Classifications

• • 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
  • 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
  • H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
• • 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
  • 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
  • H01M50/126—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers
• • 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
  • H01M50/131—Primary casings; Jackets or wrappings characterised by physical properties, e.g. gas permeability, size or heat resistance
  • H01M50/133—Thickness
• • 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 an exterior material for an electricity storage device, a manufacturing method thereof, 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.
• 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 film-like laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated from the outside is known as an exterior material for an electricity storage device.
• an exterior material for an electricity storage device made of such a film-like laminate it is required to increase the adhesive strength between the layers.
• the inventors of the present disclosure have found through their research that when a moisture-absorbed exterior material for an electricity storage device is subjected to the above-mentioned heat fusion, the absorbed moisture evaporates and air bubbles are generated within or between the layers outside the barrier layer. It has been confirmed that such a phenomenon is particularly likely to occur when, for example, in order to increase the production efficiency of the exterior material for an electricity storage device, the drying time of the exterior material for an electricity storage device is shortened, the temperature during heat fusion of the exterior material for an electricity storage device is increased to shorten the heat fusion time, or a large amount of highly hygroscopic material (such as polyamide resin) is used outside the barrier layer of the exterior material for an electricity storage device. When air bubbles are generated within or between the layers outside the barrier layer, there is a problem that the adhesive strength between the layers outside the barrier layer (for example, between the base material layer and the barrier layer) is weakened.
• the main objective of the present disclosure is to provide an exterior material for an electricity storage device that is composed of a laminate having, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, and that, when the exterior material for an electricity storage device is heat-sealed, suppresses the generation of air bubbles in and/or between layers outside the barrier layer.
• the inventors of the present disclosure conducted intensive research to solve the above problems. As a result, they discovered that in an exterior material for an electricity storage device composed of a laminate including, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, by using a polyester resin layer having a thickness of 20 ⁇ m or more for the base layer, when the exterior material for an electricity storage device is heat-sealed, the generation of air bubbles in and/or between layers outside the barrier layer is suppressed.
• the laminate includes, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer,
• the substrate layer includes a polyester resin layer,
• the exterior material for an electricity storage device wherein the polyester resin layer has a thickness of 20 ⁇ m or more.
• an exterior material for an electricity storage device that is composed of a laminate including, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, and that when the exterior material for an electricity storage device is heat-sealed, suppresses the generation of air bubbles in and/or between layers outside the barrier layer.
• a manufacturing method for the exterior material for an electricity storage device and an electricity storage device that uses the exterior material for an electricity storage device.
• 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 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 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 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 exterior material for an electricity storage device according to the present disclosure.
• FIG. 2 is a schematic diagram for illustrating a method for housing an electricity storage device element in a package formed from the exterior material for an electricity storage device of the present disclosure.
• FIG. 2 is a schematic diagram for explaining a method for measuring the seal strength of an exterior material for an electricity storage device when heat-sealed at 210° C.
• FIG. 2 is a schematic diagram for explaining a method for measuring the seal strength of an exterior material for an electricity storage device when heat-sealed at 210° C.
• the exterior material for an electricity storage device disclosed herein is composed of a laminate including, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, and the base layer includes a polyester resin layer, and the polyester resin layer has a thickness of 20 ⁇ m or more. According to the exterior material for an electricity storage device disclosed herein, by having this configuration, when the exterior material for an electricity storage device is heat-sealed, the generation of air bubbles is suppressed within and/or between layers outside the barrier layer.
• a numerical range indicated by “to” means “greater than or equal to” or “less than or equal to.”
• the expression “2 to 15 mm” means 2 mm or more and 15 mm or less.
• the upper limit or lower limit value described in a certain numerical range may be replaced with the upper limit or lower limit value of another numerical range described in stages.
• a numerical range may be formed by combining an upper limit value and an upper limit value, an upper limit value and a lower limit value, or a lower limit value and a lower limit value, each of which is described separately.
• the upper limit value or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.
• the exterior material for an electric storage device 10 of the present disclosure is composed of a laminate including a base layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order, as shown in FIG. 1, for example.
• the base layer 1 is the outermost layer
• the heat-sealable resin layer 4 is the innermost layer.
• the barrier layer 3 is used as a reference, and the heat-sealable resin layer 4 side is the inner side of the barrier layer 3, and the base layer 1 side is the outer side of the barrier layer 3.
• the substrate layer 1 includes a polyester resin layer 11.
• the substrate layer 1 may be composed of a single layer of the polyester resin layer 11, or may further include a resin layer 12 in addition to the polyester resin layer 11.
• the resin layer 12 may be a layer formed of a polyester resin, or may be a layer formed of a resin different from the polyester resin.
• the polyester resin layer 11 and the resin layer 12 may be laminated directly, or may be laminated via an adhesive layer 12a.
• the polyester resin layer 11 is located outside the resin layer 12.
• the exterior material 10 for an electricity storage device may have an adhesive layer 2 between the base layer 1 and the barrier layer 3, if necessary, for the purpose of increasing the adhesion between these layers.
• the exterior material 10 for an electricity storage device may have an adhesive layer 5 between the barrier layer 3 and the heat-sealable resin layer 4, if necessary, for the purpose of increasing the adhesion between these layers.
• a surface coating layer 6 or the like may be provided on the outside of the base layer 1 (the side opposite to the heat-sealable resin layer 4) if necessary.
• the thickness of the laminate constituting the exterior material 10 for an electricity storage device is not particularly limited, but from the viewpoint of cost reduction, energy density improvement, etc., examples of the thickness include about 300 ⁇ m or less, about 260 ⁇ m or less, about 210 ⁇ m or less, and preferably about 190 ⁇ m or less, about 180 ⁇ m or less, about 155 ⁇ m or less, and about 120 ⁇ m or less.
• the thickness of the laminate constituting the electricity storage device exterior material 10 is preferably about 35 ⁇ m or more, about 45 ⁇ m or more, about 60 ⁇ m or more, about 155 ⁇ m or more, and about 160 ⁇ m or more.
• preferred ranges of the laminate constituting the exterior material 10 for an electrical storage device are, for example, about 35 to 300 ⁇ m, about 35 to 260 ⁇ m, about 35 to 210 ⁇ m, about 35 to 190 ⁇ m, about 35 to 180 ⁇ m, about 35 to 155 ⁇ m, about 35 to 120 ⁇ m, about 45 to 300 ⁇ m, about 45 to 260 ⁇ m, about 45 to 210 ⁇ m, about 45 to 190 ⁇ m, about 45 to 180 ⁇ m, about 45 to 155 ⁇ m, about 45 to 120 ⁇ m, about 60 to 300 ⁇ m, about 60 to 260 ⁇ m, about 60 to 210 ⁇ m, about 60 to 1
• the thickness include about 90 ⁇ m, about 60 to 180 ⁇ m, about 60 to 155 ⁇ m, about 60 to 120 ⁇ m, about 155 to 300 ⁇ m, about 155 to 260 ⁇ m, about 155 to 210 ⁇ m, about 155 to 190 ⁇ m, about 155 to 180
• the ratio of the total thickness of the base material layer 1, the adhesive layer 2 provided as needed, the barrier layer 3, the adhesive layer 5 provided as needed, the heat-sealable resin layer 4, and the surface coating layer 6 provided as needed to the thickness (total thickness) of the laminate constituting the exterior material 10 for a storage battery device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
• the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the exterior material 10 for a storage battery device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
• the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the exterior material 10 for an electric storage device can be, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
• the exterior material for an electricity storage device disclosed herein has a moisture content when exposed to an environment of 25°C temperature and 50% relative humidity for 24 hours of preferably about 2700 ppm or less, more preferably about 2500 ppm or less, even more preferably about 2000 ppm or less, and even more preferably 1000 ppm or less.
• the lower limit can be, for example, about 0 ppm, about 100 ppm, or about 200 ppm, with a preferred range being about 0 ppm to 2700 ppm.
• the base material layer 1 located on the outside includes a polyester resin layer 11 having a thickness of 20 ⁇ m or more.
• the polyester resin included in the polyester resin layer 11 has low water absorption and can suppress the penetration of moisture from the outside of the base material layer 1 to the barrier layer 3 side. For this reason, the exterior material for an electric storage device disclosed herein can reduce the moisture content when exposed to an environment at a temperature of 25°C and a relative humidity of 50%, as described above.
• the moisture content of the exterior material for an electric storage device when exposed to an environment at a temperature of 25°C and a relative humidity of 50% for 24 hours is measured by the following procedure.
• the sample to be measured (exterior material for power storage devices) is stored for 24 hours in an environment with a temperature of 25°C, a relative humidity of 1% or less, and a dew point of -20°C or less, and then stored for 24 hours in an environment with a temperature of 25°C and a relative humidity of 50%, and a sample with a size of 100mm x 100mm is cut out from the center and used.
• the moisture content is measured by using a Karl Fischer moisture meter and an evaporator placed in an environment with a temperature of 25°C, a relative humidity of 1% or less, and a dew point of -20°C or less, and measured by the moisture evaporation-coulometric titration method.
• the sample is wrapped in a package that can be isolated from the outside air and brought into the measurement environment, and is placed in the measurement device within 30 minutes after being removed from the package.
• the measurement conditions are as follows.
• Component to be measured water, titration cell type: two-liquid cell, type of detection electrode: bipolar platinum electrode, material of diaphragm: ceramic, end point detection method: AC polarization method using bipolar platinum detection electrode, end point judgment method: drift stability judgment, heating temperature: 180°C, cell purge time: 120 seconds, back purge time: 180 seconds, stability judgment value: 0.1 ⁇ g/min, end point potential 200 mV.
• the measurement results are calculated using the ratio of the weight of water to the weight of the sample (unit: ppm), and the average value of three measurements is rounded off to the nearest tenth.
• Commercially available anolyte and catholyte are used as titration reagents.
• the exterior material for an electricity storage device obtained by the same method as that described above in ⁇ Moisture content of exterior material for electricity storage device> and exposed to an environment at a temperature of 25°C and a relative humidity of 50% for 24 hours, has a seal strength when heat-sealed at a temperature of 210°C of preferably about 120 N/15 mm or more, more preferably about 140 N/15 mm or more, and even more preferably about 160 N/15 mm or more, with an upper limit of, for example, 200 N/
• the strength include 15mm, 190N/15mm, and 180N/15mm, and preferred ranges include about 120-200N/15mm, about 120-190N/15mm, about 120-180N/15mm, about 140-200N/15mm, about 140-190N/15mm, about 140-180N/15mm, about 160-200N/15mm, about 160-190N/15mm, and about 160-180N/15mm.
• the method for measuring the seal strength is as follows.
• the battery packaging material is cut into strips with a width of 15 mm in the TD direction as test pieces to prepare the battery packaging material. Specifically, as shown in FIG. 7, first, each battery packaging material is cut into 60 mm (TD direction) x 200 mm (MD direction) (FIG. 7a). Next, the battery packaging material is folded in half in the MD direction at the fold P (middle in the MD direction) so that the heat-sealable resin layers face each other (FIG. 7b).
• the heat-sealable resin layers are heat-sealed to each other about 10 mm inside the fold P in the MD direction under the conditions of a seal width of 7 mm, a temperature of 210° C., a surface pressure of 1.0 MPa, and a time of 3 seconds (FIG. 7c).
• the shaded area S is the heat-sealed part.
• the test piece is cut in the MD direction (cut at the position of the two-dot chain line in FIG. 7d) so that the width in the TD direction is 15 mm, and a test piece is obtained (FIG. 7e).
• test piece 13 is left at each measurement temperature for 2 minutes, and the heat-sealable resin layer of the heat-sealed part is peeled off at a speed of 300 mm/min using a tensile tester in each measurement temperature environment (FIG. 8).
• the maximum strength at the time of peeling is the seal strength (N/15 mm).
• the distance between the chucks is 50 mm.
• the average value of three measurements is taken.
• the test piece 13 may peel off (break) at the heat seal interface A shown in FIG. 8, or may break at a part other than the heat seal interface A (for example, the position B in FIG. 8).
• the molding depth of the exterior material for an electricity storage device of the present disclosure obtained in the above ⁇ Moisture content of the exterior material for an electricity storage device> exposed to an environment at a temperature of 25°C and a relative humidity of 50% for 24 hours is measured under the following conditions
• the molding depth is preferably about 10 mm or more, more preferably about 15 mm or more, and even more preferably about 19 mm or more, with the upper limit being, for example, about 32 mm, about 30 mm, or about 28 mm, and preferred ranges include about 10 to 32 mm, about 10 to 30 mm, about 10 to 28 mm, about 15 to 32 mm, about 15 to 30 mm, about 15 to 28 mm, about 19 to 32 mm, about 19 to 30 mm, and about 19 to 28 mm.
• Each electrical storage device exterior material was cut into a square with a length (MD) of 200 mm and a width (TD) of 200 mm to prepare a test sample.
• the MD of the electrical storage device exterior material corresponds to the rolling direction (RD) of the aluminum alloy foil
• the TD of the electrical storage device exterior material corresponds to the TD of the aluminum alloy foil.
• the maximum height roughness (nominal value of Rz) specified in Table 2 of the comparative surface roughness standard piece is 3.2 ⁇ m.
• the molding depth was changed in 0.5 mm increments from the molding depth of 0.5 mm at a pressing pressure (surface pressure) of 0.25 MPa, and cold molding (one-stage drawing molding) was performed on 10 samples each.
• the above test sample was placed on the female mold so that the heat-fusible resin layer side was located on the male mold side and molding was performed.
• the clearance between the male mold and the female mold was 0.3 mm.
• the sample after cold molding was irradiated with a penlight in a dark room to confirm whether pinholes or cracks were generated in the aluminum foil due to the transmission of light.
• the deepest molding depth at which no pinholes or cracks occurred in the aluminum foil in any of the 10 samples was defined as A mm, and the number of samples at which pinholes, etc. occurred in the aluminum foil at the shallowest molding depth was defined as B.
• the value calculated by the following formula was rounded off to two decimal places to determine the limit molding depth of the exterior material for an electricity storage device.
• Limit forming depth A mm + (0.5 mm/10 pieces) x (10 pieces - B pieces)
• the exterior material for an electricity storage device of the present disclosure has A/(the maximum value of A, B, C), B/(the maximum value of A, B, C), and C/(the maximum value of A, B, C) all within the range of 0.40 to 1.00, as calculated by the following tensile test. This provides a good balance of the tensile stress of the exterior material for an electricity storage device, and allows it to exhibit high formability.
• the substrate layer 1 is a layer provided for the purpose of exhibiting the function as a substrate of the exterior material for an electricity storage device, etc.
• the substrate layer 1 is located on the outer layer side of the exterior material for an electricity storage device.
• the substrate layer 1 includes a polyester resin layer 11.
• the substrate layer 1 may be composed of a single layer of polyester resin layer 11, or the substrate layer 1 may further include a resin layer 12 in addition to the polyester resin layer 11.
• the resin layer 12 may be a layer formed of a polyester resin, or may be a layer formed of a resin different from polyester resin.
• the resin layer 12 is a layer formed of a resin other than polyester resin, it is possible to impart different properties to the base material layer 1 compared to when the base material layer 1 is formed only of a polyester resin layer.
• the resin layer 12 is formed of a polyamide resin, since polyamide resin has superior moldability compared to polyester resin, it is possible to improve the moldability of the entire exterior material for a storage battery device.
• Polyamide resin has higher water absorption than polyester resin and is likely to cause the generation of bubbles due to the above-mentioned heat fusion.
• the exterior material for a storage battery device of the present disclosure since the base material layer 1 contains a polyester resin layer 11 containing a polyester resin with low water absorption and has a thickness of 20 ⁇ m or more, the polyester resin layer 11 can suppress the penetration of moisture from the outside of the barrier layer 3. Therefore, the exterior material for a storage battery device of the present disclosure can achieve both the suppression of bubble generation and the improvement of moldability.
• the polyester resin layer 11 and the resin layer 12 may be laminated directly or via an adhesive layer 12a.
• the polyester resin layer 11 is located on the outer side of the resin layer 12.
• the polyester resin layer 11 is a resin layer containing polyester as a main component.
• the main component means that the content of polyester in the resin components contained in the polyester resin layer 11 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.
• polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters.
• copolymer polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit.
• polyethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate
• polyethylene (terephthalate/isophthalate) polyethylene (terephthalate/adipate)
• polyethylene (terephthalate/sodium sulfoisophthalate) polyethylene (terephthalate/sodium isophthalate)
• polyethylene (terephthalate/phenyl-dicarboxylate) polyethylene (terephthalate/decane dicarboxylate).
• polyethylene terephthalate is preferred.
• These polyesters may be used alone or in combination of two or more.
• the polyester resin layer 11 can be formed, for example, from a polyester resin film.
• a preformed polyester resin film may be used as the polyester resin layer 11.
• the polyester forming the polyester resin layer 11 may be formed into a film on the surface of an adjacent layer by extrusion molding, coating, or the like, to form the polyester resin layer 11 from the polyester resin film.
• the polyester resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, with biaxially stretched films being preferred. Examples of stretching methods for forming a biaxially stretched film include sequential biaxial stretching, inflation, and simultaneous biaxial stretching. Examples of methods for coating the polyester resin include roll coating, gravure coating, and extrusion coating.
• the polyester resin layer 11 may be a single layer, or may be composed of two or more layers.
• the polyester resin layer 11 may be a laminate in which resin films are laminated with an adhesive or the like, or may be a laminate of polyester resin films in which resins are co-extruded to form two or more layers.
• a laminate of polyester resin films in which resins are co-extruded to form two or more layers may be used as the polyester resin layer 11 without being stretched, or may be uniaxially or biaxially stretched to form the polyester resin layer 11.
• Additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and colorants may be present on at least one of the surface and interior of the polyester resin layer 11. Only one type of additive may be used, or two or more types may be mixed together.
• the thickness of the polyester resin layer 11 is not particularly limited as long as it is 20 ⁇ m or more and does not impede the effects of the present disclosure. From the viewpoint of more optimally exerting the effects of the present disclosure, the thickness of the polyester resin layer 11 is preferably about 22 ⁇ m or more, about 25 ⁇ m or more, about 27 ⁇ m or more, more preferably about 30 ⁇ m or more, about 32 ⁇ m or more, and even about 35 ⁇ m or more, and is preferably about 100 ⁇ m or less, more preferably about 78 ⁇ m or less, even more preferably about 75 ⁇ m or less, and even more preferably about 50 ⁇ m or less, and the preferred ranges are about 22 to 100 ⁇ m, about 22 to 78 ⁇ m, about 22 to 75 ⁇ m, and about 22 to 50 ⁇ m.
• the polyester resin layer 11 is composed of two or more layers, and the thickness of each polyester resin layer is less than 20 ⁇ m, but the total thickness of the polyester resin layers is 20 ⁇ m or more, the thickness of the polyester resin layer 11 is the total thickness of the layers.
• the substrate layer 1 further includes a resin layer 12 in addition to the polyester resin layer 11, there are no particular restrictions on the material forming the resin layer 12, as long as it has the function of a substrate, i.e., at least insulating properties.
• the resin layer 12 can be formed, for example, from a resin film.
• a preformed resin film may be used as the resin layer 12 when the resin layer 12 is laminated with the polyester resin layer 11, the barrier layer 3, etc. to manufacture the exterior material for a storage device 10 of the present disclosure.
• the resin forming the resin layer 12 may be formed into a film on the surface of the polyester resin layer 11, the barrier layer 3, etc. by extrusion molding or coating, etc., to form the resin layer 12 formed from the resin film.
• the resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, and biaxially stretched films are preferred. Examples of stretching methods for forming a biaxially stretched film include sequential biaxial stretching, inflation, and simultaneous biaxial stretching. Examples of methods for applying the resin include roll coating, gravure coating, and extrusion coating.
• the resin that forms the resin layer 12 examples include resins such as polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenolic resin, as well as modified versions of these resins.
• the resin that forms the resin layer 12 may also be a copolymer of these resins, or a modified version of the copolymer. It may also be a mixture of these resins.
• the resin layer 12 preferably contains these resins as the main component, and more preferably contains polyamide as the main component.
• the main component means that the content of the resin components contained in the resin layer 12 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.
• the resin layer 12 containing polyamide as the main component means that the content of polyamide among the resin components contained in the resin layer 12 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.
• polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) which contain structural units derived from terephthalic acid and/or isophthalic acid, and aromatic polyamides such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); polyamides copolymerized with lactam components or isocyanate components such as 4,4'-diphenylmethane diisocyanate; polyesteramide copolymers and polyetheresteramide copolymers which are copolymer,
• the resin layer 12 may be a single layer, or may be composed of two or more layers.
• the resin layer 12 may be a laminate in which resin films are laminated with an adhesive or the like, or may be a laminate of resin films in which resins are co-extruded into two or more layers.
• a laminate of resin films in which resins are co-extruded into two or more layers may be used as the resin layer 12 without being stretched, or may be uniaxially or biaxially stretched to become the resin layer 12.
• Additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and colorants may be present on at least one of the surface and interior of the resin layer 12. Only one type of additive may be used, or two or more types may be mixed together.
• the thickness of the resin layer 12 is preferably about 7 ⁇ m or more, about 12 ⁇ m or more, about 15 ⁇ m or more, more preferably about 20 ⁇ m or more, and even more preferably about 25 ⁇ m or more, and is preferably about 50 ⁇ m or less, more preferably about 40 ⁇ m or less, even more preferably about 30 ⁇ m or less, and even more preferably about 25 ⁇ m or less, with preferred ranges being about 7 to 50 ⁇ m, and about 7 to 40 ⁇ m.
• the resin layer 12 is made of a polyamide resin film, it is preferable to satisfy these thicknesses from the viewpoint of suppressing the generation of bubbles in the exterior material for the electric storage device and enhancing the moldability.
• the ratio of the thickness of the polyester resin layer 11 to the thickness of the resin layer 12 is preferably about 0.9 or more, more preferably about 1.0 or more, or about 1.5 or more, and is preferably about 7.0 or less, more preferably about 6.0 or less, with preferred ranges being about 0.9 to 7.0, about 0.9 to 6.0, about 1.0 to 7.0, about 1.0 to 6.0, about 1.5 to 7.0, or about 1.5 to 6.0.
• the laminate may be one in which the polyester resin layer 11 and the resin layer 12 are directly laminated together, as described above, or one in which the polyester resin layer 11 and the resin layer 12 are laminated together via the adhesive layer 12a, the latter being more preferred.
• the adhesive that forms adhesive layer 12a can be the same as the adhesive that forms adhesive layer 2, which will be described later.
• the method for laminating the polyester resin layer 11 and the resin layer 12 is not particularly limited, and known methods can be used, such as dry lamination, sandwich lamination, extrusion lamination, and thermal lamination, with dry lamination being preferred.
• a polyurethane adhesive as the adhesive for forming the adhesive layer 12a.
• An anchor coat layer may be formed on the polyester resin layer 11 or the resin layer 12 before laminating. Examples of the anchor coat layer include the same adhesive as the adhesive layer 2 described below. In this case, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 ⁇ m.
• the thickness of the adhesive layer 12a is not particularly limited as long as it can bond the polyester resin layer 11 and the resin layer 12, but is, for example, about 1 ⁇ m or more, about 2 ⁇ m or more.
• the thickness of the adhesive layer 12a is, for example, about 10 ⁇ m or less, about 5 ⁇ m or less. Preferred ranges for the thickness of the adhesive layer 12a include about 1 to 10 ⁇ m, about 1 to 5 ⁇ m, about 2 to 10 ⁇ m, and about 2 to 5 ⁇ m.
• the substrate layer 1 is preferably formed of a single layer of polyester resin layer 11, or a laminate of polyester resin layer 11 and resin layer 12 containing polyamide resin.
• the laminate of polyester resin layer 11 and resin layer 12 containing polyamide resin may be one in which polyester resin layer 11 and resin layer 12 are directly laminated together, or one in which polyester resin layer 11 and resin layer 12 are laminated together via adhesive layer 12a, the latter being more preferred.
• the substrate layer 1 include a single layer of polyester resin film, a laminate of polyester resin film and nylon resin film, and a laminate of two or more layers of polyester resin film, with a laminate of stretched polyester film and stretched nylon film being preferred.
• a laminate of polyester resin film and polyester resin film, or a laminate of polyester resin film and polyamide resin film is preferred, and a laminate of polyethylene terephthalate film and polyethylene terephthalate film, or a laminate of polyethylene terephthalate film and nylon film is more preferred.
• polyester resin has low moisture permeability, it is preferred that the polyester resin film be located as the outermost layer of the substrate layer 1 when the substrate layer 1 is a laminate of two or more layers of resin film.
• the two or more resin films may be laminated via an adhesive.
• Preferred adhesives include those similar to those exemplified in the adhesive layer 2 described below.
• the method for laminating two or more resin films is not particularly limited, and known methods can be used, such as dry lamination, sandwich lamination, extrusion lamination, and thermal lamination, and preferably dry lamination.
• a polyurethane adhesive as the adhesive.
• the thickness of the adhesive is, for example, about 2 to 5 ⁇ m.
• an anchor coat layer may be formed on the resin film and laminated.
• the anchor coat layer may be the same as the adhesive exemplified in the adhesive layer 2 described below. In this case, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 ⁇ m.
• Additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and colorants may be present on at least one of the surface and interior of the base layer 1. Only one type of additive may be used, or two or more types may be mixed together.
• a lubricant is present on at least one of the surface and the inside of the base material layer 1.
• the lubricant is not particularly limited, but preferably includes amide-based lubricants.
• Specific examples of amide-based lubricants include, for example, saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides.
• saturated fatty acid amides include lauric acid amides, palmitic acid amides, stearic acid amides, behenic acid amides, and hydroxystearic acid amides.
• unsaturated fatty acid amides include oleic acid amides and erucic acid amides.
• substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide.
• methylol amides include methylol stearic acid amide.
• saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide, etc.
• unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide, etc.
• fatty acid ester amides include stearamide ethyl stearate, etc.
• aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide.
• the lubricant may be used alone or in combination of two or more types, preferably in combination of two or more types.
• the amount of the lubricant present is not particularly limited, but may be, for example, about 3 mg/m 2 or more, preferably about 4 mg/m 2 or more, or about 5 mg/m 2 or more.
• the amount of the lubricant present on the surface of the base layer 1 may be, for example, about 15 mg/m 2 or less, preferably about 14 mg/m 2 or less, or about 10 mg/m 2 or less.
• the preferred range of the amount of the lubricant present on the surface of the base layer 1 is about 3 to 15 mg/m 2 , about 3 to 14 mg/m 2 , about 3 to 10 mg/m 2 , about 4 to 15 mg/m 2 , about 4 to 14 mg/m 2 , about 4 to 10 mg/m 2 , about 5 to 15 mg/m 2 , about 5 to 14 mg/m 2 , or about 5 to 10 mg/m 2 .
• the lubricant present on the surface of the base layer 1 may be a lubricant exuded from the resin that constitutes the base layer 1, or a lubricant applied to the surface of the base layer 1.
• the thickness of the base layer 1 is not particularly limited as long as the polyester resin layer 11 is 20 ⁇ m or more, and the effect of the present disclosure is not hindered. From the viewpoint of more optimally exerting the effect of the present disclosure, the thickness of the base layer 1 is preferably about 22 ⁇ m or more, about 25 ⁇ m or more, more preferably about 40 ⁇ m or more, and even more preferably about 50 ⁇ m or more, and is preferably about 100 ⁇ m or less, more preferably about 90 ⁇ m or less, even more preferably about 80 ⁇ m or less, and even more preferably about 75 ⁇ m or less, and the preferred ranges are about 20 to 100 ⁇ m, about 20 to 90 ⁇ m, about 20 to 80 ⁇ m, and about 30 to 40 ⁇ m.
• Examples include about 0 ⁇ m, about 20 to 75 ⁇ m, about 22 to 100 ⁇ m, about 22 to 90 ⁇ m, about 22 to 80 ⁇ m, about 22 to 75 ⁇ m, about 25 to 100 ⁇ m, about 25 to 90 ⁇ m, about 25 to 80 ⁇ m, about 25 to 75 ⁇ m, about 40 to 100 ⁇ m, about 40 to 90 ⁇ m, about 40 to 80 ⁇ m, about 40 to 75 ⁇ m, about 50 to 100 ⁇ m, about 50 to 90 ⁇ m, about 50 to 80 ⁇ m, and about 50 to 75 ⁇ m.
• the base layer 1 contains a colorant, so that the exterior material for the electricity storage device can be colored.
• Known colorants such as pigments and dyes can be used as the colorant.
• only one type of colorant may be used, or two or more types may be mixed together.
• the type of pigment is not particularly limited as long as it does not impair the function of the substrate layer 1 as a substrate.
• organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments.
• examples of inorganic pigments include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments. Other examples include finely powdered mica and fish scale foil.
• carbon black is preferred in order to give the exterior material for an electricity storage device a black appearance. Also, from the perspective of dissipating heat generated by the electricity storage device, it is preferable to use mica.
• the average particle size of the pigment is not particularly limited, and may be, for example, about 0.03 to 5 ⁇ m, and preferably about 0.05 to 2 ⁇ m.
• the average particle size of the pigment is the median size measured with a laser diffraction/scattering type particle size distribution measuring device.
• the content of the colorant in the base layer 1 is not particularly limited as long as the exterior material for the electricity storage device is colored, and may be, for example, about 5 to 60% by mass, and preferably about 10 to 40% by mass.
• DSC differential scanning calorimetry
• the barrier layer can be dissolved with dilute hydrochloric acid, the base layer can be extracted, washed with water, and dried for measurement.
• the heat of transition (heat of crystallization) is determined by cooling using a differential scanning calorimeter according to the following procedure. According to JIS K7122:2024, the sample is held at 0°C for 1 minute, then heated to 280°C at a heating rate of 10°C/min and held there for 5 minutes. The sample is then cooled to 0°C at a cooling rate of 10°C/min to plot a DSC curve.
• the flow rate of nitrogen gas is 50 ml/min.
• the adhesive layer 2 is a layer that is provided between the base layer 1 and the barrier layer 3 as necessary for the purpose of increasing the adhesion between them.
• the adhesive layer 2 is formed from an adhesive capable of bonding the base layer 1 and the barrier layer 3.
• the adhesive used to form the adhesive layer 2 may be any of a chemical reaction type, a solvent volatilization type, a hot melt type, a hot pressure type, etc. It may also be a two-component curing adhesive (two-component adhesive), a one-component curing adhesive (one-component adhesive), or a resin that does not involve a curing reaction.
• the adhesive layer 2 may be a single layer or multiple layers.
• polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters; polyethers; polyurethanes; epoxy resins; phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymer polyamides; polyolefin resins such as polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins; polyvinyl acetate; cellulose; (meth)acrylic resins; polyimides; polycarbonates; amino resins such as urea resins and melamine resins; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; and silicone resins.
• polyesters such as polyethylene terephthalate, polybutylene terephthalate,
• adhesive components may be used alone or in combination of two or more.
• polyurethane adhesives are preferred.
• the adhesive strength of these adhesive component resins can be increased by using an appropriate curing agent in combination.
• the curing agent is selected from polyisocyanates, multifunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, and the like, depending on the functional groups of the adhesive components.
• the polyurethane adhesive may be, for example, a polyurethane adhesive containing a first agent containing a polyol compound and a second agent containing an isocyanate compound.
• a two-part curing polyurethane adhesive may preferably be used, in which a polyol such as polyester polyol, polyether polyol, or acrylic polyol is used as the first agent, and an aromatic or aliphatic polyisocyanate is used as the second agent.
• the polyurethane adhesive may be, for example, a polyurethane adhesive containing a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance, and an isocyanate compound.
• the polyurethane adhesive may be, for example, a polyurethane adhesive containing a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance, and a polyol compound.
• the polyurethane adhesive may be, for example, a polyurethane adhesive in which a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance is cured by reacting it with moisture in the air or the like.
• the polyol compound it is preferable to use a polyester polyol having a hydroxyl group on the side chain in addition to the hydroxyl group at the end of the repeating unit.
• the second agent may be an aliphatic, alicyclic, aromatic, or araliphatic isocyanate compound.
• isocyanate compound examples include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI).
• polyisocyanate compound examples include polyfunctional isocyanate modified compounds of one or more of these diisocyanates.
• the adhesive layer 2 is formed from a polyurethane adhesive, which gives the exterior material for the electricity storage device excellent electrolyte resistance, and prevents the base layer 1 from peeling off even if electrolyte adheres to the side surface.
• the adhesive layer 2 is permitted to contain other components as long as they do not impair adhesion, and may contain colorants, thermoplastic elastomers, tackifiers, fillers, etc.
• a colorant in the adhesive layer 2, the exterior material for the electricity storage device can be colored.
• known colorants such as pigments and dyes can be used.
• only one type of colorant may be used, or two or more types may be mixed together.
• organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments
• inorganic pigments include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, as well as finely powdered mica and fish scale foil.
• carbon black is preferred, for example to give the exterior material for an electricity storage device a black appearance.
• the average particle size of the pigment is not particularly limited, and may be, for example, about 0.03 to 5 ⁇ m, and preferably about 0.05 to 2 ⁇ m.
• the average particle size of the pigment is the median size measured with a laser diffraction/scattering type particle size distribution measuring device.
• the content of the colorant in the adhesive layer 2 is not particularly limited as long as the exterior material for the electricity storage device is colored, and may be, for example, about 5 to 60% by mass, and preferably 10 to 40% by mass.
• the thickness of the adhesive layer 2 is not particularly limited as long as it can bond the base layer 1 and the barrier layer 3, but is, for example, about 1 ⁇ m or more, about 2 ⁇ m or more, or about 4 ⁇ m or more.
• the thickness of the adhesive layer 2 is, for example, about 10 ⁇ m or less, about 7 ⁇ m or more, or about 5 ⁇ m or less.
• the preferred ranges of the thickness of the adhesive layer 2 include about 1 to 10 ⁇ m, about 1 to 7 ⁇ m, about 1 to 5 ⁇ m, about 2 to 10 ⁇ m, about 2 to 7 ⁇ m, about 2 to 5 ⁇ m, about 4 to 10 ⁇ m, about 4 to 7 ⁇ m, and about 4 to 5 ⁇ m.
• the preferred ranges are, for example, about 4 ⁇ m or more, about 10 ⁇ m or less, about 7 ⁇ m or more, and about 5 ⁇ m or less, and preferred ranges include about 4 to 10 ⁇ m, about 4 to 7 ⁇ m, and about 4 to 5 ⁇ m.
• the colored layer is a layer (not shown) that is provided between the base material layer 1 and the barrier layer 3 as necessary.
• a colored layer may be provided between the base material layer 1 and the adhesive layer 2, or between the adhesive layer 2 and the barrier layer 3. Also, a colored layer may be provided on the outside of the base material layer 1. By providing a colored layer, the exterior material for an electricity storage device can be colored.
• the colored layer can be formed, for example, by applying an ink containing a colorant to the surface of the base layer 1 or the surface of the barrier layer 3.
• a colorant known substances such as pigments and dyes can be used.
• only one type of colorant may be used, or two or more types may be mixed together.
• colorants contained in the colored layer include those exemplified in the [Adhesive layer 2] section.
• the barrier layer 3 is a layer that at least prevents the infiltration of moisture.
• the barrier layer 3 may be, for example, a metal foil, a vapor deposition film, or a resin layer having barrier properties.
• the vapor deposition film include a metal vapor deposition film, an inorganic oxide vapor deposition film, and a carbon-containing inorganic oxide vapor deposition film.
• the resin layer include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, and ethylene-vinyl alcohol copolymers.
• the barrier layer 3 examples include resin films having at least one of these vapor deposition films and resin layers.
• the barrier layer 3 may be provided in multiple layers. It is preferable that the barrier layer 3 includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 3 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, it is preferable that the barrier layer 3 includes at least one of aluminum alloy foil and stainless steel foil.
• the layer made of the above-mentioned metal material may contain recycled metal material.
• recycled metal material include recycled aluminum alloy, stainless steel, titanium steel, or steel plate. These recycled materials can be obtained by known methods. Recycled aluminum alloy can be obtained by the manufacturing method described in WO 2022/092231.
• the barrier layer 3 may be made of only recycled materials, or may be made of a mixture of recycled and virgin materials. Note that recycled metal materials refer to metal materials that have been made reusable by collecting, isolating, and refining various products used in the city and waste from manufacturing processes. Virgin metal materials refer to new metal materials that have been refined from natural metal resources (raw materials) and are not recycled materials.
• the aluminum alloy foil is preferably a soft aluminum alloy foil composed of, for example, an annealed aluminum alloy, and from the viewpoint of further improving formability, it is preferably an aluminum alloy foil containing iron.
• the iron content is preferably 0.1 to 9.0 mass%, and more preferably 0.5 to 2.0 mass%.
• soft aluminum alloy foils examples include aluminum alloy foils having a composition specified in JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Silicon, magnesium, copper, manganese, etc. may also be added as necessary. Softening can be achieved by annealing or other treatments.
• stainless steel foil examples include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. Furthermore, from the viewpoint of providing an exterior material for an electricity storage device with excellent formability, it is preferable that the stainless steel foil is made of austenitic stainless steel.
• austenitic stainless steels that make up the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.
• the thickness of the barrier layer 3 should at least function as a barrier layer that prevents moisture from penetrating, and may be, for example, about 9 to 200 ⁇ m.
• the thickness of the barrier layer 3 is preferably about 10 ⁇ m or more, about 20 ⁇ m or more, about 25 ⁇ m or more, more preferably about 50 ⁇ m or more, about 52 ⁇ m or more, about 60 ⁇ m or more, about 70 ⁇ m or more, and even more preferably about 80 ⁇ m or more.
• the thickness of the barrier layer 3 is preferably about 100 ⁇ m or less, about 95 ⁇ m or less, about 90 ⁇ m or less, about 80 ⁇ m or less, about 50 ⁇ m or less, about 40 ⁇ m or less, or about 35 ⁇ m or less.
• preferred ranges of the thickness of the barrier layer 3 are about 10 to 100 ⁇ m, about 10 to 95 ⁇ m, about 10 to 90 ⁇ m, about 10 to 80 ⁇ m, about 10 to 50 ⁇ m, about 10 to 40 ⁇ m, about 10 to 35 ⁇ m, about 20 to 100 ⁇ m, about 20 to 95 ⁇ m, about 20 to 90 ⁇ m, about 20 to 80 ⁇ m, about 20 to 50 ⁇ m, about 20 to 40 ⁇ m, about 20 to 35 ⁇ m, about 25 to 100 ⁇ m, about 25 to 95 ⁇ m, about 25 to 90 ⁇ m, about 25 to 80 ⁇ m, about 25 to 50 ⁇ m, about 25
• Examples of the thickness include about 40 ⁇ m, about 25 to 35 ⁇ m, about 50 to 100 ⁇ m, about 50 to 95 ⁇ m, about 50 to 90 ⁇ m, about 50 to 80 ⁇ m, about 52 to 100 ⁇ m, about 52 to 95 ⁇ m, about 52 to 90 ⁇ m, about 52 to 80 ⁇ m, about 60 to
• the thickness of the barrier layer 3 is preferably about 50 ⁇ m or more, about 52 ⁇ m or more, more preferably about 60 mm or more, even more preferably about 70 ⁇ m or more, and even more preferably about 80 ⁇ m or more, and is preferably about 100 ⁇ m or less, more preferably about 95 ⁇ m or less, even more preferably about 90 ⁇ m or less, and even more preferably about 80 ⁇ m or less.
• the thickness of the stainless steel foil is preferably about 60 ⁇ m or less, more preferably about 50 ⁇ m or less, even more preferably about 40 ⁇ m or less, even more preferably about 30 ⁇ m or less, and particularly preferably about 25 ⁇ m or less.
• the thickness of the stainless steel foil is preferably about 10 ⁇ m or more, more preferably about 15 ⁇ m or more.
• preferred ranges of the thickness of the stainless steel foil include about 10 to 60 ⁇ m, about 10 to 50 ⁇ m, about 10 to 40 ⁇ m, about 10 to 30 ⁇ m, about 10 to 25 ⁇ m, about 15 to 60 ⁇ m, about 15 to 50 ⁇ m, about 15 to 40 ⁇ m, about 15 to 30 ⁇ m, and about 15 to 25 ⁇ m.
• the barrier layer 3 when the barrier layer 3 is a metal foil, it is preferable to provide a corrosion-resistant film at least on the surface opposite to the base layer in order to prevent dissolution and corrosion.
• the barrier layer 3 may be provided with a corrosion-resistant film on both sides.
• the corrosion-resistant film refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) by performing, for example, hydrothermal transformation treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment with nickel or chromium, or corrosion prevention treatment by applying a coating agent on the surface of the barrier layer.
• the corrosion-resistant film means a film that improves the acid resistance of the barrier layer (acid-resistant film), a film that improves the alkali resistance of the barrier layer (alkali-resistant film), etc.
• a treatment for forming a corrosion-resistant film one type may be performed, or two or more types may be combined. In addition to one layer, multiple layers can be formed.
• hydrothermal transformation treatment and anodizing treatment are treatments in which the metal foil surface is dissolved by a treatment agent to form a metal compound with excellent corrosion resistance. These treatments may also be included in the definition of chemical conversion treatment.
• the barrier layer 3 has a corrosion-resistant coating
• the corrosion-resistant coating is included in the barrier layer 3.
• the corrosion-resistant coating prevents delamination between the barrier layer (e.g., aluminum alloy foil) and the base layer during molding of the exterior material for the power storage device, prevents dissolution and corrosion of the barrier layer surface due to hydrogen fluoride produced by the reaction between the electrolyte and water, and in particular prevents dissolution and corrosion of aluminum oxide present on the barrier layer surface when the barrier layer is an aluminum alloy foil, and also improves the adhesion (wettability) of the barrier layer surface, preventing delamination between the base layer and barrier layer during heat sealing and between the base layer and barrier layer during molding.
• the barrier layer e.g., aluminum alloy foil
• Various corrosion-resistant films formed by chemical conversion treatments are known, including mainly corrosion-resistant films containing at least one of phosphates, chromates, fluorides, triazine thiol compounds, and rare earth oxides.
• Chemical conversion treatments using phosphates and chromates include, for example, chromate chromate treatment, phosphoric acid chromate treatment, phosphoric acid-chromate treatment, and chromate treatment.
• chromium compounds used in these treatments include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromate acetyl acetate, chromium chloride, and potassium chromium sulfate.
• phosphorus compounds used in these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid.
• chromate treatments include etching chromate treatment, electrolytic chromate treatment, and coating-type chromate treatment, with coating-type chromate treatment being preferred.
• a barrier layer e.g., an aluminum alloy foil
• a known method such as an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or an acid activation method, and then a treatment liquid mainly composed of a metal phosphate such as Cr (chromium) phosphate, Ti (titanium) phosphate, Zr (zirconium) phosphate, or Zn (zinc) phosphate, or a mixture of these metal salts, or a treatment liquid mainly composed of a nonmetallic phosphate and a mixture of these nonmetallic salts, or a treatment liquid consisting of a mixture of these with a synthetic resin, or the like, is applied to the degreased surface by a known coating method such as a roll coating method, a gravure printing method, a dipping method, or the like, and then dried.
• a known coating method such as a roll coating method, a gravure printing method, a dipping method, or the like
• the treatment liquid various solvents such as water, alcohol-based solvents, hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, and ether-based solvents can be used, and water is preferred.
• the resin component used here may be a polymer such as a phenolic resin or an acrylic resin, and may be a chromate treatment using an aminated phenolic polymer having a repeating unit represented by the following general formulas (1) to (4).
• the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more.
• the acrylic resin is preferably polyacrylic acid, acrylic acid methacrylic acid ester copolymer, acrylic acid maleic acid copolymer, acrylic acid styrene copolymer, or a derivative thereof such as a sodium salt, an ammonium salt, or an amine salt.
• a derivative of polyacrylic acid such as an ammonium salt, a sodium salt, or an amine salt of polyacrylic acid is preferable.
• polyacrylic acid means a polymer of acrylic acid.
• the acrylic resin is also preferably a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic anhydride, and is also preferably an ammonium salt, a sodium salt, or an amine salt of a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic anhydride. Only one type of acrylic resin may be used, or two or more types may be mixed and used.
• X represents a hydrogen atom, a hydroxy group, an alkyl group, a hydroxyalkyl group, an allyl group, or a benzyl group.
• R 1 and R 2 may be the same or different and represent a hydroxy group, an alkyl group, or a hydroxyalkyl group.
• examples of the alkyl group represented by X, R 1 , and R 2 include linear or branched alkyl groups having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group.
• Examples of the hydroxyalkyl group represented by X, R 1 , and R 2 include linear or branched alkyl groups having 1 to 4 carbon atoms and substituted with one hydroxy group, such as a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, and a 4-hydroxybutyl group.
• the alkyl groups and hydroxyalkyl groups represented by X, R 1 , and R 2 may be the same or different.
• X is preferably a hydrogen atom, a hydroxy group, or a hydroxyalkyl group.
• the number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulae (1) to (4) is preferably about 500 to 1,000,000, for example, and more preferably about 1,000 to 20,000.
• the aminated phenol polymer is produced, for example, by polycondensing a phenol compound or a naphthol compound with formaldehyde to produce a polymer consisting of the repeating units represented by the general formula (1) or (3), and then introducing a functional group (-CH 2 NR 1 R 2 ) into the polymer obtained above using formaldehyde and an amine (R 1 R 2 NH).
• the aminated phenol polymer may be used alone or in combination of two or more types.
• corrosion-resistant films include thin films formed by a coating-type corrosion prevention treatment in which a coating agent containing at least one selected from the group consisting of rare earth element oxide sol, anionic polymer, and cationic polymer is applied.
• the coating agent may further contain phosphoric acid or phosphate, and a crosslinking agent for crosslinking the polymer.
• the rare earth element oxide sol has rare earth element oxide fine particles (e.g., particles with an average particle size of 100 nm or less) dispersed in a liquid dispersion medium.
• rare earth element oxides include cerium oxide, yttrium oxide, neodymium oxide, and lanthanum oxide, and cerium oxide is preferred from the viewpoint of further improving adhesion.
• the rare earth element oxide contained in the corrosion-resistant film can be used alone or in combination of two or more types.
• liquid dispersion media for the rare earth element oxide sol include various solvents such as water, alcohol-based solvents, hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, and ether-based solvents, and water is preferred.
• the cationic polymer for example, polyethyleneimine, an ionic polymer complex consisting of a polymer having polyethyleneimine and a carboxylic acid, a primary amine grafted acrylic resin in which a primary amine is graft-polymerized to an acrylic main skeleton, polyallylamine or a derivative thereof, aminated phenol, etc. are preferable.
• the anionic polymer poly(meth)acrylic acid or a salt thereof, or a copolymer mainly composed of (meth)acrylic acid or a salt thereof is preferable.
• the crosslinking agent is at least one selected from the group consisting of a compound having any one of the functional groups of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, and a silane coupling agent.
• the phosphoric acid or the phosphoric acid salt is a condensed phosphoric acid or a condensed phosphate salt.
• a corrosion-resistant coating is one formed by applying a solution of fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, or barium sulfate dispersed in phosphoric acid to the surface of the barrier layer and then baking the coating at 150°C or higher.
• metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, or barium sulfate dispersed in phosphoric acid
• the corrosion-resistant coating may have a laminated structure in which at least one of a cationic polymer and an anionic polymer is further laminated.
• a cationic polymer and anionic polymer include those described above.
• composition of the corrosion-resistant coating can be analyzed, for example, using time-of-flight secondary ion mass spectrometry.
• the amount of the corrosion-resistant coating formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited, but for example, in the case of performing a coating-type chromate treatment, it is desirable for the chromate compound to be contained in an amount, calculated as chromium, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, per 1 m2 of the surface of the barrier layer 3 , of a phosphorus compound, calculated as phosphorus, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and of an aminated phenol polymer, calculated as phosphorus, of about 1.0 to 200 mg, preferably about 5.0 to 150 mg.
• the thickness of the corrosion-resistant film is not particularly limited, but is preferably about 1 nm to 20 ⁇ m, more preferably about 1 nm to 100 nm, and even more preferably about 1 nm to 50 nm, from the viewpoint of the cohesive force of the film and the adhesive force with the barrier layer and the heat-sealable resin layer.
• the thickness of the corrosion-resistant film can be measured by observation with a transmission electron microscope, or by a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron energy loss spectroscopy.
• peaks derived from secondary ions composed of Ce, P, and O for example, at least one of Ce 2 PO 4 + and CePO 4 -
• secondary ions composed of Cr, P, and O for example, at least one of CrPO 2 + and CrPO 4 -
• the chemical conversion treatment is carried out by applying a solution containing a compound used to form a corrosion-resistant film to the surface of the barrier layer by bar coating, roll coating, gravure coating, immersion, or other methods, and then heating the barrier layer to a temperature of about 70 to 200°C.
• the barrier layer may be subjected to a degreasing treatment by an alkali immersion method, electrolytic cleaning method, acid cleaning method, electrolytic acid cleaning method, or other method.
• an acid degreasing agent in which a fluorine-containing compound is dissolved in an inorganic acid for the degreasing treatment, it is possible to not only degrease the metal foil but also form a fluoride of the metal, which is in a passive state, and in such cases, only the degreasing treatment may be carried out.
• the heat-sealable resin layer 4 corresponds to the innermost layer and is a layer (sealant layer) that functions to seal the electricity storage device elements by heat-sealing the heat-sealable resin layers to each other when the electricity storage device is assembled.
• the resin constituting the heat-sealable resin layer 4 is not particularly limited as long as it is heat-sealable, but is preferably a resin containing a polyolefin skeleton such as polyolefin or acid-modified polyolefin.
• the resin constituting the heat-sealable resin layer 4 can be analyzed to contain a polyolefin skeleton, for example, by infrared spectroscopy, gas chromatography mass spectrometry, etc.
• a peak derived from maleic anhydride is detected near the wave number 1760 cm -1 and near the wave number 1780 cm -1 .
• the heat-sealable resin layer 4 is a layer composed of maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected by infrared spectroscopy.
• the degree of acid modification is low, the peak may be small and not detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.
• the heat-sealable resin layer 4 preferably contains a resin containing a polyolefin skeleton as a main component, more preferably contains polyolefin as a main component, and even more preferably contains polypropylene as a main component.
• the main component means that the content of the resin components contained in the heat-sealable resin layer 4 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.
• the heat-sealable resin layer 4 containing polypropylene as a main component means that the content of polypropylene among the resin components contained in the heat-sealable resin layer 4 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.
• 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.
• polypropylene is preferred.
• 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 types.
• the polyolefin may also be a cyclic polyolefin.
• Cyclic polyolefins are copolymers of olefins and cyclic monomers, and examples of olefins that are constituent monomers of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene.
• Examples of cyclic monomers that are constituent monomers of cyclic polyolefins include cyclic alkenes such as norbornene; and cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, cyclic alkenes are preferred, and norbornene is more preferred.
• the polyolefin may be an acid-modified polyolefin.
• An acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of a polyolefin with an acid component.
• the polyolefin to be acid-modified may be the above-mentioned polyolefin, a copolymer obtained by copolymerizing the above-mentioned polyolefin with a polar molecule such as acrylic acid or methacrylic acid, or a polymer such as a cross-linked polyolefin.
• the acid component used for the acid modification include carboxylic acids or anhydrides such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.
• the acid-modified polyolefin may be an acid-modified cyclic polyolefin.
• An acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by replacing it with an acid component, or by block polymerizing or graft polymerizing an acid component onto a cyclic polyolefin.
• the cyclic polyolefin to be acid-modified is the same as described above.
• the acid component used for the acid modification is the same as the acid component used for the modification of the polyolefin described above.
• Preferred acid-modified polyolefins include polyolefins modified with carboxylic acids or their anhydrides, polypropylenes modified with carboxylic acids or their anhydrides, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.
• the heat-sealable resin layer 4 may be formed of one type of resin alone, or may be formed of a blend polymer of two or more types of resin. Furthermore, the heat-sealable resin layer 4 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 4 When manufacturing the exterior material 10 for an electricity storage device of the present disclosure by laminating the heat-sealable resin layer 4 with the barrier layer 3, the adhesive layer 5, etc., a preformed resin film may be used as the heat-sealable resin layer 4.
• the heat-sealable resin that forms the heat-sealable resin layer 4 may be formed into a film on the surface of the barrier layer 3, the adhesive layer 5, etc. by extrusion molding, coating, etc., to form the heat-sealable resin layer 4 from the resin film.
• the heat-sealable resin layer 4 may also contain a lubricant, etc., if necessary.
• a lubricant When the heat-sealable resin layer 4 contains a lubricant, the moldability of the exterior material for the power storage device can be improved. There are no particular limitations on the lubricant, and any known lubricant can be used.
• the lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of the lubricant include those exemplified for the base layer 1.
• the lubricant may be used alone or in combination of two or more types, and it is preferable to use a combination of two or more types.
• a lubricant is present on at least one of the surface and the inside of the heat-sealable resin layer 4.
• the lubricant is not particularly limited, but preferably includes amide-based lubricants.
• Specific examples of amide-based lubricants include, for example, saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides.
• saturated fatty acid amides include lauric acid amides, palmitic acid amides, stearic acid amides, behenic acid amides, and hydroxystearic acid amides.
• unsaturated fatty acid amides include oleic acid amides and erucic acid amides.
• substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide.
• methylol amides include methylol stearic acid amide.
• saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide, etc.
• unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide, etc.
• fatty acid ester amides include stearamide ethyl stearate, etc.
• aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide.
• the lubricant may be used alone or in combination of two or more types, preferably in combination of two or more types.
• the amount thereof is not particularly limited, but from the viewpoint of improving the moldability of the exterior material for a storage battery device, it is preferably about 1 mg / m 2 or more, more preferably about 3 mg / m 2 or more, even more preferably about 5 mg / m 2 or more, even more preferably about 10 mg / m 2 or more, and even more preferably about 15 mg / m 2 or more, and also preferably about 50 mg / m 2 or less, and even more preferably about 40 mg / m 2 or less, and preferred ranges include about 1 to 50 mg / m 2 , about 1 to 40 mg / m 2 , about 3 to 50 mg / m 2 , about 3 to 40 mg / m 2 , about 5 to 50 mg / m 2 , about 5 to 40 mg / m 2 , about 10 to 50 mg / m 2 , about 10 to 40 mg / m 2 , about 10 to 40 mg / m 2 , about 10 to 40 mg /
• the amount thereof is not particularly limited, but from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferably at least about 100 ppm, more preferably at least about 300 ppm, even more preferably at least about 500 ppm, and is preferably at most about 3000 ppm, more preferably at most about 2000 ppm, and preferred ranges include about 100-3000 ppm, about 100-2000 ppm, about 300-3000 ppm, about 300-2000 ppm, about 500-3000 ppm, and about 500-2000 ppm.
• the above amount of lubricant is the total amount of lubricant.
• the amount of the first type of lubricant is not particularly limited, but from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferably about 100 ppm or more, more preferably about 300 ppm or more, and even more preferably about 500 ppm or more, and is preferably about 3000 ppm or less, more preferably about 2000 ppm or less, and preferred ranges include about 100 to 3000 ppm, about 100 to 2000 ppm, about 300 to 3000 ppm, about 300 to 2000 ppm, about 500 to 3000 ppm, and about 500 to 2000 ppm.
• the amount of the second type of lubricant is not particularly limited, but from the viewpoint of improving the moldability of the exterior material for an electrical storage device, it is preferably about 50 ppm or more, more preferably about 100 ppm or more, and even more preferably about 200 ppm or more, and is preferably about 1500 ppm or less, more preferably about 1000 ppm or less, and preferred ranges include about 50 to 1500 ppm, about 50 to 1000 ppm, about 100 to 1500 ppm, about 100 to 1000 ppm, about 200 to 1500 ppm, and about 200 to 1000 ppm.
• the lubricant present on the surface of the heat-sealable resin layer 4 may be a lubricant exuded from the resin that constitutes the heat-sealable resin layer 4, or a lubricant applied to the surface of the heat-sealable resin layer 4.
• the thickness of the heat-sealable resin layer 4 is not particularly limited as long as the heat-sealable resin layers are heat-sealed to each other to seal the electricity storage device element, but may be, for example, about 100 ⁇ m or less, preferably about 85 ⁇ m or less, and more preferably about 15 to 85 ⁇ m.
• the thickness of the adhesive layer 5 described below is 10 ⁇ m or more
• the thickness of the heat-sealable resin layer 4 is preferably about 85 ⁇ m or less, and more preferably about 15 to 45 ⁇ m.
• the thickness of the heat-sealable resin layer 4 is preferably about 20 ⁇ m or more, and more preferably about 35 to 85 ⁇ m.
• the adhesive layer 5 is a layer that is provided, if necessary, between the barrier layer 3 (or the corrosion-resistant coating) and the heat-sealable resin layer 4 in order to firmly bond them together.
• the adhesive layer 5 is formed from a resin capable of bonding the barrier layer 3 and the heat-sealable resin layer 4.
• the resin used to form the adhesive layer 5 may be, for example, the same adhesive as exemplified for the adhesive layer 2.
• the resin used to form the adhesive layer 5 contains a polyolefin skeleton, and examples of the resin include the polyolefin, acid-modified polyolefin, cyclic polyolefin, and acid-modified cyclic polyolefin exemplified in the above-mentioned heat-sealable resin layer 4.
• the adhesive layer 5 contains an acid-modified polyolefin.
• the acid-modified component examples include dicarboxylic acids such as maleic acid, itaconic acid, succinic acid, and adipic acid, and their anhydrides, acrylic acid, and methacrylic acid, but maleic anhydride is most preferable in terms of ease of modification and versatility.
• the olefin component is a polypropylene-based resin, and it is most preferable that the adhesive layer 5 contains maleic anhydride-modified polypropylene.
• the adhesive layer 5 preferably contains a resin containing a polyolefin skeleton as a main component, more preferably contains an acid-modified polyolefin as a main component, and even more preferably contains an acid-modified polypropylene as a main component.
• the main component means that the content of the resin component contained in the adhesive layer 5 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.
• the adhesive layer 5 contains acid-modified polypropylene as a main component
• the content of the acid-modified polypropylene among the resin components contained in the adhesive layer 5 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.
• the resin constituting the adhesive layer 5 can be analyzed for polyolefin skeleton by infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited.
• the resin constituting the adhesive layer 5 can be analyzed for acid-modified polyolefin by, for example, measuring maleic anhydride-modified polyolefin by infrared spectroscopy, whereby peaks derived from maleic anhydride are detected at wave numbers of about 1760 cm -1 and about 1780 cm -1 . However, if the degree of acid modification is low, the peaks may become small and not be detected. In that case, analysis can be performed by nuclear magnetic resonance spectroscopy.
• the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent.
• Preferred examples of the acid-modified polyolefin include those mentioned above.
• the adhesive layer 5 is preferably a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group, and is particularly preferably a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group and a compound having an epoxy group.
• the adhesive layer 5 preferably contains at least one selected from the group consisting of polyurethane, polyester, and epoxy resin, and more preferably contains polyurethane and epoxy resin.
• an ester resin formed by the reaction of an epoxy group with a maleic anhydride group, and an amide ester resin formed by the reaction of an oxazoline group with a maleic anhydride group are preferable.
• a curing agent such as a compound having an isocyanate group, a compound having an oxazoline group, or an epoxy resin remain in the adhesive layer 5
• the presence of the unreacted substances can be confirmed by a method selected from, for example, infrared spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), etc.
• a curing agent having a heterocycle include curing agents having an oxazoline group and curing agents having an epoxy group.
• curing agents having a C-O-C bond include curing agents having an oxazoline group and curing agents having an epoxy group.
• the adhesive layer 5 is a cured product of a resin composition containing these curing agents can be confirmed by, for example, gas chromatography mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), or other methods.
• GCMS gas chromatography mass spectrometry
• IR infrared spectroscopy
• TOF-SIMS time-of-flight secondary ion mass spectrometry
• XPS X-ray photoelectron spectroscopy
• the compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively increasing the adhesion between the barrier layer 3 and the adhesive layer 5, a polyfunctional isocyanate compound is preferably used.
• the polyfunctional isocyanate compound is not particularly limited as long as it has two or more isocyanate groups.
• Specific examples of polyfunctional isocyanate-based curing agents include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymerized or nurated versions of these, mixtures of these, and copolymers with other polymers.
• Other examples include adducts, biurets, and isocyanurates.
• the content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass % in the resin composition constituting the adhesive layer 5, and more preferably in the range of 0.5 to 40 mass %. This effectively improves the adhesion between the barrier layer 3 and the adhesive layer 5.
• the compound having an oxazoline group is not particularly limited as long as it has an oxazoline skeleton.
• Specific examples of compounds having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain.
• examples of commercially available products include the Epocross series manufactured by Nippon Shokubai Co., Ltd.
• the proportion of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass % in the resin composition constituting the adhesive layer 5, and more preferably in the range of 0.5 to 40 mass %. This effectively improves the adhesion between the barrier layer 3 and the adhesive layer 5.
• An example of a compound having an epoxy group is an epoxy resin.
• the epoxy resin there are no particular limitations on the epoxy resin, so long as it is a resin capable of forming a crosslinked structure by the epoxy groups present in the molecule, and any known epoxy resin can be used.
• the weight average molecular weight of the epoxy resin is preferably about 50 to 2000, more preferably about 100 to 1000, and even more preferably about 200 to 800.
• the weight average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC) under conditions using polystyrene as a standard sample.
• epoxy resins include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, bisphenol F glycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, etc.
• One type of epoxy resin may be used alone, or two or more types may be used in combination.
• the proportion of epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass % in the resin composition constituting the adhesive layer 5, and more preferably in the range of 0.5 to 40 mass %. This effectively improves the adhesion between the barrier layer 3 and the adhesive layer 5.
• the polyurethane is not particularly limited, and any known polyurethane can be used.
• the adhesive layer 5 may be, for example, a cured product of a two-component curing polyurethane.
• the proportion of polyurethane in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass % in the resin composition constituting the adhesive layer 5, and more preferably in the range of 0.5 to 40 mass %. This effectively improves the adhesion between the barrier layer 3 and the adhesive layer 5 in an atmosphere containing components that induce corrosion of the barrier layer, such as an electrolyte.
• the adhesive layer 5 is a cured product of a resin composition containing at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and an epoxy resin, and the acid-modified polyolefin, the acid-modified polyolefin functions as a base agent, and the compound having an isocyanate group, the compound having an oxazoline group, and the compound having an epoxy group each function as a curing agent.
• the adhesive layer 5 may contain a modifier having a carbodiimide group.
• the heat-sealable resin layer 4 When manufacturing the exterior material 10 for an electricity storage device of the present disclosure by laminating the adhesive layer 5 with the barrier layer 3, the heat-sealable resin layer 4, etc., a preformed resin film may be used as the adhesive layer 5.
• the heat-sealable resin that forms the adhesive layer 5 may be formed into a film on the surface of the barrier layer 3, the heat-sealable resin layer 4, etc. by extrusion molding, coating, etc., to form the adhesive layer 5 from the resin film.
• the thickness of the adhesive layer 5 is preferably about 50 ⁇ m or less, about 40 ⁇ m or less, about 30 ⁇ m or less, about 20 ⁇ m or less, or about 5 ⁇ m or less.
• the thickness of the adhesive layer 5 is preferably about 0.1 ⁇ m or more, or about 0.5 ⁇ m or more.
• the thickness of the adhesive layer 5 is preferably in the range of about 0.1 to 50 ⁇ m, about 0.1 to 40 ⁇ m, about 0.1 to 30 ⁇ m, about 0.1 to 20 ⁇ m, about 0.1 to 5 ⁇ m, about 0.5 to 50 ⁇ m, about 0.5 to 40 ⁇ m, about 0.5 to 30 ⁇ m, about 0.5 to 20 ⁇ m, or about 0.5 to 5 ⁇ m.
• the thickness is preferably about 1 to 10 ⁇ m, and more preferably about 1 to 5 ⁇ m.
• the thickness is preferably about 2 to 50 ⁇ m, more preferably about 10 to 40 ⁇ m.
• the adhesive layer 5 can be formed, for example, by applying the resin composition and curing it by heating or the like.
• the heat-sealable resin layer 4 and the adhesive layer 5 can be formed, for example, by extrusion molding.
• the exterior material for an electricity storage device may, if necessary, have a surface coating layer 6 on the substrate layer 1 (the side of the substrate layer 1 opposite to the barrier layer 3) for the purpose of improving at least one of design, electrolyte resistance, scratch resistance, formability, etc.
• the surface coating layer 6 is a layer located on the outermost layer side of the exterior material for an electricity storage device when an electricity storage device is assembled using the exterior material for an electricity storage device.
• the surface coating layer 6 may be made of, for example, a resin such as polyvinylidene chloride, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, or phenol resin, or a modified product of these resins. It may also be a copolymer of these resins, or a modified product of the copolymer. It may also be a mixture of these resins.
• the resin is preferably a curable resin.
• the surface coating layer 6 is preferably made of a cured product of a resin composition containing a curable resin.
• the resin forming the surface coating layer 6 is a curable resin
• the resin may be either a one-component curable type or a two-component curable type, but is preferably a two-component curable type.
• two-component curable resins include two-component curable polyurethane, two-component curable polyester, and two-component curable epoxy resin. Among these, two-component curable polyurethane is preferred.
• the two-component curing polyurethane may be, for example, a polyurethane containing a first agent containing a polyol compound and a second agent containing an isocyanate compound.
• the two-component curing polyurethane may be a polyurethane containing a polyol such as polyester polyol, polyether polyol, or acrylic polyol as the first agent and an aromatic or aliphatic polyisocyanate as the second agent.
• the polyurethane may be, for example, a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance, and a polyurethane containing an isocyanate compound.
• the polyurethane may be, for example, a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance, and a polyurethane containing a polyol compound.
• the polyurethane may be, for example, a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance, and a polyurethane containing a polyol compound.
• the polyurethane may be, for example, a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance, and cured by reacting it with moisture in the air or the like.
• polystyrene resin As the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group on the side chain in addition to the hydroxyl group at the end of the repeating unit.
• a polyester polyol having a hydroxyl group on the side chain in addition to the hydroxyl group at the end of the repeating unit.
• an aliphatic, alicyclic, aromatic, or araliphatic isocyanate compound may be used.
• isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI).
• examples of the isocyanate compounds include polyfunctional isocyanate modified products of one or more of these diisocyanates.
• a polymer e.g., a trimer
• an aliphatic isocyanate compound refers to an isocyanate that has an aliphatic group and does not have an aromatic ring
• an alicyclic isocyanate compound refers to an isocyanate that has an alicyclic hydrocarbon group
• an aromatic isocyanate compound refers to an isocyanate that has an aromatic ring.
• the surface coating layer 6 is formed from polyurethane, which gives the exterior material for the electricity storage device excellent electrolyte resistance.
• the surface coating layer 6 may contain additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, pigments, etc., on at least one of the surface and the interior of the surface coating layer 6, as necessary, depending on the functionality to be provided to the surface of the surface coating layer 6.
• additives include fine particles with an average particle size of about 0.5 nm to 5 ⁇ m.
• the average particle size of the additive is the median size measured by a laser diffraction/scattering type particle size distribution measuring device.
• the additive may be either inorganic or organic. There are also no particular limitations on the shape of the additive, and examples include spherical, fibrous, plate-like, amorphous, and scaly shapes.
• additives include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high melting point nylon, acrylate resin, cross-linked acrylic, cross-linked styrene, cross-linked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, etc.
• the additives may be used alone or in combination of two or more.
• silica, barium sulfate, and titanium oxide are preferable from the viewpoint of dispersion stability and cost.
• the additives may be subjected to various surface treatments such as insulation treatment and high dispersion treatment.
• the method for forming the surface coating layer 6 is not particularly limited, and examples include a method of applying a resin that forms the surface coating layer 6. When an additive is added to the surface coating layer 6, a resin mixed with the additive may be applied.
• a lubricant is present on at least one of the surface and the inside of the surface coating layer 6.
• the lubricant is not particularly limited, but preferably includes amide-based lubricants.
• Specific examples of amide-based lubricants include, for example, saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides.
• saturated fatty acid amides include lauric acid amides, palmitic acid amides, stearic acid amides, behenic acid amides, and hydroxystearic acid amides.
• unsaturated fatty acid amides include oleic acid amides and erucic acid amides.
• substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide.
• methylol amides include methylol stearic acid amide.
• saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide, etc.
• unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide, etc.
• fatty acid ester amides include stearamide ethyl stearate, etc.
• aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide.
• the lubricant may be used alone or in combination of two or more types, preferably in combination of two or more types.
• the amount of the lubricant present is not particularly limited, and may be, for example, about 3 mg/m 2 or more, preferably about 4 mg/m 2 or more, or about 5 mg/m 2 or more.
• the amount of the lubricant present on the surface of the surface coating layer 6 may be, for example, about 15 mg/m 2 or less, preferably about 14 mg/m 2 or less, or about 10 mg/m 2 or less.
• the preferred range of the amount of the lubricant present on the surface of the surface coating layer 6 may be about 3 to 15 mg/m 2 , about 3 to 14 mg/m 2 , about 3 to 10 mg/m 2 , about 4 to 15 mg/m 2 , about 4 to 14 mg/m 2 , about 4 to 10 mg/m 2 , about 5 to 15 mg/m 2 , about 5 to 14 mg/m 2 , or about 5 to 10 mg/m 2 .
• the lubricant present on the surface of the surface coating layer 6 may be a lubricant exuded from the resin that constitutes the surface coating layer 6, or a lubricant applied to the surface of the surface coating layer 6.
• the surface coating layer 6 contains a colorant, so that the exterior material for the electricity storage device can be colored.
• Known colorants such as pigments and dyes can be used as the colorant.
• only one type of colorant may be used, or two or more types may be mixed together.
• the type of pigment is not particularly limited, and examples of organic pigments include azo, phthalocyanine, quinacridone, anthraquinone, dioxazine, indigothioindigo, perinone-perylene, isoindolenine, and benzimidazolone pigments, while examples of inorganic pigments include carbon black, titanium oxide, cadmium, lead, chromium oxide, and iron pigments, as well as finely powdered mica and fish scale foil.
• colorants carbon black is preferred in order to give the exterior material for an electricity storage device a black appearance. Also, from the viewpoint of dissipating heat generated by the electricity storage device, it is preferable to use mica.
• the average particle size of the pigment is not particularly limited, and may be, for example, about 0.03 to 5 ⁇ m, and preferably about 0.05 to 2 ⁇ m.
• the average particle size of the pigment is the median size measured with a laser diffraction/scattering type particle size distribution measuring device.
• the content of the colorant in the surface coating layer 6 is not particularly limited as long as the exterior material for the electricity storage device is colored, and may be, for example, about 5 to 60 mass %, and preferably about 10 to 40 mass %.
• the thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above-mentioned functions of the surface coating layer 6, and may be, for example, about 0.5 to 10 ⁇ m, and preferably about 1 to 5 ⁇ m.
• the manufacturing method of the exterior material for an electricity storage device is not particularly limited as long as a laminate in which each layer included in the exterior material for an electricity storage device of the present disclosure is laminated can be obtained, and an example of the manufacturing method includes a method including a step of laminating at least the base layer 1, the barrier layer 3, and the heat-fusible resin layer 4 in this order.
• laminate A An example of a method for manufacturing an exterior material for a power storage device according to the present disclosure is as follows. First, a laminate (hereinafter sometimes referred to as "laminate A") is formed in which a base layer 1, an adhesive layer 2, and a barrier layer 3 are laminated in this order. Specifically, laminate A can be formed by a dry lamination method in which an adhesive used to form adhesive layer 2 is applied to base layer 1 or to barrier layer 3, the surface of which has been chemically treated as necessary, by a coating method such as gravure coating or roll coating, and then dried, and the barrier layer 3 or base layer 1 is laminated thereon to harden adhesive layer 2.
• a dry lamination method in which an adhesive used to form adhesive layer 2 is applied to base layer 1 or to barrier layer 3, the surface of which has been chemically treated as necessary, by a coating method such as gravure coating or roll coating, and then dried, and the barrier layer 3 or base layer 1 is laminated thereon to harden adhesive layer 2.
• the heat-sealable resin layer 4 is laminated on the barrier layer 3 of the laminate A.
• the heat-sealable resin layer 4 may be laminated on the barrier layer 3 of the laminate A by a method such as thermal lamination or extrusion lamination.
• the adhesive layer 5 and the heat-sealable resin layer 4 may be laminated, for example, by (1) extrusion lamination, (2) thermal lamination, (3) sandwich lamination, or (4) dry lamination.
• Extrusion lamination includes, for example, a method of laminating the adhesive layer 5 and the heat-sealable resin layer 4 by extruding them onto the barrier layer 3 of the laminate A (co-extrusion lamination, tandem lamination).
• Examples of the (2) thermal lamination method include a method of forming a laminate in which an adhesive layer 5 and a heat-sealable resin layer 4 are laminated separately, and laminating this on the barrier layer 3 of the laminate A, or a method of forming a laminate in which an adhesive layer 5 is laminated on the barrier layer 3 of the laminate A, and laminating this on the heat-sealable resin layer 4.
• Examples of the (3) sandwich lamination method include a method of laminating the laminate A and the heat-sealable resin layer 4 via the adhesive layer 5 while pouring a molten adhesive layer 5 between the barrier layer 3 of the laminate A and the heat-sealable resin layer 4 previously formed into a sheet.
• Examples of the (4) dry lamination method include a method of coating the barrier layer 3 of the laminate A with an adhesive for forming the adhesive layer 5, drying the adhesive layer 5, or baking the adhesive layer 3, and laminating the heat-sealable resin layer 4 previously formed into a sheet on the adhesive layer 5.
• the surface coating layer 6 is laminated on the surface of the substrate layer 1 opposite the barrier layer 3.
• the surface coating layer 6 can be formed, for example, by applying the above-mentioned resin that forms the surface coating layer 6 to the surface of the substrate layer 1.
• the order of the step of laminating the barrier layer 3 on the surface of the substrate layer 1 and the step of laminating the surface coating layer 6 on the surface of the substrate layer 1 is not particularly limited.
• the barrier layer 3 may be formed on the surface of the substrate layer 1 opposite the surface coating layer 6.
• a laminate which includes, in this order, the optional surface coating layer 6, the substrate layer 1, the optional adhesive layer 2, the barrier layer 3, the optional adhesive layer 5, and the heat-sealable resin layer 4.
• the laminate may be subjected to a heat treatment.
• each layer constituting the laminate may be subjected to a surface activation treatment such as corona treatment, blast treatment, oxidation treatment, or ozone treatment, as necessary, to improve its suitability for processing.
• a surface activation treatment such as corona treatment, blast treatment, oxidation treatment, or ozone treatment, as necessary, to improve its suitability for processing.
• the exterior material for an electricity storage device of the present disclosure is used in a package for hermetically housing an electricity storage device element such as a positive electrode, a negative electrode, and an electrolyte. That is, an electricity storage device can be formed by housing an electricity storage device element having at least a positive electrode, a negative electrode, and an electrolyte in a package formed by the exterior material for an electricity storage device of the present disclosure. In other words, an electricity storage device can be formed by wrapping an electricity storage device element with the exterior material for an electricity storage device of the present disclosure.
• an electricity storage device element having at least a positive electrode, a negative electrode, and an electrolyte is covered with the exterior material for an electricity storage device of the present disclosure in such a manner that a flange portion (a region where the heat-sealable resin layers contact each other) can be formed around the periphery of the electricity storage device element with metal terminals connected to each of the positive electrode and negative electrode protruding outward, and the heat-sealable resin layers of the flange portion are heat-sealed to provide an electricity storage device using the exterior material for an electricity storage device.
• a flange portion a region where the heat-sealable resin layers contact each other
• the package is formed so that the heat-sealable resin portion of the exterior material for an electricity storage device of the present disclosure faces inside (the surface in contact with the electricity storage device element).
• the heat-sealable resin layers of two electrical storage device exterior materials may be stacked facing each other, and the peripheral portions of the stacked electrical storage device exterior materials may be heat-sealed to form a package.
• one electrical storage device exterior material may be folded back and stacked, and the peripheral portions may be heat-sealed to form a package.
• the sides other than the folded side may be heat-sealed to form a package by sealing on three sides, or the materials may be folded back and sealed on all four sides so that a flange portion can be formed.
• the package may be formed by heat-sealing the innermost heat-sealable resin layer and the outermost heat-sealable resin layer.
• the power storage device element may be sealed by a lid in addition to the exterior material for the power storage device. That is, the exterior material for the power storage device and the lid constitute an exterior body (exterior body for the power storage device) that seals the power storage device element.
• the power storage device element may be housed inside the exterior material for the power storage device that is configured in a cylindrical shape, and the opening may be closed by the lid.
• the power storage device element connected to the lid may be housed inside the exterior material for the power storage device that is configured in a cylindrical shape so that an opening is formed, and the opening may be closed by the lid.
• the lid and the exterior material for the power storage device are preferably joined by any means. From the viewpoint of reducing the dead space between the power storage device element and the exterior material for the power storage device in order to improve the volumetric energy density of the power storage device, the exterior material for the power storage device is preferably wrapped around the power storage device element and the lid.
• the lid body can be formed, for example, from a resin molded product, a metal molded product, an exterior material for an electricity storage device, or a combination of these.
• the lid body when the lid body is expressed as a resin molded product, this does not include an embodiment in which the lid body is composed only of a film as defined by JIS K6900-1994 [Plastics terminology].
• the lid body when the lid body is a metal molded product, the lid body also functions as a metal terminal, so the metal terminal can be omitted.
• the lid body may be composed of a resin material and a conductive material.
• a recess for accommodating an electricity storage device element may be formed in the exterior material for the electricity storage device by deep drawing or stretch molding.
• a recess may be provided in one exterior material for the electricity storage device and no recess may be provided in the other exterior material for the electricity storage device, or a recess may be provided in the other exterior material for the electricity storage device.
• the exterior material for an electric storage device of the present disclosure can be suitably used for an electric storage device such as a battery (including a condenser, a capacitor, etc.).
• the exterior material for an electric storage device of the present disclosure may be used for either a primary battery or a secondary battery, but is preferably used for a secondary battery.
• the type of secondary battery to which the exterior material for an electric storage device of the present disclosure is applied is not particularly limited, and examples thereof include lithium ion batteries, lithium ion polymer batteries, all-solid batteries, semi-solid batteries, quasi-solid batteries, polymer batteries, all-resin 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, capacitors, etc.
• suitable applications of the exterior material for an electric storage device of the present disclosure include lithium ion batteries, lithium ion polymer batteries, and all-solid batteries.
• Example 1 As the substrate layer, a laminate was prepared in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and an oriented nylon (ONy) film (thickness 25 ⁇ m) were bonded with an adhesive layer (thickness 3 ⁇ m, a two-component curing urethane adhesive (formed of a polyol compound and an aromatic isocyanate compound).
• PET polyethylene terephthalate
• ONy oriented nylon
• an adhesive layer thickness 3 ⁇ m, a two-component curing urethane adhesive (formed of a polyol compound and an aromatic isocyanate compound).
• an aluminum foil JIS H4160:1994 A8021H-O (thickness 80 ⁇ m) was prepared as the barrier layer. Both sides of the aluminum foil were subjected to a chemical conversion treatment.
• the chemical conversion treatment of the aluminum foil was performed by applying a treatment liquid consisting of a phenolic resin, a chromium fluoride compound, and phosphoric acid to both sides of the aluminum foil by a roll coating method so that the coating amount of chromium was 10 mg/ m2 (dry mass), and baking the resulting mixture.
• a two-component curing urethane adhesive (polyol compound and aromatic isocyanate compound) was used to dry laminate the stretched nylon film side of the base layer and the barrier layer, and then an aging treatment was performed to create a laminate of base layer/adhesive layer (thickness 3 ⁇ m)/barrier layer.
• maleic anhydride modified polypropylene (PPa) as an adhesive layer (40 ⁇ m thick) and random polypropylene (PP) as a heat-sealable resin layer (40 ⁇ m thick) were co-extruded onto the barrier layer of each of the laminates obtained above, thereby laminating an adhesive layer/heat-sealable resin layer onto the barrier layer.
• an exterior material for an electricity storage device was obtained, consisting of a laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer were laminated in this order.
• Example 2 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that an aluminum foil (JIS H4160:1994 A8021H-O (thickness 60 ⁇ m)) was used as the barrier layer instead of an aluminum foil (JIS H4160:1994 A8021H-O (thickness 80 ⁇ m)).
• an aluminum foil JIS H4160:1994 A8021H-O (thickness 60 ⁇ m)
• Example 3 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer bonding between the base layer and the barrier layer was changed from 3 ⁇ m to 5 ⁇ m.
• Example 4 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that the thickness of the adhesive layer bonding between the base layer and the barrier layer was changed from 3 ⁇ m to 5 ⁇ m.
• Example 5 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 ⁇ m) and an oriented nylon (ONy) film (thickness: 25 ⁇ m) were bonded together with an adhesive layer (thickness: 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• an adhesive layer thickness: 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)
• Example 6 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 ⁇ m) and an oriented nylon (ONy) film (thickness: 25 ⁇ m) were bonded together with an adhesive layer (thickness: 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• an adhesive layer thickness: 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)
• Example 7 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and an oriented nylon (ONy) film (thickness 15 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Example 8 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and an oriented nylon (ONy) film (thickness 15 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Example 9 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 ⁇ m) and an oriented nylon (ONy) film (thickness: 15 ⁇ m) were bonded together with an adhesive layer (thickness: 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Example 10 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 ⁇ m) and an oriented nylon (ONy) film (thickness: 15 ⁇ m) were bonded together with an adhesive layer (thickness: 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Example 11 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 75 ⁇ m) and an oriented nylon (ONy) film (thickness 15 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Example 12 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 75 ⁇ m) and an oriented nylon (ONy) film (thickness 15 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Example 13 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 25 ⁇ m) was used as the base layer.
• PET polyethylene terephthalate
• Example 14 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 25 ⁇ m) was used as the base layer.
• PET polyethylene terephthalate
• Example 15 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 ⁇ m) was used as the base layer.
• PET polyethylene terephthalate
• Example 16 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 ⁇ m) was used as the base layer.
• PET polyethylene terephthalate
• Example 17 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 75 ⁇ m) was used as the base layer.
• PET polyethylene terephthalate
• Example 18 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 75 ⁇ m) was used as the base layer.
• PET polyethylene terephthalate
• Example 19 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 20 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially oriented polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 21 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 22 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 23 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 38 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially oriented polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 24 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 38 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially oriented polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 25 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 40 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially oriented polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 26 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 40 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially oriented polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 27 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Example 28 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET polyethylene terephthalate
• PET biaxially oriented polyethylene terephthalate
• Comparative Example 1 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and an oriented nylon (ONy) film (thickness 25 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Comparative Example 2 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and an oriented nylon (ONy) film (thickness 25 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Comparative Example 3 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and an oriented nylon (ONy) film (thickness 15 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• Comparative Example 4 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and an oriented nylon (ONy) film (thickness 15 ⁇ m) were bonded together with an adhesive layer (thickness 3 ⁇ m, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound)) was used as the base layer.
• PET biaxially stretched polyethylene terephthalate
• ONy oriented nylon
• the moisture content was measured by the moisture vaporization-coulometric titration method using a Karl Fischer moisture meter and an evaporator placed in an environment of 25°C temperature, 1% or less humidity, and -20°C or less dew point.
• the sample was wrapped in a package that can be blocked from the outside air and brought into the measurement environment, and was placed in the measurement device within 30 minutes after being removed from the package.
• the measurement conditions are as follows.
• Component to be measured water, titration cell type: two-liquid cell, type of detection electrode: bipolar platinum electrode, material of diaphragm: ceramic, end point detection method: AC polarization method using bipolar platinum detection electrode, end point judgment method: drift stability judgment, heating temperature: 180°C, cell purge time: 120 seconds, back purge time: 180 seconds, stability judgment value: 0.1 ⁇ g/min, end point potential 200 mV.
• the measurement results were calculated using the ratio of the weight of water to the weight of the sample (unit: ppm), and the average value of three measurements was rounded off to the nearest ten.
• Commercially available anolyte and catholyte (ChemAqua anolyte AGE and ChemAqua catholyte CGE) were used as titration reagents.
• each battery packaging material was cut into 60 mm (TD direction) x 200 mm (MD direction) (FIG. 7a).
• the battery packaging material was folded in half in the MD direction at the fold P (middle of the MD direction) so that the heat-sealable resin layers faced each other (FIG. 7b).
• the heat-sealable resin layers were heat-sealed together at a seal width of 7 mm, a temperature of 210° C., a surface pressure of 1.0 MPa, and for 3 seconds, about 10 mm inside from the fold P (FIG. 7c).
• the hatched portion S is the heat-sealed portion.
• test piece was cut in the MD direction (cut at the position of the two-dot chain line in FIG. 7d) so that the width in the TD direction was 15 mm, and a test piece was obtained (FIG. 7e).
• test piece 13 was left at the measurement temperature for 2 minutes, and the heat-sealable resin layer of the heat-sealed portion was peeled off at a speed of 300 mm/min in the measurement temperature environment using a tensile tester (manufactured by Shimadzu Corporation, AG-Xplus (trade name)) (FIG. 8).
• the maximum strength at the time of peeling was taken as the seal strength (N/15 mm).
• the distance between the chucks was 50 mm.
• the average value of three measurements was taken.
• test piece 13 may peel off (break) at the heat seal interface A shown in Fig. 8, or may break at a portion (e.g., position B in Fig. 8) other than the heat seal interface A.
• breaking strength is recorded in Table 1 as the seal strength.
• ⁇ Molding depth of exterior material for power storage device> The molding depth of the exterior material for an electricity storage device obtained in the above ⁇ Moisture content of the exterior material for an electricity storage device> that had been exposed to an environment of a temperature of 25° C. and a relative humidity of 50% for 24 hours was measured under the following conditions. The results are shown in Table 1.
• Each electrical storage device exterior material was cut into a square with a length (MD) of 200 mm and a width (TD) of 200 mm to prepare a test sample.
• the MD of the electrical storage device exterior material corresponds to the rolling direction (RD) of the aluminum alloy foil
• the TD of the electrical storage device exterior material corresponds to the TD of the aluminum alloy foil.
• the maximum height roughness (nominal value of Rz) specified in Table 2 of the comparative surface roughness standard piece is 3.2 ⁇ m.
• the molding depth was changed in 0.5 mm increments from the molding depth of 0.5 mm at a pressing pressure (surface pressure) of 0.25 MPa, and cold molding (one-stage drawing molding) was performed on 10 samples each.
• the above test sample was placed on the female mold so that the heat-fusible resin layer side was located on the male mold side and molding was performed.
• the clearance between the male mold and the female mold was 0.3 mm.
• the sample after cold molding was irradiated with a penlight in a dark room to confirm whether pinholes or cracks were generated in the aluminum foil due to the transmission of light.
• the deepest molding depth at which no pinholes or cracks occurred in the aluminum foil in any of the 10 samples was defined as A mm, and the number of samples at which pinholes, etc. occurred in the aluminum foil at the shallowest molding depth was defined as B.
• the value calculated by the following formula was rounded off to two decimal places to determine the limit molding depth of the exterior material for an electricity storage device.
• Limit forming depth A mm + (0.5 mm/10 pieces) x (10 pieces - B pieces)
• the exterior materials for storage batteries in Examples 1 to 28 contain a polyethylene terephthalate (PET) film having a thickness of 20 ⁇ m or more in the base layer, and no foaming was observed during heat fusion, even though they were exposed to an environment of 25°C and 50% relative humidity for 24 hours outside the barrier layer.
• PET polyethylene terephthalate
• Examples 1 to 12 despite the base layer containing a highly hygroscopic stretched nylon film (ONy), a particularly excellent effect was demonstrated in that no foaming was observed during heat fusion.
• the exterior materials for storage batteries in Examples 1 to 12 also have the advantage of excellent moldability, since they contain a stretched nylon film in the base layer.
• the adhesive layer between the base layer and the barrier layer was designed to be as thick as 5 ⁇ m, and in this case too, no foaming was observed during heat fusion, and excellent moldability was demonstrated.
• the base layer contained a polyethylene terephthalate (PET) film, but the thickness was 12 ⁇ m, and foaming was confirmed on the outer side of the barrier layer during heat fusion.
• PET polyethylene terephthalate
• Example 1-4 a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and an oriented nylon (ONy) film (thickness 25 ⁇ m) are bonded with an adhesive layer (thickness 3 ⁇ m two-component curing type urethane adhesive (formed of a polyol compound and an aromatic isocyanate compound)) and the substrate layer used in Comparative Example 1-2 (a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and an oriented nylon (ONy) film (thickness 25 ⁇ m) are bonded with an adhesive layer (thickness 3 ⁇ m two-component curing type urethane adhesive (formed of a polyol compound and an aromatic isocyanate compound))) were each subjected to differential scanning calorimetry (DS)
• the base material layer used in Examples 1-4 had a peak area (heat of crystallization) of 30.0 J/g or less during the cooling process in DSC measurements, which means that it has low crystallinity and is less likely to crack, contributing to the high formability of the exterior material for power storage devices.
• ⁇ Tensile test of exterior material for power storage device> Tensile tests were performed under the following conditions for the exterior materials for power storage devices obtained in Example 1, Comparative Examples 1 and 2, and the tensile strength (N/15mm) at 25mm displacement and the tensile strength (N/15mm) at 10mm displacement in the MD direction, TD direction, and 45° direction (45° clockwise from the MD direction) were measured three times, and the average values were rounded off to the third decimal place and described.
• ) between the tensile strength at 25mm displacement (N/15mm) and the tensile strength at 10mm displacement (N/15mm) was calculated for each of the MD direction, TD direction, and 45° direction. Furthermore, these differences were divided by the displacement difference of 15mm (25mm-10mm), and the respective values were designated as MD direction: A, TD direction: B, and 45° direction: C.
• A/(maximum value of A, B, and C), B/(maximum value of A, B, and C), and C/(maximum value of A, B, and C) The results are shown in Table 3.
• the exterior material for an electricity storage device in Example 1 has A/(the maximum value of A, B, C), B/(the maximum value of A, B, C), and C/(the maximum value of A, B, C) all within the range of 0.40 to 1.00 in all directions, including MD, TD, and 45°, demonstrating a good balance with respect to tensile stress and high formability.
• the laminate includes, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer,
• the substrate layer includes a polyester resin layer,
• the exterior material for an electricity storage device wherein the polyester resin layer has a thickness of 20 ⁇ m or more.
• Item 2. The exterior material for an electricity storage device according to Item 1, wherein the exterior material for an electricity storage device has a moisture content of 2700 ppm or less when exposed to an environment at a temperature of 25° C. and a relative humidity of 50% for 24 hours.
• Item 3 The exterior material for an electricity storage device according to Item 1 or 2, wherein the barrier layer has a thickness of 50 ⁇ m or more.
• the method includes a step of obtaining a laminate in which at least a base layer, a barrier layer, and a heat-sealable resin layer are laminated in this order from the outside,
• the substrate layer includes a polyester resin layer
• 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 package formed from the exterior material for an electricity storage device according to any one of Items 1 to 3.

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