KR100574819B1 - Pouch for packing cell of the Li secondary battery and portable storage battery - Google Patents

Abstract

The present invention relates to a lithium secondary battery and a portable battery cell packaging encapsulant and a method for manufacturing the same using a laminated plastic film, and more particularly, a surface protective layer, a molding and a base layer, a moisture barrier and a gas barrier layer, an anticorrosion layer, and an adhesive water. The present invention relates to a lithium secondary battery and a portable battery cell packaging encapsulant using a laminated plastic film, and a method for manufacturing the same, wherein the ground layer, the melt extrusion resin layer, and the heat sealing layer are laminated in this order. The packaging material for lithium secondary battery and portable storage battery produced by the battery cell is short and light in manufacturing time, free of shape, and excellent in heat resistance, electrical insulation, moisture proof and gas barrier property, chemical resistance, heat sealing strength and formability, Safely protects the power generation device by smoothing the flow of electrons.

Plastic Film, Lithium, Secondary Battery, Portable, Storage Battery, Cell Packaging Encapsulant, Surface Protection Layer, Molding and Substrate Layer, Moisture-Proof and Gas Barrier Layer, Anti-Corrosion Layer, Adhesive Resin Layer, Melt Extrusion Resin Layer, Ozone Radiation, Heat Seal Layer , Heat resistance, electrical insulation, chemical resistance, formability.

Description

Pouch for packing cell of the Li secondary battery and portable storage battery}             

1 is a cross-sectional view of a lithium secondary battery and a portable battery cell packaging encapsulant according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: surface protective layer 2: molding and substrate layer

3: moisture proof and gas barrier layer 4: corrosion protection layer

5: adhesive resin layer 6: melt extrusion resin layer

7: heat seal layer 8, 9: adhesive layer

The present invention relates to a lithium secondary battery and a portable battery cell packaging encapsulant and a method for manufacturing the same using a laminated plastic film, and more particularly, a surface protective layer, a molding and a base layer, a moisture barrier and a gas barrier layer, an anticorrosion layer, and an adhesive water. Lithium 2 is excellent in heat resistance, electrical insulation, moisture resistance and gas barrier properties, chemical resistance, heat sealing strength and formability by using a laminated plastic film characterized in that the lamination layer, the melt-extrusion resin layer and the heat sealing layer are laminated in order. The present invention relates to a sealing material for packaging a secondary battery and a portable storage battery cell, and a method of manufacturing the same.

A lithium battery, also called a lithium secondary battery, refers to a battery which has a polymer polymer electrolyte and generates electric current by the movement of lithium ions, and includes a cathode and an anode active material made from a polymer polymer.

The composition of the lithium battery is a positive electrode current collector (alumina, nickel), a positive electrode active material layer (made of a polymer positive electrode material such as metal oxide, carbon black, metal sulfide, electrolyte, polyacrylonitrile), electrolyte layer (propylene carbonate, ethylene Carbonate electrolytes such as carbonate, dimethyl carbonate, ethylene methyl carbonate, ethylene dimethyl carbonate, dimethyl carbonate, inorganic solid electrolytes from lithium salts, gel electrolytes, and the like, a negative electrode active material layer (lithium metal, alloy, carbon, electrolyte, Polymer negative electrode materials such as polyacrylonitrile), negative electrode current collectors (copper, nickel, stainless steel), and packages containing them.

Lithium secondary batteries can be classified into lithium metal batteries using liquid electrolytes, lithium ion batteries, and lithium polymer batteries using polymer solid electrolytes, depending on the type of electrolyte.

Such lithium secondary batteries are used in personal computers, portable terminal devices (mobile phones, PDAs, etc.), video cameras, electric vehicles, energy storage batteries, robots, satellites, and the like.

As a packaging material for the lithium secondary battery, generally a metal can that is press-processed and containerized into a cylindrical or parallelepiped shape, and an aluminum can is mainly used.

However, since the packaging material has a hard outer wall of the container, the shape of the battery itself is determined by the shape of the metal can. Therefore, the dimensions of the hardware using the battery are determined by the battery. do. In addition, aluminum cans have a disadvantage in that they are thick, take a lot of time from initial design to manufacture, and are bulky and heavy.

Therefore, in recent years, a pouch-like multilayer film has been developed and used. In this case, although there is no restriction on the degree of freedom of the shape of the hardware using the battery by the battery itself, the physical properties and functions required as a packaging material of a lithium battery are sufficiently satisfied. Satisfactory packaging materials have not been developed yet.

As the required physical properties and functions, as the electrode is made of metal, the innermost layer of the multilayer film is required to have thermal adhesiveness with the metal, and the temperature rise of the battery, which is the contents of the lithium battery, due to charging and discharging, The heat resistance as stability of the adhesion by this is calculated | required.

Lithium battery is a battery contents, acid and heat are generated by hydrolysis when electrolyte is exposed to moisture, strong acidic toxic gas (Gas) is generated when combined with hydrogen when exposed to air, and there is a risk of explosion. In addition, this electrolyte has a high permeability and penetrates into scratches caused by cracks of laminated plastics in various types of cell packaging operations, and corrodes aluminum to cause loss of battery function. As a packaging material, water vapor and air can be blocked from the outside. Desirable moisture proof and barrier properties are required.

Korean Patent Laid-Open Publication No. 1999-0074357 relates to a lithium ion polymer battery, and relates to a lithium ion polymer battery having a sealing structure capable of preventing leakage of an electrolyte solution. A heat adhesive material is laminated on upper and lower surfaces of an ordinary aluminum thin film. Disclosed is a method of sealing a battery using an insulating packaging material which is an insulating film of a conventional form. Korean Patent Application No. 2000-0035752 relates to a non-aqueous electrolyte battery, and relates to a non-aqueous electrolyte battery which can improve impact resistance while maintaining the airtightness of a laminate film. Disclosed is a method of providing a resin layer on at least one side of a battery element when heat-sealing the exterior material to seal the battery element so that the resin layer has an impact monolayer action to protect the battery element from impact.

However, in addition to the prior art, more research is still required in terms of improving physical properties and functions of packaging materials.

The present invention is to solve the above problems, the object of the present invention is that the thickness of the existing aluminum cans in use, takes a lot of time from the first design to production, the shape is constant when used in digital electronic devices It reduces the degree of freedom, reduces the volume and weight, and improves the disadvantages of using a laminated plastic film that is light, short in production time, light in weight, free in shape, and protects the battery cell to smooth the flow of electrons. To provide a packaging encapsulant that can generate power. In addition, the present invention is to provide a packaging sealing material excellent in heat resistance, electrical insulation, moisture-proof and gas barrier properties, chemical resistance, heat sealing strength and moldability, which are physical properties and functions required as a packaging material of a lithium battery as a laminated film.

In order to achieve the above object, the present invention is a packaging material for a lithium secondary battery and a portable storage cell, a surface protection layer for protecting the surface of the packaging material, a molding and substrate layer imparting formability to the packaging material, water vapor and air from the outside of the packaging material Moisture proof and gas barrier layer to prevent intrusion, corrosion prevention layer to prevent corrosion of packaging materials, adhesive resin layer to facilitate adhesion with metal, melt extrusion resin layer to provide adhesion by coating with melt extrusion coating, and packaging material Provided is a lithium secondary battery and a portable battery cell packaging encapsulant using a laminated plastic film and a method of manufacturing the same, wherein the heat sealing layers sealed by heat are sequentially stacked.

The surface protection layer is characterized by consisting of a polyester film excellent in electrolyte resistance to protect the surface of the packaging material by the electrolyte.

The molding and the base layer are for imparting moldability to the packaging material. In the case of the encapsulation type, there is no significant problem, and thus the molding layer is not meaningful.

In addition, the surface protective layer and the molding and the base layer, the molding and the base layer and the moisture and gas barrier layer is characterized in that the laminated using a urethane base two-component adhesive which is excellent in heat resistance.

The moisture-proof and gas-blocking layer is made of a material of a metal thin film, preferably soft aluminum foil, in order to prevent water vapor and air infiltration from the outside.

The anti-corrosion layer is characterized in that the corrosion-resistant coating on the inner surface of the material of the metal thin film in order to prevent corrosion of the packaging material, in particular, moisture-proof and gas barrier layer.

The adhesive resin layer is characterized in that the adhesive resin is easily coated on the material of the metal thin film so that the moisture-proof and the gas barrier layer is easily bonded to the metal.

The melt-extruded resin layer is coated with a melt-extrusion coating to provide an adhesive force to laminate the heat seal layer, characterized in that the polypropylene or polyethylene resin is melt-extruded coating. At this time, during the melt extrusion coating may additionally emit ozone.

The heat-sealing layer is a resin layer capable of sealing by heat so that the packaging material can be sealed by heat with the cell, wherein the resin used is a plastic film formed by adding a modified resin containing a rubber component to the resin in the case of a molding type. It is characterized by consisting of a film.

Hereinafter, the present invention will be described in more detail.

The surface protective layer is to protect the surface of the packaging material by the electrolyte during the production process operation, characterized in that made of a polyester (polyester) film having excellent electrolyte resistance. The polyester film resin usable at this time may be polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (Poly) butylene naphthalate (PBN), copolyester and polycarbonate (PC) may be made of one or more selected from the group consisting of.

In order for the surface protective layer to effectively protect the surface of the packaging material, the thickness of the film used is generally 1.2 µm to 25 µm, preferably 1.2 µm to 9.0 µm.

The molding and the base layer are intended to impart moldability to the packaging material. In the case of a lithium secondary battery and a portable battery cell packaging encapsulant, the packaging method may be largely classified into a bag type and a molding type. The molding layer is not significant because there is no big problem, but the molding type is characterized by using a biaxially stretched polyamide (Polyamides) film which can be molded in consideration of the capacity and size of the battery. The biaxially stretched polyamide film resins usable here include nylon 6, nylon 6.6, copolymers of nylon 6 and nylon 6.6, nylon 6.10 and polymethacylylene amiamide (MXD 6). Characterized in that one selected from the group consisting of.

The thickness of the film of the molding and the base layer is characterized in that 15 to 50 ㎛, preferably 15 to 25 ㎛.

The surface protective layer, the molding and the substrate layer, and the molding and the substrate layer, and the moisture proof and gas barrier layer are laminated using an adhesive. At this time, the surface protective layer and the molding and base layer, the molding and base layer and the moisture and gas barrier layer is laminated using an adhesive having excellent heat resistance, generally a polyurethane adhesive, preferably a urethane base two-component adhesive. It is characterized by. As described above, since a high temperature is generated by heat generation during movement of the battery in the inner-packed cell, the adhesive may be separated from the surface protective layer and the molding and the base layer in the case of a weak adhesive. It is to use a good adhesive.

The heat resistance of the adhesive is measured by checking whether separation occurs after being put in a dry oven set to a certain temperature in a laminated state or in a commercialized state, after a predetermined time has elapsed. In general, the heat resistance of the adhesive should not occur even after at least 5 minutes at 150 ℃ or 10 seconds at 260 ℃.

The moisture and gas barrier layer is a layer for preventing the ingress of water vapor and air from the outside into the battery, and in the case of the electrolyte in the lithium secondary battery and portable battery cell components, hydrogen when exposed to moisture or air In combination with, a highly acidic toxic gas is produced, which poses a risk of explosion. At this time, in the case of the embossing type (Embossing Type) is formed in a certain cup shape, it is characterized in that the use of a metal thin film material to prevent moisture by preventing moisture and various gases, fundamentally pouch type (Pouch) type) is no exception. In this case, the material most bonded to the moisture-proof and gas barrier layer may be a film deposited with a metal such as soft aluminum and nickel having high tensile strength and elongation, or an inorganic compound such as silicon oxide or alumina. Is characterized by consisting of a soft aluminum foil.

The soft aluminum foil used as the moisture proof and gas barrier layer has a thickness of 5 to 200 μm, preferably 20 to 150 μm.

In addition, the aluminum material used as the moisture barrier and gas barrier layer has good insulation properties of aluminum containing iron, less occurrence of pinholes due to bending as a lamination agent, and easy formation of sidewalls when forming an embossed exterior. It is known to be possible. At this time, when the iron content of aluminum is less than 0.6% by weight, effects such as prevention of pinhole generation and improvement of embossing formability are not recognized, but when the iron content of aluminum exceeds 2.0% by weight, flexibility as aluminum This is inhibited and the workability deteriorates in forming the sealing material as the laminating agent. In addition, if silicon content is excessively increased to more than 0.9%, the magnetic properties are improved, but workability that can be molded into a bag becomes worse.When the content is reduced to less than 0.05%, the strength of the product is weakened and elongation rate is decreased to form a bag. The workability that can be molded becomes poor.

Therefore, it is preferable to use a product having a high content of silicon (Si) and iron (Fe) as the soft aluminum foil material, and in the case of silicon, the silicon content is 0.05 to 0.9% by weight, preferably 0.05 to 0.3% by weight. In the case of iron, the iron content is characterized in that 0.6 to 2.0% by weight, preferably 0.6 to 1.7% by weight.

The anti-corrosion layer is to prevent corrosion of the packaging material by the electrolyte, in particular the material of the metal thin film of the moisture-proof and gas barrier layer, preferably aluminum, in the case of lithium secondary batteries and portable storage batteries, the electrolyte and the polymer for the smooth flow of electrons In this case, LiPF ₆ (Lithium Hexafluorophosphate), which is the main component of the electrolyte, and carbonate series, which is the main component of the solvent, have strong permeability, and in the case of various types of cell packaging work, they penetrate into scratches due to cracks of laminated plastics to corrode aluminum. Because it loses the function of the battery, it is characterized in that the corrosion-resistant coating on the inner surface of aluminum in order to fundamentally prevent this. At this time, the anti-corrosion layer is at least one compound selected from the group consisting of organic compounds of non-Chromate (Non-Chromate), that is, organic resins such as titanium resin, zirconium, phosphate, organic-free, organic compound on the inner surface of the aluminum Characterized in that it improves the corrosion resistance. Conventionally, a chromate-based corrosion inhibitor is used on a metal surface, and regulations are severely restricted to substances that adversely affect the environment. In the present invention, a coating is formed by coating with a non-chromate-based substance.

The adhesive resin layer is characterized in that the adhesive resin is easily coated on aluminum to facilitate the adhesion with a metal, preferably aluminum. In the case of batteries requiring heat resistance, polypropylene resin is generally used as a material for heat-sealing layer. In this case, since aluminum is not directly attached to the melt-extrusion coating, it is easy to adhere to aluminum so that it is easily attached to aluminum. It is to coat the adhesive resin.

At this time, the adhesive resin is characterized in that at least one selected from the group consisting of modified polyethylene (modified PE), modified polypropylene (modified PP), modified acrylic resin and the like dissolved in the solvent.

The melt extrusion resin layer is a method of laminating a so-called plastic film, which serves to bond the upper and lower two layers by providing an adhesive force by coating the film by melt extrusion coating. The melt extrusion resin layer is formed by melting and extruding a polypropylene resin or polyethylene resin to coat a polypropylene resin or polyethylene resin film on the adhesive resin layer. That is, the melt extrusion resin layer is for laminating the film of the aluminum and the heat-sealing layer of the moisture proof and gas barrier layer coated with the corrosion preventing layer and the adhesive resin layer, the film of the aluminum and the heat-sealing layer polypropylene or polyethylene resin Is melt-extruded using a melt-extruded resin layer is laminated in a process of heat adhesion and fusion.

At this time, ozone is radiated using an ozone generating device, which is an additional machine that emits ozone during the melt extrusion coating, thereby enhancing the adhesion by peroxidizing the surface of the melt extrusion coating resin, and simultaneously forming an ozone film to improve barrier properties. The adhesion and sealing property between the adhesive resin layer, the melt extrusion resin layer and the heat seal layer can be improved.

The inventors have found through many experiments that the adhesion was improved by spinning ozone on the resin extruded during melt extrusion coating. As for the device for emitting ozone, Korea registered patent No. 0407447 is a high concentration ozone generator, Korea registered patent no. As a technique related to the solution was possible.

The ozone generator compresses air in the air by using an air compressor to separate nitrogen and oxygen from an oxygen generator and uses only pure oxygen, and produces high concentration of ozone by using a plasma silent discharge system using high frequency and high voltage. . The ozonated air is injected into the resin discharge port through the air nozzle to enhance the film adhesion strength by strongly oxidizing the resin film.

On the other hand, the coating thickness of the melt extrusion resin layer is characterized in that 10 to 80 ㎛, preferably 10 to 40 ㎛.

The heat-sealing layer is sealed by heat regardless of the packaging method when packaging the lithium secondary battery and the portable storage cell, characterized in that to use a resin layer capable of sealing by heat to seal the packaging material with heat. In this case, the resin used is polyethylene or polypropylene to prevent cracking, whitening, pinhole, etc. of the heat-sealing layer due to the molding conditions during molding and the slipperiness and thermal sealing strength characteristics of the mold surface in the molding machine during molding. Plastic film formed by adding at least one selected from the group consisting of ethylene, butadiene, ethylene propylene rubber, and the like to at least one selected from the group consisting of ethylene copolymers and propylene copolymers, preferably modified polypropylene. It features.

On the other hand, when packaging a lithium secondary battery and a portable battery cell having a large capacity, a thick film having improved electrical insulation resistance is used. At this time, the use thickness of the film is characterized in that 20 to 150 ㎛.

A layer structure of a lithium secondary battery and a portable battery cell packaging encapsulant and a method of manufacturing the same will be described in more detail below with reference to the accompanying drawings. However, the scope of the present invention is not limited to the drawings below.

1 is a cross-sectional view showing the layer configuration of a lithium secondary battery and a portable battery cell packaging encapsulant according to the present invention. As shown in FIG. 1, the lithium secondary battery and the portable battery cell packaging encapsulant of the present invention include a surface protective layer 1, a molding and base layer 2, a moisture proof and gas barrier layer 3, a corrosion preventing layer 4, It consists of the adhesive resin layer 5, the melt-extrusion resin layer 6, and the heat sealing layer 7.

In addition, a method for manufacturing the lithium secondary battery and portable battery cell packaging encapsulant, comprising: a first step of laminating the surface protective layer (1) and the molding and base layer (2) using a urethane adhesive;

A second step of laminating the moisture-proof and gas barrier layer (3) by using a urethane adhesive in the molding and base layer (2);

A third process of coating the anti-corrosion layer 4 on the moisture proof and gas barrier layer 3 using a coating machine;

A fourth step of coating an adhesive resin layer (5) on the corrosion preventing layer to be attached to the metal; And

And a fifth step of thermally attaching and fusion-bonding the heat sealing layer 7 using the melt-extrusion coated melt-extruded resin layer 6 while applying the resin film to the adhesive resin layer 5 by melt-extrusion coating. .

At this time, during the melt extrusion coating in the fifth process, the adhesive resin layer 5, the melt extrusion value layer 6, and the heat seal layer 7 may be attached by ozone radiation. When the melt-extrusion coating is performed by ozone spinning, the surface of the melt-extruded resin layer 6 may be oxidized to improve adhesion, and an ozone film may be formed to improve barrier properties.

In more detail, in the first process, the surface protective layer 1 fabric is made of a very thin, moldable, and excellent polyester electrolyte fabric resistance. In addition, the biaxially stretched polyamide film which is excellent in shaping | molding is used for the shaping | molding and the base material layer 2 fabric.

In the second process, the moisture proof and gas barrier layer 3 uses a soft aluminum foil having high tensile strength and elongation due to its high silicon and iron content, which is a thin metal thin film.

The anti-corrosion layer 4 is coated on the fabric laminated in the third process by using a coating machine such as gravure, comma or reverser.

In the fourth process, the adhesive resin layer 5 is formed of a metal and a film, that is, an anticorrosion layer 4, in a state in which at least one resin selected from the group consisting of modified polyethylene, modified polypropylene, modified acrylic resin, and the like is dissolved in a solvent. This coated moisture-proof and gas barrier layer (3) is a special resin layer with excellent adhesion between the aluminum and the film of the melt-extruded resin layer (6).

In the case of the heat sealing layer 7 used in the fifth step, in order to prevent slippage and heat sealing strength characteristics of the mold surface in the molding machine when working as a molding type, cracking, whitening, pinhole, etc. of the heat sealing layer during molding. Plastic film formed by adding at least one selected from the group consisting of ethylene, butadiene, ethylene propylene rubber, etc. to at least one selected from the group consisting of polyethylene, polypropylene, ethylene copolymer, propylene copolymer, and the like, preferably modified Use polypropylene. In addition, in the fifth step, an ozone scavenger can be used during ozone emission.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are only illustrative of the present invention, and the scope of the present invention is not limited by the following Examples and Experimental Examples.

Example 1.

Polyethylene terephthalate (PET) film (1,7 μm thick), which is a surface protective layer, and biaxially stretched polyamide film (20 μm, thick), which is the molding and base material layer (2), were laminated using a urethane base two-component adhesive. The aluminum foil (Al-Foil), which is a moisture-proof and gas barrier layer (3), is laminated to the molding and base layer (2) using a urethane base two-component adhesive, and then the moisture and gas barrier layer (3). ) After the thin film is coated on the surface using a coating machine (5 μm in thickness), the modified polypropylene resin is dissolved in a solvent on the surface of the coated anti-corrosion layer (5). ) After coating a film (thickness 10 μm), the heat-sealing layer 7 is formed by applying a polypropylene resin film (thickness 18 μm) to the surface of the adhesive resin layer 5 by a melt-extrusion coating to form a melt-extruded resin layer 6. Polypropylene resin melt pressure in modified polypropylene resin (CPP) Coatings were prepared (with a thickness of 35 ㎛) of the melt-extruded to be a heat-sealed using the resin layer 6 in Example 1, a lithium secondary battery and a handheld battery cell packaging material of the bag.

PET / OPA / Al-Foil / Corrosion Prevention Layer / Adhesive Resin Layer / PP / Modified PP

Example 2.

The modified polypropylene resin, which is a heat seal layer 7, is heat-bonded and fused using the melt-extruded resin layer 6 in which polypropylene resin is melt-extruded and coated. At this time, an ozone radiator (Model: Lami-Tek 200a) , Manufactured by Yulchon Chemical Co., Ltd., was carried out in the same manner as in Example 1, except that 200 g of ozone per hour was radiated onto the surface of the extruded resin, and the lithium secondary battery of Example 2 and portable A battery cell packaging encapsulant was prepared.

PET / OPA / Al-Foli / Corrosion Prevention Layer / Adhesive Resin Layer / PP (Ozone Treatment) / Modified PP

Comparative Example 1.

Polyethylene terephthalate film (PET, 10 µm thick), which is a surface protective layer, and biaxially stretched polyamide film (OPA, 25 µm thick), which is a molding and base layer 2, are laminated using a urethane base two-component adhesive. The aluminum foil (Al-Foil) (thickness 60 µm), which is a moisture-proof and gas barrier layer 3, is laminated to the molding and base layer 2 using a urethane base two-component adhesive, and then the moisture-proof and gas barrier layer ( 3) The modified polypropylene film (40 micrometers in thickness) which is a heat sealing layer 7 on the surface was laminated | stacked using the urethane base two-component adhesive, and the sealing material for packaging lithium secondary batteries and portable storage cell cells of the comparative example 1 was manufactured. .

PET / OPA / Al-Foil / Modified PP

Comparative Example 2.

Polyethylene terephthalate film (PET, 10 μm thick), which is a surface protective layer, and biaxially stretched polyamide film (OPA, 20 μm thick), which is a molding and base material layer 2, are laminated using a urethane base two-component adhesive. The aluminum foil (Al-Foil), which is a moisture-proof and gas-blocking layer 3, is laminated to the molding and base layer 2 using a urethane base two-component adhesive, and then the moisture-proof and gas-blocking layer ( 3) A polypropylene resin film was coated on the surface using a urethane base two-component adhesive, followed by melt extrusion coating of the modified polypropylene resin, which is a heat-sealing layer 7, to form a film (thickness 15 μm). A lithium secondary battery and a portable battery cell packaging encapsulant were prepared.

PET // OPA // Al-Foil // PP // Modified PP

Comparative Example 3.

Moisture-proof and gas barrier layer 3 aluminum foil (Al-Foil, 50 μm thick) is laminated on biaxially stretched polyamide film (OPA, 20 μm thick), which is a molding and base material layer (2), using a urethane base two-component adhesive. Then, the modified polypropylene film (thickness 40 μm), which is a heat-sealing layer 7, is laminated on the surface of the moisture-proof and gas barrier layer 3 by using a urethane base two-component adhesive to form a lithium secondary battery of Comparative Example 3 and A portable battery cell packaging encapsulant was prepared.

OPA / Al-Foil / Modified PP

Comparative Example 4.

Moisture-proof and gas barrier layer (3) aluminum foil (Al-Foil) (thickness: 60 µm) was laminated on a biaxially stretched polyamide film (25 µm thick), which is a molding and base material layer (2), using a urethane base two-component adhesive. Next, a polypropylene resin film (thickness 10 μm) was coated on the surface of the moisture and gas barrier layer 3 using a urethane base two-component adhesive, and then a modified polypropylene film (thickness 40 μm), which is a heat seal layer 7, was laminated. The lithium secondary battery and the portable battery cell packaging sealing material of Comparative Example 4 were prepared.

OPA / Al-Foil / PP / Modified PP

Comparative Example 5.

Moisture-proof and aluminum foil (Al-Foil) (thickness 50 μm), which is moisture-proof and gas barrier layer (3), is laminated on a biaxially stretched polyamide film (thickness 20 μm) that is a molding and substrate layer (2) using a urethane base two-component adhesive Next, after the modified polypropylene resin is coated on the surface of the moisture-proof and gas barrier layer 3 in a state in which a modified polypropylene resin is dissolved in a solvent (thickness 10 μm), the polypropylene is coated on the surface of the adhesive resin layer 5. The resin is melt-extruded and coated with a polypropylene resin film (thickness of 18 μm) to form a melt-extruded resin layer (6), which is extruded at a dose of 200 g per hour using an ozone spinning device (Lami-Tec 200A). The modified polypropylene film (thickness 35 mu m), which is the heat-sealing layer 7, was laminated while radiating ozone to the ground surface, to prepare a lithium secondary battery and a portable battery cell packaging encapsulant of Comparative Example 5.

OPA / Al-Foil / Adhesive Resin Layer / PP (Ozone Treatment) / Modified PP

Comparative Example 6.

The lithium secondary battery of Comparative Example 6 and Comparative Example 6 in the same manner, except that the corrosion-proof layer 4 (thickness of 5 ㎛) coated with a thin film using a coating machine on the moisture-proof and gas barrier layer (3) surface in Comparative Example 5 and A portable battery cell packaging encapsulant was prepared.

OPA / Al-Foil / Corrosion Prevention Layer / Adhesive Resin Layer / PP (Ozone Treatment) / Modified PP

Experimental Example 1. Long-term high temperature leaving test

The heat resistance, battery insulation, moisture resistance, and gas barrier properties of the packaging materials were examined through long-term high temperature standing tests. At this time, the lithium secondary battery and portable battery cell packaging encapsulant of Examples 1 and 2 and Comparative Examples 1 and 2 were molded-type bags (35 mm * 45 mm * 5.5 mm and 33 mm * 55 mm * 5.5 mm). Electrolyte solution added with 1 mole of LiPF ₆ (Lithium Hexafluoro Phosphate) to a solvent in which EC (ethylene carbonate), DMC (dimethyl carbonate), and DEC (diethyl carbonate) were mixed in a 1: 1 ratio, respectively. After 5 g injection into the bag, the change over time during long-term high temperature leaving, ie, heat seal layer separation, electrical insulation resistance, water vapor transmission rate (after 7 days), and aluminum corrosion were observed. The separation of the heat seal layer was visually observed whether the heat fusion layer 7 and the melt-extrusion coating layer 6 of each packaging material was separated, and the electric insulation resistance was measured by an electric insulation resistance measuring instrument (3154 DIGITAL MΩ HiTESTER). The water vapor permeation was measured for 7 days storage under the above conditions, and the degree of aluminum corrosion was visually observed for the degree of corrosion of aluminum in each packaging material.

As a result, as can be seen in Table 1, in the case of heat sealing layer separation, no separation was observed in the packaging materials of Examples 1 and 2, the packaging material of Comparative Example 1 was separated after 3 days, Comparative Example 2 Was found to separate after 5 days.

In the case of electrical insulation resistance, the packaging materials of Examples 1 and 2 showed resistance even at 2000 MΩ or more, but the packaging materials of Comparative Examples 1 and 2 showed resistance only at 2000 MΩ or less.

After 7 days, the water vapor transmission rate of the packaging materials of Examples 1 and 2 was 50 PPM or less, but the packaging materials of Comparative Examples 1 and 2 were 500 PPM or more.

In addition, when looking at the degree of aluminum corrosion, the packaging materials of Examples 1 and 2 did not show corrosion during the test period, but the packaging material of Comparative Example 1 was corroded after 5 days and the packaging material of Comparative Example 2 after 7 days.

As a result, it can be seen that the packaging materials of Examples 1 and 2 of the present invention exhibited superior quality during long-term high temperature prevention than the packaging materials of Comparative Examples 1 and 2.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Heat Seal Layer Separation 3 days later After 5 days No separation No separation Electrical insulation resistance 2000 MΩ or less 2000 MΩ or less 2000 MΩ or more 2000 MΩ or more Water vapor transmission rate (after 7 days) 500 PPM or more 400 PPM or more 50 PPM or less 50 PPM or less Aluminum corrosion Corrosion after 5 days Corrosion after 7 days No corrosion No corrosion

Experimental Example 2. Charge / Discharge Test

In order to determine the stability during charging and discharging of the packaging material, charging and discharging tests were performed on the lithium secondary battery and the portable battery cell packaging encapsulant prepared in Examples 1 and 2 and Comparative Examples 1 and 2, and the change in dislocation amount and The degree of heat seal layer separation was observed .

As a result, as can be seen in Table 2, in the case of the encapsulant of Examples 1 and 2 showed excellent quality in the dislocation amount change and heat sealing layer separation surface during the charge and discharge test, in the case of the encapsulant of Comparative Example 1, The quality was insufficient in the amount of change and the separation of heat seal layer, Comparative Example 2 was also inadequate in the change of dislocation amount, and the quality was normal in the separation of heat seal layer.

As a result, it was found that the packaging materials of Examples 1 and 2 were safe even when the battery was charged or discharged.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Potential change × × ◎ ◎ Heat Seal Layer Separation × △ ◎ ◎  * × Poor, △ Normal, O Good, ◎ Excellent

Experimental Example 3 Characteristics of Electrolyte Solution

In order to determine the characteristics of the electrolyte solution as one of the chemical resistance of the packaging material, the electrolyte resistance characteristics of the lithium secondary battery and the portable storage battery cell encapsulation material prepared in Examples 1 and 2 and Comparative Examples 3 to 6 were measured. The electrolyte was injected and sealed in each packaging material and the properties were observed while storing .

As a result, as can be seen in Table 3, it was found that the packaging materials of Examples 1 and 2 were excellent in the case of surface properties, while the packaging materials of Comparative Examples 3 to 6 were insufficient. In addition, the heat-sealing layer characteristics of the packaging materials of Examples 1 and 2 were generally excellent, while the packaging materials of Comparative Examples 3 to 6 were generally insufficient.

Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Example 1 Example 2 Surface characteristics × × × × ◎ ◎ Heat Sealing Layer Properties × × O ◎ O ◎  * × Poor, △ Normal, O Good, ◎ Excellent

Reference Example 1. Separation test of heat seal layer during electrolyte precipitation

In order to determine the heat-sealing strength of the packaging material, a heat-sealing layer separation test was performed during the precipitation of the electrolyte. At this time, after the specimens were prepared, each sample was precipitated in a similar electrolyte, and then the heat-sealing layer 7 and the melt-extruded resin layer. The presence or absence of separation in (6) was examined .

At this time, sample 1 was prepared by laminating a modified polypropylene film, which is a heat-sealing layer 7, with a urethane base two-component adhesive on aluminum foil, and sample 2 was formed by coating a polypropylene resin film with aluminum foil and a melt extrusion coating. The extruded resin layer 6 is laminated using a urethane base two-component adhesive, and the modified polypropylene resin, which is a heat seal layer 7, is used as the medium by the melt-extruded resin layer 6 in which the polypropylene resin is melt-extruded and coated. It was produced by heat adhesion and fusion. In addition, Sample 3 is a melt-extruded resin layer formed by coating a polypropylene resin film on the surface of the adhesive resin layer after coating the adhesive resin layer (5) film in which the modified polypropylene resin is dissolved in a solvent on aluminum. After the formation of (6), the modified polypropylene resin, which is a heat seal layer 9, was prepared by heat adhesion and fusion using the melt-extruded resin layer 6, and the sample 4 was heated during the manufacturing process of the sample 3. An ozone spinning device (Lami-Tec 200A, manufactured by Yulchon Chemical Co., Ltd.) when thermally attaching and fusion of the modified polypropylene resin, which is a sealing layer 7, by using the melt extrusion resin layer 6 in which polypropylene is melt-extruded and coated. Was prepared in the same manner as in Sample 3, except for emitting ozone using.

As a result, as shown in Table 4 below, Sample 3 prepared by the method of aluminum foil / adhesive resin layer / melt extrusion resin layer / heat sealing layer and aluminum foil / adhesive resin layer / melt extrusion resin layer (ozone treatment) The precipitation of the electrolyte solution of the sample 4 prepared by the method of the heat sealing layer was excellent in the heat sealing layer separation surface, and also did not show a difference according to the temperature when the temperature was changed to 65 ℃ and 85 ℃.

Temperature time Sample 1 Sample 2 Sample 3 Sample 4 65 ℃ electrolyte 12 hours later O ◎ ◎ ◎ 1 day later  × O ◎ ◎ 7 days later  ×  × ◎ ◎ 30 days later  ×  × ◎ ◎ 50 days later  ×  × ◎ ◎ 85 ℃ electrolyte 8 hours later  × O ◎ ◎ 24 hours later  × △ ◎ ◎ 2 days later  ×  × ◎ ◎ 7 days later  ×  × ◎ ◎ 30 days later  ×  × ◎ ◎  * × Poor, △ Normal, O Good, ◎ Excellent

Reference Example 2. Molding Depth Test during Molding

In order to determine the formability of the packaging material, a molding depth test was performed according to the aluminum material during molding. At this time, after the specimen was manufactured, the molding condition was examined according to the molding depth. As the specimen, the product was manufactured using ordinary aluminum foil (AL-Foil) and silicon (Si) and iron (Fe) as special aluminum foil. Products made using high content products (0.1 wt% and 1.0 wt% respectively) were used and tested at molding depths of 4 to 8 mm.

As a result, as shown in Table 5, it was found that the product to which the special aluminum foil having high silicon and iron content is applied is superior in formability to the product using the general aluminum foil.

division Thickness of General Aluminum Foil (㎛) Thickness of Special Aluminum Foil (㎛) Forming depth 20 40 60 80 100 20 40 50 80 100 4mm  × △ △ O O O ◎ ◎ ◎ ◎ 5 mm  ×  × △ △ O  × ◎ ◎ ◎ ◎ 6 mm  ×  ×  ×  × △  × ◎ ◎ ◎ ◎ 7 mm  ×  ×  ×  ×  ×  × O O ◎ ◎ 8 mm  ×  ×  ×  ×  ×  × O O ◎ ◎   * × Poor, △ Normal, O Good, ◎ Excellent

As described above, lithium is composed of a surface protective layer, an adhesive layer, a molding and substrate layer, an adhesive layer, a moisture proof and gas barrier layer, an anti-corrosion layer, an adhesive resin layer, a melt extrusion resin layer and a heat sealing layer according to the present invention. The sealing material for packaging a secondary battery and a portable storage battery cell can be manufactured. In addition, when the present invention is used, the manufacturing time is short and light, the shape is free, and heat resistance, electrical insulation, moisture resistance, and gas barrier property, chemical resistance, heat sealing strength, and moldability are excellent, thus protecting the battery cell safely and allowing the flow of electrons. It is effective to obtain a lithium secondary battery and a portable side battery cell packaging encapsulant that can generate power by smoothly.

Claims (17)

As a packaging material for a lithium secondary battery and a portable storage cell, A surface protective layer protecting the surface of the packaging material; Molding and base layer for imparting moldability to the packaging material; Prevents the ingress of water vapor and air from the outside of the packaging material, made of a soft aluminum foil, the soft aluminum foil contains silicon (Si) and iron (Fe) at the same time for the purpose of improving moldability, the content of each of 0.05 to 0.9 weight Moisture and gas barrier layers with a% and 0.6 to 2.0% by weight; A corrosion prevention layer which prevents corrosion of the packaging material and is a non-chromate acid resistant film formed on an inner surface of the flexible aluminum foil; To facilitate adhesion to the soft aluminum foil, the adhesive resin in a state in which at least one selected from the group consisting of modified polyethylene (modified PE), modified polypropylene (modified PP), and modified acrylic resin is dissolved in a solvent. Adhesive resin layer coated on the corrosion protection layer; A melt-extruded resin layer formed by melting and extruding a polypropylene resin or a polyethylene resin on the adhesive resin layer and coating a film, and performing ozone spinning on the surface of the melt-extruded resin to be formed on the adhesive resin layer; And A heat sealing layer for sealing the packaging material with the cells in a heat; Lithium secondary battery and a portable battery cell packaging encapsulant using a laminated plastic film, characterized in that laminated in this order. The method of claim 1, The surface protective layer is a lithium secondary battery and a portable battery cell packaging encapsulant, characterized in that the polyester film. The method of claim 2, The polyester film resin may include polyethylene terephthalate (PET), poly butylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (Poly butylene naphthalate); PBN), co-polyester and polycarbonate (PC) comprising at least one selected from the group consisting of lithium secondary battery and portable battery cell packaging encapsulant. The method of claim 1, The molding and base material layer is a biaxially stretched polyamide film, characterized in that the lithium secondary battery and portable battery cell packaging encapsulant. The method of claim 4, wherein The biaxially stretched polyamide film resin is a group consisting of nylon 6, nylon 6.6, a copolymer of nylon 6 and nylon 6.6, nylon 6.10 and polymethacylsilylene amidamide (MXD 6). A lithium secondary battery and a portable battery cell packaging encapsulant, comprising at least one selected from. The method of claim 1, And the surface protective layer, the molding and base layer, the molding and base layer, and the moisture proof and gas barrier layer are laminated using a urethane-based two-component adhesive. delete The method of claim 1, The thickness of the soft aluminum foil is 5 to 200 ㎛ cell packaging sealing material, characterized in that. delete delete delete delete delete The method of claim 1, The heat-sealing layer is a plastic film formed by adding at least one selected from the group consisting of ethylene, butadiene, ethylene propylene rubber to at least one selected from the group consisting of polyethylene, polypropylene, ethylene copolymer and propylene copolymer A lithium secondary battery and a portable battery cell packaging encapsulant. A method for manufacturing a lithium secondary battery and a portable battery cell packaging encapsulant according to claim 1, A first step of laminating the surface protective layer (1) and the molding and base layer (2) with a urethane adhesive; A second step of laminating the moisture proof and gas barrier layer (3) by using a urethane adhesive for the molding and base layer (2); A third process of coating the anti-corrosion layer 4 on the moisture proof and gas barrier layer 3 using a coating machine; A fourth step of forming the adhesive resin layer 5 on the corrosion preventing layer; And While coating the adhesive resin layer (5) with a melt-extrusion coating film of the melt-extruded resin, the heat-sealing layer (7) is heat-bonded and fused and laminated, while the melt-extruded coating ozone radiation on the surface of the melt-extruded resin A method for manufacturing a lithium secondary battery and a portable battery cell packaging encapsulant comprising a fifth step of performing a treatment. delete  The method of claim 15, The method of manufacturing a lithium secondary battery and a portable battery cell packaging encapsulant, wherein the corrosion preventing layer (4) in the third process is a thin film coating using a coating machine of gravure, comma or reverse (Reverser).

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