Power storage device and power storage device covering-material

Abstract

Provided is a power storage device covering-material in which an opening can be accurately formed in a sealant layer.　The present invention pertains to a power storage device covering-material in which a base material layer 11, a metal foil layer 12, a gas barrier layer 13, an adhesive layer 14, and a sealant layer 15 are laminated. The sealant layer 15 is provided with a planned opening section 2a in which an opening section 2 is planned to be formed by removing a sealant layer-use resin. The adhesive layer 14 is provided with a non-adhesive coated section 14b, which is provided corresponding to the planned opening section 2a, and an adhesive coated section 14a, which is provided corresponding to a section other than the planned opening section. The external haze of the gas barrier layer 13 measured on the basis of JIS K 7136:2000 is 20 or more.

Description

Electricity storage device and exterior material for the same

[0001] The present invention relates to an electricity storage device such as an all-solid-state battery used as a high-power battery such as an in-vehicle battery, a battery for portable devices such as a mobile electronic device, or a battery for storing regenerative energy, and an exterior material for the electricity storage device.

[0002] All-solid-state batteries use solid electrolytes, so they do not leak or develop dendrites, and the separator is not damaged. Therefore, there are no concerns about fires caused by separator damage, and they are attracting a lot of attention from a safety perspective.

[0003] A typical all-solid-state battery is configured by sealing an all-solid-state battery body, such as an electrode active material and a solid electrolyte, inside an exterior material serving as a casing. As research into solid electrolytes advances in all-solid-state batteries, it has gradually become apparent that the performance required of the exterior material differs from that of exterior materials for batteries using conventional liquid electrolytes, and various exterior materials have been proposed to satisfy the performance requirements for all-solid-state batteries.

[0004] The exterior material for an all-solid-state battery has a basic structure including a metal foil layer and a heat-sealing layer (sealant layer) laminated on the inside of the metal foil layer, and the all-solid-state battery main body is encapsulated by heat-sealing the sealant layer.

[0005] For example, the all-solid-state battery packaging material disclosed in Patent Document 1 below has a protective film interposed between a metal foil layer and a sealant layer, and uses a sealant layer with high hydrogen sulfide gas permeability. Furthermore, the all-solid-state battery packaging material disclosed in Patent Document 2 uses a sealant layer with low hydrogen sulfide gas permeability. Furthermore, the all-solid-state battery packaging material disclosed in Patent Document 3 uses a gas-absorbing sealant layer. Furthermore, the all-solid-state battery packaging material disclosed in Patent Document 4 is configured by laminating a vapor-deposited film layer on the inner surface of a sealant layer.

[0006] However, sulfide-based all-solid-state batteries that are expected to have high capacities have a problem in that gases such as hydrogen sulfide gas generated by a reaction between the solid electrolyte and water may leak.

[0007] On the other hand, all-solid-state batteries have a higher resistance and generate more heat than liquid electrolytes because electron (ion) exchange occurs in the solid electrolyte during charging and discharging. However, it is believed that the performance of all-solid-state batteries is not affected even in high-temperature environments, and currently, no consideration has been given to high-temperature countermeasures (cooling performance) including in the above-mentioned Patent Documents 1 to 4. However, as battery technology advances toward higher output and higher capacity, it is fully expected that improved cooling performance will also be required in all-solid-state batteries in the future.

[0008] Therefore, the applicant of the present application has proposed an all-solid-state battery that can prevent leakage of hydrogen sulfide gas and the like while ensuring sufficient cooling performance, as disclosed in Patent Document 5 below.

[0009] In this all-solid-state battery, the exterior material is constructed by sequentially laminating a metal foil layer, a gas barrier layer, and a sealant layer on the inner surface of a base layer, and an opening is formed in the sealant layer to expose the gas barrier layer to the inside. In this all-solid-state battery, the gas barrier layer prevents leakage of hydrogen sulfide gas and the like, while the opening improves cooling performance.

[0010] In this all-solid-state battery, an opening is formed by removing a part (a planned opening portion) of the sealant layer in the packaging sheet in which the sealant layer is laminated over the entire inner surface of the gas barrier layer.

[0011] Japanese Patent No. 6777276 Japanese Patent No. 6747636 JP 2020-187855 JP 2020-187835 WO 2023 / 022087

[0012] However, because the exterior material of an all-solid-state battery is composed of a film-like laminate (laminate sheet), it is difficult to accurately determine the boundary between the portion of the sealant layer to be removed (the intended opening portion) and the portion to be left, and this makes it difficult to properly remove the sealant layer corresponding to the opening, resulting in the problem of difficulty in forming an opening with excellent dimensional accuracy.

[0013] The above describes the issues with all-solid-state batteries, but similar issues may arise in other power storage devices.

[0014] The preferred embodiments of the present invention have been made in light of the above and / or other deficiencies in the related art, and provide significant improvements over existing methods and / or apparatus.

[0015] The present invention has been made in view of the above-mentioned problems, and aims to provide an electricity storage device and an exterior material for an electricity storage device that can reliably form an opening with excellent dimensional accuracy in a sealant layer.

[0016] Other objects and advantages of the present invention will be apparent from the following preferred embodiments.

[0017] In order to solve the above problems, the present invention comprises the following means.

[0018] [1] An exterior packaging material for an electricity storage device, comprising: a resin base layer; a metal foil layer laminated on the inner surface side of the base layer; a gas barrier layer laminated on the inner surface side of the metal foil layer; and a resin sealant layer laminated on the inner surface side of the gas barrier layer via an adhesive layer, wherein the sealant layer has a planned opening portion where an opening will be formed by removing the sealant layer resin, and the adhesive layer has an adhesive-uncoated portion that is provided in correspondence with the planned opening portion and where no adhesive is present, and an adhesive-coated portion that is provided in correspondence with a portion other than the planned opening portion and where adhesive is present, and wherein the external haze of the gas barrier layer measured in accordance with JIS K 7136:2000 is 20 or more.

[0019] [2] The packaging material for an electricity storage device according to the preceding paragraph 1, wherein the sealant layer has a total haze of 10 or less.

[0020] [3] An opening-equipped exterior packaging material for an electrical storage device according to the preceding item 1 or 2, characterized in that an opening is formed in the sealant layer by removing the resin for the sealant layer in the intended opening portion.

[0021] [4] An electricity storage device comprising the exterior material for an electricity storage device according to the preceding item 1 or 2, and an electricity storage device main body exteriorized with the exterior material for an electricity storage device, wherein an opening is formed in the sealant layer of the exterior material for an electricity storage device by removing the sealant layer resin from the intended opening portion, and the opening is positioned opposite the electricity storage device main body.

[0022] [5] The electricity storage device according to the preceding paragraph 4, further comprising: a case body provided with a recessed storage section in which the electricity storage device body is housed; and a closing member attached to the case body in a state of closing an open portion of the storage section, wherein at least one of the case body and the closing member is made of the exterior material for an electricity storage device.

[0023] According to the packaging material for an electricity storage device of invention [1], light that is incident on the adhesive-coated portion is less likely to be diffused on the surface of the gas barrier layer, while light that is incident on the adhesive-uncoated portion is more likely to be scattered on the surface of the gas barrier layer. Therefore, by setting the external haze of the gas barrier layer high, the difference in light intensity between the light reflected from the adhesive-coated portion and the light reflected from the adhesive-uncoated portion increases, and when removing part of the sealant layer to form an opening, the boundary position between the adhesive-coated portion and the adhesive-uncoated portion can be more accurately grasped using a photoelectric sensor or the like, and the sealant layer can be cut away more accurately along that boundary position.

[0024] According to the packaging material for an electricity storage device of invention [2], the total haze of the sealant layer is set low, so that the reflected light (emitted light) from the gas barrier layer is hardly affected by the haze of the sealant layer. Based on the difference in the amount of light reflected from the gas barrier layer, the boundary position between the adhesive-coated portion and the adhesive-uncoated portion can be more accurately determined using a photoelectric sensor or the like, and the sealant layer can be cut away more accurately along that boundary position.

[0025] According to the packaging material for an electricity storage device with an opening of the invention [3], it is possible to form an opening with high precision in the sealant layer, as in the above inventions [1] and [2].

[0026] According to the electricity storage devices of the inventions [4] and [5], similarly to the inventions [1] and [2], highly accurate openings can be formed in the sealant layer.

[0027] FIG. 1 is a schematic cross-sectional view showing an all-solid-state battery as an electricity storage device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an enlarged view of a main portion of FIG. 1. FIG. 3 is an exploded perspective view showing an all-solid-state battery according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing an exterior material for a case body in an all-solid-state battery according to an embodiment of the present invention. FIG. 5A is a schematic inner view for explaining a method for detecting an opening in an exterior material according to an embodiment of the present invention. FIG. 5B is a schematic cross-sectional view for explaining a method for detecting an opening in an exterior material according to an embodiment of the present invention. FIG. 6 is a schematic cross-sectional view for explaining a method for forming an opening in an exterior material according to an embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing a mold device for molding a case body using an exterior material with an opening according to an embodiment of the present invention. FIG. 8 is a schematic cross-sectional view showing an all-solid-state battery according to a first modified example of the present invention. FIG. 9 is a schematic cross-sectional view showing an all-solid-state battery according to a second modified example of the present invention. FIG. 10 is a schematic cross-sectional view showing an all-solid-state battery according to a third modified example of the present invention. FIG. 11 is a schematic cross-sectional view showing an all-solid-state battery according to a fourth modified example of the present invention.

[0028] Fig. 1 is a schematic cross-sectional view showing an all-solid-state battery as an electricity storage device according to an embodiment of the present invention, Fig. 2 is a schematic cross-sectional view showing an enlarged view of a main part of Fig. 1, and Fig. 3 is an exploded perspective view showing a schematic view of the all-solid-state battery according to the embodiment. As shown in these figures, the all-solid-state battery according to this embodiment includes a case body 3 and a closing member 4 as a casing, and an all-solid-state battery body 5 housed and sealed in the casing.

[0029] 4 is a schematic cross-sectional view showing an exterior material 1 constituting the case body 3 of an all-solid-state battery according to an embodiment. As shown in the figure, the exterior material 1 includes a base material layer 11 disposed on the outermost side, a metal foil layer 12 laminated and bonded to the inner surface of the base material layer 11 via a first adhesive layer (not shown), a heat-resistant gas barrier layer 13 laminated and bonded to the inner surface of the metal foil layer 12 via a second adhesive layer (not shown), and a sealant layer 15 laminated and bonded to the inner surface of the gas barrier layer 13 via a third adhesive layer 14. In the present invention, when describing the positions of the layers constituting the exterior material 1 in terms of directions, the direction toward the base material layer 11 (upper side in FIG. 4 ) is referred to as the outside, and the direction toward the sealant layer (thermally fused resin layer) 15 (lower side in FIG. 4 ) is referred to as the inside.

[0030] The exterior material 1 constituting the blocking member 4 also has the same structure as the exterior material 1 constituting the case body 3 described above.

[0031] The case body 3 is formed from a molded exterior material 1 and integrally includes a top wall 31, a side wall (circumferential side wall) 32 extending downward from the outer periphery of the top wall 31, and a flange 33 provided on the outer periphery of the lower end of the side wall 32. A storage section 35 is formed inside the top wall 31 and the side wall 32. The closing member 4 is formed from the sheet-like exterior material 1. The all-solid-state battery body 5 is housed in the storage section 35 of the case body 3, and the closing member 4 is arranged to close the open lower end of the storage section 35. The closing member 4 is arranged with its sealant layer 15 facing inward (upward), and the sealant layer 15 of the flange 33 of the case body 3 and the sealant layer 15 of the outer periphery of the closing member 4 are overlapped and face each other. The overlapped sealant layers 15 are joined together by thermal bonding (heat sealing) to form an all-solid-state battery in which the all-solid-state battery body 5 is housed in a sealed state within the casing (the case body 3 and the closing member 4).

[0032] Furthermore, the case body 3 of the all-solid-state battery has an opening 2 formed in a portion corresponding to the accommodation portion 35, where the resin constituting the sealant layer 15 and the adhesive constituting the adhesive layer 14 are not present. Furthermore, the closing member 4 also has an opening 2 formed in a portion corresponding to the accommodation portion 35, where the resin for the sealant layer and the adhesive for the adhesive layer are not present. Through the opening 2 in the case body 3 and the closing member 4, the gas barrier layer 13 of the exterior material 1 is exposed inside the accommodation portion 35 and is disposed so as to face the all-solid-state battery body 5.

[0033] Furthermore, in the all-solid-state battery of this embodiment, a tab lead (not shown) is provided for taking out electricity. One end (inner end) of this tab lead is adhesively fixed to the all-solid-state battery body 5, and the middle part is arranged so as to pass through the heat-sealed part between the flange 33 of the case body 3 and the outer peripheral edge part of the closing member 4, and the other end side is drawn out to the outside.

[0034] Each part of the all-solid-state battery of this embodiment will be described in detail below.

[0035] The base material layer 11 of the packaging material 1 is made of a heat-resistant resin film having a thickness of 5 μm to 50 μm. Suitable resins that can be used to make up this base material layer 11 include oriented polyamide film, oriented polyester (PET, PBT, PEN, etc.), and oriented polyolefin (OPP, etc.).

[0036] The metal foil layer 12 has a thickness set to 5 μm to 120 μm and has the function of blocking the penetration of oxygen and moisture from the surface (outer surface) side. Aluminum foil, SUS foil (stainless steel foil), copper foil, nickel foil, etc. can be suitably used as this metal foil layer 12. In this embodiment, the terms "aluminum," "copper," and "nickel" are used to mean alloys thereof.

[0037] Furthermore, if the metal foil layer 12 is subjected to a plating process or the like, the risk of pinholes occurring is reduced, and the function of blocking the penetration of oxygen and moisture can be further improved.

[0038] Furthermore, if the metal foil layer 12 is subjected to a chemical conversion treatment such as chromate treatment, the corrosion resistance is further improved, so that defects such as chipping can be more reliably prevented, and the adhesion to the resin can be improved, thereby further improving durability.

[0039] The sealant layer (heat-sealable resin layer) 15 has a thickness of 20 μm to 100 μm and is made of a film of heat-adhesive (heat-sealable) resin. Suitable resins for the sealant layer 15 include polyethylene (LLDPE, LDPE, HDPE), polyolefins such as polypropylene, cyclic polyolefins, olefin copolymers, acid-modified products thereof, and ionomers, such as non-oriented polypropylene (CPP, IPP).

[0040] Considering that electricity is extracted using a tab lead, that is, in consideration of sealing properties and adhesiveness with the tab lead, it is preferable to use a polypropylene-based resin (non-oriented polypropylene film (CPP, IPP)) as the sealant layer 15.

[0041] The gas barrier layer 13 is made of a heat-resistant and insulating resin film. Suitable resins for the gas barrier layer 13 include polyamides (such as 6-nylon, 66-nylon, and MXD nylon), polyesters (PET, PBT, and PEN), polyvinylidene chloride (PVDC), polyethylenes (LLDPE, LDPE, and HDPE), polyolefins such as polypropylene (CPP and OPP), olefin copolymers, acid-modified versions of these, and ionomers.

[0042] In this embodiment, the thickness of the gas barrier layer 13 is preferably set to 3 μm to 50 μm, and more preferably to 10 μm to 40 μm. That is, when the thickness of the gas barrier layer 13 is set within this range, the hydrogen sulfide gas and water vapor gas permeation suppression effect can be reliably obtained, and even if the sealant layer 15 melts and flows out due to thermal adhesion, the gas barrier layer 13 can reliably ensure insulation. In other words, if the gas barrier layer 13 is too thin, there is a risk that the gas permeation suppression effect and insulation property cannot be ensured, which is undesirable. Conversely, if the gas barrier layer 13 is too thick, not only will it be impossible to reduce the thickness of the packaging material 1, but the full effect of making the layer thicker than necessary will also be undesirable.

[0043] In this embodiment, it is preferable to use a resin film as the gas barrier layer 13. That is, the entire film serves as a barrier layer, and therefore, unlike a vapor-deposited film or the like, no barrier cracks occur, and the barrier properties can be improved.

[0044] Furthermore, a non-stretched film or a stretched film can be used as the resin film constituting the gas barrier layer 13, and it is particularly preferable to use a stretched film. That is, when a stretched film is used, heat resistance, insulating properties, formability, and gas barrier properties can be further improved.

[0045] The gas barrier layer 13 of the present embodiment has good insulating properties, and maintains good insulating properties even after the all-solid-state battery body 5 is enclosed (sealed) with the case body 3 and the closing member 4 as the exterior material 1 of the present embodiment.

[0046] In this embodiment, the resin constituting the gas barrier layer 13 has a water vapor permeability of 50 (g / m) or less, as measured in accordance with JIS K7129-1 (humidity sensor method, 40°C, 90% Rh). ２ It is preferable to adjust the water vapor transmission rate to 50 (g / m ２ / day) or less, the gas permeation prevention effect of the gas barrier layer 13 can prevent the intrusion of moisture such as water vapor gas from the outside, thereby suppressing the generation of hydrogen sulfide gas due to the reaction between moisture and the solid electrolyte, and more reliably preventing the leakage of hydrogen sulfide gas and the like.

[0047] In the present embodiment, it is preferable to use a resin having a thermal conductivity of 0.2 W / m·K or more as the resin constituting the gas barrier layer 13. That is, when this configuration is used, the heat transfer properties of the gas barrier layer 13 can be sufficiently ensured, and the cooling properties of the all-solid-state battery body 5 can be further improved.

[0048] Furthermore, in this embodiment, it is preferable to use a resin constituting the gas barrier layer 13 that has a melting point 10°C or more higher than that of the resin constituting the sealant layer 15. In other words, if the gas barrier layer 13 has a high melting point, there will be no change in the thickness of the gas barrier layer 13 during heat sealing after the solid state battery is housed, the water vapor permeation prevention function of the gas barrier layer 13 can be well maintained, and the generation of hydrogen sulfide gas can be more reliably suppressed. In this embodiment, the melting point is measured as the melting peak temperature of DSC measured in accordance with JIS K7121-1987.

[0049] In this embodiment, two-component curing dry lamination adhesives such as polyurethane adhesives, acrylic adhesives, polyacrylate adhesives, modified polypropylene adhesives, polyester adhesives, polyamide adhesives, and epoxy adhesives can be suitably used for the first adhesive layer that bonds the base material layer 11 and the metal foil layer 12, the second adhesive layer that bonds the metal foil layer 12 and the gas barrier layer 13, and the third adhesive layer 14 that bonds the gas barrier layer 13 and the sealant layer 15. The thicknesses of these first to third adhesive layers are preferably set to 1 μm to 6 μm.

[0050] In the present embodiment, the second adhesive layer that bonds the metal foil layer 12 and the gas barrier layer 13 can be formed by using an adhesive resin (a polyolefin-based resin such as polyolefin, carboxylic acid-modified polyolefin, or metal-modified polyolefin, a polyvinyl acetate-based resin, a (meth)acrylic resin, or an amino resin) instead of an adhesive, and laminating the adhesive resin and the resin that forms the gas barrier layer 13 onto the metal foil layer 12 by co-extruding them (extrusion lamination method), or by forming a laminate in which the adhesive resin and the gas barrier layer 13 are laminated in advance, and then laminating this laminate on the metal foil layer 12 by thermal lamination, or by pouring molten adhesive resin between the metal foil layer 12 and the gas barrier layer 13 while bonding the metal foil layer 12 and the gas barrier layer 13 together (sand lamination method), or the like.

[0051] In this embodiment, the opening 2 on the case body 3 side has its outer peripheral edge 21 provided on the flange 33 of the case body 3. Furthermore, the opening 2 on the closing member 4 side has its opening edge 21 formed to correspond to the opening edge 21 of the opening 2 of the case body 3.

[0052] In the present embodiment, the opening 2 formed in the case body 3 and the closing member 4 is not provided with any adhesive that constitutes the adhesive layer 14, and the gas barrier layer 13 is exposed (exposed) to the inside through the opening 2, and in a state where the all-solid-state battery is fabricated, the gas barrier layer 13 is disposed so as to face the upper surface, the peripheral side surface, and the lower surface of the all-solid-state battery body 5.

[0053] Next, a method for manufacturing the exterior material 1 in this embodiment will be described. Needless to say, in the present invention, the method for manufacturing the exterior material 1 is not limited (the same applies to the method for manufacturing the case body 3 and the method for manufacturing the all-solid-state battery, which will be described later).

[0054] In this embodiment, first, a laminate without a sealant layer is produced by, for example, a dry lamination method. That is, a resin film for the base layer 11 is bonded via an adhesive to the outer surface of a metal foil for the metal foil layer 12, which has been subjected to a surface treatment and a chemical conversion treatment as necessary, and a resin film for the gas barrier layer 13 is bonded via an adhesive to the inner surface of the metal foil, thereby producing a laminate without a sealant layer, in which the metal foil layer 12 and the gas barrier layer 13 are laminated on the inner surface side of the base layer 11.

[0055] It should be noted that when producing a laminate without a sealant layer, it is also possible to produce it by a method other than the dry lamination method, such as the extrusion lamination method, as described above. For example, the above laminate may be produced by extruding and laminating the resin composition for the base layer 11 and the resin composition for the gas barrier layer 13 onto the inner and outer surfaces of a metal foil, respectively.

[0056] Next, the adhesive that constitutes the adhesive layer 14 is applied to the inner surface of the laminate without the sealant layer (the inner surface of the gas barrier layer 13) using a gravure roll or the like. During this application, the adhesive is applied to the inner surface of the gas barrier layer 13, excluding the portion where the opening 2 in the sealant layer 15 is to be formed (the planned opening portion 2a), to form an adhesive-coated portion 14a, while the adhesive is not applied to the portion corresponding to the planned opening portion 2a, to form an adhesive-uncoated portion 14b.

[0057] Then, a resin film for a sealant layer is attached to the inner surface of the gas barrier layer 13 having the adhesive-uncoated portion 14b via the adhesive layer 14 (adhesive-coated portion 14a), and then dried. The resin film for a sealant layer is also provided in the portion corresponding to the adhesive-uncoated portion 14b.

[0058] 6, the area between the adhesive-coated portion 14a and the intended opening portion 2a is cut away, and the intended opening portion 2a, which is the sealant layer 15 of the adhesive-uncoated portion 14b, is cut away to form the opening 2. This cutting method can be performed using a laser cutter, a roll blade, a punching blade (such as a Thomson blade or an etching blade), an ultrasonic cutter, or the like. Of these, it is preferable to use a laser cutter, which can perform processing with high precision.

[0059] In this embodiment, as shown in Figures 5A and 5B, it is preferable to automatically cut out the sealant layer 15 at the intended opening portion 2a using an opening position detection device 81 and a laser cutting device 82 to form the opening 2.

[0060] That is, opening position detection device 81 detects the boundary position between adhesive-coated portion 14a and adhesive-uncoated portion 14b, and is equipped with a detection sensor such as a photoelectric sensor that detects the amount of reflected light of light irradiated from a light source onto the test object, and detects the boundary position between adhesive-coated portion 14a and adhesive-uncoated portion 14b based on the difference in light amount, etc. For example, light is irradiated from the light source of opening position detection device 81 toward the test object (exterior material 1), and the boundary is detected based on the reflected light of that light. 5B , light X1 and X2 emitted from the light source toward the adhesive-coated portion 14a of the exterior material 1 passes through the adhesive-coated portion 14a and becomes reflected light Y1 and Y2 reflected from the surface of the gas barrier layer 13 (the interface between the adhesive-coated portion 14a and the gas barrier layer 13) and the surface of the adhesive-coated portion 14a, while light X3 emitted from the light source toward the adhesive-uncoated portion 14b of the exterior body 1 passes through the adhesive-uncoated portion (gap portion) 14b and becomes reflected light Y3 reflected from the surface of the gas barrier layer 13. The reflected light Y1 and Y2 from the adhesive-coated portion 14a and the reflected light Y3 from the adhesive-uncoated portion 14b have different light intensities, as will be described later, and the boundary position between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b is detected based on this difference in light intensity.

[0061] The laser cutting device 82 is also ２ The opening position detecting device 82 is configured with a laser cutting device or the like, and based on position information from the opening position detecting device 81, cuts the boundary position between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b, i.e., the outer peripheral edge portion 21a of the intended opening portion 2a, and cuts away the sealant layer 15 of the intended opening portion 2a to form the opening 2. In this way, the opening 2 is automatically formed in the exterior packaging material 1, and an exterior packaging material with an opening is manufactured. Therefore, by using the opening position detecting device 81 and the laser cutting device 82, the opening 2 can be automatically formed in the exterior packaging material 1, and an exterior packaging material with an opening can be manufactured.

[0062] In the exterior packaging material 1 before the opening 2 of this embodiment is formed, when the L value, which is the lightness of the adhesive-coated portion 14a measured from the sealant layer 15 side (inner surface side), is "La" and the L value, which is the lightness of the adhesive-uncoated portion 14b, is "Lb," the absolute value of ΔL (lightness difference), which is the absolute value of the difference between La and Lb, needs to be set to 0.5 or more. In other words, the relationship |La - Lb| = ΔL ≧ 0.5 needs to be established.

[0063] In other words, by satisfying the above relational expression, the brightness difference ΔL between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b is large, and therefore the difference in light intensity between the reflected light Y1, Y2 from the adhesive-coated portion 14a and the reflected light Y3 from the adhesive-uncoated portion 14b (see Figure 5B) is large, and the above-mentioned photoelectric sensor can accurately and appropriately capture the boundary position between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b, making it possible to form a highly accurate opening 2.

[0064] In this embodiment, a spectrophotometer such as a CM-2500C manufactured by Konica Minolta can be suitably used to measure the L value of the adhesive-coated portion 14a and the L value of the adhesive-uncoated portion 14b.

[0065] In this embodiment, when measuring the color difference (L value), the specular reflection stipulated in 4.1.2 or 4.2.2 of the colorimetry (measurement) in Section 5 of Part 4 of JIS K 5600-4-5 (1999 edition) General Test Method for Coating Films is excluded, and the color difference (L value) is measured in accordance with CIE 1976 (L ＊ a ＊ b ＊ The color of the test sample was measured in color coordinates (lightness L, saturation a, hue b). CIE stands for Commission Internationale de l'Eclairage (International Commission on Illumination).

[0066] In this embodiment, it is also preferable to adjust the external haze of the gas barrier layer 13 to not less than 20. That is, light that enters the gas barrier layer (resin) 13 from the adhesive-coated portion (resin) 14a passes through the resin / resin interface and has a narrow refractive index range, while light that enters the gas barrier layer (resin) 13 from the adhesive-uncoated portion (air) 14b passes through the air / resin interface and has a wide refractive index range. As a result, as shown in Figure 5B, light X1 and X2 irradiated onto the adhesive-coated portion 14a are not easily diffused when reflected on the surface of the gas barrier layer 13 (the interface with the adhesive-coated portion 14a) or the surface of the adhesive-coated portion 14a, whereas light X3 irradiated onto the adhesive-uncoated portion 14b is easily diffused when reflected on the surface of the gas barrier layer 13. Therefore, when the external haze of the gas barrier layer 13 is large, such as 20 or more, the difference in light intensity between the reflected light Y1, Y2 from the adhesive-coated portion 14a and the reflected light Y3 from the adhesive-uncoated portion 14b becomes large, and the photoelectric sensor can accurately and appropriately capture the boundary position between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b, thereby allowing for the formation of a highly accurate opening 2.

[0067] The haze of the gas barrier layer 13 includes a total haze, an internal haze, and an external haze, and these hazes have the following relationship: total haze (%) = internal haze (%) + external haze (%). In this embodiment, the total haze and internal haze are calculated, and the value obtained by subtracting the internal haze from the total haze is used as the external haze.

[0068] When measuring haze, a film (film sample) for the gas barrier layer is used. The haze (total haze) of this film sample is measured in accordance with JIS K 7136:2000 (Method for determining haze of plastic transparent materials). When measuring internal haze, silicone oil is applied to both sides of the film sample, and the oiled film sample is sandwiched between glass plates for measurement, thereby determining the haze (internal haze) from which external haze factors due to unevenness on the film surface are removed. The external haze is determined based on the film haze (total haze) and internal haze thus obtained.

[0069] In this embodiment, the haze of the gas barrier layer 13 can be suitably measured using a Murakami Color Research Laboratory HAZEMETER HM-150 or the like.

[0070] In this embodiment, it is also preferable to adjust the total haze of the sealant layer 15 to be equal to or less than 10. In other words, when the total haze of the sealant layer 15 is equal to or less than 10, the amount of reflected light Y1 to Y3 is hardly affected by the haze of the sealant layer 15, and therefore the boundary position between the adhesive-coated portion and the adhesive-uncoated portion can be accurately detected by the photoelectric sensor based on the difference in light amount due to diffusion of the reflected light Y1 to Y3 from the gas barrier layer 13, making it possible to form the opening 2 with higher precision.

[0071] In this embodiment, the haze of the sealant layer 15 can be preferably measured using a Murakami Color Research Laboratory HAZEMETER HM-150 or the like.

[0072] In this embodiment, it is preferable to adjust the arithmetic mean height Sa of the gas barrier layer 13 to 0.2 μm or more. That is, when the arithmetic mean height Sa of the gas barrier layer 13 is 0.2 μm or more, similar to the adjustment of haze, as shown in FIG. 5B , light X1 and X2 irradiated onto the adhesive-coated portion 14a is not easily diffused when reflected from the surface of the gas barrier layer 13 (the interface with the adhesive-coated portion 14a) or the surface of the adhesive-coated portion 14a, whereas light X3 irradiated onto the adhesive-uncoated portion 14b is easily diffused when reflected from the surface of the gas barrier layer 13. This increases the difference in light intensity between the light Y1 and Y2 reflected from the adhesive-coated portion 14a and the light Y3 reflected from the adhesive-uncoated portion 14b, allowing the photoelectric sensor to accurately and appropriately detect the boundary position between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b, thereby enabling the formation of highly accurate openings 2.

[0073] In this embodiment, when measuring the arithmetic mean height Sa, the sample surface (gas barrier layer surface) is observed with a white light interferometer in accordance with the method specified in ISO25178 to determine the arithmetic mean height Sa.

[0074] In this embodiment, the arithmetic mean height Sa of the gas barrier layer 13 can be suitably measured using a white light interferometer such as VS1330 manufactured by Hitachi High-Tech Science.

[0075] In this embodiment, it is preferable to adjust the arithmetic mean height Sa of the sealant layer 15 to less than 0.2 μm. That is, when the arithmetic mean height Sa of the sealant layer 15 is less than 0.2 μm, the arithmetic mean height Sa of the sealant layer 15 has almost no effect on the light intensity of the reflected light Y1 to Y3, and therefore the photoelectric sensor can accurately detect the boundary position between the adhesive-coated portion and the adhesive-uncoated portion based on the difference in light intensity due to diffusion of the reflected light Y1 to Y3 from the gas barrier layer 13, thereby making it possible to form the opening 2 with even higher precision.

[0076] In this embodiment, the arithmetic mean height Sa of the sealant layer 15 can be suitably measured using a white light interferometer such as Hitachi High-Tech Science's VS1330.

[0077] In this embodiment, it is preferable to adjust the gloss value of the gas barrier layer 13 to 100 or less. That is, when the gloss value of the gas barrier layer 13 is 100 or less, similarly to the adjustment of the haze and arithmetic mean height Sa, as shown in Fig. 5B , the light X1 and X2 irradiated onto the adhesive-coated portion 14a is not easily diffused when reflected from the surface of the gas barrier layer 13 (the interface with the adhesive-coated portion 14a) or the surface of the adhesive-coated portion 14a, whereas the light X3 irradiated onto the adhesive-uncoated portion 14b is easily diffused when reflected from the surface of the gas barrier layer 13. This increases the difference in light intensity between the light Y1 and Y2 reflected from the adhesive-coated portion 14a and the light Y3 reflected from the adhesive-uncoated portion 14b, allowing the photoelectric sensor to accurately and appropriately detect the boundary position between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b, thereby enabling the formation of the opening 2 with high precision.

[0078] In this embodiment, the gloss value is a value measured at an incident angle of 60° in accordance with JIS Z 8741:1997.

[0079] In this embodiment, the gloss value of the gas barrier layer 13 can be suitably measured using a device such as micro-TRI-gloss-s manufactured by BYK Corporation.

[0080] In this embodiment, it is preferable to adjust the gloss value of the sealant layer 15 to a value exceeding (excluding) 100. In other words, when the gloss value of the sealant layer 15 exceeds 100, the difference in light intensity between the reflected light Y1, Y2 from the adhesive-coated portion 14a and the reflected light Y3 from the adhesive-uncoated portion 14b is enhanced, thereby further improving the detectability by the photoelectric sensor.

[0081] In this embodiment, the gloss value of the sealant layer 15 can be suitably measured using a device such as micro-TRI-gloss-s manufactured by BYK Corporation.

[0082] Next, we will explain how to mold the sheet-like exterior material with an opening obtained as described above to produce the case body 3. First, as shown in Figure 6, the sheet-like exterior material 1 for the case body before molding includes a planned top wall portion 31a that is the portion intended to become the top wall 31, a planned side wall portion 32a that is the portion intended to become the side wall 32, and a planned flange portion 33a that is the portion intended to become the flange 33.

[0083] In this embodiment, the outer peripheral edge 21a of the intended opening portion 2a is set within the range of the intended flange portion 33a.

[0084] 7 is a schematic cross-sectional view showing a mold device for molding the case body 3 using the opening-equipped exterior material 1. As shown in the figure, this mold device includes a die 6 as an upper mold, and a punch 7 and a blank holder 70 as a lower mold.

[0085] The die 6 has a molding recess 65 formed on the lower surface thereof for molding the housing portion 35 (top wall 31 and side wall 32 ) of the case body 3 .

[0086] The punch 7 is disposed in correspondence with the forming recess 65 of the die 6 , and the blank holder die 70 is disposed on the outer periphery of the punch 7 and faces the outer periphery of the lower surface of the die 6 .

[0087] The opening-equipped exterior material 1 serving as the molding material is then placed so that its planned sidewall portion 32a corresponds to the outer peripheral edge of the tip of the punch 7. In this state, the planned flange portion 33a of the exterior material 1 is sandwiched and supported by the outer periphery of the die 6 and the blank holder die 70, and the punch 7 is driven into the molding recess 65 of the die 6, thereby pressing the exterior material 1. This produces a case body molded body (molding material) having a concave storage portion 35 (top wall 31 and side wall 32) and a flange 33 outside the storage portion 35. The flange 33 of this molded body is then cut to a predetermined size, thereby producing the case body 3 of this embodiment. In this case body 3, the opening 2 is disposed over the entire area of ​​the storage portion 35, and the outer peripheral edge 21 of the opening 2 is disposed on the flange 33, as shown in FIGS. 1 to 3 .

[0088] 1 to 3 , in this embodiment, an all-solid-state battery is produced by packaging a solid-state battery body 5 using the case body 3 and the sheet-like closing member 4. That is, the all-solid-state battery body 5 is housed in the housing portion 35 of the case body 3, and the closing member 4 is arranged so as to close the open portion of the housing portion 35 from below, and the sealant layer 15 of the flange 33 of the case body 3 and the sealant layer 15 of the outer peripheral edge of the closing member 4 are arranged so as to face and overlap each other. In this state, the flange 33 of the case body 3 and the outer peripheral edge of the closing member 4 are sandwiched between a pair of sealing dies and heated. As a result, the overlapping sealant layers 15 are heat-sealed and joined together, and an all-solid-state battery is produced in which the all-solid-state battery body 5 is housed in an airtight state within the case body 3 and the closing member 4.

[0089] According to the all-solid-state battery of the present embodiment having the above-described configuration, the gas barrier layer 13 is provided between the metal foil layer 12 and the sealant layer 15 in the case body 3 and the closing member 4, and the opening 2 is formed in the top wall 31 and the side wall 32 by removing a part of the sealant layer 15. Therefore, heat generated from the all-solid-state battery body 5 is efficiently transferred to the metal foil layer 12 via the opening 2 and the gas barrier layer 13 and dissipated without being blocked by the sealant layer 15, thereby ensuring sufficient heat dissipation and cooling properties.

[0090] In particular, in the present embodiment, the outer peripheral edge 21 of the opening 2 in the case body 3 is set to the flange 33 of the case body 3, so that a large opening 2 can be formed that corresponds to almost the entire area of ​​the all-solid-state battery body 5, and heat dissipation and cooling properties can be further improved.

[0091] Furthermore, in this embodiment, by specifying the difference in L value between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b of the exterior material 1, the haze value of the gas barrier layer 13 and the sealant layer 15, the arithmetic mean height Sa of the gas barrier layer 13 and the sealant layer 15, and the gloss value of the gas barrier layer 13 and the sealant layer 15, as already described, it is possible to increase the difference in light intensity between the reflected light Y1, Y2 from the adhesive-coated portion 14a and the reflected light Y3 from the adhesive-uncoated portion 14b, and the photoelectric sensor can accurately and appropriately detect the boundary position between the adhesive-coated portion 14a and the adhesive-uncoated portion 14b, thereby more reliably forming a highly accurate opening 2.

[0092] Furthermore, according to the all-solid-state battery of this embodiment, since the gas barrier layer 13 is disposed on the inner surface side of the metal foil layer 12, even if the solid electrolyte of the all-solid-state battery body 5 reacts with moisture in the outside air to generate hydrogen sulfide gas or the like, leakage of the gas can be reliably prevented by the gas barrier layer 13. Furthermore, the gas permeation prevention action of the gas barrier layer 13 can prevent the intrusion of moisture such as water vapor gas from the outside, and therefore the generation of hydrogen sulfide gas itself due to the reaction between the moisture and the solid electrolyte can also be suppressed, making it possible to more reliably prevent leakage of hydrogen sulfide gas or the like.

[0093] Furthermore, in the all-solid-state battery of this embodiment, in the portion where the opening 2 is formed, although the sealant layer 15 is not present between the all-solid-state battery body 5 and the metal foil layer 12, the gas barrier layer 13 having insulating properties is disposed therebetween, and therefore, the gas barrier layer 13 can reliably ensure insulation.

[0094] Furthermore, when cutting the exterior packaging material 1 with a laser cutter or the like to form the opening 2, laser damage may be formed in the outer peripheral edge 21 of the opening, which may result in defects such as cracks or pinholes. However, in this embodiment, the outer peripheral edge 21 of the opening is formed in the flange 33 of the case body 3, so that the adverse effects of the damaged area can be avoided. That is, the flange 33 of the case body 3, which is a molded body, is heat-sealed, and a resin reservoir formed by the heat sealing is formed in the damaged area (the outer peripheral edge 21 of the opening). Therefore, the resin reservoir can cover and repair the damaged area, so that the adverse effects of the damaged area due to laser cutting can be reliably avoided.

[0095] Furthermore, in the all-solid-state battery of this embodiment, the sealant layer 15 is not formed in the portion of the exterior packaging material 1 that corresponds to the all-solid-state battery body 5, and therefore, the space for accommodating the all-solid-state battery body 5 can be made larger (thicker) accordingly. Therefore, in the all-solid-state battery of this embodiment, compared to conventional all-solid-state batteries, a larger-sized all-solid-state battery body 5 can be accommodated without changing the external dimensions of the case body 3, and therefore, high output and high capacity can be achieved while achieving a thinner design.

[0096] Furthermore, in the all-solid-state battery of this embodiment, the sealant layer 15 is provided on the flange 33 provided around the entire periphery of the case body 3, and therefore the sealant layer 15 provided around the entire periphery can reliably seal the entire periphery of the all-solid-state battery, ensuring good sealing performance.

[0097] In the all-solid-state battery of the above embodiment, the case where the opening 2 is formed in both the case body 3 and the closing member 4 has been described as an example, but the present invention is not limited to this. As shown in FIG. 8 , the opening 2 may be formed in the case body 3, and the opening 2 may not be formed in the closing member 4.

[0098] In addition, the all-solid-state battery of this embodiment shown in FIG. 1 is arranged so that the case body 3 is disposed on the upper side and the blocking member 4 is disposed on the lower side, but this is not limited thereto. In the present invention, the all-solid-state battery shown in FIG. 1 may be inverted, that is, the case body 3 which is a molded body is disposed on the lower side and the sheet-like blocking member 4 is disposed on the upper side.

[0099] In the above embodiment, the edge 21 of the opening 2 is set within the flange 33, but the present invention is not limited to this. For example, in the present invention, the edge 21 of the opening 2 may be set in the side wall 32 of the case body 3 as shown in Fig. 9, or the edge 21 of the opening 2 may be set in the top wall (bottom wall) 33 of the case body 3 as shown in Fig. 10. In other words, the shape and size of the opening 2 are not particularly limited in the present invention.

[0100] Furthermore, in the present invention, a molded body may be used as the blocking member 4. For example, as shown in Fig. 11 , a tray-shaped molded body having a shape obtained by inverting the case body 3 upside down may be used as the blocking member 4, and the casing of the all-solid-state battery may be formed by the case body 3 which is a molded body and the tray-shaped blocking member 4 which is also a molded body. In this case, by using a similar configuration for the blocking member 4 as the case body 3, the same effect can be obtained with the blocking member 4.

[0101] In the above embodiment, a case has been described in which an all-solid-state battery is used as the electricity storage device of the present invention, but the present invention is not limited to this, and can also be applied to electricity storage devices other than all-solid-state batteries.

[0102]

[0103] Example 1: A laminate material was prepared as a sample (exterior packaging material) by laminating, from the outer surface side, a base layer, a first adhesive layer, a metal foil layer, a second adhesive layer, a gas barrier layer, a third adhesive layer, and a sealant layer in this order. Specifically, a 40 μm-thick aluminum foil (specified in JIS H4160 A8079-O) was used as the metal foil layer on the outer surface (glossy side). A 25 μm-thick stretched nylon film (ONY) was used as the base layer, with a two-component curing polyester-urethane adhesive serving as the first adhesive layer. Furthermore, a 12 μm-thick matte PET (polyethylene terephthalate) film was used as the gas barrier layer on the inner surface (matte side) of the metal foil layer, with a two-component curing polyester-urethane adhesive serving as the second adhesive layer, as shown in Table 1. Furthermore, as shown in Table 1, an 80 μm thick CPP (unstretched polypropylene: CPP (1)) film was laminated as a sealant layer on the inner surface of the gas barrier layer via a two-component curing polyester-urethane adhesive as a third adhesive layer. At this time, the third adhesive layer was not applied to the intended opening area. The size of this adhesive-uncoated area (intended opening area) was a rectangle measuring 100 mm × 200 mm (see Figures 4 and 5A, etc.).

[0104] The layers of the laminated film (laminate material) thus obtained were laminated together, and then cured at 40° C. for 5 days to prepare a sample (exterior packaging material) of Example 1.

[0105] For the sample of Example 1, the L value (Lb) of the adhesive-uncoated area (the area to be opened) and the L value (La) of the adhesive-coated area were measured from the inside using a Konica Minolta spectrophotometer (CM-2500c), and the lightness difference (ΔL = |La - Lb|) between the adhesive-uncoated area and the adhesive-coated area was determined. Furthermore, as shown in Table 1, the haze, arithmetic mean height Sa, and gloss value of each resin film were measured using the methods described in the above embodiment.

[0106]

[0107] Table 2 shows the relationship between the types of resin films for the gas barrier layer and the resin films for the sealant layer used in Example 1 (including the following Examples 2 to 6 and Comparative Examples 1 to 3), the product names, and the main physical properties.

[0108] Examples 2 to 6 and Comparative Examples 1 to 3 Samples (exterior materials) with adhesive-uncoated portions were prepared in the same manner as in Example 1 above, except that the films for the gas barrier layer and the resin films for the sealant layer shown in Table 1 were used, and the lightness difference ΔL, haze, arithmetic mean height Sa, and gloss value were similarly determined. The results are also shown in Table 1.

[0109] <Formation of openings and evaluation of detectability> Furthermore, for each of the above examples and comparative examples, an opening formation device consisting of an opening position detection device and a laser cutting device (see FIG. 5A) was used to remove the sealant layer from the intended opening portion (adhesive-uncoated portion).

[0110] The opening position detection device used was an MR101 scanning head manufactured by Nireco Corporation. This detection device uses an LED as a light source, and the difference in the amount of light reflected (light quantity) between the colored adhesive uncoated area and the colored adhesive coated area is received by an SPD (silicon photodiode), a photoelectric sensor, and the outer periphery position of the colored adhesive uncoated area (planned opening area) is detected based on a mechanism that outputs a voltage proportional to the light quantity.

[0111] The laser cutting equipment is CO ２ A laser cutting device was used, which cut and removed only the sealant layer (CPP film) on the colored adhesive-uncoated area based on the position information of the colored adhesive-uncoated area (planned opening area) in the center of each sample detected by the opening position detection device, to create an exposed area (opening) of the gas barrier layer (matte PET film) measuring 100 mm wide x 200 mm long.

[0112] In the detectability shown in Table 1, "○" indicates that the outer peripheral position of the adhesive-uncoated portion could be accurately detected and an opening could be formed with high precision, while "×" indicates that the outer peripheral position of the adhesive-uncoated portion could not be sufficiently detected and an opening could not be formed.

[0113] <Evaluation Results> As is clear from Table 1, for the samples of Examples 1 to 6, the opening position detection device was able to accurately detect the adhesive-uncoated portion, and the laser cutting device was able to precisely cut and remove the sealant layer (CPP film) on the adhesive-uncoated portion, thereby forming highly accurate openings. In contrast, for the samples of Comparative Examples 1 to 3, the opening position detection device was unable to detect the adhesive-uncoated portion, the laser cutting device did not work, and the adhesive-uncoated portion could not be removed.

[0114] This application claims priority to Japanese Patent Application No. 2023-115619, filed on July 14, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0115] It should be understood that the terms and expressions used herein are used for the purpose of explanation and not for limiting interpretation, and do not exclude any equivalents of the features shown and described herein, but also allow various modifications within the claimed scope of the present invention.

[0116] The exterior packaging material for an electricity storage device of the present invention can be suitably used as a material for a battery case (casing) for accommodating an all-solid-state battery main body such as an all-solid-state battery.

[0117] DESCRIPTION OF SYMBOLS 1: Exterior material 11: Base material layer 12: Metal foil layer 13: Gas barrier layer 14: Adhesive layer (third adhesive layer) 14a: Adhesive-coated portion 14b: Adhesive-uncoated portion 15: Sealant layer 2: Opening 2a: Pre-opening portion 3: Case body 35: Storage portion 4: Closing member 5: All-solid-state battery body

Claims

1. An exterior material for an electricity storage device comprising: a resin base layer; a metal foil layer laminated on the inner surface side of the base layer; a gas barrier layer laminated on the inner surface side of the metal foil layer; and a resin sealant layer laminated on the inner surface side of the gas barrier layer via an adhesive layer, wherein the sealant layer has a planned opening portion where an opening will be formed by removing the sealant layer resin, and the adhesive layer has an adhesive-uncoated portion corresponding to the planned opening portion and where no adhesive is present, and an adhesive-coated portion corresponding to a portion other than the planned opening portion and where adhesive is present, and wherein the external haze of the gas barrier layer measured in accordance with JIS K 7136:2000 is 20 or more.

2. The packaging material for an electricity storage device according to claim 1, wherein the total haze of the sealant layer is 10 or less.

3. An exterior material for a storage battery device with an opening, characterized in that the sealant layer in the exterior material for a storage battery device according to claim 1 or 2 has an opening formed in the sealant layer by removing the resin for the sealant layer in the intended opening portion.

4. An electricity storage device comprising the exterior material for an electricity storage device according to claim 1 or 2, and an electricity storage device main body exteriorized with the exterior material for an electricity storage device, wherein an opening is formed in the sealant layer of the exterior material for an electricity storage device by removing the sealant layer resin from the intended opening portion, and the opening is positioned opposite the electricity storage device main body.

5. The energy storage device according to claim 4, comprising a case body provided with a recessed storage section in which the energy storage device main body is housed, and a blocking member attached to the case body in a state of blocking an open portion of the storage section, wherein at least one of the case body and the blocking member is constituted by the exterior material for the energy storage device.

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