pouch battery cell is reduced, thereby improving the sealing quality of the pouch.

[0023] Therefore, the sealing performance of the pouch cell is improved, thereby enhancing the stability of the individual pouch cell.

[0024] In addition, the gas generated inside the pouch during the charging or discharging process of a single pouch battery cell can be effectively discharged to the outside.

[0025] Therefore, it delays or prevents the occurrence of soft-pack venting caused by gas inside the soft-pack, thereby improving the safety of the soft-pack battery cell.

[0026] Furthermore, even if venting occurs due to the pressure generated by the gas inside the soft package, the venting can be guided through the gas venting pipe.

[0027] Therefore, exhaust can be predicted, making it easy to manage individual pouch cells or battery modules.

[0028] The effects of this disclosure are not limited to those illustrated above; various other effects are included in this specification. Attached Figure Description

[0029] Figure 1 This is a perspective view schematically showing a pouch cell according to a first embodiment of the present disclosure.

[0030] Figure 2This is a schematic plan view of a pouch cell according to a first embodiment of the present disclosure.

[0031] Figure 3 It is schematically shown along Figure 1 A cross-sectional view of the section cut by line A-A'.

[0032] Figure 4 This is a perspective view schematically showing a pouch cell according to a second embodiment of the present disclosure.

[0033] Figure 5 This is a schematic plan view of a pouch cell according to a second embodiment of the present disclosure.

[0034] Figure 6 This is a flowchart schematically illustrating a method for manufacturing a pouch cell according to a third embodiment of the present disclosure.

[0035] Figure 7 This is a flowchart schematically illustrating a method for manufacturing a pouch cell according to a fourth embodiment of the present disclosure.

[0036] Figure 8 This is a perspective view schematically showing the state of an unsealed tube combined with a gas emission tube in a method for manufacturing a pouch cell according to a fourth embodiment of the present disclosure.

[0037] Figure 9 This is a perspective view schematically showing the state in which a gas emission pipe, combined with an unsealed tube, is inserted into a pouch cell in a pouch cell manufacturing method according to a fourth embodiment of the present disclosure.

[0038] Those skilled in the art will understand that the elements in the accompanying drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to others to aid in understanding the various embodiments. Detailed Implementation

[0039] In the following description, embodiments of the present disclosure will be illustrated 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 various different forms and is not limited to or confined to the following embodiments.

[0040] To clearly explain this disclosure, detailed descriptions of parts or related known techniques unrelated to the description, which might unnecessarily obscure the essential points of this disclosure, have been omitted. Throughout this specification, when adding reference numerals for components in each figure, the same or similar components are given the same or similar reference numerals.

[0041] Furthermore, the terms or words used in this specification and claims should not be limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical ideas of this disclosure, in accordance with the principle that inventors can appropriately define the concepts of terms in order to best interpret their invention.

[0042] Pouch cells have advantages such as good space efficiency and the ability to perform various battery designs because the internal space is filled with the battery (electrolyte solution) and the manufactured cells are thin and have high energy density.

[0043] In the manufacturing process of a pouch cell, an electrolyte solution for immersing the electrode assembly housed within the pouch is injected into the pouch, and the pouch is sealed after removing any gas generated inside. However, the surface of the pouch to be sealed may be contaminated with electrolyte solution, which could lead to poor sealing quality.

[0044] Therefore, in order to improve the sealing quality of the pouch cell, a method for manufacturing a pouch cell is needed to inject electrolyte solution into the pouch cell so that the pouch cell does not become contaminated with electrolyte solution.

[0045] Furthermore, the internal gas generated by repeated charging and discharging can increase the pressure of individual pouch cells, and in some cases, the seal of the sealing portion may be damaged due to the increased pressure. This reduction in the sealing performance of the sealing portion can cause a problem, such as venting that forces the pouch to open due to pressure.

[0046] Therefore, a pouch cell exhibiting venting cannot be used as a secondary battery. Thus, in order to prevent or delay the occurrence of venting and the forced opening of the pouch, this disclosure provides a pouch cell comprising a configuration that allows gas inside the pouch to be vented to the outside of the pouch (e.g., the surrounding environment).

[0047] First Embodiment Figure 1 This is a schematic perspective view of a pouch cell 10 according to a first embodiment of the present disclosure. Figure 2 This is a schematic plan view of a pouch cell 10 according to a first embodiment of the present disclosure, viewed from above.

[0048] The pouch cell 10 described in this disclosure can refer to a rechargeable battery capable of charging and discharging. For example, the pouch cell 10 can be referred to as a rechargeable battery in which an electrode assembly 100, including an anode, a cathode, and a separator, is disposed inside a pouch 200, and the shape and size of the pouch 200 are designed to surround and enclose or enclose the electrode assembly 100. Alternatively, the pouch cell 10 can be referred to as a rechargeable battery in which the electrode assembly 100, including an anode, a cathode, and a separator, is contained within the pouch 200 along with an electrolyte solution.

[0049] The flexible packaging 200 may include a cup portion 210 and a platform portion 220. Since the cup portion 210 has space for placing the electrode assembly 100, the electrode assembly 100 can be disposed within the cup portion 210 of the flexible packaging 200. Furthermore, the platform portion 220 can be arranged at the edge of the cup portion 210 and can be sealed. Here, sealing can be referred to as a process of sealing the flexible packaging 200 by heat and pressure.

[0050] The electrode assembly 100 can be in the form of a stacked anode, cathode, and diaphragm, or in the form of a jelly-roll, and the flexible package 200 can house the electrode assembly 100. For example, the electrode assembly 100 and the electrolyte solution can be housed inside the molded cup portion 210 of the flexible package 200.

[0051] Reference Figure 1 The electrode lead 400 can be electrically connected to the electrode assembly 100 and can be configured to protrude to the outside of the pouch 200. The pouch cell 10 can supply electrical energy to the outside through the electrode lead 400 protruding to the outside of the pouch 200. Therefore, the electrode lead 400 can be a conductor.

[0052] The lead film can cover the electrode lead 400, thereby insulating the pouch 200 and the electrode lead 400 from each other. For example, the lead film can be disposed on both sides of the electrode lead 400 and cover the electrode lead 400. The lead films can be configured as a pair and disposed on both sides of the electrode lead 400 respectively.

[0053] Meanwhile, the lead film may contain insulating material to insulate the pouch 200 from the electrode lead 400. The electrode lead 400 may have a generally rectangular parallelepiped shape, but is not necessarily limited to this.

[0054] As the pouch cell 10 is repeatedly charged and discharged, gas may be generated, thereby increasing the internal pressure of the pouch 200. For example, when the internal pressure of the pouch 200 increases excessively, the pouch may be forced to open to release gas, causing the pouch cell 10 to lose its function.

[0055] According to an embodiment, the electrolyte solution can be contained together with the electrode assembly 100 inside the pouch 200 of the pouch cell 10. Here, inside the pouch 200 of the pouch cell 10, residual moisture in the electrolyte solution or moisture that has seeped in from the outside may react with the lithium salt to generate hydrogen fluoride (HF), and gases such as carbon dioxide, carbon monoxide, ethylene, and methane may be generated due to the decomposition of the electrolyte solution. Furthermore, depending on the cathode material included in the electrode assembly 100 of the pouch cell 10, hydrogen and HF may be additionally generated, thus overheating may occur during charging and discharging due to overcharging and internal short circuits. Therefore, a large amount of gas may be generated inside the pouch 200. Due to the generation of gas, the pressure inside the pouch may increase. The increased pressure may cause the pouch 200 to expand or partially rupture, resulting in gas release.

[0056] In this regard, the pouch cell 10 according to the first embodiment of the present disclosure may include a gas exhaust pipe 300 as an example of a configuration for effectively discharging gas accumulated in the pouch 200 to the outside of the pouch 200.

[0057] Reference Figure 1 and Figure 2 The gas emission pipe 300 of the pouch cell 10 can be configured such that it extends from the inside of the pouch 200 to the outside. Here, the gas emission pipe 300 can be fixed in a position where it is placed within the pouch 200. For example, in the pouch cell 10, a pair of pouches 200 facing each other can be joined by a seal, and the gas emission pipe 300 can be disposed between the sealing portions of the facing pouches 200. According to an embodiment, the gas emission pipe 300 can be configured to be inserted into the platform portion 220 of the pouch 200.

[0058] Meanwhile, the gas inside the pouch 200 can pass through the surface of the gas discharge pipe 300 and move to the outside. For example, the gas collected in the cup portion 210 of the pouch 200 can diffuse into the interior of the gas discharge pipe 300, pass through the surface of the gas discharge pipe 300, and be discharged to the outside of the pouch battery cell 10.

[0059] According to a first embodiment of the present disclosure, the pouch cell 10 includes a gas discharge pipe 300, which allows gas generated inside the pouch 200 due to repeated charging and discharging to be effectively discharged to the outside of the pouch 200.

[0060] Figure 3 It is schematically shown along Figure 1 A cross-sectional view of the section cut by line A-A'.

[0061] As an example of a configuration that allows gas to pass through effectively, the gas discharge pipe 300 of the pouch cell 10 according to the first embodiment of this disclosure may be composed of multiple layers. Specifically, the gas discharge pipe 300 may include an inner layer 301, a permeable layer 302, and an outer layer 303.

[0062] The inner layer 301 and outer layer 303 can have heat-based sealing properties or heat and pressure-based sealing properties. As an example, the inner layer 301 and outer layer 303 can contain the same material that is sealed by heat and pressure as the innermost layer of the soft package 200. Furthermore, the inner layer 301 and outer layer 303 can be partially melted by heat and have adhesive properties. Therefore, in addition to sealing methods based on heat and pressure, sealing methods utilizing ultrasound or the like can also be applied to the inner layer 301 and outer layer 303.

[0063] For example, the inner layer 301 and outer layer 303 of the gas exhaust pipe 300 can be made of one or more materials selected from the group consisting of: polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester fiber, polyparaphenylenebenzobisoxazole, polyarylate, polytetrafluoroethylene, and glass fiber. For example, polyolefin resins such as polypropylene (PP) or polyethylene (PE) can be used primarily. Polypropylene (PP) has excellent mechanical properties (e.g., tensile strength, rigidity, surface hardness, abrasion resistance, and heat resistance) and excellent chemical properties (e.g., corrosion resistance), therefore polypropylene (PP) can be primarily used to manufacture the inner layer 301 or outer layer 303. Furthermore, the inner layer 301 and outer layer 303 can also be made of cast polypropylene, acid-modified polypropylene, or a polypropylene-butene-ethylene terpolymer. Here, acid-modified polypropylene can be maleic anhydride polypropylene (MAH PP).

[0064] The permeable layer 302 can be disposed between the inner layer 301 and the outer layer 303. Therefore, the gas discharge pipe 300 can have a configuration including the inner layer 301, the permeable layer 302 and the outer layer 303, which are arranged from the inside to the outside.

[0065] The permeable layer 302 can have high air permeability. The inner layer 301 and the outer layer 303 can be air permeable, and the permeable layer 302 can have higher air permeability than the inner layer 301 and the outer layer 303. For example, the permeable layer 302 can contain a fluoropolymer resin with excellent air permeability. For example, the permeable layer 302 can be made of polytetrafluoroethylene (PTFE).

[0066] Since the gas discharge pipe 300 includes a permeable layer 302, gas can be effectively discharged through permeation.

[0067] As an example of a configuration to prevent the electrolyte solution inside the soft pack 200 from leaking to the outside, the gas discharge pipe 300 according to the first embodiment of the present disclosure may include a sealing portion 310.

[0068] The gas discharge pipe 300 can be configured to extend from the inside of the flexible housing 200 to the outside. Here, the sealing portion 310 can protrude to the outside of the flexible housing 200. If the sealing portion 310 is located inside the flexible housing 200, when gas is discharged to the outside of the flexible housing 200, the gas must pass through both the surface of the gas discharge pipe 300 and the surface of the flexible housing 200. Therefore, the path for the gas to be discharged to the outside of the flexible housing 200 may become longer. In other words, because the sealing portion 310 is located outside the flexible housing 200, the gas can be effectively discharged to the outside of the flexible housing 200 through the surface of the gas discharge pipe 300.

[0069] The surface of the sealing portion 310 may also consist of an inner layer 301, a permeable layer 302, and an outer layer 303. The sealing portion 310 can be sealed by sealing the inner layers 301 facing each other. As described above, the inner layers 301 are sealed to each other by techniques such as heat sealing and pressure sealing. That is, the inner layers 301 facing each other can adhere to each other by sealing, thereby sealing the sealing portion 310 of the gas discharge pipe 300.

[0070] For example, the area of ​​the sealing portion 310 can be determined taking into account the gas emission performance of the pouch cell 10 and the direction of venting. For example, if the amount of gas generated inside the pouch 200 is greater than the amount of gas emitted through the gas emission pipe 300, the sealing portion 310 can be opened to induce venting. Here, the sealing strength between the inner layers 301 can be determined by adjusting the area of ​​the sealing portion 310, and the sealing strength of the sealing portion 310 can be set to be weaker than the sealing strength of the pouch 200. Therefore, if necessary, venting can be induced through the sealing portion 310 of the gas emission pipe 300.

[0071] When the direction of venting through the seal 310 is predicted in this way, it is easy to prepare for it even when venting of the pouch cell 10 is in progress. That is, it is easy to manage the pouch cell 10 or the battery module including multiple pouch cells 10, and it can improve stability.

[0072] The gas emission pipe 300 of the pouch cell 10 according to the first embodiment of the present disclosure may further include a channel portion 320.

[0073] The channel portion 320 of the gas discharge pipe 300 can be a generally tubular shape with an internal space through which gas can pass. Furthermore, the channel portion 320 of the gas discharge pipe 300 can be configured to extend from the sealing portion 310 into the interior of the flexible housing 200. Therefore, the channel portion 320 can form a space communicating with the interior of the flexible housing 200, through which gas can move. Gas inside the flexible housing 200 moves into this space, and the moving gas can pass through the surface of the gas discharge pipe 300 and be discharged to the outside of the flexible housing 200.

[0074] The surface of the channel portion 320 may also consist of an inner layer 301, a permeable layer 302, and an outer layer 303. The outer layer 303 of the channel portion 320 can be sealed to the flexible housing 200. As described above, the outer layer 303 can have sealing performance based on heat and pressure. Furthermore, the inner layer 301 of the flexible housing 200 can also be sealed using techniques such as heat and pressure. For example, due to the sealing of the channel portion 320 and the flexible housing 200 (parts 210, 220), leakage of electrolyte solution into the space between the gas discharge pipe 300 and the flexible housing 200 can be prevented.

[0075] Meanwhile, the gas emission pipe 300 of the pouch cell 10 according to the first embodiment of this disclosure can be used as a channel for injecting electrolyte solution through it during the manufacturing process of the pouch cell.

[0076] In this regard, the manufacturing process of a pouch cell may include injecting an electrolyte solution into the pouch 200 to immerse the electrode assembly 100 in the electrolyte solution. In the prior art, the sealing quality deteriorates because the sealing portion of the pouch 200 is contaminated with the electrolyte solution. However, as in this disclosure, when the electrolyte solution is injected into the pouch 200 through the gas exhaust pipe 300, most of the sealing portion of the pouch 200, except for a portion of the gas exhaust pipe 300, can be sealed before the electrolyte solution is injected. Therefore, most of the sealing portion of the pouch 200 is not contaminated with the electrolyte solution, thus improving the sealing quality.

[0077] The gas exhaust pipe 300 of the pouch cell 10 according to the first embodiment of this disclosure can be used not only as an electrolyte solution injection port during the pouch cell manufacturing process, but also as an exhaust channel for discharging gases generated during the charging / discharging of the finished pouch cell 10. In the third embodiment, the gas exhaust pipe 300 used in the pouch cell manufacturing process will be described in detail.

[0078] Regarding the location of the gas discharge pipe 300, the gas discharge pipe 300 can be arranged spaced apart from the electrode lead 400. That is, the gas discharge pipe 300 can be arranged with a gap between it and the electrode lead 400. The electrode lead 400 can be electrically connected to the electrode assembly 100 and can extend to the outside of the flexible package 200. For example, the electrode lead 400 can be generally located at the center of the width direction of the flexible package 200, and the gas discharge pipe 300 can be eccentrically located on one side of the width direction of the flexible package 200. Here, using... Figure 2 Based on this, the width direction of the soft pack 200 can be referred to as the vertical direction.

[0079] When the gas discharge pipe 300 is arranged with a gap between the gas discharge pipe 300 and the electrode lead 400, the movement or flow of gas to the outside of the soft package 200 is less affected by the electrode lead 400, so the gas can be effectively discharged to the outside of the soft package 200.

[0080] The finished pouch cell 10 according to the first embodiment of this disclosure includes a gas emission pipe 300. The gas emission pipe 300 can also be used to effectively inject electrolyte solution during the manufacturing process, and internal gases generated during charging / discharging can be discharged to the outside through the gas emission pipe 300. Therefore, in this way, the occurrence of venting, etc., can be delayed or prevented, thereby improving the stability of the pouch cell 10.

[0081] Second Embodiment Figure 4 This is a schematic perspective view of a pouch cell 10' according to a second embodiment of the present disclosure. Figure 5 This is a schematic plan view of a pouch cell 10' according to a second embodiment of the present disclosure.

[0082] In the following text, a detailed description of the same configuration as that of the pouch cell 10 according to the first embodiment of the present disclosure will be omitted, and the differences will be mainly described.

[0083] The shape of the gas exhaust pipe 300' in the pouch cell 10' according to the second embodiment of the present disclosure may be different from the shape of the gas exhaust pipe in the pouch cell 10 according to the first embodiment of the present disclosure.

[0084] As an example of a configuration for effectively venting gases, the gas vent pipe 300' of the pouch cell 10' according to the second embodiment of this disclosure may include a first gas vent pipe 300-1 and a second gas vent pipe 300-2.

[0085] The first gas emission pipe 300-1 and the second gas emission pipe 300-2 may have substantially the same shape and may be configured with the same layered structure. That is, each of the first gas emission pipe 300-1 and the second gas emission pipe 300-2 may have a three-layer structure consisting of an inner layer 301, a permeable layer 302, and an outer layer 303, one end of which can be sealed. The shape of each of the first gas emission pipe 300-1 and the second gas emission pipe 300-2 may be similar to the shape of the gas emission pipe 300 of the pouch cell 10 described in the first embodiment of this disclosure, and therefore its detailed description will be omitted.

[0086] Reference Figure 4 and Figure 5 The first gas discharge pipe 300-1 can be located at one end along the length of the flexible package 200, and the second gas discharge pipe 300-2 can be located at the other end along the length of the flexible package 200. Here, taking... Figure 5 Based on this, the length direction can refer to the horizontal direction.

[0087] In the pouch cell 10', the gas inside the pouch 200 is discharged through two points (i.e., the first gas discharge pipe 300-1 and the second gas discharge pipe 300-2), thus improving gas removal performance. Furthermore, since the first gas discharge pipe 300-1 is located at one end and the second gas discharge pipe 300-2 is located at the opposite end, gas can be discharged more efficiently.

[0088] For example, the first gas discharge pipe 300-1 can be eccentrically positioned on one side of the width direction of the flexible package 200, and the second gas discharge pipe 300-2 can be eccentrically positioned on the other side of the width direction of the flexible package 200. Here, taking... Figure 5 Based on this, the width direction can be referred to as the vertical direction.

[0089] In other words, the first gas discharge pipe 300-1 and the second gas discharge pipe 300-2 can be located approximately symmetrically about the center of the pouch cell 200. Therefore, gas can be discharged more efficiently from the pouch cell 10'.

[0090] Meanwhile, according to the second embodiment of this disclosure, the first gas emission pipe 300-1 of the gas emission pipe 300 can be used as a channel for injecting electrolyte solution during the manufacturing process of a pouch cell. Furthermore, when electrolyte solution is injected through the first gas emission pipe 300-1 during the manufacturing process of a pouch cell, the second gas emission pipe 300-2 of the gas emission pipe 300 can be used as a channel for removing gas from inside the pouch 200. That is, the second gas emission pipe 300-2 creates a vacuum inside the pouch 200 so that the electrode assembly 100 can be uniformly immersed in the electrolyte solution injected through the first gas emission pipe 300-1. The first gas emission pipe 300-1 and the second gas emission pipe 300-2 are positioned substantially symmetrically about the center of the pouch 200. Therefore, during the manufacturing process of a pouch cell, when gas removal from the interior of the pouch 200 and electrolyte solution injection are performed simultaneously, mutual interference can be reduced, and process efficiency can be improved.

[0091] Third Embodiment Figure 6 This is a flowchart schematically illustrating a method for manufacturing a pouch cell according to a third embodiment of the present disclosure.

[0092] The method for manufacturing a pouch cell according to the third embodiment of this disclosure may include step S1 of arranging a gas discharge pipe 300 at the edge of a pouch 200 in which an electrode assembly 100 is internally housed. Specifically, the gas discharge pipe 300 may be disposed on the platform portion 220 of the pouch 200. Here, the gas discharge pipe 300 serves as a channel for injecting an electrolyte solution, and therefore may have a generally tubular shape.

[0093] Next, step S2 can be performed, in which the unsealed tube 500 is inserted into the gas discharge tube 300 provided on the platform portion 220 of the flexible package 200 (for example, see...). Figure 8 Here, the unsealed tube 500 may contain a fluoropolymer resin, which lacks the ability to form a seal. Therefore, the unsealed tube 500 may prevent the edge of the gas discharge tube 300 from sealing with the edge of the flexible sleeve 200 when that edge is sealed. The unsealed tube 500 may have a similar shape to the gas discharge tube 300, but may have a smaller diameter than the gas discharge tube 300 for easy insertion into the gas discharge tube 300.

[0094] After the unsealed tube 500 is inserted and positioned inside the gas discharge pipe 300, step S3, sealing the edge of the flexible sleeve 200, can be performed. Here, the outer layer 303 of the gas discharge pipe 300 and the flexible sleeve 200, which have sealing properties, can be sealed together. In contrast, since the unsealed tube 500, which lacks sealing properties, is positioned inside the gas discharge pipe 300, the interior of the gas discharge pipe 300 may not be sealed even during the edge sealing step. This is because the unsealed tube 500 is inserted into the gas discharge pipe 300, and in this state, the inner layers 301 of the gas discharge pipe 300, which have sealing properties, do not contact each other due to the presence of the unsealed tube 500.

[0095] After sealing the pouch 200 in step S3, step S4, injecting the electrolyte solution into the pouch 200 through the gas discharge pipe 300, can be performed. In other words, in the pouch battery cell manufacturing method according to the third embodiment of this disclosure, since the electrolyte solution injection step is performed after the pouch sealing step, the edges of the pouch 200 are sealed before the pouch 200 becomes contaminated with the electrolyte solution, thereby improving the sealing quality.

[0096] Meanwhile, the gas emission pipe 300 may include a first gas emission pipe 300-1 disposed at one end along the length of the pouch 200 and a second gas emission pipe 300-2 disposed at the other end along the length of the pouch 200. Here, the electrolyte solution can be injected into the pouch 200 through the first gas emission pipe 300-1, and the gas inside the pouch 200 can be removed through the second gas emission pipe 300-2. Therefore, in the pouch battery cell manufacturing method according to this embodiment, the electrode assembly 100 inside the pouch 200 is more uniformly immersed in the electrolyte solution, thereby improving the immersion characteristics of the electrolyte solution.

[0097] In step S4, after removing the gas inside the soft package 200 through the second gas exhaust pipe 300-2, the electrolyte solution can be injected through the first gas exhaust pipe 300-1. In this case, since the inside of the soft package 200 is essentially under vacuum, the electrode assembly 100 can be uniformly immersed in the electrolyte solution.

[0098] Furthermore, while the electrolyte solution is injected through the first gas discharge pipe 300-1, gas can be removed through the second gas discharge pipe 300-2. In this case, the process efficiency can be improved because the time consumed in this process is shortened. Here, as the distance between the first gas discharge pipe 300-1 and the second gas discharge pipe 300-2 increases, the interference between gas removal and electrolyte solution injection can be reduced.

[0099] After the electrolyte solution is injected into the flexible package 200, step S5 can be performed to remove the unsealed tube 500 from the gas discharge tube 300. Since the unsealed tube 500 is contaminated with electrolyte solution during the electrolyte solution injection process, the inner layer 301 of the sealed gas discharge tube 300 may be contaminated with a relatively small amount of electrolyte solution.

[0100] After removing the unsealed tube 500, step S6 can be performed to seal one end of the gas emission tube 300. Because the electrolyte solution is blocked by the unsealed tube 500, the inner layer 301 of the gas emission tube 300, which has sealing properties, is contaminated with a relatively small amount of electrolyte solution. Therefore, the sealing quality of the gas emission tube 300 can be improved. Here, the inner layers 301 facing each other at one end of the gas emission tube 300 can be sealed together by heat and pressure. Due to the seal, one end of the gas emission tube 300 can be sealed, preventing the electrolyte solution inside the pouch 200 from leaking to the outside. Here, the sealing area of ​​the gas emission tube 300 can be determined taking into account the gas emission performance and exhaust prevention pressure of the finished pouch cell 10.

[0101] In the method for manufacturing a pouch cell according to the third embodiment of this disclosure, the pouch 200 is sealed before the step of injecting the electrolyte solution into the pouch 200, that is, in a state where the pouch 200 is not contaminated with the electrolyte solution. This lack of contamination improves the sealing quality. Therefore, venting and the like can be prevented, and the stability of the pouch cell 10 can be improved. Furthermore, since the electrolyte solution is injected in a state where the gas inside the pouch 200 has been removed, the immersion characteristics of the electrolyte solution can be improved. In other words, the performance and quality of the finished pouch cell 10 can be improved.

[0102] Fourth embodiment Figure 7 This is a flowchart schematically illustrating a method for manufacturing a pouch cell according to a fourth embodiment of the present disclosure. Figure 8 This is a perspective view schematically showing the state in which the unsealed tube 500 and the gas emission tube 300 are combined in a method for manufacturing a pouch cell according to the fourth embodiment of this disclosure. Figure 9 This is a perspective view schematically showing the state in which a gas emission pipe 300, combined with an unsealed tube 500, is inserted into a pouch 200 in a pouch cell manufacturing method according to a fourth embodiment of the present disclosure.

[0103] In the following text, descriptions of steps identical to those in the method for manufacturing a pouch cell according to the third embodiment of this disclosure will be omitted, and the differences will be described primarily.

[0104] Reference Figure 7The method for manufacturing a pouch cell according to the fourth embodiment of this disclosure may include step S1' of combining an unsealed tube 500 with a gas emission tube 300. That is, in the method for manufacturing a pouch cell according to the fourth embodiment of this disclosure, the unsealed tube 500 can be pre-combined with the gas emission tube 300 before the gas emission tube 300 is disposed inside the pouch 200. This differs from the method for manufacturing a pouch cell according to the third embodiment of this disclosure, in which the unsealed tube 500 is inserted after the gas emission tube 300 is disposed inside the pouch 200.

[0105] Reference Figure 8 In step S1', the unsealed tube 500 can be joined to the gas discharge tube 300 with the outer peripheral surface of the unsealed tube 500 facing each other and the inner peripheral surface of the gas discharge tube 300 facing each other. Here, the unsealed tube 500 serves as a channel for the injection of electrolyte solution, and therefore can have a generally tubular shape. Furthermore, in order to efficiently inject electrolyte solution, the length of the unsealed tube 500 can be longer than the length of the gas discharge tube 300.

[0106] As an example of a method for combining a gas discharge pipe 300 and an unsealed pipe 500, the unsealed pipe 500 can be inserted into the gas discharge pipe 300. Alternatively, in another example, the gas discharge pipe 300 can be formed by winding a sheet having the same layer structure as the gas discharge pipe 300 around the outer peripheral surface of the unsealed pipe 500 and then connecting the two ends of the sheet.

[0107] Next, step S2' can be performed whereby the gas exhaust pipe 300, which is connected to the unsealed pipe 500, is arranged on the edge of the flexible housing 200. Specifically, the gas exhaust pipe 300, which is connected to the unsealed pipe 500, can be provided on the platform portion 220 of the flexible housing 200.

[0108] For example, the diameter of the gas emission pipe 300 can vary depending on the required gas emission performance or electrolyte solution injection rate of the pouch cell 10. When the diameter of the gas emission pipe 300 is relatively small, it may be difficult to efficiently insert the unsealed tube 500 into the gas emission pipe 300 disposed inside the pouch 200. In this regard, in the pouch cell manufacturing method according to the fourth embodiment of the present disclosure, the unsealed tube 500 and the gas emission pipe 300 can be joined before the gas emission pipe 300 is disposed inside the pouch 200. Therefore, the gas emission pipe 300 and the unsealed tube 500 can be joined relatively easily. This can improve the efficiency of the pouch cell manufacturing process.

[0109] After the gas discharge pipe 300, which is connected to the unsealed pipe 500, is placed inside the flexible housing 200, step S3' of sealing the edge of the flexible housing 200 can be performed. Here, since the unsealed pipe 500, which does not have sealing performance, is placed inside the gas discharge pipe 300, the inside of the gas discharge pipe 300 may not be sealed even in step S3' of sealing the edge of the flexible housing 200.

[0110] Next, step S4', injecting the electrolyte solution into the flexible package 200 through the unsealed tube 500, can be performed. The steps of removing the unsealed tube 500 and sealing one end of the gas discharge tube 300 after injecting the electrolyte solution into the flexible package 200 can be the same as those in the third embodiment of this disclosure. Furthermore, similar to the third embodiment, in the fourth embodiment, since the electrolyte solution injection step is performed after the flexible package sealing step, the edges of the flexible package 200 are sealed before the flexible package 200 becomes contaminated with the electrolyte solution, thus improving the sealing quality.

[0111] Although this disclosure has been described with reference to limited embodiments and accompanying drawings, it is not limited thereto, and various implementations can be made by those skilled in the art to which this disclosure pertains within the scope of the technical concept of this disclosure and the equivalents of the claims described below.

[0112] [Explanation of reference numerals in the attached image] 10, 10', 10'': Soft-pack battery cells 100: Electrode assembly 200: Soft Pack 210: Cup section 220: Platform Department 300, 300': Gas exhaust pipe 300-1: First gas exhaust pipe 300-2: Second gas exhaust pipe 301: Inner layer 302: Through layer 303: Outer layer 310: Sealing part 320: Passage Department 400: Electrode lead 500: Unsealed pipe

Claims

1. A pouch battery cell comprising: an electrode assembly; a pouch that houses the electrode assembly inside; and a gas discharge tube that is disposed so as to extend from the inside of the pouch to the outside, wherein a gas inside the pouch is discharged to the outside of the pouch through the gas discharge tube. The gas discharge tube includes:

2. The pouch battery cell of claim 1, wherein, an inner layer and an outer layer that have heat-based sealing properties; and a permeation layer that is arranged between the inner layer and the outer layer and has higher gas permeability than the inner layer and the outer layer. The inner layer and the outer layer contain a polyolefin-based resin, and 3. The pouch battery cell of claim 2, wherein, the permeation layer contains polytetrafluoroethylene (PTFE). The gas discharge tube further includes a sealing portion that protrudes to the outside of the pouch and has an inner layer that is closed by sealing.

4. The pouch battery cell of claim 1, wherein, The gas discharge tube further includes a passage portion that extends from the sealing portion to the inside of the pouch and forms a space that communicates with the inside of the pouch through which a gas can move.

5. The pouch battery cell of claim 4, wherein, The outer layer of the passage portion is closed by sealing with the pouch.

6. The pouch battery cell of claim 5, wherein, 7. The pouch battery cell according to claim 1, further comprising: an electrode lead that is electrically connected to the electrode assembly and extends to the outside of the pouch, wherein the gas discharge tube is disposed in a state in which there is a gap between the gas discharge tube and the electrode lead. The pouch includes:

8. The pouch battery cell of claim 1, wherein, a cup portion whose inside has a space in which the electrode assembly is disposed; and a platform portion that is arranged at an edge of the cup portion and is sealed, wherein the gas discharge tube is disposed so as to be interposed in the platform portion. The gas discharge tube includes:

9. The pouch battery cell of claim 1, wherein, a first gas discharge tube that is disposed at one end in a length direction of the pouch; and a second gas discharge tube that is disposed at the other end in the length direction of the pouch. The first gas discharge tube is disposed eccentrically at one side in a width direction of the pouch, and 10. The pouch battery cell of claim 9, wherein, the second gas discharge tube is disposed eccentrically at the other side in the width direction of the pouch.

11. A method of manufacturing a pouch battery cell, the method comprising: (S1) arranging a gas discharge tube at an edge of a pouch that houses an electrode assembly inside; (S2) inserting an unsealed tube that is configured to prevent the gas discharge tube from being sealed, into the gas discharge tube; (S3) sealing the edge of the pouch; and (S4) injecting an electrolyte solution into the pouch through the gas discharge tube. The gas discharge tube includes: a first gas discharge tube that is disposed at one end in a length direction of the pouch; and 12. The method of claim 11, wherein, a second gas discharge tube that is disposed at the other end in the length direction of the pouch, wherein, in the step (S4) of injecting the electrolyte solution, the electrolyte solution is injected into the pouch through the first gas discharge tube, and a gas inside the pouch is removed through the second gas discharge tube.

13. The method according to claim 11, further comprising: ​ ​ (S5) removing the unsealed tube after the electrolyte solution is injected into the pouch; and (S6) sealing one end of the gas discharge tube.

14. The method of claim 11, wherein, The unsealed tube contains a fluorine-based resin that does not have sealing properties.

15. A method of manufacturing a pouch battery cell, the method comprising: (S1') joining an unsealed tube to a gas discharge tube with the outer peripheral surface of the unsealed tube facing the inner peripheral surface of the gas discharge tube; (S2') arranging the gas discharge tube joined to the unsealed tube at the edge of a pouch that internally houses an electrode assembly; (S3') sealing the edge of the pouch; and (S4') injecting an electrolyte solution into the pouch through the unsealed tube.

16. The method according to claim 15, further comprising: (S5') removing the unsealed tube after the electrolyte solution is injected into the pouch; and (S6') sealing one end of the gas discharge tube.

17. The method of claim 15, wherein, The unsealed tube contains a fluorine-based resin that does not have sealing properties.

18. The method of claim 16, wherein, The sealing strength of the sealed end of the gas discharge tube is set to be weaker than the sealing strength of the edge of the pouch. The unsealed tube contains a fluorine-based resin that does not have sealing properties. The sealing strength of the sealed end of the gas discharge tube is set to be weaker than the sealing strength of the edge of the pouch.

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