KR20150110324A - Exterior for electrochemical device and electrochemical device - Google Patents

Abstract

The present invention relates to an exterior material for an electrochemical device comprising: a metal foil layer (4); and a thermoplastic resin unstretched film layer (3) as an inner layer wherein a metal plating layer (8) is formed on at least one side of the metal foil layer (4). By having this configuration, it is possible to achieve a sufficient reduction in weight and possible to suppress an invasion of water from outside and in addition, possible to provide an exterior material for an electrochemical device capable of preventing a diffusion of an electrolyte solution.

Description

[0001] EXTERIOR FOR ELECTROCHEMICAL DEVICE AND ELECTROCHEMICAL DEVICE [0002]

The present invention relates to a thin and lightweight battery for electrochemical devices such as batteries, capacitors, capacitors, hybrid cars, electric vehicles, wind power generators, photovoltaic generators, and batteries used in portable devices such as smart phones and tablets, And an electrochemical device enclosed by the exterior material.

In the present specification, the term " outer layer " does not mean the outermost side of the casing, but means that it is disposed outside the metal foil layer.

In the present specification, the meaning of "aluminum" is used to mean aluminum and its alloys.

2. Description of the Related Art Along with the thinning and lightening of mobile electrical appliances such as smart phones and tablet terminals, there has been a demand for an outer casing of an electrochemical device such as a lithium ion battery, a lithium polymer battery, a lithium ion capacitor, an electric double- Lighter weight is achieved by using a laminate outer material in which a plastic film is stuck on both sides of the aluminum foil in place of the can. Also, as an application thereof, a power source for an electric vehicle, a large-sized power source for power storage, a capacitor, and the like are also packaged with a laminate outer cover having the above-described configuration.

As the laminate sheathing material, a heat-resistant stretched film is stuck to one surface of an aluminum foil to be a barrier layer, and a heat-sealable non-stretch film capable of heat sealing is stuck to the other surface of the aluminum foil And even when a sheathing material having a total thickness of about 100 mu m is formed by such a constitution, it has a function of preventing moisture and various gases from penetrating into the interior thereof and preventing leakage of the electrolyte solution (refer to Patent Document 1). The outer sheath of Example 1 of Patent Document 1 has a thickness of about 98 占 퐉, and the outer sheath of Example 2 has a thickness of about 103 占 퐉.

Patent Document 1: Japanese Patent Laid-Open No. 2002-25511

In recent years, however, the mobile electrical apparatuses and the like are being made more thinner and lighter, and electrochemical devices mounted thereon are required to be made thinner and lighter. Development is progressing in order to make thinner and lighter. At present, the aluminum foil is made of a material having a thickness of 30 탆 or more, which means that there is no possibility of occurrence of pin holes. If the thickness is less than 30 mu m, there is a possibility that pinholes will occur in the aluminum foil. It is known that the thinner the thickness, the more the number of pinholes increases. In the presence of pinholes, the aluminum foil can not function as a barrier layer, so that it is not possible to prevent the entry of moisture from the outside, and there is a problem that diffusion and leakage of the electrolytic solution can not be prevented.

On the other hand, when the thickness of the aluminum foil is set to 30 占 퐉 or more in order to eliminate pinholes in the aluminum foil, the total thickness of the aluminum foil as the covering material is at least 80 占 퐉 or more, .

Therefore, even when it is used as a jacket for a small electrochemical device such as a lithium ion battery having a small capacity of about 30 mA to 500 mA, in practice, large-sized electricity such as a lithium ion battery having a capacity exceeding 500 mA It is required to use a material having the same specification as that of a casing material for a chemical device. Particularly, thinning and weight reduction of a casing material for a small size electrochemical device having a capacity of 30 mA to 500 mA has become a big problem.

The present invention has been made in view of such a technical background, and it is an object of the present invention to provide a jacket for an electrochemical device capable of being sufficiently lightweight and capable of preventing invasion of moisture from the outside and preventing diffusion of an electrolytic solution The purpose.

In order to achieve the above object, the present invention provides the following means.

[1] A jacket for an electrochemical device comprising a metal foil layer and a thermoplastic resin undrawn film layer as an inner layer,

And a metal plating layer is formed on at least one surface of the metal foil layer.

[2] An outer casing for an electrochemical device comprising an outer layer, a thermoplastic resin undrawn film layer as an inner layer, and a metal foil layer interposed between the outer layer and the inner layer,

And a metal plating layer is formed on at least one surface of the metal foil layer.

[3] The enclosure for an electrochemical device according to the above 2, wherein the outer layer is a heat-resistant resin film layer.

[4] The exterior member for an electrochemical device according to the above item 2, wherein the outer layer is a heat-resistant resin coat layer formed by applying a heat-resistant resin.

[5] An exterior member for an electrochemical device according to any one of items 1 to 4, wherein the metal foil layer has a thickness of 5 μm or more and less than 30 μm.

[6] An exterior member for an electrochemical device according to any one of items 1 to 5, wherein the metal plating layer has a thickness of 0.5 μm to 5 μm.

[7] The jacket for an electrochemical device according to any one of items 1 to 6, wherein the metal plating layer is a plating layer composed of at least one kind of metallic material selected from the group consisting of nickel, zinc, tin, chromium and cobalt.

[8] An exterior material for an electrochemical device according to any one of items 1 to 7, wherein the exterior material has a thickness of 30 μm to 80 μm.

[9] An electrochemical device comprising:

An electrochemical device external packaging material according to any one of items 1 to 8,

Wherein the electrochemical device body portion is enclosed by the exterior material.

In the invention of [1] and [2], since the metal plating layer is formed on at least one surface of the metal foil layer, even if the metal foil has pinholes due to the thinning of the metal foil, It is possible to suppress the penetration of moisture of the electrolyte and to prevent diffusion and leakage of the electrolytic solution to the outside. Even when the thickness of the metal foil layer is designed to be thin (for example, 5 μm or more and less than 30 μm) and reduced in weight, it is possible to improve the various effects by the presence of the metal plating layer as described above. It is possible to suppress the penetration of moisture of the electrolytic solution and prevent the diffusion of the electrolytic solution. Therefore, according to the present invention, it is possible to secure an excellent water barrier property and an excellent electrolyte diffusion preventive property while achieving sufficient thin film and light weight. The electrochemical device thus enclosed using the skin material of the present invention which is made thin and lightweight can improve the weight energy density and the volume energy density of the electrochemical device. Further, since the metal plating layer is formed on at least one surface of the metal foil layer, the resistance to puncture resistance of the metal foil itself can be further improved.

Further, in the invention of [2], since the outer layer is provided, it is possible to secure a sufficient puncture strength as the jacket, and to improve the puncture resistance.

In the invention of [3], since the outer layer is a heat-resistant resin film layer, the stamper strength can be further improved as a casing.

In the invention of [4], since the outer layer is a heat-resistant resin coat layer formed by applying a heat-resistant resin, the stamper strength can be further improved as a sheathing material. Further, the heat-resistant resin coat layer can be made thinner as compared with the case where the heat-resistant resin film layer constitutes the outer layer.

According to the invention of [5], since the thickness of the metal foil layer is less than 5 탆 and less than 30 탆, thinning and light weight can be achieved while ensuring excellent moisture barrier property and excellent electrolyte diffusion prevention property.

In the invention of [6], since the thickness of the metal plating layer is 0.5 μm to 5 μm, excellent water barrier property and excellent electrolytic solution diffusion prevention property can be ensured while achieving sufficient thin film and light weight.

In the invention of [7], since the metal plating layer is a plating layer composed of at least one kind of metal material selected from the group consisting of nickel, zinc, tin, chromium and cobalt, it is possible to further improve the moisture barrier property and the more excellent electrolyte It is possible to secure the diffusion preventing property and further improve the stamper strength as the exterior material.

According to the invention of [8], since the thickness of the casing is 30 to 80 탆, an electrochemical device enclosed with this casing can further improve the weight energy density and the volume energy density of the electrochemical device.

In the invention (electrochemical device) of [9], there is provided an electrochemical device which can secure an excellent moisture barrier property and an excellent electrolyte diffusion preventing property by a casing, and improve a weight energy density and a volume energy density .

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing one embodiment (first embodiment) of a casing for electrochemical devices of the present invention. Fig.
2 is a cross-sectional view showing another embodiment (second embodiment) of the casing for electrochemical devices of the present invention.
3 is a sectional view showing still another embodiment (third embodiment) of the casing for electrochemical devices of the present invention.
4 is a cross-sectional view showing another embodiment (fourth embodiment) of the casing material for an electrochemical device of the present invention
5 is a cross-sectional view showing one embodiment of the electrochemical device of the present invention.
Fig. 6 is a perspective view showing a casing (planar type) constituting the electrochemical device of Fig. 5, an electrochemical device main body part and a casing material (molded in a three-dimensional shape) before being heat sealed.

Fig. 1 shows an embodiment of an outer casing 1 for an electrochemical device according to the present invention. The exterior material 1 for the electrochemical device is formed on one surface of a barrier layer 10 formed by forming metal plating layers 8 on both surfaces of a metal foil layer 4 through a first adhesive layer 5, (Inner layer) 3 is integrally laminated on the other surface of the barrier layer 10 with the second adhesive layer 6 interposed therebetween, and the thermoplastic resin undrawn film layer (inner layer) 3 is integrally laminated on the other surface of the barrier layer 10 . In the present embodiment, the outer layer 2 is composed of the heat-resistant resin film layer 12.

In the embodiment shown in Fig. 1, the barrier layer 10 is formed with metal plating layers 8, 8 on both sides of the metal foil layer 4, but is not particularly limited to such a configuration, A structure in which the metal plating layer 8 is formed on only one side of the metal foil layer 4 may be adopted as shown in Fig.

That is, in the embodiment shown in Fig. 2, the exterior member 1 for an electrochemical device has a structure in which the metal layer 8 is formed on one surface of the metal foil layer 4, The outer layer 2 is laminated and integrated with the first adhesive layer 5 on the surface of the metal plating layer 8 and the metal layer 4 is formed on the other surface of the barrier layer 10, (Inner layer) 3 is laminated and integrated with the thermoplastic resin undrawn film layer (inner layer) 3 via the second adhesive layer 6 on the surface of the thermoplastic resin film. In this embodiment, the outer layer 2 is composed of the heat-resistant resin film layer 12.

3, the outer casing 1 for an electrochemical device has a structure in which the metal plating layer 8 is formed on one surface of the metal foil layer 4 and the other surface of the barrier layer 10 The outer layer 2 is laminated and integrated with the first adhesive layer 5 on the surface of the metal foil layer 4 and on one surface of the barrier layer 10 (Inner layer) 3 is laminated and integrated with the thermoplastic resin non-stretched film layer (inner layer) 3 through the second adhesive layer 6 on the surface of the thermoplastic resin film. In this embodiment, the outer layer 2 is composed of the heat-resistant resin film layer 12.

4, the outer casing 1 for an electrochemical device is provided on one surface of the barrier layer 10 in which metal plating layers 8, 8 are formed on both surfaces of the metal foil layer 4 And the heat resistant resin coat layer 13 as the outer layer 2 are laminated and integrated with each other and the thermoplastic resin unstretched film layer (the inner layer 1) is formed on the other surface of the barrier layer 10 through the second adhesive layer 6, ) 3 are laminated and integrated.

In the present invention, as described above, the metal plating layer 8 is formed on at least one surface of the metal foil layer 4, and even if pinholes are present in the metal foil layer 4 due to the thinning of the metal foil, It is considered that the end opening in the depth direction of the pinhole (thickness direction of the metal foil) is almost closed by the metal plating layer 8. It is also considered that the plating portion of the metal plating layer 8 penetrates into the pinhole of the metal foil layer 4 from the inside of the pinhole (the region further inside the hole from the end opening in the pinhole) .

Since the metal plating layer 8 is formed on at least one surface of the metal foil layer 4 in the sheathing material 1 for an electrochemical device, a pinhole exists in the metal foil layer 4 due to the thinning of the metal foil The penetration of moisture from the outside can be suppressed by the metal plating layer 4, and diffusion and leakage of the electrolytic solution to the outside can be suppressed. Since the various effects can be improved by the presence of the metal plating layer 4 as described above, the thickness of the metal foil layer 4 is designed to be thin (for example, less than 5 탆 and less than 30 탆) , It is possible to suppress the intrusion of moisture from the outside as the casing member 1 and to prevent the diffusion of the electrolytic solution. Therefore, according to the present invention, it is possible to secure an excellent water barrier property and an excellent electrolyte diffusion preventive property while achieving sufficient thin film and light weight. The electrochemical device 30 thus enclosed using the facer material 1 of the present invention which is made thin and lightweight can improve the weight energy density and the volume energy density of the electrochemical device. Further, since the metal plating layer 8 is formed on at least one surface of the metal foil layer 4, the resistance to bite provided by the metal foil itself can be further improved.

In the embodiment shown in Figs. 1 to 4, since the outer layer 2 is provided in all of the embodiments, it is possible to secure a sufficient stamper strength as the sheath 1 and to sufficiently improve the stamper resistance.

1 and 4, the metal plating layer 8 formed on one surface of the metal foil layer 4, the metal foil layer 4, And the metal plating layer 8 formed on the other side of the metal foil layer 4 are present in the laminated structure shown in Figs. (Two layers of the metal plating layer 8 formed on one side), it is possible to secure a superior moisture barrier property and a better electrolyte diffusion preventing property.

In the present invention, when the thickness of the metal foil layer 4 is set to less than 30 탆 in order to achieve a sufficient weight, pinholes may be generated in the metal foil. On the other hand, (The structure in which the metal foil layer 4 and the double metal barrier layer of one metal plating layer 8 are provided), the possibility of peeling off a very small part due to a change in stress or the like can not be denied. It can be said that there is practically no possibility that the position (specific point) of the pinhole of the metal foil layer 4 and the position (specific point) of the peeling point of the metal plating layer 8 are substantially the same. And excellent electrolyte diffusion prevention property can be ensured.

1 and 4, a metal plating layer 8 formed on one surface of the metal foil layer 4, a metal plating layer 8 formed on the other surface of the metal foil layer 4, (Specific point) of the pinhole of the metal foil layer 4 and the peeling point (specific point) of the one metal plating layer 8 and the other metal plating layer 8 (The constitution of Figs. 1 and 4) in which these triple barrier portions are provided, there is a possibility that the peeling points (specific points) of the three constituent elements (A structure provided with a double barrier portion), it is possible to ensure a superior moisture barrier property and a better electrolyte diffusion preventive property.

In the present invention, the metal foil layer 4 plays a role of imparting gas barrier properties to the exterior material 1 to prevent intrusion of oxygen and moisture. The thickness of the metal foil layer 4 is preferably 5 mu m or more and less than 30 mu m. By setting the thickness within this range, thinning and lightening can be achieved, and by adjusting the thickness of the metal plating layer 8, it is possible to secure excellent water barrier properties and excellent electrolyte diffusion preventing property as the entire casing material 1 . In particular, the thickness of the metal foil layer 4 is more preferably 5 탆 or more and less than 20 탆, and particularly preferably 5 탆 to 18 탆. The metal foil is not particularly limited, and examples thereof include aluminum foil, stainless steel foil, nickel foil, copper foil and titanium foil. Among them, it is preferable to use an aluminum foil from the viewpoint of weight reduction and cost.

The outer layer 2 and the inner layer (thermoplastic resin unstretched film layer) 3 are layers made of a resin, and the resin layer has a very small amount, but light, oxygen and liquid may penetrate deeply from the outside of the case And the contents (electrolyte, food, medicines, etc.) of the battery may penetrate deeply from the inside. When these intrusions reach the metal foil layer 4, they become a cause of corrosion of the metal foil layer. In the present invention, it is preferable that a chemical film is formed on at least the surface of the thermoplastic resin layer (3) side of the metal foil. In this case, the corrosion resistance of the metal foil layer (4) can be improved. In particular, it is particularly preferable to adopt a configuration in which a chemical conversion coating is formed on both surfaces of the metal foil. In this case, the corrosion resistance of the metal foil layer 4 can be sufficiently improved.

The chemical conversion coating is a coating formed by performing a chemical conversion treatment on the surface of a metal foil. For example, the chemical conversion coating can be formed by performing a chromate treatment on a metal foil or a non-chromium plating treatment using a zirconium compound. For example, in the case of the chromate treatment, an aqueous solution of a mixture of any one of the following 1) to 3) is applied to the surface of the metal foil subjected to the degreasing treatment, followed by drying.

1) an aqueous solution of a mixture comprising at least one compound selected from the group consisting of phosphoric acid, chromic acid, and metal salts of fluoride and non-metal salts of fluoride

2) a mixture containing at least one resin selected from the group consisting of phosphoric acid, an acrylic resin, a chitosan derivative resin and a phenol resin, and at least one compound selected from the group consisting of chromic acid and chromium (III) salt Aqueous solution

3) at least one resin selected from the group consisting of phosphoric acid, an acrylic resin, a chitosan derivative resin and a phenol resin; at least one compound selected from the group consisting of chromic acid and chromium (III) salt; And a non-metallic salt of a metal salt and a fluoride.

The above-mentioned chemical conversion coating is preferably from 0.1 mg / m 2 to 50 mg / m 2, particularly preferably from 2 mg / m 2 to 20 mg / m 2 as the chromium adhering amount (per one side).

The metal constituting the metal plating layer 8 is not particularly limited, and examples thereof include nickel, zinc, tin, chromium, cobalt, gold, silver and platinum. Among them, the metal plating layer 8 is preferably a plating layer composed of at least one kind of metal material selected from the group consisting of nickel, zinc, tin, chromium and cobalt, It is possible to further secure the moisture barrier property and the more excellent electrolyte diffusion preventive property and to further improve the stamper strength as the casing member 1. [

It is preferable that the thickness (T) of the metal plating layer 8 (the thickness of the plating layer formed on one surface when the plating layer is formed on both surfaces) is set to 0.5 탆 to 5 탆. If the thickness of the metal foil layer 4 is less than 30 탆, pinholes may be generated in the metal foil. By adjusting the thickness T of the metal plating layer 8 in accordance with the thickness of the metal foil, It is possible to secure an excellent moisture barrier property and an excellent electrolyte diffusion preventive property as a whole. In particular, the thickness (T) of the metal plating layer 8 (the thickness of the plating layer formed on one surface when the plating layer is formed on both surfaces) More preferably 5 占 퐉 (see Figs. 1 to 4). In addition, when nickel is used as the metal constituting the metal plating layer 8, there is an advantage that the sticking strength can be further improved as compared with the case of using other metals.

The method of the metal plating is not particularly limited, and examples thereof include an electroless plating method, an electroplating method, and a vacuum plating method. Among them, the metal plating layer 8 is preferably formed by electroless plating. The metal plating layer formed by the electroless plating method can reliably ensure an excellent water barrier property and an excellent electrolytic solution diffusion preventive property, as compared with the case of forming by a electroplating method, a more uniform plating layer without stains, (The metal plating layer 8 formed by the electroless plating method) has a high adhesiveness to the aluminum foil layer 4 when the aluminum foil layer 4 is an aluminum foil layer.

The thermoplastic resin unstretched film layer (inner layer) 3 has excellent chemical resistance against electrolytes having high corrosiveness used in a lithium ion secondary battery or the like, and also plays a role of imparting heat resistance to the casing material .

The resin constituting the thermoplastic resin non-stretched film layer 3 is not particularly limited, and examples thereof include polyethylene, polypropylene, ionomer, ethylene ethyl acrylate (EEA), ethylene methyl acrylate (EAA) (EMMA), ethylene-vinyl acetate copolymer resin (EVA), maleic anhydride-modified polypropylene, maleic anhydride-modified polyethylene, and the like.

The thickness of the thermoplastic resin non-stretched film layer 3 is preferably set to 20 to 80 탆. By setting the thickness to 20 mu m or more, the occurrence of pinholes can be sufficiently prevented, and by setting the thickness to 80 mu m or less, the amount of resin used can be reduced and the cost can be reduced. In particular, it is particularly preferable that the thickness of the thermoplastic resin unstretched film layer 3 is set to 30 탆 to 50 탆. The thermoplastic resin non-stretched film layer 3 may be a single layer or a multilayer.

In the present invention, the outer layer 2 is a member mainly responsible for ensuring good moldability as a jacket, that is, it plays a role of preventing the metal foil from being broken by necking at the time of molding. Further, in the present invention, it is preferable that the outer layer 2 is not necessarily an essential constituent layer.

The outer layer 2 is preferably composed of a heat resistant resin film layer 12 or a heat resistant resin coat layer 13 formed by applying a heat resistant resin. In this case, there is an advantage that the stamper strength can be further improved as the facer material 1. [

The heat resistant resin film layer 12 is not particularly limited, and for example, a stretched polyamide film (stretched nylon film or the like) or a stretched polyester film is preferably used. As the heat-resistant resin film layer 12, biaxially oriented polyamide film (biaxially oriented nylon film, etc.), biaxially oriented polybutylene terephthalate (PBT) film, biaxially oriented polyethylene terephthalate (PET) Film or a biaxially stretched polyethylene naphthalate (PEN) film. Examples of the nylon include, but are not limited to, 6 nylon, 6,6 nylon, and MXD nylon. The heat-resistant resin film layer 12 may be formed of a single layer (a single stretched film), or may be a multi-layered biaxially oriented PET film / 2 made of a stretched polyester film / stretched polyamide film A multi-layer made of an axially stretched nylon film, or the like).

Among them, the heat-resistant resin film layer 12 is a multilayer structure comprising a biaxially oriented polyester film disposed on the outer side and a biaxially oriented polyamide film disposed on the first adhesive layer 5 side desirable. It is preferable that the heat-resistant resin film layer 12 has a multilayer structure including a biaxially oriented polyethylene terephthalate film disposed on the outer side and a biaxially stretched nylon film disposed on the first adhesive layer 5 side desirable.

The heat resistant resin film layer 12 may be made of a heat resistant resin undrawn film such as a polycarbonate unstretched film or a polyimide unstretched film.

The thickness of the heat resistant resin film layer 12 is preferably set to 12 to 50 탆.

The heat resistant resin coat layer 13 is a coat layer formed by applying a heat resistant resin. For example, the heat-resistant resin can be applied to the surface of the metal foil layer 4. (On the surface of the metal plating layer 8) on one side of the barrier layer 10 in which the metal plating layer 8 is formed on at least one surface of the metal foil layer 4 .

The heat resistant resin constituting the heat resistant resin coat layer 13 is not particularly limited, and examples thereof include an acrylic resin, an epoxy resin, a urethane resin, a polyolefin resin and a fluorine resin. Above all, it is preferable to use a fluorine resin based on tetrafluoroethylene or fluoroethylene vinyl ether in view of excellent heat resistance and chemical resistance. Further, additives such as fine particles (silica, acrylic beads, etc.) and ink may be added to the heat resistant resin in order to change the appearance of the exterior material to improve the designability.

The resin coating method is not particularly limited, and examples thereof include a gravure roll method, a reverse roll coating method, a lip roll coating method, and a die coating method. The thickness of the heat resistant resin coat layer 13 is preferably set to 0.1 to 40 탆. In particular, the thickness of the heat-resistant resin coat layer 13 is more preferably set to 0.1 to 20 占 퐉.

The vapor deposition layer may be laminated on the outer surface and / or the inner surface of the outer layer 2 (the surface on the metal foil layer 4 side). By providing such a vapor deposition layer, it is possible to secure further superior water barrier properties and more excellent electrolyte diffusion preventive property. It is preferable that the vapor deposition layer is composed of at least one kind of material selected from the group consisting of metal, metal oxide and fluoride. Examples of the metal include, but are not limited to, aluminum, chromium, zinc, nickel, gold, silver, platinum and the like. The metal oxide is not particularly limited, and examples thereof include alumina, silica, titanium oxide, zirconium oxide, and the like. The fluoride is not particularly limited, and examples thereof include magnesium fluoride and the like. In particular, it is particularly preferable that the material (deposition material) for forming the vapor deposition layer is at least one material selected from the group consisting of aluminum, alumina and silica.

The first adhesive layer 5 is not particularly limited, and examples thereof include a polyurethane adhesive layer, a polyester polyurethane adhesive layer, and a polyether polyurethane adhesive layer. The thickness of the first adhesive layer 5 is preferably set to 1 탆 to 5 탆. Particularly, from the viewpoint of thinning and lightening of the exterior material, it is particularly preferable that the thickness of the first adhesive layer 5 is set to 1 탆 to 3 탆.

Although the second adhesive layer 6 is not particularly limited, for example, those exemplified as the first adhesive layer 5 may be used, but it is preferable to use a polyolefin-based adhesive having a small expansion caused by an electrolytic solution Do. The thickness of the second adhesive layer 6 is preferably set to 1 탆 to 5 탆. Particularly, from the viewpoint of thinning and lightening of the exterior material, it is particularly preferable that the thickness of the second adhesive layer 6 is set to 1 탆 to 3 탆.

The barrier layer 10 (the barrier layer 10 in which the metal plating layer 8 is formed on at least one surface of the metal foil layer 4) and the outer layer 2 (the heat-resistant resin film layer 12) , The heat resistant resin coat layer 13, etc.) is not particularly limited, but a method called dry lamination can be recommended. Specifically, the prepared first adhesive is applied to the upper surface or the lower surface of the outer layer 2 of the barrier layer 10, or both surfaces thereof, and the solvent is evaporated to form a dried film, And the outer layer (2). Thereafter, it is cured according to the curing conditions of the first adhesive. Thereby, the barrier layer 10 and the outer layer 2 are bonded to each other through the first adhesive layer 5. Examples of the application method of the first adhesive include a gravure coating method, a reverse roll coating method, and a lip roll coating method.

The barrier layer 10 (the barrier layer 10 in which the metal plating layer 8 is formed on at least one surface of the metal foil layer 4) and the thermoplastic resin non-stretch film layer 3 After the second adhesive is applied and dried, the barrier layer 10 and the thermoplastic resin non-stretched film layer (not shown) are bonded to each other in the same manner as in the above-described bonding of the barrier layer 10 and the outer layer 2, (3) are laminated on one another.

The thermoplastic resin layer (3) and the outer layer (2) may contain an additive. Examples of such additives include, but are not limited to, antiblocking agents (silica, talc, kaolin, acrylic resin beads, etc.), lubricants (fatty acid amide, wax, etc.), antioxidants (hindered phenol, etc.) .

The thickness of the facer material 1 of the present invention is preferably set to 30 탆 to 80 탆. It is possible to improve the weight energy density and the volume energy density of the electrochemical device 30 enclosed by the outer sheath 1. In particular, it is more preferable that the thickness of the exterior member 1 is set to 30 탆 to 65 탆.

The outer layer 2 is not an essential constituent layer and the barrier layer 10 (the metal plating layer 8 is formed on at least one surface of the metal foil layer 4) (Inner layer) 3 is laminated and integrated on one surface of the thermoplastic resin non-stretchable film layer (the barrier layer 10 formed with the thermoplastic resin resin layer 6) through the second adhesive layer 6 may be employed.

In the above embodiment, the first adhesive layer 5 and the second adhesive layer 6 are provided. However, these two layers 5 and 6 are not essential constituent layers, May be adopted.

In addition, the outer sheath 1 of the present invention is not particularly limited to the laminated structure rolls shown in Figs. 1 to 4, but may also be provided with another layer to improve its function as an outer sheath.

Molding cases (such as a battery case) for an electrochemical device can be obtained by molding (the deep drawing molding, extrusion molding, etc.) of the exterior member 1 of the present invention.

Next, an embodiment of the electrochemical device 30 of the present invention is shown in Figs. 5 and 6. Fig. As shown in Figs. 5 and 6, an electrochemical device main body (electrochemical element) 31 having a substantially rectangular parallelepiped shape is provided in the housing recess of the molding case 1A obtained by molding the casing material 1 of the present invention The outer casing 1 of the present invention is disposed on the electrochemical device main body portion 31 with its inner layer 3 side inside (lower side), and the inner side layer 3 of the planar casing material 1 The inner layer 3 of the molding case 1A and the inner layer 3 of the flange portion (sealing peripheral portion) 29 of the molding case 1A are sealed and sealed by the heat seal, ).

5, reference numeral 39 denotes a heat seal portion in which the periphery of the casing member 1 and the flange portion (sealing periphery portion) 29 of the molding case 1A are joined (welded).

The electrochemical device main body 31 is not particularly limited, and examples thereof include a battery main body, a capacitor main body, and a capacitor main body.

The width of the heat seal part 39 is preferably set to 0.5 mm or more. By setting it to 0.5 mm or more, sealing can be reliably performed. In particular, the width of the heat seal part 39 is preferably set to 3 mm to 15 mm.

Example

Next, specific examples of the present invention will be described, but the present invention is not limited to these examples.

<Example 1>

(Non-electrolytic nickel plating) was performed on the soft aluminum foil 4 having a thickness of 15 탆 (A8079 soft aluminum alloy foil 4 defined by JISH4000) T) 2 탆 thick nickel plating layer 8 was formed to obtain a double-side-plated aluminum foil (barrier layer 10) having a thickness of 19 탆.

Next, a chemical liquor consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water and alcohol is applied to both surfaces of the double-coated aluminum foil (barrier layer 10) To prepare a double-coated aluminum foil having a chemical conversion coating on both surfaces thereof. The adhesion amount of chromium by this chemical conversion coating is 5 mg / m 2 on one side.

Next, a two-liquid curable polyester-urethane resin adhesive is applied to one surface of the double-coated aluminum foil having the chemical conversion coatings formed on both surfaces thereof and dried to form a first adhesive layer 5, A biaxially stretched polyester film 2 having a thickness of 12 탆 was stuck on the surface of the layer 5 and a two-part curing type polyolefin adhesive agent (acid-modified polypropylene as a subject (2-part curing type adhesive using hexamethylene diisocyanate as a curing agent) was applied and dried to form a second adhesive layer 6. On the surface of the second adhesive layer 6, an unstretched polypropylene film (3). This laminate was allowed to stand (cure) for 3 days under an environment of 40 占 폚 to obtain an exterior member (thickness 62 占 퐉) (1) for electrochemical devices shown in Fig.

<Practical Example 2>

(Thickness: 54 m) (1) shown in Fig. 1 was produced in the same manner as in Example 1, except that a soft aluminum alloy foil having a thickness of 7 m was used instead of the soft aluminum alloy foil having a thickness of 15 m. .

&Lt; Example 3 >

(Thickness 59 占 퐉) 1 shown in Fig. 1 was obtained in the same manner as in Example 1 except that the thickness T of the nickel plating layer 8 was changed to 0.5 占 퐉.

<Example 4>

Electroless nickel plating (carizen plating) was performed on a soft aluminum foil (A8079 soft aluminum alloy foil 4) having a thickness of 15 mu m as a double-sided plated aluminum foil (4) Plated aluminum foil having a thickness of 19 占 퐉 obtained by laminating a tin plating layer having a thickness of 1 占 퐉 on each of both surfaces thereof after electroless tin plating was performed after forming a nickel plated layer having a thickness of 5 占 퐉, (Thickness: 62 m) (1) for the electrochemical device shown in Fig. 1 was obtained.

&Lt; Example 5 >

Plated aluminum foil in which a nickel plated layer 8 having a thickness of 2 탆 was formed on one side of a soft aluminum foil instead of a double-plated aluminum foil was used in place of the single- (Thickness: 60 mu m) (1) for a device was obtained. In addition, the biaxially stretched polyester film 2 was stuck to the plated surface 8 side of the single-surface-plated aluminum foil (see Fig. 2).

&Lt; Example 6 >

(TDI) and hexamethylene diisocyanate (HDI) were mixed so as to have a mass ratio of 1: 1, using a copolymer of tetrafluoroethylene and vinyl acetate as the main resin, And 18 parts by mass of the above-mentioned curing agent were mixed to obtain a coating resin (heat-resistant resin).

Next, 80 parts by mass of the above-mentioned coating resin (heat-resistant resin), 10 parts by mass of barium sulfate and 10 parts by mass of granular silica was added to the resin composition, and ethyl acetate was added as a solvent to adjust the solid content to 19 mass% Respectively.

Subsequently, the resin solution was coated on one surface (the surface of the plated layer 8) of the both-side plated aluminum foil having the chemical conversion coatings formed on both sides obtained in Example 1 by the gravure roll method and then dried to dry Heat-resistant resin coat layer 13 having a thickness of 2 占 퐉 was laminated on the other surface (the surface of the plated layer 8) of the aluminum foil and a two-liquid curing type polyolefin adhesive agent (2-part curing type adhesive using hexamethylene diisocyanate as a curing agent) was applied and dried to form a second adhesive layer 6. On the surface of the second adhesive layer 6, an unstretched polypropylene The film (3) was fused. This laminate was allowed to stand (cure) for 3 days under an environment of 40 占 폚 to obtain an outer casing (thickness 50 占 퐉) (1) for electrochemical devices shown in Fig.

<Comparative Example 1>

A jacket for an electrochemical device was obtained in the same manner as in Example 1 except that a soft aluminum foil having a thickness of 15 mu m (A8079 soft aluminum alloy foil specified by JISH4000) was used instead of the double-sided plated aluminum foil having a thickness of 19 mu m.

<Comparative Example 2>

A jacket for an electrochemical device was obtained in the same manner as in Example 1 except that a soft aluminum foil having a thickness of 40 占 퐉 (A8079 soft aluminum alloy foil specified by JISH4000) was used instead of the double-side plated aluminum foil having a thickness of 19 占 퐉.

A battery (simulated battery) was prepared as described below by using the outer casing for each electrochemical device obtained as described above. First, the exterior material was cut into a size of 120 mm long × 100 mm wide, and the cut exterior material was cut into 100 mm length × 80 mm × depth (width) by using a mold made of a male mold and a female mold The molding case 1A having the flange portion 29 around it was formed by emboss molding in the shape of a substantially rectangular parallelepiped having an opening of 2 mm (see Fig. 6). Further, emboss molding was carried out so that the inner surface of the substantially rectangular parallelepiped-shaped bottom surface opened on the top was an unstretched polypropylene film (inner layer) 3. On the other hand, a cut product (hereinafter referred to as a "planar-shaped facer") of the facer material 1 of 120 mm length × 100 mm width without embossing was also prepared (see FIG. 6).

A flexible aluminum foil having a thickness of 30 占 퐉, a polypropylene film having a thickness of 100 占 퐉, and a soft copper foil having a thickness of 30 占 퐉 were layered to form a simulated electrode having a size of 95 mm long × 75 mm wide, 10) were stacked to obtain an electrochemical device main body portion (simulated product) 31 (see Fig. 6).

5, after the electrochemical device main body portion 31 is loaded in the substantially rectangular parallelepiped emboss portion of the upper surface opening of the molding case 1A, the molding case 1A and the above- The planar outer sheath 1 is overlapped with each other such that the inner layers 3 face each other and the periphery of the inner layer 3 of the planar sheathing material 1 and the flange portion 29 of the molding case 1A Was subjected to heat seal bonding by damping at a pressure of 0.3 MPa for 3 seconds to form a heat seal part 39. The heat seal part 39 was then heat- This was allowed to stand in a dry room at a dew point of -60 DEG C for 24 hours.

Next, an electrolytic solution (ethylene carbonate: dimethylene carbonate: dimethyl carbonate in a ratio of 1: 1: 1) was injected into the heat seal joint body through the openings of one side not yet joined in the dry room at a dew point of -60 캜 using a syringe, 10 ml of LiPF ₆ solution obtained by adding LiPF ₆ to a mixed carbonate mixed in a volume ratio of 1: 1) was injected into the interior of the reactor, and then, under a reduced pressure of 0.086 MPa, The sealing of the battery (simulated battery) 30 shown in Fig. 5 was completed by hitting the one side of the joint by bending the metallic hot plate heated to 200 캜 for 3 seconds under the pressure of 0.3 MPa to perform the heat seal bonding .

The battery (simulated battery) obtained as described above was evaluated for water barrier property by measurement of the water content in the electrolytic solution in the simulated battery and evaluation of the electrolyte diffusion preventive property based on the following evaluation test method. The results are shown in Tables 2 and 3.

&Lt; Evaluation method of moisture barrier property >

9 samples (simulated cells) were prepared for each of the examples and each comparative example. The samples were stored in a first temperature and humidity chamber at 40 DEG C and a humidity of 90%, a second temperature and humidity chamber at 60 DEG C and a humidity of 90% Three pieces were placed in a third temperature and humidity chamber having a humidity of 90%, one piece was taken out after one week, one piece was taken out after two weeks, one piece was taken out after three weeks, One milliliter of the electrolytic solution in the battery was taken out, and the water content in the electrolytic solution was measured using a Karl Fischer moisture meter ("AQ2250" manufactured by Hiranuma Industrial Co., Ltd.).

The results of Table 2 show that the moisture content after the lapse of one week compared with the initial moisture content (before the start of the test) is obviously increased. This means that the water content in the polypropylene film of the simulated battery, Is thought to have been eluted into the electrolytic solution. In comparison with the results of Comparative Example 1 (moisture content after 1, 2, and 3 weeks), no extreme (substantial) increase in moisture was observed in the simulated battery constructed using the sheathing materials of Examples 1 to 5, An excellent effect of moisture barrier by the exterior material can be confirmed.

&Lt; Evaluation Test of Electrolyte Diffusion Resistance >

Three samples (simulated cells) were prepared for each example and each comparative example, and the respective masses (hereinafter referred to as &quot; initial mass &quot;) were measured with an electronic balance. Each sample was placed in a tray made of polypropylene and placed in a first thermostatic chamber at 40 ° C, a second thermostatic chamber at 60 ° C, and a third thermostatic chamber at 80 ° C, respectively. After one week, And mass measurement was carried out, and the temperature was immediately returned to the corresponding thermostat. Mass specimens were similarly measured after two weeks and three weeks later. At this time, the mass is reduced by the amount of leakage of the electrolytic solution, and there is no change in mass when the electrolytic solution does not leak.

X = {(mass after one week) - (initial mass)} / (initial mass) x 100

Y = {(mass after 2 weeks) - (initial mass)} / (initial mass) x 100

Z = {(mass after 3 weeks) - (initial mass)} / (initial mass) x 100

The mass change rate (X) (%) after the lapse of one week, the mass change rate (Y) (%) after the lapse of two weeks, and the mass change rate (Z) (%) after the lapse of three weeks were respectively calculated by the above-

As apparent from Tables 1 to 3, the battery (simulated battery) constructed using the casing for electrochemical devices of Examples 1 to 6 according to the present invention, compared with the casing of Comparative Example 1 in which the metal plating layer is not provided, Despite the fact that the thickness of the casing is equal (lightweight), it is excellent in moisture barrier property and also in preventing the diffusion of the electrolytic solution. That is, in the battery (simulated battery) constructed using the casing for electrochemical devices of Examples 1 to 6 according to the present invention, it is possible to satisfy at the same time three excellent moisture barrier properties, excellent electrolyte diffusion prevention property, and sufficient lightness .

On the other hand, in the case of Comparative Example 1 in which the metal plating layer is not provided, the weight of the exterior material is reduced, but the water barrier property is inferior and the diffusion prevention property of the electrolytic solution is inferior. In the case of the exterior material of Comparative Example 2, the water barrier property was excellent, and the diffusion preventing property of the electrolytic solution was also excellent, but the weight was not reduced. Thus, in Comparative Examples 1 and 2, it was not possible to satisfy at the same time three excellent moisture barrier properties, excellent electrolyte diffusion preventive property, and sufficient lightweight property.

Further, from the comparison between the moisture content after 1, 2, and 3 weeks of Example 3 in which the thickness of the metal plating layer was 0.5 占 퐉 and the moisture content after 1, 2, and 3 weeks of Example 1 in which the thickness of the metal plating layer was 2 占 퐉 , And it was found that the moisture barrier property was further improved as the thickness of the metal plating layer became thicker.

The mass change rate after 1, 2, and 3 weeks of Example 3 in which the thickness of the metal plating layer was 0.5 占 퐉 and the mass change rate after 1, 2, and 3 weeks of Example 1 in which the thickness of the metal plating layer was 2 占 퐉 From the contrast, it was found that the thicker the metal plating layer, the better the diffusion prevention of the electrolyte solution.

[Industrial Availability]

The casing material for an electrochemical device according to the present invention is suitably used, for example, as a battery casing material and a condenser casing material, and is not particularly limited to such use. Among them, the casing material for an electrochemical device according to the present invention is suitable as a casing material for a small electrochemical device having a capacity of 30 mA to 500 mA.

The electrochemical device according to the present invention is, for example,

1) Lithium polymer batteries, lithium ion batteries, lithium ion capacitors, electric double layer capacitors used in mobile devices such as smart phones and tablets.

2) Power of hybrid cars, electric cars and so on.

3) It is suitable as a battery or a condenser used for the shaft of wind power generation, solar power generation, and night electricity, but is not particularly limited to such an application.

This application is a continuation of Japanese Patent Application No. 2014-60266, filed on March 24, 2014, which is incorporated herein by reference in its entirety.

The terms and explanations used here are used for explaining the embodiments of the present invention, and the present invention is not limited thereto. It is intended that the present invention not be limited by any of the details of the description provided herein except as defined in the appended claims.

1: Enclosure for electrochemical devices
2: outer layer
3: thermoplastic resin unstretched film layer (inner layer)
4: metal foil layer
5: First adhesive layer
6: Second adhesive layer
8: metal plating layer
10: barrier layer
12: Heat-resistant resin film layer
13: Heat resistant resin coat layer
30: electrochemical device
31: electrochemical device main body (electrochemical device)
T: thickness of the plating layer

Claims (9)

An outer jacket for an electrochemical device comprising a metal foil layer and a thermoplastic resin undrawn film layer as an inner layer,
And a metal plating layer is formed on at least one surface of the metal foil layer. An outer casing for an electrochemical device comprising an outer layer, a thermoplastic resin undrawn film layer as an inner layer, and a metal foil layer interposed between the outer layer and the inner layer,
And a metal plating layer is formed on at least one surface of the metal foil layer. 3. The method of claim 2,
Wherein the outer layer is a heat-resistant resin film layer. 3. The method of claim 2,
Wherein the outer layer is a heat-resistant resin coat layer formed by applying a heat-resistant resin. 5. The method according to any one of claims 1 to 4,
Wherein the thickness of the metal foil layer is 5 占 퐉 or more and less than 30 占 퐉. 6. The method according to any one of claims 1 to 5,
Wherein the thickness of the metal plating layer is 0.5 占 퐉 to 5 占 퐉. 7. The method according to any one of claims 1 to 6,
Wherein the metal plating layer is a plating layer composed of at least one kind of metal material selected from the group consisting of nickel, zinc, tin, chromium and cobalt. 8. The method according to any one of claims 1 to 7,
Wherein the thickness of the exterior material is 30 占 퐉 to 80 占 퐉. An electrochemical device body portion,
9. An electrochemical device comprising an outer casing for an electrochemical device according to any one of claims 1 to 8,
Wherein the electrochemical device body portion is enclosed by the exterior material.

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