Exterior material for a power storage device, method for manufacturing the same, and power storage device

Abstract

Provided is an exterior packaging material for an electricity storage device that has a surface coating layer on its outer surface, wherein the surface coating layer that constitutes the outer surface has high adhesion to an adhesive tape in a high-temperature environment. [Solution] The exterior material for an electricity storage device is composed of a laminate having, in order from the outside, at least a surface coating layer 6, a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4, and the logarithmic decrement ΔE at 60°C in rigid pendulum measurement of the outer surface of the surface coating layer of the laminate is 0.12 or less.

Description

Technical Field

[0001] The present disclosure relates to an exterior material for a power storage device, a method for manufacturing the same, and a power storage device.

Background Art

[0002] Conventionally, various types of power storage devices have been developed. In any power storage device, an exterior material is an essential member for sealing power storage device elements such as electrodes and electrolytes. Conventionally, metal exterior materials have been frequently used as exterior materials for power storage devices.

[0003] On the other hand, in recent years, with the improvement in performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., various shapes have been required for power storage devices, and thinning and weight reduction have been demanded. However, the conventionally frequently used metal exterior materials for power storage devices have the drawbacks that it is difficult to follow the diversification of shapes and there is also a limit to weight reduction.

[0004] Therefore, in recent years, as an exterior material for a power storage device that can be easily processed into various shapes and can achieve thinning and weight reduction, a film-like laminate in which a base material layer / barrier layer / heat-sealable resin layer are sequentially laminated has been proposed (see, for example, Patent Document 1).

[0005] In such an exterior material for a power storage device, generally, a recess is formed by cold forming, power storage device elements such as electrodes and electrolytic solution are arranged in the space formed by the recess, and the heat-sealable resin layer is heat-sealed to obtain a power storage device in which the power storage device elements are housed inside the exterior material for a power storage device.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In an exterior material for a power storage device composed of a film-like laminate, a surface coating layer may be provided on the outside of the base material layer for the purpose of protecting the base material layer and imparting design properties.

[0008] In addition, a power storage device is fixed to a housing of various products via an adhesive tape (double-sided adhesive tape) or the like. The power storage device is fixed to the housing by bringing the surface of the power storage device (that is, the surface of the exterior material for the power storage device) into close contact with the adhesive tape. For this reason, a high adhesiveness with the adhesive tape is required for the outer surface of the exterior material for the power storage device that constitutes the surface of the power storage device. In particular, the exterior material for the power storage device may be exposed to a high-temperature environment, such as an electric vehicle, a hybrid electric vehicle, a personal computer, a camera, a mobile phone, etc. A high adhesiveness in a high-temperature environment (for example, about 60°C) with respect to the adhesive tape is also required for the outer surface of the exterior material for the power storage device.

[0009] Under such circumstances, the main object of the first embodiment of the present disclosure is to provide an exterior material for a power storage device having a surface coating layer on the outer surface, wherein the surface coating layer constituting the outer surface has high adhesiveness with an adhesive tape in a high-temperature environment.

[0010] In addition, in the manufacturing process of the power storage device, after accommodating a power storage device element such as an electrolyte in a package formed by the formed exterior material for the power storage device, a baking process is performed in a high-temperature environment (for example, about 80 to 120°C) for the purpose of making the power storage device element fit in.

[0011] From the viewpoint of productivity (for example, restrictions on the space for the baking process), this baking process is performed by stacking the power storage devices. For this reason, in a high-temperature environment, there are problems such that the power storage devices are transported and stacked, and at this time, the power storage devices are easily damaged, such as losing their shape due to impact or getting streaks or abrasion marks.

[0012] Under such circumstances, the main object of the second embodiment of the present disclosure is to provide an exterior material for a power storage device that is less likely to be damaged in a high-temperature environment.

Means for Solving the Problems

[0013] The inventors of the present disclosure conducted intensive studies to solve the problems of the first embodiment described above. As a result, it is composed of a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, and the logarithmic decrement ΔE at 60° C. in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less. It has been found that the exterior material for a power storage device has high adhesion to an adhesive tape.

[0014] The first embodiment of the present disclosure was completed by further studies based on these findings. That is, the first embodiment of the present disclosure provides an invention in the following aspects. It is composed of a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, An exterior material for a power storage device, wherein the logarithmic decrement ΔE at 60° C. in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less.

[0015] In addition, the inventors of the present disclosure conducted intensive studies to solve the problems of the second embodiment described above. As a result, it is composed of a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, and the logarithmic decrement ΔE at 110° C. in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less. It has been found that the exterior material for a power storage device is less likely to be damaged in a high-temperature environment (110° C.).

[0016] The second embodiment of the present disclosure was completed by further studies based on these findings. That is, the second embodiment of the present disclosure provides an invention in the following aspects. It is composed of a laminate including at least, in order from the outside, a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer. An exterior material for a power storage device, wherein a logarithmic decrement ΔE at 110 °C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less.

Advantages of the Invention

[0017] According to the first embodiment of the present disclosure, there is provided an exterior material for a power storage device having a surface coating layer on the outer surface, wherein the surface coating layer constituting the outer surface has high adhesion to an adhesive tape in a high-temperature environment (for example, about 60 °C). Further, according to the first embodiment of the present disclosure, there can also be provided a method for manufacturing the exterior material for a power storage device and a power storage device using the exterior material for a power storage device.

[0018] According to the second embodiment of the present disclosure, there can be provided an exterior material for a power storage device that is less likely to be damaged in a high-temperature environment. Further, according to the second embodiment of the present disclosure, there can also be provided a method for manufacturing the exterior material for a power storage device and a power storage device using the exterior material for a power storage device.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

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Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0020] The exterior material for a power storage device according to the first embodiment of the present disclosure is composed of a laminate including at least, in order from the outside, a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, and is characterized in that the logarithmic decrement ΔE at 60°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less. The exterior material for a power storage device according to the first embodiment of the present disclosure has such a configuration that the surface coating layer constituting the outer surface can exhibit high adhesion to an adhesive tape in a high-temperature environment (for example, about 60°C).

[0021] Further, the exterior material for a power storage device according to the second embodiment of the present disclosure is composed of a laminate including at least, in order from the outside, a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, and is characterized in that the logarithmic decrement ΔE at 110°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less. The exterior material for a power storage device according to the first embodiment of the present disclosure has such a configuration that it is less likely to be damaged in a high-temperature environment.

[0022] Hereinafter, the exterior material for a power storage device of the present disclosure will be described in detail. In this specification, regarding matters specific to the first embodiment and the second embodiment of the present disclosure, it is clearly stated that they are matters related to each embodiment, and regarding matters common to the first embodiment and the second embodiment, they are described in the present disclosure without particular clarification, and duplicate descriptions are omitted as appropriate. Also, in this specification, the numerical range indicated by "~" means "or more" and "or less". For example, the notation of 2~15 mm means 2 mm or more and 15 mm or less.

[0023] 1. Laminated Structure and Physical Properties of Exterior Material for Energy Storage Device The exterior material 10 for a power storage device of the present disclosure is composed of a laminate including, for example, as shown in FIGS. 1 to 3, a surface coating layer 6, a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order from the outside. In the exterior material 10 for a power storage device, the surface coating layer 6 is the outermost layer, and the heat-sealable resin layer 4 is the innermost layer. When assembling a power storage device using the exterior material 10 for a power storage device and a power storage device element, the power storage device element is accommodated in a space formed by heat-sealing the peripheral portions with the heat-sealable resin layers 4 of the exterior material 10 for a power storage device facing each other. In the laminate constituting the exterior material 10 for a power storage device of the present disclosure, with the barrier layer 3 as a reference, the side of the heat-sealable resin layer 4 is the inner side with respect to the barrier layer 3, and the side of the surface coating layer 6 is the outer side with respect to the barrier layer 3.

[0024] In the present disclosure, the exterior material 10 for a power storage device may, for example, as shown in FIGS. 2 to 3, have an adhesive layer 2 between the base material layer 1 and the barrier layer 3 as needed for the purpose of enhancing the adhesiveness between these layers. Although not shown, a coloring layer may be provided between the base material layer 1 and the barrier layer 3. Further, for example, as shown in FIG. 3, an adhesive layer 5 may be provided between the barrier layer 3 and the heat-sealable resin layer 4 as needed for the purpose of enhancing the adhesiveness between these layers.

[0025] In the present disclosure, the thickness of the laminate constituting the exterior material 10 for a power storage device is not particularly limited. However, from the viewpoints of cost reduction, improvement of energy density, etc., the upper limit is preferably about 190 μm or less, about 180 μm or less, about 160 μm or less, about 155 μm or less, about 140 μm or less, about 130 μm or less, about 120 μm or less. Also, from the viewpoint of maintaining the function of the exterior material for a power storage device of protecting the power storage device element, the thickness of the laminate constituting the exterior material 10 for a power storage device is preferably about 35 μm or more, about 45 μm or more, about 60 μm or more, about 75 μm or more, about 80 μm or more. Regarding the preferable range of the thickness of the laminate constituting the exterior material 10 for a power storage device, for example, about 35 to 190 μm, about 35 to 180 μm, about 35 to 160 μm, about 35 to 155 μm, about 35 to 140 μm, about 35 to 130 μm, about 35 to 120 μm, about 45 to 190 μm, about 45 to 180 μm, about 45 to 160 μm, about 45 to 155 μm, about 45 to 140 μm, about 45 to 130 μm, about 45 to 120 μm, about 60 to 190 μm, about 60 to 180 μm, about 60 to 160 μm, about 60 to 155 μm, about 60 to 140 μm, about 60 to 130 μm, about 60 to 120 μm, about 75 to 190 μm, about 75 to 180 μm, about 75 to 160 μm, about 75 to 155 μm, about 75 to 140 μm, about 75 to 130 μm, about 75 to 120 μm, about 80 to 190 μm, about 80 to 180 μm, about 80 to 160 μm, about 80 to 155 μm, about 80 to 140 μm, about 80 to 130 μm, about 80 to 120 μm can be mentioned. Among these, about 80 to 130 μm is particularly preferable.

[0026] In the exterior material 10 for a power storage device of the present disclosure, the ratio of the total thickness of the surface coating layer 6, the base material layer 1, the adhesive layer 2 provided as necessary, the barrier layer 3, the adhesive layer 5 provided as necessary, and the heat-sealable resin layer 4 to the thickness (total thickness) of the laminate constituting the exterior material 10 for a power storage device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. As a specific example, when the exterior material 10 for a power storage device of the present disclosure includes the surface coating layer 6, the base material layer 1, the adhesive layer 2, the barrier layer 3, the adhesive layer 5, and the heat-sealable resin layer 4, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the exterior material 10 for a power storage device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. Further, even when the exterior material 10 for a power storage device of the present disclosure is a laminate including the surface coating layer 6, the base material layer 1, the adhesive layer 2, the barrier layer 3, and the heat-sealable resin layer 4, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the exterior material 10 for a power storage device can be, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

[0027] In the exterior material 10 for a power storage device according to the first embodiment of the present disclosure, the logarithmic decrement ΔE at 60°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer 6 of the laminate constituting the exterior material 10 for a power storage device is 0.120 or less. In the exterior material 10 for a power storage device of the first embodiment, by having the above-mentioned logarithmic decrement ΔE under the high-temperature condition of 60°C, high adhesion of the surface coating layer 6 to the adhesive tape in a high-temperature environment is ensured. More specifically, in the exterior material 10 for a power storage device of the first embodiment, since the logarithmic decrement ΔE of the surface coating layer at 60°C is set to a very small value of 0.120 or less, it can be said that the surface coating layer has a very hard property in a high-temperature environment of 60°C. Therefore, when a force is applied to peel the adhesive tape attached to the surface coating layer from the surface coating layer, it is considered that the surface coating layer is difficult to move and exhibits high adhesion. The surface of the power storage device (that is, the outer surface of the exterior material for a power storage device) is brought into close contact with the adhesive tape to fix the power storage device to the housing.

[0028] In the first embodiment, the logarithmic decrement ΔE of the surface coating layer 6 at 60°C may be 0.120 or less. However, from the viewpoint of more preferably exhibiting high adhesion of the surface coating layer 6 to the adhesive tape in a high-temperature environment, it is preferably about 0.100 or less, more preferably about 0.085 or less, and even more preferably 0.080 or less. Also, from the same viewpoint, the logarithmic decrement ΔE of the surface coating layer 6 at 60°C is preferably about 0.030 or more, more preferably about 0.050 or more, and even more preferably about 0.060 or more. The preferable range of the logarithmic decrement ΔE of the surface coating layer 6 at 60°C is about 0.030 to 0.120, about 0.030 to 0.100, about 0.030 to 0.085, about 0.030 to 0.080, about 0.050 to 0.120, about 0.050 to 0.100, about 0.050 to 0.085, about 0.050 to 0.080, about 0.060 to 0.120, about 0.060 to 0.100, about 0.060 to 0.085, about 0.060 to 0.080. Among these, about 0.050 to 0.080 or about 0.060 to 0.080 is particularly preferable.

[0029] Also, in the first embodiment, from the viewpoint of preferably exhibiting high adhesion of the surface coating layer 6 to the adhesive tape in a room-temperature environment, the logarithmic decrement ΔE of the surface coating layer 6 at 30°C is preferably 0.080 or less, more preferably 0.070 or less, and even more preferably 0.060 or less. Also, from the same viewpoint, the logarithmic decrement ΔE of the surface coating layer 6 at 30°C is preferably 0.030 or more, more preferably 0.040 or more, and even more preferably 0.046 or more. The preferable range of the logarithmic decrement ΔE of the surface coating layer 6 at 30°C is about 0.030 to 0.080, about 0.030 to 0.070, about 0.030 to 0.060, about 0.040 to 0.080, about 0.040 to 0.070, about 0.040 to 0.060, about 0.046 to 0.080, about 0.046 to 0.070, about 0.046 to 0.060. In the first embodiment, the logarithmic decrement ΔE at 60°C or 30°C is measured as follows, respectively.

[0030] [Measurement of the logarithmic attenuation rate ΔE of the outer surface of the surface coating layer in the first embodiment] The exterior material for the power storage device is cut into a rectangle with a width (TD: Transverse Direction) of 15 mm and a length (MD: Machine Direction) of 100 mm. Next, the heat-sealable resin layer is peeled off from the barrier layer. When there is an adhesive layer between the heat-sealable resin layer and the barrier layer, the adhesive layer is also peeled off from the barrier layer. Specifically, a cut is made from the surface coating layer side to the barrier layer at a position 20 mm from the end in the length direction. Pull from the left and right around the cut, expand the cuts in the surface coating layer and the barrier layer to cut, and stretch the heat-sealable resin layer (and further the adhesive layer). At the same time as stretching the heat-sealable resin layer (and further the adhesive layer), the heat-sealable resin layer (and further the adhesive layer) is peeled off from the barrier layer. In this way, the exterior material for the power storage device from which the heat-sealable resin layer (and further the adhesive layer) has been peeled off is cut into a rectangle with a width (TD) of 15 mm and a length (MD: Machine Direction) of 50 mm to obtain a test sample S. As shown in Fig. 5, using a rigid pendulum physical property tester (model number: RPT-3000W, manufactured by A&D Company, Ltd.), FRB-100 is used for the frame of the pendulum 30, and a cylindrical cylinder edge 30a (RBP-080) is used for the edge part, and the initial amplitude is set to about 0.3 degree. The pendulum 30 is installed so that the central axis direction of the cylindrical cylinder is orthogonal to the MD direction of the test sample S. Also, in order to prevent the test sample S from floating or warping during measurement, Kapton tape is attached and fixed at a location that does not affect the measurement result of the test sample S. The cylindrical cylinder edge 30a is brought into contact with the outer surface of the surface coating layer. Next, using a cold and hot block 31 (CHB-100), the logarithmic decrement ΔE of the surface coating layer is measured in the temperature range from 30 °C to 200 °C at a heating rate of 3 °C / min. Note that if the temperature is raised to 90 °C or higher, it is not necessary to raise it to 200 °C. The logarithmic decrement ΔE of the surface coating layer of the test sample S at a temperature of 60 °C or 30 °C is adopted. The test samples that have been measured once are not used, and the average value measured with N = 2 using newly cut test samples is used. Note that if only exterior materials for power storage devices with a size smaller than the test samples of the above size can be prepared, test samples with a measurable size range are prepared for measurement.Even when the MD and TD of the test sample cannot be specified, since the MD and TD do not significantly affect the measurement results, the measurement is performed on the test sample prepared without specifying the direction. Further, when preparing a test sample by obtaining an exterior material for a power storage device from the power storage device, the exterior material for the power storage device is obtained from a location where the influence of molding, such as the top surface or side surface of the power storage device, is small.

[0031] In the first embodiment, the logarithmic decrement ΔE at 60 °C and the logarithmic decrement ΔE at 30 °C can be adjusted by the composition of the resin composition forming the surface coating layer 6 (types and contents of resin, filler, etc.), curing conditions, molecular weight, number of functional groups, crosslink density, bulkiness of substituents, and the like.

[0032] Further, in the exterior material 10 for a power storage device of the second embodiment, the logarithmic decrement ΔE at 110 °C in the measurement of the rigid pendulum on the outer surface of the surface coating layer 6 of the laminate constituting the exterior material 10 for a power storage device is 0.200 or less. In the exterior material 10 for a power storage device of the second embodiment, by having the logarithmic decrement ΔE in a high-temperature environment of 110 °C, the exterior material for a power storage device is less likely to be damaged in a high-temperature environment.

[0033] In the second embodiment, the logarithmic decrement ΔE at 110 °C may be 0.200 or less. From the viewpoint of further preferably enhancing the damage resistance in a high-temperature environment, it is preferably about 0.180 or less, more preferably about 0.160 or less, still more preferably 0.145 or less. Also, it is preferably about 0.100 or more, more preferably about 0.120 or more. Preferred ranges include about 0.100 to 0.200, about 0.100 to 0.180, about 0.100 to 0.160, about 0.100 to 0.145, about 0.120 to 0.200, about 0.120 to 0.180, about 0.120 to 0.160, about 0.120 to 0.145. Among these, about 0.120 to 0.160 is particularly preferred.

[0034] In addition, in the second embodiment, from the viewpoint of enhancing the damage resistance not only in a high-temperature environment but also in a room-temperature environment, the logarithmic decrement ΔE at 30°C in the measurement of the rigid pendulum of the outer surface of the surface coating layer 6 of the laminate constituting the exterior material for the power storage device of the second embodiment is preferably about 0.080 or less, more preferably about 0.060 or less, and preferably about 0.020 or more, more preferably about 0.030 or more. Preferred ranges include about 0.020 to 0.080, about 0.020 to 0.060, about 0.030 to 0.080, and about 0.030 to 0.060. Among these, about 0.030 to 0.060 is particularly preferred.

[0035] In the second embodiment, the logarithmic decrement ΔE at 110°C or 30°C is measured as follows.

[0036] [Measurement of the Logarithmic Decrement ΔE of the Outer Surface of the Surface Coating Layer in the Second Embodiment] The exterior material for the energy storage device is cut into a rectangle with a width (TD: Transverse Direction) of 15 mm and a length (MD: Machine Direction) of 100 mm. Next, the heat-fusible resin layer is peeled off from the barrier layer. When there is an adhesive layer between the heat-fusible resin layer and the barrier layer, the adhesive layer is also peeled off from the barrier layer. Specifically, a cut is made from the end in the length direction at 20 mm to the barrier layer from the surface coating layer side. Pull from the left and right around the cut, expand the cut of the surface coating layer and the barrier layer to cut, and stretch the heat-fusible resin layer (and further the adhesive layer). At the same time as stretching the heat-fusible resin layer (and further the adhesive layer), the heat-fusible resin layer (and further the adhesive layer) is peeled off from the barrier layer. In this way, the exterior material for the energy storage device from which the heat-fusible resin layer (and further the adhesive layer) has been peeled off is cut into a rectangle with a width (TD) of 15 mm and a length (MD: Machine Direction) of 50 mm to obtain a test sample S (Figure 5). The reason for peeling off the heat-fusible resin layer (and further the adhesive layer) from the barrier layer to obtain a sample of the exterior material for the energy storage device outside the barrier layer (a sample including the surface coating layer, the base material layer, and the barrier layer) is to exclude the influence of the heat-fusible resin layer in the measurement of the logarithmic decrement rate ΔE. As shown in Figure 5, using a rigid pendulum physical property tester (model number: RPT-3000W, manufactured by A&D Company, Ltd.), FRB-100 is used for the frame of the pendulum 30, and a cylindrical cylinder edge 30a (RBP-080) is used for the edge part, and the initial amplitude is set to about 0.3 degree. The pendulum 30 is installed so that the central axis direction of the cylindrical cylinder is orthogonal to the MD direction of the test sample S. Also, in order to prevent the test sample S from floating or warping during the measurement, a Kapton tape is attached and fixed at a location that does not affect the measurement result of the test sample S. The cylindrical cylinder edge 30a is brought into contact with the outer surface of the surface coating layer. Next, using a cold and hot block 31 (CHB-100), the logarithmic decrement rate ΔE of the surface coating layer is measured in the temperature range from 30°C to 200°C at a heating rate of 3°C / min. Note that if the temperature is raised to 110°C or higher, it is not necessary to raise it to 200°C. The logarithmic decrement rate ΔE of the surface coating layer of the test sample S at a temperature of 110°C or 30°C is adopted.Instead of using the test sample S that has been measured once, the average value measured with N = 2 using a newly cut test sample S is used. If only an exterior material for a power storage device with a size smaller than the test sample S of the above size can be prepared, a test sample S with a measurable size range is prepared for measurement. Also, even when the MD and TD of the test sample S cannot be specified, since the MD and TD do not have a significant impact on the measurement results, the test sample S prepared without specifying the direction is measured. Further, when obtaining an exterior material for a power storage device from a power storage device to prepare a test sample S, the exterior material for a power storage device is obtained from a location with little influence from molding, such as the top surface or side surface of the power storage device.

[0037] In the second embodiment, the logarithmic decrement ΔE at 110°C and the logarithmic decrement ΔE at 30°C can be adjusted by the composition of the resin composition forming the surface coating layer 6 (types and contents of resin, curing agent, filler, etc.), curing conditions, molecular weight, number of functional groups, crosslink density, bulkiness of substituents, etc.

[0038] Also, in the second embodiment, as the resin forming the surface coating layer 6, a resin having a hard property in a high-temperature environment is selected from commercially available resins, a resin composition forming the surface coating layer 6 is prepared, the logarithmic decrement ΔE at 110°C is measured, and a resin with a logarithmic decrement ΔE of 0.200 or less can be adopted for the surface coating layer 6.

[0039] Furthermore, in the exterior material for a power storage device of the second embodiment, since the barrier layer 3 contains a stainless steel foil, it becomes easier to set the logarithmic decrement ΔE at 110°C to 0.200 or less compared to the case where the barrier layer 3 is formed of an aluminum alloy foil, for example. This is presumably because the stainless steel foil has a harder property compared to the aluminum alloy foil.

[0040] Also, from the perspective of making the outer surface of the exterior material 10 for the power storage device of the present disclosure into a matte finish design, in the exterior material 10 for the power storage device of the present disclosure, as the arithmetic mean roughness Ra1 of the outer surface of the surface coating layer 6, it is preferably about 0.10 μm or more, more preferably about 0.20 μm or more, still more preferably about 0.30 μm or more, still more preferably about 0.40 μm or more, still more preferably 0.50 or more, and also preferably about 0.90 μm or less, more preferably about 0.80 μm or less, still more preferably about 0.70 μm or less. Preferred ranges include about 0.10 to 0.90 μm, about 0.10 to 0.80 μm, about 0.10 to 0.70 μm, about 0.20 to 0.90 μm, about 0.20 to 0.80 μm, about 0.20 to 0.70 μm, about 0.30 to 0.90 μm, about 0.30 to 0.80 μm, about 0.30 to 0.70 μm, about 0.40 to 0.90 μm, about 0.40 to 0.80 μm, about 0.40 to 0.70 μm, about 0.50 to 0.90 μm, about 0.50 to 0.80 μm, about 0.50 to 0.70 μm. Among these, about 0.20 to 0.80 μm is particularly preferred.

[0041] 2. Each Layer Forming the Exterior Material for Energy Storage Device [Surface coating layer 6] The exterior material 10 for the power storage device of the first embodiment includes a surface coating layer 6 on the upper side of the base material layer 1 (the side opposite to the barrier layer 3 of the base material layer 1) for the purpose of improving at least one of design, electrolyte resistance, scratch resistance, formability, etc. Also, the exterior material 10 for the power storage device of the second embodiment includes a surface coating layer 6 on the upper side of the base material layer 1 (the side opposite to the barrier layer 3 of the base material layer 1) for the purpose of improving damage resistance in a high-temperature environment. In the present disclosure, the surface coating layer 6 is the layer located on the outermost layer of the exterior material 10 for the power storage device when assembling the power storage device using the exterior material for the power storage device. That is, the surface coating layer 6 constitutes the outer surface of the exterior material 10 for the power storage device of the present disclosure.

[0042] The resin contained in the resin composition for forming the surface coating layer 6 of the first embodiment is not particularly limited, provided that the logarithmic decrement ΔE at 60°C is 0.120 or less. As described above, in the first embodiment, the logarithmic decrement ΔE at 60°C and the logarithmic decrement ΔE at 30°C can be adjusted by the composition of the resin composition for forming the surface coating layer 6 (types and contents of resin, filler, etc.), curing conditions, molecular weight, number of functional groups, crosslink density, bulkiness of substituents, and the like. Further, in the first embodiment, as the resin for forming the surface coating layer 6, a resin having a hard property in a high-temperature environment is selected from commercially available resins, a resin composition for forming the surface coating layer 6 is prepared, the logarithmic decrement ΔE at 60°C is measured, and a resin having a logarithmic decrement ΔE of 0.120 or less can be employed for the surface coating layer 6.

[0043] Also, the resin contained in the resin composition for forming the surface coating layer 6 of the second embodiment is not particularly limited, provided that the logarithmic decrement ΔE at 110°C is 0.200 or less. As described above, in the second embodiment, the logarithmic decrement ΔE at 110°C and the logarithmic decrement ΔE at 30°C can be adjusted by the composition of the resin composition for forming the surface coating layer 6 (types and contents of resin, curing agent, filler, etc.), curing conditions, molecular weight, number of functional groups, crosslink density, bulkiness of substituents, and the like. Further, in the second embodiment, as the resin for forming the surface coating layer 6, a resin having a hard property in a high-temperature environment is selected from commercially available resins, a resin composition for forming the surface coating layer 6 is prepared, the logarithmic decrement ΔE at 110°C is measured, and a resin having a logarithmic decrement ΔE of 0.200 or less can be employed for the surface coating layer 6.

[0044] In the surface coating layer 6 of the present disclosure, specific examples of the resin include, for example, resins such as polyvinylidene chloride, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenolic resin, and modified products of these resins. Further, they may be copolymers of these resins or modified products of the copolymers. Furthermore, they may be mixtures of these resins. The resin is preferably a curable resin. That is, it is preferable that the surface coating layer 6 is composed of a cured product of a resin composition containing a curable resin.

[0045] The curable resin may be either a one-component curing type or a two-component curing type, but preferably a two-component curing type. Examples of the two-component curing type resin include, for example, two-component curing type polyurethane, two-component curing type polyester, two-component curing type epoxy resin, etc. Among these, two-component curing type polyurethane is preferable.

[0046] Examples of two-component curable polyurethanes include polyurethanes containing a first component containing a polyol compound and a second component containing an isocyanate compound. Preferably, a two-component curable polyurethane using a polyol such as a polyester polyol, a polyether polyol, or an acrylic polyol as the first component and an aromatic or aliphatic polyisocyanate as the second component can be mentioned. In addition, examples of polyurethanes include polyurethanes containing a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound and an isocyanate compound, polyurethanes containing a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound and a polyol compound, and polyurethanes cured by reacting a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound with moisture in the air or the like. As the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group not only at the terminal of the repeating unit but also in the side chain. Examples of the second component include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds. Examples of the isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), etc. In addition, examples include polyfunctional isocyanate modified products derived from one or more of these diisocyanates. Also, a multimer (for example, a trimer) can be used as the polyisocyanate compound. Examples of such multimers include adducts, biurets, and nurates. Note that an aliphatic isocyanate compound refers to an isocyanate having an aliphatic group and no aromatic ring, an alicyclic isocyanate compound refers to an isocyanate having an alicyclic hydrocarbon group, and an aromatic isocyanate compound refers to an isocyanate having an aromatic ring.Since the surface coating layer 6 is formed of polyurethane, the exterior material for the power storage device is imparted with excellent electrolyte resistance.

[0047] In the first embodiment, from the viewpoint of more suitably enhancing the adhesion between the adhesive tape and the surface coating layer 6, it is preferable that the adhesive component of the adhesive tape and the resin contained in the resin composition forming the surface coating layer 6 contain common components. For the adhesive tape, for example, adhesives such as synthetic rubber-based, acrylic-based, and silicone-based adhesives are used as the adhesive component, and among these, acrylic adhesives are widely used. Therefore, as the resin contained in the resin composition forming the surface coating layer 6 of the first embodiment, an acrylic resin is preferable. Also, a two-component type polyurethane with acrylic polyol as the first component is preferable.

[0048] In the resin composition forming the surface coating layer 6 of the first embodiment, when the resin is a polyurethane containing a first component containing a polyol compound and a second component containing an isocyanate compound, for example, by adjusting the ratio of the first component and the second component, the logarithmic decrement ΔE at 60°C or 30°C can also be adjusted.

[0049] In the surface coating layer 6 of the first embodiment, on at least one of the surface and the inside of the surface coating layer 6, according to the functionality to be provided on the surface coating layer 6 and its surface, etc., if necessary, fillers, lubricants, anti-blocking agents, matting agents, flame retardants, antioxidants, tackifiers, anti-static agents, etc. may be included as additives. Examples of the additives include fine particles having an average particle diameter of about 0.5 nm to 5 μm. The average particle diameter of the additives is the median diameter measured by a laser diffraction / scattering type particle size distribution measuring device.

[0050] In the first embodiment, the additives may be either inorganic substances or organic substances. Also, the shape of the additives is not particularly limited, and examples include spherical, fibrous, plate-like, amorphous, and scaly shapes.

[0051] In the first embodiment, specific examples of the additive include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotube, high melting point nylon, acrylate resin, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, and the like. The additive may be used alone or in combination of two or more. Among these additives, from the viewpoints of dispersion stability and cost, silica, barium sulfate, and titanium oxide are preferably used. Further, various surface treatments such as insulation treatment and high dispersibility treatment may be performed on the surface of the additive.

[0052] In the first embodiment, among the additives, the filler is preferably in the form of particles. Examples of the filler include inorganic fillers (preferably inorganic particles) and organic fillers (preferably organic particles). The filler contained in the surface coating layer 6 may be of one type or two or more types. It is also preferable to use an inorganic filler and an organic filler in combination. Also, the shape of the filler is not particularly limited, and examples include spherical, fibrous, plate-like, amorphous, and scaly.

[0053] Further, in the resin composition for forming the surface coating layer 6 of the second embodiment, when the resin is a polyurethane containing a first agent (main agent) containing a polyol compound and a second agent (curing agent) containing an isocyanate compound, for example, by adjusting the ratio of the first agent to the second agent, the logarithmic decrement rate ΔE at 110 ° C can also be adjusted.

[0054] The surface coating layer 6 of the present disclosure preferably contains a resin and a filler. In the second embodiment, by including a filler, the surface coating layer 6 can be made into a matte design. The filler is preferably in the form of particles. Examples of the filler include inorganic fillers (preferably inorganic particles) and organic fillers (preferably organic particles). When the surface coating layer 6 of the second embodiment contains a filler, the filler contained in the surface coating layer 6 may be of one type or two or more types. It is also preferable to use an inorganic filler and an organic filler in combination. Also, the shape of the filler is not particularly limited, and examples include spherical, fibrous, plate-like, amorphous, and flaky shapes.

[0055] In the present disclosure, the average particle diameter of the filler is not particularly limited, but from the perspective of making the exterior material 10 for the power storage device into a matte design, for example, it is about 0.01 to 5 μm. The average particle diameter of the filler is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device. The average particle diameter of the filler is preferably not more than the thickness of the surface coating layer 6.

[0056] In the present disclosure, as the inorganic filler, those that can make the surface coating layer 6 into a matte tone are preferred, and there is no particular limitation. Examples include silica, talc, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, 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, gold, aluminum, copper, nickel and other particles. Among these, silica particles are particularly preferred.

[0057] In addition, in the present disclosure, the organic filler is not particularly limited as long as the surface coating layer 6 can be made into a matte finish, and examples include particles such as nylon, polyacrylate, polystyrene, polyethylene, benzoguanamine, or cross-linked products thereof.

[0058] The content of the filler contained in the surface coating layer 6 of the first embodiment is not particularly limited as long as the logarithmic decrement ΔE at 60°C in the rigid pendulum measurement of the outer surface of the surface coating layer 6 is 0.120 or less. However, based on 100 parts by mass of the resin in the resin composition forming the surface coating layer 6, it is preferably about 3 parts by mass or more, more preferably about 10 parts by mass or more, and is preferably about 30 parts by mass or less, more preferably about 20 parts by mass or less. Preferred ranges include about 3 to 30 parts by mass, about 3 to 20 parts by mass, about 10 to 30 parts by mass, and about 10 to 20 parts by mass.

[0059] In addition, the content of the filler contained in the surface coating layer 6 of the second embodiment is not particularly limited as long as the logarithmic decrement ΔE at 110°C in the rigid pendulum measurement of the outer surface of the surface coating layer 6 is 0.200 or less. However, based on 100 parts by mass of the resin in the resin composition forming the surface coating layer 6, it is preferably about 3 parts by mass or more, more preferably about 10 parts by mass or more, and is preferably about 30 parts by mass or less, more preferably about 20 parts by mass or less. Preferred ranges include about 3 to 30 parts by mass, about 3 to 20 parts by mass, about 10 to 30 parts by mass, and about 10 to 20 parts by mass.

[0060] On at least one of the surface and the interior of the surface coating layer 6 of the present disclosure, additives such as lubricants, colorants, antiblocking agents, flame retardants, antioxidants, tackifiers, and antistatic agents described later may be further included as necessary according to the functionality to be provided on the surface coating layer 6 and its surface.

[0061] In addition, in the present disclosure, when the surface coating layer 6 contains a colorant, known colorants such as pigments and dyes can be used as the colorant. 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 surface coating layer 6 are the same as those exemplified in the column of [adhesive layer 2]. Further, the preferable content of the colorant contained in the surface coating layer 6 is also the same as the content described in the column of [adhesive layer 2].

[0062] In the present disclosure, the lubricant is not particularly limited, but preferably an amide-based lubricant. Specific examples of the amide-based lubricant include, for example, saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, aromatic bisamides, and the like. Specific examples of the saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, and the like. Specific examples of the unsaturated fatty acid amides include oleic acid amide, erucic acid amide, and the like. Specific examples of the substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, and the like. Specific examples of the methylol amides include methylol stearic acid amide, and the like. Specific examples of the saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide, and the like. Specific examples of the unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide, and the like. Specific examples of the fatty acid ester amides include stearoamide ethyl stearate, and the like. Specific examples of the aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, N,N'-distearyl isophthalic acid amide, and the like. The lubricant may be used alone or in combination of two or more.

[0063] In the present disclosure, when a lubricant is present on the surface of the surface coating layer 6, the amount of its presence is not particularly limited, but is preferably about 3 mg / m 2 or more, more preferably 4 to 15 mg / m 2 or so, still more preferably 5 to 14 mg / m 2 or so.

[0064] In the present disclosure, the lubricant present on the surface of the surface coating layer 6 may be one obtained by exuding the lubricant contained in the resin constituting the surface coating layer 6, or may be one obtained by applying a lubricant to the surface of the surface coating layer 6.

[0065] In the present disclosure, 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.

[0066] In the present disclosure, the thickness of the surface coating layer 6 is not particularly limited as long as the above-described functions as the surface coating layer 6 are exhibited, and examples thereof include about 0.5 to 10 μm, preferably about 1 to 5 μm.

[0067] [Base material layer 1] In the present disclosure, the base material layer 1 is a layer provided for the purpose of, for example, exhibiting the function as a base material of the exterior material for a power storage device. The base material layer 1 is located between the surface coating layer 6 and the barrier layer 3 of the exterior material 10 for a power storage device. When the adhesive layer 2 is provided, it is located between the surface coating layer 6 and the adhesive layer 2.

[0068] The material for forming the base material layer 1 is not particularly limited as long as it has the function as a base material, that is, at least has insulation. The base material layer 1 can be formed using, for example, a resin, and the resin may contain an additive described later.

[0069] When the base material layer 1 is formed 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 preferred. Examples of the stretching method for forming the biaxially stretched film include a sequential biaxial stretching method, an inflation method, a simultaneous biaxial stretching method, etc. Examples of the method for applying the resin include a roll coating method, a gravure coating method, an extrusion coating method, etc.

[0070] Examples of the resin for forming the base material layer 1 include resins such as polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenol resin, and modified products of these resins. Further, the resin for forming the base material layer 1 may be a copolymer of these resins, or a modified product of the copolymer. Furthermore, it may be a mixture of these resins.

[0071] Among these, the resins preferably used for forming the base material layer 1 include polyester and polyamide.

[0072] Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolyester, etc. Examples of the copolyester include copolyesters having ethylene terephthalate as the main repeating unit. Specifically, copolyester polyesters obtained by polymerizing ethylene isophthalate with ethylene terephthalate as the main repeating unit (hereinafter abbreviated following polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), polyethylene (terephthalate / decanedicarboxylate), etc. These polyesters may be used alone or in combination of two or more.

[0073] Examples of the polyamide include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; hexamethylenediamine-isophthalic acid-terephthalic acid copolyamide polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (where I represents isophthalic acid and T represents terephthalic acid) containing structural units derived from terephthalic acid and / or isophthalic acid, polyamides containing aromatics such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (poly-bis(4-aminocyclohexyl)methane adipamide); furthermore, polyamides copolymerized with lactam components or isocyanate components such as 4,4'-diphenylmethane-diisocyanate, polyester amide copolymers and polyether ester amide copolymers which are copolymers of copolyamides with polyesters or polyalkylene ether glycols; and polyamides such as these copolymers. These polyamides may be used alone or in combination of two or more.

[0074] The base material layer 1 preferably contains at least one of a polyester film, a polyamide film, and a polyolefin film, preferably contains at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, and more preferably contains at least one of a biaxially stretched polyethylene terephthalate film, a biaxially stretched polybutylene terephthalate film, a biaxially stretched nylon film, and a biaxially stretched polypropylene film.

[0075] 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 laminate obtained by laminating resin films with an adhesive or the like, or may be a laminate of resin films obtained by co-extruding resins into two or more layers. Further, the laminate of resin films obtained by co-extruding resins into two or more layers may be used as the base material layer 1 without stretching, or may be uniaxially or biaxially stretched to be used as the base material layer 1.

[0076] In the base material layer 1, specific examples of the laminate of two or more resin films include a laminate of a polyester film and a nylon film, a laminate of two or more nylon films, a laminate of two or more polyester films, etc. Preferably, a laminate of a stretched nylon film and a stretched polyester film, a laminate of two or more stretched nylon films, and a laminate of two or more stretched polyester films are preferred. For example, when the base material layer 1 is a laminate of two resin films, a laminate of a polyester resin film and a polyester resin film, a laminate of a polyamide resin film and a polyamide resin film, or a laminate of a polyester resin film and a polyamide resin film is preferred, and a laminate of a polyethylene terephthalate film and a polyethylene terephthalate film, a laminate of nylon films, or a laminate of a polyethylene terephthalate film and a nylon film is more preferred. Further, since the polyester resin is less likely to change color when, for example, an electrolytic solution adheres to the surface, when the base material layer 1 is a laminate of two or more resin films, it is preferable that the polyester resin film is located on the outermost side of the base material layer 1.

[0077] When the base material layer 1 is a laminate of two or more resin films, the two or more resin films may be laminated via an adhesive. Preferred adhesives include the same ones as the adhesives exemplified in the adhesive layer 2 described later. Note that the method of laminating two or more resin films is not particularly limited, and known methods can be adopted. For example, dry lamination method, sandwich lamination method, extrusion lamination method, thermal lamination method, etc. can be mentioned, and preferably the dry lamination method can be mentioned. When laminating by the dry lamination 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. Also, an anchor coat layer may be formed on the resin film and laminated. The anchor coat layer includes the same ones as the adhesives 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.

[0078] Further, additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be present on at least one of the surface and the interior of the base material layer 1. Only one type of additive may be used, or two or more types may be mixed and used.

[0079] The thickness of the base material layer 1 is not particularly limited as long as it exhibits the function of the base material. For example, it is 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 each resin film constituting each layer is preferably about 2 to 25 μm.

[0080] [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 needed for the purpose of enhancing the adhesiveness therebetween.

[0081] The adhesive layer 2 is formed of an adhesive capable of bonding the base material layer 1 and the barrier layer 3. The adhesive used for forming the adhesive layer 2 is not limited, and it may be any of chemical reaction type, solvent volatile type, hot melt type, hot press type, etc. Further, it may be a two-component curable adhesive (two-component adhesive), a one-component curable adhesive (one-component adhesive), or a resin without a curing reaction. Also, the adhesive layer 2 may be a single layer or a multilayer.

[0082] Specific examples of the adhesive components contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester; polyethers; polyurethanes; epoxy resins; phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolyamide; polyolefin resins such as polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin; polyvinyl acetate; cellulose; (meth)acrylic resins; polyimides; polycarbonates; amino resins such as urea resin and melamine resin; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; and silicone resins. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane adhesive is preferably used. In addition, the resins serving as these adhesive components can enhance the adhesive strength by using an appropriate curing agent in combination. The curing agent is appropriately selected from polyisocyanates, polyfunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, etc., according to the functional groups of the adhesive components.

[0083] Examples of polyurethane adhesives include polyurethane adhesives containing a first agent containing a polyol compound and a second agent containing an isocyanate compound. Preferably, a two-component curable polyurethane adhesive using a polyol such as polyester polyol, polyether polyol, or acrylic polyol as the first agent and an aromatic or aliphatic polyisocyanate as the second agent can be mentioned. Further, examples of polyurethane adhesives include polyurethane adhesives containing a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound and an isocyanate compound. Further, examples of polyurethane adhesives include polyurethane adhesives containing a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound and a polyol compound. Further, examples of polyurethane adhesives include polyurethane adhesives cured by reacting a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound with moisture in the air or the like. As the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group not only at the terminal of the repeating unit but also in the side chain. Examples of the second agent include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds. Examples of the isocyanate compound include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), and the like. Further, examples include polyfunctional isocyanate modified products derived from one or more of these diisocyanates. Further, a multimer (for example, a trimer) can also be used as the polyisocyanate compound. Examples of such multimers include adducts, biurets, and nurates. By forming the adhesive layer 2 with a polyurethane adhesive, excellent electrolyte resistance is imparted to the exterior material for the power storage device, and peeling of the base material layer 1 is suppressed even when the electrolyte adheres to the side surface.

[0084] In addition, as long as the adhesiveness is not inhibited, the addition of other components is allowed in the adhesive layer 2, and it may contain a colorant, a thermoplastic elastomer, a tackifier, a filler, and the like. 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. Also, only one type of colorant may be used, or two or more types may be mixed and used.

[0085] The type of the pigment is not particularly limited as long as it does not impair the adhesiveness of the adhesive layer 2. Examples of the organic pigment include pigments such as azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments. Examples of the inorganic pigment include pigments such as carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, iron-based, and copper-based pigments. In addition, fine powders of mica (muscovite), fish scale foil, and the like can be mentioned.

[0086] Among the colorants, for example, in order to make the appearance of the exterior material for the power storage device black, carbon black is preferable.

[0087] The average particle diameter of the pigment is not particularly limited, and for example, it is about 0.05 to 5 μm, preferably about 0.08 to 2 μm. The average particle diameter of the pigment is the median diameter measured by a laser diffraction / scattering type particle size distribution measuring device.

[0088] 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. For example, it is about 5 to 60% by mass, preferably about 10 to 40% by mass.

[0089] 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. For example, it is about 1 μm or more, about 2 μm or more. Also, the thickness of the adhesive layer 2 is, for example, about 10 μm or less, about 5 μm or less. Also, the preferable range of the thickness of the adhesive layer 2 includes about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[0090] [Coloring layer] The coloring layer is a layer provided between the base material layer 1 and the barrier layer 3 as needed (omitted from illustration). When having the adhesive layer 2, the coloring 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. Also, the coloring layer may be provided outside the base material layer 1. By providing the coloring layer, the exterior material for the power storage device can be colored. A colored adhesive layer 2 and a coloring layer may be provided between the base material layer 1 and the barrier layer 3.

[0091] The coloring layer can be formed, for example, by applying 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. Also, only one type of colorant may be used, or two or more types may be mixed and used.

[0092] Specific examples of the colorant contained in the coloring layer are the same as those exemplified in the column of [adhesive layer 2].

[0093] [Barrier layer 3] In the exterior material for the power storage device, the barrier layer 3 is a layer that at least suppresses the intrusion of moisture.

[0094] Examples of the barrier layer 3 include a metal foil having barrier properties, a vapor deposition film, a resin layer, etc. 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, etc. Examples of the resin layer include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having a fluoroalkyl group, and polymers mainly composed of fluoroalkyl units, ethylene-vinyl alcohol copolymers, etc. Further, examples of the barrier layer 3 also include a resin film provided with at least one of these vapor deposition films and resin layers. A plurality of barrier layers 3 may be provided. The barrier layer 3 preferably includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 3 include aluminum alloy, stainless steel, titanium steel, steel, etc. When used as a metal foil, it preferably includes at least one of an aluminum alloy foil and a stainless steel foil. Further, in the second embodiment, from the viewpoint of more suitably enhancing the damage resistance in a high-temperature environment, it is preferable to include a stainless steel foil.

[0095] The aluminum alloy foil is preferably a soft aluminum alloy foil composed of, for example, an annealed aluminum alloy or the like from the viewpoint of improving the formability of the exterior material for the power storage device. From the viewpoint of further improving the formability, it is preferably an aluminum alloy foil containing iron. In the aluminum alloy foil containing iron (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, and more preferably 0.5 to 2.0% by mass. When the iron content is 0.1% by mass or more, an exterior material for the power storage device having better formability can be obtained. When the iron content is 9.0% by mass or less, an exterior material for the power storage device having better flexibility can be obtained. Examples of the soft aluminum alloy foil include aluminum alloy foils having compositions defined in JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Also, silicon, magnesium, copper, manganese, etc. may be added as necessary. The softening can be performed by annealing or the like.

[0096] Examples of the stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation-hardening stainless steel foils. From the viewpoint of providing an exterior material for the power storage device with excellent formability, the stainless steel foil is preferably composed of austenitic stainless steel.

[0097] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L, etc. Among these, SUS304 is particularly preferred.

[0098] In the case of a metal foil, the thickness of the barrier layer 3 only needs to exhibit the function as a barrier layer that at least suppresses the ingress of moisture. For example, it can be about 9 to 200 μm. The thickness of the barrier layer 3 is preferably about 85 μm or less, more preferably about 50 μm or less, still more preferably about 40 μm or less, and particularly preferably about 35 μm or less. Also, the thickness of the barrier layer 3 is preferably about 10 μm or more, still more preferably about 20 μm or more, and more preferably about 25 μm or more. Further, the preferable range of the thickness of the barrier layer 3 includes about 10 to 85 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 35 μm, about 20 to 85 μm, 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 composed of an aluminum alloy foil, the above-mentioned range is particularly preferable. In particular, when the barrier layer 3 is composed of a stainless steel foil, 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, still more preferably about 30 μm or less, and particularly preferably about 25 μm or less. Also, the thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Further, the preferable range of the thickness of the stainless steel foil includes about 10 to 60 μm, about 10 to 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.

[0099] Further, when the barrier layer 3 is a metal foil, it is preferable to provide a corrosion-resistant film 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 corrosion-resistant films on both sides. Here, the corrosion-resistant film refers to, for example, a thin film obtained by performing a hot water conversion treatment such as a boehmite treatment, a chemical conversion treatment, an anodizing treatment, a plating treatment such as nickel or chromium, or a corrosion prevention treatment of applying a coating agent on the surface of the barrier layer to provide the barrier layer with corrosion resistance (e.g., acid resistance, alkali resistance, etc.). Specifically, the corrosion-resistant film means a film that improves the acid resistance of the barrier layer (acid-resistant film), a film that improves the alkali resistance of the barrier layer (alkali-resistant film), and the like. As the treatment for forming the corrosion-resistant film, one type may be performed, or two or more types may be combined. Further, not only a single layer but also a multilayer structure can be formed. Furthermore, among these treatments, the hot water conversion treatment and the anodizing treatment are treatments that dissolve the surface of the metal foil with a treatment agent to form a metal compound having excellent corrosion resistance. Note that these treatments may be included in the definition of the chemical conversion treatment. Also, when the barrier layer 3 is provided with a corrosion-resistant film, the barrier layer 3 includes the corrosion-resistant film.

[0100] The corrosion-resistant film prevents delamination between the barrier layer (e.g., aluminum alloy foil) and the base material layer during the molding of the exterior material for the power storage device, and prevents dissolution and corrosion of the surface of the barrier layer due to hydrogen fluoride generated by the reaction of the electrolyte and moisture. In particular, when the barrier layer is an aluminum alloy foil, it prevents dissolution and corrosion of aluminum oxide present on the surface of the barrier layer, and improves the adhesiveness (wettability) of the surface of the barrier layer, showing the effect of preventing delamination between the base material layer and the barrier layer during heat sealing and preventing delamination between the base material layer and the barrier layer during molding.

[0101] As the corrosion-resistant film formed by chemical conversion treatment, various ones are known, and mainly include corrosion-resistant films containing at least one of phosphates, chromates, fluorides, triazine thiol compounds, and rare earth oxides. Examples of chemical conversion treatments using phosphates and chromates include chromic acid chromate treatment, phosphoric acid chromate treatment, phosphoric acid-chromate treatment, chromate treatment, etc. Examples of chromium compounds used in these treatments include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium metaphosphate, acetylacetate chromium, chromium chloride, potassium chromium sulfate, etc. Examples of phosphorus compounds used in these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid, etc. Examples of chromate treatments include etching chromate treatment, electrolytic chromate treatment, coating-type chromate treatment, etc., and coating-type chromate treatment is preferred. This coating-type chromate treatment first degreases at least the inner layer side surface of the barrier layer (for example, aluminum alloy foil) by well-known treatment methods such as alkali immersion method, electrolytic cleaning method, acid cleaning method, electrolytic acid cleaning method, acid activation method, etc. Then, a treatment liquid mainly composed of metal phosphates such as chromium (Cr) phosphate, titanium (Ti) phosphate, zirconium (Zr) phosphate, zinc (Zn) phosphate, etc. and mixtures of these metal salts, or a treatment liquid mainly composed of non-metal phosphates and mixtures of these non-metal salts, or a treatment liquid composed of a mixture of these and synthetic resin, etc. is applied by well-known coating methods such as roll coating method, gravure printing method, dipping method, etc. and dried. For the treatment liquid, various solvents such as water, alcohol-based solvents, hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, ether-based solvents, etc. can be used, and water is preferred. Examples of the resin component used at this time include polymers such as phenolic resins and acrylic resins, and chromate treatment using an aminophenol polymer having repeating units represented by the following general formulas (1) to (4). In the aminophenol 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.The acrylic resin is preferably a derivative of polyacrylic acid, an acrylic acid-methacrylic acid ester copolymer, an acrylic acid-maleic acid copolymer, an acrylic acid-styrene copolymer, or their sodium salts, ammonium salts, amine salts, etc. Particularly preferred are derivatives of polyacrylic acid such as ammonium salts, sodium salts, or amine salts of polyacrylic acid. In the present disclosure, polyacrylic acid means a polymer of acrylic acid. Also, the acrylic resin is preferably a copolymer of acrylic acid and a dicarboxylic acid or dicarboxylic anhydride, and preferably an ammonium salt, sodium salt, or amine salt of the copolymer of acrylic acid and a dicarboxylic acid or dicarboxylic anhydride. The acrylic resin may be used alone or in combination of two or more.

[0102]

Chem.

[0103]

Chem.

[0104]

Chem.

[0105]

Chem.

[0106] In 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. Also, R 1 and R 2 each independently represent a hydroxy group, an alkyl group, or a hydroxyalkyl group. In general formulas (1) to (4), X, R 1 and R 2Examples of the alkyl group represented by [alkyl group] include linear or branched alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and tert-butyl group. Further, X, R 1 and R 2 Examples of the hydroxyalkyl group represented by [hydroxyalkyl group] include linear or branched alkyl groups having 1 to 4 carbon atoms substituted with one hydroxy group such as hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, and 4-hydroxybutyl group. In General Formulas (1) to (4), the alkyl groups and hydroxyalkyl groups represented by X, R 1 and R 2 may be the same or different from each other. In 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 aminated phenol polymer having the repeating unit represented by General Formulas (1) to (4) is preferably about 500 to 1,000,000, and more preferably about 1,000 to 20,000. The aminated phenol polymer is produced, for example, by polycondensing a phenol compound or a naphthol compound and formaldehyde to produce a polymer composed of the repeating unit represented by the above General Formula (1) or General Formula (3), and then introducing a functional group (-CH2NR 1 R 2 ) into the polymer obtained above using formaldehyde and an amine (R 1 R 2 NH). The aminated phenol polymer is used alone or in admixture of two or more.

[0107] As another example of the corrosion-resistant film, there is a thin film formed by a coating-type corrosion prevention treatment in which a coating agent containing at least one selected from the group consisting of rare earth element oxide sols, anionic polymers, and cationic polymers is applied. The coating agent may further contain phosphoric acid or a phosphate, and a crosslinking agent for crosslinking the polymer. In the rare earth element oxide sol, fine particles of a 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, neodymium oxide, lanthanum oxide, etc., and cerium oxide is preferable from the viewpoint of further improving the adhesion. The rare earth element oxide contained in the corrosion-resistant film can 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 solvents, hydrocarbon solvents, ketone solvents, ester solvents, and ether solvents can be used, and water is preferable. Examples of the cationic polymer include polyethyleneimine, an ion 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 to an acrylic main skeleton, polyallylamine or its derivative, and aminated phenol. Further, as the anionic polymer, it is preferably poly(meth)acrylic acid or its salt, or a copolymer having (meth)acrylic acid or its salt as a main component. Further, it is preferable that the crosslinking agent is at least one selected from the group consisting of a compound having any functional group 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 the phosphate is condensed phosphoric acid or condensed phosphate.

[0108] As an example of the corrosion-resistant film, there is one formed by applying, to the surface of a barrier layer, a material 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, and performing a baking treatment at 150°C or higher.

[0109] The corrosion-resistant film may, if necessary, have a laminated structure in which at least one of a cationic polymer and an anionic polymer is further laminated. Examples of the cationic polymer and the anionic polymer include those described above.

[0110] Note that the analysis of the composition of the corrosion-resistant film can be performed, for example, using time-of-flight secondary ion mass spectrometry.

[0111] 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. For example, in the case of performing a coating-type chromate treatment, per 1 m 2 of the surface of the barrier layer 3, it is preferably contained at a ratio of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, of the chromium compound in terms of chromium, about 0.5 to 50 mg, preferably about 1.0 to 40 mg, of the phosphorus compound in terms of phosphorus, and about 1.0 to 200 mg, preferably about 5.0 to 150 mg, of the aminated phenol polymer.

[0112] The thickness of the corrosion-resistant film is not particularly limited. However, from the viewpoints of the cohesion of the film and the adhesion to the barrier layer or the heat-sealable resin layer, it is preferably about 1 nm to 20 μm, more preferably about 1 nm to 100 nm, and even 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 energy loss spectroscopy. By analyzing the composition of the corrosion-resistant film using time-of-flight secondary ion mass spectrometry, for example, peaks derived from secondary ions composed of Ce, P, and O (for example, at least one of Ce2PO4 + , CePO4 - etc.) and, for example, secondary ions composed of Cr, P, and O (for example, at least one of CrPO2 + , CrPO4 - etc.) are detected.

[0113] The chemical conversion treatment is carried out by applying a solution containing a compound used for forming a corrosion-resistant film to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method, etc., and then heating the barrier layer to a temperature of about 70 to 200 °C. Further, before applying the chemical conversion treatment to the barrier layer, the barrier layer may be preliminarily subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, etc. By performing the degreasing treatment in this way, it becomes possible to perform the chemical conversion treatment on the surface of the barrier layer more efficiently. 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 a degreasing effect on the metal foil but also a fluoride of a passive metal. In such a case, only the degreasing treatment may be performed.

[0114] [Thermally fusible resin layer 4] In the exterior material for a power storage device of the present disclosure, the thermally fusible resin layer 4 corresponds to the innermost layer and is a layer (sealing layer) that exhibits a function of thermally fusing the thermally fusible resin layers to seal the power storage device element during the assembly of the power storage device.

[0115] The resin constituting the thermally fusible resin layer 4 is not particularly limited as long as it is thermally fusible, but resins containing a polyolefin backbone such as polyolefin and acid-modified polyolefin are preferable. The fact that the resin constituting the thermally fusible resin layer 4 contains a polyolefin backbone can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, etc. Further, when the resin constituting the thermally fusible resin layer 4 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring maleic anhydride-modified polyolefin by infrared spectroscopy, peaks derived from maleic anhydride are detected in the vicinity of a wave number of 1760 cm -1 and in the vicinity of a wave number of 1780 cm -1 When the thermally fusible resin layer 4 is a layer composed of maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected when measured by infrared spectroscopy. However, if the degree of acid modification is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

[0116] Examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylene such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and terpolymers of ethylene-butene-propylene. Among these, polypropylene is preferred. The polyolefin resin in the case of being a copolymer may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more.

[0117] Further, the polyolefin may be a cyclic polyolefin. The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer. Examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, isoprene, etc. Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, norbornadiene, etc. Among these, cyclic alkenes are preferred, and norbornene is more preferred.

[0118] The acid-modified polyolefin is a polymer obtained by modifying a polyolefin by block polymerization or graft polymerization with an acid component. As the polyolefin to be acid-modified, the above-mentioned polyolefin, a copolymer obtained by copolymerizing a polar molecule such as acrylic acid or methacrylic acid with the above-mentioned polyolefin, 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, itaconic anhydride, or their anhydrides.

[0119] The acid-modified polyolefin may be an acid-modified cyclic polyolefin. The acid-modified cyclic polyolefin is a polymer obtained by copolymerizing part of the monomers constituting the cyclic polyolefin by replacing it with an acid component, or by block polymerization or graft polymerization of an acid component onto the cyclic polyolefin. The cyclic polyolefin to be acid-modified is the same as described above. Also, the acid component used for acid modification is the same as the acid component used for the modification of the above polyolefin.

[0120] Preferred acid-modified polyolefins include polyolefins modified with carboxylic acid or its anhydride, polypropylenes modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

[0121] The heat-sealable resin layer 4 may be formed of a single resin alone, or may be formed of a blend polymer combining two or more resins. Further, the heat-sealable resin layer 4 may be formed of only one layer, but may also be formed of two or more layers with the same or different resins.

[0122] Also, the heat-sealable resin layer 4 may contain a lubricant or the like as necessary. When the heat-sealable resin layer 4 contains a lubricant, the moldability of the exterior material for the power storage device can be enhanced. The lubricant is not particularly limited, and known lubricants can be used. The lubricant may be used alone or in combination of two or more.

[0123] The lubricant is not particularly limited, but preferably includes amide-based lubricants. Specific examples of the lubricant include those exemplified in the base material layer 1. The lubricant may be used alone or in combination of two or more.

[0124] When a lubricant is present on the surface of the heat-sealable resin layer 4, its amount of presence is not particularly limited. However, from the viewpoint of enhancing the moldability of the exterior material for the power storage device, it is preferably about 10 to 50 mg / m 2 level, more preferably about 15 to 40 mg / m 2 level.

[0125] The lubricant present on the surface of the heat-sealable resin layer 4 may be one obtained by exuding the lubricant contained in the resin constituting the heat-sealable resin layer 4, or may be one obtained by applying a lubricant to the surface of the heat-sealable resin layer 4.

[0126] Also, the thickness of the heat-sealable resin layer 4 is not particularly limited as long as the heat-sealable resin layers can exhibit the function of heat-sealing to seal the power storage device element. For example, it is about 100 μm or less, preferably about 85 μm or less, more preferably about 15 to 85 μm. In addition, for example, when the thickness of the adhesive layer 5 described later is 10 μm or more, the thickness of the heat-sealable 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-sealable resin layer 4 is preferably about 20 μm or more, more preferably about 35 to 85 μm.

[0127] [Adhesive layer 5] In the exterior material for the power storage device of the present disclosure, the adhesive layer 5 is a layer provided between the barrier layer 3 (or the corrosion-resistant film) and the heat-sealable resin layer 4 as necessary to firmly bond them.

[0128] The subsequent layer 5 is formed of a resin capable of adhering the barrier layer 3 and the heat-sealable resin layer 4. As the resin used for forming the adhesive layer 5, for example, the same adhesives as those exemplified for the adhesive layer 2 can be used. Further, from the viewpoint of firmly adhering the adhesive layer 5 and the heat-sealable resin layer 4, it is preferable that the resin used for forming the adhesive layer 5 contains a polyolefin backbone, and examples thereof include the polyolefins and acid-modified polyolefins exemplified for the aforementioned heat-sealable resin layer 4. On the other hand, from the viewpoint of firmly adhering the barrier layer 3 and the adhesive layer 5, it is preferable that the adhesive layer 5 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, anhydrides thereof, acrylic acid, methacrylic acid, etc., and maleic anhydride is most preferable in terms of ease of modification and versatility. Further, from the viewpoint of the heat resistance of the exterior material for the power storage device, the olefin component is preferably a polypropylene-based resin, and it is most preferable that the adhesive layer 5 contains maleic anhydride-modified polypropylene.

[0129] The fact that the resin constituting the adhesive layer 5 contains a polyolefin backbone can be analyzed, for example, by infrared spectroscopy, gas chromatography-mass spectrometry, etc., and the analysis method is not particularly limited. Further, the fact that the resin constituting the adhesive layer 5 contains an acid-modified polyolefin, for example, when measuring maleic anhydride-modified polyolefin by infrared spectroscopy, peaks derived from maleic anhydride are detected in the vicinity of a wave number of 1760 cm -1 and in the vicinity of a wave number of 1780 cm -1 . However, if the degree of acid modification is low, the peak may become small and not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

[0130] Furthermore, from the viewpoints of durability such as heat resistance and resistance to the contents of the exterior material for the power storage device, and ensuring moldability while reducing the thickness, it is more preferable that the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. As the acid-modified polyolefin, preferably, the aforementioned ones can be exemplified.

[0131] Further, the adhesive layer 5 is preferably 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. Particularly preferably, it 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 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 the reaction of an oxazoline group and a maleic anhydride group are preferable. When unreacted substances of curing agents such as a compound having an isocyanate group, a compound having an oxazoline group, and an epoxy resin remain in the adhesive layer 5, the presence of the unreacted substances can be confirmed by a method selected from, for example, infrared spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), etc.

[0132] Further, from the viewpoint of further enhancing the adhesion between the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 is preferably a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of an oxygen atom, a heterocyclic ring, a C=N bond, and a C-O-C bond. Examples of the curing agent having a heterocyclic ring 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. That the adhesive layer 5 is a cured product of a resin composition containing these curing agents can be confirmed by methods such as gas chromatography-mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), etc.

[0133] The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively enhancing the adhesion between the barrier layer 3 and the adhesive layer 5, a polyfunctional isocyanate compound is preferably used. 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 pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), those obtained by polymerizing or nurating these, mixtures thereof, and copolymers with other polymers. Further, adducts, biurets, isocyanurates, etc. are included.

[0134] The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Thereby, the adhesion between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

[0135] 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. Further, as commercially available products, for example, Epocros series manufactured by Nippon Shokubai Co., Ltd. are included.

[0136] The ratio of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Thereby, the adhesion between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

[0137] Examples of the compound having an epoxy group include, for example, epoxy resins. The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure by the epoxy groups present in the molecule, and known epoxy resins can be used. The weight average molecular weight of the epoxy resin is preferably about 50 to 2000, more preferably about 100 to 1000, 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 conditions using polystyrene as a standard sample.

[0138] Specific examples of the epoxy resin include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, bisphenol F type glycidyl ether, novolak glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether and the like. The epoxy resin may be used alone or in combination of two or more.

[0139] The proportion of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and more preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Thereby, the adhesion between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

[0140] The polyurethane is not particularly limited, and known polyurethanes can be used. The adhesive layer 5 may be, for example, a cured product of a two-component curable polyurethane.

[0141] The proportion of the polyurethane in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and more preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Thereby, the adhesion between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced in an atmosphere where there are components that induce corrosion of the barrier layer such as an electrolytic solution.

[0142] In addition, 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.

[0143] The adhesive layer 5 may contain a modifier having a carbodiimide group.

[0144] 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. Also, the thickness of the adhesive layer 5 is preferably about 0.1 μm or more, about 0.5 μm or more. Further, as the range of the thickness of the adhesive layer 5, preferably about 0.1 to 50 μm, about 0.1 to 40 μm, about 0.1 to 30 μm, about 0.1 to 20 μm, about 0.1 to 5 μm, about 0.5 to 50 μm, about 0.5 to 40 μm, about 0.5 to 30 μm, about 0.5 to 20 μm, about 0.5 to 5 μm can be mentioned. More specifically, in the case of the adhesive exemplified in the adhesive layer 2 or a cured product of an acid-modified polyolefin and a curing agent, preferably about 1 to 10 μm, more preferably about 1 to 5 μm can be mentioned. Also, in the case of using the resin exemplified in the heat-fusible resin layer 4, preferably about 2 to 50 μm, more preferably about 10 to 40 μm can be mentioned. When the adhesive layer 5 is the adhesive exemplified in the adhesive layer 2 or a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, for example, the adhesive layer 5 can be formed by applying the resin composition and curing it by heating or the like. Also, in the case of using the resin exemplified in the heat-fusible resin layer 4, for example, it can be formed by extrusion molding of the heat-fusible resin layer 4 and the adhesive layer 5.

[0145] 3. Manufacturing Method of Exterior Material for Energy Storage Device In the first embodiment of the present disclosure, the method for manufacturing the exterior material for a power storage device is not particularly limited as long as a laminate in which each layer included in the exterior material for a power storage device of the first embodiment is laminated is obtained. Examples of the method include a method including a step of obtaining a laminate in which at least a surface coating layer 6, a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 are laminated in this order from the outside. Specifically, the method for manufacturing the exterior material for a power storage device of the first embodiment includes a step of obtaining a laminate in which at least a surface coating layer 6, a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 are laminated in this order from the outside, and the logarithmic decrement ΔE at 60° C. in the rigid pendulum measurement of the outer surface of the surface coating layer 6 of the laminate is 0.120 or less. Further, the method for manufacturing the exterior material for a power storage device of the second embodiment includes a step of obtaining a laminate in which at least a surface coating layer 6, a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 are laminated in this order from the outside, and the logarithmic decrement ΔE at 110° C. in the rigid pendulum measurement of the outer surface of the surface coating layer 6 of the laminate is 0.200 or less.

[0146] As an example of the method for manufacturing the exterior material for a power storage device of the present disclosure, it is as follows. First, a laminate (hereinafter, may also be referred to as "laminate A") in which a base material layer 1, an adhesive layer 2, and a barrier layer 3 are laminated in this order is formed. Specifically, the formation of laminate A is performed by applying an adhesive used for forming the adhesive layer 2 onto the base material layer 1 or the barrier layer 3 whose surface has been subjected to chemical conversion treatment as necessary by a coating method such as a gravure coating method or a roll coating method, drying, and then laminating the barrier layer 3 or the base material layer 1 and curing the adhesive layer 2 by a dry lamination method.

[0147] Next, a heat-sealable resin layer 4 is laminated on the barrier layer 3 of the laminate A. When directly laminating the heat-sealable resin layer 4 on the barrier layer 3, it may be laminated on the barrier layer 3 of the laminate A by methods such as the thermal lamination method or the extrusion lamination method. Further, when an adhesive layer 5 is provided between the barrier layer 3 and the heat-sealable resin layer 4, for example, (1) a method of laminating by extruding the adhesive layer 5 and the heat-sealable resin layer 4 on the barrier layer 3 of the laminate A (co-extrusion lamination method, tandem lamination method), (2) separately forming a laminate in which the adhesive layer 5 and the heat-sealable resin layer 4 are laminated, and laminating this on the barrier layer 3 of the laminate A by the thermal lamination method, or forming a laminate in which the adhesive layer 5 is laminated on the barrier layer 3 of the laminate A and laminating this with the heat-sealable resin layer 4 by the thermal lamination method, (3) a method of bonding the laminate A and the heat-sealable resin layer 4 via the adhesive layer 5 while pouring the molten adhesive layer 5 between the barrier layer 3 of the laminate A and the heat-sealable resin layer 4 previously formed into a sheet shape (sandwich lamination method), (4) a method of laminating by solution-coating an adhesive for forming the adhesive layer 5 on the barrier layer 3 of the laminate A, drying, and further baking, and laminating the heat-sealable resin layer 4 previously formed into a sheet shape on this adhesive layer 5, etc. may be mentioned.

[0148] Next, a surface coating layer 6 is laminated on the surface of the base material layer 1 on the side opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above resin composition for forming the surface coating layer 6 to the surface of the base material layer 1 and curing it. 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 on the side opposite to the surface coating layer 6.

[0149] As described above, a laminate including, in order from the outside, a surface coating layer 6 / a base material layer 1 / an adhesive layer 2 provided as needed / a barrier layer 3 / an adhesive layer 5 provided as needed / a heat-fusible resin layer 4 is formed. However, in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as needed, it may be further subjected to heat treatment. Also, as described above, a colored layer may be provided between the base material layer 1 and the barrier layer 3.

[0150] 4. Use of Exterior Material for Energy Storage Device The exterior material for a power storage device of the present disclosure is used for a package for sealing and housing power storage device elements such as a positive electrode, a negative electrode, and an electrolyte. 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 obtain a power storage device.

[0151] Specifically, a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte is coated with the exterior material for a power storage device of the present disclosure in a state where metal terminals connected to each of the positive electrode and the negative electrode protrude outward, so that a flange portion (a region where heat-sealable resin layers contact each other) can be formed at the periphery of the power storage device element, and the heat-sealable resin layers of the flange portion are heat-sealed and sealed, thereby providing a power storage device using the exterior material for a power storage device. When the power storage device element is accommodated in a package formed by the exterior material for a power storage device of the present disclosure, the heat-sealable resin portion of the exterior material for a power storage device of the present disclosure is made to be the inner side (the surface in contact with the power storage device element) to form the package. The heat-sealable resin layers of two exterior materials for a power storage device may be opposed to each other and overlapped, and the peripheral portions of the overlapped exterior materials for a power storage device may be heat-sealed to form a package. Also, as in the example shown in FIG. 4, one exterior material for a power storage device may be folded back and overlapped, and the peripheral portion may be heat-sealed to form a package. When folding back and overlapping, as in the example shown in FIG. 4, the sides other than the folded side may be heat-sealed to form a package by a three-sided seal, or may be folded back so that a flange portion can be formed and four-sided sealed. Further, a recess for accommodating the power storage device element may be formed in the exterior material for a power storage device by deep drawing or protrusion forming. As in the example shown in FIG. 4, a recess may be provided in one exterior material for a power storage device and not provided in the other exterior material for a power storage device, or a recess may also be provided in the other exterior material for a power storage device.

[0152] The exterior material for a power storage device of the present disclosure can be suitably used for power storage devices such as batteries (including capacitors, capacitors, etc.). Further, the exterior material for a power storage device of the present disclosure can be used for either a primary battery or a secondary battery, but is preferably used for a secondary battery. There is no particular limitation on the type of secondary battery to which the exterior material for a power storage device of the present disclosure is applied. For example, lithium ion batteries, lithium ion polymer batteries, all-solid-state batteries, lead-acid batteries, nickel-hydrogen storage batteries, nickel-cadmium storage batteries, nickel-iron storage batteries, nickel-zinc storage batteries, silver oxide-zinc storage batteries, metal-air batteries, polyvalent cation batteries, capacitors, capacitors, etc. can be mentioned. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries can be mentioned as suitable application targets for the exterior material for a power storage device of the present disclosure.

Examples

[0153] Examples and comparative examples are shown below to explain the present disclosure in detail. However, the present disclosure is not limited to the examples.

[0154] <Manufacture of Exterior Material for Power Storage Device According to the First Embodiment> [Example 1A] As the base material layer, a stretched nylon (ONy) film (thickness 15 μm) was prepared. Further, as the barrier layer, an aluminum foil (JIS H4160:1994 A8021H-O (thickness 35 μm)) was prepared. Next, using an adhesive (two-component urethane adhesive containing a colorant) described later, the barrier layer and the base material layer were laminated by the dry lamination method, and then an aging treatment was carried out to produce a laminate of the base material layer / adhesive layer / barrier layer. Both sides of the aluminum foil were subjected to a chemical conversion treatment. The chemical conversion treatment of the aluminum foil was carried out by applying a treatment liquid composed of a phenol resin, a chromium fluoride compound, and phosphoric acid to both sides of the aluminum foil by a roll coating method so that the coating amount of chromium was 10 mg / m 2 (dry mass), and baking.

[0155] Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness: 20 μm) and random polypropylene as a heat-sealable resin layer (thickness: 15 μm) were co-extruded onto the barrier layer of each laminate obtained above, thereby laminating the adhesive layer / heat-sealable resin layer on the barrier layer. Further, the following resin composition 1A was applied to the surface of the base material layer of the obtained laminate to a thickness of 3 μm and cured under the formation conditions of 3 days in an environment of 40°C to 100°C, thereby forming a matte-finish surface coating layer. An exterior material for a power storage device was obtained, which consisted of a laminate (lamination structure A, total thickness: 91 μm) in which, in order from the outside, a surface coating layer (3 μm) / base material layer (thickness: 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / heat-sealable resin layer (15 μm) were laminated.

[0156] [Examples 2A to 5A] In the formation of the surface coating layer, except that the following resin compositions 2A to 5A were used instead of resin composition 1A to form the surface coating layer, in the same manner as in Example 1A, an exterior material for a power storage device was obtained, which consisted of a laminate (lamination structure A, total thickness: 91 μm) in which, in order from the outside, a surface coating layer (3 μm) / base material layer (thickness: 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / heat-sealable resin layer (15 μm) were laminated.

[0157] [Example 6A] An exterior material for a power storage device was obtained, which consisted of a laminate (lamination structure B, total thickness: 77 μm) in which, in order from the outside, a surface coating layer (3 μm) / base material layer (thickness: 12 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (14 μm) / heat-sealable resin layer (10 μm) were laminated. This was done in the same manner as in Example 2A, except that a stretched nylon (ONy) film (thickness: 12 μm) was used instead of the stretched nylon (ONy) film (thickness: 15 μm) as the base material layer, and the thickness of the adhesive layer was 14 μm and the thickness of the heat-sealable resin layer was 10 μm.

[0158] [Example 7A] A power storage device exterior material was obtained which consisted of a laminate (lamination structure C, total thickness 80 μm) in which, in the order from the outside, a surface coating layer (3 μm) / substrate layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (14 μm) / heat-fusible resin layer (10 μm) were laminated, in the same manner as in Example 2A except that the thickness of the subsequent layer was 14 μm and the thickness of the heat-fusible resin layer was 10 μm.

[0159] [Example 8A] A power storage device exterior material was obtained which consisted of a laminate (lamination structure D, total thickness 80 μm) in which, in the order from the outside, a surface coating layer (3 μm) / substrate layer (thickness 20 μm) / adhesive layer (3 μm) / barrier layer (30 μm) / adhesive layer (14 μm) / heat-fusible resin layer (10 μm) were laminated, in the same manner as in Example 2A except that a stretched nylon (ONy) film (thickness 20 μm) was used instead of the stretched nylon (ONy) film (thickness 15 μm) as the substrate layer, an aluminum foil (JIS H4160:1994 A8021H-O (thickness 30 μm)) was used instead of the aluminum foil (JIS H4160:1994 A8021H-O (thickness 35 μm)) as the barrier layer, the thickness of the adhesive layer was 14 μm, and the thickness of the heat-fusible resin layer was 10 μm.

[0160] [Example 9A] A power storage device exterior material was obtained which consisted of a laminate (lamination structure E, total thickness 91 μm) in which, in the order from the outside, a surface coating layer (3 μm) / substrate layer (thickness 20 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (15 μm) / heat-fusible resin layer (15 μm) were laminated, in the same manner as in Example 2A except that a stretched nylon (ONy) film (thickness 20 μm) was used instead of the stretched nylon (ONy) film (thickness 15 μm) as the substrate layer, and the thickness of the adhesive layer was 15 μm and the thickness of the heat-fusible resin layer was 15 μm.

[0161] [Example 10A] As the barrier layer, aluminum foil (JIS H4160:1994 A8021H-O (thickness 40 μm)) was used instead of aluminum foil (JIS H4160:1994 A8021H-O (thickness 35 μm)), and except that the thickness of the adhesive layer was 15 μm and the thickness of the heat-fusible resin layer was 15 μm, in the same manner as in Example 2A, from the outside in order, a surface coating layer (3 μm) / substrate layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (40 μm) / adhesive layer (15 μm) / heat-fusible resin layer (15 μm) were laminated to obtain an exterior material for a power storage device composed of a laminate (lamination structure F, total thickness 91 μm).

[0162] [Example 11A] As the substrate layer, a stretched nylon (ONy) film (thickness 12 μm) was prepared. Also, as the barrier layer, a stainless steel foil (SUS304 (thickness 20 μm)) was prepared. Next, using an adhesive (two-component urethane adhesive containing a colorant) described later, the barrier layer and the substrate layer were laminated by the dry lamination method, and then an aging treatment was carried out to produce a laminate of the substrate layer / adhesive layer / barrier layer. Chemical conversion treatment was applied to both sides of the stainless steel foil. The chemical conversion treatment of the stainless steel foil was carried out by applying a treatment liquid composed of a phenol resin, a chromium fluoride compound, and phosphoric acid to both sides of the stainless steel foil by the roll coating method so that the coating amount of chromium was 10 mg / m 2 (dry mass), and baking.

[0163] Next, the barrier layer and the heat-sealable resin layer of each laminate obtained above were adhered by the dry lamination method using a modified olefin-based adhesive (the thickness of the adhesive layer after curing is 3 μm), and the adhesive layer and the heat-sealable resin layer were laminated on the barrier layer. As the heat-sealable resin layer, an unstretched polypropylene film (thickness 20 μm) was used. Further, the following resin composition 1A was applied to the surface of the base material layer of the obtained laminate so as to have a thickness of 3 μm, and cured under the formation conditions of 3 days in an environment of 40°C to 100°C, thereby forming a matte-finish surface coating layer. From the outside in order, a surface coating layer (3 μm) / base material layer (thickness 12 μm) / adhesive layer (3 μm) / barrier layer (20 μm) / adhesive layer (3 μm) / heat-sealable resin layer (20 μm) was laminated. An exterior material for a power storage device composed of a laminate (laminate structure G, total thickness 61 μm) was obtained.

[0164] [Comparative Example 1A] In the formation of the surface coating layer, except that the following resin composition 6A was used instead of the resin composition 1A to form the surface coating layer, in the same manner as in Example 1A, from the outside in order, a surface coating layer (3 μm) / base material layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / heat-sealable resin layer (15 μm) was laminated. An exterior material for a power storage device composed of a laminate (laminate structure A, total thickness 91 μm) was obtained.

[0165] <Resin composition and formation conditions used for forming the surface coating layer> (Resin composition 1A (used in Examples 1A and 11A)) A resin composition containing a resin (a polyurethane formed from a mixture of an acrylic polyol compound and an aliphatic isocyanate compound), an inorganic filler (silica particles with an average particle diameter of 1 μm), an organic filler (average particle diameter 2 μm), and an olefin-based wax

[0166] (Resin composition 2A (used in Examples 2A and 6A to 10A)) A resin composition comprising a resin (a polyurethane formed from a mixture of an acrylic polyol compound, an aromatic isocyanate compound, and a urethane resin), an inorganic filler (silica particles with an average particle diameter of 1 μm), and an organic filler (with an average particle diameter of 2 μm).

[0167] (Resin composition 3A (used in Example 3A)) A resin composition similar to resin composition 2A, except that the amount of the aromatic isocyanate compound used in resin composition 2A is 1 / 2 of the amount used in resin composition 2A.

[0168] (Resin composition 4A (used in Example 4A)) A resin composition similar to resin composition 2A, except that the amount of the aromatic isocyanate compound used in resin composition 2A is 1 / 4 of the amount used in resin composition 2A.

[0169] (Resin composition 5A (used in Example 5A)) A resin composition similar to resin composition 2A, except that the amount of the aromatic isocyanate compound used in resin composition 2A is 1 / 10 of the amount used in resin composition 2A.

[0170] (Resin composition 6A (used in Comparative Example 1A)) The same materials as those used in resin composition 1A in Example 1A were used, except that an aliphatic isocyanate compound different from resin composition 1A used in Example 1A was used.

[0171] [Measurement of the logarithmic decrement ΔE of the outer surface of the surface coating layer] The exterior material for the power storage device was cut into a rectangle with a width (TD: Transverse Direction) of 15 mm and a length (MD: Machine Direction) of 100 mm. Next, the adhesive layer and the heat-sealable resin layer were peeled off from the barrier layer. Specifically, a cut was made from the surface coating layer side to the barrier layer at a position 20 mm from the end in the length direction. Pulling from the left and right around the cut, the cuts in the surface coating layer and the barrier layer were expanded and cut, and the adhesive layer and the heat-sealable resin layer were stretched. At the same time as stretching the adhesive layer and the heat-sealable resin layer, the adhesive layer and the heat-sealable resin layer were peeled off from the barrier layer. In this way, the exterior material for the power storage device with the adhesive layer and the heat-sealable resin layer peeled off was cut into a rectangle with a width (TD) of 15 mm and a length (MD: Machine Direction) of 50 mm to obtain a test sample S. Next, as shown in FIG. 5, using a rigid pendulum physical property tester (model number: RPT-3000W, manufactured by A&D Company, Ltd.), FRB-100 was used for the frame of the pendulum 30, and a cylindrical cylinder edge 30a (RBP-080) was used for the edge part, and the initial amplitude was set to approximately 0.3 degree. The pendulum 30 was installed so that the central axis direction of the cylindrical cylinder was orthogonal to the MD direction of the test sample S. Also, in order to prevent the test sample S from floating or warping during measurement, Kapton tape was attached and fixed at a location that did not affect the measurement result of the test sample S. The cylindrical cylinder edge 30a was brought into contact with the outer surface of the surface coating layer. Next, using a cold and hot block 31 (CHB-100), the logarithmic decrement ΔE of the surface coating layer was measured in the temperature range from 30°C to 200°C at a heating rate of 3°C / min. The logarithmic decrement ΔE of the surface coating layer of the test sample S at a temperature of 30°C and the logarithmic decrement ΔE in the state where the temperature reached 60°C were respectively adopted. The average value measured with N = 2 using a newly cut test sample instead of using the test sample that had been measured once was used.

[0172] [Tape Adhesion Evaluation] The adhesion of the adhesive tape to the outer surface of the surface coating layer of the exterior material for the power storage device was evaluated by the following procedure. This will be described with reference to FIGS. 6 and 7. The exterior material 10 for the power storage device was cut into a rectangular shape with a length of 60 mm (MD) and a width of 50 mm (TD). As shown in the schematic diagrams of FIGS. 6 and 7, a double-sided adhesive tape 41 (60 mm in length × 50 mm in width) was attached to one side of an acrylic plate 40 (2 mm in thickness, 75 mm in length × 50 mm in width), and the heat-sealing resin layer 4 side of the cut exterior material 10 for the power storage device was attached to the double-sided adhesive tape 41. On the other hand, two aluminum foils 43 (one side has a finish, the other side has no finish, 35 μm in thickness, 150 mm in length × 15 mm in width) and a double-sided adhesive tape 42 (containing an acrylic-based adhesive as the adhesive, 50 mm in length × 12.5 mm in width) were prepared, and the finished side of the aluminum foil 43 and one side of the double-sided adhesive tape 42 were attached to each other. Next, one side of the double-sided adhesive tape 42 attached to the aluminum foil 43 and the outer surface of the surface coating layer 6 of the exterior material 10 for the power storage device attached to the acrylic plate were lightly attached, and then, from the aluminum foil 43 side, a roller (2 kg) was moved back and forth once to bring the double-sided adhesive tape 42 into close contact with the outer surface of the surface coating layer 6 of the exterior material 10 for the power storage device, and it was left at room temperature (25°C) for 1 hour to obtain a test sample. Next, in a 60°C environment or a 30°C environment, the portion of the acrylic plate 40 where the double-sided adhesive tape 41 was not attached and the end of the aluminum foil 43 where the double-sided adhesive tape 42 was not attached were each chucked and pulled in the 180° direction, and the average value of the stroke from 20 mm to 80 mm was used as the evaluation of the tape adhesion. As the tensile testing machine, a product named AG-Xplus manufactured by Shimadzu Corporation was used, and the measurement conditions were a tensile speed of 300 mm / min and a stroke of 90 mm. The evaluation value of the tape adhesion used the average value measured with N = 2. The results are shown in Table 1A.

[0173]

Table 1A

[0174] Comparative Example 1A is an exterior material for a power storage device having a conventional standard surface coating layer, and the logarithmic decrement ΔE at 60°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer exceeds 0.12. On the other hand, for the exterior materials for power storage devices of Examples 1A-11A, the logarithmic decrement ΔE at 60°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer is 0.12 or less. It can be seen that the exterior materials for power storage devices of Examples 1A-11A have high tape adhesion not only at 30°C but also in a high-temperature environment of 60°C.

[0175] As described above, the first embodiment of the present disclosure provides an invention in the following aspects. Item 1A. A laminate comprising, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, An exterior material for a power storage device, wherein the logarithmic decrement ΔE at 60°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less. Item 2A. The exterior material for a power storage device according to Item 1A, wherein the logarithmic decrement ΔE at 30°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.080 or less. Item 3A. The exterior material for a power storage device according to Item 1A or 2A, comprising an adhesive layer between the base material layer and the barrier layer. Item 4A. The exterior material for a power storage device according to Item 3A, wherein the adhesive layer is colored. Item 5A. The exterior material for a power storage device according to any one of Items 1A to 4A, comprising a colored layer between the base material layer and the barrier layer. Item 6A. The exterior material for a power storage device according to any one of Items 1A to 5A, wherein the logarithmic decrement ΔE at 60°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.060 or more. Item 7A. A method for manufacturing an exterior material for a power storage device, comprising a step of obtaining a laminate in which at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer are laminated in order from the outside. A method for manufacturing an exterior material for a power storage device, wherein the logarithmic decrement ΔE at 60 °C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less. Item 8A. 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 the exterior material for a power storage device according to any one of Items 1A to 6A.

[0176] <Manufacture of Exterior Material for Power Storage Device According to Second Embodiment> [Example 1B] As a base material layer, a stretched nylon (ONy) film (thickness 12 μm) was prepared. Also, as a barrier layer, a stainless steel foil (SUS304 (thickness 20 μm)) was prepared. Next, using an adhesive (two-component urethane adhesive containing a colorant) described later, the barrier layer and the base material layer were laminated by a dry lamination method, and then an aging treatment was carried out to produce a laminate of the base material layer / adhesive layer / barrier layer. Chemical conversion treatment was applied to both sides of the stainless steel foil. The chemical conversion treatment of the stainless steel foil was carried out by applying a treatment solution composed of a phenolic resin, a chromium fluoride compound, and phosphoric acid to both sides of the stainless steel foil by a roll coating method so that the coating amount of chromium was 10 mg / m 2 (dry mass) and baking.

[0177] Next, the barrier layer and the heat-sealable resin layer of each laminate obtained above were adhered by a dry lamination method using a modified olefin-based adhesive (the thickness of the adhesive layer after curing is 3 μm), and an adhesive layer and a heat-sealable resin layer were laminated on the barrier layer. As the heat-sealable resin layer, an unstretched polypropylene film (thickness 20 μm) was used. Further, the following resin composition 1B was applied to the surface of the base material layer of the obtained laminate to a thickness of 3 μm, and cured under the formation conditions of 3 days in an environment of 40 °C to 100 °C to form a matte-finish surface coating layer. An exterior material for a power storage device composed of a laminate (total thickness 61 μm) in which a surface coating layer (3 μm) / base material layer (thickness 12 μm) / adhesive layer (3 μm) / barrier layer (20 μm) / adhesive layer (3 μm) / heat-sealable resin layer (20 μm) are laminated from the outside was obtained.

[0178] [Example 2B] As the base material layer, a stretched nylon (ONy) film (thickness 15 μm) was prepared. Also, as the barrier layer, an aluminum foil (JIS H4160:1994 A8021H-O (thickness 35 μm)) was prepared. Next, using the adhesive (two-component urethane adhesive containing a colorant) described later, the barrier layer and the base material layer were laminated by the dry lamination method, and then an aging treatment was carried out to produce a laminate of the base material layer / adhesive layer / barrier layer. Chemical conversion treatment was applied to both sides of the aluminum foil. The chemical conversion treatment of the aluminum foil was carried out by applying a treatment liquid composed of a phenolic resin, a chromium fluoride compound, and phosphoric acid to both sides of the aluminum foil by the roll coating method so that the coating amount of chromium was 10 mg / m 2 (dry mass), and baking it.

[0179] Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness 20 μm) and random polypropylene as a heat-sealable resin layer (thickness 20 μm) were co-extruded onto the barrier layer of each laminate obtained above, so that an adhesive layer / heat-sealable resin layer was laminated on the barrier layer. Further, the following resin composition 2B was applied to the surface of the base material layer of the obtained laminate to a thickness of 3 μm, and cured under the formation conditions of 3 days in an environment of 40°C to 100°C to form a matte-finish surface coating layer. From the outside in order, a surface coating layer (3 μm) / base material layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / heat-sealable resin layer (20 μm) was laminated. An exterior material for a power storage device was obtained.

[0180] [Example 3B] An exterior material for a power storage device was obtained which consisted of a laminate (total thickness 61 μm) in which a surface coating layer (3 μm) / base material layer (thickness 12 μm) / adhesive layer (3 μm) / barrier layer (20 μm) / adhesive layer (3 μm) / heat-sealable resin layer (20 μm) was laminated from the outside in order, in the same manner as in Example 1B except that resin composition 2B was used instead of resin composition 1B for the formation of the surface coating layer.

[0181] [Example 4B] A laminated body for an exterior material for a power storage device was obtained in the same manner as in Example 1B, except that Resin Composition 3B was used instead of Resin Composition 1B for forming the surface coating layer. The laminated body had, from the outside in order, a surface coating layer (3 μm) / a base material layer (12 μm thick) / an adhesive layer (3 μm) / a barrier layer (20 μm) / an adhesive layer (3 μm) / a heat-sealable resin layer (20 μm) laminated thereon (total thickness: 61 μm).

[0182] [Comparative Example 1B] An exterior material for a power storage device was obtained in the same manner as in Example 2B, except that the following Resin Composition 1B was used instead of Resin Composition 2B for forming the surface coating layer.

[0183] [Resin Composition Used for Forming Surface Coating Layer and Forming Conditions] (Resin Composition 1B (used in Example 1B and Comparative Example 1B)) A resin composition containing a resin (a polyurethane formed from a mixture of an acrylic polyol compound, an aliphatic isocyanate compound, and a urethane resin), an inorganic filler (silica particles with an average particle diameter of 1 μm), and an organic filler (average particle diameter: 2 μm)

[0184] (Resin Composition 2B (used in Example 2B and Example 3B)) A resin composition containing a resin (a polyurethane formed from a mixture of an acrylic polyol compound, an aromatic isocyanate compound, and a urethane resin), an inorganic filler (silica particles with an average particle diameter of 1 μm), and an organic filler (average particle diameter: 2 μm)

[0185] (Resin Composition 3B (used in Example 4B)) A resin composition containing a resin (a polyurethane formed from a mixture of an acrylic polyol compound, an aromatic isocyanate compound, and a urethane resin) and an inorganic filler (silica particles with an average particle diameter of 1 μm) (a composition in which no organic filler was blended in Resin Composition 2B)

[0186] [Measurement of Logarithmic Decay Rate ΔE of Outer Surface of Surface Coating Layer] The exterior material for the power storage device was cut into a rectangle with a width (TD: Transverse Direction) of 15 mm and a length (MD: Machine Direction) of 100 mm. Next, the adhesive layer and the heat-sealable resin layer were peeled off from the barrier layer. Specifically, a cut was made from the end in the length direction at 20 mm from the surface coating layer side to the barrier layer. Pulling from the left and right around the cut, the cuts in the surface coating layer and the barrier layer were expanded and cut, and the adhesive layer and the heat-sealable resin layer were stretched. At the same time as stretching the adhesive layer and the heat-sealable resin layer, the adhesive layer and the heat-sealable resin layer were peeled off from the barrier layer. In this way, the exterior material for the power storage device from which the adhesive layer and the heat-sealable resin layer were peeled off was cut into a rectangle with a width (TD) of 15 mm and a length (MD: Machine Direction) of 50 mm to obtain a test sample S. Next, as shown in FIG. 5, using a rigid pendulum physical property tester (model number: RPT-3000W, manufactured by A&D Company, Ltd.), FRB-100 was used for the frame of the pendulum 30, and a cylindrical cylinder edge 30a (RBP-080) was used for the edge part, and the initial amplitude was set to about 0.3 degrees. The pendulum 30 was installed so that the central axis direction of the cylindrical cylinder was orthogonal to the MD direction of the test sample S. Also, in order to prevent the test sample S from floating or warping during measurement, Kapton tape was attached and fixed at a location that did not affect the measurement result of the test sample S. The cylindrical cylinder edge 30a was brought into contact with the outer surface of the surface coating layer. Next, using a cold and hot block 31 (CHB-100), the logarithmic decrement ΔE of the surface coating layer was measured in the temperature range from 30°C to 200°C at a heating rate of 3°C / min. The logarithmic decrement ΔE of the surface coating layer of the test sample S at a temperature of 30°C and the logarithmic decrement ΔE in the state where the temperature reached 110°C were respectively adopted. The average value measured with N = 2 using a newly cut test sample S instead of the test sample S that had been measured once was used.

[0187] [Evaluation of damage resistance at 110°C] The exterior material for the energy storage device was cut into rectangles with a width (TD: Transverse Direction) of 30 mm × a length (MD: Machine Direction) of 100 mm to obtain test pieces. Next, with the surface coating layer on the upper side, the test pieces were placed on a flat glass plate of 150 mm square, and the ends of the test pieces were fixed with tape so that the heat-sealable resin layer was in close contact with the glass plate. In this state, the test pieces were left standing in an oven at 110°C for 10 minutes. Next, the test pieces were taken out of the oven, and the subsequent steps were carried out promptly. A ruler was placed on the surface coating layer of the test piece, and the surface of the surface coating layer was scratched with a pencil with a sharpened tip (using pencils with a lead hardness of 4B, B, and 2H respectively). Next, the test pieces were removed from the glass plate, and the surface on the heat-sealable resin layer side was observed, and the damage resistance of the exterior material for the 110°C energy storage device was evaluated according to the following criteria. The results are shown in Table 1. A: No convex shape or distinct streak marks are confirmed on the heat-sealable resin layer side. B: A slight convex shape is confirmed on the heat-sealable resin layer side, and no distinct streak marks are confirmed. C: A large convex shape or distinct streak marks are confirmed on the heat-sealable resin layer side.

[0188] [Evaluation of damage resistance at 30°C] The exterior material for the energy storage device was cut into rectangles with a width (TD: Transverse Direction) of 30 mm × a length (MD: Machine Direction) of 100 mm to obtain test pieces. Next, with the surface coating layer on the upper side, the test pieces were placed on a flat glass plate of 150 mm square, and the ends of the test pieces were fixed with tape so that the heat-sealable resin layer was in close contact with the glass plate. In this state, the test pieces were placed in an environment at 30°C, a ruler was placed on the surface coating layer of the test piece, and the surface of the surface coating layer was scratched with a pencil with a sharpened tip (using pencils with a lead hardness of 4B, B, and 2H respectively). Next, the test pieces were removed from the glass plate, and the surface on the heat-sealable resin layer side was observed, and the damage resistance of the exterior material for the 110°C energy storage device was evaluated according to the following criteria. The results are shown in Table 1. A: No convex shape or distinct streak marks are confirmed on the heat-sealable resin layer side. B: Slight convex shapes are confirmed on the side of the heat-sealing resin layer, and distinct streak marks are not confirmed. C: Large convex shapes and distinct streak marks are confirmed on the side of the heat-sealing resin layer.

[0189]

Table 1B

[0190] For the exterior materials for power storage devices of Examples 1B - 4B, the logarithmic decrement ΔE at 110°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer is 0.200 or less. When using a pencil of B with a core hardness harder than 4B for the exterior materials for power storage devices of Examples 1B - 4B in a high-temperature environment of 110°C, no large convex shapes or distinct streak marks were confirmed on the side of the heat-sealing resin layer, and it was confirmed that they are less likely to be damaged. In particular, for the exterior materials for power storage devices of Examples 1B, 3B, and 4B, even when using a pencil of 2H with a very hard core in a high-temperature environment of 110°C, no convex shapes or distinct streak marks were confirmed on the side of the heat-sealing resin layer, and it was confirmed that they are less likely to be damaged.

[0191] As described above, the second embodiment of the present disclosure provides an invention in the following aspects. Item 1B. A power storage device exterior material composed of a laminate including at least, in order from the outside, a surface coating layer, a base material layer, a barrier layer, and a heat-sealing resin layer, wherein the logarithmic decrement ΔE at 110°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less. Item 2B. The power storage device exterior material according to Item 1B, wherein the barrier layer contains a stainless steel foil. Item 3B. The power storage device exterior material according to Item 1B or 2B, wherein the logarithmic decrement ΔE at 30°C in the measurement of the rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.080 or less. Item 4B. The power storage device exterior material according to any one of Items 1B to 3B, wherein the surface coating layer contains a resin and a filler. Item 5B. The exterior material for a power storage device according to any one of Items 1B to 4B, comprising an adhesive layer between the base material layer and the barrier layer. Item 6B. The exterior material for a power storage device according to any one of Items 1B to 5B, wherein the logarithmic decrement ΔE at 110 °C in the measurement of the rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.145 or less. Item 7B. The exterior material for a power storage device according to any one of Items 1B to 6B, comprising an adhesive layer between the barrier layer and the heat-sealable resin layer. Item 8B. A method for manufacturing an exterior material for a power storage device, comprising a step of obtaining a laminate in which at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer are laminated in order from the outside. The method for manufacturing an exterior material for a power storage device, wherein the logarithmic decrement ΔE at 110 °C in the measurement of the rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less. Item 9B. A power storage device, wherein a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the exterior material for a power storage device according to any one of Items 1B to 7B.

Explanation of Signs

[0192] 1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-sealable resin layer 5 Adhesive layer 6 Surface coating layer 10 Exterior material for a power storage device 30 Pendulum 30a Cylindrical cylinder edge 31 Cold and heat block 32 Vibration displacement detector 33 Weight 40 Acrylic plate 41 Double-sided adhesive tape 42 Double-sided adhesive tape 43 Aluminum foil S Test sample

Claims

1. It is composed of a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, Titanium oxide is contained in at least one of the surface and the interior of the surface coating layer, An exterior material for a power storage device, wherein the logarithmic decrement ΔE at 60°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less.

2. It is composed of a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, Silica is contained in at least one of the surface and the interior of the surface coating layer, An exterior material for a power storage device, wherein the logarithmic decrement ΔE at 60°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less.

3. It is composed of a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, Kaolin is contained in at least one of the surface and the interior of the surface coating layer, An exterior material for a power storage device, wherein the logarithmic decrement ΔE at 60°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less.

4. It is composed of a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer, At least one selected from the group consisting of silica, talc, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, 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, gold, aluminum, copper, and nickel is contained in at least one of the surface and the interior of the surface coating layer, The exterior material for a power storage device, wherein the logarithmic decrement ΔE at 60°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less.

5. The exterior material for a power storage device according to any one of claims 1 to 4, wherein the logarithmic decrement ΔE at 60°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.060 or more.

6. It is composed of a laminate including at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer in order from the outside, Titanium oxide is contained in at least one of the surface and the interior of the surface coating layer, The exterior material for a power storage device, wherein the logarithmic decrement ΔE at 110°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less.

7. It is composed of a laminate including at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer in order from the outside, Silica is contained in at least one of the surface and the interior of the surface coating layer, The exterior material for a power storage device, wherein the logarithmic decrement ΔE at 110°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less.

8. It is composed of a laminate including at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer in order from the outside, Kaolin is contained in at least one of the surface and the interior of the surface coating layer, The exterior material for a power storage device, wherein the logarithmic decrement ΔE at 110°C in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less.

9. It is composed of a laminate including at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer in order from the outside, At least one of the surface and the interior of the surface coating layer contains at least one selected from the group consisting of silica, talc, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, 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, gold, aluminum, copper, and nickel. An exterior material for a power storage device, wherein the logarithmic decrement ΔE at 110 ° C. in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less.

10. The exterior material for a power storage device according to any one of claims 6 to 9, wherein the logarithmic decrement ΔE at 110 ° C. in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.145 or less.

11. The exterior material for a power storage device according to any one of claims 1 to 10, wherein the logarithmic decrement ΔE at 30 ° C. in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.080 or less.

12. The exterior material for a power storage device according to any one of claims 1 to 11, wherein the surface coating layer is formed of a polyurethane containing a polyol compound and an aliphatic isocyanate compound.

13. The exterior material for a power storage device according to any one of claims 1 to 11, wherein the surface coating layer is formed of a polyurethane containing a polyol compound and an aromatic isocyanate compound.

14. The exterior material for a power storage device according to any one of claims 1 to 13, wherein at least one of the surface and the interior of the surface coating layer further contains an organic filler.

15. A method for manufacturing an exterior material for a power storage device, A step of obtaining a laminate in which at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer are laminated in order from the outside is provided. At least one of the surface and the inside of the surface coating layer contains at least one selected from the group consisting of silica, talc, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, 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, gold, aluminum, copper, and nickel. A method for manufacturing an exterior material for a power storage device, wherein the logarithmic decrement ΔE at 60 ° C. in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.120 or less.

16. A method for manufacturing an exterior material for a power storage device, A step of obtaining a laminate in which at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer are laminated in order from the outside is provided. At least one of the surface and the inside of the surface coating layer contains at least one selected from the group consisting of silica, talc, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, 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, gold, aluminum, copper, and nickel. A method for manufacturing an exterior material for a power storage device, wherein the logarithmic decrement ΔE at 110 ° C. in the measurement of a rigid pendulum on the outer surface of the surface coating layer of the laminate is 0.200 or less.

17. 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 the exterior material for a power storage device according to any one of claims 1 to 14.

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