阅读说明：本技术 袋形成设备和方法 (Bag forming apparatus and method ) 是由 郑太轸 崔恒準 朴根何 具滋训 表廷官 于 2018-12-06 设计创作，主要内容包括：为了解决问题,根据本发明实施方式的袋形成设备包括：从顶表面向内凹入形成有成形空间的模具；将所述成形空间分隔成第一成形空间和第二成形空间的分隔壁；脱模件,所述脱模件设置在所述模具上方,并且当袋膜安置在所述模具的顶表面上时,所述脱模件下降,以隔着所述袋膜接触所述模具,从而固定所述袋膜；和电磁力产生部分,所述电磁力产生部分设置在所述成形空间上方并且产生电磁力,从而向所述成形空间施加电磁力。(To solve the problem, a bag forming apparatus according to an embodiment of the present invention includes: a mold recessed inward from the top surface to form a forming space; a partition wall dividing the forming space into a first forming space and a second forming space; a demolding member disposed above the mold, and lowered to contact the mold across the bag film when the bag film is seated on the top surface of the mold, thereby fixing the bag film; and an electromagnetic force generating part disposed above the forming space and generating an electromagnetic force to apply the electromagnetic force to the forming space.)

1. A bag forming apparatus comprising:

a mold recessed inward from the top surface to form a forming space;

a partition wall dividing the forming space into a first forming space and a second forming space;

a demolding member disposed above the mold, and lowered to contact the mold across the bag film when the bag film is seated on the top surface of the mold, thereby fixing the bag film; and

an electromagnetic force generating part disposed above the forming space and generating an electromagnetic force, thereby applying the electromagnetic force to the forming space.

2. The pouch forming apparatus as defined in claim 1, wherein the electromagnetic force generating portion is disposed above the first forming space.

3. A bag forming apparatus according to claim 2, wherein the electromagnetic force generating portion applies the electromagnetic force to the first forming space and then moves above the second forming space.

4. A bag forming apparatus according to claim 2, wherein the electromagnetic force generating portion is further provided above the second forming space.

5. The pouch forming apparatus as defined in claim 1, wherein the dividing wall has a thickness of 0.1mm to 3 mm.

6. A pouch forming apparatus as defined in claim 5, wherein the dividing wall has a thickness of 1mm to 2 mm.

7. The bag forming apparatus as claimed in claim 1, wherein the ejector contacts only a peripheral portion of the forming space across the bag film, thereby fixing the bag film.

8. The pouch forming apparatus of claim 1, wherein the dividing wall has an upwardly projecting curved surface.

9. A method of forming a bag comprising:

a setting step of setting a bag film on a top surface of a mold so as to cover an open end of a forming space recessed inward from the top surface of the mold and partitioned into a plurality of spaces by partition walls;

a demolding part descending step of descending a demolding part arranged above the mold;

a fixing step of fixing the bag film to the mold release member; and

a forming step of generating an electromagnetic force at an electromagnetic force generating portion provided above the forming space to apply the electromagnetic force to the forming space, so that a first cup-shaped portion and a second cup-shaped portion are respectively drawn in the bag film along the first forming space and the second forming space.

10. The pouch forming method as defined in claim 9, wherein the electromagnetic force generating part is disposed above the first forming space.

11. The method of forming a bag of claim 10, wherein the forming step comprises:

a step of causing the electromagnetic force generating portion to apply an electromagnetic force to the first forming space;

a step of drawing the first cup-shaped portion in the bag film;

a step of moving the electromagnetic force generating part to an upper side of the second forming space;

a step of causing the electromagnetic force generating portion to apply an electromagnetic force to the second forming space; and

a step of drawing the second cup-shaped portion in the bag film.

12. The pouch forming method as defined in claim 10, wherein the electromagnetic force generating part is further provided above the second forming space.

13. The pouch forming method as claimed in claim 12, wherein in the step of applying the electromagnetic force, the electromagnetic force generating part applies the electromagnetic force to the first forming space and the second forming space at the same time.

14. A pouch forming method as defined in claim 9, wherein the partition wall has a thickness of 0.1mm to 3 mm.

15. A pouch forming method as defined in claim 14, wherein the partition wall has a thickness of 1mm to 2 mm.

16. The pouch forming method according to claim 9, wherein in the fixing step, the releasing member contacts only a peripheral portion of the forming space across the pouch film, thereby fixing the pouch film.

Technical Field

Cross Reference to Related Applications

This application claims the benefit of priority from korean patent application No. 10-2018-0011293, filed on 30/1/2018, which is hereby incorporated by reference in its entirety.

Background

In general, secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, lithium ion batteries, and lithium ion polymer batteries. Such secondary batteries are being applied to small-sized products such as digital cameras, P-DVDs, MP3P, mobile phones, PDAs, Portable Game devices (Portable Game devices), Power tools (Power tools), electric bicycles (E-bike), and the like; and large products requiring high power such as electric vehicles and hybrid vehicles; an energy storage device for storing excess electrical power or renewable energy; and a backup energy storage device.

Such secondary batteries are classified into Pouch Type (Pouch Type) secondary batteries and Can Type (Can Type) secondary batteries according to the material of a case in which an electrode assembly is received. In a Pouch Type (Pouch Type) secondary battery, an electrode assembly is received in a Pouch made of a flexible polymer material. Further, in a Can Type (Can Type) secondary battery, an electrode assembly is accommodated in a case made of a metal or plastic material.

Generally, a pouch, which is a case of a pouch type secondary battery, is manufactured by Drawing (Drawing) a cup-shaped portion in a pouch film made of a flexible material. Further, the electrode assembly and the electrolyte are received in the receiving space of the cup portion, and then the cup portion is sealed to manufacture the secondary battery.

The bag comprises an upper bag and a lower bag. One side of the upper bag and one side of the lower bag may be connected to each other. Here, two cup portions may be formed in the upper and lower pockets, respectively. To manufacture the bag, first two cup-shaped portions are drawn at positions adjacent to each other on the bag film, and then the bag film is bent so that the two cup-shaped portions face each other.

In order to improve the energy efficiency of the secondary battery, it is necessary to reduce unnecessary volume as a whole. For this reason, the upper bag and the lower bag must be connected to each other to reduce the area of the non-sealing portion where sealing is not performed. Here, the width of the non-sealing portion is proportional to the distance between the two cup portions. Therefore, when two cup portions are formed simultaneously in the pouch film, the two cup portions must be formed such that the distance between them is reduced.

Fig. 1 is a schematic view showing a state before a bag film 435 is drawn by using a bag forming apparatus 3 according to the related art.

According to the related art, the bag film 435 is placed on the mold, and the demolding member 32 fixes the bag film 435. Then, the bag film 435 is stretched by using the punch 33 to perform drawing. Here, when the two cup-shaped portions 433 are formed, as shown in fig. 1, a partition wall 312 that partitions the forming space of the mold 31 into two spaces is provided. Thus, the distance between the first cup-shaped portion 4331 and the second cup-shaped portion 4331 is determined by the thickness t1 of the partition wall 312. However, since a physical force is applied to the bag film 435 in the drawing method, the bag film 435 may be broken at a portion thereof located on the partition wall 312.

Fig. 2 is a schematic view illustrating a process of drawing a pouch film 435 by using a pouch forming apparatus 3 according to the related art, and fig. 3 is a perspective view of a secondary battery 4 including a pouch formed by using the pouch forming apparatus 3.

In order to prevent the above problem from occurring, as shown in fig. 2, the ejector 32 contacts the top surface of the partition wall 312 and the peripheral portion of the forming space via the bag film 435, thereby fixing the bag film 435. However, the top surface of the partition wall 312 must be secured over a predetermined area so that the release member 32 contacts the top surface of the partition wall 312. Here, there is a limit to reducing the thickness t1 of the partition wall 312 to at least 5mm or less. That is, as shown in fig. 3, there is a limit to reduce the width D1 of the non-sealing portion 4342 to 2.5mm or less. In addition, the top surface of the partition wall 312 must be flat so that the release member 32 contacts the partition wall 312. Thus, there is still a possibility that the bag film 435 is broken.

Disclosure of Invention

Technical problem

An object to be achieved by the present invention is to provide a bag forming apparatus and method that reduce the area of a non-seal portion formed when a bag film formed with two cup portions is bent.

The object of the present invention is not limited to the above object but other objects not described herein will be clearly understood by those skilled in the art from the following description.

Technical scheme

In order to solve the above-described problems, a bag forming apparatus according to an embodiment of the present invention includes: a mold recessed inward from the top surface to form a forming space; a partition wall dividing the forming space into a first forming space and a second forming space; a demolding member disposed above the mold, and lowered to contact the mold across the bag film when the bag film is seated on the top surface of the mold, thereby fixing the bag film; and an electromagnetic force generating part disposed above the forming space and generating an electromagnetic force to apply the electromagnetic force to the forming space.

The electromagnetic force generating part may be disposed above the first forming space.

The electromagnetic force generating part may apply an electromagnetic force to the first forming space and then move above the second forming space.

The electromagnetic force generating part may be further disposed above the second forming space.

The partition wall may have a thickness of 0.1mm to 3 mm.

The demolding member may contact only a peripheral portion of the forming space across the bag film, thereby fixing the bag film.

The partition wall may have a curved surface protruding upward.

In order to solve the above problems, a pouch forming method according to an embodiment of the present invention includes: a setting step of setting a bag film on a top surface of a mold so as to cover an open end of a forming space recessed inward from the top surface of the mold and partitioned into a plurality of spaces by partition walls; a demolding part descending step of descending a demolding part arranged above the mold; a fixing step of fixing the bag film to the mold release member; and a forming step of generating an electromagnetic force at an electromagnetic force generating portion provided above the forming space to apply the electromagnetic force to the forming space, so that a first cup-shaped portion and a second cup-shaped portion are respectively drawn in the bag film along the first forming space and the second forming space.

The electromagnetic force generating part may be disposed above the first forming space.

The forming step may include: a step of causing the electromagnetic force generating portion to apply an electromagnetic force to the first forming space; a step of drawing the first cup-shaped portion in the bag film; a step of moving the electromagnetic force generating part to an upper side of the second forming space; a step of causing the electromagnetic force generating portion to apply an electromagnetic force to the second forming space; and a step of drawing out the second cup-shaped portion in the bag film.

The electromagnetic force generating part may be further disposed above the second forming space.

In the applying of the electromagnetic force, the electromagnetic force generating part may apply the electromagnetic force to the first forming space and the second forming space at the same time.

The partition wall may have a thickness of 0.1mm to 3 mm.

In the fixing step, the release member may contact only a peripheral portion of the forming space across the pouch film, thereby fixing the pouch film.

Specific details of other embodiments are included in the detailed description and the accompanying drawings.

Advantageous effects

Embodiments of the present invention can have at least the following effects.

Since the non-sealing portion is manufactured to have a width of 1mm or less, the area of the non-sealing portion can be reduced, thereby improving energy efficiency.

When the mold release member contacts the mold across the bag film to fix the bag film, it is sufficient to contact the peripheral portion of the forming space without contacting the partition wall.

The effects of the present invention are not limited by the foregoing description, and therefore, more various effects are referred to in the present application.

Drawings

Fig. 1 is a schematic view showing a state before a bag film is drawn by using a bag forming apparatus according to the related art.

Fig. 2 is a schematic view illustrating a process of drawing a bag film by using a bag forming apparatus according to the related art.

Fig. 3 is a perspective view of a secondary battery including a pouch formed by using a pouch forming apparatus.

Fig. 4 is an assembly view of a pouch-type secondary battery including a battery case formed by using the pouch forming apparatus according to the embodiment of the present invention.

Fig. 5 is a sectional view of a pouch film for a secondary battery formed by using the pouch forming apparatus according to the embodiment of the present invention.

Fig. 6 is a flowchart illustrating a pouch forming method according to an embodiment of the present invention.

Fig. 7 is a schematic view illustrating a state in which a bag film is seated on a top surface of a mold of a bag forming apparatus according to an embodiment of the present invention.

Fig. 8 is a schematic diagram illustrating a state in which the electromagnetic force generating part of the bag forming apparatus forms the first cup-shaped part according to the embodiment of the present invention.

Fig. 9 is a schematic view illustrating a state in which an electromagnetic force generating part of the bag forming apparatus moves from an upper side of the first forming space to an upper side of the second forming space according to the embodiment of the present invention.

Fig. 10 is a schematic view illustrating a state in which the electromagnetic force generating portion of the bag forming apparatus forms the second cup portion, according to the embodiment of the present invention.

Fig. 11 is a perspective view of a secondary battery including a pouch formed by using the pouch forming apparatus according to an embodiment of the present invention.

Fig. 12 is a flowchart illustrating a pouch forming method according to another embodiment of the present invention.

Fig. 13 is a schematic view illustrating a state in which a bag film is seated on a top surface of a mold of a bag forming apparatus according to another embodiment of the present invention.

Fig. 14 is a schematic view illustrating a state in which the electromagnetic force generating portion of the bag forming apparatus forms the first cup-shaped portion and the second cup-shaped portion, according to another embodiment of the present invention.

Detailed Description

Advantages and features of the present disclosure and methods of accomplishing the same will be set forth in the embodiments described below with reference to the accompanying drawings. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Furthermore, the invention is limited only by the scope of the claims. Like reference numerals refer to like elements throughout.

Unless the terms used in the present invention are defined differently, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. Furthermore, unless clearly and clearly defined in the specification, terms defined in a general dictionary should not be ideally or excessively interpreted to have formal meanings.

In the following description, technical terms are used to explain specific exemplary embodiments only, and do not limit the present invention. In this application, singular terms may include plural unless specifically mentioned. The meaning of "comprising" and/or "comprising" does not exclude other elements than those mentioned.

Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings.

Fig. 4 is an assembly view of the pouch type secondary battery 2, the pouch type secondary battery 2 including a battery case 23 formed by using the pouch forming apparatus 1 according to the embodiment of the present invention.

In general, to manufacture the lithium secondary battery 2, first, a slurry in which an electrode active material, a binder, and a plasticizer are mixed is applied to a positive electrode current collector and a negative electrode current collector to manufacture a positive electrode and a negative electrode. Then, the positive electrode and the negative electrode are laminated on both sides of a Separator to form the electrode assembly 20. Further, the electrode assembly 20 is accommodated in the battery case 23, and an electrolyte is injected in the battery case 23. Then, the battery case 23 is sealed.

As shown in fig. 4, the Electrode assembly 20 includes an Electrode Tab (Electrode Tab) 21. The electrode tab 21 is connected to each of the positive and negative electrodes of the electrode assembly 20 to protrude to the outside of the electrode assembly 20, thereby providing a path for electrons to move between the inside and the outside of the electrode assembly 20. The electrode current collector of the electrode assembly 20 is composed of a portion coated with the slurry and a terminal end to which the slurry is not applied, i.e., an uncoated portion. Further, the electrode tab 21 may be formed by cutting the uncoated portion or connecting a separate conductive member to the uncoated portion by ultrasonic welding. As shown in fig. 4, the electrode tabs 21 may protrude from one side of the electrode assembly 20 in the same direction, but the present invention is not limited thereto. For example, the electrode tabs may protrude in different directions from each other.

In the Electrode assembly 20, an Electrode Lead (Electrode Lead)22 is connected to the Electrode tab 21 by Spot welding (Spot). Further, a portion of the electrode lead 22 is surrounded by the insulating portion 24. The insulating part 24 may be provided to be confined in a sealing part 2341 (see fig. 11) in which the upper and lower pockets 231 and 232 are thermally fused, thereby allowing the electrode leads 22 to be coupled to the battery case 23. In addition, the current generated from the electrode assembly 20 may be prevented from flowing to the battery case 23 through the electrode leads 22, and the sealing of the battery case 23 may be maintained. Accordingly, the insulating portion 24 may be made of a nonconductive nonconductor having a nonconductive property. In general, although an insulating tape easily attached to the electrode lead 22 and having a relatively thin thickness is mainly used as the insulating portion 24, the present invention is not limited thereto. For example, various members may be used as the insulating portion 14 as long as the members can insulate the electrode leads 22.

The electrode leads 22 may extend in the same direction or in different directions from each other according to the formation positions of the positive and negative electrode tabs 211 and 212. The positive electrode lead 221 and the negative electrode lead 222 may be made of different materials from each other. That is, the positive electrode lead 221 may be made of the same material as the positive electrode collector, i.e., an aluminum (Al) material, and the negative electrode lead 222 may be made of the same material as the negative electrode collector, i.e., a copper (Cu) material or a copper material coated with nickel (Ni). Further, the portion of the electrode lead 22 protruding to the outside of the battery case 23 may be provided as a terminal portion and may be electrically connected to an external terminal.

In the pouch-type secondary battery 2 according to the embodiment of the present invention, the battery case 23 may be a pouch made of a flexible material. Hereinafter, a case where the battery case 23 is a pouch will be described. Further, the battery case 23 accommodates the electrode assembly 20 such that a portion, i.e., a terminal portion, of the electrode lead 22 is exposed, and then the battery case 23 is sealed. As shown in fig. 4, the battery case 23 includes an upper pocket 231 and a lower pocket 232. A cup portion 233 is formed in each of the upper and lower pockets 231 and 232 to provide a receiving space 2333 in which the electrode assembly 20 is received. Here, the upper pouch 231 and the lower pouch 232 may be bent relative to each other to prevent the electrode assembly 20 from being separated to the outside of the battery case 23. Here, as shown in fig. 4, one side of the upper pouch 231 and one side of the lower pouch 232 are connected to each other, but not limited thereto. For example, the upper and lower pockets 231 and 232 may be manufactured differently, i.e., may be manufactured separately to be separated from each other.

When the electrode lead 22 is connected to the electrode tab 21 of the electrode assembly 20, and the insulating part 24 is formed on a portion of the electrode lead 22, the electrode assembly 20 is received in the receiving space 2333, and the upper and lower pockets 231 and 232 are covered opposite to each other. Further, when an electrolyte is injected and a sealing part 2341 (see fig. 11) formed on the edge of each of the upper and lower pouches 231 and 232 is sealed, the secondary battery 2 is manufactured.

Fig. 5 is a sectional view of a pouch film 235 for a secondary battery formed by using the pouch forming apparatus 1 according to the embodiment of the present invention.

Generally, the battery case 23 is manufactured by performing Drawing (Drawing) on the pouch film 235. That is, the pouch film 235 is stretched to form the cup portion 233, thereby manufacturing the battery case 23. The pouch film 235 includes: a Gas Barrier Layer (Gas Barrier Layer)2351, a Surface protective Layer (Surface protective Layer)2352, and a Sealant Layer (Sealant Layer) 2353.

The gas barrier layer 2351 may ensure mechanical strength of the battery case 23, block the entrance and exit of gas or moisture outside the secondary battery, and prevent leakage of the electrolyte. Typically, the gas barrier layer 2351 comprises a metal. In particular, aluminum Foil (Al Foil) is mainly used for the gas barrier layer 2351. Aluminum can ensure a predetermined level or more of mechanical strength while being lightweight. Therefore, aluminum can ensure supplement and heat dissipation to the electrochemical properties of the electrode assembly 20 and the electrolyte.

The surface protection layer 2352 is made of a polymer and is disposed at the outermost layer to protect the secondary battery 2 from external friction and impact and also to electrically insulate the electrode assembly 20 from the outside. Here, the outermost layer means a direction opposite to the direction in which the electrode assembly 20 is disposed, that is, an outward direction with reference to the gas barrier layer 2351. A polymer such as Nylon (Nylon) resin or polyethylene terephthalate (PET) having abrasion resistance and heat resistance is mainly used for the surface protective layer 2352. Further, the surface protection layer 2352 may have a single layer structure made of one material or a composite layer structure in which two or more materials form layers, respectively.

The sealant layer 2353 is made of polymer and disposed at the innermost layer to directly contact the electrode assembly 20. When the pouch film 235 having the laminate structure as described above is drawn (Drawing) by using a punch or the like, the pouch-type battery case 23 may be manufactured while a portion thereof is stretched to form the cup-shaped portion 233 of the receiving space 2333 having a pouch shape. In addition, when the electrode assembly 20 is received in the receiving space 2333, an electrolyte is injected. Thereafter, when the upper pouch 231 and the lower pouch 232 are brought into contact with each other and thermocompression is performed on the sealing part 2341 (see fig. 11), the sealant layers 2353 may be adhered to each other, thereby sealing the battery case 23. Here, since the sealant layer 2353 directly contacts the electrode assembly 20, the sealant layer 2353 must have insulation properties. Further, since the sealant layer 2353 contacts the electrolyte, the sealant layer 2353 must have corrosion resistance. Further, since the inside of the battery case 23 is completely sealed to prevent the material from moving between the inside and the outside of the battery case 23, high sealability must be achieved. That is, the sealing portion 2341 in which the sealant layers 2353 are adhered to each other should have excellent adhesive strength. In general, a polyolefin-based resin such as polypropylene (PP) or Polyethylene (PE) may be mainly used for the sealant layer 2353. Polypropylene (PP) is excellent in mechanical properties such as tensile strength, rigidity, surface hardness, abrasion resistance, and heat resistance, and chemical properties such as corrosion resistance, and is therefore mainly used for the sealant layer 2353. In addition, the sealant layer may be made of coated Polypropylene (capped Polypropylene) or Polypropylene-butylene-ethylene terpolymer. Further, the sealant layer 2353 may have a single layer structure made of one material or a composite layer structure in which two or more materials form layers, respectively.

Fig. 6 is a flowchart illustrating a pouch forming method according to an embodiment of the present invention.

The bag forming method according to an embodiment of the present invention includes: a setting step (S601 and S1201) of setting the bag film 235 on the top surface of the mold 11 to cover the open end of the forming space 111, the forming space 111 being recessed inward from the top surface of the mold 11 and partitioned into a plurality of spaces by the partition walls 112; a mold release lowering step (S602 and S1202) of lowering a mold release member 12 provided above a mold 11; a fixing step (S603 and S1203) of fixing the bag film 235 to the mold release 12; and a forming step (S604 to S609 and S1204 to S1206) of generating an electromagnetic force by the electromagnetic force generating portion 13 disposed above the forming space 111 to apply the electromagnetic force to the forming space 111, so that the first cup-shaped portion 2331 and the second cup-shaped portion 2332 are respectively drawn in the bag film 235 along the first forming space 1111 and the second forming space 1112. The partition wall 112 has a thickness t2 of 0.1mm to 3mm, preferably 1mm to 2 mm.

Therefore, according to the present invention, instead of physically shaping the bag film 235 by using a punch, applying an electromagnetic force to shape the bag film 235, the partition wall 112 between the two cup-shaped portions 233 has a very thin thickness, specifically, a thickness of 2mm or less. Therefore, since the non-sealing portion 2342 is manufactured such that the width D2 is reduced to 1mm or less, the area of the non-sealing portion 2342 can be reduced, thereby improving energy efficiency.

In particular, in the bag forming method according to the embodiment of the present invention, the forming step includes: a step of causing the electromagnetic force generating portion 13 to apply an electromagnetic force to the first forming space 1111 in a state where the electromagnetic force generating portion 13 is first disposed above the first forming space 1111; a step of drawing a first cup-shaped portion 2331 in the pouch film 235; a step of moving the electromagnetic force generating part 13 to an upper side of the second forming space 1112; a step of causing the electromagnetic force generating portion 13 to apply an electromagnetic force to the second forming space 1112; and a step of drawing a second cup-shaped portion 2332 in the pouch film 235.

Hereinafter, each step shown in fig. 6 will be described with reference to fig. 7 to 11.

Fig. 7 is a schematic view illustrating a state in which the bag film 235 is disposed on the top surface of the mold 11 of the bag forming apparatus 1 according to the embodiment of the present invention.

The bag forming apparatus 1 according to the embodiment of the present invention includes: a mold 11 recessed inward from the top surface to form a forming space 111; a partition wall 112 partitioning the forming space 111 into a first forming space 1111 and a second forming space 1112; a release member 12, the release member 12 being disposed above the mold 11, and when the bag film 235 is placed on the top surface of the mold 11, the release member 12 descends to contact the mold 11 across the bag film 235, thereby fixing the bag film 235; and an electromagnetic force generating part 13, the electromagnetic force generating part 13 being disposed above the forming space 111 to generate an electromagnetic force, thereby applying the electromagnetic force to the forming space 111.

The mold 11 provides a location where the bag film 235 of the object to be formed is placed. In order to then draw the bag film 235, the die 11 includes a forming space 111 formed recessed inward from the top surface. The bag film 235 must be stably seated on the top surface of the mold 11. Therefore, it is preferable that the remaining area of the mold 11 except the area where the forming space 111 is formed is flat and parallel to the ground. However, the present invention is not limited thereto. For example, various shapes such as a lattice pattern or fine irregularities may be formed on the top surface of the mold 11 in order to easily fix the bag film 235 later. To form the cup portion 233 in the pouch film 235, first, as shown in fig. 7, the pouch film 235 is placed on the top surface of the mold 11 (S601).

The forming space 111 may have a shape and size corresponding to the outer appearance of the cup portion 233 to be formed by forming the pouch film 235. Here, correspondence of shape and size may mean that even if the same or a specific difference exists, the difference is within a range of deviation. Therefore, if the cup portion 233 has a rectangular shape, the forming space 111 may also have a rectangular shape. If the cup-shaped portion 233 has a circular shape, the forming space 111 may also have a circular shape. When the bag film 235 is placed on the top surface of the mold 11, the bag film 235 is placed to cover the open end of the forming space 111, so that the forming space 111 is disposed in an area where the cup portion 233 will be formed later.

The partition wall 112 divides the forming space 111 into a first forming space 1111 and a second forming space 1112. According to the embodiment of the invention, since it is necessary to form the plurality of cup portions 233 in the pouch film 235, the forming space 111 may be divided into a plurality of spaces by the partition walls 112. Here, the partition wall 312 may have a very thick thickness of 5mm or more according to the related art. However, the partition wall 112 according to the present invention may have a thickness t2 of 0.1mm to 3mm, preferably 1mm to 2 mm. Further, since the two cup-shaped portions as the pockets of the battery case 230 are bent facing each other, the non-sealing portion 2342 (see fig. 11) may have a width D2 corresponding to about half of the distance between the two cup-shaped portions 233. Further, the thickness t2 of the partition wall 112 has a length corresponding to the distance between the two cup portions 233. Therefore, since the partition wall 112 has the thickness t2 as described above, the non-sealing portion 2342 can be manufactured with the width D2 reduced to 1.5mm or less, particularly 1mm or less. That is, according to the related art, the non-sealing portion 4342 has a width of at least 2.5 mm. According to the present invention, the non-sealing portion 2342 may have a width D2 of 1.5mm or less, and the area of the non-sealing portion 2342 is reduced by 40% or more, thereby improving energy efficiency.

The release member 12 is disposed above the mold 11 to fix the bag film 235. As shown in fig. 7, when the bag film 235 is seated on the top surface of the mold 11, the demolding member 12 is lowered (S602). Further, the mold release 12 contacts the mold 11 through the bag film 235 and presses the bag film 235 from above, thereby fixing the bag film 235 (S603). Here, the fact that the mold release 12 contacts the mold 11 through the bag film 235 means that these members do not directly contact each other, but indirectly contact each other through the bag film 235. When the cup-shaped portion 233 is formed later, the release member 12 uniformly presses the bag film 235, thereby uniformly dispersing the stretching force applied to the bag film 235. As a result, when the pouch film 235 is fixed, the bottom surface of the mold release 12 contacts the top surface of the pouch film 235. Thus, the stripper member 12 may have a substantially flat bottom surface. However, the present invention is not limited thereto. For example, in order to more easily fix the bag film 235, various shapes such as a lattice pattern or fine irregularities may be formed on the bottom surface of the mold release member 12.

As described above, in the bag drawing method according to the related art, since the physical force is applied to the bag film 435 by using the punch 33, the bag film 435 may be broken at the portion thereof located on the partition wall 312. In order to prevent the above problem from occurring, the release member 32 must contact the partition wall 312 and the peripheral portion of the forming space 111 via the bag film 435 to fix the bag film 435. However, the top surface of the partition wall 312 must be secured over a predetermined area so that the release member 32 contacts the partition wall 312. Here, there is a limit to reducing the thickness t1 of the partition wall 312 to at least 5mm or less.

However, in the pouch forming method according to the embodiment of the present invention, since the electromagnetic force is applied instead of the physical force applied through the punch, the rupture of the pouch film 235 does not occur at the portion of the pouch film 235 located on the partition wall 112. Therefore, the partition wall 112 can be very thin since the release member 12 does not need to contact the partition wall 112 to fix the bag film 235. That is, the mold release member 12 according to the embodiment of the present invention may contact only the peripheral portion of the forming space 111 through the bag film 235 without contacting the partition wall 112. Therefore, the pouch film 235 may not be necessarily fixed. Furthermore, since the release member 12 does not need to contact the partition wall 112 to fix the bag film 235, the partition wall 112 does not need to have a flat top surface. Therefore, in order to more effectively prevent the bag film 235 from being broken, the partition wall 112 may have a curved top surface protruding upward. Here, the curved surface may have a semicircular shape when viewed from the front. In this case, it is preferable that the curved surface has a radius of curvature corresponding to half of the thickness t2 of the partition wall 112.

Fig. 8 is a schematic view illustrating a state in which the electromagnetic force generating part 13 of the bag forming apparatus 1 forms the first cup-shaped part 2331, according to the embodiment of the present invention.

The electromagnetic force generating part 13 may be disposed above the forming space 111 to apply an electromagnetic force to the forming space 111, thereby stretching the bag film 235. Accordingly, the cup portion 233 may be formed in the pouch film 235 to manufacture a pouch. A penetrating portion is formed substantially at the center of the bottom surface of the ejector 12. Further, the electromagnetic force generating portion 13 may be provided to pass through the releasing member 12 via a penetrating portion. However, it is not limited thereto. For example, the electromagnetic force generating portion 13 may be provided on a bottom surface of a supporting portion provided inside the unmolding member 12 to support the unmolding member 12. That is, the electromagnetic force generating part 13 may be disposed at various positions as long as the electromagnetic force generating part 13 is disposed above the forming space 111.

The electromagnetic force generating part 13 according to the embodiment of the present invention may move between the upper side of the first forming space 1111 and the upper side of the second forming space 1112. Accordingly, the electromagnetic force generating part 13 may be disposed above the first forming space 1111 to apply the electromagnetic force to the first forming space 1111 and then move to an upper side of the second forming space 1112. Here, a moving part for moving the electromagnetic force generating part 13 and a control part for controlling the electromagnetic force generating part 13 may be further provided. The moving part may comprise a general motor and a rail. When the motor is driven, the electromagnetic force generating part 13 may move along the rail. Thus, the track may extend all the way from the upper side of the first forming space 1111 to the upper side of the second forming space 1112.

The electromagnetic force generating part 13 receives a current from the outside to generate an electromagnetic force, to this end, the electromagnetic force generating part 13 includes at least one coil, power is supplied from an external power supply device to the high-capacity capacitor, and a charge/discharge switch is operated by a control circuit such that a current attenuated in a very short time of 100 to 900? s is discharged through the capacitor to the coil, and thus, a variation of magnetic Flux (magnetic Flux) occurs in the coil, and an induced electromotive force is generated in the pouch film 235 located at an adjacent position, and particularly, since the pouch film 235 includes the gas blocking layer 2351 made of metal, an induced electromotive force is generated in the gas blocking layer 2351 of the pouch film 235.

[ equation 1]

This is called Faraday's Law. In equation 1, ε represents an induced electromotive force, Φ represents a magnetic flux, and t represents time.

In addition, an Induced Current (Induced Current) flows in the bag film 235 in a direction opposite to the direction of the supplied Current due to the Induced electromotive force. The Force applied to a conductor through which current flows in a magnetic field is called the Lorentz Force (Lorentz's Force). This force may become an electromagnetic force for shaping the bag film 235. That is, the induced current flows to the bag film 235, and the bag film 235 is shaped by receiving the lorentz force. The lorentz force is proportional to the magnitude of the induced current and is obtained from the following equation.

[ equation 2]

F＝Idl×B

In equation 2, I represents a current flowing through a conductor, dl represents a length of the conductor, B is a magnetic flux density, and F is a lorentz force. Further, a lorentz force is generated in a direction perpendicular to a plane defined by the length d1 of the conductor and the magnetic flux density B.

As shown in fig. 8, the electromagnetic force generating portion 13 is first disposed above the first forming space 1111 (S604) to generate an electromagnetic force, thereby applying the electromagnetic force to the first forming space 1111 (S605). Then, the first cup-shaped portion 2331 is drawn in the bag film 235 along the first forming space 1111 by an electromagnetic force (S606).

Fig. 9 is a schematic view illustrating a state in which the electromagnetic force generating part 13 of the bag forming apparatus 1 moves from the upper side of the first forming space 1111 to the upper side of the second forming space 1112 according to the embodiment of the present invention. Fig. 10 is a schematic view illustrating a state in which the electromagnetic force generating part 13 of the bag forming apparatus 1 forms the second cup-shaped portion 2332, according to the embodiment of the present invention.

After the first cup-shaped portion 2331 is formed in the bag film 235, as shown in fig. 9, the electromagnetic force generating portion 13 is moved from the upper side of the first forming space 1111 to the upper side of the second forming space 1112 (S607). Then, as shown in fig. 10, an electromagnetic force may be generated to apply the electromagnetic force to the second forming space 1112 (S608). Then, a second cup-shaped portion 2332 is drawn in the bag film 235 along the second forming space 1112 by an electromagnetic force (S609).

Fig. 11 is a perspective view of a secondary battery 2, the secondary battery 2 including a pouch formed by using the pouch forming apparatus 1 according to the embodiment of the present invention.

The pouch may be formed by the above-described method using the pouch forming apparatus 1 according to the embodiment of the present invention to manufacture the secondary battery 2. Therefore, as shown in fig. 11, the non-sealing portion 2342 of the secondary battery 2 may be manufactured to have a width D2 of 1.5mm or less, particularly 1mm or less, thereby reducing the area of the non-sealing portion 2342.

Fig. 12 is a flowchart illustrating a pouch forming method according to another embodiment of the present invention.

The electromagnetic force generating part 13 according to an embodiment of the present invention may move between an upper side of the first forming space 1111 and an upper side of the second forming space 1112. Accordingly, the electromagnetic force generating part 13 may be disposed above the first forming space 1111 to apply the electromagnetic force to the first forming space 1111 and then move to an upper side of the second forming space 1112.

However, in the bag forming apparatus 1a according to another embodiment of the present invention, the electromagnetic force generating portion 13a is disposed simultaneously above the first forming space 1111 and the second forming space 1112. Further, the electromagnetic force generating part 13a may apply the electromagnetic force to the first forming space 1111 and the second forming space 1112 at the same time. In the following, further embodiments of the present invention will be described with reference to the drawings, wherein like reference numerals refer to like elements throughout. This is for ease of description and is not intended to limit the scope of the claims.

Hereinafter, each step shown in the flowchart of fig. 12 will be described with reference to fig. 13 to 14.

Fig. 13 is a schematic view illustrating a state in which a bag film 235 is disposed on the top surface of the mold 11 of the bag forming apparatus 1a according to another embodiment of the present invention.

The bag forming apparatus 1a according to another embodiment of the present invention includes a mold 111, a partition wall 112, a releasing member 12, and an electromagnetic force generating portion 13 a. Furthermore, the partition wall 112 has a thickness t2 of 0.1mm to 3mm, preferably 1mm to 2 mm.

To form the cup portion 233 in the pouch film 235, first, as shown in fig. 13, the pouch film 235 is placed on the top surface of the mold 11 (S1201). Further, the demolding member 12 is lowered (S1202) to contact the mold 11 through the bag film 235 and press the bag film 235 from above to fix the bag film 235 (S1203).

Fig. 14 is a schematic view illustrating a state in which the electromagnetic force generating part 13a of the bag forming apparatus 1a forms the first cup-shaped part 2331 and the second cup-shaped part 2332 according to another embodiment of the present invention.

The electromagnetic force generating portion 13a according to another embodiment of the present invention is disposed above the first forming space 1111 and above the second forming space 1112 (S1204). Here, the electromagnetic force generating part 13a may be provided in plurality, and thus, disposed above each of the first forming space 1111 and the second forming space 1112. Alternatively, as shown in fig. 14, one electromagnetic force generating portion 13a may be integrally provided, and thus, simultaneously provided above the first forming space 1111 and the second forming space 1112.

Further, the electromagnetic force generating portion 13a simultaneously applies the electromagnetic force to the first forming space 1111 and the second forming space 1112 (S1205). Here, the simultaneous application of the electromagnetic force may include a case where the electromagnetic force is simultaneously applied to the first forming space 1111 and the second forming space 1112, and a case where the electromagnetic force is first applied to the first forming space 1111 and then applied to the second forming space 1112 at a predetermined time interval. Then, the first and second cup-shaped portions 2331 and 2332 are respectively drawn in the bag film 235 along the first and second forming spaces 1111 and 1112 by an electromagnetic force (S1206).

The pouch may be formed by the above-described method using the pouch forming apparatus 1a according to another embodiment of the present invention to manufacture the secondary battery 2. Therefore, as shown in fig. 11, the non-sealing portion 2342 of the secondary battery 2 may be manufactured to have a width D2 of 1.5mm or less, particularly 1mm or less, thereby reducing the area of the non-sealing portion 2342.

It will be appreciated by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the above disclosed embodiments are to be considered illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description and the exemplary embodiments described therein. Various modifications made within the scope of the claims of the present invention and their equivalents are considered to fall within the scope of the present invention.