Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/122—Composite material consisting of a mixture of organic and inorganic materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/183—Sealing members
  • H01M50/19—Sealing members characterised by the material
  • H01M50/193—Organic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/78—Cases; Housings; Encapsulations; Mountings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G2/00—Details of capacitors not covered by a single one of groups H01G4/00-H01G11/00
  • H01G2/10—Housing; Encapsulation
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
  • H01M50/105—Pouches or flexible bags
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/117—Inorganic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/117—Inorganic material
  • H01M50/119—Metals
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/121—Organic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
  • H01M50/126—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers
  • H01M50/129—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers with two or more layers of only organic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/131—Primary casings; Jackets or wrappings characterised by physical properties, e.g. gas permeability, size or heat resistance
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/14—Primary casings; Jackets or wrappings for protecting against damage caused by external factors
  • H01M50/141—Primary casings; Jackets or wrappings for protecting against damage caused by external factors for protecting against humidity
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/183—Sealing members
  • H01M50/184—Sealing members characterised by their shape or structure
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/183—Sealing members
  • H01M50/186—Sealing members characterised by the disposition of the sealing members
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/471—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof
  • H01M50/474—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof characterised by their position inside the cells
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/471—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof
  • H01M50/48—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof characterised by the material
  • H01M50/483—Inorganic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/471—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof
  • H01M50/48—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof characterised by the material
  • H01M50/486—Organic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/531—Electrode connections inside a battery casing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/543—Terminals
  • H01M50/552—Terminals characterised by their shape
  • H01M50/553—Terminals adapted for prismatic, pouch or rectangular cells
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/78—Cases; Housings; Encapsulations; Mountings
  • H01G11/80—Gaskets; Sealings
• • 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

• This disclosure relates to a resin film for an electricity storage device and an electricity storage device.
• exterior materials are essential components for sealing the electricity storage device elements, such as the electrodes and electrolyte.
• metallic exterior materials have been widely used as exterior materials for electricity storage devices.
• a film-like laminate in which a base layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer are laminated in this order has been proposed as an exterior material for an electricity storage device that can be easily processed into a variety of shapes and can be made thin and lightweight (see, for example, Patent Document 1).
• recesses are generally formed by cold forming, electricity storage device elements such as electrodes and electrolyte are placed in the space formed by the recesses, and the heat-sealable resin layer is heat-sealed to obtain an electricity storage device in which the electricity storage device elements are housed inside the exterior material for electricity storage devices.
• a barrier layer made of, for example, metal foil.
• the heat-sealable resin layer of the exterior material absorbs water before the electricity storage device element is sealed with the exterior material, there is a risk that the moisture in the heat-sealable resin layer will penetrate into the electricity storage device element after the electricity storage device element is sealed.
• the main objective of this disclosure is to provide a resin film for electricity storage devices that has excellent insulating properties and prevents moisture from penetrating into the interior of electricity storage device elements.
• the inventors of the present disclosure conducted intensive research to solve the above problems. As a result, they discovered that by configuring a resin film for an electricity storage device with two or more layers, and setting the content of water absorbing agent in at least one of the two or more layers to 5 mass% or more, and setting the content of water absorbing agent in at least one of the two or more layers to less than 5 mass%, it is possible to suppress the penetration of moisture into the interior of an electricity storage device element while providing excellent insulation properties.
• a resin film for an electricity storage device is composed of two or more layers, the two or more layers include at least one layer A having a water absorbing agent content of 5% by mass or more, and at least one layer B having a water absorbing agent content of less than 5% by mass;
• 1 is a schematic diagram showing an example of a cross-sectional structure of a resin film for an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of a resin film for an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior material for an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure.
• 1 is a schematic perspective view illustrating an example of an electricity storage device according to the present disclosure.
• 1 is a schematic diagram showing an example of a cross-sectional structure of an electricity storage device according to the present disclosure.
• the resin film for an electricity storage device disclosed herein is composed of two or more layers, and the two or more layers are characterized by including at least one layer A having a water absorbing agent content of 5% by mass or more, and at least one layer B having a water absorbing agent content of less than 5% by mass.
• the resin film for an electricity storage device disclosed herein has excellent insulation properties and can suppress the penetration of moisture into the interior of the electricity storage device element.
• the resin film for electricity storage devices disclosed herein is described in detail below.
• 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 greater and 15 mm or less.
• a method for confirming the MD of the resin film for an electricity storage device there is a method of observing the cross section of the resin film for an electricity storage device (for example, the cross section of the acid-modified polyolefin layer or polyolefin layer) with an electron microscope to confirm the sea-island structure.
• the direction parallel to the cross section in which the average diameter of the island shape in the direction perpendicular to the thickness direction of the resin film for an electricity storage device was maximum can be determined as the MD.
• the cross section in the length direction of the resin film for an electricity storage device and each cross section (10 cross sections in total) at an angle of 10 degrees from the direction parallel to the cross section in the length direction to the direction perpendicular to the cross section in the length direction are observed with an electron microscope to confirm the sea-island structure.
• the shape of each individual island is observed in each cross section.
• the straight line distance connecting the leftmost end in the direction perpendicular to the thickness direction of the resin film for an electricity storage device and the rightmost end in the perpendicular direction is taken as the diameter y.
• the average of the diameters y of the top 20 island shapes in descending order of diameter y is calculated.
• the direction parallel to the cross section in which the average diameter y of the island shape is the largest is determined to be the MD.
• the resin film for an electricity storage device can be left in an environment of 150°C for 2 minutes, and the thermal shrinkage rate measured, and the direction with the larger shrinkage rate can be determined to be the MD.
• the resin film for power storage device of the present disclosure is composed of two or more layers.
• the two or more layers include at least one layer A having a water absorbing agent content of 5% by mass or more and at least one layer B having a water absorbing agent content of less than 5% by mass.
• the layer A having a water absorbing agent content of 5% by mass or more is referred to as the first layer 11, and the layer B having a water absorbing agent content of less than 5% by mass is referred to as the second layer 12.
• the third layer 13 is referred to as the layer B having a water absorbing agent content of less than 5% by mass.
• the resin film for an electricity storage device has excellent insulating properties and can suppress the intrusion of moisture into the interior of an electricity storage device element, and therefore can be suitably used as a resin film for an electricity storage device.
• the resin film 1 for an electricity storage device is suitable for use in the following applications: 1) an application in which it is disposed between an exterior material for an electricity storage device and an electricity storage device element; 2) an application in which it is used as a heat-sealable resin layer of an exterior material for an electricity storage device; 3) an application in which it is used as an adhesive layer between a barrier layer and a heat-sealable resin layer of an exterior material for an electricity storage device; or 4) an application in which it is used as an adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of an electricity storage device element and an exterior material for an electricity storage device that seals the electricity storage device element.
• the resin film for an electricity storage device can also be used to be interposed between heat-sealable resin layers at a position where the heat-sealable resin layers of the exterior material for an electricity storage device are heat-sealed to each other.
• the resin film 1 for an electricity storage device is disposed between an exterior material for an electricity storage device and an electricity storage device element
• the resin film 1 for an electricity storage device of the present disclosure is disposed between the exterior material 3 of an electricity storage device 10 and an electricity storage device element 4, as shown in the schematic diagrams of Figures 5 to 9.
• a barrier layer (e.g., made of metal foil) is provided on the film-like exterior material.
• a barrier layer By providing a barrier layer, it is possible to suppress the penetration of moisture from the outside of the barrier layer.
• the heat-sealable resin layer of the exterior material is heat-sealed to seal the electricity storage device element, the end face of the heat-sealable resin layer is exposed to the outside, and there is a risk of moisture penetrating from the end face of the heat-sealable resin layer.
• the heat-sealable resin layer of the exterior material absorbs water before sealing the electricity storage device element with the exterior material, there is a risk that the moisture in the heat-sealable resin layer will penetrate into the electricity storage device element after the electricity storage device element is sealed.
• the resin film 1 for an electricity storage device of the present disclosure is disposed between the exterior material 3 and the electricity storage device element 4 of the electricity storage device 10, it is possible to effectively prevent moisture from penetrating from the end of the heat-sealable resin layer of the exterior material, and the moisture contained in the heat-sealable resin layer of the exterior material from penetrating into the electricity storage device element. That is, since the resin film 1 for an electricity storage device of the present disclosure contains a water absorbing agent, the resin film 1 for an electricity storage device absorbs and retains moisture that has penetrated from the heat-sealable resin layer of the exterior material, thereby preventing moisture from reaching the electricity storage device element 4. Furthermore, since the resin film 1 for an electricity storage device of the present disclosure includes layer B with a water absorbing agent content of less than 5% by mass, it is possible to ensure excellent insulation.
• the resin film 1 for an electric storage device of the present disclosure is used as 2) a heat-sealable resin layer of an exterior material for an electric storage device
• the resin film 1 for an electric storage device of the present disclosure is used as the heat-sealable resin layer 35 of an exterior material for an electric storage device 3 composed of a laminate having at least a base layer 31, a barrier layer 33, and a heat-sealable resin layer 35 in this order, as shown in FIG. 3.
• the resin film 1 for an electric storage device of the present disclosure is used as 3) an adhesive layer between a barrier layer and a heat-sealable resin layer of an exterior material for an electric storage device
• the resin film 1 for an electric storage device of the present disclosure is used as the adhesive layer 34 of an exterior material for an electric storage device 3 composed of a laminate having at least a base layer 31, a barrier layer 33, an adhesive layer 34, and a heat-sealable resin layer 35 in this order, as shown in FIG. 3.
• the heat-sealable resin layer of the exterior material when the heat-sealable resin layer of the exterior material is heat-sealed to seal the electricity storage device element, the end faces of the heat-sealable resin layer are exposed to the outside, and so there is a risk of moisture penetrating from the end faces of the heat-sealable resin layer. Furthermore, if the heat-sealable resin layer of the exterior material absorbs water before the electricity storage device element is sealed with the exterior material, there is a risk that moisture in the heat-sealable resin layer will penetrate into the electricity storage device element after the electricity storage device element is sealed. The same applies to the adhesive layer located between the barrier layer and the heat-sealable resin layer.
• the resin film 1 for an electricity storage device of the present disclosure as the heat-sealable resin layer or adhesive layer of the exterior material 3, it is possible to effectively prevent moisture from penetrating from the end of the heat-sealable resin layer of the exterior material, and the moisture contained in the heat-sealable resin layer or adhesive layer of the exterior material from penetrating into the electricity storage device element. That is, since the resin film 1 for an electricity storage device of the present disclosure contains a water absorbing agent, the resin film 1 for an electricity storage device absorbs and retains moisture that has penetrated from the heat-sealable resin layer of the exterior material, thereby preventing moisture from reaching the electricity storage device element 4. Furthermore, since the resin film 1 for an electricity storage device of the present disclosure includes layer B with a water absorbing agent content of less than 5% by mass, it is possible to ensure excellent insulation.
• the resin film 1 for an electricity storage device of the present disclosure is used as an adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of an electricity storage device element and an exterior material for an electricity storage device that encapsulates the electricity storage device element, as shown in Figure 4, the resin film 1 for an electricity storage device is used as an adhesive film for a metal terminal 21.
• the adhesive film for metal terminals Because the end faces of the adhesive film for metal terminals are exposed to the outside, there is a risk that moisture may penetrate through the end faces of the adhesive film for metal terminals. In addition, if the adhesive film for metal terminals absorbs water before it is interposed between the metal terminal and the exterior material for the electricity storage device, there is a risk that the moisture in the adhesive film for metal terminals may penetrate into the electricity storage device element after the adhesive film for metal terminals is interposed between the metal terminal and the exterior material for the electricity storage device.
• the resin film 1 for an electricity storage device of the present disclosure as an adhesive film for a metal terminal, it is possible to effectively prevent the infiltration of moisture from the ends of the adhesive film for a metal terminal and the infiltration of moisture contained in the adhesive film for a metal terminal.
• the resin film 1 for an electricity storage device of the present disclosure contains a water absorbing agent, the resin film 1 for an electricity storage device absorbs and retains moisture that has infiltrated from the adhesive film for a metal terminal, thereby preventing the moisture from reaching the electricity storage device element 4.
• the resin film 1 for an electricity storage device of the present disclosure includes layer B with a water absorbing agent content of less than 5% by mass, it is possible to ensure excellent insulation properties.
• the moisture to be absorbed is gaseous and/or liquid moisture.
• the moisture to be absorbed generates various outgases when absorbed, for example, in a solid electrolyte type lithium ion battery.
• the energy storage device 10 has a structure in which the energy storage device element 4 is sealed with the exterior material 3, as shown in, for example, Figures 4 to 11.
• the metal terminal 2 protrudes outside the exterior material 3.
• the metal terminal 2 is connected to each of the positive and negative electrodes of the energy storage device element 4.
• An adhesive film 21 for metal terminals is disposed between the metal terminal 2 and the exterior material 3, and the adhesion between the metal terminal 2 and the heat-sealable resin layer 35 of the exterior material is enhanced.
• the energy storage device 10 is sealed by covering the energy storage device element 4 with the exterior material 3 so that a flange portion (peripheral portion 3a of the exterior material 3) of the exterior material 3 can be formed around the periphery of the energy storage device element 4, and then heat-sealing the flange portion of the exterior material 3 to seal it.
• the exterior material 3 is used to house the energy storage device element 4, the exterior material 3 is used so that the heat-sealable resin layer 35 of the exterior material 3 faces inside (the surface in contact with the energy storage device element 4).
• the adhesive film 1 for an electrical storage device of the present disclosure is used as an adhesive film for a metal terminal, for example, by coloring the adhesive film for a metal terminal, the adhesive film for a metal terminal can be positioned with high positional accuracy between the metal terminal and the exterior material for an electrical storage device.
• the layer constituting the surface of the adhesive film for a metal terminal on the metal terminal side is preferably composed of an acid-modified polyolefin. This makes it possible to increase the adhesion of the adhesive film for a metal terminal to the metal terminal.
• the exterior material 3 is wrapped (wrapped around the body) around the electricity storage device element 4 (rectangular parallelepiped shape in Figs. 10 and 11) with the heat-sealable resin layer of the exterior material 3 for the electricity storage device facing inward, and the heat-sealable resin layers are heat-sealed to form a heat-sealed portion 70, and a lid 60 is arranged to close the openings at both ends.
• the resin film for the electricity storage device 1 of the present disclosure may be arranged between the exterior material 3 wrapped around the body of the resin film for the electricity storage device and the electricity storage device element 4.
• the lid 60 constitutes a part of the exterior material 3 for the electricity storage device, and the resin film for the electricity storage device 1 of the present disclosure is arranged between the exterior material 3 and the electricity storage device element 4.
• the lid 60 may be composed of one member or multiple members.
• the resin film 1 for an electricity storage device of the present disclosure may be located over the entire surface of the exterior material 3 on the electricity storage device element 4 side (the heat-sealable resin layer 35 side), or may be located over a portion of the surface on the electricity storage device element 4 side (the heat-sealable resin layer 35 side).
• the resin film 1 for an electricity storage device is preferably located between the exterior material 3 and the electricity storage device element 4 of the electricity storage device 10 so as to be located over the entire surface of the exterior material 3 on the electricity storage device element 4 side (the heat-sealable resin layer 35 side) (see schematic diagrams of Figures 5 to 9).
• the resin film 1 for the electric storage device may be disposed only between the exterior material 3 for the electric storage device and the electric storage device element 4, or as shown in FIG. 6, the resin film 1 for the electric storage device may be disposed between the peripheral portion 3a (heat-sealed portion) of the exterior material 3 and the electric storage device element 4, or as shown in FIG.
• the electric storage device element 4 may be covered with the resin film 1 for the electric storage device, or as shown in FIG. 8, a part of the surface of the metal terminal 2 may be further covered with the resin film 1 for the electric storage device. Furthermore, as shown in FIG. 9, the resin film 1 for the electric storage device of the present disclosure may be disposed between the exterior material 3 and the electric storage device element 4 of the electric storage device 10 so that the electric storage device element 4 is sealed by the resin film 1 for the electric storage device. The resin film 1 for the electric storage device may also be present between the exterior material 3 and the metal terminal 2 and heat-sealed.
• the resin film 1 for an electricity storage device When the resin film 1 for an electricity storage device is located at the flange portion of the exterior material 3 (peripheral portion 3a of the exterior material 3), it is preferable that the resin film 1 for an electricity storage device has heat fusion properties.
• the resin film 1 for an electricity storage device since the resin film 1 for an electricity storage device is located at the flange portion where the exterior material 3 is heat sealed, it is preferable that the resin film 1 for an electricity storage device has heat fusion properties with the heat-sealable resin layer 35 and the adhesive film 21 for the metal terminal. It is also preferable that the resin films 1 for an electricity storage device have heat fusion properties with each other.
• layer A which has a water absorbing agent content of 5% by mass or more, may be a single layer or multiple layers, and is preferably a single layer.
• Layer B which has a water absorbing agent content of less than 5% by mass, may be a single layer or multiple layers.
• the resin film 1 for an electricity storage device of the present disclosure is composed of two or more layers, for example, as shown in Figures 1 and 2.
• Figure 1 shows a resin film 1 for an electricity storage device composed of a two-layer laminate in which a first layer 11 and a second layer 12 are laminated
• Figure 2 shows a resin film 1 for an electricity storage device composed of a three-layer laminate in which a second layer 12, a first layer 11, and a third layer 13 are laminated in this order.
• the first layer 11 is layer A with a water absorbent content of 5% by mass or more
• the second layer 12 and the third layer 13 are layer B with a water absorbent content of less than 5% by mass.
• a layer containing a water absorbing agent may be referred to as a "water absorbing layer.” That is, in the present disclosure, layer A (first layer 11) with a water absorbing agent content of 5% by mass or more is a water absorbing layer, and layer B (second layer 12 and third layer 13) with a water absorbing agent content of less than 5% by mass is also a water absorbing layer when it contains a water absorbing agent.
• Specific examples of the laminated structure of the resin film for electrical storage devices 1 include a laminated structure in which the first layer 11 is a water absorbing layer and the second layer 12 is a layer that does not contain a water absorbing agent in FIG. 1.
• examples of the laminated structure in which the first layer 11 located in the middle is a water absorbing layer and the second layer 12 and third layer 13 located on the surface are layers that do not contain a water absorbing agent in FIG. 2.
• the two or more layers of the resin film for an electricity storage device may include at least one layer A having a water absorbing agent content of 5% by mass or more and at least one layer B having a water absorbing agent content of less than 5% by mass, but from the viewpoint of more suitably exerting the effects of the present disclosure, the content of the water absorbing agent in layer A is preferably about 10% by mass or more, more preferably about 15% by mass or more, and also preferably about 50% by mass or less, more preferably about 40% by mass or less, and even more preferably about 30% by mass or less, and preferred ranges include about 5 to 50% by mass, about 5 to 40% by mass, about 5 to 30% by mass, about 10 to 50% by mass, about 10 to 40% by mass, about 10 to 30% by mass, about 15 to 50% by mass, about 15 to 40% by mass, and about 15 to 30% by mass.
• the content of the water-absorbing agent in Layer A exceeds 50% by mass, there is a concern that foreign matter may be generated in Layer A, resulting in poor film formation, reduced interlayer adhesion, and reduced laminate strength or seal strength. On the other hand, if the content of the water-absorbing agent is 5% or less, sufficient water absorption cannot be achieved.
• the content of the water-absorbing agent in layer B which has a water-absorbing agent content of less than 5% by mass, is preferably about 3% by mass or less, and more preferably 0% by mass, and examples of preferred ranges include about 0 to 5% by mass and about 0 to 3% by mass.
• the thickness of layer A having a water absorbing agent content of 5% by mass or more is preferably about 3 ⁇ m or more, more preferably about 5 ⁇ m or more, even more preferably about 10 ⁇ m or more, and is preferably about 200 ⁇ m or less, more preferably about 150 ⁇ m or less, even more preferably about 100 ⁇ m or less.
• Preferred ranges include about 3 to 200 ⁇ m, about 3 to 150 ⁇ m, about 3 to 100 ⁇ m, about 5 to 200 ⁇ m, about 5 to 150 ⁇ m, about 5 to 100 ⁇ m, about 10 to 200 ⁇ m, about 10 to 150 ⁇ m, and about 10 to 100 ⁇ m.
• the thickness of layer B in which the content of the water absorbent is less than 5 mass % is preferably about 3 ⁇ m or more, more preferably about 5 ⁇ m or more, even more preferably about 10 ⁇ m or more, and is preferably about 100 ⁇ m or less, more preferably about 80 ⁇ m or less, even more preferably about 50 ⁇ m or less, and preferred ranges include about 3 to 100 ⁇ m, about 3 to 80 ⁇ m, about 3 to 50 ⁇ m, about 5 to 100 ⁇ m, about 5 to 80 ⁇ m, about 5 to 50 ⁇ m, about 10 to 100 ⁇ m, about 10 to 80 ⁇ m, and about 10 to 50 ⁇ m.
• the total thickness of the resin film 1 for an electricity storage device is not particularly limited as long as it provides the effects of the present invention, and is preferably at least about 10 ⁇ m, more preferably at least about 15 ⁇ m, and even more preferably at least about 20 ⁇ m, and is preferably no more than about 1000 ⁇ m, more preferably no more than about 900 ⁇ m, and even more preferably no more than about 500 ⁇ m.
• Preferred ranges for the thickness include about 10 to 1000 ⁇ m, about 10 to 900 ⁇ m, about 10 to 500 ⁇ m, about 15 to 1000 ⁇ m, about 15 to 900 ⁇ m, about 15 to 500 ⁇ m, about 20 to 1000 ⁇ m, about 20 to 900 ⁇ m, and about 20 to 500 ⁇ m.
• the total thickness may be within the above-mentioned range, but is preferably at least about 30 ⁇ m, more preferably at least about 50 ⁇ m, and even more preferably at least about 60 ⁇ m, and is preferably no more than about 1000 ⁇ m, more preferably no more than about 500 ⁇ m, and even more preferably no more than about 300 ⁇ m.
• Preferred ranges include about 30 to 1000 ⁇ m, about 30 to 500 ⁇ m, about 30 to 300 ⁇ m, about 50 to 1000 ⁇ m, about 50 to 500 ⁇ m, about 50 to 300 ⁇ m, about 60 to 1000 ⁇ m, about 60 to 500 ⁇ m, and about 60 to 300 ⁇ m.
• the ratio of the thickness of layer B, in which the content of the water absorbent is less than 5 mass%, to the total thickness of the resin film for electrical storage devices 1 is preferably about 0.80 or less, more preferably about 0.75 or less, and even more preferably about 0.50 or less, with the lower limit being, for example, about 0.01, about 0.05, or about 0.10, and preferred ranges include about 0.01 to 0.80, about 0.01 to 0.75, about 0.01 to 0.50, about 0.05 to 0.80, about 0.05 to 0.75, about 0.05 to 0.50, about 0.10 to 0.80, about 0.10 to 0.75, or about 0.10 to 0.50.
• At least one layer preferably contains a heat-sealable resin. Furthermore, it is preferable that one or both sides of the resin film 1 for an electricity storage device have heat-sealability.
• the resin film 1 for an electricity storage device in the above-mentioned application 2) where the resin film 1 for an electricity storage device is used as a heat-sealable resin layer of an exterior material for an electricity storage device, at least one side of the resin film 1 for an electricity storage device must have heat-sealability. It is particularly preferable that all layers of the resin film 1 for an electricity storage device contain a heat-sealable resin.
• the resin film 1 for the electric storage device is disposed between the exterior material for the electric storage device and the electric storage device element
• the resin film 1 for the electric storage device when the resin film 1 for the electric storage device is located at the flange portion of the exterior material 3 (peripheral portion 3a of the exterior material 3), it is preferable to enhance the thermal adhesion of the resin film 1 for the electric storage device.
• the resin film 1 for the electric storage device is composed of three or more layers, it is preferable that the layer located at the surface (the second layer 12 and the third layer 13 in FIG. 2) contains a thermal adhesion resin.
• the layer located at the surface does not contain a water absorbing agent (particularly an inorganic water absorbing agent).
• a water absorbing agent particularly an inorganic water absorbing agent.
• the water absorption layer is provided between the layers located at the surface. This is because if the water absorption layer is located at the surface, it absorbs moisture in the air before the electric storage device is manufactured, and the water absorption performance of the water absorption layer is likely to decrease.
• the third layer 13 located on the exterior material 3 side is the water absorption layer. This is because the third layer 13 is close to the exterior material 3 and easily absorbs moisture that has infiltrated from the exterior material 3 side.
• the second layer 12 located on the electricity storage device element 4 side is the water absorption layer. This is because the second layer 12 is close to the electricity storage device element 4 and easily absorbs moisture contained in the electricity storage device element 4.
• the resin contained in the resin film 1 for electric storage devices is not particularly limited as long as it does not impair the effects of the present disclosure.
• it is preferably a thermoplastic resin, and more preferably a heat-sealable resin.
• the resin include thermoplastic resins such as polyolefin, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenolic resin, as well as modified products of these resins.
• the resin forming the resin film 1 for electric storage devices may be a copolymer of these resins or a modified product of the copolymer. It may also be a mixture of these resins.
• heat-sealable resins such as polyolefin and polyester are preferred.
• 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.
• 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 copoly
• the polyolefin resin When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more. Among these, polypropylene is particularly preferred because of its excellent heat fusion properties.
• the polypropylene may be either random polypropylene or homopolypropylene, but random polypropylene is preferred from the viewpoints of water absorption speed and film-forming properties.
• 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.
• polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate/isophthalate)), polyethylene (terephthalate/adipate), polyethylene (terephthalate/sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate), and polyethylene (terephthalate/decane dicarboxylate).
• polyethylene (terephthalate/isophthalate) polyethylene (terephthalate/adipate)
• polyethylene (terephthalate/sodium sulfoisophthalate) polyethylene
• Terephthalate/sodium isophthalate polyethylene (terephthalate/phenyl-dicarboxylate)
• polyethylene (terephthalate/decane dicarboxylate) polyethylene (terephthalate
• the resin contained in the resin film for electric storage devices 1 may contain an elastomer.
• the elastomer plays a role in ensuring the durability of the resin film for electric storage devices 1 in a high-temperature environment while increasing its flexibility.
• Preferred elastomers include at least one thermoplastic elastomer selected from polyesters, polyamides, polyurethanes, polyolefins, polystyrenes, and polyethers, or thermoplastic elastomers that are copolymers of these.
• the content of the elastomer is not particularly limited as long as it can ensure the durability of the resin film for electric storage devices 1 in a high-temperature environment while increasing its flexibility, and is, for example, 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 even more preferably about 3.0% by mass or more.
• 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.
• Preferred ranges of the content include about 0.1 to 10.0% by mass, about 0.1 to 8.0% by mass, about 0.1 to 5.0% by mass, about 0.5 to 10.0% by mass, about 0.5 to 8.0% by mass, about 0.5 to 5.0% by mass, about 1.0 to 10.0% by mass, about 1.0 to 8.0% by mass, about 1.0 to 5.0% by mass, about 3.0 to 10.0% by mass, about 3.0 to 8.0% by mass, and about 3.0 to 5.0% by mass.
• the resin content in the resin film 1 for electrical storage devices can be, for example, 40.0% by mass or more, 45.0% by mass or more, 50.0% by mass or more, 55.0% by mass or more, 60.0% by mass or more, 65.0% by mass or more, 70.0% by mass or more, 75.0% by mass or more, 80.0% by mass or more, 85.0% by mass or more, 90.0% by mass or more, 95.0% by mass or more, 99.0% by mass or more, 99.5% by mass or more, 99.9% by mass or more, etc.
• the content of the absorbent contained in the resin film for an electricity storage device is preferably 3% by mass or more, more preferably 6% by mass or more, and even more preferably 9% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, and preferred ranges include about 3 to 30% by mass, about 3 to 25% by mass, about 3 to 20% by mass, about 6 to 30% by mass, about 6 to 25% by mass, about 6 to 20% by mass, about 9 to 30% by mass, about 9 to 25% by mass, and about 9 to 20% by mass.
• the water absorbing agent contained in the resin film 1 for a power storage device is not particularly limited as long as it is dispersed in the resin film and exhibits water absorption.
• an inorganic water absorbing agent can be suitably used.
• the inorganic water absorbing agent for example, an alkali metal compound, an alkaline earth metal compound, etc. are preferable.
• preferable inorganic water absorbing agents include calcium oxide, anhydrous magnesium sulfate, magnesium oxide, calcium chloride, zeolite, aluminum oxide, silica gel, alumina gel, and burnt alum.
• inorganic chemical water absorbing agents have a higher water absorbing effect than inorganic physical water absorbing agents, can reduce the content, and are easy to achieve sufficient water absorption and heat fusion in a single layer.
• inorganic chemical water absorbing agents calcium oxide, anhydrous magnesium sulfate, and magnesium oxide are particularly preferable because they release less moisture again, have high stability over time in a low humidity state inside the package, and have an absolute dry effect.
• the bone-dry effect refers to the effect of absorbing water until the relative humidity is close to 0%
• the humidity control effect refers to the effect of absorbing water when the humidity is high and releasing moisture when the humidity is low, thereby keeping the humidity constant.
• inorganic chemical absorbents with a high temperature range for re-releasing moisture are preferred.
• the water absorbing agent contained in the water absorbing layer is preferably contained via a master batch in which the water absorbing agent and resin are melt blended. Specifically, the water absorbing agent is melt blended at a relatively high concentration with the resin to prepare a master batch. The obtained master batch is further mixed with the resin and formed into a film to form the water absorbing layer.
• the content of the water absorbing agent in the master batch is preferably about 20 to 90 mass %, more preferably about 30 to 70 mass %. Within the above range, it is easy to contain a necessary and sufficient amount of water absorbing agent in a dispersed state in the water absorbing layer.
• the resin film 1 for an electricity storage device can contain various plastic compounding agents and additives, for example, for the purpose of improving or modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, release properties, flame retardancy, mold resistance, electrical properties, strength, etc.
• the content can be any amount depending on the purpose, ranging from a trace amount to several tens of percent.
• typical additives that can be contained include, for example, antiblocking agents, lubricants, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, etc.
• the content of solid particles in layer A of the two or more layers in the resin film for an electrical storage device 1 of the present disclosure is preferably about 10% by mass or more, more preferably about 15% by mass or more, and also preferably about 50% by mass or less, more preferably about 40% by mass or less, and even more preferably about 30% by mass or less, with preferred ranges being about 5-50% by mass, about 5-40% by mass, about 5-30% by mass, about 10-50% by mass, about 10-40% by mass, about 10-30% by mass, about 15-50% by mass, about 15-40% by mass, and about 15-30% by mass.
• layer B which has a water absorbing agent content of less than 5% by mass, has a solid particle content of preferably less than about 5%, more preferably less than about 3% by mass, and even more preferably 0% by mass, with preferred ranges being about 0-5% by mass, about 0-3% by mass, and the like.
• solid particles include some of the water absorbents exemplified above, as well as pigments (e.g., carbon black, titanium oxide, cadmium, lead, chromium oxide, iron, etc.) and fillers (silica, etc.).
• the resin film for an electricity storage device disclosed herein has a dielectric breakdown strength after water absorption, measured by the following measurement method, of preferably about 40 kV/mm or more, more preferably about 50 to 200 kV/mm, and even more preferably about 50 to 150 kV/mm.
• a 10 cm square resin film for a storage battery device is prepared and immersed in warm water at 80°C. The immersion is continued until the water absorbing agent in the resin film for a storage battery device absorbs 100% of the water, to obtain a resin film for a storage battery device after water absorption.
• the water absorbing agent in the resin film is judged to have absorbed 100% of the water when the weight of the resin film does not change due to immersion.
• the water absorption degree of the resin film for a storage battery device is calculated from the weight of the film before and after immersion.
• the dielectric breakdown strength of the resin film for a storage battery device after water absorption is measured in accordance with the provisions of JIS C 2110-1:2016 under the following measurement conditions: 23°C in air, short-time method for boosting voltage (AC, 50 Hz), boosting rate of 0.3 kV/s, and electrodes of 25 mm ⁇ cylinder/75 mm ⁇ cylinder.
• the measured value is the average value of 5 samples.
• the method for producing the resin film 1 for use in an electrical storage device is not particularly limited as long as the resin film 1 for use in an electrical storage device can be obtained, and known or commonly used film-forming methods and lamination methods can be applied.
• the resin film 1 for use in an electrical storage device can be produced by known film-forming methods and/or lamination methods, such as an extrusion method or a co-extrusion method, a cast molding method, a T-die method, a cutting method, or an inflation method.
• a film constituting each layer that has been produced in advance may be laminated via an adhesive layer, a molten resin composition may be laminated on a layer that has been produced in advance by extrusion or co-extrusion, a plurality of layers may be simultaneously produced and laminated by melt pressure bonding, or one or more resins may be applied and dried to coat another layer.
• the layers constituting the resin film 1 for electricity storage devices can be laminated by extrusion or co-extrusion using an extrusion coating method, or can be laminated via an adhesive layer after film formation using an inflation method or casting method.
• lamination can also be performed via an adhesive layer as necessary.
• a film that has already been formed can be laminated and bonded via an adhesive layer that has been laminated using an extrusion coating method, dry lamination method, non-solvent lamination method, etc. Then, an aging treatment can be performed as necessary.
• the resin composition forming the layer is first heated and melted, and then expanded and stretched in the required width direction using a T-die to extrude or co-extrude in a curtain shape, and the molten resin is allowed to flow down onto the surface to be laminated and sandwiched between a rubber roll and a cooled metal roll, thereby simultaneously forming the layer and laminating and adhering to the surface to be laminated.
• the melt flow rate (MFR) of the resin component contained in each layer is preferably 0.2 to 50 g/10 min, more preferably 0.5 to 30 g/10 min. If the MFR is smaller or larger than the above range, the processability is likely to be inferior.
• MFR is a value measured using a method conforming to JIS K7210.
• the melt flow rate (MFR) of the resin component contained in each layer is preferably 0.2 to 10 g/10 min, and more preferably 0.2 to 9.5 g/10 min. If the MFR is smaller or larger than the above range, the processability is likely to be inferior.
• a desired surface treatment can be applied in advance, as necessary, to the surface of each layer.
• a corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, etc. can be optionally applied to form a corona treatment layer, ozone treatment layer, plasma treatment layer, oxidation treatment layer, etc.
• various coating layers such as a primer coating layer, an undercoat coating layer, an anchor coating layer, an adhesive layer, and a vapor deposition anchor coating layer can be optionally formed on the surface to form a surface treatment layer.
• a resin composition containing a polyester resin, a polyamide resin, a polyurethane resin, an epoxy resin, a phenol 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 the main component of the vehicle can be used.
• Each layer constituting the resin film for the electricity storage device can be further uniaxially or biaxially stretched by a conventionally known method using a tenter method, a tubular method, or the like, as necessary.
• the electricity storage device 10 of the present disclosure has a structure in which the electricity storage device element 4 is sealed with the exterior material 3.
• the electricity storage device 10 is sealed by covering the electricity storage device element 4 with the exterior material 3 so that a flange portion (peripheral portion 3a of the exterior material 3) of the exterior material 3 can be formed around the periphery of the electricity storage device element 4, and then heat-sealing the flange portion of the exterior material 3 to form a hermetic seal.
• the resin film for an energy storage device 1 may be located over the entire surface of the exterior material 3 on the energy storage device element 4 side (the heat-sealable resin layer 35 side), or may be located over a portion of the surface on the energy storage device element 4 side (the heat-sealable resin layer 35 side).
• the resin film for an energy storage device 1 is disposed between the exterior material 3 and the energy storage device element 4 of the energy storage device 10 so as to be located over the entire surface of the exterior material 3 on the energy storage device element 4 side (the heat-sealable resin layer 35 side) (see schematic diagrams of Figures 5 to 9).
• the resin film 1 for the electric storage device may be disposed only between the exterior material 3 for the electric storage device and the electric storage device element 4, or as shown in FIG. 6, the resin film 1 for the electric storage device may be disposed between the peripheral portion 3a (heat-sealed portion) of the exterior material 3 and the electric storage device element 4, or as shown in FIG.
• the electric storage device element 4 may be covered with the resin film 1 for the electric storage device, or as shown in FIG. 8, a part of the surface of the metal terminal 2 may be further covered with the resin film 1 for the electric storage device. Furthermore, as shown in FIG. 9, the resin film 1 for the electric storage device of the present disclosure may be disposed between the exterior material 3 and the electric storage device element 4 of the electric storage device 10 so that the electric storage device element 4 is sealed by the resin film 1 for the electric storage device. The resin film 1 for the electric storage device may also be present between the exterior material 3 and the metal terminal 2 and heat-sealed.
• the resin film 1 for an electricity storage device of the present disclosure is used as the heat-sealable resin layer 35 of the exterior material for an electricity storage device 3 composed of a laminate having at least a base layer 31, a barrier layer 33, and a heat-sealable resin layer 35 in this order, as shown in FIG. 3.
• the resin film 1 for an energy storage device in the application described above in 4) where the resin film 1 for an energy storage device is used as an adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of the energy storage device element and an exterior material for an energy storage device that encapsulates the energy storage device element, as shown in FIG. 4, the resin film 1 for an energy storage device is used as an adhesive film for a metal terminal 21.
• the exterior material 3 may be a metal can or a laminated film having a barrier layer.
• the exterior material 3 made of a laminated film may have a laminated structure consisting of a laminate having at least a base material layer 31, a barrier layer 33, and a heat-sealable resin layer 35 in this order.
• FIG. 3 shows an example of a cross-sectional structure of the exterior material 3, in which the base material layer 31, an adhesive layer 32 provided as needed, a barrier layer 33, an adhesive layer 34 provided as needed, and a heat-sealable resin layer 35 are laminated in this order.
• the base material layer 31 is the outer layer side
• the heat-sealable resin layer 35 is the innermost layer.
• FIGS. 4 to 9 show the electricity storage device 10 in the case where an embossed type exterior material 3 formed by embossing or the like is used, but the exterior material 3 may be an unformed pouch type.
• the pouch type includes three-sided seal, four-sided seal, pillow type, etc., and any type may be used.
• the thickness of the laminate constituting the exterior material 3 is not particularly limited, but from the viewpoints of cost reduction and energy density improvement, the upper limit is, for example, about 190 ⁇ m or less, preferably about 180 ⁇ m or less, about 160 ⁇ m or less, about 155 ⁇ m or less, about 140 ⁇ m or less, about 130 ⁇ m or less, and about 120 ⁇ m or less, and from the viewpoints of maintaining the function of the exterior material 3 to protect the energy storage device element 4, the lower limit is preferably about 35 ⁇ m or more, about 45 ⁇ m or more, about 60 ⁇ m or more, and about 80 ⁇ m or more, and preferred ranges are, for example, about 35 to 190 ⁇ m, about 35 to 180 ⁇ m, about 35 to 160 ⁇ m, and about 35 to 1 Examples include about 55 ⁇ m, about 35 to 140 ⁇ m, about 35 to 130 ⁇ m, about 35 to 120 ⁇ m, about 45 to 190 ⁇ m, about 45 to 180 ⁇ m, about 45 to 160 ⁇ m
• the resin film 1 for an electricity storage device disclosed herein can be suitably applied to an exterior material for an all-solid-state battery.
• the thickness of the laminate constituting the exterior material for an all-solid-state battery is not particularly limited, but from the viewpoints of cost reduction, energy density improvement, etc., it is preferably about 10,000 ⁇ m or less, about 8,000 ⁇ m or less, or about 5,000 ⁇ m or less, and from the viewpoint of maintaining the function of the exterior material for an all-solid-state battery to protect the battery element, it is preferably about 1 Examples of preferred ranges include about 100 to 10,000 ⁇ m, about 100 to 8,000 ⁇ m, about 100 to 5,000 ⁇ m, about 150 to 10,000 ⁇ m, about 150 to 8,000 ⁇ m, about 150 to 5,000 ⁇ m, about 200 to 10,000 ⁇ m, about 200 to 8,000 ⁇ m, and about 200 to 5,000 ⁇ m, with about 200 to 5,000 ⁇ m being particularly preferred.
• the base material layer 31 is a layer that functions as a base material of the exterior packaging material, and is a layer that forms the outermost layer side.
• the material forming the base layer 31 is not particularly limited, as long as it is insulating.
• materials forming the base layer 31 include polyester, polyamide, epoxy, acrylic, fluororesin, polyurethane, silicone resin, phenol, polyetherimide, polyimide, and mixtures and copolymers thereof.
• Polyesters such as polyethylene terephthalate and polybutylene terephthalate have the advantage of being highly resistant to electrolyte and being less susceptible to whitening due to adhesion of electrolyte, and are therefore preferably used as materials for forming the base layer 31.
• polyamide film has excellent stretchability and can prevent whitening due to resin cracking of the base layer 31 during molding, and is therefore preferably used as materials for forming the base layer 31.
• the substrate layer 31 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, uniaxially or biaxially stretched resin films, especially biaxially stretched resin films, are preferably used as the substrate layer 31 because their heat resistance is improved by oriented crystallization.
• the resin film forming the base layer 31 is preferably nylon or polyester, and more preferably biaxially oriented nylon or biaxially oriented polyester.
• all-solid-state batteries are often sealed at high temperatures of 200°C or higher in order to withstand temperatures of 150°C or higher, and biaxially oriented polyester is the most suitable.
• the base layer 31 can be laminated with resin films of different materials to improve pinhole resistance and insulation when used as a package for a power storage device.
• resin films of different materials include a multi-layer structure in which a polyester film is laminated with a nylon film, or a multi-layer structure in which biaxially oriented polyester is laminated with a biaxially oriented nylon.
• the resin films may be bonded via an adhesive, or may be directly laminated without an adhesive.
• bonding without an adhesive examples include methods of bonding in a hot melt state, such as co-extrusion, sand lamination, and thermal lamination.
• the base layer 31 may be made low-friction to improve formability.
• the base layer 31 low-friction there are no particular limitations on the coefficient of friction of its surface, but an example of this is 1.0 or less.
• Examples of ways to make the base layer 31 low-friction include matte treatment, forming a thin layer of a slip agent, and combinations of these.
• the thickness of the base layer 31 is, for example, about 3 ⁇ m or more, about 4 ⁇ m or more, about 5 ⁇ m or more, about 10 ⁇ m or more, about 15 ⁇ m or more, and about 100 ⁇ m or less, about 75 ⁇ m or less, about 50 ⁇ m or less, about 30 ⁇ m or less, and preferred ranges are about 3 to 100 ⁇ m, about 3 to 75 ⁇ m, about 3 to 50 ⁇ m, about 3 to 30 ⁇ m, and about 4 to 100 ⁇ m.
• the adhesive layer 32 is a layer that is disposed on the base material layer 31 as necessary in order to impart adhesion to the base material layer 31. That is, the adhesive layer 32 is provided between the base material layer 31 and the barrier layer 33.
• the adhesive layer 32 is formed from an adhesive capable of bonding the base layer 31 and the barrier layer 33.
• the adhesive used to form the adhesive layer 32 may be a two-component curing adhesive or a one-component curing adhesive.
• the resin component of the adhesive that can be used to form the adhesive layer 32 is preferably a polyurethane-based two-component curing adhesive; polyamide, polyester, or a blend resin of these with modified polyolefin, from the viewpoint of excellent ductility, durability under high humidity conditions, yellowing prevention, and thermal degradation prevention during heat sealing, and effectively suppressing the decrease in laminate strength between the base layer 31 and the barrier layer 33 and preventing delamination.
• the adhesive layer 32 may be multi-layered with different adhesive components.
• the adhesive layer 32 is multi-layered with different adhesive components, it is preferable to select a resin with excellent adhesion to the base layer 31 as the adhesive component arranged on the base layer 31 side, and an adhesive component with excellent adhesion to the barrier layer 33 as the adhesive component arranged on the barrier layer 33 side, from the viewpoint of improving the laminate strength between the base layer 31 and the barrier layer 33.
• the adhesive component arranged on the barrier layer 33 side is preferably an acid-modified polyolefin, a metal-modified polyolefin, a mixed resin of polyester and acid-modified polyolefin, a resin containing a copolymerized polyester, an alicyclic isocyanate compound, etc.
• the thickness of the adhesive layer 32 is, for example, about 2 to 50 ⁇ m, and preferably about 3 to 25 ⁇ m.
• the barrier layer 33 is a layer that has the function of preventing water vapor, oxygen, light, and the like from penetrating into the inside of the power storage device element in addition to improving the strength of the exterior material.
• the barrier layer 33 is preferably a metal layer, that is, a layer formed of a metal. Specific examples of metals constituting the barrier layer 33 include aluminum, stainless steel, and titanium, and aluminum is preferred.
• the barrier layer 33 can be formed, for example, of a metal foil, a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, or a film provided with these vapor deposition films, and is preferably formed of a metal foil, and more preferably formed of an aluminum foil.
• the barrier layer is more preferably formed from a soft aluminum foil such as annealed aluminum (JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O).
• a soft aluminum foil such as annealed aluminum
• the thickness of the barrier layer 33 is preferably about 10 to 200 ⁇ m, more preferably about 20 to 100 ⁇ m, from the viewpoint of making the exterior material thin and making it difficult for pinholes to occur even when molded. From the viewpoint of imparting high moldability or high rigidity to the exterior material 3 for an electrical storage device, the thickness of the barrier layer 33 is preferably about 45 ⁇ m or more, more preferably about 50 ⁇ m or more, preferably about 85 ⁇ m or less, more preferably 75 ⁇ m or less, and preferred ranges include about 45 to 85 ⁇ m, about 45 to 75 ⁇ m, about 50 to 85 ⁇ m, and about 50 to 75 ⁇ m.
• barrier layer 33 it is preferable that at least one surface, and preferably both surfaces, of the barrier layer 33 are chemically treated to stabilize adhesion and prevent dissolution and corrosion.
• chemical treatment refers to a process for forming a corrosion-resistant film on the surface of the barrier layer.
• the adhesive layer 34 is a layer that is provided, if necessary, between the barrier layer 33 and the heat-sealable resin layer 35 in order to firmly bond the heat-sealable resin layer 35.
• the adhesive layer 34 is formed from an adhesive capable of bonding the barrier layer 33 and the heat-sealable resin layer 35.
• an adhesive capable of bonding the barrier layer 33 and the heat-sealable resin layer 35.
• examples include an adhesive made of a polyester polyol compound and an alicyclic isocyanate compound.
• the thickness of the adhesive layer 34 is, for example, about 1 to 40 ⁇ m, and preferably about 2 to 30 ⁇ m.
• the heat-sealable resin layer 35 corresponds to the innermost layer, and is a layer that seals the electricity storage device elements by being heat-sealed to each other when the electricity storage device is assembled.
• the resin component used in the heat-sealable resin layer 35 is not particularly limited, as long as it is heat-sealable.
• resin film 1 for an electricity storage device of the present disclosure is used as the heat-sealable resin layer of the exterior material for an electricity storage device described above in 2), as shown in FIG. 3, the resin film 1 for an electricity storage device of the present disclosure is used as the heat-sealable resin layer 35 of the exterior material for an electricity storage device 3 composed of a laminate having at least a base layer 31, a barrier layer 33, and a heat-sealable resin layer 35 in this order.
• polystyrene resin 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.
• the 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 more preferred.
• Styrene is also an example of a constituting monomer.
• crystalline or amorphous polyolefins preferred are crystalline or amorphous polyolefins, cyclic polyolefins, and blended polymers thereof; more preferred are polyethylene, polypropylene, copolymers of ethylene and norbornene, and blended polymers of two or more of these.
• the heat-sealable resin layer 35 may be formed from one type of resin component alone, or may be formed from a blend polymer of two or more types of resin components. Furthermore, the heat-sealable resin layer 35 may be formed from only one layer, or may be formed from two or more layers of the same or different resin components.
• the thickness of the heat-sealable resin layer 35 is not particularly limited, but may be about 2 to 2000 ⁇ m, preferably about 5 to 1000 ⁇ m, and more preferably about 10 to 500 ⁇ m.
• the resin film 1 for an electricity storage device can be suitably applied to an exterior material for an all-solid-state battery, and the melting point of the heat-sealable resin layer 35 of the exterior material for an all-solid-state battery is preferably 150 to 250°C, more preferably 180 to 270°C, even more preferably 200 to 270°C, and even more preferably 200 to 250°C.
• examples of resins contained in the heat-sealable resin layer 35 of the all-solid-state battery exterior material include polyolefins such as polypropylene and polyethylene, acid-modified polyolefins such as acid-modified polypropylene and acid-modified polyethylene, and polybutylene terephthalate.
• polybutylene terephthalate has excellent heat resistance, so in the all-solid-state battery exterior material, the heat-sealable resin layer 35 is preferably formed from a polybutylene terephthalate film.
• the polybutylene terephthalate film forming the heat-sealable resin layer 35 may be prepared by laminating a pre-prepared polybutylene terephthalate film with the adhesive layer 34 to form the heat-sealable resin layer 35, or the resin forming the polybutylene terephthalate film may be melt-extruded to form a film and then laminated with the adhesive layer 34, or the resin forming the heat-sealable resin layer 35 and the resin forming the adhesive layer 34 may be co-extruded to form the film.
• the polybutylene terephthalate film may be a stretched polybutylene terephthalate film or an unstretched polybutylene terephthalate film, and is preferably an unstretched polybutylene terephthalate film.
• the polybutylene terephthalate film preferably further contains an elastomer.
• the elastomer plays a role in ensuring the durability of the polybutylene terephthalate film in a high-temperature environment while increasing its flexibility.
• Preferred elastomers include at least one thermoplastic elastomer selected from polyesters, polyamides, polyurethanes, polyolefins, polystyrenes, and polyethers, or thermoplastic elastomers that are copolymers of these.
• the content of the elastomer is not particularly limited as long as it can ensure the durability of the polybutylene terephthalate film in a high-temperature environment while increasing its flexibility, and is, for example, 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 even more preferably about 3.0% by mass or more.
• 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.
• Preferred ranges of the content include about 0.1 to 10.0% by mass, about 0.1 to 8.0% by mass, about 0.1 to 5.0% by mass, about 0.5 to 10.0% by mass, about 0.5 to 8.0% by mass, about 0.5 to 5.0% by mass, about 1.0 to 10.0% by mass, about 1.0 to 8.0% by mass, about 1.0 to 5.0% by mass, about 3.0 to 10.0% by mass, about 3.0 to 8.0% by mass, and about 3.0 to 5.0% by mass.
• the heat-sealable resin layer 35 may be formed of only one layer, or may be formed of two or more layers of the same or different resins.
• the heat-sealable resin layer 35 is formed of two or more layers, at least one layer is formed of a polybutylene terephthalate film, and the polybutylene terephthalate film is preferably the innermost layer of the all-solid-state battery exterior material.
• the layer that adheres to the adhesive layer 34 is preferably a polybutylene terephthalate film.
• the layer that is not formed of a polybutylene terephthalate film may be a layer formed of, for example, a polyolefin such as polypropylene or polyethylene, or an acid-modified polyolefin such as acid-modified polypropylene or acid-modified polyethylene.
• a polyolefin such as polypropylene or polyethylene
• an acid-modified polyolefin such as acid-modified polypropylene or acid-modified polyethylene.
• the heat-sealable resin layer 35 is preferably composed of only a polybutylene terephthalate film.
• the power storage device of the present disclosure is a power storage device such as a battery (including a condenser, a capacitor, etc.).
• the power storage device of the present disclosure may be either a primary battery or a secondary battery, but is preferably used in a secondary battery.
• a secondary battery There are no particular limitations on the type of secondary battery, and examples include lithium ion batteries, lithium ion polymer batteries, all-solid-state batteries, lead acid batteries, nickel-hydrogen batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air batteries, polyvalent cation batteries, condensers, and capacitors.
• examples of the power storage device of the present disclosure include lithium ion batteries, lithium ion polymer batteries, and all-solid-state batteries, and are particularly suitable for use in all-solid-state batteries.
• Example 1 Random polypropylene films (water absorbing agent content 0 mass%, thickness 10 ⁇ m) were laminated on both sides of a random polypropylene film (thickness 30 ⁇ m) containing 20 mass% calcium oxide (CaO) as a water absorbing agent, to produce a resin film for an electricity storage device having a three-layer structure of r-PP (water absorbing agent content 0 mass%, 10 ⁇ m)/r-PP (water absorbing agent content 20 mass%, 30 ⁇ m)/r-PP (water absorbing agent content 0 mass%, 10 ⁇ m).
• Example 2 A random polypropylene film (water absorbing agent content 0 mass %, thickness 20 ⁇ m) was laminated on one side of a random polypropylene film (thickness 30 ⁇ m) containing 20 mass % CaO as a water absorbing agent, to produce a two-layered resin film for an electricity storage device of r-PP (water absorbing agent content 0 mass %, 20 ⁇ m)/r-PP (water absorbing agent content 20 mass %, 30 ⁇ m).
• the resin film for an electricity storage device of Example 2 is used with the r-PP (water absorbing agent content 0 mass %, 20 ⁇ m) side disposed on the exterior material side, and the r-PP (water absorbing agent content 20 mass %, 30 ⁇ m) disposed on the electricity storage device element side.
• Example 3 A random polypropylene film (water absorbing agent content 0 mass%, thickness 20 ⁇ m) was laminated on one side of a random polypropylene film (thickness 30 ⁇ m) containing 20 mass% CaO as a water absorbing agent to produce a two-layered resin film for an electricity storage device of r-PP (water absorbing agent content 20 mass%, 30 ⁇ m)/r-PP (water absorbing agent content 0 mass%, 20 ⁇ m) in the same manner as in Example 2.
• r-PP water absorbing agent content 20 mass%, 30 ⁇ m
• r-PP water absorbing agent content 0 mass%, 20 ⁇ m
• the resin film for an electricity storage device in Example 3 is used with the r-PP (water absorbing agent content 0 mass%, thickness 20 ⁇ m) side disposed on the electricity storage device element side, and the r-PP (water absorbing agent content 20 mass%, 30 ⁇ m) disposed on the exterior material side.
• Example 4 A random polypropylene film (thickness 15 ⁇ m) containing 20 mass % of CaO as a water absorbing agent was laminated on both sides of a random polypropylene film (water absorbing agent content 0 mass %, thickness 20 ⁇ m), to produce a resin film for an electricity storage device having a three-layer structure of r-PP (water absorbing agent content 20 mass %, 15 ⁇ m)/r-PP (water absorbing agent content 0 mass %, 20 ⁇ m)/r-PP (water absorbing agent content 20 mass %, 15 ⁇ m).
• Example 5 A random polypropylene film (water absorbing agent content 0 mass%, thickness 10 ⁇ m) was laminated on each side of a random polypropylene film (thickness 30 ⁇ m) containing 20 mass% CaO as a water absorbing agent and 5 mass% titanium oxide particles as solid particles, to produce a resin film for an electricity storage device having a three-layer structure of r-PP (water absorbing agent content 0 mass%, 10 ⁇ m)/r-PP (water absorbing agent content 20 mass%, 30 ⁇ m)/r-PP (water absorbing agent content 0 mass%, 10 ⁇ m).
• Example 6 A polybutylene terephthalate film (water absorbing agent content 0 mass%, thickness 10 ⁇ m) was laminated on each of both sides of a polybutylene terephthalate film (thickness 30 ⁇ m) containing 20 mass% CaO as a water absorbing agent, to produce a resin film for an electricity storage device having a three-layer structure of PBT (water absorbing agent content 0 mass%, 10 ⁇ m)/PBT (water absorbing agent content 20 mass%, 30 ⁇ m)/PBT (water absorbing agent content 0 mass%, 10 ⁇ m).
• PBT water absorbing agent content 0 mass%, 10 ⁇ m
• PBT water absorbing agent content 20 mass%, 30 ⁇ m
• PBT water absorbing agent content 0 mass%, 10 ⁇ m
• Example 7 A resin film for an electric storage device was produced in the same manner as in Example 2, and this was used as a heat-sealable resin layer of an exterior material for an electric storage device.
• a polyethylene terephthalate film (thickness 25 ⁇ m or 12 ⁇ m) was subjected to corona treatment on the bonding surface side, and a nylon film (thickness 25 ⁇ m) was prepared.
• a nylon film (thickness 25 ⁇ m) was prepared.
• As the barrier layer an aluminum alloy foil (JIS H4160: 1994 A8021H-O, thickness 40 ⁇ m) was prepared.
• the heat-sealable resin layer the resin film for an electric storage device was used.
• a two-component curing urethane adhesive (polyester polyol and alicyclic isocyanate compound) was used to produce a laminate in which a polyethylene terephthalate film and a nylon film, and a nylon film and a barrier layer were bonded together by a dry lamination method. Further, the barrier layer side of the obtained laminate was adhered to the resin film for a power storage device by a dry lamination method using a two-component curing urethane adhesive (polyester polyol and alicyclic isocyanate compound), and an adhesive layer (4 ⁇ m)/resin film for a power storage device was laminated on the barrier layer.
• the obtained laminate was aged and heated to obtain an exterior material for a power storage device consisting of a laminate in which polyethylene terephthalate film/adhesive layer/nylon film/adhesive layer/barrier layer/adhesive layer/resin film for a power storage device were laminated in this order.
• the heat-sealable resin layers were laminated in the order of r-PP (water absorbing agent content 20% by mass, 30 ⁇ m)/r-PP (water absorbing agent content 0% by mass, 20 ⁇ m) from the barrier layer side.
• Example 8 Two sheets of resin film for electric storage device were produced in the same manner as in Example 2, and these were used as adhesive films for metal terminals (length 10 mm, width 55 mm). At the center of the length of an aluminum metal terminal (length 60 mm, width 45 mm, thickness 400 ⁇ m), the metal terminal was sandwiched between two adhesive films for metal terminals so as to be perpendicular to the length direction, and the adhesive films for metal terminals were attached to the metal terminals by hot pressing (temperature 190° C., pressure 0.25 MPa, 16 seconds) from both sides, thereby obtaining a metal terminal with an adhesive film for metal terminal.
• the adhesive films for metal terminals are laminated in the order of r-PP (water absorbent content 20% by mass, 30 ⁇ m)/r-PP (water absorbent content 0% by mass, 20 ⁇ m) from the metal terminal side.
• Example 9 Random polypropylene films (water absorbing agent content 0 mass%, thickness 5 ⁇ m) were laminated on both sides of a random polypropylene film (thickness 40 ⁇ m) containing 15 mass% calcium oxide (CaO) as a water absorbing agent, to produce a resin film for an electricity storage device having a three-layer structure of r-PP (water absorbing agent content 0 mass%, thickness 5 ⁇ m)/r-PP (water absorbing agent content 15 mass%, 40 ⁇ m)/r-PP (water absorbing agent content 0 mass%, 5 ⁇ m).
• Example 10 A random polypropylene film (water absorbing agent content 0 mass %, thickness 90 ⁇ m) was laminated on one side of a random polypropylene film (thickness 30 ⁇ m) containing 20 mass % CaO as a water absorbing agent, to produce a two-layered resin film for an electricity storage device of r-PP (water absorbing agent content 0 mass %, 90 ⁇ m)/r-PP (water absorbing agent content 20 mass %, 30 ⁇ m).
• the resin film for an electricity storage device of Example 10 is used with the r-PP (water absorbing agent content 0 mass %, 90 ⁇ m) side disposed on the exterior material side, and the r-PP (water absorbing agent content 20 mass %, 30 ⁇ m) disposed on the electricity storage device element side.
• Example 11 A random polypropylene film (water absorbing agent content 4 mass%, thickness 10 ⁇ m) containing 4 mass% calcium oxide (CaO) as a water absorbing agent was laminated on both sides of a random polypropylene film (thickness 30 ⁇ m) containing 17.4 mass% calcium oxide (CaO) as a water absorbing agent, to produce a resin film for an electricity storage device having a three-layer structure of r-PP (water absorbing agent content 4 mass%, 10 ⁇ m)/r-PP (water absorbing agent content 17.4 mass%, 30 ⁇ m)/r-PP (water absorbing agent content 4 mass%, 10 ⁇ m).
• Example 12 A random polypropylene film (water absorbing agent content 0 mass %, thickness 30 ⁇ m) containing 20 mass % of CaO as a water absorbing agent was laminated on one side of a random polypropylene film (water absorbing agent content 20 mass %, thickness 90 ⁇ m) to produce a two-layered resin film for a power storage device of r-PP (water absorbing agent content 20 mass %, 90 ⁇ m)/r-PP (water absorbing agent content 0 mass %, 30 ⁇ m).
• the resin film for a power storage device of Example 12 is used with the r-PP (water absorbing agent content 20 mass %, 90 ⁇ m) side disposed on the exterior material side and the r-PP (water absorbing agent content 0 mass %, 30 ⁇ m) disposed on the power storage device element side.
• Example 13 A random polypropylene film (water absorbing agent content 0 mass %, thickness 20 ⁇ m) containing 45 mass % of CaO as a water absorbing agent was laminated on one side of a random polypropylene film (water absorbing agent content 45 mass %, thickness 30 ⁇ m) to produce a two-layered resin film for an electric storage device of r-PP (water absorbing agent content 45 mass %, 30 ⁇ m) / r-PP (water absorbing agent content 0 mass %, 20 ⁇ m).
• the resin film for an electric storage device of Example 13 is used with the r-PP (water absorbing agent content 45 mass %, 30 ⁇ m) side disposed on the exterior material side and the r-PP (water absorbing agent content 0 mass %, 20 ⁇ m) disposed on the electric storage device element side.
• Random polypropylene films (water absorbing agent content 0 mass%, thickness 10 ⁇ m) were laminated on both sides of a random polypropylene film (thickness 30 ⁇ m) containing 20 mass% magnesium oxide (MgO) as a water absorbing agent, to produce a resin film for an electricity storage device having a three-layer structure of r-PP (water absorbing agent content 0 mass%, 10 ⁇ m)/r-PP (water absorbing agent content 20 mass%, 30 ⁇ m)/r-PP (water absorbing agent content 0 mass%, 10 ⁇ m).
• r-PP water absorbing agent content 0 mass%, 10 ⁇ m
• r-PP water absorbing agent content 20 mass%, 30 ⁇ m
• r-PP water absorbing agent content 0 mass%, 10 ⁇ m
• Example 15 A random polypropylene film (water absorbing agent content 0 mass%, thickness 10 ⁇ m) was laminated on both sides of a random polypropylene film (thickness 30 ⁇ m) containing 20 mass% magnesium sulfate ( MgSO4 ) as a water absorbing agent, to produce a resin film for an electricity storage device having a three-layer structure of r-PP (water absorbing agent content 0 mass%, thickness 10 ⁇ m)/r-PP (water absorbing agent content 20 mass%, 30 ⁇ m)/r-PP (water absorbing agent content 0 mass%, 10 ⁇ m).
• Example 16 A maleic anhydride modified random polypropylene film (water absorbing agent content 0 mass% thickness 20 ⁇ m) was laminated on one side of a random polypropylene film (thickness 30 ⁇ m) containing 20 mass% CaO as a water absorbing agent, to produce a two-layered resin film for a storage battery device of r-PPa (water absorbing agent content 0 mass% 20 ⁇ m)/r-PP (water absorbing agent content 20 mass% 30 ⁇ m).
• the resin film for a storage battery device of Example 16 is an adhesive film for metal terminals, and is used by arranging the r-PP (water absorbing agent content 20 mass% 30 ⁇ m) side on the exterior material side and the r-PPA (water absorbing agent content 0 mass% 20 ⁇ m) side on the metal terminal side.
• Example 17 A maleic anhydride-modified homopolypropylene film (water absorbing agent content 0 mass%, thickness 20 ⁇ m) was laminated on one side of a homopolypropylene film (thickness 30 ⁇ m) containing 20 mass% CaO as a water absorbing agent, to produce a two-layered resin film for a storage battery device of h-PPa (water absorbing agent content 0 mass%, 20 ⁇ m)/h-PP (water absorbing agent content 20 mass%, 30 ⁇ m).
• the resin film for a storage battery device of Example 17 is an adhesive film for metal terminals, and is used such that the h-PP (water absorbing agent content 20 mass%, 30 ⁇ m) side is disposed on the exterior material side, and the h-PPA (water absorbing agent content 0 mass%, 20 ⁇ m) side is disposed on the metal terminal side.
• h-PP water absorbing agent content 20 mass%, 30 ⁇ m
• h-PPA water absorbing agent content 0 mass%, 20 ⁇ m
• Example 18 A maleic anhydride modified random polypropylene film (thickness 20 ⁇ m) containing 1% by mass of CaO as a water absorbent was laminated on one side of a random polypropylene film (thickness 30 ⁇ m) containing 20% by mass of CaO as a water absorbent, to produce a two-layered resin film for a storage battery device of r-PPa (water absorbent content 1% by mass 20 ⁇ m) / r-PP (water absorbent content 20% by mass 30 ⁇ m).
• the resin film for a storage battery device of Example 18 is an adhesive film for metal terminals, and is used by arranging the r-PP (water absorbent content 20% by mass 30 ⁇ m) side on the exterior material side and the r-PPA (water absorbent content 1% by mass 20 ⁇ m) on the metal terminal side.
• Example 19 A random polypropylene film (thickness 30 ⁇ m) containing 20% by mass of calcium oxide (CaO) as a water absorbent was laminated on one side of a maleic anhydride-modified random polypropylene film (water absorbent content 0% by mass, thickness 10 ⁇ m), and a random polypropylene film (water absorbent content 0% by mass, thickness 10 ⁇ m) was laminated on the other side to produce a three-layered resin film for a storage battery device of r-PPa (water absorbent content 0% by mass, 10 ⁇ m) / r-PP (water absorbent content 20% by mass, 30 ⁇ m) / r-PP (water absorbent content 0% by mass, 10 ⁇ m).
• r-PPa water absorbent content 0% by mass, 10 ⁇ m
• r-PP water absorbent content 20% by mass, 30 ⁇ m
• r-PP water absorbent content 0% by mass, 10 ⁇ m
• the resin film for a storage battery device of Example 19 is an adhesive film for metal terminals, and is used by arranging the r-PP (water absorbent content 0% by mass, 10 ⁇ m) side on the exterior material side and the r-PPA (water absorbent content 0% by mass, 10 ⁇ m) on the metal terminal side.
• Example 20 A maleic anhydride-modified random polypropylene film (water-absorbing agent content 0% by mass, thickness 10 ⁇ m) containing a black pigment was laminated on one side of a homopolypropylene film (thickness 30 ⁇ m) containing 20% by mass of calcium oxide (CaO) as a water-absorbing agent, and a random polypropylene film (water-absorbing agent content 0% by mass, thickness 10 ⁇ m) was laminated on the other side to produce a three-layered resin film for a power storage device of black r-PPa (water-absorbing agent content 0% by mass, 10 ⁇ m) / h-PP (water-absorbing agent content 20% by mass, 30 ⁇ m) / r-PP (water-absorbing agent content 0% by mass, 10 ⁇ m).
• black r-PPa water-absorbing agent content 0% by mass, 10 ⁇ m
• h-PP water-absorbing agent content 20% by mass, 30 ⁇ m
• r-PP water-absorbing agent content 0%
• the resin film for a power storage device of Example 20 is an adhesive film for metal terminals, and is used by arranging the black r-PPa (water-absorbing agent content 0% by mass, 10 ⁇ m) side on the metal terminal side and the r-PP (water-absorbing agent content 0% by mass, 10 ⁇ m) on the exterior material side.
• Boost method Short-time method (AC, 50Hz) Voltage rise rate: 0.3 kV/s Electrodes: 25 mm diameter cylinder/75 mm diameter cylinder
• Equipment Dielectric breakdown test equipment YST-243-100RHO (Yamayo Tester Co., Ltd.) (Evaluation criteria)
• A' Dielectric breakdown strength is 100 kV/mm or more
• C Dielectric breakdown strength is less than 40 kV/mm
• metal terminals with adhesive films for metal terminals were prepared.
• Aluminum alloy foil JIS H4160:1994 A8079H-O
• a treatment agent consisting of three components, acrylic resin, chromium (III) nitrate compound, and phosphoric acid, so that the treatment layer was about 100 nm thick to prepare a surface-treated metal terminal.
• the metal terminal was heat sealed at 190°C x 0.25MPa (surface pressure applied to the silicone rubber) x 16 seconds using a flat press machine with a metal head and 3.0mm thick silicone rubber with a hardness of 40 attached to both the top and bottom, to prepare a metal terminal with an adhesive film for metal terminal, in which the adhesive film for metal terminal/surface-treated metal terminal/adhesive film for metal terminal were laminated in this order.
• the MD of the metal terminal and the MD of the adhesive film for metal terminal were arranged so as to be perpendicular to each other.
• An exterior material for a power storage device (hereinafter, sometimes simply referred to as "exterior material") was prepared.
• a base layer (thickness 30 ⁇ m) consisting of a polyethylene terephthalate film (thickness 12 ⁇ m)/adhesive layer (thickness 3 ⁇ m)/nylon film (thickness 15 ⁇ m) was laminated on an aluminum alloy foil (thickness 40 ⁇ m JIS H4160: 1994 A8079H-O) by dry lamination, and a heat-sealing resin layer was laminated on the other surface by co-extrusion.
• a two-liquid urethane adhesive (polyol compound and aromatic isocyanate compound) was applied on the nylon film, and an adhesive layer (thickness 3 ⁇ m) was formed on the nylon film.
• the adhesive layer and a polyethylene terephthalate film were laminated on the nylon film to prepare a base layer.
• a two-liquid urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of a barrier layer consisting of an aluminum alloy foil, and an adhesive layer (thickness 3 ⁇ m) was formed on the aluminum alloy foil.
• the adhesive layer and the substrate layer with the nylon film side as the adhesive surface were laminated on the aluminum alloy foil, and then aging treatment was performed to produce a substrate layer/adhesive layer/barrier layer laminate.
• an adhesive layer (40 ⁇ m thick, arranged on the metal layer side) made of maleic anhydride-modified polypropylene resin and a heat-sealable resin layer (40 ⁇ m thick, innermost layer) made of random polypropylene resin were co-extruded on the barrier layer of the laminate to laminate the adhesive layer/heat-sealable resin layer on the barrier layer, thereby obtaining an exterior material for a power storage device in which the substrate layer, adhesive layer, barrier layer, adhesive layer, and heat-sealable resin layer were laminated in this order.
• the exterior material was cut to a size of TD 60 mm and MD 200 mm, and the exterior material was placed facing each other with the heat-sealable resin layer on the inside, and the metal terminal with adhesive film for metal terminal obtained above was sandwiched between the opposing heat-sealable resin layers.
• the exterior material was laminated so that the MD and TD of the exterior material were aligned with the TD and MD directions of the metal terminal with adhesive film for metal terminal, respectively.
• the exterior material was heat-sealed using a heat seal tester under conditions of width 7 mm, 190 ° C. x 0.25 MPa x 16 seconds, and naturally cooled to 25 ° C.
• the 7 mm width is the MD direction of the exterior material.
• these heat-sealing conditions are temperature conditions suitable for the resin used in the adhesive film for metal terminal.
• the heat-sealed portion of the obtained laminate is configured such that the exterior material / adhesive film for metal terminal / metal terminal / adhesive film for metal terminal / exterior material are laminated in this order.
• the laminate was cut in a direction perpendicular to the seal width of 7 mm to obtain a sample with a width of 15 mm. At this time, the sample was obtained from the center part of the laminate.
• the width of 15 mm corresponds to the TD direction of the exterior material.
• the seal strength against the metal terminal was evaluated according to the following criteria. The results are shown in Table 2.
• a resin film for an electricity storage device is composed of two or more layers, The two or more layers include at least one layer A having a water absorbing agent content of 5 mass % or more and at least one layer B having a water absorbing agent content of less than 5 mass %.
• Item 2. The resin film for an electricity storage device according to Item 1, wherein at least one of the Layer B has a water absorbing agent content of 0%.
• Item 3. The resin film for an electricity storage device according to item 1 or 2, wherein at least one of the two or more layers has a solid particle content of less than 5 mass %.
• the resin film for an electrical storage device according to any one of Items 1 to 3, wherein the water absorbing agent includes an inorganic water absorbing agent.
• Item 5 The resin film for an electricity storage device according to any one of Items 1 to 4, wherein the water absorbing agent includes at least one selected from the group consisting of calcium oxide, anhydrous magnesium sulfate, magnesium oxide, calcium chloride, zeolite, aluminum oxide, silica gel, alumina gel, and calcined alum.
• Item 6 The resin film for an electricity storage device according to any one of Items 1 to 5, wherein at least one of the two or more layers contains a heat-sealable resin.
• Item 8 The resin film for an electricity storage device according to any one of Items 1 to 7, wherein the resin film for an electricity storage device after absorbing water has a dielectric breakdown strength of 40 kV/mm or more, as measured by the following measurement method. (Measurement of dielectric breakdown strength after water absorption)
• a 10 cm square resin film for a storage battery device is prepared and immersed in warm water at 80°C. The immersion is continued until the water absorbing agent in the resin film for a storage battery device absorbs 100% of the water, to obtain a resin film for a storage battery device after absorbing water.
• the water absorption degree of the resin film for a storage battery device is calculated from the weight of the film before and after immersion.
• the dielectric breakdown strength of the resin film for a storage battery device after absorbing water is measured in accordance with the provisions of JIS C 2110-1:2016 under the following measurement conditions: 23°C in air, short-time voltage increase method (AC, 50 Hz), voltage increase rate of 0.3 kV/s, and electrodes of 25 mm ⁇ cylinder/75 mm ⁇ cylinder.
• the measured value is the average value measured for five samples. Item 9.
• the resin film for an electricity storage device according to any one of Items 1 to 8, wherein the resin film for an electricity storage device is 1) disposed between an exterior material for an electricity storage device and an electricity storage device element, 2) used as a heat-sealable resin layer of an exterior material for an electricity storage device, 3) used as an adhesive layer between a barrier layer and a heat-sealable resin layer of an exterior material for an electricity storage device, or 4) used as an adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of an electricity storage device element and an exterior material for an electricity storage device that encapsulates the electricity storage device element.
• Item 10 Item 10.
• An electricity storage device in which an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a packaging body formed from an exterior material, Item 10.
• An electricity storage device comprising: the resin film for an electricity storage device according to any one of items 1 to 9, disposed between the exterior material and the electricity storage device.
• Reference Signs List 1 Resin film for electricity storage device 2: Metal terminal 3: Exterior material 3a: Peripheral edge portion of exterior material 4: Electricity storage device element 10: Electricity storage device 11: First layer 12: Second layer 13: Third layer 21: Adhesive film for metal terminal 31: Substrate layer 32: Adhesive layer 33: Barrier layer 34: Adhesive layer 35: Heat-sealable resin layer

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• Chemical & Material Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Engineering & Computer Science (AREA)
• Inorganic Chemistry (AREA)
• Power Engineering (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Composite Materials (AREA)
• Materials Engineering (AREA)
• Electric Double-Layer Capacitors Or The Like (AREA)
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• 2023
  • 2023-10-12 EP EP23877339.4A patent/EP4604281A1/en active Pending
  • 2023-10-12 WO PCT/JP2023/037091 patent/WO2024080338A1/ja not_active Ceased
  • 2023-10-12 JP JP2024513426A patent/JP7657366B2/ja active Active
  • 2023-10-12 CN CN202380072555.4A patent/CN120019529A/zh active Pending
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  • 2023-10-12 KR KR1020257006517A patent/KR20250087517A/ko active Pending
• 2024
  • 2024-09-06 JP JP2024154008A patent/JP2024161269A/ja active Pending

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