KR20160075306A - Exterior material for electricity storage device and electricity storage device - Google Patents

Abstract

According to the present invention, an exterior material (1) for an electricity storage device comprises a heat resistant resin layer (2) as an outer layer, a thermoplastic resin layer (3) as an inner layer, and a metal foil layer (4) arranged between both layers. A resin coat layer (7) is deposited on an outer surface of the heat resistant resin layer (2) and contains a resin and filler. Satisfactory formability can be secured. Curling (bending) can be prevented. Preferably, the aspect ratio of the filler is 5 or higher.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an exterior material for electric storage devices,

The present invention relates to a casing for a battery device such as a battery or a condenser used for a battery, a condenser, a hybrid car, an electric car, a wind power generator, a solar power generator, The present invention relates to a power storage device enclosed with an exterior material.

Description of the Related Art [0002] In recent years, as mobile electrical appliances such as smart phones and tablet terminals have become thinner and lighter in weight, they have been used as exterior materials for electric storage devices such as lithium ion secondary batteries, lithium polymer secondary batteries, lithium ion capacitors, A laminate composed of a heat resistant resin layer / an adhesive layer / a metal foil layer / an adhesive layer / a thermoplastic resin layer is used in place of a conventional metal can (see Patent Documents 1 and 2). Normally, extrusion molding or deep drawing molding is performed on the above-described laminate, so that it is molded into a three-dimensional shape such as an approximately rectangular parallelepiped shape. Also, power sources for electric vehicles, large-sized power sources for electric power storage, and capacitors have also been increasingly externally enclosed in the laminated body (outer casing).

As the heat-resistant resin film as the outer layer, a polyamide resin film or a polyester resin film is generally used from the viewpoint of securing good moldability during extrusion molding and deep drawing molding 1, 2).

Patent Document 1: Japanese Patent Application Laid-Open No. 2011-98759 Patent Document 2: JP-A-2005-26152

However, polyamide resin film layers, polyester resin film layers, and the like have high hygroscopicity, and therefore, there is a problem that curling (warpage) tends to occur due to moisture absorption or the like in a casing using such a film as an outer layer. When a polyamide resin film was used, curling was particularly likely to occur.

If such curl is generated in the casing, the casing can not be mounted in the correct position when the casing is molded. In addition to the occurrence of defective molding, the battery element is loaded in the formed battery case to hatch the periphery of the casing Defective positions such as occurrence of wrinkles in the heat seal portion were liable to occur.

SUMMARY OF THE INVENTION The present invention has been made in view of such a technical background, and an object of the present invention is to provide a casing for a power storage device which can secure good moldability and prevent curling (occurrence of warpage).

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

[1] An outer casing for a power storage device comprising a heat-resistant resin layer as an outer layer, a thermoplastic resin layer as an inner layer, and a metal foil layer interposed between the both layers,

A resin coat layer is laminated on the outer surface side of the heat resistant resin layer,

Characterized in that the resin coat layer contains a resin and a filler.

[2] The exterior material for an electric storage device according to the above 1, wherein the filler is a filler having an aspect ratio of 5 or more.

[3] The exterior member for electric storage devices according to the item 1 or 2, wherein the resin is at least one resin selected from the group consisting of urethane resin, phenoxy resin and fluorine resin.

[4] A power storage device comprising: a power storage device main body part; and an exterior material for an electric storage device according to any one of items 1 to 3,

Wherein the power storage device main body portion is enclosed by the exterior material.

In the invention of [1], a resin coat layer containing a resin and a filler is laminated on the outer surface side of the heat-resistant resin layer in the casing, and the penetration of moisture from the outside by the presence of the filler- . Therefore, penetration of moisture into the heat resistant resin layer and moisture absorption of the heat resistant resin layer can be prevented, and curling (occurrence of warpage) of the exterior material can be prevented. Further, since the resin coat layer containing the resin and the filler is laminated on the outer surface side of the heat-resistant resin layer, the strength of the heat-resistant resin layer can be suppressed from lowering to improve the moldability, can do.

In the invention of [2], since the filler having an aspect ratio of 5 or more is used as the filler, penetration of moisture and moisture from the outside can be sufficiently suppressed by the presence of the resin coat layer, have.

In the invention of [3], as the resin constituting the resin coat layer, the above specific resins (urethane resin, phenoxy resin and one or more kinds of resins selected from the group consisting of fluorine resin) are used, And the chemical resistance. Therefore, the electrolyte solution resistance can be improved by arranging the resin coat layer on the outer surface side (for example, even if the electrolyte solution adheres to the outer surface of the casing member, no trouble occurs).

According to the invention of [4], there is provided a high-quality power storage device which is enclosed with a casing material in which curling is hardly generated.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing an embodiment of a casing for a power storage device according to the present invention. Fig.
2 is a cross-sectional view showing an embodiment of a power storage device constructed using a casing for a power storage device according to the present invention.
(B) is a perspective view showing a state where a warp is formed in the evaluation sample, (C) is a perspective view showing a state in which a warp is formed in the evaluation sample, (B) is a perspective view Sectional view of the XX line in Fig.

Fig. 1 shows an embodiment of a casing member 1 for a power storage device according to the present invention. The exterior member 1 for the power storage device is used for a lithium ion secondary battery case. The outer casing 1 for the power storage device is provided for forming, for example, deep drawing or extrusion molding, and is used as a case of a secondary battery or the like.

The outer casing 1 for power storage device is formed by laminating and integrating a heat resistant resin layer (outer layer) 2 through a first adhesive layer 5 on one surface 4a of the metal foil layer 4, A thermoplastic resin layer (inner layer) 3 is laminated and integrated on the other surface 4b of the heat resistant resin layer 2 via the second adhesive layer 6 and a resin coat layer 7 (See Fig. 1).

In the present invention, the resin coat layer (resin coating layer) 7 is laminated on the outer surface side of the heat resistant resin layer 2. The resin coat layer 7 contains a resin and a filler (filler). The resin coat layer 7 is formed, for example, by coating a coating liquid containing a resin and a filler on the outer surface of the heat resistant resin layer 2. The coating liquid may or may not contain a solvent. The coating liquid may be in a paste form. The solvent is not particularly limited, and examples thereof include ethyl acetate, propyl acetate, butyl acetate, methyl ethyl ketone (MEK), toluene, xylene, methylcyclohexane and the like. Examples of the method for applying the coating liquid include a gravure coating method, a spray coating method, and a brushing method.

Examples of the resin include, but are not limited to, urethane resin, phenoxy resin, fluorine resin, epoxy resin, acrylic resin, polyolefin resin, chlorine resin, styrene resin and elastomer resin have. Among them, it is preferable to use one or more resins selected from the group consisting of a urethane resin, a phenoxy resin and a fluorine resin. As the resin, it is particularly preferable to use a combination of a urethane resin and a phenoxy resin. In this case, the resin can have moldability, flexibility, electrolyte resistance, printability, and abrasion resistance. In this case, the mixing ratio is preferably set in the range of 20/80 to 80/20 (mass ratio) of the urethane resin / phenoxy resin.

Examples of the filler include, but are not limited to, metals (aluminum, silver, iron and the like), silica flakes, glass flakes, muscovite (mica), gold mica (non-expansive mica) The surface of the above-exemplified material may be used as a metal or an alloy thereof, in addition to the above-mentioned materials such as a metal oxide, a metal oxide, a metal oxide, a metal oxide, a metal oxide, a metal oxide, Metal oxide (iron oxide, boehmite, alumina, low-soda alumina, titanium oxide, etc.), boron nitride, ceramics, and the like. As the filler (filler), only one type may be used, or two or more types may be used in combination.

As the filler, it is preferable to use a filler having an aspect ratio of 5 or more. In this case, penetration of moisture and water vapor from the outside into the heat resistant resin layer 2 is sufficiently suppressed by the resin coat layer 7 So that curling of the casing can be sufficiently prevented.

The shape of the filler is not particularly limited, and examples thereof include flakes, discs, flat plates, thin plates, flakes, or spheres. In any of these shapes, it is preferable to use a filler having an aspect ratio of 5 or more.

The " aspect ratio " is the ratio of the maximum diameter to the minimum diameter in the filler. That is, " aspect ratio = maximum filler / minimum filler ". The maximum diameter of the filler is determined based on the average value of the filler contained therein, and the minimum value of the filler is used as the average value of the filler contained therein. For example, in the case where the filler is a scaly or flat plate, the average length of the longitudinal length of the filler (maximum diameter) is 5 占 퐉, the width of the filler is 3 占 퐉 in average value, 0.2 μm, the aspect ratio of the filler is 5 / 0.2 = 25.

It is preferable that the filler has a long diameter of 0.1 mu m to 20 mu m. It is preferable that the thickness of the filler is 0.01 탆 to 2 탆.

The content of the resin in the resin coat layer 7 is preferably 95 mass% to 40 mass%. The content of the filler in the resin coat layer 7 is preferably 5% by mass to 60% by mass. Since the content of the filler is 5 mass% or more, the water vapor barrier performance by the resin coat layer 7 can be improved and improved. When the filler content is 60 mass% or less, the adhesiveness of the resin coat layer 7 to the heat resistant resin layer 2 can be sufficiently secured. In particular, it is particularly preferable that the content of the filler in the resin coat layer 7 is 20 mass% to 50 mass%.

The thickness (dry thickness) of the resin coat layer 7 is preferably set to 0.5 탆 to 5 탆. The thickness of the resin coat layer 7 is 0.5 mu m or more so that the water vapor barrier property of the resin coat layer 7 can be further improved. When the thickness is 5 mu m or less, the lightweight of the facer material 1 and the energy density of the electrical storage device can be sufficiently secured.

The resin coat layer 7 may have a laminated structure of two or more layers. For example, a two-layer laminated structure of a first resin coat layer containing a resin and a filler / a second resin coat layer containing a resin and a filler may be used. The filler used for the first resin coat layer and the filler used for the second resin coat layer may be the same or different.

In the resin coat layer 7, the maximum surface (the surface having the largest area) of the filler is the surface of the resin coat layer 7 when the filler is in the shape of a flake, a disk, a flat plate, a thin plate, And in this case, the water vapor barrier performance by the resin coat layer 7 can be further improved. Such a configuration arranged in a substantially parallel shape can be realized by dispersing in an organic solvent, applying it, and drying it with hot air.

The resin coat layer 7 exhibits a color tone, a metallic luster, and a color of a pearl tone (tone) peculiar to the filler by the filler to be added.

The resin coat layer 7 preferably contains an isocyanate component in addition to the resin and filler. As the isocyanate component, it is preferable to use a bifunctional or higher polyfunctional isocyanate compound. Examples of the polyfunctional isocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, methylene bis (4,1-phenylene) diisocyanate, and the like. Among them, tolylene diisocyanate and hexamethylene diisocyanate are preferably used in combination.

As the heat-resistant resin constituting the heat-resistant resin layer (outer layer) 2, a heat-resistant resin which does not melt at the heat room temperature at the time of heat sealing is used. As the heat resistant resin, it is preferable to use a heat resistant resin having a melting point higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layer (3) by at least 10 DEG C, and a heat resistant resin having a melting point higher than the melting point of the thermoplastic resin by 20 DEG C or more It is particularly preferable to use them.

The heat resistant resin layer (outer layer) 2 is not particularly limited, and for example, a polyamide film such as a nylon film, a polyester film, and the like are preferably used. As the heat resistant resin layer 2, a biaxially oriented polyamide film such as a biaxially oriented nylon film, a biaxially oriented polybutylene terephthalate (PBT) film, a biaxially oriented polyethylene terephthalate (PET) film, or a biaxially oriented poly It is particularly preferred to use a biaxially oriented polyethylene naphthalate (PEN) film. The nylon film is not particularly limited, and examples thereof include 6 nylon film, 6,6 nylon film, and MXD nylon film. The heat resistant resin layer 2 may be formed of a single layer or may be formed of a multilayer (eg, PET film / nylon film multilayer) formed of a polyester film / polyamide film.

The thickness of the heat resistant resin layer 2 is preferably 5 to 80 탆. By setting the upper limit to a value not lower than the appropriate lower limit value, sufficient strength can be ensured as an outer sheath, and by setting the upper limit to the appropriate upper limit or less, the stress during molding such as extrusion molding and drawing molding can be reduced and moldability can be improved.

The thermoplastic resin layer (inner layer) 3 plays a role of imparting excellent chemical resistance to an electrolyte or the like having high corrosivity, which is used in a lithium ion secondary battery or the like, as well as imparting heat resistance to the casing .

The thermoplastic resin layer 3 is not particularly limited, but is preferably a thermoplastic resin undrawn film layer. The thermoplastic resin non-stretched film layer 3 is formed of at least one kind of thermoplastic resin selected from the group consisting of polyethylene, polypropylene, olefin-based copolymer, acid-modified product thereof and ionomer thereof, It is preferable that it is constituted by an unstretched film made of a resin.

The thickness of the thermoplastic resin 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 layer 3 is set to 30 탆 to 50 탆. The thermoplastic resin layer 3 may be a single layer or a multilayer.

The metal foil layer 4 plays a role of imparting gas barrier properties to the exterior material 1 so as to prevent the intrusion of oxygen and moisture. The metal foil layer 4 is not particularly limited, and examples thereof include aluminum foil, copper foil and SUS (stainless steel) foil. Aluminum foil and SUS foil are generally used. The thickness of the metal foil layer 4 is preferably 15 to 80 탆. It is possible to prevent the occurrence of pinholes at the time of rolling at the time of producing the metal foil and to reduce the stress at the time of forming such as extrusion forming and drawing forming by being 80 탆 or less, . As the material of the aluminum foil, the A material of A8079 and the O material of A8021 are preferable.

It is preferable that the metal foil layer 4 is chemically treated at least on the inner surface 4b (the surface on the second adhesive layer 6 side). Since such a chemical treatment is carried out, the corrosion of the surface of the metal foil by the contents (electrolytic solution of the battery, etc.) can be sufficiently prevented.

For example, the metal foil is subjected to a chemical conversion treatment by the following process. That is, for example, on the surface of the metal foil subjected to the degreasing treatment,

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; An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts and non-metal salts of fluorides

After applying any of the aqueous solutions of 1) to 3) above, the chemical conversion treatment is carried out by drying.

The above-mentioned chemical conversion film 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 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. In particular, 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 molding case (battery case or the like) can be obtained by molding (the deep drawing molding, extrusion molding, etc.) of the exterior member 1 of the present invention. In addition, the outer sheath 1 of the present invention can be used as it is without being provided for molding.

An embodiment of the electrical storage device 20 constructed using the facer material 1 of the present invention is shown in Fig. This electric storage device 20 is a lithium ion secondary battery.

The battery 20 includes an electrolyte 21, a tab lead 22, a planar outer sheath 1 not provided for molding, and an accommodating recess 11b obtained by molding the outer sheath 1 (See Fig. 2). The power storage device main body portion 19 is constituted by the electrolyte 21 and the tab lead 22 or the like.

The electrolyte 21 and a part of the tab lead 22 are accommodated in the accommodating concave portion 11b of the molding case 11 and the planar outer casing 1 is disposed on the molding case 11 (The inner layer 3 of the outer casing 1) and the sealing periphery 11a of the molding casing 11 are joined and sealed to each other, . The distal end of the tab lead 22 is led out to the outside (see FIG. 2).

Example

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

<Example 1>

60 parts by mass of a urethane resin, 40 parts by mass of a phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 1 part by mass of hexaaryl isocyanate (TDI) , 7.5 parts by mass of methylene diisocyanate, 15 parts by mass of flaky aluminum powder (aspect ratio 3 占 퐉) having an aspect ratio of 48, 370 parts by mass of methyl ethyl ketone (MEK), 300 parts by mass of toluene and 200 parts by mass of isopropanol Was coated with a gravure roll and then heated and dried with hot air at 80 캜 to form a resin coat layer 7 having a thickness of 3 탆 on one side of the polyamide film 2.

A chemical liquor consisting of phosphoric acid, polyacrylic acid, trivalent chromium compound, water, and alcohol was applied to both sides of an aluminum foil (A8021 O material) 4 having a thickness of 35 탆 on one side and dried at 180 캜, To form a film. The amount of chromium deposited on this chemical conversion coating was 10 mg / m 2 per one side.

Next, a biaxially oriented polyamide film (2) with the resin coat layer (7) is laminated on one surface (4a) of the chemically treated aluminum foil (4) through a two - liquid curing type urethane adhesive Dry laminated (put together). At this time, the exposed surface of the biaxially oriented polyamide film (2) (the surface on which the resin coat layer was not laminated) was brought into contact with the urethane adhesive agent (5) and laminated.

Next, an adhesive liquid was applied to the other surface 4b of the aluminum foil 4 by using a gravure roll, and then dried by hot air at 80 DEG C to form a 3 mu m thick adhesive resin layer ) (6). 15 parts by mass of a maleic acid-modified polypropylene (a modified polypropylene resin obtained by graft-polymerizing maleic anhydride on a copolymer of propylene and ethylene at a melting point of 80 ° C) as the above-mentioned adhesive liquid was mixed in a mixed solvent (toluene / methyl ethyl ketone = 8 parts by mass / 2 parts by mass of a mixed solvent), 0.9 parts by mass of a polymer substance of hexamethylene diisocyanate was mixed.

Next, on the surface of the adhesive resin layer 6 formed on the other surface 4b of the aluminum foil 4, a layer having a melting point of 140 占 폚, MFR (melt flow rate) of 4.5 g / A laminate of a propylene-ethylene random copolymer film (inner layer: sealant layer) 3 was laminated to obtain a jacket 1 for a power storage device having the structure shown in Fig.

<Practical Example 2>

A biaxially oriented PET (polyethylene terephthalate) film having a thickness of 25 占 퐉 was used in place of the biaxially stretched polyamide film having a thickness of 25 占 퐉 and 100 parts by mass of fluororesin and 7.5 parts by mass of tolylene diisocyanate (TDI) , 7.5 parts by mass of hexamethylene diisocyanate, 20 parts by mass of a glass powder having an aspect ratio of 25 (10 占 퐉 long), 365 parts by mass of methyl ethyl ketone (MEK), 300 parts by mass of toluene and 200 parts by mass of isopropanol Except for this, in the same manner as in Example 1, a jacket 1 for a power storage device having the structure shown in Fig. 1 was obtained.

&Lt; Example 3 >

As the coating liquid, 60 parts by mass of urethane resin, 40 parts by mass of phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 7.5 parts by mass of hexamethylene diisocyanate, 25 parts by mass of graphite powder having an aspect ratio of 15 A casing member 1 for a power storage device shown in Fig. 1 was obtained in the same manner as in Example 1 except that a coating liquid containing 360 parts by mass of ethyl ketone (MEK), 300 parts by mass of toluene and 200 parts by mass of isopropanol was used .

<Example 4>

60 parts by mass of a urethane resin, 40 parts by mass of a phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 7.5 parts by mass of hexamethylene diisocyanate, silver-coated mica powder (having a major diameter of 3 占 퐉) having an aspect ratio of 89, Except that a coating liquid containing 25 parts by mass of methyl ethyl ketone (MEK), 360 parts by mass of toluene, and 200 parts by mass of isopropanol was used in place of the coating liquid for electric storage device (1).

&Lt; Example 5 >

60 parts by mass of a urethane resin, 40 parts by mass of a phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 7.5 parts by mass of hexamethylene diisocyanate, 25 parts by mass of silver vapor-deposited silica particles having an aspect ratio of 50 , 360 parts by mass of methyl ethyl ketone (MEK), 300 parts by mass of toluene, and 200 parts by mass of isopropanol was used in place of the coating liquid for electric storage device 1 shown in Fig. 1, .

&Lt; Example 6 >

60 parts by mass of urethane resin, 40 parts by mass of phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 7.5 parts by mass of hexamethylene diisocyanate, 25 parts by mass of iron oxide-coated glass powder having an aspect ratio of 30 , 360 parts by mass of methyl ethyl ketone (MEK), 300 parts by mass of toluene, and 200 parts by mass of isopropanol was used in place of the coating liquid for electric storage device 1 shown in Fig. 1, .

&Lt; Example 7 >

60 parts by mass of a urethane resin, 40 parts by mass of a phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 7.5 parts by mass of hexamethylene diisocyanate, 25 parts by mass of an iron oxide powder having an aspect ratio of 80 (long diameter 20 占 퐉) A casing member 1 for a power storage device shown in Fig. 1 was obtained in the same manner as in Example 1 except that a coating liquid containing 360 parts by mass of ethyl ketone (MEK), 300 parts by mass of toluene and 200 parts by mass of isopropanol was used .

&Lt; Example 8 >

As the coating liquid, 60 parts by mass of a urethane resin, 40 parts by mass of a phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 7.5 parts by mass of hexamethylene diisocyanate, and boehmite alumina powder (long diameter 5 μm) 25 having an aspect ratio of 52 , A coating liquid containing 360 parts by mass of methyl ethyl ketone (MEK), 300 parts by mass of toluene and 200 parts by mass of isopropanol was used in place of the coating liquid for the electrical storage device (Fig. 1 1).

&Lt; Example 9 &

As a coating liquid, 60 parts by mass of a urethane resin, 40 parts by mass of a phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 7.5 parts by mass of hexamethylene diisocyanate, and hexagonal boron particles having an aspect ratio of 7 ), 360 parts by mass of methyl ethyl ketone (MEK), 300 parts by mass of toluene, and 200 parts by mass of isopropanol was used in place of the coating liquid for the electrical storage device Thereby obtaining the facer material 1.

&Lt; Example 10 &

60 parts by mass of urethane resin, 40 parts by mass of phenoxy resin, 7.5 parts by mass of tolylene diisocyanate (TDI), 7.5 parts by mass of hexamethylene diisocyanate, 25 masses of spherical silica particles having an aspect ratio of 1 (diameter of 2.5 mu m) A coating liquid containing 360 parts by weight of methyl ethyl ketone (MEK), 300 parts by weight of toluene and 200 parts by weight of isopropanol was used in place of the coating liquid for the electrical storage device 1 ).

<Comparative Example 1>

Except that the resin-coated layer was not provided on the resin-coated layer.

<Comparative Example 2>

As in the case of Example 1, except that a coating liquid (containing no filler) containing 100 parts by mass of a urethane resin, 360 parts by mass of methyl ethyl ketone (MEK), 300 parts by mass of toluene, and 200 parts by mass of isopropanol was used as the coating liquid. Thereby obtaining a casing for a device.

[Table 1]

The exterior materials for each power storage device obtained as described above were subjected to performance evaluation based on the following evaluation methods. The results are shown in Table 1.

<Moldability Evaluation Method>

Extrusion molding was carried out in the form of a substantially rectangular parallelepiped having a length of 55 mm and a width of 35 mm with respect to the facings using an extrusion molding machine (trade name: TP-25C-X2) manufactured by Amadaj Co., The presence or absence of pinholes and cracks at the corners at the corners in the specimen was investigated, and the &quot; maximum forming depth (mm) &quot; , The maximum molding depth was 7.0 mm or more, the maximum molding depth was 6.0 mm or more and 7.0 mm or less, and the maximum molding depth was 6.0 mm or less.

&Lt; Evaluation of electrolyte resistance &

As an evaluation of chemical resistance and solvent resistance, an electrolytic solution composed of a solution obtained by dissolving a lithium salt of hexafluoride to a concentration of 1 mol / l in a mixed solvent obtained by mixing ethylene carbonate and diethylene carbonate at a volume ratio of 1: (Resin coat layer) of the exterior material, left standing at room temperature for 24 hours, and wiped off the electrolyte with an ethanol-impregnated cloth. The state of discoloration after wiping off the electrolyte was examined and evaluated according to the following criteria.

(Criteria)

"○" ... No discoloration

"△" ... Pale discoloration, but not noticeable

"×" ... There is a noticeable discoloration.

&Lt; Evaluation method of curling resistance &

As shown in Fig. 3 (A), a slab crossing at a central point (center) along a diagonal line of a square (the length of one slab 31 is 40 mm The other side of the slit 31 was inserted into the resin coat layer 7 so that the inner layer 3 was placed on the upper side of the horizontal band in the room under an environment of a relative humidity of 75% To the lower side. After one hour elapsed from this state, the height (deflection amount) H from the upper surface of the horizontal stand to the highest portion (central point portion) of the sample was measured (see Fig. 3 (C)). , Those having a height H of less than 10 mm were evaluated as &quot;? &Quot;, those having a height H of 10 mm or more and less than 15 mm were evaluated as &quot; DELTA &quot;

As apparent from Table 1, the outer sheath for electric storage devices of Examples 1 to 10 of the present invention has a maximum molding depth and is capable of securing excellent formability even when deep forming is performed, , And also has excellent curl resistance. Among them, curling (warpage) of the electric storage device for Examples 1 to 9 using a filler having an aspect ratio of 5 or more can be sufficiently prevented.

On the other hand, the exterior materials of Comparative Examples 1 and 2 are large in warpage and inferior in curl-preventing property.

[Industrial Availability]

As a concrete example of the outer casing for a power storage device according to the present invention, for example,

· Power storage devices such as lithium secondary batteries (lithium ion batteries, lithium polymer batteries, etc.)

· Lithium ion capacitor

· It is used as the exterior material of various electric storage devices such as electric double layer capacitors.

This application is a continuation-in-part of Japanese Patent Application No. 2014-257222, filed on December 19, 2014, which is incorporated herein by reference in its entirety.

The terms and explanations used herein 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: Outer material for power storage device
2: Heat resistant resin layer (outer layer)
3: thermoplastic resin layer (inner layer)
4: metal foil layer
5: First adhesive layer
6: Second adhesive layer
7: resin coat layer
11: Molded case
19: Power storage device main body part
20: Power storage device

Claims (10)

1. A casing for a power storage device comprising a heat resistant resin layer as an outer layer, a thermoplastic resin layer as an inner layer, and a metal foil layer interposed between the both layers,
A resin coat layer is laminated on the outer surface side of the heat resistant resin layer,
Characterized in that the resin coat layer contains a resin and a filler. The method according to claim 1,
Wherein the filler is a filler having an aspect ratio of 5 or more. 3. The method according to claim 1 or 2,
Wherein the resin is one or more resins selected from the group consisting of a urethane resin, a phenoxy resin, and a fluorine resin. 3. The method according to claim 1 or 2,
Wherein the filler has a long diameter of 0.1 mu m to 20 mu m and a thickness of the filler is 0.01 mu m to 2 mu m. 3. The method according to claim 1 or 2,
And the content of the resin in the resin coat layer is 95 mass% to 40 mass%. 3. The method according to claim 1 or 2,
And the content of the filler in the resin coat layer is 5% by mass to 60% by mass. 3. The method according to claim 1 or 2,
Wherein the resin coat layer has a thickness (dry thickness) of 0.5 占 퐉 to 5 占 퐉. 3. The method according to claim 1 or 2,
Wherein the resin coat layer has a laminated structure of a plurality of layers of two or more layers. 3. The method according to claim 1 or 2,
The resin is one or more resins selected from the group consisting of a urethane resin, a phenoxy resin and a fluorine resin,
The filler has a long diameter of 0.1 mu m to 20 mu m, a thickness of the filler is 0.01 mu m to 2 mu m,
Wherein the content of the resin in the resin coat layer is 95 mass% to 40 mass%, the content of the filler in the resin coat layer is 5 mass% to 60 mass%
Wherein the resin coat layer has a thickness (dry thickness) of 0.5 占 퐉 to 5 占 퐉. A power storage device main body part,
An electric storage device for an electric storage device according to any one of claims 1 to 9,
Wherein the power storage device main body portion is enclosed by the exterior material.

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