Packaging film for power storage device and power storage device

Abstract

To provide a packaging film for a power storage device having prescribed CO2 permeability.SOLUTION: A packaging film for a power storage device includes at least a heat-fusible resin layer, and has a CO2 permeation amount under the environment at a temperature of 30°C of 100 cc 100 μm / m2 / 24hr / atm or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a packaging film for an electricity storage device and an electricity storage device. [Background technology]

[0002] Various types of electricity storage devices have been developed, and in all of these devices, exterior materials are essential components for sealing electricity storage device elements such as electrodes and electrolytes. Conventionally, metallic exterior materials have been widely used as packaging films for electricity storage devices.

[0003] Meanwhile, in recent years, various shapes and thinner and lighter weight are being required for electricity storage devices along with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc. However, the conventionally widely used metallic packaging films for electricity storage devices have the drawbacks of being difficult to keep up with the diversification of shapes and also having limitations on weight reduction.

[0004] In recent years, a film-like laminate in which a base material layer, a metal layer, and a heat-sealable resin layer are laminated in this order has been proposed as a packaging film for electricity storage devices that can be easily processed into a variety of shapes and can be made thin and lightweight (see, for example, Patent Document 1).

[0005] In such packaging films for electricity storage devices, recesses are generally formed by cold forming, electricity storage device elements such as electrodes and electrolyte are placed in the space formed by the recesses, and the heat-sealable resin layer is heat-sealed to obtain an electricity storage device in which the electricity storage device elements are housed inside the packaging film for electricity storage devices. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-287971 A Summary of the Invention [Problem to be solved by the invention]

[0007] (First aspect) In the manufacturing process of an electricity storage device, generally, an electricity storage device element is accommodated in a packaging film for an electricity storage device, which is then temporarily sealed, and an initial charge / discharge process, an aging process, etc. are performed. In these processes, it is known that gases such as CO2 are generated from the electricity storage device element, and currently, electricity storage devices are manufactured using a packaging film for an electricity storage device that is larger than the size required for the final electricity storage device (for example, more than twice the size required to seal the electricity storage device element) in order to provide a space for holding the gas inside the temporarily sealed package (made of a packaging film for an electricity storage device) and further to remove the space holding the gas and release the gas to the outside.

[0008] The inventors of the present disclosure have created a problem of providing new value by imparting CO2 permeability to a packaging film for an electricity storage device.

[0009] A primary object of a first aspect of the present disclosure is to provide a packaging film for an electricity storage device having a predetermined CO2 permeability.

[0010] (Second aspect) Furthermore, a metal terminal protrudes from the heat-sealed portion of the packaging film for electricity storage devices, and the electricity storage device element sealed with the packaging film for electricity storage devices is electrically connected to the outside by the metal terminal electrically connected to the electrode of the electricity storage device element. That is, among the heat-sealed portions of the packaging film for electricity storage devices, the portion where the metal terminal is present is heat-sealed in a state where the metal terminal is sandwiched between the heat-sealable resin layer. Since the metal terminal and the heat-sealable resin layer are made of different materials, adhesion is likely to decrease at the interface between the metal terminal and the heat-sealable resin layer.

[0011] Furthermore, by not providing a metal layer in the packaging film for electricity storage devices, there is an advantage in that the packaging film can be made thinner and lighter.

[0012] The inventors of the present disclosure have created a problem that provides new value in a packaging film for an electricity storage device by combining the advantage of adhesion to metal with the advantage of not having a metal layer.

[0013] A main object of a second aspect of the present disclosure is to provide a packaging film for electricity storage devices that has adhesion to metal and does not have a metal layer formed from metal.

[0014] (Third aspect) In the manufacturing process of the electricity storage device, generally, after the electricity storage device element is accommodated in the packaging film for the electricity storage device, the periphery of the packaging film for the electricity storage device is sealed to temporarily seal it. Then, an initial charge / discharge process and an aging process are performed. The packaging film for the electricity storage device provided in the secondary battery includes a metal layer and therefore has a shielding property. Therefore, when the electricity storage device element is sealed by the packaging film for the electricity storage device, it is not possible to check whether the periphery of the packaging film for the electricity storage device is properly sealed. Therefore, the electricity storage device cannot be manufactured suitably.

[0015] An object of a third aspect of the present disclosure is to provide an electricity storage device manufacturing method capable of suitably manufacturing an electricity storage device, and an electricity storage device manufactured by this manufacturing method.

[0016] (Fourth aspect) In the manufacturing process of an electricity storage device, generally, after an electricity storage device element is accommodated in a packaging film for an electricity storage device, the periphery of the packaging film for an electricity storage device is sealed to temporarily seal the device. Then, an initial charge / discharge process, an aging process, and the like are performed. In these processes, it is known that gases such as CO2 are generated from the electricity storage device element. In order to provide a space for holding the gas inside the temporarily sealed package (made of the packaging film for an electricity storage device), and further to remove the space in which the gas is held and release the gas to the outside, the electricity storage device is currently manufactured using a packaging film for an electricity storage device that is larger than the size required for the final product of the electricity storage device (for example, more than twice the size required to seal the electricity storage device element). For this reason, the manufacturing process of the electricity storage device is complicated.

[0017] A fourth aspect of the present disclosure has an object to provide an electricity storage device manufacturing method that can easily manufacture an electricity storage device, and an electricity storage device manufactured by this manufacturing method.

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

[0019] An object of the fifth embodiment of the present disclosure is to provide an electricity storage device having high added-value functions. [Means for solving the problem]

[0020] (First aspect) A first aspect of the present disclosure provides the invention having the following aspects. A packaging film for an electricity storage device comprising at least a heat-sealable resin layer, CO2 permeation rate in a 30℃ environment is 100cc·100μm / m 2 Packaging film for electricity storage devices with a durability of 24hr / atm or more.

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

[0022] (Third aspect) A manufacturing method for an electricity storage device according to a first aspect of the third embodiment of the present disclosure is a manufacturing method for an electricity storage device, the electricity storage device comprising an electricity storage device element and an inner packaging body that houses the electricity storage device element, the inner packaging body being constituted by a transparent packaging film for electricity storage devices, the method including an inner packaging step of wrapping the electricity storage device element with the packaging film for electricity storage devices, and an inner sealing step, which is performed after the inner packaging step, of sealing the packaging film for electricity storage devices so that the electricity storage device element is hermetically sealed by the packaging film for electricity storage devices.

[0023] A manufacturing method for an electricity storage device according to a second aspect of the third embodiment of the present disclosure is a manufacturing method for an electricity storage device according to the first aspect, wherein the packaging film for the electricity storage device further has gas permeability, and further includes a degassing step performed after the inner sealing step in which gas generated from the electricity storage device elements is released through the packaging film for the electricity storage device.

[0024] A manufacturing method for an electricity storage device according to a third aspect of the third embodiment of the present disclosure is a manufacturing method for an electricity storage device according to the second aspect, wherein in the inner packaging step, the electricity storage device elements are wrapped in a packaging film for the electricity storage device that is substantially the same size as the inner packaging body of the finished electricity storage device.

[0025] The electricity storage device according to a fourth aspect of the third embodiment of the present disclosure comprises an electricity storage device element, an inner packaging body that houses the electricity storage device element, and an outer packaging body that houses the inner packaging body in which the electricity storage device element is housed, wherein the inner packaging body is formed of a transparent packaging film for electricity storage devices.

[0026] An energy storage device according to a fifth aspect of the third embodiment of the present disclosure is the energy storage device according to the fourth aspect, further comprising a metal terminal electrically connected to the energy storage device element and a tab film arranged between the inner packaging body and the metal terminal, wherein 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 portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0027] An energy storage device according to a sixth aspect of the third embodiment of the present disclosure is the energy storage device according to the fourth aspect, further comprising a metal terminal electrically connected to the energy storage device element, and a tab film arranged between the inner packaging body and the outer packaging body and the metal terminal, wherein the inner packaging body and the outer packaging body are joined to the metal terminal via the tab film, and the entire inner packaging body is covered by the outer packaging body.

[0028] The seventh aspect of the third embodiment of the present disclosure is an energy storage device according to the fourth aspect, further comprising a metal terminal electrically connected to the energy storage device element, the inner packaging body and the metal terminal are joined, and at least a portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0029] An eighth aspect of the third embodiment of the present disclosure is an energy storage device according to the fourth aspect, further comprising a metal terminal electrically connected to the energy storage device element, the inner packaging body and the outer packaging body being joined to the metal terminal, and the entire inner packaging body being covered by the outer packaging body.

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

[0031] (Fourth aspect) A manufacturing method for an electricity storage device according to a first aspect of the fourth embodiment of the present disclosure is a manufacturing method for an electricity storage device, the electricity storage device comprising an electricity storage device element and an inner packaging body that houses the electricity storage device element, the inner packaging body being constituted by a packaging film for an electricity storage device having gas permeability, and the method includes an inner packaging step of wrapping the electricity storage device element with the packaging film for an electricity storage device, an inner sealing step that is performed after the inner packaging step of sealing the packaging film for an electricity storage device so that the electricity storage device element is hermetically sealed by the packaging film for an electricity storage device, and a degassing step that is performed after the inner sealing step of releasing gas generated from the electricity storage device element through the packaging film for an electricity storage device.

[0032] A manufacturing method for an electricity storage device according to a second aspect of the fourth embodiment of the present disclosure is a manufacturing method for an electricity storage device according to the first aspect, wherein in the inner packaging step, the electricity storage device elements are wrapped in a packaging film for the electricity storage device that is substantially the same size as the inner packaging body of the finished electricity storage device.

[0033] The third aspect of the fourth embodiment of the present disclosure provides an electricity storage device comprising an electricity storage device element, an inner packaging body that houses the electricity storage device element, and an outer packaging body that houses the inner packaging body in which the electricity storage device element is housed, wherein the inner packaging body is formed from a gas-permeable packaging film for electricity storage devices.

[0034] An energy storage device according to a fourth aspect of the fourth embodiment of the present disclosure is an energy storage device according to the third aspect, further comprising a metal terminal electrically connected to the energy storage device element and a tab film arranged between the inner packaging body and the metal terminal, wherein 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 portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

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

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

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

[0038] (Fifth aspect) The energy storage device according to a first aspect of the fifth embodiment of the present disclosure comprises an energy storage device element, an inner packaging body that houses the energy storage device element, an outer packaging body that houses the inner packaging body in which the energy storage device element is housed, and a functional object that is arranged between the inner packaging body and the outer packaging body, and the functional object has impact absorption properties.

[0039] The second aspect of the fifth embodiment of the present disclosure provides an energy storage device comprising an energy storage device element, an inner packaging body that houses the energy storage device element, an outer packaging body that houses the inner packaging body in which the energy storage device element is housed, and a functional object that is arranged between the inner packaging body and the outer packaging body, wherein the functional object is flame retardant.

[0040] The third aspect of the fifth embodiment of the present disclosure provides an electricity storage device comprising an electricity storage device element, an inner packaging body that houses the electricity storage device element, an outer packaging body that houses the inner packaging body in which the electricity storage device element is housed, and a functional object that is arranged between the inner packaging body and the outer packaging body, wherein the functional object has cooling properties.

[0041] The fourth aspect of the fifth embodiment of the present disclosure provides an electricity storage device comprising an electricity storage device element, an inner packaging body that houses the electricity storage device element, an outer packaging body that houses the inner packaging body with the electricity 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 fire extinguishing properties.

[0042] The fifth aspect of the fifth embodiment of the present disclosure provides an electricity storage device comprising an electricity storage device element, an inner packaging body that houses the electricity storage device element, and an outer packaging body that houses the inner packaging body in which the electricity storage device element is housed, wherein at least one of the inner packaging body and the outer packaging body has at least one of shock absorption properties, flame retardancy, cooling properties, and fire extinguishing properties.

[0043] An electricity storage device according to a sixth aspect of the fifth embodiment of the present disclosure is the electricity storage device according to any one of the first to fifth aspects, wherein the inner wrapping body has at least one of transparency and gas permeability.

[0044] An electricity storage device according to a seventh aspect of the fifth embodiment of the present disclosure is an electricity storage device according to any one of the first to sixth aspects, further comprising a metal terminal electrically connected to the electricity storage device element and a tab film arranged between the inner packaging body and the metal terminal, wherein 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 portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

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

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

[0047] An energy storage device according to a tenth aspect of the fifth embodiment of the present disclosure is an energy storage device according to any one of the first to sixth aspects, further comprising a metal terminal electrically connected to the energy storage device element, the inner packaging body and the outer packaging body are joined to the metal terminal, and the entire inner packaging body is covered by the outer packaging body. Effect of the Invention

[0048] According to the first aspect of the present disclosure, a packaging film for an electricity storage device having a predetermined CO2 permeability can be provided. The packaging film for an electricity storage device according to the first aspect of the present disclosure can be suitably used as a packaging film for directly packaging an electricity storage device element. For example, in an electricity storage device in which an electricity storage device element is housed in a double-structured packaging body having an inner packaging body and an outer packaging body, the packaging film for an electricity storage device according to the first aspect of the present disclosure can be suitably used to form the inner packaging body. For example, by using the packaging film for an electricity storage device according to the first aspect of the present disclosure as the inner packaging body, sealing the electricity storage device element in the inner packaging body before housing it in the outer packaging body, and performing an initial charge / discharge process and an aging process, gas (particularly CO2) generated from the electricity storage device element can be suitably released to the outside during these processes. Therefore, it is no longer necessary to provide a space for retaining gas inside the temporarily sealed packaging film for the electricity storage device, as is the case when using an exterior material for the electricity storage device having a conventional barrier layer, and it is no longer necessary to use a packaging film for the electricity storage device that is larger than that required for the final product electricity storage device (for example, more than twice the size required to seal the electricity storage device elements) in order to remove the space containing the gas and release the gas to the outside.

[0049] Furthermore, according to the first aspect of the present disclosure, it is possible to provide an electricity storage device that utilizes the packaging film for electricity storage devices.

[0050] According to the second aspect of the present disclosure, a packaging film for an electricity storage device can be provided that has adhesiveness to metal and does not have a metal layer formed of metal. Since the packaging film for an electricity storage device according to the second aspect of the present disclosure has adhesiveness to metal, it can be adhered to, for example, a metal terminal. Specifically, the electricity storage device element can be sealed in a state in which the metal terminal is sandwiched between the heat-sealable resin layers. Furthermore, since it does not have a metal layer formed of metal, the packaging film for an electricity storage device can be made lighter and thinner. Furthermore, for example, according to the second aspect of the present disclosure, the packaging body that houses the electricity storage device can have a double structure of an inner packaging body and an outer packaging body, and the packaging film for an electricity storage device according to the present disclosure can be suitably used as the inner packaging body. According to the present disclosure, an electricity storage device using the packaging film for an electricity storage device can also be provided.

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

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

[0053] The electricity storage device according to the fifth aspect of the present disclosure has high added-value functions. [Brief description of the drawings]

[0054] [Figure 1] 1 is a schematic diagram showing an example of a cross-sectional structure of a packaging film for an electricity storage device according to the present disclosure. [Diagram 2] 1 is a schematic diagram showing an example of a cross-sectional structure of a packaging film for an electricity storage device according to the present disclosure. [Diagram 3] 1 is a schematic diagram showing an example of a cross-sectional structure of a packaging film for an electricity storage device according to the present disclosure. [Figure 4] 1 is a schematic diagram showing an example of a cross-sectional structure of a packaging film for an electricity storage device according to the present disclosure. [Diagram 5]3 is a schematic diagram for explaining a method of housing an electricity storage device element in a package formed from the electricity storage device packaging film of the present disclosure. FIG. [Figure 6] 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure. [Figure 7] 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure. [Figure 8] 1A to 1C are plan views of electricity storage devices according to embodiments A1, B1 and C1 of the first and second aspects, and according to the third, fourth and fifth aspects. [Figure 9] 9 is a cross-sectional view taken along line D2-D2 of the first and second embodiments A1 and B1, the third embodiment, and the fourth embodiment of FIG. 8. [Figure 10] 9 is a flowchart showing an example of a method for manufacturing an electricity accumulation device for the first and second embodiments A1 and B1, the third and fourth aspects of FIG. 8. [Figure 11] 11 is a diagram relating to the inner wrapping step of FIG. 10, and is the same for the embodiment C1 of the first and second aspects, the third aspect, the fourth aspect and the fifth aspect. [Figure 12] 11 is a diagram relating to the first inner sealing step of FIG. 10, and is the same for embodiment C1 of the first and second aspects, the third, fourth and fifth aspects. [Figure 13] 11 is a diagram relating to the second inner sealing step of FIG. 10, and is the same for embodiment C1 of the first and second aspects, the third, fourth and fifth aspects. [Figure 14] 10 is a flowchart showing an example of a method for manufacturing an electricity storage device according to embodiments A2 and B2 of the first and second aspects, the third and fourth aspects. [Figure 15] 15 is a diagram relating to the inner wrapping step of FIG. 14, and is the same for embodiment C2 of the first and second aspects, the third, fourth and fifth aspects. [Figure 16]15 is a diagram relating to the first inner sealing step of FIG. 14, and is similar to embodiment C2 of the first and second aspects, the third, fourth and fifth aspects. [Figure 17] 15 is a diagram relating to the second inner sealing step of FIG. 14, and is the same for embodiment C2 of the first aspect and the second aspect, the third aspect, the fourth aspect and the fifth aspect. [Figure 18] 15 is a diagram relating to the inner sealing step of FIG. 14, and is similar to embodiment C2 of the first and second aspects, the third, fourth and fifth aspects. [Figure 19] 10 is a cross-sectional view of a terminal seal portion of an electricity storage device according to embodiments A2 and B2 of the first and second aspects, a third aspect, and a fourth aspect. FIG. [Figure 20] FIG. 13 is a cross-sectional view of a terminal seal portion of electricity storage devices according to embodiments A3 and B3 of the first and second aspects, the third aspect, and the fourth aspect. [Figure 21] FIG. 13 is a cross-sectional view of a terminal seal portion of electricity storage devices according to embodiments A3 and B3 of the first and second aspects, the third aspect, and the fourth aspect. [Figure 22] 9 is a cross-sectional view taken along line D2-D2 of the embodiment C1 of the first and second aspects and the fifth aspect of FIG. 8. FIG. [Figure 23] 9 is a flowchart showing an example of a method for manufacturing an electricity accumulation device for the embodiment C1 of the first and second aspects and the fifth aspect of FIG. 8. [Figure 24] 13 is a flowchart showing an example of a method for manufacturing an electricity accumulation device according to embodiment C2 of the first and second aspects, and a fifth aspect. [Diagram 25] 13 is a cross-sectional view of a terminal seal portion of an electricity storage device according to embodiment C2 of the first and second aspects, and a fifth aspect. FIG. [Figure 26] FIG. 13 is a cross-sectional view of a terminal seal portion of an electricity storage device according to embodiment C3 of the first and second aspects, and a fifth aspect. [Figure 27]FIG. 13 is a cross-sectional view of a terminal seal portion of an electricity storage device according to embodiment C3 of the first and second aspects, and a fifth aspect. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] The packaging film for an electricity storage device according to the first aspect of the present disclosure is a packaging film for an electricity storage device that includes at least a heat-sealable resin layer, and has a CO2 permeation rate of 100 cc·100 μm / m in an environment at a temperature of 30° C. 2 / 24hr / atm or higher.

[0056] A packaging film for an electricity storage device according to a second aspect of the present disclosure is a packaging film for an electricity storage device having at least a heat-sealable resin layer, which is characterized by having adhesion to metal and not having a metal layer formed from metal.

[0057] The packaging film for a power storage device of the present disclosure will be described in detail below. In the present disclosure, a numerical range indicated by "~" means "more than or equal to" or "less than or equal to". For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less. In the numerical ranges described in the present disclosure in stages, the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of another numerical range described in stages. In addition, a numerical range may be formed by combining an upper limit and an upper limit, an upper limit and a lower limit, or a lower limit and a lower limit, each of which is described separately. In the numerical ranges described in the present disclosure, the upper limit or lower limit described in a certain numerical range may be replaced with a value shown in the examples.

[0058] In the present disclosure, the shielding layer means a layer that blocks light transmission, and when the packaging film for an electricity storage device of the present disclosure has a shielding layer, the shielding layer makes it difficult to see the contents of the electricity storage device (e.g., electricity storage device elements). In addition, the metal layer means a layer formed of metal, and examples thereof include metal foil and metal plate, and the thickness of the metal foil is, for example, about 10 to 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, matters specific to each of the first to fifth aspects of the present disclosure will be clearly indicated as to which aspect the description pertains to, and matters common to each aspect will be comprehensively described as matters related to the present disclosure without any particular indication. Note that, first, the contents common to the entire present disclosure and the contents related to the first and second aspects of the present disclosure will be described, and then the contents related to the third to fifth aspects will be described.

[0060] 1.Layer structure and physical properties of packaging film for energy storage devices 1 to 4, the packaging film 10 for an electricity storage device according to the present disclosure includes at least a heat-sealable resin layer 1. When assembling an electricity storage device using the packaging film 10 for an electricity storage device and an electricity storage device element, the heat-sealable resin layers 1 of the packaging film 10 for an electricity storage device are placed opposite each other, and the electricity storage device element is housed in a space formed by heat-sealing the peripheral portions.

[0061] As shown in Fig. 1, the packaging film 10 for an electricity storage device may be composed only of a heat-sealable resin layer 1. When the packaging film 10 for an electricity storage device is composed only of a 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] 2 to 4, the packaging film 10 for an electricity storage device according to 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 an electricity storage device, the resin layer 2 is on the outside and the heat-sealable resin layer 1 is on the inside (the innermost layer). When the packaging film 10 for an electricity storage device is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, it is preferable to impart adhesion 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 and 4, the packaging film 10 for an electricity storage device according to the present disclosure is preferably composed of a laminate including at least a resin layer 2, a substrate 3, and the heat-sealable resin layer 1. In such a packaging film 10 for an electricity storage device, the resin layer 2 is on the outside, the heat-sealable resin layer 1 is on the inside (the innermost layer), and the substrate 3 is located between the resin layer 2 and the heat-sealable resin layer 1. Even when the packaging film 10 for an electricity storage device is composed of a laminate including the resin layer 2, the substrate 3, and the heat-sealable resin layer 1, it is preferable to impart adhesion 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 Figures 2 and 4, adhesive layers 4 and 5 can be provided between the resin layer 2 and the substrate 3 or the heat-sealable resin layer 1, and between the heat-sealable resin layer 1 and the substrate 3 or the resin layer 2, respectively.

[0065] The packaging film 10 for an electricity storage device according to the first embodiment of the present disclosure has a CO2 permeation rate of 100 cc·100 μm / m in an environment at a temperature of 30° C. 2 / 24hr / atm or more, preferably about 200cc 100μm / m 2 / 24hr / atm or more, more preferably about 300cc·100μm / m 2 / 24hr / atm or more, more preferably about 500cc 100μm / m 2 The CO2 permeation amount of the packaging film 10 for an electricity storage device according to the first embodiment of the present disclosure is, for example, about 2000 cc·100 μm / m 2 / 24hr / atm or less, preferably about 1000cc 100μm / m 2 / 24hr / atm or less, more preferably about 800cc·100μm / m 2 / 24hr / atm or less, and the preferred range is 100 to 2000cc 100μm / m 2 / 24hr / atm, 100~1000cc・100μm / m 2 / 24hr / atm, 100~800cc・100μm / m 2Approximately / 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 CO₂ permeability of the packaging film for the power storage device is as follows.

[0066] <Measurement of CO₂ Permeability> In accordance with JIS K7126 - 1 (Plastics - Films and Sheets - Test Method for Gas Permeability - Part 1: Differential Pressure Method), in an atmosphere of 30°C, the CO₂ 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 amount.

[0067] When imparting shielding properties to the packaging film 10 for the power storage device of the present disclosure, 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, 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 packaging film 10 for the power storage device 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 necessary.

[0069] The thickness of the laminate constituting the packaging film 10 for electricity storage devices is not particularly limited, but from the viewpoints of cost reduction, energy density improvement, etc., it is, for example, 190 μm or less, preferably about 180 μm or less, about 170 μm or less. In addition, from the viewpoint of maintaining the function of the packaging film for electricity storage devices, which is to protect the electricity storage device elements, the thickness of the laminate constituting the packaging film 10 for electricity storage devices is preferably about 35 μm or more, about 45 μm or more, about 60 μm or more. In addition, the preferred range of the laminate constituting the packaging film 10 for electricity storage devices is, 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, and particularly preferably about 45 to 170 μm.

[0070] In the packaging film 10 for electricity storage devices, the ratio of the total thickness of the resin layer 2, adhesive layer 4, substrate 3, adhesive layer 5, and heat-sealable resin layer 1 to the thickness (total thickness) of the laminate constituting the packaging film 10 for electricity storage devices 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 electricity storage devices of the present disclosure includes the resin layer 2, adhesive layer 4, substrate 3, adhesive layer 5, and 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 electricity storage devices is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. Furthermore, even when the packaging film 10 for an electricity storage device of the present disclosure is a laminate including a resin layer 2, an adhesive layer 4, and a 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 an electricity 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.

[0071] The laminate constituting the packaging film 10 for an electricity storage device of the present disclosure can have a total light transmittance measured in accordance with the provisions of JIS K7361-1:1997 of, for example, 20% or less, 15% or less, 10% or less, 8% or less, etc. Furthermore, the laminate constituting the packaging film 10 for an electricity storage device of the present disclosure can have a total light transmittance measured in accordance with the provisions of JIS K7361-1:1997 of, for example, 80% or more, 85% or more, 90% or more, etc. The lower the total light transmittance, the higher the shielding property of the packaging film 10 for an electricity storage device can be exhibited. On the other hand, the higher the total light transmittance, the higher the light transmittance of the packaging film 10 for an electricity storage device can be exhibited. The lower limit of the total light transmittance is 0%, and the upper limit is 100%. The total light transmittance of the packaging film for power storage devices is measured in accordance with the measurement method specified in JIS K7361-1:1997 using a commercially available spectrophotometer (e.g., JASCO Corporation's UV-Vis-Near-Infrared Spectrophotometer V-670) in the visible light region (400-700 nm), and the average value is taken as the total light transmittance. The measurement conditions are as follows: a halogen lamp is used as the light source, UV / Vis bandwidth: 5.0 nm, scanning speed: 1000 nm / min, response: Medium, data acquisition interval: 1.0 nm.

[0072] The packaging film 10 for the electricity storage device can be black. When the packaging film 10 for the electricity storage device is black, the packaging film 10 for the electricity storage device has high shielding properties and high anti-counterfeiting effects. In addition, in the manufacturing process of the electricity storage device, it becomes possible to grasp the position with a sensor with higher accuracy, and it becomes possible to transport the packaging film 10 for the electricity storage device and seal the electricity storage device elements more accurately. Furthermore, it is possible to unify the electricity storage device and other electrical equipment in black to give the product a sense of luxury.

[0073] The packaging film 10 for an electricity storage device according to the second embodiment of the present disclosure has a CO2 permeation rate of preferably 100 cc·100 μm / m in an environment at a temperature of 30° C. 2 / 24hr / atm or more, and more preferably about 200cc 100μm / m 2Above / 24hr / atm, more preferably about 300 cc·100μm / m 2 Above / 24hr / atm, more preferably about 500 cc·100μm / m 2 Above / 24hr / atm. Further, the CO2 permeation amount of the packaging film 10 for the power storage device according to the second aspect of the present disclosure 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 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 CO2 permeation amount of the packaging film for the power storage device is as follows.

[0074] <Measurement of CO2 Permeation Amount> In accordance with JIS K7126-1 (Plastics - Films and sheets - Gas permeability test method - Part 1: Differential pressure method), the amount of CO2 that permeates through a φ60 mm piece of packaging film 10 for electricity storage devices in an atmosphere at 30°C is quantitatively analyzed by gas chromatography to measure the amount of CO2 that permeates through the φ60 mm piece of packaging film 10 for electricity storage devices.

[0075] 2. Each layer that forms the packaging film for electricity storage devices [Thermal adhesive resin layer 1] In the packaging film 10 for an electricity storage device of the present disclosure, the heat-sealable resin layer 1 corresponds to the innermost layer and is a layer (sealant layer) that functions to seal the electricity storage device elements by heat-sealing the heat-sealable resin layers together when the electricity storage device is assembled.

[0076] The packaging film 10 for an electricity storage device according to the first embodiment of the present disclosure may or may not have adhesiveness to metal, but preferably has adhesiveness to metal. For example, when the packaging film 10 for an electricity storage device according to the first embodiment is composed of only 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. When the packaging film 10 for an electricity storage device according to the first embodiment is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, it is preferable that at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1 is given adhesiveness to metal. Also, when the packaging film 10 for an electricity storage device according to the first embodiment is composed of a laminate including the resin layer 2, the substrate 3, and the heat-sealable resin layer 1, it is sufficient to give 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.

[0077] Furthermore, when a shielding layer S is provided in the packaging film 10 for an electricity storage device of the first embodiment of the present disclosure, it is preferable that the heat-sealable resin layer 1 of the packaging film 10 for an electricity storage device is transparent and is used by laminating it with a shielding layer S constituted by a layer separate from the heat-sealable resin layer 1, but the shielding layer S may also be constituted by blending the above-mentioned colorant or the like with the heat-sealable resin layer 1.

[0078] In addition, when the packaging film 10 for an electricity storage device according to the second embodiment 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 adhesion to metal. In the case where the packaging film 10 for an electricity storage device according to the second embodiment is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1 may be provided with adhesion to metal. In the case where the packaging film 10 for an electricity storage device according to the second embodiment is composed of a laminate including the resin layer 2, the substrate 3, and the heat-sealable resin layer 1, at least one of the outer surface of the resin layer 2 and the inner surface of the heat-sealable resin layer 1 may be provided with adhesion to metal.

[0079] When providing a shielding layer S in the packaging film 10 for electricity storage devices of the second embodiment, it is preferable that the heat-sealable resin layer 1 is transparent and is used by laminating it with a shielding layer S composed of a layer separate from the heat-sealable resin layer 1, but the shielding layer S may also be formed by blending the above-mentioned colorant or the like with the heat-sealable resin layer 1.

[0080] The resin constituting the heat-sealable resin layer 1 in the first embodiment is heat-sealable, and the CO2 permeation amount of the packaging film 10 for an electricity storage device is 100 cc·100 μm / m 2 Although there is no particular limitation as long as the maximum is 1 / 24hr / atm or more, polyolefins and resins containing a polyolefin skeleton such as acid-modified polyolefins are preferred. Polyolefins are preferred because they have heat fusion properties and also have a very high CO2 permeability.

[0081] The resin constituting the heat-fusible resin layer 1 in the second embodiment is not particularly limited as long as it is heat-fusible, but is preferably a resin containing a polyolefin skeleton such as polyolefin or acid-modified polyolefin.

[0082] The resin constituting the thermally adhesive resin layer 1 can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, etc. Furthermore, when the resin constituting the thermally adhesive resin layer 1 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, a peak derived from maleic anhydride at a wave number of 1760 cm is detected. -1 Nearby and wave number 1780cm -1 A peak derived from maleic anhydride is detected near the peak. When the thermally adhesive resin layer 1 is a layer composed of maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected by infrared spectroscopy. However, if the degree of acid modification is low, the peak becomes small and may not be detected. In that case, analysis can be performed by nuclear magnetic resonance spectroscopy.

[0083] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes 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); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. Among these, polypropylene is preferred. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more.

[0084] The polyolefin may be a cyclic polyolefin. The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefins constituting the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of the cyclic monomers constituting the cyclic polyolefin include cyclic alkenes such as norbornene; and 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. An acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of a polyolefin with an acid component. The polyolefin to be acid-modified may be 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. In addition, examples of the acid component used for the acid modification include carboxylic acids or anhydrides such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[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 it with an acid component, or by block-polymerizing or graft-polymerizing an acid component to the cyclic polyolefin. The cyclic polyolefin to be acid-modified is the same as described above. The acid component used for the acid modification is the same as the acid component used for the modification of the polyolefin.

[0087] Preferred acid-modified polyolefins include polyolefins modified with a carboxylic acid or anhydride thereof, polypropylenes modified with a carboxylic acid or anhydride thereof, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

[0088] The thermally adhesive resin layer 1 may be formed of one type of resin alone, or may be formed of a blend polymer of two or more types of resins. Furthermore, the thermally adhesive resin layer 1 may be formed of only one layer, or may be formed of two or more layers of the same or different resins.

[0089] When at least a part of the inner surface of the packaging film 10 for an electricity storage device is to be bonded to a metal (e.g., 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 made of an acid-modified polyolefin (acid-modified polypropylene, acid-modified polyethylene, etc.). The above-mentioned non-acid-modified polyolefin does not have adhesiveness to metal, and therefore is not suitable as a resin for forming the inner surface of the heat-sealable resin layer 1 when metal adhesiveness is to be imparted to the inner surface of the heat-sealable resin layer 1.

[0090] The heat-sealable resin layer 1 may contain a lubricant, etc., if necessary. When the heat-sealable resin layer 1 contains a lubricant, the formability of the packaging film for the electricity storage device can be improved. The lubricant is not particularly limited, and a known lubricant can be used. The lubricant may be used alone or in combination of two or more kinds.

[0091] The lubricant is not particularly limited, but preferably includes an amide-based lubricant. 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 types of lubricants, adhesion of the lubricant to a die when cold-forming the packaging film 10 for the electricity storage device with a die due to the interaction between the lubricants, etc., can be reduced, and continuous productivity of the electricity storage device can be suitably improved. This also applies to 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 of the lubricant present is not particularly limited. From the viewpoint of improving the formability of the packaging film for the electricity storage device, however, it is preferably 10 to 50 mg / m 2 about 15 to 40 mg / m 2 The degree of

[0093] The lubricant present on the surface of the heat-fusible resin layer 1 may be a lubricant exuded from the resin constituting the heat-fusible resin layer 1, or a lubricant applied to the surface of the heat-fusible resin layer 1.

[0094] The thickness of the heat-sealable resin layer 1 is not particularly limited as long as it functions to seal the electricity storage device elements by heat-sealing the heat-sealable resin layers to each other, but may be, for example, 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 functioning as a base material of the packaging film for an electricity storage device, etc. When the packaging film 10 for an electricity storage device has the resin layer 2, the resin layer 2 is located on the outer layer side of the packaging film for an electricity storage device.

[0096] The material forming the resin layer 2 in the first embodiment is at least insulating, and the CO2 permeation amount of the packaging film 10 for the electricity storage device is 100 cc·100 μm / m 2 / 24hr / atm or more is not particularly limited. The resin layer 2 of the first embodiment can be formed using a resin, and the resin may contain an additive described later. When the shielding layer S is provided in the packaging film 10 for an electricity storage device of the first embodiment, it is preferable that the resin layer 2 is transparent and is used by laminating with the shielding layer S constituted by a layer other than the resin layer 2, but the shielding layer S may be constituted by blending a colorant described later or the like with the resin layer 2.

[0097] The material for forming the resin layer 2 of the second embodiment is not particularly limited, as long as it has at least insulating properties. The resin layer 2 of the second embodiment can be formed using a resin, which may contain an additive described later. The resin layer 2 of the second embodiment is preferably transparent and laminated with a shielding layer S composed of a layer other than the resin layer 2, but the shielding layer S may be formed by blending a colorant described later with the resin layer 2.

[0098] In the present disclosure, the resin layer 2 may be, for example, a resin film formed from a resin, or may be formed by applying a resin. The resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, and biaxially stretched films are preferred. Examples of stretching methods for forming biaxially stretched films include sequential biaxial stretching, inflation, and simultaneous biaxial stretching. Examples of methods for applying a resin include roll coating, gravure coating, and extrusion coating.

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

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

[0101] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyesters. Examples of copolymerized polyesters include copolymerized polyesters in which ethylene terephthalate is the main repeating unit. Specific examples of polyesters include copolymerized polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), and polyethylene (terephthalate / decane dicarboxylate). These polyesters may be used alone or in combination of two or more.

[0102] Specific examples of polyamides 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 (I represents isophthalic acid, and T represents terephthalic acid) that contain structural units derived from terephthalic acid and / or isophthalic acid, and polyamides containing aromatic compounds such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); polyamides copolymerized with a lactam component or an isocyanate component such as 4,4'-diphenylmethane diisocyanate; polyesteramide copolymers and polyetheresteramide copolymers that are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and polyamides such as copolymers of these copolymers. These polyamides may be used alone or in combination of two or more.

[0103] In addition, the polyolefin is preferably a resin having a polyolefin skeleton, such as polyolefin or acid-modified polyolefin. The polyolefin is preferable from the viewpoint of imparting heat fusion to the outer surface of the resin layer 2. Specific examples of the polyolefin include the same polyolefins as those exemplified for the heat fusion resin layer 1 described above.

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

[0105] In the present disclosure, when at least a part of the outer surface of the packaging film 10 for an electricity storage device is adhered to a metal or the like, the resin layer 2 is the outermost layer, and the outer surface of the resin layer 2 has adhesiveness to 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 made of an acid-modified polyolefin (acid-modified polypropylene, acid-modified polyethylene, etc.). As described for the heat-sealable resin layer 4, the above-mentioned non-acid-modified polyolefin does not have adhesiveness to metal, and therefore is not suitable as a resin constituting the outer surface of the resin layer 2 when metal adhesiveness is imparted to the outer surface of the resin layer 2. Note that, as described above, when adhesiveness to metal is imparted to the outer surface of the base material layer 1, the packaging film 10 for an electricity storage device can be used as an inner packaging body, and the outer surface of the packaging film 10 for an electricity storage device can be suitably adhered to an outer packaging body made of metal (for example, metal foil, metal can, etc.).

[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 a resin film is laminated with an adhesive or an adhesion promoter, or may be a laminate of resin films in which resins are co-extruded to form two or more layers. In addition, a laminate of resin films in which resins are co-extruded to form two or more layers may be used as the resin layer 2 as is, 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, and a laminate of two or more polyester films, and 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. 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 a nylon film and a nylon film, or a laminate of a polyethylene terephthalate film and a nylon film is more preferred. In addition, when the resin layer 2 is a laminate of two or more resin films, it is preferred that the polyester resin film is located in the outermost layer of the resin layer 2, because the polyester resin is less likely to discolor when, for example, an electrolyte is attached to the surface.

[0108] In addition, from the viewpoint of imparting thermal fusion to the outer surface of the resin layer 2 of the present disclosure, specific examples of the laminate of two or more resin films are preferably 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 polypropylene film and polyethylene terephthalate film, a laminate of polypropylene film and polyethylene naphthalate film, a laminate of polypropylene film and polybutylene terephthalate film, a laminate of acid-modified polypropylene film and polyethylene terephthalate film, a laminate of acid-modified polypropylene film and polyethylene naphthalate film, and a laminate of acid-modified polypropylene film and polybutylene terephthalate film are preferred. In addition, 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 preferred. 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 preferred.

[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. Preferred adhesives and adhesion promoters include those similar to those exemplified in the adhesive layers 4 and 5 described below. The method for laminating two or more resin films is not particularly limited, and a known method can be adopted, for example, a dry lamination method, a sandwich lamination method, an extrusion lamination method, a thermal lamination method, etc., and preferably a dry lamination method. When laminating by the dry lamination method, it is preferable to use a polyurethane adhesive as the adhesive. In this case, the thickness of the adhesive is, for example, about 2 to 5 μm. In addition, an anchor coat layer may be formed on the resin film and laminated. The anchor coat layer may be the same as the adhesive exemplified in the adhesive layers 4 and 5 described below. In this case, 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 lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be present on at least one of the surface and the interior of the 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 improving the formability 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 is preferably an amide-based lubricant. Specific examples of amide-based lubricants 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, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amides, palmitic acid amides, stearic acid amides, behenic acid amides, and hydroxystearic acid amides. Specific examples of unsaturated fatty acid amides include oleic acid amides and erucic acid amides. Specific examples of substituted amides include N-oleyl palmitic acid amides, N-stearyl stearic acid amides, N-stearyl oleic acid amides, N-oleyl stearic acid amides, and N-stearyl erucic acid amides. Specific examples of methylol amides include methylol stearic acid amides. Specific examples of 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, etc. Specific examples of 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, etc. Specific examples of fatty acid ester amides include stearamide ethyl stearate, etc. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, N,N'-distearylisophthalic acid amide, etc. 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 of the lubricant present is not particularly limited, but is preferably about 3 mg / m 2 More preferably, 4 to 15 mg / m 2 about 5 to 14 mg / m 2 The degree of

[0113] In the present disclosure, the lubricant present on the surface of resin layer 2 may be a lubricant exuded from the resin constituting resin layer 2, or a lubricant applied to the surface of resin layer 2.

[0114] In the present disclosure, the thickness of the resin layer 2 is not particularly limited, but may be, for example, about 3 to 50 μm, and preferably about 10 to 35 μm. When the resin layer 2 is a laminate of two or more resin films, the thickness of each of the resin films constituting the layers is preferably about 2 to 25 μm.

[0115] [Base material 3] In the packaging film 10 for an electricity storage device according to the present disclosure, the substrate 3 is a layer that functions as a support. When the packaging film 10 for an electricity storage device includes a resin layer 2, a substrate 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 (the innermost layer), and the substrate 3 is located between the resin layer 2 and the heat-sealable resin layer 1.

[0116] In the packaging film 10 for an electricity storage device according to the present disclosure, a colorant or the like can be blended into the base material 3 to form a shielding layer S.

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

[0118] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolymerized polyesters mainly composed of ethylene terephthalate as repeating units, copolymerized polyesters mainly composed of butylene terephthalate as repeating units, etc. Specific examples of copolymerized polyesters mainly composed of ethylene terephthalate as repeating units include copolymer polyesters in which ethylene terephthalate as a main repeating unit is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), polyethylene (terephthalate / decane dicarboxylate), etc. Specific examples of copolymer polyesters containing butylene terephthalate as the main repeating unit include copolymer polyesters in which butylene terephthalate is the main repeating unit and is polymerized with butylene isophthalate (hereinafter abbreviated as polybutylene (terephthalate / isophthalate)), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate, etc. These polyesters may be used alone or in combination of two or more.

[0119] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; crystalline or amorphous polypropylenes 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 ethylene-butene-propylene terpolymers. Among these polyolefins, polyethylene and polypropylene are preferred, and polypropylene is more preferred. In addition, since the substrate 3 has excellent electrolyte resistance, it is preferred that the substrate 3 contains homopolypropylene, it is more preferred that the substrate 3 is formed of homopolypropylene, and it is even more preferred that the substrate 3 is an unstretched homopolypropylene film.

[0120] Specific examples of polyamides 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 (I represents isophthalic acid, and T represents terephthalic acid) containing structural units derived from terephthalic acid and / or isophthalic acid, and aromatic polyamides such as polymetaxylylene adipamide (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); polyamides copolymerized with lactam components and isocyanate components such as 4,4'-diphenylmethane-diisocyanate, polyesteramide copolymers and polyetheresteramide copolymers which are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and copolymers thereof. These polyamides may be used alone or in combination of two or more.

[0121] The substrate 3 of the present disclosure may be formed of a nonwoven fabric made of the above-mentioned resin. When the substrate 3 is a nonwoven fabric, the substrate 3 is preferably made of the above-mentioned polyolefin resin, polyamide resin, or the like.

[0122] The substrate 3 of the present disclosure may be a single layer or multiple layers.

[0123] When the substrate 3 of the present disclosure is composed of a resin film, the surface of the substrate 3 may be subjected to a known adhesion enhancing means such as corona discharge treatment, ozone treatment, or plasma treatment, as necessary.

[0124] From the viewpoint of more suitably 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, even more preferably about 50 μm or less, and even more preferably about 40 μm or less. The thickness of the base material 3 is preferably about 5 μm or more, more preferably about 8 μm or more, and even 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 layer 4,5] In the packaging film 10 for an electricity storage device of the present disclosure, the adhesive layers 4 and 5 are layers that are provided as necessary between the resin layer 2 and the substrate 3 or the heat-sealable resin layer 1, and between the heat-sealable resin layer 1 and the substrate 3 or the resin layer 2, respectively, for the purpose of enhancing adhesion therebetween. The adhesive layer 4 bonds the resin layer 2 to the substrate 3 or the heat-sealable resin layer 1. The adhesive layer 5 bonds the heat-sealable resin layer 1 to the resin layer 2 or the substrate 3. The above-mentioned anchor coat layer can also be used as the adhesive layers 4 and 5.

[0126] In the packaging film 10 for a storage battery device, a colorant or the like can be blended into the adhesive layers 4 and 5 to form the shielding layer S. For example, if a colorant is blended into the adhesive forming the adhesive layer 4 and a shielding layer is formed by one coating, there is no need to provide a separate shielding layer at a location other than the adhesive layer 4. In this way, the number of steps is reduced, production efficiency is improved, and the risk of foreign matter contamination is reduced compared to, for example, a case in which a separate colored layer is provided as a shielding layer. In addition, if a colored layer is provided between the resin layer 2 and the adhesive layer 4, there is a risk that the interfacial strength between the resin layer 2 and the colored layer and between the colored layer and the adhesive layer 4 will 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, 5 are formed of an adhesive or an adhesion promoter that can adhere to the resin layer 2 or the heat-fusible resin layer 1. The adhesive used to form the adhesive layers 4, 5 is not limited, and may be any of a chemical reaction type, a solvent volatilization type, a thermal melting type, a thermal pressure type, etc. Also, it may be a two-component curing adhesive (two-component adhesive), a one-component curing adhesive (one-component adhesive), or a resin that does not involve a curing reaction. Also, the adhesive layers 4, 5 may be a single layer or a multilayer.

[0128] Specific examples of adhesive components contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyesters; polyethers; polyurethanes; epoxy resins; phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins; polyvinyl acetate; cellulose; (meth)acrylic resins; polyimides; polycarbonates; amino resins such as urea resins and melamine resins; 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, polyurethane adhesives are preferred. In addition, the adhesive strength of these adhesive component resins can be increased by using an appropriate curing agent in combination. The curing agent is selected from polyisocyanates, multifunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, and the like, depending on the functional groups of the adhesive components.

[0129] Examples of polyurethane adhesives include polyurethane adhesives containing a first agent containing a polyol compound and a second agent containing an isocyanate compound. A two-liquid curing type polyurethane adhesive is preferably used, in which a polyol such as polyester polyol, polyether polyol, and acrylic polyol is used as the first agent, and an aromatic or aliphatic polyisocyanate is used as the second agent. Examples of polyurethane adhesives include polyurethane adhesives containing a polyurethane compound in which a polyol compound and an isocyanate compound have been reacted in advance, and an isocyanate compound. Examples of polyurethane adhesives include polyurethane adhesives containing a polyurethane compound in which a polyol compound and an isocyanate compound have been reacted in advance, and a polyol compound. Examples of polyurethane adhesives include polyurethane adhesives in which a polyurethane compound in which a polyol compound and an isocyanate compound have been reacted in advance is cured by reacting it with moisture in the air or the like. As the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group on the side chain in addition to the hydroxyl group at the end of the repeating unit. Examples of the second agent include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds. Examples of isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI). In addition, examples include polyfunctional isocyanate modified products of one or more of these diisocyanates. In addition, a polymer (e.g., a trimer) can also be used as the polyisocyanate compound. Examples of such a polymer include an adduct, a biuret, and a nurate. The adhesive layers 4 and 5 are formed of a polyurethane adhesive, which gives the packaging film for the electricity storage device excellent electrolyte resistance, and prevents the resin layer 2 from peeling off even if the electrolyte adheres to the side surface.

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

[0131] [ka]

[0132] In addition, the adhesive layers 4 and 5 may contain other components as long as they do not impair adhesion, and may contain colorants, thermoplastic elastomers, tackifiers, fillers, etc. The adhesive layers 4 and 5 contain a colorant, so that the packaging film for the electricity storage device can be colored. If the adhesive layers 4 and 5 are colored to an extent that the packaging film for the electricity storage device can be given shielding properties, the adhesive layers 4 and 5 can be used as the shielding layer S. As the colorant, known pigments, dyes, etc. can be used. In addition, only one type of colorant may be used, or two or more types may be mixed together.

[0133] The type of pigment is not particularly limited as long as it does not impair the adhesiveness of the adhesive layers 4 and 5. Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments, while examples of inorganic pigments include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, iron-based, and copper-based pigments, and other examples include fine powder of mica, fish scale foil, and the like.

[0134] Among colorants, for example, in order to make the appearance of the packaging film for the electricity storage device black, a black colorant is preferred, and among black colorants, carbon black is preferred. By using a black colorant to produce a black packaging film for the electricity storage device 10, the packaging film for the electricity storage device 10 has high shielding properties and high anti-counterfeiting effects. In addition, in the manufacturing process of the electricity storage device, it is possible to grasp the position with a sensor with higher accuracy, and it is possible to transport the packaging film for the electricity storage device 10 and seal the electricity storage device element more accurately. Furthermore, it is possible to unify the electricity storage device and other electrical equipment in black to give the product a sense of luxury. Carbon black is a more preferred colorant in terms of its high shielding properties.

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

[0136] The content of the pigment in the adhesive layers 4, 5 is not particularly limited as long as the packaging film for electricity storage devices is colored, and is, for example, about 5 to 60 mass %, preferably 10 to 40 mass %.

[0137] The thickness of the adhesive layers 4 and 5 is not particularly limited as long as it can bond the resin layer 2 and the heat-fusible resin layer 1, but is, for example, about 1 μm or more, about 2 μm or more. The thickness of the adhesive layers 4 and 5 is, for example, about 10 μm or less, about 5 μm or less. The preferred range of the thickness of the adhesive layers 4 and 5 is about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, or about 2 to 5 μm.

[0138] [Colored layer C] In the present disclosure, although not shown, the colored layer C is a layer provided between the resin layer 2 and the heat-sealable resin layer 1, and on the outside of the resin layer 2, as necessary. When the adhesive layers 4 and 5 are provided, the colored layer C may be provided between the resin layer 2 and the adhesive layers 4 and 5. By providing the colored layer C, the packaging film for the electric storage device can be colored. If the colored layer C is colored to an extent that the packaging film for the electric storage device can be given shielding properties, the colored layer C can be the shielding layer S. In the packaging film for the electric storage device 10, it is preferable that the colored layer C is the shielding layer S. The colored layer C between the resin layer 2 and the heat-sealable resin layer 1 may be referred to as the inner colored layer, and the colored layer C on the outside of the resin layer 2 may be referred to as the outer colored layer. It is preferable that the colored layer C is provided on at least one surface of the resin layer 2 (i.e., the resin layer 2 and the colored layer C are in contact with each other).

[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 substances such as pigments and dyes can be used. Furthermore, only one type of colorant may be used, or two or more types may be mixed together.

[0140] In the present disclosure, specific examples of the colorant contained in the colored layer C include the same as those exemplified in the section [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 an electricity storage device is colored, but is, for example, about 1 μm or more, about 2 μm or more. The thickness of the colored layer C is, for example, about 10 μm or less, about 5 μm or less. Preferred ranges for 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 an electricity storage device according to the present disclosure may have a surface coating layer (not shown) on the resin layer 2 (the side of the resin layer 2 opposite to the heat-sealable resin layer 1) as necessary, for the purpose of improving at least one of design, electrolyte resistance, scratch resistance, formability, and the like. The surface coating layer is a layer located on the outermost layer side of the packaging film for an electricity storage device when an electricity storage device is assembled using the packaging film for an electricity storage device. The surface coating layer may be blended with the above-mentioned colorant or the like to form a shielding layer S.

[0143] The surface coating layer may be, for example, a resin such as polyvinylidene chloride, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, or phenol resin, or a modified product of these resins. It may also be a copolymer of these resins or a modified product of the copolymer. Furthermore, it may be a mixture of these resins. The resin is preferably a curable resin. That is, the surface coating layer is preferably composed of a cured product of a resin composition containing a curable resin.

[0144] When the resin 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 is preferably a two-component curable type. Examples of two-component curable resins include two-component curable polyurethane, two-component curable polyester, and two-component curable epoxy resin. Among these, two-component curable polyurethane is preferred.

[0145] Examples of two-component curing polyurethane include polyurethanes containing a first agent containing a polyol compound and a second agent containing an isocyanate compound. Preferably, two-component curing polyurethanes are made of a polyol such as polyester polyol, polyether polyol, and acrylic polyol as the first agent, and an aromatic or aliphatic polyisocyanate as the second agent. Examples of polyurethanes include polyurethane compounds in which a polyol compound and an isocyanate compound have been reacted in advance, and polyurethanes containing an isocyanate compound. Examples of polyurethanes include polyurethane compounds in which a polyol compound and an isocyanate compound have been reacted in advance, and polyurethanes containing a polyol compound. Examples of polyurethanes include polyurethanes in which a polyurethane compound in which a polyol compound and an isocyanate compound have been reacted in advance is cured by reacting it with moisture in the air or the like. As the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group on the side chain in addition to the hydroxyl group at the end of the repeating unit. As the second agent, aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds are included. Examples of isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI). In addition, examples of the isocyanate compounds include polyfunctional isocyanate modified compounds made from one or more of these diisocyanates. In addition, a polymer (e.g., a trimer) can also be used as the polyisocyanate compound. Examples of such polymers include adducts, biurets, and nurates. In addition, 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 formed from polyurethane imparts excellent electrolyte resistance to the packaging film for electricity storage devices.

[0146] The surface coating layer may contain additives such as the above-mentioned lubricant, antiblocking agent, matting agent, flame retardant, antioxidant, tackifier, and antistatic agent in at least one of the surface and the inside of the surface coating layer, as necessary, depending on the functionality to be provided to the surface of the surface coating layer. Examples of the additives include fine particles having an average particle size of about 0.5 nm to 5 μm. The average particle size of the additive is the median size measured by a laser diffraction / scattering type particle size distribution measuring device.

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

[0148] Specific examples of additives include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, 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 preferable from the viewpoint of dispersion stability and cost. In addition, the additives may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment.

[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 it exhibits the above-mentioned functions as a surface coating layer, and may be, for example, about 0.5 to 10 μm, and preferably about 1 to 5 μm.

[0151] 3. Manufacturing method of packaging film for power storage devices The method for producing the packaging film for an electricity storage device is not particularly limited as long as the packaging film for an electricity storage device of the present disclosure can be obtained. For example, when the packaging film for an electricity storage device of the first embodiment 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 a resin layer and a heat-sealable resin layer are laminated in this order from the outside, and the laminate has a CO2 permeation rate of 100 cc·100 μm / m in an environment at a temperature of 30° C. 2 For example, when the packaging film for an electricity storage device according to the second embodiment 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 a resin layer and a heat-sealable resin layer are laminated in this order from the outside, and the laminate has adhesion to metal and does not have a metal layer formed of metal.

[0152] An example of a manufacturing method in which the packaging film for an electricity storage device of the present disclosure is configured as a laminate including the resin layer 2, the adhesive layer 4, the substrate 3, the adhesive layer 5, and the heat-sealable resin layer 1 in this order is as follows. First, materials for configuring each layer are prepared. Next, the resin layer 2 and the substrate 3 are laminated via the adhesive layer 4, and the substrate 3 and the heat-sealable resin layer 1 are laminated via the adhesive layer 5. Specifically, the resin layer 2 and the substrate 3 are laminated by a dry lamination method or the like using an adhesive that forms the adhesive layer 4, so that the resin layer 2, the adhesive layer 4, and the substrate 3 are laminated, and further, the substrate 3 and the heat-sealable resin layer 1 are laminated by a dry lamination method or the like using an adhesive that forms the adhesive layer 5, so that the packaging film for an electricity storage device 10 can be manufactured. Furthermore, when the resin layer 2, the substrate 3, and the heat-sealable resin layer 1 are laminated without the adhesive layers 4 and 5, the packaging film 10 for an electricity storage device can be manufactured by a method of melt-extruding the resin constituting the resin layer 2 onto one side of the substrate 3, and melt-extruding the resin constituting the heat-sealable resin layer 1 onto the other side of the substrate 3. When a colored layer is provided, it is sufficient to form a colored layer on the surface of the resin layer 2 and then laminate the substrate 3 and the heat-sealable resin layer 1. When a surface coating layer is provided, it can be formed, for example, by applying the above-mentioned resin composition for forming the surface coating layer onto the surface of the resin layer 2 and curing it.

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

[0154] 4. Applications of packaging films for energy storage devices The packaging film for an electricity storage device according to the present disclosure is used in a package for hermetically housing an electricity storage device element such as a positive electrode, a negative electrode, an electrolyte, etc. That is, an electricity storage device can be formed by housing an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte in a package formed by the packaging film for an electricity storage device according to the present disclosure.

[0155] Specifically, an electricity storage device element having at least a positive electrode, a negative electrode, and an electrolyte is covered with the packaging film for electricity storage devices of the present disclosure in a state in which metal terminals connected to each of the positive electrode and negative electrode protrude outward, so that a flange portion (a region where the heat-sealable resin layers contact each other) can be formed around the periphery of the electricity storage device element, and the heat-sealable resin layers of the flange portion are heat-sealed to provide an electricity storage device using the packaging film for electricity storage devices. When an electricity storage device element is housed in a package formed with the packaging film for electricity storage devices of the present disclosure, the package is formed so that the heat-sealable resin portion of the packaging film for electricity storage devices of the present disclosure faces inside (the surface in contact with the electricity storage device element). The heat-sealable resin layers of two packaging films for an electricity storage device may be placed face to face with each other, and the peripheral portions of the placed packaging films for an electricity storage device may be heat-sealed to form a package. Alternatively, as shown in the example of FIG. 5, one packaging film for an electricity storage device may be folded back and placed back, and the peripheral portions may be heat-sealed to form a package. When the packaging film is folded back and placed back, as shown in the example of FIG. 5, the sides other than the folded side may be heat-sealed to form a package by sealing on three sides, or the packaging film may be folded back and sealed on four sides so that a flange portion can be formed. In addition, the packaging film for an electricity storage device may be formed with a recess for accommodating an electricity storage device element by deep drawing or bulging. As shown in the example of FIG. 5, one packaging film for an electricity storage device may have a recess and the other packaging film for an electricity storage device may not have a recess, or the other packaging film for an electricity storage device may also have a recess.

[0156] 7, the packaging film 10 for an electricity storage device according to the present disclosure can be suitably used as the inner packaging body 10a of an electricity storage device 30 in which an electricity storage device element 32 is accommodated in a container having a double structure of an inner packaging body 10a and an outer packaging body 20. That is, an electricity storage device element 32 having at least a positive electrode, a negative electrode, and an electrolyte is accommodated in the inner packaging body 10a formed by the packaging film 10 for an electricity storage device according to the present disclosure, and the inner packaging body 10a is further accommodated in the outer packaging body 20, thereby obtaining an electricity storage device 30 in which an electricity storage device element is accommodated in a container having a double structure of the inner packaging body 10a and the outer packaging body 20. One or more members in which an electricity storage device element 32 is accommodated in the inner packaging body 10a formed by the packaging film 10 for an electricity storage device according to the present disclosure are prepared, and the one or more members are accommodated in the outer packaging body 20 to form the electricity storage device 30. Although each corner is depicted as a right angle in FIGS. 5 to 7, the angle of each corner or edge is not limited, and each corner or edge may be rounded.

[0157] 7, the metal terminals 31 connected to the positive and negative electrodes of the electricity storage device element 32 are protruding outward, and the electricity storage device element 32 is covered so that a flange portion (region where the heat-sealable resin layers 1 come into contact with each other, the peripheral portion 30a of the inner packaging body 10a) of the inner packaging body 10a formed by the packaging film 10 for electricity storage devices can be formed around the periphery of the electricity storage device element 32, and the heat-sealable resin layers 1 of the flange portion are heat-sealed to each other to seal the electricity storage device element 32 with the heat-sealable resin layer 1 adhered to the metal terminal 10. When the inner surface of the heat-sealable resin layer 1 of the packaging film 10 for electricity storage devices of the present disclosure has adhesiveness to metal, it can be suitably used as a packaging film for directly packaging the electricity storage device element 32 by adhering it to the metal terminal 31. In an electricity storage device 30 in which an electricity storage device element 32 is housed in a double-structured packaging body including an inner packaging body 10a and an outer packaging body 20 as shown in Fig. 7, the packaging film 10 for an electricity storage device of the present disclosure can be suitably used to form the inner packaging body 10a. Since the metal terminal 31 and the heat-sealable resin layer of the packaging film are made of different materials, adhesion is generally 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, but the packaging film 10 for an electricity storage device of the present disclosure has adhesion to metal, and therefore can seal the electricity storage device element 32 while adhering it to the metal terminal 31 without using such an adhesive film.

[0158] The outer packaging body 20 is not particularly limited, and may be a packaging film or a metal can constituted by a film-like laminate in which a base layer / metal layer / thermally adhesive resin layer are laminated in that order.

[0159] The packaging film for an electricity storage device of the present disclosure can be suitably used for an electricity storage device such as a battery (including a condenser, a capacitor, etc.). The packaging film for an electricity storage device of the present disclosure may be used for either a primary battery or a secondary battery, but is preferably used for a secondary battery. The type of secondary battery to which the packaging film for an electricity storage device of the present disclosure is applied is not particularly limited, and examples thereof include lithium ion batteries, lithium ion polymer batteries, all-solid-state batteries, lead-acid batteries, nickel-hydrogen batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air batteries, polyvalent cation batteries, condensers, and capacitors. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are suitable applications of the packaging film for an electricity storage device of the present disclosure.

[0160] Furthermore, the packaging film for an electricity storage device according to the first embodiment of the present disclosure (at least a packaging film for an electricity storage device having a heat-sealable resin layer, the CO2 permeation amount in an environment at a temperature of 30°C being 100 cc·100 μm / m 2 / 24hr / atm or more) and the packaging film for an electricity storage device of the second aspect of the present disclosure (a packaging film for an electricity storage device having at least a heat-sealable resin layer, the packaging film for an electricity storage device having adhesion to metal, and the packaging film for an electricity storage device having no metal layer formed from metal) can be suitably applied to an electricity storage device or a manufacturing method thereof according to embodiment A (embodiments A1-A5 and their modifications), an electricity storage device or a manufacturing method thereof according to embodiment B (embodiments B1-B5 and their modifications), and an electricity storage device or a manufacturing method thereof according to embodiment C (embodiments C1-C5 and their modifications), respectively, which are shown below. Hereinafter, these embodiments A, B, and C in the first and second aspects will be described in detail.

[0161] <Embodiment A> As described above, in the manufacturing process of an electricity storage device, generally, after an electricity storage device element is accommodated in a packaging film for an electricity storage device, the periphery of the packaging film for an electricity storage device is sealed to temporarily seal the device. Then, an initial charge / discharge process, an aging process, and the like are performed. In these processes, it is known that gases such as CO2 are generated from the electricity storage device element, and in order to provide a space for holding the gas inside the temporarily sealed package (made of the packaging film for an electricity storage device) and further to remove the space in which the gas is held and release the gas to the outside, the electricity storage device is currently manufactured using a packaging film for an electricity storage device that is larger than the size required for the final product of the electricity storage device (for example, more than twice the size required to seal the electricity storage device element). For this reason, the manufacturing process of the electricity storage device is complicated.

[0162] An object of the invention according to embodiment A is to provide an electricity storage device manufacturing method that can easily manufacture an electricity storage device, and an electricity storage device manufactured by this manufacturing method.

[0163] A manufacturing method for an electricity storage device according to a first aspect of the invention in accordance with embodiment A is a manufacturing method for an electricity storage device, the electricity storage device comprising an electricity storage device element and an inner packaging body that houses the electricity storage device element, the inner packaging body being constituted by a packaging film for an electricity storage device having gas permeability, and the method includes an inner packaging step of wrapping the electricity storage device element with the packaging film for an electricity storage device, an inner sealing step that is carried out after the inner packaging step of sealing the packaging film for an electricity storage device so that the electricity storage device element is hermetically sealed by the packaging film for an electricity storage device, and a degassing step that is carried out after the inner sealing step of releasing gas generated from the electricity storage device element through the packaging film for an electricity storage device.

[0164] The manufacturing method for an electricity storage device according to a second aspect of the invention in accordance with embodiment A is a manufacturing method for an electricity storage device according to the first aspect, in which, in the inner packaging step, the electricity storage device elements are wrapped in a packaging film for the electricity storage device that is substantially the same size as the inner packaging body provided in the finished electricity storage device.

[0165] The energy storage device according to a third aspect of the invention in accordance with embodiment A comprises an energy storage device element, an inner packaging body that houses the energy storage device element, and an outer packaging body that houses the inner packaging body in which the energy storage device element is housed, wherein the inner packaging body is formed from a gas-permeable packaging film for energy storage devices.

[0166] The fourth aspect of the invention relating to embodiment A is an energy storage device according to the third aspect, further comprising a metal terminal electrically connected to the energy storage device element and a tab film arranged between the inner packaging body and the metal terminal, wherein 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 portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0167] The fifth aspect of the invention relating to embodiment A is an energy storage device according to the third aspect, further comprising a metal terminal electrically connected to the energy storage device element, and a tab film arranged between the inner packaging body and the outer packaging body and the metal terminal, wherein the inner packaging body and the outer packaging body are joined to the metal terminal via the tab film, and the entire inner packaging body is covered by the outer packaging body.

[0168] The sixth aspect of the invention relating to embodiment A is an energy storage device according to the third aspect, further comprising a metal terminal electrically connected to the energy storage device element, the inner packaging body and the metal terminal are joined, and at least a portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0169] An electricity storage device according to a seventh aspect of the invention, which is related to embodiment A, is the electricity storage device according to any one of the third to sixth aspects, wherein the packaging film for the electricity storage device further has transparency.

[0170] [Embodiment A1] FIG. 8 shows a plan view of the electricity storage device 100 according to the present embodiment A1. FIG. 9 is a cross-sectional view taken along the line D2-D2 in FIG. 8. In FIG. 8, a portion that is not visible from the outside is partially shown by dotted lines for reference. Hereinafter, for convenience of explanation, unless otherwise specified, the up-down 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 up-down direction in FIG. 9 is referred to as the "up-down direction". However, the orientation of the electricity storage device 100 during use is not limited to this. In addition, in FIG. 8, the relative positional relationship between the inner wrapping body 210 and the outer wrapping body 220 is simplified for the sake of simplicity of the drawing.

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

[0172] The housing 110 includes a container 110A. The container 110A includes an inner packaging body 210 and an outer packaging body 220. The inner packaging body 210 accommodates the power storage device element 120. The outer packaging body 220 accommodates the inner packaging body 210 in a state in which the power storage device element 120 is accommodated. An internal space S1 is formed inside the inner packaging body 210. The inner packaging body 210 includes packaging films 211 and 212 for a power storage device. The outer packaging body 220 includes exterior films 221 and 222. At the outer periphery of the container 110A in a 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. The peripheral seal portion 150 forms an internal space S1 of the container 110A that is isolated from the external space in the inner packaging body 210. The peripheral seal portion 150 defines the peripheral edge of the internal space S1 of the container 110A. The heat seal mode referred to here may be heat fusion from a heat source, ultrasonic fusion, or the like. In any case, the peripheral seal portion 150 refers to the portion where the inner wrapping body 210 and the outer wrapping 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, 153, and a bottom seal portion 154. The top seal portion 151 includes a portion that is sealed by sandwiching the metal terminal 130 and the tab film 140 (hereinafter referred to as "terminal seal portion 151A"), and extends in the front-rear direction. The pair of side seal portions 152, 153 extend in the left-right direction. The side seal portion 152 and the side seal portion 153 face each other across the internal space S1. The bottom seal portion 154 faces the top seal portion 151 across the internal space S1. The bottom seal portion 154 extends in the front-rear direction.

[0174] 9, the terminal seal portion 151A of the top seal portion 151 is formed by laminating, from the top, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the metal terminal 130, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. This makes it easy to form the top seal portion 151. Note that, in a portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, a portion where only the pair of tab films 140 are sandwiched between the inner packaging body 210 and the outer packaging body 220, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. Furthermore, the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion bordered by the step in FIG. 9) is formed by laminating, from the top, the electricity storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, and the electricity storage device packaging film 212, which are integrated together. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the exterior films 221, 222 are not present and the inner portion of the terminal seal portion 151A where the exterior films 221, 222 are present (the right portion bordered by the step in FIG. 9), but FIG. 8 illustrates the area of ​​the peripheral seal portion 150 from a bird's eye view and does not show the step that serves as the boundary.

[0175] The electricity storage device packaging films 211, 212 constituting the inner packaging body 210 have gas permeability from the viewpoint of easily manufacturing the electricity storage device 100. Below, preferred examples of the electricity storage device packaging films 211, 212 constituting the inner packaging body 210 will be described. Note that hereinafter, when there is no particular distinction between the electricity storage device packaging films 211, 212, the electricity storage device packaging films 211, 212 may be collectively referred to as the electricity storage device packaging film 10.

[0176] The shape of the inner packaging body 210 is not particularly limited, and may be, for example, a bag-like (pouch-like) shape. The bag-like shape may be a three-sided sealed type, a four-sided sealed type, a pillow type, a gusset type, or the like. The inner packaging body 210 of this embodiment A1 has a shape as shown in FIG. 9, and is manufactured by heat-sealing a packaging film 212 for an electricity storage device formed into a tray shape and a packaging film 211 for an electricity storage device, which is also formed into a tray shape and is superimposed on the packaging film 212 for an electricity storage device, along the outer periphery in a plan view. The packaging film 212 for an electricity storage device includes a flange portion 212A having a square ring shape corresponding to the outer periphery in a plan view, and a molded portion 212B that is continuous with the inner edge of the flange portion 212A and bulges downward therefrom. Similarly, the packaging film 211 for an electricity storage device includes a flange portion 211A having a square ring shape corresponding to the outer periphery in a plan view, and a flange portion 211B that is continuous with the inner edge of the flange portion 211A and bulges upward therefrom. The electricity storage device packaging films 211, 212 are overlapped such that the respective molded portions 211B, 212B bulge in opposite directions. In this state, the flange portion 211A of the electricity storage device packaging film 211 and the flange portion 212A of the electricity storage device packaging film 212 are heat sealed so as to be integrated together, forming a part of the peripheral seal portion 150. Note that one of the electricity storage device packaging films 211, 212 may be in the form of a sheet.

[0177] The exterior films 221, 222 constituting the outer packaging body 220 are, for example, made of a resin molded product or film. The resin molded product referred to here can be manufactured by a method such as injection molding, compressed air molding, vacuum molding, blow molding, etc., and in-mold molding may be performed to impart design and functionality. The type of resin may be polyolefin, polyester, nylon, ABS, etc. Furthermore, the film referred to here is, for example, a resin film that can be manufactured by a method such as an inflation method or a T-die method, or a film in which such a resin film is laminated on a metal foil or metal plate. Furthermore, the film referred to here may or may not be stretched, and may be a single-layer film or a multilayer film. Furthermore, the multilayer film referred to here may be manufactured by a coating method, may be a film in which multiple films are bonded together with an adhesive, or may be manufactured by a multilayer extrusion method.

[0178] The exterior films 221, 222 can be configured in various ways, but in this embodiment A1, they are configured from a laminate film. The laminate film can be a laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated. The base layer functions as a base material for the exterior films 221, 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 a function of preventing at least moisture and the like from penetrating into the power storage device 100 in addition to improving the strength of the exterior films 221, 222, and is typically a metal layer made of 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.

[0179] The shape of the outer packaging body 220 is not particularly limited, and may be, for example, a bag-like (pouch-like) shape. The bag-like shape may be a three-sided seal type, a four-sided seal type, a pillow type, a gusset type, or the like. 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 into a tray shape and an exterior film 221 similarly formed into a tray shape and superimposed on the exterior film 222 along the outer periphery in a plan view. The exterior film 222 includes a square ring-shaped flange portion 222A corresponding to the outer periphery 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 a square ring-shaped flange portion 221A corresponding to the outer periphery in a plan view, and a flange 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 overlapped 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 to be integrated together, forming a part of the peripheral seal portion 150. Note that one of the exterior films 221 and 222 may be in the form of a sheet.

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

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

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

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

[0184] The metal terminal 130 is a metal terminal used for inputting and outputting electric power to and from the power storage device element 120. The metal terminal 130 is disposed, for example, in the top seal portion 151 of the container 110A, one of which constitutes a positive terminal and the other of which constitutes a negative terminal. One end in the left-right direction of each metal terminal 130 is electrically connected to an 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 vehicles and hybrid vehicles in which a large number of power storage devices 100 are connected in series and used at high voltage. 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, in the side seal portions 152 and 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, etc. When the power storage device element 120 is a lithium ion battery, the metal terminal 130 connected to the positive electrode is typically made of aluminum or the like, and the metal terminal 130 connected to the negative electrode is typically made of copper, nickel, etc.

[0186] The tab film 140 is a so-called adhesive film, and is configured to adhere to both the electricity storage device packaging films 211, 212 and the metal terminal 130. By using the tab film 140, the metal terminal 130 and the innermost layer (thermally adhesive resin layer) of the electricity storage device packaging films 211, 212 can be fixed to each other even if they are made of different materials. Note that the tab film 140 is integrated by being fused and fixed to the metal terminal 130 in advance, and the electricity storage device packaging films 211, 212 are fused to the metal terminal 130 to which the tab film 140 is fixed.

[0187] [Method of manufacturing electricity storage device] 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 wrapping step of step S11, as shown in Fig. 11, the electricity storage device element 120 is wrapped in the formed electricity storage device packaging films 211, 212. In the electricity storage device 100 of the present embodiment A1, the electricity storage device packaging films 211, 212 are gas permeable, so there is no need to form an auxiliary chamber for temporarily storing gas generated from the electricity storage device element 120 in an initial filling step or the like described below. Therefore, in the inner wrapping step, the electricity storage device element 120 is wrapped in the electricity storage device packaging films 211, 212 having substantially the same size as the electricity storage device packaging films 211, 212 provided in the inner packaging body 210 of the completed electricity storage device 100. This allows the manufacturing process of the electricity storage device 100 to be simplified. In addition, the amount of material used for the electricity storage device 100 can be reduced. Substantially the same size includes a case where the size is larger than the electricity storage device packaging films 211, 212 included in the inner packaging body 210 of the completed electricity storage device 100 to the extent that a sub-chamber cannot be formed. Note that the electricity storage device element 120 is previously connected to the metal terminal 130, and the tab film 140 is joined to the metal terminal 130.

[0189] The first inner sealing step in step S12 is carried out after the inner packaging step. In the first inner sealing step, as shown in Fig. 12, the portions of the periphery of the electricity storage device packaging films 211, 212 that correspond to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 are sealed. Completion of the first inner sealing step forms an opening 213 in the portion of the periphery of the electricity storage device packaging films 211, 212 where the side seal portion 153 is to be formed. After the first inner sealing step, a vacuum drying step in step S13 is carried out.

[0190] The electrolyte injection process in step S14 is carried out 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 step in step S15 is performed after the electrolyte injection step. As shown in FIG. 16, in the second inner sealing step, the opening 213 is closed by sealing the portion of the periphery of the packaging films 211 and 212 for the electricity storage device where the side seal portion 153 is to be formed. According to the electricity storage device 100, since the packaging films 211 and 212 for the electricity storage device have transparency, it is possible to easily check whether the packaging films 211 and 212 for the electricity storage device are properly sealed after the first inner sealing step or the second inner sealing step is completed. Therefore, the electricity storage device 100 can be suitably manufactured. The state in which the packaging films 211 and 212 for the electricity storage device 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 packaging films 211 and 212 for the electricity storage device are sealed with a foreign object in between. The second state is a state where a part of the part that should be sealed is not sealed. The third state is a state where a part that should not be sealed is sealed. After the second inside sealing process, the initial charge / discharge process of step S16 and the aging process of step S17 are performed in order.

[0192] The degassing step in step S18 is carried out in parallel with the initial charge / discharge step and the aging step. In this embodiment A1, the electricity storage device packaging films 211, 212 are gas permeable, and therefore, when the initial charge / discharge step and the aging step are carried out, gas such as carbon dioxide generated from the electricity storage device element 120 is discharged to the outside through the electricity storage device packaging films 211, 212. After the degassing step, the main charging step in step S19 is carried out.

[0193] The outer wrapping step of step S20 is carried out after the main charging step. In the outer wrapping step, the inner wrapping body 210 containing the power storage device element 120 is wrapped in exterior films 221, 222.

[0194] The outer sealing step in step S21 is carried out after the outer wrapping step. In the outer sealing step, the periphery of the exterior films 221, 222 is sealed to form a peripheral seal portion 150.

[0195] [Characteristics of the energy storage device] In the electricity storage device 100 of the present embodiment A1, the electricity storage device packaging films 211, 212 are gas permeable, so there is no need to form an auxiliary chamber for temporarily storing gas generated from the electricity storage device element 120 in an initial filling step or the like described below. This makes it possible to simplify the manufacturing process for the electricity storage device 100. Furthermore, the amount of material used in the electricity storage device 100 can be reduced.

[0196] [Embodiment A2] The electricity storage device 100 of embodiment A2 differs from embodiment A1 in that the electricity storage device packaging films 211, 212 are not transparent, but the other configurations are the same as those of embodiment A1. The electricity storage device 100 of embodiment A2 will be described below, focusing on the differences from embodiment A2.

[0197] [Method of manufacturing electricity storage device] 11 is a flowchart showing an example of a method for manufacturing the power storage device 100 according to embodiment A2. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0198] In the inner packaging step of step S31, as shown in Fig. 12, the electricity storage device element 120 is packaged in the formed electricity storage device packaging films 211, 212. In the electricity storage device 100 of the present embodiment A2, an auxiliary chamber 214 is formed for temporarily storing gas generated from the electricity storage device element 120 in an initial filling step or the like. For this reason, in the inner packaging step, the electricity storage device element 120 is packaged in the electricity storage device packaging films 211, 212 which are larger than the electricity storage device packaging films 211, 212 provided in the inner packaging body 210 of the completed electricity storage device 100. A storage chamber 215 for storing more gas generated from the electricity storage device element 120 is formed in the auxiliary chamber 214 of the electricity storage device packaging films 211, 212.

[0199] 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 of the periphery of the electricity storage device packaging films 211, 212 corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 are sealed so as to extend to the auxiliary chamber 214. Completion of the first inner sealing step forms an opening 213 in a portion 216 that faces the portion of the periphery of the electricity storage device packaging films 211, 212 where the side seal portion 153 is to be formed, across the auxiliary chamber 214. After the first inner sealing step, a vacuum drying step of step S33 is performed.

[0200] The electrolyte injection process in 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).

[0201] The second inner sealing step of step S35 is performed after the electrolyte injection step. As shown in Fig. 17, in the second inner sealing step, the opening 213 is closed by sealing a portion 216 of the periphery of the packaging films 211, 212 for electricity storage devices, which is opposite to a portion where the side seal portion 153 is to be formed, via the auxiliary chamber 214. After the second inner sealing step, the initial charge / discharge step of step S36 and the aging step of step S37 are performed in this order.

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

[0203] The auxiliary chamber removing step of step S39 is performed after the degassing step. In the auxiliary chamber removing step, the auxiliary chamber 214 is removed by cutting the electricity storage device packaging films 211, 212 along the dashed dotted line XA shown in Fig. 17 so that the auxiliary chamber 214 has the same size as the inner packaging body 210 of the completed electricity storage device 100.

[0204] The inside sealing step of step S40 is performed after the auxiliary chamber removing step. In the inside sealing step, the portions of the periphery of the packaging films 211, 212 for electricity storage devices that correspond to the side seal portion 153 are sealed as shown in Fig. 18. After the inside sealing step, a main charging step of step S41 is performed.

[0205] The outer wrapping step of step S42 is carried out after the main charging step. In the outer wrapping step, the inner wrapping body 210 containing the power storage device element 120 is wrapped in exterior films 221, 222.

[0206] The outer sealing step in step S43 is carried out after the outer wrapping step. In the outer sealing step, the periphery of the exterior films 221, 222 is sealed to form a peripheral seal portion 150.

[0207] [Embodiment A3] The power storage device 300 of the embodiment A3 differs from the embodiment A1 in that the configuration of the terminal seal portion 151A is different, and other configurations are the same as those of the embodiment A1. The following describes the power storage device 300 of the embodiment A3, focusing on the differences from the embodiment A1.

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

[0209] The flange portion 221A of the exterior film 221 is joined to one tab film 140. The flange portion 222A of the exterior film 222 is joined to the other tab film 140. An end 221X of the flange portion 221A is located farther from the electricity storage device element 120 than an end 211X of the electricity storage device packaging film 211. An end 222X of the flange portion 222A is located farther from the electricity storage device element 120 than an end 212X of the electricity storage device packaging film 212. Therefore, the entire inner packaging body 210 is covered by the outer packaging body 220.

[0210] [Characteristics of the energy storage device] According to the power storage device 300, since the inner packaging body 210 is covered by the outer packaging body 220, intrusion of moisture and the like from the outside into the internal space S1 of the inner packaging body 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 similar to those of embodiment A1. The following describes the power storage device 400 of embodiment A4, focusing on the differences from embodiment A1.

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

[0213] The end 221X of the flange portion 221A is located closer to the electricity storage device element 120 than the end 211X of the packaging film 211 for an electricity storage device. Therefore, at least a part of the outer edge of the inner packaging body 210 is exposed from the outer packaging body 220. Note that the end 221X of the flange portion 221A may be located in the same position as the end 211X of the packaging film 211 for an electricity storage device in the left-right direction, or farther from the electricity storage device element 120 than the end 211X of the packaging film 211 for an electricity 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 electricity 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 electricity storage device. The end 222X of the flange portion 222A is located closer to the electricity storage device element 120 than the end 212X of the packaging film 212 for the electricity storage device. Therefore, at least a part of the outer edge of the inner packaging body 210 is exposed from the outer packaging body 220. Note that the end 222X of the flange portion 222A may be located at the same position as the end 212X of the packaging film 212 for the electricity storage device in the left-right direction, or farther from the electricity storage device element 120 than the end 212X of the packaging film 212 for the electricity storage device.

[0215] [Characteristics of the energy storage device] According to the electricity storage device 400, the number of parts is reduced because the electricity storage device packaging films 211, 212 and the metal terminal 130 are joined together without the tab film 140. In addition, the manufacturing method of the electricity storage device 400 can be simplified.

[0216] [Embodiment A5] The power storage device 500 of embodiment A5 differs from embodiment A4 in that the configuration of the terminal seal portion 451A is different, and other configurations are similar to those of embodiment A4. The following describes the power storage device 500 of embodiment A5, focusing on the differences from embodiment A4.

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

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

[0219] [Characteristics of the energy storage device] According to the electricity storage device 500, the inner packaging body 210 is covered by the outer packaging body 220, which prevents moisture and the like from entering the internal space S1 of the inner packaging body 210 from the outside. Also, according to the electricity storage device 500, the packaging films 211, 212 for electricity storage devices and the metal terminal 130 are joined without the tab film 140, which reduces the number of parts. Also, the manufacturing method of the electricity storage device 500 can be simplified.

[0220] [Variations] The above-described embodiments are examples of possible forms of the power storage device and the manufacturing method of the power storage device according to the present disclosure, and are not intended to limit the forms. The power storage device and the manufacturing method of the power storage device according to the present disclosure may take forms different from those exemplified in the embodiments. 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. Below, some examples of modified versions of each embodiment are shown. The following modified versions can be combined with each other as long as they are not technically inconsistent.

[0221] In the electricity storage device 100 of embodiment A1, one outer packaging body 220 may be configured to house a plurality of inner packaging bodies 210 in a state in which the electricity storage device elements 120 are housed therein. In this modification, the sizes of the plurality of inner packaging bodies 210 may be different or the same. According to this modification, the plurality of electricity storage device elements 120 can be connected in series or in parallel, so that the voltage can be easily adjusted.

[0222] In the electricity storage device 100 of the embodiment A1, the electricity storage device packaging films 211, 212 do not need to be transparent. The electricity storage device packaging films 211, 212 only need to be gas permeable.

[0223] In the electricity storage device 100 of embodiment A1, the inner packaging body 210 may be formed by folding one electricity storage device packaging film 211 and heat sealing the peripheral portion. Similarly, the outer packaging body 220 may be formed by folding one exterior film 221 and heat sealing the peripheral portion.

[0224] <Embodiment B> In the manufacturing process of the electricity storage device, generally, after the electricity storage device element is accommodated in the packaging film for the electricity storage device, the periphery of the packaging film for the electricity storage device is sealed to temporarily seal it. Then, an initial charge / discharge process and an aging process are performed. The packaging film for the electricity storage device provided in the secondary battery includes a metal layer and therefore has a shielding property. Therefore, when the electricity storage device element is sealed by the packaging film for the electricity storage device, it is not possible to check whether the periphery of the packaging film for the electricity storage device is properly sealed. Therefore, the electricity storage device cannot be manufactured suitably.

[0225] An object of the invention according to embodiment B is to provide an electricity storage device manufacturing method capable of suitably manufacturing an electricity storage device, and an electricity storage device manufactured by this manufacturing method.

[0226] A manufacturing method for an electricity storage device according to a first aspect of the invention in embodiment B is a manufacturing method for an electricity storage device, the electricity storage device comprising an electricity storage device element and an inner packaging body that houses the electricity storage device element, the inner packaging body being constituted by a transparent packaging film for electricity storage devices, and the method includes an inner packaging step of wrapping the electricity storage device element with the packaging film for electricity storage devices, and an inner sealing step that is carried out after the inner packaging step of sealing the packaging film for electricity storage devices so that the electricity storage device element is hermetically sealed by the packaging film for electricity storage devices.

[0227] A manufacturing method for an electricity storage device according to a second aspect of the invention in accordance with embodiment B is a manufacturing method for an electricity storage device according to the first aspect, wherein the packaging film for the electricity storage device further has gas permeability, and further comprises a degassing step carried out after the inner sealing step, in which gas generated from the electricity storage device elements is released through the packaging film for the electricity storage device.

[0228] A manufacturing method for an electricity storage device according to a third aspect of the invention in accordance with embodiment B is a manufacturing method for an electricity storage device according to the second aspect, in which in the inner packaging step, the electricity storage device elements are wrapped in a packaging film for the electricity storage device that is substantially the same size as the inner packaging body provided in the finished electricity storage device.

[0229] The electricity storage device according to a fourth aspect of the invention in embodiment B comprises an electricity storage device element, an inner packaging body that houses the electricity storage device element, and an outer packaging body that houses the inner packaging body in which the electricity storage device element is housed, and the inner packaging body is constituted by a transparent packaging film for electricity storage devices.

[0230] The fifth aspect of the invention relating to embodiment B is an energy storage device according to the fourth aspect, further comprising a metal terminal electrically connected to the energy storage device element and a tab film arranged between the inner packaging body and the metal terminal, wherein 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 portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0231] The sixth aspect of the invention relating to embodiment B is an energy storage device according to the fourth aspect, further comprising a metal terminal electrically connected to the energy storage device element, and a tab film arranged between the inner packaging body and the outer packaging body and the metal terminal, wherein the inner packaging body and the outer packaging body are joined to the metal terminal via the tab film, and the entire inner packaging body is covered by the outer packaging body.

[0232] The seventh aspect of the invention relating to embodiment B is the energy storage device relating to the fourth aspect, further comprising a metal terminal electrically connected to the energy storage device element, the inner packaging body and the metal terminal are joined, and at least a portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

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

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

[0235] [Embodiment B1] FIG. 8 shows a plan view of the electricity storage device 100 according to the present embodiment B1. FIG. 9 is a cross-sectional view taken along the line D2-D2 in FIG. 8. In FIG. 8, a portion that is not visible from the outside is partially shown by dotted lines for reference. Hereinafter, for convenience of explanation, unless otherwise specified, the up-down 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 up-down direction in FIG. 9 is referred to as the "up-down direction". However, the orientation of the electricity storage device 100 during use is not limited to this. In addition, in FIG. 8, the relative positional relationship between the inner wrapping body 210 and the outer wrapping body 220 is simplified for the sake of simplicity of the drawing.

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

[0237] The housing 110 includes a container 110A. The container 110A includes an inner packaging body 210 and an outer packaging body 220. The inner packaging body 210 accommodates the power storage device element 120. The outer packaging body 220 accommodates the inner packaging body 210 in a state in which the power storage device element 120 is accommodated. An internal space S1 is formed inside the inner packaging body 210. The inner packaging body 210 includes packaging films 211 and 212 for a power storage device. The outer packaging body 220 includes exterior films 221 and 222. At the outer periphery of the container 110A in a 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. The peripheral seal portion 150 forms an internal space S1 of the container 110A that is isolated from the external space in the inner packaging body 210. The peripheral seal portion 150 defines the peripheral edge of the internal space S1 of the container 110A. The heat seal mode referred to here may be heat fusion from a heat source, ultrasonic fusion, or the like. In any case, the peripheral seal portion 150 refers to the portion where the inner wrapping body 210 and the outer wrapping body 220 are fused and integrated.

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

[0239] 9, the terminal seal portion 151A of the top seal portion 151 is formed by laminating, from the top, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the metal terminal 130, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. This makes it easy to form the top seal portion 151. Note that, in a portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, a portion where only the pair of tab films 140 are sandwiched between the inner packaging body 210 and the outer packaging body 220, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. Furthermore, the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion bordered by the step in FIG. 9) is formed by laminating, from the top, the electricity storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, and the electricity storage device packaging film 212, which are integrated together. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the exterior films 221, 222 are not present and the inner portion of the terminal seal portion 151A where the exterior films 221, 222 are present (the right portion bordered by the step in FIG. 9), but FIG. 8 illustrates the area of ​​the peripheral seal portion 150 from a bird's eye view and does not show the step that serves as the boundary.

[0240] The electricity storage device packaging films 211, 212 constituting the inner packaging body 210 are transparent overall from the viewpoint of suitably manufacturing the electricity storage device 100. Below, preferred examples of the electricity storage device packaging films 211, 212 constituting the inner packaging body 210 are described. Note that hereinafter, when there is no particular distinction between the electricity storage device packaging films 211, 212, the electricity storage device packaging films 211, 212 may be collectively referred to as the electricity storage device packaging film 10.

[0241] The shape of the inner packaging body 210 is not particularly limited, and may be, for example, a bag-like (pouch-like) shape. The bag-like shape may be a three-sided sealed type, a four-sided sealed type, a pillow type, a gusset type, or the like. The inner packaging body 210 of this embodiment B1 has a shape as shown in FIG. 9, and is manufactured by heat-sealing a packaging film 212 for an electricity storage device formed into a tray shape and a packaging film 211 for an electricity storage device, which is also formed into a tray shape and is superimposed on the packaging film 212 for an electricity storage device, along the outer periphery in a plan view. The packaging film 212 for an electricity storage device includes a flange portion 212A having a square ring shape corresponding to the outer periphery in a plan view, and a molded portion 212B that is continuous with the inner edge of the flange portion 212A and bulges downward therefrom. Similarly, the packaging film 211 for an electricity storage device includes a flange portion 211A having a square ring shape corresponding to the outer periphery in a plan view, and a flange portion 211B that is continuous with the inner edge of the flange portion 211A and bulges upward therefrom. The electricity storage device packaging films 211, 212 are overlapped such that the respective molded portions 211B, 212B bulge in opposite directions. In this state, the flange portion 211A of the electricity storage device packaging film 211 and the flange portion 212A of the electricity storage device packaging film 212 are heat sealed so as to be integrated together, forming a part of the peripheral seal portion 150. Note that one of the electricity storage device packaging films 211, 212 may be in the form of a sheet.

[0242] The exterior films 221, 222 constituting the outer packaging body 220 are, for example, made of a resin molded product or film. The resin molded product referred to here can be manufactured by a method such as injection molding, compressed air molding, vacuum molding, blow molding, etc., and in-mold molding may be performed to impart design and functionality. The type of resin may be polyolefin, polyester, nylon, ABS, etc. Furthermore, the film referred to here is, for example, a resin film that can be manufactured by a method such as an inflation method or a T-die method, or a film in which such a resin film is laminated on a metal foil or metal plate. Furthermore, the film referred to here may or may not be stretched, and may be a single-layer film or a multilayer film. Furthermore, the multilayer film referred to here may be manufactured by a coating method, may be a film in which multiple films are bonded together with an adhesive, or may be manufactured by a multilayer extrusion method.

[0243] The exterior films 221, 222 can be configured in various ways, but in this embodiment B1, they are configured from a laminate film. The laminate film can be a laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated. The base layer functions as a base material for the exterior films 221, 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 a function of preventing at least moisture and the like from penetrating into the power storage device 100 in addition to improving the strength of the exterior films 221, 222, and is typically a metal layer made of 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.

[0244] The shape of the outer packaging body 220 is not particularly limited, and may be, for example, a bag-like (pouch-like) shape. The bag-like shape may be a three-sided seal type, a four-sided seal type, a pillow type, a gusset type, or the like. 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 into a tray shape and an exterior film 221 similarly formed into a tray shape and superimposed on the exterior film 222 along the outer periphery in a plan view. The exterior film 222 includes a square ring-shaped flange portion 222A corresponding to the outer periphery 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 a square ring-shaped flange portion 221A corresponding to the outer periphery in a plan view, and a flange 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 overlapped 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 to be integrated together, forming a part of the peripheral seal portion 150. Note that one of the exterior films 221 and 222 may be in the form of a sheet.

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

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

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

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

[0249] The metal terminal 130 is a metal terminal used for inputting and outputting electric power to and from the power storage device element 120. The metal terminal 130 is disposed, for example, in the top seal portion 151 of the container 110A, one of which constitutes a positive terminal and the other of which constitutes a negative terminal. One end in the left-right direction of each metal terminal 130 is electrically connected to an 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 vehicles and hybrid vehicles in which a large number of power storage devices 100 are connected in series and used at high voltage. 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, in the side seal portions 152 and 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 made of aluminum or the like, and the metal terminal 130 connected to the negative electrode is typically made of copper, nickel, etc.

[0251] The tab film 140 is a so-called adhesive film, and is configured to adhere to both the electricity storage device packaging films 211, 212 and the metal terminal 130. By using the tab film 140, the metal terminal 130 and the innermost layer (thermally adhesive resin layer) of the electricity storage device packaging films 211, 212 can be fixed to each other even if they are made of different materials. Note that the tab film 140 is integrated by being fused and fixed to the metal terminal 130 in advance, and the electricity storage device packaging films 211, 212 are fused to the metal terminal 130 to which the tab film 140 is fixed.

[0252] [Method of manufacturing electricity storage device] 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 wrapping step of step S11, as shown in Fig. 11, the electricity storage device element 120 is wrapped in the formed electricity storage device packaging films 211, 212. In the electricity storage device 100 of the present embodiment B1, since the electricity storage device packaging films 211, 212 are gas permeable, there is no need to form an auxiliary chamber for temporarily storing gas generated from the electricity storage device element 120 in an initial filling step or the like described below. Therefore, in the inner wrapping step, the electricity storage device element 120 is wrapped in the electricity storage device packaging films 211, 212 having substantially the same size as the electricity storage device packaging films 211, 212 provided in the inner packaging body 210 of the completed electricity storage device 100. Therefore, the manufacturing process of the electricity storage device 100 can be simplified. Furthermore, the amount of material used for the electricity storage device 100 can be reduced. Substantially the same size includes a case where the size is larger than the electricity storage device packaging films 211, 212 included in the inner packaging body 210 of the completed electricity storage device 100 to the extent that a sub-chamber cannot be formed. Note that the electricity storage device element 120 is previously connected to the metal terminal 130, and the tab film 140 is joined to the metal terminal 130.

[0254] The first inner sealing step in step S12 is carried out after the inner packaging step. In the first inner sealing step, as shown in Fig. 12, the portions of the periphery of the electricity storage device packaging films 211, 212 that correspond to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 are sealed. Completion of the first inner sealing step forms an opening 213 in the portion of the periphery of the electricity storage device packaging films 211, 212 where the side seal portion 153 is to be formed. After the first inner sealing step, a vacuum drying step in step S13 is carried out.

[0255] The electrolyte injection process in step S14 is carried out 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 step of step S15 is performed after the electrolyte injection step. As shown in Fig. 10, in the second inner sealing step, the opening 213 is closed by sealing the peripheral portion of the packaging films 211, 212 for the electricity storage device where the side seal portion 153 is to be formed. After the second inner sealing step, the initial charge / discharge step of step S16 and the aging step of step S17 are performed in order.

[0257] The degassing step in step S18 is carried out in parallel with the initial charge / discharge step and the aging step. In this embodiment B1, the electricity storage device packaging films 211, 212 are gas permeable, and therefore, when the initial charge / discharge step and the aging step are carried out, gas such as carbon dioxide generated from the electricity storage device element 120 is discharged to the outside through the electricity storage device packaging films 211, 212. After the degassing step, the main charging step in step S19 is carried out.

[0258] The outer wrapping step of step S20 is carried out after the main charging step. In the outer wrapping step, the inner wrapping body 210 containing the power storage device element 120 is wrapped in exterior films 221, 222.

[0259] The outer sealing step in step S21 is carried out after the outer wrapping step. In the outer sealing step, the periphery of the exterior films 221, 222 is sealed to form a peripheral seal portion 150.

[0260] [Characteristics of the energy storage device] According to the electricity storage device 100, since the electricity storage device packaging films 211 and 212 have transparency, it is possible to easily check whether the electricity storage device packaging films 211 and 212 are properly sealed after the first inner sealing step or the second inner sealing step is completed. This allows the electricity storage device 100 to be suitably manufactured. The state in which the electricity storage device packaging films 211 and 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 electricity storage device packaging films 211 and 212 are sealed with a foreign object caught between them. The second state is a state in which a part that should be sealed is not sealed. The third state is a state in which a part that should not be sealed is sealed.

[0261] [Embodiment B2] The electricity storage device 100 of embodiment B2 differs from embodiment B1 in that the electricity storage device packaging films 211, 212 are not gas permeable, or in that, compared to embodiment B1, they do not have gas permeability to the extent that the degassing step of step S18 described above is performed, but the other configurations are similar to those of embodiment B1. The electricity storage device 100 of embodiment B2 will be described below, focusing on the differences from embodiment B2.

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

[0263] In the inner wrapping step of step S31, as shown in Fig. 15, the electricity storage device element 120 is wrapped in the formed electricity storage device packaging films 211, 212. In the electricity storage device 100 of the present embodiment B2, since the electricity storage device packaging films 211, 212 are not gas permeable, it is preferable to form an auxiliary chamber 214 for temporarily storing gas generated from the electricity storage device element 120 in the initial filling step or the like. For this reason, in the inner wrapping step, the electricity storage device element 120 is wrapped in the electricity storage device packaging films 211, 212 that are larger than the electricity storage device packaging films 211, 212 provided in the inner packaging body 210 of the completed electricity storage device 100. In the auxiliary chamber 214 of the electricity storage device packaging films 211, 212, a storage chamber 215 for storing more gas generated from the electricity storage device element 120 is formed.

[0264] 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 of the periphery of the electricity storage device packaging films 211, 212 corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 are sealed so as to extend to the auxiliary chamber 214. Completion of the first inner sealing step forms an opening 213 in a portion 216 that faces the portion of the periphery of the electricity storage device packaging films 211, 212 where the side seal portion 153 is to be formed, across the auxiliary chamber 214. After the first inner sealing step, a vacuum drying step of step S33 is performed.

[0265] The electrolyte injection process in 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 step of step S35 is performed after the electrolyte injection step. As shown in Fig. 17, in the second inner sealing step, the opening 213 is closed by sealing a portion 216 of the periphery of the packaging films 211, 212 for electricity storage devices, which is opposite to a portion where the side seal portion 153 is to be formed, via the auxiliary chamber 214. After the second inner sealing step, the initial charge / discharge step of step S36 and the aging step of step S37 are performed in this order.

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

[0268] The auxiliary chamber removing step of step S39 is performed after the degassing step. In the auxiliary chamber removing step, the auxiliary chamber 214 is removed by cutting the electricity storage device packaging films 211, 212 along the dashed dotted line XA shown in Fig. 17 so that the auxiliary chamber 214 has the same size as the inner packaging body 210 of the completed electricity storage device 100.

[0269] The inside sealing step of step S40 is performed after the auxiliary chamber removing step. In the inside sealing step, the portions of the periphery of the packaging films 211, 212 for electricity storage devices that correspond to the side seal portion 153 are sealed as shown in Fig. 18. After the inside sealing step, a main charging step of step S41 is performed.

[0270] The outer wrapping step of step S42 is carried out after the main charging step. In the outer wrapping step, the inner wrapping body 210 containing the power storage device element 120 is wrapped in exterior films 221, 222.

[0271] The outer sealing step in step S43 is carried out after the outer wrapping step. In the outer sealing step, the periphery of the exterior films 221, 222 is sealed to form a peripheral seal portion 150.

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

[0273] [Embodiment B3] The power storage device 300 of embodiment B3 differs from embodiment B1 in that the configuration of the terminal seal portion 151A is different, and other configurations are similar to those of embodiment B1. The following describes the power storage device 300 of embodiment B3, focusing on the differences from embodiment B1.

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

[0275] The flange portion 221A of the exterior film 221 is joined to one tab film 140. The flange portion 222A of the exterior film 222 is joined to the other tab film 140. An end 221X of the flange portion 221A is located farther from the electricity storage device element 120 than an end 211X of the electricity storage device packaging film 211. An end 222X of the flange portion 222A is located farther from the electricity storage device element 120 than an end 212X of the electricity storage device packaging film 212. Therefore, the entire inner packaging body 210 is covered by the outer packaging body 220.

[0276] [Characteristics of the energy storage device] According to the power storage device 300, since the inner packaging body 210 is covered by the outer packaging body 220, intrusion of moisture and the like from the outside into the internal space S1 of the inner packaging body 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 similar to those of embodiment B1. The following describes the power storage device 400 of embodiment B4, focusing on the differences from embodiment B1.

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

[0279] The end 221X of the flange portion 221A is located closer to the electricity storage device element 120 than the end 211X of the packaging film 211 for an electricity storage device. Therefore, at least a part of the outer edge of the inner packaging body 210 is exposed from the outer packaging body 220. Note that the end 221X of the flange portion 221A may be located in the same position as the end 211X of the packaging film 211 for an electricity storage device in the left-right direction, or farther from the electricity storage device element 120 than the end 211X of the packaging film 211 for an electricity 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 electricity 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 electricity storage device. The end 222X of the flange portion 222A is located closer to the electricity storage device element 120 than the end 212X of the packaging film 212 for the electricity storage device. Therefore, at least a part of the outer edge of the inner packaging body 210 is exposed from the outer packaging body 220. Note that the end 222X of the flange portion 222A may be located at the same position as the end 212X of the packaging film 212 for the electricity storage device in the left-right direction, or farther from the electricity storage device element 120 than the end 212X of the packaging film 212 for the electricity storage device.

[0281] [Characteristics of the energy storage device] According to the electricity storage device 400, the number of parts is reduced because the electricity storage device packaging films 211, 212 and the metal terminal 130 are joined together without the tab film 140. In addition, the manufacturing method of the electricity storage device 400 can be simplified.

[0282] [Embodiment B5] The power storage device 500 of embodiment B5 differs from embodiment B4 in that the configuration of the terminal seal portion 451A is different, and other configurations are similar to those of embodiment B4. The following describes the power storage device 500 of embodiment B5, focusing on the differences from embodiment B4.

[0283] 21 is a cross-sectional view of a terminal seal portion 551A included in an electricity storage device 500 of embodiment B5. In the terminal seal portion 551A, a part of a flange portion 211A of the electricity storage device packaging film 211 is joined to the metal terminal 130. A part of a flange portion 212A of the electricity storage device packaging film 212 is joined to the metal terminal 130.

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

[0285] [Characteristics of the energy storage device] According to the electricity storage device 500, the inner packaging body 210 is covered by the outer packaging body 220, which prevents moisture and the like from entering the internal space S1 of the inner packaging body 210 from the outside. Also, according to the electricity storage device 500, the packaging films 211, 212 for electricity storage devices and the metal terminal 130 are joined without the tab film 140, which reduces the number of parts. Also, the manufacturing method of the electricity storage device 500 can be simplified.

[0286] [Variations] The above-mentioned respective embodiments B are examples of possible forms of the electricity storage device and the manufacturing method of the electricity storage device according to the present disclosure, and are not intended to limit the forms. The electricity storage device and the manufacturing method of the electricity storage device according to the present disclosure may take forms different from those exemplified in the respective embodiments. 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 modified forms of each embodiment are shown below. Note that the following modified forms can be combined with each other as long as there is no technical contradiction.

[0287] In the electricity storage device 100 of embodiment B1, one outer packaging body 220 may be configured to house a plurality of inner packaging bodies 210 in a state in which the electricity storage device elements 120 are housed therein. In this modification, the sizes of the plurality of inner packaging bodies 210 may be different or the same. According to this modification, the plurality of electricity storage device elements 120 can be connected in series or in parallel, so that the voltage can be easily adjusted.

[0288] In the electricity storage device 100 of the embodiment B1, the electricity storage device packaging films 211, 212 do not need to be gas permeable. It is sufficient that the electricity storage device packaging films 211, 212 are at least transparent.

[0289] In the electricity storage device 100 of embodiment B1, the inner packaging body 210 may be formed by folding one electricity storage device packaging film 211 and heat sealing the peripheral portion. Similarly, the outer packaging body 220 may be formed by folding one exterior film 221 and heat sealing the peripheral portion.

[0290] <Embodiment C> In addition to the functions that electricity storage devices usually have, it is preferable that the electricity storage device has a function with high added value.

[0291] An object of the invention according to embodiment C is to provide an electricity storage device having high added-value functions.

[0292] The energy storage device according to a first aspect of the invention in embodiment C comprises an energy storage device element, an inner packaging body that houses the energy storage device element, an outer packaging body that houses the inner packaging body in which the energy storage device element is housed, and a functional object that is arranged between the inner packaging body and the outer packaging body, and the functional object has impact absorbing properties.

[0293] An energy storage device according to a second aspect of the invention in embodiment C comprises an energy storage device element, an inner packaging body that houses the energy storage device element, an outer packaging body that houses the inner packaging body in which the energy storage device element is housed, and a functional object that is arranged between the inner packaging body and the outer packaging body, and the functional object is flame retardant.

[0294] An energy storage device according to a third aspect of the invention in embodiment C comprises an energy storage device element, an inner packaging body that houses the energy storage device element, an outer packaging body that houses the inner packaging body in which the energy storage device element is housed, and a functional object that is arranged between the inner packaging body and the outer packaging body, and the functional object has cooling properties.

[0295] The energy storage device according to a fourth aspect of the invention in embodiment C comprises an energy storage device element, an inner packaging body that houses the energy storage device element, an outer packaging body that houses the inner packaging body in which the energy storage device element is housed, and a functional object that is arranged between the inner packaging body and the outer packaging body, and the functional object has fire-extinguishing properties.

[0296] The energy storage device according to a fifth aspect of the invention, relating to embodiment C, comprises an energy storage device element, an inner packaging body that houses the energy storage device element, and an outer packaging body that houses the inner packaging body in which the energy storage device element is housed, and at least one of the inner packaging body and the outer packaging body has at least one of shock absorption properties, flame retardancy, cooling properties, and fire extinguishing properties.

[0297] An electricity storage device according to a sixth aspect of the present invention, according to embodiment C, is the electricity storage device according to any one of the first to fifth aspects, wherein the inner wrapping body has at least one of transparency and gas permeability.

[0298] The seventh aspect of the invention relating to embodiment C is an energy storage device according to any one of the first to sixth aspects, further comprising a metal terminal electrically connected to the energy storage device element and a tab film arranged between the inner packaging body and the metal terminal, wherein 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 portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0299] The energy storage device according to an eighth aspect of the invention, which relates to embodiment C, is an energy storage device according to any one of the first to sixth aspects, further comprising a metal terminal electrically connected to the energy storage device element, and a tab film arranged between the inner packaging body and the outer packaging body and the metal terminal, wherein the inner packaging body and the outer packaging body are joined to the metal terminal via the tab film, and the entire inner packaging body is covered by the outer packaging body.

[0300] The ninth aspect of the invention relating to embodiment C is an energy storage device according to any one of the first to sixth aspects, further comprising a metal terminal electrically connected to the energy storage device element, the inner packaging body and the metal terminal are joined, and at least a portion of the outer edge of the inner packaging body is exposed from the outer packaging body.

[0301] The energy storage device according to a tenth aspect of the invention, relating to embodiment C, is an energy storage device according to any one of the first to sixth aspects, further comprising a metal terminal electrically connected to the energy storage device element, the inner packaging body and the outer packaging body are joined to the metal terminal, and the entire inner packaging body is covered by the outer packaging body.

[0302] [Embodiment C1] FIG. 8 shows a plan view of the electricity storage device 100 according to the present embodiment C1. FIG. 22 is a cross-sectional view taken along the line D2-D2 in FIG. 8. In FIG. 8, a portion that is not visible from the outside is partially shown by dotted lines for reference. Hereinafter, for convenience of explanation, unless otherwise specified, the up-down 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 up-down direction in FIG. 22 is referred to as the "up-down direction". However, the orientation of the electricity storage device 100 during use is not limited to this. In addition, in FIG. 8, the relative positional relationship between the inner wrapping body 210 and the outer wrapping body 220 is simplified for the sake of simplicity of the drawing.

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

[0304] The housing 110 includes a container 110A. The container 110A includes an inner packaging body 210 and an outer packaging body 220. The inner packaging body 210 accommodates the power storage device element 120. The outer packaging body 220 accommodates the inner packaging body 210 in a state in which the power storage device element 120 is accommodated. An internal space S1 is formed inside the inner packaging body 210. The inner packaging body 210 includes packaging films 211 and 212 for a power storage device. The outer packaging body 220 includes exterior films 221 and 222. At the outer periphery of the container 110A in a 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. The peripheral seal portion 150 forms an internal space S1 of the container 110A that is isolated from the external space in the inner packaging body 210. The peripheral seal portion 150 defines the peripheral edge of the internal space S1 of the container 110A. The heat seal mode referred to here may be heat fusion from a heat source, ultrasonic fusion, or the like. In any case, the peripheral seal portion 150 refers to the portion where the inner wrapping body 210 and the outer wrapping body 220 are fused and integrated.

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

[0306] 22, the terminal seal portion 151A of the top seal portion 151 is formed by laminating, from the top, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the metal terminal 130, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. This makes it easy to form the top seal portion 151. Note that, in a portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, a portion where only the pair of tab films 140 are sandwiched between the inner packaging body 210 and the outer packaging body 220, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222 are laminated, from the top, and these are integrated together. Furthermore, the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion bordered by the step in FIG. 22) is formed by laminating, from the top, the electricity storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, and the electricity storage device packaging film 212, which are integrated together. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the exterior films 221, 222 are not present and the inner portion of the terminal seal portion 151A where the exterior films 221, 222 are present (the right portion bordered by the step in FIG. 22), but FIG. 8 illustrates the area of ​​the peripheral seal portion 150 from a bird's eye view and does not show the step that serves as the boundary.

[0307] The electricity storage device packaging films 211, 212 constituting the inner packaging body 210 preferably have transparency as a whole from the viewpoint of suitable production of the electricity storage device 100. The electricity storage device packaging films 211, 212 preferably have gas permeability from the viewpoint of easy production of the electricity storage device 100. Below, preferred examples of the electricity storage device packaging films 211, 212 constituting the inner packaging body 210 will be described. Note that hereinafter, when there is no particular distinction between the electricity storage device packaging films 211, 212, the electricity storage device packaging films 211, 212 may be collectively referred to as the electricity storage device packaging film 10.

[0308] The shape of the inner packaging body 210 is not particularly limited, and may be, for example, a bag-like (pouch-like) shape. The bag-like shape may be a three-sided sealed type, a four-sided sealed type, a pillow type, a gusset type, or the like. The inner packaging body 210 of this embodiment C1 has a shape as shown in FIG. 22 and is manufactured by heat-sealing a packaging film 212 for an electricity storage device formed into a tray shape and a packaging film 211 for an electricity storage device, which is also formed into a tray shape and is superimposed on the packaging film 212 for an electricity storage device, along the outer periphery in a plan view. The packaging film 212 for an electricity storage device includes a flange portion 212A having a square ring shape corresponding to the outer periphery in a plan view, and a molded portion 212B that is continuous with the inner edge of the flange portion 212A and bulges downward therefrom. Similarly, the packaging film 211 for an electricity storage device includes a flange portion 211A having a square ring shape corresponding to the outer periphery in a plan view, and a flange portion 211B that is continuous with the inner edge of the flange portion 211A and bulges upward therefrom. The electricity storage device packaging films 211, 212 are overlapped such that the respective molded portions 211B, 212B bulge in opposite directions. In this state, the flange portion 211A of the electricity storage device packaging film 211 and the flange portion 212A of the electricity storage device packaging film 212 are heat sealed so as to be integrated together, forming a part of the peripheral seal portion 150. Note that one of the electricity storage device packaging films 211, 212 may be in the form of a sheet.

[0309] The exterior films 221, 222 constituting the outer packaging body 220 are, for example, made of a resin molded product or film. The resin molded product referred to here can be manufactured by a method such as injection molding, compressed air molding, vacuum molding, blow molding, etc., and in-mold molding may be performed to impart design and functionality. The type of resin may be polyolefin, polyester, nylon, ABS, etc. Furthermore, the film referred to here is, for example, a resin film that can be manufactured by a method such as an inflation method or a T-die method, or a film in which such a resin film is laminated on a metal foil or metal plate. Furthermore, the film referred to here may or may not be stretched, and may be a single-layer film or a multilayer film. Furthermore, the multilayer film referred to here may be manufactured by a coating method, may be a film in which multiple films are bonded together with an adhesive, or may be manufactured by a multilayer extrusion method.

[0310] The exterior films 221, 222 can be configured in various ways, but in this embodiment C1, they are configured from a laminate film. The laminate film can be a laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated. The base layer functions as a base material for the exterior films 221, 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 a function of preventing at least moisture and the like from penetrating into the power storage device 100 in addition to improving the strength of the exterior films 221, 222, and is typically a metal layer made of 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.

[0311] The shape of the outer packaging body 220 is not particularly limited, and may be, for example, a bag-like (pouch-like) shape. The bag-like shape may be a three-sided seal type, a four-sided seal type, a pillow type, a gusset type, or the like. The container 110A of this embodiment C1 has a shape as shown in FIG. 22 and is manufactured by heat-sealing an exterior film 222 formed into a tray shape and an exterior film 221 similarly formed into a tray shape and superimposed on the exterior film 222 along the outer periphery in a plan view. The exterior film 222 includes a square ring-shaped flange portion 222A corresponding to the outer periphery 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 a square ring-shaped flange portion 221A corresponding to the outer periphery in a plan view, and a flange 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 overlapped 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 to be integrated together, forming a part of the peripheral seal portion 150. Note that one of the exterior films 221 and 222 may be in the form of a sheet.

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

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

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

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

[0316] The metal terminal 130 is a metal terminal used for inputting and outputting electric power to and from the power storage device element 120. The metal terminal 130 is disposed, for example, in the top seal portion 151 of the container 110A, one of which constitutes a positive terminal and the other of which constitutes a negative terminal. One end in the left-right direction of each metal terminal 130 is electrically connected to an 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 vehicles and hybrid vehicles in which a large number of power storage devices 100 are connected in series and used at high voltage. 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, in the side seal portions 152 and 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, etc. When the power storage device element 120 is a lithium ion battery, the metal terminal 130 connected to the positive electrode is typically made of aluminum or the like, and the metal terminal 130 connected to the negative electrode is typically made of copper, nickel, etc.

[0318] The tab film 140 is a so-called adhesive film, and is configured to adhere to both the electricity storage device packaging films 211, 212 and the metal terminal 130. By using the tab film 140, the metal terminal 130 and the innermost layer (thermally adhesive resin layer) of the electricity storage device packaging films 211, 212 can be fixed to each other even if they are made of different materials. Note that the tab film 140 is integrated by being fused and fixed to the metal terminal 130 in advance, and the electricity storage device packaging films 211, 212 are fused to the metal terminal 130 to which the tab film 140 is fixed.

[0319] The power storage device 100 according to the present embodiment C1 includes a functional object 230 so as to have a high added-value function in addition to the functions of a general power storage device. The functional object 230 has at least one function of shock absorption, flame retardancy, cooling, and fire extinguishing. The functional object 230 is disposed between the inner wrapping body 210 and the outer wrapping body 220. The specific form of the functional object 230 can be selected arbitrarily. The functional object 230 may be in the form of a sheet such as a film, a liquid that can be applied to a film, or a granular or liquid form 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, for example, wrapped around the inner packaging body 210 and joined to the inner packaging body 210. The functional object 230 may be joined to the inner packaging body 210 so as to cover at least a part of the surface of the inner packaging body 210, but it is preferable that the functional object 230 is joined to the inner packaging body 210 so as to cover almost the entire surface of the inner packaging body 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 packaging body 210 or the inner surface of the outer packaging body 220. The functional object 230 may be applied to at least a part of the surface of the inner packaging body 210, but it is preferable that the functional object 230 is applied to substantially the entire surface of the inner packaging body 210. Note that the functional object 230 being a liquid that can be applied to a film or the like includes a state in which it can be sprayed onto the inner packaging body 210 and the outer packaging body 220 by a spray or the like.

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

[0323] The functional object 230 having impact absorbing properties is, for example, a non-crosslinked highly expanded polyethylene sheet, an electron beam crosslinked highly expanded polyethylene sheet, a heat-welded composite highly expanded polyethylene sheet, or nitrile rubber.

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

[0325] The functional object 230 having a cooling property is, for example, a highly thermally conductive film, a highly thermally conductive adhesive sheet, or an extremely highly thermally conductive 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 common powder-based fire extinguishing agent such as 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, from the viewpoint of suppressing a decrease in the function of the electricity storage device 100, a fire extinguishing agent that does not contain water is preferable.

[0327] The fireproof film may be a known fireproof film. The fireproof film is, for example, a laminated film having a substrate (substrate layer) and an extinguishing agent-containing layer in this order. The extinguishing agent-containing layer may be provided on at least a part of one surface of the substrate, but is preferably provided on the entire surface of the substrate. The substrate is within the substrate and has a region carrying the extinguishing agent component and the binder resin on the side of the extinguishing agent-containing layer.

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

[0329] The substrate has voids, and may be, for example, a nonwoven fabric formed by entangling nonflammable or flame-retardant fibers, or a woven fabric formed by weaving nonflammable or flame-retardant fibers. Examples of nonflammable or flame-retardant fibers include glass fibers, ceramic fibers, metal fibers, cellulose fibers, polyester fibers, carbon fibers, graphite fibers, and thermosetting resin fibers. From the viewpoint of excellent nonflammability, glass fibers and ceramic fibers can be used. Examples of substrates include glass cloth and nonflammable paper. As the substrate, a nonflammable substrate that meets the first class of flame retardancy specified in JIS Z 2150-1966 can also be used.

[0330] The supported region in the substrate is formed by the penetration of a part of the coating liquid into the substrate when a coating film is formed on the surface of the substrate using a coating liquid containing the extinguishing agent component and the binder resin. It can be said that the substrate has a supported region of the extinguishing agent component and the binder resin and a non-supported region thereof.

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

[0332] [Method of manufacturing electricity storage device] 23 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.

[0333] In the inner wrapping step of step S11, as shown in FIG. 24, the electricity storage device element 120 is wrapped in the formed electricity storage device packaging films 211, 212. In the electricity storage device 100 of the present embodiment C1, since the electricity storage device packaging films 211, 212 are gas permeable, there is no need to form an auxiliary chamber for temporarily storing gas generated from the electricity storage device element 120 in an initial filling step or the like described below. Therefore, in the inner wrapping step, the electricity storage device element 120 is wrapped in the electricity storage device packaging films 211, 212 having substantially the same size as the electricity storage device packaging films 211, 212 provided in the inner packaging body 210 of the completed electricity storage device 100. Therefore, the manufacturing process of the electricity storage device 100 can be simplified. Furthermore, the amount of material used for the electricity storage device 100 can be reduced. Substantially the same size includes a case where the size is larger than the electricity storage device packaging films 211, 212 included in the inner packaging body 210 of the completed electricity storage device 100 to the extent that a sub-chamber cannot be formed. Note that the electricity storage device element 120 is previously connected to the metal terminal 130, and the tab film 140 is joined to the metal terminal 130.

[0334] The first inner sealing step in step S12 is carried out after the inner packaging step. In the first inner sealing step, as shown in Fig. 12, the portions of the periphery of the electricity storage device packaging films 211, 212 that correspond to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 are sealed. Completion of the first inner sealing step forms an opening 213 in the portion of the periphery of the electricity storage device packaging films 211, 212 where the side seal portion 153 is to be formed. After the first inner sealing step, a vacuum drying step in step S13 is carried out.

[0335] The electrolyte injection process in step S14 is carried out 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 step in step S15 is performed after the electrolyte injection step. As shown in FIG. 23, in the second inner sealing step, the opening 213 is closed by sealing the portion of the periphery of the packaging films 211 and 212 for the electricity storage device where the side seal portion 153 is to be formed. According to the electricity storage device 100, since the packaging films 211 and 212 for the electricity storage device have transparency, it is possible to easily check whether the packaging films 211 and 212 for the electricity storage device are properly sealed after the first inner sealing step or the second inner sealing step is completed. Therefore, the electricity storage device 100 can be suitably manufactured. The state in which the packaging films 211 and 212 for the electricity storage device 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 packaging films 211 and 212 for the electricity storage device are sealed with a foreign object in between. The second state is a state where a part of the part that should be sealed is not sealed. The third state is a state where a part that should not be sealed is sealed. After the second inside sealing process, the initial charge / discharge process of step S16 and the aging process of step S17 are performed in order.

[0337] The degassing step in step S18 is carried out in parallel with the initial charge / discharge step and the aging step. In this embodiment C1, the electricity storage device packaging films 211, 212 are gas permeable, so that gases such as carbon dioxide generated from the electricity storage device element 120 during the initial charge / discharge step and the aging step are discharged to the outside through the electricity storage device packaging films 211, 212. After the degassing step, the main charging step in step S19 is carried out.

[0338] The arrangement step of step S20 is performed after the main filling step. In the arrangement step, the functional object 230 is arranged between the inner packaging body 210 and the outer packaging body 230 according to the specific form of the functional object 230. When the functional object 230 is in the form of a sheet such as a film, the functional object 230 is, for example, wrapped around the inner packaging body 210 and joined to the inner packaging body 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 packaging body 210 or the inner surface of the outer packaging body 220.

[0339] The outer wrapping step of step S21 is carried out after the arrangement step. In the outer wrapping step, the inner wrapping body 210 containing the electricity storage device element 120 is wrapped with exterior films 221, 222.

[0340] The outer sealing step of step S22 is performed after the outer packaging step. In the outer sealing step, the periphery of the exterior films 221, 222 is sealed to form the periphery seal portion 150. When the functional object 230 is in a granular or liquid form having a predetermined fluidity (viscosity), the arranging step may be performed in the outer sealing step, for example, by filling the functional object 230 from an opening in a portion where the bottom seal portion 154 is to be formed after the top seal portion 151, the side seal portions 152, 153 of the periphery seal portion 150 are formed.

[0341] [Characteristics of the energy storage device] The power storage device 100 has high added value because it includes the functional object 230 .

[0342] [Embodiment C2] The electricity storage device 100 of embodiment C2 differs from embodiment C1 in that the electricity storage device packaging films 211, 212 are not gas permeable, or in that, compared to embodiment C1, they do not have gas permeability to the extent that the degassing step of step S18 described above is performed, but the other configurations are similar to those of embodiment C1. The electricity storage device 100 of embodiment C2 will be described below, focusing on the differences from embodiment C2.

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

[0344] In the inner wrapping step of step S31, as shown in Fig. 15, the electricity storage device element 120 is wrapped in the formed electricity storage device packaging films 211, 212. In the electricity storage device 100 of the present embodiment C2, since the electricity storage device packaging films 211, 212 are not gas permeable, it is preferable to form an auxiliary chamber 214 for temporarily storing gas generated from the electricity storage device element 120 in the initial filling step or the like. For this reason, in the inner wrapping step, the electricity storage device element 120 is wrapped in the electricity storage device packaging films 211, 212 that are larger than the electricity storage device packaging films 211, 212 provided in the inner packaging body 210 of the completed electricity storage device 100. In the auxiliary chamber 214 of the electricity storage device packaging films 211, 212, a storage chamber 215 for storing more gas generated from the electricity storage device element 120 is formed.

[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 of the periphery of the electricity storage device packaging films 211, 212 corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 are sealed so as to extend to the auxiliary chamber 214. Completion of the first inner sealing step forms an opening 213 in a portion 216 that faces the portion of the periphery of the electricity storage device packaging films 211, 212 where the side seal portion 153 is to be formed, across the auxiliary chamber 214. After the first inner sealing step, a vacuum drying step of step S33 is performed.

[0346] The electrolyte injection process in 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).

[0347] The second inner sealing step of step S35 is performed after the electrolyte injection step. As shown in Fig. 17, in the second inner sealing step, the opening 213 is closed by sealing a portion 216 of the periphery of the packaging films 211, 212 for electricity storage devices, which is opposite to a portion where the side seal portion 153 is to be formed, via the auxiliary chamber 214. After the second inner sealing step, the initial charge / discharge step of step S36 and the aging step of step S37 are performed in this order.

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

[0349] The auxiliary chamber removing step of step S39 is performed after the degassing step. In the auxiliary chamber removing step, the auxiliary chamber 214 is removed by cutting the electricity storage device packaging films 211, 212 along the dashed dotted line XA shown in Fig. 17 so that the auxiliary chamber 214 has the same size as the inner packaging body 210 of the completed electricity storage device 100.

[0350] The inside sealing step of step S40 is performed after the auxiliary chamber removing step. In the inside sealing step, the portions of the periphery of the packaging films 211, 212 for electricity storage devices that correspond to the side seal portion 153 are sealed as shown in Fig. 18. After the inside sealing step, a main charging step of step S41 is performed.

[0351] The arrangement step of step S42 is performed after the main filling step. In the arrangement step, the functional object 230 is arranged between the inner packaging body 210 and the outer packaging body 230 according to the specific form of the functional object 230. When the functional object 230 is in the form of a sheet such as a film, the functional object 230 is, for example, wrapped around the inner packaging body 210 and joined to the inner packaging body 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 packaging body 210 or the inner surface of the outer packaging body 220.

[0352] The outer wrapping step of step S43 is carried out after the arrangement step. In the outer wrapping step, the inner wrapping body 210 containing the electricity storage device element 120 is wrapped in exterior films 221, 222.

[0353] The outer sealing step of step S44 is performed after the outer packaging step. In the outer sealing step, the periphery of the exterior films 221, 222 is sealed to form the periphery seal portion 150. When the functional object 230 is in a granular or liquid form having a predetermined fluidity (viscosity), the arranging step may be performed in the outer sealing step, for example, by filling the functional object 230 from an opening in a portion where the bottom seal portion 154 is to be formed after the top seal portion 151, the side seal portions 152, 153 of the periphery seal portion 150 are formed.

[0354] [Characteristics of the energy storage device] According to the power storage device 100 of the embodiment C3, since the functional object 230 is provided, the same effects as those of the power storage device 100 of the embodiment C1 can be obtained.

[0355] [Embodiment C3] The power storage device 300 of embodiment C3 differs from embodiment C1 in that the configuration of the terminal seal portion 151A is different, and other configurations are similar to those of embodiment C1. The following describes the power storage device 300 of embodiment C3, focusing on the differences from embodiment C1.

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

[0357] The flange portion 221A of the exterior film 221 is joined to one tab film 140. The flange portion 222A of the exterior film 222 is joined to the other tab film 140. An end 221X of the flange portion 221A is located farther from the electricity storage device element 120 than an end 211X of the electricity storage device packaging film 211. An end 222X of the flange portion 222A is located farther from the electricity storage device element 120 than an end 212X of the electricity storage device packaging film 212. Therefore, the entire inner packaging body 210 is covered by the outer packaging body 220.

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

[0359] [Embodiment C4] The power storage device 400 of embodiment C4 differs from embodiment C in that the configuration of the terminal seal portion 151A is different, and other configurations are similar to those of embodiment C1. The following describes the power storage device 400 of embodiment C4, focusing on the differences from embodiment C1.

[0360] 26 is a cross-sectional view of a terminal seal portion 451A included in an electricity storage device 400 of embodiment C4. The electricity storage device 400 does not have a tab film 140. In the terminal seal portion 451A of the electricity storage device 400, from the top, an exterior film 221, an electricity storage device packaging film 211, a metal terminal 130, an electricity storage device packaging film 212, and an exterior film 222 are laminated and integrated.

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

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

[0363] [Characteristics of the energy storage device] According to the electricity storage device 400, the number of parts is reduced because the electricity storage device packaging films 211, 212 and the metal terminal 130 are joined together without the tab film 140. In addition, the manufacturing method of the electricity storage device 400 can be simplified.

[0364] [Embodiment C5] The power storage device 500 of embodiment C5 differs from embodiment C4 in that the configuration of the terminal seal portion 451A is different, and other configurations are similar to those of embodiment C4. The following describes the power storage device 500 of embodiment C5, focusing on the differences from embodiment C4.

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

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

[0367] [Characteristics of the energy storage device] According to the electricity storage device 500, the inner packaging body 210 is covered by the outer packaging body 220, which prevents moisture and the like from entering the internal space S1 of the inner packaging body 210 from the outside. Also, according to the electricity storage device 500, the packaging films 211, 212 for electricity storage devices and the metal terminal 130 are joined without the tab film 140, which reduces the number of parts. Also, the manufacturing method of the electricity storage device 500 can be simplified.

[0368] [Variations] The above-mentioned respective embodiments C are examples of possible forms of the electricity storage device and the manufacturing method of the electricity storage device according to the present disclosure, and are not intended to limit the forms. The electricity storage device and the manufacturing method of the electricity storage device according to the present disclosure may take forms different from those exemplified in the respective embodiments. 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 modified forms of each embodiment are shown below. Note that the following modified forms can be combined with each other as long as there is no technical contradiction.

[0369] In the electricity storage device 100 of embodiment C1, the functional object 230 may be contained in at least one of the electricity storage device packaging films 211, 212 or the exterior films 221, 222. That is, the electricity 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 absorption properties, flame retardancy, cooling properties, and fire extinguishing properties.

[0370] In the electricity storage device 100 of embodiment C1, one outer packaging body 220 may be configured to house a plurality of inner packaging bodies 210 in a state in which the electricity storage device elements 120 are housed therein. In this modification, the sizes of the plurality of inner packaging bodies 210 may be different or the same. According to this modification, the plurality of electricity storage device elements 120 can be connected in series or in parallel, so that the voltage can be easily adjusted.

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

[0372] In the electricity storage device 100 of embodiment C1, the inner packaging body 210 may be formed by folding one electricity storage device packaging film 211 and heat sealing the peripheral portion. Similarly, the outer packaging body 220 may be formed by folding one exterior film 221 and heat sealing the peripheral portion.

[0373] <Third aspect> [Embodiment 1] FIG. 8 shows a plan view of the electricity storage device 100 according to the first embodiment. FIG. 9 is a cross-sectional view taken along the line D2-D2 in FIG. 8. In FIG. 8, a portion that is not visible from the outside is partially shown by dotted lines for reference. Hereinafter, for convenience of explanation, unless otherwise specified, the up-down 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 up-down direction in FIG. 9 is referred to as the "up-down direction". However, the orientation of the electricity storage device 100 during use is not limited to this. In addition, in FIG. 8, the relative positional relationship between the inner wrapping body 210 and the outer wrapping body 220 is simplified for the sake of simplicity of the drawing.

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

[0375] The housing 110 includes a container 110A. The container 110A includes an inner packaging body 210 and an outer packaging body 220. The inner packaging body 210 accommodates the power storage device element 120. The outer packaging body 220 accommodates the inner packaging body 210 in a state in which the power storage device element 120 is accommodated. An internal space S1 is formed inside the inner packaging body 210. The inner packaging body 210 includes packaging films 211 and 212 for a power storage device. The outer packaging body 220 includes exterior films 221 and 222. At the outer periphery of the container 110A in a 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. The peripheral seal portion 150 forms an internal space S1 of the container 110A that is isolated from the external space in the inner packaging body 210. The peripheral seal portion 150 defines the peripheral edge of the internal space S1 of the container 110A. The heat seal mode referred to here may be heat fusion from a heat source, ultrasonic fusion, or the like. In any case, the peripheral seal portion 150 refers to the portion where the inner wrapping body 210 and the outer wrapping body 220 are fused and integrated.

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

[0377] 9, the terminal seal portion 151A of the top seal portion 151 is formed by laminating, from the top, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the metal terminal 130, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. This makes it easy to form the top seal portion 151. Note that, in a portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, a portion where only the pair of tab films 140 are sandwiched between the inner packaging body 210 and the outer packaging body 220, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. Furthermore, the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion bordered by the step in FIG. 9) is formed by laminating, from the top, the electricity storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, and the electricity storage device packaging film 212, which are integrated together. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the exterior films 221, 222 are not present and the inner portion of the terminal seal portion 151A where the exterior films 221, 222 are present (the right portion bordered by the step in FIG. 9), but FIG. 8 illustrates the area of ​​the peripheral seal portion 150 from a bird's eye view and does not show the step that serves as the boundary.

[0378] The electricity storage device packaging films 211, 212 constituting the inner packaging body 210 are transparent overall from the viewpoint of suitably manufacturing the electricity storage device 100. Below, preferred examples of the electricity storage device packaging films 211, 212 constituting the inner packaging body 210 are described. Note that hereinafter, when there is no particular distinction between the electricity storage device packaging films 211, 212, the electricity storage device packaging films 211, 212 may be collectively referred to as the electricity storage device packaging film 10.

[0379] [Laminate structure and physical properties of the packaging film for electricity storage devices according to the third embodiment] 1 to 4, the packaging film 10 for an electricity storage device according to the third embodiment includes at least a heat-sealable resin layer 1. When assembling an electricity storage device using the packaging film 10 for an electricity storage device and an electricity storage device element, the heat-sealable resin layers 1 of the packaging film 10 for an electricity storage device are placed opposite each other, and the peripheral portions are heat-sealed to form a space in which the electricity storage device element is housed.

[0380] The packaging film 10 for an electricity storage device in the third embodiment may be composed only of a heat-sealable resin layer 1, as shown in Fig. 1. When the packaging film 10 for an electricity storage device is composed only of a 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] 2 to 4, the packaging film 10 for an electricity storage device according to the third embodiment 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 an electricity storage device, the resin layer 2 is on the outside and the heat-sealable resin layer 1 is on the inside (the innermost layer). When the packaging film 10 for an electricity storage device is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, it is preferable to impart adhesion to metal to at least one of the outside surface of the resin layer 2 and the inside surface of the heat-sealable resin layer 1, and it is more preferable to impart adhesion to metal to the inside surface of the heat-sealable resin layer 1 that faces the metal terminal 130.

[0382] Furthermore, the packaging film 10 for an electricity storage device according to the third embodiment is preferably composed of a laminate including at least a resin layer 2, a substrate 3, and the heat-sealable resin layer 1, as shown in Figs. 3 and 4. In such a packaging film 10 for an electricity storage device, the resin layer 2 is on the outside, the heat-sealable resin layer 1 is on the inside (the innermost layer), and the substrate 3 is located between the resin layer 2 and the heat-sealable resin layer 1. Even when the packaging film 10 for an electricity storage device is composed of a laminate including the resin layer 2, the substrate 3, and the heat-sealable resin layer 1, it is preferable to impart adhesion 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 adhesion to metal to the inner surface of the heat-sealable resin layer 1 that faces 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-fusible resin layer 1, and as shown in FIG. 4, an adhesive layer 5 can be provided between the heat-fusible resin layer 1 and the substrate 3.

[0384] The packaging film 10 for an electricity storage device according to the third embodiment has a CO2 permeation rate of 100 cc·100 μm / m in an environment at a temperature of 30° C. 2 / 24hr / atm or more is preferable, and about 200cc 100μm / m is more preferable. 2 / 24hr / atm or more, and even more preferably about 300cc·100μm / m 2 / 24hr / atm or more, and even more preferably about 500cc·100μm / m 2 The CO2 permeation amount of the packaging film 10 for an electricity storage device according to the third embodiment is, for example, about 2000 cc·100 μm / m 2 / 24hr / atm or less, preferably about 1000cc 100μm / m 2 / 24hr / atm or less, more preferably about 800cc·100μm / m 2 / 24hr / atm or less, and the preferred range is 100 to 2000cc 100μm / m 2 / 24hr / atm, 100~1000cc・100μm / m 2 / 24hr / atm, 100~800cc・100μm / m 2 / 24hr / atm, 200~2000cc・100μm / m 2 / 24hr / atm, 200~1000cc・100μm / m 2 / 24hr / atm, 200~800cc・100μm / m 2 / 24hr / atm, 300~2000cc・100μm / m 2 / 24hr / atm, 300~1000cc・100μm / m 2 / 24hr / atm, 300~800cc・100μm / m 2 / 24hr / atm, 500~2000cc・100μm / m 2 / 24hr / atm, 500~1000cc・100μm / m 2 / 24hr / atm, 500~800cc・100μm / m 2 The method for measuring the CO2 permeation rate of the packaging film for electricity storage devices is as follows.

[0385] [Measurement of CO2 transmission rate] In accordance with JIS K7126-1 (Plastics - Films and sheets - Gas permeability test method - Part 1: Differential pressure method), the amount of CO2 that permeates through a φ60 mm piece of packaging film 10 for electricity storage devices in an atmosphere at 30°C is quantitatively analyzed by gas chromatography to measure the amount of CO2 that permeates through the φ60 mm piece of packaging film 10 for electricity storage devices.

[0386] Although not shown, 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 thermally adhesive resin layer 1 side) as required.

[0387] The thickness of the laminate constituting the packaging film 10 for electricity storage devices of the third embodiment is not particularly limited, but from the viewpoints of cost reduction, energy density improvement, etc., it is, for example, 190 μm or less, preferably about 180 μm or less, about 170 μm or less. In addition, from the viewpoint of maintaining the function of the packaging film for electricity storage devices, which is to protect the electricity storage device elements, the thickness of the laminate constituting the packaging film 10 for electricity storage devices is preferably about 35 μm or more, about 45 μm or more, about 60 μm or more. In addition, the preferred range of the laminate constituting the packaging film 10 for electricity storage devices is, 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, and particularly preferably about 45 to 170 μm.

[0388] In the packaging film 10 for an electricity storage device of the third embodiment, the ratio of the total thickness of the resin layer 2, adhesive layer 4, substrate 3, adhesive layer 5, and heat-sealable resin layer 1 to the thickness (total thickness) of the laminate constituting the packaging film 10 for an electricity 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 an electricity storage device of the third embodiment includes the resin layer 2, adhesive layer 4, substrate 3, adhesive layer 5, and 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 an electricity storage device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. Furthermore, even when the packaging film 10 for electricity storage devices of the third embodiment is a laminate including a resin layer 2, an adhesive layer 4, and a 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 electricity storage devices 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 a power storage device of the third embodiment can have a total light transmittance measured in accordance with the provisions of JIS K7361-1:1997 of, for example, 80% or more, 85% or more, 90% or more. The lower the total light transmittance, the higher the shielding property of the packaging film 10 for a power storage device. On the other hand, the higher the total light transmittance, the higher the light transmittance of the packaging film 10 for a power storage device. Therefore, by keeping the total light transmittance at a certain lower limit, the desired transparency can be maintained. The lower limit of the total light transmittance is 0%, and the upper limit is 100%. The total light transmittance of the packaging film for a power storage device is measured in the visible light region (400 to 700 nm) using a commercially available spectrophotometer (for example, UV-Visible Near-Infrared Spectrophotometer V-670 manufactured by JASCO Corporation) in accordance with the measurement method prescribed in JIS K7361-1:1997, and the average value is taken as the total light transmittance. The measurement conditions are as follows: a halogen lamp is used 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 an electricity storage device according to the third embodiment can be colored black and transparent by making it black. When the packaging film 10 for an electricity storage device is made black, it has a unique color, which makes it highly distinctive and highly designed. In addition, in the manufacturing process of the electricity storage device, it becomes possible to grasp the position with a sensor with higher accuracy, and it becomes possible to transport the packaging film 10 for an electricity storage device and seal the electricity storage device elements more accurately. Furthermore, it is possible to unify the electricity storage device and other electrical equipment in black to give the product a sense of luxury.

[0391] <Layers Constituting the Packaging Film for Electricity Storage Devices of the Third Embodiment> Each layer constituting the packaging film for electricity storage devices of the third embodiment is the same as that of the packaging films for electricity storage devices of the first and second embodiments, and therefore description thereof will be omitted.

[0392] [Method for producing packaging film for electricity storage device according to the third embodiment] The method for producing the packaging film for an electricity storage device of the third embodiment is not particularly limited as long as the packaging film for an electricity storage device of the third embodiment can be obtained. For example, when the packaging film for an electricity storage device of the third embodiment 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 a resin layer and a heat-sealable resin layer are laminated in this order from the outside, and the laminate has a CO2 permeation rate of 100 cc·100 μm / m in an environment at a temperature of 30° C. 2 / 24hr / atm or higher is preferable.

[0393] An example of a manufacturing method in which the packaging film for an electricity storage device of the third embodiment is configured as a laminate including the resin layer 2, the adhesive layer 4, the substrate 3, the adhesive layer 5, and the heat-sealable resin layer 1 in this order is as follows. First, materials for configuring each layer are prepared. Next, the resin layer 2 and the substrate 3 are laminated via the adhesive layer 4, and the substrate 3 and the heat-sealable resin layer 1 are laminated via the adhesive layer 5. Specifically, the resin layer 2 and the substrate 3 are laminated by a dry lamination method or the like using an adhesive that forms the adhesive layer 4, so that the resin layer 2, the adhesive layer 4, and the substrate 3 are laminated, and further, the substrate 3 and the heat-sealable resin layer 1 are laminated by a dry lamination method or the like using an adhesive that forms the adhesive layer 5, so that the packaging film for an electricity storage device 10 can be manufactured. Furthermore, when the resin layer 2, the substrate 3, and the heat-sealable resin layer 1 are laminated without the adhesive layers 4 and 5, the packaging film 10 for an electricity storage device can be manufactured by a method of melt-extruding the resin constituting the resin layer 2 onto one side of the substrate 3, and melt-extruding the resin constituting the heat-sealable resin layer 1 onto the other side of the substrate 3. When a colored layer is provided, it is sufficient to form a colored layer on the surface of the resin layer 2 and then laminate the substrate 3 and the heat-sealable resin layer 1. When a surface coating layer is provided, it can be formed, for example, by applying the above-mentioned resin composition for forming the surface coating layer onto 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 electricity storage device packaging film 10 may be subjected to a heat treatment.

[0395] The shape of the inner packaging body 210 of the third embodiment is not particularly limited, and may be, for example, a bag-like (pouch-like) shape. Possible bag-like shapes here include a three-sided sealed type, a four-sided sealed type, a pillow type, and a gusset type. The inner packaging body 210 of the present embodiment 1 has a shape as shown in FIG. 2, and is manufactured by heat-sealing a packaging film 212 for an electricity storage device formed into a tray shape and a packaging film 211 for an electricity storage device, which is also formed into a tray shape and is superimposed on the packaging film 212 for an electricity storage device, along the outer periphery in a plan view. The packaging film 212 for an electricity storage device includes a flange portion 212A having a rectangular ring shape corresponding to the outer periphery in a plan view, and a molded portion 212B that is continuous with the inner edge of the flange portion 212A and bulges downward therefrom. Similarly, the electricity storage device packaging film 211 includes a rectangular annular flange portion 211A corresponding to the outer periphery in a plan view, and a flange portion 211B that is continuous with the inner edge of the flange portion 211A and bulges upward therefrom. The electricity storage device packaging films 211, 212 are overlapped such that the respective formed portions 211B, 212B bulge in opposite directions. In this state, the flange portion 211A of the electricity storage device packaging film 211 and the flange portion 212A of the electricity storage device packaging film 212 are heat-sealed so as to be integrated together, and form a part of the peripheral seal portion 150. One of the electricity storage device packaging films 211, 212 may be in the form of a sheet.

[0396] The exterior films 221, 222 constituting the outer packaging body 220 of the third embodiment are, for example, made of a resin molded product or film. The resin molded product referred to here can be manufactured by a method such as injection molding, compressed air molding, vacuum molding, blow molding, etc., and in-mold molding may be performed to impart design and functionality. The type of resin may be polyolefin, polyester, nylon, ABS, etc. Furthermore, the film referred to here is, for example, a resin film that can be manufactured by a method such as an inflation method or a T-die method, or a film in which such a resin film is laminated on a metal foil or metal plate. Furthermore, the film referred to here may or may not be stretched, and may be a single-layer film or a multilayer film. Furthermore, the multilayer film referred to here may be manufactured by a coating method, may be a film in which multiple films are bonded with an adhesive, or may be manufactured by a multilayer extrusion method.

[0397] The exterior films 221 and 222 of the third aspect can be configured in various ways, but in the present embodiment 1, they are configured from a laminate film. The laminate film can be a laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated. The base layer functions as a base material for the exterior 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 a function of preventing at least moisture and the like from penetrating into 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 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 packaging body 220 of the third embodiment is not particularly limited, and can be, for example, a bag-like (pouch-like) shape. The bag-like shape here can be a three-sided seal type, a four-sided seal type, a pillow type, a gusset type, or the like. The container 110A of the present embodiment 1 has a shape as shown in FIG. 2, and is manufactured by heat-sealing an exterior film 222 formed into a tray shape and an exterior film 221 similarly formed into a tray shape and superimposed on the exterior film 222 along the outer periphery in a plan view. The exterior film 222 includes a square ring-shaped flange portion 222A corresponding to the outer periphery 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 a square ring-shaped flange portion 221A corresponding to the outer periphery in a plan view, and a flange 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 overlapped 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 to be integrated together, forming a part of the peripheral seal portion 150. Note that one of the exterior films 221 and 222 may be in the form of a sheet.

[0399] 2, in the terminal seal portion 151A, a portion of the flange portion 211A of the electricity storage device packaging film 211 is joined to one tab film 140. A portion of the flange portion 212A of the electricity 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 embodiment is joined to the flange portion 211A of the packaging film 211 for an electricity storage device. The end 221X of the flange portion 221A is located closer to the electricity storage device element 120 than the end 211X of the packaging film 211 for an electricity storage device. Therefore, at least a part of the outer edge of the inner packaging body 210 is exposed from the outer packaging body 220. Note that the end 221X of the flange portion 221A may be located in the same position as the end 211X of the packaging film 211 for an electricity storage device in the left-right direction, or farther from the electricity storage device element 120 than the end 211X of the packaging film 211 for an electricity storage device.

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

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

[0403] The metal terminal 130 is a metal terminal used for inputting and outputting electric power to and from the power storage device element 120. The metal terminal 130 is disposed, for example, in the top seal portion 151 of the container 110A, one of which constitutes a positive terminal and the other of which constitutes a negative terminal. One end in the left-right direction of each metal terminal 130 is electrically connected to an 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 vehicles and hybrid vehicles in which a large number of power storage devices 100 are connected in series and used at high voltage. 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, in the side seal portions 152 and 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, etc. When the power storage device element 120 is a lithium ion battery, the metal terminal 130 connected to the positive electrode is typically made of aluminum or the like, and the metal terminal 130 connected to the negative electrode is typically made of copper, nickel, etc.

[0405] The tab film 140 is a so-called adhesive film, and is configured to adhere to both the electricity storage device packaging films 211, 212 and the metal terminal 130. By using the tab film 140, the metal terminal 130 and the innermost layer (thermally adhesive resin layer) of the electricity storage device packaging films 211, 212 can be fixed to each other even if they are made of different materials. Note that the tab film 140 is integrated by being fused and fixed to the metal terminal 130 in advance, and the electricity storage device packaging films 211, 212 are fused to the metal terminal 130 to which the tab film 140 is fixed.

[0406] [Method for producing the electricity storage device according to the third embodiment] 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.

[0407] In the inner wrapping step of step S11, as shown in Fig. 11, the electricity storage device element 120 is wrapped in the formed electricity storage device packaging films 211, 212. In the electricity storage device 100 of the first embodiment, since the electricity storage device packaging films 211, 212 are gas permeable, there is no need to form an auxiliary chamber for temporarily storing gas generated from the electricity storage device element 120 in an initial filling step described below or the like. Therefore, in the inner wrapping step, the electricity storage device element 120 is wrapped in the electricity storage device packaging films 211, 212 having substantially the same size as the electricity storage device packaging films 211, 212 provided in the inner packaging body 210 of the completed electricity storage device 100. Therefore, the manufacturing process of the electricity storage device 100 can be simplified. Furthermore, the amount of material used for the electricity storage device 100 can be reduced. Substantially the same size includes a case where the size is larger than the electricity storage device packaging films 211, 212 included in the inner packaging body 210 of the completed electricity storage device 100 to the extent that a sub-chamber cannot be formed. Note that the electricity storage device element 120 is previously connected to the metal terminal 130, and the tab film 140 is joined to the metal terminal 130.

[0408] The first inner sealing step in step S12 is carried out after the inner packaging step. In the first inner sealing step, as shown in Fig. 12, the portions of the periphery of the electricity storage device packaging films 211, 212 that correspond to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 are sealed. Completion of the first inner sealing step forms an opening 213 in the portion of the periphery of the electricity storage device packaging films 211, 212 where the side seal portion 153 is to be formed. After the first inner sealing step, a vacuum drying step in step S13 is carried out.

[0409] The electrolyte injection process in step S14 is carried out after the vacuum drying process. In the electrolyte injection process, the electrolyte is injected through the opening 213 (see FIG. 12).

[0410] The second inner sealing step of step S15 is performed after the electrolyte injection step. As shown in Fig. 13, in the second inner sealing step, the opening 213 is closed by sealing the peripheral portion of the packaging films 211, 212 for the electricity storage device where the side seal portion 153 is to be formed. After the second inner sealing step, the initial charge / discharge step of step S16 and the aging step of step S17 are performed in order.

[0411] The degassing step in step S18 is carried out in parallel with the initial charge / discharge step and the aging step. In the present embodiment 1, the electricity storage device packaging films 211, 212 are gas permeable, and therefore, when the initial charge / discharge step and the aging step are carried out, gas such as carbon dioxide generated from the electricity storage device element 120 is discharged to the outside through the electricity storage device packaging films 211, 212. After the degassing step, the main charging step in step S19 is carried out.

[0412] The outer wrapping step of step S20 is carried out after the main charging step. In the outer wrapping step, the inner wrapping body 210 containing the power storage device element 120 is wrapped in exterior films 221, 222.

[0413] The outer sealing step in step S21 is carried out after the outer wrapping step. In the outer sealing step, the periphery of the exterior films 221, 222 is sealed to form a peripheral seal portion 150.

[0414] [Characteristics of the electricity storage device according to the third embodiment] According to the electricity storage device 100, since the electricity storage device packaging films 211 and 212 have transparency, it is possible to easily check whether the electricity storage device packaging films 211 and 212 are properly sealed after the first inner sealing step or the second inner sealing step is completed. This allows the electricity storage device 100 to be suitably manufactured. The state in which the electricity storage device packaging films 211 and 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 electricity storage device packaging films 211 and 212 are sealed with a foreign object caught between them. The second state is a state in which a part that should be sealed is not sealed. The third state is a state in which a part that should not be sealed is sealed.

[0415] [Embodiment 2 of the third aspect] The electricity storage device 100 of the second embodiment differs from the first embodiment in that the electricity storage device packaging films 211, 212 are not gas permeable, or in that, compared to the first embodiment, they do not have gas permeability to the extent that the degassing step of step S18 described above is performed, but the other configurations are similar to those of the first embodiment. The electricity storage device 100 of the second embodiment will be described below, focusing on the differences from the second embodiment.

[0416] [Method of manufacturing electricity storage device] 14 is a flowchart showing an example of a method for manufacturing the power storage device 100 according to the second embodiment. The method for manufacturing the power storage device 100 includes a plurality of steps.

[0417] In the inner wrapping step of step S31, as shown in Fig. 15, the electricity storage device element 120 is wrapped in the formed electricity storage device packaging films 211, 212. In the electricity storage device 100 of the second embodiment, since the electricity storage device packaging films 211, 212 are not gas permeable, it is preferable to form an auxiliary chamber 214 for temporarily storing gas generated from the electricity storage device element 120 in the initial filling step or the like. For this reason, in the inner wrapping step, the electricity storage device element 120 is wrapped in the electricity storage device packaging films 211, 212 that are larger than the electricity storage device packaging films 211, 212 provided in the inner packaging body 210 of the completed electricity storage device 100. In the auxiliary chamber 214 of the electricity storage device packaging films 211, 212, a storage chamber 215 for storing more gas generated from the electricity storage device element 120 is formed.

[0418] 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 of the periphery of the electricity storage device packaging films 211, 212 corresponding to the top seal portion 151, the side seal portion 152, and the bottom seal portion 154 are sealed so as to extend to the auxiliary chamber 214. Completion of the first inner sealing step forms an opening 213 in a portion 216 that faces the portion of the periphery of the electricity storage device packaging films 211, 212 where the side seal portion 153 is to be formed, across the auxiliary chamber 214. After the first inner sealing step, a vacuum drying step of step S33 is performed.

[0419] The electrolyte injection process in 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 step of step S35 is performed after the electrolyte injection step. As shown in Fig. 17, in the second inner sealing step, the opening 213 is closed by sealing a portion 216 of the periphery of the packaging films 211, 212 for electricity storage devices, which is opposite to a portion where the side seal portion 153 is to be formed, via the auxiliary chamber 214. After the second inner sealing step, the initial charge / discharge step of step S36 and the aging step of step S37 are performed in this order.

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

[0422] The auxiliary chamber removing step of step S39 is performed after the degassing step. In the auxiliary chamber removing step, the auxiliary chamber 214 is removed by cutting the electricity storage device packaging films 211, 212 along the dashed dotted line XA shown in Fig. 17 so that the auxiliary chamber 214 has the same size as the inner packaging body 210 of the completed electricity storage device 100.

[0423] The inside sealing step of step S40 is performed after the auxiliary chamber removing step. In the inside sealing step, the portions of the periphery of the packaging films 211, 212 for electricity storage devices that correspond to the side seal portion 153 are sealed as shown in Fig. 18. After the inside sealing step, a main charging step of step S41 is performed.

[0424] The outer wrapping step of step S42 is carried out after the main charging step. In the outer wrapping step, the inner wrapping body 210 containing the power storage device element 120 is wrapped in exterior films 221, 222.

[0425] The outer sealing step in step S43 is carried out after the outer wrapping step. In the outer sealing step, the periphery of the exterior films 221, 222 is sealed to form a peripheral seal portion 150.

[0426] [Characteristics of the energy storage device] According to the electricity storage device 100 of the third embodiment, the electricity storage device packaging films 211 and 212 have transparency, and therefore the same effects as those of the electricity storage device 100 of the first embodiment can be obtained.

[0427] [Embodiment 3 of the third aspect] The power storage device 300 of the third embodiment differs from the first embodiment in that the configuration of the terminal seal portion 151A is different, and other configurations are similar to those of the first embodiment. The following describes the power storage device 300 of the third embodiment, focusing on the differences from the first embodiment.

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

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

[0430] [Characteristics of the energy storage device] According to the power storage device 300, since the inner packaging body 210 is covered by the outer packaging body 220, intrusion 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 of the fourth embodiment differs from the first embodiment in that the configuration of the terminal seal portion 151A is different, and other configurations are similar to those of the first embodiment. The following describes the power storage device 400 of the fourth embodiment, focusing on the differences from the first embodiment.

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

[0433] The end 221X of the flange portion 221A is located closer to the electricity storage device element 120 than the end 211X of the packaging film 211 for an electricity storage device. Therefore, at least a part of the outer edge of the inner packaging body 210 is exposed from the outer packaging body 220. Note that the end 221X of the flange portion 221A may be located in the same position as the end 211X of the packaging film 211 for an electricity storage device in the left-right direction, or farther from the electricity storage device element 120 than the end 211X of the packaging film 211 for an electricity 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 the electricity 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 electricity storage device. The end 222X of the flange portion 222A is located closer to the electricity storage device element 120 than the end 212X of the packaging film 212 for the electricity storage device. Therefore, at least a part of the outer edge of the inner packaging body 210 is exposed from the outer packaging body 220. Note that the end 222X of the flange portion 222A may be located at the same position as the end 212X of the packaging film 212 for the electricity storage device in the left-right direction, or farther from the electricity storage device element 120 than the end 212X of the packaging film 212 for the electricity storage device.

[0435] [Characteristics of the energy storage device] According to the electricity storage device 400, the number of parts is reduced because the electricity storage device packaging films 211, 212 and the metal terminal 130 are joined together without the tab film 140. In addition, the manufacturing method of the electricity storage device 400 can be simplified.

[0436] [Embodiment 5 of the third aspect] The power storage device 500 of the fifth embodiment differs from the fourth embodiment in that the configuration of the terminal seal portion 451A is different, and other configurations are similar to those of the fourth embodiment. The following describes the power storage device 500 of the fifth embodiment, focusing on the differences from the fourth embodiment.

[0437] 21 is a cross-sectional view of a terminal seal portion 551A included in an electricity storage device 500 of embodiment 5. In the terminal seal portion 551A, a part of a flange portion 211A of the electricity storage device packaging film 211 is joined to the metal terminal 130. A part of a flange portion 212A of the electricity storage device packaging film 212 is joined to the metal terminal 130.

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

[0439] [Characteristics of the energy storage device] According to the electricity storage device 500, the inner packaging body 210 is covered by the outer packaging body 220, which prevents moisture and the like from entering the internal space S1 of the inner packaging body 210 from the outside. Also, according to the electricity storage device 500, the packaging films 211, 212 for electricity storage devices and the metal terminal 130 are joined without the tab film 140, which reduces the number of parts. Also, the manufacturing method of the electricity 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 electricity storage device and the manufacturing method of the electricity storage device according to the present disclosure can take, and is not intended to limit the form. The electricity storage device and the manufacturing method of the electricity storage device according to the present disclosure can take a form different from the form 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 modified examples of each embodiment are shown below. Note that the following modified examples can be combined with each other as long as there is no technical contradiction.

[0441] In the electricity storage device 100 of the first embodiment of the third aspect, one outer packaging body 220 may be configured to house a plurality of inner packaging bodies 210 in a state in which the electricity storage device elements 120 are housed therein. In this modification, the sizes of the plurality of inner packaging bodies 210 may be different or the same. According to this modification, the plurality of electricity storage device elements 120 can be connected in series or in parallel, so that the voltage can be easily adjusted.

[0442] In the electricity storage device 100 according to the first embodiment of the third aspect, the electricity storage device packaging films 211, 212 do not need to be gas permeable. The electricity storage device packaging films 211, 212 only need to be transparent.

[0443] In the electricity storage device 100 of the first embodiment of the third aspect, the inner packaging body 210 may be formed by folding one electricity storage device packaging film 211 and heat sealing the peripheral portion. Similarly, the outer packaging body 220 may be formed by folding one exterior film 221 and heat sealing the peripheral portion.

[0444] <Fourth aspect> [Embodiment 1] FIG. 8 shows a plan view of the electricity storage device 100 according to the first embodiment of the fourth aspect. FIG. 9 is a cross-sectional view taken along the line D2-D2 in FIG. 8. In FIG. 8, a portion that is not visible from the outside is partially shown by dotted lines for reference. In the following, for convenience of explanation, unless otherwise specified, the up-down 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 up-down direction in FIG. 9 is referred to as the "up-down direction". However, the orientation of the electricity storage device 100 during use is not limited to this. In addition, in FIG. 8, the relative positional relationship between the inner wrapping body 210 and the outer wrapping body 220 is simplified for the sake of simplicity of the drawing.

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

[0446] The housing 110 includes a container 110A. The container 110A includes an inner packaging body 210 and an outer packaging body 220. The inner packaging body 210 accommodates the power storage device element 120. The outer packaging body 220 accommodates the inner packaging body 210 in a state in which the power storage device element 120 is accommodated. An internal space S1 is formed inside the inner packaging body 210. The inner packaging body 210 includes packaging films 211 and 212 for a power storage device. The outer packaging body 220 includes exterior films 221 and 222. At the outer periphery of the container 110A in a 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. The peripheral seal portion 150 forms an internal space S1 of the container 110A that is isolated from the external space in the inner packaging body 210. The peripheral seal portion 150 defines the peripheral edge of the internal space S1 of the container 110A. The heat seal mode referred to here may be heat fusion from a heat source, ultrasonic fusion, or the like. In any case, the peripheral seal portion 150 refers to the portion where the inner wrapping body 210 and the outer wrapping body 220 are fused and integrated.

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

[0448] 9, the terminal seal portion 151A of the top seal portion 151 is formed by laminating, from the top, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the metal terminal 130, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. This makes it easy to form the top seal portion 151. Note that, in a portion of the top seal portion 151 other than the terminal seal portion 151A, in other words, a portion where only the pair of tab films 140 are sandwiched between the inner packaging body 210 and the outer packaging body 220, the exterior film 221, the packaging film 211 for the electricity storage device, one tab film 140, the other tab film 140, the packaging film 212 for the electricity storage device, and the exterior film 222, which are integrated together. Furthermore, the outer portion of the terminal seal portion 151A of the top seal portion 151 (the left portion bordered by the step in FIG. 9) is formed by laminating, from the top, the electricity storage device packaging film 211, one tab film 140, the metal terminal 130, the other tab film 140, and the electricity storage device packaging film 212, which are integrated together. Therefore, there is a step between the outer portion of the terminal seal portion 151A where the exterior films 221, 222 are not present and the inner portion of the terminal seal portion 151A where the exterior films 221, 222 are present (the right portion bordered by the step in FIG. 9), but FIG. 8 illustrates the area of ​​the peripheral seal portion 150 from a bird's eye view and does not show the step that serves as the boundary.

[0449] The electricity storage device packaging films 211, 212 constituting the inner packaging body 210 have gas permeability from the viewpoint of easily manufacturing the electricity storage device 100. Below, preferred examples of the electricity storage device packaging films 211, 212 constituting the inner packaging body 210 will be described. Note that hereinafter, when there is no particular distinction between the electricity storage device packaging films 211, 212, the electricity storage device packaging films 211, 212 may be collectively referred to as the electricity storage device packaging film 10.

[0450] [Laminate structure and physical properties of the fourth embodiment of the packaging film for electricity storage devices] 1 to 4, the packaging film 10 for an electricity storage device according to the fourth embodiment includes at least a heat-sealable resin layer 1. When assembling an electricity storage device using the packaging film 10 for an electricity storage device and an electricity storage device element, the heat-sealable resin layers 1 of the packaging film 10 for an electricity storage device are placed opposite each other, and the peripheral portions are heat-sealed to form a space in which the electricity storage device element is housed.

[0451] The packaging film 10 for an electricity storage device in the fourth embodiment may be composed only of a heat-sealable resin layer 1, as shown in Fig. 1. When the packaging film 10 for an electricity storage device is composed only of a 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 that the inner surface of the heat-sealable resin layer 1 facing the metal terminal 130 has adhesiveness to metal.

[0452] 2 to 4, the packaging film 10 for an electricity storage device according to the fourth embodiment 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 an electricity storage device, the resin layer 2 is on the outside and the heat-sealable resin layer 1 is on the inside (the innermost layer). When the packaging film 10 for an electricity storage device is composed of a laminate including the resin layer 2 and the heat-sealable resin layer 1, it is preferable to impart adhesion to metal to at least one of the outside surface of the resin layer 2 and the inside surface of the heat-sealable resin layer 1, and it is more preferable to impart adhesion to metal to the inside surface of the heat-sealable resin layer 1 that faces the metal terminal 130.

[0453] Furthermore, as shown in Figs. 3 and 4, the packaging film 10 for an electricity storage device according to the fourth embodiment is preferably composed of a laminate including at least a resin layer 2, a substrate 3, and the heat-sealable resin layer 1. In such a packaging film 10 for an electricity storage device, the resin layer 2 is on the outside, the heat-sealable resin layer 1 is on the inside (the innermost layer), and the substrate 3 is located between the resin layer 2 and the heat-sealable resin layer 1. Even when the packaging film 10 for an electricity storage device is composed of a laminate including the resin layer 2, the substrate 3, and the heat-sealable resin layer 1, it is preferable to impart adhesion 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.

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

[0455] The packaging film 10 for an electricity storage device according to the fourth embodiment has a CO2 permeation rate of 100 cc·100 μm / m in an environment at a temperature of 30° C. 2 / 24hr / atm or more is preferable, and about 200cc 100μm / m is more preferable. 2 / 24hr / atm or more, and even more preferably about 300cc·100μm / m 2 / 24hr / atm or more, and even more preferably about 500cc·100μm / m 2 The CO2 permeation amount of the packaging film 10 for an electricity storage device according to the fourth embodiment is, for example, about 2000 cc·100 μm / m 2 / 24hr / atm or less, preferably about 1000cc 100μm / m 2 / 24hr / atm or less, more preferably about 800cc·100μm / m 2 / 24hr / atm or less, and the preferred range is 100 to 2000cc 100μm / m 2 / 24hr / atm, 100~1000cc・100μm / m 2 / 24hr / atm, 100~800cc・100μm / m 2 / 24hr / atm, 200~2000cc・100μm / m 2 / 24hr / atm, 200~1000cc・100μm / m 2 / 24hr / atm, 200~800cc・100μm / m 2 / 24hr / atm, 300~2000cc・100μm / m 2 / 24hr / atm, 300~1000cc・100μm / m 2 / 24hr / atm, 300~800cc・100μm / m 2 / 24hr / atm, 500~2000cc・100μm / m 2 / 24hr / atm, 500~1000cc・100μm / m 2 / 24hr / atm, 500~800cc・100μm / m 2 The method for measuring the CO2 permeation rate of the packaging film for electricity storage devices is as follows.

[0456] [Measurement of CO2 transmission rate] In accordance with JIS K7126-1 (Plastics - Films and sheets - Gas permeability test method - Part 1: Differential pressure method), the amount of CO2 that permeates through a φ60 mm piece of packaging film 10 for electricity storage devices in an atmosphere at 30°C is quantitatively analyzed by gas chromatography to measure the amount of CO2 that permeates through the φ60 mm piece of packaging film 10 for electricity storage devices.

[0457] When the fourth embodiment of the packaging film 10 for an electricity storage device is provided with shielding properties, at least one layer included in the packaging film 10 for an electricity storage device may be a shielding layer S having shielding properties. For example, Fig. 2 illustrates a configuration in which the adhesive layer 4 that bonds between the resin layer 2 and the heat-sealable resin layer 1 is the shielding layer S, and Fig. 4 illustrates a configuration in which the adhesive layer 4 that bonds between the resin layer 2 and the substrate 3 is the shielding layer S. In the fourth embodiment, any layer included in the packaging film 10 for an electricity storage device may be the shielding layer S.

[0458] Although not shown, 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 thermally adhesive resin layer 1 side) as required.

[0459] The thickness of the laminate constituting the packaging film 10 for electricity storage devices of the fourth embodiment is not particularly limited, bu...

Claims

1. A packaging film for an electricity storage device comprising at least a heat-sealable resin layer, The laminate includes, in order from the outside, at least a resin layer and the thermally adhesive resin layer, The thickness of the laminate is 190 μm or less, The resin layer includes at least one selected from the group consisting of polyester and polyamide, CO in a 30°C environment 2 Permeability: 100cc / 100μm / m 2 . / 24hr / atm or more.

2. The packaging film for an electricity storage device according to claim 1 , wherein an inner surface of the heat-sealable resin layer has adhesiveness to metal.

3. The packaging film for an electricity storage device according to claim 1 or 2, wherein the laminate has a thickness of 170 µm or less.

4. The packaging film for an electricity storage device according to claim 1 or 2, wherein the resin layer has a thickness of 3 μm or more and 50 μm or less.

5. The packaging film for an electricity storage device according to claim 1 or 2, wherein the heat-sealable resin layer has a thickness of 85 μm or less.

6. The packaging film for an electricity storage device according to claim 1 , wherein the resin layer contains polyester.

7. 3. 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 electricity storage devices according to claim 1 or 2.

8. An electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is contained in an inner packaging body formed from the packaging film for electricity storage devices according to claim 1 or 2, The power storage device, wherein the inner packaging is further contained within an outer packaging.

9. The power storage device according to claim 8 , wherein the outer packaging body has a metal layer formed of a metal.

10. The electricity storage device according to claim 7 , wherein the packaging film for the electricity storage device is in contact with a metal terminal electrically connected to the positive electrode or the negative electrode.

11. 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 laminate includes, in order from the outside, at least a resin layer and the thermally adhesive resin layer, The thickness of the laminate is 190 μm or less, The resin layer includes at least one selected from the group consisting of polyester and polyamide, CO in a 30°C environment 2 Permeability: 100cc / 100μm / m 2 3. A method for producing a packaging film for an electricity storage device, wherein the film has a compressive strength of 1000 MPa or more and a compressive strength of 1000 MPa or more.

Images