JP7206873B2 - Electric storage device manufacturing method and electric storage device quality control method - Google Patents

Description

The present disclosure relates to a method for manufacturing an electricity storage device and a method for quality control of an electricity storage device.

BACKGROUND ART Conventionally, various types of electricity storage devices have been developed. In all electricity storage devices, packaging materials (exterior materials) are indispensable members for sealing electricity storage device elements such as electrodes and electrolytes. Conventionally, metal exterior materials have been widely used as exterior materials.

On the other hand, in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., power storage devices are required to have various shapes, and are required to be thinner and lighter. However, metal exterior materials, which have been widely used in the past, have the drawback that it is difficult to follow the diversification of shapes and there is a limit to weight reduction.

Therefore, in recent years, as an exterior material that can be easily processed into various shapes and that can be made thinner and lighter, a film-like exterior material, in which a base material, an aluminum foil layer, and a heat-fusible resin layer are sequentially laminated, has been developed. Proposed.

In such a film-like exterior material, a recess is generally formed by cold forming, and an electricity storage device element such as an electrode or an electrolytic solution is placed in the space formed by the recess, and a heat-sealable resin is placed in the space formed by the recess. By heat-sealing the layers together, an electricity storage device in which the electricity storage device element is accommodated inside the exterior material is obtained.

JP 2008-287971 A

When the electrical storage device element is enclosed using the film-like exterior material as described above, the heat-sealable resin layers on the periphery of the exterior material are heat-sealed. At this time, the metal terminals connected to the electricity storage device elements are sandwiched between the heat-fusible resin layers, and the heat-fusible resin layers are sealed with each other. is electrically connected to

For example, when the film-like exterior material forms a container having a rectangular shape in a plan view, the metal terminals electrically connected to the electricity storage device elements protrude to the outside, and at the periphery of the container, A heat-sealable resin layer on the metal terminal-side peripheral portion where the metal terminal is located, and a heat-sealable resin on the side peripheral portion orthogonal to the metal terminal-side peripheral portion and located on the side of the electricity storage device. A sealing step is performed in which the layers are heat-sealed to seal the electricity storage device element. By heat-sealing the heat-sealable resin layer on the metal terminal-side peripheral portion and by heat-sealing the heat-sealable resin layer on the side-side peripheral portion orthogonal to the metal terminal-side peripheral portion, these peripheral edges At the intersections of the parts (that is, the corners of the container having a rectangular shape in plan view), heat sealing is performed twice. As a result of studies by the present inventors, it has become clear that when an electricity storage device is manufactured through such a sealing process, an electricity storage device with low insulation may be manufactured.

Under such circumstances, the main object of the present disclosure is to provide a method of manufacturing an electricity storage device with excellent insulation. Another object of the present disclosure is to provide a quality control method for controlling that an electricity storage device with excellent insulation is manufactured.

The present inventors have made intensive studies to solve the above problems. As a result, at the periphery of the container having a rectangular shape in a plan view, which is composed of a laminate including a base material layer located outside, a barrier layer, and a heat-fusible resin layer located inside in this order, the heat A method for manufacturing an electricity storage device in which an electricity storage device element is sealed with a packaging body formed by heat-sealing a fusible resin layer, wherein a metal terminal electrically connected to the electricity storage device element is provided. The heat-sealable resin layer is heat-sealed at least on the metal terminal-side peripheral edge portion where the metal terminal is located, and the power storage device is perpendicular to the metal terminal-side peripheral edge portion at the peripheral edge of the container so as to protrude to the outside. A sealing step of heat-sealing the heat-sealable resin layer on the side peripheral edge portion located on the side of the device and sealing the electricity storage device element with the package, and The power storage device to be tested is extracted from the power storage devices, and the metal terminal side peripheral edge portion of the heat-sealed portion on the periphery of the package of the power storage device to be tested is heat-sealed. The thickness A of the heat-sealable resin layer in the part, the thickness B of the heat-sealable resin layer in the second heat-sealed part where the side peripheral edge is heat-sealed, and the portion that is not heat-sealed When the thickness C of the heat-fusible resin layer is measured and the thickness C is taken as 100%, it is confirmed that the ratio of the thickness A is within a predetermined range and the ratio of the thickness B is within a predetermined range. It has been found that by confirming, it is possible to determine whether or not the heat-sealing conditions in the sealing step are appropriate, and that an electricity storage device having excellent insulation can be manufactured.

The present disclosure has been completed through further studies based on these findings. That is, the present disclosure provides inventions in the following aspects.
At the periphery of a container having a rectangular shape in plan view, which is composed of a laminate including a base material layer located outside, a barrier layer, and a heat-fusible resin layer located inside in this order, the heat-fusible property A method for manufacturing an electricity storage device in which an electricity storage device element is sealed with a package formed by heat-sealing a resin layer,
The method for manufacturing the electricity storage device is such that the metal terminal electrically connected to the electricity storage device element protrudes to the outside, and at least the metal terminal side where the metal terminal is located is located at the periphery of the housing body. Thermal bonding of the heat-fusible resin layer on the peripheral edge and heat of the heat-fusible resin layer on the side peripheral edge that is perpendicular to the metal terminal side peripheral edge and located on the side of the electricity storage device. a sealing step of fusing and sealing the electricity storage device element with a package;
The power storage device to be tested is extracted from the power storage devices obtained in the sealing step, and the metal terminal side peripheral edge portion of the heat-sealed portion on the periphery of the package of the power storage device to be tested is heated. The thickness A of the heat-fusible resin layer in the first heat-fusible portion that is fused, and the heat-fusible resin layer in the second heat-fusible portion that heat-bonds the side peripheral edge portion. and the thickness C of the heat-sealable resin layer in the portion not heat-sealed, and confirm whether the following thickness relationship I and thickness relationship II are satisfied, a thickness confirmation process;
Thickness relationship I: When the thickness C is 100%, the ratio of the thickness A is 70% or more and 95% or less Thickness relationship II: When the thickness C is 100%, the thickness B The ratio is 60% or more and 95% or less As a result of the thickness confirmation step, if both the thickness relationship I and the thickness relationship II are satisfied, the heat sealing conditions in the sealing step are appropriate. Determined, the electricity storage device is manufactured under the heat-sealing conditions,
If at least one of the thickness relationship I and the thickness relationship II is not satisfied, it is determined that the heat sealing conditions in the sealing step are inappropriate, and the heat sealing conditions in the sealing step are changed. a determination step of changing and subjecting to the thickness confirmation step again;
A method for manufacturing an electricity storage device, comprising:

ADVANTAGE OF THE INVENTION According to this indication, the method of manufacturing an electrical storage device excellent in insulation can be provided. Moreover, according to the present disclosure, it is also possible to provide a quality control method for controlling whether an electricity storage device having excellent insulation is manufactured.

It is an example of the laminated structure of the laminated body (armor material) which comprises the container. It is an example of the laminated structure of the laminated body (armor material) which comprises the container. 1 is a schematic diagram of an electricity storage device manufactured by a method for manufacturing an electricity storage device of the present disclosure; FIG. It is a schematic diagram of a heat-fusible resin layer for explaining observation of a cross section inside a heat-fusible part in an example.

A method for manufacturing an electricity storage device according to the present disclosure is a storage device having a rectangular shape in a plan view, which is composed of a laminate including a base material layer located outside, a barrier layer, and a heat-sealable resin layer located inside in this order. A method for manufacturing an electricity storage device in which an electricity storage device element is sealed with a package body formed by heat-sealing the heat-sealable resin layer at the peripheral edge of the body, the method comprising at least the following sealing: It is characterized by having a stopping step, a thickness checking step, and a judging step in this order.

(sealing process)
With the metal terminals electrically connected to the electricity storage device elements protruding to the outside, at least the heat of the heat-sealable resin layer on the metal terminal side peripheral edge portion where the metal terminals are located on the peripheral edge of the housing body. The heat-sealing resin layer is heat-sealed on the side edge portion perpendicular to the metal terminal side edge portion and located on the side edge of the electricity storage device, and the electricity storage device element is sealed with the packaging body. sealing process.

(Thickness confirmation process)
The power storage device to be tested is extracted from the power storage devices obtained in the sealing step, and of the heat-sealed portion on the periphery of the package of the power storage device to be tested, the peripheral portion on the metal terminal side is heat-sealed. The thickness A of the heat-fusible resin layer in the first heat-fusible portion, the thickness B of the heat-fusible resin layer in the second heat-fusible portion heat-bonded to the side peripheral edge, and the heat-fusible A thickness confirmation step of measuring the thickness C of the heat-fusible resin layer in the unbonded portion and confirming whether or not the following thickness relationship I and thickness relationship II are satisfied.
Thickness relationship I: When the thickness C is 100%, the ratio of the thickness A is 70% or more and 95% or less Thickness relationship II: When the thickness C is 100%, the thickness B The ratio is 60% or more and 95% or less

(Determination process)
As a result of the thickness confirmation step, when both the thickness relationship I and the thickness relationship II are satisfied, it is determined that the heat sealing conditions in the sealing step are appropriate, and the power storage device is formed under the heat sealing conditions. If at least one of the thickness relationship I and the thickness relationship II is not satisfied, it is determined that the heat sealing conditions in the sealing step are inappropriate, and heat sealing in the sealing step A step of changing the conditions and performing the thickness confirmation step again.

The method for manufacturing an electricity storage device of the present disclosure includes at least the sealing step, the thickness confirmation step, and the determination step in this order, so that an electricity storage device with excellent insulation can be manufactured. Specifically, in the thickness confirmation step and the determination step, the thickness A and the thickness B of the electricity storage device obtained in the sealing step are controlled to a specific thickness ratio, so that the heat in the sealing step Since the electric storage device is manufactured after confirming that the fusion bonding conditions are appropriate, the manufacture of an electric storage device with poor insulation is preferably avoided, and the electric storage device manufacturing method as a whole has excellent insulation. A method for manufacturing an electric storage device is provided. In the method for manufacturing an electricity storage device of the present disclosure, the thickness confirmation step and determination step performed by extracting the test subject electricity storage device from among the electricity storage devices obtained in the sealing step are performed, for example, from once for each production lot. It should be done several times. That is, in one lot of electricity storage devices to be manufactured (for example, about 100 to 1000 electricity storage devices are manufactured in one lot), the heat sealing conditions and the composition of each layer constituting the container are usually Since the thickness and the like are not changed, if the thickness confirmation process and the judgment process are performed once or several times per lot, it is possible to continuously manufacture an electricity storage device (good product) with excellent insulation. On the other hand, when the heat-sealing conditions in the sealing process, the composition and thickness of each layer constituting the housing body, etc. are changed, each time the storage device to be tested is selected from the storage devices obtained in the sealing process It is preferable to perform the thickness confirmation step and determination step by extracting the .

In addition, the quality control method in the method for manufacturing an electricity storage device of the present disclosure targets the quality control of the electricity storage device manufactured by the manufacturing method including the sealing step, and includes the thickness confirmation step and the determination step described above. is characterized by

In the quality control method in the manufacturing process of the electric storage device of the present disclosure, the electric storage device manufactured by the manufacturing method including the sealing process described above is subject to quality control, and at least the thickness confirmation process and the determination process are provided. Therefore, it is possible to provide a quality control method for controlling that an electricity storage device with excellent insulation is manufactured. With regard to the quality control method in the manufacturing process of the electricity storage device of the present disclosure, the thickness A and the thickness B of the electricity storage device are controlled to a specific thickness ratio by the thickness confirmation step and the determination step. Since it is possible to manufacture an electricity storage device after confirming that the heat-sealing conditions in the process are appropriate, the manufacture of an electricity storage device with poor insulation is preferably avoided, and the entire method for manufacturing an electricity storage device is achieved. As a result, it is possible to manufacture an electricity storage device having excellent insulation.

Note that the quality control method of the present disclosure may also be performed, for example, once or several times for each lot in the process of manufacturing an electricity storage device. In the manufacturing process of the electricity storage device, if the heat sealing conditions in the sealing process, the composition and thickness of each layer constituting the container, etc. are changed, each time, from the electricity storage device obtained in the sealing process , it is preferable to extract the power storage device to be tested and apply the quality control method of the present disclosure.

Hereinafter, the method for manufacturing an electricity storage device of the present disclosure and the quality control method in the manufacturing process of the electricity storage device will be described in detail with reference to FIGS. In the present disclosure, the numerical range indicated by "-" means "more than" and "less than". For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

1. Method for Manufacturing Electricity Storage Device In the method for manufacturing an electricity storage device of the present disclosure, the electricity storage device has a structure in which the electricity storage device element 30 is sealed with a package. Moreover, the package sealing the electricity storage device element 30 is formed by heat-sealing the periphery of the container 20 having a rectangular shape in a plan view. Specifically, the container 20 is composed of a laminate 100 that includes a base material layer 1 located outside, a barrier layer 3, and a heat-fusible resin layer 4 located inside in this order, The heat-sealable resin layers 4 facing each other are heat-sealed at the periphery of the container 20 to form a package. The details of the laminate 100 forming the container 20 will be described later.

In housing the electricity storage device element, the laminate 100 including the base material layer 1 located outside, the barrier layer 3, and the heat-fusible resin layer 4 located inside in this order is used as the exterior material of the electricity storage device 10. , the packaging material is molded into a bag shape to form a container 20 having a rectangular shape in a plan view. Inside the housing body 20, an electricity storage device element 30 (for example, an electrolyte, an electrode, etc.) is housed. For the purpose of enlarging the space for accommodating the electricity storage device element 30, the exterior material is formed with a concave portion extending from the heat-fusible resin layer 4 toward the base layer 1 side by molding using a mold or the like. good too. The power storage device element 30 can be accommodated in the recess. In addition, the shape of the container 20 is not particularly limited as long as it is rectangular in plan view and has a heat-sealed portion, which will be described later. may

(sealing process)
In the sealing step, the metal terminals 40 electrically connected to the electricity storage device elements 30 protrude to the outside, and at least the metal terminal-side peripheral edge portion where the metal terminals 40 are located on the periphery of the container 20 is closed. and the heat-sealable resin layer 4 of the side peripheral edge portion perpendicular to the metal terminal side peripheral portion and located on the side side of the electricity storage device 10 are heat-sealed, respectively. is a step of sealing the electricity storage device element.

In the sealing step, in order to seal (seal) the electricity storage device element 30 , all open portions of the periphery of the container 20 are sealed. For example, in the schematic diagram of FIG. 3, the metal terminal side peripheral edge portion (z1 side peripheral edge portion) where the metal terminal 40 is located, and the two side peripheral edge portions (x1 direction The heat-fusible resin layer is heat-sealed at the first side peripheral portion on the x2 side and the second side peripheral portion on the x2 side. The peripheral edge portion facing the metal terminal side peripheral edge portion where the metal terminal 40 is located is a portion where the laminated body 100 used as the exterior material is folded back, and does not need to be heat-sealed because it does not have an opening.

In the schematic diagram of FIG. 3 , the metal terminal side peripheral edge portion where the metal terminal 40 is located is the peripheral edge portion located on the z1 direction side of the electricity storage device 10 . In addition, in FIG. 3 , the side edge portion positioned on the side edge of the electricity storage device 10 is the second side edge portion positioned on the x2 direction side of the electricity storage device 10 . In addition, the first side peripheral edge portion facing the second side peripheral edge portion located on the x2 direction side of the electricity storage device 10 (that is, the first side peripheral edge portion located on the x1 direction side of the energy storage device 10) is also made of metal. It is a side peripheral edge located on the side of the electric storage device 10 orthogonal to the metal terminal side peripheral edge where the terminal 40 is located. There are no particular restrictions on the sealing order of the first side peripheral portion located on the x1 direction side of the electricity storage device 10 and the second side peripheral portion located on the x2 direction side of the energy storage device 10 .

In the sealing step, the ratio of the thicknesses A and B of the heat-fusible resin layer 4, which is confirmed in the thickness confirmation step described later, depends on the composition and thickness of each layer constituting the container, and the heat-sealing conditions (heat sealing conditions) can be suitably adjusted. Specifically, by adjusting the surface pressure (pressure applied to the heat-sealing resin layer by the heat-seal bar), temperature, time, etc. in heat sealing of the heat-sealing resin layer 4, the heat-sealing resin By adjusting the extent to which the layer 4 is crushed by heat and pressure during heat sealing, the ratio of the thicknesses A and B of the heat-fusible resin layer 4 can be set appropriately. Therefore, in the sealing step, the ratio of the thicknesses A and B of the heat-sealable resin layer 4 in each heat-sealed portion becomes the ratio of the thicknesses A and B confirmed in the thickness confirmation step described later. In this manner, the composition and thickness of each layer and the heat-sealing conditions are adjusted to heat-seal the heat-sealable resin layer 4 of each heat-sealing portion.

From the viewpoint of setting the ratio of the thicknesses A and B of the heat-sealable resin layer 4 to an appropriate value, the heat-sealing conditions are set according to the composition and thickness of each layer constituting the container 20. For example, The surface pressure is preferably selected from the range of 0.1 to 2.0 MPa, the temperature is preferably selected from the range of 170 to 210° C., and the time is selected from the range of 1 to 15 seconds.

(Thickness confirmation process)
In the thickness confirmation step, the power storage device to be tested is extracted from among the power storage devices 10 obtained in the sealing step, and the metal terminal is located in the heat-sealed portion on the periphery of the package of the power storage device to be tested. The thickness A of the heat-sealable resin layer 4 in the first heat-sealed portion 11, which heat-seales the metal terminal side peripheral portion located on the side, and the side-side peripheral portion located on the side, are heat-sealed. The thickness B of the heat-sealable resin layer 4 in the second heat-sealed portion 12 and the heat-sealable resin layer of the portion that is not heat-sealed (for example, the central portion of the container having a rectangular shape in plan view) It is a step of measuring the thickness C of 4 and confirming whether or not the following thickness relationship I and thickness relationship II are satisfied. The details of the method for measuring the thickness will be described later.
Thickness Relationship I: When the thickness C is 100%, the ratio of the thickness A is 70% or more and 95% or less.
Thickness Relationship II: When the thickness C is 100%, the ratio of the thickness B is 60% or more and 95% or less.

(Determination process)
In the determination step, when both the thickness relationships I and II are satisfied as a result of the thickness confirmation step, it is determined that the heat sealing conditions in the sealing step are appropriate, and the power storage device is manufactured under the heat sealing conditions. can be manufactured. Further, if at least one of the thickness relationships I and II is not satisfied, it is determined that the heat sealing conditions in the sealing step are inappropriate, the heat sealing conditions in the sealing step are changed, and again, It uses for the said thickness confirmation process. In the manufacturing method of the present disclosure, the heat-fusible resin layer is appropriately heat-sealed by providing the thickness confirmation step and the determination step, and an electricity storage device having excellent insulation is manufactured. be.

From the viewpoint of manufacturing an electricity storage device with excellent insulation, the ratio of the thickness A of the heat-sealable resin layer 4 in the first heat-sealable portion 11 is preferably about 75% or more, more preferably about 80%. above, preferably about 90% or less, more preferably about 85% or less, preferably about 70 to 90%, about 70 to 85%, about 75 to 95%, about 75 to 90% , about 75 to 85%, about 80 to 95%, about 80 to 90%, and about 80 to 85%. From the same point of view, the ratio of the thickness B of the heat-sealable resin layer 4 in the second heat-sealing portion 12 is preferably about 65% or more, more preferably about 70% or more, and preferably about 90%. % or less, more preferably about 85% or less. %, about 70 to 90%, and about 70 to 85%. The thicknesses A, B, and C of the heat-fusible resin layers are each obtained by measuring the thickness of the cross section of the heat-fusible resin layer. Specifically, for the thickness A of the heat-sealable resin layer, the thickness of the section of the first heat-sealed portion where the metal terminal is located is measured. As for the thickness B of the heat-sealable resin layer, the thickness of the cross section near the central portion of the second heat-sealed portion is measured. As for the thickness C of the heat-fusible resin layer, the thickness is measured for the cross section of the top surface portion 14 of the container 20 in the portion where the heat-fusible resin layer is not heat-sealed. The thicknesses A, B, and C of the heat-fusible resin layers 4 are respectively the total thicknesses of the heat-fusible resin layers 4 facing each other in the package. For example, when the heat-fusible resin layer 4 is a single layer in the laminate 100 constituting the container 20, the thicknesses A and B of the heat-fusible resin layers are is the total thickness of the two heat-fusible resin layers (see thickness W in FIG. 4), and the thickness C of the heat-fusible resin layer is the heat-fusible resin layer 2 in the top surface portion 14 of the container 20 is the sum of the thicknesses of the two

From the viewpoint of manufacturing an electricity storage device with excellent insulation, the ratio of the thickness A of the heat-fusible resin layer 4 is preferably larger than the ratio of the thickness B thereof.

2. Quality Control Method in Manufacturing Process of Electricity Storage Device The quality control method in the manufacturing process of the electricity storage device of the present disclosure comprises a base material layer 1 located outside, a barrier layer 3, and a heat-sealable resin layer 4 located inside. The power storage device element 30 is formed by a package formed by heat-sealing the heat-sealable resin layer 4 at the periphery of the container 20, which has a rectangular shape in plan view and is composed of the laminated body 100 provided in this order. A quality control method for a sealed electricity storage device.

In the quality control method of the present disclosure, the metal terminals 40 electrically connected to the electricity storage device element 30 are protruded to the outside, and at least the metal terminals 40 are positioned at the periphery of the container 20. The heat of the heat-sealable resin layer 4 on the side peripheral portion and the heat of the heat-sealable resin layer 4 on the side peripheral portion perpendicular to the metal terminal side peripheral portion and located on the side of the electricity storage device 30 An electric storage device manufactured by a manufacturing method including a sealing step of fusing and sealing the electric storage device element 30 with a package is subject to quality control.

The sealing process, the thickness confirmation process, and the determination process are the same as those described in the above-mentioned "1. Method for manufacturing an electricity storage device". According to the quality control method of the present disclosure, it is possible to suitably manage the production process of an electricity storage device so that an electricity storage device with excellent insulation (that is, a non-defective product) is manufactured.

As described above, the quality control method of the present disclosure may also be performed once or several times for each lot, for example, in the manufacturing process of the electricity storage device. In the manufacturing process of the electricity storage device, if the heat sealing conditions in the sealing process, the composition and thickness of each layer constituting the container, etc. are changed, each time, from the electricity storage device obtained in the sealing process , it is preferable to extract the power storage device to be tested and apply the quality control method of the present disclosure.

[Laminate (armoring material) constituting container]
In the present disclosure, the container housing the electricity storage device element is composed of a laminate comprising at least an outer substrate layer, a barrier layer, and an inner heat-fusible resin layer in this order. It is A preferred configuration of the laminate will be described in detail below.

Laminate Structure of Laminate (Exterior Material) The laminate (hereinafter sometimes referred to as "exterior material") constituting the container of the power storage device of the present disclosure includes at least a base material, as shown in FIG. It is composed of a laminate comprising a layer 1, a barrier layer 3, and a heat-fusible resin layer 4 in this order. In the exterior material, the substrate layer 1 is the outermost layer, and the heat-fusible resin layer 4 is the innermost layer. When an electricity storage device is assembled using an exterior material and an electricity storage device element, electricity is stored in a space formed by heat-sealing the peripheral edges of the heat-sealable resin layers 4 of the exterior material while facing each other. A device element 30 is accommodated.

For example, as shown in FIG. 2, the exterior material has an adhesive layer 2 between the base material layer 1 and the barrier layer 3 for the purpose of improving the adhesion between these layers, if necessary. may be For example, as shown in FIG. 2, an adhesive layer 5 is optionally provided between the barrier layer 3 and the heat-fusible resin layer 4 for the purpose of enhancing the adhesion between these layers. may be Although not shown, a surface coating layer or the like may be provided on the outside of the base material layer 1 (the side opposite to the heat-fusible resin layer 4 side), if necessary.

The thickness of the laminate 100 constituting the exterior material is not particularly limited, but from the viewpoint of cost reduction, improvement of energy density, etc., it is preferably about 180 μm or less, about 155 μm or less, or about 120 μm or less. From the viewpoint of maintaining the function of the exterior material of protecting the about 120 μm, about 45 to 180 μm, about 45 to 155 μm, about 45 to 120 μm, about 60 to 180 μm, about 60 to 155 μm, and about 60 to 120 μm.

Each layer constituting the exterior material [base layer 1]
The base material layer 1 is a layer provided for the purpose of exhibiting a function as a base material of the exterior material. The base material layer 1 is positioned on the outer layer side of the exterior material.

The material forming the base material layer 1 is not particularly limited as long as it functions as a base material, that is, at least has insulating properties. The base material layer 1 can be formed using, for example, a resin, and the resin may contain additives described later.

When the substrate layer 1 is formed of resin, the substrate layer 1 may be, for example, a resin film formed of resin, or may be formed by applying resin. The resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, with biaxially stretched films being preferred. Examples of stretching methods for forming a biaxially stretched film include successive biaxial stretching, inflation, and simultaneous biaxial stretching. Methods for applying the resin include a roll coating method, a gravure coating method, an extrusion coating method, and the like.

Examples of the resin forming the base material layer 1 include resins such as polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenolic resin, and modified products of these resins. Further, the resin forming the base material layer 1 may be a copolymer of these resins or a modified product of the copolymer. Furthermore, it may be a mixture of these resins.

As resin which forms the base material layer 1, polyester and polyamide are preferably mentioned among these.

Specific examples of polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester. Examples of copolyester include copolyester having ethylene terephthalate as a main repeating unit. Specifically, copolymer polyester polymerized with ethylene isophthalate with ethylene terephthalate as the main repeating unit (hereinafter abbreviated after polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate), polyethylene (terephthalate/decanedicarboxylate), and the like. These polyesters may be used singly or in combination of two or more.

Further, as the polyamide, specifically, aliphatic polyamide such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, copolymer of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid Hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamide such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) containing structural units derived from, polyamide MXD6 (polymetallic Polyamides containing aromatics such as silylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); Copolymerized polyamides, polyesteramide copolymers and polyetheresteramide copolymers which are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and polyamides such as these copolymers. These polyamides may be used singly or in combination of two or more.

The substrate layer 1 preferably includes at least one of a polyester film, a polyamide film, and a polyolefin film, preferably includes at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, More preferably, at least one of an oriented polyethylene terephthalate film, an oriented polybutylene terephthalate film, an oriented nylon film, and an oriented polypropylene film is included, and the biaxially oriented polyethylene terephthalate film, biaxially oriented polybutylene terephthalate film, and biaxially oriented nylon film , biaxially oriented polypropylene film.

The base material layer 1 may be a single layer, or may be composed of two or more layers. When the substrate layer 1 is composed of two or more layers, the substrate layer 1 may be a laminate obtained by laminating resin films with an adhesive or the like, or may be formed by co-extrusion of resin to form two or more layers. It may also be a laminate of resin films. A laminate of two or more resin films formed by coextrusion of resin may be used as the base material layer 1 without being stretched, or may be used as the base material layer 1 by being uniaxially or biaxially stretched.

Specific examples of the laminate of two or more resin films in the substrate layer 1 include a laminate of a polyester film and a nylon film, a laminate of nylon films of two or more layers, and a laminate of polyester films of two or more layers. etc., preferably a laminate of a stretched nylon film and a stretched polyester film, a laminate of two or more layers of stretched nylon films, and a laminate of two or more layers of stretched polyester films. For example, when the substrate layer 1 is a laminate of two layers of resin films, a laminate of polyester resin films and polyester resin films, a laminate of polyamide resin films and polyamide resin films, or a laminate of polyester resin films and polyamide resin films. A laminate is preferred, and a laminate of polyethylene terephthalate film and polyethylene terephthalate film, a laminate of nylon film and nylon film, or a laminate of polyethylene terephthalate film and nylon film is more preferred. In addition, the polyester resin is resistant to discoloration when, for example, an electrolytic solution adheres to the surface. It is preferably located in the outermost layer.

When the substrate layer 1 is a laminate of two or more layers of resin films, the two or more layers of resin films may be laminated via an adhesive. Preferred adhesives are the same as those exemplified for the adhesive layer 2 described later. The method for laminating two or more layers of resin films is not particularly limited, and known methods can be employed. Examples thereof include dry lamination, sandwich lamination, extrusion lamination, thermal lamination, and the like. A lamination method is mentioned. When laminating by dry lamination, it is preferable to use a polyurethane adhesive as the adhesive. At this time, the thickness of the adhesive is, for example, about 2 to 5 μm. Alternatively, an anchor coat layer may be formed on the resin film and laminated. As the anchor coat layer, the same adhesives as those exemplified in the adhesive layer 2 described later can be used. At this time, the thickness of the anchor coat layer is, for example, about 0.01 μm to 1.0 μm.

At least one of the surface and the inside of the substrate layer 1 may contain additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents. good. Only one type of additive may be used, or two or more types may be mixed and used.

In the present disclosure, it is preferable that a lubricant exists on the surface of the base material layer 1 from the viewpoint of improving the moldability of the exterior material. The lubricant is not particularly limited, but preferably includes an amide-based lubricant. Lubricants may be used singly or in combination of two or more.

The lubricant present on the surface of the substrate layer 1 may be obtained by exuding the lubricant contained in the resin constituting the substrate layer 1, or by coating the surface of the substrate layer 1 with the lubricant. may

The thickness of the base material layer 1 is not particularly limited as long as it functions as a base material. When the substrate layer 1 is a laminate of two or more resin films, the thickness of each resin film constituting each layer is preferably about 2 to 25 μm.

[Adhesive layer 2]
The adhesive layer 2 is a layer provided between the base material layer 1 and the barrier layer 3 as necessary for the purpose of improving the adhesiveness between them.

The adhesive layer 2 is made of an adhesive capable of bonding the base material layer 1 and the barrier layer 3 together. The adhesive used to form the adhesive layer 2 is not limited, but may be, for example, a two-component curing adhesive (two-component adhesive), or a one-component curing adhesive (one-component adhesive ). Furthermore, the adhesive used to form the adhesive layer 2 may be any of chemical reaction type, solvent volatilization type, hot melt type, hot pressure type, and the like. Further, the adhesive layer 2 may be a single layer or multiple layers.

Specific examples of the adhesive component contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester; polyether; polyurethane; epoxy resin; Phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefin resins such as polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins; polyvinyl acetate; cellulose; (meth)acrylic resins; polyimide; polycarbonate; amino resin such as urea resin and melamine resin; rubber such as chloroprene rubber, nitrile rubber and styrene-butadiene rubber; These adhesive components may be used singly or in combination of two or more. Among these adhesive components, polyurethane adhesives are preferred.

Examples of polyurethane adhesives include polyurethane adhesives containing a main agent containing a polyol compound and a curing agent containing an isocyanate compound.

Further, the adhesive layer 2 may contain other components as long as they do not impede adhesion, and may contain colorants, thermoplastic elastomers, tackifiers, fillers, and the like. Since the adhesive layer 2 contains a coloring agent, the exterior material can be colored. Known substances such as pigments and dyes can be used as the colorant. In addition, only one type of colorant may be used, or two or more types may be mixed and used.

The type of pigment is not particularly limited as long as it does not impair the adhesiveness of the adhesive layer 2 . Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, and isoindolenine-based pigments. Pigments such as black, titanium oxide, cadmium, lead, and chromium oxide may be used. Other examples include fine powder of mica (mica), fish scale foil, and the like.

Among the coloring agents, carbon black is preferable, for example, in order to make the external appearance of the exterior material black.

The average particle size of the pigment is not particularly limited, and is, for example, approximately 0.05 to 5 μm, preferably approximately 0.08 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction/scattering particle size distribution analyzer.

The content of the pigment in the adhesive layer 2 is not particularly limited as long as the exterior material is colored.

The thickness of the adhesive layer 2 is not particularly limited as long as the substrate layer 1 and the barrier layer 3 can be adhered. Preferred ranges include about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[Colored layer]
The colored layer is a layer provided as necessary between the base layer 1 and the barrier layer 3 (not shown). When the adhesive layer 2 is provided, a colored layer may be provided between the base material layer 1 and the adhesive layer 2 and between the adhesive layer 2 and the barrier layer 3 . Further, a colored layer may be provided outside the base material layer 1 . By providing the colored layer, the exterior material can be colored.

The colored layer can be formed, for example, by applying ink containing a coloring agent to the surface of the substrate layer 1, the adhesive layer 2, or the barrier layer 3. Known substances such as pigments and dyes can be used as the colorant. In addition, only one type of colorant may be used, or two or more types may be mixed and used.

Specific examples of the colorant contained in the colored layer are the same as those exemplified in the section [Adhesive layer 2].

[Barrier layer 3]
The barrier layer 3 is a layer that prevents at least the infiltration of moisture.

As the barrier layer 3, for example, a metal foil, a deposited film, a resin layer, or the like having barrier properties can be used. The deposited film includes a metal deposited film, an inorganic oxide deposited film, a carbon-containing inorganic oxide deposited film, and the like, and the resin layer includes polyvinylidene chloride and the like. The barrier layer 3 may also include a resin film provided with at least one of these deposited films and resin layers. A plurality of barrier layers 3 may be provided. The barrier layer 3 preferably includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 3 include aluminum alloy, stainless steel, titanium steel, and the like. When used as a metal foil, at least one of an aluminum alloy foil and a stainless steel foil may be included. preferable.

From the viewpoint of improving the formability of the exterior material, the aluminum alloy foil is more preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy. It is preferably an aluminum alloy foil containing. In the aluminum alloy foil containing iron (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. When the iron content is 0.1% by mass or more, it is possible to obtain an exterior material having superior formability. When the iron content is 9.0% by mass or less, it is possible to obtain an exterior material having superior flexibility. As the soft aluminum alloy foil, for example, JIS H4160: 1994 A8021H-O, JIS H4160: 1994 A8079H-O, JIS H4000: 2014 A8021P-O, or an aluminum alloy having a composition specified by JIS H4000: 2014 A8079P-O foil.

Examples of stainless steel foils include austenitic, ferritic, austenitic/ferritic, martensitic, and precipitation hardened stainless steel foils. Furthermore, from the viewpoint of providing an exterior material having excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L, etc. Among these, SUS304 is particularly preferable.

The thickness of the barrier layer 3, in the case of a metal foil, is sufficient to exhibit at least the function of a barrier layer that prevents permeation of moisture, and is, for example, about 9 to 200 μm. The thickness of the barrier layer 3 is, for example, preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, particularly preferably about 35 μm or less, and preferably about 10 μm or more, more preferably about 10 μm or more. About 20 μm or more, more preferably about 25 μm or more, and the preferred range of the thickness is about 10 to 85 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 35 μm, about 20 to 85 μm, and 20 to 50 μm. about 20 to 40 μm, about 20 to 35 μm, about 25 to 85 μm, about 25 to 50 μm, about 25 to 40 μm, and about 25 to 35 μm. When the barrier layer 3 is made of an aluminum alloy foil, the above range is particularly preferred. In particular, when the barrier layer 3 is made of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, and even more preferably about 40 μm or less. 30 μm or less, particularly preferably about 25 μm or less, preferably about 10 μm or more, more preferably about 15 μm or more. About 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

Moreover, when the barrier layer 3 is a metal foil, it is preferable that at least the surface opposite to the base material layer is provided with a corrosion-resistant film in order to prevent dissolution and corrosion. The barrier layer 3 may be provided with a corrosion resistant coating on both sides. Here, the corrosion-resistant film is, for example, a hydrothermal transformation treatment such as boehmite treatment, a chemical conversion treatment, an anodizing treatment, or a corrosion prevention treatment of applying a coating agent to the surface of the barrier layer. It refers to a thin film that provides properties. As the treatment for forming the corrosion-resistant film, one type may be performed, or two or more types may be used in combination. Among these treatments, the hydrothermal transformation treatment and the anodizing treatment are treatments in which the surface of the metal foil is dissolved with a treatment agent to form a metal compound having excellent corrosion resistance. These treatments are sometimes included in the definition of chemical conversion treatment. When the barrier layer 3 has a corrosion-resistant film, the barrier layer 3 includes the corrosion-resistant film.

Various types of corrosion-resistant coatings formed by chemical conversion treatment are known, and are mainly composed of at least one of phosphates, chromates, fluorides, triazinethiol compounds, and rare earth oxides. and corrosion-resistant coatings containing.

[Heat-fusible resin layer 4]
The heat-fusible resin layer 4 corresponds to the innermost layer, and is a layer (sealant layer) that performs the function of sealing the electricity storage device element by heat-sealing the heat-fusible resin layers to each other when assembling the electricity storage device. .

The resin constituting the heat-fusible resin layer 4 is not particularly limited as long as it is heat-fusible, but resins containing polyolefin skeletons such as polyolefins and acid-modified polyolefins are preferable. The inclusion of a polyolefin skeleton in the resin constituting the heat-fusible resin layer 4 can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, or the like. Further, when the resin constituting the heat-fusible resin layer 4 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected near wavenumbers of 1760 cm ⁻¹ and 1780 cm ⁻¹ . In the case where the heat-fusible resin layer 4 is a layer composed of maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected when measured by infrared spectroscopy. However, if the degree of acid denaturation is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; block copolymers of ethylene), random copolymers of polypropylene (for example, random copolymers of propylene and ethylene); propylene-α-olefin copolymers; ethylene-butene-propylene terpolymers; Among these, polypropylene is preferred. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin-based resins may be used alone or in combination of two or more.

Also, the polyolefin may be a cyclic polyolefin. A cyclic polyolefin is a copolymer of an olefin and a cyclic monomer. Examples of the olefin, which is a constituent monomer of the cyclic polyolefin, include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. be done. Examples of cyclic monomers constituting cyclic polyolefins include cyclic alkenes such as norbornene; cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene and norbornadiene. Among these, cyclic alkenes are preferred, and norbornene is more preferred.

Acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of polyolefin with an acid component. As the acid-modified polyolefin, the above polyolefin, a copolymer obtained by copolymerizing the above polyolefin with a polar molecule such as acrylic acid or methacrylic acid, or a polymer such as crosslinked polyolefin can be used. Examples of acid components used for acid modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride and itaconic anhydride, and anhydrides thereof.

The acid-modified polyolefin may be an acid-modified cyclic polyolefin. Acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin in place of the acid component, or by block-polymerizing or graft-polymerizing the acid component to the cyclic polyolefin. be. The acid-modified cyclic polyolefin is the same as described above. The acid component used for acid modification is the same as the acid component used for modification of polyolefin.

Preferred acid-modified polyolefins include carboxylic acid- or anhydride-modified polyolefins, carboxylic acid- or anhydride-modified polypropylenes, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

The heat-fusible resin layer 4 may be formed of one type of resin alone, or may be formed of a blend polymer in which two or more types of resin are combined. Furthermore, the heat-fusible resin layer 4 may be formed of only one layer, or may be formed of two or more layers of the same or different resins.

Moreover, the heat-fusible resin layer 4 may contain a lubricant or the like as necessary. When the heat-fusible resin layer 4 contains a lubricant, it is possible to improve the moldability of the power storage device exterior material. The lubricant is not particularly limited, and known lubricants can be used. Lubricants may be used singly or in combination of two or more.

The lubricant is not particularly limited, but preferably includes an amide-based lubricant.

The lubricant present on the surface of the heat-fusible resin layer 4 may be obtained by exuding the lubricant contained in the resin constituting the heat-fusible resin layer 4 . The surface may be coated with a lubricant.

The thickness of the heat-fusible resin layer 4 is not particularly limited as long as the heat-fusible resin layers are heat-sealed to each other to exhibit the function of sealing the electricity storage device element. About 85 μm or less, more preferably about 15 to 85 μm. For example, when the thickness of the adhesive layer 5 described later is 10 μm or more, the thickness of the heat-fusible resin layer 4 is preferably about 85 μm or less, more preferably about 15 to 45 μm. When the thickness of the adhesive layer 5 described later is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-fusible resin layer 4 is preferably about 20 μm or more, more preferably 35 to 85 μm. degree.

[Adhesion layer 5]
The adhesive layer 5 is a layer provided between the barrier layer 3 (or the acid-resistant film) and the heat-fusible resin layer 4 as necessary in order to firmly bond them.

The adhesive layer 5 is made of a resin capable of bonding the barrier layer 3 (or acid-resistant coating) and the heat-sealable resin layer 4 together. As the resin used for forming the adhesive layer 5, for example, the same adhesives as those exemplified for the adhesive layer 2 can be used. As the resin used for forming the adhesive layer 5, the polyolefins and acid-modified polyolefins exemplified for the heat-fusible resin layer 4 can also be used. From the viewpoint of firmly bonding the barrier layer 3 (or the acid-resistant film) and the heat-sealable resin layer 4, the acid-modified polyolefin includes polyolefins modified with carboxylic acid or its anhydride, carboxylic acid or its anhydride. Polypropylene modified with , maleic anhydride-modified polyolefin, and maleic anhydride-modified polypropylene are particularly preferred. That is, the resin forming the adhesive layer 5 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. Whether the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected near wavenumbers of 1760 cm ⁻¹ and 1780 cm ⁻¹ . However, if the degree of acid denaturation is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

From the viewpoint of firmly bonding the barrier layer 3 (or the acid-resistant film) and the heat-fusible resin layer 4, the adhesive layer 5 preferably contains an acid-modified polyolefin.

Furthermore, from the viewpoint of making the exterior material excellent in shape stability after molding while reducing the thickness of the exterior material, the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. is more preferred. Preferred examples of the acid-modified polyolefin include those mentioned above.

The adhesive layer 5 is at least one selected from the group consisting of acid-modified polyolefins, compounds having an isocyanate group, compounds having an oxazoline group, epoxy resins (compounds having an epoxy group), carbodiimide compounds, polyurethanes, and polyesters. It is preferably a cured product of a resin composition containing an acid-modified polyolefin, a compound having an isocyanate group, an epoxy resin (a compound having an epoxy group), and at least one selected from the group consisting of polyurethane. A cured product of a resin composition containing one curing agent is particularly preferred. In addition, when unreacted products of a curing agent such as a compound having an isocyanate group, a compound having an oxazoline group, an epoxy resin (a compound having an epoxy group), a carbodiimide compound, polyurethane, and polyester remain in the adhesive layer 5 , the presence of unreacted substances can be confirmed by a method selected from, for example, infrared spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

In addition, from the viewpoint of firmly bonding the barrier layer 3 (or acid-resistant film) and the heat-fusible resin layer 4, the adhesive layer 5 contains oxygen atoms, heterocycles, C═N bonds, and C—O—C It is preferably a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of bonds. Examples of the curing agent having a heterocyclic ring include compounds having an oxazoline group, epoxy resins (compounds having an epoxy group), and the like. Moreover, the curing agent having a C=N bond includes compounds having an oxazoline group, compounds having an isocyanate group, and the like. Examples of curing agents having a C—O—C bond include compounds having an oxazoline group, epoxy resins (compounds having an epoxy group), polyurethanes, and the like. The adhesive layer 5 is a cured product of a resin composition containing these curing agents, for example, gas chromatography mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF -SIMS) and X-ray photoelectron spectroscopy (XPS).

The isocyanate group-containing compound is not particularly limited, but from the viewpoint of strong adhesion between the barrier layer 3 (or acid-resistant film) and the adhesive layer 5, polyfunctional isocyanate compounds are preferred. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of polyfunctional isocyanate-based curing agents include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymers or nurates thereof. compounds, mixtures thereof, copolymers with other polymers, and the like.

The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. A range is more preferred.

The compound having an oxazoline group is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of compounds having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain. Moreover, as a commercial item, the Epocross series by Nippon Shokubai Co., Ltd. etc. are mentioned, for example.

The ratio of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably 0.5 to 40% by mass, in the resin composition constituting the adhesive layer 5. is more preferable. Thereby, the adhesive strength between the barrier layer 3 (or the acid-resistant film) and the adhesive layer 5 can be effectively increased.

The epoxy resin (compound having an epoxy group) is not particularly limited as long as it is a resin capable of forming a crosslinked structure with the epoxy groups present in the molecule, and known epoxy resins can be used. The weight average molecular weight of the epoxy resin is preferably about 50 to 2000, more preferably about 100 to 1000, still more preferably about 200 to 800. In the present disclosure, the weight average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard sample.

Specific examples of epoxy resins include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, and the like. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more types.

The proportion of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably in the range of 0.5 to 40% by mass, in the resin composition constituting the adhesive layer 5. is more preferred. Thereby, the adhesive strength between the barrier layer 3 (or the acid-resistant film) and the adhesive layer 5 can be effectively increased.

The carbodiimide compound is not particularly limited as long as it is a compound having at least one carbodiimide group (-N=C=N-). As the carbodiimide compound, a polycarbodiimide compound having at least two carbodiimide groups is preferred.

The ratio of the carbodiimide compound in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably in the range of 0.5 to 40% by mass, in the resin composition constituting the adhesive layer 5. is more preferred. Thereby, the adhesive strength between the barrier layer 3 (or the acid-resistant film) and the adhesive layer 5 can be effectively increased.

As the polyurethane in the adhesive layer 5, for example, a combination of a polyol compound and a polyisocyanate compound, a combination of a polyurethane compound having a hydroxyl group and a polyisocyanate compound, a combination of a polyurethane compound having an isocyanate group and a polyol compound, or the like is used as a curing agent. can be used as

The proportion of polyurethane in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably in the range of 0.5 to 40% by mass, in the resin composition constituting the adhesive layer 5. more preferred. Thereby, the adhesive strength between the barrier layer 3 (or the acid-resistant film) and the adhesive layer 5 can be effectively increased.

As the polyester in the adhesive layer 5, for example, an amide ester resin is preferable. Amide ester resins are generally produced by the reaction of carboxyl groups and oxazoline groups.

The proportion of polyester in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably in the range of 0.5 to 40% by mass, in the resin composition constituting the adhesive layer 5. more preferred. Thereby, the adhesive strength between the barrier layer 3 (or the acid-resistant film) and the adhesive layer 5 can be effectively increased.

The adhesive layer 5 is at least one selected from the group consisting of an acid-modified polyolefin, a compound having an isocyanate group, a compound having an oxazoline group, an epoxy resin (a compound having an epoxy group), a carbodiimide compound, a polyurethane, and a polyester. In the case of a cured product of a resin composition containing, acid-modified polyolefin functions as a main agent, a compound having an isocyanate group, a compound having an oxazoline group, an epoxy resin (a compound having an epoxy group), a carbodiimide compound, polyurethane, and polyester each function as a curing agent.

From the viewpoint of increasing the adhesive strength between the barrier layer 3 (or acid-resistant film) and the heat-fusible resin layer 4 by the adhesive layer 5, the curing agent may be composed of two or more compounds.

The content of the curing agent in the resin composition forming the adhesive layer 5 is preferably in the range of about 0.1 to 50% by mass, more preferably in the range of about 0.1 to 30% by mass. More preferably, it is in the range of about 0.1 to 10% by mass.

The thickness of the adhesive layer 5 is preferably about 50 μm or less, about 40 μm or less, about 30 μm or less, about 20 μm or less, about 5 μm or less, and preferably about 0.1 μm or more and about 0.5 μm or more. The thickness range is preferably about 0.1 to 50 μm, about 0.1 to 40 μm, about 0.1 to 30 μm, about 0.1 to 20 μm, about 0.1 to 5 μm, About 0.5 to 50 μm, about 0.5 to 40 μm, about 0.5 to 30 μm, about 0.5 to 20 μm, and about 0.5 to 5 μm can be mentioned. More specifically, when the adhesive exemplified for the adhesive layer 2 is used, the thickness is preferably about 2 to 10 μm, more preferably about 2 to 5 μm. In the case of using the resin exemplified for the heat-fusible resin layer 4, the thickness is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, still more preferably about 0.5 to 5 μm. When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing it by heating or the like.

For the purpose of at least one of improving design, electrolyte resistance, scratch resistance, moldability, etc., the exterior material for an electricity storage device of the present disclosure is provided on the base layer 1 (base layer 1 (the side opposite to the barrier layer 3) may be provided with a surface coating layer 6. The surface coating layer 6 is a layer positioned on the outermost layer side of the exterior material for an electricity storage device when an electricity storage device is assembled using the exterior material for an electricity storage device.

The surface coating layer 6 can be formed of resin such as polyvinylidene chloride, polyester, polyurethane, acrylic resin, and epoxy resin, for example.

When the resin forming the surface coating layer 6 is a curable resin, the resin may be either a one-component curable type or a two-component curable type, preferably the two-component curable type. Examples of the two-liquid curing resin include two-liquid curing polyurethane, two-liquid curing polyester, and two-liquid curing epoxy resin. Among these, two-liquid curable polyurethane is preferred.

Examples of two-liquid curable polyurethanes include polyurethanes containing a main agent containing a polyol compound and a curing agent containing an isocyanate compound. Preferable examples include two-component curing type polyurethanes using polyols such as polyester polyols, polyether polyols, and acrylic polyols as main agents and aromatic or aliphatic polyisocyanates as curing agents. Moreover, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group in a side chain in addition to the terminal hydroxyl group of the repeating unit. Since the surface coating layer 6 is made of polyurethane, the exterior material for an electric storage device is imparted with excellent electrolyte resistance.

At least one of the surface and the inside of the surface coating layer 6 may be coated with the above-described lubricant or anti-rust agent as necessary depending on the functionality to be provided on the surface coating layer 6 and its surface. Additives such as blocking agents, matting agents, flame retardants, antioxidants, tackifiers and antistatic agents may be included. Examples of the additive include fine particles having an average particle size of about 0.5 nm to 5 μm. The average particle size of the additive is the median size measured with a laser diffraction/scattering particle size distribution analyzer.

Additives may be either inorganic or organic. Also, the shape of the additive is not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, scale-like, and the like.

Specific examples of additives include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, and antimony oxide. , titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotube, high melting point nylon, acrylate resin, Crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, and the like. Additives may be used singly or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferred from the viewpoint of dispersion stability and cost. In addition, the additive may be subjected to various surface treatments such as insulation treatment and high-dispersion treatment.

A method for forming the surface coating layer 6 is not particularly limited, and an example thereof includes a method of applying a resin for forming the surface coating layer 6 . When adding additives to the surface coating layer 6, a resin mixed with the additives may be applied.

The thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above functions as the surface coating layer 6, and is, for example, approximately 0.5 to 10 μm, preferably approximately 1 to 5 μm.

Method for manufacturing a laminate (armoring material) The method for manufacturing an exterior material for an electricity storage device is not particularly limited as long as a laminate obtained by laminating each layer included in the exterior material for an electricity storage device of the present disclosure is obtained. A method including a step of laminating the material layer 1, the barrier layer 3, and the heat-fusible resin 4 in this order may be mentioned.

An example of the method for manufacturing the exterior material for an electricity storage device of the present disclosure is as follows. First, a layered body (hereinafter also referred to as "layered body A") is formed by laminating a substrate layer 1, an adhesive layer 2, and a barrier layer 3 in this order. Specifically, the laminate A is formed by applying an adhesive used for forming the adhesive layer 2 on the substrate layer 1 or on the barrier layer 3 whose surface is chemically treated as necessary, by a gravure coating method, It can be performed by a dry lamination method in which the barrier layer 3 or the substrate layer 1 is laminated and the adhesive layer 2 is cured after coating and drying by a coating method such as a roll coating method.

Next, on the barrier layer 3 of the laminate A, the heat-fusible resin layer 4 is laminated. When the heat-fusible resin layer 4 is directly laminated on the barrier layer 3, the heat-fusible resin layer 4 is laminated on the barrier layer 3 of the laminate A by a method such as thermal lamination or extrusion lamination. do it. When the adhesive layer 5 is provided between the barrier layer 3 and the heat-fusible resin layer 4, for example, (1) the adhesive layer 5 and the heat-fusible resin layer are placed on the barrier layer 3 of the laminate A. 4 (co-extrusion lamination method, tandem lamination method); A method of laminating on the barrier layer 3 of the laminate A by a thermal lamination method, or forming a laminate in which an adhesive layer 5 is laminated on the barrier layer 3 of the laminate A, and laminating this with a heat-fusible resin layer 4 by a thermal lamination method Lamination method (3) While pouring the melted adhesive layer 5 between the barrier layer 3 of the laminate A and the heat-fusible resin layer 4 formed into a sheet in advance, the adhesive layer 5 is interposed. (4) coating the barrier layer 3 of the laminate A with an adhesive for forming the adhesive layer 5 in solution, A drying method, a baking method, or the like is used to laminate the adhesive layer 5 , and a heat-fusible resin layer 4 that has been formed into a sheet in advance is laminated on the adhesive layer 5 .

When providing the surface coating layer 6 , the surface coating layer 6 is laminated on the surface of the substrate layer 1 opposite to the barrier layer 3 . The surface coating layer 6 can be formed, for example, by coating the surface of the substrate layer 1 with the above-described resin for forming the surface coating layer 6 . The order of the step of laminating the barrier layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer 6 on the surface of the base material layer 1 is not particularly limited. For example, after forming the surface coating layer 6 on the surface of the substrate layer 1 , the barrier layer 3 may be formed on the surface of the substrate layer 1 opposite to the surface coating layer 6 .

Surface coating layer 6/base layer 1/optionally provided adhesive layer 2/barrier layer 3/optionally provided adhesive layer 5/thermal fusion bonding as described above A laminate having the flexible resin layer 4 in this order is formed, and in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as necessary, it may be further subjected to heat treatment.

In the exterior material for an electricity storage device, each layer constituting the laminate may be subjected to surface activation treatment such as corona treatment, blasting treatment, oxidation treatment, and ozone treatment to improve processability as necessary. . For example, by subjecting the surface of the substrate layer 1 opposite to the barrier layer 3 to corona treatment, the printability of the ink onto the surface of the substrate layer 1 can be improved.

Use of power storage device The power storage device exterior material of the present disclosure can be suitably used for power storage devices such as batteries (including capacitors, capacitors, etc.). Moreover, although the exterior material for an electricity storage device of the present disclosure may be used for either a primary battery or a secondary battery, it is preferably a secondary battery. The type of secondary battery to which the power storage device exterior material of the present disclosure is applied is not particularly limited. Cadmium storage batteries, nickel/iron storage batteries, nickel/zinc storage batteries, silver oxide/zinc storage batteries, metal-air batteries, polyvalent cation batteries, capacitors, capacitors, and the like. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries can be mentioned as suitable targets for application of the power storage device exterior material of the present disclosure.

EXAMPLES The present disclosure will be described in detail below with reference to examples and comparative examples. However, the present disclosure is not limited to the examples.

[Examples 1 to 6 and Comparative Examples 1 to 6]
<Manufacturing of laminate (exterior material) constituting container>
As a substrate layer, a laminated film was prepared by bonding a polyethylene terephthalate film (thickness 12 μm) and a biaxially oriented nylon film (thickness 15 μm) with an adhesive layer (polyol compound and aromatic isocyanate compound). Next, a barrier layer made of aluminum foil (JIS H4160: 1994 A8021H-O, thickness 40 μm) with an acid-resistant film formed on both sides was laminated on the biaxially oriented nylon film of the base layer by a dry lamination method. rice field. Specifically, one side of an aluminum foil with an acid-resistant film (chromate treatment) formed on both sides is coated with a two-component curable urethane adhesive (polyol compound and aromatic isocyanate compound), and the adhesive is applied onto the aluminum foil. A layer (thickness 3 μm after curing) was formed. Next, after laminating the adhesive layer on the aluminum foil and the biaxially oriented nylon film side of the substrate layer, an aging treatment is performed to produce a laminate of substrate layer/adhesive layer/barrier layer. bottom.

Next, a maleic anhydride-modified polypropylene (40 μm thick) as an adhesive layer and a polypropylene (40 μm thick) as a heat-fusible resin layer are co-extruded on the barrier layer of the resulting laminate. Thus, the adhesive layer/heat-fusible resin layer was laminated on the barrier layer. Next, by aging and heating the obtained laminate, polyethylene terephthalate film (12 μm)/adhesive layer (3 μm)/biaxially oriented nylon film (15 μm)/adhesive layer (3 μm)/barrier layer ( 40 μm)/adhesive layer (40 μm)/thermally-fusible resin layer (40 μm) were laminated in this order to obtain an exterior material.

<Production of test sample>
A test sample (electricity storage device in which no electricity storage device element is enclosed) having a structure as shown in FIG. 3 was manufactured using the obtained exterior material. However, unlike the test sample in FIG. 3, two strips were used as the exterior material, and the test sample was manufactured by heat-sealing the heat-fusible resin layers on one side 15 in FIG. . Specifically, the exterior material was cut into a rectangle having a length (MD) of 80 mm and a width (TD) of 120 mm to create two strips. The MD of the power storage device exterior material corresponds to the rolling direction (RD) of the aluminum alloy foil, and the TD of the power storage device exterior material corresponds to the TD of the aluminum alloy foil. Next, in an environment of 25 ° C., each strip is placed in a molding die (female mold) having a rectangular aperture of 32 mm (MD) x 55 mm (TD). Book 1 (reference) The maximum height roughness (nominal value of Rz) specified in Table 2 of the surface roughness standard piece for comparison is 3.2 μm. Corner R 2.0 mm, ridge R 1.0 mm) Mold corresponding to (male mold, surface is JIS B 0659-1: 2002 Annex 1 (reference) Maximum height roughness (nominal value of Rz ) is 1.6 μm, using a corner radius of 2.0 mm and a ridgeline radius of 1.0 mm, pressurization (surface pressure) is 0.25 MPa, and cold forming (pull-in one-stage forming) is performed at a depth of 3.0 mm. , forming a cup-shaped housing in the center. Next, with nothing inside, the two strips were stacked so that the heat-sealable resin layer was on the inside, and the metal terminals were attached by heat-sealing using a heat-seal bar (7 mm wide). The first heat-sealed portion 11 shown in FIG. 3 was formed by interposing the first heat-sealed portion 11, and the heat-sealed portion opposite thereto was formed. Next, the second heat-sealed portion 12 of FIG. 3 is formed, and the heat-sealed portion facing the second heat-sealed portion 12 is formed to form a bag shape, thereby obtaining a test sample having a rectangular package in plan view. Obtained. The metal terminal of the positive electrode is an aluminum foil, and the metal terminal of the negative electrode is a CuNi-plated foil, each having a thickness of 0.1 mm, a length of 30 mm, and a width of 5 mm, and subjected to the same chromate treatment as the barrier layer. An adhesive film was interposed between each of the metal terminals and the heat-sealable resin layer. The adhesive film is a maleic anhydride-modified polypropylene film (thickness 100 μm). In each example and comparative example, the heat-sealing conditions were such that the surface pressure was adjusted between 0.1 MPa and 2.0 MPa (surface pressure shown in Table 1), the temperature was 190 ° C., and the sealing time was 3 seconds. The width was 7 mm. By changing the heat-sealing conditions, the ratio of the thickness of the heat-sealed portion of the heat-sealable resin layer based on the thickness of the portion where the heat-sealable resin layer is not heat-sealed (100%). changes. As the surface pressure increases, the heat-sealable resin layer is crushed and the thickness of the heat-sealed portion becomes thinner, but the adhesion tends to increase. According to the above procedure, the ratio of the thickness A of the heat-fusible resin layer in the first heat-fusible part 11 when the thickness C of the heat-fusible resin layer in the portion not heat-sealed is 100% and the ratio of the thickness B of the heat-sealable resin layer in the second heat-sealing portion 12 to the values shown in Table 1 (electricity storage device in which no electricity storage device element is enclosed). The thicknesses A, B, and C of the heat-fusible resin layer were each obtained by measuring the thickness of the cross section of the heat-fusible resin layer. Specifically, for the thickness A of the heat-sealable resin layer, the thickness of the section of the first heat-sealed portion where the metal terminal is located was measured. For the thickness B of the heat-sealable resin layer, the thickness of the cross section near the central portion of the second heat-sealed portion was measured. As for the thickness C of the heat-fusible resin layer, the cross-sectional thickness of the top surface portion 14 of the package was measured among the portions where the heat-fusible resin layer was not heat-sealed. The thicknesses A, B, and C of the heat-fusible resin layers are each the sum of the thicknesses of the heat-fusible resin layers facing each other in the package. The thicknesses A, B, and C of the heat-fusible resin layer are determined by cutting the package in the thickness direction using a microtome, exposing the cross-section of the heat-fusible resin layer, and observing it with a microscope. made a measurement

<Insulation evaluation>
The exterior material was cut into a rectangle having a length (MD) of 80 mm and a width (TD) of 120 mm. . Next, the lithium-ion battery element is enclosed in the obtained container so that the metal terminal extends outward from one side of the opening, and the electrolyte is added and the metal terminals (positive electrode terminal and negative electrode terminal) are sandwiched. While doing so, the opening was hermetically sealed with a width of 7 mm to fabricate a lithium ion battery. At this time, the heat sealing was performed under the same sealing conditions as in Example 1-6 and Comparative Example 1-6 (for this reason, the thickness of the heat-sealable resin layer in the heat-sealed portion was the same as the test sample The heat-sealed portion of the side seal of the obtained lithium ion battery was then bent inward and restored. Next, an insulation evaluation test against cracks was carried out using an impulse application method (lithium ion battery insulation tester manufactured by Nihon Technart Co., Ltd.). First, 10 of the above lithium ion batteries were prepared, and an impulse voltage of 100 V was applied between the negative terminal of each lithium ion battery and the aluminum foil of the packaging material, and the voltage drop after 99 msec was 40 V. Those within the range were considered to have passed the test. The three-level evaluation criteria were set as follows based on the number of NG samples (failure, voltage drop of 40 V or more). Table 1 shows the evaluation results.
NG number in 10 samples A: NG number 0 B: NG number 1 to 4 C: NG number 5 or more

<Observation of the inside of the heat-sealed part>
First heat-sealed portion 11, second heat-sealed portion 12, and first heat-sealed portion 11 and second heat-sealed portion of each test sample obtained in Example 1-6 and Comparative Example 1-6 The crossing portion 13 with 12 was cut in the thickness direction to observe the shape in which the heat-fusible resin layer protrudes inside the container. A microtome (manufactured by Yamato Koki Kogyo: REM-710 Litratome) was used for cutting. In each heat-sealed portion, the cross-sectional shape of the heat-sealable resin layer protruding inward has a shape as shown in the schematic diagram of FIG. As shown in FIG. 4, the shortest distance X between the straight line Y connecting the ends A1 and A2 and the projecting tip A was measured to evaluate the protrusion of the heat-fusible resin layer at the heat-sealed portion. In FIG. 4, only the vicinity of the heat-sealed portion of the heat-sealable resin layer of the container of the test sample is drawn, and the tip A of the protruding portion is inside the electricity storage device, and the heat-sealed portion is The portion where the flexible resin layer 4 faces is the heat-sealed portion. When the exterior material is heat-sealed from the upper and lower sides of the heat-fusible resin layer, the heat-fusible resin layer forms a protruding portion that protrudes toward the inside of the container. If the protrusion inward from the heat-sealed portion is large, the heat-sealable resin layer is greatly crushed (that is, the thickness of the heat-sealable resin layer at the heat-sealed portion is thin), and the ends A1, It can be said that there is a high possibility that cracks originating from A2 will occur, and that the insulation is likely to deteriorate. Evaluation criteria are as follows. Table 1 shows the results.
A: The shortest distance X is less than 10 µm.
B: The shortest distance X is 10 μm or more and less than 50 μm.
C: The shortest distance X is 50 μm or more.

That is, the present disclosure provides inventions in the following aspects.
Section 1. At the periphery of a container having a rectangular shape in plan view, which is composed of a laminate including a base material layer located outside, a barrier layer, and a heat-fusible resin layer located inside in this order, the heat-fusible property A method for manufacturing an electricity storage device in which an electricity storage device element is sealed with a package formed by heat-sealing a resin layer,
The method for manufacturing the electricity storage device is such that the metal terminal electrically connected to the electricity storage device element protrudes to the outside, and at least the metal terminal side where the metal terminal is located is located at the periphery of the housing body. Thermal bonding of the heat-fusible resin layer on the peripheral edge and heat of the heat-fusible resin layer on the side peripheral edge that is perpendicular to the metal terminal side peripheral edge and located on the side of the electricity storage device. a sealing step of fusing and sealing the electricity storage device element with the package;
The power storage device to be tested is extracted from the power storage devices obtained in the sealing step, and the metal terminal side peripheral edge portion of the heat-sealed portion on the periphery of the package of the power storage device to be tested is heated. The thickness A of the heat-fusible resin layer in the first heat-fusible portion that is fused, and the heat-fusible resin layer in the second heat-fusible portion that heat-bonds the side peripheral edge portion. and the thickness C of the heat-sealable resin layer in the portion not heat-sealed, and confirm whether the following thickness relationship I and thickness relationship II are satisfied, a thickness confirmation process;
Thickness relationship I: When the thickness C is 100%, the ratio of the thickness A is 70% or more and 95% or less Thickness relationship II: When the thickness C is 100%, the thickness B The ratio is 60% or more and 95% or less As a result of the thickness confirmation step, if both the thickness relationship I and the thickness relationship II are satisfied, the heat sealing conditions in the sealing step are appropriate. Determined, the electricity storage device is manufactured under the heat-sealing conditions,
If at least one of the thickness relationship I and the thickness relationship II is not satisfied, it is determined that the heat sealing conditions in the sealing step are inappropriate, and the heat sealing conditions in the sealing step are changed. a determination step of changing and subjecting to the thickness confirmation step again;
A method for manufacturing an electricity storage device, comprising:
Section 2. At the periphery of a container having a rectangular shape in plan view, which is composed of a laminate including a base material layer located outside, a barrier layer, and a heat-fusible resin layer located inside in this order, the heat-fusible property A quality control method for an electricity storage device in which an electricity storage device element is sealed with a package formed by heat-sealing a resin layer,
The quality control method is such that a metal terminal electrically connected to the electricity storage device element protrudes to the outside, and at least a metal terminal side peripheral edge portion where the metal terminal is located on the periphery of the housing body and the heat-sealing of the heat-sealing resin layer on the side peripheral edge portion perpendicular to the metal terminal side peripheral portion and located on the side side of the electricity storage device. and sealing the power storage device element with the package, the power storage device manufactured by a manufacturing method comprising a sealing step is subject to quality control,
The power storage device to be tested is extracted from the power storage devices obtained in the sealing step, and the metal terminal side peripheral edge portion of the heat-sealed portion on the periphery of the package of the power storage device to be tested is heated. The thickness A of the heat-fusible resin layer in the first heat-fusible portion that is fused, and the heat-fusible resin layer in the second heat-fusible portion that heat-bonds the side peripheral edge portion. and the thickness C of the heat-sealable resin layer in the portion not heat-sealed, and confirm whether the following thickness relationship I and thickness relationship II are satisfied, a thickness confirmation process;
Thickness relationship I: When the thickness C is 100%, the ratio of the thickness A is 70% or more and 95% or less Thickness relationship II: When the thickness C is 100%, the thickness B The ratio is 60% or more and 95% or less As a result of the thickness confirmation step, if both the thickness relationship I and the thickness relationship II are satisfied, the heat sealing conditions in the sealing step are appropriate. Determined, the electricity storage device is manufactured under the heat-sealing conditions,
If at least one of the thickness relationship I and the thickness relationship II is not satisfied, it is determined that the heat sealing conditions in the sealing step are inappropriate, and the heat sealing conditions in the sealing step are changed. a determination step of changing and subjecting to the thickness confirmation step again;
A quality control method in a manufacturing process of an electricity storage device, comprising:

Reference Signs List 1 Base layer 2 Adhesive layer 3 Barrier layer 4 Heat-fusible resin layer 5 Adhesive layer 10 Electricity storage device 11 First heat-sealed portion (heat-sealed portion of metal terminal side peripheral edge)
12 Second heat-sealed portion (heat-sealed portion of side peripheral edge)
13 Intersection portion between the first heat-sealed portion and the second heat-sealed portion 14 Portion where the heat-sealable resin layer is not heat-sealed (top surface portion)
15 One side opposite to one side where the metal terminal is located 20 Container 30 Electricity storage device element 40 Metal terminal 100 Laminate constituting the container

Claims (2)

At the periphery of a container having a rectangular shape in plan view, which is composed of a laminate including a base material layer located outside, a barrier layer, and a heat-fusible resin layer located inside in this order, the heat-fusible property A method for manufacturing an electricity storage device in which an electricity storage device element is sealed with a package formed by heat-sealing a resin layer,
The method for manufacturing the electricity storage device is such that the metal terminal electrically connected to the electricity storage device element protrudes to the outside, and at least the metal terminal side where the metal terminal is located is located at the periphery of the housing body. Thermal bonding of the heat-fusible resin layer on the peripheral edge and heat of the heat-fusible resin layer on the side peripheral edge that is perpendicular to the metal terminal side peripheral edge and located on the side of the electricity storage device. a sealing step of fusing and sealing the electricity storage device element with the package;
The power storage device to be tested is extracted from the power storage devices obtained in the sealing step, and the metal terminal side peripheral edge portion of the heat-sealed portion on the periphery of the package of the power storage device to be tested is heat-fused. The thickness A of the heat-fusible resin layer in the first heat-fusible portion that is attached, and the thickness of the heat-fusible resin layer in the second heat-fusible portion that heat-bonds the side peripheral edge portion Measure the thickness B and the thickness C of the heat-fusible resin layer in the portion that is not heat-sealed, and confirm whether or not the following thickness relationship I and thickness relationship II are satisfied. a confirmation process;
Thickness relationship I: When the thickness C is 100%, the ratio of the thickness A is 70% or more and 95% or less Thickness relationship II: When the thickness C is 100%, the thickness B The ratio is 60% or more and 95% or less As a result of the thickness confirmation step, if both the thickness relationship I and the thickness relationship II are satisfied, the heat sealing conditions in the sealing step are appropriate. Determined, the electricity storage device is manufactured under the heat-sealing conditions,
If at least one of the thickness relationship I and the thickness relationship II is not satisfied, it is determined that the heat sealing conditions in the sealing step are inappropriate, and the heat sealing conditions in the sealing step are changed. a determination step of changing and subjecting to the thickness confirmation step again;
and
For the thickness A of the heat-sealable resin layer, the thickness of the section of the first heat-sealed portion where the metal terminal is located is measured,
For the thickness B of the heat-sealable resin layer, the thickness of the cross section near the central portion of the second heat-sealed portion is measured,
The method for manufacturing an electricity storage device , wherein the ratio of the thickness A of the heat-fusible resin layer is not greater than the ratio of the thickness B. At the periphery of a container having a rectangular shape in plan view, which is composed of a laminate including a base material layer located outside, a barrier layer, and a heat-fusible resin layer located inside in this order, the heat-fusible property A quality control method for an electricity storage device in which an electricity storage device element is sealed with a package formed by heat-sealing a resin layer,
The quality control method is such that a metal terminal electrically connected to the electricity storage device element protrudes to the outside, and at least a metal terminal side peripheral edge portion where the metal terminal is located on the periphery of the housing body and the heat-sealing of the heat-sealing resin layer on the side peripheral edge portion perpendicular to the metal terminal side peripheral portion and located on the side side of the electricity storage device. and sealing the power storage device element with the package, the power storage device manufactured by a manufacturing method comprising a sealing step is subject to quality control,
The power storage device to be tested is extracted from the power storage devices obtained in the sealing step, and the metal terminal side peripheral edge portion of the heat-sealed portion on the periphery of the package of the power storage device to be tested is heat-fused. The thickness A of the heat-fusible resin layer in the first heat-fusible portion that is attached, and the thickness of the heat-fusible resin layer in the second heat-fusible portion that heat-bonds the side peripheral edge portion Measure the thickness B and the thickness C of the heat-fusible resin layer in the portion that is not heat-sealed, and confirm whether or not the following thickness relationship I and thickness relationship II are satisfied. a confirmation process;
Thickness relationship I: When the thickness C is 100%, the ratio of the thickness A is 70% or more and 95% or less Thickness relationship II: When the thickness C is 100%, the thickness B The ratio is 60% or more and 95% or less As a result of the thickness confirmation step, if both the thickness relationship I and the thickness relationship II are satisfied, the heat sealing conditions in the sealing step are appropriate. Determined, the electricity storage device is manufactured under the heat-sealing conditions,
If at least one of the thickness relationship I and the thickness relationship II is not satisfied, it is determined that the heat sealing conditions in the sealing step are inappropriate, and the heat sealing conditions in the sealing step are changed. a determination step of changing and subjecting to the thickness confirmation step again;
and
For the thickness A of the heat-sealable resin layer, the thickness of the section of the first heat-sealed portion where the metal terminal is located is measured,
For the thickness B of the heat-sealable resin layer, the thickness of the cross section near the central portion of the second heat-sealed portion is measured,
A quality control method in a manufacturing process of an electricity storage device , wherein the ratio of the thickness A of the heat-fusible resin layer is not greater than the ratio of the thickness B.

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