Electricity storage device

Abstract

The electricity storage device includes an electrode body, an electrode terminal connected to the electrode body, and an exterior body sealing the electrode body. The exterior body is configured from a film-like exterior member, the exterior body includes a first sealing portion that bonds the exterior member in a state in which the exterior member covers the electrode body, and the exterior member includes a barrier layer. The electricity storage device has an electricity storage device resin film disposed on at least a portion of the inner side of the barrier layer. The resin film for electricity storage devices contains at least one of a water absorbent and a gas absorbent.

Description

Technical Field

[0001] The present invention relates to an electrical storage device. Background Art

[0002] Currently, various types of electrical storage devices are being developed. However, in all electrical storage devices, an outer package member is an essential component for sealing the electrode body such as electrodes and electrolytes. In the prior art, metal outer package members are mostly used as outer package members for electrical storage devices.

[0003] On the other hand, in recent years, with the high-performance development of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., various shapes are required for electrical storage devices, and thin and light designs are also required. Therefore, the metal outer package members for electrical storage devices that are mostly used in the prior art have the disadvantages of being difficult to follow the diversification of shapes and having limitations in terms of weight reduction.

[0004] Therefore, in the prior art, as an outer package member for an electrical storage device that can be easily processed into various shapes and can achieve thin and light designs, a film-like laminate obtained by laminating a base material layer / a barrier layer / a bonding layer / a heat-sealable resin layer in this order has been proposed (for example, refer to Patent Document 1).

[0005] In such an outer package member for an electrical storage device, a recess is usually formed by cold forming, and an electrode body such as electrodes and electrolyte is disposed in the space formed by the recess, and the heat-sealable resin layer is heat-sealed, whereby an electrical storage device in which the electrode body is housed inside the outer package member for the electrical storage device can be obtained.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008-287971. Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] When moisture penetrates into the inside of the electrode body, the performance of the electrical storage device deteriorates. Therefore, for example, when using the aforementioned film-like laminate as an outer package member, a barrier layer (for example, composed of a metal foil) is provided. By providing the barrier layer, it is possible to suppress the penetration of moisture from the outside of the barrier layer.

[0011] However, when the heat-sealable resin layer of the outer package member is heat-sealed to seal the electrode body, the end face of the heat-sealable resin layer is exposed to the outside, so there is a possibility that moisture penetrates from the end face of the heat-sealable resin layer.

[0012] In addition, when the heat-sealable resin layer of the exterior member absorbs water before the electrode body is sealed with the exterior member, there is a possibility that the moisture in the heat-sealable resin layer may penetrate into the electrode body after the electrode body is sealed.

[0013] In addition, in the case where the electrical storage device is a all-solid-state battery, when moisture comes into contact with the solid electrolyte contained in the elements constituting the all-solid-state battery, there is a possibility that gases such as hydrogen sulfide may be generated depending on the type of the solid electrolyte.

[0014] An object of the present invention is to provide an electrical storage device capable of suppressing at least one of intrusion of moisture into the electrode body and absorption of gases generated from the electrode body.

[0015] Technical means for solving the problem

[0016] The electrical storage device according to the first aspect of the present invention includes an electrode body, an electrode terminal connected to the electrode body, and an exterior body that seals the electrode body. The exterior body is composed of a film-shaped exterior member, and the exterior body includes a first sealing portion that joins the exterior member in a state where the exterior member covers the electrode body. The exterior member includes a barrier layer. The electrical storage device has a resin film for electrical storage device disposed at least in part on the inner side of the barrier layer. The resin film for electrical storage device contains at least one of a water absorbent and a gas absorbent.

[0017] The electrical storage device according to the second aspect of the present invention is the electrical storage device according to the first aspect, wherein the resin film for electrical storage device serves as the heat-sealable resin layer of the exterior member.

[0018] The electrical storage device according to the third aspect of the present invention is the electrical storage device according to the first or second aspect, wherein the resin film for electrical storage device serves as a terminal bonding film that joins the exterior member and the electrode terminal.

[0019] The electrical storage device according to the fourth aspect of the present invention is the electrical storage device according to any one of the first to third aspects, and further includes a lid body that is provided with the electrode terminal and is disposed on the side of the electrode body, and a part of the lid body is joined to the exterior member.

[0020] The electrical storage device according to the fifth aspect of the present invention is the electrical storage device according to the fourth aspect, and the material constituting the lid body includes at least one of a resin material and a metal material.

[0021] The electrical storage device according to the sixth aspect of the present invention is the electrical storage device according to the fourth or fifth aspect, and the resin film for electrical storage device is disposed at least in part between the lid body and the electrode body.

[0022] The electrical storage device according to the seventh aspect of the present invention is the electrical storage device according to any one of the fourth to sixth aspects, wherein the electrical storage device is disposed at least partially between the lid body and the electrode terminal with a resin film.

[0023] The electrical storage device according to the eighth aspect of the present invention is the electrical storage device according to any one of the fourth to seventh aspects, wherein the electrical storage device is disposed at least partially between the lid body and the exterior member with a resin film.

[0024] The electrical storage device according to the ninth aspect of the present invention is the electrical storage device according to any one of the fourth to eighth aspects, wherein the lid body has a hole through which the electrode terminal passes, and the electrical storage device is disposed in the hole with a resin film.

[0025] The electrical storage device according to the tenth aspect of the present invention is the electrical storage device according to any one of the fourth to ninth aspects, wherein the lid body includes a first surface facing the electrode body and a second surface opposite to the first surface, and the electrical storage device is joined to at least a part of the second surface of the lid body with a resin film.

[0026] Effects of the Invention

[0027] According to the present invention, it is possible to provide an electrical storage device that can achieve at least one of suppressing intrusion of moisture into the interior of the electrode body and absorbing hydrogen sulfide generated from the electrode body. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A is a perspective view schematically showing the electrical storage device of the first embodiment.

[0029] Figure 1B is showing Figure 1A an example of a cross-sectional view of the layer structure of the exterior member.

[0030] Figure 2 is a plan view schematically showing the electrical storage device.

[0031] Figure 3 is a side view schematically showing the electrical storage device.

[0032] Figure 4 is a view showing, from the side, the state in which the exterior member is wound around the electrode body during the manufacturing process of the electrical storage device of the first embodiment.

[0033] Figure 5 is a view showing, from below, the state in which the exterior member is wound around the electrode body during the manufacturing process of the electrical storage device of the first embodiment.

[0034] Figure 6 is schematically showing Figure 2 a part of the VI-VI cross section.

[0035] Figure 7A It is a diagram for explaining the formation method of the second sealing portion.

[0036] Figure 7B It shows along Figure 2 Another example of a cross-sectional view taken along line VI-VI.

[0037] Figure 7C It shows along Figure 2 Another example of a cross-sectional view taken along line VI-VI.

[0038] Figure 7D It shows along Figure 2 Another example of a cross-sectional view taken along line VI-VI.

[0039] Figure 7E It shows along Figure 2 Another example of a cross-sectional view taken along line VI-VI.

[0040] Figure 7F It is a cross-sectional view showing an example of the layer structure of the resin film for a storage device included in the storage device of the first embodiment.

[0041] Figure 7G It is a cross-sectional view showing another example of the layer structure of the resin film for a storage device included in the storage device of the first embodiment.

[0042] Figure 7H It is a cross-sectional view showing another example of the layer structure of the resin film for a storage device included in the storage device of the first embodiment.

[0043] Figure 8 It is a flowchart showing the manufacturing sequence of the storage device of the first embodiment.

[0044] Figure 9 It is a top view schematically showing the storage device of the second embodiment.

[0045] Figure 10 It is a side view schematically showing the storage device.

[0046] Figure 11 It is a perspective view schematically showing the lid.

[0047] Figure 12 It is a diagram showing the first example of integrally forming the lid and the electrode terminal.

[0048] Figure 13 It is a diagram showing the second example of integrally forming the lid and the electrode terminal.

[0049] Figure 14 It is a flowchart showing the manufacturing sequence of the storage device of the second embodiment.

[0050] Figure 15 It is a flowchart showing another manufacturing sequence of the electrical storage device according to the second embodiment.

[0051] Figure 16 It is a view showing the state in which an exterior member is wound around an electrode body in the third embodiment as seen from the side.

[0052] Figure 17 It is a view showing the state in which an exterior member is wound around an electrode body and a lid is attached to the exterior member in the third embodiment as seen from below.

[0053] Figure 18 It is a flowchart showing the manufacturing sequence of the electrical storage device according to the third embodiment.

[0054] Figure 19 It is a top view schematically showing the electrical storage device according to the fourth embodiment.

[0055] Figure 20 It is a side view schematically showing the electrical storage device according to the fourth embodiment.

[0056] Figure 21 It is a view showing the state in which an exterior member is wound around an electrode body in a modified example as seen from the side.

[0057] Figure 22 It is a perspective view schematically showing the electrical storage device of the modified example.

[0058] Figure 23 It is a perspective view schematically showing the lid of the modified example and the electrode terminal attached to the lid.

[0059] Figure 24 It is a view showing the insertion step of the manufacturing method of the electrical storage device of the modified example.

[0060] Figure 25 It is a perspective view schematically showing the lid of the modified example and the electrode terminal attached to the lid.

[0061] Figure 26 It is schematically showing the installation of Figure 23 The perspective view of the electrical storage device with the lid.

[0062] Figure 27 It is a front view schematically showing the lid of another modified example.

[0063] Figure 28 It is a front view schematically showing the lid of yet another modified example.

[0064] Figure 29A It is a cross-sectional view showing an arrangement example of the resin film for the electrical storage device in the electrical storage device according to the second embodiment.

[0065] Figure 29B is a cross-sectional view showing another arrangement example of the resin film for the electrical storage device in the electrical storage device indicated by Figure 29A .

[0066] Figure 29C is a cross-sectional view showing yet another arrangement example of the resin film for the electrical storage device in the electrical storage device indicated by Figure 29A .

[0067] Figure 30 is a top view schematically showing the electrical storage device of another modification

[0068] Figure 31 is a view showing, from the side, the state in which an exterior member is wound around the electrode body during the manufacturing process of the electrical storage device of another modification

[0069] Figure 32 is Figure 31 an enlarged view of the X portion of

[0070] Figure 33 is a cross-sectional view of the electrical storage device of a modification

[0071] Figure 34 is a cross-sectional view of the electrical storage device of a modification DETAILED DESCRIPTION OF THE INVENTION

[0072] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same or corresponding parts in the drawings are given the same reference numerals and will not be described repeatedly. In addition, in the present embodiment, the numerical range indicated by "~" means "above" and "below". For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less. In the numerical ranges described in stages in the present embodiment, the upper limit value or the lower limit value described in a certain numerical range can be replaced with the upper limit value or the lower limit value of the numerical range described in other stages. In addition, the upper limit value and the upper limit value, the upper limit value and the lower limit value, or the lower limit value and the lower limit value described separately can be combined to form a numerical range, respectively.

[0073] [1. First Embodiment]

[0074] <1-1. Structure of Electrical Storage Device>

[0075] Figure 1A is a perspective view schematically showing the electrical storage device 10 of the first embodiment Figure 2 is a top view schematically showing the electrical storage device 10 Figure 3 is a side view schematically showing the electrical storage device 10. In addition, in Figure 2 and Figure 3In each of the figures, the UD direction of the arrow indicates the thickness direction of the electrical storage device 10, and the LR direction of the arrow indicates the width direction of the electrical storage device 10. In addition, the FB direction of the arrow indicates the depth direction of the electrical storage device 10. The directions indicated by the arrows UDLRFB are the same in the following figures as well.

[0076] Refer to Figure 1A 、 Figure 1B 、 Figure 2 and Figure 3 ,the electrical storage device 10 includes an electrode body 200, an outer package 100, and a plurality (two) of electrode terminals 300. The electrode body 200 includes electrodes (a positive electrode and a negative electrode) and a separator that constitute an electrical storage component such as a lithium-ion battery, a capacitor, or an all-solid-state battery. The shape of the electrode body 200 is substantially a rectangular parallelepiped. Herein, "substantially a rectangular parallelepiped" means that in addition to including a complete rectangular parallelepiped, it also includes a solid that can be regarded as a rectangular parallelepiped by modifying the shape of a part of the outer surface.

[0077] The electrode terminal 300 is a metal terminal for inputting and outputting electric power of the electrode body 200. One end of the electrode terminal 300 is electrically connected to the electrode (positive electrode or negative electrode) included in the electrode body 200, and the other end protrudes outward from the edge of the outer package 100.

[0078] The metal material constituting the electrode terminal 300 is, for example, aluminum, nickel, copper, etc. For example, when the electrode body 200 is a lithium-ion battery, the electrode terminal 300 connected to the positive electrode is usually made of aluminum or the like, and the electrode terminal 300 connected to the negative electrode is usually made of copper, nickel, etc.

[0079] The outer package 100 is composed of a film-like outer packaging member 101 ( Figure 4 etc.) and seals the electrode body 200. In the electrical storage device 10, the outer package 100 is formed by winding the outer packaging member 101 around the electrode body 200 and sealing the open portion.

[0080] For example, there is a method of forming a storage portion (recess) for storing the electrode body 200 in the exterior member 101 by cold forming. However, it is not easy to form a deep storage portion by such a method. When it is desired to form a storage portion (recess) relatively deeply (for example, a forming depth of 15 mm) by cold forming, there is a high possibility that pinholes and cracks are generated in the exterior member, resulting in a decrease in battery performance. On the other hand, since the exterior body 100 seals the electrode body 200 by winding the exterior member 101 around the electrode body 200, it is possible to easily seal the electrode body 200 regardless of the thickness of the electrode body 200. In addition, in order to reduce the dead space between the electrode body 200 and the exterior member 101 and improve the volumetric energy density of the electrical storage device 10, it is preferable that the exterior member 101 is wound in a state of being in contact with the outer surface of the electrode body 200. In addition, in a all-solid-state battery, in order to exhibit battery performance, it is necessary to uniformly apply a high pressure from the outer surface of the battery. From this viewpoint, it is also necessary to eliminate the space between the electrode body 200 and the exterior member 101. Therefore, it is preferable that the exterior member 101 is wound in a state of being in contact with the outer surface of the electrode body 200.

[0081] Figure 1B FIG. 4 is a cross-sectional view showing an example of the layer structure of the exterior member 101. The exterior member 101 is, for example, a laminate 101Z (laminated film) having a base material layer 101A, a barrier layer 101B, and a heat-sealable resin layer 101C in this order. Among them, it is not necessary for the exterior member 101 to include all of these layers. For example, the base material layer 101A may not be included. Among them, the exterior member 101 is preferably heat-sealable.

[0082] The base material layer 101A included in the exterior member 101 is a layer for imparting heat resistance to the exterior member 101 and suppressing the generation of pinholes that may occur during processing or circulation. The base material layer 101A is formed by including at least one of a stretched polyester resin layer and a stretched polyamide resin layer, for example. For example, by including at least one of a stretched polyester resin layer and a stretched polyamide resin layer in the base material layer 101A, the barrier layer 101B can be protected during processing of the exterior member 101, and breakage of the exterior member 101 can be suppressed. In addition, from the viewpoint of increasing the ductility of the exterior member 101, the stretched polyester resin layer is preferably a biaxially stretched polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially stretched polyamide resin layer. Further, from the aspect of excellent puncture strength or impact strength, the stretched polyester resin layer is preferably a biaxially stretched polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is preferably a biaxially stretched nylon (ONy) film. Among them, the base material layer 101A may also be formed by including both a stretched polyester resin layer and a stretched polyamide resin layer. The thickness of the base material layer 101A is, from the aspect of film strength, preferably 5 to 300 μm, more preferably 20 to 150 μm, for example.

[0083] In addition, the barrier layer 101B included in the exterior member 101 is made of, for example, a metal foil in terms of workability such as moisture resistance and ductility and cost. Specifically, aluminum, a steel plate, stainless steel, etc. can be used as the metal foil. In addition, from the viewpoints of packaging suitability and pinhole resistance when packaging the electrode body 200, the metal foil preferably contains iron. The content of iron in the metal foil is preferably 0.5 to 5.0% by mass, more preferably 0.7 to 2.0% by mass. By making the iron content 0.5% by mass or more, packaging suitability, excellent pinhole resistance, and ductility of the exterior member 101 can be obtained. In addition, by making the iron content 5.0% by mass or less, excellent flexibility of the exterior member 101 can be obtained.

[0084] From the viewpoints of barrier property, pinhole resistance, and packaging suitability, the thickness of the barrier layer 101B is preferably, for example, 15 to 100 μm, more preferably 30 to 80 μm. By making the thickness of the barrier layer 101B 15 μm or more, the exterior member 101 is not easily broken even when stressed by packaging processing. By making the thickness of the barrier layer 101B 100 μm or less, an increase in the mass of the exterior member 101 can be reduced, and a decrease in the weight energy density of the electrical storage device 10 can be suppressed.

[0085] In addition, when the barrier layer 101B is a metal foil, in order to prevent dissolution, corrosion, etc., it is preferable to provide a corrosion-resistant coating film at least on the surface opposite to the base material layer 101A. The barrier layer 101B may have corrosion-resistant coating films on both sides. Here, the corrosion-resistant coating film is, for example, a film that makes the barrier layer 101B have corrosion resistance (such as acid resistance, alkali resistance, etc.) by performing a hot water conversion treatment such as a boehmite treatment, a chemical synthesis treatment, an anodizing treatment, a plating treatment of nickel, chromium, etc., or a corrosion prevention treatment of applying a coating material on the surface of the barrier layer 101B. Specifically, the corrosion-resistant coating film refers to a coating film that improves the acid resistance of the barrier layer 101B (acid-resistant coating film), a coating film that improves the alkali resistance of the barrier layer 101B (alkali-resistant coating film), etc. As the treatment for forming the corrosion-resistant coating film, one kind can be performed, or two or more kinds can be combined. In addition, not only one layer but also multiple layers can be formed. Further, in these treatments, the hot water conversion treatment and the anodizing treatment are treatments that dissolve the surface of the metal foil with a treatment agent and form a metal compound with excellent corrosion resistance. In addition, these treatments are sometimes included in the definition of the chemical synthesis treatment. In addition, when the barrier layer 101B has a corrosion-resistant coating film, the corrosion-resistant coating film is included as the barrier layer 101B.

[0086] When forming the exterior member 101, the corrosion-resistant coating film prevents delamination between the barrier layer 101B (e.g., aluminum alloy foil) and the base material layer 101A, and prevents dissolution and corrosion of the surface of the barrier layer 101B due to hydrogen fluoride generated by the reaction of the electrolyte and moisture. In particular, when the barrier layer 101B is an aluminum alloy foil, it prevents dissolution and corrosion of the aluminum oxide on the surface of the barrier layer 101B. The corrosion-resistant coating film also has the effects of improving the adhesiveness (wettability) of the surface of the barrier layer 101B, preventing delamination between the base material layer 101A and the barrier layer 101B during heat sealing, and preventing delamination between the base material layer 101A and the barrier layer 101B during the forming of the exterior member 101.

[0087] In addition, the heat-sealable resin layer 101C included in the exterior member 101 is a layer that imparts heat-sealing-based airtightness to the exterior member 101. As the heat-sealable resin layer 101C, a resin film made of a polyolefin resin or an acid-modified polyolefin resin obtained by graft-modifying a polyolefin resin with an acid such as maleic anhydride can be cited. From the viewpoints of airtightness and strength, the thickness of the heat-sealable resin layer 101C is preferably 20 to 300 μm, more preferably 40 to 150 μm, for example.

[0088] When the heat-sealable resin layer 101C is too hard, it slips at the contact point with the coil or at the contact point with the device when the exterior member 101 is made into the exterior body 100 using the device, and there is a problem that it cannot be transported properly. In addition, when a scratch is generated on the exterior member 101 due to the friction, damage is generated in the heat-sealable resin layer 101C. Since the heat-sealing strength may decrease due to the damage generated in the heat-sealable resin layer 101C, the heat-sealable resin layer preferably has a moderately smooth property. Therefore, when using a non-smooth material or a material that is not easily smoothed as the material constituting the heat-sealable resin layer 101C, a lubricant is preferably added from the viewpoint of transportability.

[0089] Furthermore, from the viewpoints of stain resistance and processability, the heat-sealable resin layer 101C preferably has a tensile elastic modulus in the range of 500 MPa or more and 1000 MPa or less as measured according to JIS K7161:2014. As a more preferable range of the tensile elastic modulus of the heat-sealable resin layer 101C, a range of 500 MPa or more and 800 MPa or less can be cited. As a further preferable range, a range of 500 MPa or more and 750 MPa or less can be cited. As a further preferable range, a range of 500 MPa or more and 700 MPa or less can be cited. As a further preferable range, a range of 510 MPa or more and 700 MPa or less can be cited.

[0090] By making the tensile elastic modulus of the heat-sealable resin layer 101C 500 MPa or more, contamination of the device during the forming and transportation of the exterior body 100 can be effectively suppressed. That is, by making the tensile elastic modulus of the heat-sealable resin layer 101C 500 MPa or more, the lubricant on the surface of the heat-sealable resin layer 101C is not easily scraped off by the device or the like. Therefore, the lubricant on the surface portion of the heat-sealable resin layer 101C is not easily transferred to the device or the like, and contamination of the device or the like can be effectively suppressed. In addition, by making the tensile elastic modulus of the heat-sealable resin layer 101C 1000 MPa or less, high sealing strength can be obtained by heat sealing. That is, by making the tensile elastic modulus of the heat-sealable resin layer 101C 1000 MPa or less, the heat-sealable resin layer 101C is not easily embrittled, and therefore high sealing strength can be obtained by heat sealing. When the tensile elastic modulus of the heat-sealable resin layer 101C exceeds 1000 MPa, there are problems such as the heat-sealable resin layer 101C becoming embrittled, easy peeling between the barrier layer 101B laminated with the adhesive layer, reduction of the sealing strength, whitening and cracking in the extended portion due to the extension of the bent portion during the forming of the exterior body 100, resulting in a reduction in battery performance. In addition, when the tensile elastic modulus of the heat-sealable resin layer 101C exceeds 1000 MPa, the extrudability decreases, which is the main cause of the reduction in productivity. Therefore, in the exterior component 101 of the electrical storage device 10 of the present embodiment, by making the tensile elastic modulus of the heat-sealable resin layer 101C in the range of 500 to 1000 MPa, the contamination suppression effect of the device or the like and the improvement effect of the sealing strength achieved by heat sealing can be appropriately obtained. Among them, the tensile elastic modulus of the heat-sealable resin layer 101C can be adjusted by adjusting the molecular weight, melt flow rate (MFR), etc. of the resin constituting the heat-sealable resin layer 101C.

[0091] In addition, in the case where the docking operation, bending operation, etc. of the sealing portions for pillow sealing during the production of the exterior body 100 are called processing, the same technical problems as described above occur during this processing. Especially during processing, scars are likely to occur on the exterior component 101. Therefore, it is important to solve the above technical problems. By making the tensile elastic modulus of the heat-sealable resin layer 101C in the range of 500 MPa or more and 1000 MPa or less, good processing can be achieved.

[0092] The exterior component 101 is preferably on the outer side of the heat-sealable resin layer 101C ( Figure 1BAt a position on the upper side of [the relevant part], more preferably at a position outside the barrier layer 101B, there is one or more layers with a buffering function (hereinafter referred to as "buffer layer"). The buffer layer can be laminated outside the substrate layer 101A, and the substrate layer 101A can also have the function of the buffer layer. When the exterior member 101 has a plurality of buffer layers, the plurality of buffer layers can be adjacent to each other or can be laminated with a layer such as the substrate layer 101A or the barrier layer 101B in between.

[0093] The material constituting the buffer layer can be arbitrarily selected from materials with buffering characteristics. Materials with buffering characteristics are, for example, rubber, non-woven fabric, or foamed sheet. Rubber is, for example, natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably around 20 to 90. The material constituting the non-woven fabric is preferably a material with excellent heat resistance. When the buffer layer is made of non-woven fabric, the lower limit value of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and even more preferably 1000 μm. When the buffer layer is made of non-woven fabric, the upper limit value of the thickness of the buffer layer is preferably 5000 μm, more preferably 3000 μm. The preferred range of the thickness of the buffer layer is 100 μm to 5000 μm, 100 μm to 3000 μm, 200 μm to 5000 μm, 200 μm to 3000 μm, 1000 μm to 5000 μm, or 1000 μm to 3000 μm. Among them, the most preferred range of the thickness of the buffer layer is 1000 μm to 3000 μm.

[0094] When the buffer layer is made of rubber, the lower limit value of the thickness of the buffer layer is preferably 0.5 mm. When the buffer layer is made of rubber, the upper limit value of the thickness of the buffer layer is preferably 10 mm, more preferably 5 mm, and even more preferably 2 mm. When the buffer layer is made of rubber, the preferred range of the thickness of the buffer layer is 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0095] When the exterior member 101 has a buffer layer, the buffer layer functions as a buffer and can prevent the exterior member 101 from being damaged due to the collision when the electrical storage device 10 falls or the transportation during the manufacturing of the electrical storage device 10.

[0096] Since the outer package 100 in the present embodiment can form a deep storage portion, the weight of the electrode body 200 increases, and the impact on the outer package 100 due to collision or the like becomes large. Therefore, in the present embodiment, when the thickness of the outer package member 101 is 195 μm or less and the thickness of the barrier layer 101B is included in the range of 20 to 85 μm, the puncture strength measured by the method conforming to the provisions of JIS Z1707:1997 when punctured from the base material layer 101A side of the outer package member 101 is preferably 30 N or more. The preferred range of the puncture strength can be, for example, about 30 to 45 N, about 30 to 40 N, about 35 to 45 N, or about 35 to 40 N. Herein, the method for measuring the puncture strength of the outer package member 101 is as follows.

[0097] The puncture strength from the base material layer 101A side of the outer package member 101 is measured by the method conforming to the provisions of JIS Z1707:1997. Specifically, in a measurement environment of 23 ± 2°C and a relative humidity of (50 ± 5)%, the test piece is fixed with a table having a diameter of 115 mm with an opening having a diameter of 15 mm in the center and a pressing plate, and a needle having a diameter of 1.0 mm and a semi-circular tip shape with a radius of 0.5 mm is punctured at a speed of 50 ± 5 mm per minute, and the maximum stress until the needle penetrates is measured. The number of test pieces is 5, and their average value is obtained. In addition, when the number of test pieces is insufficient for 5 measurements, the number that can be measured is measured, and their average value is obtained. Herein, as the measurement device for the puncture strength, the ZP-500N (dynamometer) and MX2-500N (measurement table) manufactured by IMADA Co., Ltd. of Japan can be used.

[0098] In the electrical storage device 10 of the present embodiment, as the weight of the electrode body 200 increases, friction between electrical storage devices 10, friction between the electrical storage device 10 and surrounding components, and friction during transportation of the electrical storage device 10 are likely to occur. Therefore, in the present embodiment, it is preferable that the surface on the substrate layer 101A side of the exterior member 101 has good fixability of the ink liquid (good printing characteristics), and the ink liquid after fixing is not easily erased. From such a viewpoint, it is preferable that the contact angle of the surface on the substrate layer 101A side of the exterior member 101 of the present embodiment is 80° or less. That is, in the exterior member 101, when the substrate layer 101A constitutes the outermost surface, the contact angle of the surface of the substrate layer 101A is 80° or less. In addition, when a coating is provided outside the substrate layer 101A, the contact angle of the surface of the coating is 80° or less. In the present embodiment, since the contact angle of the surface on the substrate layer 101A side of the exterior member 101 is 80° or less, the ink liquid is not easily repelled on the surface on the substrate layer 101A side, the printing characteristics are excellent, and the ink liquid after fixing is not easily erased. In particular, for the exterior member 101 in which the formability is improved by the presence of a lubricant on the surface on the substrate layer 101A side, when the ink liquid is printed by pad printing, the ink liquid may be repelled on the surface on the substrate layer 101A side, resulting in poor printing. However, for the exterior member 101 of the electrical storage device 10 of the present embodiment, even in such a case, since the contact angle of the surface on the substrate layer 101A side is 80° or less, the ink liquid is not easily repelled, and it is particularly suitable as an exterior member 101 for forming printing characters or the like on the surface of the substrate layer 101A by pad printing.

[0099] In the present embodiment, from the viewpoint of improving printing suitability and making the ink liquid after fixing not easily erased, it is more preferable that the contact angle of the surface on the substrate layer 101A side is 79° or less, and further preferably 72° or less. The contact angle of the surface on the substrate layer 101A side can be obtained by using LSE - A210 manufactured by NIC Corporation, Japan, and measuring the contact angle of the interface between the substrate and the water droplet 5 seconds after the water droplet starts.

[0100] In the present embodiment, the contact angle of the surface on the substrate layer 101A side can be appropriately 80° or less, for example, by performing corona treatment on the surface on the substrate layer 101A side. The corona treatment can be performed by irradiating corona discharge on the surface on the substrate layer 101A side using a commercially available corona surface treatment device. The conditions of the corona treatment are, for example, an irradiation power of 1 kW or more and a speed of 10 MT / min. By treating the surface on the substrate layer 101A side under such conditions, the contact angle of the surface on the substrate layer 101A side can be made 80° or less.

[0101] In addition, when printing ink on the surface of the exterior member 101, after performing corona treatment, a step of printing ink on at least a part of the surface of the base material layer 101A is carried out. As the printing method, there is no particular limitation. When printing on the formed exterior member 101, inkjet printing and pad printing are preferably used. In the exterior member 101 of the electrical storage device 10 of the present embodiment, since the contact angle of the surface on the side of the base material layer 101A is set to 80° or less, even when pad printing in which the ink easily bounces off is used for the base material layer 101A having a lubricant on the surface, the ink can be appropriately printed. Therefore, on at least a part of the surface of the base material layer 101A, for example, printing such as barcodes, patterns, and characters can be appropriately formed.

[0102] Figure 4 FIG. is a view showing a state in which the exterior member 101 is wound around the electrode body 200 during the manufacturing process of the electrical storage device 10 from the side. As Figure 4 shown, the exterior member 101 is wound around the electrode body 200. In this case, the outermost layer of the electrode body 200 does not necessarily have to be an electrode. For example, it can also be a protective tape or a separator. In a state where the exterior member 101 is wound around the electrode body 200, the first sealing portion 110 is formed by heat-sealing the opposing surfaces (heat-sealable resin layers) of the exterior member 101 to each other. Among them, the first sealing portion 110 can be formed by joining the innermost layer and the outermost layer of the exterior member 101. In this case, the innermost layer and the outermost layer of the exterior member 101 are preferably the heat-sealable resin layers 101C.

[0103] The base portion of the first sealing portion 110 is preferably located on the edge 135 of the exterior body 100. In the present embodiment, the edge 135 is formed by the boundary between the first surface 130 and the second surface 140 having an area smaller than that of the first surface 130. That is, in the present embodiment, it can be said that the base portion of the first sealing portion 110 is formed at the boundary between the first surface 130 and the second surface 140 and exists on either the first surface 130 or the second surface 140. The base portion of the first sealing portion 110 can also be located outside the edge 135. In the electrical storage device 10, the first sealing portion 110 is bent toward the second surface 140 side with the edge 135 as the center. In the electrical storage device 10, the first sealing portion 110 contacts the second surface 140 and covers substantially the entire second surface 140. Among them, "substantially the entire second surface 140" means a region occupying more than 75% of the area of the second surface 140.

[0104] That is, in the electrical storage device 10, the first sealing portion 110 is not formed on the first surface 130 with a larger area. Compared with the case where a sealing portion such as the first sealing portion 110 is in contact with the first surface 130, the first surface 130 is flat. Therefore, even if another electrical storage device 10 is placed on the first surface 130, the other electrical storage device 10 does not tilt. As a result, according to the electrical storage device 10, it is possible to suppress uneven distribution of the pressure applied to the lower electrical storage device 10 when a plurality of electrical storage devices 10 are stacked. In other words, when a module is formed by stacking a plurality of electrical storage devices 10, it is possible to arrange the first sealing portion 110 not on the surface (first surface 130) adjacent to the adjacent electrical storage device 10. In addition, in a all-solid-state battery, such a structure is also preferable from the viewpoint that a high pressure needs to be uniformly applied from the outer surface of the battery in order to exhibit battery performance.

[0105] In addition, in the electrical storage device 10, the root portion of the first sealing portion 110 is located on the edge 135 of the outer package 100. Therefore, according to the electrical storage device 10, compared with the case where the root portion of the first sealing portion 110 is on the second surface 140 (for example, in the arrow UD direction, the central portion of the second surface 140), the bonding area of the first sealing portion 110 can be ensured widely. In addition, the bonding area of the first sealing portion 110 is not necessarily the entire area of the first sealing portion 110. For example, it may be only a part of the first sealing portion 110 such as near the root portion of the first sealing portion 110.

[0106] In addition, in the electrical storage device 10, substantially the entire second surface 140 is covered by the first sealing portion 110. That is, in the electrical storage device 10, for example, compared with the case where the first sealing portion 110 covers only an area less than half of the second surface 140, the length of the first sealing portion 110 in the arrow UD direction is longer (refer to Figure 3 ). Therefore, according to the electrical storage device 10, the bonding area of the first sealing portion 110 can be ensured widely. In addition, since substantially the entire second surface 140 is covered by the first sealing portion 110, even if the electrical storage device 10 is erected so that the second surface 140 is in contact with the placement surface, the electrical storage device 10 is stable. That is, the electrical storage device 10 is not easily tilted with respect to the placement surface. Therefore, such a structure is also effective, for example, when a plurality of electrical storage devices 10 are arranged horizontally to form a module.

[0107] Figure 5 It is a view showing a state in which the outer package member 101 is wound around the electrode body 200 during the manufacturing process of the electrical storage device 10 from below. As Figure 5As shown, in the electrical storage device 10, the direction along the side 135 is the TD (Transverse Direction) of the exterior member 101, and the direction orthogonal to the side 135 is the MD (Machine Direction or longitudinal direction) of the exterior member 101. That is, the direction along the side 135 is the direction (TD) orthogonal to the flow direction (MD) of the exterior member 101.

[0108] In the electrical storage device 10, the first sealing portion 110 is bent along the side 135, and the direction along the side 135 is the direction orthogonal to the flow direction of the exterior member 101. Therefore, according to the electrical storage device 10, even if a crease is formed in the direction orthogonal to the flow direction of the exterior member 101, the exterior member 101 is not easily broken, and thus the possibility of the first sealing portion 110 being broken due to the bending of the first sealing portion 110 can be reduced.

[0109] The flow direction (MD) of the exterior member 101 corresponds to the rolling direction (RD) of the metal foil (such as an aluminum alloy foil) of the barrier layer contained in the exterior member 101. The TD of the exterior member 101 corresponds to the TD of the metal foil. The rolling direction (RD) of the metal foil can be judged based on the rolling marks.

[0110] In addition, the sea-island structure can be confirmed by observing a plurality of cross-sections of the heat-sealable resin layer of the exterior member 101 using an electron microscope, and the direction parallel to the cross-section with the largest average island diameter in the direction perpendicular to the thickness direction of the heat-sealable resin layer (hereinafter also referred to as the "length direction of the heat-sealable resin layer") is judged as the MD. In the case where the MD of the exterior member 101 cannot be determined based on the rolling marks of the metal foil, this method can be used to determine the MD.

[0111] Specifically, for the cross-section in the length direction of the heat-sealable resin layer, and for each cross-section (a total of 10 cross-sections) obtained by successively changing the angle by 10 degrees from the direction parallel to the cross-section in the length direction until the direction perpendicular to the cross-section in the length direction, the sea-island structure is confirmed by observing each using an electron microscope photograph. Then, for each island on each cross-section, the diameter d of the island is measured based on the straight-line distance connecting the two ends in the direction perpendicular to the thickness direction of the heat-sealable resin layer. Then, for each cross-section, the average of the diameters d of the largest 20 islands is calculated starting from the larger side. Then, the direction parallel to the cross-section with the largest average diameter d of the islands is judged as the MD.

[0112] Figure 6 is a schematic representation of Figure 2 a part of the VI-VI cross-section of. As Figure 6 shown, the second sealing portion 120 seals the electrode terminal 300 in a state where the exterior body 100 sandwiches it.

[0113] Figure 7A This is a diagram for explaining the formation method of the second sealing portion 120. As Figure 7A shown, the exterior member 101 is folded, and the second sealing portion 120 is formed by heat-sealing the opposite faces (heat-sealable resin layers) of the exterior member 101 to each other. Among them, the electrode terminal 300 is located between the opposite faces of the exterior member 101, but Figure 7A the illustration thereof is omitted in Figures 7B - 7E . In addition, between the electrode terminal 300 and the exterior member 101, a terminal bonding film 30 that bonds both metal and resin may also be disposed (refer to

[0114] As the bonding film, for example, a resin film composed of a polyolefin resin or an acid-modified polyolefin resin obtained by graft-modifying a polyolefin resin with an acid such as maleic anhydride can be used as a structure having one layer or two or more layers. When the bonding film has two or more layers, it is preferable to dispose a resin film composed of a polyolefin resin on the side joined to the exterior member 101. When the bonding film has two or more layers, it is preferable to dispose a resin film composed of an acid-modified polyolefin resin obtained by graft-modifying a polyolefin resin with an acid such as maleic anhydride on the side joined to the electrode terminal 300.

[0115] Referring again to Figure 6 , the electrode body 200 includes a plurality of electrodes 210 (positive electrode and negative electrode). The current collectors 215 extending from each electrode 210 are connected to the electrode terminal 300. In the electrical storage device 10, a part of the electrode terminal 300 located outside the exterior body 100 is located at a position approximately half of the thickness of the electrical storage device 10 in the thickness direction of the electrical storage device 10. That is, the length L2 is approximately half of the length L1. Among them, "approximately half of the thickness of the electrical storage device 10" means 35% to 65% of the thickness of the electrical storage device 10.

[0116] Therefore, according to the electrical storage device 10, for example, compared with the case where the electrode terminal 300 is located at a position substantially the same as the first surface 130 in the thickness direction of the electrical storage device 10, the difference between the longest distance and the shortest distance among the distances between each of the plurality of electrodes 210 and the electrode terminal 300 can be reduced.

[0117] Since the performance of the electrical storage device 10 deteriorates when moisture penetrates into the interior of the electrode body 200, for example, in the case where the aforementioned film-like laminate is used as the exterior member 101, a barrier layer 101B (for example, composed of a metal foil) is provided. By providing the barrier layer 101B, the penetration of moisture from the outside of the barrier layer 101B can be suppressed.

[0118] However, when the heat-fusible resin layer 101C of the exterior member 101 is heat-fused to seal the electrode body 200, the end face of the heat-fusible resin layer 101C is exposed to the outside, so there is a problem that moisture infiltrates from the end face of the heat-fusible resin layer 101C.

[0119] In addition, when the heat-fusible resin layer 101C of the exterior member 101 absorbs water before the electrode body 200 is sealed with the exterior member 101, it is possible that moisture in the heat-fusible resin layer 101C infiltrates into the electrode body 200 after the electrode body 200 is sealed.

[0120] In addition, when the electrical storage device 10 is a all-solid-state battery, when moisture comes into contact with the solid electrolyte included in the elements constituting the all-solid-state battery, depending on the type of the solid electrolyte, gases such as hydrogen sulfide may be generated.

[0121] The electrical storage device 10 of the present embodiment is provided with a resin film 20 for electrical storage device (hereinafter referred to as "film 20") in order to suppress at least one of the intrusion of moisture into the electrode body 200 and the absorption of gases such as hydrogen sulfide generated from the electrode body 200. The film 20 contains at least one of a water absorbent and a gas absorbent. Hereinafter, the case where the film 20 contains at least a water absorbent is sometimes referred to as the first mode of the film 20. The case where the film 20 contains at least a gas absorbent is sometimes referred to as the second mode of the film 20.

[0122] In the electrical storage device 10, the position where the film 20 is disposed can be arbitrarily selected as long as it is inside the barrier layer 101B of the exterior member 101. In the present embodiment, being inside the barrier layer 101B means being on the opposite side of the substrate layer 101A with respect to the barrier layer 101B in the stacking direction of the respective layers 101A to 101C of the exterior member 101. By disposing the film 20 of the first mode inside the barrier layer 101B of the exterior member 101, it is possible to suppress the intrusion of moisture from the end portion of the heat-sealable resin layer 101C of the exterior member 101 and the intrusion of moisture contained in the heat-sealable resin layer 101C of the exterior member 101 into the electrode body 200. That is, since the film 20 of the electrical storage device 10 having the first mode contains a water absorbent, the film 20 absorbs water and retains the moisture intruded from the heat-sealable resin layer 101C of the exterior member 101, thereby suppressing the moisture from reaching the electrode body 200. In addition, by disposing the film 20 of the second mode inside the barrier layer 101B of the exterior member 101, for example, when the electrode body 200 is an all-solid-state battery, it is possible to absorb gases such as hydrogen sulfide generated by the contact of the solid electrolyte layer included in the elements constituting the all-solid-state battery with moisture. That is, in the electrical storage device 10 including the film 20 of the second mode, since the film 20 contains a gas absorbent, it is possible to use the film 20 to absorb gases such as hydrogen sulfide generated from the electrode body 200. Therefore, it is possible to suppress an excessive increase in the internal pressure of the exterior body 100. Hereinafter, a specific configuration example of the film 20 in the electrical storage device 10 will be described.

[0123] As shown in Figure 1B , the film 20 can also be used as the heat-sealable resin layer 101C of the exterior member 101. The film 20 can also be used as an adhesive layer between the barrier layer 101B and the heat-sealable resin layer 101C. The film 20 can also be used as an adhesive film between the heat-sealable resin layers 101C facing each other at a position where the heat-sealable resin layers 101C of the exterior member 101 such as the first sealing portion 110 are heat-sealed to each other. When the film 20 is used as an adhesive film, the film 20 can also have a function of releasing gas to the outside by peeling off the portion of the film 20 in the heat-sealable resin layer 101C when the internal pressure of the exterior body 100 rises due to gas generated from the electrode body 200.

[0124] Figure 7B is another cross-sectional view along the Figure 2 VI-VI line. In the example shown in Figure 7B , the film 20 is disposed between the exterior member 101 and the electrode body 200 so as to cover substantially the entire upper surface and the lower surface of the electrode body 200. The film 20 and the inner surface (heat-sealable resin layer 101C) of the exterior member 101 may or may not be joined.

[0125] Figure 7C is a cross-sectional view showing another example along the Figure 2 VI-VI line. In the example shown in Figure 7C , the film 20 is disposed between the exterior member 101 and the electrode body 200 so as to cover substantially the entire side surface of the electrode body 200. The film 20 and the inner surface (heat-fusible resin layer 101C) of the exterior member 101 may or may not be joined.

[0126] Figure 7D is a cross-sectional view showing another example along the Figure 2 VI-VI line. In the example shown in Figure 7D , the film 20 is disposed between the exterior member 101 and the electrode body 200 so as to cover substantially the entire electrode body 200. The film 20 and the inner surface (heat-fusible resin layer 101C) of the exterior member 101 may or may not be joined.

[0127] Figure 7E is a cross-sectional view showing another example along the Figure 2 VI-VI line. In the example shown in Figure 7E , the electrical storage device 10 has a terminal bonding film 30 that bonds both metal and resin between the electrode terminal 300 and the exterior member 101. In the example shown in Figure 7E , the film 20 is used as the terminal bonding film 30.

[0128] Since the end face of the terminal bonding film 30 is exposed to the outside, there is a problem that moisture penetrates from the end face of the terminal bonding film 30. Further, when the terminal bonding film 30 absorbs water before being disposed between the electrode terminal 300 and the exterior member 101, there is also a problem that moisture in the terminal bonding film 30 penetrates into the electrode body 200 after the terminal bonding film 30 is disposed between the electrode terminal 300 and the exterior member 101.

[0129] By using the film 20 of the first mode as the terminal bonding film 30, it is possible to effectively suppress the intrusion of moisture from the end portion of the terminal bonding film 30 and the intrusion of moisture contained in the terminal bonding film 30 into the electrode body 200. That is, in the electrical storage device 10 having the film 20 of the first mode, since the film 20 contains a water absorbent, the film 20 absorbs water and retains the moisture intruded from the terminal bonding film 30, thereby suppressing the moisture from reaching the electrode body 200. In addition, by using the film 20 of the second mode as the terminal bonding film 30, for example, when the electrode body 200 is a all-solid-state battery, it is possible to effectively absorb gases such as hydrogen sulfide generated by the contact of the solid electrolyte layer included in the elements constituting the all-solid-state battery with moisture. That is, in the electrical storage device 10 including the film 20 of the second mode, since the film 20 contains a gas absorbent, the film 20 can absorb gases such as hydrogen sulfide generated from the electrode body 200. Therefore, gases such as hydrogen sulfide are not easily released to the outside.

[0130] <1-2. Specific Structure of Resin Film for Electrical Storage Device>

[0131] In the first mode of the film 20, the moisture to be absorbed is gaseous and / or liquid moisture. In addition, as described later, the gas absorption film of the first mode of the present embodiment can also include sulfur-based gases in the absorption target as needed. Examples of sulfur-based gases include hydrogen sulfide, dimethyl sulfide, methyl mercaptan, and sulfur oxides represented by SO x When the moisture of the absorption target is absorbed by a solid electrolyte type lithium ion battery, for example, various emission gases are generated, and sulfur-based gases are components of the emission gases (for example, generated in the case where the electrical storage device 10 is an all-solid-state battery using a sulfide-based inorganic solid electrolyte and in the case of a lithium secondary battery using lithium sulfur in the positive electrode).

[0132] The film 20 of the present embodiment can be composed of a single layer as shown in Figure 7F For example, it can also be composed of two or more layers as shown in Figure 7G and Figure 7H shown. Figure 7G The film 20 represented by a laminate obtained by laminating the first layer 21 and the second layer 22 is shown. Figure 7H The film 20 represented by a laminate obtained by sequentially laminating the second layer 22, the first layer 21, and the third layer 23 is shown.

[0133] In the first mode, when the film 20 is composed of two or more layers, at least one of the two or more layers may contain a water absorbent. In the present embodiment, the layer containing the water absorbent is sometimes referred to as the "water absorption layer". As a specific example of the laminated structure of the film 20 of the first mode, for example, it is possible to list in Figure 7GIn the [structure], the first layer 21 on the side of the exterior member 101 is a water-absorbing layer, and the second layer 22 on the side of the electrode body 200 is a layer structure that does not contain a water absorbent. In addition, for example, it can be cited: in Figure 7H In the [structure], the middle first layer 21 is a water-absorbing layer, and the second layer 22 on the side of the electrode body 200 and the third layer 23 on the side of the exterior member 101 are layer structures that do not contain a water absorbent; at least one of the first layer 21 and the third layer 23 is a water-absorbing layer, and the second layer 22 is a layer structure that does not contain a water absorbent, etc.

[0134] In the second mode, when the film 20 is composed of two or more layers, at least one of the two or more layers may contain a gas absorbent. The gas absorbent is, for example, at least one of a sulfur-based gas absorbent, a carbon dioxide absorbent, and an oxygen absorbent. In the present embodiment, for the second mode of the film 20, the case where the gas absorbent is a sulfur-based gas absorbent will be described as an example. As a specific example of the laminated structure of the film 20 in the second mode, for example, it can be cited: in Figure 7G In the [structure], the first layer 21 on the side of the exterior member 101 is a sulfur-based gas absorption layer, and the second layer 22 on the side of the electrode body 200 is a layer structure that does not contain a sulfur-based gas absorbent; the first layer 21 on the side of the exterior member 101 is a layer that does not contain a sulfur-based gas absorption layer, and the second layer 22 on the side of the electrode body 200 is a layer structure that contains a sulfur-based gas absorbent. In addition, for example, it can be cited: in Figure 7H In the [structure], the middle first layer 21 is a sulfur-based gas absorption layer, and the second layer 22 on the side of the electrode body 200 and the third layer 23 on the side of the exterior member 101 are layer structures that do not contain a sulfur-based gas absorbent; at least one of the first layer 21 and the third layer 23 is a sulfur-based gas absorption layer, and the second layer 22 is a layer structure that does not contain a sulfur-based gas absorbent; the middle first layer 21 is a layer that does not contain a sulfur-based gas absorption layer, and the second layer 22 on the side of the electrode body 200 and the third layer 23 on the side of the exterior member 101 are layer structures that contain a sulfur-based gas absorbent; at least one of the first layer 21 and the third layer 23 is a layer that does not contain a sulfur-based gas absorption layer, and the second layer 22 is a layer structure that contains a sulfur-based gas absorbent, etc. Since hydrogen sulfide gas is generated from the electrode body 200, it is preferable that the second layer 22 on the side of the electrode body 200 is a sulfur-based gas absorption layer.

[0135] In the first mode, it is preferable that one or both sides of the film 20 have heat sealability. When the film 20 in the first mode is located at the second sealing portion 120 of the exterior member 101, it is preferable to improve the heat sealability of the film 20. Therefore, for example, when the film 20 is composed of three or more layers, it is preferable that the layer on the surface (if it is Figure 7H, the second layer 22 and the third layer 23 contain a heat-sealable resin. In addition, from the viewpoint of suppressing a decrease in the heat-sealability of the layer located on the surface, it is preferable that the layer located on the surface does not contain a water absorbent (especially an inorganic water absorbent). In the electrical storage device 10, from the viewpoint of more appropriately exhibiting the water absorption performance of the water absorption layer of the film 20, the water absorption layer is preferably provided between the layers located on the surface. This is because when the water absorption layer is located on the surface, before the electrical storage device 10 is manufactured, moisture in the atmosphere is absorbed, and the water absorption performance of the water absorption layer is likely to decrease. In addition, in the electrical storage device 10, regarding the water absorption layer, it is preferable that the third layer 23 on the side of the exterior member 101 is the water absorption layer. This is because the third layer 23 is close to the exterior member 101, and moisture infiltrating from the side of the exterior member 101 is easily absorbed. In addition, in the electrical storage device 10, regarding the water absorption layer, it is preferable that the second layer 22 on the side of the electrode body 200 is the water absorption layer. This is because the second layer 22 is close to the electrode body 200, and moisture contained in the electrode body 200 is easily absorbed.

[0136] In the second mode, it is also preferable that one or both surfaces of the film 20 have heat-sealability. When the film 20 in the second mode is located in the second sealing portion 120 of the exterior member 101, it is preferable to improve the heat-sealability of the film 20. Therefore, for example, when the film 20 is composed of three or more layers, the layer located on the surface (if it is Figure 7H , the second layer 22 and the third layer 23) preferably contains a heat-sealable resin. In addition, from the viewpoint of suppressing a decrease in the heat-sealability of the layer located on the surface, it is preferable that the layer located on the surface does not contain a sulfur-based gas absorbent.

[0137] In addition to containing a water absorbent, the film 20 of the first mode may further contain a sulfur-based gas absorbent described later. In the present embodiment, the layer containing the sulfur-based gas absorbent is sometimes referred to as a "sulfur-based gas absorption layer". When the sulfur-based gas absorbent is contained, the sulfur-based gas absorbent may be contained in the water absorption layer or in a layer that does not contain a water absorbent. When the film 20 is composed of two or more layers, it is preferable that the sulfur-based gas absorbent is contained in a layer that does not contain a water absorbent to form a sulfur-based gas absorption layer. In addition, as concerns when multiple types of particles are contained in a single layer, it can be cited that it is difficult for the particles to be dispersed when forming the film 20, pores are generated in the film, and the strength of the film 20 varies depending on the location. In addition, when the amount of particles contained in a single layer is a certain amount or more, the stretchability and strength of the film decrease, so there is also a concern that it is easily damaged at the corners of the battery or the like. If the amount is small, even if the water absorbent and the sulfur-based gas absorbent are contained in a single layer, there is no such concern as described above. However, in order to maintain the water absorption effect and the sulfur-based gas absorption effect for a long time, it is preferable that the water absorption layer and the sulfur-based gas absorption layer are different layers.

[0138] When the film 20 in the first mode is composed of two or more layers, specific examples of the laminated structure of the film 20 include, for example: Figure 7G in which the first layer 21 is a water absorption layer and the second layer 22 is a chalcogen-based gas absorption layer. In addition, for example, it can be cited: in Figure 7H in which the first layer 21 is a water absorption layer and at least one of the second layer 22 and the third layer 23 is a chalcogen-based gas absorption layer; at least one of the first layer 21 and the third layer 23 is a water absorption layer and the second layer 22 is a chalcogen-based gas absorption layer, etc. Since hydrogen sulfide gas is generated from the electrode body 200, it is preferable that the second layer 22 located on the electrode body 200 side is a chalcogen-based gas absorption layer. In addition, as described above, since it is preferable to provide the water absorption layer between the layers located on the surface, in the above, the most preferable laminated structure is that the first layer 21 located between the second layer 22 and the third layer 23 is a water absorption layer and the second layer 22 located on the electrode body 200 side is a chalcogen-based gas absorption layer.

[0139] In addition, the film 20 in the second mode may further contain a water absorbent described later in addition to the chalcogen-based gas absorbent. As described above, in the present embodiment, the layer containing the water absorbent is sometimes referred to as a "water absorption layer". When the water absorbent is included, the water absorbent may be included in the chalcogen-based gas absorption layer or in a layer that does not contain the water absorbent. When the film 20 in the second mode is composed of two or more layers, it is preferable that the water absorbent is included in a layer that does not contain the chalcogen-based gas absorbent to form a water absorption layer. In addition, as concerns when a single layer contains multiple types of particles, it can be cited that it is difficult for the particles to be dispersed when forming the film 20, pores are formed in the film, and the strength of the film 20 varies depending on the location. In addition, when the amount of particles contained in a single layer is above a certain amount, the stretchability and strength of the film decrease, so there is also a concern that it is easy to break due to the corners of the battery, etc. If the amount is small, there is no such concern even if the water absorbent and the chalcogen-based gas absorbent are included in a single layer, but in order to maintain the water absorption effect and the chalcogen-based gas absorption effect for a long time, it is preferable that the water absorption layer and the chalcogen-based gas absorption layer are different layers.

[0140] When the film 20 in the second mode is composed of two or more layers, specific examples of the laminated structure of the film 20 include, for example: in Figure 7G in which the first layer 21 is a chalcogen-based gas absorption layer and the second layer 22 is a water absorption layer. In addition, for example, it can be cited: in Figure 7HIn [the structure], the first layer 21 is a chalcogen gas absorption layer, and at least one of the second layer 22 and the third layer 23 is a water absorption layer; at least one of the first layer 21 and the third layer 23 is a chalcogen gas absorption layer, and the second layer 22 is a water absorption layer, etc. In the electrical storage device 10, from the viewpoint of more suitably exhibiting the water absorption performance of the water absorption layer of the film 20, it is preferable that the water absorption layer is provided between the layers located on the surface. This is because when the water absorption layer is on the surface, moisture in the atmosphere is absorbed before the electrical storage device 10 is manufactured, and the water absorption performance of the water absorption layer is likely to decrease. Most preferably, the first layer 21 located between the second layer 22 and the third layer 23 is the water absorption layer described later, and the second layer 22 on the side of the electrode body 200 is a laminated structure of a chalcogen gas absorption layer. In addition, in the electrical storage device 10, regarding the water absorption layer, it is preferable that the third layer 23 on the side of the exterior member 101 is the water absorption layer. This is because the third layer 23 is close to the exterior member 101, and moisture infiltrating from the side of the exterior member 101 is easily absorbed. In addition, in the electrical storage device 10, regarding the water absorption layer, it is preferable that the second layer 22 on the side of the electrode body 200 is the water absorption layer. This is because the second layer 22 is close to the electrode body 200, and moisture contained in the electrode body 200 is easily absorbed.

[0141] In the present embodiment, as the resin contained in the film 20, there is no particular limitation as long as the effects of the present embodiment are not hindered. For example, a thermoplastic resin is preferable, and a heat-sealable resin is more preferable. Specific examples of the resin include thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenol resin, and modified products of these resins. In addition, the resin forming the film 20 may be a copolymer of these resins, or a modified product of the copolymer. Further, it may also be a mixture of these resins. Among these resins, heat-sealable resins such as polyester and polyolefin are preferable.

[0142] As the polyester, specifically, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolyester, etc. can be cited. In addition, as the copolyester, copolyesters having ethylene terephthalate as the main repeating unit can be cited. Specifically, copolyester resins such as copolymers of ethylene terephthalate as the main repeating unit and ethylene isophthalate (hereinafter abbreviated as polyethylene (ethylene terephthalate / isophthalate)), polyethylene (ethylene terephthalate / adipate), polyethylene (terephthalate / sodium isophthalate sulfonate), polyethylene (ethylene terephthalate / disodium isophthalate), polyethylene (ethylene terephthalate / phenyl dicarboxylate), polyethylene (ethylene terephthalate / sebacate), etc. can be cited. These polyesters can be used alone or in combination of two or more. Among them, polybutylene terephthalate is particularly preferred from the viewpoint of improving heat resistance and pressure resistance (for example, reduction of insulation performance when the electrode body 200 is sealed with the exterior member 101 (caused by nonconformance due to heat sealing)).

[0143] In addition, as the polyolefin, specifically, polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, etc.; ethylene-α-olefin copolymer; polypropylene such as homopolypropylene, block copolymer of polypropylene (for example, block copolymer of propylene and ethylene), random copolymer of polypropylene (for example, random copolymer of propylene and ethylene), etc.; propylene-α-olefin copolymer; terpolymer of ethylene-butene-propylene, etc. The polyolefin resin in the case of being a copolymer can be a block copolymer or a random copolymer. These polyolefin resins can be used alone or in combination of two or more. Among them, polypropylene is particularly preferred because of its excellent heat weldability.

[0144] The resin contained in the film 20 preferably contains, as a main component, a resin having a polyolefin backbone, more preferably contains polyolefin as a main component, and still more preferably contains polypropylene as a main component. Here, the main component means that, among the resin components contained in the film 20, the content rate of a resin component is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, and still more preferably 99% by mass or more. For example, the meaning that the resin contained in the film 20 contains polypropylene as a main component is that, among the resin components contained in the film 20, the content rate of polypropylene is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, and still more preferably 99% by mass or more.

[0145] The resin contained in the film 20 preferably contains polyester as a main component. Here, the main component means that, among the resin components contained in the film 20, the content rate of a resin component is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, and still more preferably 99% by mass or more. For example, the meaning that the resin contained in the film 20 contains polyester as a main component is that, among the resin components contained in the film 20, the content rate of polyester is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, and still more preferably 99% by mass or more.

[0146] When manufacturing the film 20 of the present embodiment, a resin film formed in advance may be used as the film 20. In addition, the resin for forming the film 20 can be formed into a film by extrusion molding, coating, etc., and the resin formed from the resin film is used.

[0147] In the present embodiment, the resin contained in the film 20 may contain an elastomer. The elastomer serves to improve the flexibility of the film 20 while ensuring its durability in a high-temperature environment. As a preferred elastomer, at least one or more thermoplastic elastomers selected from polyester-based, polyamide-based, polyurethane-based, polyolefin-based, polystyrene-based, and polyether-based elastomers, or a thermoplastic elastomer that is a copolymer thereof, etc. can be cited. In the film 20, the content of the elastomer is not particularly limited as long as it can improve the flexibility of the film 20 while ensuring its durability in a high-temperature environment. For example, it is about 0.1% by mass or more, preferably about 0.5% by mass or more, more preferably about 1.0% by mass or more, and further preferably about 3.0% by mass or more. In addition, the content is, for example, about 10.0% by mass or less, about 8.0% by mass or less, about 5.0% by mass or less, etc. As a preferred range of this content, 0.1 to 10.0% by mass, 0.1 to 8.0% by mass, 0.1 to 5.0% by mass, 0.5 to 10.0% by mass, 0.5 to 8.0% by mass, 0.5 to 5.0% by mass, 1.0 to 10.0% by mass, 1.0 to 8.0% by mass, 1.0 to 5.0% by mass, 3.0 to 10.0% by mass, 3.0 to 8.0% by mass, 3.0 to 5.0% by mass, etc. can be cited.

[0148] As the content rate of the resin contained in the film 20 in the first mode, for example, it is 99.9% by mass or more, preferably 99.5% by mass or more, and further preferably 99.0% by mass or more.

[0149] In addition, as the content rate of the resin contained in the film 20 in the second mode, for example, it is 50% by mass or more, preferably 55% by mass or more, and further preferably 60% by mass or more.

[0150] The water absorbent contained in the film 20 of the first mode is not particularly limited as long as it can be dispersed in the resin film to exhibit water absorption. For example, from the viewpoint of the stability over time in the electrical storage device 10, an inorganic water absorbent can be appropriately used. Preferred specific examples of the inorganic water absorbent include calcium oxide, anhydrous magnesium sulfate, magnesium oxide, calcium chloride, zeolite, alumina, silica gel, alumina gel, and burnt alum. Generally, among inorganic water absorbents, inorganic chemical water absorbents have a higher water absorption effect than inorganic physical water absorbents, can reduce the content, and it is easy to achieve sufficient water absorption and heat meltability with a single layer. Moreover, among inorganic chemical water absorbents, calcium oxide, anhydrous magnesium sulfate, and magnesium oxide are particularly preferred because they have less re-release of moisture, high stability over time in a low humidity state inside the package, and have a dry-out effect. Here, the dry-out effect refers to the effect of absorbing water until the relative humidity is near 0%, and the humidity control effect refers to the effect of absorbing water when the humidity is high, releasing water when the humidity is low, and keeping the humidity constant. In addition, for example, in the case of use in a high-temperature environment such as for all-solid-state batteries, an inorganic chemical absorbent with a high temperature range for re-releasing moisture is preferred.

[0151] In the first mode, as the resin contained in the water absorption layer, the same resins as those exemplified for the resin contained in the film 20 can be exemplified.

[0152] In addition, in the first mode, the content rate of the resin contained in the water absorption layer of the film 20 is, for example, 50% by mass or more, preferably 55% by mass or more, and more preferably 60% by mass or more.

[0153] In the first mode, the content of the water absorbent contained in the film 20 is not particularly limited as long as the effects of the present embodiment can be obtained. With respect to 100 parts by mass of the resin contained in the film 20, it is preferably about 0.5 parts by mass or more, more preferably about 2 parts by mass or more, and further preferably about 3 parts by mass or more. In addition, it is preferably about 50 parts by mass or less, more preferably about 45 parts by mass or less, and further preferably 40 parts by mass or less. As the preferred range of this content, it is possible to list about 0.5 to 50 parts by mass, about 0.5 to 45 parts by mass, about 0.5 to 40 parts by mass, about 2 to 50 parts by mass, about 2 to 45 parts by mass, about 2 to 40 parts by mass, about 3 to 50 parts by mass, about 3 to 45 parts by mass, about 3 to 40 parts by mass. In addition, the content of the water absorbent contained in the water absorption layer of the film 20 is not particularly limited as long as the effects of the present embodiment can be exerted. With respect to 100 parts by mass of the resin contained in the water absorption layer, it is preferably about 0.5 parts by mass or more, more preferably about 2 parts by mass or more, and further preferably about 3 parts by mass or more. In addition, it is preferably about 50 parts by mass or less, more preferably about 45 parts by mass or less, and further preferably 40 parts by mass or less. As the preferred range of this content, it is possible to list about 0.5 to 50 parts by mass, about 0.5 to 45 parts by mass, about 0.5 to 40 parts by mass, about 2 to 50 parts by mass, about 2 to 45 parts by mass, about 2 to 40 parts by mass, about 3 to 50 parts by mass, about 3 to 45 parts by mass, about 3 to 40 parts by mass.

[0154] In the film 20 of the first mode, the water absorbent contained in the water absorption layer is preferably contained, for example, via a masterbatch obtained by melt-mixing the water absorbent and the resin. Specifically, the water absorbent is melt-mixed with the resin at a relatively high concentration to prepare a masterbatch. The obtained masterbatch is further mixed with the resin and formed into a film shape, whereby a water absorption layer can be formed. The content of the water absorbent in the masterbatch is preferably about 20 to 90% by mass, more preferably about 30 to 70% by mass. If it is within the above range, it is possible to easily contain the water absorbent in a state where the water absorbent is dispersed in the water absorption layer in a necessary and sufficient amount.

[0155] In addition, as described above, the film 20 of the first mode may further contain a chalcogen gas absorbent in addition to the water absorbent. The chalcogen gas absorbent preferably contains a chalcogen gas physical absorbent and / or a chalcogen gas chemical absorbent. By using various chalcogen gas absorbents simultaneously, for example, using a chalcogen gas physical absorbent and a chalcogen gas chemical absorbent simultaneously, it is possible to easily absorb a variety of chalcogen gases. The chalcogen gas absorbent is used, for example, in powder form. The maximum particle size of the chalcogen gas absorbent is preferably 20 μm or less, and the number average particle size of the powder is preferably 0.1 μm or more and 15 μm or less. When the number average particle size is less than the above range, the chalcogen gas absorbent is likely to aggregate, and when the number average particle size is greater than the above range, the homogeneity of the chalcogen gas absorption film may deteriorate, and the surface area of the chalcogen gas absorbent becomes smaller, so there is a problem of deterioration of chalcogen gas absorption.

[0156] (Chalcogen gas physical absorbent)

[0157] The chalcogen gas physical absorbent is a gas absorbent having the function of physically absorbing the chalcogen gas to be absorbed. The chalcogen gas physical absorbent preferably contains SiO 2 / Al 2 O 3 having a molar ratio of 1 / 1 to 2000 / 1 and being one or more selected from hydrophobic zeolite, bentonite, and sepiolite.

[0158] Hydrophobic zeolite is a zeolite having excellent absorbability for molecules with low polarity such as chalcogen gases and having a porous structure. Generally, for zeolite, the higher the molar ratio of SiO 2 / Al 2 O 3 , the higher the hydrophobicity. Moreover, due to the increase in hydrophobicity, it becomes easy to absorb molecules with low polarity such as chalcogen gases. On the contrary, the affinity with molecules with high polarity such as water becomes low, and it is difficult to absorb them. The SiO 2 / Al 2 O 3 molar ratio of the hydrophobic zeolite is preferably 30 / 1 to 10000 / 1, more preferably 35 / 1 to 9000 / 1, and still more preferably 40 / 1 to 8500 / 1. In addition, the hydrophobic zeolite has high heat resistance and can maintain the absorption effect even when exposed to a high temperature of 230 °C or higher. In the present invention, from the balance between chalcogen gas absorption performance and ease of availability, a hydrophobic zeolite having a molar ratio within the above range is preferably used.

[0159] Bentonite is an inorganic substance mainly composed of montmorillonite as a clay mineral, containing a large amount of layered aluminum silicate, and containing minerals such as quartz and feldspar as impurities. Bentonite includes, for example: Na-type bentonite containing a large amount of Na + ions, Ca-type bentonite containing a large amount of Ca 2+Ca-type bentonite of ions, activated bentonite obtained by artificially converting Ca-type bentonite to Na-type by adding several wt% of sodium carbonate, etc.

[0160] Sepiolite is a clay mineral mainly composed of hydrated magnesium silicate. The general chemical composition is represented by Mg 8 Si 12 O 30 (OH 2 ) 4 (OH) 4 ·6 - 8H 2 O, and has a porous structure. The pH (3% suspension), from the aspect of ease of acquisition, is preferably 8.0 - 9.0, more preferably 8.9 - 9.3.

[0161] (Sulfur-based gas chemical absorbent)

[0162] A sulfur-based gas chemical absorbent is a gas absorbent that has the function of chemically absorbing or decomposing the sulfur-based gas of the gas to be absorbed. Moreover, through chemical absorption or decomposition, it is not easily affected by water, etc., and once the absorbed sulfur-based gas molecules are not easily detached, and absorption can be carried out efficiently. In addition, the decomposition products are absorbed by a sulfur-based gas physical absorbent or a sulfur-based gas chemical absorbent. The sulfur-based gas chemical absorbent preferably contains one or more selected from inorganic substances loaded with metal oxides, glasses mixed with metals, and glasses mixed with metal ions. The metal oxide in the inorganic substance loaded with the metal oxide preferably contains one or more selected from CuO, ZnO, AgO. In addition, the inorganic substance for loading is preferably an inorganic porous body such as zeolite. The metal species of the metal in the glass mixed with the metal or the metal ions in the glass mixed with the metal ions preferably includes one or more selected from Ca, Mg, Na, Cu, Zn, Ag, Pt, Au, Fe, Al, Ni.

[0163] In the first mode, the content of the chalcogen gas absorbent in the film 20 is not particularly limited as long as it can absorb chalcogen gas. Relative to 100 parts by mass of the resin contained in the film 20, it is preferably about 0.1 part by mass or more, more preferably about 0.2 part by mass or more, and further preferably about 0.3 part by mass or more. In addition, it is preferably about 30 parts by mass or less, more preferably about 27 parts by mass or less, and further preferably 25 parts by mass or less. As the preferred range of this content, about 0.1 to 30 parts by mass, about 0.1 to 27 parts by mass, about 0.1 to 25 parts by mass, about 0.2 to 30 parts by mass, about 0.2 to 27 parts by mass, about 0.2 to 25 parts by mass, about 0.3 to 30 parts by mass, about 0.3 to 27 parts by mass, and about 0.3 to 25 parts by mass can be cited. In addition, the content of the chalcogen gas absorbent contained in the chalcogen gas absorption layer of the film 20 is not particularly limited as long as it can absorb chalcogen gas. Relative to 100 parts by mass of the resin contained in the chalcogen gas absorption layer, it is preferably about 5 parts by mass or more, more preferably about 6 parts by mass or more, and further preferably about 7 parts by mass or more. In addition, it is preferably about 60 parts by mass or less, more preferably about 55 parts by mass or less, further preferably about 50 parts by mass or less, and about 30 parts by mass or less. As the preferred range of this content, about 5 to 60 parts by mass, about 5 to 55 parts by mass, about 5 to 50 parts by mass, about 5 to 30 parts by mass, about 6 to 60 parts by mass, about 6 to 55 parts by mass, about 6 to 50 parts by mass, about 6 to 30 parts by mass, about 7 to 60 parts by mass, about 7 to 55 parts by mass, about 7 to 50 parts by mass, and about 7 to 30 parts by mass can be cited.

[0164] In the first mode, the content rate of the resin contained in the chalcogen gas absorption layer is, for example, 50% by mass or more, preferably 55% by mass or more, and further preferably 60% by mass or more.

[0165] In the first mode, the chalcogen gas absorbent contained in the chalcogen gas absorption layer is preferably contained via a masterbatch obtained by melt-mixing the chalcogen gas absorbent and the resin. Specifically, it is preferable to adjust the masterbatch by melt-mixing the chalcogen gas absorbent with the resin at a relatively high concentration, and then dry-mix the masterbatch with other components so as to achieve the required concentration in the chalcogen gas absorption layer for use. Each of the chalcogen gas absorbent and the resin to be melt-mixed can be one type or two or more types. The content of the chalcogen gas absorbent in the masterbatch is preferably about 20 to 90% by mass, more preferably about 30 to 70% by mass. If it is within the above range, it is possible to easily contain a necessary and sufficient amount of the chalcogen gas absorbent in a state dispersed in the chalcogen gas absorption layer.

[0166] In the first mode, as the resin contained in the chalcogen gas absorbent layer, the same resin as the resin exemplified as the resin contained in the water absorbent layer can be exemplified.

[0167] As described above, when the chalcogen gas absorbent is contained in the film 20 of the first mode, the chalcogen gas absorbent can be contained in the water absorbent layer or in a layer that does not contain a water absorbent. When the chalcogen gas absorbent is contained in the water absorbent layer, the water absorbent layer also functions as a chalcogen gas absorbent layer.

[0168] The film 20 of the first mode can contain various plastic compounding agents, additives, etc. for the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, smoothness, mold release properties, flame retardancy, antifungal properties, electrical properties, strength, etc. As its content, it can be arbitrarily contained from a very small amount to several tens of %, depending on the purpose. Among the above, as general additives, for example, an anti-blocking agent, a lubricant, a crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a pigment, a resin for modification, etc. can be contained.

[0169] The thickness of the film 20 of the first mode is not particularly limited as long as the effects of the present invention can be obtained. It is preferably about 10 μm or more, more preferably about 15 μm or more, and further preferably about 20 μm or more. In addition, it is preferably about 1000 μm or less, more preferably about 900 μm or less, and further preferably about 500 μm or less. As the preferred range of this thickness, 10 to 1000 μm, 10 to 900 μm, 10 to 500 μm, 15 to 1000 μm, 15 to 900 μm, 15 to 500 μm, 20 to 1000 μm, 20 to 900 μm, 20 to 500 μm can be cited.

[0170] In addition, in the first mode, when the film 20 is composed of two or more layers, the thickness of the film 20 may be as described above for each layer. For example, regarding the thickness of the water absorption layer, it is preferably about 5 μm or more, more preferably about 6 μm or more, and further preferably about 7 μm or more. In addition, it is preferably about 500 μm or less, more preferably about 400 μm or less, and further preferably about 300 μm or less. As the preferred range of this thickness, values such as about 5 to 500 μm, about 5 to 400 μm, about 5 to 300 μm, about 6 to 500 μm, about 6 to 400 μm, about 6 to 300 μm, about 7 to 500 μm, about 7 to 400 μm, and about 7 to 300 μm can be cited. In addition, regarding the thickness of the chalcogenide gas absorption layer, it is preferably about 5 μm or more, more preferably about 7 μm or more, and further preferably about 10 μm or more. In addition, it is preferably about 500 μm or less, more preferably about 400 μm or less, and further preferably about 300 μm or less. As the preferred range of this thickness, values such as about 5 to 500 μm, about 5 to 400 μm, about 5 to 300 μm, about 7 to 500 μm, about 7 to 400 μm, about 7 to 300 μm, about 10 to 500 μm, about 10 to 400 μm, and about 10 to 300 μm can be cited.

[0171] In addition, in the second mode, the chalcogenide gas absorbent preferably contains a chalcogenide gas physical absorbent and / or a chalcogenide gas chemical absorbent. By using various chalcogenide gas absorbents simultaneously, for example, by using a chalcogenide gas physical absorbent and a chalcogenide gas chemical absorbent simultaneously, it is possible to easily absorb a variety of chalcogenide gases. The chalcogenide gas absorbent is used, for example, in powder form. The maximum particle size of the chalcogenide gas absorbent is preferably 20 μm or less, and the number average particle size of the powder is preferably 0.1 μm or more, 1.0 μm or more, etc. In addition, it is preferably 15 μm or less, 10 μm or less, 8 μm or less, etc. As the preferred range, values such as about 0.1 to 15 μm, about 0.1 to 10 μm, about 0.1 to 8 μm, about 1 to 15 μm, about 1 to 10 μm, and about 1 to 8 μm can be cited. When the number average particle size is less than the above range, the chalcogenide gas absorbent is likely to aggregate, and when the number average particle size is greater than the above range, the homogeneity of the chalcogenide gas absorption film may deteriorate, and the surface area of the chalcogenide gas absorbent becomes smaller, so the chalcogenide gas absorption may deteriorate.

[0172] (Chalcogenide gas physical absorbent)

[0173] The chalcogenide gas physical absorbent is a gas absorbent that has the function of physically absorbing the chalcogenide gas to be absorbed. The chalcogenide gas physical absorbent preferably contains SiO 2 / Al 2 O 3One or more selected from hydrophobic zeolite, bentonite, and sepiolite with a molar ratio of 1 / 1 to 2000 / 1.

[0174] Specific examples of hydrophobic zeolite, bentonite, and sepiolite are omitted as described in the first mode.

[0175] (Sulfur-based gas chemical absorbent)

[0176] The sulfur-based gas chemical absorbent is omitted as described in the first mode.

[0177] As the resin contained in the sulfur-based gas absorption layer, the same resins as those exemplified for the resin contained in the film 20 can be exemplified.

[0178] In the second mode, the content of the sulfur-based gas absorbent in the film 20 is not particularly limited as long as it can absorb sulfur-based gases. Per 100 parts by mass of the resin contained in the film 20, it is preferably about 0.1 part by mass or more, more preferably about 0.2 part by mass or more, and further preferably about 0.3 part by mass or more. In addition, it is preferably about 30 parts by mass or less, more preferably about 29 parts by mass or less, and further preferably 28 parts by mass or less. As the preferred range of this content, 0.1 to 30 parts by mass, 0.1 to 29 parts by mass, 0.1 to 28 parts by mass, 0.2 to 30 parts by mass, 0.2 to 29 parts by mass, 0.2 to 28 parts by mass, 0.3 to 30 parts by mass, 0.3 to 29 parts by mass, 0.3 to 28 parts by mass can be cited. In addition, the content of the sulfur-based gas absorbent contained in the sulfur-based gas absorption layer of the film 20 is not particularly limited as long as it can absorb sulfur-based gases. Per 100 parts by mass of the resin contained in the sulfur-based gas absorption layer, it is preferably about 5 parts by mass or more, more preferably about 6 parts by mass or more, and further preferably about 7 parts by mass or more. In addition, it is preferably about 60 parts by mass or less, more preferably about 55 parts by mass or less, further preferably about 50 parts by mass or less, and further preferably about 30 parts by mass or less. As the preferred range of this content, 5 to 60 parts by mass, 5 to 55 parts by mass, 5 to 50 parts by mass, 5 to 30 parts by mass, 6 to 60 parts by mass, 6 to 55 parts by mass, 6 to 50 parts by mass, 6 to 30 parts by mass, 7 to 60 parts by mass, 7 to 55 parts by mass, 7 to 50 parts by mass, 7 to 30 parts by mass can be cited.

[0179] In the second mode, the content ratio of the resin contained in the sulfur-based gas absorption layer is, for example, 40% by mass or more, preferably 45% by mass or more, and further preferably 50% by mass or more.

[0180] In the second mode, the chalcogen gas absorbent contained in the chalcogen gas absorption layer is preferably contained via a masterbatch obtained by melt-mixing the chalcogen gas absorbent and a resin. Specifically, it is preferable to adjust the masterbatch by melt-mixing the chalcogen gas absorbent and the resin at a relatively high concentration, and then dry-mix the masterbatch with other components so as to achieve the required concentration in the chalcogen gas absorption layer for use. Each of the chalcogen gas absorbent and the resin to be melt-mixed may be one type or two or more types. The content of the chalcogen gas absorbent in the masterbatch is preferably about 20 to 90% by mass, more preferably about 30 to 70% by mass. If it is within the above range, it is possible to easily contain a necessary and sufficient amount of the chalcogen gas absorbent in a state of being dispersed in the chalcogen gas absorption layer.

[0181] In addition, as described above, in the second mode, the film 20 may further contain a water absorbent in addition to the chalcogen gas absorbent. The water absorbent contained in the film 20 is not particularly limited as long as it can be dispersed in the resin film to exhibit water absorption. For example, from the viewpoint of the stability over time in the electrical storage device 10, an inorganic water absorbent can be appropriately used. Preferred specific examples of the inorganic water absorbent include calcium oxide, anhydrous magnesium sulfate, magnesium oxide, calcium chloride, zeolite, alumina, silica gel, alumina gel, and burnt alum. Generally, among inorganic water absorbents, inorganic chemical water absorbents have a higher water absorption effect than inorganic physical water absorbents, can reduce the content, and it is easy to achieve sufficient water absorption and heat weldability with a single layer. Moreover, among inorganic chemical water absorbents, calcium oxide, anhydrous magnesium sulfate, and magnesium oxide are particularly preferred because they have little re-release of moisture, high stability over time in a low humidity state in the package, and have a dry-out effect. Among them, the dry-out effect means the effect of absorbing water until the relative humidity becomes near 0%, and the humidity control effect means the effect of absorbing water at high humidity and releasing water at low humidity to keep the humidity constant. In addition, for example, in the case of use in a high-temperature environment such as for all-solid-state batteries, an inorganic chemical absorbent with a high temperature region for re-releasing moisture is preferred.

[0182] In the second mode, the content of the water absorbent contained in the film 20 is not particularly limited as long as the effects of the present embodiment can be obtained. Relative to 100 parts by mass of the resin contained in the film 20, it is preferably about 0.5 parts by mass or more, more preferably about 2 parts by mass or more, and further preferably about 3 parts by mass or more. In addition, it is preferably about 50 parts by mass or less, more preferably about 45 parts by mass or less, and further preferably 40 parts by mass or less. As the preferred range of this content, about 0.5 to 50 parts by mass, about 0.5 to 45 parts by mass, about 0.5 to 40 parts by mass, about 2 to 50 parts by mass, about 2 to 45 parts by mass, about 2 to 40 parts by mass, about 3 to 50 parts by mass, about 3 to 45 parts by mass, about 3 to 40 parts by mass can be cited. In addition, the content of the water absorbent contained in the water absorption layer of the film 20 is not particularly limited as long as the effects of the present embodiment can be obtained. Relative to 100 parts by mass of the resin contained in the water absorption layer, it is preferably about 0.5 parts by mass or more, more preferably about 2 parts by mass or more, and further preferably about 3 parts by mass or more. In addition, it is preferably about 50 parts by mass or less, more preferably about 45 parts by mass or less, and further preferably 40 parts by mass or less. As the preferred range of this content, about 0.5 to 50 parts by mass, about 0.5 to 45 parts by mass, about 0.5 to 40 parts by mass, about 2 to 50 parts by mass, about 2 to 45 parts by mass, about 2 to 40 parts by mass, about 3 to 50 parts by mass, about 3 to 45 parts by mass, about 3 to 40 parts by mass can be cited.

[0183] In the film 20 of the second mode, the water absorbent contained in the water absorption layer is preferably contained, for example, via a masterbatch obtained by melt-mixing the water absorbent and the resin. Specifically, the water absorbent is melt-mixed with the resin at a relatively high concentration to prepare a masterbatch. The obtained masterbatch is further mixed with the resin, and the water absorption layer is formed by shaping it into a film. The content of the water absorbent in the masterbatch is preferably about 20 to 90% by mass, more preferably about 30 to 70% by mass. If it is within the above range, a necessary and sufficient amount of the water absorbent can be easily contained in a state of being dispersed in the water absorption layer.

[0184] In the second mode, as the resin contained in the water absorption layer, the same resins as those exemplified as the resins contained in the film 20 can be cited.

[0185] In addition, in the second mode, the content rate of the resin contained in the water absorption layer of the film 20 is, for example, 50% by mass or more, preferably 55% by mass or more, and further preferably 60% by mass or more.

[0186] As described above, when the water absorbent is included in the film 20 of the second mode, the water absorbent may be included in the chalcogen gas absorption layer or in a layer that does not contain a chalcogen gas absorbent. When the water absorbent is included in the chalcogen gas absorption layer, the chalcogen gas absorption layer also functions as a water absorption layer.

[0187] In the second mode, the film 20 can contain various plastic compounding agents, additives, etc. for the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, smoothness, mold release properties, flame retardancy, anti-mold properties, electrical characteristics, strength, etc. As its content, it can be contained arbitrarily from a very small amount to several tens of %, according to its purpose. Among the above, as common additives, for example, an anti-blocking agent, a lubricant, a crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a pigment, a resin for modification, etc. can be contained.

[0188] In the second mode, the thickness of the film 20 is not particularly limited as long as the effects of the present invention can be obtained. It is preferably about 25 μm or more, more preferably about 30 μm or more, and further preferably about 40 μm or more. In addition, it is preferably about 250 μm or less, more preferably about 240 μm or less, and further preferably about 230 μm or less. As the preferred range of this thickness, about 25 - 250 μm, about 25 - 240 μm, about 25 - 230 μm, about 30 - 250 μm, about 30 - 240 μm, about 30 - 230 μm, about 40 - 250 μm, about 40 - 240 μm, about 40 - 230 μm can be cited.

[0189] In addition, in the second mode, when the film 20 is composed of two or more layers, the thickness of the film 20 may be the above-mentioned thickness as the thickness of each layer. For example, regarding the thickness of the chalcogen-based gas absorption layer, it is preferably about 10 μm or more, more preferably about 15 μm or more, and further preferably about 20 μm or more. In addition, for example, it is about 100 μm or less, preferably about 95 μm or less, more preferably about 90 μm or less, and further preferably about 85 μm or less. As the preferred range of this thickness, values such as about 10 - 100 μm, about 10 - 95 μm, about 10 - 90 μm, about 10 - 85 μm, about 15 - 100 μm, about 15 - 95 μm, about 15 - 90 μm, about 15 - 85 μm, about 20 - 100 μm, about 20 - 95 μm, about 20 - 90 μm, and about 20 - 85 μm can be cited. In addition, regarding the thickness of the water absorption layer, it is preferably about 5 μm or more, more preferably about 6 μm or more, and further preferably about 7 μm or more. In addition, it is preferably about 60 μm or less, more preferably about 55 μm or less, and further preferably about 50 μm or less. As the preferred range of this thickness, values such as about 5 - 60 μm, about 5 - 55 μm, about 5 - 50 μm, about 6 - 60 μm, about 6 - 55 μm, about 6 - 50 μm, about 7 - 60 μm, about 7 - 55 μm, and about 7 - 50 μm can be cited.

[0190] (Method for manufacturing the film 20)

[0191] In the present embodiment, the method for manufacturing the film 20 is not particularly limited as long as the film 20 can be obtained, and known or conventional film formation methods and lamination methods can be applied. The manufacturing of the film 20 can be carried out, for example, by using known film formation methods such as the extrusion method, co-extrusion method, casting method, T-die method, cutting method, and blow molding method and / or lamination methods. When the film 20 is composed of two or more layers, for example, the films constituting each layer prepared in advance can be laminated via an adhesive layer, the molten resin composition can be laminated on the previously prepared layer by extrusion or co-extrusion, multiple layers can be laminated simultaneously by melt bonding while being formed, or one or two or more kinds of resins can be coated and dried on other layers.

[0192] In the first mode, the layers constituting the film 20 such as the water absorption layer (chalcogen-based gas absorption layer) can be extruded or co-extruded, laminated by the extrusion coating method, or laminated via an adhesive layer after film formation by the blow molding method or casting method. In the case of using the extrusion coating method, lamination via an adhesive layer can also be carried out as needed. Alternatively, the film for the water absorption layer (or chalcogen-based gas absorption layer) prepared in advance can be laminated and bonded via the laminated adhesive layer by the extrusion coating method, dry lamination method, non-solvent composite lamination method, etc. Moreover, aging treatment can be carried out as needed.

[0193] In the first method, for example, when laminating a water-absorbing layer or the like using the extrusion coating method, first, the resin composition for forming the layer such as the water-absorbing layer is heated to be melted, and is stretched and enlarged in the required width direction using a T-die and extruded or co-extruded in a curtain shape, and the molten resin is allowed to flow downward on the surface to be laminated, and is clamped by a rubber roll and a cooled metal roll. Thus, it is possible to simultaneously form the layer such as the water-absorbing layer and laminate and bond it to the surface to be laminated. The melt flow rate (MFR) of the resin component contained in each layer in the case of laminating using the extrusion coating method is preferably 0.2 to 50 g / 10 minutes, more preferably 0.5 to 30 g / 10 minutes. When the MFR is smaller or larger than the above range, the processability is likely to deteriorate. In addition, in this specification, the MFR is a value measured according to the method conforming to JIS K7210.

[0194] In the first method, the melt flow rate (MFR) of the resin component contained in each layer in the case of using the inflation method is preferably 0.2 to 10 g / 10 minutes, more preferably 0.2 to 9.5 g / 10 minutes. When the MFR is smaller or larger than the above range, the processability is likely to deteriorate.

[0195] In the second method, it is possible to extrude or co-extrude the layer constituting the sulfur-based gas absorption layer (water-absorbing layer) or the like, laminate using the extrusion coating method, or laminate via an adhesive layer after film formation using the inflation method or the casting method. In the case of adopting the extrusion coating method, it is also possible to laminate via an adhesive layer as needed. Alternatively, a film for the sulfur-based gas absorption layer (or water-absorbing layer) that has been preformed can be laminated and bonded via the laminated adhesive layer using the extrusion coating method, the dry lamination method, the non-solvent composite lamination method, or the like. Moreover, an aging treatment can be performed as needed.

[0196] In the second method, for example, when laminating the sulfur-based gas absorption layer or the like using the extrusion coating method, first, the resin composition for forming the layer such as the sulfur-based gas absorption layer is heated to be melted, and is stretched and enlarged in the required width direction using a T-die and extruded or co-extruded in a curtain shape, and the molten resin is allowed to flow downward on the surface to be laminated, and is clamped by a rubber roll and a cooled metal roll. Thus, it is possible to simultaneously form the layer such as the sulfur-based gas absorption layer and laminate and bond it to the surface to be laminated. The melt flow rate (MFR) of the resin component contained in each layer in the case of laminating using the extrusion coating method is preferably 0.2 to 50 g / 10 minutes, more preferably 0.5 to 30 g / 10 minutes. When the MFR is smaller or larger than the above range, the processability is likely to deteriorate. In addition, in this specification, the MFR is a value measured according to the method conforming to JIS K7210.

[0197] Also in the second method, when the blow molding method is used, the melt flow rate (MFR) of the resin component contained in each layer is preferably 0.2 to 10 g / 10 minutes, more preferably 0.2 to 9.5 g / 10 minutes. When the MFR is smaller or larger than the above range, the processability is likely to deteriorate.

[0198] In addition, in the present embodiment, between the respective layers constituting the film 20, in order to improve the adhesiveness, the surfaces of the respective layers may be subjected to a desired surface treatment in advance as needed. For example, pretreatment such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen or nitrogen, glow discharge treatment, oxidation treatment using chemicals, etc. may be arbitrarily performed to form a corona treatment layer, an ozone treatment layer, a plasma treatment layer, an oxidation treatment layer, etc. Alternatively, various coating agent layers such as a primer layer, an intermediate coating agent layer, a top coating agent layer, an adhesive layer, and an evaporated top coating agent layer may be arbitrarily formed on the surface as a surface treatment layer. In the above various coating agent layers, for example, a resin composition having a main component using a polyester resin, a polyamide resin, a polyurethane resin, an epoxy resin, a phenolic resin, a (meth)acrylic resin, a polyvinyl acetate resin, a polyolefin resin such as polyethylene or polypropylene or a copolymer or modified resin thereof, a cellulose resin, etc. as a carrier can be used.

[0199] In the present embodiment, each layer constituting the film 20 may be further uniaxially or biaxially stretched by a known method using a tenter frame method, a tube frame method, etc. as needed.

[0200] <1-3. Manufacturing method of electrical storage device>

[0201] Figure 8 It is a flowchart showing the manufacturing sequence of the electrical storage device 10. Figure 8 The processes shown are performed, for example, by a manufacturing apparatus for the electrical storage device 10.

[0202] The manufacturing apparatus winds the exterior member 101 around the electrode body 200 (step S100). The manufacturing apparatus forms the first seal portion 110 by heat-sealing the opposing surfaces (heat-sealable resin layers) of the exterior member 101 to each other (step S110). Thus, Figure 4 、 Figure 5 the shown unfinished product is prepared.

[0203] The manufacturing apparatus bends the first seal portion 110 so that the first seal portion 110 contacts the second surface 140 (step S120). The manufacturing apparatus folds the exterior member 101 in a state of accommodating the electrode body 200, and forms the second seal portion 120 by heat-sealing the opposing surfaces (heat-sealable resin layers) of the exterior member 101 to each other (step S130). Thus, the electrical storage device 10 is completed.

[0204] <1-4. Features>

[0205] The electrical storage device 10 with the film 20 in the first mode, since the film 20 contains a water absorbent, absorbs water through the film 20 and retains the water infiltrated from the heat-sealable resin layer 101C of the exterior member 101, and can suppress the water from reaching the electrode body 200. The electrical storage device 10 with the film 20 in the second mode, since the film 20 contains a chalcogenide gas absorbent, can absorb hydrogen sulfide generated from the electrode body 200 by using the film 20. Therefore, an excessive increase in the internal pressure of the exterior body 100 can be suppressed.

[0206] In addition, in the electrical storage device 10 of the first embodiment, the first sealing portion 110 is bent toward the second surface 140 with a smaller area. That is, the first sealing portion 110 does not exist on the first surface 130 with a larger area. Therefore, even if another electrical storage device 10 is placed on the first surface 130, the other electrical storage device 10 does not tilt. As a result, according to the electrical storage device 10, uneven distribution of the pressure applied to the lower electrical storage device 10 when a plurality of electrical storage devices 10 are stacked can be suppressed. In addition, in the case of being used for an all-solid-state battery, since it is necessary to uniformly apply a high pressure from the battery outer surface to exhibit battery performance, the packaging method of the present invention is preferable. In addition, in the electrical storage device 10, the base portion of the first sealing portion 110 is located on the edge 135 of the exterior body 100. Therefore, according to the electrical storage device 10, when the first sealing portion 110 is located on the second surface 140, a wider bonding margin of the first sealing portion 110 can be ensured compared with the case where the base portion of the first sealing portion 110 is located on the second surface 140.

[0207] [2. Second Embodiment]

[0208] In the electrical storage device 10 of the first embodiment, the second sealing portion 120 is formed by heat-sealing the opposing surfaces of the exterior member 101 by folding the exterior member 101. However, the shape and formation method of the second sealing portion 120 are not limited thereto. Hereinafter, the description will be centered on the parts different from the first embodiment, and the description of the parts common to the first embodiment will be omitted.

[0209] <2-1. Structure of Electrical Storage Device>

[0210] Figure 9 is a schematic plan view showing the electrical storage device 10X of the second embodiment. Figure 10 is a schematic side view showing the electrical storage device 10X. Figure 11 is a schematic perspective view showing the lid body 400.

[0211] Refer to Figure 9 、 Figure 10 and Figure 11, the exterior body 100X is formed by inserting the cover body 400 into each of the openings at both ends of the exterior member 101 wound around the electrode body 200. In the state where the cover body 400 is inserted, the second sealing portion 120X is formed by heat-sealing the exterior member 101 and the cover body 400.

[0212] The lid body 400 is a bottomed tray-shaped component that is rectangular when viewed from above. For example, it is formed by cold-forming the exterior component 101. Here, the lid body 400 does not necessarily have to be composed of the exterior component 101, and it can also be a metal-formed product or a resin-formed product. That is, the material constituting the lid body 400 can include at least one of a resin material and a metal material. For example, the lid body 400 can also have: a main body portion composed of a metal material; and a covering body that covers a part of the main body portion and is composed of a resin material. The covering body can be a frame-shaped object made of a resin-formed product or an adhesive film suitable for bonding to both the metal material and the resin material. The main body portion is preferably joined to the exterior component 101 via the covering body. In the electrical storage device 10X, the lid body 400 is arranged such that the bottom surface side of the lid body 400 is located inside the exterior body 100X. Here, in the electrical storage device 10X, the bottom surface side of the lid body 400 does not necessarily have to be located inside the exterior body 100X. In the electrical storage device 10X, it is also possible that the bottom surface side of the lid body 400 is located outside the exterior body 100X. In the case where the lid body 400 is a metal-formed product or a resin-formed product, the material constituting the lid body 400 preferably has a certain thickness so that even when the electrical storage devices 10X are arranged in an overlapping manner, deformation of the exterior body 100X can be suppressed. The minimum value of the thickness of the material constituting the lid body 400 is, for example, 1.0 mm, more preferably 3 mm, and further preferably 4 mm. The maximum value of the thickness of the material constituting the lid body 400 is, for example, 10 mm, more preferably 8.0 mm, and further preferably 7.0 mm. The maximum value of the thickness of the material constituting the lid body 400 can also be 10 mm or more. The preferred range of the thickness of the material constituting the lid body 400 is 1.0 mm to 10 mm, 1.0 mm to 8.0 mm, 1.0 mm to 7.0 mm, 3.0 mm to 10 mm, 3.0 mm to 8.0 mm, 3.0 mm to 7.0 mm, 4.0 mm to 10 mm, 4.0 mm to 8.0 mm, 4.0 mm to 7.0 mm. In this specification, when the lid body 400 is described as a metal-formed product or a resin-formed product, the material constituting the lid body 400 does not include a film. A film refers to, for example, a film-like article made of plastic with a thickness less than 250 μm as defined by the "Packaging Terms" standard of JIS (Japanese Industrial Standards). Here, the thickness of the material constituting the lid body 400 can vary depending on the part of the lid body 400. When the thickness of the material constituting the lid body 400 varies depending on the part of the lid body 400, the thickness of the material constituting the lid body 400 is the thickness of the thickest part.

[0213] In addition, in a state where the electrode body 200 is housed, the electrode terminal 300 protrudes to the outside of the exterior body 100X through between the lid body 400 and the exterior member 101. That is, the lid body 400 and the exterior member 101 are heat-sealed in a state of sandwiching the electrode terminal 300. Among them, in the electrical storage device 10X, the position where the electrode terminal 300 protrudes to the outside does not necessarily have to be between the lid body 400 and the exterior member 101. For example, the electrode terminal 300 may also protrude to the outside from a hole formed in any one of the six surfaces of the exterior body 100X. In this case, a minute gap between the exterior body 100X and the electrode terminal 300 is filled with, for example, resin.

[0214] In addition, in the electrical storage device 10X, the lid body 400 and the electrode terminal 300 are provided separately. However, the lid body 400 and the electrode terminal 300 do not necessarily have to be provided separately. For example, the lid body 400 and the electrode terminal 300 may also be integrally formed.

[0215] Figure 12 It is a diagram showing a first example in which the lid body 400 and the electrode terminal 300 are integrally formed. As Figure 12 shown, in the first example, the electrode terminal 300 is pre-heat-sealed on the side surface of the lid body 400. In addition, for example, in a case where the lid body 400 is constituted by the exterior member 101, a bonding film that bonds both the metal and the resin described in the first embodiment may be disposed between the lid body 400 and the electrode terminal 300. When the bonding film is two or more layers, it is preferable to dispose a resin film made of a polyolefin-based resin on the side that joins the lid body 400. When the bonding film is two or more layers, it is preferable to dispose a resin film made of an acid-modified polyolefin-based resin obtained by graft-modifying a polyolefin-based resin with an acid such as maleic anhydride on the side that joins the electrode terminal 300.

[0216] Figure 13 It is a diagram showing a second example in which the lid body 400 and the electrode terminal 300 are integrally formed. As Figure 13 shown, in the second example, the electrode terminal 300 penetrates through a hole formed in the bottom surface portion of the lid body 400. A minute gap in the hole in the bottom surface of the lid body 400 is filled with, for example, resin.

[0217] In addition, in the electrical storage device 10X, a gas valve may also be installed in a hole formed in any one of the six surfaces of the second sealing portion 120X or the exterior body 100X. The gas valve is constituted by, for example, a check valve or a rupture valve, and is configured to be able to reduce the pressure when the pressure inside the exterior body 100X has risen due to gas generated inside the electrical storage device 10X.

[0218] <2-2. Manufacturing method of electrical storage device>

[0219] Figure 14It is a flowchart showing the manufacturing sequence of the electrical storage device 10X. Figure 14 The processes shown are performed, for example, by a manufacturing apparatus for the electrical storage device 10X.

[0220] The manufacturing apparatus winds the exterior member 101 around the electrode body 200 (step S200). The manufacturing apparatus forms the first seal portion 110 by heat-sealing the opposing surfaces (heat-sealable resin layers) of the exterior member 101 to each other (step S210). Thus, Figure 4 , Figure 5 the unfinished product shown is completed.

[0221] The manufacturing apparatus bends the first seal portion 110 so that the first seal portion 110 contacts the second surface 140 (step S220). The manufacturing apparatus houses the electrode body 200 in the unfinished product completed in step S220, and attaches the lid bodies 400 to the respective openings at both ends thereof (step S230). The manufacturing apparatus forms the second seal portion 120X by heat-sealing the exterior member 101 and the lid bodies 400 (step S240). Thus, the electrical storage device 10X is completed.

[0222] <2-3. Features>

[0223] Also in the electrical storage device 10X of the second embodiment, the first seal portion 110 is bent toward the second surface 140 with a smaller area. Therefore, according to the electrical storage device 10X, it is possible to suppress uneven distribution of the pressure applied to the lower electrical storage device 10X when a plurality of electrical storage devices 10X are stacked.

[0224] <2-4. Other Features>

[0225] Furthermore, in the electrical storage device 10X of the second embodiment, the first seal portion 110 does not necessarily have to be bent toward the second surface 140 with a smaller area. For example, the first seal portion 110 may also be bent toward the first surface 130 with a larger area. In addition, the base portion of the first seal portion 110 does not necessarily have to be located on the edge 135 of the exterior body 100X. The base portion of the first seal portion 110 may also be located, for example, on a surface of the exterior body 100X other than the lid body 400. Even in this case, the electrical storage device 10X of the second embodiment includes, for example, the features shown below.

[0226] The electrical storage device 10X includes an electrode body (electrode body 200) and an exterior body (exterior body 100X) that seals the electrode body (electrode body 200). The exterior body (exterior body 100X) is wound around the electrode body (electrode body 200) and includes an exterior member (exterior member 101) having openings formed at both ends and lid bodies (lid bodies 400) that seal the above openings.

[0227] In the electrical storage device 10X, the second sealing portion 120X (see FIG. 7) is not formed by heat-sealing the opposing surfaces of the exterior member 101 to each other as in the first embodiment. In the electrical storage device 10X, the opening of the exterior member 101 wound around the electrode body 200 is sealed by the lid body 400. That is, the second sealing portion 120X is formed at the overlapping portion of the lid body 400 and the exterior member 101 (see Figure 9 and Figure 10 ). With such a structure, by adjusting the depth L3 of the lid body 400 ( Figure 11 ), it is possible to easily narrow the area of the second sealing portion 120X.

[0228] In addition, in the electrical storage device 10X, at the positions of the corners C1 ( Figure 9 and Figure 10 ) of the electrode body 200 covered by the exterior member 101, an excessive load is not generated due to the corners C1 being punctured by the exterior member 101. As described above, this is because in the electrical storage device 10X, the second sealing portion 120X is not formed by heat-sealing the opposing surfaces of the exterior member 101 to each other as in the first embodiment.

[0229] In addition, the manufacturing order of the electrical storage device 10X is not limited to the order shown in the Figure 14 flowchart. For example, the electrical storage device 10X may also be manufactured in the order shown in the Figure 15 flowchart.

[0230] Figure 15 is a flowchart showing another manufacturing order of the electrical storage device 10X according to the second embodiment. Figure 15 The processes shown, for example, are performed by a manufacturing apparatus for the electrical storage device 10X. The manufacturing apparatus mounts a component in which the electrode terminal 300 and the lid body 400 are integrated (for example, the components shown in Figure 12 , 13 ) to the electrode body 200 (step S250). For example, the electrode terminal 300 is welded to the electrode body 200. After that, the manufacturing apparatus winds the exterior member 101 around the electrode body 200 (step S260). The manufacturing apparatus forms the first sealing portion 110 by heat-sealing the opposing surfaces (heat-fusible resin layers) of the exterior member 101 to each other, and forms the second sealing portion 120X by heat-sealing the exterior member 101 and the lid body 400 (step S270). Thus, the electrical storage device 10X is completed. The electrical storage device 10X may also be manufactured in such an order.

[0231] [3. Third Embodiment]

[0232] For the purpose of allowing the electrolyte to penetrate into the electrode body and the like in the battery manufacturing process, a step of aging a storage device in a temporarily sealed state in a specified temperature environment for a specified period of time (hereinafter referred to as the aging step) is usually performed. In the aging step, gas is generated from the electrode body 200, and this gas needs to be discharged to the outside of the battery. In the storage device 10X of the second embodiment, no mechanism is provided for releasing the gas generated in the aging step at the final stage of manufacturing the storage device 10X. In the storage device 10Y of the third embodiment, a mechanism is provided for releasing the gas generated from the electrode body 200 at the final stage of manufacturing the storage device 10Y. In addition, the following description will focus on the parts different from the second embodiment, and the description of the parts common to the second embodiment will be omitted.

[0233] <3-1. Structure of the storage device>

[0234] Figure 16 It is a view showing, from the side, the state in which the exterior member 101Y is wound around the electrode body 200 during the manufacturing process of the storage device 10Y. Figure 17 It is a view showing, from below, the state in which the exterior member 101Y is wound around the electrode body 200 and the lid body 400 is attached to the exterior member 101Y during the manufacturing process of the storage device 10Y.

[0235] As Figure 16 and Figure 17 shown, a sheet portion 150 is formed in a state where the exterior member 101Y is wound around the electrode body 200. The sheet portion 150 is formed by joining the opposing surfaces of the exterior member 101Y to each other in a state where the exterior member 101Y is wound around the electrode body 200. More specifically, the sheet portion 150 is formed by joining (heat-sealing) the peripheries of the opposing surfaces to each other in a state where the exterior member 101Y is wound around the electrode body 200. That is, in the sheet portion 150, a first sealing portion 154 is formed at the periphery.

[0236] In addition, a space 152 is formed in the sheet portion 150 where the opposing surfaces of the exterior member 101Y are not joined to each other. Near the edge 135, a joined region 151 where the opposing surfaces of the exterior member 101Y are joined to each other and an unjoined region 153 where the opposing surfaces of the exterior member 101Y are not joined to each other are alternately arranged. That is, in the sheet portion 150, a pattern of the joined region 151 is formed along the edge 135.

[0237] The gas generated from the electrode body 200 is discharged to the outside of the outer package 100Y by removing a part of the sheet portion 150 or the like to release the sealed state of the outer package 100Y. The gas discharged to the outside of the outer package 100Y here is not necessarily limited to the gas generated from the electrode body 200, and may also be a gas other than the gas generated from the electrode body 200, such as air, water vapor, or hydrogen sulfide.

[0238] After that, by heat-sealing in a strip shape the portion including the vicinity of the side 135, the outer package 100Y becomes a sealed state again. Thus, the electrical storage device 10Y is completed. In the completed electrical storage device 10Y, in the vicinity of the side 135, regions where the bonding strength between the opposing surfaces of the outer package member 101Y is strong and regions where the bonding strength between the surfaces is weak are alternately arranged along the side 135. In other words, in the heat-sealed portion near the side 135, thin portions and thick portions are alternately arranged along the side 135. This is because, by heat-sealing the vicinity of the side 135 again, the non-bonded region 153 is hermetically sealed once, and the bonded region 151 is hermetically sealed twice.

[0239] <3-2. Manufacturing method of electrical storage device>

[0240] Figure 18 is a flowchart showing the manufacturing sequence of the electrical storage device 10Y. Figure 18 The processes shown are performed, for example, by a manufacturing apparatus for the electrical storage device 10Y.

[0241] The manufacturing apparatus winds the outer package member 101Y around the electrode body 200 (step S300). The manufacturing apparatus forms the first seal portion 154 by heat-sealing the peripheries of the opposing surfaces (heat-fusible resin layers) of the outer package member 101Y (step S310). The manufacturing apparatus forms the pattern of the bonded region 151 by heat-sealing the opposing surfaces of the outer package member 101Y in the vicinity of the side 135 (step S320).

[0242] The manufacturing apparatus installs the lid bodies 400 at the opening portions at both ends in a state where the unfinished product prepared in step S320 houses the electrode body 200 (step S330). The manufacturing apparatus forms the second seal portion 120X by heat-sealing the outer package member 101Y and the lid bodies 400 (step S340). After that, an aging process is performed.

[0243] The manufacturing apparatus releases the gas generated in the aging process by cutting the sheet portion 150 or the like (step S350). The manufacturing apparatus re-seals the outer package 100Y by heat-sealing in a strip shape the portion of the sheet portion 150 including the bonded region 151 and removing the end edge portion. After that, by bending the sheet portion 150 toward the second surface 140 side, the electrical storage device 10Y is completed.

[0244] <3-3. Features>

[0245] In the electrical storage device 10Y of the third embodiment as well, the sheet portion 150 including the first sealing portion 154 is bent toward the second surface 140 with a smaller area. Therefore, according to the electrical storage device 10Y, it is possible to suppress uneven distribution of the pressure applied to the lower electrical storage device 10Y when a plurality of electrical storage devices 10Y are stacked. In the case of being used for an all-solid-state battery, in order to exhibit battery performance, it is necessary to uniformly apply a high pressure from the outer surface of the battery. Therefore, the packaging method of the present invention is preferred.

[0246] [4. Fourth Embodiment]

[0247] In the electrical storage device 10X of the second embodiment, the position where the electrode terminal 300 protrudes to the outside is located between the lid body 400 and the exterior member 101. However, the position where the electrode terminal 300 protrudes to the outside is not limited thereto. Hereinafter, the description will be centered on the parts different from the second embodiment, and the description of the parts common to the second embodiment will be omitted.

[0248] <4-1. Structure of Electrical Storage Device>

[0249] Figure 19 It is a top view schematically showing the electrical storage device 10XA of the fourth embodiment. Figure 20 It is a side view schematically showing the electrical storage device 10XA. The exterior body 100X of the electrical storage device 10XA includes a pair of long sides 100XA and a pair of short sides 100XB in a top view. The exterior body 100X is formed by respectively inserting the lid body 400 into the opening portions along the long sides 100XA of the exterior member 101 wound around the electrode body 200. In a state where the lid body 400 is inserted, the second sealing portion 120X is formed by heat-sealing the exterior member 101 and the lid body 400. A through-hole (not shown) is formed in the lid body 400. Two electrode terminals 300 protrude from the through-hole of the lid body 400 to the outside of the exterior body 100X. The two electrode terminals 300 are in the shape along the long sides 100XA of the exterior body 100X. The minute gap between the through-hole and the electrode terminals 300 is filled with resin, for example. In the fourth embodiment, the first sealing portion 110 is formed on one side of the pair of short sides 100XB.

[0250] In the thickness direction (arrow UD direction) of the electrical storage device 10XA, the position where the electrode terminals 300 protrude in the lid body 400 can be arbitrarily selected. In the fourth embodiment, as Figure 20As shown, the electrode terminal 300 protrudes from the substantially central portion of the lid body 400 to the outside of the outer package 100X in the thickness direction of the electrical storage device 10XA. The length of the electrode terminal 300 in the depth direction (arrow FB direction) of the electrical storage device 10XA can be arbitrarily selected. In the fourth embodiment, the length of the electrode terminal 300 in the depth direction (arrow FB direction) of the electrical storage device 10XA is substantially the same as the length of the electrode body 200.

[0251] <4-2. Features>

[0252] In the electrical storage device 10XA of the fourth embodiment, since the electrode terminal 300 is arranged in the form of the long side 100XA having a longer length along the depth direction, a larger electrode terminal 300 can be used. Therefore, a high-output electrical storage device 10XA can be provided.

[0253] [5. Modification Example]

[0254] The above-described embodiments are examples of the modes that the electrical storage device of the present invention can take, and do not limit the modes. Regarding the electrical storage device of the present invention, modes different from the modes exemplified in the above-described embodiments can be adopted. One example is a mode obtained by replacing, changing, or omitting a part of the structure of the above-described embodiments, or a mode obtained by adding a new structure to the above-described embodiments. Several examples of the modification examples of the above-described embodiments are shown below. In addition, the above-described embodiments can be combined within a range where there is no technical contradiction.

[0255] <5-1>

[0256] In the first to fourth embodiments, one outer package member is wound around the electrode body 200. However, the outer package member wound around the electrode body 200 is not necessarily limited to one piece. For example, two or more outer package members may be wound around the electrode body 200.

[0257] Figure 21 It is a view showing a state in which the outer package members 101Z1 and 101Z2 are wound around the electrode body 200 during the manufacturing process of the electrical storage device in the modification example from the side. As Figure 21As shown, the electrode body 200 is surrounded by the outer packaging members 101Z1 and 101Z2. The first sealing portion 110Z is formed by joining the opposing surfaces of the outer packaging members 101Z1 and 101Z2 to each other. In this example, each first sealing portion 110Z is bent not toward the first surface 130Z side but toward the second surface 140Z side. With such a structure, it is also possible to obtain an uneven effect of the distribution of the pressure applied to the lower storage device when a plurality of storage devices are stacked. In the case of being used for an all-solid-state battery, since it is necessary to uniformly apply a high pressure from the battery outer surface to exhibit battery performance, the packaging method of the present invention is preferred. Further, in this example, each first sealing portion 110Z does not have to be bent. Further, in this modification, each sealing portion 110Z may also be sealed in a state of sandwiching a part of the electrode terminal 300. Further, in this modification, each first sealing portion 110Z does not have to be formed at the edge 135Z, and may protrude outward from the approximate center of the second surface 140Z in the thickness direction of the storage device.

[0258] <5-2>

[0259] Further, in the first to fourth embodiments, the electrode body 200 is a so-called stacked type formed by laminating a plurality of electrodes 210, but the form of the electrode body 200 is not limited thereto. The electrode body 200 may be, for example, a so-called wound type formed by winding a positive electrode and a negative electrode with a separator interposed therebetween. Further, the electrode body 200 may be formed by laminating a plurality of so-called wound-type electrode bodies.

[0260] <5-3>

[0261] Further, in the first to fourth embodiments, the second surface 140 is a plane extending downward from the first surface 130 substantially at a right angle. However, the form of the second surface 140 is not limited thereto. For example, consider a case where the electrode body 200 is a wound-type electrode body and a plane and a curved surface are formed on the outer periphery. Here, the area of the plane is larger than the area of the curved surface, the first surface 130 covers the plane of the electrode body, and the second surface 140 covers the curved surface of the electrode body. In this case, the second surface 140 may be formed of a curved surface. In this case, the boundary portion where the second surface 140 extends downward from the first surface 130 is the edge 135.

[0262] <5-4>

[0263] Further, in the third embodiment, the joining regions 151 are formed at four locations. However, the number of locations where the joining regions 151 are formed is not limited thereto. For example, the joining regions 151 may be formed only at two locations near both ends along the edge 135 and / or at one location near the center of the edge 135, or may be formed at five or more locations.

[0264] <5-5>

[0265] In addition, in the second embodiment, the electrode terminal 300 is disposed in the second sealing portion 120X. However, in the outer package 100X, the position where the electrode terminal 300 is disposed is not limited thereto. For example, as Figure 22 shown, in the second embodiment, the electrode terminal 300 can also be disposed in the first sealing portion 110. In other words, the first sealing portion 110 is sealed in a state of sandwiching the electrode terminal 300. In this modified example, at least one of the two electrode terminals 300 can be bent toward the second surface 140 side, can be bent toward the side opposite to the second surface 140, or can be bent in a manner that does not protrude outward from the side 135. In this modified example, since the electrode terminal 300 and the first sealing portion 110 can be easily sealed, the sealing performance of the outer package 100X can be improved. In addition, the electrode body 200 can be easily accommodated in the outer package 100X. In addition, in this modified example, for example, as in the second embodiment, the lid bodies 400 are respectively inserted into the opening portions at both ends of the outer package member 101X. In a state where the lid bodies 400 are inserted, the second sealing portion 120 is formed by heat-sealing the outer package member 101X and the lid bodies 400. In addition, in the first embodiment, the electrode terminal 300 can also be disposed in the first sealing portion 110.

[0266] <5-6>

[0267] In addition, in the second embodiment, the structure of the lid body 400 can be arbitrarily changed. Figure 23 is a perspective view of a lid body 500 showing a modified example of the lid body 400. The lid body 500 is, for example, plate-shaped and includes an electrode body 200 (refer to Figure 9)Opposite first surface 500A and second surface 500B on the opposite side of the first surface 500A. A hole 500C penetrating the first surface 500A and the second surface 500B is formed at the center of the lid body 500. The material constituting the lid body 500 includes, for example, a resin material. The lid body 500 may also be constituted by including a metal material. That is, the material constituting the lid body 500 may include at least one of a resin material and a metal material. For example, the lid body 500 may have: a main body portion constituted by including a metal material; and a covering body that covers a part of the main body portion and is constituted by including a resin material. The covering body may be a frame-shaped object of a resin molded product or an adhesive film suitable for bonding to both the metal material and the resin material. The main body portion is preferably joined to the exterior member 101 with the covering body interposed therebetween. In this modification, it is preferable to install a terminal bonding film 530 that bonds to both the electrode terminal 300 and the lid body 500 within a specified range of the electrode terminal 300 that includes a portion joined to the lid body 500. The mode of the terminal bonding film 530 is the same as the mode of the terminal bonding film 30 described in the first embodiment. In this modification, the manufacturing method of the electrical storage device 10X may include: a step of electrically connecting the electrode body 200 and the electrode terminal 300; a step of manufacturing the lid body 500; and a step of inserting the electrode terminal 300 in a state connected to the electrode body 200 into the hole 500C of the lid body 500 (refer to Figure 24 , hereinafter referred to as the "insertion step").

[0268] When the lid body 500 is plate-shaped, it is preferable that the lid body 500 has a certain thickness so that even when the electrical storage devices 10X are stacked, deformation of the exterior body 100X can be suppressed. From another perspective, when the lid body 500 is plate-shaped, it is preferable that the side surface of the lid body 500 has a certain thickness so that when forming the second sealing portion 120X, the side surface of the lid body 500 and the exterior component 101X can be properly heat-sealed. The minimum value of the thickness of the lid body 500 is, for example, 1.0 mm, more preferably 3 mm, and further preferably 4 mm. The maximum value of the thickness of the lid body 500 is, for example, 10 mm, more preferably 8.0 mm, and further preferably 7.0 mm. The maximum value of the thickness of the lid body 500 can be 10 mm or more. The preferred range of the thickness of the material constituting the lid body 500 is 1.0 mm to 10 mm, 1.0 mm to 8.0 mm, 1.0 mm to 7.0 mm, 3.0 mm to 10 mm, 3.0 mm to 8.0 mm, 3.0 mm to 7.0 mm, 4.0 mm to 10 mm, 4.0 mm to 8.0 mm, 4.0 mm to 7.0 mm. In this specification, when the lid body 500 is described as plate-shaped, the material constituting the lid body 500 does not include the film specified by the "Packaging Terms" standard of JIS (Japanese Industrial Standards). Herein, the thickness of the lid body 500 may vary depending on the part of the lid body 500. When the thickness of the lid body 500 varies depending on the part, the thickness of the lid body 500 is the thickness of the thickest part.

[0269] The lid body 500 is composed of components divided into a first part 510 and a second part 520, and the first part 510 and the second part 520 can also be manufactured by joining them in a manner that sandwiches the electrode terminal 300 and the terminal bonding film 530. In addition, in these modified examples, when a gap is generated between the terminal bonding film 530 and the hole 530C, this gap is preferably filled with a resin material such as hot melt or resin welding.

[0270] When the lid body 500 is composed of components divided into a first part 510 and a second part 520, the relationship between the width LA of the electrode terminal 300 and the width LB of the lid body 500 can be arbitrarily selected. From the perspective of more firmly joining the electrode terminal 300 and the lid body 500, the ratio RA of the width LA to the width LB is preferably 50% or more. In Figure 25 In the example shown, the width LA and the width LB are substantially the same, in other words, the ratio RA is 100%. When the ratio RA is 50% or more, the area of the electrode terminal 300 that is joined to the lid body 500 is wide, so by heating the electrode terminal 300, the electrode terminal 300 and the lid body 500 can be more firmly joined. In addition, in this modified example, the width LC of the terminal bonding film 530 is preferably substantially the same as the width LA of the electrode terminal 300.

[0271] The lid body 500 can be manufactured by insert - molding the lid body 500 onto the electrode terminal 300 in a state where the terminal - bonding film 530 is installed. The manufacturing method of the electrical storage device 10X in this case includes: a step of electrically connecting the electrode body 200 and the electrode terminal 300; and a step of insert - molding the lid body 500 onto the electrode terminal 300 in a state of being connected to the electrode body 200 (hereinafter referred to as the "insert - molding step"). After the insert - molding step, the outer packaging member 101 is wound around the electrode body 200 and the lid body 500. Among them, in the insert - molding step, it is preferable to dispose a heat - insulating material for protecting the electrode body 200 between the electrode body 200 and the portion forming the lid body 500. The heat - insulating material is preferably removed after the insert - molding step.

[0272] In addition, in these modified examples, it can be as Figure 26 shown, in a state where the lid body 500 is embedded, the outer package 100X forms the second sealing portion 120X by joining the outer packaging member 101 and the second surface 500B of the lid body 500. The joining means of the outer packaging member 101 and the second surface 500B of the lid body 500 is, for example, heat - sealing. In this modified example, since the outer packaging member 101 joins with a wider range of the lid body 500, the sealing performance of the outer package 100X can be improved. In addition, it can also be that the lid body is formed by bending the terminal - bonding film 530, and the second sealing portion 120X is formed by joining an arbitrary portion of the terminal - bonding film 530 and the outer packaging member 101X. In addition, in these modified examples, it is preferable to laminate a barrier layer on at least a part of the surface of the lid body 500. Or, in the case where the lid body 500 has a plurality of layers, the barrier layer can be formed in any layer. The material constituting the barrier layer is, for example, aluminum, a steel plate, or stainless steel.

[0273] Figure 27 is a front view of the lid body 600 which is another modified example of the lid body 400 of the second embodiment. The lid body 600 includes a metal portion 610 which is a part where the metal is exposed to the surface, and the metal portion 610 and the electrode 210 of the electrode body 200 are welded. The lid body 600 can be entirely composed of only the metal portion 610, or can be partially formed with the metal portion 610. In the case where the metal portion 610 is partially formed, the lid body 600 is composed of a material having a multi - layer structure including a metal layer. In the case where the lid body 600 is composed of a material having a multi - layer structure with a metal layer as an intermediate layer, the metal portion 610 is a portion where the layers other than the metal layer are removed in such a manner that the metal layer is exposed. In Figure 27 the example shown, since the metal portion 610 of the lid body 600 functions as an electrode terminal, there is no need for a space between the lid body 600 and the electrode 210. Therefore, the electrical storage device 10X (refer to Figure 9 ) can be configured to be small.

[0274] Figure 28 It is a front view of a lid body 700 which is another modified example of the lid body 400 in the second embodiment. The lid body 700 includes: a metal part 710 made of a metal material; and a non-metal part 720 made of a resin material and connected to the metal part 710. The metal part 710 is welded to the electrode 210 of the electrode body 200. In Figure 28 the example shown, since the metal part 710 of the lid body 700 functions as an electrode terminal, there is no need for a space between the lid body 700 and the electrode 210. Therefore, the electrical storage device 10X (refer to Figure 9 ) can be configured to be small.

[0275] <5-7>

[0276] The electrical storage device 10X of the second embodiment or a modified example of the second embodiment may also include the film 20 described in the first embodiment. In the electrical storage device 10X, the position where the film 20 is disposed can be arbitrarily selected as long as it is inside the barrier layer 101B of the exterior member 101 (refer to Figure 2 ). By disposing the film 20 of the first embodiment at a position inside the barrier layer 101B of the exterior member 101, it is possible to suppress the intrusion of moisture from the end of the heat-sealable resin layer 101C of the exterior member 101 and the intrusion of moisture contained in the heat-sealable resin layer 101C of the exterior member 101 into the electrode body 200. That is, in the electrical storage device 10X including the film 20 of the first embodiment, since the film 20 contains a water absorbent, the film 20 absorbs and retains the moisture intruded from the heat-sealable resin layer 101C of the exterior member 101, and it is possible to suppress the moisture from reaching the electrode body 200. In addition, by disposing the film 20 of the second embodiment inside the barrier layer 101B of the exterior member 101, for example, when the electrode body 200 is an all-solid-state battery, it is possible to absorb gases such as hydrogen sulfide generated by the contact of the solid electrolyte layer contained in the elements constituting the all-solid-state battery with moisture. That is, in the electrical storage device 10X including the film 20 of the second embodiment, since the film 20 contains a gas absorbent, it is possible to absorb gases such as hydrogen sulfide generated from the electrode body 200 by the film 20.

[0277] Figure 29A It is a cross-sectional view showing a modified example of the electrical storage device 10X of the second embodiment. In Figure 29A the example shown, the film 20 is disposed between the exterior member 101 and the electrode body 200 so as to cover substantially the entire upper surface and the lower surface of the electrode body 200. The film 20 and the inner surface (heat-sealable resin layer 101C) of the exterior member 101 may or may not be joined. At least a part of the film 20 may also be disposed between the exterior member 101 and the lid body 500.

[0278] Figure 29BThis is a cross-sectional view showing another modified example of the electrical storage device 10X according to the second embodiment. In Figure 29B In the example shown, the film 20 is disposed between the lid body 500 and the electrode body 200 so as to cover substantially the entire side surface of the electrode body 200. The film 20 and the first surface 500A of the lid body 500 may or may not be joined. The film 20 and the first surface 500A of the lid body 500 may be in contact with each other or may be spaced apart. The film 20 may also be disposed between the exterior member 101 and the electrode body 200 so as to cover substantially the entire electrode body 200. The film 20 and the inner surface (heat-sealable resin layer 101C) of the exterior member 101 may or may not be joined.

[0279] Figure 29C This is a cross-sectional view showing another modified example of the electrical storage device 10X according to the second embodiment. In Figure 29C In the example shown, the electrical storage device 10X has a terminal bonding film 530 that bonds to both metal and resin between the electrode terminal 300 and the lid body 500. In Figure 29C In the example shown, the film 20 is used as the terminal bonding film 530. The film 20 is preferably disposed at least in the hole 500C of the lid body 500. The film 20 may also protrude from the hole 500C of the lid body 500. There is a problem that moisture may enter the electrical storage device 10X including the lid body 500 through the hole 500C of the lid body 500. Since the film 20 of the electrical storage device 10X according to the first mode contains a water absorbent, the film 20 absorbs water and retains the moisture that has entered through the hole 500C of the lid body 500, thereby suppressing the moisture from reaching the electrode body 200. Since the film 20 of the electrical storage device 10X according to the second mode contains a gas absorbent, the film 20 can absorb gases such as hydrogen sulfide generated from the electrode body 200. Therefore, gases such as hydrogen sulfide are less likely to be released to the outside through the hole 500C of the lid body 500.

[0280] As Figure 23 shown, when the lid body 500 is composed of at least a first part 510 and a second part 520, the film 20 may also be disposed at least in part between the first part 510 and the second part 520. Further, for example, when the lid body 500 is composed of one part and the electrode terminal 300 is disposed between the top surface of the lid body 500 and the exterior member 101, the film 20 serving as the terminal bonding film 530 may also be disposed between the top surface of the lid body 500 and the exterior member 101.

[0281] <5-8>

[0282] Further, in the first embodiment, the second sealing portion 120 is formed by folding the exterior member 101 and heat-sealing the heat-sealable resin layers of the exterior member 101 to each other. However, the method of forming the second sealing portion 120 is not limited thereto.Figure 30 FIG. 0 is a top view schematically showing a power storage device 10 having a second sealing portion 120Y with a modified example. The exterior member 101 has a protruding portion 101XA extending outward from the exterior body 100, and the second sealing portion 120Y is formed by heat-sealing the heat-sealable resin layers of the protruding portion 101XA to each other. In the portion of the protruding portion 101XA where the electrode terminal 300 is disposed, the heat-sealable resin layer of the protruding portion 101XA and the electrode terminal 300 are heat-sealed. According to this modified example, since the second sealing portion 120Y can be heat-sealed more firmly, the sealing property of the exterior body 100 can be improved. Further, in this modified example, portions of the protruding portion 101XA that are not heat-sealed to the electrode terminal 300 can be cut as needed. Further, this modified example can also be applied to Figure 22 the modified example shown.

[0283] <5-9>

[0284] In the first embodiment, the method for forming the first sealing portion 110 can be arbitrarily selected. As Figure 31 shown, for example, the manufacturing apparatus may also form the first sealing portion 110 by pressing the sealing strip 800 at a position spaced apart from the base portion 135X of the predetermined portion 110Y in the exterior body 100 where the first sealing portion 110 is to be formed in step S110 (see Figure 8 ). According to this manufacturing method, as Figure 32 shown, a concave portion 110X can be formed in the first sealing portion 110 as a trace of the sealing strip 800 being pressed. In the portion of the exterior body 100 where the concave portion 110X is formed, the opposing surfaces (heat-sealable resin layers) of the exterior member 101 are directly joined to each other. Between the concave portion 110X and the base portion 135X in the exterior body 100, a part of the resin constituting the exterior member 101 melts between the opposing surfaces of the exterior member 101 to form an aggregation portion 900. Between the concave portion 110X and the base portion 135X in the exterior body 100, the opposing surfaces (heat-sealable resin layers) of the exterior member 101 are joined to each other via the aggregation portion 900. That is, in this modified example, the first sealing portion 110 includes: a portion where the opposing surfaces of the exterior member 101 are directly joined to each other; and a portion where the opposing surfaces of the exterior member 101 are joined to each other via the aggregation portion 900. Since the intrusion of water vapor and the like from the outside into the interior of the exterior body 100 is blocked by the aggregation portion 900, the barrier property of the exterior body 100 can be improved. Among them, when the sealing strip 800 is pressed against the portion 110Y, the opposing surfaces of the exterior member 101 in the portion where the aggregation portion 900 is formed, in other words, between the concave portion 110X and the base portion 135X, need to be in contact with each other.

[0285] The distance X between the base portion 135X in the LR direction and the edge 810 of the sealing strip 800, in other words, the distance between the base portion 135X in the LR direction and the concave portion 110X, can be arbitrarily selected. From the viewpoint of forming the aggregation portion 900 in a wider range, the distance X is preferably, for example, 1 mm or more, more preferably 1.5 mm or more, and still more preferably 1.7 mm or more. From the viewpoint of making the first sealing portion 110 small, the distance X is preferably, for example, 10 mm or less, more preferably 5 mm or less, and still more preferably 3 mm or less. The preferred range of the distance X can be listed, for example, around 1 mm or more and 10 mm or less, around 1 mm or more and 5 mm or less, around 1 mm or more and 3 mm or less, around 1.5 mm or more and 10 mm or less, around 1.5 mm or more and 5 mm or less, around 1.5 mm or more and 3 mm or less, around 1.7 mm or more and 10 mm or less, around 1.7 mm or more and 5 mm or less, around 1.7 mm or more and 3 mm or less. The distance X is most preferably 2 mm, for example. In addition, the distance X can also be substantially 0. In the case where the distance X is substantially 0, the sealing strip 800 is pressed against the exterior body 100 such that the base portion 135X substantially coincides with the edge 810 of the sealing strip 800. Here, the so-called substantial coincidence includes: the case where the base portion 135X completely coincides with the edge 810 of the sealing strip 800; and the case where the positions of the base portion 135X and the edge 810 of the sealing strip 800 are slightly deviated due to errors during manufacturing or the like. Therefore, the so-called distance X being substantially 0 also includes, for example, the case where the distance X is less than 1 mm. These modified examples can also be similarly applied to the second to fourth embodiments. In addition, depending on the shape of the portion of the concave portion 110X corresponding to the edge 810 of the sealing strip 800, there may be a case where the distance between the base portion 135X and the concave portion 110X is not constant. In this case, the distance X can be the distance between the center of the concave portion 110X in the FB direction and the center of the base portion 135X. In another example, the distance X can also be calculated based on the average value of a plurality of values including the maximum value and the minimum value of the distance between the base portion 135X and the concave portion 110X. Similarly, depending on the shape of the base portion 135X, there may be a case where the distance between the base portion 135X and the concave portion 110X is not constant. In this case, the distance X can be the distance between the center of the base portion 135X in the FB direction and the center of the concave portion 110X. In another example, the distance X can also be calculated based on the average value of a plurality of values including the maximum value and the minimum value of the distance between the concave portion 110X and the base portion 135X.

[0286] In the second embodiment, as Figure 33As shown, the exterior body 100X may also include a barrier film 91 that inhibits the permeation of the electrolytic solution. The barrier film 91 is preferably disposed at least between the inner surface of the exterior component 101X and the electrode body 200. The barrier film 91 is preferably joined to the inner surface of the exterior component 101X. The barrier film 91 is preferably made of a material that allows the gas generated inside the exterior body 100X to permeate. Examples of the material constituting the barrier film 91 include a resin film or a porous film. Since the exterior body 100X has the barrier film 91, the deterioration of the exterior component 101X due to the electrolytic solution can be inhibited.

[0287] In the first embodiment, as Figure 34 shown, the exterior body 100 may also include a cushioning film 92 for enhancing the strength of the exterior component 101. The cushioning film 92 is preferably disposed at least at the corner portion 100Z of the exterior body 100 in the inner surface of the exterior component 101. Since the exterior body 100 includes the cushioning film 92, the generation of pinholes in the exterior body 100 can be inhibited. Examples of the material constituting the cushioning film 92 include a polyester-based material, a polyolefin-based material, or a fluorine-based material. In this modification, as Figure 34 shown, the second sealing portion 120 may also be formed by joining the inner surface of the exterior component 101 and the electrode terminal 300. The space 93 between the second sealing portion 120 and the electrode body 200 is preferably filled with the electrolytic solution.

[0288] In the first embodiment, it has been described that the terminal bonding film 30 that bonds both metal and resin may be disposed between the electrode terminal 300 and the exterior component 101, but in other embodiments, the terminal bonding film 30 may be disposed in the same manner.

[0289] In the second embodiment, it has been described that the terminal bonding film 30 that bonds both metal and resin is disposed between the lid body 400 and the electrode terminal 300 in the same manner as in the first embodiment, but in other embodiments, a bonding film may be disposed in the same manner.

[0290] [6. Examples]

[0291] The inventors of the present application manufactured the electrical storage devices of Example 1, Example 2, and Comparative Example 1, and conducted a test to confirm whether moisture invaded the electrode body. In addition, hereinafter, for the sake of convenience of explanation, the same elements as those in the embodiments among the elements constituting the electrical storage devices of Example 1, Example 2, and Comparative Example 1 may be given the same reference numerals as those in the embodiments for description.

[0292] The electrical storage devices of Example 1, Example 2, and Comparative Example 1 have a structure corresponding to the electrical storage device 10X of the second embodiment. The electrical storage devices of Example 1, Example 2, and Comparative Example 1 include two lid bodies 500 (refer to Figure 23)。However, in the electrical storage devices of Example 1, Example 2, and Comparative Example 1, the two lid bodies 500 are not divided into a first part 510 and a second part 520. The size of the two lid bodies 500 is a width of 100 mm, a height of 30 mm, and a thickness of 5 mm. In the electrical storage devices of Example 1, Example 2, and Comparative Example 1, an aluminum block is used in place of the electrode body 200. The size of the aluminum block is a width of 100 mm, a height of 30 mm, and a thickness of 150 mm.

[0293] The inventors of the present application joined the film 20 of the first type to the first surface 500A of the two lid bodies 500. The size of one film 20 is a width of 100 mm and a height of 30 mm. The film 20 is a film obtained by leaving it to dry in a vacuum oven (-50 MPa) for 24 hours before the test (before encapsulation). In the electrical storage device of Example 1, three films 20 are respectively overlapped and joined to the first surface 500A of the two lid bodies 500. In the electrical storage device of Example 2, six films 20 are respectively overlapped and joined to the first surface 500A of the two lid bodies 500. In the electrical storage devices of Example 1 and Example 2, the film 20 covers substantially the entire first surface 500A of the lid body 500. In the electrical storage device of Comparative Example 1, the film 20 is not joined to the lid body 500.

[0294] The inventors of the present application wound the outer packaging member 101 around the aluminum block and the two lid bodies 500 to which the film 20 was joined, to form a first sealing portion 110. The size of the outer packaging member 101 is a rectangular shape of 300 mm × 160 mm. The heat sealing conditions when forming the first sealing portion 110 are a temperature of 190°C, a pressure of 1 MPa, and a time of 3 seconds.

[0295] Next, the inventors of the present application formed a second sealing portion 120 by heat-sealing the sides (a total of eight sides) of the two lid bodies 500 and the outer packaging member 101. The heat sealing conditions when forming the second sealing portion 120 are a temperature of 180°C, a pressure of 0.2 MPa, and a time of 5 seconds.

[0296] Next, the inventors of the present application cut the electrical storage devices of Example 1, Example 2, and Comparative Example 1 in half at a position 80 mm from the end of the lid body 500 to form an opening, and removed the aluminum block from the opening. Then, 20 g of a salt-free electrolyte (EC:DMC:DEC = 1:1:1) was injected from the opening, and then the heat-meltable resin layers 101C located at the opening were heat-sealed to each other twice with a sealing strip 7 mm wide under strong heat. When performing the second strong heat-sealing, the strong heat-sealing was performed in such a manner that it overlapped the first strong heat-sealing portion by 4 mm. Therefore, the sealing width of the opening is 10 mm. The heat sealing conditions when heat-sealing the heat-meltable resin layers 101C located at the opening to each other are a temperature of 220°C, a pressure of 0.45 MPa, and a time of 3 seconds.

[0297] After placing the electrical storage devices of Example 1, Example 2, and Comparative Example 1 in a constant temperature bath at a temperature of 65°C and a humidity of 90% for 1 week, any part of the outer package member 101 was unsealed, and the moisture content of the salt-free electrolyte therein was measured using the Karl Fischer method. The Karl Fischer moisture meter used in this test was the Karl Fischer moisture meter MKC-610 manufactured by Kyoto Electronics Industry Co., Ltd. The anolyte used was KEMAQUA anolyte AGE, and the catholyte was KEMAQUA catholyte CGE. Regarding the electrical storage devices of Example 1, Example 2, and Comparative Example 1, for the moisture content of the salt-free electrolyte after the test, 3 measurements were made using 1 g of the sample, and the average value of the 3 measurements was used as the measurement result. Among them, the 1 g sample contained an error of about 0.95 g to 1.05 g.

[0298] For the electrical storage device of Example 1, the moisture content of the salt-free electrolyte after the test, obtained by subtracting the moisture content of the salt-free electrolyte before the test, was 3 mg. For the electrical storage device of Example 2, the moisture content of the salt-free electrolyte after the test, obtained by subtracting the moisture content of the salt-free electrolyte before the test, was 1.5 mg. For the electrical storage device of Comparative Example 1, the moisture content of the salt-free electrolyte after the test, obtained by subtracting the moisture content of the salt-free electrolyte before the test, was 25 mg.

[0299] It was confirmed that: for the electrical storage devices of Example 1 and Example 2, compared with the moisture content of the electrolyte before the test, the moisture content of the electrolyte slightly increased. Based on this result, it can be considered that the electrical storage device including the film 20 of the first mode can suppress the intrusion of moisture from the end of the heat-sealable resin layer 101C of the outer package member 101 and the intrusion of moisture contained in the heat-sealable resin layer 101C of the outer package member 101 into the electrode body 200.

[0300] [7. Supplementary Notes]

[0301] The first mode of the film 20 in each of the above embodiments includes the following matters.

[0302] Item 1A. A resin film for an electrical storage device, which is disposed at a position inside the barrier layer of the outer package member in the electrical storage device and contains a water absorbent.

[0303] Item 2A. The resin film for an electrical storage device according to Item 1A, wherein the water absorbent is an inorganic water absorbent.

[0304] Item 3A. The resin film for an electrical storage device according to Item 1A or Item 2A, wherein the water absorbent is at least 1 selected from calcium oxide, anhydrous magnesium sulfate, magnesium oxide, calcium chloride, zeolite, alumina, silica gel, alumina gel, and burnt alum.

[0305] Item 4A. The resin film for electric storage device according to any one of Items 1A to 3A, wherein the content of the water absorbent is 0.1 part by mass or more with respect to 100 parts by mass of the resin contained in the resin film for electric storage device.

[0306] Item 5A. The resin film for electric storage device according to any one of Items 1A to 4A, which is composed of two or more layers.

[0307] Item 6A. The resin film for electric storage device according to Item 5A, wherein at least one layer of the two or more layers contains the water absorbent, and at least one layer contains a sulfur-based gas absorbent.

[0308] Item 7A. The resin film for electric storage device according to any one of Items 1A to 6A, wherein the layer of the resin film for electric storage device containing the water absorbent contains 0.5 part by mass or more of the absorbent with respect to 100 parts by mass of the resin.

[0309] Item 8A. The resin film for electric storage device according to any one of Items 1A to 7A, which contains a heat-sealable resin.

[0310] Item 9A. The resin film for electric storage device according to Item 8A, wherein the heat-sealable resin contains at least one selected from polyester and polyolefin.

[0311] The second mode of the film 20 of each of the above embodiments includes the matters described below.

[0312] Item 1B. A resin film for electric storage device, which is disposed at a position inside the barrier layer of the exterior member in the electric storage device and contains a sulfur-based gas absorbent.

[0313] Item 2B. The resin film for electric storage device according to Item 1B, wherein the content of the sulfur-based gas absorbent is 0.1 part by mass or more with respect to 100 parts by mass of the resin contained in the resin film for electric storage device.

[0314] Item 3B. The resin film for electric storage device according to Item 1B or 2B, wherein the maximum particle size of the sulfur-based gas absorbent is 20 μm or less, and the number average particle size is 0.1 μm or more and 15 μm or less.

[0315] Item 4B. The resin film for electric storage device according to any one of Items 1B to 3B, wherein the sulfur-based gas absorbent contains at least one selected from a sulfur-based gas chemical absorbent and a sulfur-based gas physical absorbent.

[0316] Item 5B. The resin film for electric storage device according to Item 4B, wherein the sulfur-based gas physical absorbent contains SiO selected from 2 / Al 2 O 3At least one of hydrophobic zeolite, bentonite, and sepiolite with a molar ratio of 1 / 1 to 2000 / 1.

[0317] Item 6B. The resin film for an electrical storage device according to Item 4B or 5B, wherein the sulfur-based gas chemical absorbent is a metal oxide, or an inorganic substance loaded or mixed with a metal or metal ions.

[0318] Item 7B. The resin film for an electrical storage device according to Item 6B, wherein the metal oxide contains at least one selected from CuO, ZnO, and AgO.

[0319] Item 8B. The resin film for an electrical storage device according to Item 6B or 7B, wherein the metal species in the inorganic substance loaded or mixed with a metal or metal ions is at least one selected from Ca, Mg, Na, Cu, Zn, Ag, Pt, Au, Fe, Al, and Ni.

[0320] Item 9B. The resin film for an electrical storage device according to any one of Items 1B to 8B, wherein the layer of the resin film for an electrical storage device containing the sulfur-based gas absorbent contains 5 parts by mass or more of the sulfur-based gas absorbent relative to 100 parts by mass of the resin.

[0321] Item 10B. The resin film for an electrical storage device according to any one of Items 1B to 9B, which contains a heat-sealable resin.

[0322] Item 11B. The resin film for an electrical storage device according to Item 10B, wherein the heat-sealable resin contains at least one selected from polyester and polyolefin.

[0323] Explanation of reference numerals

[0324] 10, 10X, 10XA, 10Y, 10Z Electrical storage devices

[0325] 20 Resin film for an electrical storage device

[0326] 30 Adhesive film for terminals

[0327] 100, 100X, 100Y Exterior bodies

[0328] 101, 101Y, 101Z1, 101Z2 Exterior components

[0329] 101A Substrate layer

[0330] 101B Barrier layer

[0331] 101C Heat-sealable resin layer

[0332] 101Z Laminate

[0333] 101X Protrusion

[0334] The first sealing parts of 110, 110Z, and 154

[0335] The recess of 110X

[0336] The second sealing parts of 120, 120X, and 120Y

[0337] The first surfaces of 130 and 130Z

[0338] The edges of 135 and 135Z

[0339] The base parts of 135X

[0340] The second surfaces of 140 and 140Z

[0341] The sheet parts of 150

[0342] The bonding areas of 151

[0343] The spaces of 152

[0344] The unbonded areas of 153

[0345] The electrode body of 200

[0346] The electrodes of 210

[0347] The current collectors of 215

[0348] The electrode terminals of 300

[0349] The first surface of 500A

[0350] The second surface of 500B

[0351] The covers of 400, 500, and 700

[0352] The metal parts of 610 and 710

[0353] The sealing strips of 800

[0354] Corner C1.

Claims

1. A storage device, characterized in that, comprising: an electrode body; an electrode terminal connected to the electrode body; and an exterior body that seals the electrode body, the exterior body being composed of a film-shaped exterior component, the exterior body including a first sealing portion that joins the exterior component in a state where the exterior component wraps the electrode body, the exterior component including a barrier layer, the storage device having a resin film for storage device disposed at least partially on the inner side of the barrier layer, the resin film for storage device containing at least one of a water absorbent and a gas absorbent.

2. The storage device according to claim 1, characterized in that: the resin film for storage device serves as a heat-sealable resin layer of the exterior component.

3. The storage device according to claim 1 or 2, characterized in that: the resin film for storage device serves as a terminal bonding film that joins the exterior component and the electrode terminal.

4. The storage device according to claim 1 or 2, characterized in that: further comprising a cover body on which the electrode terminal is mounted and disposed on the side of the electrode body, a part of the cover body being joined to the exterior component.

5. The storage device according to claim 4, characterized in that: the material constituting the cover body contains at least one of a resin material and a metal material.

6. The storage device according to claim 4, characterized in that: the resin film for storage device is disposed at least partially between the cover body and the electrode body.

7. The storage device according to claim 4, characterized in that: the resin film for storage device is disposed at least partially between the cover body and the electrode terminal.

8. The storage device according to claim 4, characterized in that: the resin film for storage device is disposed at least partially between the cover body and the exterior component.

9. The storage device according to claim 4, characterized in that: the cover body has a hole through which the electrode terminal passes, the resin film for storage device being disposed in the hole.

10. The storage device according to claim 4, characterized in that: the cover body includes a first surface facing the electrode body and a second surface opposite to the first surface, the resin film for storage device being joined to at least a part of the second surface of the cover body.

Images