KR100846296B1 - Pouch for packing cell and method for preparing the same - Google Patents

Abstract

The present invention relates to a cell packaging encapsulant such as a lithium secondary battery or a portable storage battery, and a manufacturing method thereof. According to the cell packaging encapsulant such as the lithium secondary battery or the portable storage battery of the present invention, it is possible to fundamentally improve the electrolyte resistance, which is a characteristic particularly required for the cell packaging encapsulant, to prevent corrosion of the barrier layer by the electrolyte, and to seal the sealant layer and the barrier. Delamination of the layer can be prevented. In addition, the cell packaging encapsulant such as the lithium secondary battery or the portable storage battery of the present invention can freely protect the cell and have a free shape, excellent barrier property, excellent moldability and impact resistance, and air (oxygen) permeation. Excellent anti-permeability, moisture-permeability, puncture strength, short manufacturing time, high process efficiency, low cost and light characteristics.

Lithium battery, storage battery, cell packaging encapsulant, sealant layer, metal, oxide, deposited film

Description

Pouch for packing cell and method for preparing the same

1 is a schematic view showing a laminated film configuration of a cell packaging material according to an embodiment of the present invention.

The present invention relates to a cell packaging encapsulant such as a lithium secondary battery or a portable storage battery, and a manufacturing method thereof.

As cell packaging materials for lithium secondary batteries, portable storage batteries and the like, packaging materials formed by pressing a metal, in particular aluminum, into a cylindrical or parallelepiped shape or the like have been mainly used. However, in the case of such a metal can packaging material, there is a restriction that the outer wall of the container is hard so that the shape of the battery itself is determined by the shape of the metal can packaging material.

In order to overcome this limitation, a packaging material technology made of a multilayer plastic film has been developed.

For example, Korean Patent Application No. 2003-7002427 discloses a cell pouch composed of a base layer, an adhesive layer, a barrier layer, a dry lamination layer, and a sealant layer, wherein the sealant layer is composed of a low flow polypropylene layer and a high flow polypropylene layer. It is. Meanwhile, Korean Patent Laid-Open Publication No. 2002-0030737 discloses a cell pouch structure laminated using biaxially stretched nylon, polyethylene terephthalate (PET), and polyolefin resin on a base film and a surface protective layer. Coating of fluorine, silicone and acrylic resins on films is also disclosed.

However, the conventional cell pouches including the above techniques have a problem inherent in cell pouches such that the adhesive strength and insulation resistance between the multilayer film layers are lowered due to the continuous stress from the electrolyte after cell manufacture. There was also a problem in that the metal surface was corroded by the hydrofluoric acid generated by the metal and the adhesive surface was separated.

In addition, in the conventional cell pouch, there is a case in which a melt-extruded resin layer is used instead of an adhesive layer, thereby causing a whitening phenomenon of the sealant layer and deterioration of slip properties.

In addition, in the conventional cell pouch, nylon was mainly used as a surface protective layer. However, in the case of using nylon, there was a problem in that the electrolyte melted in the nylon film during the electrolyte injection process during the battery manufacturing process. When PET is laminated together on the surface protective layer of the cell pouch, there is a problem that the PET lamination process is added, thereby decreasing process efficiency and lacking formability of PET.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide electrolytic solution property which is a characteristic particularly required for a cell packaging encapsulant such as a lithium secondary battery or a portable storage battery. The present invention provides a cell packaging encapsulant and a method of manufacturing the same, which can fundamentally improve, prevent corrosion of a barrier layer by an electrolyte, and prevent delamination of a sealant layer and a barrier layer.

It is also an object of the present invention to freely protect the cell, freely shape, excellent barrier properties, excellent moldability, impact resistance, excellent air (oxygen) permeation resistance, moisture permeability, and puncture strength In addition, the present invention provides a cell packaging encapsulant having a short manufacturing time, high process efficiency, low cost, and a method of manufacturing the same.

The above object of the present invention, the outermost layer film; A first adhesive resin layer formed on the outermost layer film; A barrier layer formed on the first adhesive resin layer; A second adhesive resin layer formed on the barrier layer; A sealant layer formed on the second adhesive resin layer; wherein the sealant layer is formed of SiO ₂ on a polyolefin film comprising a single layer or a multilayer; Or a deposition layer of an oxide of Al ₂ O ₃ or a metal which is any one selected from the group consisting of Cu, Fe, Sn, Zn, Ag and Al.

Moreover, the objective of this invention mentioned above is the outermost layer film which is a polyester film containing 100-110 mol parts of acid components with respect to 130 mol parts of glycol components; A first adhesive resin layer formed on the outermost layer film; A barrier layer formed on the first adhesive resin layer; A second adhesive resin layer formed on the barrier layer; A sealant layer formed on the second adhesive resin layer; wherein the sealant layer is formed of SiO ₂ on a polyolefin film comprising a single layer or a multilayer; Or a deposition layer of an oxide of Al ₂ O ₃ or a metal which is any one selected from the group consisting of Cu, Fe, Sn, Zn, Ag and Al.

In one embodiment of the present invention, it is preferable that any one or more additives of a catalyst, a slip agent or a stabilizer are further added to the polyester film.

In one embodiment of the present invention, the inner surface or both sides of the polyester film is preferably corona treated.

In one embodiment of the present invention, the thickness of the deposited layer is preferably 200 to 500 kPa.

In one embodiment of the present invention, it is preferable that the polyolefin film is a polyolefin film formed of three layers, and more preferably two adjacent polyolefins among the polyolefin films formed of the three layers are polyolefins having different crystallinity.

In one embodiment of the present invention, the first adhesive resin layer is preferably a urethane-based adhesive resin layer.

In one embodiment of the present invention, the barrier layer is made of aluminum foil, it is preferable that a non-chromate-based corrosion protection layer is formed on both sides of the aluminum foil, the aluminum foil is silicon (Si) and iron (Fe) ) At the same time, the content is more preferably 0.05 to 0.9% by weight and 0.6 to 2.0% by weight, respectively.

In one embodiment of the present invention, the second adhesive resin layer is preferably a melt-extruded resin layer formed by melt-extrusion of the resin, the second adhesive resin layer is more preferably a urethane-based adhesive resin layer.

The above object of the present invention, the step of forming a barrier layer using the first adhesive resin on the outermost layer film (S1); And forming a sealant layer using a second adhesive resin on the barrier layer (S2). In the step S2, SiO ₂ is formed on a polyolefin film composed of a single layer or a multilayer. Or forming a sealant layer by depositing an oxide of Al ₂ O ₃ or a metal selected from the group consisting of Cu, Fe, Sn, Zn, Ag, and Al. do.

In addition, the object of the present invention, forming a barrier layer using a first adhesive resin on the outermost layer film of the polyester film containing 100 to 110 mole parts of the acid component relative to 130 mole parts of the glycol component (S1); And forming a sealant layer using a second adhesive resin on the barrier layer (S2). In the step S2, SiO ₂ is formed on a polyolefin film composed of a single layer or a multilayer. Or by depositing a metal which is an oxide of Al ₂ O ₃ or a metal selected from the group consisting of Cu, Fe, Sn, Zn, Ag and Al to form the sealant layer. Is achieved.

In one embodiment of the present invention, in the step S1, it is preferable to further add at least one additive of a catalyst, a slip agent or a stabilizer to the polyester film.

In one embodiment of the present invention, in the step S1, it is preferable to corona treatment on the inner surface or both sides of the polyester film.

In one embodiment of the present invention, it is preferable to use a urethane-based adhesive as the first adhesive resin in the step S1.

In one embodiment of the present invention, in the step S1 to form the barrier layer of aluminum foil, it is preferable to further form a non-chromate-based corrosion protection layer on both sides of the aluminum foil, silicon (Si) More preferably, aluminum foil containing 0.05 to 0.9% by weight and 0.6 to 2.0% by weight of iron (Fe), respectively.

In one embodiment of the present invention, in the step S2 it is preferable that the deposition thickness during the deposition is 200 to 500 kPa.

In one embodiment of the present invention, it is preferable to use a melt-extruded resin melt-extruded resin as the second adhesive resin in the step S2, it is more preferable to use a urethane-based adhesive.

In one embodiment of the present invention, in the step S2, it is preferable to use a polyolefin film formed of three layers as the polyolefin film, and the polyolefins having different crystallinities from two adjacent polyolefins among the polyolefin films formed of the three layers are different from each other. It is more preferable to set it as.

In one embodiment of the present invention, in the step S2, the deposition is preferably made by any one of physical vapor deposition, chemical vapor deposition, resistive heating deposition, plasma deposition, ion plating or sputtering.

EMBODIMENT OF THE INVENTION Hereinafter, the cell packaging sealing material which concerns on this invention, and its manufacturing method are explained in full detail.

In the present invention, in the cell packaging encapsulant, SiO ₂ is applied to the sealant layer. Or by forming a deposited layer of an oxide of Al ₂ O ₃ or a metal which is one selected from the group consisting of Cu, Fe, Sn, Zn, Ag, and Al (which may be two or more complexes of any of the above oxides or metals). It prevents the electrolyte from penetrating into the internal barrier layer for a long time by providing electrolyte resistance, and prevents the surface corrosion of the barrier layer made of aluminum by hydrogen fluoride by the reaction between the electrolyte and water, and also gives the barriness. Together to prevent delamination with the barrier layer. Furthermore, in the present invention, in particular, the outermost film is freely formed by using a polyester film containing an acid component in an amount of 100 to 110 moles with respect to 130 moles of the glycol component. It is excellent in impact resistance, and in particular, the electrolyte resistance, air (oxygen) penetration prevention, moisture permeability, and puncture strength are further increased.

1 is a schematic view showing a laminated film configuration of a cell packaging material according to an embodiment of the present invention.

As shown in FIG. 1, the cell packaging material according to an exemplary embodiment of the present invention may include an outermost layer film 10, a first adhesive resin layer 20, a barrier layer 30, and a second adhesive resin layer 40. The sealant layer 50 is laminated in this order.

The outermost layer film 10 may be, for example, a biaxially stretched polyester film having excellent mechanical strength, and in particular, a polyester film containing an acid component of 100 to 110 mol parts with respect to 130 mol parts of a glycol component of the polyester film. It is preferable to use. As described above, the polyester film in which the molar ratio of the acid component is adjusted with respect to the glycol component is excellent in moldability, moisture permeability, impact resistance, air (oxygen) permeation resistance, puncture strength, and electrolyte resistance, and thus, especially in cell pouches. It is suitable as an outer layer film.

The glycol component of the film is, for example, propane diol and the acid component is, for example, dimethyl terephthalate, terephthalic acid, naphthalenedicarboxylic acid, isophthalic acid, adipic acid and the like. Meanwhile, additives such as a catalyst, a slip agent, and a stabilizer may be added to the polyester film in a conventional addition amount. In particular, the slip agent increases the slip properties, thereby reducing the coefficient of friction during molding, thereby facilitating molding, and when the friction coefficient is large, short break points are formed, thereby preventing the problem of cracking of aluminum.

It is preferable to use the thickness of the film 12 to 100㎛, it is preferable to use the corona treatment on the inner surface or both sides to enhance the adhesion.

The film having the above-described structure is a film having all the required characteristics of the nylon film or the PET film, and particularly, the film is applied to the outermost layer film 30 of the cell packaging material to increase the electrolyte resistance and protect the barrier layer 30 from the electrolyte solution. In addition, it improves the resistance to sting from the outside by increasing the sticking strength, and is excellent in moisture permeability prevention and air permeability.

The barrier layer 30 is a layer for blocking invasion of moisture, gas, oxygen, etc. into the battery, and may be formed of a film of a metal such as soft aluminum or nickel, or an inorganic compound such as silicon oxide or alumina. Although it is possible to use the soft aluminum foil, it is preferable because of the high tensile strength and elongation.

In addition, the aluminum foil preferably contains iron. In the case of containing iron, aluminum has good insulation properties, and pinholes are less likely to occur due to bending as a lamination agent, and in particular, when forming an embossed exterior Can also be easily formed. At this time, when the iron content is less than 0.6% by weight, there is no effect of preventing the occurrence of pinholes, improving the embossing formability, and when the iron content is higher than 2.0% by weight, the flexibility as aluminum is impaired, and the encapsulant as the laminating agent. In molding, the workability becomes poor. In addition, it is preferable that the aluminum contains silicon, wherein if the silicon content is excessively increased to more than 0.9% by weight, the magnetic properties are improved, but workability that can be formed into an encapsulated product is deteriorated, and is less than 0.05% by weight. If the content is reduced, the strength of the product is weakened and the elongation rate is lowered, resulting in poor processability to form a bag.

Therefore, the aluminum foil contains silicon (Si) and iron (Fe), but in particular, from the viewpoint of formability and workability, the silicon content is preferably 0.05 to 0.9 wt%, and preferably the iron content is 0.6 to 2.0 wt%. .

On the other hand, it is preferable that the aluminum is subjected to a non-chromate treatment for foil corrosion protection and adhesive strength improvement. The non-chromate treatment is to form an acid resistant film with at least one compound selected from the group consisting of organic and inorganic and organic compounds such as titanium resin, zirconium and phosphate. At this time, the non-chromate treatment is particularly preferable because treatment on both sides of the aluminum foil can further increase salt resistance.

The outermost layer film 10 and the barrier layer 30 are bonded by the first adhesive resin 20 (S1). As said 1st adhesive resin, the adhesive agent containing resins, such as an epoxy type, a phenol type, a melamine type, a polyimide type, a polyester type, a urethane type, a polyethylene terephthalate copolymer, a polyether urethane type, is used. In the case of the inner-packed cell, high temperature is generated due to heat generation during movement, and in the case of an adhesive having low heat resistance, it may cause separation of the layer to be adhered. It is preferable to use the urethane type adhesive agent which is especially excellent in this viewpoint from heat resistance.

The sealant layer 50 may be formed by depositing an oxide, such as SiO ₂ , Al ₂ O ₃ , or a metal, such as Cu, Fe, Sn, Zn, Ag, or Al, on a single layer or multilayer laminate film of polyolefin. It not only imparts barrier properties, but also prevents delamination with the barrier layer, and in particular, provides excellent electrolyte resistance and prevents aluminum surface corrosion by hydrogen fluoride generated by the reaction between the electrolyte and water.

In the present invention, the sealant layer is SiO ₂ , Al ₂ O ₃ It is by directly depositing an oxide of any one of the above, or a metal of any one of Cu, Fe, Sn, Zn, Ag, or Al, so that no additional barrier layer is formed. As a result, high barrier properties can be obtained and excellent electrolyte resistance can prevent penetration of the electrolyte. It is also more effective in preventing delamination (layer separation) between the barrier layer and the sealant layer due to the penetration of the electrolyte. In addition, the present invention is more advantageous in terms of manufacturing process efficiency and manufacturing cost reduction by depositing the oxide or metal directly on the sealant layer. Furthermore, depositing directly on the sealant layer as described above has the advantage of enabling uniform distribution of the oxide or metal in the sealant layer and very easy control of the distribution.

The deposition is performed by physical vapor deposition, chemical vapor deposition, resistive heating deposition, plasma deposition, ion plating or sputtering, and the deposition thickness is preferably 200 ~ 500Å, if less than 200Å, the deposition uniformity is not good, 500 좋지 If exceeded, moldability decreases and cracks are caused.

On the other hand, as the polyolefin film, a polyolefin film formed of three layers is particularly preferable. That is, when the polyolefin film on which the oxide or the metal is deposited is formed of three layers, penetration of the electrolyte can be effectively prevented. The polyolefin film may be formed into four or more layers in excess of three layers, but a polyolefin film formed of three layers is most preferred in terms of process efficiency and economics.

More preferably, two adjacent polyolefins among the polyolefin films formed of the above three layers are polyolefins having different crystallinities.

That is, since the polyolefin film is not 100% gas barrier property, the electrolyte is permeable and the adhesion strength between the barrier layer and the sealant layer is reduced. To solve this, a layer is formed of polyolefins having different crystallinities. Even if the electrolyte permeates the first layer, the permeability decreases while contacting the second layer made of a polyolefin component having a different degree of crystallinity from the first layer, while permeating while contacting a third layer made of a polyolefin having a different degree of crystallinity from the second layer. The possibility can be further blocked. For example, when the film formed of the three layers of the polyolefin is PP / PE / PP, when the film formed of the three layers of PP / PP / PP is different from the film formed of the three layers of PP / PP, PE having different crystallinity is located in the second layer. It becomes more difficult itself and even if it is permeable, there is an advantage that can dramatically reduce the permeation time.

On the other hand, as a film thickness of the said sealant layer 50, 5-120 micrometers is preferable.

The barrier layer 30 and the sealant layer 50 are bonded by the second adhesive resin 40 (S2).

As the second adhesive resin, a melt-extruded resin layer formed by melt-extrusion coating of (modified) polypropylene or (modified) polyethylene resin may be used to provide adhesion. At this time, it is preferable that it is 10-80 micrometers, and, as for the coating thickness of the said melt extrusion resin layer, it is more preferable that it is 10-40 micrometers. When the molten extruded resin is coated, the surface of the molten extruded resin coated by ozone may be additionally oxidized to improve adhesion and at the same time to form an ozone film to improve barrier properties and sealability.

On the other hand, in the present invention, when the molten extruded resin layer is formed as the second adhesive resin layer, since the workability is lowered and the manufacturing cost is expensive, a general urethane adhesive is used instead of the melt extruded resin. As a result, it is particularly excellent in terms of workability, yield, and cost.

Hereinafter, the present invention will be described in more detail by explaining preferred examples and experimental examples of the present invention. However, the present invention is not limited to the following examples, and various forms of embodiments can be implemented within the scope of the appended claims, and the following examples are only ordinary in the art while making the disclosure of the present invention complete. It is intended to facilitate the implementation of the invention to those with knowledge.

[Experiment 1: Evaluation of Electrolyte Resistance, Thermal Adhesive Strength, Formability, and Layer Peeling Phenomena of a Packaging Material Having a Deposition Sealant Layer]

The film of the Example and the comparative example was comprised as follows, respectively.

Example 1 Biaxially stretched polyester film / urethane adhesive layer / barrier layer (Al) / polypropylene melt-extruded resin layer / containing 100 mol parts of terephthalic acid as the acid component relative to 130 mol parts of 1,3-propane diol as the glycol component A sealant layer in which Al ₂ O ₃ was deposited on a polyolefin film formed of _three layers (deposition thickness was 200 s, 300 s, 400 s and 500 s, respectively, and the same result was obtained and expressed in Example 1). For reference, the thickness is an average value calculated after three measurements using a micro gauge (MITUTOYO 1 / 1,000 mm), which is also the same below.

Example 2 Biaxially stretched polyester film / urethane adhesive layer / barrier layer (Al) / urethane adhesive layer / 3 layer containing 100 mol parts of terephthalic acid as the acid component relative to 130 mol parts of 1,3-propane diol as the glycol component Sealant layer in which Al ₂ O ₃ was deposited on the formed polyolefin film (deposit thickness was obtained in each range of 200 to 500 Hz such as 200 Hz, 300 Hz, 400 Hz, 500 Hz and the like and expressed as Example 2)

Comparative Example 3 (Comparative Example with Different Deposition Thickness): Biaxially stretched polyester film / urethane adhesive layer / barrier layer containing 100 mol parts of terephthalic acid as the acid component with respect to 130 mol parts of 1,3-propane diol as the glycol component. Sealant layer in which Al ₂ O ₃ is deposited on a polyolefin film formed of (Al) / urethane adhesive layer / three layers (deposition thickness is the same in each range of less than 1 ~ 200Å such as 1 1, 10Å, 100Å, 150Å, 190Å, 199Å, etc.) Results were obtained and expressed in Comparative Example 3)

Comparative Example 4 (Comparative Example with Different Deposition Thickness): Biaxially stretched polyester film / urethane adhesive layer / barrier layer containing 100 mol parts of terephthalic acid as the acid component with respect to 130 mol parts of 1,3-propane diol as the glycol component. Sealant layer in which Al ₂ O ₃ was deposited on a polyolefin film formed of (Al) / urethane adhesive layer / 3 layers (deposit thickness was obtained in the range of more than 500 Hz such as 503 Å, 505 Å, 510 Å, 515 Å and Comparative Example 4 Expressed as

Comparative Example 1: Biaxially stretched polyester film / urethane adhesive layer / barrier layer (Al) / non-chromate system of titanium resin containing 100 mol parts of terephthalic acid as the acid component with respect to 130 mol parts of 1,3-propane diol as the glycol component Corrosion protection layer / Polypropylene melt extrusion resin layer / Polypropylene (or polyethylene) sealant layer

Comparative Example 2: Biaxially stretched polyester film / urethane adhesive layer / barrier layer (Al) / non-chromate system of titanium-based resin containing 100 mol parts of terephthalic acid as the acid component relative to 130 mol parts of 1,3-propane diol as the glycol component Corrosion protection layer / urethane adhesive layer / polypropylene (or polyethylene) sealant layer

The cell pouches prepared from the films of each of the examples and the comparative examples configured as described above were evaluated for electrolyte resistance, heat adhesive strength, formability and layer peeling. Each measuring method is as follows.

Electrolytic solution resistance  Test

When an electrolyte solution (EC: DMC: DEC 1: 1: 1 LiPF ₆ 1M solution, general purpose solvent) was injected into the pouch and sealed, it was intended to check whether the electrolyte penetrated into the crack and sealing surface of the barrier layer aluminum.

Specifically, a pouch with three sides sealed and sprayed twice to the molding site and the sealing surface with a solution mixed with an electrolyte in a red ink capable of confirming penetration, the other side was sealed. After the pouch was removed for 5 minutes under vacuum (65 cmHg), the pouch was removed, and a portion of the molded three-contact point and the sealing surface were cut to visually check whether the red electrolyte penetrated into the aluminum side. 100 samples of Examples 1 to 2 and Comparative Examples 1 to 3 were prepared. At this time, the number of penetrated samples is represented as "○", 1 to 5 penetrated is represented as "△", and 6 or more are marked as "x".

Heat seal  Strength test

After heat-sealing the inner surface and the inner surface of the pouch specimen was measured the heat bond strength. Specifically, the pouch specimen was cut to A4 size and folded half so that the sealing surface of the specimen abuts. Heat seal test machine (Toyoseiki HG-100) Using a cross-section Heat Seal Bar (Heat Seal Bar) was heat-sealed at 190 ° C, 200 ° C, 210 ° C specimens at 2 at 3.0 sec. Subsequently, the heat-sealed specimens were cut to a width of 15 mm, and the thermal bond strength was measured and measured using the tensile strength device (SHIMADZU AGS-100D) in accordance with JIS K 7127 test regulations. In the case of 0.2 MPa, 3s, or 180 degree cross-section yarns, depending on the thickness of Al, 3kgf or more is indicated by "○", and ideally, 4.5kgf or more is indicated by "◎".

Formability testing

When the pouch was molded, cracking of the aluminum layer and whitening of the sealant layer were confirmed. Specifically, the pouch specimen was molded to a depth of 5 mm using a molding machine and visually checked for cracks or whitening. The case where no crack or whitening phenomenon has occurred is represented by "(circle)", and the case where a crack and whitening phenomenon occurs is represented by "x".

Layer peel strength ( Delamination  Property evaluation)

Delamination strength was measured at the time of peeling the Al layer and the sealant layer of the pouch specimen. Specifically, the pouch specimen was cut to a predetermined size (width 15mm × length 150mm), and the Al layer and the sealant layer of the prepared specimen were peeled off. The peeled specimen was mounted on a tensile strength tester (SHIMADZU AGS-100D), and the test method measured physical properties according to the JIS K 7127 test standard and determined the measured value. The thing which is less than 500 gf is represented by "X", The thing which is 500 or more and less than 1000 gf is represented by "(circle)", The thing which is 0.1 kgf or more is represented by "(◎)".

Table 1 shows the results of measurement of the electrolyte resistance, heat adhesive strength, moldability, and layer peel strength of Examples and Comparative Examples.

Example 1 Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 1 Comparative Example 2 Electrolytic solution resistance ○ ○ △ ○ △ × Heat bond strength ◎ ◎ ○ ◎ ○ ○ Layer peel strength ◎ ◎ ○ ◎ ○ × Formability ○ ○ ○ × ○ ○

As can be seen from the above, in the case of Comparative Example 2, the organic electrolyte meets the moisture to form hydrofluoric acid, which penetrates the polyolefin resin and melts the adhesive layer, thereby causing swelling of the sealant layer and the barrier layer (Al). It was. In Comparative Example 1, the adhesion between the barrier layer and the sealant layer was made of a melt-extruded resin layer, so that the electrolyte resistance and the peeling strength were superior to those of Comparative Example 2. On the other hand, in the case of Comparative Example 3, not only the deposition uniformity was not good, but also after the time, the electrolyte was infiltrated on the side where the deposition was not good, so that the swelling occurred. In the case of Comparative Example 4, moldability was poor. On the other hand, in the case of Examples 1 and 2, even if time passed, the electrolyte resistance was excellent, and both were excellent in thermal adhesive strength, moldability, and layer peeling strength.

[Experiment 2-Measurement of electrolyte resistance, moldability, moisture permeability, impact resistance, air (oxygen) permeation resistance, puncture strength when only the outermost layer film was different]

EXAMPLES AND COMPARATIVE EXAMPLE The film structure was as follows.

Example 1 is a biaxially stretched polyester film / urethane adhesive layer / barrier layer (Al-thickness 80㎛) / urethane adhesive layer containing 100 mol parts of terephthalic acid as the acid component relative to 130 mol parts of 1,3-propane diol as the glycol component / A sealant layer in which Al ₂ O ₃ was deposited on a polyolefin film formed of _three layers (deposit thickness was 200 Å, 300 Å, 400 Å, 500 200, etc. in the range of 200 ~ 500 Å and the same result was obtained and expressed in Example 1) It was.

In Example 2, the biaxially stretched polyester film containing 110 mol parts of terephthalic acid with respect to 130 mol parts of 1, 3- propane diols as a glycol component was used for the outermost film in Example 1 above.

In Comparative Example 1, the outermost layer film was used as the nylon film in Example 1.

In Comparative Example 2, the outermost layer film in Example 1 was a composite film in which PET and PET were laminated under the nylon.

In Comparative Example 3, the outermost layer film in Example 1 was a composite film in which nylon was laminated under the PET film and the PET film.

In Comparative Example 4, the biaxially stretched polyester film containing 113 mol parts of terephthalic acid was used as the glycol component in 130 mol parts of 1,3-propane diol as the glycol component in Example 1.

In Comparative Example 5, a biaxially stretched polyester film containing 108 mol parts of terephthalic acid was used as the glycol component in 130 mol parts of 1,3-propane diol as the glycol component in Example 1.

Pouches were prepared using the films of Examples and Comparative Examples, and the following were measured for electrolyte resistance, moldability, moisture permeability, air permeability (oxygen) permeability, and sting strength.

Electrolytic solution resistance  Test

After dropping one or two drops of electrolyte into the prepared outermost layer of the pouch, the surface was confirmed after 60 minutes. The case where the surface is free of greening and unevenness is indicated by "○", and the case where the surface melts or unevenness is indicated by "x".

Formability testing

When the pouch was molded, cracking of the aluminum layer and whitening of the sealant layer were confirmed. Specifically, the pouch specimen was molded to a depth of 5 mm using a molding machine and visually checked for cracks or whitening. The case where no crack or whitening phenomenon has occurred is represented by "(circle)", and the case where a crack and whitening phenomenon occurs is represented by "x".

For reference, when the pouch is forcibly tensioned, the polymer film is crystallized together with stretching and cracks are generated to generate white powder, that is, whitening. This prevents the barrier or other outer layer from performing properly.

Moisture permeability  Test

Since the battery could not function as a battery when exposed to external moisture, the moisture permeability of the pouch was measured.

Specifically, the specimen was cut into a size of 100mm × 100mm, and the moisture permeability was measured and measured according to ASTM F-1249 test standard using a permeability meter (PERMATRAN) installed in a 23 ° C, 65% RH constant temperature and humidity chamber. The pouch may be slightly different depending on the thickness of Al, but is less than 0.0001070 g / m ² / day, and the moisture permeability is good and is marked as "○", and when it exceeds 0.0001070 g / m ² / day, it is marked as "×". .

Air (oxygen) Penetration prevention  Measure

The internal environment of the battery is an inert gas, that is, an inert gas atmosphere. When an active gas such as oxygen in the air contacts the internal materials constituting the battery, side reactions occur and it is difficult to expect good performance. Therefore, the degree of air permeation resistance of oxygen (oxygen) was measured.

Specifically, the specimen was cut into a size of 100 mm × 100 mm. The air permeability was measured and determined according to the ASTM D-3985 test standard using an air permeability meter (OXTRAN) installed at 23 ° C. and 65% RH constant temperature and humidity room. In the O ₂ Level (100%) atmosphere, the oxygen permeation prevention was good when it was 1.0 cc / m ² / day or less, and this was expressed as "○", and when it was more than 1.0 cc / m ² / day, it was expressed as "x".

Impact resistance test

When the product is used and exploded by external shock when used in consumer, the internal electrolyte is flammable and there is a risk of explosion. Therefore, after cutting the pouch specimen in half, the strength of the specimen was measured by pulling both sides at a constant speed.

Specifically, the specimen was cut to a constant size of 50 mm in width x 150 mm in length. The cut specimens were cut to a width of 25 mm x a length of 75 mm, each half in width and length. Using a tensile strength instrument (SHIMADZU AGS-100D), the degree of impact resistance was measured according to the JIS K 7128 test rule. When the barrier layer of aluminum is 80 μm, 500 g / 15 mm or more is indicated as “○”, and when the barrier layer is less than 500 g / 15 mm, “×” is represented.

Sting strength test

In case of sharp edges during consumer use after the manufacture of the finished product, the internal electrolyte leaks. Since the internal electrolyte is a flammable material, there is a risk of explosion. Therefore, the pouch specimen was pulled to both sides and then stabbed with a sharp needle to measure the puncture strength as the force received when the needle penetrated.

Specifically, the specimen was cut to a constant size of width 80mm x length 80mm. Tensile strength instrument (SHIMADZU AGS-100D) was used, and the tensile strength test apparatus was changed to a pressure test, and then a bee needle determined by the Japanese Ministry of Agriculture and Forestry Standard was mounted. The test method measured physical properties and obtained the measured values according to the Japanese Agriculture Ministry's Test Regulations. The case where the sticking strength value is 10 kgf or more is represented by "(circle)", and the case where it is less than 10 kgf is represented by "x".

Table 2 shows the electrolyte resistance, moldability, moisture permeability, air (oxygen) permeation resistance, impact resistance, and puncture strength of the Examples and Comparative Examples, respectively.

Electrolytic solution resistance Formability Moisture permeability Oxygen Permeation Prevention Impact resistance Stinging strength Example 1 ○ ○ ○ ○ ○ ○ Example 2 ○ ○ ○ ○ ○ ○ Comparative Example 1 × ○ × × × × Comparative Example 2 ○ × × ○ ○ × Comparative Example 3 ○ × × ○ ○ × Comparative Example 4 × ○ × × ○ × Comparative Example 5 × ○ × × ○ ×

As can be seen from the above, Examples 1 and 2 showed excellent results in all of electrolyte resistance, moldability, moisture permeability, oxygen permeation resistance, impact resistance, and sting strength, but the nylon film was used alone. In Comparative Example 1, electrolyte resistance and moisture permeability were poor, and moldability, impact resistance, and puncture strength were also low. In Comparative Examples 2 and 3 employing PET together with nylon, the moldability was particularly low, and the moisture permeability and the puncture strength were relatively low in comparison with the examples. On the other hand, when the acid component in the outermost layer is less than 100 mole parts or more than 110 mole parts, the electrolyte resistance, moisture permeability, oxygen permeability, and sting strength were relatively poor.

Experiment 3-Measurement of Salinity Resistance of Non-Chromate Treatment Location of Aluminum as Barrier Layer

Examples and Comparative Examples were configured as follows.

Example 1 of the Experimental Example 1 (here, experiments with a deposition thickness of 300 kPa) was configured as Comparative Example 1, and compared to the case of titanium-based non-chromate treatment on one surface of aluminum in Comparative Example 1 In Example 2, the case where the titanium-based non-chromate treatment on both sides of the aluminum in Comparative Example 1 as an example.

Salinity Resistance Test

The battery's external environment contained traces of Na, which corroded Al inside the pouch and prevented it from functioning as a packaging material.

Specifically prepared cell pouch specimen was immersed in 3.5% NaCl solution (water 96.5g + sun salt 3.5g) and the degree of corrosion of aluminum was visually confirmed.

The pouch was impregnated with the 3.5% sodium chloride solution, and no corrosion was observed in the normal 4 days or more, as indicated by "○", and in the case of 7 days or more, the ideal was indicated as "◎". When corrosion appeared in less than 4 days was represented by "△".

Table 3 shows the salt resistance results of the examples and the comparative examples.

Salinity resistance Example ◎ Comparative Example 1 △ Comparative Example 2 ○

As can be seen from the above, in the case of non-chromate treatment, the salinity resistance was increased in comparison with the non-chromate treatment, but especially in the case of non-chromate treatment on both sides of aluminum, the salt resistance was greatly increased.

According to the cell packaging encapsulant such as the lithium secondary battery or the portable storage battery of the present invention, it is possible to fundamentally improve the electrolyte resistance, which is a characteristic particularly required for the cell packaging encapsulant, to prevent corrosion of the barrier layer by the electrolyte, and to seal the sealant layer and the barrier. Delamination of the layer can be prevented. In addition, the cell packaging encapsulant such as the lithium secondary battery or the portable storage battery of the present invention can freely protect the cell and have a free shape, excellent barrier property, excellent moldability and impact resistance, and air (oxygen) permeation. Excellent anti-permeability, moisture-permeability, puncture strength, short manufacturing time, high process efficiency, low cost and light characteristics.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (25)

Outermost resin film; A first adhesive resin layer formed on the outermost resin film; A barrier layer comprising a metal or an inorganic compound formed on the first adhesive resin layer; A second adhesive resin layer formed on the barrier layer; And As a cell packaging material comprising; a sealant layer formed on the second adhesive resin layer, The sealant layer is formed on the polyolefin film consisting of a single layer or a multilayer formed with a deposition layer of an oxide of SiO ₂ or Al ₂ O ₃ or a metal selected from the group consisting of Cu, Fe, Sn, Zn, Ag and Al A cell packaging material characterized by the above. The outermost layer film which is a polyester film containing 100-110 mol parts of acid components with respect to 130 mol parts of glycol components; A first adhesive resin layer formed on the outermost layer film; A barrier layer comprising a metal or an inorganic compound formed on the first adhesive resin layer; A second adhesive resin layer formed on the barrier layer; And As a cell packaging material comprising; a sealant layer formed on the second adhesive resin layer, The sealant layer is formed on the polyolefin film consisting of a single layer or a multilayer formed with a deposition layer of an oxide of SiO ₂ or Al ₂ O ₃ or a metal selected from the group consisting of Cu, Fe, Sn, Zn, Ag and Al A cell packaging material characterized by the above. The method of claim 2, Cell packaging material, characterized in that further addition of at least one of a catalyst, a slip agent or a stabilizer to the polyester film of the outermost layer. The method of claim 2 or 3, Cell packaging material, characterized in that the inner surface or both sides of the outermost polyester film is corona treated. The method according to claim 1 or 2, The thickness of the deposition layer of the oxide or metal of the sealant layer is a cell packaging material, characterized in that 200 to 500 kPa. The method according to claim 1 or 2, The polyolefin film is a polyolefin film formed of three layers, wherein two adjacent polyolefins among the polyolefin films formed of the three layers are polyolefins having different crystallinities from each other. The method according to claim 1 or 2, The first adhesive resin layer is a cell packaging material, characterized in that the urethane-based adhesive resin layer. The method according to claim 1 or 2, The barrier layer is made of aluminum foil cell packaging material. The method of claim 8, Cell packaging material, characterized in that the non-chromate-based corrosion protection layer is formed on both sides of the aluminum foil. The method of claim 9, The aluminum foil contains silicon (Si) and iron (Fe) at the same time, the content of the cell packaging material, characterized in that 0.05 to 0.9% by weight and 0.6 to 2.0% by weight, respectively. The method according to claim 1 or 2, The second adhesive resin layer is a cell packaging material, characterized in that the melt-extruded resin layer formed by melt-extruded resin. The method according to claim 1 or 2, The second adhesive resin layer is a cell packaging material, characterized in that the urethane-based adhesive resin layer. Forming a barrier layer including a metal or an inorganic compound using a first adhesive resin on an outermost resin film (S1); And A method of manufacturing a cell packaging material comprising; forming a sealant layer on the barrier layer by using a second adhesive resin (S2) In the step S2, the sealant layer is deposited by depositing a metal of SiO ₂ or Al ₂ O ₃ or a metal selected from the group consisting of Cu, Fe, Sn, Zn, Ag, and Al on a polyolefin film composed of a single layer or a multilayer. Method for producing a cell packaging material, characterized in that to form a. Forming a barrier layer including a metal or an inorganic compound by using a first adhesive resin on an outermost layer film which is a polyester film having an acid component of 100 to 110 mole parts relative to 130 mole parts of a glycol component (S1); And A method of manufacturing a cell packaging material comprising; forming a sealant layer on the barrier layer by using a second adhesive resin (S2) In the step S2, the sealant layer is deposited by depositing a metal of SiO ₂ or Al ₂ O ₃ or a metal selected from the group consisting of Cu, Fe, Sn, Zn, Ag, and Al on a polyolefin film composed of a single layer or a multilayer. Method for producing a cell packaging material, characterized in that to form a. The method of claim 14, In the step S1, the method for producing a cell packaging material, characterized in that further adding at least one additive of a catalyst, a slip agent or a stabilizer to the polyester film of the outermost layer. The method according to claim 14 or 15, In the step S1, the method for producing a cell packaging material, characterized in that the corona treatment on the inner surface or both sides of the polyester film of the outermost layer. The method according to claim 13 or 14, In the step S1, the method for producing a cell packaging material, characterized in that using the urethane-based adhesive as the first adhesive resin. The method according to claim 13 or 14, In the step S1, the method for manufacturing a cell packaging material, characterized in that to form the barrier layer of aluminum foil. The method of claim 18, In the step S1, the method for producing a cell packaging material, characterized in that the non-chromate-based corrosion protection layer is further formed on both sides of the aluminum foil. The method of claim 19, In the step S1, as the aluminum foil, a method for producing a cell packaging material, characterized in that aluminum (Si) and iron (Fe) content containing 0.05 to 0.9% by weight and 0.6 to 2.0% by weight, respectively. The method according to claim 13 or 14, In the step S2, a method of manufacturing a cell packaging material, characterized in that the melt-extruded resin melt-extruded resin as the second adhesive resin. The method according to claim 13 or 14, In the step S2, the method for producing a cell packaging material, characterized in that using the urethane-based adhesive as the second adhesive resin. The method according to claim 13 or 14, In the step S2, a method of manufacturing a cell packaging material, characterized in that the deposition thickness is 200 to 500 kPa when the oxide or metal is deposited in the sealant layer. The method according to claim 13 or 14, In the step S2, the method of manufacturing a cell packaging material, characterized in that the deposition is made by any one of physical vapor deposition, chemical vapor deposition, resistive heating deposition, plasma deposition, ion plating or sputtering. The method according to claim 13 or 14, In the step S2, using a polyolefin film formed of three layers as the polyolefin film, the method for producing a cell packaging material, characterized in that two adjacent polyolefins of the polyolefin film formed of the three layers is a polyolefin having a different crystallinity.

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