JP6550285B2 - Exterior material for storage device and storage device - Google Patents

Description

  The present invention relates to an external packaging material for a storage battery device having flexibility, a tube type outer package for a storage battery device, and a storage battery device.

  In recent years, along with the reduction in thickness and weight of mobile electric devices such as smartphones and tablet terminals, storage devices such as lithium ion secondary batteries, lithium polymer secondary batteries, lithium ion capacitors, electric double layer capacitors and the like mounted thereon 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

  As the above-mentioned cable battery, being flexible and lightweight is called for, and for this reason, a thinner thing is called for also as an exterior material.

  However, the sheath material for a cable battery described in Patent Document 2 is provided with a sealant resin layer on both sides of the barrier layer, and 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 thickness of the sealant resin layer is increased in order to eliminate the decrease in seal bonding strength, there is a problem that the weight reduction of the exterior material can not be achieved.

  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] A packaging material for an electricity storage device, which is wound in a tube shape to form a flexible tube type packaging body,
The exterior material includes a heat-resistant resin layer as an outer layer, a heat-fusion resin layer as an inner layer, and a metal foil layer disposed between the two layers.
A metal plated layer is disposed between the heat-resistant resin layer and the metal foil layer, or / and between the heat-fusible resin layer and the metal foil layer. Material.

  [2] The packaging material for a storage battery device according to the above 1, wherein the metal plating layer is a plating layer composed of at least one metal material selected from the group consisting of nickel, zinc, tin, chromium and cobalt.

  [3] The packaging material for a storage battery device according to the above 1 or 2, wherein the thickness of the metal foil layer is 5 μm or more and 25 μm or less.

  [4] The sheathing material according to any one of the preceding items 1 to 3 is wound in a tube shape with the heat fusible resin layer inside, and one end of both ends in the winding direction of the sheathing material A tube type exterior body for an electricity storage device, wherein the inner surface of the other end and the inner surface of the other end are overlapped and the inner surface of the one end and the inner surface of the other end are heat-sealed.

  [5] An electricity storage device comprising: the tube type exterior body described in the preceding paragraph 4; and an electricity storage device main body having flexibility which is accommodated in the tube type exterior body.

  In the invention of [1], since the metal plating layer is disposed between the heat resistant resin layer and the metal foil layer, and / or between the heat sealable resin layer and the metal foil layer, the metal foil is Even if pinholes exist in the metal foil layer by thinning the film, it is possible to suppress the penetration of moisture from the outside by the metal plating layer, and also to suppress the diffusion and leakage of the electrolyte to the outside. Thus, the above effects can be achieved by the presence of the metal plating layer, so even if the thickness of the metal foil layer is designed to be thin (for example, 5 μm or more and 25 μm or less) by that amount, the exterior material can be used from the outside 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 secure 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. Furthermore, since the metal plating layer is laminated, the puncture resistance of the exterior material can be further improved.

  In the invention of [2], since the metal plating layer is made of the above-described specific metal, it is possible to secure more excellent moisture barrier properties and more excellent electrolyte solution diffusion preventing properties, and further the puncture strength as the exterior material. It can be improved.

  In the invention of [3], the thickness of the metal foil layer is 5 μm or more and 25 μm or less. Therefore, while securing excellent moisture barrier properties and excellent electrolytic solution diffusion preventing properties, the outer packaging material is further thinned and lightened. Can be

  According to the invention [4], a tube type exterior body for an electricity storage device is provided in which an excellent moisture barrier property and an excellent electrolyte solution diffusion preventing property are secured while achieving sufficient thinning and weight reduction.

  In the invention of [5], 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 fusible 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 metal plated layer 17 is disposed between the heat resistant resin layer 12 and the metal foil layer 14 (see FIG. 1), and the heat fusible resin layer 13 and the metal foil layer 14 are formed. A configuration in which a metal plating layer 17 is disposed (see FIG. 2), or a metal plating layer 17 is disposed between the heat resistant resin layer 12 and the metal foil layer 14 and the heat fusible resin layer Either of the configuration in which the metal plating layer 17 is disposed also between the element 13 and the metal foil layer 14 is employed.

  In the embodiment shown in FIG. 1, the metal plating layer 17 is formed on one surface of the metal foil layer 14 in the storage material for an electricity storage device 1, and the first adhesive layer 15 is formed on the surface of the metal plating layer 17. The heat resistant resin layer (outer layer) 12 is laminated and integrated, and the thermoplastic resin layer (inner layer) 13 is integrally laminated on the other surface of the metal foil layer 14 via the second adhesive layer 16. It consists of

  Further, in the embodiment shown in FIG. 2, the metal plating layer 17 is formed on one surface of the metal foil layer 14 in the electric storage device packaging material 1, and the second adhesive layer 16 is formed on the surface of the metal plating layer 17. The thermoplastic resin layer (inner layer) 13 is integrally laminated via the other, and the heat resistant resin layer (outer layer) 12 is integrally laminated on the other surface of the metal foil layer 14 via the first adhesive layer 15 It consists of a standardized structure.

  Although the metal plating layer 17 is provided only on one side of the metal foil layer 14 in the embodiment shown in FIGS. 1 and 2, the present invention is not particularly limited to such a configuration. You may employ | adopt the structure in which the metal plating layers 17 and 17 were provided.

  In the packaging material 1 for an electric storage device, the metal plating 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”. With this configuration, even if pinholes exist in the metal foil layer 14 by thinning the metal foil, the metal plating layer 17 can suppress the entry of moisture from the outside and the outside of the electrolytic solution. It is also possible to control the diffusion and leakage. Thus, the above effects can be achieved by the presence of the metal plating layer 17, and accordingly, even if the thickness of the metal foil layer is designed thin (for example, 5 μm or more and 25 μm or less) to reduce the weight, the exterior as the exterior material At the same time, it is possible to suppress the infiltration of water from the solution and also prevent the diffusion of the electrolyte. Therefore, according to the present invention, it is possible to secure 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 occur in the metal foil, while metal plating Although it can not be denied that the layer 17 may be partially peeled off due to stress change or the like, the configuration shown in FIGS. 1 and 2 (a configuration in which the double barrier of the metal foil layer 14 and one metal plating layer 17 is provided) In the above, it can be said that there is virtually 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 metal plating layer 17 overlap. It is possible to secure the properties and the excellent electrolyte solution diffusion preventing property.

  In the above embodiment, the metal plating layer 17 is formed on at least one surface of the metal foil layer 14, and even if pinholes are present in the metal foil layer 14 due to thinning of the metal foil, It is considered that the end opening in the depth direction (the thickness direction of the metal foil) of the pinhole is substantially closed by the metal plating layer 17. In addition, the plated portion of the metal plating layer 17 may penetrate to the inside of the pin hole in the metal foil layer 14 (a region where the hole further penetrates from the end opening of the pin hole) and may be substantially closed or closed. It is considered to be a thing.

  In the present invention, the heat resistant resin layer (outer layer) 12 is a member mainly playing a role as a protective layer, and as a heat resistant resin constituting the heat resistant resin layer (heat resistant resin film layer etc.) 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.

  The heat-resistant resin layer 12 is not particularly limited. For example, a stretched polyamide film (stretched nylon film or the like) or a stretched polyester film is preferably used. 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. The nylon is not particularly limited, and examples thereof include 6 nylon, 6, 6 nylon, and MXD nylon. The heat-resistant resin layer 12 may be formed as a single layer (single stretched film), or, for example, a multilayer composed of a stretched polyester film / stretched polyamide film (biaxially stretched PET film / two 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. In the case of using a biaxially stretched polyamide film as the heat resistant resin layer 12, the thickness is more preferably 15 μm to 25 μm.

  The metal constituting the metal plating layer 17 is not particularly limited, and examples thereof include nickel, zinc, tin, chromium, cobalt, gold, silver, platinum and the like. Among them, the metal plating layer 17 is preferably a plating layer composed of at least one metal material selected from the group consisting of nickel, zinc, tin, chromium and cobalt, and at least one of these specific metal materials is preferably used. In the case of being constituted by a species, it is possible to ensure a further excellent moisture barrier property and a further excellent electrolytic solution diffusion preventing property, and further improve the piercing strength as the exterior material 1.

  The thickness of the metal plating layer 17 (the thickness of the plating layer formed on one side when the plating layer is formed on both sides) is preferably set to 0.5 μm to 5 μm. If the thickness of the metal foil layer 4 is less than 30 μm, pinholes may occur in the metal foil, but by adjusting the thickness of the metal plating layer 17 by adjusting the thickness of the metal foil according to the thickness of the metal foil. As a whole, the exterior material 1 can have excellent moisture barrier properties and excellent electrolyte solution diffusion preventing properties. Among them, the thickness of the metal plating layer 17 (the thickness of the plating layer formed on one side when the plating layer is formed on both sides) is sufficient to reduce the thickness of the pinholes of the metal foil layer 14 It is more preferable to set to 0.5 micrometer-2 micrometers from a viewpoint of blocking, and it is especially preferable to set to 0.5 micrometer-1 micrometer. In addition, when nickel is used as a metal which comprises the metal plating layer 17, there exists an advantage which can improve piercing strength more compared with the case where other metals are used.

  The method of metal plating is not particularly limited, and examples thereof include an electroless plating method, an electroplating method, a vacuum plating method and the like. Among them, the metal plating layer 17 is preferably formed by an electroless plating method. The metal plating layer formed by the electroless plating method has a more uniform and uniform plating layer than the one formed by the electroplating method, and has excellent moisture barrier properties and excellent electrolyte solution diffusion preventing properties. In particular, when the metal foil layer 14 is an aluminum foil layer, the metal plating layer (metal plating layer formed by the electroless plating method) 17 has high adhesion to the aluminum foil layer 14. Play an advantageous effect.

  The metal plating layer 17 is preferably disposed between the heat resistant resin layer 12 and the metal foil layer 14. In this case, the metal plating layer 17 is more preferably formed by plating a metal material on the outer surface (surface on the heat resistant resin layer 12 side) of the metal foil layer 14. Of course, the metal plating layer 17 may be formed by plating the inner surface of the heat-resistant resin layer (outer layer) 12 with a metal material.

  The metal plating layer 17 may be disposed between the heat-fusible resin layer 13 and the metal foil layer 14. In this case, the metal plating layer 17 is preferably formed by plating a metal material on the inner surface of the metal foil layer 14 (the surface on the side of the heat fusible resin layer 13). Of course, the metal plating layer 17 may be formed by plating a metal material on the inner surface of the heat fusible resin layer (inner layer) 13.

  The heat-sealable resin layer (inner layer) 13 has excellent chemical resistance to highly corrosive electrolytes used in lithium ion secondary batteries etc. Play a role in granting

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

  The thickness of the heat-fusible resin layer 13 is preferably set to 15 μm to 30 μm. While sufficient heat seal strength can be secured by setting it as 15 micrometers or more, it contributes to thin film formation and weight reduction by setting to 30 micrometers or less. 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 the role of providing the exterior material 1 with a gas barrier property that prevents the entry of oxygen and moisture. 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 metal plating layer 17, the moisture barrier property excellent as the whole exterior material 1 and the excellent electrolytic solution are obtained. Diffusion prevention 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. The metal foil is not particularly limited, and examples thereof include aluminum foil, stainless steel foil, nickel foil, copper foil, titanium foil and the like. 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 risk that light, oxygen and liquid may enter, and the contents (battery electrolyte) may penetrate 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 a mixture of any of the following 1) to 3) is coated on the surface of the metal foil subjected to the degreasing treatment, 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 metal salts and nonmetal salts of fluorides.

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. Among them, the thickness of the first adhesive layer 15 is particularly preferably set to 1 μm to 3 μm from the viewpoint of reducing the thickness and weight of the packaging material.

  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. Among them, the thickness of the second adhesive layer 16 is particularly preferably set to 1 μm to 3 μm from the viewpoint of reducing the thickness and weight of the packaging material.

  The method of 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. In addition, as a coating method of a 1st adhesive agent, a gravure coat method, a reverse roll coat method, a lip roll coat method etc. can be illustrated.

  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. The dry lamination method etc. which bond the metal foil layer 14 and the heat-fusible resin film layer 13 after apply | coating and drying the adhesive agent 16 can be illustrated.

  Additives may be added to the heat-fusible resin layer 13 and the heat-resistant resin layer 12. Such additives are not particularly limited. For example, antiblocking agents (silica, talc, kaolin, acrylic resin beads, etc.), lubricants (fatty acid amides, waxes, 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 gravimetric energy density and volumetric 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 packaging material 1 of the present invention is not particularly limited to the laminated structure shown in FIGS. 1 and 2, and a layer can be further added to improve the function as the packaging material. 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 power storage device 30 is a lithium ion secondary battery, and includes a tube type exterior body 32 and a flexible power storage device main body portion (battery main body portion) 31 accommodated in the tube type exterior body 32. . The tube type exterior body 32 is wound in a tube shape with the heat fusible resin layer 13 inside, and the end portion 2 of both ends of the exterior material 1 in the winding direction. 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 stacked on each other. 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 the outer diameter of the tube type exterior body 32 are not particularly limited, and are set corresponding to the size of the storage device 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 face 2c of the one end 2 and the end face 3c of the other end 3 of the wrapping material 1 in the winding direction are both inside the tube type exterior body 32 (the electricity storage device body 31 side). Since it is disposed outside the tube type exterior body 32 without being disposed, there is no possibility that the end face exposed portion of the metal foil layer 14 exposed at the end faces 2c, 3c, the adhesive 15, 16 etc. Thereby, the useful life of the tube type exterior body 32 can be significantly extended.

  In the present invention, the 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
By performing electroless nickel plating (Kanigen plating) on a soft aluminum foil (soft aluminum alloy foil of A8079 specified by JIS H4160) having a thickness of 15 μm, one surface of the aluminum foil 14 (the surface on the outer layer forming side) 1) was formed to obtain a single-sided plated aluminum foil.

Next, a chemical conversion treatment solution consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water and alcohol is applied to both sides of the single-sided plated aluminum foil, and then dried at 150 ° C. Thus, a single-sided plated aluminum foil having a chemical conversion film formed on both sides was prepared. The chromium deposition amount by this chemical conversion 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 single-sided nickel-plated aluminum foil 14 (conversion film on the surface of the plating layer 17) having a chemical conversion film (not shown) formed on both surfaces. And dried to form a first adhesive layer 15, and a 12 .mu.m thick biaxially stretched polyethylene terephthalate (PET) film 12 is bonded to the surface of the first adhesive layer 15, and the aluminum foil 14 is formed. The other surface is coated with a two-component curable adhesive (a two-component curable adhesive containing acid-modified polypropylene as a main component and hexamethylene diisocyanate as a curing agent) and dried to form a second adhesive layer 16; The unstretched polypropylene film 13 having a thickness of 20 μm was attached to the surface of the adhesive layer 16. The laminate was allowed to stand in an environment of 40 ° C. for 3 days (to undergo curing) to obtain an exterior material 1 for a storage battery device 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
Example 3 and Example 3 except that a zinc-plated layer having a thickness of 3 μm is formed on one surface of the aluminum foil 14 (the surface on the outer layer formation side) instead of forming a nickel-plated layer having a thickness of 1 μm. Similarly, a packaging material 1 for a storage battery device shown in FIG. 1 was obtained.

Example 6
Example 3 is the same as Example 3 except that instead of forming a 1 μm thick nickel plating layer on one surface of the aluminum foil 14 (the side on the outer layer forming side), a 4 μm thick tin plating layer is formed. Similarly, a packaging material 1 for a storage battery device shown in FIG. 1 was obtained.

Example 7
Instead of forming a nickel plating layer with a thickness of 1 μm on one surface of the aluminum foil 14 (surface on the outer layer forming side), a chromium plating layer with a thickness of 0.5 μm is formed instead of the embodiment. In the same manner as in No. 3, the exterior material 1 for a storage battery device shown in FIG. 1 was obtained.

Example 8
A cobalt plated layer having a thickness of 1 μm is formed in place of forming a nickel plated layer having a thickness of 1 μm on one surface of the aluminum foil 14 (the surface on the outer layer forming side). Similarly, a packaging material 1 for a storage battery device shown in FIG. 1 was obtained.

Example 9
By performing electroless nickel plating (Kanigen plating) on a soft aluminum foil (soft aluminum alloy foil of A8079 specified by JIS H4160) having a thickness of 15 μm, one surface of the aluminum foil 14 (the surface on the inner layer formation side) 1) was formed to obtain a single-sided plated aluminum foil.

Next, a chemical conversion treatment solution consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water and alcohol is applied to both sides of the single-sided plated aluminum foil, and then dried at 150 ° C. Thus, a single-sided plated aluminum foil having a chemical conversion film formed on both sides was prepared. The chromium deposition amount by this chemical conversion film was 5 mg / m ^{2 on} one side.

  Next, a two-component curable polyester-urethane resin adhesive is applied to the other surface of the single-sided nickel-plated aluminum foil 14 having the chemical conversion film (not shown) formed on both surfaces, and dried to form a first adhesive layer. 15 is formed, and a biaxially stretched nylon film 12 with a thickness of 15 .mu.m is attached to the surface of the first adhesive layer 15, and on one surface of the aluminum foil 14 (conversion film on the surface of the plating layer 17). A two-part curing adhesive (a two-part curing adhesive containing acid-modified polypropylene as a main component and hexamethylene diisocyanate as a curing agent) is applied and dried to form a second adhesive layer 16, the second adhesive layer The unstretched polypropylene film 13 with a thickness of 20 μm was attached to the surface of the 16th. The laminate was allowed to stand for 3 days in an environment of 40 ° C. (curing) to obtain an exterior material 1 for a storage battery device shown in FIG.

Comparative Example 1
The exterior of the electricity storage device is the same as in Example 1 except that a 15 μm thick aluminum foil (without a plated layer) is used instead of the 15 μm thick aluminum foil having a nickel plated layer formed on one side. I got the material.

Comparative Example 2
The exterior of the electricity storage device is the same as in Example 2 except that a 15 μm thick aluminum foil (without a plated layer) is used instead of the 15 μm thick aluminum foil having a nickel plated layer formed on one side. I got the material.

Comparative Example 3
The exterior of the electricity storage device is the same as in Example 3, except that a 15 μm thick aluminum foil (without a plated layer) is used instead of the 15 μm thick aluminum foil having a nickel plated layer formed on one side. I got the material.

Comparative Example 4
The exterior of the electricity storage device was prepared in the same manner as in Example 4, except that the 15 μm thick aluminum foil having a nickel plating layer formed on one side was used instead of the 15 μm thick aluminum foil (without the plating layer). I got the material.

Comparative Example 5
The exterior of the electricity storage device is the same as in Example 3, except that a 30 μm thick aluminum foil (without a plated layer) is used instead of the 15 μm thick aluminum foil having a nickel plated layer formed on one side. I got the material.

  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 1 is an average value of measured values of five test pieces.

<Areal density measurement method>
The exterior material is punched into a square shape (100 cm ² ) of 10 cm long × 10 cm wide, 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>
The battery (simulated battery) was created as follows using each exterior material for electrical storage devices obtained as mentioned above.

  A soft aluminum foil with a thickness of 30 μm, a polypropylene film with a thickness of 100 μm, and a soft copper foil with a thickness of 30 μm are stacked in layers to form a simulated electrode, and 10 sheets of this simulated electrode are stacked to form a cable-like storage device. 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. Of the two end portions of the wrapping material 1 in the winding direction, the inner surface 2a of one end 2 and the inner surface 3a of the other end 3 are superposed, and the metal heating plate heated to 200 ° C. The heat-fusion resin layer 13 of the inner surface 2a of the one end portion 2 and the heat-fusion resin layer 13 of the inner surface 3a of the other end portion 3 are thermally fused by applying for 3 seconds at a pressure of 0.3 MPa. 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. The sealing was completed to obtain a battery (simulated battery) 30 shown in FIG.

  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, after preparing three samples (simulated batteries) for each example and each comparative example and arranging three samples each in a constant temperature and humidity chamber at 60 ° C. and a humidity of 90%, one sample is taken after one week. Take 2 pieces, take out 1 piece after 2 weeks, take out 1 piece after 3 weeks, take out 1 mL of the electrolyte inside the battery using a syringe for each, and use 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 packaging materials of Examples 1 to 9 of the present invention have a smaller surface density as compared with Comparative Example 5 in which the 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 (the amounts of water after 1, 2 and 3 weeks), in the simulated battery constructed using the exterior material of Examples 1 to 9, the 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 exterior material for a storage battery device of Examples 1 to 9 according to the present invention can ensure high barrier properties while achieving weight reduction. 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 packaging material for a storage battery device according to the present invention is suitably used as a packaging material for a storage battery device having flexibility (for example, a lithium ion secondary battery, an electric double layer capacitor, etc.), but is particularly limited to the illustrated 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 ... Outer cover material 2 for electrical storage devices ... One end part 2a ... Inner surface 3 ... Other end part 3a ... Inner surface 12 ... Heat resistant resin layer (outside layer)
13: Heat fusible resin layer (inner layer)
14 ... metal foil layer 17 ... metal plating layer 30 ... electricity storage device 31 ... electricity storage device main part 32 ... tube type exterior body for electricity storage device

Claims (5)

A packaging material for an electricity storage device, wherein the packaging material is wound in a tube shape to form a flexible tube type packaging body,
The exterior material includes a heat-resistant resin layer as an outer layer, a heat-fusion resin layer as an inner layer, and a metal foil layer disposed between the two layers.
A metal plated layer is disposed between the heat-resistant resin layer and the metal foil layer, or / and between the heat-fusible resin layer and the metal foil layer. Material.   The packaging material for a storage battery device according to claim 1, wherein the metal plating layer is a plating layer composed of at least one metal material selected from the group consisting of nickel, zinc, tin, chromium and cobalt.   The exterior material for a storage battery device according to claim 1, wherein a thickness of the metal foil layer is 5 μm or more and 25 μm or less.   The armoring material according to any one of claims 1 to 3 is wound in a tube shape with the heat fusible resin layer inside, and the inner surface of one end of the both ends in the winding direction of the armoring 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 4; and an electricity storage device main body having flexibility which is accommodated in the tube type exterior body.

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