Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/102—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
  • H01M50/129—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers with two or more layers of only organic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/131—Primary casings; Jackets or wrappings characterised by physical properties, e.g. gas permeability, size or heat resistance
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/131—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

• the present disclosure relates to an exterior material for a power storage device, a method for manufacturing the same, and a power storage device.
• base material layer/barrier layer/adhesive layer/thermal adhesive resin layer were sequentially laminated as exterior materials for power storage devices that can be easily processed into various shapes and can be made thinner and lighter.
• a film-like laminate has been proposed (see, for example, Patent Document 1).
• a recess is formed by cold forming, power storage device elements such as electrodes and electrolyte are arranged in the space formed by the recess, and heat-sealable resin is placed in the space formed by the recess.
• heat-sealing the layers a power storage device in which power storage device elements are housed inside the power storage device exterior material is obtained.
• Power storage devices are used for a variety of purposes, and the needs for power storage devices are diverse.
• the inventors of the present disclosure believe that if a power storage device is provided that has the function of thermally bonding to an adherend, for example, the power storage device can be fixed in a product by thermal bonding, or multiple power storage devices can be stacked together. By heat-sealing and fixing them in a stacked state, even if multiple power storage devices are built into a product in a stacked state, each power storage device is fixed, so there is no risk of power storage due to product vibration, etc. We believe that this has the advantage of suppressing device misalignment and damage caused by shocks transmitted to each energy storage device when external force is applied to the product.
• the present disclosure addresses these new challenges and provides a new method for use in power storage devices that can be used as an exterior material for power storage devices by heat-sealing the outer surface of the power storage device to an adherend. Its main purpose is to provide exterior materials.
• the laminate structure of the exterior material for a power storage device is a laminate including, in order from the outside, at least a first heat-fusible resin layer, a barrier layer, and a second heat-fusible resin layer;
• the heat-fusible resin layer and the second heat-fusible resin layer are each made of a resin whose main component is polyethylene, instead of polypropylene, which is generally used as a heat-fusible resin layer for exterior materials for power storage devices.
• the present disclosure has been completed through further studies based on these findings. That is, the present disclosure provides inventions of the following aspects. Consisting of a laminate including, in order from the outside, at least a first heat-fusible resin layer, a barrier layer, and a second heat-fusible resin layer,
• the first heat-fusible resin layer contains polyethylene as a main component
• the second heat-fusible resin layer is an exterior material for a power storage device, which contains polyethylene as a main component.
• a novel exterior material for an electricity storage device which can be used as an exterior material for an electricity storage device by heat-sealing the outer surface of the energy storage device to an adherend.
• a method for manufacturing an exterior material for a power storage device and a power storage device it is possible to provide a novel exterior material for an electricity storage device, which can be used as an exterior material for an electricity storage device by heat-sealing the outer surface of the energy storage device to an adherend.
• FIG. 3 is a schematic diagram for explaining a method of measuring seal strength.
• FIG. 3 is a schematic diagram for explaining a method of measuring seal strength.
• FIG. 3 is a schematic diagram for explaining an insulation evaluation method.
• the exterior material for a power storage device is composed of a laminate including, in order from the outside, at least a first heat-fusible resin layer, a barrier layer, and a second heat-fusible resin layer;
• the heat-fusible resin layer contains polyethylene as a main component, and the second heat-fusible resin layer contains polyethylene as a main component.
• the numerical range indicated by " ⁇ " means “more than” or “less than”.
• the expression 2 to 15 mm means 2 mm or more and 15 mm or less.
• the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of another numerical range described step by step.
• the upper limit value and the upper limit value, the upper limit value and the lower limit value, or the lower limit value and the lower limit value, which are described separately, may be combined to form a numerical range.
• the upper limit or lower limit described in a certain numerical range may be replaced with the value shown in the Examples.
• the barrier layer 5 described below in the exterior material for a power storage device it is usually possible to distinguish between MD (Machine Direction) and TD (Transverse Direction) in the manufacturing process.
• MD Machine Direction
• TD Transverse Direction
• the barrier layer 5 is made of metal foil such as aluminum alloy foil or stainless steel foil
• the MD of the laminate and the RD of the metal foil usually match, so the surface of the metal foil of the laminate is observed and the rolling direction (RD) of the metal foil is identified. By doing so, the MD of the laminate can be specified. Further, since the TD of the laminate is perpendicular to the MD of the laminate, the TD of the laminate can also be specified.
• the MD of the exterior material for a power storage device cannot be identified due to rolling marks on metal foil such as aluminum alloy foil or stainless steel foil, it can be identified by the following method.
• a method for confirming the MD of the exterior material for power storage devices there is a method of observing a cross section of the heat-fusible resin layer of the exterior material for power storage devices with an electron microscope to confirm the sea-island structure.
• the MD can be determined as the direction parallel to the cross section in which the average diameter of the island shape in the direction perpendicular to the thickness direction of the heat-fusible resin layer is maximum.
• the angle is changed by 10 degrees from the longitudinal cross section of the heat-fusible resin layer and the direction parallel to the longitudinal cross section, until the angle is perpendicular to the longitudinal cross section.
• Each cross section (10 cross sections in total) is observed using an electron microscope to confirm the sea-island structure.
• the shape of each individual island is observed.
• the straight line distance connecting the leftmost end in the direction perpendicular to the thickness direction of the heat-fusible resin layer and the rightmost end in the perpendicular direction is defined as the diameter y.
• the average of the top 20 diameters y of the island shape is calculated in descending order of diameter y.
• the direction parallel to the cross section where the average diameter y of the island shape is the largest is determined to be the MD.
• the exterior material 10 for power storage devices of the present disclosure includes, for example, as shown in FIG. It is composed of a laminate including a heat-fusible resin layer 2.
• the first heat-fusible resin layer 1 is the outermost layer
• the second heat-fusible resin layer 2 is the innermost layer.
• the power storage device using the exterior material for power storage device of the present disclosure can be used by heat-sealing the surface of the first heat-fusible resin layer 1 side that constitutes the outer surface of the power storage device to an adherend. I can do it.
• a power storage device in a product is fixed by heat fusion, or if multiple power storage devices are stacked and fixed by heat fusion, multiple power storage devices can be stacked and incorporated into the product.
• Even in cases where the individual power storage devices are fixed there are advantages such as being able to prevent the power storage devices from shifting due to product vibration or damage caused by shocks transmitted to each power storage device when external force is applied to the product. be.
• the second heat-fusible resin layer 2 side is on the inner side than the barrier layer 5
• the first heat-sealing resin layer 2 side is on the inner side than the barrier layer 5
• the fusible resin layer 1 side is the outside.
• the exterior material 10 for an electricity storage device is made of materials that are necessary for the purpose of increasing the adhesiveness between the first heat-fusible resin layer 1 and a layer adjacent thereto.
• the first adhesive layer 12 may be provided depending on the situation.
• a second adhesive layer may be used as necessary for the purpose of increasing the adhesiveness between the second heat-fusible resin layer 2 and a layer adjacent thereto. It may have a layer 22.
• the exterior material 10 for power storage devices includes a layer between the first heat-fusible resin layer 1 and the barrier layer 5 to increase the heat resistance of the exterior material 10 for power storage devices.
• the first heat-resistant layer 3 may be included if necessary.
• the exterior material 10 for a power storage device has a structure in which the first heat resistant layer 3 and the barrier layer 5 are bonded together for the purpose of increasing the adhesiveness between the first heat resistant layer 3 and the barrier layer 5.
• a third adhesive layer 32 may be provided between the two.
• a fourth adhesive layer 42 may be included.
• the thickness of the laminate constituting the exterior material 10 for power storage devices is not particularly limited, but from the viewpoint of cost reduction, energy density improvement, etc., it is, for example, 300 ⁇ m or less, preferably about 250 ⁇ m or less, about 230 ⁇ m or less, about 210 ⁇ m or less can be mentioned.
• the thickness of the laminate constituting the power storage device exterior material 10 is preferably approximately 60 ⁇ m or more, approximately 80 ⁇ m or more, or approximately Examples include 100 ⁇ m or more.
• preferred ranges of the laminate constituting the exterior material 10 for power storage devices include, for example, about 60 to 300 ⁇ m, about 60 to 250 ⁇ m, about 60 to 230 ⁇ m, about 60 to 210 ⁇ m, about 80 to 300 ⁇ m, and about 80 to 250 ⁇ m. , about 80 to 230 ⁇ m, about 80 to 210 ⁇ m, about 100 to 300 ⁇ m, about 100 to 250 ⁇ m, about 100 to 230 ⁇ m, and about 100 to 210 ⁇ m, and in particular, about 100 to 230 ⁇ m when making the electricity storage device lightweight and thin.
• the thickness is preferably about 230 to 300 ⁇ m.
• the first heat-fusible resin layer 1, the first adhesive layer 12 provided as needed, and the necessary A first heat-resistant layer 3 provided as necessary, a third adhesive layer 32 provided as necessary, a barrier layer 5, a fourth adhesive layer 42 provided as necessary, a second heat-resistant layer 4 provided as necessary.
• the ratio of the total thickness of the second adhesive layer 22 and the second heat-fusible resin layer 2, which are provided as necessary, is preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more. % or more.
• the exterior material 10 for a power storage device of the present disclosure includes a first heat-fusible resin layer 1, a first adhesive layer 12, a first heat-resistant layer 3, a third adhesive layer 32, a barrier layer 5, a fourth
• first heat-fusible resin layer 1 a first heat-fusible resin layer 1
• first adhesive layer 12 a first adhesive layer 12
• first heat-resistant layer 3 a third adhesive layer 32
• barrier layer 5 a fourth
• the ratio of the total thickness of each layer is preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more.
• the exterior material 10 for a power storage device of the present disclosure includes a first heat-fusible resin layer 1 , a first adhesive layer 12 , a first heat-resistant layer 3 , a third adhesive layer 32 , a barrier layer 5 , a second heat-resistant layer 4 , the second adhesive layer 22, and the second heat-fusible resin layer 2, the ratio of the total thickness of each of these layers to the thickness (total thickness) of the laminate constituting the exterior material 10 for power storage device is , for example, 80% or more, preferably 90% or more, more preferably 95% or more, still more preferably 98% or more.
• the exterior material 10 for a power storage device of the present disclosure includes a first heat-fusible resin layer 1 , a first adhesive layer 12 , a first heat-resistant layer 3 , a barrier layer 5 , a second heat-resistant layer 4 , a second adhesive layer 22 , and the second heat-fusible resin layer 2, the ratio of the total thickness of each of these layers to the thickness (total thickness) of the laminate constituting the exterior material 10 for power storage device is, for example, 80% or more, It is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
• the exterior material for a power storage device of the present disclosure is produced using the first heat-fusible resin of the exterior material for a power storage device 10 under the conditions of each temperature (° C.), surface pressure (MPa), and time (seconds) listed in Table 1.
• the seal strength (25°C environment) of the test sample obtained by heat-sealing the layers 1 to each other is preferably about 30 N/15 mm or more, more preferably about 35 N, as measured in accordance with the provisions of JIS K7127:1999. /15mm or more, more preferably about 40N/15mm or more, and the upper limit is, for example, about 150N/15mm or less, and preferable ranges are about 30 to 150N/15mm, about 35 to 150N/15mm, and 40 to 150N/15mm. That's about it.
• a specific method for measuring the seal strength in a 25°C environment is as follows.
• the seal strength of the exterior material for a power storage device at a measurement temperature of 25° C. environment is measured as follows.
• an exterior material for a power storage device cut into strips having a width in the TD direction of 15 mm is prepared. Specifically, as shown in FIG. 6, first, each exterior material for an electricity storage device is cut into 60 mm (TD direction) x 200 mm (MD direction) (FIG. 6a). Next, the exterior material for a power storage device is folded in half in the MD direction at a crease P (middle in the MD direction) so that the first heat-fusible resin layers on the outside face each other (FIG. 6b).
• the first heat-fusible resin layer of the heat-sealed portion of the test sample 13 is peeled off at a rate of 300 mm/min using a tensile testing machine (FIG. 7).
• the maximum strength at the time of peeling is defined as the seal strength (N/15 mm).
• the distance between chucks is 50 mm.
• the average value of three measurements is taken.
• the test sample 13 is peeled off (destroyed) at the heat seal interface A shown in FIG. In some cases, the test sample 13 may break. When the test sample 13 breaks, the breaking strength is taken as the sealing strength.
• the total thickness of the first heat-resistant layer 3 and the second heat-resistant layer 4 is measured for the exterior material for an energy storage device before and after the heat sealing, and the total thickness of the exterior material for the energy storage device before and after the heat sealing is measured.
• the ratio (%) of the total thickness of the first heat-resistant layer 3 and the second heat-resistant layer 4 after heat sealing to the total thickness of the first heat-resistant layer 3 and the second heat-resistant layer 4 is preferably about 60% or more, more preferably is about 70% or more, more preferably about 80% or more, and the upper limit is, for example, 95% or less, and the preferable range is about 60 to 95%, about 70 to 95%, and 80 to 95%. The degree is mentioned.
• the sample used in [Measurement of thickness residual rate] uses the exterior material for the electricity storage device before and after heat sealing, and the first heat-resistant layer and the second heat-resistant layer are Measure the total thickness of the layers and calculate the ratio (%) of the total thickness of the first heat-resistant layer and second heat-resistant layer after heat-sealing to the total thickness of the first heat-resistant layer and second heat-resistant layer before heat-sealing. do.
• the residual rate of total thickness is the average value for two measurement samples.
• a microtome to cut the measurement sample in the thickness direction, aiming at the middle of the 7 mm head width of the heat seal seal bar and the middle of the sample width of 60 mm, and observe the obtained cross section with a laser microscope. and do it.
• the exterior material for a power storage device of the present disclosure has a time until a short circuit occurs, which is measured in the following insulation evaluation, preferably about 20 seconds or more, more preferably about 30 seconds or more, and still more preferably about 40 seconds.
• the upper limit is, for example, about 180 seconds or less, and preferable ranges include about 20 to 180 seconds, about 30 to 180 seconds, and about 40 to 180 seconds.
• the exterior material 10 for a power storage device is cut to produce a strip with a width of 40 mm and a length of 100 mm, which is used as a test sample.
• the width refers to the TD direction
• the length refers to the MD direction.
• the center of the strip in the width direction is made to coincide with the center of the aluminum plate 30 in the width direction.
• the positive electrode of the tester is connected to the aluminum plate 30, and the negative electrode is connected to the exterior material for the power storage device.
• the negative electrode of the tester insert an alligator clip so that it reaches the barrier layer from the first heat-fusible resin layer side of the exterior material for the power storage device, and electrically connect the negative electrode of the tester and the barrier layer.
• the tester is prepared to issue a continuity (short circuit) signal when the applied voltage is 100 V and the resistance is less than 200 M ⁇ .
• the first heat-fusible resin layer 1, the first adhesive layer 12, the first heat-resistant layer 3, the third adhesive layer 32, the barrier layer 5, the fourth adhesive layer 42, the second heat-resistant layer 4, the second It is composed of a laminate including an adhesive layer 22 and a second heat-fusible resin layer 2 (9-layer composition).
• the thickness of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 is about 30 to 80 ⁇ m (more preferably about 40 to 60 ⁇ m), and the thickness of the first heat-resistant layer 3 and the second heat-fusible resin layer
• the thickness of the heat-resistant layer 4 is about 15 to 50 ⁇ m (more preferably about 20 to 40 ⁇ m), and the thickness of the first adhesive layer 12 , the second adhesive layer 22 , the third adhesive layer 32 , and the fourth adhesive layer 42
• the thickness of each layer is approximately 1 to 7 ⁇ m (and further approximately 2 to 5 ⁇ m).
• the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 each have a content of polyethylene (preferably high-density polyethylene, acid-modified polyethylene, or polyethylene with a melting peak temperature of 110 to 135°C). is 80% by mass or more (furthermore, 90% by mass or more, even 95% by mass or more), and the first heat-resistant layer 3 and the second heat-resistant layer 4 are each made of polypropylene resin (preferably polypropylene and acid-modified polypropylene).
• polyethylene preferably high-density polyethylene, acid-modified polyethylene, or polyethylene with a melting peak temperature of 110 to 135°C
• the first heat-resistant layer 3 and the second heat-resistant layer 4 are each made of polypropylene resin (preferably polypropylene and acid-modified polypropylene).
• the content of at least one of them is 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). ). It is preferable that the first adhesive layer 12, the second adhesive layer 22, the third adhesive layer 32, and the fourth adhesive layer 42 each contain acid-modified polyolefin. In the laminated configuration A, the first heat-resistant layer 3 is particularly preferably formed of unstretched polypropylene or maleic anhydride-modified polypropylene.
• the first heat-fusible resin layer 1, the first adhesive layer 12, the first heat-resistant layer 3, the third adhesive layer 32, the barrier layer 5, the second heat-resistant layer 4, the second adhesive layer 22, and the It is composed of a laminate including two heat-fusible resin layers 2 (8-layer composition).
• the thickness of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 is about 30 to 80 ⁇ m (more preferably about 40 to 60 ⁇ m), and the thickness of the first heat-resistant layer 3 and the second heat-fusible resin layer
• the thickness of the heat-resistant layer 4 is about 15 to 50 ⁇ m (more preferably about 20 to 40 ⁇ m)
• the thickness of the first adhesive layer 12, the second adhesive layer 22, and the third adhesive layer 32 is about 15 to 50 ⁇ m, respectively. , about 1 to 7 ⁇ m (even about 2 to 5 ⁇ m).
• the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 each have a content of polyethylene (preferably high-density polyethylene, acid-modified polyethylene, or polyethylene with a melting peak temperature of 110 to 135°C). is 80% by mass or more (further, 90% by mass or more, even 95% by mass or more), and the first heat-resistant layer 3 has a content of polypropylene resin (preferably polypropylene) of 50% by mass or more, preferably 60% by mass or more.
• the second heat-resistant layer 4 is composed of polypropylene resin ( Preferably, the content of acid-modified polypropylene is 80% by mass or more (more preferably 90% by mass or more, further still 95% by mass or more).
• the first adhesive layer 12, the second adhesive layer 22, and the third adhesive layer 32 each contain acid-modified polyolefin.
• the first heat-resistant layer 3 is particularly preferably formed of unstretched polypropylene or maleic anhydride-modified polypropylene
• the second heat-resistant layer 4 is preferably formed of maleic anhydride-modified polypropylene. Particularly preferred.
• the first heat-fusible resin layer 1 In order from the outside, the first heat-fusible resin layer 1, the first adhesive layer 12, the first heat-resistant layer 3, the barrier layer 5, the second heat-resistant layer 4, the second adhesive layer 22, and the second heat-fusible resin. It is constructed from a laminate including layer 2 (seven-layer construction).
• the thickness of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 is about 30 to 80 ⁇ m (more preferably about 40 to 60 ⁇ m), and the thickness of the first heat-resistant layer 3 and the second heat-fusible resin layer
• the thickness of the heat-resistant layer 4 is about 15 to 50 ⁇ m (more preferably about 20 to 40 ⁇ m)
• the thickness of the first adhesive layer 12 and the second adhesive layer 22 is about 1 to 7 ⁇ m (more preferably about 20 to 40 ⁇ m). is approximately 2 to 5 ⁇ m).
• the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 each have a content of polyethylene (preferably high-density polyethylene, acid-modified polyethylene, or polyethylene with a melting peak temperature of 110 to 135°C). is 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, still more preferably 95% by mass or more), and the first The heat-resistant layer 3 and the second heat-resistant layer 4 each have a polypropylene resin (preferably acid-modified polypropylene) content of 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably It is 80% by mass or more (more preferably 90% by mass or more, even more preferably 95% by mass or more).
• polyethylene preferably high-density polyethylene, acid-modified polyethylene, or polyethylene with a melting peak temperature of 110 to 135°C.
• first adhesive layer 12 and the second adhesive layer 22 each contain acid-modified polyolefin.
• first heat-resistant layer 3 and the second heat-resistant layer 4 are each formed of maleic anhydride-modified polypropylene.
• first heat-fusible resin layer 1 is a layer that constitutes the outer surface of an exterior material for an electricity storage device, and when applied to an electricity storage device, the outer surface of the electricity storage device is heated to an adherend. This is a layer that performs the function of fusing.
• the second heat-fusible resin layer 2 corresponds to the innermost layer, and the second heat-fusible resin layers 2 are heat-fused to each other during assembly of the power storage device. This is a layer (sealant layer) that functions to seal the electricity storage device element.
• the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 each contain polyethylene as a main component.
• containing polyethylene as a main component means that the content of polyethylene is, for example, 50% by mass among the resin components contained in the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2.
• the above is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, still more preferably 98% by mass or more, and This means that it is preferably 99% by mass or more, and the polyethylene content may be 100% by mass.
• the resin component other than polyethylene is not particularly limited as long as it does not impede the effects of the present disclosure, and examples thereof include polypropylene.
• the water vapor permeability of the polyethylene of the first heat-fusible resin layer 1 in an environment of 40°C and 90% RH is preferably 0.50 g ⁇ mm/m 2 ⁇ 24 h or less, more preferably 0.40 g ⁇ mm/m 2 - 24 hours or less, more preferably 0.30 g ⁇ mm/m 2 ⁇ 24 hours or less.
• the method for measuring water vapor permeability is as follows. The unit of water vapor permeability is g/( m2 ⁇ 24h), but in order to make it easier to compare the numerical values of test samples with different thicknesses, the numerical value obtained by measurement is calculated using a thickness of 1.0 mm. The unit g ⁇ mm/m 2 ⁇ 24h was used.
• Water vapor permeability is measured in accordance with JIS K 7129-2 "Plastics - Films and sheets - How to determine water vapor permeability - Part 2: Infrared sensor method". After cutting a film-like sample into 100 mm x 100 mm, it was measured at 40° C. and 90% RH to determine the water vapor permeability.
• polyethylene examples include polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene.
• polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene.
• high-density polyethylene is preferred from the viewpoint of more suitably exhibiting the effects of the present disclosure.
• These polyethylenes may be used alone or in combination of two or more.
• High-density polyethylene has low water vapor permeability and is particularly preferred as a layer included in the exterior material for power storage devices.
• acid-modified polyethylene may be sufficient as polyethylene.
• Acid-modified polyethylene is a polymer modified by block polymerization or graft polymerization of polyethylene with an acid component.
• the acid-modified polyethylene the above-mentioned polyethylene, a copolymer obtained by copolymerizing the above-mentioned polyethylene with a polar molecule such as acrylic acid or methacrylic acid, or a polymer such as crosslinked polyolefin can also be used.
• examples of the acid component used for acid modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, or their anhydrides.
• Preferred acid-modified polyethylenes include polyethylenes modified with carboxylic acids or their anhydrides.
• first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 are each analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected.
• maleic anhydride-modified polyethylene is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected at wave numbers around 1760 cm -1 and around 1780 cm -1 wave numbers.
• first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 each contain maleic anhydride-modified polyethylene
• a peak derived from maleic anhydride is detected when measured by infrared spectroscopy. Ru.
• the degree of acid modification is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.
• the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 may each be formed from one type of resin alone, or may be formed from a blended polymer that is a combination of two or more types of resin. Good too. Further, each of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 may be formed of only one layer, but may be formed of two or more layers of the same or different resins. Good too.
• the melting peak temperatures of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 are preferably about 130°C or less, more preferably The temperature is about 110 to 130°C, more preferably about 120 to 130°C.
• the melting peak temperature is 110°C or higher, blocking occurs easily during winding during heating in the aging process when manufacturing the exterior material for power storage devices, and the melting peak temperature is 130°C.
• At least one of the surface and inside of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 includes a lubricant, a flame retardant, an anti-blocking agent, an antioxidant, a light stabilizer, Additives such as tackifiers and antistatic agents may also be present. Only one type of additive may be used, or a mixture of two or more types may be used.
• a lubricant may be present on the surfaces of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2, respectively.
• the lubricant is not particularly limited, but preferably includes an amide lubricant.
• Specific examples of amide lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, aromatic bisamides, and the like.
• saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, and the like.
• unsaturated fatty acid amides include oleic acid amide and erucic acid amide.
• substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, and the like.
• methylolamide include methylolstearamide and the like.
• saturated fatty acid bisamides include methylene bisstearamide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, and hexamethylene bis stearic acid amide.
• saturated fatty acid bisamides include methylene bisstearamide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, and hexamethylene bis stearic acid amide.
• Examples include acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide, and the like.
• unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyladipic acid amide, and N,N'-dioleyl sebacic acid amide.
• fatty acid ester amides include stearamide ethyl stearate.
• aromatic bisamides include m-xylylene bisstearamide, m-xylylene bishydroxystearamide, and N,N'-distearylisophthalic acid amide.
• One type of lubricant may be used alone, or two or more types may be used in combination.
• the amount thereof is not particularly limited, but is preferably about 3 mg/m 2 or more, for example. Examples include about 4 mg/m 2 or more, about 5 mg/m 2 or more. Further, the amount of lubricant present on the surface of the first heat-fusible resin layer 1 is, for example, about 15 mg/m 2 or less, preferably about 14 mg/m 2 or less, and about 10 mg/m 2 or less.
• the preferable range of the amount of lubricant present on the surface of the first heat-fusible resin layer 1 is about 3 to 15 mg/m 2 , about 3 to 14 mg/m 2 , about 3 to 10 mg/m 2 , and about 4 to 15 mg/m 2 .
• Examples include about 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 , and about 5 to 10 mg/m 2 .
• the lubricants present on the surfaces of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 constitute the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2, respectively.
• the lubricant contained in the resin may be exuded, or the lubricant may be applied to the surface of the first heat-fusible resin layer 1.
• the thickness of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 is preferably about 20 ⁇ m or more, and more preferably about 20 ⁇ m or more.
• the thickness of the first heat-fusible resin layer 1 and the second heat-fusible resin layer 2 is about 20 ⁇ m or more, the sealing strength is easily increased, and when the thickness is about 100 ⁇ m or less, the Energy density becomes easier to improve.
• the first heat-fusible resin layer 1 is formed using a pre-formed resin film (i.e., a resin film containing polyethylene as a main component (polyethylene film)).
• a resin film containing polyethylene as a main component polyethylene film
• the resin forming the first heat-fusible resin layer 1 i.e., polyethylene
• the first heat-fusible resin layer 1 may be formed by forming a resin (main component) into a film (that is, a resin film (polyethylene film)) by extrusion molding, coating, or the like.
• a pre-formed resin film i.e., a resin film containing polyethylene as a main component (polyethylene film)
• a second heat-fusible resin When layer 2 is laminated with barrier layer 5, second heat-resistant layer 4, etc., which will be described later, the resin that forms the second heat-fusible resin layer 2 (i.e., the resin whose main component is polyethylene) is extruded or coated.
• the second heat-fusible resin layer 2 may be formed into a film (ie, as a resin film (polyethylene film)) by a method such as the following.
• the resin film may be an unstretched film or a stretched film.
• Examples of the stretched film include uniaxially stretched film and biaxially stretched film, with biaxially stretched film being preferred.
• Examples of the stretching method for forming a biaxially stretched film include a sequential biaxial stretching method, an inflation method, and a simultaneous biaxial stretching method.
• Examples of methods for applying the resin include roll coating, gravure coating, and extrusion coating.
• the first heat-resistant layer 3 is a layer provided between the first heat-fusible resin layer 1 and the barrier layer 5 as necessary for the purpose of increasing the heat resistance of the exterior material 10 for an electricity storage device. be. Further, the second heat-resistant layer 4 is provided between the second heat-fusible resin layer 2 and the barrier layer 5 as necessary for the purpose of increasing the heat resistance of the exterior material 10 for an electricity storage device. It is a layer.
• the first heat-resistant layer 3 and the second heat-resistant layer 4 can each be formed of resin or the like with excellent heat resistance.
• the melting peak temperatures of the first heat-resistant layer 3 and the second heat-resistant layer 4 are preferably about 130° C. or higher, more preferably about 140 to 300° C., and even more preferably about 140 to 300° C. is about 150 to 250°C. Since the melting peak temperature of the first heat-resistant layer 3 and the second heat-resistant layer 4 is 130°C or higher, high heat resistance can be exhibited, and since the melting peak temperature is 250°C or lower, costs can be reduced. advantageous in terms of
• Examples of the resin forming the first heat-resistant layer 3 and the second heat-resistant layer 4 include resins such as polyolefin, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenol resin, respectively. Examples include modified resins. Further, the resin forming the first heat-resistant layer 3 and the second heat-resistant layer 4 may be a copolymer of these resins, or may be a modified product of the copolymer. Furthermore, a mixture of these resins may be used.
• the resins forming the first heat-resistant layer 3 and the second heat-resistant layer 4 are preferably polyolefin or polyester.
• the polyolefin includes polypropylene such as homopolypropylene, a block copolymer of polypropylene (for example, a block copolymer of propylene and ethylene), and a random copolymer of polypropylene (for example, a random copolymer of propylene and ethylene); Polymer; terpolymer of ethylene-butene-propylene and the like.
• polypropylene is preferred.
• the polyolefin resin in the case of a copolymer may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more.
• the polyolefin may be a cyclic polyolefin.
• a cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. It will be done.
• the polyolefin may be an acid-modified polyolefin.
• Acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of polyolefin with an acid component.
• the acid-modified polyolefin the aforementioned polyolefins, copolymers obtained by copolymerizing the aforementioned polyolefins with polar molecules such as acrylic acid or methacrylic acid, or polymers such as crosslinked polyolefins can also be used.
• examples of the acid component used for acid modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, or their anhydrides.
• the acid-modified polyolefin may be an acid-modified cyclic polyolefin.
• Acid-modified cyclic polyolefin is a polymer obtained by copolymerizing some of the monomers constituting the cyclic polyolefin in place of the acid component, or by block polymerizing or graft polymerizing the acid component to the cyclic polyolefin. be.
• the cyclic polyolefin to be acid-modified is the same as described above. Further, the acid component used for acid modification is the same as the acid component used for modifying the polyolefin described above.
• Preferred acid-modified polyolefins include polyolefins modified with carboxylic acid or its anhydride, polypropylene modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefin, and maleic anhydride-modified polypropylene.
• polyester examples include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolymerized polyester, and the like.
• copolyester examples include copolyesters containing ethylene terephthalate as a main repeating unit. Specifically, copolymer polyester polymerized with ethylene isophthalate with ethylene terephthalate as the main repeating unit (hereinafter abbreviated as polyethylene (terephthalate/isophthalate)), polyethylene (terephthalate/adipate), polyethylene (terephthalate/adipate), etc.
• polyesters examples include sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate), and polyethylene (terephthalate/decanedicarboxylate). These polyesters may be used alone or in combination of two or more.
• the first heat-resistant layer 3 and the second heat-resistant layer 4 may each be formed from one type of resin alone, or may be formed from a blended polymer that is a combination of two or more types of resin. Further, each of the first heat-resistant layer 3 and the second heat-resistant layer 4 may be formed of only one layer, or may be formed of two or more layers of the same or different resins.
• a pre-formed resin film may be used to form the first heat-resistant layer 3, or the first heat-resistant layer 3 may be replaced by a barrier layer 5 or a first heat-melting layer 5, which will be described later.
• the first heat-resistant layer 3 may be formed by forming the resin forming the first heat-resistant layer 3 into a film (ie, a resin film) by extrusion molding, coating, or the like.
• a pre-formed resin film may be used, or when the second heat-resistant layer 4 is laminated with a barrier layer 5, a second heat-fusible resin layer 2, etc., which will be described later.
• the second heat-resistant layer 4 may be formed by forming the resin forming the second heat-resistant layer 4 into a film (ie, a resin film) by extrusion molding, coating, or the like.
• the resin film may be an unstretched film or a stretched film.
• the stretched film include uniaxially stretched film and biaxially stretched film, with biaxially stretched film being preferred.
• Examples of the stretching method for forming a biaxially stretched film include a sequential biaxial stretching method, an inflation method, and a simultaneous biaxial stretching method.
• methods for applying the resin include roll coating, gravure coating, and extrusion coating.
• the thickness of the first heat-resistant layer 3 and the second heat-resistant layer 4 is preferably about 5 ⁇ m or more, more preferably about 10 ⁇ m or more, and even more preferably about 20 ⁇ 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 the preferable range is about 5 to 50 ⁇ m, about 5 to 40 ⁇ m, about 5 to 30 ⁇ m, and 10 to Examples include about 50 ⁇ m, about 10 to 40 ⁇ m, about 10 to 30 ⁇ m, about 20 to 50 ⁇ m, about 20 to 40 ⁇ m, and about 20 to 30 ⁇ m.
• the thickness of the first heat-resistant layer 3 and the second heat-resistant layer 4 is about 5 ⁇ m or more, resistance to physical contact is increased, and when the thickness is about 50 ⁇ m or less, the energy density of the electricity storage device can be improved. .
• the first adhesive layer 12 is a layer provided as necessary for the purpose of increasing the adhesiveness between the first heat-fusible resin layer 1 and a layer adjacent thereto. Therefore, the first adhesive layer 12 is adjacent to the first heat-fusible resin layer 1 .
• the second adhesive layer 22 is a layer provided as necessary for the purpose of increasing the adhesiveness between the second heat-fusible resin layer 2 and a layer adjacent thereto. Therefore, the second adhesive layer 22 is adjacent to the second heat-fusible resin layer 2.
• the third adhesive layer 32 is provided between the first heat resistant layer 3 and the barrier layer 5 as necessary for the purpose of increasing the adhesiveness between the first heat resistant layer 3 and the barrier layer 5.
• the fourth adhesive layer 42 is provided between the second heat resistant layer 4 and the barrier layer 5 as necessary for the purpose of increasing the adhesiveness between the second heat resistant layer 4 and the barrier layer 5. It is a layer.
• the fourth adhesive layer 42 is adjacent to the second heat-resistant layer 4 .
• the first adhesive layer 12, the second adhesive layer 22, the third adhesive layer 32, and the fourth adhesive layer 42 are each formed of a resin (adhesive) having adhesive properties.
• the adhesives used for forming the first adhesive layer 12, the second adhesive layer 22, the third adhesive layer 32, and the fourth adhesive layer 42 are not particularly limited, and are chemical reaction type, solvent volatilization type, thermal adhesive, etc. Any type of adhesive, such as a melt type adhesive or a hot pressure type adhesive, may be used. Further, the adhesive may be a two-component curing adhesive (two-component adhesive) or a one-component curing adhesive (one-component adhesive), which does not involve a curing reaction. It may also be made of resin.
• the first adhesive layer 12, the second adhesive layer 22, the third adhesive layer 32, and the fourth adhesive layer 42 may each be a single layer or a multilayer.
• the adhesive components contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester; polyether; polyurethane; epoxy resin; Phenol resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefin resins such as polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins; polyvinyl acetate; cellulose; (meth)acrylic resins; Examples include polyimide; polycarbonate; amino resins such as urea resin and melamine resin; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; and silicone resins.
• polyesters such as polyethylene terephthalate, polybuty
• adhesive components may be used alone or in combination of two or more.
• polyurethane polyurethane adhesive
• 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 among polyisocyanates, polyfunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, etc., depending on the functional groups of the adhesive component.
• polyurethane adhesive examples include a polyurethane adhesive that includes a first part containing a polyol compound and a second part containing an isocyanate compound.
• Preferred examples include two-component curing polyurethane adhesives in which a polyol such as a polyester polyol, a polyether polyol, or an acrylic polyol is used as a first part and an aromatic or aliphatic polyisocyanate is used as a second part.
• examples of the polyurethane adhesive include a polyurethane adhesive containing a polyurethane compound prepared by reacting a polyol compound and an isocyanate compound in advance, and an isocyanate compound.
• examples of the polyurethane adhesive include a polyurethane adhesive containing a polyurethane compound prepared by reacting a polyol compound and an isocyanate compound in advance, and a polyol compound.
• examples of the polyurethane adhesive include, for example, a polyurethane adhesive obtained by curing a polyurethane compound obtained by reacting a polyol compound and an isocyanate compound in advance with moisture in the air or the like.
• the polyol compound it is preferable to use a polyester polyol having a hydroxyl group in the side chain in addition to the hydroxyl group at the end of the repeating unit.
• Examples of the second agent include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds.
• isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), and diphenylmethane diisocyanate. (MDI), naphthalene diisocyanate (NDI), and the like. Also included are polyfunctional isocyanate modified products of one or more of these diisocyanates.
• the polyisocyanate compound It is also possible to use multimers (for example trimers) as the polyisocyanate compound. Such multimers include adducts, biurets, nurates, and the like. Since the adhesive layer is formed of a polyurethane adhesive, the exterior material for the power storage device has excellent electrolyte resistance, and even if the electrolyte adheres to the side surface, the first heat-fusible resin layer 1 will not peel off. suppressed.
• multimers for example trimers
• Such multimers include adducts, biurets, nurates, and the like. Since the adhesive layer is formed of a polyurethane adhesive, the exterior material for the power storage device has excellent electrolyte resistance, and even if the electrolyte adheres to the side surface, the first heat-fusible resin layer 1 will not peel off. suppressed.
• first adhesive layer 12, the second adhesive layer 22, the third adhesive layer 32, and the fourth adhesive layer 42 are allowed to contain other components as long as they do not impede the adhesive properties, such as colorants and thermoplastic elastomers. , a tackifier, a filler, etc.
• the first adhesive layer 12, the second adhesive layer 22, the third adhesive layer 32, and the fourth adhesive layer 42 each contain a coloring agent, so that the exterior material for the electricity storage device can be colored.
• the colorant known colorants such as pigments and dyes can be used.
• only one type of coloring agent may be used, or two or more types of coloring agents may be used in combination.
• the type of pigment is not particularly limited as long as it does not impair the adhesive properties of the first adhesive layer 12, second adhesive layer 22, third adhesive layer 32, and fourth adhesive layer 42.
• organic pigments include azo pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, dioxazine pigments, indigothioindigo pigments, perinone-perylene pigments, isoindolenine pigments, and benzimidazolone pigments.
• the pigment include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and in addition, mica (mica) fine powder, fish scale foil, and the like.
• carbon black is preferable, for example, in order to make the exterior of the power storage device exterior black.
• the average particle diameter of the pigment is not particularly limited, and may be, for example, about 0.05 to 5 ⁇ m, preferably about 0.08 to 2 ⁇ m. Note that the average particle diameter of the pigment is the median diameter measured by a laser diffraction/scattering particle diameter distribution measuring device.
• the pigment content in the first adhesive layer 12, the second adhesive layer 22, the third adhesive layer 32, and the fourth adhesive layer 42 is not particularly limited as long as the exterior material for the electricity storage device is colored, for example.
• the amount may be about 5 to 60% by weight, preferably 10 to 40% by weight.
• the thicknesses of the first adhesive layer 12, the second adhesive layer 22, the third adhesive layer 32, and the fourth adhesive layer 42 are not particularly limited, but are, for example, about 1 ⁇ m or more, about 2 ⁇ m or more, and, for example, , about 10 ⁇ m or less, about 7 ⁇ m or less, about 5 ⁇ m or less, and preferred ranges are 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, and about 2 to 5 ⁇ m. Can be mentioned.
• the colored layer is a layer provided as necessary between the first heat-fusible resin layer 1 and the barrier layer 5 (not shown).
• a colored layer may be provided between the first heat-fusible resin layer 1 and the first adhesive layer 12 and between the first adhesive layer 12 and the barrier layer 5. .
• the colored layer can be formed, for example, by applying ink containing a coloring agent to the surface of the first heat-fusible resin layer 1 or the surface of the barrier layer 5.
• a coloring agent known colorants such as pigments and dyes can be used.
• only one type of coloring agent may be used, or two or more types of coloring agents may be used in combination.
• coloring agent contained in the colored layer As specific examples of the coloring agent contained in the colored layer, the same ones as those exemplified in the column [first adhesive layer 12, second adhesive layer 22, third adhesive layer 32, fourth adhesive layer 42] are exemplified. Ru.
• the barrier layer 5 is a layer that prevents at least moisture from entering.
• Examples of the barrier layer 5 include metal foil, vapor deposited film, and resin layer having barrier properties.
• Examples of the vapor-deposited film include a metal vapor-deposited film, an inorganic oxide vapor-deposited film, a carbon-containing inorganic oxide vapor-deposited film, etc.
• resin layers include polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), and tetrafluoroethylene.
• Examples include fluorine-containing resins such as polymers containing fluoroethylene (TFE) as a main component, polymers having a fluoroalkyl group, and polymers containing fluoroalkyl units as a main component, and ethylene vinyl alcohol copolymers.
• examples of the barrier layer 5 include a resin film provided with at least one of these vapor-deposited films and a resin layer.
• a plurality of barrier layers 5 may be provided. It is preferable that the barrier layer 5 includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 5 include aluminum alloy, stainless steel, titanium steel, steel plate, etc. When used as metal foil, it includes at least one of aluminum alloy foil and stainless steel foil. It is preferable.
• the aluminum alloy foil When the aluminum alloy foil is required to have formability as an exterior material for a power storage device, it is more preferable to use a soft aluminum alloy foil made of annealed aluminum alloy, for example, and when higher formability is required. In such cases, it is preferable to use an aluminum alloy foil containing iron.
• the iron content In the aluminum alloy foil containing iron (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. When the iron content is 0.1% by mass or more, it is possible to obtain an exterior material for a power storage device that has better formability. By having an iron content of 9.0% by mass or less, it is possible to obtain an exterior material for a power storage device that has more excellent flexibility.
• soft aluminum alloy foil examples include JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P- Aluminum alloy with a composition specified by O
• One example is foil.
• silicon, magnesium, copper, manganese, etc. may be added as necessary.
• softening can be performed by annealing treatment or the like.
• the stainless steel foil examples include austenitic, ferritic, austenite-ferritic, martensitic, and precipitation hardening stainless steel foils. If further formability is required, the stainless steel foil is preferably made of austenitic stainless steel.
• austenitic stainless steel constituting the stainless steel foil examples include SUS304, SUS301, SUS316L, etc. Among these, SUS304 is particularly preferred.
• the thickness of the barrier layer 5 may be about 9 to 200 ⁇ m, as long as it can at least function as a barrier layer to prevent moisture from entering.
• the thickness of the barrier layer 5 is preferably about 85 ⁇ m or less, more preferably about 50 ⁇ m or less, even more preferably about 40 ⁇ m or less, particularly preferably about 35 ⁇ m or less. Further, the thickness of the barrier layer 5 is preferably about 10 ⁇ m or more, more preferably about 20 ⁇ m or more, and even more preferably about 25 ⁇ m or more.
• the preferable range of the thickness of the barrier layer 5 is about 10 to 85 ⁇ m, about 10 to 50 ⁇ m, about 10 to 40 ⁇ m, about 10 to 35 ⁇ m, about 20 to 85 ⁇ m, about 20 to 50 ⁇ m, about 20 to 40 ⁇ m, and about 20 to 40 ⁇ m. Examples include about 35 ⁇ m, about 25 to 85 ⁇ m, about 25 to 50 ⁇ m, about 25 to 40 ⁇ m, and about 25 to 35 ⁇ m.
• the barrier layer 5 is made of aluminum alloy foil, the above-mentioned range is particularly preferable.
• the thickness of the barrier layer 3 is preferably about 35 ⁇ m or more, more preferably about 45 ⁇ m or more, still more preferably about 50 ⁇ m or more, and It is preferably about 55 ⁇ m or more, and preferably about 200 ⁇ m or less, more preferably about 85 ⁇ m or less, even more preferably about 75 ⁇ m or less, even more preferably about 70 ⁇ m or less, and the preferable range is about 35 to 200 ⁇ m, 35 ⁇ m or less.
• the thickness of the stainless steel foil is preferably about 60 ⁇ m or less, more preferably about 50 ⁇ m or less, still more preferably about 40 ⁇ m or less, and even more preferably about 30 ⁇ m. It is particularly preferably about 25 ⁇ m or less. Further, the thickness of the stainless steel foil is preferably about 10 ⁇ m or more, more preferably about 15 ⁇ m or more. Further, the preferable range of the thickness of the stainless steel foil is 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, and about 15 to 50 ⁇ m. Examples include about 40 ⁇ m, about 15 to 30 ⁇ m, and about 15 to 25 ⁇ m.
• the barrier layer 5 is a metal foil, it is preferable that a corrosion-resistant film is provided at least on the surface opposite to the first heat-fusible resin layer in order to prevent dissolution and corrosion.
• the barrier layer 5 may be provided with a corrosion-resistant coating on both sides.
• the corrosion-resistant film refers to, for example, hydrothermal conversion treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment with nickel or chromium, or corrosion prevention treatment such as applying a coating agent to the surface of the barrier layer.
• the corrosion-resistant film refers to 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), and the like.
• the treatment for forming a corrosion-resistant film one type of treatment may be performed or a combination of two or more types may be performed. Furthermore, it is possible to have not only one layer but also multiple layers.
• hydrothermal conversion treatment and anodization treatment are treatments in which the surface of the metal foil is dissolved with a treatment agent to form a metal compound with excellent corrosion resistance. Note that these treatments may be included in the definition of chemical conversion treatment.
• the barrier layer 5 includes a corrosion-resistant film
• the barrier layer 5 includes the corrosion-resistant film.
• the corrosion-resistant film is produced by preventing delamination between the barrier layer (for example, aluminum alloy foil) and the first heat-fusible resin layer, and by a reaction between electrolyte and moisture during molding of the exterior material for power storage devices.
• Hydrogen fluoride prevents the surface of the barrier layer from dissolving and corroding, especially when the barrier layer is made of aluminum alloy foil, the aluminum oxide present on the surface of the barrier layer is prevented from dissolving and corroding, and also prevents the adhesion of the surface of the barrier layer.
• corrosion-resistant coatings are known that are formed by chemical conversion treatment, and mainly include at least one of phosphates, chromates, fluorides, triazinethiol compounds, and rare earth oxides. Examples include corrosion-resistant coatings containing. Examples of chemical conversion treatments using phosphates and chromates include chromic acid chromate treatment, phosphoric acid chromate treatment, phosphoric acid-chromate treatment, and chromate treatment.
• Examples of the compound include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium diphosphate, chromic acid acetylacetate, chromium chloride, potassium chromium sulfate, and the like.
• examples of phosphorus compounds used in these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid.
• Examples of the chromate treatment include etching chromate treatment, electrolytic chromate treatment, coating type chromate treatment, and coating type chromate treatment is preferred.
• the inner layer side of the barrier layer (for example, aluminum alloy foil) is first coated using a well-known method such as an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid activation method, etc.
• Degrease treatment is performed using a treatment method, and then metal phosphates such as Cr (chromium) phosphate, Ti (titanium) phosphate, Zr (zirconium) phosphate, and Zn (zinc) phosphate are applied to the degreased surface.
• Treatment liquids whose main components are salts and mixtures of these metal salts, treatment liquids whose main components are nonmetallic phosphoric acid salts and mixtures of these nonmetallic salts, or combinations of these with synthetic resins, etc.
• This is a process in which a treatment liquid consisting of a mixture is applied by a well-known coating method such as a roll coating method, a gravure printing method, or a dipping method, and then dried.
• Various solvents such as water, alcohol solvents, hydrocarbon solvents, ketone solvents, ester solvents, and ether solvents can be used as the treatment liquid, and water is preferable.
• the resin component used at this time includes polymers such as phenolic resins and acrylic resins, and aminated phenol polymers having repeating units represented by the following general formulas (1) to (4) are used. Examples include chromate treatment.
• the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. Good too.
• the acrylic resin must be polyacrylic acid, acrylic acid methacrylate copolymer, acrylic acid maleic acid copolymer, acrylic acid styrene copolymer, or derivatives thereof such as sodium salt, ammonium salt, or amine salt. is preferred.
• polyacrylic acid derivatives such as ammonium salts, sodium salts, or amine salts of polyacrylic acid.
• polyacrylic acid refers to a polymer of acrylic acid.
• the acrylic resin is also preferably a copolymer of acrylic acid and dicarboxylic acid or dicarboxylic anhydride, such as ammonium salt, sodium salt, Or it is also preferable that it is an amine salt. Only one type of acrylic resin may be used, or a mixture of two or more types may be 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 are each the same or different and represent a hydroxy group, an alkyl group, or a hydroxyalkyl group.
• the alkyl group represented by Examples include straight chain or branched alkyl groups having 1 to 4 carbon atoms such as tert-butyl group.
• examples of the hydroxyalkyl group represented by X, R 1 and R 2 include hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, Straight chain or branched chain with 1 to 4 carbon atoms substituted with one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group Examples include alkyl groups. In the general formulas (1) to (4), 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 repeating units represented by general formulas (1) to (4) is preferably about 500 to 1,000,000, and preferably about 1,000 to 20,000, for example. More preferred.
• Aminated phenol polymers can be produced, for example, by polycondensing a phenol compound or a naphthol compound with formaldehyde to produce a polymer consisting of repeating units represented by the above general formula (1) or general formula (3), and then adding formaldehyde to the polymer. and amine (R 1 R 2 NH) to introduce a functional group (-CH 2 NR 1 R 2 ) into the polymer obtained above.
• Aminated phenol polymers may be used alone or in combination of two or more.
• a corrosion-resistant film is a film formed by a coating-type corrosion-preventing treatment in which a coating agent containing at least one selected from the group consisting of a rare earth element oxide sol, an anionic polymer, and a cationic polymer is applied.
• a coating agent containing at least one selected from the group consisting of a rare earth element oxide sol, an anionic polymer, and a cationic polymer is applied.
• the coating agent may further contain phosphoric acid or a phosphate salt, a crosslinking agent for crosslinking the polymer.
• the rare earth element oxide sol includes rare earth element oxide fine particles (for example, 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, with cerium oxide being preferred from the viewpoint of further improving adhesion.
• the rare earth element oxides contained in the corrosion-resistant film can be used alone or in combination of two or more.
• various solvents such as water, alcohol solvents, hydrocarbon solvents, ketone solvents, ester solvents, and ether solvents can be used, with water being preferred.
• the cationic polymer examples include polyethyleneimine, an ionic polymer complex consisting of a polymer containing polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin in which a primary amine is graft-polymerized onto an acrylic main skeleton, polyallylamine or its derivatives. , aminated phenol, etc. are preferred.
• the anionic polymer is preferably poly(meth)acrylic acid or a salt thereof, or a copolymer containing (meth)acrylic acid or a salt thereof as a main component.
• the crosslinking agent is at least one selected from the group consisting of a compound having a functional group such as an isocyanate group, a glycidyl group, a carboxyl group, or an oxazoline group, and a silane coupling agent.
• the phosphoric acid or phosphate is a condensed phosphoric acid or a condensed phosphate.
• An example of a corrosion-resistant film is to coat fine particles of barium sulfate or metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide in phosphoric acid on the surface of the barrier layer. Examples include those formed by performing baking treatment at temperatures above .degree.
• the corrosion-resistant film may have a laminated structure in which at least one of a cationic polymer and an anionic polymer is further laminated, if necessary.
• a cationic polymer and anionic polymer include those mentioned above.
• composition of the corrosion-resistant film can be analyzed using, for example, time-of-flight secondary ion mass spectrometry.
• the amount of the corrosion-resistant film formed on the surface of the barrier layer 5 in the chemical conversion treatment is not particularly limited. is, for example, about 0.5 to 50 mg, preferably about 1.0 to 40 mg, in terms of chromium, the phosphorus compound is, for example, about 0.5 to 50 mg, preferably about 1.0 to 40 mg, in terms of phosphorus, and the aminated phenol polymer. It is desirable that the content is, for example, 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 from the viewpoint of the cohesive force of the film and the adhesion with the barrier layer and the heat-fusible resin layer, it is preferably about 1 nm to 20 ⁇ m, more preferably 1 nm to 100 nm. More preferably, it is about 1 nm to 50 nm.
• the thickness of the corrosion-resistant film can be measured by observation using a transmission electron microscope, or by a combination of observation using a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy.
• composition of the corrosion-resistant film using time-of-flight secondary ion mass spectrometry reveals that, for example, secondary ions consisting of Ce, P, and O (for example, at least one of Ce 2 PO 4 + , CePO 4 - , etc.) peaks derived from secondary ions (for example, at least one of CrPO 2 + and CrPO 4 - ) made of Cr, P, and O are detected.
• secondary ions consisting of Ce, P, and O for example, at least one of Ce 2 PO 4 + , CePO 4 - , etc.
• Chemical conversion treatment involves applying a solution containing a compound used to form a corrosion-resistant film to the surface of the barrier layer using a bar coating method, roll coating method, gravure coating method, dipping method, etc., and then changing the temperature of the barrier layer. This is done by heating to a temperature of about 70 to 200°C.
• the barrier layer may be previously subjected to a degreasing treatment using an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing treatment in this manner, it becomes possible to perform the chemical conversion treatment on the surface of the barrier layer more efficiently.
• Method for manufacturing an exterior material for an energy storage device is not particularly limited as long as a laminate in which each layer of the exterior material for an energy storage device of the present disclosure is laminated can be obtained.
• a method including a step of laminating the heat-fusible resin layer 1, the barrier layer 5, and the second heat-fusible resin layer 2 in this order can be mentioned.
• the first heat-fusible resin layer 1 contains polyethylene as a main component
• the second heat-fusible resin layer 2 contains polyethylene as a main component. There is.
• An example of the method for manufacturing the exterior material for a power storage device of the present disclosure is as follows.
• a laminate is formed in which the first heat-fusible resin layer 1, the first adhesive layer 12, and the barrier layer 5 are laminated in this order.
• the formation of the laminate is performed by applying an adhesive used to form the first adhesive layer 12 on the first heat-fusible resin layer 1 or on the barrier layer 5 whose surface has been subjected to chemical conversion treatment if necessary. is coated and dried by a coating method such as a gravure coating method or a roll coating method, and then the barrier layer 5 or the first heat-fusible resin layer 1 is laminated and the first adhesive layer 12 is cured by a dry lamination method. It can be carried out.
• a laminate is formed in which the first heat-fusible resin layer 1, the first adhesive layer 12, and the first heat-resistant layer 3 are laminated in this order.
• the formation of the laminate is performed by applying the adhesive used for forming the first adhesive layer 12 on the first heat-fusible resin layer 1 or the first heat-resistant layer 3 using a gravure coating method, a roll coating method, etc. It can be performed by a dry lamination method in which the first heat-resistant layer 3 or the first heat-fusible resin layer 1 is laminated and the first adhesive layer 12 is cured after coating and drying by a coating method such as a coating method.
• a coating method such as a coating method.
• the adhesive used to form the third adhesive layer 32 is applied to the first heat-resistant layer 3 or to the barrier layer 5 whose surface has been subjected to a chemical conversion treatment if necessary, by a coating method such as a gravure coating method or a roll coating method.
• a coating method such as a gravure coating method or a roll coating method.
• This can be carried out by a dry lamination method in which after coating and drying, the barrier layer 5 or the first heat-resistant layer 3 is laminated and the third adhesive layer 32 is cured.
• extrusion molding or thermal fusion of the first heat-resistant layer 3 can be used.
• the second heat-fusible resin layer 2 is laminated on the barrier layer 5 of the obtained laminate.
• the adhesive used to form the second adhesive layer 22 is coated on the second heat-fusible resin layer 2 or on the barrier layer 5 whose surface has been subjected to a chemical conversion treatment if necessary, using a gravure coating method or a roll coating method. It can be performed by a dry lamination method in which the barrier layer 5 or the second heat-fusible resin layer 2 is laminated and the second adhesive layer 22 is cured after coating and drying by a coating method such as a coating method.
• a laminate is formed in which the second heat-fusible resin layer 2, the second adhesive layer 22, and the second heat-resistant layer 4 are laminated in this order.
• the formation of the laminate is performed by applying the adhesive used for forming the second adhesive layer 22 on the second heat-fusible resin layer 2 or the second heat-resistant layer 4 using a gravure coating method or a roll method. It can be performed by a dry lamination method in which the second heat-resistant layer 4 or the second heat-fusible resin layer 2 is laminated and the second adhesive layer 22 is cured after coating and drying by a coating method such as a coating method.
• a coating method such as a coating method.
• the adhesive used to form the fourth adhesive layer 42 may be applied on the second heat-resistant layer 4 or on the barrier layer 5 whose surface has been subjected to a chemical conversion treatment if necessary, by a coating method such as a gravure coating method or a roll coating method. This can be carried out by a dry lamination method in which the barrier layer 5 or the second heat-resistant layer 4 is laminated after coating and drying, and the fourth adhesive layer 42 is cured. Furthermore, when the second heat-resistant layer 4 and the barrier layer 5 are laminated without interposing the fourth adhesive layer 42, extrusion molding or thermal fusion of the second heat-resistant layer 4 can be used.
• first heat-fusible resin layer 1 / first adhesive layer 12 provided as necessary / first heat-resistant layer 3 provided as necessary / third adhesive layer provided as necessary 32/Barrier layer 5/Fourth adhesive layer 42 provided as necessary/Second heat-resistant layer 4 provided as necessary/Second adhesive layer 22 provided as necessary/Second heat-fusible resin layer 2 is formed in this order, and the adhesiveness of the first adhesive layer 12, second adhesive layer 22, third adhesive layer 32, and fourth adhesive layer 42 provided as necessary is strengthened. For this reason, it may be further subjected to heat treatment.
• the exterior packaging material for power storage devices of the present disclosure is used for a package for sealing and accommodating power storage device elements such as a positive electrode, a negative electrode, and an electrolyte. That is, a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte can be housed in a package formed of the exterior material for a power storage device according to the present disclosure to form a power storage device.
• an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is prepared using the exterior material for an electricity storage device of the present disclosure, with metal terminals connected to each of the positive electrode and the negative electrode protruding outward. , Covering the electricity storage device element so that a flange portion (an area where the heat-fusible resin layers contact each other) is formed around the periphery of the power storage device element, and sealing the heat-fusible resin layers of the flange portion by heat-sealing each other. provides an electricity storage device using an exterior material for an electricity storage device.
• the heat-fusible resin portion of the power storage device exterior material of the present disclosure is placed on the inside (the surface in contact with the power storage device element). ) to form a package.
• the heat-fusible resin layers of two exterior materials for power storage devices may be stacked facing each other, and the peripheral edges of the stacked exterior materials for power storage devices may be heat-sealed to form a package; As in the example shown in FIG. 5, a package may be formed by folding and overlapping one exterior material for a power storage device and heat-sealing the peripheral edge portions.
• the package When folded and stacked, the package may be formed by heat-sealing the sides other than the folded edges and sealing on three sides, as shown in the example shown in Fig. 5, or the package may be folded back so that a flange can be formed. It may be sealed on all sides, or the exterior material for the power storage device is wrapped around the power storage device element and the heat-sealable resin layers are sealed to form a heat-sealed part and the openings at both ends are closed. A lid body or the like may be arranged in this manner and sealed by heat-sealing with the exterior material for the power storage device wrapped around the power storage device element.
• the lid body can be formed of, for example, a resin molded product, a metal molded product, an exterior material for a power storage device, or the like. Further, a recessed portion for accommodating the power storage device element may be formed in the exterior material for the power storage device by deep drawing or stretch molding. As in the example shown in FIG. 5, one exterior material for an energy storage device may have a recess and the other exterior material for an energy storage device may not have a recess, or the other exterior material for an energy storage device may also have a recess. may be provided.
• the exterior material for power storage devices of the present disclosure can be suitably used for power storage devices such as batteries (including capacitors, capacitors, etc.). Further, the exterior material for a power 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 types of secondary batteries to which the exterior material for power storage devices of the present disclosure is applied are not particularly limited, and include, for example, lithium-ion batteries, lithium-ion polymer batteries, all-solid-state batteries, semi-solid-state batteries, pseudo-solid-state batteries, and polymer batteries.
• lithium ion batteries and lithium ion polymer batteries are suitable for application of the exterior material for power storage devices of the present disclosure.
• power storage devices are used for various purposes, and the needs for power storage devices are also diverse. Since the exterior material 10 for a power storage device of the present disclosure has a function of thermally fusing an adherend, it can also provide a power storage device with a function of thermally fusing an adherend. . If the power storage device of the present disclosure is fixed in a product by heat fusion, or if a plurality of power storage devices are stacked and fixed by heat fusion, the plurality of power storage devices can be incorporated into the product in a stacked state. Even in cases where the power storage devices are fixed, each power storage device is fixed, which has the advantage of suppressing misalignment of the power storage devices due to product vibration or damage caused by shocks transmitted to each power storage device when external force is applied to the product. There is.
• Example 1 As the first heat-fusible resin layer and the second heat-fusible resin layer, high-density polyethylene (HDPE) films (thickness 50 ⁇ m, melting peak temperature 130°C, water vapor permeability 0.28 g ⁇ mm/m 2 ⁇ 24h) was prepared. Unstretched polypropylene (CPP) films (thickness: 30 ⁇ m, melting peak temperature: 161° C., water vapor permeability: 0.40 g ⁇ mm/m 2 ⁇ 24 h) were prepared as the first heat-resistant layer and the second heat-resistant layer, respectively.
• HDPE high-density polyethylene
• CPP Unstretched polypropylene
• aluminum alloy foil As a barrier layer, aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 40 ⁇ m) was prepared. Both sides of the aluminum alloy foil were chemically treated. The chemical conversion treatment of the aluminum alloy foil was performed using phenol resin, A treatment solution consisting of a chromium fluoride compound and phosphoric acid was applied to both sides of an aluminum alloy foil using a roll coating method so that the amount of chromium applied was 10 mg/m 2 (dry mass), and then baked. .
• the first A laminate 1 was obtained in which a heat-fusible resin layer (thickness: 50 ⁇ m)/first adhesive layer (thickness after curing: 1.5 ⁇ m)/first heat-resistant layer (thickness: 30 ⁇ m) were laminated in this order from the outside. .
• first heat-fusible resin layer (thickness: 50 ⁇ m) / first adhesive layer (thickness after curing is 1.5 ⁇ m) / first heat-resistant layer (thickness: 30 ⁇ m) / third adhesive layer (after curing)
• first heat-fusible resin layer (thickness: 50 ⁇ m) / first adhesive layer (thickness after curing is 1.5 ⁇ m) / first heat-resistant layer (thickness: 30 ⁇ m) / third adhesive layer (after curing)
• a laminate 3 of 1.5 ⁇ m thick/barrier layer (40 ⁇ m thick) was prepared.
• the surface of the laminate 3 on the barrier layer side and the surface of the laminate 2 on the second heat-resistant layer side are bonded together using a polyolefin adhesive (acid-modified polyolefin compound) that forms a fourth adhesive layer.
• a polyolefin adhesive acid-modified polyolefin compound
• Example 2 As the first heat-fusible resin layer and the second heat-fusible resin layer, high-density polyethylene (HDPE) films (thickness 50 ⁇ m, melting peak temperature 130°C, water vapor permeability 0.28 g ⁇ mm/m 2 ⁇ 24h) was prepared. As the first heat-resistant layer, an unstretched polypropylene (CPP) film (thickness: 30 ⁇ m, melting peak temperature: 161° C., water vapor permeability: 0.40 g ⁇ mm/m 2 ⁇ 24 h) was prepared.
• HDPE high-density polyethylene
• CPP unstretched polypropylene
• maleic anhydride-modified polypropylene (PPa) (thickness: 30 ⁇ m, melting peak temperature: 160° C., water vapor permeability: 0.45 g ⁇ mm/m 2 ⁇ 24 h) was prepared.
• PPa polypropylene
• aluminum alloy foil JIS H4160:1994 A8021H-O (thickness 40 ⁇ m) was prepared. Both sides of the aluminum alloy foil were chemically treated.
• the chemical conversion treatment of the aluminum alloy foil was performed using phenol resin, A treatment solution consisting of a chromium fluoride compound and phosphoric acid was applied to both sides of an aluminum alloy foil using a roll coating method so that the amount of chromium applied was 10 mg/m 2 (dry mass), and then baked. .
• the first heat-fusible resin layer and the first heat-resistant layer were adhered using a polyolefin adhesive (acid-modified polyolefin compound) forming the first adhesive layer, and then subjected to aging treatment.
• a polyolefin adhesive acid-modified polyolefin compound
• the first heat-fusible resin layer (thickness: 50 ⁇ m)/first adhesive layer (thickness after curing is 1.5 ⁇ m)/first heat-resistant layer (thickness: 30 ⁇ m) are laminated in order from the outside.
• a laminate 1 was obtained.
• the surface of the laminate 1 on the first heat-resistant layer side and the barrier layer were bonded using a polyolefin adhesive (acid-modified polyolefin compound) that forms the third adhesive layer.
• a polyolefin adhesive acid-modified polyolefin compound
• a laminate 3 of /third adhesive layer (thickness after curing is 1.5 ⁇ m)/barrier layer (thickness 40 ⁇ m) was produced.
• a second heat-resistant layer was laminated on the barrier layer side surface of the laminate 3 by melt-extruding the resin forming the second heat-resistant layer. Furthermore, the surface of the second heat-resistant layer side of the obtained laminate and the second heat-fusible resin layer are adhered using a polyolefin adhesive (acid-modified polyolefin compound) that forms the second adhesive layer, and aging is performed.
• a polyolefin adhesive acid-modified polyolefin compound
• the treatment is carried out to laminate the second heat-fusible resin layer, and the first heat-fusible resin layer (thickness: 50 ⁇ m)/first adhesive layer (thickness after curing is 1.5 ⁇ m)/first Heat-resistant layer (30 ⁇ m thick) / 3rd adhesive layer (1.5 ⁇ m thick after curing) / Barrier layer (40 ⁇ m thick) / 2nd heat-resistant layer (30 ⁇ m thick) / 2nd adhesive layer (1.5 ⁇ m thick after curing)
• a laminate of 1.5 ⁇ m thick/2nd heat-fusible resin layer (50 ⁇ m thick) was produced, and used as an exterior material for a power storage device.
• Example 3 As the first heat-fusible resin layer and the second heat-fusible resin layer, high-density polyethylene (HDPE) films (thickness 50 ⁇ m, melting peak temperature 130°C, water vapor permeability 0.28 g ⁇ mm/m 2 ⁇ 24h) was prepared. In addition, maleic anhydride-modified polypropylene (PPa) (thickness 30 ⁇ m, melting peak temperature 160°C, water vapor permeability 0.45 g ⁇ mm/m 2 ⁇ 24 h) was used as the first heat-resistant layer and the second heat-resistant layer, respectively. . As a barrier layer, aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 40 ⁇ m) was prepared.
• JIS H4160:1994 A8021H-O thickness 40 ⁇ m
• Both sides of the aluminum alloy foil were chemically treated.
• the chemical conversion treatment of the aluminum alloy foil was performed using phenol resin, A treatment solution consisting of a chromium fluoride compound and phosphoric acid was applied to both sides of an aluminum alloy foil using a roll coating method so that the amount of chromium applied was 10 mg/m 2 (dry mass), and then baked. .
• a resin forming a first heat-resistant layer is melt-extruded on one surface of the barrier layer to form a first heat-resistant layer, and a resin forming a second heat-resistant layer is further formed on the other surface of the barrier layer.
• a second heat-resistant layer was formed by melt-extruding to obtain a laminate of first heat-resistant layer (thickness: 30 ⁇ m)/barrier layer (thickness: 40 ⁇ m)/second heat-resistant layer (thickness: 30 ⁇ m).
• the first heat-resistant layer (thickness: 30 ⁇ m) side surface of the obtained laminate and the first heat-fusible resin layer are bonded together using a polyolefin adhesive (acid-modified polyolefin compound) that forms the first adhesive layer. ), and by performing aging treatment, the first heat-fusible resin layer (thickness: 50 ⁇ m)/first adhesive layer (thickness after curing: 1.5 ⁇ m)/first heat-resistant layer ( A laminate was obtained in which layers (thickness: 30 ⁇ m)/barrier layer (thickness: 40 ⁇ m)/second heat-resistant layer (thickness: 30 ⁇ m) were laminated in this order from the outside.
• a polyolefin adhesive acid-modified polyolefin compound
• the second heat-resistant layer (thickness: 30 ⁇ m) side surface of the obtained laminate and the second heat-fusible resin layer are bonded using a polyolefin adhesive (acid-modified polyolefin compound) that forms the second adhesive layer.
• a polyolefin adhesive acid-modified polyolefin compound
• Example 4 As the first heat-fusible resin layer and the second heat-fusible resin layer, high-density polyethylene (HDPE) films (thickness 50 ⁇ m, melting peak temperature 130°C, water vapor permeability 0.28 g ⁇ mm/m 2 ⁇ Example 3 except that a maleic anhydride-modified polyethylene (PEa) film (thickness 50 ⁇ m, melting peak temperature 128°C, water vapor permeability 0.46 g mm/m 2 ⁇ 24 h) was used instead of 24 h).
• HDPE high-density polyethylene
• PEa maleic anhydride-modified polyethylene
• Example 5 As the first heat-resistant layer and the second heat-resistant layer, anhydrous anhydride was used instead of maleic anhydride-modified polypropylene (PPa) (thickness 30 ⁇ m, melting peak temperature 160°C, water vapor permeability 0.45 g ⁇ mm/m 2 ⁇ 24 h).
• PPa maleic anhydride-modified polypropylene
• the first heat-fusible resin layer (thickness 50 ⁇ m) was prepared in the same manner as in Example 3, except that a laminate (formed by melt extrusion of PPa and PP ) of ) / first adhesive layer (thickness after curing is 1.5 ⁇ m) / first heat-resistant layer (thickness 30 ⁇ m) / barrier layer (thickness 40 ⁇ m) / second heat-resistant layer (thickness 30 ⁇ m) / second adhesive layer (Thickness after curing: 1.5 ⁇ m)/Second heat-fusible resin layer (thickness: 50 ⁇ m) A laminate was produced and used as an exterior material for a power storage device
• Example 6 As the first heat-resistant layer and the second heat-resistant layer, anhydrous anhydride was used instead of maleic anhydride-modified polypropylene (PPa) (thickness 30 ⁇ m, melting peak temperature 160°C, water vapor permeability 0.45 g ⁇ mm/m 2 ⁇ 24 h).
• PPa maleic anhydride-modified polypropylene
• the first heat-fusible resin layer (thickness 50 ⁇ m) was prepared in the same manner as in Example 4, except that a laminate (formed by melt extrusion of PPa and PP) of ) / first adhesive layer (thickness after curing is 1.5 ⁇ m) / first heat-resistant layer (thickness 30 ⁇ m) / barrier layer (thickness 40 ⁇ m) / second heat-resistant layer (thickness 30 ⁇ m) / second adhesive layer (Thickness after curing: 1.5 ⁇ m)/Second heat-fusible resin layer (thickness: 50 ⁇ m) A laminate was produced and used as an exterior material for a power storage device.
• Comparative example 1 Polypropylene (PP) (thickness 50 ⁇ m, melting peak temperature 160°C, water vapor permeability 0.40 g ⁇ mm/m 2 ⁇ 24 h) was used as the first heat-fusible resin layer and the second heat-fusible resin layer, respectively. Prepared. In addition, maleic anhydride-modified polypropylene (PPa) (thickness 30 ⁇ m, melting peak temperature 160°C, water vapor permeability 0.45 g ⁇ mm/m 2 ⁇ 24 h) was used as the first heat-resistant layer and the second heat-resistant layer, respectively. . As a barrier layer, aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 40 ⁇ m) was prepared.
• Both sides of the aluminum alloy foil were chemically treated.
• the chemical conversion treatment of the aluminum alloy foil was performed using phenol resin, A treatment solution consisting of a chromium fluoride compound and phosphoric acid was applied to both sides of an aluminum alloy foil using a roll coating method so that the amount of chromium applied was 10 mg/m 2 (dry mass), and then baked. .
• a resin forming a first heat-resistant layer is melt-extruded on one surface of the barrier layer to form a first heat-resistant layer, and a resin forming a second heat-resistant layer is further formed on the other surface of the barrier layer.
• a second heat-resistant layer was formed by melt-extruding to obtain a laminate of first heat-resistant layer (thickness: 30 ⁇ m)/barrier layer (thickness: 40 ⁇ m)/second heat-resistant layer (thickness: 30 ⁇ m).
• first heat-resistant layer (thickness: 30 ⁇ m) side surface of the obtained laminate
• first heat-fusible resin layer (thickness: A laminate was obtained in which the following layers were sequentially laminated from the outside: first heat-resistant layer (thickness: 50 ⁇ m)/first heat-resistant layer (thickness: 30 ⁇ m)/barrier layer (thickness: 40 ⁇ m)/second heat-resistant layer (thickness: 30 ⁇ m).
• a resin forming a second heat-fusible resin layer is melt-extruded on the second heat-resistant layer (thickness: 30 ⁇ m) side surface of the obtained laminate, and a first heat-fusible resin layer (thickness: 50 ⁇ m) is melt-extruded.
• first heat-resistant layer (thickness: 30 ⁇ m)/barrier layer (thickness: 40 ⁇ m)/second heat-resistant layer (thickness: 30 ⁇ m)/second heat-fusible resin layer (thickness: 50 ⁇ m).
• Comparative example 2 As the first heat-resistant layer and the second heat-resistant layer, anhydrous anhydride was used instead of maleic anhydride-modified polypropylene (PPa) (thickness 30 ⁇ m, melting peak temperature 160°C, water vapor permeability 0.45 g ⁇ mm/m 2 ⁇ 24 h).
• PPa maleic anhydride-modified polypropylene
• PPa Maleic acid-modified polypropylene (PPa) (thickness 15 ⁇ m, melting peak temperature 160°C, water vapor permeability 0.45 g ⁇ mm/m 2 ⁇ 24 h) and polypropylene (PP) (thickness 15 ⁇ m, melting peak temperature 160°C, water vapor permeability 0)
• the unit of water vapor permeability is g/( m2 ⁇ 24h), but in order to make it easier to compare the numerical values of test samples with different thicknesses, the numerical value obtained by measurement is calculated using a thickness of 1.0 mm.
• the unit g ⁇ mm/m 2 ⁇ 24h was used.
• test sample 13 was left for 2 minutes at each measurement temperature, and in each measurement temperature environment, a tensile tester (manufactured by Shimadzu Corporation, AG-Xplus (trade name)) was used to test the first thermal bonding property of the thermally bonded part.
• the resin layer was peeled off at a speed of 300 mm/min (FIG. 7).
• the maximum strength at the time of peeling was defined as the seal strength (N/15 mm).
• the distance between chucks is 50 mm.
• the average value of three measurements was taken. Seal strength was evaluated based on the following criteria. The results are shown in Table 1. In the measurement of seal strength, the test sample 13 is peeled off (destroyed) at the heat seal interface A shown in FIG.
• the test sample 13 may break.
• the breaking strength is taken as the sealing strength.
• the sample used in [Measurement of thickness residual rate] uses the exterior material for a power storage device before and after heat sealing, and the first heat-resistant layer and the second heat-resistant layer. Measure the total thickness of the layer, and calculate the ratio (%) of the total thickness of the first heat-resistant layer and second heat-resistant layer after heat-sealing to the total thickness of the first heat-resistant layer and second heat-resistant layer before heat-sealing. did.
• the residual rate of total thickness was the average value of the two measurement samples.
• the thickness was measured by cutting the measurement sample in the thickness direction using a microtome (REM-710 litratome manufactured by Daiwa Koki Industries), and observing the obtained cross section with a laser microscope (VK-9700 manufactured by Keyence). went.
• the thickness residual rate was evaluated based on the following criteria. The results are shown in Table 1.
• C Thickness remaining rate is less than 70%.
• the exterior material 10 for a power storage device was cut to produce a strip with a width of 40 mm and a length of 100 mm, which was used as a test sample.
• the width refers to the TD direction
• the length refers to the MD direction.
• the center of the strip in the width direction was made to coincide with the center of the aluminum plate 30 in the width direction.
• the positive electrode of the tester was connected to the aluminum plate 30, and the negative electrode was connected to the exterior material for the power storage device.
• the negative terminal of the tester insert an alligator clip so that it reaches the barrier layer from the first heat-fusible resin layer side of the exterior material for the power storage device, and electrically connect the negative terminal of the tester and the barrier layer.
• the tester was prepared to issue a continuity (short circuit) signal when the applied voltage was 100 V and the resistance was 200 M ⁇ or less.
• the first heat-fusible resin layers were heat-sealed to each other under the conditions of each temperature (° C.) and surface pressure (MPa) described in Section 1, and the time until a short circuit signal was generated was measured. The measurement was performed five times, and the longest and shortest points were excluded to take the average value of the three points. The insulation was evaluated based on the following criteria. The results are shown in Table 1.
• C The time until short circuit occurs is less than 20 seconds.
• the exterior materials for power storage devices of Examples 1 to 6 are composed of a laminate including, in order from the outside, at least a first heat-fusible resin layer, a barrier layer, and a second heat-fusible resin layer,
• the first heat-fusible resin layer contains polyethylene as a main component
• the second heat-fusible resin layer contains polyethylene as a main component.
• the sealing strength of the first heat-fusible resin layer located on the outside was high, and collapse after sealing was suppressed, and the insulation properties were excellent. From these results, it is evaluated that the exterior materials for power storage devices of Examples 1 to 6 can be used by heat-sealing the outer surface of the power storage device to the adherend by applying it to the power storage device. Ru.
• Item 1 Consisting of a laminate including, in order from the outside, at least a first heat-fusible resin layer, a barrier layer, and a second heat-fusible resin layer,
• the first heat-fusible resin layer contains polyethylene as a main component
• the second heat-fusible resin layer is an exterior material for a power storage device, which contains polyethylene as a main component.
• Item 2. Item 2. The exterior material for an electricity storage device according to Item 1, wherein the first heat-fusible resin layer has a thickness of 30 ⁇ m or more.
• Item 3. Item 3.
• the exterior material for an electricity storage device according to Item 1 or 2, wherein the polyethylene of the first heat-fusible resin layer is high-density polyethylene.
• the exterior material for a power storage device according to any one of Items 1 to 4, wherein the polyethylene of the second heat-fusible resin layer is high-density polyethylene.
• the exterior material for a power storage device according to any one of Items 1 to 5, wherein the first heat-fusible resin layer has a melting peak temperature of 130° C. or less. Section 7. Item 7. The exterior material for a power storage device according to any one of Items 1 to 6, wherein the second heat-fusible resin layer has a melting peak temperature of 130° C. or less. Section 8. Item 8. The exterior material for a power storage device according to any one of Items 1 to 7, further comprising a first heat-resistant layer between the first heat-fusible resin layer and the barrier layer. Item 9. Item 9. The exterior material for a power storage device according to Item 8, wherein the first heat-resistant layer contains polypropylene or acid-modified polypropylene as a main component. Item 10.
• Item 9 The exterior material for an electricity storage device according to Item 8 or 9, wherein the first heat-resistant layer has a thickness of 15 ⁇ m or more.
• Item 11. The exterior material for an electricity storage device according to any one of Items 1 to 10, further comprising a second heat-resistant layer between the barrier layer and the second heat-fusible resin layer.
• Item 12. The exterior material for a power storage device according to Item 11, wherein the second heat-resistant layer contains polypropylene or acid-modified polypropylene as a main component.
• Item 13 Item 13.
• the exterior packaging material for a power storage device according to any one of Items 1 to 16, wherein the barrier layer is made of aluminum alloy foil or stainless steel foil.
• Section 18 A step of obtaining a laminate including at least a first heat-fusible resin layer, a barrier layer, and a second heat-fusible resin layer in order from the outside, The first heat-fusible resin layer contains polyethylene as a main component, The method for manufacturing an exterior material for a power storage device, wherein the second heat-fusible resin layer contains polyethylene as a main component.
• An electricity storage device wherein an electricity storage device element comprising at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the exterior material for an electricity storage device according to any one of Items 1 to 17.
• Section 20. Item 20. The electricity storage device according to Item 19, wherein the first heat-fusible resin layer constituting the outer surface of the electricity storage device is used so as to be heat-sealed to an adherend.
• Section 21. Item 19 or 20 The power storage device according to item 19 or 20, wherein the first heat-fusible resin layers constituting the outer surface of the power storage device are thermally fused to each other so that a plurality of power storage devices are stacked. device.
• First heat-fusible resin layer Second heat-fusible resin layer 3 First heat-resistant layer 4 Second heat-resistant layer 5 Barrier layer 10 Exterior material for power storage device 12 First adhesive layer 13 Test sample 22 Second adhesive layer 20 wire 30 aluminum plate 32 third adhesive layer 42 fourth adhesive layer

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Laminated Bodies (AREA)
• Sealing Battery Cases Or Jackets (AREA)

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Citations (7)

• 2023
  • 2023-03-30 WO PCT/JP2023/013407 patent/WO2023190997A1/ja not_active Ceased
  • 2023-03-30 JP JP2024512864A patent/JPWO2023190997A1/ja active Pending

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