TW201624801A - Exterior material for power storage device and power storage device - Google Patents

Abstract

The invention provides an exterior material 1 for power storage device having features in comprising: heat-resistant resin layer 2 as outer layer, thermoplastic resin layer 3 as inside layer, and metal clad layer 4 provided between these two layers; and deposition layer is laminated at outer side of the heat-resistant resin layer 2; the deposition layer is formed by depositing deposition material selected from at least one of groups of metal, metal oxide and silicon dioxide. It can provide an exterior material for power storage device for ensuring good formability while bend occurrence (warpage occurrence) can be prevented through this constitution. The outer side of the deposition layer 7 is preferably composed of laminated protection resin layer 8. The protection resin layer 8 is formed by one or more than two of groups of acrylic acid resin, fluorine resin, polyurethane resin, polyester resin, epoxy resin and phenoxy resin.

Description

External storage material and power storage device for power storage device

The present invention relates to a battery or a capacitor used in a portable device such as a smart phone or a tablet computer, and a power storage device such as a battery or a capacitor used for power storage of a hybrid vehicle, an electric vehicle, a wind power generation, a solar power generation, and a nighttime generator. The exterior material and the power storage device externally mounted on the exterior material.

In recent years, it has become thinner and lighter in portable devices such as smart phones and tablet terminals, and is used as a power storage device such as a lithium ion battery, a lithium polymer battery, a lithium ion capacitor, or an electric double layer capacitor mounted on such devices. In the case of the exterior material, a heat-resistant resin layer/adhesive layer/metal foil layer/adhesive layer/thermoplastic resin layer is used to replace the conventional metal can (refer to Patent Documents 1 and 2). Usually, the laminated body is subjected to inflation molding or deep drawing molding to form a three-dimensional shape such as a substantially rectangular parallelepiped shape. In addition, in the case of a power source for an electric vehicle or the like, a large-sized power source for power storage, a capacitor, and the like, the laminate (the exterior material) having the above-described configuration is used, and the number of the exterior is gradually increased.

In the above-mentioned exterior material, the heat-resistant resin film as the outer layer is generally made of polyamine based on the viewpoint of ensuring good formability when performing bulging or deep drawing. A resin film or a polyester resin film (see Patent Documents 1 and 2).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2011-98759

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2005-26152

However, since the polyimide resin film or the polyester resin film has high hygroscopicity, the outer layer used as such an outer layer may have a problem of being bent (warped) due to moisture absorption or the like. Moreover, bending is particularly likely to occur when a polyimide film is used.

If the exterior material is bent in this way, it will not be able to be placed at the fixed position of the mold when the exterior material sheet is formed. In addition to the molding failure, the following problems may occur: the battery element is loaded into the formed shape. After the inside of the battery case, when the peripheral portion of the case is to be heat-sealed, the sealing position is shifted, or the heat-sealed portion is wrinkled or the like.

The present invention has been made in view of the above-described technical background, and an object of the invention is to provide an exterior material for a power storage device which can ensure good moldability and prevent occurrence of warpage (warpage occurs).

To achieve the foregoing objects, the present invention provides the following means.

[1] An exterior material 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 disposed between the two layers; The vapor-deposited layer is formed on the outer surface of the heat-resistant resin layer, and the vaporized layer is formed by vaporizing at least one of the vapor-deposited materials selected from the group consisting of metals, metal oxides, and cerium oxide.

[2] The exterior material for a storage device according to the above aspect, wherein the outer surface of the vapor deposition layer is provided with a protective resin layer, and the protective resin layer is selected from the group consisting of an acrylic resin, a fluorine resin, and an amine. A resin formed by one or two or more kinds of the group consisting of a urethane resin, a polyester resin, an epoxy resin, and a phenoxy resin.

[3] A power storage device, comprising: a power storage device main body portion; and an external storage material for a power storage device according to the above item 1 or 2; and the power storage device main body portion is external to the external storage material Installer.

According to the invention of the above aspect, the outer surface of the heat-resistant resin layer in the exterior material is laminated with an evaporation layer, and the vapor deposition layer is at least one selected from the group consisting of metals, metal oxides, and cerium oxide. The vaporized material is formed, and the presence of such a vaporized layer can further suppress the intrusion of moisture from the outside. Therefore, it is possible to prevent moisture from intruding into the heat-resistant resin layer and to prevent moisture absorption of the heat-resistant resin layer, thereby preventing the exterior material from being bent (preventing warpage from occurring). In addition, due to the heat resistance tree Since the outer layer of the fat layer has an evaporation layer, the strength of the heat-resistant resin layer can be suppressed from being lowered, and the moldability can be further improved, and the puncture strength can be further improved.

According to the invention of the second aspect, the specific protective resin layer is further laminated on the outer surface side of the vapor deposition layer, so that the peeling and falling of the vapor deposition layer can be sufficiently prevented. Therefore, the effect of suppressing the intrusion of moisture from the outside can be achieved. Lasting for a long time. Further, by laminating such a protective resin layer, it is easier to process (the workability can be improved) when the device is formed. In addition, one or two kinds of the above-mentioned specific resin (selected from the group consisting of an acrylic resin, a fluorine resin, a urethane resin, a polyester resin, an epoxy resin, and a phenoxy resin) Since the above resin) has excellent chemical resistance, the protective resin layer is disposed on the outer surface side, whereby the electrolyte solution resistance can be improved (for example, when the electrolyte adheres to the outer surface of the exterior material, no trouble is caused).

According to the invention of [3], it is possible to provide a high-quality power storage device that is externally mounted by a material that is less likely to be bent.

1‧‧‧External materials for power storage devices

2‧‧‧Heat resistant resin layer (outer layer)

3‧‧‧ thermoplastic resin layer (inner layer)

4‧‧‧metal foil layer

5‧‧‧1st adhesive layer

6‧‧‧2nd adhesive layer

7‧‧‧Steaming layer

8‧‧‧Protective resin layer

11‧‧‧Shaped housing

19‧‧‧Power storage unit body

20‧‧‧Power storage device

Fig. 1 is a cross-sectional view showing an embodiment of an exterior material for a storage battery device according to the present invention.

Fig. 2 is a cross-sectional view showing another embodiment of an exterior material for a storage battery device according to the present invention.

FIG. 3 is a cross-sectional view showing an embodiment of a power storage device including an exterior material for a power storage device according to the present invention.

[Fig. 4] An explanatory diagram of the bending prevention evaluation method, (A) is a perspective view of the state immediately after the slit is placed on the evaluation sample; (B) is an oblique view for evaluating the bending state of the sample; (C) (B) Sectional view of the XX line.

An embodiment of the exterior material 1 for a storage battery device according to the present invention is shown in Fig. 1 . The exterior material 1 for a storage device is used as a lithium ion secondary battery case. The exterior material 1 for a power storage device is used as a casing of a secondary battery by molding such as deep drawing molding or bulging molding.

The exterior material 1 for a storage device is laminated on the surface 4a on one side of the metal foil layer 4 by a first adhesive layer 5 and a heat-resistant resin layer (outer layer) 2, and the metal foil layer 4 is laminated. The other surface 4b is formed by laminating the second adhesive layer 6 with the thermoplastic resin layer (inner layer) 3, and is formed by laminating the vapor layer 7 on the outer surface of the heat resistant resin layer 2. In the present embodiment, the protective resin layer 8 is laminated on the outer surface of the vapor layer 7 (see Fig. 1).

In the present invention, the vapor layer 7 is laminated on the outer surface side of the heat resistant resin layer 2. The vapor deposition layer 7 is formed by vaporizing an evaporation material of at least one selected from the group consisting of a metal, a metal oxide, and cerium oxide. The vapor deposition material may be evaporated on the outer surface side of the heat resistant resin layer 2 during the production process, or may be evaporated on the inner surface of the protective resin layer 8. The surface of the object is steamed, and corona treatment, easy adhesion treatment, and the like may be applied in advance. The means for evaporating is not particularly limited, and examples thereof include a chemical vapor deposition method (CVD method) and a physical vapor deposition method (DVD method).

The metal is not particularly limited, and examples thereof include aluminum, chromium, gold, silver, copper, platinum, and nickel. The metal oxide is not particularly limited, and examples thereof include alumina.

The vapor deposition layer 7 may be composed of two or more vapor layers. Can be cited For example, the two layers of the vaporized layer of the cerium oxide/vaporized layer of alumina are formed.

The thickness of the vapor layer 7 is preferably set to 50 Å to 10000 Å. 50 Å or more can sufficiently prevent moisture absorption of the heat-resistant resin layer 2, and 10000 Å or less can contribute to reduction in cost, and the flexibility of the exterior material can be sufficiently ensured. Among them, the thickness of the vapor deposition layer 7 is particularly preferably set at 200 Å to 2000 Å.

In the present invention, it is preferable to further laminate the protective resin layer 8 on the outer surface side of the vapor layer 7. The protective resin layer 8 is one or two selected from the group consisting of an acrylic resin, a fluorine resin, a urethane resin, a polyester resin, an epoxy resin, and a phenoxy resin. The above resins are preferably formed. Among these, the protective resin layer 8 is particularly preferably formed of a fluorine-based resin, a urethane-based resin, a phenoxy resin, or a mixed resin of a urethane-based resin and a phenoxy resin.

The thickness of the protective resin layer 8 is preferably set to 0.5 μm to 5 μm. When the thickness is 0.5 μm or more, peeling, peeling, and damage of the vapor deposition layer can be sufficiently prevented, and the light weight of the exterior material and the energy density of the electricity storage device can be sufficiently ensured at 5 μm or less.

The heat-resistant resin constituting the heat-resistant resin layer (outer layer) 2 is a heat-resistant resin that does not melt at the heat sealing temperature when the exterior material is heat-sealed. The heat resistant resin is preferably a heat resistant resin having a melting point higher than a melting point of the thermoplastic resin constituting the thermoplastic resin layer 3 by 10 ° C or more, and the melting point is higher than the melting point of the thermoplastic resin by 20 ° C or more. The heat resistant resin is particularly excellent.

The heat-resistant resin layer (outer layer) 2 is not particularly limited, and examples thereof include a polyamide film such as a nylon film, a polyester film, and the like, and such a stretched film can be preferably used. Wherein, the heat resistant resin layer 2 is a biaxial extension using a biaxially stretched nylon film or the like. Stretched polyamide membrane, biaxially stretched polybutylene terephthalate (PBT) membrane, biaxially oriented polyethylene terephthalate (PET) membrane or biaxially extended polyethylene naphthalate (PEN) The film is especially good. The nylon film is not particularly limited, and examples thereof include a nylon film, a 6,6 nylon film, and an MXD nylon film. Further, the heat resistant resin layer 2 may be formed of a single layer, or may be formed of, for example, a plurality of layers (a plurality of layers formed of a PET film/nylon film) composed of a polyester film/polyamide film.

The thickness of the heat resistant resin layer 2 is preferably 5 μm to 50 μm. When a polyester film is used, the thickness is preferably from 5 μm to 50 μm, and when a nylon film is used, the thickness is preferably from 12 μm to 50 μm. By setting it at or above the above preferred lower limit value, it is possible to ensure sufficient strength of the packaging material, and by setting it below the above preferred upper limit value, it is possible to reduce stress during bulging forming and deep drawing forming. Formability.

The thermoplastic resin layer (inner layer) 3 has excellent chemical resistance and is responsible for imparting heat sealing properties to the packaging material even when it is used in an electrolyte solution having high corrosiveness such as a lithium ion battery or the like.

The thermoplastic resin layer 3 is not particularly limited, but is preferably a thermoplastic resin which does not have a film layer. The thermoplastic resin unstretched film layer 3 is not particularly limited, and is selected from the group consisting of polyethylene, polypropylene, and an olefinic copolymer, and at least one of a group of the acid-modified product and the ionic polymer. Preferably, the unstretched film formed of a plastic resin is used.

The thickness of the thermoplastic resin layer 3 is preferably set to 20 μm to 80 μm. By setting it at 20 μm or more, the occurrence of pinholes can be sufficiently prevented, and by setting it to 80 μm or less, the amount of the resin can be lowered to achieve cost reduction. Among them, it is particularly preferable that the thickness of the thermoplastic resin layer 3 is set to 30 μm to 50 μm. Further, the aforementioned thermoplastic resin Layer 3 may be a single layer or a plurality of layers.

The metal foil layer 4 is responsible for imparting gas barrier properties to the outer packaging material 1 to prevent oxygen or moisture from entering. The metal foil layer 4 is not particularly limited, and examples thereof include an aluminum foil, a copper foil, and a SUS (stainless steel) foil. Generally, an aluminum foil or a SUS foil is used. The material of the aluminum foil is preferably an O material of A8079 or an O material of A8021. The thickness of the metal foil layer 4 is preferably 15 μm to 80 μm. When the thickness is 15 μm or more, the production of the metal foil can prevent the occurrence of the pinholes which are delayed, and at the same time, when the thickness is 80 μm or less, the stress at the time of the inflation molding and the deep extension molding can be lowered to improve the formability.

It is preferable that the metal foil layer 4 is subjected to a chemical conversion treatment at least on the inner surface 4b (the surface on the second adhesive layer 6 side). By performing such a chemical conversion treatment, the surface corrosion of the metal foil due to the contents (electrolyte of the battery, etc.) can be sufficiently prevented. For example, the chemical conversion treatment of the metal foil can be performed by performing the treatment described below. In other words, for example, an aqueous solution of any one of the following 1) to 3) can be applied to the surface of the metal foil after the degreasing treatment, and then dried to carry out a chemical conversion treatment.

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

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

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

The chemical conversion film has a chromium adhesion amount (each side) of preferably 0.1 mg/m ² to 50 mg/m ^{2 , and particularly} preferably 2 mg/m ² to 20 mg/m ² .

The first adhesive layer 5 is not particularly limited, and examples thereof include a polyurethane adhesive layer, a polyester urethane adhesive layer, and a polyether urethane adhesive layer. The thickness of the first adhesive layer 5 is preferably set to 1 μm to 5 μm. In particular, the thickness of the first adhesive layer 5 is preferably 1 μm to 3 μm from the viewpoint of thinning and weight reduction of the exterior material.

Although the second adhesive layer 6 is not particularly limited, for example, the above-described first adhesive layer 5 can be used, but a polyolefin-based adhesive which is less likely to swell by the electrolytic solution is preferably used. The thickness of the second adhesive layer 6 is preferably set to 1 μm to 5 μm. In particular, the thickness of the second adhesive layer 6 is particularly preferably 1 μm to 3 μm from the viewpoint of thinning and weight reduction of the exterior material.

The outer casing 1 of the present invention can be obtained by molding (deep drawing, bulging molding, etc.) to obtain a molded casing (battery casing or the like). Further, the exterior material 1 of the present invention may be used as it is without being molded.

One of the battery devices 20 constructed by using the exterior material 1 of the present invention is implemented The type is shown in Figure 3. This battery device 20 is a lithium ion secondary battery.

The battery 20 includes an electrolyte 21, a tab 22, the outer casing 1 that is not formed into a flat shape, and the outer casing 1 that is molded to obtain a molded casing 11 having a housing recess 11b (see FIG. 3). ). The power storage device main body portion 19 is configured by the electrolyte 21, the tab 22, and the like.

A part of the electrolyte 21 and the tab 22 are accommodated in the housing recess 11b of the molded case 11, and the planar outer casing 1 is placed on the molded casing 11 by the peripheral portion of the outer casing 1 ( The inner layer 3) is joined to the sealing inner peripheral portion 11a (the inner layer 3) of the molded casing 11 and sealed to constitute the battery 20. Further, the tip end portion of the tab 22 is led to the outside (see Fig. 3).

Further, in the above-described embodiment, the protective resin layer 8 is laminated on the outer surface side of the vaporized layer 7. However, the configuration is not particularly limited, and for example, a protective resin may not be provided as shown in FIG. The structure of the layer 8 (the structure in which the vapor layer 7 is exposed) or the layer of the protective resin layer 8 on the outer surface side of the vapor layer 7 is replaced by another layer.

[Examples]

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

<Example 1>

Physical vaporization by electron beam heating on a single side of a 25 μm biaxially stretched polyethylene terephthalate (PET) film (melting point: 230 ° C) 2 The cerium oxide is vaporized to form a vaporized layer 7 having a thickness of 1000 Å.

On the other hand, a chemical conversion treatment liquid composed of phosphoric acid, polyacrylic acid, a trivalent chromium compound, water, or an alcohol was applied to both surfaces of the aluminum foil 4 having a thickness of 35 μm, and dried at 180 ° C to form a chemical conversion film. The chromium adhesion amount of the chemical conversion film was 10 mg/m ^{2 on} one side.

Then, on the surface 4a on the side of the aluminum foil 4 on which the chemical conversion treatment is completed, the two-liquid-curing type urethane-based adhesive (first adhesive layer) 5 and the vapor deposition layer 7 are applied. The shaft-extending PET film 2 is subjected to dry lamination (fitting). At this time, the non-steamed surface of the biaxially stretched PET film was brought into contact with the urethane-based adhesive 5 and laminated.

Next, the adhesive liquid was applied onto the other surface 4b of the aluminum foil 4 using a gravure roller, and then dried at 80 ° C in hot air to form a subsequent resin layer (second adhesive layer) 6 having a thickness of 3 μm. In the above-mentioned adhesive liquid, 85 parts by mass of a mixed solvent (toluene/methyl ethyl ketone = 8 parts by mass / 2 parts by mass of a mixed solvent) is used to dissolve a maleic acid-modified polypropylene (a copolymer of propylene and ethylene and maleic anhydride). Graft polymerization was carried out to obtain a denatured polypropylene resin; a dissolution temperature of 80 ° C) of 15 parts by mass, and a mixture of 0.9 parts by mass of a polymer of hexamethylene diisocyanate was added to form an adhesive liquid.

Next, the surface of the adhesive resin layer 6 formed on the face 4b on the other side of the aluminum foil 4 has a melting point of 140 ° C and an MFR (melt flow rate) of 4.5 g/10 minutes. A propylene-ethylene random copolymer film (inner layer; sealing layer) 3 having a thickness of 40 μm can be used to obtain an exterior material 1 for a storage device as shown in Fig. 2 .

<Example 2>

In addition to using a two-axis stretch PET film with a thickness of 12 μm (melting point 230 °C)/two-layer laminated film of a 15 μm thick biaxially stretched polyamide film (6 nylon film with a melting point of 220 ° C) (the polyimide film is disposed on the outside and is vaporized on the surface layer of the polyimide film) A biaxially stretched PET film having a thickness of 25 μm was simultaneously formed by a physical vapor deposition method of resistance heating to form an aluminum evaporated layer having a thickness of 600 Å instead of a 1000 Å thick cerium oxide vaporized layer, and the others were the same as in Example 1 to obtain The exterior material 1 for electrical storage devices which is comprised in FIG.

<Example 3>

The exterior of the electricity storage device constructed as shown in FIG. 2 was prepared in the same manner as in Example 2 except that a two-layer stretch polyimide film having a thickness of 25 μm (a nylon film having a melting point of 220 ° C) was used instead of the two-layer laminated film. Material 1.

<Example 4>

In addition to physical evaporation by electron beam heating, a 1500 Å thick cerium oxide-alumina evaporation layer (a vaporized layer obtained by vaporizing a mixture of cerium oxide and aluminum oxide) is formed instead of a 1000 Å thick cerium oxide vapor layer. In the same manner as in the first embodiment, the exterior material 1 for a storage battery device having the configuration shown in Fig. 2 was obtained.

<Example 5>

The storage was constructed as shown in Fig. 2 except that a biaxially stretched polyimide film having a thickness of 25 μm (a nylon film having a melting point of 220 ° C) was used instead of the biaxially stretched PET film having a thickness of 25 μm. The exterior material 1 for the device.

<Example 6>

A protective resin layer 8 having a thickness of 2 μm formed of a urethane resin is further laminated on the outer surface of the vaporized layer 7 which is laminated on the outer surface of the biaxially stretched polyimide film 2 In the same manner as in the fifth embodiment, the exterior material 1 for a storage battery device having the configuration shown in Fig. 1 was obtained. Further, the protective resin layer laminated on the outer surface of the vapor layer was dried by hot air drying at 80 ° C by coating with a gravure roll.

<Example 7>

In addition to the protective resin layer 8 having a thickness of 2 μm formed of a mixed resin of a urethane resin and a phenoxy resin, the outer surface of the aluminum vapor-deposited layer 7 laminated on the outer surface of the biaxially-expanded polyimide film 2 is further laminated. In the same manner as in the third embodiment, the exterior material 1 for a storage battery device having the configuration shown in Fig. 1 was obtained. Further, the protective resin layer laminated on the outer surface of the vapor layer was dried by hot air drying at 80 ° C by coating with a gravure roll.

<Example 8>

The first embodiment is the same as the first embodiment except that the thickness of the vaporized layer of the cerium oxide is set to 2000 Å instead of 1000 Å, and the protective resin layer 8 having a thickness of 2 μm made of an acrylic resin is further laminated on the outer surface of the cerium oxide vaporized layer 7. In the same manner, the exterior material 1 for a storage battery device having the configuration shown in Fig. 1 was obtained. Further, the resin layer was protected by the outer layer of the vapor layer, and was dried by hot air drying at 80 ° C by coating with a gravure roll.

<Example 9>

The film was formed in the same manner as in Example 3 except that the protective resin layer 8 having a thickness of 2 μm formed of an epoxy resin was laminated on the outer surface of the aluminum vapor-deposited layer 7 which was laminated on the outer surface of the biaxially-expanded polyimide film 2 . The exterior material 1 for electrical storage devices which consists of FIG. Further, the protective resin layer laminated on the outer surface of the vapor layer was dried by hot air drying at 80 ° C by coating with a gravure roll.

<Example 10>

The film was formed in the same manner as in Example 3 except that the protective resin layer 8 having a thickness of 2 μm formed of a polyester resin was laminated on the outer surface of the aluminum vapor-deposited layer 7 which was laminated on the outer surface of the biaxially-expanded polyimide film 2 . The exterior material 1 for electrical storage devices which consists of FIG. Further, the protective resin layer laminated on the outer surface of the vapor layer was dried by hot air drying at 80 ° C by coating with a gravure roll.

<Example 11>

The film was formed in the same manner as in Example 3 except that the protective resin layer 8 having a thickness of 2 μm formed of a fluororesin was laminated on the outer surface of the aluminum vapor-deposited layer 7 which was laminated on the outer surface of the biaxially-expanded polyimide film 2, and the like. The exterior material 1 for electrical storage devices which is comprised in FIG. Further, the protective resin layer laminated on the outer surface of the vapor layer was dried by hot air drying at 80 ° C by coating with a gravure roll.

<Comparative Example 1>

An exterior material for a storage battery device was produced in the same manner as in Example 1 except that the vapor dioxide evaporation layer was not provided.

<Comparative Example 2>

An exterior material for a storage battery device was produced in the same manner as in Example 3 except that the aluminum vapor-deposited layer was not provided.

<Comparative Example 3>

The dry surface (aluminum evaporated layer 7) of the biaxially stretched polyimide film 2 is formed with an amine group, except that the surface of one side of the aluminum foil which has been subjected to the chemical conversion treatment is dry laminated with the biaxially stretched polyimide film. The exterior material for a storage battery device was produced in the same manner as in Example 3 except that the ethyl formate-based adhesive 5 was laminated in contact.

The external materials for electrical storage devices obtained as described above were evaluated for performance based on the following evaluation method. The results are shown in Table 1.

<Formability Evaluation Method>

The bulging molding machine (No.: TP-25C-X2) manufactured by Amada Co., Ltd. was used to form a rectangular shape of a longitudinal shape of 55 mm × 35 mm in width, that is, a forming process in which the forming depth was changed, and observation was carried out. Whether or not pinholes and cracks were formed in the corner portions of the obtained molded body, the "maximum forming depth (mm)" at which such pinholes and cracks were not generated was measured. The maximum forming depth of 7.0 mm or more is "○"; the maximum forming depth of 6.0 mm or more is less than 7.0 mm, which is "△"; and the maximum forming depth of less than 6.0 mm is "X".

<Electrolyte resistance evaluation method>

The outer packaging material was cut into a test piece having a width of 15 mm, and the lithium hexafluorophosphate salt was dissolved in a mixed solvent of ethylene carbonate and diethyl carbonate in a volume ratio of 1:1 to obtain a concentration of 1 mol/ The solution of L was placed in a jar made of tetrafluoroethylene resin, and placed in an oven at 85 ° C for 1 week. The test piece was taken out and the aluminum foil 4 and the ethylene-propylene random copolymer resin layer (inner layer) were peeled off. The interface was measured for the laminate strength (adequate strength) between the two (N/15 mm width). Then, if the intensity is 10 (N/15 mm width) or more, it is "○"; if the intensity is 5 (N/15 mm width) or more and less than 10 (N/15 mm width), it is "△"; then the intensity is less than 5 (N/15 mm). The wide one is "X".

<Bending prevention evaluation method>

The outer casing is cut into a square shape of 100 mm × 100 mm, and as shown in Fig. 4 (A), a slit intersecting at a center point (center of gravity) and penetrating up and down is placed along a diagonal line of the square (the length of one slit 31) After 40 mm and the other side of the slit 31 is 40 mm long, In the room having an environment of a relative humidity of 75% and a temperature of 23 ° C, the vaporized layer 7 or the protective resin layer 8 of the sample was set as the lower side, and the inner layer 3 was placed on the water platform as the upper side. One hour after the state was maintained, the height (warpage amount) H from the upper surface of the water platform to the highest portion (central point portion) of the sample was measured (see FIG. 4(C)). If the height H is less than 10 mm, it is "○"; if the height is H10 mm or more, it is "△"; if the height is H15 mm or more, it is "X".

As is apparent from Table 1, the exterior materials for electrical storage devices according to Examples 1 to 11 of the present invention have a large maximum forming depth, and can ensure excellent formability even when deep-drawing, and have excellent electrolyte resistance. Further, there is further excellent bending prevention.

On the other hand, in the exterior materials of the comparative examples 1 to 3, the bending prevention property was inferior and the warpage was extremely large.

[The possibility of industrial use]

The exterior material for an electrical storage device of the present invention can be, for example, as:

. Power storage device such as lithium secondary battery (lithium ion battery, lithium polymer battery, etc.)

. Lithium ion capacitor

. Electric double layer capacitor

Use of exterior materials such as various power storage devices.

The present application claims priority to Japanese Patent Application No. 2014-255885, filed on Dec.

The terms and descriptions used herein are used to describe embodiments of the invention. Use, but the invention is not limited thereto. It is to be understood that any equivalents of the features disclosed and described herein are not to be construed as limited.

1‧‧‧External materials for power storage devices

2‧‧‧Heat resistant resin layer (outer layer)

3‧‧‧ thermoplastic resin layer (inner layer)

4‧‧‧metal foil layer

5‧‧‧1st adhesive layer

6‧‧‧2nd adhesive layer

7‧‧‧ resin coating

Claims (8)

An exterior material 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 disposed between the two layers; and the heat resistant resin An evaporation layer is formed on the outer surface layer of the layer, and the vapor deposition layer is formed by vaporizing at least one of a vapor-deposited material selected from the group consisting of a metal, a metal oxide, and a ceria. The exterior material for a storage battery device according to the first aspect of the invention, wherein the outer surface of the vapor deposition layer is provided with a protective resin layer, and the protective resin layer is selected from the group consisting of an acrylic resin and a fluorine resin. A resin formed by one or two or more kinds of a group of a urethane resin, a polyester resin, an epoxy resin, and a phenoxy resin. The exterior material for a storage battery device according to the first or second aspect of the invention, wherein the thickness of the vapor deposition layer is 50 Å to 10000 Å. The exterior material for a storage battery device according to claim 1 or 2, wherein the thickness of the vapor deposition layer is 200 Å to 2000 Å. The exterior material for a storage battery device according to the first aspect of the invention, wherein the protective resin layer has a thickness of 0.5 μm to 5 μm. The exterior material for a storage battery device according to the third aspect of the invention, wherein the protective resin layer has a thickness of 0.5 μm to 5 μm. The exterior material for a storage battery device according to claim 4, wherein the protective resin layer has a thickness of 0.5 μm to 5 μm. An electric storage device according to any one of the first to seventh aspects of the present invention, wherein the main body of the electric storage device according to any one of claims 1 to 7 is provided, and the main body of the electric storage device is The outside of the equipment.