Classifications

• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to an electricity storage device, a lid, a covering, and a method for manufacturing an electricity storage device.
• Patent Document 1 discloses an example of an electricity storage device.
• This electricity storage device includes an electrode body and an exterior body that seals the electrode body.
• the exterior body includes an exterior film that encases the electrode body and a lid body that is joined to the exterior film.
• the electrode body and the lid body are connected, and then the electrode body and the lid body are wrapped in an exterior film.
• the electrode body is sealed at the stage where the electrode body and the lid body are wrapped in the exterior film, so the steps of the manufacturing method are limited.
• the present invention aims to provide an electricity storage device that can be manufactured using a variety of procedures, a lid body used in this electricity storage device, a covering body that constitutes this lid body, and a manufacturing method for this electricity storage device.
• the energy storage device comprises an electrode body and an exterior body that seals the electrode body, the exterior body having an exterior film that wraps the electrode body and a lid body that seals the electrode body together with the exterior film, the lid body having a lid body that includes a metal material and a covering body that is joined to the exterior film and covers at least a portion of the lid body.
• the electric storage device is the electric storage device according to the first aspect, in which the covering has a main body portion that includes a metal material.
• the third aspect of the present invention relates to an electric storage device according to the second aspect, in which the volume of the main body is smaller than the volume of the lid body.
• the electric storage device is an electric storage device according to any one of the first to third aspects, in which the covering body has a lid seal portion that is joined to the exterior film, and a protrusion that protrudes from the lid seal portion and defines a portion that covers the edge of the lid body.
• the fifth aspect of the present invention relates to an electric storage device according to the second or third aspect, in which the covering body further has a joint that covers at least a portion of the edge of the main body.
• the sixth aspect of the present invention relates to an electricity storage device according to the fifth aspect, in which the joint is a resin molded part.
• the seventh aspect of the present invention relates to an electricity storage device according to the fifth aspect, in which the joint is an adhesive film that can be joined to metal materials and resin materials.
• the eighth aspect of the present invention relates to an electricity storage device according to the fifth aspect, in which the joint is an adhesive.
• the lid body according to the ninth aspect of the present invention is a lid body used as an exterior body for an electricity storage device, and has a lid body containing a metal material, and a covering body that is joined to an exterior film that constitutes the exterior body and covers at least a portion of the edge of the lid body.
• the covering according to the tenth aspect of the present invention is a covering constituting a lid used as an exterior body for an electricity storage device, the lid having a lid body containing a metal material, the covering being joined to an exterior film constituting the exterior body and configured to cover at least a portion of the edge of the lid body.
• the manufacturing method for an electricity storage device is a manufacturing method for an electricity storage device comprising an electrode body and an exterior body sealing the electrode body, the exterior body having an exterior film wrapping the electrode body and a lid body sealing the electrode body together with the exterior film, the lid body having a lid body comprising a metal material and a covering body joined to the exterior film and covering at least a portion of the lid body.
• the manufacturing method for the electricity storage device includes a film bonding process for bonding the exterior film and the covering body, and a closing process, which is performed after the film bonding process and for bonding the covering body and the lid body.
• the electricity storage device, lid, cover, and method for manufacturing the electricity storage device according to the present invention allow the electricity storage device to be manufactured in a variety of procedures.
• FIG. 1 is a perspective view of an electricity storage device according to an embodiment.
• 1B is a diagram showing a method for measuring the seal strength of a second sealing portion of the electricity storage device in FIG. 1A.
• 1B is a cross-sectional view showing an example of a layer structure of an exterior film included in the electricity storage device of FIG. 1A.
• FIG. 1B is a diagram showing a state in which an exterior film provided on the power storage device in FIG. 1A is unfolded.
• FIG. 1B is a perspective view of a main body portion of a covering body provided in the power storage device of FIG. 1A.
• 4B is a cross-sectional view taken along line D4B-D4B in FIG. 4A.
• FIG. 1B is a perspective view of a lid body of a lid body provided in the power storage device of FIG. 1A.
• FIG. 1B is a front view of the power storage device of FIG. 1B is a cross-sectional view taken along line D7-D7 in FIG. 1A.
• 1B is a flowchart showing an example of a method for manufacturing the electricity storage device of FIG. 1A.
• 1B is a flowchart showing another example of a method for manufacturing the electricity storage device of FIG. 1A.
• the following describes the power storage device according to an embodiment of the present invention with reference to the drawings.
• the numerical range indicated by “-” means “greater than or equal to” or “less than or equal to.”
• the expression 2-15 mm means 2 mm or more and 15 mm or less.
• FIG. 1A is a perspective view that shows a schematic diagram of an electric storage device 10 according to an embodiment.
• FIG. 1B is a diagram that shows a method for measuring the seal strength of the second sealing portion 92 of the electric storage device 10 of FIG. 1.
• FIG. 2 is a cross-sectional view that shows an example of a layer structure of an exterior film 50 that is included in the electric storage device 10 of FIG. 1A.
• FIG. 3 is a diagram that shows a state in which the exterior film 50 that is included in the electric storage device 10 of FIG. 1A is unfolded.
• FIG. 4A is a perspective view of a main body portion 70A of a covering body 70 that is included in the electric storage device of FIG.
• FIG. 4B is a cross-sectional view along the line D4B-D4B in FIG. 4A.
• FIG. 5 is a perspective view of a lid main body 80 that is included in the electric storage device 10 of FIG. 1A.
• FIG. 6 is a front view of the electric storage device 10 of FIG. 1A.
• FIG. 7 is a cross-sectional view along the line D7-D7 in FIG. 1. 1A, the direction of the arrow UD indicates the thickness direction of the power storage device 10, the direction of the arrow LR indicates the width direction of the power storage device 10, and the direction of the arrow FB indicates the depth direction of the power storage device 10.
• the directions indicated by the arrows UDLRFB are the same in the subsequent figures.
• the power storage device 10 includes an electrode body 20 including a current collector 30, and an exterior body 40.
• the electrode body 20 includes electrodes (positive and negative electrodes) constituting a power storage member such as a lithium ion battery, a capacitor, an all-solid-state battery, a semi-solid battery, a quasi-solid battery, a polymer battery, an all-resin battery, a lead-acid battery, a nickel-metal hydride battery, a nickel-cadmium battery, a nickel-iron battery, a nickel-zinc battery, a silver oxide-zinc battery, a metal-air battery, a polyvalent cation battery, or a capacitor, as well as a separator.
• a power storage member such as a lithium ion battery, a capacitor, an all-solid-state battery, a semi-solid battery, a quasi-solid battery, a polymer battery, an all-resin battery, a lead-acid battery, a nickel-metal hydride battery, a
• the shape of the electrode body 20 is an approximately rectangular parallelepiped.
• approximately rectangular parallelepiped includes not only a perfect rectangular parallelepiped, but also a solid that can be regarded as a rectangular parallelepiped by modifying the shape of a portion of the outer surface, for example.
• the shape of the electrode body 20 may be, for example, a cylinder or a polygonal prism.
• the exterior body 40 seals the electrode body 20.
• the exterior body 40 includes an exterior film 50 and a lid body 60.
• the exterior film 50 wraps the electrode body 20 so as to form a pair of openings 40A.
• the exterior film 50 is wrapped around the electrode body 20 so as to form a pair of openings 40A.
• the electrode body 20 may be housed inside the exterior film 50 configured in a cylindrical shape so as to form a pair of openings 40A, and the openings 40A may be closed by the lid body 60.
• the exterior body 40 has a pair of first surfaces 41A, 41B and a pair of second surfaces 42A, 42B. In this embodiment, the pair of first surfaces 41A, 41B are substantially the same size.
• the pair of second surfaces 42A, 42B are substantially the same size.
• the pair of first surfaces 41A, 41B have a larger area than the pair of second surfaces 42A, 42B.
• a pair of lids 60 are disposed on the sides of the electrode body 20 so as to close a pair of openings 40A.
• the exterior body 40 seals the electrode body 20 by wrapping the exterior film 50 around the electrode body 20, so that the electrode body 20 can be easily sealed regardless of the thickness of the electrode body 20.
• the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20.
• the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20.
• the exterior film 50 is a laminate (laminate film) having, for example, a base layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in this order.
• the exterior film 50 does not need to include all of these layers, and for example, the barrier layer 52 may not be included. That is, the exterior film 50 may be made of a material that is flexible and easy to bend, and may be made of, for example, a resin film.
• the exterior film 50 is preferably heat-sealable.
• the innermost and outermost layers of the exterior film 50 may be heat-sealable resin layers 53. In this case, the exterior film 50 may encase the electrode body 20 and the lid body 60 by joining the outermost and innermost layers.
• the overall thickness of the exterior film 50 can be selected as desired. From the viewpoint of strength, the thickness of the exterior film 50 is preferably 50 ⁇ m or more. From the viewpoint of formability or conformability, the thickness of the exterior film 50 is preferably 1200 ⁇ m or less. The thickness of the exterior film 50 is preferably within the range of 50 ⁇ m or more and 1200 ⁇ m or less.
• the substrate layer 51 included in the exterior film 50 is a layer for imparting heat resistance to the exterior film 50 and suppressing the occurrence of pinholes that may occur during processing or distribution.
• the substrate layer 51 is composed of, for example, at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer.
• the barrier layer 52 can be protected during processing of the exterior film 50 and breakage of the exterior film 50 can be suppressed.
• the stretched polyester resin layer is preferably a biaxially stretched polyester resin layer
• the stretched polyamide resin layer is preferably a biaxially stretched polyamide resin layer.
• the stretched polyester resin layer is more preferably a biaxially stretched polyethylene terephthalate (PET) film
• the stretched polyamide resin layer is more preferably a biaxially stretched nylon (ONy) film.
• the substrate layer 51 may be composed of both a stretched polyester resin layer and a stretched polyamide resin layer. From the standpoint of film strength, the thickness of the base layer 51 is preferably, for example, 5 to 300 ⁇ m, and more preferably 5 to 150 ⁇ m.
• the barrier layer 52 is a layer that at least prevents the intrusion of moisture.
• the barrier layer 52 is bonded to the base layer 51 via, for example, an adhesive layer 54.
• Examples of the barrier layer 52 include metal foil, vapor deposition film, and resin layer having barrier properties.
• the vapor deposition film examples include metal vapor deposition film, inorganic oxide vapor deposition film, and carbon-containing inorganic oxide vapor deposition film
• the resin layer examples include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, and ethylene-vinyl alcohol copolymers.
• CTFE chlorotrifluoroethylene
• TFE tetrafluoroethylene
• the barrier layer 52 examples include resin films having at least one layer of these vapor deposition films and resin layers. The barrier layer 52 may be provided in multiple layers.
• the barrier layer 52 includes a layer composed of a metal material.
• metal materials constituting the barrier layer 52 include aluminum alloys, stainless steel, titanium steel, and steel plates, and when used as a metal foil, it is preferable to use at least one of aluminum alloy foil and stainless steel foil.
• the layer made of the above-mentioned metal material may contain recycled metal material.
• recycled metal material include recycled aluminum alloy, stainless steel, titanium steel, or steel plate. These recycled materials can be obtained by known methods. Recycled aluminum alloy can be obtained by the manufacturing method described in WO 2022/092231.
• the barrier layer 52 may be made of only recycled material, or may be made of a mixture of recycled and virgin materials. Note that recycled metal material refers to metal material that has been made reusable by collecting, isolating, and refining various products used in the city and waste from manufacturing processes. Also, virgin metal material refers to new metal material that has been refined from natural metal resources (raw materials) and is not recycled material.
• the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy, and from the viewpoint of further improving the formability or conformability, the aluminum alloy foil is preferably an iron-containing aluminum alloy foil.
• the iron content is preferably 0.1 to 9.0 mass%, and more preferably 0.5 to 2.0 mass%.
• an exterior film 50 having better formability can be obtained.
• an exterior film 50 having better flexibility can be obtained.
• silicon, magnesium, copper, manganese, etc. may be added as necessary.
• the aluminum alloy foil is more preferably a hard aluminum alloy foil made of, for example, a work-hardened aluminum alloy.
• the hard aluminum alloy foil include aluminum alloy foils having a composition specified in JIS H4160:1994 A8021H-H18, JIS H4160:1994 A8079H-H18, JIS H4000:2014 A8021P-H14, or JIS H4000:2014 A8079P-H14.
• the aluminum alloy foil is preferably an aluminum alloy foil containing magnesium.
• the magnesium content is preferably 0.2 to 5.6% by mass, and more preferably 0.2 to 3.0% by mass.
• Examples of aluminum alloy foils containing magnesium include aluminum alloy foils having compositions specified in JIS H4000:2017 A5005P-O, JIS H4000:2017 A5050P-O, and JIS H4000:2017 A5052P-O.
• stainless steel foil examples include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. From the viewpoint of providing an exterior film 50 with excellent formability, it is preferable that the stainless steel foil is made of austenitic stainless steel.
• austenitic stainless steels that make up the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.
• the thickness of the barrier layer 52 should be such that it at least functions as a barrier layer to prevent the penetration of moisture, and may be, for example, about 9 to 1000 ⁇ m.
• the thickness of the barrier layer 52 is preferably about 85 ⁇ m or less, more preferably about 50 ⁇ m or less, even more preferably about 40 ⁇ m or less, and particularly preferably about 35 ⁇ m or less.
• the thickness of the barrier layer 52 is preferably about 9.0 ⁇ m or more, more preferably about 20 ⁇ m or more, and more preferably about 25 ⁇ m or more.
• preferred ranges of the thickness of the barrier layer 52 include about 9.0 to 1000 ⁇ m, about 9.0 to 1000 ⁇ m, about 9.0 to 1000 ⁇ m, about 9.0 to 1000 ⁇ m, about 9.0 to 85 ⁇ m, about 9.0 to 50 ⁇ m, about 9.0 to 40 ⁇ m, about 9.0 to 35 ⁇ m, about 20 to 85 ⁇ m, about 20 to 50 ⁇ m, about 20 to 40 ⁇ m, about 20 to 35 ⁇ m, about 25 to 85 ⁇ m, about 25 to 50 ⁇ m, about 25 to 40 ⁇ m, and about 25 to 35 ⁇ m.
• the barrier layer 52 is made of an aluminum alloy foil, the above-mentioned ranges are particularly preferred.
• the thickness of the barrier layer 52 is preferably about 35 ⁇ m or more, more preferably about 45 ⁇ m or more, even more preferably about 50 ⁇ m or more, and even more preferably about 55 ⁇ m or more, and is preferably about 200 ⁇ m or less, more preferably about 85 ⁇ m or less, even more preferably about 75 ⁇ m or less, and even more preferably about 70 ⁇ m or less.
• the preferable ranges are about 35 to 200 ⁇ m, about 35 to 85 ⁇ m, about 35 to 75 ⁇ m, about 35 to 70 ⁇ m, about 45 to 200 ⁇ m, about 45 to 85 ⁇ m, about 45 to 75 ⁇ m, about 45 to 70 ⁇ m, about 50 to 200 ⁇ m, about 50 to 85 ⁇ m, about 50 to 75 ⁇ m, about 50 to 70 ⁇ m, about 55 to 200 ⁇ m, about 55 to 85 ⁇ m, about 55 to 75 ⁇ m, and about 55 to 70 ⁇ m.
• the exterior film 50 has high formability, which makes deep drawing easy and can contribute to increasing the capacity of the electricity storage device.
• the thickness of the stainless steel foil is preferably about 60 ⁇ m or less, more preferably about 50 ⁇ m or less, even more preferably about 40 ⁇ m or less, even more preferably about 30 ⁇ m or less, and particularly preferably about 25 ⁇ m or less.
• the thickness of the stainless steel foil is preferably about 10 ⁇ m or more, more preferably about 15 ⁇ m or more.
• Preferred ranges for the thickness of the stainless steel foil include about 10 to 60 ⁇ m, about 10 to 50 ⁇ m, about 10 to 40 ⁇ m, about 10 to 30 ⁇ m, about 10 to 25 ⁇ m, about 15 to 60 ⁇ m, about 15 to 50 ⁇ m, about 15 to 40 ⁇ m, about 15 to 30 ⁇ m, and about 15 to 25 ⁇ m.
• the barrier layer 52 when the barrier layer 52 is an aluminum foil, it is preferable that at least the surface opposite to the base layer 51 is provided with a corrosion-resistant film in order to prevent dissolution and corrosion.
• the barrier layer 52 may be provided with a corrosion-resistant film on both sides.
• the corrosion-resistant film refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) on the barrier layer 52 by performing, for example, hydrothermal conversion treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment such as nickel or chromium, or corrosion prevention treatment by applying a coating agent on the surface of the barrier layer 52.
• the corrosion-resistant film means a film that improves the acid resistance of the barrier layer 52 (acid-resistant film), a film that improves the alkali resistance of the barrier layer 52 (alkali-resistant film), etc.
• the treatment for forming the corrosion-resistant film may be one type, or two or more types may be combined. In addition, it is possible to form not only one layer but also multiple layers. Furthermore, among these treatments, hydrothermal conversion treatment and anodizing treatment are treatments in which the metal foil surface is dissolved by a treatment agent to form metal compounds with excellent corrosion resistance. Note that these treatments may also be included in the definition of chemical conversion treatment. Also, if the barrier layer 52 has a corrosion-resistant coating, the corrosion-resistant coating is also included in the barrier layer 52.
• the corrosion-resistant coating prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base layer 51 during molding of the exterior film 50, prevents dissolution and corrosion of the surface of the barrier layer 52 due to hydrogen fluoride produced by the reaction between the electrolyte and moisture, and in particular prevents dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52 when the barrier layer 52 is an aluminum alloy foil, and improves the adhesion (wettability) of the surface of the barrier layer 52, preventing delamination between the base layer 51 and the barrier layer 52 during heat sealing and between the base layer 51 and the barrier layer 52 during molding.
• the barrier layer 52 e.g., aluminum alloy foil
• the heat-sealable resin layer 53 is bonded to the barrier layer 52, for example, via an adhesive layer 55.
• the heat-sealable resin layer 53 included in the exterior film 50 is a layer that provides the exterior film 50 with heat-sealing sealability.
• Examples of the heat-sealable resin layer 53 include resin films made of polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin resins such as polyethylene resins and polypropylene resins, or acid-modified polyolefin resins obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. From the standpoint of sealability and strength, the thickness of the heat-sealable resin layer 53 is preferably, for example, 20 to 300 ⁇ m, and more preferably 40 to 150 ⁇ m.
• the exterior film 50 has one or more layers with a buffer function (hereinafter referred to as "buffer layer") outside the heat-sealable resin layer 53, and more preferably outside the barrier layer 52.
• the buffer layer may be laminated on the outside of the base layer 51, or the base layer 51 may also function as a buffer layer.
• the multiple buffer layers may be adjacent to each other, or may be laminated via the base layer 51, the barrier layer 52, etc.
• the material constituting the buffer layer can be selected from any material having cushioning properties.
• the material having cushioning properties is, for example, rubber, nonwoven fabric, or foam sheet.
• the rubber is, for example, natural rubber, fluororubber, or silicone rubber.
• the rubber hardness is preferably about 20 to 90.
• the material constituting the nonwoven fabric is preferably a material having excellent heat resistance.
• the lower limit of the thickness of the buffer layer is preferably 100 ⁇ m, more preferably 200 ⁇ m, and even more preferably 1000 ⁇ m.
• the upper limit of the thickness of the buffer layer is preferably 5000 ⁇ m, and even more preferably 3000 ⁇ m.
• the preferred range of thickness of the buffer layer is 100 ⁇ m to 5000 ⁇ m, 100 ⁇ m to 3000 ⁇ m, 200 ⁇ m to 5000 ⁇ m, 200 ⁇ m to 3000 ⁇ m, 1000 ⁇ m to 5000 ⁇ m, or 1000 ⁇ m to 3000 ⁇ m.
• the most preferred range of thickness of the buffer layer is 1000 ⁇ m to 3000 ⁇ m.
• the lower limit of the thickness of the buffer layer is preferably 0.5 mm.
• the upper limit of the thickness of the buffer layer is preferably 10 mm, more preferably 5 mm, and even more preferably 2 mm.
• 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.
• the buffer layer functions as a cushion, preventing the exterior film 50 from being damaged by impact when the energy storage device 10 is dropped or by handling during the manufacture of the energy storage device 10.
• the lid body 60 has a cover body 70 and a lid main body 80.
• the cover 70 has a main body portion 70A and a joint portion 70B.
• the main body portion 70A has a shape similar to a hollow rectangular parallelepiped, for example.
• a space 79 is formed inside the main body portion 70A.
• the material constituting the main body portion 70A can be selected arbitrarily.
• the main body portion 70A is preferably composed of a metal material.
• “composed of a metal material” means that when the entire material constituting the main body portion 70A is taken as 100 mass%, the content of the metal material is 50 mass% or more, preferably 80 mass% or more, more preferably 90 mass% or more, and even more preferably 95 mass% or more.
• the material constituting the main body portion 70A can contain materials other than metal materials in addition to metal materials.
• the metal material constituting the main body portion 70A can be selected arbitrarily.
• the metal material constituting the main body portion 70A is, for example, aluminum, aluminum alloy, nickel, copper, or copper alloy.
• the main body 70A connected to the positive electrode is preferably made of aluminum or an aluminum alloy.
• the main body 70A connected to the negative electrode is preferably made of nickel, copper, or a copper alloy.
• the material constituting the main body 70A connected to the negative electrode may be copper plated with nickel.
• the material constituting the main body 70A may contain recycled metal materials.
• the main body 70A is made only of metal materials. Since the main body 70A is made of metal materials, it also functions as an electrode terminal. This allows the configuration of the electricity storage device 10 to be simplified.
• the main body 70A is made of a metal material, it is preferable that the main body 70A has a corrosion-resistant coating as described for the barrier layer 52.
• the main body portion 70A may be composed of a resin material.
• “composed of a resin material” means that, when the entire material constituting the main body portion 70A is taken as 100% by mass, the resin material content is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.
• the material constituting the main body portion 70A can contain materials other than the resin material in addition to the resin material.
• resins include thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenol resin, as well as modified versions of these resins.
• the resin material may be a mixture of these resins, a copolymer, or a modified version of a copolymer.
• the resin material is preferably a heat-sealable resin such as polyester or polyolefin, and more preferably polyolefin.
• the main body portion 70A may be molded by any molding method.
• the resin material contained in the material constituting the coating 70 is preferably an olefin-based random copolymer, more preferably contains a resin containing a polyolefin skeleton as a main component, even more preferably contains polyolefin as a main component, and even more preferably contains polypropylene as a main component.
• the polyolefin may be an acid-modified polyolefin.
• the resin material contained in the material constituting the coating 70 preferably contains multiple types of amide-based lubricants. Furthermore, the resin material contained in the material constituting the coating 70 preferably contains multiple types of amide-based lubricants that further contain unsaturated fatty acid amides in addition to saturated fatty acid amides.
• the resin material contained in the material constituting the coating 70 may be a polyolefin resin to which a propylene-based elastomer having a melting point higher than 150°C has been added.
• polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters.
• copolymer polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit.
• polyethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate
• polyethylene (terephthalate/isophthalate) polyethylene (terephthalate/adipate)
• polyethylene (terephthalate/sodium sulfoisophthalate) polyethylene (terephthalate/sodium isophthalate)
• polyethylene (terephthalate/phenyl-dicarboxylate) polyethylene (terephthalate/decanedicarboxylate).
• polybutylene terephthalate is the preferred resin material from the viewpoint of increasing heat resistance and pressure resistance.
• polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene- ⁇ -olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene- ⁇ -olefin copolymers; and ethylene-butene-propylene terpolymers.
• polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. Of these, polypropylene is preferred as the resin material because of its excellent heat fusion properties and electrolyte resistance.
• the resin as the resin material may contain a filler as necessary.
• fillers include glass beads, graphite, glass fiber, and carbon fiber.
• the melt mass flow rate of the resin material contained in the material constituting the main body 70A is preferably in the range of 1 g/10 min to 100 g/10 min, and more preferably in the range of 5 g/10 min to 80 g/10 min.
• the melt mass flow rate is measured based on JIS K7210-1:2014.
• the measurement temperature for the melt mass flow rate is 230°C.
• the main body 70A has a first surface 70X and a second surface 70Y.
• the first surface 70X faces the electrode body 20.
• An opening 70Z is formed over almost the entire first surface 70X.
• the second surface 70Y is the surface opposite to the first surface 70X.
• An opening 70YA is formed in the second surface 70Y into which the lid main body 80 is fitted.
• the opening 70YA penetrates the second surface 70Y.
• the shape of the opening 70YA in front view can be selected arbitrarily depending on the shape of the lid main body 80.
• the shape of the opening 70YA may be a square, a rectangle, a polygon having more than one triangle, a circle, or an ellipse. In this embodiment, the shape of the opening 70YA in front view is a rectangle.
• the corners of the opening 70YA are rounded by applying R processing.
• the main body 70A is made of a resin material, it is preferable that an adhesive film that can be bonded to metal materials and resin materials is bonded to at least a portion of the inner circumferential surface of the opening 70YA in order to suitably bond the lid main body 80.
• the main body 70A is made of a resin material, it is preferable that at least a portion of the portion of the main body 70A that corresponds to the inner circumferential surface of the opening 70YA has a layer that can be bonded to a metal material in order to suitably bond the lid main body 80.
• the main body 70A has a lid seal portion 71 and a protruding portion 77.
• the lid seal portion 71 is heat sealed to the heat-fusible resin layer 53 of the exterior film 50 via the joint portion 70B.
• the lid seal portion 71 includes a first seal surface 71A, a second seal surface 71B, a third seal surface 71C, and a fourth seal surface 71D.
• the first seal surface 71A constitutes the upper surface of the lid body 60.
• the first seal surface 71A extends in a first direction (in this embodiment, the LR direction) when viewed from the front of the lid body 60.
• the second seal surface 71B and the third seal surface 71C are connected to the first seal surface 71A and constitute the side surface of the lid body 60.
• the second seal surface 71B and the third seal surface 71C extend in a second direction (in this embodiment, the UD direction) that intersects with the first direction when viewed from the front of the lid body 60.
• the first direction and the second direction are perpendicular to each other when viewed from the front of the lid 60.
• the first direction and the second direction do not have to be perpendicular to each other when viewed from the front of the lid 60.
• the fourth seal surface 71D forms the lower surface of the lid 60.
• the fourth seal surface 71D extends in the first direction (the LR direction in this embodiment) when viewed from the front of the lid 60.
• the protrusion 77 protrudes inward from the lid seal portion 71 into the main body portion 70A.
• the protrusion 77 defines the portion that covers the lid main body 80, in other words, the opening 70YA.
• the amount by which the protrusion 77 protrudes from the lid seal portion 71 can be selected as desired. The greater the amount by which the protrusion 77 protrudes from the lid seal portion 71, the smaller the opening area of the opening 70YA. In other words, the smaller the amount by which the protrusion 77 protrudes from the lid seal portion 71, the larger the opening area of the opening 70YA.
• the protrusion 77 may be omitted from the main body portion 70A.
• the lid seal portion 71 further includes boundaries 72, 73, 74, and 75.
• Boundary 72 is the boundary between the first seal surface 71A and the second seal surface 71B.
• Boundary 73 is the boundary between the first seal surface 71A and the third seal surface 71C.
• Boundary 74 is the boundary between the fourth seal surface 71D and the second seal surface 71B.
• Boundary 75 is the boundary between the fourth seal surface 71D and the third seal surface 71C.
• the shapes of boundaries 72 to 75 may be angular, or may be rounded by applying R processing. In this embodiment, boundaries 72 to 75 are angular.
• the lid body 60 When the lid body 60 is generally plate-shaped, it is preferable that the lid body 60 has a certain degree of thickness so that deformation of the exterior body 40 is suppressed even when the power storage device 10 is arranged on top of each other. From another perspective, when the lid body 60 is plate-shaped, it is preferable that the lid seal portion 71 of the lid body 60 has a certain degree of thickness so that the lid seal portion 71 of the lid body 60 and the exterior film 50 can be suitably heat-sealed when forming the second sealing portion 92 described below.
• the minimum value of the thickness of the lid seal portion 71 of the lid body 60 is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm.
• the maximum value of the thickness of the lid seal portion 71 of the lid body 60 is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm.
• the maximum value of the thickness of the lid seal portion 71 of the lid body 60 may be 20 mm or more.
• the preferred ranges for the thickness of the lid seal portion 71 of the lid body 60 are 1.0 mm to 20 mm, 1.0 mm to 15 mm, 1.0 mm to 10 mm, 3.0 mm to 20 mm, 3.0 mm to 15 mm, 3.0 mm to 10 mm, 4.0 mm to 20 mm, 4.0 mm to 15 mm, and 4.0 mm to 10 mm.
• the thickness of the lid seal portion 71 of the lid body 60 may vary depending on the location of the lid body 60. When the thickness of the lid seal portion 71 of the lid body 60 varies depending on the location, the thickness of the lid seal portion 71 of the lid body 60 is the thickness of the thickest part.
• the lid body 80 shown in FIG. 5 is made of a metal material.
• the definition of "made of a metal material” and the specifications of the metal material constituting the lid body 80 are the same as those of the covering body 70.
• the lid body 80 has a first surface 81, a second surface 82, and a covering portion 83.
• the first surface 81 faces the electrode body 20.
• the first surface 81 is joined to the end 31 of the current collector 30 of the electrode body 20, for example, by welding.
• the second surface 82 is the surface opposite the first surface 81.
• An electrode terminal may be connected to the second surface 82.
• the lid body 80 When the lid body 80 is made of a metal material, it is preferable that the lid body 80 has a corrosion-resistant coating as described for the barrier layer 52. From the viewpoint of suitably joining the lid body 80 and the body portion 70A of the cover 70, the lid body 80 may have at least one of an adhesive film and an adhesive layer.
• the adhesive film or adhesive layer may be a single layer or a multilayer, and preferably contains at least a resin material having a polar group.
• the adhesive layer can be formed by dip coating, a dispenser, inkjet, spraying, screen printing, or the like.
• the covering portion 83 is connected to the first surface 81 and the second surface 82, and is at least partially covered by the covering body 70.
• the lid body 80 is fitted into the opening 70YA of the covering body 70, so that the entire covering portion 83 is covered by the inner surface of the opening 70YA.
• a portion of the covering portion 83 may be exposed from the covering body 70.
• the covering portion 83 includes a first covering portion 83A, a second covering portion 83B, a third covering portion 83C, and a fourth covering portion 83D.
• the first covering portion 83A constitutes the upper surface of the lid body 80.
• the first covering portion 83A extends in a first direction (LR direction in this embodiment) in a front view of the lid body 80.
• the second covering portion 83B and the third covering portion 83C are connected to the first covering portion 83A and constitute the side surface of the lid body 80.
• the second covering portion 83B and the third covering portion 83C extend in a second direction (UD direction in this embodiment) intersecting the first direction in a front view of the lid body 80.
• the first direction and the second direction are orthogonal in a front view of the lid body 80.
• the first direction and the second direction do not have to be orthogonal in a front view of the lid body 80.
• the fourth covering portion 83D constitutes the lower surface of the lid body 80.
• the fourth covering portion 83D extends in the first direction (the LR direction in this embodiment) when viewed from the front of the lid body 80.
• the coated portion 83 further includes boundaries 84, 85, 86, and 87.
• Boundary 84 is the boundary between the first coated portion 83A and the second coated portion 83B.
• Boundary 85 is the boundary between the first coated portion 83A and the third coated portion 83C.
• Boundary 86 is the boundary between the fourth coated portion 83D and the second coated portion 83B.
• Boundary 87 is the boundary between the fourth coated portion 83D and the third coated portion 83C.
• the shapes of the boundaries 84 to 88 may be angular, or may be rounded by applying R processing. In this embodiment, boundaries 84 to 87 are angular.
• the volume of the main body 70A is smaller than the volume of the lid body 80. If the volume of the main body 70A is smaller than the volume of the lid body 80, heat loss to the main body 70A is suppressed when the main body 70A and the heat-sealable resin layer 53 of the exterior film 50 are heat-sealed via the joint 70B, so the time required for heat sealing can be shortened.
• the joint 70B is arranged to suitably join the main body 70A and the heat-sealable resin layer 53 of the exterior film 50.
• the joint 70B may be, for example, a resin molded product that is made up of a resin material.
• the joint 70B is a resin molded product.
• the definition of "made up of a resin material" is the same as that explained for the main body 70A.
• the joint 70B may be an adhesive film that can be bonded to metal materials and resin materials.
• the adhesive film can be selected arbitrarily as long as it can bond the heat-sealable resin layer 53 of the exterior film 50 and the main body 70A.
• the adhesive film is preferably a laminated film having at least a heat-sealable resin layer, a heat-resistant base material layer, and a heat-sealable resin layer in this order.
• the specifications for the heat-sealable resin layer of the adhesive film can be the same as those for the heat-sealable resin layer 53.
• the acid-modified polyolefin examples include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; crystalline or amorphous polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); and ethylene-butene-propylene terpolymers.
• polyethylene and polypropylene are preferred, and polypropylene is particularly preferred.
• the acid-modified cyclic polyolefin is a copolymer of an olefin and a cyclic monomer
• examples of the olefins constituting the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, and isoprene.
• examples of the cyclic monomers constituting the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene.
• cyclic alkenes are preferred, and norbornene is even more preferred.
• Styrene is also an example of a constituting monomer.
• carboxylic acids or anhydrides thereof used for acid modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.
• the heat-sealable resin layer of the adhesive film on the side to be bonded to the exterior film 50 is preferably made of the same material as the material constituting the heat-sealable resin layer 53 of the exterior film 50.
• the adhesive film is preferably adhesive. If the adhesive film has adhesive properties, when the exterior film 50 and the main body portion 70A are joined, the exterior film 50 and the main body portion 70A are less likely to shift position relative to the other. Adhesive properties can be imparted to the adhesive film by incorporating an adhesive imparting resin into the heat-sealable resin layer of the adhesive film.
• the joint 70B may be an adhesive.
• the joint 70B may be a single layer or a multilayer, and preferably contains at least a resin material having a polar group.
• the adhesive layer can be formed by dip coating, a dispenser, inkjet, spraying, screen printing, or the like.
• the first sealing portion 91 is formed by heat sealing the opposing surfaces (heat-sealable resin layers 53) of the exterior film 50.
• the first sealing portion 91 includes a portion where the first edge 50A and the second edge 50B of the exterior film 50 shown in FIG. 3 are overlapped.
• the first sealing portion 91 extends in the longitudinal direction (FB direction) of the exterior body 40.
• the position where the first sealing portion 91 is formed in the exterior body 40 can be selected arbitrarily.
• the root 91X of the first sealing portion 91 is preferably located on the edge 43 at the boundary between the first surface 41A and the second surface 42A of the exterior body 40.
• the root 91X of the first sealing portion 91 may be located on any surface of the exterior body 40. From the viewpoint of configuring the power storage device 10 in a small size, it is preferable that the first sealing portion 91 is folded, for example, on the first surface 41A or the second surface 42A of the exterior body 40 when the power storage device 10 is used.
• the heat-sealable resin layer 53 of the exterior film 50 and the lid seal portion 71 of the main body portion 70A are heat-sealed via the joint portion 70B to form the second sealing portion 92.
• the seal strength between the heat-sealable resin layer 53 of the exterior film 50 and the lid seal portion 71 of the lid body 60 may be referred to as the seal strength of the second sealing portion 92.
• the seal strength of the second sealing portion 92 is the seal strength between the heat-sealable resin layer 53 and the lid body 60 at the long side portion of the lid seal portion 71, i.e., the lid seal portion 71 extending in the LR (width) direction in FIG. 1A.
• the seal strength of the second sealing portion 92 is measured as follows. First, a cut is made in the portion of the exterior film 50 that constitutes the first surface 41A of the exterior body 40, and three strip-shaped members 41X, 41Y, 41Z (see the two-dot chain line in FIG. 1B) are formed aligned in the LR direction. The width of the three strip-shaped members 41X, 41Y, 41Z in the LR direction is 15 mm. The ends of the strip-shaped members 41X, 41Y, 41Z are joined to the lid body 60 at the second sealing portion 92. The length of the lid body 60 in the LR direction is 45 mm or more.
• the seal strength of each of the strip-shaped members 41X, 41Y, 41Z is measured by pulling the end opposite the end joined to the lid body 60 upward in the UD direction (the direction opposite to the first surface 41B).
• the distance between the chucks in the UD direction is 10 mm.
• the seal strength of the strip members 41X, 41Y, and 41Z is the peak value of the seal strength.
• the seal strength of the second sealing portion 92 is the average value of the seal strength of the strip members 41X, 41Y, and 41Z.
• the seal strength of the three strip members is measured in the same manner as when the length of the lid body 60 in the LR direction is 45 mm or more.
• the obtained seal strengths are divided by the arbitrary width X mm and multiplied by 15 to convert them into the seal strengths of the three strip members in a width of 15 mm.
• the seal strength of the second sealing portion 92 is the average value of the seal strengths of the three strip members converted into a width of 15 mm.
• the seal strength of the second sealing portion 92 is the seal strength of the long side portion of the lid seal portion 71 of the multiple parts.
• the seal strength of the second sealing portion 92 is preferably 40 N/15 mm or more, more preferably 50 N/15 mm or more, more preferably 60 N/15 mm or more, more preferably 70 N/15 mm or more, and even more preferably 85 N/15 mm or more.
• the seal strength of the second sealing portion 92 is 40 N/15 mm or more, the state where the electrode body 20 is sealed by the exterior body 40 is maintained suitably even if the energy storage device 10 is used for, for example, several years (less than 10 years).
• the seal strength of the second sealing portion 92 is 85 N/15 mm or more, the state where the electrode body 20 is sealed by the exterior body 40 is maintained suitably even if the energy storage device 10 is used for, for example, 10 years or more.
• the seal strength of the second sealing portion 92 is preferably 300 N/15 mm or less.
• the preferred range of the seal strength of the second sealing portion 92 is 40N/15mm to 300N/15mm, 50N/15mm to 300N/15mm, 60N/15mm to 300N/15mm, 70N/15mm to 300N/15mm, or 85N/15mm to 300N/15mm.
• the manufacturing device bonds the main body 70A of the covering 70 and the heat-sealable resin layer 53 of the exterior film 50 via the bonding portion 70B by heat sealing or ultrasonic sealing. That is, the first process is a process for forming the second sealing portion 92.
• the element in which the covering 70 and the exterior film 50 are bonded is referred to as an intermediate body.
• the third step of step S3 is carried out after the first and second steps.
• the manufacturing device inserts the electrode body 20 with the lid body 80 connected thereto into the interior of the intermediate body through the opening 70YA of the main body 70A of the intermediate body.
• the electrode body 20 is accommodated inside the intermediate body.
• the opening 70YA of the main body 70A is closed by the lid body 80.
• FIG. 9 is a flow chart showing another example of a method for manufacturing an electricity storage device 10.
• the method for manufacturing an electricity storage device 10 includes, for example, an 11th step, a 12th step, a 13th step, a 14th step, a 15th step, and a 16th step.
• the 11th step to the 16th step are performed, for example, by a manufacturing device for the electricity storage device 10. At least some of the 11th step to the 16th step may be performed by an operator.
• the 11th step to the 16th step are merely names for the steps in the method for manufacturing an electricity storage device 10 for the sake of convenience, and do not necessarily refer to the order of the steps. The order of the steps below can be changed as desired.
• step S11 the manufacturing device places a pair of coating bodies 70 on the sides of the electrode body 20.
• the twelfth step of step S12 is performed after the eleventh step.
• the manufacturing device winds the exterior film 50 around the electrode body 20 and the covering 70 while tension is applied to the exterior film 50, while restricting the movement of the electrode body 20 and the covering 70 by the restricting means.
• the restricting means is, for example, a groove into which the electrode body 20 and the covering 70 are fitted.
• the restricting means may be a device that applies an external force to the electrode body 20 and the covering 70 so that the electrode body 20 and the covering 70 do not move.
• the restricting means may be a device that applies a force to the electrode body 20 and the covering 70 in the opposite direction to the direction in which the exterior film 50 is pulled.
• the restricting means may include a roller that runs on the exterior film 50 while the exterior film 50 is being pulled in order to remove wrinkles in the exterior film 50.
• the 14th step of step S14 is performed after the 13th step.
• the manufacturing device electrically connects the electrode body 20 and the lid body 80.
• the 14th step can be performed outside the covering body 70. This makes it easy to perform the 14th step.
• step S15 The fifteenth step (closing step) of step S15 is performed after the fourteenth step.
• the manufacturing device fits the lid body 80 into the opening 70YA of the body part 70A, and joins the body part 70A and the lid body 80 together, for example, by welding.
• the 16th step of step S16 is performed after the 15th step.
• the manufacturing device forms the first sealed portion 91 by heat-sealing the heat-sealable resin layer 53 in the portion including the first edge 50A of the exterior film 50 and the heat-sealable resin layer 53 in the portion including the second edge 50B.
• the above-mentioned embodiments are examples of possible forms of the electricity storage device, lid, covering, and manufacturing method of the electricity storage device according to the present invention, and are not intended to limit the forms.
• the electricity storage device, lid, covering, and manufacturing method of the electricity storage device according to the present invention may take forms different from those exemplified in the embodiments.
• One example is a form in which a part of the configuration of the embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to the embodiment.
• Some examples of modified embodiments are shown. Note that the following modified examples can be combined with each other as long as there is no technical contradiction.
• At least a part of the surface of the lid seal portion 71 in other words at least a part of the first seal surface 71A, the second seal surface 71B, the third seal surface 71C, and the fourth seal surface 71D, may be provided with a corrosion-resistant film.
• the corrosion-resistant film refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) on the surface of the lid seal portion 71 by performing, for example, hydrothermal conversion treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment such as nickel or chromium, or corrosion prevention treatment by applying a coating agent.
• the corrosion-resistant film refers to a film that improves the acid resistance of the lid seal portion 71 (acid-resistant film), a film that improves the alkali resistance of the lid seal portion 71 (alkali-resistant film), etc.
• the treatment for forming the corrosion-resistant film may be one type, or two or more types may be combined.
• hydrothermal conversion treatment and anodizing treatment are treatments in which the metal foil surface is dissolved by a treatment agent to form a metal compound with excellent corrosion resistance. Note that these treatments may also be included in the definition of chemical conversion treatment. Also, if the lid seal portion 71 is provided with a corrosion-resistant coating, the corrosion-resistant coating is also included in the lid seal portion 71.
• the covering body 70 may cover at least a portion of the first surface 81 and the second surface 82 of the lid body 80 instead of or in addition to the covering portion 83 of the lid body 80 .
• the exterior film 50 of the power storage device 10 may protrude outward from at least one of the two lid bodies 60 in the FB direction.
• the electrode body 20 is sealed by closing the portion of the exterior film 50 that protrudes outward from the lid body 60.
• the portion of the exterior film 50 that protrudes outward from the lid body 60 may be folded inward so that the outer surfaces of the exterior film 50 come into contact with each other, as in a Goebel-top container, or may be folded toward any surface of the exterior body 40, as in a brick container.
• the exterior body 40 may not have one of the two lid bodies 60.
• the electrode body 20 in a portion of the exterior body 40 where the lid body 60 is omitted, the electrode body 20 is sealed by closing a portion of the exterior film 50 that protrudes outward beyond the electrode body 20.
• the portion of the exterior film 50 that protrudes outward beyond the electrode body 20 may be folded like a Goebel-top container or a brick container, as in the seventh modification.
• the outer shape of the exterior body 40 can be changed as desired.
• the outer shape of the exterior body 40 may be a cylinder, a prism, or a cube.
• the electrode body 20 is wrapped in one exterior film 50 , but it may be wrapped in two or more exterior films 50 .
• Electrode body 40 Exterior body 50: Exterior film 60: Lid body 70: Cover body 70A: Main body 70B: Joint portion 71: Lid seal portion 77: Protrusion 80: Lid body

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