JP2018085295A - Exterior material for power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exterior material for a power storage device having excellent slipperiness on an outer layer side while retaining the electrolyte solution resistance of a base material layer.SOLUTION: An exterior material 1 for a power storage device comprises at least a base material layer 13, a metal foil layer 11, a sealant adhesive layer 15 and a sealant layer 16 in this order. In the exterior material 1 for a power storage device, the base material layer 13 includes a lubricant of 7.5-10.5 in SP value (Solubility Parameter). The lubricant is a reactive lubricant, which a silicone-based lubricant having one or more kinds of reactive groups selected from a hydroxyl group, a glycidyl group, a carboxyl group, an amino group, an acryloyl group, a vinyl group and an allyl group.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exterior material for an electricity storage device.

  As a battery exterior material for mobile devices such as smart phones that are made thinner, for example, a laminated film including an epoxy resin layer, a metal foil layer, and a heat-adhesive resin layer in this order has been proposed (for example, see Patent Document 1). .

JP 2001-176465 A

  In the technique of Patent Document 1, an epoxy coating layer is formed on the barrier layer as a base material layer in order to reduce the thickness of the exterior material. On the other hand, in order to improve molding processability, A lubricant is applied to the surface of the resin layer (the layer in contact with the battery contents). However, it has been found that the required amount of molding processing cannot be obtained only by imparting slipperiness to the inner layer.

  Therefore, when a lubricant is added to the coating liquid for forming the base material layer in order to impart slipping property to the base material layer on the outer layer side, the base material layer may be altered when the electrolytic solution adheres. I found out. After completion as an electricity storage device (for example, a battery), there is generally no opportunity for the electrolyte solution to come into contact with the base material layer, but there is a possibility that the base material layer and the electrolyte solution come into contact in the process of manufacturing the electricity storage device. The exterior material in which the base material layer is altered by such contact is treated as a defective product.

  This invention is made | formed in view of the said situation, and it aims at providing the exterior material for electrical storage devices which has the outstanding slidability on the outer layer side, maintaining the electrolyte solution tolerance of a base material layer.

  An exterior material for an electricity storage device, comprising at least a base material layer, a metal foil layer, a sealant adhesive layer, and a sealant layer in this order, wherein the base material layer contains a lubricant having an SP value of 7.5 or less or 10.5 or more. provide.

  If it is the exterior material of this invention, while being able to maintain the electrolyte solution tolerance of a base material layer, the outstanding sliding property can be provided to the base material layer surface used as an outer layer side.

  In the present invention, the lubricant is preferably a reactive lubricant. Thereby, while being able to provide the outstanding slipperiness to the base-material layer surface, it becomes easy to maintain electrolyte solution tolerance.

  In the present invention, the reactive lubricant is a silicone-based lubricant having at least one reactive group selected from the group consisting of a hydroxyl group, a glycidyl group, a carboxyl group, an amino group, an acryloyl group, a vinyl group, and an allyl group. Is preferred. Thereby, the slipperiness which was excellent in the base-material layer surface can be provided, and it becomes easy to maintain electrolyte solution tolerance.

  In the present invention, the lubricant is preferably composed of a polymer compound having a weight average molecular weight of 2000 or more. Thereby, it becomes easy to improve electrolyte solution tolerance.

  In this invention, it is preferable that a base material layer consists of at least 1 sort (s) selected from the group which consists of a polyester resin, a urethane resin, a fluororesin, an epoxy resin, an amino resin, an acrylic resin, and a phenol resin. Thereby, it becomes easy to improve electrolyte solution tolerance.

  The packaging material for an electricity storage device of the present invention is preferably for a lithium ion battery. In the present invention, the base material layer is excellent in resistance to aprotic solvents such as propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, which are electrolytes used in lithium ion batteries.

  ADVANTAGE OF THE INVENTION According to this invention, the exterior material for electrical storage devices which has the outstanding slidability on the outer layer side can be provided, maintaining the electrolyte solution tolerance of a base material layer.

It is sectional drawing which shows the exterior | packing material for electrical storage devices which concerns on one Embodiment of this invention.

<Exterior materials for electricity storage devices>
An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an electricity storage device exterior material (hereinafter simply referred to as “exterior material”) 1 of the present embodiment.

  The exterior material of the present embodiment includes a first corrosion prevention layer and a base material layer in this order on the first surface of the metal foil layer, and a second corrosion prevention layer on the second surface of the metal foil layer, A sealant adhesive layer and a sealant layer are provided in this order. That is, as shown in FIG. 1, the exterior material 1 includes a metal foil layer 11 that exhibits a barrier function, a first corrosion prevention layer 12 that is sequentially formed on the first surface of the metal foil layer 11, and a base. A material layer 13, a second corrosion prevention layer 14 formed on the second surface of the metal foil layer 11, and a sealant adhesive layer 15 and a sealant layer 16 sequentially formed on the second corrosion prevention layer 14. I have. When forming an electrical storage device using the exterior material 1, the base material layer 13 becomes an outermost layer, and the sealant layer 16 becomes an innermost layer.

[Metal foil layer]
As the metal foil layer 11, various metal foils made of aluminum, copper, copper alloy, stainless steel, nickel, iron, magnesium, titanium, and the like can be used, and among these, workability such as moisture resistance and ductility can be used. From the surface, aluminum foil, copper foil, and stainless steel foil are preferable. Furthermore, an aluminum foil is more preferable from the viewpoint of cost. A general soft aluminum foil can be used as the aluminum foil. Among these, an aluminum foil containing iron is preferable from the viewpoint of excellent pinhole resistance and extensibility during molding.

  0.1-9.0 mass% is preferable and, as for content of iron in the aluminum foil (100 mass%) containing iron, 0.5-2.0 mass% is more preferable. When the iron content is 0.1% by mass or more, the exterior material 1 is more excellent in pinhole resistance and spreadability. If the iron content is 9.0% by mass or less, the exterior material 1 is more excellent in flexibility.

  The thickness of the metal foil layer 11 is preferably 9 to 200 μm and more preferably 15 to 100 μm from the viewpoints of barrier properties, pinhole resistance, workability, and the like.

[Base material layer]
The base material layer 13 provides heat resistance in the sealing process when manufacturing the electricity storage device, and electrolyte resistance that does not change even when the electrolyte is attached to the exterior material 1 and can be a pin that can occur during processing and distribution. It plays a role in suppressing the generation of holes.

  The base material layer 13 is formed of a resin, and is preferably formed directly on the first corrosion prevention layer 12 formed on the first surface of the metal foil layer 11, preferably without an adhesive layer. In addition, the base material layer 13 formed by coating can also be called a coating layer.

  The base material layer 13 can be formed using various resins such as a polyester resin, a urethane resin, a fluororesin, an epoxy resin, an amino resin, an acrylic resin, a phenol resin, and polyvinyl alcohol. From the viewpoint of stretchability, polyester resin, urethane resin, fluororesin, epoxy resin, amino resin, acrylic resin, and phenol resin are preferable. Furthermore, polyester resin and urethane resin are preferable from the viewpoint of followability when stretched to the metal foil layer 11. More preferred.

  As the polyester resin, there are a solvent-soluble type and a water-dispersed type. Examples of the solvent-soluble type include those obtained by substituting a part of raw material polyalcohol ethylene glycol or the like with cyclohexanedimethanol or neopentyl glycol. In terms of solvent solubility, the polyester resin is more preferably an amorphous polyester resin in which a part of ethylene glycol is replaced with cyclohexanedimethanol in polyethylene terephthalate obtained by dehydration condensation of terephthalic acid and ethylene glycol. Amorphous polyester resins can be used alone or in combination. Examples of the water dispersion type include polyesters obtained by polycondensation of a carboxylic acid component composed of a divalent or higher polyvalent carboxylic acid compound and an alcohol component composed of a divalent or higher polyhydric alcohol compound, and a sulfonic acid metal base. In addition, a hydrophilic polar group such as a carboxyl group or a phosphate group is introduced and dispersed in water.

  Examples of the urethane resin include a two-component curing type and a water dispersion type. As the two-component curable type, for example, an acrylic polyol having a hydroxyl group in the molecule, a polyester polyol, a polyether polyol, etc., and a TDI, MDI, XDI, IPDI, HDI, etc. having an isocyanate group in the molecule The isocyanate is added as a curing agent to give a coating solution. In addition, after apply | coating the said coating liquid, in order to dry a solvent and to accelerate | stimulate reaction with a hydroxyl group and isocyanate, a coating film can be obtained by performing the aging process for 60 degreeC for 5 days, for example. Examples of the water dispersion type include polyol components such as polyether diol, polyester diol, and polycarbonate diol having a hydroxyl group in the molecule, and TDI, MDI, XDI, IPDI, and HDI types having an isocyanate group in the molecule. And a product obtained by introducing a hydrophilic group (self-emulsifying type) into the reaction product with isocyanate and dispersing in water.

  The base material layer 13 contains a lubricant having an SP value (Solubility Parameter) of 7.5 or less or 10.5 or more. The SP value is preferably 7.2 or less or 11 or more, and more preferably 7 or less or 11.5 or more. When the SP value of the lubricant is 7.5 or less or 10.5 or more, good slipperiness can be imparted to the surface of the base material layer while maintaining the electrolytic solution resistance of the base material layer. For example, in the case of a lithium ion battery that is a kind of power storage device, an electrolyte solution is an aprotic solvent such as propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, or ethyl methyl carbonate, and SP of the electrolyte solution is used. The value is about 8-10. According to the knowledge of the inventors, it is found that the use of a lubricant whose SP value is close to the electrolytic solution may cause swelling by the electrolytic solution or dissolution in the electrolytic solution, and the base material layer 13 may be altered. It was. In addition, although the minimum or upper limit of SP value is not specifically limited, From a compatible viewpoint with resin which comprises the base material layer 13, it can be 5 or more and 15 or less, respectively.

  The lubricant is preferably a reactive lubricant having a functional group capable of reacting with the resin constituting the base material layer 13 or interacting with the resin constituting the base material layer 13 by hydrogen bonding or the like.

  Examples of the lubricant having an SP value of 7.5 or less or 10.5 or more include polydimethylsiloxane, and particularly reactive lubricants include hydroxyl group, glycidyl group, carboxyl group, amino group, acryloyl group, vinyl group and allyl. And a silicone-based lubricant (polydimethylsiloxane) having a reactive functional group (reactive group) such as a group. Of these, polydimethylsiloxane having a hydroxyl group is preferred from the viewpoint that the SP value can be particularly increased.

The SP value can be measured, for example, by extracting a lubricant from the base material layer 13 with a solvent and using a cloud point titration method. In the cloud point titration method, the following formula is used by using the SP values (δ1, δ2) of two kinds of poor solvents with known SP values and the amount of solvent (V1, V2) in which turbidity is generated when titrating the poor solvent. The SP value (δ) can be calculated according to
δ = (V1 ^ (1/2) × δ1 + V2 ^ (1/2) × δ2) / (V1 ^ (1/2) + V2 ^ (1/2)).

  The lubricant is preferably made of a polymer compound having a weight average molecular weight of 2000 or more. That is, it is preferable that the above-mentioned polydimethylsiloxane has a weight average molecular weight of 2000 or more. If the weight average molecular weight is 2000 or more, swelling by the electrolytic solution and dissolution in the electrolytic solution are difficult to occur, and it is easy to prevent the base material layer 13 from being altered. From such a viewpoint, the weight average molecular weight is more preferably 2500 or more. The upper limit of the weight average molecular weight is not particularly limited, but can be 10,000 or less from the viewpoint of coating suitability.

  The weight average molecular weight can be measured, for example, by gel permeation chromatography or sedimentation equilibrium method.

  The content of the lubricant is preferably 0.5 to 5.0% by mass on the basis of the total mass of the base material layer 13 in terms of imparting sufficient slipping property to the base material layer 13, and preferably 1.0 to 3%. 0.0 mass% is more preferable.

  The thickness of the base material layer 13 is preferably 3 to 30 μm and more preferably 5 to 20 μm from the viewpoint of maintaining insulation and stretchability. Since the base material layer 13 can be directly formed on the first corrosion prevention layer 12 formed on the first surface of the metal foil layer 11, by making the thickness of the base material layer 13 20 μm or less, It is also easy to make the structure thinner than the outer packaging material.

[Corrosion prevention layer]
The first corrosion prevention layer 12 and the second corrosion prevention layer 14 (hereinafter referred to as “corrosion prevention layer”) prevent corrosion of the metal foil layer 11 by the electrolytic solution or hydrofluoric acid generated by the reaction between the electrolytic solution and moisture. Play a role to suppress. Moreover, it plays the role which raises the adhesive force of the base material layer 13 and the metal foil layer 11, and the metal foil layer 11 and the sealant contact bonding layer 15.

  Examples of the corrosion prevention layer include a coating film formed by a coating type or immersion type acid-resistant corrosion prevention treatment agent, and a metal oxide layer derived from a metal element constituting the metal foil layer 11. Such a coating film or layer is excellent in the effect of preventing corrosion against acid. As the coating film, for example, a ceriazol-treated coating film, a chromate salt, a phosphate salt, a fluoride, and various thermosetting resins with a corrosion prevention treatment agent composed of cerium oxide, phosphate and various thermosetting resins. Examples thereof include a chromate-treated coating film with a preventive treatment agent. In addition, if it is a coating film from which the corrosion resistance of the metal foil layer 11 is fully obtained, it will not be limited to what was mentioned above. For example, a coating film formed by phosphate treatment, boehmite treatment, or the like may be used. On the other hand, examples of the metal oxide layer derived from the metal element constituting the metal foil layer 11 include layers according to the metal foil layer 11 used. For example, when an aluminum foil is used as the metal foil layer 11, the aluminum oxide layer functions as a corrosion prevention layer. These corrosion prevention layers can be used in a single layer or in combination of a plurality of layers. Further, the first corrosion prevention layer 12 and the second corrosion prevention layer 14 may have the same configuration or different configurations. Further, an additive such as a silane coupling agent may be added to the corrosion prevention layer.

  The thickness of the corrosion prevention layer is preferably 10 nm to 5 μm, more preferably 20 to 500 nm, from the viewpoint of the corrosion prevention function and the function as an anchor.

[Sealant adhesive layer]
The sealant adhesive layer 15 is a layer that bonds the metal foil layer 11 on which the second corrosion prevention layer 14 is formed and the sealant layer 16. The exterior material 1 is roughly divided into two, a thermal laminate configuration and a dry laminate configuration, depending on the adhesive component that forms the sealant adhesive layer 15.

  In the case of a thermal laminate configuration, the adhesive component for forming the sealant adhesive layer 15 is preferably an acid-modified polyolefin resin obtained by graft-modifying a polyolefin resin with an acid such as maleic anhydride. Since the acid-modified polyolefin-based resin is one in which a polar group is introduced into a part of the non-polar polyolefin-based resin, for example, a non-polar layer formed of a polyolefin-based resin film or the like as the sealant layer 16 is used. Further, when a layer having polarity is used as the second corrosion prevention layer 14, it is possible to firmly adhere to both of these layers. In addition, by using an acid-modified polyolefin resin, resistance to contents such as an electrolytic solution is improved, and even if hydrofluoric acid is generated inside the battery, it is easy to prevent a decrease in adhesion due to deterioration of the sealant adhesive layer 15. . The acid-modified polyolefin resin used for the sealant adhesive layer 15 may be one type or two or more types.

  Examples of the polyolefin resin used for the acid-modified polyolefin resin include low density, medium density or high density polyethylene; ethylene-α olefin copolymer; homo, block or random polypropylene; propylene-α olefin copolymer. Can be mentioned. In addition, a copolymer obtained by copolymerizing a polar molecule such as acrylic acid or methacrylic acid with the aforementioned one, a polymer such as a crosslinked polyolefin, and the like can also be used. Examples of the acid that modifies the polyolefin-based resin include carboxylic acid and acid anhydride, and maleic anhydride is preferable.

  In the case of a thermal laminate configuration, the sealant adhesive layer 15 can be formed by extruding the adhesive component with an extrusion device.

  In the case of a dry laminate configuration, as an adhesive component of the sealant adhesive layer 15, for example, a bifunctional or higher functional aromatic or aliphatic isocyanate compound acts as a curing agent on a main component such as polyester polyol, polyether polyol, or acrylic polyol. And a two-component curable polyurethane adhesive. However, since the polyurethane-based adhesive has a highly hydrolyzable bond such as an ester group or a urethane group, a thermal laminate configuration is preferable for applications that require higher reliability.

  The sealant adhesive layer 15 having a dry laminate structure can be formed by applying an adhesive component on the second corrosion prevention layer 14 and then drying it. If a polyurethane adhesive is used, after coating, for example, by aging at 40 ° C. for 4 days or more, the reaction of the hydroxyl group of the main agent and the isocyanate group of the curing agent proceeds to enable strong adhesion. It becomes.

  The thickness of the sealant adhesive layer 15 is preferably 2 to 50 μm and more preferably 3 to 20 μm from the viewpoints of adhesiveness, followability, workability, and the like.

  When the sealant adhesive layer 15 has a dry laminate configuration, the lubricant contained in the sealant layer 16 or the lubricant applied on the sealant layer 16 is trapped by the sealant adhesive layer 15 and the slipperiness of the sealant layer 16 is reduced. Tend. Therefore, from the viewpoint of maintaining the slipperiness of the sealant layer 16, the sealant adhesive layer 15 is preferably formed by forming an acid-modified polyolefin resin with an extrusion device and laminating with a heat laminate.

[Sealant layer]
The sealant layer 16 is a layer that imparts sealing properties by heat sealing in the exterior material 1. Examples of the sealant layer 16 include a polyolefin resin, or a resin film made of an acid-modified polyolefin resin obtained by graft-modifying a polyolefin resin with an acid such as maleic anhydride.

  Examples of the polyolefin resin include low density, medium density or high density polyethylene; ethylene-α olefin copolymer; homo, block or random polypropylene; propylene-α olefin copolymer. These polyolefin resin may be used individually by 1 type, and may use 2 or more types together.

  Examples of the acid that modifies the polyolefin resin include the same acids as those described in the description of the sealant adhesive layer 15.

  The sealant layer 16 may be a single layer film or a multilayer film, and may be selected according to a required function. For example, in terms of imparting moisture resistance, a multilayer film in which a resin such as an ethylene-cyclic olefin copolymer or polymethylpentene is interposed can be used.

  The sealant layer 16 may contain various additives such as a flame retardant, a lubricant, an antiblocking agent, an antioxidant, a light stabilizer, and a tackifier.

  The thickness of the sealant layer 16 is preferably 5 to 50 μm and more preferably 10 to 30 μm from the viewpoint of ensuring insulation.

  The exterior material 1 may be one in which the sealant layer 16 is laminated by dry lamination. From the viewpoint of the slipperiness of the sealant layer 16, the sealant adhesive layer 15 is an acid-modified polyolefin resin, sandwich lamination, or coextrusion method. It is preferable that the sealant layer 16 is laminated.

<Method for manufacturing exterior material for power storage device>
Hereinafter, the manufacturing method of the exterior material 1 of this embodiment is demonstrated. Specifically, although the method which has the following process (1)-(3) is mentioned as the manufacturing method, the following content is an example and the manufacturing method of the exterior | packing material 1 is not limited to the following content.

  Process 1: The process of forming the 1st corrosion prevention layer 12 and the 2nd corrosion prevention layer 14 on both surfaces (1st surface and 2nd surface) of the metal foil layer 11. FIG.

  Process 2: The process of forming the base material layer 13 on the 1st corrosion prevention layer 12 formed in the 1st surface of the metal foil layer 11 using the raw material (resin material) for base material layers.

  Process 3: The process of bonding the sealant layer 16 on the 2nd corrosion prevention layer 14 formed in the 2nd surface of the metal foil layer 11 via the sealant adhesive layer 15.

(Process 1)
For example, a corrosion prevention treatment agent is applied to both surfaces of the metal foil layer 11 and dried to form the first corrosion prevention layer 12 and the second corrosion prevention layer 14. Examples of the corrosion prevention treatment agent include the above-described corrosion prevention treatment agent for ceriazole treatment and corrosion prevention treatment agent for chromate treatment. The coating method of the corrosion inhibitor is not particularly limited, and various methods such as gravure coating, reverse coating, roll coating, and bar coating can be employed. Alternatively, by oxidizing the surface of the metal foil layer 11, metal oxide layers derived from the metal elements constituting the metal foil layer 11 on both surfaces of the metal foil layer 11 (the first corrosion prevention layer 12 and the second corrosion prevention layer 12). A corrosion protection layer 14) is formed. Note that one surface of the metal foil layer 11 may be treated with a corrosion preventing treatment agent and the other surface may be oxidized.

(Process 2)
On the first corrosion prevention layer 12 formed on the first surface of the metal foil layer 11, a substrate layer raw material (resin material) serving as a substrate layer is applied and dried to form a substrate layer 13. Form. The application method is not particularly limited, and various methods such as gravure coating, reverse coating, roll coating, and bar coating can be employed. After coating, for example, curing acceleration can be obtained by aging treatment at 60 ° C. for 7 days.

(Process 3)
A sealant adhesive layer 15 is formed on the second corrosion prevention layer 14 of the laminate in which the base material layer 13, the first corrosion prevention layer 12, the metal foil layer 11, and the second corrosion prevention layer 14 are laminated in this order. Then, the laminate and the resin film forming the sealant layer 16 are bonded together. At this time, the sealant adhesive layer 15 and the sealant layer 16 can be coextruded to be laminated on the laminate.

  The exterior material 1 is obtained by the steps (1) to (3) described above. In addition, the process sequence of the manufacturing method of the cladding | exterior_material 1 is not limited to the method of implementing process (1)-(3) sequentially. For example, step (2) may be performed after performing step (3).

  The two exterior materials 1 obtained in this way are prepared and the sealant layers 16 are opposed to each other, or the exterior material 1 is folded back so that the sealant layers 16 are opposed to each other, and become power generation elements and terminals inside. By arranging a tab member or the like and joining the peripheral edges by heat sealing, a cell of an electricity storage device using the exterior material 1 is completed.

  In addition, the exterior material 1 of this embodiment is excellent in resistance to aprotic solvents such as propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. Therefore, the exterior material 1 can be suitably used as an exterior material for a lithium ion battery using these as an electrolytic solution.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description.

[Materials used]
The material used for preparation of the exterior material of an Example and a comparative example is shown below.

(Base material layer)

(Base layer side corrosion prevention layer: first corrosion prevention layer)
Corrosion prevention layer B-1: Cerium oxide layer (layer thickness: 100 nm)

(Metal foil layer)
Metal foil C-1: Soft aluminum foil 8021 material (manufactured by Toyo Aluminum Co., Ltd., thickness 30 μm)

(Sealant layer side corrosion prevention layer: Second corrosion prevention layer)
Corrosion prevention layer D-1: Cerium oxide layer (layer thickness 100 nm)

(Sealant adhesive layer)
Adhesive resin E-1: Polypropylene resin graft-modified with maleic anhydride (trade name “Admer”, Mitsui Chemicals, layer thickness 10 μm)

(Sealant layer)
Thermal fusion resin F-1: Polypropylene resin (trade name “Prime Polypro”, manufactured by Prime Polymer Co., Ltd., layer thickness 20 μm)

(Preparation of exterior materials)
A corrosion prevention layer D-1 was formed on one surface of the metal foil C-1 by direct gravure coating. Next, the corrosion prevention layer B-1 was formed by direct gravure coating on the other surface of the metal foil C-1 where the corrosion prevention layer D-1 was not formed. Of the obtained laminate, on the surface of the metal foil C-1 on which the corrosion prevention layer B-1 is formed, any one of the base material raw materials A-1 to A-10 is 10 μm in thickness. Coating was performed to form a base material layer (coating layer).

  Next, the adhesive resin E-1 and the heat-sealing resin F-1 are coextruded with an extrusion apparatus on the corrosion prevention layer D-1 side of the laminates of the obtained examples and comparative examples, and a sealant adhesive layer is formed. A sealant layer was formed. The exterior material of each Example and the comparative example was produced through the above process.

[Various evaluations]
Various evaluations were performed according to the following methods. The evaluation results are shown in Table 2.

[Evaluation of slipperiness]
The exterior material obtained in each example was cut to a width of 60 mm and a length of 120 mm, and attached to a measurement weight (width 60 mm, length 100 mm) so that the base material layer surface was on the outside. Further, as a sample on the measuring machine main body side, the exterior material was cut into a width of 85 mm and a length of 250 mm, and attached to the measuring machine main body so that the base material layer surface was on the outside. The measuring machine used was a friction measuring machine AN-S2 (manufactured by Toyo Seiki Seisakusho). Install the weight so that the base material layer of the exterior material attached to the main body of the measuring instrument and the base material layer of the external material attached to the weight are in contact with each other, tilt the measuring table of the measuring equipment, and the angle at which the weight slides (arc degree method) The tangent was evaluated as a coefficient of static friction (JIS P8147 tilt method). The obtained static friction coefficient was evaluated according to the following criteria.
“A”: Static coefficient of friction is less than 0.30.
“B”: Static friction coefficient is 0.30 or more and less than 0.40.
“C”: Static friction coefficient is 0.40 or more.

[Evaluation of electrolyte resistance]
Electrolytic solution (ethylene carbonate / dimethyl carbonate / diethyl carbonate = 1: 1: 1 wt%, LiPF ₆ , 1M) was dropped onto the base material layer of the exterior material obtained in each example, and left for 24 hours, and then wiped off with isopropyl alcohol. It was. Then, the external appearance of the dripping location was observed. The observation results were evaluated according to the following criteria.
“A”: The location where the electrolytic solution was dropped cannot be recognized.
“B”: The location where the electrolytic solution was dropped is altered by the electrolytic solution.

  In the Example which has the structure of this invention, the exterior material for electrical storage devices which has the slidability excellent in the outer layer side (base material layer side) was able to be provided, maintaining the electrolyte solution tolerance of a base material layer.

  DESCRIPTION OF SYMBOLS 1 ... Exterior material (exterior material) for electrical storage devices, 11 ... Metal foil layer, 12 ... 1st corrosion prevention layer, 13 ... Base material layer, 14 ... 2nd corrosion prevention layer, 15 ... Sealant adhesion layer, 16 ... Sealant layer.

Claims (6)

At least a base material layer, a metal foil layer, a sealant adhesive layer and a sealant layer are provided in this order,
The exterior material for electrical storage devices in which the said base material layer contains the lubricant whose SP value is 7.5 or less or 10.5 or more.   The exterior | packing material for electrical storage devices of Claim 1 whose said lubricant is a reactive lubricant.   The reactive lubricant is a silicone-based lubricant having at least one reactive group selected from the group consisting of a hydroxyl group, a glycidyl group, a carboxyl group, an amino group, an acryloyl group, a vinyl group, and an allyl group. An exterior material for an electricity storage device according to 1.   The exterior | packing material for electrical storage devices as described in any one of Claims 1-3 in which the said lubricant consists of a high molecular compound whose weight average molecular weight is 2000 or more.   The said base material layer consists of at least 1 sort (s) selected from the group which consists of a polyester resin, a urethane resin, a fluororesin, an epoxy resin, an amino resin, an acrylic resin, and a phenol resin, It is any one of Claims 1-4. The exterior material for electrical storage devices as described.   The exterior | packing material for electrical storage devices as described in any one of Claims 1-5 which is an object for lithium ion batteries.

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