Packaging film for power storage device and power storage device

Abstract

To provide a packaging film for a power storage device that has a predetermined CO2 permeability and that has adhesion to metal and does not have a metal layer formed from metal.SOLUTION: A packaging film for a power storage device has at least a heat-sealable resin layer and has a CO2 permeation rate of 100 cc 100 μm / m2 / 24 hr / atm or more in an environment at a temperature of 30°C.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a packaging film for a power storage device 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, a metal exterior material has been frequently used as a packaging film for a power storage device.

[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 packaging film for a power storage device has 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 a packaging film 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 / metal layer / heat-sealable resin layer are sequentially laminated has been proposed (see, for example, Patent Document 1).

[0005] In such a packaging film 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, whereby a power storage device in which the power storage device elements are housed inside the packaging film for a power storage device is obtained.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] (First Aspect) In the manufacturing process of a power storage device, generally, after a power storage device element is housed in a packaging film for a power storage device, it is temporarily sealed, and a first charge / discharge process, an aging process, etc. are performed. In these processes, it is known that gases such as CO 2 are generated from the power storage device element. In order to provide a space for holding the gas inside the temporarily sealed package (formed from the packaging film for a power storage device), and further, in order to remove the space together with the held gas and release the gas to the outside, currently, a power storage device is manufactured using a packaging film for a power storage device that is larger than the size required for the final product power storage device (for example, more than twice the size required for sealing the power storage device element).

[0008] The inventors of the present disclosure have created a problem of providing new value by imparting CO 2 permeability to the packaging film for a power storage device.

[0009] The first aspect of the present disclosure mainly aims to provide a packaging film for a power storage device having a predetermined CO 2 permeability.

[0010] (Second Aspect) Further, metal terminals protrude from the heat-sealed portion of the packaging film for a power storage device, and the power storage device element sealed by the packaging film for a power storage device is electrically connected to the outside by metal terminals electrically connected to the electrodes of the power storage device element. That is, among the portions where the packaging film for a power storage device is heat-sealed, the portions where the metal terminals are present are heat-sealed in a state where the metal terminals are sandwiched between heat-fusible resin layers. Since the metal terminals and the heat-fusible resin layers are made of different materials from each other, the adhesion is likely to decrease at the interface between the metal terminals and the heat-fusible resin layers.

[0011] In addition, by not providing a metal layer on the packaging film for the power storage device, there is an advantage that a thinner and lighter packaging film can be obtained.

[0012] The inventors of the present disclosure have created a problem of providing new value by combining the advantage of adhesiveness to metal and the advantage of not providing a metal layer in the packaging film for the power storage device.

[0013] A second aspect of the present disclosure mainly aims to provide a packaging film for a power storage device that has adhesiveness to metal and does not have a metal layer formed of metal.

[0014] (Third aspect) In the manufacturing process of the power storage device, generally, after the power storage device element is housed in the packaging film for the power storage device, the periphery of the packaging film for the power storage device is sealed to be temporarily sealed. Thereafter, the first charge / discharge process, the aging process, etc. are performed. Since the packaging film for the power storage device included in the secondary battery has a shielding property because it includes a metal layer, it is not possible to confirm whether the periphery of the packaging film for the power storage device is properly sealed in a state where the power storage device element is sealed by the packaging film for the power storage device. For this reason, the power storage device cannot be suitably manufactured.

[0015] A third aspect of the present disclosure aims to provide a manufacturing method of a power storage device that can suitably manufacture a power storage device, and a power storage device manufactured by this manufacturing method.

[0016] (Fourth aspect) In the manufacturing process of the power storage device, generally, after the power storage device element is housed in the packaging film for the power storage device, the periphery of the packaging film for the power storage device is sealed to be temporarily sealed. Thereafter, the first charge / discharge process, the aging process, etc. are performed. In these processes, CO is emitted from the power storage device element. 2Gases such as [gases not specified in the original] are known to be generated. In order to provide a space for holding the gas inside a temporarily sealed package (composed of a packaging film for a power storage device), and further, in order to remove the space together with the held gas and release the gas to the outside, currently, a power storage device is manufactured using a packaging film for a power storage device that is larger than the size required for the final power storage device product (for example, more than twice the size required for sealing the power storage device element). For this reason, the manufacturing process of the power storage device is complicated.

[0017] A fourth aspect of the present disclosure aims to provide a method for manufacturing a power storage device that can easily manufacture a power storage device, and a power storage device manufactured by this manufacturing method.

[0018] (Fifth aspect) In a power storage device, in addition to the functions that a power storage device usually has, it is preferable to have a function with high added value.

[0019] A fifth embodiment of the present disclosure aims to provide a power storage device having a function with high added value.

Means for solving the problems

[0020] (First aspect) The first aspect of the present disclosure provides an invention in the following aspects. A packaging film for a power storage device comprising at least a heat-sealable resin layer, The CO 2 transmission amount in an environment at a temperature of 30 °C is 100 cc·100 μm / m 2 / 24 hr / atm or more, a packaging film for a power storage device.

[0021] (Second aspect) The second aspect of the present disclosure provides an invention in the following aspects. A packaging film for a power storage device comprising at least a heat-sealable resin layer, The packaging film for a power storage device has adhesiveness to metal, The packaging film for the power storage device is a packaging film for a power storage device that does not have a metal layer formed of metal.

[0022] (Third aspect) A method for manufacturing a power storage device according to a first aspect of a third aspect of the present disclosure is a method for manufacturing a power storage device, the power storage device including a power storage device element and an inner package that houses the power storage device element, the inner package being constituted by a packaging film for a power storage device having transparency, the method including an inner packaging step of wrapping the power storage device element with the packaging film for a power storage device, and an inner sealing step that is performed after the inner packaging step and seals the packaging film for a power storage device so that the power storage device element is sealed with the packaging film for a power storage device.

[0023] A method for manufacturing a power storage device according to a second aspect of a third aspect of the present disclosure is a method for manufacturing a power storage device according to the first aspect, the packaging film for a power storage device further having gas permeability, and further including a gas venting step that is performed after the inner sealing step and vents gas generated from the power storage device element through the packaging film for a power storage device.

[0024] A method for manufacturing a power storage device according to a third aspect of a third aspect of the present disclosure is a method for manufacturing a power storage device according to the second aspect, wherein in the inner packaging step, the power storage device element is wrapped with the packaging film for a power storage device having substantially the same size as the inner package included in the completed power storage device.

[0025] A power storage device according to a fourth aspect of a third aspect of the present disclosure includes a power storage device element, an inner package that houses the power storage device element, and an outer package that houses the inner package in a state where the power storage device element is housed, the inner package being constituted by a packaging film for a power storage device having transparency.

[0026] The power storage device according to the fifth aspect of the third aspect of the present disclosure is a power storage device according to the fourth aspect, further including a metal terminal electrically connected to the power storage device element, and a tab film disposed between the inner package and the metal terminal. The outer package is joined to the inner package, the inner package and the metal terminal are joined via the tab film, and at least a part of the outer edge of the inner package is exposed from the outer package.

[0027] The power storage device according to the sixth aspect of the third aspect of the present disclosure is a power storage device according to the fourth aspect, further including a metal terminal electrically connected to the power storage device element, and a tab film disposed between the inner package, the outer package, and the metal terminal. The inner package, the outer package, and the metal terminal are joined via the tab film, and the entire inner package is covered by the outer package.

[0028] The power storage device according to the seventh aspect of the third aspect of the present disclosure is a power storage device according to the fourth aspect, further including a metal terminal electrically connected to the power storage device element. The inner package and the metal terminal are joined, and at least a part of the outer edge of the inner package is exposed from the outer package.

[0029] The power storage device according to the eighth aspect of the third aspect of the present disclosure is a power storage device according to the fourth aspect, further including a metal terminal electrically connected to the power storage device element. The inner package, the outer package, and the metal terminal are joined, and the entire inner package is covered by the outer package.

[0030] The power storage device according to the ninth aspect of the third aspect of the present disclosure is a power storage device according to any one of the third to eighth aspects, and the packaging film for the power storage device further has gas permeability.

[0031] (Fourth Aspect) The manufacturing method of a power storage device according to the first aspect of the fourth aspect of the present disclosure is a manufacturing method of a power storage device, wherein the power storage device includes a power storage device element and an inner package that houses the power storage device element. The inner package is composed of a packaging film for a power storage device having gas permeability. The manufacturing method includes an inner packaging step of wrapping the power storage device element with the packaging film for a power storage device, an inner sealing step that is performed after the inner packaging step and seals the power storage device element with the packaging film for a power storage device, and a gas venting step that is performed after the inner sealing step and vents gas generated from the power storage device element through the packaging film for a power storage device.

[0032] The manufacturing method of a power storage device according to the second aspect of the fourth aspect of the present disclosure is the manufacturing method of a power storage device according to the first aspect. In the inner packaging step, the power storage device element is wrapped with the packaging film for a power storage device having substantially the same size as the inner package included in the completed power storage device.

[0033] A power storage device according to the third aspect of the fourth aspect of the present disclosure includes a power storage device element, an inner package that houses the power storage device element, and an outer package that houses the inner package in a state where the power storage device element is housed. The inner package is composed of a packaging film for a power storage device having gas permeability.

[0034] A power storage device according to the fourth aspect of the fourth aspect of the present disclosure is the power storage device according to the third aspect, further including a metal terminal electrically connected to the power storage device element and a tab film disposed between the inner package and the metal terminal. The outer package is joined to the inner package, the inner package and the metal terminal are joined via the tab film, and at least a part of the outer edge of the inner package is exposed from the outer package.

[0035] The power storage device according to the fifth aspect of the fourth aspect of the present disclosure is the power storage device according to the third aspect, further comprising a metal terminal electrically connected to the power storage device element, and a tab film disposed between the inner packaging body, the outer packaging body, and the metal terminal, wherein the inner packaging body, the outer packaging body, and the metal terminal are joined via the tab film, and the entire inner packaging body is covered by the outer packaging body.

[0036] The power storage device according to the sixth aspect of the fourth aspect of the present disclosure is the power storage device according to the third aspect, further comprising a metal terminal electrically connected to the power storage device element, wherein the inner packaging body and the metal terminal are joined, and at least a part of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0037] The power storage device according to the seventh aspect of the fourth aspect of the present disclosure is the power storage device according to any one of the third to sixth aspects, wherein the packaging film for the power storage device further has transparency.

[0038] (Fifth Aspect) The power storage device according to the first aspect of the fifth aspect of the present disclosure includes a power storage device element, an inner packaging body that houses the power storage device element, an outer packaging body that houses the inner packaging body with the power storage device element housed therein, and a functional object disposed between the inner packaging body and the outer packaging body, wherein the functional object has shock absorbency.

[0039] The power storage device according to the second aspect of the fifth aspect of the present disclosure includes a power storage device element, an inner packaging body that houses the power storage device element, an outer packaging body that houses the inner packaging body with the power storage device element housed therein, and a functional object disposed between the inner packaging body and the outer packaging body, wherein the functional object has flame retardancy.

[0040] The power storage device according to the third aspect of the fifth aspect of the present disclosure includes a power storage device element, an inner package that houses the power storage device element, an outer package that houses the inner package in a state where the power storage device element is housed, and a functional object disposed between the inner package and the outer package, and the functional object has coolability.

[0041] The power storage device according to the fourth aspect of the fifth aspect of the present disclosure includes a power storage device element, an inner package that houses the power storage device element, an outer package that houses the inner package in a state where the power storage device element is housed, and a functional object disposed between the inner package and the outer package, and the functional object has fire extinguishing properties.

[0042] The power storage device according to the fifth aspect of the fifth aspect of the present disclosure includes a power storage device element, an inner package that houses the power storage device element, and an outer package that houses the inner package in a state where the power storage device element is housed, and at least one of the inner package and the outer package has at least one of shock absorbability, flame retardancy, coolability, and fire extinguishing properties.

[0043] The power storage device according to the sixth aspect of the fifth aspect of the present disclosure is a power storage device according to any one of the first aspect to the fifth aspect, and the inner package has at least one of transparency and gas permeability.

[0044] The power storage device according to the seventh aspect of the fifth aspect of the present disclosure is a power storage device according to any one of the first aspect to the sixth aspect, and further includes a metal terminal electrically connected to the power storage device element and a tab film disposed between the inner package and the metal terminal, the outer package is joined to the inner package, the inner package and the metal terminal are joined via the tab film, and at least a part of the outer edge of the inner package is exposed from the outer package.

[0045] The power storage device according to the eighth aspect of the fifth aspect of the present disclosure is a power storage device according to any one of the first aspect to the sixth aspect, further comprising a metal terminal electrically connected to the power storage device element, and a tab film disposed between the inner packaging body, the outer packaging body, and the metal terminal, wherein the inner packaging body, the outer packaging body, and the metal terminal are joined via the tab film, and the entire inner packaging body is covered by the outer packaging body.

[0046] The power storage device according to the ninth aspect of the fifth aspect of the present disclosure is a power storage device according to any one of the first aspect to the sixth aspect, further comprising a metal terminal electrically connected to the power storage device element, wherein the inner packaging body and the metal terminal are joined, and at least a part of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0047] The power storage device according to the tenth aspect of the fifth aspect of the present disclosure is a power storage device according to any one of the first aspect to the sixth aspect, further comprising a metal terminal electrically connected to the power storage device element, wherein the inner packaging body, the outer packaging body, and the metal terminal are joined, and the entire inner packaging body is covered by the outer packaging body.

Advantages of the Invention

[0048] According to the first aspect of the present disclosure, a packaging film for a power storage device having a predetermined CO 2 permeability can be provided. Further, the packaging film for a power storage device according to the first aspect of the present disclosure can be suitably used as a packaging film for directly packaging a power storage device element. For example, in a power storage device in which a power storage device element is housed in a dual-structured packaging body including an inner packaging body and an outer packaging body, the packaging film for a power storage device according to the first aspect of the present disclosure can be suitably used for forming the inner packaging body. For example, by using the packaging film for a power storage device according to the first aspect of the present disclosure as the inner packaging body, sealing the power storage device element in the inner packaging body before housing it in the outer packaging body, and performing the first charge / discharge process and the aging process, the gas generated from the power storage device element (especially CO 2) can be suitably released to the outside during these processes. Therefore, unlike the case of using an exterior material for a power storage device having a conventional barrier layer, it is not necessary to provide a space for holding gas inside the packaging film for the power storage device that is temporarily sealed, and further, to remove the space together with the held gas to release the gas to the outside, it is not necessary to use a packaging film for the power storage device that is larger than the size required for the power storage device that finally becomes a product (for example, more than twice the size required for sealing the power storage device element).

[0049] Furthermore, according to the first aspect of the present disclosure, it is also possible to provide a power storage device using the packaging film for the power storage device.

[0050] According to the second aspect of the present disclosure, it is possible to provide a packaging film for a power storage device that has adhesiveness to a metal and does not have a metal layer formed of a metal. Since the packaging film for the power storage device according to the second aspect of the present disclosure has adhesiveness to a metal, it can be adhered to, for example, a metal terminal. Specifically, the power storage device element can be sealed in a state where the metal terminal is sandwiched between heat-sealable resin layers. In addition, since it does not have a metal layer formed of a metal, the packaging film for the power storage device can be reduced in weight and made thinner. Further, for example, according to the second aspect of the present disclosure, it is also possible to make the package for housing the power storage device have a double structure of an inner package and an outer package, and suitably use the packaging film for the power storage device of the present disclosure as the inner package. According to the present disclosure, it is also possible to provide a power storage device using the packaging film for the power storage device.

[0051] According to the manufacturing method of the power storage device and the power storage device according to the third aspect of the present disclosure, the power storage device can be suitably manufactured.

[0052] According to the manufacturing method of the power storage device and the power storage device according to the fourth aspect of the present disclosure, the power storage device can be easily manufactured.

[0053] According to the power storage device related to the fifth aspect of the present disclosure, it has a highly value-added function.

Brief Description of the Drawings

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[0055] The packaging film for an electric storage device according to the first aspect of the present disclosure is a packaging film for an electric storage device including at least a heat-sealable resin layer, and has a CO 2 permeation amount of 100 cc·100 μm / m 2 / 24 hr / atm or more at an environment temperature of 30°C.

[0056] The packaging film for an electric storage device according to the second aspect of the present disclosure is a packaging film for an electric storage device including at least a heat-sealable resin layer, which has adhesiveness to a metal and does not have a metal layer formed of a metal.

[0057] Hereinafter, the packaging film for the power storage device of the present disclosure will be described in detail. In the present disclosure, 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. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Further, the upper limit value and the upper limit value, the upper limit value and the lower limit value, or the lower limit value and the lower limit value described separately may be combined to form a numerical range, respectively. Also, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.

[0058] Also, in the present disclosure, the shielding layer means a layer that shields light transmission. When the packaging film for the power storage device of the present disclosure has a shielding layer, the contents of the power storage device (for example, the power storage device element) are made less visible by the shielding layer. Also, the metal layer means a layer formed of a metal. For example, metal foil, metal plate, etc. may be mentioned. The thickness of the metal foil is, for example, about 10~200 μm, and the thickness of the metal plate is, for example, about 200 μm to several mm.

[0059] In the description of the present disclosure, regarding the matters specific to each of the first to fifth aspects of the present disclosure, it is clearly stated which aspect the description relates to, and regarding the matters common to each aspect, they are comprehensively described as matters related to the present disclosure without particularly stating. First, the content common to the whole of the present disclosure and the content related to the first and second aspects of the present disclosure will be described, and then the content related to the third to fifth aspects will be described.

[0060] 1. Laminated Structure and Physical Properties of Packaging Film for Energy Storage Device The packaging film 10 for a power storage device of the present disclosure includes at least a heat-sealable resin layer 1, as shown in FIGS. 1 to 4, for example. When assembling a power storage device using the packaging film 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 in a state where the heat-sealable resin layers 1 of the packaging film 10 for a power storage device face each other.

[0061] As shown in FIG. 1, the packaging film 10 for a power storage device may be composed only of the heat-sealable resin layer 1. When the packaging film 10 for a power storage device is composed only of the heat-sealable resin layer 1, it is preferable that at least one surface of the heat-sealable resin layer 1 has adhesiveness to metal.

[0062] Further, as shown in FIGS. 2 to 4, the packaging film 10 for a power storage device of the present disclosure is preferably composed of a laminate including at least a resin layer 2 and a heat-sealable resin layer 1. In such a packaging film 10 for a power storage device, the resin layer 2 is on the outside and the heat-sealable resin layer 1 is on the inside (innermost layer). When the packaging film 10 for a power storage device is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, it is preferable to impart adhesiveness to metal to at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1.

[0063] Furthermore, as shown in FIGS. 3 to 4, the packaging film 10 for a power storage device of the present disclosure is preferably composed of a laminate including at least a resin layer 2, a base material 3, and the heat-sealable resin layer 1. In such a packaging film 10 for a power storage device, the resin layer 2 is on the outside, the heat-sealable resin layer 1 is on the inside (innermost layer), and the base material 3 is located between the resin layer 2 and the heat-sealable resin layer 1. Also, in the case where the packaging film 10 for a power storage device is composed of a laminate including the resin layer 2, the base material 3, and the heat-sealable resin layer 1, it is preferable to impart adhesiveness to metal to at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1.

[0064] As shown in FIGS. 2 and 4, adhesive layers 4 and 5 can be provided between the resin layer 2 and the base material 3 or the heat-sealable resin layer 1, and between the heat-sealable resin layer 1 and the base material 3 or the resin layer 2, respectively.

[0065] The power storage device packaging film 10 according to the first aspect of the present disclosure has a CO 2 transmission amount of 100 cc·100 μm / m 2 / 24 hr / atm or more at an environment temperature of 30°C, preferably about 200 cc·100 μm / m 2 / 24 hr / atm or more, more preferably about 300 cc·100 μm / m 2 / 24 hr / atm or more, still more preferably about 500 cc·100 μm / m 2 / 24 hr / atm or more. Further, the CO 2 transmission amount of the power storage device packaging film 10 according to the first aspect of the present disclosure is, for example, about 2000 cc·100 μm / m 2 / 24 hr / atm or less, preferably about 1000 cc·100 μm / m 2 / 24 hr / atm or less, more preferably about 800 cc·100 μm / m 2 / 24 hr / atm or less, and the preferable range is about 100 - 2000 cc·100 μm / m 2 / 24 hr / atm level, about 100 - 1000 cc·100 μm / m 2 / 24 hr / atm level, about 100 - 800 cc·100 μm / m 2 / 24 hr / atm level, about 200 - 2000 cc·100 μm / m 2 / 24 hr / atm level, about 200 - 1000 cc·100 μm / m 2 / 24 hr / atm level, about 200 - 800 cc·100 μm / m 2 / 24 hr / atm level, about 300 - 2000 cc·100 μm / m 2 / 24 hr / atm level, about 300 - 1000 cc·100 μm / m 2 / 24 hr / atm level, about 300 - 800 cc·100 μm / m 2 / 24 hr / atm level, about 500 - 2000 cc·100 μm / m 2About 500 - 1000 cc·100μm / m per 24 hours / atm 2 About 500 - 800 cc·100μm / m per 24 hours / atm 2 Examples include about 24 hours / atm. The CO 2 permeation rate of the packaging film for the power storage device is as follows.

[0066] <CO 2 Measurement of permeation rate In accordance with JIS K7126-1 (Plastics - Films and Sheets - Test Method for Gas Permeability - Part 1: Differential Pressure Method), at 30°C in an atmosphere, the CO 2 that has permeated through the φ60 mm of the power storage device packaging film 10 is quantitatively analyzed by gas chromatography to measure the permeation rate.

[0067] When imparting shielding properties to the power storage device packaging film 10 of the present disclosure, for at least one layer included in the power storage device packaging film 10, a shielding layer S having shielding properties may be provided. For example, FIG. 4 shows a configuration in which an adhesive layer 4 that adheres between the resin layer 2 and the base material 3 is used as the shielding layer S. In the present disclosure, any layer included in the power storage device packaging film 10 can be used as the shielding layer S.

[0068] Also, although not shown, on the outer side of the resin layer 2 (the side opposite to the heat-sealable resin layer 1 side), a surface coating layer or the like may be further provided as needed.

[0069] The thickness of the laminate constituting the packaging film 10 for the power storage device is not particularly limited, but from the viewpoints of cost reduction, improvement of energy density, etc., for example, it is 190 μm or less, preferably about 180 μm or less, about 170 μm or less. Further, as the thickness of the laminate constituting the packaging film 10 for the power storage device, from the viewpoint of maintaining the function of the packaging film for the power storage device of protecting the power storage device element, preferably it is about 35 μm or more, about 45 μm or more, about 60 μm or more. Further, regarding the preferable range of the laminate constituting the packaging film 10 for the power storage device, for example, about 35 to 190 μm, about 35 to 180 μm, about 35 to 170 μm, about 45 to 190 μm, about 45 to 180 μm, about 45 to 170 μm, about 60 to 190 μm, about 60 to 180 μm, about 60 to 170 μm can be mentioned, and particularly about 45 to 170 μm is preferable.

[0070] In the packaging film 10 for the power storage device, the ratio of the total thickness of the resin layer 2, the adhesive layer 4, the base material 3, the adhesive layer 5, and the heat-sealable resin layer 1 to the thickness (total thickness) of the laminate constituting the packaging film 10 for the power storage device is preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more. As a specific example, when the packaging film 10 for the power storage device of the present disclosure includes the resin layer 2, the adhesive layer 4, the base material 3, the adhesive layer 5, and the heat-sealable resin layer 1, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the packaging film 10 for the power storage device is preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more. Further, also when the packaging film 10 for the power storage device of the present disclosure is a laminate including the resin layer 2, the adhesive layer 4, and the heat-sealable resin layer 1, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the packaging film 10 for the power storage device can be, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more.

[0071] The laminate constituting the packaging film 10 for the power storage device of the present disclosure can have a total light transmittance measured in accordance with the provisions of JIS K7361-1:1997, for example, 20% or less, 15% or less, 10% or less, 8% or less, etc. Further, the laminate constituting the packaging film 10 for the power storage device of the present disclosure can also have a total light transmittance measured in accordance with the provisions of JIS K7361-1:1997, for example, 80% or more, 85% or more, 90% or more, etc. The lower the total light transmittance, the higher the shielding property that the packaging film 10 for the power storage device can exhibit. On the other hand, the higher the total light transmittance, the higher the light transmittance that the packaging film 10 for the power storage device can exhibit. The lower limit value of the total light transmittance is 0%, and the upper limit is 100%. The total light transmittance of the packaging film for the power storage device shall comply with the measurement method specified in JIS K7361-1:1997, use a commercially available spectrophotometer (for example, V-670 ultraviolet-visible near-infrared spectrophotometer manufactured by JASCO Corporation), measure the transmittance in the visible light region (400 to 700 nm), and take the average value as the total light transmittance. The measurement conditions are to use a halogen lamp as the light source, UV / Vis band width: 5.0 nm, scanning speed: 1000 nm / min, response: Medium, data acquisition interval: 1.0 nm.

[0072] The packaging film 10 for the power storage device can be black. When the packaging film 10 for the power storage device is black, it becomes a packaging film 10 for the power storage device with high shielding property and high forgery prevention effect. Further, in the manufacturing process of the power storage device, it becomes possible to more accurately grasp the position by the sensor, and it becomes possible to more accurately convey the packaging film 10 for the power storage device and seal the power storage device element. Furthermore, it is also possible to unify the power storage device and other electrical components in black to give a high-class feeling to the product.

[0073] The packaging film 10 for the power storage device according to the second aspect of the present disclosure has a CO 2 transmission amount at an environment temperature of 30 °C, preferably 100 cc·100 μm / m 2 / 24 hr / atm or more, more preferably about 200 cc·100 μm / m 2Above / 24hr / atm, more preferably about 300 cc·100μm / m 2 Above / 24hr / atm, more preferably about 500 cc·100μm / m 2 It is above / 24hr / atm. Also, the CO of the packaging film 10 for the power storage device of the second aspect of the present disclosure 2 Permeation amount is, for example, about 2000 cc·100μm / m 2 Below / 24hr / atm, preferably about 1000 cc·100μm / m 2 Below / 24hr / atm, more preferably about 800 cc·100μm / m 2 It is below / 24hr / atm, and the preferable range is 100 to 2000 cc·100μm / m 2 About / 24hr / atm, 100 to 1000 cc·100μm / m 2 About / 24hr / atm, 100 to 800 cc·100μm / m 2 About / 24hr / atm, 200 to 2000 cc·100μm / m 2 About / 24hr / atm, 200 to 1000 cc·100μm / m 2 About / 24hr / atm, 200 to 800 cc·100μm / m 2 About / 24hr / atm, 300 to 2000 cc·100μm / m 2 About / 24hr / atm, 300 to 1000 cc·100μm / m 2 About / 24hr / atm, 300 to 800 cc·100μm / m 2 About / 24hr / atm, 500 to 2000 cc·100μm / m 2 About / 24hr / atm, 500 to 1000 cc·100μm / m 2 About / 24hr / atm, 500 to 800 cc·100μm / m 2 About / 24hr / atm can be mentioned. The CO of the packaging film for the power storage device 2 The permeation amount is as follows.

[0074] <CO 2 Measurement of permeation amount In accordance with JIS K7126-1 (Plastics - Films and Sheets - Gas Permeability Test Methods - Part 1: Differential Pressure Method), at 30°C in an atmosphere, the CO that permeated through the φ60 mm of the packaging film 10 for the power storage device 2 is quantitatively analyzed by gas chromatography to measure the permeation amount.

[0075] 2. Each Layer Forming the Packaging Film for Energy Storage Device [Thermally fusible resin layer 1] In the packaging film 10 for the power storage device of the present disclosure, the thermally fusible resin layer 1 corresponds to the innermost layer and is a layer (sealing layer) that exhibits the function of thermally fusing the thermally fusible resin layers to seal the power storage device element during the assembly of the power storage device.

[0076] The packaging film 10 for the power storage device according to the first aspect of the present disclosure may or may not have adhesiveness to metal, but it is preferable to have adhesiveness to metal. For example, when the packaging film 10 for the power storage device of the first aspect is composed only of the thermally fusible resin layer 1, it is preferable that at least one surface of the thermally fusible resin layer 1 has adhesiveness to metal. When the packaging film 10 for the power storage device of the first aspect is composed of a laminate including the resin layer 2 and the thermally fusible resin layer 1, it is preferable to impart adhesiveness to metal for at least one of the outer surface of the resin layer 2 and the inner surface of the thermally fusible resin layer 1. Also, in the case where the packaging film 10 for the power storage device of the first aspect is composed of a laminate including the resin layer 2, the base material 3, and the thermally fusible resin layer 1, adhesiveness to metal may be imparted to at least one of the outer surface of the resin layer 2 and the inner surface of the thermally fusible resin layer 1.

[0077] Also, when providing the shielding layer S to the packaging film 10 for the power storage device according to the first aspect of the present disclosure, it is preferable that the thermally fusible resin layer 1 of the packaging film 10 for the power storage device is transparent and laminated and used with the shielding layer S composed of a layer different from the thermally fusible resin layer 1, but the shielding layer S may be constituted by blending the above-described colorant, etc. into the thermally fusible resin layer 1.

[0078] Further, when the packaging film 10 for a power storage device according to the second aspect of the present disclosure is composed only of the heat-sealable resin layer 1, at least one surface of the heat-sealable resin layer 1 has adhesiveness to metal. When the packaging film 10 for a power storage device according to the second aspect is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, adhesiveness to metal may be imparted to at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1. Also, even when the packaging film 10 for a power storage device according to the second aspect is composed of a laminate including the resin layer 2, the base material 3, and the heat-sealable resin layer 1, adhesiveness to metal may be imparted to at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1.

[0079] When the shielding layer S is provided on the packaging film 10 for a power storage device according to the second aspect, the heat-sealable resin layer 1 is preferably made transparent and laminated and used with the shielding layer S formed of a layer different from the heat-sealable resin layer 1. However, the shielding layer S may be formed by blending the above-described colorant or the like in the heat-sealable resin layer 1.

[0080] Regarding the resin constituting the heat-sealable resin layer 1 of the first aspect, it is heat-sealable and the CO 2 transmission amount is not particularly limited as long as it is 100 cc·100 μm / m 2 / 24 hr / atm or more, but resins containing a polyolefin backbone such as polyolefin and acid-modified polyolefin are preferred. Polyolefin is preferred not only because it has heat-sealability but also because the CO 2 transmission amount is very high.

[0081] Also, regarding the resin constituting the heat-sealable resin layer 1 of the second aspect, it is not particularly limited as long as it is heat-sealable, but resins containing a polyolefin backbone such as polyolefin and acid-modified polyolefin are preferred.

[0082] The fact that the resin constituting the heat-sealable resin layer 1 contains a polyolefin backbone can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, etc. Further, when the resin constituting the heat-sealable resin layer 1 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 heat-sealable resin layer 1 is a layer composed of maleic anhydride-modified polyolefin, peaks derived from maleic anhydride are detected when measured by infrared spectroscopy. 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.

[0083] Specific 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 (for example, block copolymers of propylene and ethylene), random copolymers of polypropylene (for example, random copolymers of propylene and ethylene), etc.; propylene-α-olefin copolymers; and terpolymers of ethylene-butene-propylene. Among these, polypropylene is preferable. The polyolefin resin in the case of being a copolymer may be a block copolymer or a random copolymer. These polyolefin-based resins may be used alone or in combination of two or more.

[0084] 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, and the like. 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, and norbornadiene. Among these, cyclic alkenes are preferred, and norbornene is more preferred.

[0085] The polyolefin may be an acid-modified polyolefin. The acid-modified polyolefin is a polymer obtained by block polymerization or graft polymerization of a polyolefin 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, and itaconic anhydride, or their anhydrides.

[0086] The acid-modified polyolefin may be an acid-modified cyclic polyolefin. The acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by replacing them 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-mentioned polyolefin.

[0087] Preferred acid-modified polyolefins include polyolefins modified with carboxylic acids or their anhydrides, polypropylenes modified with carboxylic acids or their anhydrides, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

[0088] The heat-sealable resin layer 1 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 1 may be formed of only one layer, but may also be formed of two or more layers with the same or different resins.

[0089] When at least a part of the inner surface of the packaging film 10 for a power storage device is adhered to a metal (for example, a metal terminal), the inner surface of the heat-sealable resin layer 1 has adhesiveness to the metal. In order to impart metal adhesiveness to the inner surface of the heat-sealable resin layer 1, for example, it is preferable that the inner surface of the heat-sealable resin layer 1 is composed of an acid-modified polyolefin (such as acid-modified polypropylene or acid-modified polyethylene). Since the unmodified polyolefin described above does not have adhesiveness to the metal, it is not suitable as the resin constituting the inner surface of the heat-sealable resin layer 1 when imparting metal adhesiveness to the inner surface of the heat-sealable resin layer 1.

[0090] Also, the heat-sealable resin layer 1 may contain a lubricant or the like as necessary. When the heat-sealable resin layer 1 contains a lubricant, the moldability of the packaging film for a 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.

[0091] The lubricant is not particularly limited, but amide-based lubricants are preferably used. Specific examples of the lubricant include those exemplified in the resin layer 2. The lubricant may be used alone or in combination of two or more. By combining two or more lubricants, due to the interaction between the lubricants, when the packaging film 10 for a power storage device is cold-formed in a mold, the adhesion of the lubricant to the mold can be reduced, and the continuous productivity of the power storage device can be suitably increased. This is the same for the case where a lubricant is used in the resin layer 2 described later.

[0092] When a lubricant is present on the surface of the heat-sealable resin layer 1, the amount thereof is not particularly limited, but from the viewpoint of enhancing the formability of the packaging film for a power storage device, it is preferably about 10 to 50 mg / m 2 and more preferably about 15 to 40 mg / m 2 .

[0093] The lubricant present on the surface of the heat-sealable resin layer 1 may be one obtained by exuding the lubricant contained in the resin constituting the heat-sealable resin layer 1, or may be one obtained by applying a lubricant to the surface of the heat-sealable resin layer 1.

[0094] Further, the thickness of the heat-sealable resin layer 1 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 150 μm or less, preferably about 85 μm or less, more preferably about 15 to 85 μm, and even more preferably about 35 to 85 μm.

[0095] [Resin layer 2] In the present disclosure, the resin layer 2 is a layer provided for the purpose of, for example, exerting the function as a base material of the packaging film for a power storage device. When the packaging film 10 for a power storage device has the resin layer 2, the resin layer 2 is located on the outer layer side of the packaging film for a power storage device.

[0096] Regarding the material for forming the resin layer 2 of the first aspect, it has at least insulation properties and the CO of the packaging film 10 for a power storage device 2The permeation amount is 100 cc·100 μm / m 2 There is no particular limitation as long as it is 100 cc·100 μm / m / 24 hr / atm or more. The resin layer 2 of the first aspect can be formed using a resin, and the resin may contain additives described later. When providing the shielding layer S on the packaging film 10 for a power storage device of the first aspect, the resin layer 2 is preferably made transparent and laminated with the shielding layer S formed of a layer different from the resin layer 2 for use, but the shielding layer S may be constituted by blending a colorant or the like described later in the resin layer 2.

[0097] Also, regarding the material for forming the resin layer 2 of the second aspect, there is no particular limitation as long as it has at least insulation properties. The resin layer 2 of the second aspect can be formed using a resin, and the resin may contain additives described later. The resin layer 2 of the second aspect is preferably made transparent and laminated with the shielding layer S formed of a layer different from the resin layer 2 for use, but the shielding layer S may be constituted by blending a colorant or the like described later in the resin layer 2.

[0098] In the present disclosure, the resin layer 2 may be, for example, a resin film formed of a resin or a film 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.

[0099] In the present disclosure, examples of the resin for forming the resin layer 2 include resins such as polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenol resin, and modified products of these resins. Also, the resin for forming the resin layer 2 may be a copolymer of these resins, a modified product of the copolymer, or a mixture of these resins.

[0100] In the present disclosure, among these, the resin for forming the resin layer 2 is preferably polyester, polyamide, or polyolefin.

[0101] Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolyester, and the like. 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), and the like. These polyesters may be used alone or in combination of two or more.

[0102] In addition, 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 copolymer polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (where I represents isophthalic acid and T represents terephthalic acid) that contain structural units derived from terephthalic acid and / or isophthalic acid, and 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, and polyester amide copolymers and polyether ester amide copolymers that are copolymers of copolymer polyamides with polyesters or polyalkylene ether glycols; polyamides such as these copolymers and the like. These polyamides may be used alone or in combination of two or more.

[0103] In addition, as the polyolefin, resins containing a polyolefin backbone such as polyolefins and acid-modified polyolefins are preferred. Polyolefins are preferred from the viewpoint of imparting heat fusibility to the outer surface of the resin layer 2. Specific examples of the polyolefin are the same as those exemplified for the heat fusible resin layer 1 described above.

[0104] In the present disclosure, the resin layer 2 preferably contains at least one of a polyester film, a polyamide film, a polyolefin film, and an acid-modified polyolefin film, more preferably contains at least one of a stretched polyester film, a stretched polyamide film, a stretched polyolefin film, and a stretched acid-modified polyolefin film, still more preferably contains at least one of a biaxially stretched polyethylene terephthalate film, a biaxially stretched polybutylene terephthalate film, a biaxially stretched nylon film, a biaxially stretched polypropylene film, and a biaxially stretched acid-modified polypropylene film.

[0105] In the present disclosure, when at least a part of the outer surface of the packaging film 10 for a power storage device is adhered to a metal or the like, the resin layer 2 is used as the outermost layer, and the outer surface of the resin layer 2 has adhesiveness to the metal. In order to impart metal adhesiveness to the outer surface of the resin layer 2, for example, it is preferable that the outer surface of the resin layer 2 is constituted by an acid-modified polyolefin (such as acid-modified polypropylene or acid-modified polyethylene). As described for the heat-sealing resin layer 4, since the above-mentioned unmodified polyolefin does not have adhesiveness to the metal, it is not suitable as the resin constituting the outer surface of the resin layer 2 when imparting metal adhesiveness to the outer surface of the resin layer 2. As described above, when adhesiveness to the metal is imparted to the outer surface of the base material layer 1, the packaging film 10 for a power storage device can be preferably adhered as an inner package to an outer package constituted by a metal (such as a metal foil or a metal can) on the outer surface of the packaging film 10 for a power storage device.

[0106] In the present disclosure, the resin layer 2 may be a single layer or may be composed of two or more layers. When the resin layer 2 is composed of two or more layers, the resin layer 2 may be a laminate in which resin films are laminated with an adhesive or an adhesion promoter, etc., or may be a laminate of resin films obtained by co-extruding resins to form two or more layers. Further, a laminate of resin films obtained by co-extruding resins to form two or more layers may be used as the resin layer 2 as it is without stretching, or may be uniaxially or biaxially stretched to form the resin layer 2.

[0107] In the resin layer 2 of the present disclosure, 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 resin layer 2 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 its surface, when the resin layer 2 is a laminate of two or more resin films, it is preferable that the polyester resin film is located on the outermost layer of the resin layer 2.

[0108] From the viewpoint of imparting heat sealability to the outer surface of the resin layer 2 of the present disclosure, specific examples of the laminate of two or more resin films include a laminate of polyolefin and polyester, a laminate of polyolefin and polyolefin, and a laminate of polyolefin and polyamide. For example, in the case of a laminate of polyolefin and polyester, a laminate of a polypropylene film and a polyethylene terephthalate film, a laminate of a polypropylene film and a polyethylene naphthalate film, a laminate of a polypropylene film and a polybutylene terephthalate film, a laminate of an acid-modified polypropylene film and a polyethylene terephthalate film, a laminate of an acid-modified polypropylene film and a polyethylene naphthalate film, and a laminate of an acid-modified polypropylene film and a polybutylene terephthalate film are preferable. Further, for example, in the case of a laminate of polyolefin and polyolefin, a laminate of polypropylene and polypropylene, a laminate of acid-modified polypropylene and acid-modified polypropylene, and a laminate of acid-modified polypropylene and polypropylene are preferable. In the case of a laminate of polyolefin and polyamide, a laminate of polypropylene and nylon, and a laminate of acid-modified polypropylene and nylon are preferable.

[0109] In the present disclosure, when the resin layer 2 is a laminate of two or more resin films, the two or more resin films may be laminated via an adhesive or an adhesion promoter. Examples of preferable adhesives and adhesion promoters include the same ones as the adhesives and adhesion promoters exemplified in the adhesive layers 4 and 5 described below. Note that the method for laminating two or more resin films is not particularly limited, and known methods can be adopted. Examples thereof include a dry lamination method, a sandwich lamination method, an extrusion lamination method, and a thermal lamination method, and preferably, a dry lamination method. 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. Further, an anchor coat layer may be formed on and laminated to the resin film. Examples of the anchor coat layer include the same ones as the adhesives exemplified in the adhesive layers 4 and 5 described below. At this time, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 μm. The anchor coat layer can be used as the adhesive layers 4 and 5.

[0110] In the present disclosure, additives such as a lubricant, a flame retardant, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent may be present on at least one of the surface and the inside of the resin layer 2. Only one type of additive may be used, or two or more types may be mixed and used.

[0111] In the present disclosure, from the viewpoint of enhancing the moldability of the packaging film for the power storage device, it is preferable that a lubricant is present on the surface of the resin layer 2. 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 stearamide 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 kinds.

[0112] In the present disclosure, when a lubricant is present on the surface of the resin layer 2, the amount thereof 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.

[0113] In the present disclosure, the lubricant present on the surface of the resin layer 2 may be one obtained by exuding the lubricant contained in the resin constituting the resin layer 2, or may be one obtained by applying a lubricant to the surface of the resin layer 2.

[0114] In the present disclosure, the thickness of the resin layer 2 is not particularly limited, but for example, it is about 3 to 50 μm, preferably about 10 to 35 μm. When the resin layer 2 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.

[0115] [Base material 3] In the power storage device packaging film 10 of the present disclosure, the base material 3 is a layer that functions as a support. When the power storage device packaging film 10 includes a resin layer 2, a base material 3, and a heat-sealable resin layer 1, the resin layer 2 is on the outside, the heat-sealable resin layer 1 is on the inside (innermost layer), and the base material 3 is located between the resin layer 2 and the heat-sealable resin layer 1.

[0116] In the power storage device packaging film 10 of the present disclosure, a shielding layer S can be formed by blending a coloring agent or the like into the base material 3.

[0117] The material for forming the base material 3 of the present disclosure is not particularly limited. Examples of the material for forming the base material 3 include polyolefin resins, polyamide resins, polyester resins, epoxy resins, acrylic resins, fluorine resins, silicone resins, phenol resins, polyetherimides, polyimides, polycarbonates, and mixtures and copolymers thereof. Among these, polyolefin resins are particularly preferred. That is, the material for forming the base material 3 is preferably a resin containing a polyolefin backbone such as polyolefin and acid-modified polyolefin. Whether the resin constituting the base material 3 contains a polyolefin backbone can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, and the like.

[0118] Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, a copolymer polyester having ethylene terephthalate as a main repeating unit, a copolymer polyester having butylene terephthalate as a main repeating unit, and the like. Further, examples of the copolymer polyester having ethylene terephthalate as a main repeating unit specifically include a copolymer polyester obtained by polymerizing ethylene isophthalate with ethylene terephthalate as a main repeating unit (hereinafter abbreviated following polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), polyethylene (terephthalate / decanedicarboxylate), and the like. Further, examples of the copolymer polyester having butylene terephthalate as a main repeating unit specifically include a copolymer polyester obtained by polymerizing butylene isophthalate with butylene terephthalate as a main repeating unit (hereinafter abbreviated following polybutylene (terephthalate / isophthalate)), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate, and the like. These polyesters may be used alone or in combination of two or more.

[0119] Examples of polyolefins specifically include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; crystalline or amorphous polypropylene such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); and terpolymers of ethylene-butene-propylene. Among these polyolefins, polyethylene and polypropylene are preferably used, and polypropylene is more preferably used. Further, since it has excellent electrolyte resistance, the base material 3 preferably contains homopolypropylene, more preferably is formed of homopolypropylene, and even more preferably is an unstretched homopolypropylene film.

[0120] Examples of polyamides specifically 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 copolymer 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, and polyamides containing aromatics such as polymetaxylylene adipamide (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); further, polyamides copolymerized with lactam components or isocyanate components such as 4,4'-diphenylmethane-diisocyanate, and polyester amide copolymers and polyether ester amide copolymers that are copolymers of copolyamides and polyesters or polyalkylene ether glycols; and these copolymers and the like. These polyamides may be used alone or in combination of two or more.

[0121] Further, the base material 3 of the present disclosure may be formed of a nonwoven fabric formed of the above resin. When the base material 3 is a nonwoven fabric, the base material 3 is preferably composed of the aforementioned polyolefin resin, polyamide resin, or the like.

[0122] The base material 3 of the present disclosure may be a single layer or a multilayer.

[0123] When the base material 3 of the present disclosure is composed of a resin film, known adhesion means such as corona discharge treatment, ozone treatment, plasma treatment, etc. may be applied to the surface of the base material 3 as necessary.

[0124] From the viewpoint of more preferably achieving the effects of the present disclosure, the thickness of the base material 3 is preferably 80 μm or less, more preferably 60 μm or less, still more preferably about 50 μm or less, and even more preferably about 40 μm or less. Also, the thickness of the base material 3 is preferably about 5 μm or more, more preferably about 8 μm or more, and still more preferably about 10 μm or more. Preferred ranges of the thickness of the base material 3 include about 5 to 80 μm, about 5 to 60 μm, about 5 to 50 μm, about 5 to 40 μm, about 8 to 80 μm, about 8 to 60 μm, about 8 to 50 μm, about 8 to 40 μm, about 10 to 80 μm, about 10 to 60 μm, about 10 to 50 μm, and about 10 to 40 μm.

[0125] [Adhesive layers 4, 5] In the packaging film 10 for a power storage device of the present disclosure, the adhesive layers 4 and 5 are layers provided between them as necessary for the purpose of enhancing the adhesiveness between the resin layer 2 and the base material 3 or the heat-sealable resin layer 1, and between the heat-sealable resin layer 1 and the base material 3 or the resin layer 2. The adhesive layer 4 adheres the resin layer 2 to the base material 3 or the heat-sealable resin layer 1. The adhesive layer 5 adheres the heat-sealable resin layer 1 to the resin layer 2 or the base material 3. The aforementioned anchor coat layer can also be used as the adhesive layers 4 and 5.

[0126] In the packaging film 10 for the energy storage device, a colorant or the like can be blended into the adhesive layers 4 and 5 to form a shielding layer S. For example, if a colorant is blended into the adhesive forming the adhesive layer 4 and the shielding layer is formed by a single coating, there is no need to separately provide a shielding layer at locations other than the adhesive layer 4. By doing so, for example, compared with the case of separately providing a colored layer as the shielding layer, the number of steps is reduced, the production efficiency is improved, and the risk of foreign matter mixing is reduced. Further, when a colored layer is provided between the resin layer 2 and the adhesive layer 4, the interfacial strength between the resin layer 2 and the colored layer and between the colored layer and the adhesive layer 4 may decrease. Therefore, from the viewpoint of long-term use, it is preferable to blend a colorant into the adhesive layer 4.

[0127] The adhesive layers 4 and 5 are formed of an adhesive or an adhesion promoter that can adhere to the resin layer 2 or the heat-sealable resin layer 1. The adhesive used for forming the adhesive layers 4 and 5 is not limited, and it may be any of a chemical reaction type, a solvent volatilization type, a hot melt type, a 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 that does not involve a curing reaction. Further, the adhesive layers 4 and 5 may be single-layer or multi-layer.

[0128] Specific examples of the adhesive component contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and 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 resin 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.

[0129] Examples of the polyurethane adhesive include a polyurethane adhesive comprising a first agent containing a polyol compound and a second agent containing an isocyanate compound. Preferably, a two-component curable polyurethane adhesive is used, in which a polyol such as polyester polyol, polyether polyol, or acrylic polyol is used as the first agent, and an aromatic or aliphatic polyisocyanate is used as the second agent. Further examples of the polyurethane adhesive include a polyurethane adhesive comprising a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound, and an isocyanate compound. Also, examples of the polyurethane adhesive include a polyurethane adhesive comprising a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound, and a polyol compound. Further, examples of the polyurethane adhesive include a polyurethane adhesive 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. Also, 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 layers 4 and 5 from a polyurethane adhesive, excellent electrolyte resistance is imparted to the packaging film for the power storage device, and peeling of the resin layer 2 is suppressed even when the electrolyte adheres to the side surface.

[0130] In addition, the adhesion promoter used for forming the adhesive layers 4 and 5 is not limited either. As the adhesion promoter, for example, well-known adhesion promoters such as isocyanate-based, polyethyleneimine-based, polyester-based, polyurethane-based, polybutadiene-based, etc. can be used. However, as a result of experiments, those composed of isocyanate components selected from triisocyanate monomers and polymeric MDI were excellent in laminate strength and had little decrease in laminate strength after electrolyte immersion. In particular, the best results were obtained when using an adhesion promoter composed of triphenylmethane-4,4',4''-triisocyanate, which is a triisocyanate monomer, or polymethylene polyphenyl polyisocyanate (NCO content is about 30% and viscosity is 200 - 700 mPa·s), which is a polymeric MDI. Next, tris(p-isocyanatophenyl) thiophosphate, which is also a triisocyanate monomer, and a two-component curable adhesion promoter with a polyethyleneimine-based main agent and polycarbodiimide as a crosslinking agent showed good results. The adhesive layers 4 and 5 using the adhesion promoter can be formed by coating and drying using well-known coating methods such as bar coating method, roll coating method, gravure coating method, etc. As the coating amount, in the case of an adhesion promoter composed of triisocyanate, it is 20 - 100 mg / m 2 , preferably 40 - 60 mg / m 2 . In the case of an adhesion promoter composed of polymeric MDI, it is 40 - 150 mg / m 2 , preferably 60 - 100 mg / m 2 . In the case of a two-component curable adhesion promoter with a polyethyleneimine-based main agent and polycarbodiimide as a crosslinking agent, it is 5 - 50 mg / m 2 , preferably 10 - 30 mg / m 2 . Note that a triisocyanate monomer is a monomer having three isocyanate groups in one molecule, and polymeric MDI is a mixture of MDI and MDI oligomers polymerized from MDI, and is represented by the following formula (1).

[0131]

Chemical formula

[0132] Further, as long as the adhesives layers 4 and 5 do not inhibit adhesiveness, addition of other components is permitted, and they may contain a colorant, a thermoplastic elastomer, a tackifier, a filler, or the like. Since the adhesives layers 4 and 5 contain a colorant, the packaging film for a power storage device can be colored. If the adhesives layers 4 and 5 are colored to such an extent that the packaging film for a power storage device can be imparted with shielding properties, the adhesives layers 4 and 5 can serve as a shielding layer S. As the colorant, known ones such as pigments and dyes can be used. Further, only one type of colorant may be used, or two or more types may be mixed and used.

[0133] The type of the pigment is not particularly limited as long as it does not impair the adhesiveness of the adhesives layers 4 and 5. Examples of the organic pigment include pigments such as azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolinone-based, benzimidazolone-based pigments, and examples of the inorganic pigment include pigments such as carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, iron-based, copper-based pigments, and in addition, fine powders of mica (muscovite), fish scale foil, and the like can be mentioned.

[0134] Among the colorants, for example, in order to make the appearance of the packaging film for a power storage device black, a black colorant is preferable, and among the black colorants, carbon black is preferable. By using a black colorant to form the black packaging film 10 for a power storage device, the packaging film 10 for a power storage device has high shielding properties and a high forgery prevention effect. Further, in the manufacturing process of the power storage device, it becomes possible to more accurately grasp the position by a sensor, and it becomes possible to more accurately convey the packaging film 10 for a power storage device and seal the power storage device element. Furthermore, it is also possible to unify the power storage device and other electrical components in black to give a high-class feeling as a product. Carbon black is a more preferable colorant in terms of high shielding properties.

[0135] The average particle diameter of the pigment is not particularly limited, and examples thereof include about 0.05 to 5 μm, preferably about 0.08 to 2 μm. Further, the average particle diameter of the carbon black is within the range of 0.161 to 0.221 μm. The average particle diameter of the pigment is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device.

[0136] The content of the pigment in the adhesive layers 4 and 5 is not particularly limited as long as the packaging film for the power storage device is colored, and examples thereof include about 5 to 60% by mass, preferably about 10 to 40% by mass.

[0137] The thickness of the adhesive layers 4 and 5 is not particularly limited as long as the resin layer 2 and the heat-fusible resin layer 1 can be adhered, and examples thereof include about 1 μm or more, about 2 μm or more. Further, the thickness of the adhesive layers 4 and 5 is, for example, about 10 μm or less, about 5 μm or less. Also, preferred ranges of the thickness of the adhesive layers 4 and 5 include about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[0138] [Coloring layer C] In the present disclosure, although not shown in the drawings, the coloring layer C is a layer that is provided as necessary between the resin layer 2 and the heat-fusible resin layer 1 or outside the resin layer 2. When having the adhesive layers 4 and 5, the coloring layer C may be provided between the resin layer 2 and the adhesive layers 4 and 5. By providing the coloring layer C, the packaging film for the power storage device can be colored. If the coloring layer C is colored to such an extent that the packaging film for the power storage device can be imparted with shielding properties, the coloring layer C can be used as the shielding layer S. In the power storage device packaging film 10, it is preferable that the coloring layer C is used as the shielding layer S. There is a case where the coloring layer C inside the resin layer 2 is called an inner coloring layer, and the coloring layer C outside the resin layer 2 is called an outer coloring layer. The coloring layer C is preferably provided on at least one surface of the resin layer 2 (that is, the resin layer 2 and the coloring layer C are in contact).

[0139] In the present disclosure, the colored layer C can be formed, for example, by applying an ink containing a colorant to the surface of the resin layer 2. As the colorant, known ones such as pigments and dyes can be used. Further, only one type of colorant may be used, or two or more types may be mixed and used.

[0140] In the present disclosure, specific examples of the colorant contained in the colored layer C are the same as those exemplified in the column of [adhesive layers 4, 5].

[0141] In the present disclosure, the thickness of the colored layer C is not particularly limited as long as the packaging film 10 for the power storage device is colored. For example, it is about 1 μm or more, about 2 μm or more. Further, the thickness of the colored layer C is, for example, about 10 μm or less, about 5 μm or less. Further, preferred ranges of the thickness of the colored layer C include about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[0142] [Surface coating layer] The packaging film for the power storage device of the present disclosure may be provided with a surface coating layer (not shown) on the resin layer 2 (on the side opposite to the heat-sealable resin layer 1 of the resin layer 2) as needed for at least one purpose such as improving design, electrolyte resistance, scratch resistance, and moldability. The surface coating layer is a layer located on the outermost layer side of the packaging film for the power storage device when the power storage device is assembled using the packaging film for the power storage device. The surface coating layer may be formulated with the aforementioned colorant or the like to form the shielding layer S.

[0143] Examples of the surface coating layer include resins such as polyvinylidene chloride, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenol resin, and modified products of these resins. Further, copolymers of these resins may be used, or modified products of the copolymers may be used. Furthermore, mixtures of these resins may be used. The resin is preferably a curable resin. That is, it is preferable that the surface coating layer is composed of a cured product of a resin composition containing a curable resin.

[0144] When the resin for forming the surface coating layer is a curable resin, the resin may be either a one-component curable type or a two-component curable type, but preferably a two-component curable type. Examples of the two-component curable resin include two-component curable polyurethane, two-component curable polyester, two-component curable epoxy resin, etc. Among these, two-component curable polyurethane is preferable.

[0145] Examples of two-component curable polyurethanes include polyurethanes containing a first agent containing a polyol compound and a second agent containing an isocyanate compound. Preferably, polyurethanes are those in which polyols such as polyester polyols, polyether polyols, and acrylic polyols are used as the first agent and aromatic or aliphatic polyisocyanates are used as the second agent. Examples of polyurethanes also include polyurethanes containing a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound and an isocyanate compound. Examples of polyurethanes also include polyurethanes containing a polyurethane compound obtained by previously reacting a polyol compound and an isocyanate compound and a polyol compound. Examples of polyurethanes also include 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 agent 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), and the like. Also included are 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. Such multimers include adducts, biurets, nurates, and the like. 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.The surface coating layer is formed of polyurethane, imparting excellent electrolyte resistance to the packaging film for the power storage device.

[0146] At least one of the surface and the interior of the surface coating layer may, as required, contain additives such as the aforementioned lubricants, antiblocking agents, matting agents, flame retardants, antioxidants, tackifiers, antistatic agents, etc., according to the functionality to be provided on the surface coating layer and its surface. 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 shall be the median diameter measured by a laser diffraction / scattering particle size distribution measuring device.

[0147] The additives may be either inorganic or organic substances. Also, the shape of the additives is not particularly limited, and examples include spherical, fibrous, plate-like, amorphous, scaly, etc.

[0148] Specific examples of the additives 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 nanotubes, high melting point nylon, acrylate resin, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, etc. The additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferably mentioned from the viewpoints of dispersion stability and cost, etc. Also, various surface treatments such as insulation treatment and high dispersibility treatment may be applied to the surface of the additives.

[0149] The method for forming the surface coating layer is not particularly limited, and examples thereof include a method of applying a resin for forming the surface coating layer. When an additive is blended in the surface coating layer, a resin mixed with the additive may be applied.

[0150] The thickness of the surface coating layer is not particularly limited as long as the above-described function as the surface coating layer is exhibited, and examples thereof include about 0.5 to 10 μm, preferably about 1 to 5 μm.

[0151] 3. Manufacturing Method of Packaging Film for Energy Storage Device The method for manufacturing the packaging film for a power storage device is not particularly limited as long as the packaging film for a power storage device of the present disclosure can be obtained. For example, when the packaging film for a power storage device of the first aspect of the present disclosure includes a resin layer 2 and a heat-sealable resin layer 1, the method includes a step of obtaining a laminate in which at least the resin layer and the heat-sealable resin layer are laminated in order from the outside. The laminate has a CO 2 permeation amount of 100 cc·100 μm / m 2 / 24 hr / atm or more in an environment at a temperature of 30°C. Further, for example, when the packaging film for a power storage device of the second aspect of the present disclosure includes a resin layer 2 and a heat-sealable resin layer 1, the method includes a step of obtaining a laminate in which at least the resin layer and the heat-sealable resin layer are laminated in order from the outside. The laminate has adhesiveness to a metal and does not have a metal layer formed of a metal.

[0152] As an example of a manufacturing method when the packaging film for a power storage device of the present disclosure is composed of a laminate including a resin layer 2, an adhesive layer 4, a base material 3, an adhesive layer 5, and a heat-sealable resin layer 1 in this order, it is as follows. First, prepare the materials constituting each layer. Next, laminate the resin layer 2 and the base material 3 via the adhesive layer 4 and laminate the base material 3 and the heat-sealable resin layer 1 via the adhesive layer 5. Specifically, using the adhesive forming the adhesive layer 4, laminate the resin layer 2 and the base material 3 by a dry lamination method or the like, whereby the resin layer 2, the adhesive layer 4, and the base material 3 are laminated. Further, using the adhesive forming the adhesive layer 5, laminate the base material 3 and the heat-sealable resin layer 1 by a dry lamination method or the like, whereby the packaging film 10 for a power storage device can be manufactured. When laminating the resin layer 2, the base material 3, and the heat-sealable resin layer 1 without using the adhesive layers 4 and 5, the packaging film 10 for a power storage device can be manufactured by a method such as melt-extruding the resin constituting the resin layer 2 on one side of the base material 3 and melt-extruding the resin constituting the heat-sealable resin layer 1 on the other side of the base material 3. When providing a colored layer, the colored layer may be formed on the surface of the resin layer 2 and then laminated with the base material 3 or the heat-sealable resin layer 1. When providing a surface coating layer, for example, the above resin composition for forming the surface coating layer can be applied to the surface of the resin layer 2 and cured to form it.

[0153] In order to strengthen the adhesiveness of the adhesive layers 4 and 5, the packaging film 10 for a power storage device may be further subjected to a heat treatment.

[0154] 4. Use of Packaging Film for Energy Storage Device The packaging film for a power storage device of the present disclosure is used for a package for sealing and accommodating 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 accommodated in a package formed by the packaging film for a power storage device of the present disclosure to obtain a power storage device.

[0155] Specifically, a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte is covered with the packaging film 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 packaging film for a power storage device. When the power storage device element is accommodated in the package formed by the packaging film for a power storage device of the present disclosure, the heat-sealable resin portion of the packaging film for a power storage device of the present disclosure is made to be on the inner side (the surface in contact with the power storage device element) to form the package. The heat-sealable resin layers of two packaging films for a power storage device may be opposed and overlapped, and the peripheral portion of the overlapped packaging films for a power storage device may be heat-sealed to form a package. Also, as in the example shown in FIG. 5, one packaging film 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. 5, the sides other than the folded-back side may be heat-sealed to form a package by a three-side seal, or may be folded back so that a flange portion can be formed and four-side sealed. Further, a recess for accommodating the power storage device element may be formed in the packaging film for a power storage device by deep drawing or protrusion forming. As in the example shown in FIG. 5, a recess may be provided in one packaging film for a power storage device and not provided in the other packaging film for a power storage device, or a recess may also be provided in the other packaging film for a power storage device.

[0156] Further, as shown in FIG. 7, the packaging film 10 for a power storage device of the present disclosure can be suitably used as the inner packaging body 10a of a power storage device 30 in which a power storage device element 32 is housed in a container having a double structure of an inner packaging body 10a and an outer packaging body 20. That is, a power storage device element 32 including at least a positive electrode, a negative electrode, and an electrolyte is housed in the inner packaging body 10a formed by the packaging film 10 for a power storage device of the present disclosure, and further, by housing the inner packaging body 10a in the outer packaging body 20, a power storage device 30 in which the power storage device element is housed in a container having a double structure of the inner packaging body 10a and the outer packaging body 20 is obtained. One or more members in which the power storage device element 32 is housed in the inner packaging body 10a formed by the packaging film 10 for a power storage device of the present disclosure are prepared, and one or more members are housed in the outer packaging body 20 to form the power storage device 30. In FIGS. 5 to 7, each corner is drawn at a right angle, but the angles of each corner and ridge line are not limited, and each corner and ridge line may be rounded.

[0157] In the power storage device 30 of FIG. 7, with the metal terminals 31 connected to the positive and negative electrodes of the power storage device element 32 protruding outward, at the periphery of the power storage device element 32, a flange portion (a region where the heat-sealable resin layers 1 contact each other, the peripheral portion 30a of the inner package 10a) of the inner package 10a formed by the power storage device packaging film 10 can be formed and covered. By heat-sealing the heat-sealable resin layers 1 of the flange portion, while the heat-sealable resin layer 1 adheres to the metal terminal 10, the power storage device element 32 is sealed by the inner package 10a. When the inner surface of the heat-sealable resin layer 1 of the power storage device packaging film 10 of the present disclosure has adhesiveness to metal, it can be suitably used as a packaging film for directly packaging the power storage device element 32 so as to adhere to the metal terminal 31. In the power storage device 30 in which the power storage device element 32 is accommodated in a double-structured package including the inner package 10a and the outer package 20 as shown in FIG. 7, the power storage device packaging film 10 of the present disclosure can be suitably used for the formation of the inner package 10a. Since the metal terminal 31 and the heat-sealable resin layer of the packaging film are made of different materials from each other, generally, the adhesion is likely to decrease at the interface between the metal terminal 31 and the heat-sealable resin layer. For this reason, an adhesive film is generally disposed between the metal terminal and the heat-sealable resin layer of the packaging film. However, since the power storage device packaging film 10 of the present disclosure has adhesiveness to metal, the power storage device element 32 can be sealed while adhering to the metal terminal 31 without using such an adhesive film.

[0158] The outer package 20 is not particularly limited, and a packaging film formed of a film-like laminate in which a base material layer / metal layer / heat-sealable resin layer are sequentially laminated, a metal can, etc. can be used.

[0159] The packaging film 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 packaging film 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 packaging film 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 storage batteries, nickel metal hydride batteries, nickel cadmium batteries, nickel iron batteries, nickel zinc batteries, silver oxide zinc 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 of the packaging film for a power storage device of the present disclosure.

[0160] Furthermore, the packaging film for a power storage device according to the first aspect of the present disclosure (a packaging film for a power storage device including at least a heat-sealable resin layer, and the CO 2 transmission amount in an environment at a temperature of 30 ° C is 100 cc·100 μm / m 2 / 24 hr / atm or more, a packaging film for a power storage device) and the packaging film for a power storage device according to the second aspect of the present disclosure (a packaging film for a power storage device including at least a heat-sealable resin layer, the packaging film for a power storage device has adhesiveness to metal, and the packaging film for a power storage device does not have a metal layer formed of metal) can be suitably applied to a power storage device according to Embodiment A (Embodiments A1-A5 and modifications thereof) shown below or a manufacturing method thereof, a power storage device according to Embodiment B (Embodiments B1-B5 and modifications thereof) or a manufacturing method thereof, and a power storage device according to Embodiment C (Embodiments C1-C5 and modifications thereof) or a manufacturing method thereof. Hereinafter, these Embodiments A, B, and C in the first aspect and the second aspect will be described in detail.

[0161] <Embodiment A> As described above, in the manufacturing process of the power storage device, generally, after the power storage device element is housed in the packaging film for the power storage device, the periphery of the packaging film for the power storage device is sealed to be temporarily sealed. Thereafter, the first charge / discharge process, the aging process, etc. are performed. In these processes, it is known that gases such as CO 2 are generated from the power storage device element. In order to provide a space for holding the gas inside the temporarily sealed package (formed from the packaging film for the power storage device), and further, in order to remove the space together with the held gas and release the gas to the outside, currently, the power storage device is manufactured using a packaging film for the power storage device that is larger than the size required for the final product power storage device (for example, more than twice the size required for sealing the power storage device element). For this reason, the manufacturing process of the power storage device is complicated.

[0162] An object of the invention according to Embodiment A is to provide a method for manufacturing a power storage device that can easily manufacture a power storage device, and a power storage device manufactured by this manufacturing method.

[0163] A method for manufacturing a power storage device according to a first aspect of the invention according to Embodiment A is a method for manufacturing a power storage device, wherein the power storage device includes a power storage device element and an inner package for housing the power storage device element, the inner package is formed of a packaging film for the power storage device having gas permeability, and includes an inner packaging step of wrapping the power storage device element with the packaging film for the power storage device, an inner sealing step that is performed after the inner packaging step and seals the power storage device element with the packaging film for the power storage device, and a gas venting step that is performed after the inner sealing step and releases the gas generated from the power storage device element through the packaging film for the power storage device.

[0164] The manufacturing method of the power storage device according to the second aspect of the invention according to Embodiment A is the manufacturing method of the power storage device according to the first aspect, wherein in the inner packaging step, the power storage device element is wrapped with the packaging film for the power storage device having substantially the same size as the inner package included in the completed power storage device.

[0165] The power storage device according to the third aspect of the invention according to Embodiment A includes a power storage device element, an inner package that houses the power storage device element, and an outer package that houses the inner package in a state where the power storage device element is housed. The inner package is composed of a packaging film for the power storage device having gas permeability.

[0166] The power storage device according to the fourth aspect of the invention according to Embodiment A is the power storage device according to the third aspect, and further includes a metal terminal electrically connected to the power storage device element and a tab film disposed between the inner package and the metal terminal. The outer package is joined to the inner package, the inner package and the metal terminal are joined via the tab film, and at least a part of the outer edge of the inner package is exposed from the outer package.

[0167] The power storage device according to the fifth aspect of the invention according to Embodiment A is the power storage device according to the third aspect, and further includes a metal terminal electrically connected to the power storage device element and a tab film disposed between the inner package, the outer package, and the metal terminal. The inner package, the outer package, and the metal terminal are joined via the tab film, and the entire inner package is covered by the outer package.

[0168] The power storage device according to the sixth aspect of the invention according to Embodiment A is the power storage device according to the third aspect, and further includes a metal terminal electrically connected to the power storage device element. The inner package and the metal terminal are joined, and at least a part of the outer edge of the inner package is exposed from the outer package.

[0169] The power storage device according to the seventh aspect of the invention according to Embodiment A is a power storage device according to any one of the third to sixth aspects, and the packaging film for the power storage device further has transparency.

[0170] [Embodiment A1] FIG. 8 shows a plan view of the power storage device 100 according to Embodiment A1 of the present invention. FIG. 9 is a cross-sectional view taken along line D2-D2 of FIG. 8. In FIG. 8, parts that are not normally visible from the outside are partially shown by dotted lines for reference. Hereinafter, for convenience of explanation, unless otherwise specified, the vertical direction in FIG. 8 is referred to as the "front-rear direction", the left-right direction is referred to as the "left-right direction", and the vertical direction in FIG. 9 is referred to as the "vertical direction". However, the orientation of the power storage device 100 during use is not limited to this. Also, in FIG. 8, for simplicity of the drawing, the relative positional relationship between the inner packaging body 210 and the outer packaging body 220 is simplified.

[0171] The power storage device 100 includes a container 110, a power storage device element 120, a pair of metal terminals 130, and a pair of tab films 140. The container 110 includes an internal space S1 and a peripheral seal portion 150. The power storage device element 120 is housed in the internal space S1 of the container 110. One end of the metal terminal 130 is joined to the power storage device element 120, and the other end protrudes outward from the peripheral seal portion 150 of the container 110. A part between one end and the other end of the metal terminal 130 is fused to the peripheral seal portion 150 via the tab film 140.

[0172] The container 110 includes a container body 110A. The container body 110A includes an inner packaging body 210 and an outer packaging body 220. The inner packaging body 210 houses the power storage device element 120. The outer packaging body 220 houses the inner packaging body 210 in a state where the power storage device element 120 is housed. The internal space S1 is formed inside the inner packaging body 210. The inner packaging body 210 includes power storage device packaging films 211 and 212. The outer packaging body 220 includes outer packaging films 221 and 222. At the outer peripheral portion of the container body 110A in plan view, the inner packaging body 210 and the outer packaging body 220 are heat-sealed and fused to each other, thereby forming a peripheral seal portion 150. And, the internal space S1 of the container body 110A blocked from the external space is formed in the inner packaging body 210 by this peripheral seal portion 150. The peripheral seal portion 150 defines the periphery of the internal space S1 of the container body 110A. Here, the heat-sealing modes assumed include modes such as heat fusion from a heat source and ultrasonic fusion. In any case, the peripheral seal portion 150 means a portion where the inner packaging body 210 and the outer packaging body 220 are fused and integrated.

[0173] The peripheral seal portion 150 includes a top seal portion 151, a pair of side seal portions 152 and 153, and a bottom seal portion 154. The top seal portion 151 includes a portion (hereinafter referred to as "terminal seal portion 151A") that is sealed with the metal terminal 130 and the tab film 140 interposed therebetween, and extends in the front-rear direction. The pair of side seal portions 152 and 153 extend in the left-right direction. The side seal portion 152 and the side seal portion 153 face each other via the internal space S1. The bottom seal portion 154 faces the top seal portion 151 via the internal space S1. The bottom seal portion 154 extends in the front-rear direction.

[0174] As shown in FIG. 9, the terminal seal portion 151A of the top seal portion 151 is laminated, in order from the top, with an outer film 221, a power storage device packaging film 211, one tab film 140, a metal terminal 130, the other tab film 140, a power storage device packaging film 212, and an outer film 222, and these are integrated. Therefore, the top seal portion 151 can be easily formed. Note that, for the portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, the portion where only the pair of tab films 140 are sandwiched by the inner package 210 and the outer package 220, is laminated, in order from the top, with an outer film 221, a power storage device packaging film 211, one tab film 140, the other tab film 140, a power storage device packaging film 212, and an outer film 222, and these are integrated. Further, the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion in FIG. 9 with the step as the boundary) is laminated, in order from the top, with a power storage device packaging film 211, one tab film 140, a metal terminal 130, the other tab film 140, and a power storage device packaging film 212, and these are integrated. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the outer films 221 and 222 do not exist and the inner portion of the terminal seal portion 151A where the outer films 221 and 222 exist (the right portion in FIG. 9 with the step as the boundary). However, FIG. 8 is an illustration of the region of the peripheral seal portion 150 from an overhead view, and the boundary step is not shown.

[0175] The power storage device packaging films 211 and 212 that constitute the inner package 210 have gas permeability from the viewpoint of facilitating the manufacture of the power storage device 100. Hereinafter, preferred examples of the power storage device packaging films 211 and 212 that constitute the inner package 210 will be described. Note that, hereinafter, when the power storage device packaging films 211 and 212 are not particularly distinguished, the power storage device packaging films 211 and 212 may be collectively referred to as the power storage device packaging film 10.

[0176] The shape of the inner package 210 is not particularly limited, and for example, it can be in a bag shape (pouch shape). Examples of the bag shape here include a three-side seal type, a four-side seal type, a pillow type, a gusset type, etc. The inner package 210 of the present Embodiment A1 has a shape as shown in FIG. 9, and is manufactured by heat-sealing a packaging film 212 for a power storage device formed in a tray shape and a packaging film 211 for a power storage device also formed in a tray shape and stacked on top of the packaging film 212 for a power storage device along the outer peripheral portion in a plan view. The packaging film 212 for a power storage device includes an angular annular flange portion 212A corresponding to the outer peripheral portion in a plan view, and a molded portion 212B continuous with the inner edge of the flange portion 212A and bulging downward therefrom. Similarly, the packaging film 211 for a power storage device includes an angular annular flange portion 211A corresponding to the outer peripheral portion in a plan view, and a portion 211B continuous with the inner edge of the flange portion 211A and bulging upward therefrom. The packaging films 211 and 212 for a power storage device are stacked so that the respective molded portions 211B and 212B bulge in opposite directions. In this state, the flange portion 211A of the packaging film 211 for a power storage device and the flange portion 212A of the packaging film 212 for a power storage device are heat-sealed so as to be integrated, and constitute a part of the peripheral seal portion 150. Note that one of the packaging films 211 and 212 for a power storage device may be in a sheet shape.

[0177] The exterior films 221 and 222 that constitute the outer package 220 are composed of, for example, resin molded products or films. The resin molded product referred to here can be manufactured by methods such as injection molding, pressure air molding, vacuum molding, blow molding, etc., and in-mold molding may be performed to impart design and functionality. The type of resin can be polyolefin, polyester, nylon, ABS, etc. Also, the film referred to here is, for example, a resin film that can be manufactured by methods such as the inflation method or the T-die method, or a laminate of such a resin film and a metal foil or metal plate. Also, the film referred to here may or may not be stretched, and may be a single-layer film or a multilayer film. Also, the multilayer film referred to here may be manufactured by a coating method, may be a laminate of multiple films adhered by an adhesive or the like, or may be manufactured by a multilayer extrusion method.

[0178] The exterior films 221 and 222 can be configured in various ways, but in the present Embodiment A1, they are composed of a laminate film. The laminate film can be a laminate of a base material layer, a barrier layer, and a heat-sealable resin layer. The base material layer functions as the base material of the exterior films 221 and 222, typically forms the outer layer side of the outer package 220, and is a resin layer having insulating properties. The barrier layer has the function of preventing at least moisture and the like from entering the power storage device 100 in addition to improving the strength of the exterior films 221 and 222, and is typically a metal layer made of an aluminum alloy foil or the like. The heat-sealable resin layer is typically made of a heat-sealable resin such as polyolefin and forms the innermost layer of the outer package 220.

[0179] The shape of the outer package 220 is not particularly limited, and for example, it can be in a bag shape (pouch shape). The bag shape mentioned here can include a three-side seal type, a four-side seal type, a pillow type, a gusset type, etc. The container 110A of the present Embodiment A1 has a shape as shown in FIG. 9, and is manufactured by heat-sealing an exterior film 222 formed in a tray shape and an exterior film 221 also formed in a tray shape and superposed on the exterior film 222 from above along the outer peripheral portion in a plan view. The exterior film 222 includes an angular annular flange portion 222A corresponding to the outer peripheral portion in a plan view, and a molded portion 222B continuous with the inner edge of the flange portion 222A and bulging downward therefrom. Similarly, the exterior film 221 includes an angular annular flange portion 221A corresponding to the outer peripheral portion in a plan view, and a portion 221B continuous with the inner edge of the flange portion 221A and bulging upward therefrom. The exterior films 221 and 222 are superposed so that their respective molded portions 221B and 222B bulge in opposite directions. In this state, the flange portion 221A of the exterior film 221 and the flange portion 222A of the exterior film 222 are heat-sealed so as to be integrated, and constitute a part of the peripheral seal portion 150. Note that one of the exterior films 221 and 222 may be in a sheet shape.

[0180] As shown in FIG. 9, in the terminal seal portion 151A, a part of the flange portion 211A of the power storage device packaging film 211 is joined to one tab film 140. A part of the flange portion 212A of the power storage device packaging film 212 is joined to the other tab film 140.

[0181] The flange portion 221A of the outer film 221 is joined to the flange portion 211A of the packaging film 211 for the power storage device. The end portion 221X of the flange portion 221A is located closer to the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 221X of the flange portion 221A may be located at the same position as the end portion 211X of the packaging film 211 for the power storage device in the left - right direction, or may be located farther from the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device.

[0182] The flange portion 222A of the outer film 222 is joined to the flange portion 212A of the packaging film 212 for the power storage device. The end portion 222X of the flange portion 222A is located closer to the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 222X of the flange portion 222A may be located at the same position as the end portion 212X of the packaging film 212 for the power storage device in the left - right direction, or may be located farther from the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device.

[0183] The power storage device element 120 includes at least a positive electrode, a negative electrode, and an electrolyte, and is, for example, a power storage member such as a lithium - ion battery (secondary battery) or a capacitor.

[0184] The metal terminal 130 is a metal terminal used for power input and output of the power storage device element 120. The metal terminal 130 is disposed, for example, at the top seal portion 151 of the container 110A, with one forming the positive electrode side terminal and the other forming the negative electrode side terminal. One end of each metal terminal 130 in the left-right direction is electrically connected to the electrode (positive electrode or negative electrode) of the power storage device element 120 in the internal space S1 of the container 110A, and the other end protrudes outward from the peripheral seal portion 150. The above-described form of the power storage device 100 is particularly preferable for use in electric vehicles such as electric cars and hybrid cars that use a large number of power storage devices 100 connected in series at a high voltage. Note that the attachment positions of the two metal terminals 130 constituting the positive and negative electrodes are not particularly limited, and may be disposed, for example, at the side seal portions 152, 153, or the bottom seal portion 154 of the peripheral seal portion 150.

[0185] The metal material constituting the metal terminal 130 is, for example, aluminum, nickel, copper, or the like. When the power storage device element 120 is a lithium ion battery, the metal terminal 130 connected to the positive electrode is typically constituted by aluminum or the like, and the metal terminal 130 connected to the negative electrode is typically constituted by copper, nickel, or the like.

[0186] The tab film 140 is a so-called adhesive film and is configured to adhere to both the power storage device packaging films 211 and 212 and the metal terminal 130. By means of the tab film 140, even if the metal terminal 130 and the innermost layer (heat-sealable resin layer) of the power storage device packaging films 211 and 212 are made of different materials, the two can be fixed. Note that the tab film 140 is integrated by being pre-fused and fixed to the metal terminal 130, and the power storage device packaging films 211 and 212 are fused to the metal terminal 130 to which the tab film 140 is fixed.

[0187] [Method for manufacturing a power storage device] FIG. 10 is a flowchart showing an example of a method for manufacturing the power storage device 100. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0188] In the inner packaging process of step S11, as shown in FIG. 11, the formed power storage device packaging films 211 and 212 wrap the power storage device element 120. In the power storage device 100 of Embodiment A1, since the power storage device packaging films 211 and 212 have gas permeability, it is not necessary to form a sub-chamber for temporarily storing the gas generated from the power storage device element 120 in the first filling process and the like described later. Therefore, in the inner packaging process, the power storage device element 120 is wrapped by the power storage device packaging films 211 and 212 having substantially the same size as the power storage device packaging films 211 and 212 included in the inner package 210 of the completed power storage device 100. Therefore, the manufacturing process of the power storage device 100 can be simplified. Also, the materials used for the power storage device 100 can be reduced. Substantially the same size includes the case where it is larger than the power storage device packaging films 211 and 212 included in the inner package 210 of the completed power storage device 100 to such an extent that a sub-chamber cannot be formed. Note that a metal terminal 130 is connected to the power storage device element 120 in advance, and a tab film 140 is joined to the metal terminal 130.

[0189] The first inner sealing process of step S12 is performed after the inner packaging process. In the first inner sealing process, as shown in FIG. 12, the portions corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 among the peripheries of the power storage device packaging films 211 and 212 are sealed. When the first inner sealing process is completed, an opening 213 is formed in the portion where the side seal portion 153 is to be formed among the peripheries of the power storage device packaging films 211 and 212. After the first inner sealing process, the vacuum drying process of step S13 is performed.

[0190] The electrolyte injection process of step S14 is performed after the vacuum drying process. In the electrolyte injection process, the electrolyte is injected through the opening 213 (see FIG. 12).

[0191] The second inner sealing process in step S15 is performed after the electrolytic solution injection process. As shown in FIG. 16, in the second inner sealing process, the portion of the peripheries of the power storage device packaging films 211 and 212 where the side seal portion 153 is to be formed is sealed, thereby closing the opening 213. According to the power storage device 100, since the power storage device packaging films 211 and 212 have transparency, after the first inner sealing process or the second inner sealing process is completed, it is possible to easily confirm whether the power storage device packaging film 211 and the power storage device packaging film 212 are properly sealed. Therefore, the power storage device 100 can be suitably manufactured. Note that the state in which the power storage device packaging film 211 and the power storage device packaging film 212 are not properly sealed includes, for example, a first state, a second state, or a third state. The first state is a state in which the power storage device packaging film 211 and the power storage device packaging film 212 are sealed in a state of biting foreign matter. The second state is a state in which a part of the portion to be sealed is not sealed. The third state is a state in which a portion that should not be sealed is sealed. After the second inner sealing process, the first charge and discharge process in step S16 and the aging process in step S17 are sequentially performed.

[0192] The gas venting process in step S18 is performed in parallel with the first charge and discharge process and the aging process. In the present embodiment A1, since the power storage device packaging films 211 and 212 have gas permeability, when the first charge and discharge process and the aging process are being performed, gases such as carbon dioxide generated from the power storage device element 120 are discharged to the outside through the power storage device packaging films 211 and 212. After the gas venting process, the main charging process in step S19 is performed.

[0193] The outer packaging process in step S20 is performed after the main charging process. In the outer packaging process, the inner package 210 in a state in which the power storage device element 120 is housed is wrapped with the outer packaging films 221 and 222.

[0194] The outer sealing process in step S21 is carried out after the outer packaging process. In the outer sealing process, the peripheral edges of the outer packaging films 221 and 222 are sealed to form the peripheral seal portion 150.

[0195] [Features of the power storage device] In the power storage device 100 of the present embodiment A1, since the power storage device packaging films 211 and 212 have gas permeability, it is not necessary to form a sub-chamber for temporarily storing the gas generated from the power storage device element 120 in the first filling process and the like described later. Therefore, the manufacturing process of the power storage device 100 can be simplified. Also, the amount of materials used in the power storage device 100 can be reduced.

[0196] [Embodiment A2] The power storage device 100 of embodiment A2 is different from embodiment A1 in that the power storage device packaging films 211 and 212 do not have transparency, and the other configurations are the same as those of embodiment A1. Hereinafter, the power storage device 100 of embodiment A2 will be described centering on the parts different from embodiment A2.

[0197] [Manufacturing method of the power storage device] FIG. 11 is a flowchart showing an example of the manufacturing method of the power storage device 100 of embodiment A2. The manufacturing method of the power storage device 100 includes a plurality of steps.

[0198] In the inner packaging process of step S31, as shown in FIG. 12, the formed power storage device packaging films 211 and 212 wrap the power storage device element 120. In the power storage device 100 of the present embodiment A2, a sub-chamber 214 is formed to temporarily store the gas generated from the power storage device element 120 in the first filling process or the like. Therefore, in the inner packaging process, the power storage device element 120 is wrapped by the power storage device packaging films 211 and 212 that are larger than the power storage device packaging films 211 and 212 included in the inner package 210 of the completed power storage device 100. An accommodation chamber 215 is formed in the sub-chamber 214 of the power storage device packaging films 211 and 212 to store more gas generated from the power storage device element 120.

[0199] The first inner sealing process of step S32 is performed after the inner packaging process. In the first inner sealing process, as shown in FIG. 16, the portions corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 among the peripheries of the power storage device packaging films 211 and 212 are sealed so as to extend to the sub-chamber 214. When the first inner sealing process is completed, an opening 213 is formed in the portion 216 that faces the portion where the side seal portion 153 of the peripheries of the power storage device packaging films 211 and 212 is to be formed via the sub-chamber 214. After the first inner sealing process, the vacuum drying process of step S33 is performed.

[0200] The electrolyte injection process of step S34 is performed after the vacuum drying process. In the electrolyte injection process, the electrolyte is injected through the opening 213 (see FIG. 16).

[0201] The second inner sealing process in step S35 is carried out after the electrolytic solution injection process. As shown in FIG. 17, in the second inner sealing process, the portion 216 facing the portion where the side seal portion 153 is to be formed among the peripheries of the power storage device packaging films 211 and 212 is sealed via the sub-chamber 214, whereby the opening 213 is closed. After the second inner sealing process, the initial charge and discharge process in step S36 and the aging process in step S37 are carried out in sequence.

[0202] The gas venting process in step S38 is carried out after the aging process. In the gas venting process, gases such as carbon dioxide generated from the power storage device element 120 are temporarily stored in the sub-chamber 214 of the power storage device packaging films 211 and 212.

[0203] The sub-chamber removal process in step S39 is carried out after the gas venting process. In the sub-chamber removal process, the sub-chamber 214 is removed by cutting the power storage device packaging films 211 and 212 along the dashed-dotted line XA shown in FIG. 17 so as to have the same size as the inner package 210 included in the completed power storage device 100.

[0204] The inner sealing process in step S40 is carried out after the sub-chamber removal process. In the inner sealing process, as shown in FIG. 18, the portion corresponding to the side seal portion 153 among the peripheries of the power storage device packaging films 211 and 212 is sealed. After the inner sealing process, the main charging process in step S41 is carried out.

[0205] The outer packaging process in step S42 is carried out after the main charging process. In the outer packaging process, the inner package 210 in a state where the power storage device element 120 is accommodated is wrapped by the outer packaging films 221 and 222.

[0206] The outer sealing process in step S43 is carried out after the outer packaging process. In the outer sealing process, the peripheries of the outer packaging films 221 and 222 are sealed, whereby the peripheral seal portion 150 is formed.

[0207] [Embodiment A3] The power storage device 300 of Embodiment A3 differs from Embodiment A1 in that the configuration of the terminal seal portion 151A is different, and other configurations are the same as those of Embodiment A1. Hereinafter, the power storage device 300 of Embodiment A3 will be described centering on the parts different from Embodiment A1.

[0208] FIG. 19 is a cross-sectional view of the terminal seal portion 351A included in the power storage device 300 of Embodiment A3. In the terminal seal portion 351A, a part of the flange portion 211A of the power storage device packaging film 211 is joined to one tab film 140. A part of the flange portion 212A of the power storage device packaging film 212 is joined to the other tab film 140.

[0209] The flange portion 221A of the outer packaging film 221 is joined to one tab film 140. The flange portion 222A of the outer packaging film 222 is joined to the other tab film 140. The end portion 221X of the flange portion 221A is located farther from the power storage device element 120 than the end portion 211X of the power storage device packaging film 211. The end portion 222X of the flange portion 222A is located farther from the power storage device element 120 than the end portion 212X of the power storage device packaging film 212. For this reason, the entire inner package 210 is covered by the outer package 220.

[0210] [Features of the Power Storage Device] According to the power storage device 300, since the inner package 210 is covered by the outer package 220, entry of moisture and the like from the outside into the internal space S1 of the inner package 210 is suppressed.

[0211] [Embodiment A4] The power storage device 400 of Embodiment A4 differs from Embodiment A1 in that the configuration of the terminal seal portion 151A is different, and other configurations are the same as those of Embodiment A1. Hereinafter, the power storage device 400 of Embodiment A4 will be described centering on the parts different from Embodiment A1.

[0212] FIG. 20 is a cross-sectional view of a terminal seal portion 451A included in the power storage device 400 of Embodiment A4. The power storage device 400 does not have a tab film 140. In the terminal seal portion 451A of the power storage device 400, an exterior film 221, a packaging film 211 for the power storage device, a metal terminal 130, a packaging film 212 for the power storage device, and an exterior film 222 are laminated in this order from above, and these are integrated.

[0213] The end portion 221X of the flange portion 221A is located closer to the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 221X of the flange portion 221A may be located at the same position as the end portion 211X of the packaging film 211 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device.

[0214] The flange portion 221A of the exterior film 221 is joined to the flange portion 211A of the packaging film 211 for the power storage device. The flange portion 222A of the exterior film 222 is joined to the flange portion 212A of the packaging film 212 for the power storage device. The end portion 222X of the flange portion 222A is located closer to the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 222X of the flange portion 222A may be located at the same position as the end portion 212X of the packaging film 212 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device.

[0215] [Features of the power storage device] According to the power storage device 400, since the packaging films 211 and 212 for the power storage device and the metal terminal 130 are joined without passing through the tab film 140, the number of components is small. Further, the manufacturing method of the power storage device 400 can be simplified.

[0216] [Embodiment A5] The power storage device 500 of Embodiment A5 is different from Embodiment A4 in that the configuration of the terminal seal portion 451A is different, and the other configurations are the same as those of Embodiment A4. Hereinafter, the power storage device 500 of Embodiment A5 will be described centering on the parts different from Embodiment A4.

[0217] FIG. 21 is a cross-sectional view of the terminal seal portion 551A included in the power storage device 500 of Embodiment A5. In the terminal seal portion 551A, a part of the flange portion 211A of the power storage device packaging film 211 is joined to the metal terminal 130. A part of the flange portion 212A of the power storage device packaging film 212 is joined to the metal terminal 130.

[0218] The flange portion 221A of the outer packaging film 221 is joined to the metal terminal 130. The flange portion 222A of the outer packaging film 222 is joined to the metal terminal 130. The end portion 221X of the flange portion 221A is located farther from the power storage device element 120 than the end portion 211X of the power storage device packaging film 211. The end portion 222X of the flange portion 222A is located farther from the power storage device element 120 than the end portion 212X of the power storage device packaging film 212. For this reason, the entire inner package 210 is covered by the outer package 220.

[0219] [Features of the Power Storage Device] According to the power storage device 500, since the inner package 210 is covered by the outer package 220, the intrusion of moisture and the like from the outside into the internal space S1 of the inner package 210 is suppressed. Further, according to the power storage device 500, since the power storage device packaging films 211 and 212 and the metal terminal 130 are joined without passing through the tab film 140, the number of components is small. Also, the manufacturing method of the power storage device 500 can be simplified.

[0220] [Modification Example] Each of the above embodiments is an example of a form that a power storage device and a method for manufacturing a power storage device according to the present disclosure can take, and is not intended to limit the form. The power storage device and the method for manufacturing a power storage device according to the present disclosure can take forms different from those exemplified in each embodiment. One example is a form in which a part of the configuration of each embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to each embodiment. Some examples of modifications of each embodiment are shown below. Note that the following modifications can be combined with each other as long as there is no technical contradiction.

[0221] In the power storage device 100 of Embodiment A1, one outer package 220 may be configured to accommodate a plurality of inner packages 210 in a state where the power storage device element 120 is accommodated. In this modification, the sizes of the plurality of inner packages 210 may be different or the same. According to this modification, since a plurality of power storage device elements 120 can be connected in series or in parallel, the voltage can be easily adjusted.

[0222] In the power storage device 100 of Embodiment A1, the power storage device packaging films 211 and 212 may not have transparency. The power storage device packaging films 211 and 212 only need to have at least gas permeability.

[0223] In the power storage device 100 of Embodiment A1, the inner package 210 may be configured by folding one power storage device packaging film 211 and heat-sealing the peripheral edge. Similarly, the outer package 220 may be configured by folding one outer packaging film 221 and heat-sealing the peripheral edge.

[0224] <Embodiment B> In the manufacturing process of a power storage device, generally, after a power storage device element is housed in a packaging film for the power storage device, the periphery of the packaging film for the power storage device is sealed to be temporarily sealed. Thereafter, a first charge / discharge process, an aging process, etc. are performed. Since the packaging film for the power storage device included in the secondary battery contains a metal layer, it has shielding properties. Therefore, in a state where the power storage device element is sealed by the packaging film for the power storage device, it is impossible to confirm whether the periphery of the packaging film for the power storage device is properly sealed. For this reason, the power storage device cannot be preferably manufactured.

[0225] An object of the invention according to Embodiment B is to provide a method for manufacturing a power storage device that can preferably manufacture a power storage device, and a power storage device manufactured by this manufacturing method.

[0226] A method for manufacturing a power storage device according to a first aspect of the invention according to Embodiment B is a method for manufacturing a power storage device, the power storage device including a power storage device element and an inner package that houses the power storage device element, the inner package being constituted by a packaging film for the power storage device having transparency, and including an inner packaging step of wrapping the power storage device element with the packaging film for the power storage device, and an inner sealing step that is performed after the inner packaging step and seals the packaging film for the power storage device so that the power storage device element is sealed with the packaging film for the power storage device.

[0227] A method for manufacturing a power storage device according to a second aspect of the invention according to Embodiment B is the method for manufacturing a power storage device according to the first aspect, the packaging film for the power storage device further having gas permeability, and further including a gas venting step that is performed after the inner sealing step and vents gas generated from the power storage device element through the packaging film for the power storage device.

[0228] The method for manufacturing a power storage device according to the third aspect of the invention according to Embodiment B is the method for manufacturing a power storage device according to the second aspect, wherein in the inner packaging step, the power storage device element is wrapped with the packaging film for power storage device having substantially the same size as the inner packaging body included in the completed power storage device.

[0229] The power storage device according to the fourth aspect of the invention according to Embodiment B includes a power storage device element, an inner packaging body that houses the power storage device element, and an outer packaging body that houses the inner packaging body in a state where the power storage device element is housed. The inner packaging body is composed of a packaging film for power storage device having transparency.

[0230] The power storage device according to the fifth aspect of the invention according to Embodiment B is the power storage device according to the fourth aspect, further including a metal terminal electrically connected to the power storage device element and a tab film disposed between the inner packaging body and the metal terminal. The outer packaging body is joined to the inner packaging body, the inner packaging body and the metal terminal are joined via the tab film, and at least a part of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0231] The power storage device according to the sixth aspect of the invention according to Embodiment B is the power storage device according to the fourth aspect, further including a metal terminal electrically connected to the power storage device element and a tab film disposed between the inner packaging body, the outer packaging body, and the metal terminal. The inner packaging body, the outer packaging body, and the metal terminal are joined via the tab film, and the entire inner packaging body is covered by the outer packaging body.

[0232] The power storage device according to the seventh aspect of the invention according to Embodiment B is the power storage device according to the fourth aspect, further including a metal terminal electrically connected to the power storage device element. The inner packaging body and the metal terminal are joined, and at least a part of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0233] The power storage device according to the eighth aspect of the invention according to Embodiment B is the power storage device according to the fourth aspect, further comprising a metal terminal electrically connected to the power storage device element, wherein the inner packaging body, the outer packaging body, and the metal terminal are joined, and the entire inner packaging body is covered by the outer packaging body.

[0234] The power storage device according to the ninth aspect of the invention according to Embodiment B is the power storage device according to any one of the third to eighth aspects, wherein the packaging film for the power storage device further has gas permeability.

[0235] [Embodiment B1] FIG. 8 shows a plan view of a power storage device 100 according to Embodiment B1 of the present invention. FIG. 9 is a cross-sectional view taken along line D2-D2 of FIG. 8. In FIG. 8, parts that are not normally visible from the outside are partially shown by dotted lines for reference. Hereinafter, for convenience of explanation, unless otherwise specified, the vertical direction in FIG. 8 is referred to as the "front-rear direction", the horizontal direction is referred to as the "left-right direction", and the vertical direction in FIG. 9 is referred to as the "up-down direction". However, the orientation of the power storage device 100 during use is not limited thereto. Also, in FIG. 8, for simplification of the drawing, the relative positional relationship between the inner packaging body 210 and the outer packaging body 220 is simplified.

[0236] The power storage device 100 includes a container 110, a power storage device element 120, a pair of metal terminals 130, and a pair of tab films 140. The container 110 includes an internal space S1 and a peripheral seal portion 150. The power storage device element 120 is housed in the internal space S1 of the container 110. One end of the metal terminal 130 is joined to the power storage device element 120, and the other end protrudes outward from the peripheral seal portion 150 of the container 110. A part between one end and the other end of the metal terminal 130 is fused to the peripheral seal portion 150 via the tab film 140.

[0237] The container 110 includes a vessel 110A. The vessel 110A includes an inner package 210 and an outer package 220. The inner package 210 houses the power storage device element 120. The outer package 220 houses the inner package 210 with the power storage device element 120 accommodated therein. The internal space S1 is formed inside the inner package 210. The inner package 210 includes power storage device packaging films 211 and 212. The outer package 220 includes outer packaging films 221 and 222. At the outer peripheral portion of the vessel 110A in plan view, the inner package 210 and the outer package 220 are heat-sealed and fused to each other, thereby forming a peripheral seal portion 150. And, the internal space S1 of the vessel 110A blocked from the external space is formed in the inner package 210 by this peripheral seal portion 150. The peripheral seal portion 150 defines the periphery of the internal space S1 of the vessel 110A. Here, the heat-sealing mode is assumed to include modes such as heat fusion from a heat source and ultrasonic fusion. In any case, the peripheral seal portion 150 means a portion where the inner package 210 and the outer package 220 are fused and integrated.

[0238] The peripheral seal portion 150 includes a top seal portion 151, a pair of side seal portions 152 and 153, and a bottom seal portion 154. The top seal portion 151 includes a portion (hereinafter referred to as "terminal seal portion 151A") that is sealed with the metal terminal 130 and the tab film 140 interposed therebetween, and extends in the front-rear direction. The pair of side seal portions 152 and 153 extend in the left-right direction. The side seal portion 152 and the side seal portion 153 face each other via the internal space S1. The bottom seal portion 154 faces the top seal portion 151 via the internal space S1. The bottom seal portion 154 extends in the front-rear direction.

[0239] As shown in FIG. 9, the terminal seal portion 151A of the top seal portion 151 is laminated, in order from the top, with an outer film 221, a power storage device packaging film 211, one tab film 140, a metal terminal 130, the other tab film 140, a power storage device packaging film 212, and an outer film 222, and these are integrated. Therefore, the top seal portion 151 can be easily formed. Note that, for the portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, the portion where only the pair of tab films 140 are sandwiched by the inner package 210 and the outer package 220, the outer film 221, the power storage device packaging film 211, one tab film 140, the other tab film 140, the power storage device packaging film 212, and the outer film 222 are laminated, in order from the top, and these are integrated. Further, for the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion in FIG. 9 with the step as the boundary), the power storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, and the power storage device packaging film 212 are laminated, in order from the top, and these are integrated. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the outer films 221 and 222 do not exist and the inner portion of the terminal seal portion 151A where the outer films 221 and 222 exist (the right portion in FIG. 9 with the step as the boundary). However, FIG. 8 is an overview description of the area of the peripheral seal portion 150, and the boundary step is not shown.

[0240] The power storage device packaging films 211 and 212 that constitute the inner package 210 are, as a whole, transparent from the viewpoint of suitably manufacturing the power storage device 100. Hereinafter, preferred examples of the power storage device packaging films 211 and 212 that constitute the inner package 210 will be described. Note that, hereinafter, when the power storage device packaging films 211 and 212 are not particularly distinguished, the power storage device packaging films 211 and 212 may be collectively referred to as the power storage device packaging film 10.

[0241] The shape of the inner package 210 is not particularly limited, and for example, it can be in a bag shape (pouch shape). The bag shape mentioned here includes a three-side seal type, a four-side seal type, a pillow type, a gusset type, etc. The inner package 210 of the present Embodiment B1 has a shape as shown in FIG. 9, and is manufactured by heat-sealing a packaging film 212 for a power storage device formed in a tray shape and a packaging film 211 for a power storage device also formed in a tray shape and overlapped from above the packaging film 212 for a power storage device along the outer peripheral portion in a plan view. The packaging film 212 for a power storage device includes an angular annular flange portion 212A corresponding to the outer peripheral portion in a plan view, and a molded portion 212B continuous with the inner edge of the flange portion 212A and bulging downward therefrom. Similarly, the packaging film 211 for a power storage device includes an angular annular flange portion 211A corresponding to the outer peripheral portion in a plan view, and 211B continuous with the inner edge of the flange portion 211A and bulging upward therefrom. The packaging films 211 and 212 for a power storage device are overlapped so that the respective molded portions 211B and 212B bulge in opposite directions. In this state, the flange portion 211A of the packaging film 211 for a power storage device and the flange portion 212A of the packaging film 212 for a power storage device are heat-sealed so as to be integrated, and constitute a part of the peripheral seal portion 150. Note that one of the packaging films 211 and 212 for a power storage device may be in a sheet shape.

[0242] The exterior films 221 and 222 that constitute the outer package 220 are composed of, for example, resin molded products or films. The resin molded products referred to here can be manufactured by methods such as injection molding, pressure air molding, vacuum molding, blow molding, etc., and in-mold molding may be performed to impart designability and functionality. The types of resins can be polyolefin, polyester, nylon, ABS, etc. Also, the films referred to here are, for example, resin films that can be manufactured by methods such as the inflation method or the T-die method, or those obtained by laminating such resin films on a metal foil or a metal plate. Further, the films referred to here may or may not be stretched, and may be single-layer films or multilayer films. Also, the multilayer films referred to here may be manufactured by a coating method, may be those in which a plurality of films are adhered by an adhesive or the like, or may be manufactured by a multilayer extrusion method.

[0243] The exterior films 221 and 222 can be configured in various ways, but in the present Embodiment B1, they are composed of laminated films. The laminated film can be a laminate in which a base material layer, a barrier layer, and a heat-sealable resin layer are laminated. The base material layer functions as the base material of the exterior films 221 and 222, typically forms the outer layer side of the outer package 220, and is a resin layer having insulating properties. The barrier layer has the function of preventing at least moisture and the like from entering the power storage device 100 in addition to improving the strength of the exterior films 221 and 222, and is typically a metal layer made of an aluminum alloy foil or the like. The heat-sealable resin layer is typically made of a heat-sealable resin such as polyolefin and forms the innermost layer of the outer package 220.

[0244] The shape of the outer package 220 is not particularly limited, and for example, it can be in the shape of a bag (pouch shape). The bag shape mentioned here can include a three-side seal type, a four-side seal type, a pillow type, a gusset type, etc. The container 110A of the present Embodiment B1 has a shape as shown in FIG. 9, and is manufactured by heat-sealing an exterior film 222 formed in a tray shape and an exterior film 221 also formed in a tray shape and superposed on the exterior film 222 from above along the outer peripheral portion in a plan view. The exterior film 222 includes an angular annular flange portion 222A corresponding to the outer peripheral portion in a plan view, and a molded portion 222B continuous with the inner edge of the flange portion 222A and bulging downward therefrom. Similarly, the exterior film 221 includes an angular annular flange portion 221A corresponding to the outer peripheral portion in a plan view, and a portion 221B continuous with the inner edge of the flange portion 221A and bulging upward therefrom. The exterior films 221 and 222 are superposed such that the respective molded portions 221B and 222B bulge in opposite directions. In this state, the flange portion 221A of the exterior film 221 and the flange portion 222A of the exterior film 222 are heat-sealed so as to be integrated, and constitute a part of the peripheral seal portion 150. Note that one of the exterior films 221 and 222 may be in a sheet shape.

[0245] As shown in FIG. 9, in the terminal seal portion 151A, a part of the flange portion 211A of the power storage device packaging film 211 is joined to one tab film 140. A part of the flange portion 212A of the power storage device packaging film 212 is joined to the other tab film 140.

[0246] The flange portion 221A of the outer packaging film 221 is joined to the flange portion 211A of the packaging film 211 for the power storage device. The end portion 221X of the flange portion 221A is located closer to the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 221X of the flange portion 221A may be located at the same position as the end portion 211X of the packaging film 211 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device.

[0247] The flange portion 222A of the outer packaging film 222 is joined to the flange portion 212A of the packaging film 212 for the power storage device. The end portion 222X of the flange portion 222A is located closer to the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 222X of the flange portion 222A may be located at the same position as the end portion 212X of the packaging film 212 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device.

[0248] The power storage device element 120 includes at least a positive electrode, a negative electrode, and an electrolyte, and is, for example, a power storage member such as a lithium ion battery (secondary battery) or a capacitor.

[0249] The metal terminal 130 is a metal terminal used for power input and output of the power storage device element 120. The metal terminal 130 is disposed, for example, at the top seal portion 151 of the container 110A, with one forming the positive electrode side terminal and the other forming the negative electrode side terminal. One end of each metal terminal 130 in the left-right direction is electrically connected to the electrode (positive electrode or negative electrode) of the power storage device element 120 in the internal space S1 of the container 110A, and the other end protrudes outward from the peripheral seal portion 150. The above form of the power storage device 100 is particularly preferable for use in electric vehicles such as electric cars and hybrid cars that use a large number of power storage devices 100 connected in series at a high voltage. Note that the attachment positions of the two metal terminals 130 constituting the positive and negative electrodes are not particularly limited, and may be disposed, for example, at the side seal portions 152, 153, or the bottom seal portion 154 of the peripheral seal portion 150.

[0250] The metal material constituting the metal terminal 130 is, for example, aluminum, nickel, copper, etc. When the power storage device element 120 is a lithium ion battery, the metal terminal 130 connected to the positive electrode is typically constituted by aluminum or the like, and the metal terminal 130 connected to the negative electrode is typically constituted by copper, nickel, or the like.

[0251] The tab film 140 is a so-called adhesive film and is configured to adhere to both the power storage device packaging films 211, 212 and the metal terminal 130. By means of the tab film 140, even if the metal terminal 130 and the innermost layer (heat-sealable resin layer) of the power storage device packaging films 211, 212 are made of different materials, the two can be fixed. Note that the tab film 140 is integrated by being pre-fused and fixed to the metal terminal 130, and the power storage device packaging films 211, 212 are fused to the metal terminal 130 to which the tab film 140 is fixed.

[0252] [Method for manufacturing a power storage device] FIG. 10 is a flowchart showing an example of a method for manufacturing the power storage device 100. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0253] In the inner packaging process of step S11, as shown in FIG. 11, the power storage device element 120 is wrapped by the formed packaging films 211 and 212 for the power storage device. In the power storage device 100 of the present embodiment B1, since the packaging films 211 and 212 for the power storage device have gas permeability, it is not necessary to form a sub-chamber for temporarily storing the gas generated from the power storage device element 120 in the first filling process and the like described later. Therefore, in the inner packaging process, the power storage device element 120 is wrapped by the packaging films 211 and 212 for the power storage device having substantially the same size as the packaging films 211 and 212 included in the inner package 210 of the completed power storage device 100. Therefore, the manufacturing process of the power storage device 100 can be simplified. In addition, the materials used for the power storage device 100 can be reduced. Substantially the same size includes the case where it is larger than the packaging films 211 and 212 for the power storage device included in the inner package 210 of the completed power storage device 100 to such an extent that a sub-chamber cannot be formed. Note that a metal terminal 130 is connected to the power storage device element 120 in advance, and a tab film 140 is joined to the metal terminal 130.

[0254] The first inner sealing process of step S12 is performed after the inner packaging process. In the first inner sealing process, as shown in FIG. 12, the portions corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 among the peripheries of the packaging films 211 and 212 for the power storage device are sealed. By completing the first inner sealing process, an opening 213 is formed in a portion where a side seal portion 153 is to be formed among the peripheries of the packaging films 211 and 212 for the power storage device. After the first inner sealing process, the vacuum drying process of step S13 is performed.

[0255] The electrolyte injection process of step S14 is performed after the vacuum drying process. In the electrolyte injection process, the electrolyte is injected through the opening 213 (see FIG. 12).

[0256] The second inner sealing process in step S15 is carried out after the electrolyte injection process. As shown in FIG. 10, in the second inner sealing process, the portion of the peripheries of the power storage device packaging films 211 and 212 where the side seal portion 153 is to be formed is sealed, thereby closing the opening 213. After the second inner sealing process, the initial charge and discharge process in step S16 and the aging process in step S17 are carried out in sequence.

[0257] The gas venting process in step S18 is carried out in parallel with the initial charge and discharge process and the aging process. In the present embodiment B1, since the power storage device packaging films 211 and 212 have gas permeability, when the initial charge and discharge process and the aging process are carried out, gases such as carbon dioxide generated from the power storage device element 120 are discharged to the outside through the power storage device packaging films 211 and 212. After the gas venting process, the main charging process in step S19 is carried out.

[0258] The outer packaging process in step S20 is carried out after the main charging process. In the outer packaging process, the inner package 210 in a state where the power storage device element 120 is accommodated is wrapped by the outer packaging films 221 and 222.

[0259] The outer sealing process in step S21 is carried out after the outer packaging process. In the outer sealing process, the peripheries of the outer packaging films 221 and 222 are sealed, thereby forming the peripheral seal portion 150.

[0260] [Features of the power storage device] According to the power storage device 100, since the packaging films 211 and 212 for the power storage device have transparency, it is possible to easily confirm whether the packaging film 211 for the power storage device and the packaging film 212 for the power storage device are properly sealed after the first inner sealing step or the second inner sealing step is completed. Therefore, the power storage device 100 can be preferably manufactured. Note that the state where the packaging film 211 for the power storage device and the packaging film 212 for the power storage device are not properly sealed includes, for example, the first state, the second state, or the third state. The first state is a state where the packaging film 211 for the power storage device and the packaging film 212 for the power storage device are sealed in a state of biting foreign matter. The second state is a state where a part of the portion to be sealed is not sealed. The third state is a state where a portion that should not be sealed is sealed.

[0261] [Embodiment B2] The power storage device 100 of Embodiment B2 is different from Embodiment B1 in that the packaging films 211 and 212 for the power storage device do not have gas permeability, or in that it does not have gas permeability to the extent of performing the gas venting step of step S18 described above as compared with Embodiment B1, and other configurations are the same as those of Embodiment B1. Hereinafter, the power storage device 100 of Embodiment B2 will be described centering on the parts different from Embodiment B2.

[0262] [Method for manufacturing a power storage device] FIG. 11 is a flowchart showing an example of a method for manufacturing the power storage device 100 of Embodiment B2. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0263] In the inner packaging process of step S31, as shown in FIG. 15, the power storage device element 120 is wrapped by the formed packaging films 211 and 212 for the power storage device. In the power storage device 100 of the present Embodiment B2, since the packaging films 211 and 212 for the power storage device do not have gas permeability, it is preferable to form a sub-chamber 214 for temporarily storing the gas generated from the power storage device element 120 in the first filling process or the like. For this reason, in the inner packaging process, the power storage device element 120 is wrapped by the packaging films 211 and 212 for the power storage device that are larger than the packaging films 211 and 212 provided in the inner package 210 of the completed power storage device 100. An accommodation chamber 215 for storing more gas generated from the power storage device element 120 is formed in the sub-chamber 214 of the packaging films 211 and 212 for the power storage device.

[0264] The first inner sealing process of step S32 is carried out after the inner packaging process. In the first inner sealing process, as shown in FIG. 16, the portions corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 among the peripheries of the packaging films 211 and 212 for the power storage device are sealed so as to extend to the sub-chamber 214. By the completion of the first inner sealing process, an opening 213 is formed in the portion 216 facing through the sub-chamber 214 the portion where the side seal portion 153 of the peripheries of the packaging films 211 and 212 for the power storage device is to be formed. After the first inner sealing process, the vacuum drying process of step S33 is carried out.

[0265] The electrolyte injection process of step S34 is carried out after the vacuum drying process. In the electrolyte injection process, the electrolyte is injected through the opening 213 (see FIG. 16).

[0266] The second inner sealing process in step S35 is carried out after the electrolyte injection process. As shown in FIG. 17, in the second inner sealing process, the portion 216 that faces the portion where the side seal portion 153 is to be formed among the peripheries of the power storage device packaging films 211 and 212 via the sub chamber 214 is sealed, whereby the opening 213 is closed. After the second inner sealing process, the initial charge and discharge process in step S36 and the aging process in step S37 are carried out in sequence.

[0267] The gas venting process in step S38 is carried out after the aging process. In the gas venting process, gases such as carbon dioxide generated from the power storage device element 120 are temporarily stored in the sub chamber 214 of the power storage device packaging films 211 and 212.

[0268] The sub chamber removal process in step S39 is carried out after the gas venting process. In the sub chamber removal process, the sub chamber 214 is removed by cutting the power storage device packaging films 211 and 212 along the dashed line XA shown in FIG. 17 so as to have the same size as the inner package 210 included in the completed power storage device 100.

[0269] The inner sealing process in step S40 is carried out after the sub chamber removal process. In the inner sealing process, as shown in FIG. 18, the portion corresponding to the side seal portion 153 among the peripheries of the power storage device packaging films 211 and 212 is sealed. After the inner sealing process, the main charging process in step S41 is carried out.

[0270] The outer packaging process in step S42 is carried out after the main charging process. In the outer packaging process, the inner package 210 in a state where the power storage device element 120 is accommodated is wrapped by the outer packaging films 221 and 222.

[0271] The outer sealing process in step S43 is carried out after the outer packaging process. In the outer sealing process, the peripheries of the outer packaging films 221 and 222 are sealed, whereby the peripheral seal portion 150 is formed.

[0272] [Features of the energy storage device] According to the energy storage device 100 of Embodiment B3, since the packaging films 211 and 212 for the energy storage device have transparency, the same effects as those of the energy storage device 100 of Embodiment B1 can be obtained.

[0273] [Embodiment B3] The energy storage device 300 of Embodiment B3 is different from Embodiment B1 in that the configuration of the terminal seal portion 151A is different, and the other configurations are the same as those of Embodiment B1. Hereinafter, the energy storage device 300 of Embodiment B3 will be described centering on the parts different from Embodiment B1.

[0274] FIG. 19 is a cross-sectional view of the terminal seal portion 351A included in the energy storage device 300 of Embodiment B3. In the terminal seal portion 351A, a part of the flange portion 211A of the packaging film 211 for the energy storage device is joined to one tab film 140. A part of the flange portion 212A of the packaging film 212 for the energy storage device is joined to the other tab film 140.

[0275] The flange portion 221A of the outer packaging film 221 is joined to one tab film 140. The flange portion 222A of the outer packaging film 222 is joined to the other tab film 140. The end portion 221X of the flange portion 221A is located farther from the energy storage device element 120 than the end portion 211X of the packaging film 211 for the energy storage device. The end portion 222X of the flange portion 222A is located farther from the energy storage device element 120 than the end portion 212X of the packaging film 212 for the energy storage device. For this reason, the entire inner package 210 is covered by the outer package 220.

[0276] [Features of the energy storage device] According to the energy storage device 300, since the inner package 210 is covered by the outer package 220, the intrusion of moisture and the like from the outside into the internal space S1 of the inner package 210 is suppressed.

[0277] [Embodiment B4] The power storage device 400 of Embodiment B4 differs from Embodiment B1 in that the configuration of the terminal seal portion 151A is different, and other configurations are the same as those of Embodiment B1. Hereinafter, the power storage device 400 of Embodiment B4 will be described focusing on the parts different from Embodiment B1.

[0278] FIG. 20 is a cross-sectional view of the terminal seal portion 451A included in the power storage device 400 of Embodiment B4. The power storage device 400 does not have the tab film 140. In the terminal seal portion 451A of the power storage device 400, the exterior film 221, the packaging film 211 for the power storage device, the metal terminal 130, the packaging film 212 for the power storage device, and the exterior film 222 are laminated in order from above, and these are integrated.

[0279] The end portion 221X of the flange portion 221A is located closer to the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 221X of the flange portion 221A may be located at the same position as the end portion 211X of the packaging film 211 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device.

[0280] The flange portion 221A of the exterior film 221 is joined to the flange portion 211A of the packaging film 211 for the power storage device. The flange portion 222A of the exterior film 222 is joined to the flange portion 212A of the packaging film 212 for the power storage device. The end portion 222X of the flange portion 222A is located closer to the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 222X of the flange portion 222A may be located at the same position as the end portion 212X of the packaging film 212 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device.

[0281] [Features of the energy storage device] According to the energy storage device 400, since the packaging films 211 and 212 for the energy storage device and the metal terminals 130 are joined without passing through the tab film 140, the number of components is small. Also, the manufacturing method of the energy storage device 400 can be simplified.

[0282] [Embodiment B5] The energy storage device 500 of Embodiment B5 differs from Embodiment B4 in that the configuration of the terminal seal portion 451A is different, and the other configurations are the same as those of Embodiment B4. Hereinafter, the energy storage device 500 of Embodiment B5 will be described centering on the parts different from Embodiment B4.

[0283] FIG. 21 is a cross-sectional view of the terminal seal portion 551A provided in the energy storage device 500 of Embodiment B5. In the terminal seal portion 551A, a part of the flange portion 211A of the packaging film 211 for the energy storage device is joined to the metal terminal 130. A part of the flange portion 212A of the packaging film 212 for the energy storage device is joined to the metal terminal 130.

[0284] The flange portion 221A of the outer packaging film 221 is joined to the metal terminal 130. The flange portion 222A of the outer packaging film 222 is joined to the metal terminal 130. The end portion 221X of the flange portion 221A is located farther from the energy storage device element 120 than the end portion 211X of the packaging film 211 for the energy storage device. The end portion 222X of the flange portion 222A is located farther from the energy storage device element 120 than the end portion 212X of the packaging film 212 for the energy storage device. For this reason, the entire inner package 210 is covered by the outer package 220.

[0285] [Features of the energy storage device] According to the power storage device 500, since the inner packaging body 210 is covered by the outer packaging body 220, the intrusion of moisture and the like from the outside into the internal space S1 of the inner packaging body 210 is suppressed. Also, according to the power storage device 500, since the packaging films 211 and 212 for the power storage device and the metal terminals 130 are joined without going through the tab film 140, the number of components is small. Also, the manufacturing method of the power storage device 500 can be simplified.

[0286] [Modification Example] Each of the above-described Embodiment B is an example of a form that the power storage device and the manufacturing method of the power storage device according to the present disclosure can take, and is not intended to limit that form. The power storage device and the manufacturing method of the power storage device according to the present disclosure can take a form different from the forms illustrated in each embodiment. One example is a form in which a part of the configuration of each embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to each embodiment. Some examples of modification examples of each embodiment are shown below. Note that the following modification examples can be combined with each other as long as there is no technical contradiction.

[0287] In the power storage device 100 of Embodiment B1, one outer packaging body 220 may be configured to accommodate a plurality of inner packaging bodies 210 in a state where the power storage device elements 120 are accommodated. In this modification example, the sizes of the plurality of inner packaging bodies 210 may be different or the same. According to this modification example, since a plurality of power storage device elements 120 can be connected in series or in parallel, the voltage can be easily adjusted.

[0288] In the power storage device 100 of Embodiment B1, the packaging films 211 and 212 for the power storage device may not have gas permeability. The packaging films 211 and 212 for the power storage device only need to have at least transparency.

[0289] In the power storage device 100 of Embodiment B1, the inner packaging body 210 may be configured by folding a single power storage device packaging film 211 and heat-sealing the peripheral edge. Similarly, the outer packaging body 220 may be configured by folding a single exterior film 221 and heat-sealing the peripheral edge.

[0290] <Embodiment C> In a power storage device, in addition to the functions that the power storage device normally has, it is preferable to have functions with high added value.

[0291] The invention according to Embodiment C aims to provide a power storage device having functions with high added value.

[0292] The power storage device according to the first aspect of the invention according to Embodiment C includes a power storage device element, an inner packaging body that houses the power storage device element, an outer packaging body that houses the inner packaging body with the power storage device element housed therein, and a functional object disposed between the inner packaging body and the outer packaging body, and the functional object has shock absorbency.

[0293] The power storage device according to the second aspect of the invention according to Embodiment C includes a power storage device element, an inner packaging body that houses the power storage device element, an outer packaging body that houses the inner packaging body with the power storage device element housed therein, and a functional object disposed between the inner packaging body and the outer packaging body, and the functional object has flame retardancy.

[0294] The power storage device according to the third aspect of the invention according to Embodiment C includes a power storage device element, an inner packaging body that houses the power storage device element, an outer packaging body that houses the inner packaging body with the power storage device element housed therein, and a functional object disposed between the inner packaging body and the outer packaging body, and the functional object has coolability.

[0295] The power storage device according to the fourth aspect of the invention according to Embodiment C includes a power storage device element, an inner package that houses the power storage device element, an outer package that houses the inner package in a state where the power storage device element is housed, and a functional object disposed between the inner package and the outer package, and the functional object has fire extinguishing properties.

[0296] The power storage device according to the fifth aspect of the invention according to Embodiment C includes a power storage device element, an inner package that houses the power storage device element, and an outer package that houses the inner package in a state where the power storage device element is housed, and at least one of the inner package and the outer package has at least one of shock absorbency, flame retardancy, coolability, and fire extinguishing properties.

[0297] The power storage device according to the sixth aspect of the invention according to Embodiment C is a power storage device according to any one of the first to fifth aspects, and the inner package has at least one of transparency and gas permeability.

[0298] The power storage device according to the seventh aspect of the invention according to Embodiment C is a power storage device according to any one of the first to sixth aspects, and further includes a metal terminal electrically connected to the power storage device element and a tab film disposed between the inner package and the metal terminal, the outer package is joined to the inner package, the inner package and the metal terminal are joined via the tab film, and at least a part of the outer edge of the inner package is exposed from the outer package.

[0299] The power storage device according to the eighth aspect of the invention according to Embodiment C is a power storage device according to any one of the first to sixth aspects, and further includes a metal terminal electrically connected to the power storage device element and a tab film disposed between the inner package, the outer package, and the metal terminal, the inner package, the outer package, and the metal terminal are joined via the tab film, and the entire inner package is covered by the outer package.

[0300] The power storage device according to the ninth aspect of the invention according to Embodiment C is a power storage device according to any one of the first to sixth aspects, further comprising a metal terminal electrically connected to the power storage device element, wherein the inner package and the metal terminal are joined, and at least a part of the outer edge of the inner package is exposed from the outer package.

[0301] The power storage device according to the tenth aspect of the invention according to Embodiment C is a power storage device according to any one of the first to sixth aspects, further comprising a metal terminal electrically connected to the power storage device element, wherein the inner package, the outer package, and the metal terminal are joined, and the whole of the inner package is covered by the outer package.

[0302] [Embodiment C1] FIG. 8 shows a plan view of a power storage device 100 according to Embodiment C1 of the present invention. FIG. 22 is a cross-sectional view taken along line D2-D2 of FIG. 8. In FIG. 8, parts that are not normally visible from the outside are partially shown by dotted lines for reference. Hereinafter, for convenience of explanation, unless otherwise specified, the vertical direction in FIG. 8 is referred to as the "front-rear direction", the horizontal direction is referred to as the "left-right direction", and the vertical direction in FIG. 22 is referred to as the "up-down direction". However, the orientation of the power storage device 100 during use is not limited thereto. Also, in FIG. 8, for simplicity of the drawing, the relative positional relationship between the inner package 210 and the outer package 220 is simplified.

[0303] The power storage device 100 includes a container 110, a power storage device element 120, a pair of metal terminals 130, and a pair of tab films 140. The container 110 includes an internal space S1 and a peripheral seal portion 150. The power storage device element 120 is housed in the internal space S1 of the container 110. One end of the metal terminal 130 is joined to the power storage device element 120, and the other end protrudes outward from the peripheral seal portion 150 of the container 110. A part between one end and the other end of the metal terminal 130 is fused to the peripheral seal portion 150 via the tab film 140.

[0304] The container 110 includes a container body 110A. The container body 110A includes an inner package 210 and an outer package 220. The inner package 210 houses the power storage device element 120. The outer package 220 houses the inner package 210 in a state where the power storage device element 120 is housed therein. The internal space S1 is formed inside the inner package 210. The inner package 210 includes power storage device packaging films 211 and 212. The outer package 220 includes outer packaging films 221 and 222. At the outer peripheral portion of the container body 110A in plan view, the inner package 210 and the outer package 220 are heat-sealed and fused to each other, thereby forming a peripheral seal portion 150. And, the internal space S1 of the container body 110A blocked from the external space is formed in the inner package 210 by this peripheral seal portion 150. The peripheral seal portion 150 defines the periphery of the internal space S1 of the container body 110A. Here, the heat-sealing mode is assumed to include modes such as heat fusion from a heat source and ultrasonic fusion. In any case, the peripheral seal portion 150 means a portion where the inner package 210 and the outer package 220 are fused and integrated.

[0305] The peripheral seal portion 150 includes a top seal portion 151, a pair of side seal portions 152 and 153, and a bottom seal portion 154. The top seal portion 151 includes a portion (hereinafter referred to as "terminal seal portion 151A") that is sealed with the metal terminal 130 and the tab film 140 interposed therebetween and extends in the front-rear direction. The pair of side seal portions 152 and 153 extend in the left-right direction. The side seal portion 152 and the side seal portion 153 face each other with the internal space S1 therebetween. The bottom seal portion 154 faces the top seal portion 151 with the internal space S1 therebetween. The bottom seal portion 154 extends in the front-rear direction.

[0306] As shown in FIG. 22, the terminal seal portion 151A of the top seal portion 151 is laminated, in order from the top, with an exterior film 221, a power storage device packaging film 211, one tab film 140, a metal terminal 130, the other tab film 140, a power storage device packaging film 212, and an exterior film 222, and these are integrated. Therefore, the top seal portion 151 can be easily formed. Note that, for the portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, the portion where only the pair of tab films 140 are sandwiched by the inner package 210 and the outer package 220, is laminated, in order from the top, with an exterior film 221, a power storage device packaging film 211, one tab film 140, the other tab film 140, a power storage device packaging film 212, and an exterior film 222, and these are integrated. Further, the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion in FIG. 22 with the step as the boundary) is laminated, in order from the top, with a power storage device packaging film 211, one tab film 140, a metal terminal 130, the other tab film 140, and a power storage device packaging film 212, and these are integrated. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the exterior films 221 and 222 do not exist and the inner portion of the terminal seal portion 151A where the exterior films 221 and 222 exist (the right portion in FIG. 22 with the step as the boundary). However, FIG. 8 is an overview description of the region of the peripheral seal portion 150, and the boundary step is not shown.

[0307] The power storage device packaging films 211 and 212 constituting the inner package 210 preferably have transparency as a whole from the viewpoint of suitably manufacturing the power storage device 100. The power storage device packaging films 211 and 212 preferably have gas permeability from the viewpoint of easily manufacturing the power storage device 100. Hereinafter, preferred examples of the power storage device packaging films 211 and 212 constituting the inner package 210 will be described. Note that, hereinafter, when the power storage device packaging films 211 and 212 are not particularly distinguished, the power storage device packaging films 211 and 212 may be collectively referred to as the power storage device packaging film 10.

[0308] The shape of the inner package 210 is not particularly limited, and for example, it can be in a bag shape (pouch shape). The bag shape mentioned here includes a three-side seal type, a four-side seal type, a pillow type, a gusset type, etc. The inner package 210 of the present Embodiment C1 has a shape as shown in FIG. 22, and is manufactured by heat-sealing a packaging film 212 for a power storage device formed in a tray shape and a packaging film 211 for a power storage device also formed in a tray shape and overlapped from above the packaging film 212 for a power storage device along the outer peripheral portion in a plan view. The packaging film 212 for a power storage device includes an angular annular flange portion 212A corresponding to the outer peripheral portion in a plan view and a molded portion 212B continuous with the inner edge of the flange portion 212A and bulging downward therefrom. Similarly, the packaging film 211 for a power storage device includes an angular annular flange portion 211A corresponding to the outer peripheral portion in a plan view and 211B continuous with the inner edge of the flange portion 211A and bulging upward therefrom. The packaging films 211 and 212 for a power storage device are overlapped so that the respective molded portions 211B and 212B bulge in opposite directions. In this state, the flange portion 211A of the packaging film 211 for a power storage device and the flange portion 212A of the packaging film 212 for a power storage device are heat-sealed so as to be integrated, and constitute a part of the peripheral seal portion 150. Note that one of the packaging films 211 and 212 for a power storage device may be in a sheet shape.

[0309] The exterior films 221 and 222 that constitute the outer package 220 are composed of, for example, resin molded products or films. The resin molded products referred to here can be manufactured by methods such as injection molding, pressure air molding, vacuum molding, blow molding, etc., and in-mold molding may be performed to impart designability and functionality. The types of resin can be polyolefin, polyester, nylon, ABS, etc. Also, the film referred to here is, for example, a resin film that can be manufactured by methods such as the inflation method or the T-die method, or a laminate of such a resin film and a metal foil or metal plate. Further, the film referred to here may or may not be stretched, and may be a single-layer film or a multi-layer film. Also, the multi-layer film referred to here may be manufactured by a coating method, may be a laminate of multiple films adhered by an adhesive or the like, or may be manufactured by a multi-layer extrusion method.

[0310] The exterior films 221 and 222 can be configured in various ways, but in the present Embodiment C1, they are composed of a laminate film. The laminate film can be a laminate of a base material layer, a barrier layer, and a heat-sealable resin layer. The base material layer functions as the base material of the exterior films 221 and 222, typically forms the outer layer side of the outer package 220, and is a resin layer having insulating properties. The barrier layer has a function of preventing at least moisture and the like from entering the power storage device 100 in addition to improving the strength of the exterior films 221 and 222, and is typically a metal layer made of an aluminum alloy foil or the like. The heat-sealable resin layer is typically made of a heat-sealable resin such as polyolefin and forms the innermost layer of the outer package 220.

[0311] The shape of the outer package 220 is not particularly limited, and for example, it can be in a bag shape (pouch shape). The bag shape mentioned here can include a three-side seal type, a four-side seal type, a pillow type, a gusset type, etc. The container 110A of the present Embodiment C1 has a shape as shown in FIG. 22, and is manufactured by heat-sealing an exterior film 222 formed in a tray shape and an exterior film 221 also formed in a tray shape and stacked on top of the exterior film 222 along the outer peripheral portion in a plan view. The exterior film 222 includes an angular annular flange portion 222A corresponding to the outer peripheral portion in a plan view, and a molded portion 222B continuous with the inner edge of the flange portion 222A and bulging downward therefrom. Similarly, the exterior film 221 includes an angular annular flange portion 221A corresponding to the outer peripheral portion in a plan view, and a portion 221B continuous with the inner edge of the flange portion 221A and bulging upward therefrom. The exterior films 221 and 222 are stacked so that the respective molded portions 221B and 222B bulge in opposite directions. In this state, the flange portion 221A of the exterior film 221 and the flange portion 222A of the exterior film 222 are heat-sealed so as to be integrated, and constitute a part of the peripheral seal portion 150. Note that one of the exterior films 221 and 222 may be in a sheet shape.

[0312] As shown in FIG. 22, in the terminal seal portion 151A, a part of the flange portion 211A of the power storage device packaging film 211 is joined to one tab film 140. A part of the flange portion 212A of the power storage device packaging film 212 is joined to the other tab film 140.

[0313] The flange portion 221A of the outer packaging film 221 is joined to the flange portion 211A of the packaging film 211 for the power storage device. The end portion 221X of the flange portion 221A is located closer to the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 221X of the flange portion 221A may be located at the same position as the end portion 211X of the packaging film 211 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device.

[0314] The flange portion 222A of the outer packaging film 222 is joined to the flange portion 212A of the packaging film 212 for the power storage device. The end portion 222X of the flange portion 222A is located closer to the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 222X of the flange portion 222A may be located at the same position as the end portion 212X of the packaging film 212 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device.

[0315] The power storage device element 120 includes at least a positive electrode, a negative electrode, and an electrolyte, and is a power storage member such as a lithium ion battery (secondary battery) or a capacitor, for example.

[0316] The metal terminal 130 is a metal terminal used for power input and output of the power storage device element 120. The metal terminal 130 is disposed, for example, on the top seal portion 151 of the container 110A, with one constituting the positive terminal and the other constituting the negative terminal. One end of each metal terminal 130 in the left-right direction is electrically connected to the electrode (positive or negative electrode) of the power storage device element 120 in the internal space S1 of the container 110A, and the other end protrudes outward from the peripheral seal portion 150. The above-described form of the power storage device 100 is particularly preferable for use in electric vehicles such as electric cars and hybrid cars that use a large number of power storage devices 100 connected in series for use at high voltages. Note that the attachment positions of the two metal terminals 130 constituting the positive and negative terminals are not particularly limited, and may be disposed, for example, on the side seal portions 152, 153, or the bottom seal portion 154 of the peripheral seal portion 150.

[0317] The metal material constituting the metal terminal 130 is, for example, aluminum, nickel, copper, or the like. When the power storage device element 120 is a lithium ion battery, the metal terminal 130 connected to the positive electrode is typically constituted by aluminum or the like, and the metal terminal 130 connected to the negative electrode is typically constituted by copper, nickel, or the like.

[0318] The tab film 140 is a so-called adhesive film and is configured to adhere to both the power storage device packaging films 211 and 212 and the metal terminal 130. By means of the tab film 140, even if the metal terminal 130 and the innermost layer (heat-sealable resin layer) of the power storage device packaging films 211 and 212 are made of different materials, the two can be fixed. Note that the tab film 140 is integrated by being pre-fused and fixed to the metal terminal 130, and the power storage device packaging films 211 and 212 are fused to the metal terminal 130 to which the tab film 140 is fixed.

[0319] The power storage device 100 according to Embodiment C1 includes a functional object 230 so as to have functions with high added value in addition to the functions of a general power storage device. The functional object 230 has at least one function of shock absorbency, flame retardancy, coolability, and fire extinguishability. The functional object 230 is disposed between the inner package 210 and the outer package 220. The specific form of the functional object 230 can be arbitrarily selected. The functional object 230 may be in the form of a sheet such as a film, may be a liquid that can be applied to the film, or may be granular or liquid having a predetermined fluidity (viscosity).

[0320] When the functional object 230 is in the form of a sheet such as a film, the functional object 230 is wound around the inner package 210 and joined to the inner package 210, for example. The functional object 230 may be joined to the inner package 210 so as to cover at least a part of the surface of the inner package 210, but it is preferably joined to the inner package 210 so as to cover substantially the entire surface of the inner package 210.

[0321] When the functional object 230 is a liquid that can be applied to a film or the like, the functional object 230 is applied to the surface of the inner package 210 or the inner surface of the outer package 220. The functional object 230 may be applied to at least a part of the surface of the inner package 210, but it is preferably applied to substantially the entire surface of the inner package 210. Note that the liquid that can be applied to a film or the like for the functional object 230 includes a state in which it can be sprayed onto the inner package 210 and the outer package 220 by a spray or the like.

[0322] When the functional object 230 is granular or liquid having a predetermined fluidity (viscosity), the functional object 230 is filled in the space between the inner package 210 and the outer package 220. The functional object 230 may be filled in at least a part of the space between the inner package 210 and the outer package 220, but it is preferably filled in substantially the entire space between the inner package 210 and the outer package 220.

[0323] The functional object 230 having impact absorbency is, for example, an uncrosslinked highly foamed polyethylene sheet, an electron beam crosslinked highly foamed polyethylene sheet, a heat-sealed composite highly foamed polyethylene sheet, or nitrile rubber.

[0324] The functional object 230 having flame retardancy is, for example, a flame retardant polycarbonate film or a flame retardant polyethylene terephthalate.

[0325] The functional object 230 having coolability is, for example, a high thermal conductivity film, a high thermal conductivity adhesive sheet, or an ultra-high thermal conductivity graphite sheet.

[0326] The functional object 230 having fire extinguishing properties is, for example, a fire extinguishing agent or a film containing a fire extinguishing agent (hereinafter referred to as a "fireproof film"). The fire extinguishing agent is, for example, a general powder-based fire extinguishing agent such as a potassium salt, sodium bicarbonate, or phosphate, an ABC fire extinguishing agent, a BC fire extinguishing agent, or sand. When a fire extinguishing agent is used as the functional object 230, a fire extinguishing agent not containing water is preferable from the viewpoint of suppressing a decrease in the function of the power storage device 100.

[0327] As the fireproof film, a known fireproof film can be used. The fireproof film is, for example, a laminated film including a base material (base material layer) and a fire extinguishing agent-containing layer in this order. The fire extinguishing agent-containing layer may be provided on at least a part of one surface of the base material, but is preferably provided on the entire surface of the base material. The base material has a region for supporting a fire extinguishing agent component and a binder resin inside the base material and on the side of the fire extinguishing agent-containing layer.

[0328] The fireproof film can be used such that the fire extinguishing agent-containing layer faces an object that may catch fire. In the present Embodiment C1, the fireproof film is joined to the inner surface of the outer package 220 such that the fire extinguishing agent-containing layer faces the surface of the inner package 210. For example, when the power storage device element 120 catches fire, initial fire extinguishing is performed by an aerosol generated from the fire extinguishing agent-containing layer.

[0329] The base material has voids and, for example, has a non-woven fabric formed by entangling non-combustible or flame-retardant fibers, or has a woven fabric shape formed by knitting non-combustible or flame-retardant fibers. Examples of non-combustible or flame-retardant fibers include glass fibers, ceramic fibers, metal fibers, cellulose fibers, polyester fibers, carbon fibers, graphite fibers, thermosetting resin fibers, and the like. From the viewpoint of excellent non-combustibility, glass fibers and ceramic fibers can be used. Examples of the base material include glass cloth and non-combustible paper. As the base material, a non-combustible base material corresponding to Class 1 fire prevention specified in JIS Z 2150-1966 can also be used.

[0330] The loading region in the base material is formed when a part of the coating liquid penetrates into the base material when forming a coating film on the surface of the base material using a coating liquid containing a fire extinguishing agent component and a binder resin. It can be said that the base material includes a loading region of the fire extinguishing agent component and the binder resin and a non-loading region thereof.

[0331] The fire extinguishing agent-containing layer is a layer containing a fire extinguishing agent component and a binder resin. The fire extinguishing agent component generates an aerosol by combustion. The fire extinguishing agent component includes, for example, at least an inorganic oxidizing agent and a radical generator. The radical generator has an action (negative catalytic action) of stabilizing combustion radicals and suppressing the chain reaction of combustion.

[0332] [Method for manufacturing a power storage device] FIG. 23 is a flowchart showing an example of a method for manufacturing a power storage device 100. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0333] In the inner packaging process of step S11, as shown in FIG. 24, the power storage device element 120 is wrapped by the formed packaging films 211 and 212 for the power storage device. In the power storage device 100 of the present embodiment C1, since the packaging films 211 and 212 for the power storage device have gas permeability, it is not necessary to form a sub-chamber for temporarily storing the gas generated from the power storage device element 120 in the first filling process and the like described later. Therefore, in the inner packaging process, the power storage device element 120 is wrapped by the packaging films 211 and 212 for the power storage device that are substantially the same size as the packaging films 211 and 212 included in the inner package 210 of the completed power storage device 100. Therefore, the manufacturing process of the power storage device 100 can be simplified. Also, the materials used for the power storage device 100 can be reduced. Substantially the same size includes the case where it is larger than the packaging films 211 and 212 for the power storage device included in the inner package 210 of the completed power storage device 100 to such an extent that a sub-chamber cannot be formed. Note that a metal terminal 130 is connected to the power storage device element 120 in advance, and a tab film 140 is joined to the metal terminal 130.

[0334] The first inner sealing process of step S12 is performed after the inner packaging process. In the first inner sealing process, as shown in FIG. 12, the portions corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 among the peripheries of the packaging films 211 and 212 for the power storage device are sealed. By completing the first inner sealing process, an opening 213 is formed in a portion where a side seal portion 153 is to be formed among the peripheries of the packaging films 211 and 212 for the power storage device. After the first inner sealing process, the vacuum drying process of step S13 is performed.

[0335] The electrolyte injection process of step S14 is performed after the vacuum drying process. In the electrolyte injection process, the electrolyte is injected through the opening 213 (see FIG. 12).

[0336] The second inner sealing process in step S15 is carried out after the electrolyte injection process. As shown in FIG. 23, in the second inner sealing process, the opening 213 is closed by sealing a portion of the peripheral edges of the power storage device packaging films 211 and 212 where the side seal portion 153 is to be formed. According to the power storage device 100, since the power storage device packaging films 211 and 212 have transparency, after the first inner sealing process or the second inner sealing process is completed, it is possible to easily confirm whether the power storage device packaging film 211 and the power storage device packaging film 212 are properly sealed. Therefore, the power storage device 100 can be preferably manufactured. Note that the state where the power storage device packaging film 211 and the power storage device packaging film 212 are not properly sealed includes, for example, the first state, the second state, or the third state. The first state is a state where the power storage device packaging film 211 and the power storage device packaging film 212 are sealed in a state of biting foreign matter. The second state is a state where a part of the portion to be sealed is not sealed. The third state is a state where a portion that should not be sealed is sealed. After the second inner sealing process, the first charge and discharge process in step S16 and the aging process in step S17 are sequentially carried out.

[0337] The degassing process in step S18 is carried out in parallel with the first charge and discharge process and the aging process. In the present embodiment C1, since the power storage device packaging films 211 and 212 have gas permeability, when the first charge and discharge process and the aging process are carried out, gases such as carbon dioxide generated from the power storage device element 120 are discharged to the outside through the power storage device packaging films 211 and 212. After the degassing process, the main charging process in step S19 is carried out.

[0338] The placement step S20 is carried out after this filling step. In the placement step, according to the specific form of the functional object 230, the functional object 230 is placed between the inner package 210 and the outer package 230. When the functional object 230 is in the form of a sheet such as a film, the functional object 230 is, for example, wound around the inner package 210 and joined to the inner package 210. When the functional object 230 is a liquid that can be applied to a film or the like, the functional object 230 is applied to the surface of the inner package 210 or the inner surface of the outer package 220.

[0339] The outer packaging step S21 is carried out after the placement step. In the outer packaging step, the inner package 210 in a state in which the power storage device element 120 is accommodated is wrapped by the outer packaging films 221 and 222.

[0340] The outer sealing step S22 is carried out after the outer packaging step. In the outer sealing step, the peripheral edges of the outer packaging films 221 and 222 are sealed to form the peripheral seal portion 150. When the functional object 230 is granular or liquid having a predetermined fluidity (viscosity), in the placement step, for example, in the outer sealing step, after the top seal portion 151, the side seal portions 152 and 153 of the peripheral seal portion 150 are formed, it may be filled from the opening of the portion where the bottom seal portion 154 is formed.

[0341] [Features of the Power Storage Device] According to the power storage device 100, since it includes the functional object 230, the added value is high.

[0342] [Embodiment C2] The power storage device 100 of Embodiment C2 is different from Embodiment C1 in that the power storage device packaging films 211 and 212 do not have gas permeability, or in that it does not have gas permeability to the extent of performing the gas venting step S18 described above as compared with Embodiment C1, and other configurations are the same as those of Embodiment C1. Hereinafter, the power storage device 100 of Embodiment C2 will be described centering on the parts different from Embodiment C2.

[0343] [Method for manufacturing a power storage device] FIG. 24 is a flowchart showing an example of a method for manufacturing the power storage device 100 of Embodiment C2. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0344] In the inner packaging step of Step S31, as shown in FIG. 15, the power storage device element 120 is wrapped with the formed power storage device packaging films 211 and 212. In the power storage device 100 of Embodiment C2, since the power storage device packaging films 211 and 212 do not have gas permeability, it is preferable to form a sub-chamber 214 for temporarily storing the gas generated from the power storage device element 120 in the first filling step or the like. For this reason, in the inner packaging step, the power storage device element 120 is wrapped with the power storage device packaging films 211 and 212 that are larger than the power storage device packaging films 211 and 212 provided in the inner package 210 of the completed power storage device 100. An accommodation chamber 215 for storing more gas generated from the power storage device element 120 is formed in the sub-chamber 214 of the power storage device packaging films 211 and 212.

[0345] The first inner sealing step of Step S32 is performed after the inner packaging step. In the first inner sealing step, as shown in FIG. 16, the portions corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 among the peripheries of the power storage device packaging films 211 and 212 are sealed so as to extend to the sub-chamber 214. By completing the first inner sealing step, an opening 213 is formed in the portion 216 that faces the portion where the side seal portion 153 of the periphery of the power storage device packaging films 211 and 212 is to be formed via the sub-chamber 214. After the first inner sealing step, the vacuum drying step of Step S33 is performed.

[0346] The electrolyte injection step of Step S34 is performed after the vacuum drying step. In the electrolyte injection step, the electrolyte is injected through the opening 213 (see FIG. 16).

[0347] The second inner sealing process in step S35 is carried out after the electrolytic solution injection process. As shown in FIG. 17, in the second inner sealing process, the portion 216 that faces the portion where the side seal portion 153 is to be formed among the peripheries of the power storage device packaging films 211 and 212 through the sub chamber 214 is sealed, whereby the opening 213 is closed. After the second inner sealing process, the initial charge and discharge process in step S36 and the aging process in step S37 are carried out in sequence.

[0348] The gas venting process in step S38 is carried out after the aging process. In the gas venting process, gases such as carbon dioxide generated from the power storage device element 120 are temporarily stored in the sub chamber 214 of the power storage device packaging films 211 and 212.

[0349] The sub chamber removal process in step S39 is carried out after the gas venting process. In the sub chamber removal process, the sub chamber 214 is removed by cutting the power storage device packaging films 211 and 212 along the dashed-dotted line XA shown in FIG. 17 so as to have the same size as the inner package 210 included in the completed power storage device 100.

[0350] The inner sealing process in step S40 is carried out after the sub chamber removal process. In the inner sealing process, as shown in FIG. 18, the portion corresponding to the side seal portion 153 among the peripheries of the power storage device packaging films 211 and 212 is sealed. After the inner sealing process, the main charging process in step S41 is carried out.

[0351] The placement process in step S42 is carried out after the main filling process. In the placement process, according to the specific form of the functional object 230, the functional object 230 is placed between the inner package 210 and the outer package 230. When the functional object 230 is in the form of a sheet such as a film, the functional object 230 is, for example, wound around the inner package 210 and joined to the inner package 210. When the functional object 230 is a liquid that can be applied to a film or the like, the functional object 230 is applied to the surface of the inner package 210 or the inner surface of the outer package 220.

[0352] The outer packaging process in step S43 is carried out after the placement process. In the outer packaging process, the inner package 210 in a state where the power storage device element 120 is accommodated is wrapped by the outer packaging films 221 and 222.

[0353] The outer sealing process in step S44 is carried out after the outer packaging process. In the outer sealing process, the peripheral edges of the outer packaging films 221 and 222 are sealed, thereby forming the peripheral seal portion 150. When the functional object 230 is granular or liquid with a predetermined fluidity (viscosity), in the placement process, in the outer sealing process, for example, after the top seal portion 151, side seal portions 152 and 153 of the peripheral seal portion 150 are formed, it may be filled from the opening of the portion where the bottom seal portion 154 is formed.

[0354] [Features of the Power Storage Device] According to the power storage device 100 of Embodiment C3, since it includes the functional object 230, the same effects as those of the power storage device 100 of Embodiment C1 can be obtained.

[0355] [Embodiment C3] The power storage device 300 of Embodiment C3 is different from Embodiment C1 in that the configuration of the terminal seal portion 151A is different, and other configurations are the same as those of Embodiment C1. Hereinafter, the power storage device 300 of Embodiment C3 will be described centering on the parts different from Embodiment C1.

[0356] FIG. 25 is a cross-sectional view of the terminal seal portion 351A included in the power storage device 300 of Embodiment C3. In the terminal seal portion 351A, a part of the flange portion 211A of the power storage device packaging film 211 is joined to one tab film 140. A part of the flange portion 212A of the power storage device packaging film 212 is joined to the other tab film 140.

[0357] The flange portion 221A of the outer film 221 is joined to one tab film 140. The flange portion 222A of the outer film 222 is joined to the other tab film 140. The end portion 221X of the flange portion 221A is located farther from the power storage device element 120 than the end portion 211X of the power storage device packaging film 211. The end portion 222X of the flange portion 222A is located farther from the power storage device element 120 than the end portion 212X of the power storage device packaging film 212. For this reason, the entire inner package 210 is covered by the outer package 220.

[0358] [Features of the power storage device] According to the power storage device 300, since the inner package 210 is covered by the outer package 220, the intrusion of moisture and the like from the outside into the internal space S1 of the inner package 210 is suppressed.

[0359] [Embodiment C4] The power storage device 400 of Embodiment C4 is different from Embodiment C in that the configuration of the terminal seal portion 151A is different, and the other configurations are the same as those of Embodiment C1. Hereinafter, the power storage device 400 of Embodiment C4 will be described centering on the parts different from Embodiment C1.

[0360] FIG. 26 is a cross-sectional view of the terminal seal portion 451A included in the power storage device 400 of Embodiment C4. The power storage device 400 does not have the tab film 140. In the terminal seal portion 451A of the power storage device 400, the outer film 221, the power storage device packaging film 211, the metal terminal 130, the power storage device packaging film 212, and the outer film 222 are laminated in order from above, and these are integrated.

[0361] The end portion 221X of the flange portion 221A is located closer to the power storage device element 120 than the end portion 211X of the power storage device packaging film 211. Therefore, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 221X of the flange portion 221A may be located at the same position as the end portion 211X of the power storage device packaging film 211 in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 211X of the power storage device packaging film 211.

[0362] The flange portion 221A of the outer packaging film 221 is joined to the flange portion 211A of the power storage device packaging film 211. The flange portion 222A of the outer packaging film 222 is joined to the flange portion 212A of the power storage device packaging film 212. The end portion 222X of the flange portion 222A is located closer to the power storage device element 120 than the end portion 212X of the power storage device packaging film 212. Therefore, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 222X of the flange portion 222A may be located at the same position as the end portion 212X of the power storage device packaging film 212 in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 212X of the power storage device packaging film 212.

[0363] [Features of the power storage device] According to the power storage device 400, since the power storage device packaging films 211 and 212 and the metal terminals 130 are joined without passing through the tab film 140, the number of components is small. In addition, the manufacturing method of the power storage device 400 can be simplified.

[0364] [Embodiment C5] The power storage device 500 of Embodiment C5 is different from Embodiment C4 in that the configuration of the terminal seal portion 451A is different, and the other configurations are the same as those of Embodiment C4. Hereinafter, the power storage device 500 of Embodiment C5 will be described centering on the portions different from Embodiment C4.

[0365] FIG. 27 is a cross-sectional view of a terminal seal portion 551A included in the power storage device 500 according to Embodiment C5. In the terminal seal portion 551A, a part of the flange portion 211A of the power storage device packaging film 211 is joined to the metal terminal 130. A part of the flange portion 212A of the power storage device packaging film 212 is joined to the metal terminal 130.

[0366] The flange portion 221A of the outer packaging film 221 is joined to the metal terminal 130. The flange portion 222A of the outer packaging film 222 is joined to the metal terminal 130. The end portion 221X of the flange portion 221A is located farther from the power storage device element 120 than the end portion 211X of the power storage device packaging film 211. The end portion 222X of the flange portion 222A is located farther from the power storage device element 120 than the end portion 212X of the power storage device packaging film 212. For this reason, the entire inner package 210 is covered by the outer package 220.

[0367] [Features of the power storage device] According to the power storage device 500, since the inner package 210 is covered by the outer package 220, entry of moisture and the like from the outside into the internal space S1 of the inner package 210 is suppressed. Further, according to the power storage device 500, since the power storage device packaging films 211 and 212 and the metal terminal 130 are joined without passing through the tab film 140, the number of components is small. Also, the manufacturing method of the power storage device 500 can be simplified.

[0368] [Modification example] Each of the above-described Embodiments C is an example of a form that the power storage device and the manufacturing method of the power storage device according to the present disclosure can take, and is not intended to limit the form. The power storage device and the manufacturing method of the power storage device according to the present disclosure can take a form different from the forms illustrated in the respective embodiments. An example thereof is a form in which a part of the configuration of each embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to each embodiment. Some examples of modification examples of each embodiment are shown below. Note that the following modification examples can be combined with each other as long as there is no technical contradiction.

[0369] In the power storage device 100 of Embodiment C1, the functional object 230 may be contained in at least one of the power storage device packaging films 211 and 212 or the exterior films 221 and 222. That is, the power storage device 100 of this modification is configured such that at least one of the inner packaging body 210 and the outer packaging body 220 has at least one of shock absorbency, flame retardancy, coolability, and fire extinguishability.

[0370] In the power storage device 100 of Embodiment C1, one outer packaging body 220 may be configured to accommodate a plurality of inner packaging bodies 210 in a state where the power storage device elements 120 are accommodated. In this modification, the sizes of the plurality of inner packaging bodies 210 may be different or the same. According to this modification, since a plurality of power storage device elements 120 can be connected in series or in parallel, the voltage can be easily adjusted.

[0371] In the power storage device 100 of Embodiment C1, the power storage device packaging films 211 and 212 do not necessarily have transparency and gas permeability.

[0372] In the power storage device 100 of Embodiment C1, the inner packaging body 210 may be configured by folding one power storage device packaging film 211 and heat-sealing the peripheral edge. Similarly, the outer packaging body 220 may be configured by folding one exterior film 221 and heat-sealing the peripheral edge.

[0373] <Third Aspect> [Embodiment 1] FIG. 8 shows a plan view of the power storage device 100 according to Embodiment 1. FIG. 9 is a cross-sectional view taken along line D2-D2 of FIG. 8. In FIG. 8, parts that are not originally visible from the outside are partially shown by dotted lines for reference. Hereinafter, for the convenience of explanation, unless otherwise specified, the vertical direction in FIG. 8 is referred to as the "front-rear direction", the left-right direction is referred to as the "left-right direction", and the vertical direction in FIG. 9 is referred to as the "up-down direction". However, the orientation of the power storage device 100 during use is not limited to this. Also, in FIG. 8, for the sake of simplifying the drawing, the relative positional relationship between the inner package 210 and the outer package 220 is simplified.

[0374] The power storage device 100 includes a container 110, a power storage device element 120, a pair of metal terminals 130, and a pair of tab films 140. The container 110 includes an internal space S1 and a peripheral seal portion 150. The power storage device element 120 is housed in the internal space S1 of the container 110. One end of the metal terminal 130 is joined to the power storage device element 120, and the other end protrudes outward from the peripheral seal portion 150 of the container 110. A part between one end and the other end of the metal terminal 130 is fused to the peripheral seal portion 150 via the tab film 140.

[0375] The container 110 includes a vessel 110A. The vessel 110A includes an inner package 210 and an outer package 220. The inner package 210 houses the power storage device element 120. The outer package 220 houses the inner package 210 in which the power storage device element 120 is housed. The internal space S1 is formed inside the inner package 210. The inner package 210 includes power storage device packaging films 211 and 212. The outer package 220 includes outer packaging films 221 and 222. At the outer peripheral portion of the vessel 110A in plan view, the inner package 210 and the outer package 220 are heat-sealed and fused to each other, thereby forming a peripheral seal portion 150. And, the internal space S1 of the vessel 110A blocked from the external space is formed in the inner package 210 by this peripheral seal portion 150. The peripheral seal portion 150 defines the periphery of the internal space S1 of the vessel 110A. Here, the heat-sealing mode is assumed to include modes such as heat fusion from a heat source and ultrasonic fusion. In any case, the peripheral seal portion 150 means a portion where the inner package 210 and the outer package 220 are fused and integrated.

[0376] The peripheral seal portion 150 includes a top seal portion 151, a pair of side seal portions 152 and 153, and a bottom seal portion 154. The top seal portion 151 includes a portion (hereinafter referred to as "terminal seal portion 151A") that is sealed with the metal terminal 130 and the tab film 140 interposed therebetween and extends in the front-rear direction. The pair of side seal portions 152 and 153 extend in the left-right direction. The side seal portion 152 and the side seal portion 153 face each other through the internal space S1. The bottom seal portion 154 faces the top seal portion 151 through the internal space S1. The bottom seal portion 154 extends in the front-rear direction.

[0377] As shown in FIG. 9, the terminal seal portion 151A of the top seal portion 151 is laminated, in order from the top, with an outer packaging film 221, a power storage device packaging film 211, one tab film 140, a metal terminal 130, the other tab film 140, a power storage device packaging film 212, and an outer packaging film 222, and these are integrated. Therefore, the top seal portion 151 can be easily formed. Note that, for the portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, the portion where only the pair of tab films 140 are sandwiched by the inner packaging body 210 and the outer packaging body 220, the outer packaging film 221, the power storage device packaging film 211, one tab film 140, the other tab film 140, the power storage device packaging film 212, and the outer packaging film 222 are laminated in order from the top, and these are integrated. Further, for the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion in FIG. 9 with the step as the boundary), the power storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, and the power storage device packaging film 212 are laminated in order from the top, and these are integrated. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the outer packaging films 221 and 222 do not exist and the inner portion of the terminal seal portion 151A where the outer packaging films 221 and 222 exist (the right portion in FIG. 9 with the step as the boundary). However, FIG. 8 is an overview description of the region of the peripheral seal portion 150, and the boundary step is not shown.

[0378] The power storage device packaging films 211 and 212 that constitute the inner packaging body 210 are, as a whole, transparent from the viewpoint of preferably manufacturing the power storage device 100. Hereinafter, preferred examples of the power storage device packaging films 211 and 212 that constitute the inner packaging body 210 will be described. Note that, hereinafter, when the power storage device packaging films 211 and 212 are not particularly distinguished, the power storage device packaging films 211 and 212 may be collectively referred to as the power storage device packaging film 10.

[0379] [Laminated Structure and Physical Properties of Power Storage Device Packaging Film of the Third Aspect] The packaging film 10 for a power storage device according to the third aspect includes at least a heat-sealable resin layer 1, as shown in FIGS. 1 to 4, for example. When assembling a power storage device using the packaging film 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 in a state where the heat-sealable resin layers 1 of the packaging film 10 for a power storage device face each other.

[0380] The packaging film 10 for a power storage device according to the third aspect may be composed only of the heat-sealable resin layer 1, as shown in FIG. 1. When the packaging film 10 for a power storage device is composed only of the heat-sealable resin layer 1, it is preferable that at least one surface of the heat-sealable resin layer 1 has adhesiveness to metal.

[0381] Also, the packaging film 10 for a power storage device according to the third aspect is preferably composed of a laminate including at least a resin layer 2 and a heat-sealable resin layer 1, as shown in FIGS. 2 to 4. In such a packaging film 10 for a power storage device, the resin layer 2 is on the outside and the heat-sealable resin layer 1 is on the inside (innermost layer). When the packaging film 10 for a power storage device is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, it is preferable to impart adhesiveness to metal for at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1, and it is more preferable to impart adhesiveness to metal for the inner surface of the heat-sealable resin layer 1 facing the metal terminal 130.

[0382] Furthermore, as shown in FIGS. 3 to 4, the packaging film 10 for a power storage device according to the third aspect is preferably composed of a laminate including at least a resin layer 2, a base material 3, and the heat-sealable resin layer 1. In such a packaging film 10 for a power storage device, the resin layer 2 is on the outside, the heat-sealable resin layer 1 is on the inside (innermost layer), and the base material 3 is located between the resin layer 2 and the heat-sealable resin layer 1. Even when the packaging film 10 for a power storage device is composed of a laminate including a resin layer 2, a base material 3, and a heat-sealable resin layer 1, it is preferable to impart adhesiveness to at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1, and it is more preferable to impart adhesiveness to the inner surface of the heat-sealable resin layer 1 facing the metal terminal 130.

[0383] As shown in FIG. 2, an adhesive layer 4 can be provided between the resin layer 2 and the heat-sealable resin layer 1, and as shown in FIG. 4, an adhesive layer 5 can be provided between the heat-sealable resin layer 1 and the base material 3.

[0384] The packaging film 10 for a power storage device according to the third aspect has a CO 2 transmission amount at an environment temperature of 30°C of 100 cc·100 μm / m 2 / 24 hr / atm or more, more preferably about 200 cc·100 μm / m 2 / 24 hr / atm or more, even more preferably about 300 cc·100 μm / m 2 / 24 hr / atm or more, even more preferably about 500 cc·100 μm / m 2 / 24 hr / atm or more. Also, the CO 2 transmission amount of the packaging film 10 for a power storage device according to the third aspect is, for example, about 2000 cc·100 μm / m 2 / 24 hr / atm or less, preferably about 1000 cc·100 μm / m 2 / 24 hr / atm or less, more preferably about 800 cc·100 μm / m 2 / 24 hr / atm or less, and the preferable range is about 100 to 2000 cc·100 μm / m 2 / 24 hr / atm, about 100 to 1000 cc·100 μm / m2 Approximately / 24hr / atm, 100 - 800 cc·100μm / m 2 Approximately / 24hr / atm, 200 - 2000 cc·100μm / m 2 Approximately / 24hr / atm, 200 - 1000 cc·100μm / m 2 Approximately / 24hr / atm, 200 - 800 cc·100μm / m 2 Approximately / 24hr / atm, 300 - 2000 cc·100μm / m 2 Approximately / 24hr / atm, 300 - 1000 cc·100μm / m 2 Approximately / 24hr / atm, 300 - 800 cc·100μm / m 2 Approximately / 24hr / atm, 500 - 2000 cc·100μm / m 2 Approximately / 24hr / atm, 500 - 1000 cc·100μm / m 2 Approximately / 24hr / atm, 500 - 800 cc·100μm / m 2 Approximately / 24hr / atm can be mentioned. The CO 2 permeation amount measurement method of the packaging film for the power storage device is as follows.

[0385] [Measurement of CO 2 permeation amount] In accordance with JIS K7126 - 1 (Plastics - Films and Sheets - Gas Permeability Test Method - Part 1: Differential Pressure Method), at 30°C in an atmosphere, the CO 2 permeating through the φ60mm of the power storage device packaging film 10 is quantitatively analyzed by gas chromatography to measure the permeation amount.

[0386] Also, although illustration is omitted, on the outer side of the resin layer 2 (opposite to the heat - sealable resin layer 1 side), a surface coating layer or the like may be further provided as necessary.

[0387] The thickness of the laminate constituting the packaging film 10 for the power storage device according to the third aspect is not particularly limited. However, from the viewpoints of cost reduction, improvement of energy density, etc., for example, it is 190 μm or less, preferably about 180 μm or less, about 170 μm or less. Further, as the thickness of the laminate constituting the packaging film 10 for the power storage device, from the viewpoint of maintaining the function of the packaging film for the power storage device of protecting the power storage device element, preferably it is about 35 μm or more, about 45 μm or more, about 60 μm or more. Also, regarding the preferable range of the laminate constituting the packaging film 10 for the power storage device, for example, about 35 to 190 μm, about 35 to 180 μm, about 35 to 170 μm, about 45 to 190 μm, about 45 to 180 μm, about 45 to 170 μm, about 60 to 190 μm, about 60 to 180 μm, about 60 to 170 μm can be mentioned, and particularly about 45 to 170 μm is preferable.

[0388] In the packaging film 10 for the power storage device according to the third aspect, the ratio of the total thickness of the resin layer 2, the adhesive layer 4, the base material 3, the adhesive layer 5, and the heat-sealable resin layer 1 to the thickness (total thickness) of the laminate constituting the packaging film 10 for the 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 packaging film 10 for the power storage device according to the third aspect includes the resin layer 2, the adhesive layer 4, the base material 3, the adhesive layer 5, and the heat-sealable resin layer 1, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the packaging film 10 for the power storage device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. Also, when the packaging film 10 for the power storage device according to the third aspect is a laminate including the resin layer 2, the adhesive layer 4, and the heat-sealable resin layer 1, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the packaging film 10 for the 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.

[0389] The laminate constituting the packaging film 10 for the power storage device according to the third aspect can have a total light transmittance measured in accordance with the provisions of JIS K7361-1:1997, for example, 80% or more, 85% or more, 90% or more, etc. The lower the total light transmittance, the higher the shielding property that the packaging film 10 for the power storage device can exhibit. On the other hand, the higher the total light transmittance, the higher the light transmittance that the packaging film 10 for the power storage device can exhibit. Therefore, a desired transparency can be maintained by maintaining a certain lower limit of the total light transmittance. The lower limit value of the total light transmittance is 0%, and the upper limit is 100%. The total light transmittance of the packaging film for the power storage device shall comply with the measurement method specified in JIS K7361-1:1997, use a commercially available spectrophotometer (for example, manufactured by JASCO Corporation, ultraviolet-visible-near-infrared spectrophotometer V-670), measure the transmittance in the visible light region (400 to 700 nm), and take the average value as the total light transmittance. The measurement conditions are as follows: use a halogen lamp as the light source, UV / Vis bandwidth: 5.0 nm, scanning speed: 1000 nm / min, response: Medium, data acquisition interval: 1.0 nm.

[0390] The packaging film 10 for the power storage device according to the third aspect can be made into a colored transparent black color by making it black. When the packaging film 10 for the power storage device is made black, it exhibits a unique color, resulting in a highly distinguishable and highly designed packaging film 10 for the power storage device. Also, in the manufacturing process of the power storage device, it becomes possible to more accurately grasp the position by the sensor, and it becomes possible to more accurately convey the packaging film 10 for the power storage device and seal the power storage device element. Furthermore, it is also possible to unify the power storage device and other electrical components in black to give a high-class feeling to the product.

[0391] <Each layer forming the packaging film for the power storage device according to the third aspect> Regarding each layer forming the packaging film for the power storage device according to the third aspect, the description is omitted because it is common to the packaging films for the power storage device according to the first and second aspects.

[0392] [Manufacturing method of the packaging film for the power storage device according to the third aspect] The manufacturing method of the packaging film for the power storage device of the third aspect is not particularly limited as long as the packaging film for the power storage device of the third aspect can be obtained. For example, when the packaging film for the power storage device of the third aspect includes the resin layer 2 and the heat-sealable resin layer 1, it includes a step of obtaining a laminate in which at least the resin layer and the heat-sealable resin layer are laminated in order from the outside. The laminate has a CO 2 transmission amount of 100 cc·100 μm / m 2 / 24hr / atm or more, which is preferable.

[0393] As an example of the manufacturing method when the packaging film for the power storage device of the third aspect is composed of a laminate including the resin layer 2, the adhesive layer 4, the base material 3, the adhesive layer 5, and the heat-sealable resin layer 1 in this order, it is as follows. First, prepare the materials constituting each layer. Next, laminate the resin layer 2 and the base material 3 via the adhesive layer 4 and laminate the base material 3 and the heat-sealable resin layer 1 via the adhesive layer 5. Specifically, by using the adhesive forming the adhesive layer 4, laminating the resin layer 2 and the base material 3 by a dry lamination method or the like, the resin layer 2, the adhesive layer 4, and the base material 3 are laminated. Further, by using the adhesive forming the adhesive layer 5, laminating the base material 3 and the heat-sealable resin layer 1 by a dry lamination method or the like, the packaging film 10 for the power storage device can be manufactured. When laminating the resin layer 2, the base material 3, and the heat-sealable resin layer 1 without using the adhesive layers 4 and 5, the packaging film 10 for the power storage device can be manufactured by a method such as melt-extruding the resin constituting the resin layer 2 on one side of the base material 3 and melt-extruding the resin constituting the heat-sealable resin layer 1 on the other side of the base material 3. When providing a coloring layer, it may be laminated with the base material 3 or the heat-sealable resin layer 1 after forming the coloring layer on the surface of the resin layer 2. When providing a surface coating layer, for example, it can be formed by applying the above resin composition forming the surface coating layer on the surface of the resin layer 2 and curing it.

[0394] In order to strengthen the adhesiveness of the adhesive layers 4 and 5, the packaging film 10 for the power storage device may be further subjected to a heat treatment.

[0395] The shape of the inner package 210 of the third aspect is not particularly limited, and for example, it can be in the shape of a bag (pouch shape). The bag shape mentioned here includes a three-side seal type, a four-side seal type, a pillow type, a gusset type, etc. The inner package 210 of the first embodiment has a shape as shown in FIG. 2, and is manufactured by heat-sealing a packaging film 212 for a power storage device formed in a tray shape and a packaging film 211 for a power storage device also formed in a tray shape and overlapped from above the packaging film 212 for a power storage device along the outer peripheral portion in a plan view. The packaging film 212 for a power storage device includes an angular annular flange portion 212A corresponding to the outer peripheral portion in a plan view, and a molded portion 212B continuous with the inner edge of the flange portion 212A and bulging downward therefrom. Similarly, the packaging film 211 for a power storage device includes an angular annular flange portion 211A corresponding to the outer peripheral portion in a plan view, and 211B continuous with the inner edge of the flange portion 211A and bulging upward therefrom. The packaging films 211 and 212 for a power storage device are overlapped such that the respective molded portions 211B and 212B bulge in opposite directions. In this state, the flange portion 211A of the packaging film 211 for a power storage device and the flange portion 212A of the packaging film 212 for a power storage device are heat-sealed so as to be integrated, and constitute a part of the peripheral seal portion 150. Note that one of the packaging films 211 and 212 for a power storage device may be in a sheet shape.

[0396] The outer packaging films 221 and 222 that constitute the outer packaging body 220 of the third aspect are composed of, for example, resin molded products or films. The resin molded product mentioned here can be manufactured by methods such as injection molding, pressure air molding, vacuum molding, blow molding, etc., and in-mold molding may be performed to impart design and functionality. The type of resin can be polyolefin, polyester, nylon, ABS, etc. Also, the film mentioned here is, for example, a resin film that can be manufactured by methods such as the inflation method or the T-die method, or a laminate of such a resin film and a metal foil or metal plate. Also, the film mentioned here may or may not be stretched, and may be a single-layer film or a multilayer film. Also, the multilayer film mentioned here may be manufactured by a coating method, may be a laminate of multiple films adhered by an adhesive or the like, or may be manufactured by a multilayer extrusion method.

[0397] The outer packaging films 221 and 222 of the third aspect can be configured in various ways, but in the first embodiment, they are composed of a laminate film. The laminate film can be a laminate of a base material layer, a barrier layer, and a heat-sealable resin layer. The base material layer functions as the base material of the outer packaging films 221 and 222, typically forms the outer layer side of the outer packaging body 220, and is a resin layer having insulating properties. The barrier layer has the function of preventing at least moisture and the like from entering the power storage device 100 in addition to improving the strength of the outer packaging films 221 and 222, and is typically a metal layer made of an aluminum alloy foil or the like. The heat-sealable resin layer is typically made of a heat-sealable resin such as polyolefin and forms the innermost layer of the outer packaging body 220.

[0398] The shape of the outer package 220 of the third aspect is not particularly limited, and for example, it can be in the shape of a bag (pouch shape). Examples of the bag shape here include a three-side seal type, a four-side seal type, a pillow type, a gusset type, and the like. The container 110A of the first embodiment has a shape as shown in FIG. 2, and is manufactured by heat-sealing an exterior film 222 formed in a tray shape and an exterior film 221 also formed in a tray shape and stacked on top of the exterior film 222 along the outer peripheral portion in a plan view. The exterior film 222 includes an angular annular flange portion 222A corresponding to the outer peripheral portion in a plan view, and a molded portion 222B that is continuous with the inner edge of the flange portion 222A and bulges downward therefrom. Similarly, the exterior film 221 includes an angular annular flange portion 221A corresponding to the outer peripheral portion in a plan view, and a portion 221B that is continuous with the inner edge of the flange portion 221A and bulges upward therefrom. The exterior films 221 and 222 are stacked such that the molded portions 221B and 222B thereof bulge in opposite directions. In this state, the flange portion 221A of the exterior film 221 and the flange portion 222A of the exterior film 222 are heat-sealed so as to be integrated, and constitute a part of the peripheral seal portion 150. Note that one of the exterior films 221 and 222 may be in a sheet shape.

[0399] As shown in FIG. 2, in the terminal seal portion 151A, a part of the flange portion 211A of the power storage device packaging film 211 is joined to one tab film 140. A part of the flange portion 212A of the power storage device packaging film 212 is joined to the other tab film 140.

[0400] The flange portion 221A of the exterior film 221 of the third aspect is joined to the flange portion 211A of the packaging film 211 for the power storage device. The end portion 221X of the flange portion 221A is located closer to the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 221X of the flange portion 221A may be located at the same position as the end portion 211X of the packaging film 211 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 211X of the packaging film 211 for the power storage device.

[0401] The flange portion 222A of the exterior film 222 of the third aspect is joined to the flange portion 212A of the packaging film 212 for the power storage device. The end portion 222X of the flange portion 222A is located closer to the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 222X of the flange portion 222A may be located at the same position as the end portion 212X of the packaging film 212 for the power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 212X of the packaging film 212 for the power storage device.

[0402] The power storage device element 120 of the third aspect includes at least a positive electrode, a negative electrode, and an electrolyte, and is, for example, a power storage member such as a lithium ion battery (secondary battery) or a capacitor.

[0403] The metal terminal 130 is a metal terminal used for power input and output of the power storage device element 120. The metal terminal 130 is disposed, for example, on the top seal portion 151 of the container 110A, with one forming the positive electrode side terminal and the other forming the negative electrode side terminal. One end of each metal terminal 130 in the left-right direction is electrically connected to the electrode (positive electrode or negative electrode) of the power storage device element 120 in the internal space S1 of the container 110A, and the other end protrudes outward from the peripheral seal portion 150. The above-described form of the power storage device 100 is particularly preferable for use in electric vehicles such as electric cars and hybrid cars that use a large number of power storage devices 100 connected in series at a high voltage. Note that the attachment positions of the two metal terminals 130 constituting the positive and negative electrodes are not particularly limited, and may be disposed, for example, on the side seal portions 152, 153, or the bottom seal portion 154 of the peripheral seal portion 150.

[0404] The metal material constituting the metal terminal 130 is, for example, aluminum, nickel, copper, or the like. When the power storage device element 120 is a lithium ion battery, the metal terminal 130 connected to the positive electrode is typically constituted by aluminum or the like, and the metal terminal 130 connected to the negative electrode is typically constituted by copper, nickel, or the like.

[0405] The tab film 140 is a so-called adhesive film and is configured to adhere to both the power storage device packaging films 211 and 212 and the metal terminal 130. By means of the tab film 140, even if the metal terminal 130 and the innermost layer (heat-sealable resin layer) of the power storage device packaging films 211 and 212 are made of different materials, the two can be fixed. Note that the tab film 140 is integrated by being pre-fused and fixed to the metal terminal 130, and the power storage device packaging films 211 and 212 are fused to the metal terminal 130 to which the tab film 140 is fixed.

[0406] [Manufacturing Method of Power Storage Device of Third Aspect] FIG. 10 is a flowchart showing an example of a method for manufacturing a power storage device 100. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0407] In the inner packaging step of step S11, as shown in FIG. 11, the power storage device element 120 is wrapped with the formed packaging films 211 and 212 for the power storage device. In the power storage device 100 of the first embodiment, since the packaging films 211 and 212 for the power storage device have gas permeability, it is not necessary to form a sub-chamber for temporarily storing the gas generated from the power storage device element 120 in the first filling step and the like described later. Therefore, in the inner packaging step, the power storage device element 120 is wrapped with the packaging films 211 and 212 for the power storage device having substantially the same size as the packaging films 211 and 212 provided in the inner package 210 of the completed power storage device 100. Therefore, the manufacturing process of the power storage device 100 can be simplified. In addition, the materials used for the power storage device 100 can be reduced. Substantially the same size includes a case where it is larger than the packaging films 211 and 212 provided in the inner package 210 of the completed power storage device 100 to such an extent that a sub-chamber cannot be formed. Note that a metal terminal 130 is connected to the power storage device element 120 in advance, and a tab film 140 is joined to the metal terminal 130.

[0408] The first inner sealing step of step S12 is performed after the inner packaging step. In the first inner sealing step, as shown in FIG. 12, the portions corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 among the peripheries of the packaging films 211 and 212 for the power storage device are sealed. By completing the first inner sealing step, an opening 213 is formed in a portion where a side seal portion 153 is to be formed among the peripheries of the packaging films 211 and 212 for the power storage device. After the first inner sealing step, a vacuum drying step of step S13 is performed.

[0409] The electrolytic solution injection step of step S14 is performed after the vacuum drying step. In the electrolytic solution injection step, the electrolytic solution is injected through the opening 213 (see FIG. 12).

[0410] The second inner sealing process in step S15 is carried out after the electrolytic solution injection process. As shown in FIG. 13, in the second inner sealing process, the portion of the peripheral edges of the power storage device packaging films 211 and 212 where the side seal portion 153 is to be formed is sealed, thereby closing the opening 213. After the second inner sealing process, the first charge and discharge process in step S16 and the aging process in step S17 are carried out in sequence.

[0411] The gas venting process in step S18 is carried out in parallel with the first charge and discharge process and the aging process. In the first embodiment, since the power storage device packaging films 211 and 212 have gas permeability, when the first charge and discharge process and the aging process are carried out, gases such as carbon dioxide generated from the power storage device element 120 are discharged to the outside through the power storage device packaging films 211 and 212. After the gas venting process, the main charging process in step S19 is carried out.

[0412] The outer packaging process in step S20 is carried out after the main charging process. In the outer packaging process, the inner package 210 in a state where the power storage device element 120 is accommodated is wrapped by the outer packaging films 221 and 222.

[0413] The outer sealing process in step S21 is carried out after the outer packaging process. In the outer sealing process, the peripheral edges of the outer packaging films 221 and 222 are sealed, thereby forming the peripheral seal portion 150.

[0414] [Features of the power storage device of the third aspect] According to the power storage device 100, since the packaging films 211 and 212 for the power storage device have transparency, it is possible to easily confirm whether the packaging film 211 for the power storage device and the packaging film 212 for the power storage device are properly sealed after the first inner sealing step or the second inner sealing step is completed. Therefore, the power storage device 100 can be preferably manufactured. Note that the state where the packaging film 211 for the power storage device and the packaging film 212 for the power storage device are not properly sealed includes, for example, the first state, the second state, or the third state. The first state is a state where the packaging film 211 for the power storage device and the packaging film 212 for the power storage device are sealed in a state of biting foreign matter. The second state is a state where a part of the portion to be sealed is not sealed. The third state is a state where a portion that should not be sealed is sealed.

[0415] [Embodiment 2 of the Third Aspect] The power storage device 100 of Embodiment 2 is different from Embodiment 1 in that the packaging films 211 and 212 for the power storage device do not have gas permeability, or in that it does not have gas permeability to the extent that the gas venting step of step S18 described above is performed as compared with Embodiment 1, and other configurations are the same as those of Embodiment 1. Hereinafter, the power storage device 100 of Embodiment 2 will be described centering on the parts different from Embodiment 2.

[0416] [Method for Manufacturing a Power Storage Device] FIG. 14 is a flowchart showing an example of a method for manufacturing the power storage device 100 of Embodiment 2. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0417] In the inner packaging process of step S31, as shown in FIG. 15, the power storage device element 120 is wrapped by the formed packaging films 211 and 212 for the power storage device. In the power storage device 100 of the second embodiment, since the packaging films 211 and 212 for the power storage device do not have gas permeability, it is preferable to form a sub-chamber 214 for temporarily storing the gas generated from the power storage device element 120 in the first filling process or the like. For this reason, in the inner packaging process, the power storage device element 120 is wrapped by the packaging films 211 and 212 for the power storage device that are larger than the packaging films 211 and 212 provided in the inner package 210 of the completed power storage device 100. An accommodation chamber 215 for storing more gas generated from the power storage device element 120 is formed in the sub-chamber 214 of the packaging films 211 and 212 for the power storage device.

[0418] The first inner sealing process of step S32 is carried out after the inner packaging process. In the first inner sealing process, as shown in FIG. 16, the portions corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 among the peripheries of the packaging films 211 and 212 for the power storage device are sealed so as to extend to the sub-chamber 214. By completing the first inner sealing process, an opening 213 is formed in the portion 216 facing the portion where the side seal portion 153 is to be formed among the peripheries of the packaging films 211 and 212 for the power storage device through the sub-chamber 214. After the first inner sealing process, the vacuum drying process of step S33 is carried out.

[0419] The electrolyte injection process of step S34 is carried out after the vacuum drying process. In the electrolyte injection process, the electrolyte is injected through the opening 213 (see FIG. 16).

[0420] The second inner sealing process in step S35 is carried out after the electrolytic solution injection process. As shown in FIG. 17, in the second inner sealing process, the portion 216 that faces the portion where the side seal portion 153 is to be formed among the peripheries of the power storage device packaging films 211 and 212 through the sub chamber 214 is sealed, whereby the opening 213 is closed. After the second inner sealing process, the initial charge and discharge process in step S36 and the aging process in step S37 are carried out in sequence.

[0421] The gas venting process in step S38 is carried out after the aging process. In the gas venting process, gases such as carbon dioxide generated from the power storage device element 120 are temporarily stored in the sub chamber 214 of the power storage device packaging films 211 and 212.

[0422] The sub chamber removal process in step S39 is carried out after the gas venting process. In the sub chamber removal process, the sub chamber 214 is removed by cutting the power storage device packaging films 211 and 212 along the dashed-dotted line XA shown in FIG. 17 so as to have the same size as the inner package 210 included in the completed power storage device 100.

[0423] The inner sealing process in step S40 is carried out after the sub chamber removal process. In the inner sealing process, as shown in FIG. 18, the portion corresponding to the side seal portion 153 among the peripheries of the power storage device packaging films 211 and 212 is sealed. After the inner sealing process, the main charging process in step S41 is carried out.

[0424] The outer packaging process in step S42 is carried out after the main charging process. In the outer packaging process, the inner package 210 in a state where the power storage device element 120 is accommodated is wrapped by the outer packaging films 221 and 222.

[0425] The outer sealing process in step S43 is carried out after the outer packaging process. In the outer sealing process, the peripheries of the outer packaging films 221 and 222 are sealed, whereby the peripheral seal portion 150 is formed.

[0426] [Features of the energy storage device] According to the energy storage device 100 of Embodiment 3, since the packaging films 211 and 212 for the energy storage device have transparency, the same effects as those of the energy storage device 100 of Embodiment 1 can be obtained.

[0427] [Embodiment 3 of the third aspect] The energy storage device 300 of Embodiment 3 is different from Embodiment 1 in that the configuration of the terminal seal portion 151A is different, and other configurations are the same as those of Embodiment 1. Hereinafter, the energy storage device 300 of Embodiment 3 will be described centering on the parts different from Embodiment 1.

[0428] FIG. 19 is a cross-sectional view of the terminal seal portion 351A provided in the energy storage device 300 of Embodiment 3. In the terminal seal portion 351A, a part of the flange portion 211A of the packaging film 211 for the energy storage device is joined to one tab film 140. A part of the flange portion 212A of the packaging film 212 for the energy storage device is joined to the other tab film 140.

[0429] The flange portion 221A of the outer packaging film 221 is joined to one tab film 140. The flange portion 222A of the outer packaging film 222 is joined to the other tab film 140. The end portion 221X of the flange portion 221A is located farther from the energy storage device element 120 than the end portion 211X of the packaging film 211 for the energy storage device. The end portion 222X of the flange portion 222A is located farther from the energy storage device element 120 than the end portion 212X of the packaging film 212 for the energy storage device. Therefore, the entire inner packaging body 210 is covered by the outer packaging body 220.

[0430] [Features of the energy storage device] According to the energy storage device 300, since the inner packaging body 210 is covered by the outer packaging body 220, entry of moisture and the like from the outside into the internal space S1 of the inner packaging body 210 is suppressed.

[0431] [Embodiment 4 of the third aspect] The power storage device 400 according to Embodiment 4 is different from Embodiment 1 in that the configuration of the terminal seal portion 151A is different, and the other configurations are the same as those in Embodiment 1. Hereinafter, the power storage device 400 according to Embodiment 4 will be described focusing on the parts different from Embodiment 1.

[0432] FIG. 20 is a cross-sectional view of a terminal seal portion 451A included in the power storage device 400 according to Embodiment 4. The power storage device 400 does not have a tab film 140. In the terminal seal portion 451A of the power storage device 400, an exterior film 221, a packaging film 211 for power storage device, a metal terminal 130, a packaging film 212 for power storage device, and an exterior film 222 are laminated in this order from the top, and these are integrated.

[0433] The end portion 221X of the flange portion 221A is located closer to the power storage device element 120 than the end portion 211X of the packaging film 211 for power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 221X of the flange portion 221A may be located at the same position as the end portion 211X of the packaging film 211 for power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 211X of the packaging film 211 for power storage device.

[0434] The flange portion 221A of the exterior film 221 is joined to the flange portion 211A of the packaging film 211 for power storage device. The flange portion 222A of the exterior film 222 is joined to the flange portion 212A of the packaging film 212 for power storage device. The end portion 222X of the flange portion 222A is located closer to the power storage device element 120 than the end portion 212X of the packaging film 212 for power storage device. For this reason, at least a part of the outer edge of the inner package 210 is exposed from the outer package 220. Note that the end portion 222X of the flange portion 222A may be located at the same position as the end portion 212X of the packaging film 212 for power storage device in the left-right direction, or may be located farther from the power storage device element 120 than the end portion 212X of the packaging film 212 for power storage device.

[0435] [Features of the energy storage device] According to the energy storage device 400, since the packaging films 211 and 212 for the energy storage device and the metal terminal 130 are joined without passing through the tab film 140, the number of components is small. In addition, the manufacturing method of the energy storage device 400 can be simplified.

[0436] [Embodiment 5 of the third aspect] The energy storage device 500 of Embodiment 5 is different from Embodiment 4 in that the configuration of the terminal seal portion 451A is different, and the other configurations are the same as those of Embodiment 4. Hereinafter, the energy storage device 500 of Embodiment 5 will be described centering on the parts different from Embodiment 4.

[0437] FIG. 21 is a cross-sectional view of the terminal seal portion 551A provided in the energy storage device 500 of Embodiment 5. In the terminal seal portion 551A, a part of the flange portion 211A of the packaging film 211 for the energy storage device is joined to the metal terminal 130. A part of the flange portion 212A of the packaging film 212 for the energy storage device is joined to the metal terminal 130.

[0438] The flange portion 221A of the outer packaging film 221 is joined to the metal terminal 130. The flange portion 222A of the outer packaging film 222 is joined to the metal terminal 130. The end portion 221X of the flange portion 221A is located farther from the energy storage device element 120 than the end portion 211X of the packaging film 211 for the energy storage device. The end portion 222X of the flange portion 222A is located farther from the energy storage device element 120 than the end portion 212X of the packaging film 212 for the energy storage device. For this reason, the entire inner package 210 is covered by the outer package 220.

[0439] [Features of the energy storage device] According to the power storage device 500, since the inner packaging body 210 is covered by the outer packaging body 220, entry of moisture or the like from the outside into the internal space S1 of the inner packaging body 210 is suppressed. Also, according to the power storage device 500, since the power storage device packaging films 211 and 212 and the metal terminals 130 are joined without going through the tab film 140, the number of components is small. Also, the manufacturing method of the power storage device 500 can be simplified.

[0440] [Modification of the Third Aspect] Each embodiment of the third aspect is an example of a form that the power storage device and the manufacturing method of the power storage device according to the present disclosure can take, and is not intended to limit that form. The power storage device and the manufacturing method of the power storage device according to the present disclosure can take forms different from the forms exemplified in each embodiment. An example thereof is a form in which a part of the configuration of each embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to each embodiment. Some examples of modifications of each embodiment are shown below. Note that the following modifications can be combined with each other as long as there is no technical contradiction.

[0441] In the power storage device 100 of Embodiment 1 of the third aspect, one outer packaging body 220 may be configured to accommodate a plurality of inner packaging bodies 210 in a state in which the power storage device elements 120 are accommodated. In this modification, the sizes of the plurality of inner packaging bodies 210 may be different or the same. According to this modification, since a plurality of power storage device elements 120 can be connected in series or in parallel, the voltage can be easily adjusted.

[0442] In the power storage device 100 of Embodiment 1 of the third aspect, the power storage device packaging films 211 and 212 do not necessarily have gas permeability. The power storage device packaging films 211 and 212 only need to have at least transparency.

[0443] In the power storage device 100 according to the first embodiment of the third aspect, the inner packaging body 210 may be configured by folding a single power storage device packaging film 211 and heat-sealing the peripheral edge portion. Similarly, the outer packaging body 220 may be configured by folding a single exterior film 221 and heat-sealing the peripheral edge portion.

[0444] <Fourth Aspect> [First Embodiment] FIG. 8 shows a plan view of the power storage device 100 according to the first embodiment of the fourth aspect. FIG. 9 is a cross-sectional view taken along line D2-D2 of FIG. 8. In FIG. 8, portions that are not normally visible from the outside are partially shown by dotted lines for reference. Hereinafter, for convenience of explanation, unless otherwise specified, the vertical direction in FIG. 8 is referred to as the "front-rear direction", the horizontal direction is referred to as the "left-right direction", and the vertical direction in FIG. 9 is referred to as the "up-down direction". However, the orientation of the power storage device 100 during use is not limited to this. Also, in FIG. 8, for simplicity of the drawing, the relative positional relationship between the inner packaging body 210 and the outer packaging body 220 is simplified.

[0445] The power storage device 100 according to the fourth aspect includes a container 110, a power storage device element 120, a pair of metal terminals 130, and a pair of tab films 140. The container 110 includes an internal space S1 and a peripheral seal portion 150. The power storage device element 120 is housed in the internal space S1 of the container 110. One end of the metal terminal 130 is joined to the power storage device element 120, and the other end protrudes outward from the peripheral seal portion 150 of the container 110. A part between one end and the other end of the metal terminal 130 is fused to the peripheral seal portion 150 via the tab film 140.

[0446] The container 110 includes a vessel 110A. The vessel 110A includes an inner package 210 and an outer package 220. The inner package 210 houses the power storage device element 120. The outer package 220 houses the inner package 210 in a state where the power storage device element 120 is housed therein. The internal space S1 is formed inside the inner package 210. The inner package 210 includes power storage device packaging films 211 and 212. The outer package 220 includes outer packaging films 221 and 222. At the outer peripheral portion of the vessel 110A in plan view, the inner package 210 and the outer package 220 are heat-sealed and fused to each other, whereby a peripheral seal portion 150 is formed. And, the internal space S1 of the vessel 110A blocked from the external space is formed in the inner package 210 by this peripheral seal portion 150. The peripheral seal portion 150 defines the periphery of the internal space S1 of the vessel 110A. Here, the mode of heat-sealing is assumed to include modes such as heat fusion from a heat source and ultrasonic fusion. In any case, the peripheral seal portion 150 means a portion where the inner package 210 and the outer package 220 are fused and integrated.

[0447] The peripheral seal portion 150 includes a top seal portion 151, a pair of side seal portions 152 and 153, and a bottom seal portion 154. The top seal portion 151 includes a portion (hereinafter referred to as "terminal seal portion 151A") that is sealed with the metal terminal 130 and the tab film 140 interposed therebetween, and extends in the front-rear direction. The pair of side seal portions 152 and 153 extend in the left-right direction. The side seal portion 152 and the side seal portion 153 face each other with the internal space S1 therebetween. The bottom seal portion 154 faces the top seal portion 151 with the internal space S1 therebetween. The bottom seal portion 154 extends in the front-rear direction.

[0448] As shown in FIG. 9, the terminal seal portion 151A of the top seal portion 151 is laminated, in order from the top, with the exterior film 221, the power storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, the power storage device packaging film 212, and the exterior film 222, and these are integrated. Therefore, the top seal portion 151 can be easily formed. Note that, for the portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, the portion where only the pair of tab films 140 are sandwiched by the inner package 210 and the outer package 220, the exterior film 221, the power storage device packaging film 211, one tab film 140, the other tab film 140, the power storage device packaging film 212, and the exterior film 222 are laminated, in order from the top, and these are integrated. Further, the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion in FIG. 9 with the step as the boundary) is laminated, in order from the top, with the power storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, and the power storage device packaging film 212, and these are integrated. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the exterior films 221 and 222 do not exist and the inner portion of the terminal seal portion 151A where the exterior films 221 and 222 exist (the right portion in FIG. 9 with the step as the boundary). However, FIG. 8 is an illustration of the region of the peripheral seal portion 150 from an overhead view, and the boundary step is not shown.

[0449] The power storage device packaging films 211 and 212 that constitute the inner package 210 have gas permeability from the viewpoint of facilitating the manufacture of the power storage device 100. Hereinafter, preferred examples of the power storage device packaging films 211 and 212 that constitute the inner package 210 will be described. Note that, hereinafter, when the power storage device packaging films 211 and 212 are not particularly distinguished, the power storage device packaging films 211 and 212 may be collectively referred to as the power storage device packaging film 10.

[0450] [Laminated Structure and Physical Properties of Power Storage Device Packaging Film of the Fourth Aspect] As shown in FIGS. 1 to 4, for example, the packaging film 10 for a power storage device according to the fourth aspect includes at least a heat-sealable resin layer 1. When assembling a power storage device using the packaging film 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 in a state where the heat-sealable resin layers 1 of the packaging film 10 for a power storage device face each other.

[0451] As shown in FIG. 1, the packaging film 10 for a power storage device according to the fourth aspect may be composed only of the heat-sealable resin layer 1. When the packaging film 10 for a power storage device is composed only of the heat-sealable resin layer 1, it is preferable that at least one surface of the heat-sealable resin layer 1 has adhesiveness to metal, and it is more preferable to impart adhesiveness to metal to the inner surface of the heat-sealable resin layer 1 facing the metal terminal 130.

[0452] Also, as shown in FIGS. 2 to 4, the packaging film 10 for a power storage device according to the fourth aspect is preferably composed of a laminate including at least a resin layer 2 and a heat-sealable resin layer 1. In such a packaging film 10 for a power storage device, the resin layer 2 is on the outside and the heat-sealable resin layer 1 is on the inside (innermost layer). When the packaging film 10 for a power storage device is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, it is preferable to impart adhesiveness to metal to at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1, and it is more preferable to impart adhesiveness to metal to the inner surface of the heat-sealable resin layer 1 facing the metal terminal 130.

[0453] Furthermore, as shown in FIGS. 3 to 4, the packaging film 10 for a power storage device according to the fourth aspect is preferably composed of at least a laminate including a resin layer 2, a base material 3, and the heat-sealable resin layer 1. In such a packaging film 10 for a power storage device, the resin layer 2 is on the outside, the heat-sealable resin layer 1 is on the inside (innermost layer), and the base material 3 is located between the resin layer 2 and the heat-sealable resin layer 1. Even when the packaging film 10 for a power storage device is composed of a laminate including a resin layer 2, a base material 3, and a heat-sealable resin layer 1, it is preferable to impart adhesiveness to at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1 with respect to a metal.

[0454] As shown in FIG. 2, an adhesive layer 4 can be provided between the resin layer 2 and the heat-sealable resin layer 1, and as shown in FIG. 4, an adhesive layer 5 can be provided between the heat-sealable resin layer 1 and the base material 3.

[0455] The packaging film 10 for a power storage device according to the fourth aspect has a CO 2 permeation amount of 100 cc·100 μm / m 2 / 24 hr / atm or more in an environment at a temperature of 30°C, more preferably about 200 cc·100 μm / m 2 / 24 hr / atm or more, even more preferably about 300 cc·100 μm / m 2 / 24 hr / atm or more, even more preferably about 500 cc·100 μm / m 2 / 24 hr / atm or more. Also, the CO 2 permeation amount of the packaging film 10 for a power storage device according to the fourth aspect is, for example, about 2000 cc·100 μm / m 2 / 24 hr / atm or less, preferably about 1000 cc·100 μm / m 2 / 24 hr / atm or less, more preferably about 800 cc·100 μm / m 2 / 24 hr / atm or less, and the preferable range is about 100 to 2000 cc·100 μm / m 2 / 24 hr / atm, about 100 to 1000 cc·100 μm / m 2 / 24 hr / atm, about 100 to 800 cc·100 μm / m 2About 200 - 2000 cc·100μm / m per 24 hours / atm 2 About 200 - 1000 cc·100μm / m per 24 hours / atm 2 About 200 - 800 cc·100μm / m per 24 hours / atm 2 About 300 - 2000 cc·100μm / m per 24 hours / atm 2 About 300 - 1000 cc·100μm / m per 24 hours / atm 2 About 300 - 800 cc·100μm / m per 24 hours / atm 2 About 500 - 2000 cc·100μm / m per 24 hours / atm 2 About 500 - 1000 cc·100μm / m per 24 hours / atm 2 About 500 - 800 cc·100μm / m per 24 hours / atm 2 Examples include about 24 hours / atm. The method for measuring the CO 2 permeation rate of the packaging film for the power storage device is as follows.

[0456] [Measurement of CO 2 permeation rate] In accordance with JIS K7126 - 1 (Plastics - Films and Sheets - Gas Permeability Test Methods - Part 1: Differential Pressure Method), at 30°C in an atmosphere, the CO 2 permeating through the φ60 mm of the packaging film 10 for the power storage device is quantitatively analyzed by gas chromatography to measure the permeation rate.

[0457] When imparting shielding properties to the packaging film 10 for the power storage device of the fourth aspect, for at least one layer included in the packaging film 10 for the power storage device, a shielding layer S having shielding properties may be provided. For example, in FIG. 2, a configuration in which the adhesive layer 4 bonding between the resin layer 2 and the heat - fusible resin layer 1 is used as the shielding layer S is illustrated, and in FIG. 4, a configuration in which the adhesive layer 4 bonding between the resin layer 2 and the base material 3 is used as the shielding layer S is illustrated. In the fourth aspect, any layer included in the packaging film 10 for the power storage device can be used as the shielding layer S.

[0458] Also, although illustration is omitted, a surface coating layer or the like may be further provided on the outer side of the resin layer 2 (the side opposite to the heat-sealable resin layer 1) as necessary.

[0459] The thickness of the laminate constituting the power storage device packaging film 10 of the fourth aspect is not particularly limited. However, from the viewpoints of cost reduction and improvement of energy density, for example, it may be 190 μm or less, preferably about 180 μm or less, about 170 μm or less. Also, from the viewpoint of maintaining the function of the power storage device packaging film of protecting the power storage device element, the thickness of the laminate constituting the power storage device packaging film 10 is preferably about 35 μm or more, about 45 μm or more, about 60 μm or more. Also, regarding the preferable range of the laminate constituting the power storage device packaging film 10, for example, about 35 to 190 μm, about 35 to 180 μm, about 35 to 170 μm, about 45 to 190 μm, about 45 to 180 μm, about 45 to 170 μm, about 60 to 190 μm, about 60 to 180 μm, about 60 to 170 μm can be mentioned, and particularly about 45 to 170 μm is preferable.

[0460] In the packaging film 10 for a power storage device according to the fourth aspect, the ratio of the total thickness of the resin layer 2, the adhesive layer 4, the base material 3, the adhesive layer 5, and the heat-sealable resin layer 1 to the thickness (total thickness) of the laminate constituting the packaging film 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 packaging film 10 for a power storage device according to the fourth aspect includes the resin layer 2, the adhesive layer 4, the base material 3, the adhesive layer 5, and the heat-sealable resin layer 1, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the packaging film 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 packaging film 10 for a power storage device according to the fourth aspect is a laminate including the resin layer 2, the adhesive layer 4, and the heat-sealable resin layer 1, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the packaging film 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.

[0461] The laminate constituting the packaging film 10 for the power storage device according to the fourth aspect can have a total light transmittance measured in accordance with the provisions of JIS K7361-1:1997, for example, 20% or less, 15% or less, 10% or less, 8% or less, etc. Further, the laminate constituting the packaging film 10 for the power storage device according to the fourth aspect can also have a total light transmittance measured in accordance with the provisions of JIS K7361-1:1997, for example, 80% or more, 85% or more, 90% or more, etc. The lower the total light transmittance, the higher the shielding property that the packaging film 10 for the power storage device can exhibit. On the other hand, the higher the ...

Claims

1. A packaging film for an electricity storage device including at least a heat-sealable resin layer, The packaging film for an electricity storage device has adhesiveness to metal, The packaging film for an electricity storage device does not have a metal layer formed from a metal.

2. The packaging film for an electricity storage device according to claim 1 , which is constituted by a laminate including, in order from the outside, at least a resin layer and the heat-sealable resin layer.

3. The packaging film for an electricity storage device according to claim 2 , which is constituted by a laminate including, in order from the outside, at least the resin layer, a substrate, and the heat-sealable resin layer.

4. The packaging film for a storage battery device according to claim 3 , which is composed of a laminate including, in order from the outside, at least the resin layer, an adhesive layer, the substrate, and the heat-sealable resin layer.

5. The packaging film for a storage battery device according to claim 4, which is composed of a laminate including, in order from the outside, at least the resin layer, the adhesive layer, the base material, an adhesive layer, and the heat-sealable resin layer.

6. The packaging film for a storage battery device according to any one of claims 2 to 5, wherein an outer surface of the resin layer has adhesiveness to metal.

7. The packaging film for an electricity storage device according to any one of claims 2 to 5, wherein the inner surface of the heat-sealable resin layer has adhesiveness to metal.

8. An electricity storage device, comprising an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte, housed in a package formed from the packaging film for an electricity storage device according to any one of claims 1 to 5.

9. an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte, housed in an inner packaging body formed from the packaging film for an electricity storage device according to any one of claims 1 to 5; The inner packaging body is further housed in an outer packaging body.

10. The electricity storage device according to claim 9 , wherein the outer packaging body has a metal layer formed of a metal.

11. The electricity storage device according to claim 9 , wherein the packaging film for an electricity storage device is in contact with a metal terminal electrically connected to the positive electrode or the negative electrode.

12. A method for producing a packaging film for an electricity storage device, comprising at least a step of providing a heat-sealable resin layer, The packaging film for an electricity storage device has adhesiveness to metal, The packaging film for an electricity storage device does not have a metal layer formed from a metal.

Images