JP6554348B2 - Exterior material for storage device and storage device - Google Patents

Description

  The present invention relates to an exterior material for an electricity storage device having flexibility, a tube-type exterior body for an electricity storage device, and an electricity storage device.

  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 an exterior material, it replaces with the conventional metal can, and the laminated body which consists of a heat resistant resin layer / adhesive bond layer / metal foil layer / adhesive bond layer / thermoplastic resin layer is used (refer patent document 1).

  And, recently, flexible batteries have attracted attention as batteries of wearable electronic devices. Among them, a cable battery is mentioned as a typical one (Patent Document 2).

Unexamined-Japanese-Patent No. 2005-22336 WO2014 / 178590A1

  The cable battery is required to be flexible and lightweight, and for this reason, a thinner one is also required as an exterior material.

  However, the cable battery exterior material described in Patent Document 2 is provided with a sealant resin layer on both sides of the barrier layer. If the sealant resin layer is thinned for weight reduction, the seal bonding strength is reduced. Also, the strength as an exterior material decreases. On the other hand, if the sealant resin layer is made thick so as to eliminate the decrease in the seal bonding strength, there is a problem that it is not possible to reduce the weight of the exterior material.

  The present invention has been made in view of such technical background, and it is possible to ensure high barrier properties even if weight reduction is achieved by reducing the thickness of the exterior material, and a storage material for the storage device and a tube for the storage device. An object of the present invention is to provide a mold case and an electric storage device configured using the case.

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

[1] An electricity storage device exterior material that forms a tube-shaped exterior body that is wound into a tube shape and has flexibility,
The exterior material includes a heat-resistant resin layer as an outer layer, a heat-fusible resin layer as an inner layer, and a metal foil layer disposed between both layers,
A deposited layer is disposed between the heat-resistant resin layer and the metal foil layer, or / and between the heat-fusion resin layer and the metal foil layer. .

  [2] The power storage device exterior material according to [1], wherein the vapor deposition layer is disposed between the heat resistant resin layer and the metal foil layer.

  [3] The exterior material for an electricity storage device according to item 1 or 2, wherein the vapor deposition layer is formed by vapor-depositing at least one vapor deposition material selected from the group consisting of metal, metal oxide, and fluoride. .

  [4] The exterior material for an electricity storage device according to any one of items 1 to 3, wherein the thickness of the metal foil layer is 5 μm or more and less than 30 μm.

  [5] The exterior material according to any one of items 1 to 4 is wound in a tube shape with the heat-fusible resin layer inside, and one end portion of both end portions in the winding direction of the exterior material. A tube-type exterior body for an electricity storage device, wherein the inner surface of the first end portion and the inner surface of the other end portion are overlapped and the inner surface of the one end portion and the inner surface of the other end portion are heat-sealed.

  [6] An electricity storage device comprising: the tube type exterior body described in the preceding paragraph 5; and an electricity storage device main body having flexibility stored in the tube type exterior body.

  In the invention of [1], the vapor deposition layer is disposed between the heat-resistant resin layer and the metal foil layer and / or between the heat-fusible resin layer and the metal foil layer. Thus, it is possible to suppress the intrusion of moisture from the outside, and to suppress the diffusion and leakage of the electrolyte solution to the outside. Thus, since the improvement of the above-mentioned various effects can be achieved by the existence of a vapor deposition layer, even if the thickness of the metal foil layer is designed thin (for example, 5 μm or more and less than 30 μm) by that amount It is possible to suppress the entry of water and to prevent the diffusion of the electrolyte. Therefore, according to the present invention, it is possible to ensure excellent moisture barrier properties and excellent electrolyte solution diffusion preventing properties while achieving sufficient thinning and weight reduction. The storage device packaged with the packaging material of the present invention thus made thin and light can improve the weight energy density and volume energy density of the storage device.

  In the invention of [2], since the vapor deposition layer is disposed outside the metal foil layer (the vapor deposition layer is disposed between the heat resistant resin layer and the metal foil layer), the penetration of moisture from the outside Moisture barrier properties can be sufficiently improved. That is, when the thickness of the metal foil layer is set to be less than 30 μm in order to achieve a sufficient weight reduction, there is a possibility that pinholes are generated in the metal foil. On the other hand, since the vapor deposition layer is arranged on the outside, an advantageous effect that moisture from the outside can be more reliably suppressed can be obtained.

  In the invention of [3], the vapor deposition layer is formed by vapor deposition of at least one material selected from the group consisting of metals, metal oxides, and fluorides, so that the moisture barrier property is further improved and Further excellent anti-diffusion property of the electrolyte can be secured, and adhesion to the vapor deposition substrate layer (deposited layer) can be improved.

  In the invention of [4], since the thickness of the metal foil layer is 5 μm or more and less than 30 μm, it is possible to further reduce the thickness and weight while ensuring excellent moisture barrier properties and excellent electrolyte solution diffusion preventing properties. As well as being able to improve flexibility.

  According to the invention [5], a tube type exterior body for an electricity storage device is provided which has excellent moisture barrier properties and excellent electrolyte solution diffusion preventing properties while achieving sufficient thinning and weight reduction.

  In the invention of [6], since the electricity storage device main body having flexibility is accommodated in the above-mentioned tube type exterior body, excellent moisture barrier property and excellent electrolyte solution diffusion preventing property can be obtained by the tube type exterior body. While being able to be ensured, the electrical storage device which improved weight energy density and volume energy density is provided.

It is sectional drawing which shows one Embodiment of the exterior material for electrical storage devices of this invention. It is sectional drawing which shows other embodiment of the exterior material for electrical storage devices of this invention. It is a schematic sectional drawing which shows one Embodiment of the electrical storage device of this invention.

  One embodiment of the packaging material 1 for a storage battery device according to the present invention is shown in FIG. While the heat-resistant resin layer (outer layer) 12 is laminated and integrated on one surface of the metal foil layer 14 via the first adhesive layer 15, the packaging material 1 for a storage battery is formed of the metal foil layer 14. The heat sealing resin layer (inner layer) 13 is laminated and integrated on the other surface via the second adhesive layer 16. The packaging material 1 for a storage battery device of the present invention is used by being formed into a tube type packaging body 32 having flexibility by being wound in a tube shape (see FIG. 3).

  In the present invention, a vapor deposition layer 17 is disposed between the heat resistant resin layer 12 and the metal foil layer 14 (see FIG. 1), and between the heat fusible resin layer 13 and the metal foil layer 14. In the second embodiment, the deposition layer 17 is disposed between the heat-resistant resin layer 12 and the metal foil layer 14 (see FIG. 2). One of the structures by which the vapor deposition layer 17 is arrange | positioned also between the metal foil layers 14 is employ | adopted.

  In the energy storage device exterior material 1, the vapor deposition layer 17 is disposed between the heat-resistant resin layer 12 and the metal foil layer 14 and / or between the heat-fusible resin layer 13 and the metal foil layer 14. Therefore, the vapor deposition layer 17 can suppress the intrusion of moisture from the outside, and can also suppress the diffusion and leakage of the electrolytic solution to the outside. Since the various effects can be improved by the presence of the vapor deposition layer 17 as described above, even if the thickness of the metal foil layer is designed to be thin (for example, 5 μm or more and less than 30 μm) and reduced in weight, the exterior material is externally applied. In addition, it is possible to prevent the infiltration of water and also the diffusion of the electrolyte. Therefore, according to the present invention, it is possible to ensure excellent moisture barrier properties and excellent electrolyte solution diffusion preventing properties while achieving sufficient thinning and weight reduction. The energy storage device 30 packaged using the packaging material 1 of the present invention, which has been made thin and light as described above, can improve the weight energy density and volume energy density of the energy storage device.

  In the present invention, when the thickness of the metal foil layer 14 is set to less than 30 μm in order to achieve sufficient weight reduction, there is a possibility that pin holes may be generated in the metal foil, while the vapor deposited layer In the configuration of FIGS. 1 and 2 (a configuration in which the double barrier layer of the metal foil layer 14 and the vapor deposition layer 17 is provided), although the possibility of peeling off in part due to stress change etc. can not be denied. It can be said that there is substantially no possibility that the position (specific point) of the pinhole of the metal foil layer 14 and the position (specific point) of the peeling point of the vapor deposition layer 17 overlap, so excellent moisture barrier property and excellent Electrolyte diffusion prevention can be secured.

  In the present invention, the heat-resistant resin layer (heat-resistant resin film layer or the like) 12 is a member mainly playing a role as a protective layer, and is a heat-resistant resin constituting the heat-resistant resin layer (outer layer) 12 Uses a heat resistant resin which does not melt at the heat seal temperature when heat sealing the exterior material. As the heat-resistant resin, it is preferable to use a heat-resistant resin having a melting point higher by 10 ° C. or more than the melting point of the heat-bonding resin constituting the heat-bonding resin layer 13. It is particularly preferable to use a heat-resistant resin having a melting point higher than ° C.

  Although it does not specifically limit as the said heat resistant resin layer 12, For example, a stretched polyamide film (stretched nylon film etc.) and a stretched polyester film are used preferably. Among them, as the heat-resistant resin layer 12, a biaxially stretched polyamide film (biaxially stretched nylon film or the like), a biaxially stretched polybutylene terephthalate (PBT) film, a biaxially stretched polyethylene terephthalate (PET) film or a biaxially stretched polyethylene It is particularly preferred to be composed of a naphthalate (PEN) film. Although it does not specifically limit as said nylon, For example, 6 nylon, 6, 6 nylon, MXD nylon etc. are mentioned. The heat-resistant resin layer 12 may be formed of a single layer (single stretched film), or a multilayer composed of, for example, a stretched polyester film / stretched polyamide film (biaxially stretched PET film / 2 It may be formed of a multilayer or the like made of an axially stretched nylon film.

  Among them, the heat-resistant resin layer 12 has a multilayer structure including a biaxially stretched polyester film disposed on the outer side and a biaxially stretched polyamide film disposed on the first adhesive layer 15 side. preferable. Furthermore, the heat resistant resin layer 12 has a multilayer structure including a biaxially stretched polyethylene terephthalate film disposed on the outer side and a biaxially stretched nylon film disposed on the first adhesive layer 15 side. Is more preferred.

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

  The thickness of the heat resistant resin layer 12 is preferably set to 10 μm to 25 μm. When a biaxially stretched polyamide film is used as the heat resistant resin layer 12, it is more preferably set to 15 μm to 25 μm.

  The vapor deposition layer 17 is preferably composed of at least one material selected from the group consisting of metals, metal oxides, and fluorides. Although it does not specifically limit as said metal, For example, aluminum, chromium, zinc, nickel, gold | metal | money, silver, platinum etc. are mentioned. The metal oxide is not particularly limited, and examples thereof include alumina, silica, titanium oxide, and zirconium oxide. The fluoride is not particularly limited, and examples thereof include magnesium fluoride and the like. Especially, it is preferable that the material (vapor deposition material) which forms the said vapor deposition layer 17 is at least 1 sort (s) of material chosen from the group which consists of aluminum, an alumina, and a silica.

  The thickness of the vapor deposition layer 17 is preferably set to 50 Å (angstrom) to 10000 Å (angstrom). If the thickness of the metal foil layer 14 is less than 30 μm, there may be pinholes in the metal foil, but by adjusting the thickness of the vapor deposition layer 17 according to the thickness of the metal foil, It is possible to ensure excellent moisture barrier properties and excellent electrolyte solution diffusion preventing properties as the entire packaging material 1. Among them, the thickness of the vapor deposition layer 17 is more preferably in the range of 50 Å to 1000 Å, and particularly preferably in the range of 300 Å to 1000 Å (30 nm to 100 nm).

  The vapor deposition layer 17 is preferably disposed between the heat resistant resin layer 12 and the metal foil layer 14. In this case, the vapor deposition layer 17 may be formed by vapor-depositing the vapor deposition material on the inner surface of the heat resistant resin layer (outer layer) 12 (see FIG. 1), or a metal foil layer (barrier layer). ) 14 may be formed by vapor-depositing the vapor deposition material on the outer surface of 14 (surface on the side of the heat resistant resin layer 12).

  The vapor deposition layer 17 may be disposed between the heat-fusible resin layer 13 and the metal foil layer 14. In this case, the vapor deposition layer 17 may be formed by vapor-depositing the vapor deposition material on the inner surface of the heat-fusible resin layer (inner layer) 13 (see FIG. 2), or a metal foil layer ( It may be formed by vapor-depositing the vapor deposition material on the inner surface of the barrier layer 14 (the surface on the heat-fusible resin layer 13 side).

  The deposition method is not particularly limited, and examples thereof include a vacuum deposition method and a PE-CVD method.

  The heat-fusible resin layer (inner layer) 13 has excellent chemical resistance against highly corrosive electrolytes used in lithium ion secondary batteries and the like, and heat sealability is applied to the exterior material. Play a role in granting

  The resin constituting the heat-fusible resin layer 13 is not particularly limited. For example, polyethylene, polypropylene, ionomer, ethylene ethyl acrylate (EEA), ethylene methyl acrylate (EAA), ethylene methacryl Examples include acid methyl resin (EMMA), ethylene-vinyl acetate copolymer resin (EVA), maleic anhydride-modified polypropylene, and maleic anhydride-modified polyethylene.

  The thickness of the heat-fusible resin layer 13 is preferably set to 15 μm to 30 μm. When the thickness is 15 μm or more, sufficient heat seal strength can be ensured, and by setting the thickness to 30 μm or less, it contributes to reduction in thickness and weight. The heat fusible resin layer 13 is preferably formed of a heat fusible resin unstretched film layer, and the heat fusible resin unstretched film layer 13 may be a single layer, It may be a multilayer.

  The metal foil layer 14 plays a role of imparting gas barrier properties to the exterior material 1 to prevent oxygen and moisture from entering. The thickness of the metal foil layer 14 is preferably 5 μm or more and less than 30 μm. The thickness and weight can be reduced by setting this thickness range, and by adjusting the thickness of the vapor deposition layer 17, the moisture barrier property excellent as the whole exterior material 1 and the excellent electrolyte solution diffusion can be achieved. Preventability can be ensured. Among them, the thickness of the metal foil layer 14 is more preferably 5 μm or more and less than 20 μm, further preferably 5 μm to 18 μm, and particularly preferably 5 μm to 15 μm. Although it does not specifically limit as said metal foil, For example, aluminum foil, stainless steel foil, nickel foil, copper foil, titanium foil etc. are mentioned. Among them, it is preferable to use an aluminum foil from the viewpoint of weight reduction.

  The outer layer (heat-resistant resin layer) 12 and the inner layer (heat-fusing resin layer) 13 of the sheathing material 1 are layers made of resin, and these resin layers are in a very small amount, but from the outside of the case There is a possibility that light, oxygen and liquid may enter, and there is a possibility that the contents (battery electrolyte) may permeate from the inside. When these intruders reach the metal foil layer 14, they cause corrosion of the metal foil layer. In the present invention, it is preferable that a chemical conversion film is formed on at least the surface of the metal foil on the heat fusible resin layer 13 side. In this case, the corrosion resistance of the metal foil layer 14 can be improved. Among them, it is particularly preferable to adopt a configuration in which a chemical conversion film is formed on both sides of the metal foil, and in this case, the corrosion resistance of the metal foil layer 14 can be sufficiently improved.

The chemical conversion film is a film formed by subjecting the surface of a metal foil to a chemical conversion treatment, and can be formed, for example, by subjecting a metal foil to a chromate treatment or a non-chromic conversion treatment using a zirconium compound. For example, in the case of chromate treatment, an aqueous solution of any one of the following 1) to 3) is applied to the surface of the metal foil that has been degreased and then dried.
1) An aqueous solution of a mixture comprising phosphoric acid, chromic acid, and at least one compound selected from the group consisting of metal salts of fluorides and nonmetal salts of fluorides 2) phosphoric acid, acrylic resin, Aqueous solution of a mixture comprising at least one resin selected from the group consisting of chitosan derivative resins and phenolic resins, and at least one compound selected from the group consisting of chromic acid and chromium (III) salts 3) Phosphoric acid And 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 chromium (III) salts, and fluorides An aqueous solution of a mixture comprising at least one compound selected from the group consisting of a metal salt and a non-metal salt of fluoride.

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 15 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 15 is preferably set to 1 μm to 5 μm. Especially, it is especially preferable that the thickness of the said 1st adhesive bond layer 15 is set to 1 micrometer-3 micrometers from a viewpoint of thickness reduction of an exterior material and weight reduction.

  The second adhesive layer 16 is not particularly limited. For example, although one exemplified as the first adhesive layer 5 can be used, a polyolefin-based adhesive with less swelling by an electrolytic solution is used, for example. Is preferred. The thickness of the second adhesive layer 16 is preferably set to 1 μm to 5 μm. Especially, it is especially preferable that the thickness of the said 2nd adhesive bond layer 16 is set to 1 micrometer-3 micrometers from a viewpoint of thickness reduction of an exterior material and weight reduction.

  The method for bonding the metal foil layer 14 and the heat resistant resin layer 12 is not particularly limited, but a method called dry lamination can be recommended. Specifically, the prepared first adhesive 15 is applied to the upper surface of the metal foil layer 14 or the lower surface of the heat resistant resin film layer 12, or both of these surfaces, and the solvent is evaporated to form a dry film. The metal foil layer 14 and the heat resistant resin film layer 12 are pasted together. Thereafter, curing is performed according to the curing conditions of the first adhesive. Thereby, the metal foil layer 14 and the heat resistant resin layer 12 are joined via the first adhesive layer 15. Examples of the method for applying the first adhesive include a gravure coating method, a reverse roll coating method, and a lip roll coating method.

  The method of bonding the metal foil layer 14 and the heat-fusible resin film layer 13 is not particularly limited, but the second method is the same as bonding of the metal foil layer 14 and the heat-resistant resin film layer 12 described above. Examples thereof include a dry laminating method in which the metal foil layer 14 and the heat-fusible resin film layer 13 are bonded to each other after the adhesive 16 is applied and dried.

  Additives may be added to the heat-fusible resin layer 13 and the heat-resistant resin layer 12. Examples of such additives include, but are not limited to, antiblocking agents (silica, talc, kaolin, acrylic resin beads, etc.), lubricants (fatty acid amide, wax, etc.), antioxidants (hindered) And the like.

  The thickness of the packaging material 1 of the present invention is preferably set to 30 μm to 80 μm. By being 80 micrometers or less, the weight energy density and volume energy density of the electrical storage device 30 armored using this exterior material 1 can be improved. Among them, the thickness of the exterior material 1 is more preferably set to 30 μm to 65 μm.

  The exterior material 1 of the present invention is not particularly limited to the laminated structure shown in FIGS. 1 and 2, and further functions can be improved as an exterior material by adding layers. For example, in order to improve the physical durability (such as scratch prevention) of the outer surface of the exterior material, the surface (outer surface) of the heat resistant resin layer 12 may be subjected to surface treatment in the configuration shown in FIG.

  Moreover, in the said embodiment, although the structure which provided the 1st adhesive bond layer 15 and the 2nd adhesive bond layer 16 is employ | adopted, both these layers 15 and 16 are not essential structural layers, but these are not required. A configuration not provided can also be adopted.

  FIG. 3 shows an embodiment of a power storage device 30 of the present invention. The electricity storage device 30 is a lithium ion secondary battery, and includes a tube-type exterior body 32 and a flexible electricity storage device body portion (battery body portion) 31 housed in the tube-type exterior body 32. . The tube-type exterior body 32 has the electrical storage device exterior material 1 wound in a tube shape with the heat-fusible resin layer 13 inside, and one end portion 2 of both ends in the winding direction of the exterior material 1. The inner surface 2a of the other end portion 3 and the inner surface 3a of the other end portion 3 are overlapped, and the heat-fusible resin layer 13 of the inner surface 2a of the one end portion 2 and the heat-fusible resin layer 13 of the inner surface 3a of the other end portion 3 are overlapped. And are heat-sealed. The outer surface 2 b of the one end portion 2 is a heat resistant resin layer 12, and the outer surface 3 b of the other end portion 3 is a heat resistant resin layer 12. The cross-sectional shape of the tube type exterior body 32 is substantially circular. In the present embodiment, the storage device body 31 includes a positive electrode, a negative electrode, an electrolyte, and the like.

  The length and outer diameter of the tube-type exterior body 32 are not particularly limited, and are set corresponding to the size of the power storage device main body 31. For example, the outer diameter of the tube type exterior body 32 is set to 2 mm to 20 mm.

  In the electricity storage device 30, the end surface 2 c of the one end portion 2 and the end surface 3 c of the other end portion 3 in the winding direction of the exterior material 1 are both inside the tube-type exterior body 32 (on the electricity storage device main body portion 31 side). Since it is arranged outside the tube-type exterior body 32 without being arranged, there is no possibility that the end face exposed portions of the metal foil layer 14 exposed at the end faces 2c and 3c, the adhesives 15 and 16 and the like are affected by the electrolyte. Thereby, the useful life of the tube type exterior body 32 can be significantly extended.

  In the present invention, the power storage device body 31 is not particularly limited, and examples thereof include a capacitor body, a capacitor body, and the like in addition to the battery body.

  In the above embodiment, the cross-sectional shape of the tube type exterior body 32 is substantially circular, but it is not particularly limited to such a form, and the cross-sectional shape is, for example, an elliptical shape. It may be flat, it may be a flat circular shape, or may be a polygonal shape (eg, triangular shape, quadrangular shape, pentagonal shape, hexagonal shape, octagonal shape, etc.).

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

Example 1
Chemical conversion consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, alcohol on both sides of a 15 μm thick soft aluminum foil (A8079 soft aluminum alloy foil specified by JIS H4160) After apply | coating a process liquid, the aluminum foil which formed the chemical conversion film on both surfaces was prepared by drying at 150 degreeC. The amount of chromium deposited by this chemical film was 5 mg / m ^{2 on} one side.

  Next, a two-component curable polyester-urethane resin adhesive is applied to one surface of the aluminum foil 14 on which the chemical conversion film is formed on both surfaces, and dried to form a first adhesive layer 15. 1 Adhering to the surface of the adhesive layer 15 is a vapor-deposited surface of a biaxially stretched polyethylene terephthalate (PET) film 12 having a thickness of 12 μm in which an aluminum vapor-deposited layer 17 having a thickness of 500 mm (50 nm) is vapor-deposited on one side. At the same time, a two-component curable adhesive (a two-component curable adhesive mainly composed of acid-modified polypropylene and hexamethylene diisocyanate as a curing agent) is applied to the other surface of the aluminum foil 14 and dried to form a second adhesive. An unstretched polypropylene film 13 having a thickness of 20 μm was bonded to the surface of the second adhesive layer 16 as an agent layer 16. The laminated body was allowed to stand for 3 days in an environment of 40 ° C. (curing was performed), thereby obtaining an electricity storage device exterior material 1 shown in FIG.

Example 2
An exterior material for a storage battery device shown in FIG. 1 was obtained in the same manner as in Example 1 except that a 25 μm thick biaxially drawn polyethylene terephthalate film was used instead of the 12 μm thick biaxially drawn polyethylene terephthalate film. .

Example 3
An exterior material 1 for a storage battery device shown in FIG. 1 was obtained in the same manner as in Example 1 except that a biaxially stretched polyethylene film of 15 μm in thickness was used instead of the biaxially stretched polyethylene terephthalate film of 12 μm in thickness. .

Example 4
An exterior material 1 for a storage battery device shown in FIG. 1 was obtained in the same manner as in Example 1 except that a 25 μm thick biaxially stretched nylon film was used instead of the 12 μm thick biaxially stretched polyethylene terephthalate film. .

Example 5
Chemical conversion consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, alcohol on both sides of a 15 μm thick soft aluminum foil (A8079 soft aluminum alloy foil specified by JIS H4160) After apply | coating a process liquid, the aluminum foil which formed the chemical conversion film on both surfaces was prepared by drying at 150 degreeC. The amount of chromium deposited by this chemical film was 5 mg / m ^{2 on} one side.

  Next, a two-component curable polyester-urethane resin adhesive is applied to one surface of the aluminum foil 14 on which the chemical conversion film is formed on both surfaces, and dried to form a first adhesive layer 15. A biaxially stretched polyethylene terephthalate film 12 having a thickness of 12 μm is bonded to the surface of one adhesive layer 15, and a two-component curable adhesive (acid-modified polypropylene is used as a main component and hexamethylene is formed on the other surface of the aluminum foil 14. A two-component curable adhesive having a diisocyanate as a curing agent is applied and dried to form a second adhesive layer 16, and an aluminum vapor deposition with a thickness of 500 mm (50 nm) on one surface is formed on the surface of the second adhesive layer 16. The vapor-deposited surface of an unstretched polypropylene film 13 having a thickness of 20 μm on which the layer 17 was vapor-deposited by a vacuum vapor deposition method was bonded. The laminated body was allowed to stand for 3 days in an environment of 40 ° C. (curing was performed), thereby obtaining an electricity storage device exterior material 1 shown in FIG.

Example 6
The exterior material 1 for a storage battery device shown in FIG. 2 was obtained in the same manner as in Example 5 except that a biaxially stretched nylon film of 15 μm in thickness was used instead of the biaxially stretched polyethylene terephthalate film of 12 μm in thickness. .

Example 7
1 was obtained in the same manner as in Example 1 except that the aluminum vapor deposition layer having a thickness of 500 mm was replaced with the aluminum vapor deposition layer having a thickness of 200 mm.

Example 8
1 was obtained in the same manner as in Example 3 except that the aluminum vapor deposition layer having a thickness of 500 mm was replaced with the aluminum vapor deposition layer having a thickness of 200 mm.

Example 9
1 was obtained in the same manner as in Example 1 except that the aluminum vapor deposition layer having a thickness of 500 mm was replaced with the alumina vapor deposition layer having a thickness of 500 mm.

Example 10
A power storage device exterior material 1 shown in FIG. 1 was obtained in the same manner as in Example 1 except that the 500-mm-thick aluminum vapor deposition layer was replaced with a 500-mm-thick magnesium fluoride vapor-deposition layer.

Comparative Example 1
A 12 μm thick biaxially stretched polyethylene terephthalate film (without a vapor deposited layer) is used in place of a 12 μm thick biaxially stretched polyethylene terephthalate film on which an aluminum deposited layer with a thickness of 500 Å is vapor deposited by vacuum deposition on one side. Except that, an exterior material for an electricity storage device was obtained in the same manner as in Example 1.

Comparative Example 2
A 25 μm thick biaxially stretched polyethylene terephthalate film (without a vapor deposited layer) is used in place of a 25 μm thick biaxially stretched polyethylene terephthalate film on which an aluminum vapor deposited layer of 500 Å thick is deposited by vacuum deposition on one side. Except that, an exterior material for an electricity storage device was obtained in the same manner as in Example 2.

Comparative Example 3
A 15 μm thick biaxially stretched nylon film was used instead of a 15 μm thick biaxially stretched nylon film on which an aluminum vapor deposited layer with a thickness of 500 Å was vapor deposited by vacuum deposition on one side, except for using a 15 μm thick biaxially stretched nylon film In the same manner as in Example 3, an exterior material for a storage battery device was obtained.

Comparative Example 4
A 25 μm thick biaxially stretched nylon film (with no vapor deposited layer) was used in place of the 25 μm thick biaxially stretched nylon film on which an aluminum vapor deposited layer with a thickness of 500 Å was vapor deposited by vacuum deposition on one side. These were obtained in the same manner as in Example 4 to obtain an exterior material for a storage battery device.

Comparative Example 5
A 15 μm thick biaxially stretched nylon film is used instead of a 15 μm thick biaxially stretched nylon film on which a 500 Å thick aluminum deposited layer is deposited by vacuum deposition on one side, using a 15 μm thick biaxial stretched nylon film An exterior device for an electricity storage device was obtained in the same manner as in Example 3 except that the thickness of the foil was changed to 30 μm.

  The external storage materials for power storage devices obtained as described above were evaluated based on the following evaluation methods.

<Prick strength evaluation method>
According to JIS H1707 (1997) "General plastic film for food packaging", fix the test piece and test a semicircular needle with a diameter of 1.0 mm and a tip shape radius of 0.5 mm at a speed of 50 mm / min at room temperature The pieces were pierced and the maximum stress until the needle penetrated was measured. The puncture strength (N / 15 mm) shown in Table 2 is an average value of the measured values of the five test pieces.

<Areal density measurement method>
The exterior material is punched into a square shape (100 cm ² ) of 10 cm in length and 10 cm in width, and its mass M (g) is measured.
D = M × 10000 ÷ 100
The area density D (g / m ² ) was determined by the above equation. The results are shown in Table 1.

<Evaluation test method of moisture barrier property>
A battery (simulated battery) was prepared as described below using each of the power storage device exterior materials obtained as described above.

  A 30 mm thick soft aluminum foil, a 100 μm thick polypropylene film, and a 30 μm thick soft copper foil are layered to create a simulated electrode. Obtained a part (simulated product) 31.

  Thus, as shown in FIG. 3, in a mode of covering the outer peripheral surface of the cable-like power storage device main body portion 31, the heat storage adhesive resin layer (inner layer) 13 is turned inward so as to form a tube shape. The inner surface 2a of one end 2 and the inner surface 3a of the other end 3 of both ends in the winding direction of the exterior material 1 are overlapped with each other, and a metal hot plate heated to 200 ° C. is placed on the overlapped portion. By applying a pressure of 0.3 MPa for 3 seconds, the heat-sealing resin layer 13 on the inner surface 2a of the one end portion 2 and the heat-sealing resin layer 13 on the inner surface 3a of the other end portion 3 are partially heat-sealed. After heat sealing (after heat sealing), it was left in a dry room with a dew point of -60.degree. C. for 24 hours.

Next, in a dry room with a dew point of −60 ° C., an electrolyte (ethylene carbonate: dimethylene carbonate: dimethyl carbonate) using a syringe through the unjoined open portion (part of the heat seal assembly) in the heat seal assembly. After pouring and dropping 10 mL of LiPF ₆ electrolyte solution obtained by adding LiPF ₆ to a mixed carbonate in which carbonate was mixed at a volume ratio of 1: 1: 1 into 1: 0. Heat sealing (heat seal bonding) is performed by applying a metal heat plate heated to 200 ° C. at a pressure of 0.3 MPa for 3 seconds to the unjoined open portion of the heat seal assembly under a reduced pressure of 086 MPa. Thus, the sealing was completed, and the battery (simulated battery) 30 shown in FIG. 3 was obtained.

  The water barrier properties of the battery (simulated battery) obtained as described above were evaluated on the basis of the following evaluation test method by measuring the amount of water in the electrolyte solution inside the simulated battery. That is, for each example and each comparative example, three samples (simulated batteries) were prepared and placed in a constant temperature and humidity chamber at 60 ° C. and a humidity of 90%. Take out 1 piece after 2 weeks, take out 1 piece after 3 weeks, and take 1 mL of the electrolyte inside the battery using a syringe for each, and use a Karl Fischer moisture meter ("AQ2250" manufactured by Hiranuma Sangyo Co., Ltd.) The amount of water in the electrolyte was measured using this. The results are shown in Table 2.

  First, as apparent from Table 1, the external packaging materials of Examples 1 to 10 of the present invention have a smaller surface density as compared with Comparative Example 5 in which aluminum foil having a thickness of 30 μm is used. While being able to attain weight reduction, the piercing strength was also obtained sufficiently.

  In the results in Table 2, the water content after one week has clearly increased compared to the water content in the initial stage (before the start of the test). It is considered that water contained in a trace amount in the polypropylene film of the above was eluted in the electrolytic solution. From the comparison with the results of Comparative Examples 1 to 4 (water content after 1, 2, 3 weeks), in the simulated battery constructed using the exterior material of Examples 1 to 10, it is extreme (substantial) No increase in moisture was observed, and the excellent effect of the moisture barrier by the packaging material of the present invention could be confirmed.

  As described above, the power storage device exterior materials of Examples 1 to 10 according to the present invention can ensure high barrier properties while being reduced in weight. From the comparison between Example 2 and Example 4, it can be seen that the configuration using nylon as the outer layer provides higher puncture strength than the configuration using PET (polyethylene terephthalate) as the outer layer.

  The exterior material for an electricity storage device according to the present invention is suitably used as an exterior material for an electricity storage device having flexibility (for example, a lithium ion secondary battery, an electric double layer capacitor, etc.), but is particularly limited to these exemplified applications. It is not something to be done. Since the storage device according to the present invention has flexibility, it is suitably used as a cable-type storage device (for example, a lithium ion secondary battery, an electric double layer capacitor, etc.), but is particularly limited to these exemplified applications It is not a thing.

DESCRIPTION OF SYMBOLS 1 ... Exterior material 2 for electrical storage devices ... One end part 2a ... Inner surface 3 ... Other end part 3a ... Inner surface 12 ... Heat-resistant resin layer (outer layer)
13: Heat fusible resin layer (inner layer)
DESCRIPTION OF SYMBOLS 14 ... Metal foil layer 17 ... Evaporation layer 30 ... Electric storage device 31 ... Electric storage device main-body part 32 ... Tube type exterior body for electric storage devices

Claims (6)

An exterior material for an electricity storage device that forms a tube-shaped exterior body having flexibility by winding in a tube shape,
The exterior material includes a heat-resistant resin layer as an outer layer, a heat-fusible resin layer as an inner layer, and a metal foil layer disposed between both layers,
A deposited layer is disposed between the heat-resistant resin layer and the metal foil layer, or / and between the heat-fusion resin layer and the metal foil layer. .   The said vapor deposition layer is an exterior | packing material for electrical storage devices of Claim 1 arrange | positioned between the said heat resistant resin layer and the said metal foil layer.   The power storage device exterior material according to claim 1 or 2, wherein the vapor deposition layer is formed by vapor-depositing at least one vapor deposition material selected from the group consisting of metal, metal oxide, and fluoride.   The thickness of the said metal foil layer is 5 micrometers or more-less than 30 micrometers, The exterior material for electrical storage devices of any one of Claims 1-3.   The exterior material according to any one of claims 1 to 4, wherein the exterior material according to any one of claims 1 to 4 is wound in a tube shape with the heat-fusible resin layer inside, and an inner surface of one end of both ends in the winding direction of the exterior material. And an inner surface of the other end portion are overlapped, and the inner surface of the one end portion and the inner surface of the other end portion are heat-sealed.   An electricity storage device comprising: the tube type exterior body according to claim 5; and an electricity storage device main body having flexibility which is accommodated in the tube type exterior body.

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