Pouch-type secondary battery, secondary battery module including the same, and pouch used therein

Abstract

The present invention relates to a pouch-type secondary battery, a secondary battery module including the same, and a pouch used therein, and more particularly to a pouch-type secondary battery having improved insulation performance, a secondary battery module including the same, and a pouch used therein. The present invention provides a pouch-type secondary battery including an electrode assembly including an electrode and a separator, and a pouch containing the electrode assembly, the pouch including: a receiving portion in which the electrode assembly is received; and a frame portion located along an outer edge of the receiving portion to form a frame; the frame portion includes an insulating layer having an insulating material; and the insulating layer is formed by sequentially stacking a first insulating layer and a second insulating layer from the inside to the outside.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0136975 filed on October 14, 2021 and Korean Patent Application No. 10-2022-0130928 filed on October 12, 2022, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a pouch-type secondary battery, a secondary battery module including the same, and a pouch used therein, and more particularly to a pouch-type secondary battery with improved insulation performance, a secondary battery module including the same, and a pouch used therein. [Background technology]

[0003] Batteries generate electrical energy through physical and chemical reactions of materials and supply power to the outside world. They are used when a building's AC power supply cannot be obtained or DC power is required due to living environments surrounded by various electrical and electronic devices.

[0004] Among these batteries, primary batteries and secondary batteries, which are chemical batteries that use chemical reactions, are commonly used. Primary batteries are consumable batteries also known as dry batteries. Secondary batteries are rechargeable batteries manufactured using materials that can undergo repeated oxidation-reduction processes between current and materials. When a reduction reaction occurs in the material due to current, the power source is charged, and when an oxidation reaction occurs in the material, the power source is discharged. Electricity is generated by repeating this charge-discharge cycle.

[0005] Meanwhile, pouch-type secondary batteries 1, which are small in volume and offer greater design flexibility, have recently been gaining attention. More specifically, as shown in FIG. 1a, pouch-type secondary battery 1 may include an electrode assembly 1a including a positive electrode, a separator, and a negative electrode, a pouch 1b containing electrode assembly 1a, and an electrode lead 1c electrically connected to the positive and negative electrodes of electrode assembly 1a and protruding from the outside of pouch 1b. Here, lead films 1c' made of an insulating material may be attached to both sides of electrode lead 1c.

[0006] Here, the pouch 1b is typically composed of a laminate of various functional thin films.Typically, as shown in Figure 1b, the pouch 1b may have a structure in which an inner insulating layer 1ba for insulating the inner components of the pouch 1b, a metal layer 1bc for maintaining the mechanical strength of the pouch 1b, and an outer insulating layer 1bb for insulating the metal layer 1bc from the outer components are sequentially laminated from the inside to the outside.

[0007] However, the pouch-type secondary battery 1 with the above structure has a problem in that the metal layer 1bc is exposed to the outside due to the frame of the pouch 1b, which causes leakage current and reduces the insulating performance of the secondary battery. In particular, since there is not enough distance for insulation between the exposed metal layer 1bc and the electrode lead 1c, an arc occurs when an external voltage is applied, which causes damage (e.g., burn marks) to the secondary battery 10 (see Figure 1c).

[0008] Furthermore, when forming a secondary battery module using the pouch-type secondary battery 1 having the above-described structure, insulation is required between the metal layer 1bc of the pouch-type secondary battery 1 and a metal module housing (not shown), which requires additional insulation design, such as arranging the pouch-type secondary battery 1 at a distance from the module housing or inserting an insulating structure between the pouch-type secondary battery 1 and the module housing, which is troublesome. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to provide a pouch-type secondary battery with improved insulation performance, a secondary battery module including the same, and a pouch used therein. [Means for solving the problem]

[0010] The present invention provides a pouch-type secondary battery including an electrode assembly including an electrode and a separator, and a pouch containing the electrode assembly, wherein the pouch includes: a receiving portion that receives the electrode assembly; and a frame portion that is positioned along an outer edge of the receiving portion and forms a frame; the frame portion includes an insulating layer having an insulating material; and the insulating layer is formed by sequentially stacking a first insulating layer and a second insulating layer from the inside to the outside.

[0011] The pouch-type secondary battery according to the present invention may include an electrode lead connected to the electrode and protruding outward from the pouch; and the insulating layer may be formed at a position corresponding to the electrode lead.

[0012] The electrode lead may be formed to protrude outward from at least one end of the pouch, and the insulating layer may be formed on the end of the pouch from which the electrode lead protrudes.

[0013] The insulating layer may be disposed to surround the electrode lead.

[0014] Lead films made of an insulating material may be attached to both sides of the electrode lead, and the insulating layer may be disposed to surround the lead films.

[0015] In the pouch, the difference between the width of the insulating layer and the width of the lead film may be equal to or greater than the difference between the width of the lead film and the width of the electrode lead.

[0016] In the pouch, a distance between one end of the insulating layer and one end of the lead film may be equal to or greater than a thickness of the lead film.

[0017] The electrode lead may be formed to protrude in one direction from one end of the pouch.

[0018] The electrode leads may be formed to protrude in opposite directions from both ends of the pouch.

[0019] At least one of the first insulating layer and the second insulating layer may include a synthetic resin material.

[0020] The first insulating layer may include polypropylene (PP).

[0021] The second insulating layer may include PolyEthylene Terephthalate (PET).

[0022] Meanwhile, the present invention can provide a pouch comprising: a receiving section having an empty space formed therein; and a frame section positioned along the outer edge of the receiving section to form a frame; the frame section including an insulating layer having an insulating material; and the insulating layer including a first insulating layer and a second insulating layer sequentially stacked from the inside to the outside.

[0023] Meanwhile, the present invention may provide a secondary battery module formed by assembling a plurality of the above-described pouch-type secondary batteries.

[0024] Meanwhile, the present invention provides a pouch sealing method for sealing a frame of a pouch incorporating an electrode assembly including electrodes and a separator, the method including: a first sealing step of sealing an insulating layer having an insulating material in the frame; and a second sealing step of sealing a portion of the frame excluding the insulating layer, wherein the sealing temperature in the second sealing step is higher than the sealing temperature in the first sealing step. [Effects of the Invention]

[0025] The pouch-type secondary battery according to the present invention, the secondary battery module including the same, and the pouch used therein have the effect of improving the insulating performance of the secondary battery by providing an insulating layer on the frame portion.

[0026] Furthermore, the pouch-type secondary battery according to the present invention, the secondary battery module including the same, and the pouch used therein have an insulating layer formed at a position corresponding to the electrode lead, thereby ensuring a sufficient insulating distance between the electrode lead and the metal layer constituting the pouch, thereby improving the insulating performance of the secondary battery.

[0027] In addition, the pouch-type secondary battery, the secondary battery module including the same, and the pouch used therein according to the present invention have an insulating layer provided on the frame portion, which makes it possible to omit the insulation design between the module housing and the secondary battery during the manufacture of the secondary battery module, thereby reducing manufacturing costs and time. [Brief explanation of the drawings]

[0028] [Figure 1a] FIG. 1 is a front view showing the front of a pouch-type secondary battery according to the prior art. [Figure 1b] 1b is a cross-sectional view showing a cross section in direction II of the pouch-type secondary battery of FIG. 1a. FIG. [Figure 1c] 1b is a diagram showing damage to a portion of the pouch-type secondary battery of FIG. 1a. FIG. [Figure 2]1 is a front view showing the front of a pouch-type secondary battery according to the present invention. [Figure 3] 2. FIG. 3 is a cross-sectional view showing a cross section along the II-II direction in the pouch-type secondary battery of FIG. [Figure 4] 3 is a cross-sectional view showing a cross section in the III-III direction in the pouch-type secondary battery of FIG. 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily understand and practice the present invention. However, the present invention may be embodied in various different forms and should not be construed as being limited to the following embodiments.

[0030] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the explanation or of related known technologies that may obscure the gist of the present invention will be omitted, and when adding reference symbols to components in each drawing in this specification, the same or similar reference symbols will be used throughout the specification for the same or similar components.

[0031] Pouch-type secondary battery The present invention provides a pouch-type secondary battery (10) including an electrode assembly (100) including electrodes and a separator, and a pouch (200) containing the electrode assembly (100), wherein the pouch (200) includes a receiving portion (210) in which the electrode assembly (100) is received, and a frame portion (220) positioned along the outer edge of the receiving portion (210) to form a frame; the frame portion (220) includes an insulating layer (221) having an insulating material; and the insulating layer (221) is formed by sequentially stacking a first insulating layer (221a) and a second insulating layer (221b) from the inside to the outside.

[0032] First, the electrode assembly 100 includes an electrode (not shown) and a separator (not shown), and may have various configurations.

[0033] More specifically, the electrode assembly 100 may include positive and negative electrodes and a separator interposed between the electrodes. Here, the positive electrode may be formed by coating a positive electrode active material on an electrode current collector, and the negative electrode may be formed by coating a negative electrode active material on an electrode current collector.

[0034] The electrode assembly 100 may be of a stack type formed by interposing a separator between a positive electrode and a negative electrode, a jelly roll type, or a stack and folding type that is a combination of the stack type and the jelly roll type.

[0035] Meanwhile, the positive and negative electrodes may be connected to electrode leads 300 that can be electrically connected to another secondary battery or an external device.

[0036] The electrode lead 300 is connected to an electrode and protrudes outward from a pouch 200 (to be described later), and may have various configurations.

[0037] More specifically, one end of the electrode lead 300 is connected to an electrode tab (not shown) formed on an electrode, and the other end is formed to protrude outside the pouch 200, so that the electrode lead 300 can be connected to another secondary battery or an external device. Therefore, the electrode lead 300 can electrically connect the electrode assembly 100 housed inside the pouch 200 to another secondary battery or an external device outside the pouch 200.

[0038] In this case, the electrode lead 300 may be formed to protrude outward from at least one end of the pouch 200. As an example, the electrode lead 300 may be formed to protrude in one direction from one end of the pouch 200. As another example, the electrode lead 300 may be formed to protrude in opposite directions from both ends of the pouch 200 (see FIG. 2).

[0039] The material of the electrode lead 300 is not particularly limited as long as it is an electrically conductive material. For example, the material of the electrode lead 300 may include at least one of copper (Cu), aluminum (Al), nickel (Ni), iron (Fe), carbon (C), chromium (Cr), and manganese (Mn). However, the material of the electrode lead 300 is not limited to the above-mentioned materials, and may be selected from various materials in consideration of mechanical strength, flexibility, processability, etc.

[0040] In addition, the electrode lead 300 may further have lead films 300' made of an insulating material attached to both sides of the electrode lead 300 in order to improve the sealing of the pouch 200 and ensure sufficient electrical insulation.

[0041] Meanwhile, the pouch 200 is configured to house the electrode assembly 100 described above, and may have various configurations.

[0042] Specifically, the pouch 200 may house the electrode assembly 100, and the surrounding area where the electrode assembly 100 is housed may be sealed, thereby physically and chemically protecting the electrode assembly 100 from the outside.

[0043] The pouch 200 may include a receiving portion 210 in which the electrode assembly 100 is received, and a frame portion 220 positioned along the outer edge of the receiving portion 210 to form a frame.

[0044] Here, the receiving part 210 is configured to receive the electrode assembly 100 in the pouch 200, and may have various configurations.

[0045] For example, the receiving portion 210 may be any region having an empty space formed therein so as to be able to receive the electrode assembly 100. Of course, the empty space may receive not only the electrode assembly 100 but also an electrolyte solution, etc.

[0046] Meanwhile, the receiving portion 210 may include a metal layer 210c to protect internal components such as the electrode assembly 100 and the electrolyte, to complement the electrochemical properties of the electrode assembly 100 and the electrolyte, and to enhance heat dissipation, and may include a first insulating layer 210a and a second insulating layer 210b formed of an insulating material to electrically insulate the metal layer 210c from the internal and external components of the pouch 200.

[0047] In this case, the first insulating layer 210a, the metal layer 210c, and the second insulating layer 210b may be sequentially stacked from the inside to the outside of the pouch 200, as shown in FIG.

[0048] Here, the first insulating layer 210a may be made of polypropylene (PP), the second insulating layer 210b may be made of polyethylene terephthalate (PET), and the metal layer 210c may be made of aluminum (Al), etc. However, the materials of the first insulating layer 210a, the second insulating layer 210b, and the metal layer 210c are not limited thereto, and as long as the first insulating layer 210a and the second insulating layer 210b include an insulating material and the metal layer 210c includes a metal material, they may be used without any particular limitation.

[0049] Meanwhile, the frame part 220 is positioned along the outer edge of the receiving part 210 to form a frame, and may have various configurations.

[0050] 2, the frame part 220 may be disposed from the outer edge of the receiving part 210 of the pouch 200 to surround the receiving part 210, thereby forming a frame part of the pouch 200. Here, the frame part 220 may be formed integrally with the receiving part 210. In this case, due to the structure of the pouch 200, a side of the frame part 220 positioned in a direction opposite to the direction facing the receiving part 210 may be exposed to the outside.

[0051] As described above, the frame unit 220 may be sealed to mechanically and chemically protect the electrode assembly 100 accommodated in the receiving unit 210. For example, when the pouch 200 is composed of an upper pouch and a lower pouch, the frame unit 220 may be sealed by heat pressing the upper pouch and the lower pouch in a state where the upper pouch and the lower pouch are overlapped with each other.

[0052] Meanwhile, the frame part 220 may have a structure in which layers made of different materials are stacked on top of each other, like the above-described receiving part 210. In this case, the frame part 220 may include an insulating layer 221 having an insulating material to improve the insulating performance of the pouch-type secondary battery 10.

[0053] More specifically, the insulating layer 221 has a structure in which a first insulating layer 221a and a second insulating layer 221b are sequentially stacked from the inside to the outside, and various structures are possible.

[0054] Here, the first insulating layer 221a and the second insulating layer 221b can be made of any material as long as they have an insulating material.

[0055] For example, at least one of the first insulating layer 221a and the second insulating layer 221b may include a synthetic resin material. In this case, the first insulating layer 221a may include polypropylene (PP), and the second insulating layer 221b may include polyethylene terephthalate (PET). However, the materials of the first insulating layer 221a and the second insulating layer 221b are not limited thereto, and the first insulating layer 221a and the second insulating layer 221b may be made of any material having an insulating material without any particular restrictions.

[0056] Meanwhile, the insulating layer 221 may be formed in various ways on the frame part 220. For example, the insulating layer 221 may be formed on a specific region of the frame part 220 or on the entire region of the frame part 220.

[0057] Here, when the insulating layer 221 is formed in a specific region of the frame part 220, the insulating layer 221 may be provided in any region of the frame part 220. In this case, the insulating layer 221 may be formed at a position corresponding to the electrode lead 300 in order to maximize the electrical isolation distance of the electrode lead 300 having a metal material.

[0058] More specifically, since the electrode lead 300 is formed to protrude outward from at least one end of the pouch 200 as described above, the insulating layer 221 may be formed at the end of the pouch 200 from which the electrode lead 300 is protruded, as shown in FIG. 2.

[0059] In this case, the insulating layer 221 may be disposed so as to surround the electrode lead 300 from the end of the pouch 200. That is, as shown in Figures 3 and 4, the insulating layer 221 may be disposed so as to surround the electrode lead 300 by being formed in a region of the frame part 220 that faces the electrode lead 300. Here, if lead films 300' made of an insulating material are attached to both sides of the electrode lead 300, it goes without saying that the insulating layer 221 may also be disposed so as to surround the lead films 300'.

[0060] Regarding the arrangement of the insulating layer 221, a preferable difference between the width of the insulating layer 221 and the width of the lead film 300′ may be equal to or greater than the difference between the width of the lead film 300′ and the width of the electrode lead 300. Here, the y-axis direction in FIG. 2 may be the width.

[0061] In addition, a preferred distance between one end of the insulating layer 221 and one end of the lead film 300' may be equal to or greater than the thickness of the lead film 300'. Here, one end of the insulating layer 221 may be the leftmost portion of the insulating layer 221 with reference to FIG. 3, and one end of the lead film 300' may be the leftmost portion of the lead film 300' with reference to FIG. 3.

[0062] The preferable positional relationship between the insulating layer 221 and the lead film 300' described above may be a positional relationship that allows the insulating layer 221 and the lead film 300' to stably exhibit necessary insulating performance.

[0063] Meanwhile, when the insulating layer 221 is formed only in a specific region, the frame part 220 may further include a covering layer 222 formed on the remaining region excluding the specific region where the insulating layer 221 is formed.

[0064] Here, the covering layer 222 may have various configurations and is formed in the remaining area except for the specific area where the insulating layer 221 is formed. For example, the covering layer 222 may be provided adjacent to the insulating layer 221, or may be arranged alternately with the insulating layer 221 to form the frame part 220.

[0065] As shown in FIG. 4, the covering layer 222 may have a structure in which a first insulating layer 222a, a metal layer 222c, and a second insulating layer 222b are sequentially stacked from the inside to the outside.

[0066] Here, the first insulating layer 222a may be made of polypropylene (PP), the second insulating layer 222b may be made of polyethylene terephthalate (PET), and the metal layer 222c may be made of aluminum (Al), etc. However, the materials of the first insulating layer 222a, the second insulating layer 222b, and the metal layer 222c are not limited thereto, and as long as the first insulating layer 222a and the second insulating layer 222b include an insulating material and the metal layer 222c includes a metal material, they may be used without any particular limitation.

[0067] As described above, the frame part 220 may be sealed. Regarding the sealing process of sealing the frame part 220, when the frame part 220 includes the insulating layer 221 and the covering layer 222, the sealing process may include two steps.

[0068] Specifically, the sealing process may include a first sealing step of sealing the insulating layer 221 having an insulating material to the frame part 220, and a second sealing step of sealing the covering layer 222 to the frame part 220. Here, the covering layer 222 may be a portion of the frame part 220 excluding the insulating layer 221.

[0069] In addition, the sealing temperature in the second sealing step may be higher than the sealing temperature in the first sealing step. In this regard, the insulating layer 221 may be composed of a first insulating layer 221a and a second insulating layer 221b, while the covering layer 222 may further include a metal layer 222c disposed therebetween in addition to the first insulating layer 222a and the second insulating layer 222b. Therefore, a higher temperature may be required to seal the covering layer 222 than the insulating layer 221.

[0070] The above-described sealing process is merely one preferred example, and the insulating layer 221 and the covering layer 222 may be sealed in one step.

[0071] Meanwhile, components having the same name but different reference numerals in the above description may be integrally formed. That is, the first insulating layer 210a included in the accommodating portion 210, the first insulating layer 221a included in the insulating layer 221 of the frame portion 220, and the first insulating layer 222a included in the covering layer 222 may be integrally formed. The second insulating layer 210b included in the accommodating portion 210, the second insulating layer 221b included in the insulating layer 221 of the frame portion 220, and the second insulating layer 222b included in the covering layer 222 may be integrally formed. Furthermore, the metal layer 210c included in the accommodating portion 210 and the metal layer 222c included in the covering layer 222 of the frame portion 220 may be integrally formed.

[0072] Secondary Battery Module The present invention can provide a secondary battery module (not shown) formed by assembling a plurality of the above-described pouch-type secondary batteries 10. Here, the above description regarding the pouch-type secondary battery 10 can be used.

[0073] Specifically, a plurality of pouch-type secondary batteries 10 may be housed in a module housing (not shown) having an internal space. In this case, the pouch-type secondary battery 10 according to the present invention does not require an additional insulation design for insulating between the module housing and the secondary batteries, which is advantageous in that it can reduce the manufacturing time and cost of the secondary battery module.

[0074] Pouch Meanwhile, the present invention may provide a pouch 200 including a receiving portion 210 having an empty space therein and a frame portion 220 positioned along the outer edge of the receiving portion 210 to form a frame, the frame portion 220 including an insulating layer 221 having an insulating material, and the insulating layer 221 including a first insulating layer 221a and a second insulating layer 221b sequentially stacked from the inside to the outside. Here, the detailed description of the pouch 200 described above may be the same as the description of the pouch 200 in the pouch-type secondary battery 10 described above.

[0075] Furthermore, the terms and words used in this specification and claims should not be interpreted in a way that is limited to their ordinary and dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, in accordance with the principle that the inventor himself / herself can appropriately define the concept of a term in order to explain the invention in the best possible way.

[0076] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the technical spirit of the present invention and the scope of equivalents of the claims set forth below by a person having ordinary skill in the art to which the present invention pertains. [Explanation of symbols]

[0077] 10 Pouch-type secondary battery 100 electrode assembly 200 pouches 210 Storage unit 210a First insulating layer 210b Second insulating layer 210c metal layer 220 Frame section 221 Insulating layer 221a First insulating layer 221b Second insulating layer 221c metal layer 222 Covering layer 222a First insulating layer 222b Second insulating layer 222c metal layer 300 electrode leads 300' lead film

Claims

1. A pouch-type secondary battery comprising: an electrode assembly including an electrode and a separator; and a pouch containing the electrode assembly, an electrode lead connected to the electrode and protruding outward from the pouch; The pouch comprises: a receiving portion in which the electrode assembly is received; a frame portion positioned along an outer edge of the receiving portion to form a frame, the housing portion includes a housing portion first insulating layer, a housing portion metal layer, and a housing portion second insulating layer, which are sequentially stacked from the inside to the outside of the pouch, the housing portion first insulating layer being in contact with the electrode lead, the frame portion includes an insulating layer having an insulating material; The insulating layer is The insulating layer is made up of a first insulating layer and a second insulating layer, does not include a metal layer, and the first insulating layer and the second insulating layer are sequentially stacked from the inside to the outside, An insulating lead film is attached to both sides of the electrode lead, The pouch-type secondary battery is characterized in that the insulating layer is formed at a position corresponding to the electrode lead and is disposed so as to surround the lead film.

2. The electrode lead is formed to protrude outward from at least one end of the pouch, The pouch-type secondary battery according to claim 1 , wherein the insulating layer is formed on an end of the pouch from which the electrode leads protrude.

3. The pouch-type secondary battery according to claim 1 , wherein the insulating layer is disposed so as to surround the electrode lead.

4. 2. The pouch-type secondary battery according to claim 1, wherein the difference between the width of the insulating layer and the width of the lead film is equal to or greater than the difference between the width of the lead film and the width of the electrode lead.

5. 2. The pouch-type secondary battery according to claim 1, wherein a distance between one end of the insulating layer and one end of the lead film is equal to or greater than a thickness of the lead film.

6. The pouch-type secondary battery according to claim 1 , wherein the electrode lead is formed to protrude in one direction from one end of the pouch.

7. The pouch-type secondary battery according to claim 1 , wherein the electrode leads protrude in opposite directions from both ends of the pouch.

8. The pouch-type secondary battery according to claim 1 , wherein at least one of the first insulating layer and the second insulating layer is made of a synthetic resin material.

9. The pouch-type secondary battery according to claim 8, wherein the first insulating layer includes polypropylene (PP).

10. The pouch-type secondary battery according to claim 8, wherein the second insulating layer includes polyethylene terephthalate (PET).

11. A pouch containing an electrode assembly including an electrode and a separator, a storage section in which an empty space is formed; a frame portion positioned along an outer edge of the receiving portion to form a frame, the housing portion includes a housing portion first insulating layer, a housing portion metal side, and a housing portion second insulating layer, which are sequentially stacked from the inside to the outside of the pouch, the housing portion first insulating layer being connected to the electrode and contacting an electrode lead protruding from the pouch to the outside, the frame portion includes an insulating layer having an insulating material; The insulating layer is The insulating layer is made up of a first insulating layer and a second insulating layer, does not include a metal layer, and the first insulating layer and the second insulating layer are sequentially stacked from the inside to the outside, The pouch is characterized in that the insulating layer is formed at a position corresponding to the electrode lead and is arranged to surround lead films made of an insulating material attached to both sides of the electrode lead.

12. A secondary battery module formed by assembling a plurality of the pouch-type secondary batteries according to claim 1 .

13. A pouch sealing method for sealing a frame of the pouch according to claim 11, comprising: a first sealing step of sealing an insulating layer having an insulating material in the frame; a second sealing step of sealing a portion of the frame excluding the insulating layer; A pouch sealing method, wherein the temperature at which the second sealing step is performed is higher than the temperature at which the first sealing step is performed.

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