KR102282604B1 - Secondary battery pouch film containing graphene - Google Patents

Abstract

The present application relates to a film for a secondary battery pouch containing graphene and a method for manufacturing the film for a secondary battery pouch.

Description

Film for secondary battery pouch containing graphene {SECONDARY BATTERY POUCH FILM CONTAINING GRAPHENE}

The present application relates to a film for a secondary battery pouch containing graphene and a method for manufacturing the film for a secondary battery pouch.

A secondary battery pouch is used as an exterior material for packaging secondary batteries including lithium secondary batteries. The secondary battery pouch protects the battery cell composed of the electrode assembly and the electrolyte introduced into the interior by the subsequent process, and is composed of an aluminum thin film interposed in order to supplement the electrochemical properties of the battery cell and improve heat dissipation, In order to protect the battery cell from external impact, a functional polymer film is formed on the aluminum thin film as an outer layer.

The pouch-type secondary battery may be damaged for various reasons in various processes. For example, in the process of accommodating the electrode assembly in the pouch, a protruding portion such as an electrode tab or an electrode lead damages the sealant layer inside the pouch, such as cracks, and by such damage, the aluminum layer can be exposed. In addition, when the pouch is sealed, heat is applied from the outside, and even by this heat, a fine pinhole is generated or the pouch is damaged inside and a crack occurs in the inner adhesive layer, so that the aluminum layer can be exposed to the electrolyte. In addition, the adhesive layer in the form of a thin film may be damaged even by dropping, impact, pressure, or compression, and the aluminum layer is exposed to the electrolyte or the like through the damaged portion of the adhesive layer. The aluminum layer exposed to the electrolyte may be corroded by causing a chemical reaction with oxygen or moisture with the electrolyte that has penetrated or diffused into the battery. There are problems that arise. More specifically, LiPF ₆ may react with water and oxygen to generate hydrofluoric acid (HF), a corrosive gas. Such hydrofluoric acid may react with aluminum to cause a rapid exothermic reaction, and as a secondary reaction, it is adsorbed to the aluminum surface and penetrates into the tissue. Lithium may react with the atmosphere and cause ignition.

Therefore, in order to prevent contact with aluminum even when corrosive hydrofluoric acid is generated as described above, various aluminum surface modification techniques are being studied. However, since the capacity of secondary batteries is gradually increasing in capacity in recent years, there is a limit to solving the above problems only by modifying the surface of aluminum. This is constantly being discussed.

Republic of Korea Patent Publication No. 10-2013-0081445

The present application includes a sealant layer, a primer layer, an adhesive layer, a core layer and a surface layer, which may further include graphene in each layer except the core layer, a film for a secondary battery pouch; And to provide a method of manufacturing the film for the secondary battery pouch.

However, the problem to be solved by the present application is not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

A first aspect of the present application, a sealant layer; a first adhesive layer formed on the sealant layer; a primer layer formed on the first adhesive layer; a core layer formed on the primer layer; a second adhesive layer formed on the core layer; and a surface layer formed on the second adhesive layer, as a film for a secondary battery pouch, wherein at least one of the sealant layer, the primer layer, the first adhesive layer, the second adhesive layer, and the surface layer is yes It provides a film for a secondary battery pouch, which includes a pin.

The second aspect of the present application is to form a sealant layer, a core layer, and a surface layer, respectively, and to laminate the sealant layer, the core layer, and the surface layer in this order, Manufacturing a film for a secondary battery pouch according to the first aspect A method comprising: a first adhesive layer and a primer layer between the sealant layer and the core layer; a second adhesive layer between the core layer and the surface layer; the sealant layer, the primer layer, the first It provides a method for manufacturing a film for a secondary battery pouch, wherein one or more layers of the adhesive layer, the second adhesive layer, and the surface layer include graphene.

The film for a secondary battery pouch comprising graphene according to embodiments of the present application includes at least one of a sealant layer, a primer layer, an inner resin layer, a first adhesive layer, a second adhesive layer, a third adhesive layer, and a surface layer. By including graphene, even if the thickness of the core layer is thinner than the thickness of the aluminum layer of the conventional packaging material for secondary battery pouches, it can be implemented as a secondary battery pouch, increasing mechanical strength such as flame resistance and impact resistance; increased barrier properties such as moisture and oxygen; And there is an effect of increasing chemical resistance, in particular, there is an advantage that can significantly reduce the amount of aluminum used. In addition, even when only one of the sealant layer, the primer layer, the inner resin layer, the first adhesive layer, the second adhesive layer, the third adhesive layer, and the surface layer contains graphene, The effect can be exhibited, and even if graphene is included in all of the two or more layers, the desired effect can be exhibited.

1 is a schematic diagram showing a film for a secondary battery pouch according to an embodiment of the present application.
2 is a schematic view showing a film for a secondary battery pouch according to an embodiment of the present application.
3 is a photograph showing a film for a secondary battery pouch according to an embodiment of the present application.
4 is a graph of measuring the forming burst depth of a film for a secondary battery pouch according to the content of graphene according to an embodiment of the present application.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily carry out. However, the present application may be embodied in several different forms and is not limited to the embodiments and examples described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout this specification, when a part is said to be "connected" with another part, it includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element interposed therebetween. do.

Throughout this specification, when a member is said to be “on” another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members.

Throughout this specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

As used herein, the terms "about," "substantially," and the like are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and to aid in the understanding of the present application. It is used to prevent an unconscionable infringer from using the mentioned disclosure in an unreasonable manner.

As used throughout this specification, the term “step of doing” or “step of” does not mean “step for”.

Throughout this specification, the term "combination(s)" included in the expression of the Markush form means one or more mixtures or combinations selected from the group consisting of the components described in the expression of the Markush form, It means to include one or more selected from the group consisting of the above components.

Throughout this specification, reference to “A and/or B” means “A or B, or A and B”.

Throughout the present specification, the term "graphene" means that a plurality of carbon atoms are covalently linked to each other to form a polycyclic aromatic molecule, and the covalently linked carbon atoms are a basic repeating unit. It forms a 6-membered ring, but it is also possible to further include a 5-membered ring and/or a 7-membered ring. Accordingly, the sheet formed by the graphene may be viewed as a single layer of carbon atoms covalently bonded to each other, but is not limited thereto. The sheet formed by the graphene may have various structures, and such a structure may vary depending on the content of 5-membered rings and/or 7-membered rings that may be included in graphene. In addition, when the sheet formed of the graphene is made of a single layer, they may be laminated to each other to form a plurality of layers, and side end portions of the graphene sheet may be saturated with hydrogen atoms, but the present invention is not limited thereto.

Throughout this specification, the term "graphene oxide" is also referred to as graphene oxide, and may be abbreviated as "GO". The single-layer graphene may include a structure in which a functional group containing oxygen, such as a carboxyl group, a hydroxyl group, or an epoxy group, is bonded, but is not limited thereto.

Throughout this specification, the term "reduced graphene oxide" or "reduced graphene oxide" refers to graphene oxide with reduced oxygen ratio through a reduction process, and may be abbreviated as "rGO" However, the present invention is not limited thereto.

Throughout this specification, the term "graphene nano platelet" refers to a material having 10 to 100 carbon layers prepared by physical or chemical methods using natural graphite as "GNP". It may be abbreviated, but is not limited thereto.

Hereinafter, embodiments and examples of the present application will be described in detail with reference to the accompanying drawings. However, the present application is not limited to these embodiments and examples and drawings.

A first aspect of the present application, a sealant layer; a first adhesive layer formed on the sealant layer; a primer layer formed on the first adhesive layer; a core layer formed on the primer layer; a second adhesive layer formed on the core layer; and a surface layer formed on the second adhesive layer, as a film for a secondary battery pouch, wherein at least one of the sealant layer, the primer layer, the first adhesive layer, the second adhesive layer, and the surface layer is yes It provides a film for a secondary battery pouch, which includes a pin.

In one embodiment of the present application, between the second adhesive layer and the surface layer, an inner resin layer formed on the second adhesive layer; and a third adhesive layer formed on the inner resin layer, wherein at least one of the inner resin layer and the third adhesive layer may include graphene.

Specifically, the film for a secondary battery pouch according to an embodiment of the present application, the sealant layer, the primer layer, the inner resin layer, the first adhesive layer, the second adhesive layer, the third adhesive layer and the surface layer At least one layer of the graphene may be used as a film for a secondary battery pouch even if the thickness of the core layer is thinned. In addition, the film for the secondary battery pouch increases mechanical strength such as flame resistance and impact resistance; increased barrier properties such as moisture and oxygen; And there is an effect of increasing chemical resistance. In addition, when only one of the sealant layer, the primer layer, the inner resin layer, the first adhesive layer, the second adhesive layer, the third adhesive layer, and the surface layer contains graphene, the desired The effect can be exhibited, and even if graphene is included in two or all layers, the desired effect can be exhibited.

In one embodiment of the present application, the thickness of the core layer may be about 12 μm to about 80 μm. Specifically, the thickness of the core layer is about 12 μm to about 80 μm, about 12 μm to about 60 μm, about 12 μm to about 55 μm, about 12 μm to about 50 μm, about 12 μm to about 45 μm, about 12 μm to about 40 μm, about 12 μm to about 35 μm, about 12 μm to about 30 μm, about 15 μm to about 80 μm, about 15 μm to about 60 μm, about 20 μm to about 60 μm, about 25 μm to about 60 μm, about 30 μm to about 60 μm, about 20 μm to about 50 μm, about 25 μm to about 50 μm, about 30 μm to about 50 μm, about 35 μm to about 45 μm or about 40 μm to about 45 μm, but is not limited thereto. The prior art film for secondary battery pouches had durability that could be realized as a pouch film when the thickness of the core layer was at least 50 μm, but the film for secondary battery pouches according to an embodiment of the present application has a core layer thickness of 50 μm. Even if it is set to less than μm and up to 12 μm, it has the effect of having the durability that can be realized as a film for pouches.

In one embodiment of the present application, the thickness of the sealant layer may be about 30 μm to about 100 μm. Specifically, the thickness of the sealant layer is about 30 μm to about 100 μm, about 40 μm to about 100 μm, about 40 μm to about 90 μm, about 40 μm to about 80 μm, about 40 μm to about 70 μm, about 40 μm to about 60 μm, about 50 μm to about 100 μm, about 60 μm to about 100 μm, about 70 μm to about 100 μm, about 80 μm to about 100 μm, about 50 μm to about 90 μm, about 50 μm to about 80 μm or from about 60 μm to about 80 μm, but is not limited thereto.

In one embodiment of the present application, the thickness of the primer layer may be about 0.1 μm to about 5 μm. Specifically, the primer layer is about 0.1 μm to about 5 μm, about 0.1 μm to about 4 μm, about 0.1 μm to about 3 μm, about 1 μm to about 5 μm, about 1 μm to about 4 μm or about 1 μm to about 3 μm, but is not limited thereto.

In one embodiment of the present application, the thickness of the first adhesive layer, the second adhesive layer, or the third adhesive layer may be about 1 μm to about 10 μm. Specifically, the first adhesive layer, the second adhesive layer or the third adhesive layer is about 1 μm to about 10 μm, about 1 μm to about 8 μm, about 1 μm to about 6 μm, about 1 μm to about 4 μm, about 3 μm to about 10 μm, about 5 μm to about 10 μm, about 7 μm to about 10 μm, about 3 μm to about 7 μm, about 4 μm to about 6 μm, or about 1 μm to about 3 μm may be, but is not limited thereto.

In one embodiment of the present application, the thickness of the surface layer may be about 10 μm to about 30 μm. Specifically, the thickness of the surface layer is about 10 μm to about 30 μm, about 15 μm to about 30 μm, about 20 μm to about 30 μm, about 25 μm to about 30 μm, about 15 μm to about 25 μm, about 15 μm to about 20 μm or from about 20 μm to about 25 μm, but is not limited thereto.

In one embodiment of the present application, the thickness of the inner resin layer may be about 10 μm to about 30 μm, but is not limited thereto. Specifically, the thickness of the inner resin layer is about 10 μm to about 30 μm, about 15 μm to about 30 μm, about 20 μm to about 30 μm, about 25 μm to about 30 μm, about 15 μm to about 25 μm, about 15 μm to about 20 μm, about 20 μm to about 25 μm, or about 10 μm to about 20 μm.

1, the film for a small secondary battery pouch according to an embodiment of the present application, the sealant layer 10 having a thickness of about 40 μm to about 100 μm, the primer layer having a thickness of about 0.1 μm to about 5 μm ( 50), the core layer 20 having a thickness of about 12 μm to about 60 μm, the first adhesive layer 401 or the second adhesive layer 402 having a thickness of about 1 μm to about 10 μm, about 15 μm to It may be composed of the surface layer 30 having a thickness of about 30 μm. In the prior art, there is a problem in that the film cracks or bursts even when a core layer of 40 μm is formed, whereas the film for a secondary battery pouch according to an embodiment of the present application has a thickness of 40 μm and a minimum of 12 μm in the core layer. There is an advantage in that it is possible to implement a secondary battery pouch without any problems in effect. In addition, referring to FIG. 2 , the film for medium and large sized secondary battery pouches further comprising an inner resin layer 60 formed on the second adhesive layer and a third adhesive layer 403 on the inner resin layer is the same can be effective.

1 and 2, the sealant layer 10, the primer layer 50, the core layer 20, the surface layer 30; And the sealant layer 10, the primer layer 50, the core layer 20, the inner resin layer 60 and the surface layer 30 constituted a film for a secondary battery pouch, but this is only an example and a film for a secondary battery pouch Further including a film that can be used for, or including less may be included in one embodiment of the present application as long as it does not depart from the scope of the technical spirit of the present application. As an example, it may be composed of 5 layers, 7 layers, 9 layers, or 11 layers by additionally including a film that can be used in the film for secondary battery pouches, and may be composed of 2 layers including less.

In one embodiment of the present application, the graphene may increase the durability of the entire film for secondary battery pouches and decrease gas permeability and moisture permeability.

In one embodiment of the present application, one or more layers of the first adhesive layer, the second adhesive layer, and the third adhesive layer include the graphene, and the content of the graphene is the first adhesive layer, the The amount of the second adhesive layer and the third adhesive layer may be 0.005 parts by weight to 10 parts by weight based on 100 parts by weight, respectively. When the content of the graphene is less than 0.005 parts by weight, the effect of increasing the durability of the film for secondary battery pouches is insignificant, indicating the durability of the prior art. There is a problem with degradation. Specifically, the content of the graphene is 0.005 parts by weight to 10 parts by weight, 0.005 parts by weight to 5 parts by weight, 0.005 parts by weight based on 100 parts by weight of each of the first adhesive layer, the second adhesive layer, and the third adhesive layer. parts by weight to 3 parts by weight, 0.005 parts by weight to 2 parts by weight, 0.01 parts by weight to 2 parts by weight, 0.01 parts by weight to 1.5 parts by weight, 0.05 parts by weight to 1.5 parts by weight, or 0.1 parts by weight to 1.5 parts by weight.

In one embodiment of the present application, the sealant layer may include the graphene, and the content of the graphene may be 0.005 parts by weight to 10 parts by weight based on 100 parts by weight of the sealant layer. When the content of the graphene is less than 0.005 parts by weight, the effect of increasing the durability of the film for secondary battery pouches is insignificant, indicating the durability of the prior art level, and when the content of the graphene exceeds 10 parts by weight, the durability is rather reduced compared to the prior art there is a problem that Specifically, the content of the graphene is 0.005 parts by weight to 10 parts by weight, 0.005 parts by weight to 5 parts by weight, 0.005 parts by weight to 3 parts by weight, 0.005 parts by weight to 2 parts by weight, 0.01 based on 100 parts by weight of the sealant layer. It may be in an amount of 2 parts by weight to 2 parts by weight, 0.01 parts by weight to 1.5 parts by weight, 0.05 parts by weight to 1.5 parts by weight, or 0.1 parts by weight to 1.5 parts by weight.

In one embodiment of the present application, the primer layer may include the graphene, and the content of the graphene may be 0.005 parts by weight to 10 parts by weight based on 100 parts by weight of the primer layer. When the content of the graphene is less than 0.005 parts by weight, the effect of increasing the durability of the film for secondary battery pouches is insignificant, indicating the durability of the prior art level, and when the content of the graphene exceeds 10 parts by weight, the durability is rather reduced compared to the prior art there is a problem that Specifically, the content of the graphene is 0.005 parts by weight to 10 parts by weight, 0.005 parts by weight to 5 parts by weight, 0.005 parts by weight to 3 parts by weight, 0.005 parts by weight to 2 parts by weight, 0.01 with respect to 100 parts by weight of the primer layer. It may be in an amount of 2 parts by weight to 2 parts by weight, 0.01 parts by weight to 1.5 parts by weight, 0.05 parts by weight to 1.5 parts by weight, or 0.1 parts by weight to 1.5 parts by weight.

In one embodiment of the present application, the surface layer may include the graphene, and the content of the graphene may be 0.005 parts by weight to 10 parts by weight based on 100 parts by weight of the surface layer. When the content of the graphene is less than 0.005 parts by weight, the effect of increasing the durability of the film for secondary battery pouches is insignificant, indicating the durability of the prior art level, and when the content of the graphene exceeds 10 parts by weight, the durability is rather reduced compared to the prior art there is a problem that Specifically, the content of the graphene is 0.005 parts by weight to 10 parts by weight, 0.005 parts by weight to 5 parts by weight, 0.005 parts by weight to 3 parts by weight, 0.005 parts by weight to 2 parts by weight, 0.01 parts by weight based on 100 parts by weight of the surface layer. parts by weight to 2 parts by weight, 0.01 parts by weight to 1.5 parts by weight, 0.05 parts by weight to 1.5 parts by weight, or 0.1 parts by weight to 1.5 parts by weight.

In one embodiment of the present application, the graphene may be selected from the group consisting of graphene, graphene oxide (GO), reduced graphene oxide (rGO), graphene nanoplatelets, and combinations thereof. there is. Specifically, the graphene oxide includes a plurality of graphene oxide sheets, the reduced graphene oxide includes a plurality of reduced graphene oxide sheets, the plurality of graphene sheets and the plurality of reduced graphene sheets Each of the fin oxide sheets may include an oxygen-containing functional group and/or a pinhole. For example, the reduced graphene oxide may be prepared by peroxidizing graphite to obtain graphene oxide, and reducing the obtained graphene oxide to obtain reduced graphene oxide, but limited thereto it doesn't happen In the process of peroxidation of the graphite, oxygen-containing functional groups are generated at the edges of graphene and inside the graphene, and defects are generated and pinholes are generated, so that each of the reduced graphene oxide sheets finally obtained is an oxygen-containing functional group and/or may include a pinhole.

In one embodiment of the present application, the oxygen-containing functional group is selected from the group consisting of a hydroxyl group, an epoxy group, a carboxyl group, a ketone group, and combinations thereof. It may include, but is not limited to.

In one embodiment of the present application, the spacing of the voids between the plurality of graphene oxide sheets and the plurality of reduced graphene oxide sheets may be about 1 nm to about 20 nm, but is not limited thereto. can

In one embodiment of the present application, the size of the pinhole formed in the graphene oxide sheet and the reduced graphene oxide sheet may be about 0.1 nm to about 10 nm, but may not be limited thereto.

In one embodiment of the present application, the sealant layer may include polypropylene (PP) or non-stretched polypropylene (CPP). Specifically, the sealant layer is a portion where the upper pouch and the lower pouch are joined by thermal fusion, etc., and the sealant layers face each other and heat seal the corners to manufacture a secondary battery pouch. To realize a film with high mechanical strength, polypropylene (PP) or unstretched polypropylene (CPP) can be used. In particular, CPP has excellent flexibility, excellent adhesion, tensile strength, elongation, and tearing steel. The figure is similar to cellophane, but has less gas permeability, so it is suitable for use as a component of a secondary battery pouch. In addition, the polypropylene is colorless, odorless, non-toxic, hygienic, has the lowest specific gravity among plastics, has the advantage of being inexpensive, and has good gas permeability resistance, so it is suitable for use as a component of a secondary battery pouch.

In one embodiment of the present application, the core layer may include an aluminum foil or an aluminum deposition layer, but is not limited thereto.

In one embodiment of the present application, the primer layer may include modified polyethylene (modified PE), modified polypropylene (modified PP) or modified acrylic resin. The primer layer means that an adhesive resin that is easily adhered to aluminum is coated to facilitate adhesion between the aluminum component of the core layer and the sealant layer. In the case of a battery requiring heat resistance, polypropylene resin is usually used as a material for the sealant layer. At this time, the aluminum component of the core layer is not directly attached during melt extrusion coating, so it is coated with an adhesive resin for easy attachment.

In one embodiment of the present application, each of the first adhesive layer, the second adhesive layer and the third adhesive layer is a polyurethane-based adhesive, an acrylic adhesive, an epoxy-based adhesive, a polyolefin-based adhesive, an elastomeric adhesive, or a fluorine-based adhesive. may include. Since high temperature due to heat is generated when the battery is moved in the internally packaged cell, in this case, in the case of an adhesive having low heat resistance, interlayer separation occurs, so a component of the adhesive having excellent heat resistance should be used.

In one embodiment of the present application, the surface layer may include nylon (NY), polyethylene terephthalate (PET), polypropylene (PP), or polyamide (PA). Specifically, the surface layer is a portion that becomes the surface of the secondary battery pouch, protects the surface of the pouch, and can use a material having high thermal conductivity and low electrical conductivity, nylon (NY), polyethylene terephthalate (PET), poly Propylene (PP) or polyamide (PA) can be used. Nylon 6, 11, 12, 66, 610, etc. are commercialized, but nylon 6 is suitable as a non-stretched film. It has the advantage of low gas permeability.

In one embodiment of the present application, the internal resin layer may include a polyolefin such as nylon (NY), polyethylene (PE), or polypropylene (PP) or a copolymer thereof, but this Not limited. The inner resin layer provides physical properties required as a film for secondary battery pouches, such as good heat-sealing properties, moisture-proof properties, and heat resistance, and has advantages in processability such as lamination.

In one embodiment of the present application, the forming burst depth of the film for secondary battery pouches may be greater than 8.6 mm and less than 9.5 mm. Specifically, the film for a secondary battery pouch may have increased durability by including graphene in at least one of the sealant layer, the primer layer, the first adhesive layer, the second adhesive layer, and the surface layer. Therefore, when a press is applied after forming the film for a secondary battery pouch, it can have durability that does not burst even if the depth that the film for secondary battery pouch endures increases. More specifically, the mold burst depth is greater than 8.6 mm and less than 9.5 mm; greater than 8.6 mm and less than 9.5 mm; greater than 9.0 mm and less than 9.5 mm; or greater than 9.1 mm and less than 9.5 mm.

The second aspect of the present application is to form a sealant layer, a core layer, and a surface layer, respectively, and to laminate the sealant layer, the core layer, and the surface layer in this order, Manufacturing a film for a secondary battery pouch according to the first aspect A method comprising: a first adhesive layer and a primer layer between the sealant layer and the core layer; a second adhesive layer between the core layer and the surface layer; the sealant layer, the primer layer, the first It provides a method for manufacturing a film for a secondary battery pouch, wherein one or more layers of the adhesive layer, the second adhesive layer, and the surface layer include graphene.

In the first aspect and the second aspect, content that may be common to each other may be applied to both the first aspect and the second aspect even if the description thereof is omitted.

In one embodiment of the present application, the method for manufacturing the film for a secondary battery pouch comprises additionally forming an inner resin layer, and laminating the sealant layer, the core layer, the inner resin layer, and the surface layer in this order. a first adhesive layer and a primer layer between the sealant layer and the core layer, and a second adhesive layer between the core layer and the surface layer, and between the second adhesive layer and the surface layer, the The inner resin layer may be formed on a second adhesive layer, and the third adhesive layer may be formed on the inner resin layer.

In one embodiment of the present application, forming the sealant layer, the inner resin layer, and/or the surface layer comprises melting the raw materials of each of the sealant layer, the inner resin layer and the surface layer at a temperature of 230°C to 250°C. and extruding the melt at an extrusion amount of 700 kg/h to 1000 kg/h and supplying it to a T-die, and non-drawing and processing the melt supplied to the T-die. . In this case, the average thickness of each of the sealant layer may be from about 30 μm to about 100 μm, and the inner resin layer and the surface layer may include, but is not limited to.

In one embodiment of the present application, the thickness of the core layer may be about 5 μm to about 60 μm. Specifically, the thickness of the core layer is about 5 μm to about 60 μm, about 12 μm to about 60 μm, about 12 μm to about 55 μm, about 12 μm to about 50 μm, about 12 μm to about 45 μm, about 12 μm to about 40 μm, about 12 μm to about 35 μm, about 12 μm to about 30 μm, about 15 μm to about 60 μm, about 20 μm to about 60 μm, about 25 μm to about 60 μm, about 30 μm to about 60 μm, about 20 μm to about 50 μm, about 25 μm to about 50 μm, about 30 μm to about 50 μm, about 35 μm to about 45 μm, or about 40 μm to about 45 μm, but is not limited thereto. it doesn't happen

In one embodiment of the present application, forming the core layer may include processing aluminum in the form of a plate by passing a raw material (strip) containing aluminum between two rolls rotating at a recrystallization temperature or lower. . At this time, depending on the desired thickness, repeat operations 1 to 5 times may be performed. In addition, the method may include forming the core layer to have an average thickness of 12 μm to 60 μm.

In one embodiment of the present application, the laminate may include, but is not limited to, dry lamination. Specifically, the first adhesive layer may be formed through dry lamination to increase viscosity by applying a first adhesive raw material on the sealant layer and volatilizing a dilution solvent in the same space as a drying chamber. The second adhesive layer may be formed through dry lamination to increase viscosity by applying a second adhesive raw material on the core layer and volatilizing a dilution solvent in the same space as a drying chamber. In addition, the third adhesive layer may be formed through dry lamination to increase viscosity by applying a third adhesive raw material on the inner resin layer and volatilizing a dilution solvent in the same space as a drying chamber.

Hereinafter, the present application will be described in more detail with reference to Examples, but the present application is not limited thereto.

[Example]

1. Examples

1-1. Formation of sealant layer and surface layer

Polypropylene and nylon resin were prepared, melted at 240° C., and extruded at an extrusion rate of 800 kg/h, and supplied to a T-die. After that, the polypropylene melt was undrawn and processed to form a sealant layer with an average thickness of 40 μm to 80 μm, and the nylon resin melt was undrawn and processed to form a surface layer with an average thickness of 25 μm to 30 μm.

1-2. Core layer formation

An aluminum raw material (strip) was prepared and passed between two rolls rotating below the recrystallization temperature to process aluminum into a plate shape to form a core layer having an average thickness of 35 μm to 40 μm.

1-3. Formation of film for secondary battery pouch

Laminated secondary battery pouch having an average thickness of 90 μm to 185 μm by placing the sealant layer, the core layer, and the surface layer on a roller for lamination in order and moving the roller to take the sealant layer, the core layer, and the surface layer in this order A film was formed. In addition, a primer layer was additionally included between the sealant layer and the core layer. The adhesive used for the laminate was an acrylic adhesive, but one containing 0.01 parts by weight of graphene based on 100 parts by weight of the total adhesive was used (FIG. 3).

2. Comparative Example 1

A film for a secondary battery pouch was synthesized under the same conditions as in the above example, except that the thickness of the core layer was implemented as 50 μm and graphene was not contained in the adhesive component.

3. Comparative Example 2

A film for a secondary battery pouch was synthesized under the same conditions as in the above example, except that the thickness of the core layer was implemented as 40 μm and graphene was not contained in the adhesive component.

Experimental Example 1: Comparison of durability between a film for a secondary battery pouch containing graphene and the prior art

As a result of checking the films for secondary battery pouches of Examples, Comparative Examples 1 and 2, prepared above, Comparative Example 1 in which the thickness of the core layer is 50 µm and the Example in which the thickness of the core layer is 35 µm to 40 µm is moisture , oxygen, etc., and excellent durability were confirmed, but it was confirmed that Comparative Example 2 having a core layer thickness of 40 μm showed low cracks and low shielding properties such as moisture and oxygen on the surface. Therefore, it was confirmed that the embodiment containing graphene has an effect of increasing durability and shielding properties that can fully implement a film for a secondary battery pouch even when the core layer is formed thin, and that there is an advantage of significantly reducing the amount of aluminum used. Confirmed.

Experimental Example 2: A film for a secondary battery pouch containing graphene and a comparison of durability by measuring the molding burst depth of the prior art

A film for a secondary battery pouch was prepared in the same manner as in the above example, but a difference was confirmed in effect according to the content of the graphene. Specifically, in the adhesive layer, 0.0005 parts by weight, 0.001 parts by weight, 0.005 parts by weight, 0.01 parts by weight, 0.05 parts by weight, 0.1 parts by weight, 1.0 parts by weight, 1.5 parts by weight, 2.0 parts by weight based on 100 parts by weight of the total adhesive , 2.5 parts by weight, 3.0 parts by weight, 3.5 parts by weight, 4.0 parts by weight, 4.5 parts by weight, 5.0 parts by weight of graphene was added to prepare a film for a secondary battery pouch. And the effect according to the graphene content was confirmed by measuring the forming burst depth at which the secondary battery pouch film starts to burst. The mold tear depth refers to the depth at which the sheet withstands without rupture when a press is applied. The depth of the forming burst was compared and judged based on the prior art already on the market, and the forming tear depth of the commercially available sheet was 8.6 mm. The results are shown in Table 1 and FIG. 4 below.

[Table 1]

As a result of confirming the molding bursting result, when the content of the graphene was 0.0005 parts by weight and 0.001 parts by weight, the molding burst depth of the film for secondary battery pouch was 8.6 mm, confirming that it was the same as the breaking depth of the prior art, and 0.001 parts by weight or less. It was confirmed that the performance was equivalent to that of the existing product. In addition, when the content of the graphene was 3.5 parts by weight to 5 parts by weight, the molding rupture depth of the film for secondary battery pouches was 8.5 mm or less, and it was confirmed that the performance was lower than the standard of the existing product in 3.5 parts by weight or more. On the other hand, when the content of the graphene was 0.005 to 3.0 parts by weight, a molding rupture depth exceeding 8.6 mm appeared, and a depth of 9.4 mm (1 part by weight) was measured at the maximum, and according to the addition of graphene, the existing product It was confirmed that the effect of improving the durability was excellent compared to that of .

In addition, in Experimental Examples 1 and 2, only the case in which graphene was contained in the adhesive was confirmed, but these results are the same even when the graphene is contained in the sealant layer, the primer layer, the internal resin layer or the surface layer. It was confirmed that the effect appeared.

The above description of the present application is for illustration, and those of ordinary skill in the art to which the present application pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present application is indicated by the claims described below rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims, and their equivalent concepts should be construed as being included in the scope of the present application. .

10: sealant layer
20: core layer
30: surface layer
40: adhesive layer
401: first adhesive layer
402: second adhesive layer
403: third adhesive layer
50: primer layer
60: inner resin layer

Claims (13)

sealant layer;
a first adhesive layer formed on the sealant layer;
a primer layer formed on the first adhesive layer;
a core layer formed on the primer layer;
a second adhesive layer formed on the core layer; and
A surface layer formed on the second adhesive layer
A film for a secondary battery pouch comprising:
At least one of the sealant layer, the primer layer, the first adhesive layer, the second adhesive layer, and the surface layer includes graphene,
The graphene increases the durability of the entire film for secondary battery pouches and reduces gas permeability and moisture permeability,
The content of the graphene will be 0.005 parts by weight to 3 parts by weight based on 100 parts by weight of each layer,
Film for secondary battery pouch.
The method of claim 1,
between the second adhesive layer and the surface layer,
an inner resin layer formed on the second adhesive layer; and
Further comprising a third adhesive layer formed on the inner resin layer,
At least one layer of the inner resin layer and the third adhesive layer includes graphene, a film for a secondary battery pouch.
The method of claim 1,
The thickness of the core layer will be 12 μm to 80 μm, a film for a secondary battery pouch.
delete The method of claim 1,
Each of the first adhesive layer, the second adhesive layer, or all of them comprises the graphene,
The content of the graphene is 0.005 parts by weight to 3 parts by weight based on 100 parts by weight of each of the first adhesive layer and the second adhesive layer, the film for a secondary battery pouch.
The method of claim 1,
The sealant layer includes the graphene,
The content of the graphene will be 0.005 parts by weight to 3 parts by weight based on 100 parts by weight of the sealant layer, the film for a secondary battery pouch.
The method of claim 1,
The primer layer includes the graphene,
The content of the graphene is 0.005 parts by weight to 3 parts by weight based on 100 parts by weight of the primer layer, a film for a secondary battery pouch.
The method of claim 1,
The surface layer comprises the graphene,
The content of the graphene will be 0.005 parts by weight to 3 parts by weight based on 100 parts by weight of the surface layer, a film for a secondary battery pouch.
3. The method of claim 2,
The inner resin layer includes the graphene,
The content of the graphene will be 0.005 parts by weight to 3 parts by weight based on 100 parts by weight of the inner resin layer, a film for a secondary battery pouch.
The method of claim 1,
The graphene is selected from the group consisting of graphene, graphene oxide (GO), reduced graphene oxide (rGO), graphene nanoplatelets, and combinations thereof, a film for a secondary battery pouch.
The method of claim 1,
The core layer will include an aluminum foil or an aluminum deposition layer, a film for a secondary battery pouch.
forming a sealant layer, a core layer, and a surface layer, respectively;
Laminating the sealant layer, the core layer, and the surface layer in this order
A method for manufacturing a film for a secondary battery pouch according to claim 1, comprising:
A first adhesive layer and a primer layer are included between the sealant layer and the core layer, and a second adhesive layer is included between the core layer and the surface layer,
At least one of the sealant layer, the primer layer, the first adhesive layer, the second adhesive layer, and the surface layer comprises graphene,
A method of manufacturing a film for a secondary battery pouch.
13. The method of claim 12,
The thickness of the core layer will be 12 μm to 80 μm, a method for producing a film for a secondary battery pouch.

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