JP2021103687A - Exterior material for power storage device, power storage device, and method for manufacturing these - Google Patents

Abstract

To provide an exterior material for a power storage device that prevents a curl caused by molding.SOLUTION: An external material 10 for a power storage device is rectangular in plan view and composed of a film-like molded laminate that includes at least a base material layer, a barrier layer, and a thermally-adhesive resin layer in this order, and includes a rectangular parallelepiped concave part 100 that faces the thermally-adhesive resin layer in which a power storage device element is accommodated. On a straight line connecting the center of the concave part and a short side of the external material for a power storage device in the shortest distance, the external material for a power storage device includes a first short side curved face part 11A and a second short side curved face part 12A in order from the center of the concave part up to the short side of the external material for a power storage device, and includes a first long side curved face part and a second long side curved face part in order from the center of the concave part up to a long side of the external material for a power storage device. The radius of curvature of the first long side curved face part RB1 is larger than the radius of curvature of the first short side curved face part RA1, and the radius of curvature of the first long side curved face part RB1 is 3.8 mm or more.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to an exterior material for a power storage device, a power storage device, and a method for manufacturing the same.

Conventionally, various types of power storage devices have been developed, but in all power storage devices, an exterior material is an indispensable member for sealing a power storage device element such as an electrode or an electrolyte. Conventionally, a metal exterior material has been widely used as an exterior material for a power storage device.

On the other hand, in recent years, with the improvement of high performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., various shapes are required for power storage devices, and thinning and weight reduction are required. However, the metal exterior material for a power storage device, which has been widely used in the past, has a drawback that it is difficult to keep up with the diversification of shapes and there is a limit to weight reduction.

Therefore, in recent years, as an exterior material for a power storage device that can be easily processed into various shapes and can be made thinner and lighter, it is in the form of a film in which a base material layer / barrier layer / heat-sealing resin layer is sequentially laminated. Laminates have been proposed (see, for example, Patent Document 1).

In such an exterior material for a power storage device, a recess is generally formed by cold molding using a mold, and a storage device element such as an electrode or an electrolytic solution is arranged in the space formed by the recess. By heat-sealing the heat-sealing resin layer, a power storage device in which the power storage device element is housed inside the exterior material for the power storage device can be obtained.

Japanese Unexamined Patent Publication No. 2008-287971

In recent years, as a power storage device, a large size and a large aspect ratio may be required. For example, in power storage devices used in electric vehicles, hybrid electric vehicles, etc., more power storage devices can be installed in vehicles by laying them in places where the height of the floor of the vehicle is restricted (without stacking). It is being considered to be installed, and the power storage device installed in such a vehicle will be a large size and a large aspect ratio.

On the other hand, as described above, the exterior material for a power storage device composed of a film-like laminate has recesses formed by cold molding using a mold. Therefore, it is necessary to form a recess having a large size and an aspect ratio (for example, a long side of 200 mm or more and an aspect ratio of 2.5 or more) in the exterior material used for a power storage device having a large size and a large aspect ratio.

However, as a result of examination by the inventors of the present disclosure, when it is attempted to form a recess having a large size and aspect ratio in the exterior material for a power storage device composed of a film-like laminate, the peripheral edge of the exterior material for a power storage device is to be formed. It has been found that when the portion (particularly the long side portion) is curled by molding to seal the power storage device element in the recess, the heat fusion of the heat-sealing resin layer is hindered.

Under such circumstances, it is a main object of the present disclosure to provide an exterior material for a power storage device in which curling due to molding is suppressed.

The inventors of the present disclosure have made diligent studies to solve the above problems. As a result, the exterior material for a power storage device having a rectangular shape in a plan view is formed by forming a film-like laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order. The exterior material for a power storage device is formed so as to project from the heat-sealing resin layer side to the base material layer side, and a rectangular recess in which the power storage device element is housed on the heat-sealing resin layer side. When the exterior material for the power storage device is observed from the base material layer side, the center of the recess is on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short-side curved surface portion and a second short-side curved surface portion are provided in this order from the to the short side of the power storage device exterior material, and when the power storage device exterior material is observed from the base material layer side, On a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance, from the center of the recess to the long side of the exterior material for the power storage device, the first long side curved surface portion and the second The long side curved portion is provided in order, and the radius of curvature R _B ¹ of the first long side curved portion _{is larger than the radius of curvature R A} ^{1 of} the first short side curved portion, and the first long side curved portion is provided. The exterior material for a power storage device having a radius of curvature R _B ¹ of 3.8 mm or more effectively suppresses curling due to molding, and heat of the heat-sealing resin layer when the power storage device element is sealed in the recess. We found that fusion was not easily inhibited.

This disclosure has been completed by further studies based on these findings. That is, the present disclosure provides the inventions of the following aspects.
An exterior material for a power storage device having a rectangular shape in a plan view, in which a film-like laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order is formed.
The exterior material for a power storage device is formed so as to project from the heat-sealing resin layer side to the base material layer side, and has a rectangular parallelepiped shape in which the power storage device element is housed on the heat-sealing resin layer side. It has a recess and
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short side curved surface portion and a second short side curved surface portion are provided in order over the short side of the exterior material.
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A first long side curved surface portion and a second long side curved surface portion are provided in order over the long side of the exterior material.
The radius of curvature R _B ¹ of the first long side curved surface portion is larger than the _{radius of curvature R A} ^{1 of the first short side curved surface portion.}
An exterior material for a power storage device, _{wherein the radius of curvature R B} ^{1 of} the first long side curved surface portion is 3.8 mm or more.

According to the present disclosure, it is possible to provide an exterior material for a power storage device in which curling due to molding is suppressed. Further, according to the present disclosure, it is also possible to provide a method for manufacturing an exterior material for a power storage device, a power storage device, and a method for manufacturing the same.

It is a schematic cross-sectional view which shows an example of the laminated structure of the exterior material for a power storage device of this disclosure. It is a schematic cross-sectional view which shows an example of the laminated structure of the exterior material for a power storage device of this disclosure. It is a schematic cross-sectional view which shows an example of the laminated structure of the exterior material for a power storage device of this disclosure. It is a schematic cross-sectional view which shows an example of the laminated structure of the exterior material for a power storage device of this disclosure. It is a schematic diagram which made clear view of the exterior material for a power storage device of this disclosure. It is a schematic cross-sectional view (stacking structure is omitted) in line AA'in FIG. It is a schematic cross-sectional view (stacking structure is omitted) in line BB'in FIG. It is a schematic diagram for demonstrating the curl evaluation method by molding the exterior material for a power storage device. It is a schematic diagram for demonstrating the curl evaluation method by molding the exterior material for a power storage device.

The exterior material for a power storage device of the present disclosure is for a power storage device having a rectangular shape in a plan view, in which a film-like laminate including at least a base material layer, a barrier layer, and a heat-sealing resin layer is formed in this order. The exterior material for a power storage device, which is an exterior material, is formed so as to project from the heat-sealing resin layer side to the base material layer side, and the power storage device element is housed on the heat-sealing resin layer side. When the exterior material for the power storage device is observed from the base material layer side, the center of the recess and the short side of the exterior material for the power storage device are connected by the shortest distance on a straight line. A first short-side curved surface portion and a second short-side curved surface portion are provided in this order from the center of the recess to the short side of the power storage device exterior material, and the power storage device exterior material is provided as the base material layer. When observed from the side, the first long side extends from the center of the recess to the long side of the exterior material for the power storage device on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A curved surface portion and a second long side curved surface portion are provided in order, and the radius of curvature R _B ¹ of the first long side curved surface portion is larger than the _{radius of curvature R A} ^{1 of the first short side curved surface portion.} _{The radius of curvature R B} ^{1 of the} curved surface of the first long side is 3.8 mm or more. Since the exterior material for the power storage device of the present disclosure has this configuration, curling due to molding is suppressed.

Hereinafter, the exterior material for the power storage device of the present disclosure will be described in detail. In this specification, the numerical range indicated by "~" means "greater than or equal to" and "less than or equal to". For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

The present disclosure is an exterior material for a power storage device having a rectangular shape in a plan view, in which a film-like laminate including at least a base material layer, a barrier layer, and a heat-sealing resin layer is formed in this order. Hereinafter, the shape, size, and the like of the exterior material for the power storage device of the present disclosure will be described first, and then the laminated structure of the laminates constituting the exterior material for the power storage device of the present disclosure, and each layer constituting the laminate. The details of the above, the manufacturing method of the exterior material for the power storage device, and the like will be described in order.

1. 1. Shape and Size of Exterior Material for Power Storage Device The exterior material 10 for power storage device of the present disclosure projects from the heat-sealing resin layer 4 side to the base material layer 1 side as shown in the schematic views of FIGS. 5 to 7. It is molded in such a way (so that the power storage device element is housed), and a rectangular parallelepiped recess 100 in which the power storage device element is housed is provided on the heat-sealing resin layer 4 side. The recess 100 is formed by molding. That is, the exterior material 10 for a power storage device of the present disclosure is a heat-sealing resin layer for a film-like laminate including at least a base material layer 1, a barrier layer 3, and a heat-sealing resin layer 4 in this order. It is formed so as to protrude from the 4 side to the base material layer 1 side, and a rectangular parallelepiped recess 100 in which the power storage device element is housed is formed on the heat-sealing resin layer 4 side.

The exterior material 10 for a power storage device of the present disclosure is on a straight line (that is, a length) connecting the center P of the recess 100 and the short side 13A of the exterior material 10 for a power storage device at the shortest distance when observed from the base material layer 1 side. On a straight line parallel to the side 13B), a first short side curved surface portion 11A and a second short side curved surface portion 12A are provided in this order from the center P of the recess 100 to the short side 13A of the exterior material 10 for the power storage device. (See FIGS. 5 and 6). In the exterior material 10 for the power storage device of the present disclosure, the recess 100 forms a rectangular parallelepiped space and is substantially line-symmetrical (in the direction of the long side) with respect to the center P of the recess 100. The disclosed exterior material 10 for a power storage device includes a pair of first short side curved surface portions 11A and a pair of second short side curved surface portions 12A with reference to the center P of the recess 100 (FIG. 6). reference). The center P of the recess 100 is a point where a straight line connecting the intermediate points of the short sides 13A facing each other and a straight line connecting the intermediate points of the long sides 13B facing each other intersect.

The exterior material 10 for a power storage device of the present disclosure is on a straight line (that is, short) connecting the center P of the recess 100 and the long side 13B of the exterior material 10 for a power storage device at the shortest distance when observed from the base material layer 1 side. On a straight line parallel to the side 13A), a first long side curved surface portion 11B and a second long side curved surface portion 12B are provided in order from the center P of the concave portion 100 to the long side 13B of the exterior material 10 for the power storage device. (See FIGS. 5 and 7). Further, in the exterior material 10 for the power storage device of the present disclosure, the recess 100 forms a rectangular parallelepiped space and is substantially line-symmetrical (in the direction of the short side) with respect to the center P of the recess 100. The disclosed exterior material 10 for a power storage device includes a pair of second long side curved surface portions 11B and a pair of second long side curved surface portions 12B with reference to the center P of the recess 100 (FIG. 7). reference).

Further, in the exterior material 10 for a power storage device of the present disclosure, when observed from the base material layer 1 side, it is between a pair of first short side curved surface portions 11A and a pair of first long side curved surface portions. The region between 11B becomes the top surface portion 100A (flat surface portion) of the recess. Further, the region between the first short side curved surface portion 11A and the second short side curved surface portion 12A becomes the side surface portion 100B of the recess. The region between the first long side curved surface portion 11B and the second long side curved surface portion 12B is also the side surface portion 100B of the recess 100. Since the recess 100 has a rectangular parallelepiped shape, there are four side surface portions 100B. The first short side curved surface portion 11A and the first long side curved surface portion 11B are curved surface portions forming a boundary between the top surface portion and the side surface portion B of the recess, respectively.

Further, a region between the second short side curved surface portion 12A and the short side 13A of the power storage device exterior material 10, the second long side curved surface portion 12B, and the long side 13B of the power storage device exterior material 10 The area between them becomes the peripheral edge portion 100C (flange portion) of the recess 100. The second short side curved surface portion 12A and the second long side curved surface portion 12B are curved surface portions forming a boundary between the flange portion and the side surface portion B of the recess, respectively. As described above, when the peripheral edge (particularly the long side) of the exterior material for the power storage device is curled by molding and the power storage device element is sealed in the recess, the heat-sealing resin layer is heat-sealed. Be hindered. In the exterior material for a power storage device of the present disclosure, the mechanism by which curl due to molding is suppressed can be considered as follows. That is, in the recess formed by molding the exterior material for the power storage device, when the curvature of the curved surface is small, the stress of pulling the exterior material for the power storage device increases during molding, so that the base material layer shrinks after molding. It becomes large and a large molding curl is generated. On the other hand, when the curvature of the curved surface portion of the recess is large, the stress of pulling the exterior material for the power storage device during molding becomes small, so that the force with which the base material layer shrinks after molding becomes small, and the molding curl becomes small. In the exterior material 10 for a power storage device of the present disclosure, since the radius of curvature of the long side curved surface portion is larger than the curvature of the short side curved surface portion and is equal to or more than a predetermined value, molding on the long side side longer than the short side is formed. The curl is small, which is considered to suppress the molding curl on the short side.

In the exterior material 10 for a power storage device of the present disclosure, the radius of curvature R _B ¹ of the first long side curved surface portion 11B is larger than the _{radius of curvature R A} ^{1 of the first short side curved surface portion 11A.} _{Further, the radius of curvature R B} ¹ of the first long side curved surface portion 11B is 3.8 mm or more. The exterior material 10 for a power storage device of the present disclosure satisfies such a relationship of a specific radius of curvature, so that curling due to molding is suppressed. As described above, in the exterior material 10 for the power storage device of the present disclosure, the recess 100 forms a rectangular parallelepiped space, and is substantially line-symmetrical with respect to the center P of the recess 100 (long side direction, short side direction). Therefore, each pair of the first short side curved surface portion 11A, the second short side curved surface portion 12A, the first long side curved surface portion 11B, and the second long side curved surface portion 12B are present. It will have substantially the same radius of curvature.

The radius of curvature R _B ¹ of the first long side curved surface portion 11B may be larger than the _{radius of curvature R A} ^{1 of} the first short side curved surface portion 11A, and the ratio of the radius of curvature R _B ^{1 to} _{the radius of curvature R A} ¹ (radius of curvature). The R _B ¹ / radius of curvature R _A ¹ ) is, for example, about 1.1 or more, and is particularly preferably about 2.5 or more from the viewpoint of more effectively suppressing the molding curl. The upper limit of the ratio is, for example, about 3.0 or less, and the preferable range of the ratio is about 1.1 to 3.0 and about 2.5 to 3.0.

_{Further, the radius of curvature R B} ¹ of the first long side curved surface portion 11B may be 3.8 mm or more, but from the viewpoint of more effectively suppressing molding curl, it is preferably about 4.0 mm or more, more preferably. It is about 4.1 mm or more, more preferably about 4.5 mm or more, further preferably about 8.0 mm or more, and particularly preferably about 10.0 mm or more. The upper limit of the radius of curvature R _B ¹ is, for example, 12.0 mm or less, and _{the preferable range of the radius of curvature R B} ¹ is about 3.8 to 12.0 mm, about 4.0 to 12.0 mm, and so on. Examples thereof include about 4.1 to 12.0 mm, about 4.5 to 12.0 mm, about 8.0 to 12.0 mm, and about 10.0 to 12.0 mm.

Further, from the viewpoint of more effectively suppressing the molding curl, the radius of curvature _RA ¹ of the first short side curved surface portion is preferably about 3.0 mm or more, more preferably about 3.4 mm or more, still more preferably about 3. 6.6 mm or more, particularly preferably about 3.8 mm or more. _{Further, the upper limit of the radius of curvature R A} ¹ of the first short side curved surface portion is, for example, about 4.5 mm or less, and _{the preferable range of the radius of curvature R A} ¹ is about 3.0 to 4.5 mm, 3 It is about .4 to 4.5 mm, about 3.6 to 4.5 mm, and about 3.8 to 4.5 mm.

From the viewpoint of more effectively suppressing the molding curl, the radius of curvature R _B ² of the second long side curved surface portion 12B is preferably larger than the _{radius of curvature R A} ^{2 of} the second short side curved surface portion 12A. The ratio of the radius of curvature R _B ^{2 to} _{the radius of curvature R A} ² (radius of curvature R _B ² / radius of curvature R _A ² ) is, for example, about 1.2 or more, and from the viewpoint of more effectively suppressing molding curl, Particularly preferably, about 1.6 or more can be mentioned. The upper limit of the ratio is, for example, about 2.0 or less, and the preferable range of the ratio is about 1.1 to 2.0 and about 1.6 to 2.0.

Further, from the viewpoint of more effectively suppressing the molding curl, the radius of curvature R _B ² of the second long side curved surface portion is preferably about 2.6 mm or more, more preferably about 3.0 mm or more, still more preferably about 3. It is .3 mm or more, particularly preferably about 3.7 mm or more. _{Further, the upper limit of the radius of curvature R B} ² of the second long side curved surface portion is, for example, about 4.5 mm or less, and _{the preferable range of the radius of curvature R B} ² is about 2.6 to 4.5 mm, 3 The range is about 0 to 4.5 mm, about 3.3 to 4.5 mm, about 3.7 to 4.5 mm, and about 3.7 to 4.5 mm.

Further, from the viewpoint of more effectively suppressing the molding curl, the radius of curvature R _A ² of the second short side curved surface portion is preferably about 2.1 mm or more. _{The upper limit of the radius of curvature R A} ² of the second short side curved surface portion is preferably about 3.0 mm or less, more preferably about 2.5 mm or less, and the preferred range of the _{radius of curvature R A} ^{2 is} Examples thereof include about 2.1 to 3.0 mm and about 2.1 to 2.5 mm.

In the exterior material for a power storage device of the present disclosure, the length of the long side of the recess 100 may be about 200 mm or more, or about 220 mm or more when observed from the base material layer 1 side. It may be about 230 mm or more, about 240 mm or more, or about 250 mm or more. The upper limit of the length of the long side of the recess 100 is, for example, 500 mm or less, and the preferable ranges are about 200 to 500 mm, about 220 to 500 mm, about 230 to 500 mm, about 240 to 500 mm, and about 250 to 500 mm. Can be mentioned. The aspect ratio (long side / short side) of the long side and the short side of the recess 100 may be about 2.5 or more, about 2.8 or more, or about 3.0. It may be more than or equal to, and may be about 3.2 or more. The upper limit of the aspect ratio is, for example, about 4.0 or less, and preferable ranges are about 2.5 to 4.0, about 2.8 to 4.0, about 3.0 to 4.0, and 3. About .2 to 4.0 can be mentioned. As described above, conventionally, when trying to form a recess having a large size and aspect ratio, the peripheral edge portion (particularly the long side portion) of the exterior material for the power storage device is curled by molding, and the power storage device element is recessed. When sealed in, the heat fusion of the heat-sealing resin layer is inhibited. On the other hand, in the exterior material 10 for a power storage device of the present disclosure, molding curl can be suitably suppressed even if the recess 100 having such a large size and aspect ratio is formed.

Further, the exterior material 10 for a power storage device of the present disclosure may have a long side 13B having a length of about 300 mm or more or about 320 mm or more when observed from the base material layer 1 side. , It may be about 330 mm or more, it may be about 340 mm or more, or it may be about 350 mm or more. The upper limit of the length of the long side of the exterior material 10 for the power storage device is, for example, 500 mm or less. Further, the aspect ratio (long side / short side) of the long side and the short side of the exterior material 10 for the power storage device may be about 1.3 or more, or about 1.4 or more. It may be about 1.5 or more, or about 1.6 or more. The upper limit of the aspect ratio is, for example, about 2.5 or less, and the preferable ranges are about 1.3 to 2.5, about 1.4 to 2.5, about 1.5 to 2.5, and 1 Approximately 6 to 2.5 can be mentioned.

Further, in the peripheral edge portion 100C of the concave portion 100, the width of the peripheral edge portion 100C (width of the flange portion) is not particularly limited, but from the viewpoint of preferably suppressing molding curl, the short side 13A and the second short side 13A of the exterior material 10 for the power storage device. 2 The shortest distance to the short side curved surface portion 12A is preferably about 5 to 30 mm, and the shortest distance between the long side 13B of the exterior material 10 for a power storage device and the second long side curved surface portion 12B is preferably 10 to 40 mm. Degree.

In the exterior material 10 for a power storage device of the present disclosure, as a method of forming the recess 100 so as to have each radius of curvature described above, the size, aspect ratio, laminated structure, shape and size of the mold for the exterior material for the power storage device are used. Further, there is a method of adjusting the pressing pressure of the mold at the time of forming the concave portion 100 while appropriately adjusting the surface roughness and the like. For example, by adjusting the pressing pressure of the mold to be low, each radius of curvature described above can be suitably adjusted, and molding curl can be effectively suppressed.

Further, the depth D (see FIGS. 6 and 7) of the recess 100 of the exterior material 10 for the power storage device of the present disclosure is appropriately adjusted according to the size of the power storage device and the like, and is, for example, about 4 to 10 mm. Be done.

2. Laminated structure of exterior material for power storage device The exterior material 10 for power storage device of the present disclosure is a laminated body including a base material layer 1, a barrier layer 3, and a heat-sealing resin layer 4 in this order, for example, as shown in FIG. It is composed of. In the exterior material 10 for a power storage device, the base material layer 1 is on the outermost layer side, and the heat-sealing resin layer 4 is on the innermost layer. When assembling a power storage device using the power storage device exterior material 10 and the power storage device element, the peripheral portion is heat-sealed with the heat-sealing resin layers 4 of the power storage device exterior material 10 facing each other. The power storage device element is housed in the space formed by. In the laminate constituting the exterior material 10 for the power storage device of the present disclosure, the heat-sealing resin layer 4 side is inside the barrier layer 3 and the base material layer 1 side is more than the barrier layer 3 with the barrier layer 3 as a reference. It is the outside.

As shown in FIGS. 2 to 4, for example, the exterior material 10 for a power storage device is used, if necessary, for the purpose of enhancing the adhesiveness between the base material layer 1 and the barrier layer 3 and the like. It may have an adhesive layer 2. Further, for example, as shown in FIGS. 3 and 4, the adhesive layer 5 is required between the barrier layer 3 and the heat-sealing resin layer 4 for the purpose of enhancing the adhesiveness between the layers. May have. Further, as shown in FIG. 4, a surface coating layer 6 or the like may be provided on the outside of the base material layer 1 (the side opposite to the heat-sealing resin layer 4 side), if necessary.

The thickness of the laminate constituting the exterior material 10 for the power storage device is not particularly limited, but the upper limit is preferably about 180 μm or less, about 155 μm or less, about 120 μm or less from the viewpoint of cost reduction, energy density improvement, and the like. From the viewpoint of maintaining the function of the exterior material for the power storage device, which is to protect the power storage device element, the lower limit is preferably about 35 μm or more, about 45 μm or more, and about 60 μm or more, and the preferable range is about 60 μm or more. For example, about 35 to 180 μm, about 35 to 155 μm, about 35 to 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. In particular, it is preferably about 60 to 155 μm.

In the power storage device exterior material 10, the base material layer 1, the adhesive layer 2 provided as necessary, the barrier layer 3, and if necessary, with respect to the thickness (total thickness) of the laminate constituting the power storage device exterior material 10. The ratio of the total thickness of the adhesive layer 5, the heat-sealing resin layer 4, and the surface coating layer 6 provided as needed is preferably 90% or more, more preferably 95% or more. More preferably, it is 98% or more. As a specific example, when the exterior material 10 for a power storage device of the present disclosure includes a base material layer 1, an adhesive layer 2, a barrier layer 3, an adhesive layer 5, and a heat-sealing resin layer 4, the exterior for the power storage device The ratio of the total thickness of each of these layers to the thickness (total thickness) of the laminate constituting the material 10 is preferably 90% or more, more preferably 95% or more, and further preferably 98% or more. Further, even when the exterior material 10 for a power storage device of the present disclosure is a laminated body including a base material layer 1, an adhesive layer 2, a barrier layer 3, and a heat-sealing resin layer 4, the exterior material for a power storage device is also used. The ratio of the total thickness of each of these layers to the thickness (total thickness) of the laminate constituting 10 is, for example, 80% or more, preferably 90% or more, more preferably 95% or more, still more preferably 98% or more. Can be done.

3. 3. Each layer of exterior material for power storage device [base material layer 1]
In the present disclosure, the base material layer 1 is a layer provided for the purpose of exerting a function as a base material of an exterior material for a power storage device. The base material layer 1 is located on the outer layer side of the exterior material for the power storage device.

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

When the base material layer 1 is made of a resin, the base material layer 1 may be, for example, a resin film formed of a resin, or may be formed by applying a resin. The resin film may be an unstretched film or a stretched film. Examples of the stretched film include a uniaxially stretched film and a biaxially stretched film, and a biaxially stretched film is preferable. Examples of the stretching method for forming the biaxially stretched film include a sequential biaxial stretching method, an inflation method, and a simultaneous biaxial stretching method. Examples of the method for applying the resin include a roll coating method, a gravure coating method, and an extrusion coating method.

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, and phenol 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. Further, it may be a mixture of these resins.

Among these, preferable examples of the resin forming the base material layer 1 include polyester and polyamide.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester. Further, examples of the copolymerized polyester include a copolymerized polyester containing ethylene terephthalate as a repeating unit as a main component. Specifically, copolymer polyester (hereinafter abbreviated after polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / terephthalate /), which polymerizes with ethylene isophthalate using ethylene terephthalate as the main body of the repeating unit. (Sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), polyethylene (terephthalate / decandicarboxylate) and the like. These polyesters may be used alone or in combination of two or more.

Specific examples of the polyamide include an aliphatic polyamide such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and a copolymer of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid. Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamide such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I stands for isophthalic acid, T stands for terephthalic acid), polyamide MXD6 (polymethaki) containing the derived structural units. Polyamide containing aromatics such as silylene adipamide); Alicyclic polyamide such as polyamide PACM6 (polybis (4-aminocyclohexyl) methaneadipamide); Further, lactam component and isocyanate component such as 4,4'-diphenylmethane-diisocyanate Examples thereof include copolymerized polyamides, polyesteramide copolymers and polyether esteramide copolymers which are copolymers of copolymerized polyamides and polyesters and polyalkylene ether glycols; and polyamides such as these copolymers. These polyamides may be used alone or in combination of two or more.

The base material layer 1 preferably contains at least one of a polyester film, a polyamide film, and a polyolefin film, and preferably contains at least one of a stretched polyester film, a stretched polypropylene film, and a stretched polyolefin film. It is more preferable to contain at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film, preferably a biaxially stretched polyethylene terephthalate film, a biaxially stretched polybutylene terephthalate film, and a biaxially stretched nylon film. , It is more preferable to contain at least one of the biaxially stretched polypropylene films.

The base material layer 1 may be a single layer or may be composed of two or more layers. When the base material layer 1 is composed of two or more layers, the base material layer 1 may be a laminated body in which a resin film is laminated with an adhesive or the like, or the resin is co-extruded to form two or more layers. It may be a laminated body of the resin film. Further, the laminated body of the resin film obtained by co-extruding the resin into two or more layers may be used as the base material layer 1 without being stretched, or may be uniaxially stretched or biaxially stretched as the base material layer 1.

Specific examples of the laminate of two or more layers of resin film in the base material layer 1 include a laminate of a polyester film and a nylon film, a laminate of two or more layers of nylon film, and a laminate of two or more layers of polyester film. And the like, preferably, a laminate of a stretched nylon film and a stretched polyester film, a laminate of two or more layers of stretched nylon film, and a laminate of two or more layers of stretched polyester film are preferable. For example, when the base material layer 1 is a laminate of two layers of resin film, a laminate of polyester resin film and polyester resin film, a laminate of polyamide resin film and polyamide resin film, or a laminate of polyester resin film and polyamide resin film. A laminate is preferable, and a laminate of a polyethylene terephthalate film and a polyethylene terephthalate film, a laminate of a nylon film and a nylon film, or a laminate of a polyethylene terephthalate film and a nylon film is more preferable. Further, since the polyester resin is difficult to discolor when the electrolytic solution adheres to the surface, for example, when the base material layer 1 is a laminate of two or more resin films, the polyester resin film is the base material layer 1. It is preferably located in the outermost layer.

When the base material 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 include those similar to the adhesives exemplified in the adhesive layer 2 described later. The method of laminating two or more layers of resin films is not particularly limited, and known methods can be adopted. Examples thereof include a dry laminating method, a sandwich laminating method, an extrusion laminating method, and a thermal laminating method, and a dry laminating method is preferable. The laminating method can be mentioned. When laminating by the dry laminating method, 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. Further, an anchor coat layer may be formed on the resin film and laminated. Examples of the anchor coat layer include the same adhesives as those exemplified in the adhesive layer 2 described later. At this time, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 μm.

Further, even if additives such as a lubricant, a flame retardant, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent are present on at least one of the surface and the inside of the base material layer 1. Good. Only one type of additive may be used, or two or more types may be mixed and used.

In the present disclosure, from the viewpoint of enhancing the moldability of the exterior material for the power storage device, it is preferable that the lubricant is present on the surface of the base material layer 1. The lubricant is not particularly limited, but an amide-based lubricant is preferable. Specific examples of the amide-based lubricant include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitate amide, stearic acid amide, bechenic acid amide, hydroxystearic acid amide and the like. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitate amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucate amide and the like. Further, specific examples of methylolamide include methylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, and hexamethylene bisstearic. Examples thereof include acid amides, hexamethylene bisbechenic acid amides, hexamethylene hydroxystearic acid amides, N, N'-distearyl adipate amides, and N, N'-distearyl sebacic acid amides. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N, N'-diorail adipate amide, and N, N'-diorail sebacic acid amide. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate and the like. Specific examples of the aromatic bisamide include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N, N'-distearyl isophthalic acid amide. One type of lubricant may be used alone, or two or more types may be used in combination.

If a lubricant on the surface of the base material layer 1 is present, as it is its abundance is not particularly limited, preferably about 3 mg / m ² or more, more preferably 4~15mg / m ² approximately, more preferably 5~14mg / M ² is mentioned.

The lubricant existing on the surface of the base material layer 1 may be one in which the lubricant contained in the resin constituting the base material layer 1 is exuded, or one in which the lubricant is applied to the surface of the base material layer 1. You may.

The thickness of the base material layer 1 is not particularly limited as long as it functions as a base material, and examples thereof include about 3 to 50 μm, preferably about 10 to 35 μm. When the base material layer 1 is a laminate of two or more resin films, the thickness of the resin films constituting each layer is preferably about 2 to 25 μm, respectively.

[Adhesive layer 2]
In the exterior material for a power storage device of the present disclosure, 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 enhancing the adhesiveness between the base material layer 1 and the barrier layer 3.

The adhesive layer 2 is formed by an adhesive capable of adhering the base material layer 1 and the barrier layer 3. The adhesive used for forming the adhesive layer 2 is not limited, but may be any of a chemical reaction type, a solvent volatile type, a heat melting type, a hot pressure type and the like. Further, it may be a two-component curable adhesive (two-component adhesive), a one-component curable adhesive (one-component adhesive), or a resin that does not involve a curing reaction. Further, the adhesive layer 2 may be a single layer or a multilayer.

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 resin; Polyethylene such as nylon 6, nylon 66, nylon 12, copolymerized polyamide; Polyethylene resin such as polyolefin, cyclic polyolefin, acid-modified polyolefin, acid-modified cyclic polyolefin; Polyvinyl acetate; Cellulose; (Meta) acrylic resin; Polyethylene; polycarbonate; amino resin such as urea resin and melamine resin; rubber such as chloroprene rubber, nitrile rubber and styrene-butadiene rubber; silicone resin and the like. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane adhesive is preferable. In addition, the resins used as these adhesive components can be used in combination with an appropriate curing agent to increase the adhesive strength. An appropriate curing agent is selected from polyisocyanate, polyfunctional epoxy resin, oxazoline group-containing polymer, polyamine resin, acid anhydride and the like, depending on the functional group of the adhesive component.

Examples of the polyurethane adhesive include a polyurethane adhesive containing a main agent containing a polyol compound and a curing agent containing an isocyanate compound. Preferred are two-component curable polyurethane adhesives containing a polyol such as a polyester polyol, a polyether polyol, and an acrylic polyol as a main component and an aromatic or aliphatic polyisocyanate as a curing agent. Further, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group in the side chain in addition to the hydroxyl group at the end of the repeating unit. Examples of the curing agent include aliphatic, alicyclic, aromatic, and aromatic aliphatic isocyanate compounds. Examples of the isocyanate-based compound include hexamethylene diisocyanate (HDI) xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), and diphenylmethane diisocyanate ( MDI), naphthalenediocyanate (NDI) and the like. Moreover, a polyfunctional isocyanate modified product from one kind or two or more kinds of these diisocyanates and the like can be mentioned. Further, a multimer (for example, a trimer) can be used as the polyisocyanate compound. Examples of such a multimer include an adduct body, a biuret body, a nurate body and the like. Since the adhesive layer 2 is formed of the polyurethane adhesive, excellent electrolytic solution resistance is imparted to the exterior material for the power storage device, and even if the electrolytic solution adheres to the side surface, the base material layer 1 is suppressed from peeling off. ..

Further, the adhesive layer 2 may contain a colorant, a thermoplastic elastomer, a tackifier, a filler and the like, as long as the adhesiveness is not impaired, the addition of other components is permitted. Since the adhesive layer 2 contains a colorant, the exterior material for the power storage device can be colored. As the colorant, known ones such as pigments and dyes can be used. Further, 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, anthracinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindrenine-based, and benzimidazolone-based pigments, which are inorganic. Examples of the pigment include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and other examples include fine powder of mica (mica) and fish scale foil.

Among the colorants, carbon black is preferable in order to make the appearance of the exterior material for a power storage device black, for example.

The average particle size of the pigment is not particularly limited, and examples thereof include about 0.05 to 5 μm, preferably about 0.08 to 2 μm. The average particle size of the pigment is the median diameter measured by a laser diffraction / scattering type particle size distribution measuring device.

The content of the pigment in the adhesive layer 2 is not particularly limited as long as the exterior material for the power storage device is colored, and examples thereof include about 5 to 60% by mass, preferably 10 to 40% by mass.

The thickness of the adhesive layer 2 is not particularly limited as long as the base material layer 1 and the barrier layer 3 can be adhered to each other, but the lower limit is, for example, about 1 μm or more and about 2 μm or more, and the upper limit is about 10 μm or less. , About 5 μm or less, and 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 between the base material layer 1 and the barrier layer 3 as needed (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 on the outside of the base material layer 1. By providing the coloring layer, the exterior material for the power storage device can be colored.

The colored layer can be formed, for example, by applying an ink containing a colorant to the surface of the base material layer 1 or the surface of the barrier layer 3. As the colorant, known ones such as pigments and dyes can be used. Further, 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 include the same as those exemplified in the column of [Adhesive layer 2].

[Barrier layer 3]
In the exterior material for a power storage device, the barrier layer 3 is at least a layer that suppresses the infiltration of water.

Examples of the barrier layer 3 include a metal foil having a barrier property, a thin-film deposition film, a resin layer, and the like. Examples of the vapor deposition film include a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, and the like, and examples of the resin layer include polymers and tetras mainly composed of polyvinylidene chloride and chlorotrifluoroethylene (CTFE). Examples thereof include polymers containing fluoroethylene (TFE) as a main component, polymers having a fluoroalkyl group, fluorine-containing resins such as polymers containing fluoroalkyl units as a main component, and ethylene vinyl alcohol copolymers. Further, examples of the barrier layer 3 include a resin film provided with at least one of these vapor-deposited films and a resin layer. 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 an aluminum alloy, stainless steel, titanium steel, and a steel plate. When used as a metal foil, the metal material includes at least one of an aluminum alloy foil and a stainless steel foil. Is preferable.

From the viewpoint of improving the moldability of the exterior material for the power storage device, the aluminum alloy foil is more preferably a soft aluminum alloy foil composed of, for example, an aluminum alloy that has been annealed, and the viewpoint of further improving the moldability. Therefore, it is preferable that the aluminum alloy foil contains iron. 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, an exterior material for a power storage device having more excellent moldability can be obtained. When the iron content is 9.0% by mass or less, a more flexible exterior material for a power storage device can be obtained. The soft aluminum alloy foil includes, for example, an aluminum alloy having a composition defined by JIS H4160: 1994 A8021H-O, JIS H4160: 1994 A8079H-O, JIS H4000: 2014 A8021P-O, or JIS H4000: 2014 A8079P-O. Foil is mentioned. Further, if necessary, silicon, magnesium, copper, manganese and the like may be added. Further, softening can be performed by annealing or the like.

Examples of the stainless steel foil include austenite-based, ferrite-based, austenite-ferritic-based, martensitic-based, and precipitation-hardened stainless steel foils. Further, from the viewpoint of providing an exterior material for a power storage device having excellent moldability, the stainless steel foil is preferably made of austenite-based stainless steel.

Specific examples of the austenite-based stainless steel constituting the stainless steel foil include SUS304, SUS301, and SUS316L, and among these, SUS304 is particularly preferable.

In the case of a metal foil, the thickness of the barrier layer 3 may be at least a function as a barrier layer for suppressing the infiltration of water, 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, still more preferably about 40 μm or less, particularly preferably about 35 μm or less for the upper limit, and preferably about about 35 μm or less for the lower limit. 10 μm or more, more preferably about 20 μm or more, more preferably about 25 μm or more, and preferable ranges of the thickness are about 10 to 85 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 35 μm, and about 20 to 20. Examples thereof include about 85 μm, about 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 preferable. Further, in particular, when the barrier layer 3 is made of stainless steel foil, the upper limit of the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, still more preferably about 40 μm or less. More preferably, it is about 30 μm or less, particularly preferably about 25 μm or less, and the lower limit is preferably about 10 μm or more, more preferably about 15 μm or more, and the preferred thickness range is about 10 to 60 μm, 10 Examples thereof include about 50 μm, about 10 to 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.

When the barrier layer 3 is a metal foil, it is preferable that a corrosion-resistant film is provided on at least the surface opposite to the base material layer in order to prevent dissolution and corrosion. The barrier layer 3 may be provided with a corrosion-resistant film on both sides. Here, the corrosion-resistant film is, for example, a hot water transformation treatment such as boehmite treatment, a chemical conversion treatment, an anodization treatment, a plating treatment such as nickel or chromium, and a corrosion prevention treatment for applying a coating agent on the surface of the barrier layer. A thin film that makes the barrier layer corrosion resistant. As the treatment for forming the corrosion-resistant film, one type may be performed, or two or more types may be combined. Moreover, not only one layer but also multiple layers can be used. Further, among these treatments, the hydrothermal modification treatment and the anodizing treatment are treatments in which the surface of the metal foil is dissolved by a treatment agent to form a metal compound having excellent corrosion resistance. In addition, these processes may be included in the definition of chemical conversion process. When the barrier layer 3 has a corrosion-resistant film, the barrier layer 3 includes the corrosion-resistant film.

The corrosion-resistant film is formed by preventing delamination between the barrier layer (for example, aluminum alloy foil) and the base material layer during molding of the exterior material for a power storage device, and by hydrogen fluoride generated by the reaction between the electrolyte and water. , Melting and corrosion of the surface of the barrier layer, especially when the barrier layer is an aluminum alloy foil, it prevents the aluminum oxide existing on the surface of the barrier layer from melting and corroding, and the adhesiveness (wetness) of the surface of the barrier layer. The effect of preventing the corrosion between the base material layer and the barrier layer at the time of heat sealing and the prevention of the corrosion between the base material layer and the barrier layer at the time of molding is shown.

Various corrosion-resistant films formed by chemical conversion treatment are known, and mainly, at least one of phosphate, chromate, fluoride, triazinethiol compound, and rare earth oxide. Examples thereof include a corrosion-resistant film containing. Examples of the chemical conversion treatment using a phosphate or a chromium salt include a chromium acid chromate treatment, a phosphoric acid chromate treatment, a phosphoric acid-chromate treatment, a chromium salt treatment, and the like, and chromium used in these treatments. Examples of the compound include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium bicarbonate, acetylacetate chromate, chromium chloride, chromium sulfate and the like. In addition, examples of the phosphorus compound used in these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid and the like. Further, examples of the chromate treatment include etching chromate treatment, electrolytic chromate treatment, and coating type chromate treatment, and coating type chromate treatment is preferable. In this coating type chromate treatment, at least the inner layer side surface of the barrier layer (for example, aluminum alloy foil) is first known as an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid activation method and the like. Degreasing is performed by the treatment method, and then metal phosphates such as Cr phosphate (chromium) salt, Ti (titanium) phosphate, Zr (zyroxide) salt, and Zn (zinc) phosphate are applied to the degreased surface. A treatment liquid containing a salt and a mixture of these non-metal salts as a main component, or a treatment liquid containing a mixture of a phosphate non-metal salt and these non-metal salts as a main component, or a synthetic resin and the like. This is a treatment in which a treatment liquid composed of a mixture is coated by a well-known coating method such as a roll coating method, a gravure printing method, or a dipping method, and dried. As the treatment liquid, for example, various solvents such as water, alcohol-based solvent, hydrocarbon-based solvent, ketone-based solvent, ester-based solvent, and ether-based solvent can be used, and water is preferable. Examples of the resin component used at this time include polymers such as phenol-based resins and acrylic-based resins, and aminoated phenol polymers having repeating units represented by the following general formulas (1) to (4). Examples thereof include the chromate treatment used. In the amination phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. May be good. The acrylic resin shall be a polyacrylic acid, an acrylic acid methacrylate copolymer, an acrylic acid maleic acid copolymer, an acrylic acid styrene copolymer, or a derivative of these sodium salts, ammonium salts, amine salts, etc. Is preferable. In particular, derivatives of polyacrylic acid such as ammonium salt, sodium salt, and amine salt of polyacrylic acid are preferable. In the present disclosure, polyacrylic acid means a polymer of acrylic acid. Further, the acrylic resin is preferably a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride, and is an ammonium salt, a sodium salt, or a copolymer of an acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride. Alternatively, it is preferably an amine salt. Only one type of acrylic resin may be used, or two or more types may be mixed and used.

In the general formulas (1) to (4), X represents a hydrogen atom, a hydroxy group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. Further, R ¹ and R ² represent a hydroxy group, an alkyl group, or a hydroxyalkyl group, respectively, which are the same or different. In the general formulas (1) to (4) ^{, examples of the alkyl group represented by X, R 1} and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. Examples thereof include linear or branched alkyl groups having 1 to 4 carbon atoms such as tert-butyl groups. Examples of the hydroxyalkyl groups represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group and 3-. A linear or branched chain having 1 to 4 carbon atoms in which one hydroxy group such as a hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, or a 4-hydroxybutyl group is substituted. An alkyl group can be mentioned. In the general formulas (1) to (4), the ^{alkyl group and the hydroxyalkyl group represented by X, R 1} and R ² may be the same or different, respectively. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxy group or a hydroxyalkyl group. The number average molecular weight of the amination phenol polymer having the repeating unit represented by the general formulas (1) to (4) is, for example, preferably about 5 to 1,000,000, and preferably about 1,000 to 20,000. More preferred. The amination phenol polymer, for example, polycondenses a phenol compound or a naphthol compound with formaldehyde to produce a polymer composed of repeating units represented by the above general formula (1) or general formula (3), and then formsaldehyde. It is produced by introducing a functional group (-CH ₂ NR ¹ R ² ) into the polymer obtained above using amine (R ¹ R ^{2 NH).} The amination phenol polymer is used alone or in combination of two or more.

As another example of the corrosion resistant film, it is formed by a coating type corrosion prevention treatment in which a coating agent containing at least one selected from the group consisting of a rare earth element oxide sol, an anionic polymer, and a cationic polymer is applied. The thin film to be used is mentioned. The coating agent may further contain phosphoric acid or phosphate, a cross-linking agent for cross-linking the polymer. In the rare earth element oxide sol, fine particles of the rare earth element oxide (for example, particles having an average particle size of 100 nm or less) are dispersed in a liquid dispersion medium. Examples of the rare earth element oxide include cerium oxide, yttrium oxide, neodium oxide, and lanthanum oxide, and cerium oxide is preferable from the viewpoint of further improving adhesion. The rare earth element oxide contained in the corrosion-resistant film may be used alone or in combination of two or more. As the liquid dispersion medium of the rare earth element oxide sol, for example, various solvents such as water, alcohol-based solvent, hydrocarbon-based solvent, ketone-based solvent, ester-based solvent, and ether-based solvent can be used, and water is preferable. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine graft acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, polyallylamine or a derivative thereof. , Amination phenol and the like are preferable. The anionic polymer is preferably a poly (meth) acrylic acid or a salt thereof, or a copolymer containing (meth) acrylic acid or a salt thereof as a main component. Further, it is preferable that the cross-linking agent is at least one selected from the group consisting of a compound having a functional group of any of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group and a silane coupling agent. Further, it is preferable that the phosphoric acid or phosphate is condensed phosphoric acid or condensed phosphate.

As an example of the corrosion-resistant film, a film in which fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide and barium sulfate are dispersed in phosphoric acid is applied to the surface of the barrier layer, and 150 Examples thereof include those formed by performing a baking treatment at a temperature of ° C. or higher.

The corrosion-resistant film may have a laminated structure in which at least one of a cationic polymer and an anionic polymer is further laminated, if necessary. Examples of the cationic polymer and the anionic polymer include those described above.

The composition of the corrosion-resistant film can be analyzed by using, for example, a time-of-flight secondary ion mass spectrometry method.

The amount of the corrosion-resistant film formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited, but for example, in the case of performing a coating type chromate treatment, a chromic acid compound per ^{1 m 2 of the surface of the barrier layer 3} Is, for example, about 0.5 to 50 mg in terms of chromium, preferably 1.
.. About 0 to 40 mg, phosphorus compound is, for example, about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and aminoated phenol polymer is, for example, about 1.0 to 200 mg, preferably 5.0 to 150 mg. It is desirable that it is contained in a moderate proportion.

The thickness of the corrosion-resistant film is not particularly limited, but is preferably about 1 nm to 20 μm, more preferably 1 nm to 100 nm, from the viewpoint of the cohesive force of the film and the adhesion to the barrier layer and the heat-sealing resin layer. The degree, more preferably about 1 nm to 50 nm. The thickness of the corrosion-resistant film can be measured by observation with a transmission electron microscope or a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy. The time-of-flight secondary ion mass spectrometry analysis of the composition of the corrosion resistant coating using, for example, secondary ion consisting Ce and P and O (e.g., Ce ₂ PO ₄ ^+, C
ePO ₄ ^- at least one) or the like, for example, secondary ion of Cr and P and O (e.g., CrPO ₂ ^+, CrPO ₄ ^- peak derived from at least one), such as is detected.

In the chemical conversion treatment, a solution containing a compound used for forming a corrosion-resistant film is applied to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method, or the like, and then the temperature of the barrier layer is applied. It is carried out by heating so that the temperature is about 70 to 200 ° C. Further, before the chemical conversion treatment is applied to the barrier layer, the barrier layer may be subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method or the like in advance. By performing the degreasing treatment in this way, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the barrier layer. Further, by using an acid degreasing agent in which a fluorine-containing compound is dissolved in an inorganic acid for the degreasing treatment, it is possible to form not only the degreasing effect of the metal foil but also the immobile metal fluoride. In such cases, only degreasing treatment may be performed.

[Heat-sealing resin layer 4]
In the exterior material for a power storage device of the present disclosure, the heat-sealing resin layer 4 corresponds to the innermost layer, and has a function of heat-sealing the heat-sealing resin layers with each other when assembling the power storage device to seal the power storage device element. It is a layer (sealant layer) that exerts.

The resin constituting the heat-fusing resin layer 4 is not particularly limited as long as it can be heat-fused, but a resin containing a polyolefin skeleton such as polyolefin or acid-modified polyolefin is preferable. The fact that the resin constituting the heat-sealing resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, or the like. Further, when the resin constituting the heat-sealing resin layer 4 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. When the heat-sealing 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 become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; homopolypropylene and block copolymers of polypropylene (for example, with propylene). Polypropylene such as (block copolymer of ethylene), random copolymer of polypropylene (eg, random copolymer of propylene and ethylene); propylene-α-olefin copolymer; terpolymer of ethylene-butene-propylene and the like. Among these, polypropylene is preferable. When it is a copolymer, the polyolefin resin may be a block copolymer or a random copolymer. One type of these polyolefin resins may be used alone, or two or more types may be used in combination.

Further, the polyolefin may be a cyclic polyolefin. The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and 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 the cyclic monomer which is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; cyclic diene such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, cyclic alkene is preferable, and norbornene is more preferable.

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

The acid-modified polyolefin may be an acid-modified cyclic polyolefin. The 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 with the cyclic polyolefin. is there. The same applies to the cyclic polyolefin that is acid-modified. The acid component used for acid denaturation is the same as the acid component used for denaturation of the polyolefin.

Preferred acid-modified polyolefins include polyolefins modified with carboxylic acid or its anhydride, polypropylene modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefin, and maleic anhydride-modified polypropylene.

The heat-sealing resin layer 4 may be formed of one type of resin alone, or may be formed of a blended polymer in which two or more types of resins are combined. Further, the heat-sealing resin layer 4 may be formed of only one layer, but may be formed of two or more layers with the same or different resins.

Further, the heat-sealing resin layer 4 may contain a lubricant or the like, if necessary. When the heat-sealing resin layer 4 contains a lubricant, the moldability of the exterior material for a power storage device can be improved. The lubricant is not particularly limited, and a known lubricant can be used. The lubricant may be used alone or in combination of two or more.

The lubricant is not particularly limited, but an amide-based lubricant is preferable. Specific examples of the lubricant include those exemplified in the base material layer 1. One type of lubricant may be used alone, or two or more types may be used in combination.

When the lubricant is present on the surface of the heat-sealing resin layer 4, the amount of the lubricant is not particularly limited, but from the viewpoint of improving the moldability of the exterior material for the power storage device, it is preferably about ^{10 to 50 mg / m 2.} , More preferably about 15 to 40 mg / m ^2.

The lubricant existing on the surface of the heat-sealing resin layer 4 may be one in which the lubricant contained in the resin constituting the heat-sealing resin layer 4 is exuded, or the lubricant contained in the heat-sealing resin layer 4 may be exuded. The surface may be coated with a lubricant.

The thickness of the heat-sealing resin layer 4 is not particularly limited as long as the heat-sealing resin layers have a function of heat-sealing to seal the power storage device element, but is preferably about 100 μm or less, preferably about 100 μm or less. It is 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-sealing resin layer 4 is preferably about 85 μm or less, more preferably about 15 to 45 μm, for example. 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-sealing resin layer 4 is preferably about 20 μm or more, more preferably 35 to 85 μm. The degree can be mentioned.

[Adhesive layer 5]
In the exterior material for a power storage device of the present disclosure, the adhesive layer 5 is provided between the barrier layer 3 (or the corrosion-resistant film) and the heat-sealing resin layer 4 as necessary in order to firmly bond them. It is a layer to be corroded.

The adhesive layer 5 is formed of a resin capable of adhering the barrier layer 3 and the heat-sealing resin layer 4. As the resin used for forming the adhesive layer 5, for example, the same resin as the adhesive exemplified in the adhesive layer 2 can be used. Further, from the viewpoint of firmly adhering the adhesive layer 5 and the heat-sealing resin layer 4, it is preferable that the resin used for forming the adhesive layer 5 contains a polyolefin skeleton, and the above-mentioned heat-sealing property Examples thereof include the polyolefin exemplified in the resin layer 4 and the acid-modified polyolefin. On the other hand, from the viewpoint of firmly adhering the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 preferably contains an acid-modified polyolefin. Examples of the acid-modifying component include dicarboxylic acids such as maleic acid, itaconic acid, succinic acid, and adipic acid, and anhydrides thereof, acrylic acid, and methacrylic acid. Maleic acid is most preferred. From the viewpoint of heat resistance of the exterior material for the power storage device, the olefin component is preferably polypropylene-based resin, and the adhesive layer 5 most preferably contains maleic anhydride-modified polypropylene.

The fact that 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. Further, the resin constituting the adhesive layer 5 comprises an acid-modified polyolefin, for example, when measuring the infrared spectroscopy at maleic anhydride-modified polyolefin, anhydride in the vicinity of a wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1 A peak derived from maleic anhydride is detected. However, if the degree of acid denaturation is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Further, from the viewpoint of ensuring durability such as heat resistance and content resistance of the exterior material for a power storage device and ensuring moldability while reducing the thickness, the adhesive layer 5 is a resin composition containing an acid-modified polyolefin and a curing agent. It is more preferably a cured product. As the acid-modified polyolefin, the above-mentioned ones are preferably exemplified.

The adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. It is particularly preferable that the resin composition is a cured product containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group and a compound having an epoxy group. Further, the adhesive layer 5 preferably contains at least one selected from the group consisting of polyurethane, polyester, and epoxy resin, and more preferably contains polyurethane and epoxy resin. As the polyester, for example, an ester resin produced by the reaction of an epoxy group and a maleic anhydride group, and an amide ester resin produced by a reaction of an oxazoline group and a maleic anhydride group are preferable. When an unreacted substance of a curing agent such as a compound having an isocyanate group, a compound having an oxazoline group, or an epoxy resin remains in the adhesive layer 5, the presence of the unreacted substance is determined by, for example, infrared spectroscopy. It can be confirmed by a method selected from Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

Further, from the viewpoint of further enhancing the adhesion between the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 is selected from at least a group consisting of an oxygen atom, a heterocycle, a C = N bond, and a C—O—C bond. It is preferably a cured product of a resin composition containing a curing agent having one type. Examples of the curing agent having a heterocycle include a curing agent having an oxazoline group and a curing agent having an epoxy group. Examples of the curing agent having a C = N bond include a curing agent having an oxazoline group and a curing agent having an isocyanate group. Examples of the curing agent having a C—O—C bond include a curing agent having an oxazoline group and a curing agent having an epoxy group. The fact that the adhesive layer 5 is a cured product of a resin composition containing these curing agents is, for example, gas chromatograph mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF). -SIMS), X-ray photoelectron spectroscopy (XPS) and other methods can be used for confirmation.

The compound having an isocyanate group is not particularly limited, but a polyfunctional isocyanate compound is preferable from the viewpoint of effectively enhancing the adhesion between the barrier layer 3 and the adhesive layer 5. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate-based curing agent include pentandiisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI), which are polymerized or nurate. Examples thereof include chemical compounds, mixtures thereof, and copolymers with other polymers. In addition, an adduct body, a burette body, an isocyanurate body and the like can be mentioned.

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, and 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. More preferably in the range. As a result, the adhesion between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

The compound having an oxazoline group is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the compound having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain. Examples of commercially available products include the Epocross series manufactured by Nippon Shokubai Co., Ltd.

The proportion of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. It is more preferable to be in. As a result, the adhesion between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

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

Specific examples of the epoxy resin include glycidyl ether derivative of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, bisphenol F type glycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether and the like. Can be mentioned. One type of epoxy resin may be used alone, or two or more types may be used in combination.

The proportion of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. As a result, the adhesion between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

The polyurethane is not particularly limited, and known polyurethane can be used. The adhesive layer 5 may be, for example, a cured product of a two-component curable polyurethane.

The proportion of polyurethane in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. More preferred. As a result, the adhesion between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced in an atmosphere in which a component that induces corrosion of the barrier layer such as an electrolytic solution is present.

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

The adhesive layer 5 may contain a modifier having a carbodiimide group.

The upper limit of 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 the lower limit is preferably about 0.1 μm or more. , About 0.5 μm or more, and 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, 0. .1 to 5 μm, 0.5 to 50 μm, 0.5 to 40 μm, 0.5 to 30 μm, 0.5 to 20 μm, 0.5 to 5 μm. More specifically, in the case of the adhesive exemplified in the adhesive layer 2 or the cured product of the acid-modified polyolefin and the curing agent, the thickness is preferably about 1 to 10 μm, more preferably about 1 to 5 μm. Further, when the resin exemplified in the heat-sealing resin layer 4 is used, it is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. When the adhesive layer 5 is a cured product of the adhesive exemplified in the adhesive layer 2 or a resin composition containing an acid-modified polyolefin and a curing agent, for example, the resin composition is applied and cured by heating or the like. Thereby, the adhesive layer 5 can be formed. Further, when the resin exemplified in the heat-sealing resin layer 4 is used, it can be formed by, for example, extrusion molding of the heat-sealing resin layer 4 and the adhesive layer 5.

[Surface coating layer 6]
The exterior material for a power storage device of the present disclosure is above the base material layer 1 (base material layer 1), if necessary, for the purpose of improving at least one of designability, electrolytic solution resistance, scratch resistance, moldability, and the like. The surface coating layer 6 may be provided on the side opposite to the barrier layer 3 of the above. The surface coating layer 6 is a layer located on the outermost layer side of the exterior material for the power storage device when the power storage device is assembled using the exterior material for the power storage device.

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

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, but is preferably a two-component curable type. Examples of the two-component curable resin include two-component curable polyurethane, two-component curable polyester, and two-component curable epoxy resin. Of these, two-component curable polyurethane is preferable.

Examples of the two-component curable polyurethane include a polyurethane containing a main agent containing a polyol compound and a curing agent containing an isocyanate compound. Preferred are two-component curable polyurethanes containing a polyol such as a polyester polyol, a polyether polyol, and an acrylic polyol as a main component and an aromatic or aliphatic polyisocyanate as a curing agent. Further, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group in the side chain in addition to the hydroxyl group at the end of the repeating unit. Examples of the curing agent include aliphatic, alicyclic, aromatic, and aromatic aliphatic isocyanate compounds. Examples of the isocyanate-based compound include hexamethylene diisocyanate (HDI) xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), and diphenylmethane diisocyanate ( MDI), naphthalenediocyanate (NDI) and the like. Moreover, a polyfunctional isocyanate modified product from one kind or two or more kinds of these diisocyanates and the like can be mentioned. Further, a multimer (for example, a trimer) can be used as the polyisocyanate compound. Examples of such a multimer include an adduct body, a biuret body, a nurate body and the like. The aliphatic isocyanate-based compound refers to an isocyanate having an aliphatic group and no aromatic ring, and the alicyclic isocyanate-based compound refers to an isocyanate having an alicyclic hydrocarbon group, which is an aromatic isocyanate-based compound. Refers to an isocyanate having an aromatic ring. Since the surface coating layer 6 is made of polyurethane, excellent electrolytic solution resistance is imparted to the exterior material for the power storage device.

The surface coating layer 6 has the above-mentioned lubricant or antistatic agent on at least one of the surface and the inside of the surface coating layer 6, depending on the functionality and the like to be provided on the surface coating layer 6 and the surface thereof. It may contain additives such as a blocking agent, a matting agent, a flame retardant, an antioxidant, a tackifier, and an antistatic agent. Examples of the additive include fine particles having an average particle diameter of about 0.5 nm to 5 μm. The average particle size of the additive shall be the median diameter measured by a laser diffraction / scattering type particle size distribution measuring device.

The additive may be either an inorganic substance or an organic substance. The shape of the additive is also not particularly limited, and examples thereof include a spherical shape, a fibrous shape, a plate shape, an amorphous shape, and a scaly shape.

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, neodium 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 nanotubes, refractory nylon, acrylate resin, Examples thereof include crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. The additive may be used alone or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferable from the viewpoint of dispersion stability and cost. Further, the additive may be subjected to various surface treatments such as an insulation treatment and a highly dispersible treatment on the surface.

The method for forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying a resin for forming the surface coating layer 6. When an additive is blended in the surface coating layer 6, a resin mixed with the additive may be applied.

The thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above-mentioned functions as the surface coating layer 6, and examples thereof include about 0.5 to 10 μm, preferably about 1 to 5 μm.

4. The preparation method of the production method the present disclosure for an electricity storage device exterior material of the outer package for a power storage device, as long as the laminate exterior material for a power storage device formed by laminating the layers with the present invention are obtained is not particularly limited, the aforementioned There is a method including a step of forming a recess so as to satisfy the relationship of the radius of curvature of. That is, the manufacturing method of the exterior material 10 for the power storage device of the present disclosure is as follows. Details of each layer of the laminate constituting the exterior material for the power storage device, details of the radius of curvature, and the like are as described above.

A step of preparing a film-like laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order.
The laminate is molded so as to project from the heat-sealing resin layer side to the base material layer side, and a rectangular recess in which the power storage device element is housed is formed on the heat-sealing resin layer side. The process of forming (specifically, the heat-sealing resin using the female mold arranged on the base material layer side of the laminate and the male mold arranged on the heat-sealing resin layer side). A step of molding the laminate so as to project from the layer side to the base material layer side to form a rectangular recess in which the power storage device element is housed on the heat-sealing resin layer side).
Is equipped with
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short side curved surface portion and a second short side curved surface portion are provided in order over the short side of the exterior material.
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A first long side curved surface portion and a second long side curved surface portion are provided in order over the long side of the exterior material.
The radius of curvature R _B ¹ of the first long side curved surface portion is larger than the _{radius of curvature R A} ^{1 of the first short side curved surface portion.}
A method for manufacturing an exterior material for a power storage device, _{wherein the radius of curvature R B} ^{1 of} the first long side curved surface portion is 3.8 mm or more.

As described above, in the exterior material 10 for a power storage device of the present disclosure, as a method of forming the recess 100 so as to have each radius of curvature described above, the size, aspect ratio, laminated structure, and mold of the exterior material for the power storage device are used. There is a method of appropriately adjusting the shape, size, surface roughness, etc. of the mold, and further adjusting the pressing pressure of the mold when the recess 100 is formed. That is, in the method for manufacturing the exterior material 10 for a power storage device of the present disclosure, by appropriately adjusting these, the recess 100 having each radius of curvature described above can be formed. For example, in the step of forming the concave portion, by adjusting the pressing pressure of the mold to be low, each radius of curvature described above can be suitably adjusted, and the molding curl can be effectively suppressed. It is also possible to adjust the surface roughness of the mold to adjust the radius of curvature by appropriately sliding the exterior material for the power storage device during molding and pulling it into the mold.

Further, an example of a method for manufacturing a film-like laminate constituting the exterior material for a power storage device of the present disclosure is as follows. First, a laminate in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are laminated in this order (hereinafter, may be referred to as “laminate A”) is formed. Specifically, the laminated body A is formed by applying an adhesive used for forming the adhesive layer 2 on the base material layer 1 or, if necessary, on the barrier layer 3 whose surface has been chemically converted, by a gravure coating method. It can be carried out by a dry laminating method in which the barrier layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after being applied and dried by a coating method such as a roll coating method.

Next, the heat-sealing resin layer 4 is laminated on the barrier layer 3 of the laminated body A. When the heat-sealing resin layer 4 is directly laminated on the barrier layer 3, the heat-sealing resin layer 4 is laminated on the barrier layer 3 of the laminated body A by a method such as a thermal laminating method or an extrusion laminating method. do it. When the adhesive layer 5 is provided between the barrier layer 3 and the heat-sealing resin layer 4, for example, (1) the adhesive layer 5 and the heat-sealing resin layer are placed on the barrier layer 3 of the laminated body A. A method of laminating 4 by extruding (coextrusion laminating method, tandem laminating method), (2) Separately, a laminated body in which the adhesive layer 5 and the heat-sealing resin layer 4 are laminated is formed, and the laminated body A is formed. A method of laminating on the barrier layer 3 of the above by a thermal laminating method, or a laminating body in which an adhesive layer 5 is laminated on the barrier layer 3 of the laminated body A is formed, and this is formed by a heat-sealing resin layer 4 and a thermal laminating method. Method of Laminating, (3) While pouring the melted adhesive layer 5 between the barrier layer 3 of the laminated body A and the heat-sealing resin layer 4 which has been formed into a sheet in advance, the adhesive layer 5 is passed through. A method of laminating the laminated body A and the heat-sealing resin layer 4 (sandwich laminating method), (4) a solution coating of an adhesive for forming the adhesive layer 5 on the barrier layer 3 of the laminated body A is performed. Examples thereof include a method of laminating by a method of drying, a method of baking, and the like, and a method of laminating a heat-sealing resin layer 4 having a sheet-like film formed in advance on the adhesive layer 5.

When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the base material layer 1 opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above resin that forms the surface coating layer 6 to the surface of the base material layer 1. 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 base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer 6.

As described above, the surface coating layer 6 provided as needed / the base material layer 1 / the adhesive layer 2 provided as needed / the barrier layer 3 / the adhesive layer 5 provided as needed / heat fusion A laminate having the sex resin layers 4 in this order is formed, and may be further subjected to heat treatment in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as needed.

In the exterior material for a power storage device, each layer constituting the laminate may be subjected to surface activation treatment such as corona treatment, blast treatment, oxidation treatment, ozone treatment, etc., if necessary, to improve processing suitability. .. For example, by applying a corona treatment to the surface of the base material layer 1 opposite to the barrier layer 3, the printability of the ink on the surface of the base material layer 1 can be improved.

5. Applications of exterior materials for power storage devices The exterior materials for power storage devices of the present disclosure are used for packaging for sealing and accommodating power storage device elements such as positive electrodes, negative electrodes, and electrolytes. That is, a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte can be housed in a package formed of the exterior material for a power storage device of the present disclosure to form a power storage device.

Specifically, a power storage device element having at least a positive electrode, a negative electrode, and an electrolyte is provided in a state in which metal terminals connected to each of the positive electrode and the negative electrode are projected outward in the exterior material for the power storage device of the present disclosure. , The peripheral edge of the power storage device element is covered so that a flange portion (a region where the heat-sealing resin layers come into contact with each other) can be formed, and the heat-sealing resin layers of the flange portion are heat-sealed and sealed. Provides a power storage device using an exterior material for the power storage device. When the power storage device element is housed in the package formed of the power storage device exterior material of the present disclosure, the heat-sealing resin portion of the power storage device exterior material of the present disclosure is inside (the surface in contact with the power storage device element). ) To form a package.

The exterior material for a power storage device of the present disclosure can be suitably used for a power storage device such as a battery (including a capacitor, a capacitor, etc.). Further, the exterior material for the power storage device of the present disclosure may be used for either a primary battery or a secondary battery, but is preferably a secondary battery. The type of the secondary battery to which the exterior material for the power storage device of the present disclosure is applied is not particularly limited, and for example, a lithium ion battery, a lithium ion polymer battery, an all-solid-state battery, a lead storage battery, a nickel / hydrogen storage battery, and a nickel / hydrogen storage battery. Examples thereof include cadmium storage batteries, nickel / iron storage batteries, nickel / zinc storage batteries, silver oxide / zinc storage batteries, metal air batteries, polyvalent cation batteries, capacitors, and capacitors. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries can be mentioned as suitable application targets of the exterior materials for power storage devices of the present disclosure.

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.

<Manufacturing of exterior materials for power storage devices>
Examples 1-5 and Comparative Example 1
As a base material layer, an adhesive layer (cured) formed of a polyethylene terephthalate film (thickness 12 μm) and a biaxially stretched nylon film (thickness 15 μm) formed of a two-component curable urethane adhesive (polyol compound and aromatic isocyanate compound). A laminated film laminated with a later thickness of 3 μm) was prepared. Next, a barrier layer composed of an aluminum alloy foil (thickness 40 μm) having corrosion-resistant films formed on both sides was laminated on the biaxially stretched nylon film of the base material layer by a dry laminating method. Specifically, a two-component curable urethane adhesive (polyol compound and aromatic isocyanate compound) is applied to one side of an aluminum alloy foil having a corrosion-resistant film formed on both sides, and an adhesive layer is applied on the aluminum alloy foil. (Thickness after curing 3 μm) was formed. Next, after laminating the adhesive layer on the aluminum alloy foil and the biaxially stretched nylon film, an aging treatment was carried out to prepare a laminated body of the base material layer / adhesive layer / barrier layer.

Next, maleic anhydride-modified polypropylene (thickness 40 μm) as an adhesive layer and polypropylene (thickness 40 μm) as a heat-sealing resin layer were co-extruded onto the barrier layer side of the obtained laminate. An adhesive layer / heat-sealing 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 stretched nylon film (15 μm) / adhesive layer (3 μm) / barrier layer ( A film-like laminate (total thickness 153 μm) in which 40 μm) / adhesive layer (40 μm) / heat-sealing resin layer (40 μm) was laminated in this order was obtained.

Next, each of the obtained laminates was cut into strips of 360 mm (TD; Transverse Direction) × 200 mm (MD: Machine Direction). The MD of the laminated body corresponds to the rolling direction (RD) of the aluminum alloy foil, and the TD of the laminated body corresponds to the TD of the aluminum alloy foil. Next, a strip piece is placed between the molding die (female mold) having a diameter of 270 mm (TD) × 80 mm (MD) and the corresponding molding die (male mold) (the female mold side is the base material layer). On the side), use 4 cylinders (cylinder diameter φ80 mm), set the holding pressure of each cylinder to the value shown in Table 1, increase by 0.10 MPa, and cool at a molding depth of 5 mm. Molding was performed (in Examples 1 to 5 and Comparative Example 1, cold molding was performed under the same conditions other than the pressing pressure of the cylinder), and a recess 100 was provided at the position of the molding portion M in the schematic diagram of FIG. An exterior material for a power storage device (the size of the exterior material is TD357 mm and MD198 mm, the aspect ratio is about 1.8, and the recess is a size corresponding to the mold) was obtained.

The clearance between the female type and the male type was 0.5 mm. The female surface has a maximum height roughness (nominal value of Rz) of 0.8 μm specified in Table 2 of the comparative surface roughness standard piece in JIS B 0659-1: 2002 Annex 1 (reference). .. The female corner R is 2.0 mm and the ridge R is 2.5 mm. The male surface has a maximum height roughness (nominal value of Rz) of 3.2 μm specified in Table 2 of the comparative surface roughness standard piece in JIS B 0659-1: 2002 Annex 1 (reference). .. The male corner R is 2.0 mm and the ridge line R is 2.0 mm. The male corner R and ridge line R have a maximum height roughness (nominal value of Rz) of 1 specified in Table 2 of the comparative surface roughness standard piece in JIS B 0659-1: 2002 Annex 1 (reference). It is 0.6 μm.

<Measurement of radius of curvature of each curved surface of exterior material for power storage device>
The radius of curvature R _B ¹ of the first long side curved surface portion 11B of the outer package for a power storage device after the molding obtained above, the curvature of the second long side curved surface portion 12B radius R _B ^2, the first short side curved portion 11A the radius of curvature R _a ^1, the radius of curvature R _a ² of the second short side curved portion 12A, respectively, as shown in FIG. 5, the long sides 120 of the recess 100 in the central position of the short side 110, the base layer side I went on the surface. A contour measuring machine (PGI-1240, a contour measuring machine manufactured by Taylor Hobson Division, AMETEK, Inc.) was used for measuring the radius of curvature, and the needle for measurement used a shape of 60 ° and a tip R = 2 μm. The results are shown in Table 1.

<Evaluation of molding curl>
The molded exterior materials for the power storage device obtained above were placed on the horizontal plane 20 as shown in FIG. 9, respectively. Next, the height (maximum height t (mm)) at the position N where the distance y in the vertical direction from the horizontal plane 20 to the exterior material for the power storage device is the maximum was measured (the maximum height t is the exterior for the power storage device). The height at the position where the molding curl is the largest among the four sides of the material). The average value of the maximum height t measured by a Digimatic Height Gauge (manufactured by Mitutoyo Co., Ltd., HD-30AX) for each of 10 test samples was defined as a molding curl (mm). The results are shown in Table 1.

<Evaluation of defects during heat fusion>
The occurrence of defects in the heat-sealing of the heat-sealing resin layers of the exterior material for the power storage device after molding obtained above was evaluated as follows. As a heat-sealing device, a heat seal tester TP-701-B manufactured by Tester Sangyo Co., Ltd. was prepared, and two Teflon-coated metal heat seal bars having a width of 7 mm and a length of 300 mm were used. Two exterior materials for power storage devices after molding were used as a pair, and each was used as a sample. In the sample, the heat-sealing resins were arranged so as to face each other. At this time, the TD direction (long side direction) and the MD direction (short side direction) of the exterior material for the power storage device are made to match. Next, at the peripheral edge (flange portion) of the concave portion of the sample, the heat-sealing resin layers are sandwiched between the heat-sealing resin layers in the MD direction (short side direction) by a heat seal bar to heat the heat-sealing resin layers. Fusing (heat fusion conditions were 190 ° C. for 3 seconds, surface pressure 1.0 MPa). At the time of heat fusion, the heat-sealing resin layers are heated by holding both ends of the TD (long side direction) of the sample with the left and right hands and sandwiching the MD direction (short side direction) with the heat seal bar. Fused. The evaluation criteria are as follows. The results are shown in Table 1.
A +: The curl is very small and there is no problem in heat fusion work.
A: The curl is small and there is almost no problem in heat fusion work.
B: The curl is a little large, but heat fusion work is possible by pressing the curl part by hand.
C: Even if the curl portion is pressed by hand, the heat-sealing portion remains warped, making the heat-sealing work difficult.

Each radius of curvature of the curved surface portion of the concave portion shown in Table 1 is a value obtained by rounding off the second decimal point of the measured value. The molding curl (mm) is a value obtained by rounding off the first decimal point of the measured value. The air cylinder pressing pressure is a set value.

As described above, the present disclosure provides the inventions of the following aspects.
Item 1. An exterior material for a power storage device having a rectangular shape in a plan view, in which a film-like laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order is formed.
The exterior material for a power storage device is formed so as to project from the heat-sealing resin layer side to the base material layer side, and has a rectangular parallelepiped shape in which the power storage device element is housed on the heat-sealing resin layer side. It has a recess and
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short side curved surface portion and a second short side curved surface portion are provided in order over the short side of the exterior material.
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A first long side curved surface portion and a second long side curved surface portion are provided in order over the long side of the exterior material.
The radius of curvature R _B ¹ of the first long side curved surface portion is larger than the _{radius of curvature R A} ^{1 of the first short side curved surface portion.}
An exterior material for a power storage device, _{wherein the radius of curvature R B} ^{1 of} the first long side curved surface portion is 3.8 mm or more.
Item 2. Item 2. The exterior material for a power storage device according to Item 1, _{wherein the radius of curvature R A} ^{1 of} the first short side curved surface portion is 3.0 mm or more.
Item 3. Item 2. The exterior material for a power storage device according to Item 1 or 2, _{wherein the radius of curvature R B} ^{2 of} the second long side curved surface portion is 2.6 mm or more.
Item 4. Item 2. The exterior material for a power storage device according to any one of Items 1 to 3, _{wherein the radius of curvature R A} ^{2 of} the second short side curved surface portion is 2.1 mm or more.
Item 5. Item 2. The exterior material for a power storage device according to any one of Items 1 to 4, wherein the length of the long side of the recess is 200 mm or more when the exterior material for the power storage device is observed from the base material layer side. Item 6. Item 2. The exterior material for a power storage device according to any one of Items 1 to 5, wherein the thickness of the laminated body is 180 μm or less.
Item 7. A step of preparing a film-like laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order.
The laminate is formed so as to project from the heat-sealing resin layer side to the base material layer side, and a rectangular parallelepiped-shaped recess in which the power storage device element is housed is formed on the heat-sealing resin layer side. The process of forming and
Is equipped with
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short side curved surface portion and a second short side curved surface portion are provided in order over the short side of the exterior material.
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A first long side curved surface portion and a second long side curved surface portion are provided in order over the long side of the exterior material.
The radius of curvature R _B ¹ of the first long side curved surface portion is larger than the _{radius of curvature R A} ^{1 of the first short side curved surface portion.}
A method for manufacturing an exterior material for a power storage device, _{wherein the radius of curvature R B} ^{1 of} the first long side curved surface portion is 3.8 mm or more.
Item 8. A power storage device in which a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of an exterior material for the power storage device.
The exterior material for a power storage device has a rectangular shape in a plan view, in which a film-like laminate including at least a base material layer, a barrier layer, and a heat-sealing resin layer is formed in this order.
The exterior material for a power storage device is formed so as to project from the heat-sealing resin layer side to the base material layer side, and the storage device element is housed in the heat-sealing resin layer side in a rectangular parallelepiped shape. It has a recess of
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short side curved surface portion and a second short side curved surface portion are provided in order over the short side of the exterior material.
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A first long side curved surface portion and a second long side curved surface portion are provided in order over the long side of the exterior material.
_A power storage device in which the radius of curvature R _B ¹ of the first long side curved surface portion ^{is larger than the radius of curvature R A 1 of the first short side curved surface portion.}
Item 9. A power storage device comprising a step of accommodating a power storage device element having at least a positive electrode, a negative electrode, and an electrolyte in a package formed by using the exterior material for the power storage device according to any one of Items 1 to 6. Manufacturing method.

1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-sealing resin layer 5 Adhesive layer 6 Surface coating layer 10 Exterior material for power storage device 11A 1st short side curved surface 11B 1st long side curved surface 12A 2nd short side Curved surface 12B Second long side Curved surface 13A Short side of exterior material for power storage device 13B Long side of exterior material for power storage device 100 Recess 100A Top surface of recess 100B Side surface of recess 100C Edge of recess 110 Short side of recess 120 Long side of recess M Molded part P Center R _A ¹ Radius of curvature of first short side curved surface R _A ² Radius of curvature of second short side curved surface R _B ¹ Radius of curvature of first long side curved surface R _B ² Second Radius of curvature of long side curved surface

Claims (9)

An exterior material for a power storage device having a rectangular shape in a plan view, in which a film-like laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order is formed.
The exterior material for a power storage device is formed so as to project from the heat-sealing resin layer side to the base material layer side, and has a rectangular parallelepiped shape in which the power storage device element is housed on the heat-sealing resin layer side. It has a recess and
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short side curved surface portion and a second short side curved surface portion are provided in order over the short side of the exterior material.
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A first long side curved surface portion and a second long side curved surface portion are provided in order over the long side of the exterior material.
The radius of curvature R _B ¹ of the first long side curved surface portion is larger than the _{radius of curvature R A} ^{1 of the first short side curved surface portion.}
An exterior material for a power storage device, _{wherein the radius of curvature R B} ^{1 of} the first long side curved surface portion is 3.8 mm or more. The exterior material for a power storage device according to claim 1, _{wherein the radius of curvature R A} ^{1 of} the first short side curved surface portion is 3.0 mm or more. The exterior material for a power storage device according to claim 1 or 2, _{wherein the radius of curvature R B} ^{2 of} the second long side curved surface portion is 2.6 mm or more. The exterior material for a power storage device according to any one of claims 1 to 3, _{wherein the radius of curvature R A} ^{2 of} the second short side curved surface portion is 2.1 mm or more. The exterior material for a power storage device according to any one of claims 1 to 4, wherein the length of the long side of the recess is 200 mm or more when the exterior material for the power storage device is observed from the base material layer side. .. The exterior material for a power storage device according to any one of claims 1 to 5, wherein the thickness of the laminate is 180 μm or less. A step of preparing a film-like laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order.
The laminate is formed so as to project from the heat-sealing resin layer side to the base material layer side, and a rectangular parallelepiped-shaped recess in which the power storage device element is housed is formed on the heat-sealing resin layer side. The process of forming and
Is equipped with
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short side curved surface portion and a second short side curved surface portion are provided in order over the short side of the exterior material.
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A first long side curved surface portion and a second long side curved surface portion are provided in order over the long side of the exterior material.
The radius of curvature R _B ¹ of the first long side curved surface portion is larger than the _{radius of curvature R A} ^{1 of the first short side curved surface portion.}
A method for manufacturing an exterior material for a power storage device, _{wherein the radius of curvature R B} ^{1 of} the first long side curved surface portion is 3.8 mm or more. A power storage device in which a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of an exterior material for the power storage device.
The exterior material for a power storage device has a rectangular shape in a plan view, in which a film-like laminate including at least a base material layer, a barrier layer, and a heat-sealing resin layer is formed in this order.
The exterior material for a power storage device is formed so as to project from the heat-sealing resin layer side to the base material layer side, and the storage device element is housed in the heat-sealing resin layer side in a rectangular parallelepiped shape. It has a recess of
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the short side of the exterior material for the power storage device at the shortest distance. A first short side curved surface portion and a second short side curved surface portion are provided in order over the short side of the exterior material.
When the exterior material for the power storage device is observed from the base material layer side, the power storage device is used from the center of the recess on a straight line connecting the center of the recess and the long side of the exterior material for the power storage device at the shortest distance. A first long side curved surface portion and a second long side curved surface portion are provided in order over the long side of the exterior material.
_A power storage device in which the radius of curvature R _B ¹ of the first long side curved surface portion ^{is larger than the radius of curvature R A 1 of the first short side curved surface portion.} A storage device comprising at least a positive electrode, a negative electrode, and a power storage device element including an electrolyte is housed in a package formed by using the exterior material for a power storage device according to any one of claims 1 to 6. How to make the device.

Images