JP6436758B2 - Power storage device exterior material and power storage device - Google Patents

Description

  The present invention is for batteries and capacitors used for portable devices such as smartphones and tablets, hybrid vehicles, electric vehicles, wind power generation, solar power generation, storage devices such as batteries and capacitors used for storage of night electricity. The present invention relates to an exterior material and an electricity storage device that is exteriorized with the exterior material.

  In recent years, as mobile electrical devices such as smartphones and tablet terminals have become thinner and lighter, power storage devices such as lithium-ion secondary batteries, lithium-polymer secondary batteries, lithium-ion capacitors, and electric double-layer capacitors that are installed in these devices have been reduced. As the exterior material, a laminate composed of a heat resistant resin layer / adhesive layer / metal foil layer / adhesive layer / thermoplastic resin layer is used instead of a conventional metal can (see Patent Documents 1 and 2). ). Usually, the laminate is formed into a three-dimensional shape such as a substantially rectangular parallelepiped shape by performing overhang molding or deep drawing. In addition, a power source for an electric vehicle, a large-scale power source for power storage, a capacitor, and the like are increasingly covered with a laminate (exterior material) having the above-described configuration.

  In the exterior material, as the heat-resistant resin film of the outer layer, it is common to use a polyamide resin film or a polyester resin film from the viewpoint of ensuring better moldability when performing overhang molding or deep drawing. Yes (see Patent Documents 1 and 2).

JP 2011-98759 A Japanese Patent Laid-Open No. 2005-26152

  However, since the polyamide resin film layer, the polyester resin film layer, and the like have high hygroscopicity, an exterior material using such a film as an outer layer has a problem that curling (warping) is likely to occur due to moisture absorption. It was. When a polyamide resin film was used, curling was particularly likely to occur.

  When such curling occurs in the exterior material, when the exterior material sheet is molded, it cannot be mounted in the fixed position of the mold, and molding failure may occur, and the battery element is loaded in the molded battery case. When the peripheral edge of the case is heat-sealed, the sealing position is likely to be shifted, and defects such as wrinkles in the heat-sealed portion are likely to occur.

  The present invention has been made in view of such a technical background, and an object of the present invention is to provide an exterior device for an electricity storage device that can ensure good moldability and prevent curling (curling).

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

[1] A power storage device exterior material including a heat-resistant resin layer as an outer layer, a thermoplastic resin layer as an inner layer, and a metal foil layer disposed between both layers,
A vapor deposition layer is laminated on the outer surface side of the heat resistant resin layer,
The said vapor deposition layer is formed by vapor-depositing at least 1 sort (s) of vapor deposition material chosen from the group which consists of a metal, a metal oxide, and a silica, The exterior material for electrical storage devices characterized by the above-mentioned.

[2] A protective resin layer is laminated on the outer surface side of the vapor deposition layer,
The protective resin layer is formed of one or more resins selected from the group consisting of acrylic resins, fluorine resins, urethane resins, polyester resins, epoxy resins, and phenoxy resins. An exterior material for an electricity storage device according to 1.

[3] An electricity storage device body,
The exterior material for an electricity storage device according to 1 or 2 above,
The electricity storage device, wherein the electricity storage device body is covered with the exterior material.

  In the invention of [1], a vapor deposition layer is laminated on the outer surface side of the heat resistant resin layer in the exterior material, and the vapor deposition layer is formed of at least one vapor deposition material selected from the group consisting of metal, metal oxide and silica. Therefore, the presence of such a vapor deposition layer can suppress the entry of moisture from the outside. Accordingly, moisture can be prevented from entering the heat resistant resin layer and moisture absorption of the heat resistant resin layer can be prevented, so that curling of the exterior material can be prevented (warpage can be prevented). Moreover, since the vapor deposition layer is laminated | stacked on the outer surface side of the heat resistant resin layer, since the strength reduction of a heat resistant resin layer can be suppressed, a moldability can be improved more and the puncture strength can also be improved more.

  In the invention of [2], since the specific protective resin layer is laminated on the outer surface side of the vapor deposition layer, it is possible to sufficiently prevent the vapor deposition layer from peeling and dropping, and to prevent moisture from entering from the outside. Can last for a long time. Further, by laminating such a protective resin layer, processing during device creation becomes easy (workability can be improved). In addition, the specific resin (one or more resins selected from the group consisting of acrylic resins, fluorine resins, urethane resins, polyester resins, epoxy resins, and phenoxy resins) has chemical resistance. Since this protective resin layer is arranged on the outer surface side, the electrolytic solution resistance can be improved (for example, no trouble occurs even if the electrolytic solution adheres to the outer surface of the exterior material). ).

  In the invention of [3], a high-quality power storage device is provided that is packaged with an exterior material that is less likely to curl.

It is sectional drawing which shows one Embodiment of the exterior material for electrical storage devices which concerns on this invention. It is sectional drawing which shows other embodiment of the exterior material for electrical storage devices which concerns on this invention. It is sectional drawing which shows one Embodiment of the electrical storage device comprised using the exterior material for electrical storage devices which concerns on this invention. It is explanatory drawing of an anti-curl evaluation method, (A) is a perspective view in the state immediately after making a cut | incision in an evaluation sample, (B) is a perspective view in the state where curvature occurred in the evaluation sample, (C) is ( It is sectional drawing of the XX line in B).

  One embodiment of an exterior material 1 for an electricity storage device according to the present invention is shown in FIG. The power storage device exterior material 1 is used for a lithium ion secondary battery case. The power storage device exterior material 1 is used, for example, as a case of a secondary battery by being subjected to molding such as deep drawing molding or stretch molding.

  In the power storage device exterior material 1, a heat resistant resin layer (outer layer) 2 is laminated and integrated on one surface 4 a of the metal foil layer 4 via a first adhesive layer 5, and the other side of the metal foil layer 4. A thermoplastic resin layer (inner layer) 3 is laminated and integrated on the surface 4 b with a second adhesive layer 6 interposed therebetween, and a vapor deposition layer 7 is laminated on the outer surface of the heat resistant resin layer 2. In this embodiment, a protective resin layer 8 is laminated on the outer surface of the vapor deposition layer 7 (see FIG. 1).

  In the present invention, the vapor deposition layer 7 is laminated on the outer surface side of the heat resistant resin layer 2. The vapor deposition layer 7 is formed by vapor-depositing at least one vapor deposition material selected from the group consisting of metals, metal oxides, and silica. The vapor deposition material may be vapor-deposited on the outer surface of the heat-resistant resin layer 2 in the manufacturing process, or may be vapor-deposited on the inner surface of the protective resin layer 8. The surface to be vapor-deposited may be previously subjected to corona treatment, easy adhesion coating treatment, or the like. The vapor deposition technique is not particularly limited, and examples thereof include chemical vapor deposition (CVD) and physical vapor deposition (DVD).

  Although it does not specifically limit as said metal, For example, aluminum, chromium, gold | metal | money, silver, copper, platinum, nickel etc. are mentioned. Although it does not specifically limit as said metal oxide, For example, an alumina etc. are mentioned.

  The vapor deposition layer 7 may be composed of two or more vapor deposition layers. For example, a two-layer laminated structure of silica vapor deposition layer / alumina vapor deposition layer can be used.

  The thickness of the vapor deposition layer 7 is preferably set to 50 to 10000 mm. The moisture absorption of the heat-resistant resin layer 2 can be sufficiently prevented when the thickness is 50 mm or more, and the cost can be reduced and the flexibility of the exterior material can be sufficiently secured when the thickness is 10000 mm or less. Especially, it is especially preferable that the thickness of the vapor deposition layer 7 is set to 200 mm to 2000 mm.

  In the present invention, it is preferable to adopt a configuration in which a protective resin layer 8 is further laminated on the outer surface side of the vapor deposition layer 7. The protective resin layer 8 is formed of one or more resins selected from the group consisting of acrylic resins, fluorine resins, urethane resins, polyester resins, epoxy resins, and phenoxy resins. Is preferred. Among these, the protective resin layer 8 is particularly preferably formed of a fluorine resin, a urethane resin, a phenoxy resin, or a mixed resin of a urethane 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, the vapor deposition layer can be sufficiently prevented from peeling off, falling off, or being damaged, and when the thickness is 5 μm or less, the lightness of the exterior material and the energy density of the electricity storage device can be sufficiently secured.

  As the heat-resistant resin constituting the heat-resistant resin layer (outer layer) 2, a heat-resistant resin that does not melt at the heat sealing temperature when heat-sealing the exterior material is used. As the heat resistant resin, it is preferable to use a heat resistant resin having a melting point higher by 10 ° C. or higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layer 3, and having a melting point higher by 20 ° C. or higher than the melting point of the thermoplastic resin. It is particularly preferable to use a heat resistant resin.

  The heat-resistant resin layer (outer layer) 2 is not particularly limited, and examples thereof include polyamide films such as nylon films, polyester films, and the like, and these stretched films are preferably used. Among them, the heat-resistant resin layer 2 includes a biaxially stretched polyamide film such as a biaxially stretched nylon film, a biaxially stretched polybutylene terephthalate (PBT) film, a biaxially stretched polyethylene terephthalate (PET) film or a biaxially stretched polyethylene film. It is particularly preferable to use a phthalate (PEN) film. The nylon film is not particularly limited, and examples thereof include 6 nylon film, 6,6 nylon film, MXD nylon film, and the like. The heat-resistant resin layer 2 may be formed as a single layer, or may be formed as a multilayer composed of a polyester film / polyamide film (such as a multilayer composed of PET film / nylon film). Also good.

  The thickness of the heat resistant resin layer 2 is preferably 5 μm to 50 μm. When using a polyester film, the thickness is preferably 5 μm to 50 μm, and when using a nylon film, the thickness is preferably 12 μm to 50 μm. By setting it above the above preferred lower limit value, it is possible to ensure sufficient strength as an exterior material, and by setting it below the above preferred upper limit value, it is possible to reduce the stress at the time of molding such as stretch forming, draw forming, etc. and improve moldability Can be made.

  The thermoplastic resin layer (inner layer) 3 has excellent chemical resistance against highly corrosive electrolytes used in lithium ion secondary batteries and the like, and provides heat sealability to the exterior material. To play a role.

  Although it does not specifically limit as said thermoplastic resin layer 3, It is preferable that it is a thermoplastic resin unstretched film layer. The thermoplastic resin unstretched film layer 3 is not particularly limited, but is at least one thermoplastic selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers. It is preferably composed of an unstretched film made of a resin.

  The thickness of the thermoplastic resin layer 3 is preferably set to 20 μm to 80 μm. When the thickness is 20 μm or more, pinholes can be sufficiently prevented from being generated, and by setting the thickness to 80 μm or less, the amount of resin used can be reduced, and the cost can be reduced. Especially, it is especially preferable that the thickness of the thermoplastic resin layer 3 is set to 30 μm to 50 μm. The thermoplastic resin layer 3 may be a single layer or a multilayer.

  The metal foil layer 4 plays a role of imparting a gas barrier property to the exterior material 1 to prevent entry of oxygen and moisture. Although it does not specifically limit as said metal foil layer 4, For example, aluminum foil, copper foil, SUS (stainless steel) foil etc. are mentioned, Aluminum foil and SUS foil are generally used. As the material of the aluminum foil, an O material of A8079 and an O material of A8021 are preferable. The thickness of the metal foil layer 4 is preferably 15 μm to 80 μm. When it is 15 μm or more, it can prevent the occurrence of pinholes during rolling when manufacturing a metal foil, and when it is 80 μm or less, it can reduce the stress during forming such as stretch forming and draw forming, thereby improving formability. be able to.

The metal foil layer 4 is preferably subjected to chemical conversion treatment on at least the inner surface 4b (surface on the second adhesive layer 6 side). By performing such a chemical conversion treatment, corrosion of the metal foil surface by the contents (battery electrolyte or the like) can be sufficiently prevented. For example, the metal foil is subjected to chemical conversion treatment by the following treatment. That is, for example, on the surface of the metal foil that has been degreased,
1) phosphoric acid;
Chromic acid,
An aqueous solution of a mixture comprising at least one compound selected from the group consisting of a metal salt of fluoride and a nonmetal salt of fluoride; 2) phosphoric acid;
At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins;
An aqueous solution of a mixture comprising at least one compound selected from the group consisting of chromic acid and a chromium (III) salt, 3) phosphoric acid,
At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins;
At least one compound selected from the group consisting of chromic acid and a chromium (III) salt;
An aqueous solution of a mixture comprising at least one compound selected from the group consisting of a fluoride metal salt and a fluoride non-metal salt. After applying an aqueous solution of any one of the above 1) to 3), drying is performed. Then, chemical conversion treatment is performed.

The conversion coating, chromium coating weight preferably is 0.1mg / m ² ~50mg / m ² as a (per one surface), in particular 2mg / m ² ~20mg / m 2 preferred.

  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 μm to 5 μm. Especially, it is especially preferable that the thickness of the said 1st adhesive bond layer 5 is set to 1 micrometer-3 micrometers from a viewpoint of thickness reduction of an exterior material and weight reduction.

  Although it does not specifically limit as said 2nd adhesive bond layer 6, For example, what was illustrated as said 1st adhesive bond layer 5 can be used, However, The polyolefin-type adhesive agent with few swelling by electrolyte solution is used. Is preferred. The thickness of the second adhesive layer 6 is preferably set to 1 μm to 5 μm. Especially, it is especially preferable that the thickness of the said 2nd adhesive bond layer 6 is set to 1 micrometer-3 micrometers from a viewpoint of thickness reduction of an exterior material and weight reduction.

  A molded case (battery case or the like) can be obtained by molding the outer packaging material 1 of the present invention (deep drawing molding, stretch molding or the like). In addition, the exterior material 1 of this invention can also be used as it is, without using for shaping | molding.

  One embodiment of the electrical storage device 20 comprised using the exterior | packing material 1 of this invention is shown in FIG. The electricity storage device 20 is a lithium ion secondary battery.

  The battery 20 includes an electrolyte 21, a tab lead 22, the planar outer packaging material 1 that is not used for molding, and a molding case 11 having an accommodation recess 11 b obtained by molding the outer packaging material 1. (See FIG. 3). The electrolyte device main body 19 is constituted by the electrolyte 21, the tab lead 22, and the like.

  A part of the electrolyte 21 and the tab lead 22 is accommodated in the accommodating recess 11 b of the molding case 11, the planar exterior material 1 is disposed on the molding case 11, and a peripheral portion ( The inner layer 3) and the sealing peripheral edge portion 11a (the inner layer 3) of the molded case 11 are joined and sealed to form the battery 20. The leading end of the tab lead 22 is led out to the outside (see FIG. 3).

  In the above-described embodiment, the configuration in which the protective resin layer 8 is laminated on the outer surface side of the vapor deposition layer 7 is adopted. However, the configuration is not particularly limited to this, and for example, as shown in FIG. It is also possible to adopt a configuration in which the protective resin layer 8 is not provided (a configuration in which the vapor deposition layer 7 is exposed), or a configuration in which another layer is laminated on the outer surface side of the vapor deposition layer 7 instead of the protective resin layer 8. it can.

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

<Example 1>
Silica was vapor-deposited on one side of a 25 μm-thick biaxially stretched polyethylene terephthalate (PET) film (melting point: 230 ° C.) 2 by physical vapor deposition by electron beam heating to form a vapor deposition layer 7 having a thickness of 1000 mm.

On the other hand, a chemical conversion treatment solution composed of phosphoric acid, polyacrylic acid, a trivalent chromium compound, water, and alcohol was applied to both surfaces of a 35 μm thick aluminum foil 4 and dried at 180 ° C. to form a chemical conversion film. . The amount of chromium deposited on this chemical film was 10 mg / m ² per side.

  Next, the biaxially stretched PET film 2 with the vapor deposition layer 7 is dried on one surface 4a of the chemical conversion treated aluminum foil 4 via a two-component curable urethane adhesive (first adhesive layer) 5. Laminated (laminated). At this time, the biaxially stretched PET film was laminated so that the non-deposition surface of the PET film was in contact with the urethane adhesive 5.

  Next, after applying an adhesive liquid to the other surface 4b of the aluminum foil 4 using a gravure roll, the adhesive resin layer (second adhesive layer) 6 having a thickness of 3 μm is dried by hot air at 80 ° C. Formed. As the adhesive liquid, 15 parts by mass of maleic acid-modified polypropylene (modified polypropylene resin obtained by graft polymerization of maleic anhydride on a copolymer of propylene and ethylene; melting temperature: 80 ° C.) was mixed with a mixed solvent (toluene / methyl ethyl ketone = 8 An adhesive solution obtained by mixing 0.9 part by mass of a polymer of hexamethylene diisocyanate in a solution dissolved in 85 parts by mass of a mixed solvent of 2 parts by mass of 2 parts by mass) was used.

  Next, on the surface of the adhesive resin layer 6 formed on the other surface 4b of the aluminum foil 4, propylene having a thickness of 40 μm and a melting point of 140 ° C. and an MFR (melt flow rate) of 4.5 g / 10 min. -By laminating an ethylene random copolymer film (inner layer; sealant layer) 3, an exterior material 1 for an electricity storage device having the configuration shown in FIG. 2 was obtained.

<Example 2>
Instead of a 25 μm thick biaxially stretched PET film, a 12 μm thick biaxially stretched PET film (melting point 230 ° C.) / 15 μm thick biaxially stretched polyamide film (melting point 220 ° C. 6 nylon film) A film (a polyamide film is arranged on the outside and a vapor deposition layer is laminated on the polyamide film surface) is used, and an aluminum vapor deposition layer 7 having a thickness of 600 mm is replaced with a physical vapor deposition by resistance heating instead of a silica vapor deposition layer having a thickness of 1000 mm. Except that it was formed by the method, the electricity storage device exterior material 1 having the configuration shown in FIG. 2 was obtained in the same manner as in Example 1.

<Example 3>
An exterior for an electricity storage device having the configuration shown in FIG. 2 was used in the same manner as in Example 2 except that a biaxially stretched polyamide film (6 nylon film having a melting point of 220 ° C.) having a thickness of 25 μm was used instead of the two-layer laminated film. Material 1 was obtained.

<Example 4>
Example except that instead of the silica vapor deposition layer having a thickness of 1000 mm, a silica-alumina vapor deposition layer having a thickness of 1500 mm (a vapor deposition layer formed by vapor deposition of a mixture of silica and alumina) was formed by physical vapor deposition by electron beam heating. In the same manner as in Example 1, a power storage device exterior material 1 having the configuration shown in FIG.

<Example 5>
The configuration shown in FIG. 2 is the same as that of Example 1 except that a 25 μm thick biaxially stretched polyamide film (6 nylon film having a melting point of 220 ° C.) is used instead of the 25 μm thick biaxially stretched PET film. The outer packaging material 1 for an electricity storage device was obtained.

<Example 6>
FIG. 1 shows the same as in Example 5 except that a protective resin layer 8 made of urethane resin and having a thickness of 2 μm is further laminated on the outer surface of the vapor deposition layer 7 laminated on the outer surface of the biaxially stretched polyamide film 2. An exterior material 1 for an electricity storage device having a configuration was obtained. In addition, lamination | stacking of the protective resin layer on the outer surface of a vapor deposition layer was performed by apply | coating using a gravure roll and drying with 80 degreeC hot air.

<Example 7>
Example 3 except that a protective resin layer 8 having a thickness of 2 μm made of a mixed resin of urethane resin and phenoxy resin was further laminated on the outer surface of the aluminum vapor deposition layer 7 laminated on the outer surface of the biaxially stretched polyamide film 2. Thus, an exterior material 1 for an electricity storage device having the configuration shown in FIG. 1 was obtained. In addition, lamination | stacking of the protective resin layer on the outer surface of a vapor deposition layer was performed by apply | coating using a gravure roll and drying with 80 degreeC hot air.

<Example 8>
The thickness of the silica vapor deposition layer was set to 2000 mm instead of 1000 mm, and the protective resin layer 8 made of acrylic resin and having a thickness of 2 μm was further laminated on the outer surface of the silica vapor deposition layer 7 in the same manner as in Example 1. 1 to obtain the exterior device 1 for an electricity storage device having the configuration shown in FIG. In addition, lamination | stacking of the protective resin layer on the outer surface of a vapor deposition layer was performed by apply | coating using a gravure roll and drying with 80 degreeC hot air.

<Example 9>
In the same manner as in Example 3, except that a protective resin layer 8 made of epoxy resin and having a thickness of 2 μm was further laminated on the outer surface of the aluminum vapor deposition layer 7 laminated on the outer surface of the biaxially stretched polyamide film 2, FIG. The exterior device 1 for an electricity storage device having the structure shown was obtained. In addition, lamination | stacking of the protective resin layer on the outer surface of a vapor deposition layer was performed by apply | coating using a gravure roll and drying with 80 degreeC hot air.

<Example 10>
In the same manner as in Example 3, except that a protective resin layer 8 made of polyester resin and having a thickness of 2 μm was further laminated on the outer surface of the aluminum vapor deposition layer 7 laminated on the outer surface of the biaxially stretched polyamide film 2, FIG. The exterior device 1 for an electricity storage device having the structure shown was obtained. In addition, lamination | stacking of the protective resin layer on the outer surface of a vapor deposition layer was performed by apply | coating using a gravure roll and drying with 80 degreeC hot air.

<Example 11>
In the same manner as in Example 3, except that a protective resin layer 8 made of a fluororesin was further laminated on the outer surface of the aluminum vapor-deposited layer 7 laminated on the outer surface of the biaxially stretched polyamide film 2, FIG. The exterior device 1 for an electricity storage device having the structure shown was obtained. In addition, lamination | stacking of the protective resin layer on the outer surface of a vapor deposition layer was performed by apply | coating using a gravure roll and drying with 80 degreeC hot air.

<Comparative Example 1>
An exterior material for an electricity storage device was obtained in the same manner as in Example 1 except that the silica vapor deposition layer was not provided.

<Comparative Example 2>
An exterior material for an electricity storage device was obtained in the same manner as in Example 3 except that the aluminum vapor deposition layer was not provided.

<Comparative Example 3>
When the biaxially stretched polyamide film is dry-laminated on one surface of the chemically treated aluminum foil, the laminated surface is such that the vapor-deposited surface (aluminum vapor-deposited layer 7) of the biaxially stretched polyamide film 2 is in contact with the urethane adhesive 5 Except having done, it carried out similarly to Example 3, and obtained the exterior | packing material for electrical storage devices.

  Performance evaluation was performed based on the following evaluation method with respect to each outer packaging material for an electricity storage device obtained as described above. The results are shown in Table 1.

<Formability evaluation method>
Using an overhang molding machine manufactured by Amada Co., Ltd. (Part No .: TP-25C-X2), the exterior material is stretched into a substantially rectangular parallelepiped shape of 55 mm in length and 35 mm in width, that is, it is drawn by changing the molding depth. The obtained molded body was examined for the presence or absence of pinholes and cracks at the corners, and the “maximum molding depth (mm)” at which such pinholes and cracks did not occur was examined. “○” when the maximum forming depth is 7.0 mm or more, “△” when the maximum forming depth is 6.0 mm or more and less than 7.0 mm, and those where the maximum forming depth is less than 6.0 mm Was marked “x”.

<Electrolytic solution resistance evaluation method>
The exterior material is cut to a width of 15 mm to prepare a measurement piece, and the concentration of lithium hexafluorophosphate is 1 mol / L with respect to a mixed solvent in which ethylene carbonate and diethylene carbonate are mixed at a volume ratio of 1: 1. The solution dissolved in this manner and the measurement piece were placed in a wide-mouthed bottle made of ethylene tetrafluoride resin and stored in an oven at 85 ° C. for one week. Then, the measurement piece was taken out and the aluminum foil 4 and ethylene-propylene random co-polymerized After peeling at the interface of the combined resin layer (inner layer) 3, the laminate strength (adhesive strength) (N / 15 mm width) between them was measured. “◯” indicates that the adhesive strength is 10 (N / 15 mm width) or more, “△” indicates that the adhesive strength is 5 (N / 15 mm width) or more and less than 10 (N / 15 mm width), and the adhesive strength is 5 What was less than (N / 15mm width) was made into "x".

<Anti-curl evaluation method>
The exterior material is cut into a square shape of 100 mm × 100 mm, and as shown in FIG. 4A, the upper and lower through-cuts intersecting at the center point (center of gravity) along the diagonal of the square (one cut 31 is 40 mm in length, the other And the inner layer 3 with the vapor-deposited layer 7 or the protective resin layer 8 on the lower surface side on a horizontal platform in a room with a relative humidity of 75% and a temperature of 23 ° C. Was placed on the upper surface side. After 1 hour in this state, the height (warpage amount) H from the upper surface of the horizontal table to the highest portion (center point portion) of the sample was measured (see FIG. 4C). The case where the height H is less than 10 mm is indicated by “◯”, the case where the height H is 10 mm or more and less than 15 mm is indicated by “Δ”, and the case where the height H is 15 mm or more is indicated by “X”.

  As is clear from Table 1, the outer packaging materials for electricity storage devices of Examples 1 to 11 of the present invention have a large maximum molding depth, and can ensure excellent moldability even when deep molding is performed, and also have resistance to electrolyte. It was also excellent in curling prevention.

  On the other hand, the exterior materials of Comparative Examples 1 to 3 had large warpage and poor curl prevention.

As a specific example, an exterior material for an electricity storage device according to the present invention is, for example,
-Electric storage devices such as lithium secondary batteries (lithium ion batteries, lithium polymer batteries, etc.)-Used as exterior materials for various electric storage devices such as lithium ion capacitors and electric double layer capacitors.

DESCRIPTION OF SYMBOLS 1 ... Exterior material for electrical storage devices 2 ... Heat-resistant resin layer (outer layer)
3 ... Thermoplastic resin layer (inner layer)
DESCRIPTION OF SYMBOLS 4 ... Metal foil layer 5 ... 1st adhesive bond layer 6 ... 2nd adhesive bond layer 7 ... Deposition layer 8 ... Protective resin layer 11 ... Molding case 19 ... Power storage device main-body part 20 ... Power storage device

Claims (2)

A power storage device exterior material 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 both layers,
A vapor deposition layer is laminated on the outer surface side of the heat resistant resin layer,
The deposited layer is a metal state, and are intended to at least one of the evaporation material selected from the group consisting of metal oxide and silica are formed by vapor deposition,
A protective resin layer is laminated on the outer surface side of the vapor deposition layer,
The protective resin layer is an acrylic resin, fluorine resin, urethane resin, polyester resin, that you have been formed by one or more resins selected from the group consisting of epoxy resins and phenoxy resins An exterior material for an electricity storage device. An electricity storage device body,
And an exterior material for an electricity storage device according to claim 1 ,
The electricity storage device, wherein the electricity storage device body is covered with the exterior material.

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