KR101874900B1 - Cell pouch and method of preparing the same - Google Patents

Abstract

The cell pouch includes a sequentially laminated sealant layer, a first adhesive layer, a barrier layer, a second adhesive layer, and an outer layer. At this time, the first adhesive layer includes a maleic anhydride-modified polyolefin resin and a glycidylamine type epoxy curing agent.

Description

≪ Desc / Clms Page number 1 > CELL POUCH AND METHOD OF PREPARING THE SAME [

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell pouch for a secondary battery and a method of manufacturing the same. More particularly, the present specification relates to a cell pouch for a lithium ion secondary battery and a method for manufacturing the same.

Generally, a cell such as a lithium ion secondary battery is embedded (stored) in a cell pouch. Such a cell pouch may include a sealant layer, a barrier layer, and an outer layer, which are sequentially stacked, and between the sealant layer and the barrier layer and between the barrier layer and the outer layer, And further includes adhesive layers between the outer layer and the outer layer.

However, when the adhesive layer, especially the adhesive layer provided between the sealant layer and the barrier layer, is not easily adhered or easily damaged or deteriorated due to physical impact from the outside and / or electrolyte leakage from the inside, Defects such as delamination, cracks and the like may occur in the cell pouch and it may be difficult to effectively protect the cell (secondary cell) embedded therein.

Therefore, the adhesive layers for bonding the respective layers, in particular the adhesive layer provided between the sealant layer and the barrier layer, must be able to provide sufficient adhesion so that the layers are not at least partially peeled off or separated, It may be desirable to have more properties such as chemical resistance, mechanical strength, and heat resistance.

Japanese Patent No. 4668373

An object of the present invention is to provide a cell pouch having high reliability by including an adhesive layer having excellent adhesiveness, anti-fogging property, electrolyte resistance, mechanical strength and the like between the sealant layer and the barrier layer and a method for producing the same.

A cell pouch according to exemplary embodiments for achieving an object of the present invention includes a sealant layer; A first adhesive layer formed on the sealant layer; A barrier layer formed on the first adhesive layer; A second adhesive layer formed on the barrier layer; And an outer layer formed on the second adhesive layer. At this time, the first adhesive layer includes a maleic anhydride-modified polyolefin resin and a glycidylamine type epoxy curing agent.

In exemplary embodiments, the glycidylamine type epoxy curing agent may be represented by the following formula (1).

[Chemical Formula 1]

In exemplary embodiments, the glycidylamine type epoxy curing agent may be included in the first adhesive layer in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the maleic anhydride-modified polyolefin resin.

In exemplary embodiments, the sealant layer may contact a cell embedded in the cell pouch as the innermost layer of the cell pouch. The outer layer may be exposed to the outside as an outermost layer of the cell pouch.

In exemplary embodiments, the sealant layer may comprise a polypropylene-based resin or a casting polypropylene (CPP) based film.

In exemplary embodiments, the barrier layer may include one or more metals having moisture barrier and gas barrier properties.

In exemplary embodiments, the outer layer may comprise at least one selected from a polyamide-based resin and a polyester-based resin.

In exemplary embodiments, the polyamide-based resin may be nylon. The polyester resin may be polybutylene terephthalate (PBT) or polyethylene terephthalate (PET).

In exemplary embodiments, the cell pouch may be a cell pouch for a secondary cell.

In exemplary embodiments, the secondary battery may be a lithium ion secondary battery.

A method of manufacturing a cell pouch according to exemplary embodiments to accomplish an object of the present invention includes: forming a barrier layer; Forming a first adhesive layer on one side of the barrier layer using a maleic anhydride-modified polyolefin resin and a glycidylamine-type epoxy curing agent; Forming a sealant layer to be bonded to one surface of the barrier layer using the first adhesive layer; Forming a second adhesive layer on the other side of the barrier layer where the sealant layer is not formed; And forming the outer layer to be bonded to the other surface of the barrier layer so as to face the sealant layer using the second adhesive layer.

In exemplary embodiments, the glycidylamine type epoxy curing agent may be represented by the following formula (1).

[Chemical Formula 1]

The cell pouches according to exemplary embodiments of the present invention include a sequentially stacked sealant layer, a first adhesive layer, a barrier layer, a second adhesive layer, and an outer layer, wherein the second adhesive layer comprises a maleic anhydride- modified polyolefin resin and a glue By including a sidylamine type epoxy curing agent, safety can be secured between the sealant layer and the barrier layer in terms of adhesion and mechanical strength as well as in terms of chemical resistance such as antiflatability and electrolyte resistance.

Specifically, through the first adhesive layer, the sealant layer and the barrier layer may not be at least partially peeled off or separated, and may not be cracked or otherwise damaged. In addition, since the first adhesive layer is excellent in mechanical strength, antiflatability, and electrolyte resistance, the cell pouch can have improved moldability and chemical resistance.

Therefore, the secondary battery, specifically, the lithium ion secondary battery can be effectively packaged using the cell pouch.

1 illustrates a cross-sectional view of a cell pouch according to exemplary embodiments of the present invention.

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

It is to be understood that the invention is not to be limited to the specific forms disclosed, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention, As will be understood by those skilled in the art.

As used herein, the term 'cell' refers to a battery, and has the broadest meaning including all kinds of batteries such as a secondary battery and a portable battery, such as a lithium ion battery and a lithium polymer battery.

The term 'cell pouch' as used herein refers to a cell pouch capable of packaging cell components such as an anode, a cathode, and a separator impregnated in an electrolyte, and has a gas barrier property, a water barrier property, The film having the laminated structure in consideration of the shape and the like is processed into a bag shape or a box shape so that the cell component can be embedded therein.

In the present specification, "barrier property" means a property of blocking water vapor (moisture) or air from the outside of the cell and gas generated in the inside of the cell.

In the present specification, "excellent formability of cell pouch" means that a laminated film having gas barrier properties, water barrier properties, electrolyte resistance, thermal adhesiveness, and the like is easily damaged to a predetermined shape without being damaged or broken . At this time, the energy density of the secondary battery (the cell built in the cell pouch) can be increased as the depth at which the cell pouch can be formed is greater.

Cell pouch

A cell pouch according to exemplary embodiments of the present invention can be used as a cell pouch for a secondary battery, specifically, as a cell pouch for a lithium ion secondary cell.

1 illustrates a cross-sectional view of a cell pouch according to exemplary embodiments of the present invention.

Referring to FIG. 1, a cell pouch 100 includes a sealant layer 10, a first adhesive layer 15, a barrier layer 20, a second adhesive layer 25, Layer structure as shown in Fig. 1, including the outer layer 30, as shown in Fig.

The sealant layer 10 is the innermost layer of the cell pouch 100 that can contact the cell contained in the cell pouch 100 and includes a sealing resin or a film and is formed by sealing Heat fusion bonding) to provide a sealing property. The sealing resin or film is not particularly limited as long as it can be melted and sealed by heat (having thermal adhesiveness), but it can be preferably selected from a low melting point resin or film capable of heat sealing at a low temperature. Further, it is preferable that the sealing resin or film has heat resistance, insulation property, electrolytic solution resistance, cold resistance and the like.

Thus, in the exemplary embodiments, the sealant layer 10 may comprise a polypropylene-based (PP-based) resin as the sealing resin, or may be a casting polypropylene , CPP) based film. The polypropylene (PP) based resin or the non-oriented polypropylene (CPP) based film is excellent in sealing property and insulation property, and is excellent in mechanical properties such as tensile strength, rigidity and surface hardness, And thus can be usefully used in the present invention. As the polypropylene (PP) -based resin, for example, homo PP, a PP copolymer, a PP terpolymer, or the like may be used.

The sealant layer 10 may have a thickness of from about 10 [mu] m to about 100 [mu] m for good heat bond strength, i.e., sealability. If the thickness of the sealant layer 10 is less than about 10 탆, problems may occur that the electrolyte is leaked due to lack of sealing property or the packed cell is not sufficiently insulated. In addition, when the thickness of the sealant layer 10 is greater than about 100 [mu] m, the cell pouch 100 is required to have a relatively thin thickness because the other layer (s) stacked on top of the sealant layer 10 must have barrier properties, The moldability and the like may be lowered.

The first adhesive layer 15 is for bonding the sealant layer 10 and the barrier layer 20 and may be provided on the sealant layer 10. The first adhesive layer 15 can provide a high adhesion force between the sealant layer 10 and the barrier layer 20, that is, a high interlaminar peeling strength, and further preferably has chemical resistance such as electrolyte resistance and anti- An adhesive resin, and a curing agent.

Accordingly, the first adhesive layer 15 may include an anhydrous maleic acid-modified polyolefin resin graft-modified with a polyolefin resin with maleic anhydride as an adhesive resin. As the curing agent, a glycidylamine-type epoxy curing agent excellent in the properties of the anti-fogging property, the electrolyte resistance, the heat resistance, the curing property and the mechanical strength, specifically, the curing agent (NNN'N'-tetraglycidyl -4,4'-methylene-bis-benzamine). At this time, in consideration of adhesiveness (curability) of the first adhesive layer 15, the curing agent may be contained in an amount of about 0.5 to 10 parts by weight based on 100 parts by weight of the maleic anhydride-modified polyolefin resin. More specifically, if the curing agent is included in an amount exceeding about 10 parts by weight, the curing agent may remain in the first adhesive layer 15 unreacted (not participating in curing) to form a sealant layer 10 ) And the barrier layer 20 may be reduced and workability may be reduced during the coating process for forming the first adhesive layer 15, which may be undesirable from a manufacturing viewpoint. In addition, if the curing agent is contained in an amount of less than about 0.5 part by weight, the first adhesive layer 15 may not be completely cured, so that it is difficult to provide sufficient adhesion between the sealant layer 10 and the barrier layer 20 . As a result, if the curing agent is not included in an amount of about 0.5 to 10 parts by weight, it may be difficult to realize a highly reliable cell pouch 100.

[Chemical Formula 1]

The first adhesive layer 15 may have a thickness of, for example, from about 1 [mu] m to about 10 [mu] m. If the thickness of the first adhesive layer 15 is too thin to be less than about 1 μm, it may be difficult to secure a sufficient adhesion between the sealant layer 10 and the barrier layer 20, and further, the cell pouch 100 may have a sufficient degree of anti- , Electrolyte resistance, heat resistance, mechanical strength, and the like. The adhesive strength between the sealant layer 10 and the barrier layer 20 can be improved if the thickness of the first adhesive layer 15 is too thick to be more than about 10 mu m but the other layers For example, the barrier layer 20 and the outer layer 30 must be implemented with a relatively thin thickness, the cell pouch 100 may be degraded in barrier properties, strength, moldability, and the like.

The barrier layer 20 is provided on the sealant layer 10 through the first adhesive layer 15 to block moisture and air from the outside and gas generated from the inside. The barrier layer 20 may include a metal having gas barrier properties and water barrier properties and may be formed of a metal such as aluminum (Al), iron (Fe), copper (Cu), nickel (Ni), tin (A single metal or a mixture of single metals) selected from the group consisting of zinc (Zn), indium (In), tungsten (W) and the like, or two or more alloys selected therefrom. In exemplary embodiments, the barrier layer 20 may comprise aluminum (Al) or an aluminum alloy, taking into account moisture barrier properties, gas barrier properties, and formability.

The barrier layer 20 may have a thickness of, for example, about 10 um or thicker, specifically about 10 um to about 100 um, for a sufficient degree of gas barrier and water barrier properties. Further, in one embodiment, the barrier layer 20 may be surface treated with phosphoric acid, chromium, or the like, for corrosion resistance.

The second adhesive layer 25 is for bonding the barrier layer 20 and the outer layer 30 and may be provided on the barrier layer 20. The second adhesive layer 25 may include an adhesive resin and a curing agent capable of providing a high adhesive force between the barrier layer 20 and the outer layer 30, i.e., a high interlaminar peel strength. The adhesive resin may include, for example, a polyester-based adhesive resin, a polyurethane-based adhesive resin, a polyolefin-based adhesive resin, or the like. The curing agent may include, for example, an isocyanate curing agent, an epoxy curing agent, a urethane curing agent, and the like.

The second adhesive layer 25 may have a thickness of, for example, from about 1 [mu] m to about 10 [mu] m. If the thickness of the second adhesive layer 25 is too thin to be less than about 1 um, it may be difficult to secure sufficient adhesion between the barrier layer 20 and the outer layer 30. The adhesion between the barrier layer 20 and the outer layer 30 can be improved if the thickness of the second adhesive layer 25 is too thick to be more than about 10 m but the outer layer 30 laminated on the second adhesive layer 25 The strength and the like of the cell pouch 100 may be lowered because it must be implemented with a relatively thin thickness.

The outer layer 30 may be provided on the barrier layer 20 through the second adhesive layer 25 and may be exposed to the outside as the outermost layer of the cell pouch 100. The outer layer 30 may desirably have heat resistance, cold resistance, pinhole resistance, insulation, chemical resistance, moldability, etc., in addition to abrasion resistance so as to protect the barrier layer 20. Thus, in exemplary embodiments, the outer layer 30 may comprise a polyamide-based resin and / or a polyester-based resin. The polyamide-based resin may be nylon having a high elongation and favorable molding. The polyester resin may be polybutylene terephthalate (PBT) or polyethylene terephthalate (PET) which can realize high chemical resistance, pinhole property, insulation property, mechanical strength and the like, May be polybutylene terephthalate (PBT) having a higher elongation than polyethylene terephthalate (PET).

The outer layer 30 may have a thickness of about 10 탆 to 50 탆 in consideration of a sufficient degree of abrasion resistance, heat resistance, pinhole resistance, chemical resistance, moldability, and insulation. If the thickness of the outer layer 30 is too thin to be less than about 10 占 퐉, or if it is too thick to be more than about 50 占 퐉, problems may arise in the cell pouch 100 such as lowering of moldability, lowering of heat bonding strength,

As described above, the cell pouches according to exemplary embodiments of the present invention include a sequentially stacked sealant layer, a first adhesive layer, a barrier layer, a second adhesive layer, and an outer layer, wherein the second adhesive layer comprises a maleic anhydride By including the modified polyolefin resin and the glycidylamine type epoxy curing agent, safety can be secured between the sealant layer and the barrier layer in terms of adhesion and mechanical strength as well as in terms of chemical resistance such as anti-fogging property and electrolyte resistance.

Specifically, through the first adhesive layer, the sealant layer and the barrier layer may not be at least partially peeled off or separated, and may not be cracked or otherwise damaged. In addition, since the first adhesive layer is excellent in mechanical strength, antiflatability, and electrolyte resistance, the cell pouch can have improved moldability and chemical resistance.

Therefore, the secondary battery, specifically, the lithium ion secondary battery can be effectively packaged using the cell pouch.

Method of manufacturing cell pouch

A cell pouch according to exemplary embodiments of the present invention may be manufactured by performing the following processes.

The same barrier layer as that described above is formed using a metal having moisture barrier property and gas barrier property.

In exemplary embodiments, the barrier layer may be formed by depositing a metal, such as aluminum (Al) or an Al alloy, as described above, to form a metal layer deposited layer, or a metal such as aluminum Al or a metal foil including an Al alloy. At this time, the barrier layer may be formed to have a thickness of, for example, about 10 um or more, specifically about 10 to 100 um.

A first adhesive layer identical to that described above is formed on one side of the barrier layer.

In exemplary embodiments, the first adhesive layer may be formed by forming a first adhesive composition comprising a maleic anhydride-modified polyolefin resin and a glycidylamine type epoxy curing agent (represented by Formula 1) Layer and then drying and curing at a temperature of about 50 to 200 캜. The first adhesive layer may be formed to have a thickness of, for example, about 1 to 10 [mu] m.

A sealant layer to be bonded to one surface of the barrier layer is formed by using the first adhesive layer.

In exemplary embodiments, the sealant layer may be formed using a sealing resin or film as described above, such as a polypropylene (PP) based resin or an unoriented polypropylene (CPP) based film, for example, And then laminating the first film on the first adhesive layer and pressing the first film on the first adhesive layer to bond the first film to the barrier layer.

At this time, due to the excellent adhesion of the first adhesive layer, the sealant layer and the barrier layer can be firmly bonded at least partially without peeling or separation, so that the sealant layer, the barrier layer and / The cell pouch may not be damaged due to cracks or the like. Further, since the first adhesive layer has high anti-fl ux, electrolyte resistance, mechanical strength, heat resistance, etc., the first adhesive layer can contribute to the reliability improvement of the cell pouch.

And a second adhesive layer is formed on the other surface of the barrier layer where the sealant layer is not formed.

In the exemplary embodiments, the second adhesive layer may be made of an adhesive resin such as a polyester-based adhesive resin, a polyurethane-based adhesive resin, a polyolefin-based adhesive resin, or the like so as to provide a high adhesive force between the barrier layer and a subsequent- ; And a second adhesive composition comprising a curing agent such as an isocyanate curing agent, an epoxy curing agent and a urethane curing agent is formed and applied on the other side of the barrier layer on which the sealant layer is not formed, Lt; RTI ID = 0.0 >% < / RTI > The second adhesive layer may be formed to have a thickness of, for example, about 1 to 10 [mu] m.

The second adhesive layer is used to form an outer layer that is bonded to the other surface of the barrier layer so as to face the sealant layer.

In exemplary embodiments, the outer layer may be formed using a polyamide-based resin and / or a polyester-based resin, for example, to have a thickness of about 10 < RTI ID = And then laminating the second film on the second adhesive layer, and pressing the second film on the second adhesive layer to join the barrier film to the barrier layer.

Through the above-described method, it is possible to easily manufacture a cell pouch having not only an improved interlaminar adhesion between the sealant layer and the barrier layer but also excellent mechanical strength, moldability and chemical resistance.

The present invention will be described in more detail through the following embodiments. It should be understood, however, that the embodiments of the present invention disclosed herein are for illustrative purposes only, and that the embodiments of the present invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein Can not be done.

[Example]

A barrier layer having a thickness of 40 mu m was formed using a metal foil containing aluminum (Al). A first adhesive composition comprising a maleic anhydride-modified polyolefin resin and a curing agent represented by the above formula (1) is formed, applied on one side of the barrier layer, dried and cured at a temperature of 100 to 150 ° C To form a first adhesive layer. A first film having a thickness of 50 mu m was formed using a polypropylene (PP) resin, laminated on the first adhesive layer, and pressed to form a sealant layer by laminating to the barrier layer. A second adhesive layer was formed on the other surface of the barrier layer where the sealant layer was not formed. At this time, the second adhesive layer is formed by applying a second adhesive composition comprising a polyester-based adhesive resin and an isocyanate curing agent on the other side of the barrier layer on which the sealant layer is not formed, drying at a temperature of 70 to 150 ° C And curing. A second film having a thickness of 25 mu m was formed using nylon, laminated on the second adhesive layer, and pressed to form an outer layer by laminating to the barrier layer.

Thus, a cell pouch including a sequentially stacked sealant layer, a first adhesive layer (containing a curing agent represented by the following formula (1)), a barrier layer, a second adhesive layer, and an outer layer was produced.

[Comparative Example 1]

Except that the first adhesive layer was formed using the curing agent represented by the following formula (2) instead of the curing agent represented by the above formula (1).

Thus, a cell pouch including a sequentially stacked sealant layer, a first adhesive layer (containing a curing agent represented by Formula 2), a barrier layer, a second adhesive layer, and an outer layer was produced.

(2)

[Comparative Example 2]

Except that the first adhesive layer was formed by using a curing agent (hexamethylene diisocyanate (HDI)) represented by the following formula 3 instead of the curing agent represented by the above formula (1) The same procedure was followed.

Thus, a cell pouch including a sequentially stacked sealant layer, a first adhesive layer (containing a curing agent (HDI) represented by Formula 3), a barrier layer, a second adhesive layer, and an outer layer was produced.

(3)

OCN- (CH _{2) 6} -NCO

[Comparative Example 3]

Except that the first adhesive layer was formed using a curing agent (isophorone diisocyanate (IPDI)) represented by the following formula (4) instead of the curing agent represented by the above formula (1) The same procedure was followed.

Thus, a cell pouch including a sequentially stacked sealant layer, a first adhesive layer (containing a curing agent (IPDI) represented by Formula 4), a barrier layer, a second adhesive layer, and an outer layer was produced.

[Chemical Formula 4]

Cell pouch Electrolytic solution resistance  evaluation

Cell pouches prepared according to Examples and Comparative Examples 1 to 3 were impregnated with a standard electrolyte (1.0 M LiPF ₆ in EC / DEC / EMC = 1: 1: 1) to evaluate the electrolyte resistance of the cell pouches , And the peel strength between the sealant layer and the barrier layer of the cell pouches was measured at regular time intervals as shown in [Table 1]. In the measurement, the width of the sample was set to 15 mm, the gauge distance was set to 300 mm, and the peeling was carried out at a peeling rate of 200 mm / min. At this time, it was determined that the higher the peel strength was, the better the electrolyte resistance was, and the results are as shown in Table 1 below.

Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Sealant layer / barrier layer
Peel strength
(kgf / 15 mm) 24 hours after impregnation ◎ ◎ △ △ 48 hours after impregnation ◎ ○ △ △ 72 hours after impregnation ◎ ○ △ X 96 hours after impregnation ◎ ○ △ X 120 hours after impregnation ◎ △ X X 144 hours after impregnation ◎ △ X X 168 hours after impregnation ○ X X X

Excellent (◎) Good (○) Average (△) Dissatisfied (X)

Referring to Table 1, the peel strength between the sealant layer and the barrier layer was higher in the case of Examples 1 to 3 than in Comparative Examples 1 to 3. In particular, It was confirmed that the peel strength was good.

Thus, it can be seen that the reliability of the first adhesive layer provided between the sealant layer and the barrier layer is secured in terms of adhesiveness, chemical resistance, and the like, thereby realizing a highly reliable cell pouch.

Evaluation of the antibacterial property of cell pouch

The cell pouches prepared according to the examples and comparative examples 1 to 3 were prepared in the form of a pack of 100 mm x 100 mm and then a standard electrolyte (1.0 M LiPF ₆ in EC / DEC / EMC = 1: 1: 1) and water were injected and the peripheral part was sealed and stored at 75 ° C. Then, the peel strength between the sealant layer and the barrier layer of the cell pouches was measured at regular time intervals as shown in [Table 2] and [Table 3].

The solution was prepared by mixing 10 g of the standard electrolyte solution and 0.01 g of water, and a mixture of 10 g of the standard electrolyte solution and 0.1 g of water, and these were used for the 0.1% test for the heat resistance and the 1% test for the heat resistance. In the measurement, the width of the sample was 15 mm, the gauge distance was 300 mm, and the peeling was performed at a peeling rate of 200 mm / min. The higher the peel strength was, the better the anti-brittleness was judged. The results of the measurements are shown in the following Tables 2 and 3.

Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Sealant layer / barrier layer
Peel strength
(kgf / 15 mm) 24 hours after impregnation ◎ ○ △ △ 240 hours after impregnation ◎ ○ △ X 480 hours after impregnation ◎ △ △ X 720 hours after impregnation ◎ X X X 960 hours after impregnation ○ X X X 1,200 hours after impregnation ○ X X X

Excellent (◎) Good (○) Average (△) Dissatisfied (X)

Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Sealant layer / barrier layer
Peel strength
(kgf / 15 mm) 24 hours after impregnation ◎ ○ △ X 240 hours after impregnation ◎ △ △ X 480 hours after impregnation ◎ △ X X 720 hours after impregnation ○ X X X 960 hours after impregnation ○ X X X 1,200 hours after impregnation ○ X X X

Excellent (◎) Good (○) Average (△) Dissatisfied (X)

Referring to [Table 2] and [Table 3], the peel strength between the sealant layer and the barrier layer was higher in the case of Examples than Comparative Examples 1 to 3. Particularly, as the hydrofluoric acid concentration was increased, the interlaminar peeling strength was somewhat reduced. However, unlike Comparative Examples 1 to 3 in the case of Examples, it was confirmed that still good interlaminar peeling strength was exhibited even after 1,200 hours from the impregnation.

Thus, it can be seen that the reliability of the first adhesive layer provided between the sealant layer and the barrier layer is secured in terms of adhesiveness, chemical resistance, and the like, thereby realizing a highly reliable cell pouch.

Formability evaluation of cell pouch

In order to evaluate the formability of the cell pouch, the multi-layer films prepared according to Examples and Comparative Examples 1 to 3 were cut to a size of 150 mm x 150 mm, respectively, to prepare square angular specimens, and a mold having a size of 40 mm x 33 mm And the corresponding specimens were molded. At this time, the occurrence of cracks in the barrier layer was measured, and the results are shown in Table 4 below.

Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Cracks in the barrier layer ◎ ○ △ △

Excellent (◎) Good (○) Average (△) Dissatisfied (X)

Referring to Table 4, it can be seen that the multilayer films prepared according to the Examples are much more easily formed without cracks in the barrier layer than the multilayer films prepared according to Comparative Examples 1 to 3.

Thus, it can be seen that by securing the stability of the first adhesive layer provided between the sealant layer and the barrier layer in terms of adhesiveness, chemical resistance and the like, it is possible to realize a highly reliable cell pouch having improved formability .

10: sealant layer
15: First adhesive layer
20: barrier layer
25: Second adhesive layer
30: outer layer
100: cell pouch

Claims (12)

1. A cell pouch comprising:
A sealant layer;
A first adhesive layer formed on the sealant layer;
A barrier layer formed on the first adhesive layer;
A second adhesive layer formed on the barrier layer; And
And an outer layer formed on the second adhesive layer,
Wherein the first adhesive layer comprises a maleic anhydride-modified polyolefin resin and a glycidylamine type epoxy curing agent,
Wherein the glycidylamine type epoxy curing agent is represented by the following formula (1).
[Chemical Formula 1]

delete The method according to claim 1,
Wherein the glycidylamine type epoxy curing agent is contained in the first adhesive layer in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the maleic anhydride-modified polyolefin resin. The method according to claim 1,
Wherein the sealant layer is in contact with a cell embedded in the cell pouch as an innermost layer of the cell pouch,
Wherein the outer layer is exposed to the outside as an outermost layer of the cell pouch. The method according to claim 1,
Wherein the sealant layer comprises a polypropylene-based resin or a casting polypropylene (CPP) based film. The method according to claim 1,
Wherein the barrier layer comprises at least one metal having moisture barrier properties and gas barrier properties. The method according to claim 1,
Wherein the outer layer comprises at least one selected from a polyamide-based resin and a polyester-based resin. 8. The method of claim 7,
The polyamide-based resin is nylon,
Wherein the polyester resin is polybutylene terephthalate (PBT) or polyethylene terephthalate (PET). The method according to claim 1,
Wherein the cell pouch is a cell pouch for a secondary battery. 10. The method of claim 9,
Wherein the secondary battery is a lithium ion secondary battery. 11. A method of manufacturing a cell pouch according to any one of claims 1 to 10,
Forming a barrier layer;
Forming a first adhesive layer on one side of the barrier layer using a maleic anhydride-modified polyolefin resin and a glycidylamine-type epoxy curing agent;
Forming a sealant layer to be bonded to one surface of the barrier layer using the first adhesive layer;
Forming a second adhesive layer on the other side of the barrier layer where the sealant layer is not formed; And
And forming an outer layer to be bonded to the other surface of the barrier layer so as to face the sealant layer using the second adhesive layer.
delete

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