KR20240100208A - Sealing method and sealing device - Google Patents

Abstract

In the sealing method for sealing a pouch with an electrode assembly located inside, the sealing method according to an embodiment of the present invention includes a first sealing step in which the sealing portion of the pouch is sealed at a first temperature and the sealing portion is sealed at a first temperature. It may include a second sealing step of sealing at a second temperature higher than the temperature.

Description

Sealing method and sealing device {SEALING METHOD AND SEALING DEVICE}

The present invention relates to a method and device for sealing a pouch for manufacturing a pouch-type secondary battery.

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 flexible polymer material. And, the can type accommodates the electrode assembly in a case made of materials such as metal or plastic.

A pouch-type secondary battery can be manufactured by performing press processing on a flexible pouch film laminate to form a cup portion, storing the electrode assembly in the receiving space inside the cup portion, and sealing the sealing portion. The pouch film laminate is formed of a plurality of layers in which a polymer film such as polyethylene terephthalate is laminated on one side of a metal gas barrier layer, and a sealant layer made of thermoplastic polyolefin resin is laminated on the other side. When the pouch-type battery case is sealed, the sealant layers may be thermally bonded to each other to form a sealing portion.

Recently, as the capacity of pouch-type secondary batteries progresses, the demand for pouches with excellent formability is increasing. When the gas barrier layer is formed thick to manufacture a pouch with good formability, there is a problem that the sealant layer does not easily melt when sealing the pouch-type battery case.

Conventionally, to solve this problem, a method of increasing the sealing temperature and/or sealing time was used to apply more heat when sealing the pouch-type battery case. However, when the sealing temperature is increased above 220°C, the base layer melts and deforms, and when the sealing time is increased, the tact time increases, leading to a decrease in productivity.

The problem to be solved by the present invention is to provide a sealing method and a sealing device that reduce the production time by controlling the sealing temperature without deforming the base layer and reducing the sealing time.

In the sealing method for sealing a pouch with an electrode assembly located inside, the sealing method according to an embodiment of the present invention includes a first sealing step in which the sealing portion of the pouch is sealed at a first temperature and the sealing portion is sealed at a first temperature. It may include a second sealing step of sealing at a second temperature higher than the temperature.

After the first sealing step, the second sealing step may be performed.

The first temperature may be 200°C or more and less than 220°C.

The second temperature may be 220°C or more and less than 230°C.

In the first sealing step, the moisture content of the sealing portion may be lowered.

In the first sealing step, the moisture content of the sealing portion may be lower than 1000 ppm.

The pouch includes a metal layer made of a metal material and a base layer formed on the outside of the metal side and made of a polymer material. In the first sealing step, the shape of the base layer can be maintained.

In the first sealing step and the second sealing step, the pouch may be sealed for 1 second to 2 seconds.

In the sealing device for sealing a pouch with an electrode assembly located inside, the sealing device according to another embodiment of the present invention includes a first sealing part that seals the sealing part of the pouch at a first temperature, and the sealing part is connected to the first temperature. It may include a second sealing part that seals at a second temperature higher than 1 temperature, and a transfer part that transfers the pouch sealed by the first sealing part to the second sealing part.

The first temperature may be 200°C or more and less than 220°C, and the second temperature may be 220°C or more and less than 230°C.

According to a preferred embodiment of the present invention, by adjusting the sealing temperature to seal the pouch without deforming the appearance of the pouch, sealing quality can be further secured and durability and lifespan of the pouch-type secondary battery can be improved.

According to a preferred embodiment of the present invention, the efficiency of the sealing process can be increased by reducing the production time by reducing the sealing time.

In addition to this, effects that can be easily predicted by a person skilled in the art from the configurations according to the preferred embodiment of the present invention may be included.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention includes the matters described in such drawings. It should not be interpreted as limited to only .
1 is a flowchart of a sealing method according to an embodiment of the present invention.
Figure 2 is a cross-sectional view of the pouch film.
Figure 3 is an exploded and assembled view of a pouch-type secondary battery.
Figure 4 is an image showing deformation in a comparative example.
Figure 5 is an image showing a pouch manufactured by a sealing method according to an embodiment of the present invention.
Figure 4 is a perspective view of a sealing device according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

In order to clearly explain the present invention, detailed descriptions of parts unrelated to the description or related known technologies that may unnecessarily obscure the gist of the present invention have been omitted, and reference signs are added to components in each drawing in this specification. In this regard, identical or similar reference signs are used to designate identical or similar components throughout the specification.

In addition, terms or words used in this specification and patent claims should not be construed as limited to their usual or dictionary meanings, and the inventor should appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

1 is a flowchart of a sealing method according to an embodiment of the present invention.

Referring to FIG. 1, according to the sealing method according to an embodiment of the present invention, a pouch (P) type secondary battery can be manufactured by sealing the pouch (P) at high temperature and high pressure with the electrode assembly (E) located inside. You can. In this case, through the sealing method, the pouch P can be sealed more effectively through a step-by-step sealing process. For example, according to the sealing method, the pouch P may be sealed at different sealing temperatures at each stage. Specifically, after the pouch P is first sealed at a certain temperature, the pouch P may be secondarily sealed at a higher temperature. According to this process sequence and characteristics, deformation that occurs in the process of lowering the moisture content inside the pouch (P) can be prevented. Additionally, by performing a high-temperature sealing process, sealing quality can be secured and the performance and lifespan of the manufactured secondary battery can be increased.

Before explaining the sealing method according to an embodiment of the present invention, when describing the pouch (P) used in manufacturing a secondary battery, FIG. 2 is a cross-sectional view of the pouch (P) film. As shown in FIG. 2, the pouch (P) film may include a base layer (P10), a metal layer (P20), and a sealant layer (P30).

The base layer (P10) is formed on the outermost layer of the pouch (P) film and can protect the secondary battery from friction and collision with the outside. The base layer P10 is made of a polymer material and can electrically insulate the electrode assembly E from the outside.

The thickness of the base layer (P10) may be 5 μm to 100 μm, specifically 7 μm to 70 μm, and more specifically 25 μm to 60 μm. When the thickness of the base layer (P10) satisfies the above range, external insulation is excellent, and the entire pouch (P) is not thick, so the energy density compared to the volume of the secondary battery can be excellent.

The base layer (P10) according to the present invention may have a composite film structure formed by layering two or more materials. In the composite membrane structure, an adhesive layer may be additionally formed between each layer.

Specifically, the base layer (P10) according to the present invention may include a first base layer (P101) and a second base layer (P102). In this case, the first base layer (P101) is a layer disposed on the outermost layer of the pouch (P) film, and the second base layer (P102) is a layer disposed between the first base layer (P101) and the metal layer (P20). You can. The first base layer (P101) and the second base layer (P102) may each be made of different materials and/or physical properties.

As described above, the first base layer (P101) may be a layer disposed on the outermost layer of the pouch (P) film. In this case, the first base layer (P101) may serve to prevent moisture from penetrating from the outside of the pouch (P).

The first base layer (P101) is made of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, and polyparallel. It may be made of one or more materials selected from the group consisting of phenylenebenzobisoxazole, polyarylate, Teflon, and glass fiber. Preferably, the first base layer (P101) may include a polyester-based film having abrasion resistance and heat resistance. For example, the first base layer (P101) may include at least one selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, but is not limited thereto.

The thickness of the first base layer (P101) may be 10 μm to 50 μm, specifically 10 μm to 40 μm, and more specifically 12 μm to 25 μm.

As described above, the second base layer (P102) may be a layer disposed between the first base layer (P101) and the metal layer (P20). In this case, the second base layer (P102) may play a role in improving the formability of the pouch (P).

The second base layer (P102) may include at least one of polyamide-based films such as nylon 6, nylon 6,6, nylon MXD6, and nylon 4,10, but is not limited thereto. Preferably, the second base layer (P10) may include nylon 6, and in this case, there is an advantage of improving the formability of the pouch (P) due to the excellent elongation characteristics of nylon 6.

The thickness of the second base layer (P102) may be 10 μm to 50 μm, specifically 10 μm to 40 μm, and more specifically 15 μm to 35 μm.

The second base layer (P102) may include metal oxide particles. The metal oxide particles are hydroxylated through a reaction with moisture introduced into the second base layer (P102), thereby removing moisture in the second base layer (P102). The metal oxide particles may include at least one selected from the group consisting of CaO, MnO, SrO, MgO, and ZnO. Preferably, the metal oxide particles may include at least one of CaO and MgO, which is advantageous for hydroxylation with moisture.

The metal layer (P20) is laminated between the base layer (P10) and the sealant layer (P30) to secure the mechanical strength of the pouch (P), block the entry of gas or moisture outside the secondary battery, and form a pouch (P) type. This is to prevent electrolyte leakage from the inside of the battery case.

The metal layer P20 may be formed of metal. For example, the metal layer P20 may be a metal thin film containing one or more metals selected from the group consisting of aluminum (Al), copper (Cu), stainless steel (SUS), nickel, titanium, and INVAR. , but is not limited to this.

According to one embodiment of the present invention, the metal layer P20 may be formed of an aluminum alloy thin film. When forming the metal layer (P20) using an aluminum alloy thin film, it is possible to secure mechanical strength above a certain level, while being light in weight, complementing the electrochemical properties caused by the electrode assembly (E) and electrolyte, and securing heat dissipation, etc. there is. The aluminum alloy thin film contains metal elements other than aluminum (Al), for example, iron (Fe), copper (Cu), chromium (Cr), manganese (Mn), nickel (Ni), magnesium (Mg), silicon ( One or more species selected from the group consisting of Si) and zinc (Zn) may be included.

The thickness of the metal layer (P20) may be 40 μm to 100 μm, specifically 50 μm to 90 μm, and more specifically 55 μm to 85 μm. When the thickness of the metal layer (P20) satisfies the above range, formability and gas barrier performance are excellent when molding the cup portion.

The sealant layer (P30) is used to completely seal the inside of the pouch (P) type battery case by being thermally bonded to each other at the sealing portion when the pouch (P) type battery case accommodating the electrode assembly (E) inside is sealed. . To this end, the sealant layer P30 may be formed of a material having excellent thermal adhesive strength.

The sealant layer (P30) may be formed of a material having insulation, corrosion resistance, and sealing properties. Specifically, the sealant layer (P30) is in direct contact with the electrode assembly (E) and/or electrolyte inside the pouch (P) type battery case, and therefore may be formed of a material having insulation and corrosion resistance. In addition, since the sealant layer (P30) must completely seal the inside of the pouch (P) type battery case and block material movement between the inside and outside, it must be formed of a material with high sealing properties (e.g., excellent thermal bonding strength). You can. To ensure such insulation, corrosion resistance, and sealing properties, the sealant layer P30 may be formed of a polymer material.

The sealant layer (P30) is made of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, and polyparaphenylene. It may be made of one or more materials selected from the group consisting of benzobisoxazole, polyarylate, Teflon, and glass fiber, and may preferably be made of polyolefin resin such as polypropylene (PP) and/or polyethylene (PE). there is. In this case, polypropylene consists of cast polypropylene (CPP), acid modified polypropylene (PPa), polypropylene-ethylene copolymer, and/or polypropylene-butylene-ethylene terpolymer. It can be.

When explaining the process of manufacturing a secondary battery using such a pouch (P), Figure 3 is an exploded and assembled view of a pouch (P) type secondary battery. As shown in FIG. 3, the pouch (P) can be folded with the electrode assembly (E) positioned inside to accommodate the electrode assembly (E).

For example, the pouch P may be drawn, formed, or stretched by a punch or the like. As a result, the pouch P is recessed on the inside so that the electrode assembly E can include a receiving cup portion and a terrace portion that is formed along the circumference of the cup portion and is sealed.

Specifically, when the pouch P is unfolded, both sides of the pouch P may be drawn and formed with a punch or the like so as to be symmetrical with respect to the folding line. In this case, with the electrode assembly (E) seated in the cup portion on one side of the pouch (P), the pouch (P) is folded along the folding line, and the electrode assembly (E) is accommodated inside the cup portion of the pouch (P). It can be.

The electrode assembly (E) may include a stacked cell (C) in which electrodes are stacked and a lead tab (T) electrically connected to both sides of the stacked cell (C). The pouch (P) can be sealed while accommodating the electrode assembly (E) so that the end of the lead tab (T), that is, the terminal portion of the lead tab (T) is exposed.

Through the sealing method according to an embodiment of the present invention, the peripheral portion of the cup portion, that is, the terrace portion, can be sealed by high temperature and high pressure. In other words, the terrace portion of the pouch (P) may serve as a sealing portion. The sealing method may include a first sealing step (S10) and a second sealing step (S20).

In the first sealing step (S10), the sealing portion of the pouch (P) may be sealed at a first temperature. For example, the first temperature may be 200°C or more and less than 220°C. After the first sealing step (S10), in the second sealing step (S20), the sealing portion of the pouch (P) may be sealed at a second temperature that is higher than the first temperature. For example, the second temperature may be 220°C or more and less than 230°C. That is, the sealing process may be applied primarily at a temperature of 200°C or more and less than 220°C to the same sealing part, and secondarily at a temperature of 220°C or more and less than 230°C.

If the first temperature is less than 200°C, the sealing quality of the pouch P may be deteriorated due to the low temperature. Additionally, when the second temperature is 230°C or higher, the first base layer (P101) begins to melt, which may cause the appearance of the pouch (P) to be deformed.

Below, the present invention will be described in more detail through specific examples. However, the following examples are only examples to aid understanding of the present invention and do not limit the scope of the present invention. It is obvious to those skilled in the art that various changes and modifications are possible within the scope and technical spirit of the present description, and it is natural that such changes and modifications fall within the scope of the appended patent claims.

Example 1

Cut the pouch (P) to 266mm

- Primary sealing for 2 seconds at 200℃ and 0.1MPa

- Secondary sealing for 2 seconds at 220℃ and 0.1MPa

Example 2

Cut the pouch (P) to 266mm

- Primary sealing for 2 seconds at 200℃ and 0.1MPa

- Secondary sealing for 1.5 seconds at 230℃ and 0.1MPa

Example 3

Cut the pouch (P) to 266mm

- Primary sealing for 1.8 seconds at 210℃ and 0.1MPa

- Secondary sealing for 2 seconds at 220℃ and 0.1MPa

Example 4

Cut the pouch (P) to 266mm

- Primary sealing for 2 seconds at 210℃ and 0.1MPa

- Secondary sealing for 1.5 seconds at 230℃ and 0.1MPa

Comparative Example 1

Cut the pouch (P) to 266mm

- Sealing for 3 seconds at 200℃ and 0.1MPa

Comparative Example 2

Cut the pouch (P) to 266mm

- Sealing for 2 seconds at 210℃ and 0.1MPa

Comparative Example 3

Cut the pouch (P) to 266mm

- Sealing for 3 seconds at 210℃ and 0.1MPa

Comparative Example 4

Cut the pouch (P) to 266mm

- Sealing for 2 seconds at 220℃ and 0.1MPa

Comparative Example 5

Cut the pouch (P) to 266mm

- Primary sealing for 1.8 seconds at 220℃ and 0.1MPa

- Secondary sealing for 2 seconds at 210℃ and 0.1MPa

Comparative Example 6

Cut the pouch (P) to 266mm

- Primary sealing for 1.5 seconds at 220℃ and 0.1MPa

- Secondary sealing for 2 seconds at 220℃ and 0.1MPa

Comparative Example 7

Cut the pouch (P) to 266mm

- Primary sealing for 1 second at 230℃ and 0.1MPa

- Secondary sealing for 1.5 seconds at 230℃ and 0.1MPa

For each pouch (P) sealed in Examples 1 to 4 and Comparative Examples 1 to 7, it was checked whether the sealing portion was deformed in appearance. In this case, it is possible to check whether the appearance of the sealing part has been deformed by visually checking for bubbles caused by moisture or pressing marks. In this case, the amount of moisture (ppm) contained in the pouch (P) before sealing and the amount of moisture (ppm) contained in the pouch (P) after the first sealing are measured to check the relationship between the appearance deformation and the moisture content (ppm). possible.

Additionally, for each pouch P sealed in Examples 1 to 4 and Comparative Examples 1 to 7, the sealing strength of the sealing portion was measured. In this case, the sealing strength can be measured by cutting the sealing part to a width of 15mm and then opening it in a T shape at a speed of 5mm/min. If a strength of more than 10kgf/15mm is measured, the sealing quality is considered excellent.

Finally, the process time (tact time) was measured for each pouch (P) sealed in Examples 1 to 4 and Comparative Examples 1 to 7. In other words, tact time may mean the time required for one process. Specifically, the process time (tact time) may be proportional to the speed of the conveyor belt when each pouch P undergoes several processes through a transport means such as a conveyor belt.

The above measured values are summarized in Table 1 below.

Pouch (P) moisture content (ppm) Appearance deformed sealing quality process time
(Tack time) Before sealing After 1st sealing Example 1 1300 650 VariantX O 2.0s or less Example 2 1500 850 VariantX O 2.0s or less Example 3 1700 450 VariantX O 2.0s or less Example 4 2200 920 VariantX O 2.0s or less Comparative Example 1 1600 - VariantX X 3.0s Comparative example 2 600 - VariantX X 2.0s or less Comparative example 3 1300 - VariantX O 3.0s Comparative Example 4 1100 - Variation O O 2.0s or less Comparative Example 5 1600 400 VariationO O 2.0s or less Comparative Example 6 1300 700 VariationO O 2.0s or less Comparative example 7 1200 800 VariationO O 2.0s or less

Figure 4 is an image showing deformation in a comparative example.

Referring to Table 1 and Figure 4, it can be seen that in Comparative Examples 4 to 7, appearance deformation occurred. That is, when the moisture content of the pouch (P) is 1000ppm or more and the sealing process is performed at a temperature of 220°C or higher, the moisture contained inside the pouch (P) may evaporate, causing appearance deformation. Specifically, due to the nature of the components of the second base layer (P102), moisture contained in the second base layer (P102) may be vaporized by a high temperature of 220°C or higher, causing appearance deformation. For example, since the second base layer (P102) is made of nylon 6 material, which has a higher moisture content than other polymer components, a large amount of moisture may be contained in the second base layer (P102).

On the other hand, Figure 5 is an image showing a pouch manufactured by a sealing method according to an embodiment of the present invention. Referring to FIG. 5, according to the sealing method according to an embodiment of the present invention, such as Examples 1 to 4, in the process of performing the first sealing step (S10) at a first temperature of less than 220 ° C., the sealing portion Moisture content may be lowered. That is, the moisture content of the sealing portion of the pouch (P) may be lower than 1000 ppm. The second sealing step (S20) is performed at a temperature of 220°C or higher while the moisture content of the sealing portion is lower than 1000 ppm. That is, since the second sealing step (S20) is performed while the moisture content of the base layer (P10) is lower than 1000 ppm, the sealing process can be performed while maintaining the shape of the base layer (P10). More specifically, since no bubbles are generated in the second base layer (P102), the shape of the second base layer (P102) can be maintained. Therefore, according to this embodiment of the present invention, the pouch P can be sealed without deforming its appearance.

Additionally, with regard to sealing quality, in the case of Comparative Example 1, it can be confirmed that the sealing strength was not secured as it was sealed at a relatively low temperature of 200°C. Next, in the case of Comparative Example 2, it can be confirmed that the sealing strength was not secured after being sealed for 2 seconds at a relatively low temperature of 210°C.

In contrast, in the case of the present invention, the second sealing step (S20) is performed at a temperature of 220° C. or higher after the first sealing step (S10), thereby securing sealing strength and preventing the problem of deterioration of sealing quality.

Lastly, regarding the tack time, in the case of Comparative Example 3, sealing strength was secured without external deformation, but since the tack time was 3 seconds, the tack time was relatively low. If it is long, the efficiency of the sealing process may decrease.

On the other hand, in the case of the present invention, the process time (tack time) for each process may be 2 seconds or less. That is, in the first sealing step (S10) and the second sealing step (S20), the pouch P may be sealed for 1 to 2 seconds. As the process time is less than 2 seconds, the efficiency of the process can be further increased due to the characteristics of the pouch P that undergoes the process while being transported through a transport means such as a conveyor belt.

As a result, according to the sealing method according to an embodiment of the present invention, the pouch P is sealed by dividing it into a first sealing step (S10) and a second sealing step (S20) based on 220 ° C. The pouch P can be sealed while the exterior, that is, the base layer P10, is not deformed. In addition, the sealing quality of the pouch (P) can be further secured through sufficient sealing time and sealing temperature, and a pouch (P) type secondary battery with excellent sealing strength can be manufactured.

Below, a sealing device 10 according to another embodiment of the present invention will be described. The following description will be omitted for content that is the same as the technical content for the sealing method according to the embodiment of the present invention described above.

Figure 4 is a perspective view of a sealing device 10 according to another embodiment of the present invention.

Referring to FIG. 4 , the sealing device 10 may include a first sealing part 101, a second sealing part 102, a driving part 103, and a conveying part 104.

The first sealing portion 101 may seal the sealing portion of the pouch P at a first temperature. That is, the first sealing portion 101 can seal the pouch P by compressing the sealing portion of the pouch P under high temperature and high pressure. For example, the first sealing portion 101 may seal the sealing portion of the pouch P at a temperature of 200°C or more and less than 220°C.

The second sealing portion 102 may seal the sealing portion at a second temperature that is higher than the first temperature. For example, the second sealing part 102 may be located behind the first sealing part 101 based on the transfer path of the pouch P. That is, the second sealing unit 102 can receive the pouch P from the first sealing unit 101 and re-seal the area sealed by the first sealing unit 101. In this case, the second sealing portion 102 can seal the sealing portion of the pouch P at a temperature of 220°C or more and less than 230°C.

The first sealing part 101 and the second sealing part 102 may seal one end surface of the pouch P. For example, with the electrode assembly (E) accommodated inside the pouch (P), the short side of the pouch (P) may be sealed by the first sealing part 101 and the second sealing part 102. Specifically, one side of the pouch (P) where the lead tab (T) protrudes may be sealed.

The driving unit 103 is connected to the first sealing part 101 and the second sealing part 102, respectively, and can move the first sealing part 101 and the second sealing part 102. For example, the driving unit 103 connects the first sealing unit 101 and the second sealing unit 102 so that the first sealing unit 101 and the second sealing unit 102 compress the upper and lower surfaces of the pouch P. can be moved up and down.

The transfer unit 104 may transfer the pouch P sealed by the first sealing unit 101 to the second sealing unit 102. For example, the transfer unit 104 may include a transfer means such as a conveyor belt, and may transfer the pouch P along the transfer path while the pouch P is seated on the upper side.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention.

Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments.

The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

S10: First sealing step
S20: Second sealing step
10: Sealing device
101: First sealing part
102: Second sealing part
103: driving unit
104: Transfer unit
P: Pouch
E: Electrode assembly
C: Laminated cell
T: lead tab
P10: Base layer
P20: Metal layer
P30: Sealant layer
P101: First substrate layer
P102: Second substrate layer

Claims (10)

A sealing method for sealing a pouch comprising a metal layer made of a metal material and a base layer formed on the outside of the metal layer and made of a polymer material, and having an electrode assembly positioned on the inside, comprising:
A first sealing step in which the sealing portion of the pouch is sealed at a first temperature while maintaining the shape of the base layer; and
A sealing method comprising a second sealing step in which the sealing portion is sealed at a second temperature higher than the first temperature. In paragraph 1
A sealing method in which, after the first sealing step, the second sealing step is performed. In paragraph 1
A sealing method wherein the first temperature is 200°C or more and less than 220°C. In paragraph 1
A sealing method wherein the second temperature is 220°C or more and less than 230°C. In paragraph 1
In the first sealing step, the moisture content of the sealing portion is lowered. In paragraph 5
In the first sealing step, the moisture content of the sealing portion is lower than 1000 ppm. In paragraph 1
The base layer includes a first base layer disposed on the outermost layer and made of a polyester material, and a second base layer disposed between the first base layer and the metal layer and made of a nylon material,
In the first sealing step, the shape of the second base layer is maintained. In paragraph 1
In the first sealing step and the second sealing step, the pouch is sealed for 1 to 2 seconds. In the sealing device for sealing the pouch with the electrode assembly located on the inside,
a first sealing part that seals the sealing part of the pouch at a first temperature;
a second sealing part that seals the sealing part at a second temperature higher than the first temperature; and
A sealing device comprising a transfer unit that transfers the pouch sealed by the first sealing unit to the second sealing unit. In paragraph 9
The first temperature is 200°C or more and less than 220°C, and the second temperature is 220°C or more and less than 230°C.