KR20240074726A - The Apparatus And The Method For Forming Pouch - Google Patents

Abstract

A pouch forming device according to an embodiment of the present invention for solving the above problem includes a die on which a pouch film is seated on an upper surface and a molding portion recessed inward from the upper surface; a punch disposed above the forming unit and descending to insert and mold the pouch film into the forming unit; It includes a first heating wire included in the inside of the punch to generate heat, and the die has an opening formed in the inner wall of at least one corner or corner portion of the molding part, so that the opening is opened when the pouch film is molded. It includes a paraffin channel through which paraffin is discharged.

Description

Pouch forming apparatus and method {The Apparatus And The Method For Forming Pouch}

The present invention relates to a pouch forming device and method, and more specifically, to a pouch forming device and method that improves the stretching quality of the pouch film when forming the cup portion of the pouch and prevents the occurrence of wrinkles or cracks in the cup portion. .

Generally, types of secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, lithium ion batteries, and lithium ion polymer batteries. These secondary batteries are used not only for small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also for large products requiring high output such as electric vehicles and hybrid vehicles, as well as for surplus power generation. It is also applied and used in power storage devices that store power or renewable energy and backup power storage devices.

To manufacture such a secondary battery, the electrode active material slurry is first applied to the positive electrode current collector and the negative electrode current collector to manufacture the positive and negative electrodes, and then laminated on both sides of the separator to form an electrode assembly of a predetermined shape. forms. Then, the electrode assembly is stored in the battery case, and the electrolyte is injected and sealed.

Secondary batteries are classified into pouch type and can type, etc., depending on the material of the case that accommodates the electrode assembly. The pouch type accommodates the electrode assembly in a pouch made of a soft polymer material with an irregular shape.

A pouch, which is a case of a pouch-type secondary battery, is manufactured by forming a cup portion by drawing and forming a pouch film made of a flexible material. Then, when the cup portion is formed in the pouch film, the electrode assembly is stored in the receiving space of the cup portion and the sealing portion is sealed to manufacture a secondary battery.

This drawing forming is performed by inserting the pouch film into a press and applying pressure to the pouch film with a punch to stretch the pouch film. However, during the drawing and forming process, the stretching force of the pouch film was not uniform, causing wrinkles or cracks to occur in the cup portion, damaging the appearance and deteriorating the quality of the product. Additionally, if wrinkles occur, the thickness of the pouch is not uniform, creating thin and weak areas, which shortens the lifespan of the pouch. Furthermore, if a crack occurs, the metal gas barrier layer included in the pouch film may be exposed to the outside and corrode.

If the pouch film is made thick to prevent this problem, the thickness of the secondary battery itself becomes thick, reducing energy efficiency. Also, if the pouch film is stretched by setting the curvature of the edge of the cup portion to be large, the volume of the electrode assembly is reduced in order to insert the electrode assembly into the cup portion, which also reduces energy efficiency.

Korean Publication No. 2018-0092174

The problem to be solved by the present invention is to provide a pouch forming device and method that can prevent wrinkles or cracks from occurring in the cup portion by improving the stretching quality of the pouch film when forming the cup portion of the pouch.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

A pouch forming device according to an embodiment of the present invention for solving the above problem includes a die on which a pouch film is seated on an upper surface and a molding portion recessed inward from the upper surface; a punch disposed above the forming unit and descending to insert and mold the pouch film into the forming unit; It includes a first heating wire included in the inside of the punch to generate heat, and the die has an opening formed in the inner wall of at least one corner or corner portion of the molding part, so that the opening is opened when the pouch film is molded. It includes a paraffin channel through which paraffin is discharged.

In addition, the die may further include a pressure passage formed at at least one edge or corner of the molding portion to reduce the pressure of the molding portion when the pouch film is molded.

Additionally, the paraffin flow path and the pressure flow path may be formed in different positions.

Additionally, the paraffin flow path may be formed at each corner of the molded part, and the pressure flow path may be formed at each corner of the molded part.

Additionally, the pressure channel can reduce the pressure to 30 to 60 kpa.

Additionally, the pressure flow path can reduce the pressure to 40 to 50 kpa.

Additionally, the first heating wire may generate heat having a temperature of 60 to 120°C.

Additionally, the first heating wire may generate heat having a temperature of 80 to 100°C.

In addition, it may further include a second heating wire included inside the die to generate heat.

Additionally, the second heating wire may generate heat having a temperature of 60 to 120°C.

Additionally, the second heating wire may generate heat having a temperature of 80 to 100°C.

In addition, it may further include a dispenser for injecting the paraffin into the paraffin channel.

In addition, it may further include a paraffin tank that stores the paraffin and supplies the paraffin to the dispenser.

In addition, it may further include a stripper disposed above the die, descending to come into contact with the die with the pouch film interposed therebetween, and fixing the pouch film.

A pouch forming method according to an embodiment of the present invention to solve the above problem includes the steps of seating a pouch film on the upper surface of a die; A punch disposed above the molding portion recessed inward from the upper surface of the die is lowered, and heat is generated from a first heating wire included in the punch; Discharging paraffin through a paraffin channel having an opening formed in an inner wall of at least one corner or corner portion of the molding part; and forming a cup portion on the pouch film.

Additionally, in the step of discharging the paraffin, the pressure of the molding portion may be reduced through a pressure passage formed in at least one edge or corner of the molding portion.

Additionally, in the step of discharging the paraffin, the paraffin may be injected into the paraffin channel using a dispenser.

Additionally, the dispenser may receive the paraffin from a paraffin tank storing the paraffin and inject the paraffin into the paraffin channel.

Additionally, in the step of generating heat from the first heating wire, heat may also be generated from the second heating wire included in the die.

Other specific details of the invention are included in the detailed description and drawings.

According to embodiments of the present invention, there are at least the following effects.

An opening for a paraffin channel through which paraffin is discharged is formed on the inner wall of the molding section of the die of the pouch molding device, and a protective film can be formed by coating paraffin in the area of the cup portion where wrinkles or cracks are likely to occur.

In addition, a heat wire is included in the punch and die to increase the temperature of the pouch film, and a pressure channel is included in the forming part of the die to reduce the pressure inside the forming part, thereby improving the stretching quality of the pouch film when forming the cup part of the pouch. , energy efficiency is increased by minimizing the curvature of the corners of the cup, and the occurrence of wrinkles or cracks in the cup can be prevented.

The effects according to the present invention are not limited to the contents exemplified above, and further various effects are included in the present specification.

Figure 1 is an assembly diagram of a typical pouch-type secondary battery.
Figure 2 is a cross-sectional view of a typical pouch film.
Figure 3 is a flowchart showing a method of forming a pouch film by a pouch forming device according to an embodiment of the present invention.
Figure 4 is a schematic diagram of a pouch forming device according to an embodiment of the present invention.
Figure 5 is a plan view of a die according to an embodiment of the present invention.
Figure 6 is a schematic diagram showing the stripper being lowered according to an embodiment of the present invention.
Figure 7 is a schematic diagram showing the lowering of the punch according to an embodiment of the present invention.
Figure 8 is a schematic diagram showing the punch and stripper raised according to an embodiment of the present invention.
Figure 9 is a schematic diagram of a pouch forming device according to another embodiment of the present invention.
Figure 10 is a schematic diagram showing a lowered punch according to another embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to be understood by those skilled in the art in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

The terminology used herein is for describing embodiments and is not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other elements in addition to the mentioned elements.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

Figure 1 is an assembly diagram of a general pouch-type secondary battery 1.

Generally, a pouch-type secondary battery 1 includes a pouch-type battery case 13 and an electrode assembly 10 accommodated inside the battery case 13, as shown in FIG. 1 .

The electrode assembly (Electrode Assembly, 10) may be a laminated structure including two electrodes, such as an anode and a cathode, and a separator interposed between the electrodes or disposed on the left or right side of one electrode to insulate the electrodes from each other. . The laminated structure is not limited and may have various forms, such as an anode and a cathode of a predetermined size being laminated with a separator in between, or being wound in a jelly roll form. The two electrodes have a structure in which an active material slurry is applied to an electrode current collector in the form of a metal foil or metal mesh containing aluminum and copper, respectively. Slurry can typically be formed by stirring granular active materials, auxiliary conductors, binders, and plasticizers with a solvent added. The solvent is removed in a subsequent process.

As shown in FIG. 1, the electrode assembly 10 includes an electrode tab (Electrode Tab, 11). The electrode tab 11 is connected to the anode and cathode of the electrode assembly 10, respectively, and protrudes to the outside of the electrode assembly 10, providing a path for electrons to move between the inside and outside of the electrode assembly 10. . The current collector of the electrode assembly 10 consists of a portion to which the electrode active material is applied and an end portion to which the electrode active material is not applied, that is, an uncoated portion. Additionally, the electrode tab 11 may be formed by cutting the uncoated area, or may be formed by connecting a separate conductive member to the uncoated area using ultrasonic welding or the like. As shown in FIG. 1, the electrode tabs 11 may protrude side by side in the same direction from one side of the electrode assembly 10, but are not limited to this and may protrude in different directions.

An electrode lead 12 is connected to the electrode tab 11 of the electrode assembly 10 by spot welding or the like. And, a part of the electrode lead 12 is surrounded by an insulating portion 14. The insulating portion 14 is located limited to the sealing portion where the upper pouch 131 and the lower pouch 132 of the battery case 13 are heat-sealed, and is adhered to the battery case 13. In addition, electricity generated from the electrode assembly 10 is prevented from flowing into the battery case 13 through the electrode lead 12, and the sealing of the battery case 13 is maintained. Therefore, this insulating portion 14 is made of a non-conductive material that does not conduct electricity well. Generally, as the insulating portion 14, an insulating tape that is easy to attach to the electrode lead 12 and has a relatively thin thickness is often used, but it is not limited to this and various members can be used as long as the electrode lead 12 can be insulated. there is.

The electrode leads 12 may extend in the same direction or in opposite directions depending on the formation positions of the positive electrode tab 111 and the negative electrode tab 112. The anode lead 121 and the cathode lead 122 may be made of different materials. That is, the positive electrode lead 121 may be made of the same aluminum (Al) material as the positive electrode plate, and the negative lead 122 may be made of the same copper (Cu) material as the negative electrode plate or a copper material coated with nickel (Ni). And a portion of the electrode lead 12 protruding to the outside of the battery case 13 becomes a terminal portion and is electrically connected to an external terminal.

The battery case 13 is a pouch made of a soft material. And the battery case 13 accommodates the electrode assembly 10 and is sealed so that a portion of the electrode lead 12, that is, the terminal portion, is exposed. As shown in FIG. 1, this battery case 13 includes an upper pouch 131 and a lower pouch 132. A cup portion 133 is formed in the lower pouch 132 to provide a receiving space 1331 for accommodating the electrode assembly 10, and the upper pouch 131 is provided with the electrode assembly 10 in the battery case 13. The receiving space 1331 is covered from the top so that it does not escape to the outside. In Figure 1, the cup portion 133 is shown as being formed only in the lower pouch 132, but it is not limited to this and can be formed in various ways, such as being formed in the upper pouch 131. The upper pouch 131 and the lower pouch 132 may be manufactured with one side connected to each other as shown in FIG. 1, but are not limited to this and can be manufactured in various ways, such as being separated from each other and manufactured separately.

When the electrode lead 12 is connected to the electrode tab 11 of the electrode assembly 10 and the insulating portion 14 is formed in a portion of the electrode lead 12, the cup portion 133 of the lower pouch 132 is provided. The electrode assembly 10 is accommodated in the receiving space 1331, and the upper pouch 131 covers the space from the top. Then, the electrolyte solution is injected inside and the sealing portions formed on the edges of the upper pouch 131 and lower pouch 132 are sealed. The electrolyte is used to move lithium ions generated by the electrochemical reaction of the electrode during charging and discharging of the secondary battery (1), and is a non-aqueous organic electrolyte that is a mixture of lithium salt and high-purity organic solvents or a polymer using a polymer electrolyte. may include. Through this method, the pouch-type secondary battery 1 can be manufactured.

Figure 2 is a cross-sectional view of a general pouch film 134.

In general, the pouch, which is the battery case 13 of the pouch-type secondary battery 1, is manufactured by drawing and molding the pouch film 134. That is, it is manufactured by stretching the pouch film 134 with a punch 23 or the like to form the cup portion 133. According to one embodiment of the present invention, this pouch film 134, as shown in FIG. 2, includes a gas barrier layer (Gas Barrier Layer, 1341), a Surface Protection Layer (1342), and a sealant layer (Sealant layer). Layer, 1343).

The gas barrier layer 1341 secures the mechanical strength of the pouch 13, blocks gas or moisture from outside the secondary battery 1, and prevents electrolyte leakage. Generally, the gas barrier layer 1341 is made of metal, and the metal may include aluminum. Aluminum can secure mechanical strength above a certain level, while being light in weight, complementing the electrochemical properties of the electrode assembly 10 and the electrolyte, and securing heat dissipation. However, the gas barrier layer 1341 is not limited to this and various materials may be included. For example, it may be one type or a mixture of two or more types selected from the group consisting of iron (Fe), carbon (C), chromium (Cr), manganese (Mn), nickel (Ni), and aluminum (Al). At this time, when the gas barrier layer 1341 is made of a material containing iron, mechanical strength is improved, and when the gas barrier layer 1341 is made of a material containing aluminum, flexibility is improved, so it can be used considering each characteristic.

The surface protection layer 1342 is made of a first polymer and is located at the outermost layer to protect the secondary battery 1 from friction and collision with the outside and electrically insulate the electrode assembly 10 from the outside. Here, the outermost layer refers to the layer located last when facing in the direction opposite to the direction in which the electrode assembly 10 is located based on the gas barrier layer 1341. The first polymer for manufacturing this surface protective layer 1342 is polyethylene, polypropylene, polycarbonate, polyethylene terephthalate (PET), polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose, It may be made of one or more materials selected from the group consisting of aramid, nylon, polyester, polyparaphenylenebenzobisoxazole, polyarylate, Teflon, and glass fiber. In particular, polymers such as nylon resin or polyethylene terephthalate (PET), which have wear resistance and heat resistance, are mainly used. Additionally, the surface protection layer 1342 may have a single film structure made of one material, or it may have a composite film structure formed by forming layers of two or more materials.

The sealant layer 1343 is made of a second polymer and is located in the innermost layer and directly contacts the electrode assembly 10. Here, the innermost layer refers to the last layer located in the direction in which the electrode assembly 10 is located based on the gas barrier layer 1341. Pouch 13 type The pouch 13 is formed by drawing the pouch film 134 having the above-described laminated structure using a punch 23, etc., and a portion of the pouch 13 is stretched to form a bag-shaped receiving space 1331. It is manufactured while forming a cup portion 133 including. Then, when the electrode assembly 10 is accommodated in this accommodation space 1331, an electrolyte solution is injected. Afterwards, the upper pouch 131 and the lower pouch 132 are brought into contact with each other and heat-compressed on the sealing portion 134, thereby sealing the pouch 13 by bonding the sealant layers 1343 to each other. At this time, the sealant layer 1343 must have insulating properties since it is in direct contact with the electrode assembly 10, and must have corrosion resistance because it is also in contact with the electrolyte solution. In addition, since the interior must be completely sealed to block material movement between the inside and outside, it must have high sealing properties. That is, the sealing portion 134 where the sealant layers 1343 are bonded together must have excellent thermal adhesive strength. In general, the second polymer for manufacturing this sealant layer 1343 is polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, It may be made of one or more materials selected from the group consisting of nylon, polyester, polyparaphenylenebenzobisoxazole, polyarylate, Teflon, and glass fiber. In particular, polyolefin-based resins such as polypropylene (PP) or polyethylene (PE) are mainly used. Polypropylene (PP) has excellent mechanical properties such as tensile strength, rigidity, surface hardness, wear resistance, heat resistance, and chemical properties such as corrosion resistance, and is mainly used to manufacture the sealant layer 1343. Furthermore, it may be composed of cated polypropylene, acid modified polypropylene, or polypropylene-butylene-ethylene terpolymer. Here, the acid-treated polypropylene may be MAH PP (maleic anhydride polypropylene). Additionally, the sealant layer 1343 may have a single film structure made of one material or a composite film structure formed by forming two or more materials as layers.

Figure 3 is a flowchart showing a method of forming the pouch film 134 by the pouch forming device 2 according to an embodiment of the present invention.

According to one embodiment of the present invention, the paraffin flow path 213 is included in the molding portion 211 of the die 21 of the pouch molding device 2, so that the area of the cup portion 133 where wrinkles or cracks are likely to occur A protective film can be formed by coating paraffin (3) on the surface. In addition, the punch 23 and the die 21 include a heat wire to increase the temperature of the pouch film 134, and the molding portion 211 of the die 21 includes a pressure flow path 214 to form the molding portion 211. ) By reducing the internal pressure, the stretching quality of the pouch film 134 is improved when forming the cup portion 133 of the pouch, the curvature of the edge of the cup portion 133 is minimized to increase energy efficiency, and the cup portion 133 is It can prevent the occurrence of wrinkles or cracks.

To this end, the pouch forming method according to an embodiment of the present invention includes the steps of seating the pouch film 134 on the upper surface of the die 21; The punch 23 disposed above the molding portion 211 recessed inward from the upper surface of the die 21 descends, and heat is generated from the first heating wire 231 included in the punch 23. step; Discharging paraffin 3 through a paraffin flow path 213 having an opening formed in an inner wall of at least one corner or corner portion of the molding unit 211; and forming a cup portion 133 on the pouch film 134. Additionally, in the step of discharging the paraffin 3, the pressure of the molding part 211 may be reduced through the pressure passage 214 formed in at least one corner or corner of the molding part 211.

Hereinafter, the details of each step of the flowchart shown in FIG. 3 will be described together with FIGS. 4 to 8.

Figure 4 is a schematic diagram of a pouch forming device 2 according to an embodiment of the present invention.

As shown in FIG. 4, the pouch molding device 2 according to an embodiment of the present invention includes a pouch film 134 seated on the upper surface and a molding portion 211 recessed inward from the upper surface. Dai (21); a punch 23 disposed above the forming unit 211 and descending to insert and mold the pouch film 134 into the forming unit 211; It includes a first heating wire 231 included in the inside of the punch 23 and generating heat, and the die 21 is formed on at least one corner or corner of the molding part 211 to form the pouch. When the film 134 is formed, it includes a paraffin channel 213 that discharges paraffin 3. And the die 21 is formed on at least one edge or corner of the molding part 211, and forms a pressure flow path 214 that reduces the pressure of the molding part 211 when the pouch film 134 is molded. ) may further be included.

The die 21 seats the pouch film 134 on its upper surface. The upper surface of the die 21 may be substantially flat so that the pouch film 134 can be easily seated. However, it is not limited to this, and in order to easily fix the pouch film 134 in the future, the upper surface of the die 21 may be formed in various ways, such as a grid pattern or fine irregularities. To form the cup portion 133 on the pouch film 134, first, as shown in FIG. 4, the pouch film 134 is placed on the upper surface of the die 21 (S301).

The die 21 includes a molded portion 211 that is recessed inward from approximately the center of the upper surface of the die 21. This molded portion 211 has a shape and size that correspond to the outer surface of the cup portion 133 to be formed later. Here, the fact that the shape and size correspond means that even if they are the same or there is a certain amount of difference, the difference is within the range of the offset. Therefore, if the cup portion 133 has a square shape, the molded portion 211 also has a square shape, and if the cup portion 133 has a circular shape, the molded portion 211 also has a circular shape. You can have it. When the pouch film 134 is placed on the upper surface of the die 21, the pouch film 134 is placed so that the molded part 211 is located in the area where the cup part 133 will be formed later.

Die 21 includes a paraffin flow path 213. The paraffin channel 213 has an opening formed in the inner wall of at least one corner or corner portion of the molding unit 211, and discharges the paraffin 3 through the opening when the pouch film 134 is molded. At this time, according to an embodiment of the present invention, as shown in FIG. 4, it is preferable that a plurality of paraffin channels 213 are formed, each formed at a corner of the molded part 211. A detailed description of the paraffin flow path 213 will be provided later.

The stripper 22 is disposed above the die 21 and descends when the pouch film 134 is placed on the upper surface of the die 21. Then, it comes into contact with the die 21 with the pouch film 134 interposed therebetween, and the pouch film 134 is pressed and fixed from above. Here, contact with the pouch film 134 in between means not direct contact, but indirect contact through the pouch film 134. When the cup portion 133 is formed later, the stripper 22 uniformly presses the pouch film 134 to evenly distribute the stretching force applied to the pouch film 134. The lower surface of the stripper 22 contacts the upper surface of the pouch film 134 when fixing the pouch film 134. Accordingly, the lower surface of the stripper 22 may be approximately flat. However, it is not limited to this, and in order to more easily fix the pouch film 134, the lower surface of the stripper 22 may be formed in various ways, such as a grid pattern or fine irregularities.

The punch 23 descends at a constant pressure and speed to apply pressure to the upper surface of the pouch film 134 seated on the die 21 to stretch the pouch film 134. As a result, the cup portion 133 is formed in the pouch film 134 so that a pouch can be manufactured. A penetrating portion 221 is formed at approximately the center of the lower surface of the stripper 22. And, the punch 23 moves up and down while penetrating the stripper 22 through the penetrating portion 221. When the punch 23 moves up and down, the inner wall of the penetrating part 221 guides the punch 23, so that the penetrating part 221 has a shape and size corresponding to that of the punch 23. Here, the fact that the shapes correspond to each other means that the penetrating part 221 has the same or similar shape as the punch 23, so that the punch 23 easily moves up and down through the penetrating part 221. And matching the sizes means that the size of the penetrating portion 221 is larger than the size of the punch 23 by the size of the offset. If the size of the penetrating portion 221 is the same or smaller than the size of the punch 23, the punch 23 is not inserted into the penetrating portion 221, or even if it is inserted, there is friction with the inner wall of the penetrating portion 221. As a result, the punch 23 may not move up and down easily. Conversely, if the size of the penetrating part 221 is too large, the inner wall of the penetrating part 221 cannot guide the punch 23, and the punch 23 may deviate from its original position. Therefore, it is desirable that the size of the offset be an appropriate size so that the punch 23 is inserted into the penetrating portion 221 and can easily move up and down, but does not deviate from its original position. In fact, the size of the offset can be experimentally determined depending on the size and shape of the cup portion 133 to be formed.

In addition, the punch 23 has a shape and size corresponding to the molding portion 211 of the die 21. Here, the shape corresponds to the fact that the punch 23 has the same or similar shape as the molding portion 211 of the die 21, and when the cup portion 133 is formed by stretching the pouch film 134 later, the cup portion ( 133) means that it is formed in the same or similar shape as the molding portion 211 of the punch 23 and the die 21. Accordingly, if the punch 23 has a square shape, the forming portion 211 of the die 21 also has a square shape, the cup portion 133 is also formed in a square shape, and the punch 23 has a circular shape. If it has a shape, the molding portion 211 of the die 21 may also have a circular shape, and the cup portion 133 may also be formed in a circular shape. And the size corresponds to the fact that the punch 23 is inserted into the molding part 211 of the die 21 together with the pouch film 134 and stretches the pouch film 134, so the punch 23 is inserted into the die 21. This means that the thickness of the pouch film 134 is slightly smaller than the molded part 211 of .

The first heating wire 231 is included inside the punch 23 and generates heat. Accordingly, the temperature of the punch 23 increases, and when forming the pouch film 134, the punch 23 contacts the pouch film 134 and the temperature of the pouch film 134 also increases, thereby forming the pouch film 134. It can be stretched easily and uniformly. The heat generated from the first heating wire 231 may have a temperature of 60 to 120°C, and preferably may have a temperature of 80 to 100°C.

The pouch forming device 2 according to an embodiment of the present invention may further include a second heating wire 212. The second heating wire 212 is included inside the die 21 and generates heat. Therefore, the temperature of the die 21 increases, and when the pouch film 134 is molded, the pouch film 134 is gradually inserted into the molding unit 211 and the temperature of the pouch film 134 also increases, thereby forming the pouch film ( 134) can be stretched easily and uniformly. In this way, the punch 23 increases the temperature of the upper surface of the pouch film 134, and the die 21 increases the temperature of the lower surface of the pouch film 134. The heat generated from the second heating wire 212 may have a temperature of 60 to 120°C, and preferably may have a temperature of 80 to 100°C.

Die 21 may further include a pressure passage 214. The pressure flow path 214 is formed at at least one edge or corner of the molding portion 211 to reduce the pressure of the molding portion 211 when the pouch film 134 is molded. At this time, according to an embodiment of the present invention, as shown in FIG. 4, it is preferable that a plurality of pressure passages 214 are formed, each formed at a corner of the molded part 211. A detailed description of the pressure passage 214 will be provided later.

It is preferable that the forming portion 211 of the above-described die 21, the penetrating portion 221 of the stripper 22, and the punch 23 all share the same central axis. Accordingly, the vertical movement of the punch 23 can be performed smoothly.

Figure 5 is a top view of the die 21 according to one embodiment of the present invention.

According to one embodiment of the present invention, as shown in FIG. 5, die 21 includes a paraffin flow path 213. The paraffin channel 213 has an opening formed in the inner wall of at least one corner or corner portion of the molding unit 211, and discharges the paraffin 3 through the opening when the pouch film 134 is molded. Accordingly, paraffin 3 may be coated on a specific area of the cup portion 133 of the molded pouch to form a protective film. At this time, according to an embodiment of the present invention, as shown in FIG. 5, it is preferable that a plurality of paraffin channels 213 are formed, each formed at a corner of the molded part 211. As a result, paraffin 3 can be coated on the corners of the cup portion 133 of the pouch. At this time, as shown in FIGS. 4 and 5, the opening of the paraffin channel 213 may be located closer to the bottom surface of the molding unit 211 than the top surface of the die 21. Additionally, the opening may be opened in the horizontal direction. Although not shown in the drawing, the paraffin 3 is stored in a separately provided paraffin 3 tank. Then, the paraffin (3) tank supplies the stored paraffin (3) to the dispenser, and the dispenser injects the supplied paraffin (3) into the paraffin flow path (213). As a result, the paraffin 3 injected into the paraffin channel 213 can flow through the paraffin channel 213 and be discharged into the molding unit 211. When a plurality of paraffin channels 213 are formed, only one dispenser may be formed and the paraffin 3 may be injected into each paraffin channel 213 while moving. However, the present invention is not limited to this, and a plurality of dispensers may be formed, and a dispenser corresponding to each paraffin channel 213 may inject the paraffin 3 into the corresponding paraffin channel 213.

Meanwhile, according to one embodiment of the present invention, the die 21 may further include a pressure passage 214, as shown in FIG. 5. The pressure flow path 214 is formed at at least one edge or corner of the molding portion 211 to reduce the pressure inside the molding portion 211 when the pouch film 134 is molded. To this end, the pressure passage 214 sucks in air and reduces the pressure by removing surrounding air. Therefore, the stretching quality of the pouch film 134 is improved, and when the cup portion 133 of the pouch is formed, the curvature of the edge of the cup portion 133 is minimized to increase energy efficiency, and the cup portion 133 is free from wrinkles or cracks. occurrence can be prevented. This pressure channel 214 can reduce the pressure inside the molding part 211 by 30 to 60 kpa, and preferably can reduce the pressure by 40 to 50 kpa. At this time, according to an embodiment of the present invention, as shown in FIG. 5, it is preferable that a plurality of pressure passages 214 are formed, each formed at a corner of the molded part 211. By doing so, the curvature of the edge of the cup portion 133 can be minimized.

If the paraffin flow path 213 and the pressure flow path 214 discharge the paraffin 3 into the molding unit 211 through the paraffin flow path 213, the pressure flow path 214 sucks the surrounding air and the discharged paraffin (3) can also be inhaled together. Accordingly, the paraffin flow path 213 and the pressure flow path 214 are formed at different positions. By doing so, when the pressure passage 214 sucks in surrounding air, the discharged paraffin 3 may not be sucked in. In particular, according to one embodiment of the present invention, the corner of the cup portion 133 receives a lot of stretching force in all three directions, such as horizontally, vertically, and height, and is therefore the area where wrinkles or cracks are most likely to occur. Accordingly, the paraffin flow path 213 is formed at each corner of the molded part 211, and the paraffin 3 can be coated on the corner of the cup part 133. In addition, since the edges of the cup portion 133 receive a lot of stretching force in two directions, such as horizontally and vertically, there is a high possibility that wrinkles or cracks will occur. Accordingly, the pressure flow path 214 is formed at each corner of the molded portion 211, so that the curvature of the corner of the cup portion 133 can be minimized.

Figure 6 is a schematic diagram showing the stripper 22 being lowered according to an embodiment of the present invention.

When the pouch film 134 is placed on the upper surface of the die 21, the stripper 22 descends as shown in FIG. 6 (S302). And when the lower surface of the stripper 22 contacts the upper surface of the pouch film 134, the stripper 22 and the die 21 contact each other with the pouch film 134 interposed therebetween. Then, the stripper 22 presses and fixes the pouch film 134 from above (S303). At this time, the stripper 22 uniformly presses the pouch film 134 to uniformly distribute the stretching force applied to the pouch film 134 when the cup portion 133 is formed later.

Figure 7 is a schematic diagram showing the punch 23 being lowered according to an embodiment of the present invention.

When the stripper 22 fixes the pouch film 134, heat is generated from the first heating wire 231 included in the punch 23, and the punch 23 is lowered as shown in FIG. 7 to remove the pouch film ( 134) is stretched (S304). Meanwhile, when heat is generated from the first heating wire 231, heat may also be generated from the second heating wire 212 included in the die 21. As a result, the temperature of the pouch film 134 further increases, allowing the pouch film 134 to be stretched more easily and uniformly.

As the pouch film 134 is stretched, paraffin 3 is discharged through the paraffin channel 213 formed in at least one edge or corner of the molded part 211 (S305). As a result, when the pouch film 134 is stretched to form the cup portion 133, the paraffin 3 is coated on a specific area of the cup portion 133, especially the edge or corner of the cup portion 133, so that a protective film can be formed. .

In order to discharge the paraffin (3) through the paraffin flow path 213, the paraffin (3) is first stored in a separately provided paraffin (3) tank. Then, the paraffin (3) tank supplies the stored paraffin (3) to the dispenser, and the dispenser injects the supplied paraffin (3) into the paraffin flow path (213). Meanwhile, in order for the paraffin 3 to be injected into the paraffin channel 213 and then discharged into the molding unit 211, the paraffin 3 must exist as a liquid. Accordingly, a separate heating wire is formed in the paraffin (3) tank storing the paraffin (3), and the paraffin (3) can be melted into a liquid state by generating heat.

When the paraffin 3 is discharged through the paraffin flow path 213, the pressure inside the molding part 211 may be reduced through the pressure flow path 214 formed in at least one edge or corner of the molding part 211. . By doing so, the curvature of the edge of the cup portion 133 can be minimized to increase energy efficiency, and the occurrence of wrinkles or cracks in the cup portion 133 can be prevented.

Figure 8 is a schematic diagram showing the punch 23 and the stripper 22 raised according to an embodiment of the present invention.

Through the process described above, the pouch film 134 may be molded to form the cup portion 133 in the pouch (S306). Afterwards, the punch 23 and stripper 22 rise again as shown in FIG. 8. Then, a pouch can be manufactured by taking out the pouch film 134 on which the cup portion 133 is formed.

Figure 9 is a schematic diagram of a pouch forming device 2a according to another embodiment of the present invention.

In the pouch molding device 2 according to an embodiment of the present invention, paraffin channels 213 are formed at each corner of the molding portion 211, and paraffin 3 can be coated on the corners of the cup portion 133. . In addition, the pressure flow path 214 is formed at each corner of the molded portion 211, so that the curvature of the corner of the cup portion 133 can be minimized.

However, in the pouch molding device 2a according to another embodiment of the present invention, the positions of the paraffin flow path 213a and the pressure flow path 214a may be changed. That is, the openings of the paraffin flow paths 213a are formed on the inner walls of the corners of the molded part 211, so that the corners of the cup part 133 can be coated with the paraffin 3. In other words, as shown in FIGS. 9 and 10, the opening of the paraffin channel 213a may be located on the bottom surface of the molding unit 211. And, the opening may be open upward. In addition, the pressure flow path 214a is formed at each corner of the molded portion 211, so that the curvature of the corner of the cup portion 133 can be minimized.

Figure 10 is a schematic diagram showing the lowered punch 23 according to another embodiment of the present invention.

In order to form the cup portion 133 in the pouch film 134 using the pouch forming device 2a according to another embodiment of the present invention, the pouch film 134 is first placed on the upper surface of the die 21a (S301) ). And when the pouch film 134 is placed on the upper surface of the die 21a, the stripper 22 descends (S302). And when the lower surface of the stripper 22 contacts the upper surface of the pouch film 134, the stripper 22 and the die 21a contact each other with the pouch film 134 interposed therebetween. Then, the stripper 22 presses and fixes the pouch film 134 from above (S303). When the stripper 22 fixes the pouch film 134, heat is generated from the first heating wire 231 included in the punch 23, and the punch 23 descends to stretch the pouch film 134 (S304) ). At this time, heat may also be generated from the second heating wire 212 included in the die 21a.

As the pouch film 134 is stretched, paraffin 3 is discharged through the paraffin channel 213a formed in at least one edge or corner of the molded part 211 (S305). At this time, according to another embodiment of the present invention as described above, paraffin channels 213a are formed at each corner of the molded part 211. Accordingly, the paraffin 3 may be coated on the edge of the cup portion 133 to form a protective film.

In addition, when the paraffin 3 is discharged through the paraffin flow path 213a, the pressure inside the molding part 211 is reduced through the pressure flow path 214a formed in at least one corner or corner of the molding part 211. It may be possible. At this time, according to another embodiment of the present invention, pressure passages 214a are formed at each corner of the molded portion 211. Therefore, energy efficiency can be increased by minimizing the curvature of the corner of the cup portion 133, and the occurrence of wrinkles or cracks in the cup portion 133 can be prevented.

However, even according to another embodiment of the present invention, the paraffin flow path 213a and the pressure flow path 214a are formed at different positions. Thereby, when the pressure passage 214a sucks in surrounding air, the discharged paraffin 3 may not be sucked in.

Through the process described above, the pouch film 134 may be molded to form the cup portion 133 in the pouch (S306).

A person skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims described below rather than the detailed description above, and various embodiments derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

1: Secondary battery 2: Pouch forming device
10: electrode assembly 11: electrode tab
12: Electrode lead 13: Battery case
14: insulating part 21: die
22: Stripper 23: Punch
111: anode tab 112: cathode tab
121: positive lead 122: negative lead
131: upper pouch 132: lower pouch
133: Cup portion 134: Pouch film
211: forming part 212: second heating wire
213: paraffin flow path 214: pressure flow path
221: Penetrating part 231: First heating wire
1331: accommodation space 1341: gas barrier layer
1342: Surface protection layer 1343: Sealant layer

Claims (19)

A die on which a pouch film is seated on the upper surface and including a molded portion recessed inward from the upper surface;
a punch disposed above the forming unit and descending to insert and mold the pouch film into the forming unit;
It includes a first heating wire included inside the punch and generating heat,
The die is,
An opening is formed in an inner wall of at least one corner or corner portion of the molding unit, and includes a paraffin channel for discharging paraffin through the opening when the pouch film is molded. According to paragraph 1,
The die is,
The pouch forming device further includes a pressure flow path formed at at least one edge or corner of the molding portion to reduce the pressure of the molding portion when the pouch film is molded. According to paragraph 2,
The paraffin flow path and the pressure flow path are,
Pouch forming devices formed at different positions. According to paragraph 3,
The paraffin flow path is,
Formed at each corner of the molded part,
The pressure flow path is,
A pouch forming device formed at each corner of the molding part. According to paragraph 2,
The pressure flow path is,
Pouch forming device, reducing pressure from 30 to 60 kpa. According to clause 5,
The pressure flow path is,
Pouch forming device, reducing pressure from 40 to 50 kpa. According to paragraph 1,
The first heating wire is,
A pouch forming device that generates heat having a temperature of 60 to 120 °C. In clause 7,
The first heating wire is,
A pouch forming device that generates heat having a temperature of 80 to 100° C. According to paragraph 1,
A pouch forming device further comprising a second heating wire included inside the die and generating heat. According to clause 9,
The second heating wire is,
A pouch forming device that generates heat having a temperature of 60 to 120 °C. According to clause 10,
The second heating wire is,
A pouch forming device that generates heat having a temperature of 80 to 100° C. According to paragraph 1,
A pouch forming device further comprising a dispenser for injecting the paraffin into the paraffin channel. According to clause 12,
A pouch forming device further comprising a paraffin tank that stores the paraffin and supplies the paraffin to the dispenser. According to paragraph 1,
A pouch forming device further comprising a stripper disposed above the die, descending to come into contact with the die with the pouch film interposed therebetween, and fixing the pouch film. Seating the pouch film on the upper surface of the die;
A punch disposed above the molding portion recessed inward from the upper surface of the die is lowered, and heat is generated from a first heating wire included in the punch;
Discharging paraffin through a paraffin channel having an opening formed in an inner wall of at least one corner or corner portion of the molding part; and
A pouch forming method comprising forming a cup portion on the pouch film. According to clause 15,
In the step of discharging the paraffin,
A pouch forming method in which the pressure of the molded portion is reduced through a pressure channel formed in at least one edge or corner of the molded portion. According to clause 15,
In the step of discharging the paraffin,
A pouch forming method of injecting the paraffin into the paraffin channel using a dispenser. According to clause 17,
The dispenser is,
A pouch forming method of receiving the paraffin from a paraffin tank storing the paraffin and injecting the paraffin into the paraffin channel. According to clause 15,
In the step of generating heat from the first heating wire,
A pouch forming method in which heat is also generated from the second heating wire included in the die.