Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/058—Construction or manufacture
  • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• • 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
  • H01M50/103—Primary casings; Jackets or wrappings characterised by their shape or physical structure prismatic or rectangular
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/117—Inorganic material
  • H01M50/119—Metals
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/121—Organic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
  • H01M50/126—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers
  • H01M50/129—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers with two or more layers of only organic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/131—Primary casings; Jackets or wrappings characterised by physical properties, e.g. gas permeability, size or heat resistance
  • H01M50/133—Thickness
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• This disclosure relates to a laminated film for bipolar lithium-ion batteries.
• Bipolar batteries are known as electricity storage devices that have been attracting attention in recent years. Bipolar batteries use a bipolar electrode with two electrodes on a single current collector, with a positive electrode on one side and a negative electrode on the other, and an electrolyte is layered between the positive and negative electrodes of the bipolar electrode.
• the bipolar battery described in Patent Document 1 is an all-solid-state battery that is composed of multiple bipolar laminated batteries (cell stacks) that include lithium battery unit cells and internal electrode layers that are stacked alternately with the unit cells.
• the multiple laminated batteries are stacked via positive and negative electrode current collector foils, connected in parallel to each other, and sealed with molded resin.
• Nickel-metal hydride batteries are widely used as on-board power storage devices. In recent years, bipolar nickel-metal hydride batteries have also been used to save space and increase power output. Furthermore, the use of bipolar lithium-ion batteries, which have a higher energy density and can produce higher power output than nickel-metal hydride batteries, is being considered.
• nickel-metal hydride batteries use a water-based electrolyte, they do not require high water vapor barrier properties, and the battery can be made by sealing the electrolyte in a plastic casing such as polypropylene or polyethylene.
• lithium-ion batteries use an organic solvent-based electrolyte, and since hydrofluoric acid is generated when water penetrates the inside of a lithium-ion battery, the electrolyte must be covered with a film with high barrier properties.
• the film when covering the exterior of a lithium-ion battery with a film, it is effective to cover the locations where moisture is likely to penetrate.
• moisture is likely to penetrate from the side of the exterior of the bipolar lithium-ion battery (the electrodes (including the end collectors) are arranged on the main surface), so it is desirable to cover the bipolar lithium-ion battery with a film that spans the ridges from the main surface to the side.
• the film is required to have formability such as bending and drawing.
• the main objective of the present disclosure is to provide a laminate film for bipolar lithium-ion batteries that is placed on a portion of the outer surface of the bipolar lithium-ion battery and has excellent electrolyte resistance and formability.
• a laminate film comprising at least a barrier layer and a polyolefin layer provided on one side of the barrier layer, in which the polyolefin layer constitutes the surface on one side of the laminate film, and which is arranged so as to straddle the ridge line from the main surface to the side of the outer surface of a bipolar lithium-ion battery, has excellent electrolyte resistance and formability, and is suitable as a laminate film to be arranged on a portion of the outer surface of a bipolar lithium-ion battery.
• a laminated film disposed on a portion of an outer surface of a bipolar lithium ion battery includes at least a barrier layer, a polyolefin layer provided on one side of the barrier layer, and Equipped with The polyolefin layer constitutes one surface of the laminate film,
• the laminated film is arranged so as to straddle a ridge line portion from a main surface to a side surface of an outer surface of the bipolar lithium ion battery.
• a laminate film for bipolar lithium-ion batteries that is disposed on a portion of the outer surface of the bipolar lithium-ion battery and has excellent electrolyte resistance and formability.
• an electricity storage device that utilizes the laminate film.
• FIG. 1 is a schematic diagram showing an example of a cross-sectional structure of a laminate film for a bipolar lithium ion battery according to the present disclosure.
• FIG. 1 is a schematic diagram showing an example of a cross-sectional structure of a laminate film for a bipolar lithium ion battery according to the present disclosure.
• FIG. 1 is a schematic diagram showing an example of a cross-sectional structure of a laminate film for a bipolar lithium ion battery according to the present disclosure.
• FIG. 1 is a schematic diagram showing an example of a cross-sectional structure of a laminate film for a bipolar lithium ion battery according to the present disclosure.
• FIG. 1 is a schematic diagram showing an example of a cross-sectional structure of a laminate film for a bipolar lithium ion battery according to the present disclosure.
• FIG. 1 is a schematic perspective view showing an example of an embodiment in which a laminate film for a bipolar lithium ion battery according to the present disclosure is applied to the outer surface of a bipolar lithium ion battery.
• FIG. 1 is a schematic perspective view showing an example of an embodiment in which a laminate film for a bipolar lithium ion battery according to the present disclosure is applied to the outer surface of a bipolar lithium ion battery.
• FIG. 1 is a schematic perspective view showing an example of an embodiment in which a laminate film for a bipolar lithium ion battery according to the present disclosure is applied to the outer surface of a bipolar lithium ion battery.
• FIG. 1 is a schematic perspective view showing an example of an embodiment in which a laminate film for a bipolar lithium ion battery according to the present disclosure is applied to the outer surface of a bipolar lithium ion battery.
• FIG. 1 is a schematic perspective view showing an example of an embodiment in which the laminated film for bipolar lithium ion batteries of the present disclosure (one sheet that has been drawn and one sheet that has not been drawn) is applied to the outer surface of a bipolar lithium ion battery.
• FIG. 1 is a schematic perspective view showing an example of an embodiment in which the laminated film for bipolar lithium ion batteries of the present disclosure (using two draw-formed sheets) is applied to the outer surface of a bipolar lithium ion battery.
• FIG. 1 is a schematic cross-sectional view showing an example of an embodiment in which the laminate film for bipolar lithium ion batteries of the present disclosure is applied to the outer surface of a bipolar lithium ion battery.
• the laminate film for bipolar lithium ion batteries of the present disclosure (hereinafter, sometimes referred to as the laminate film of the present disclosure) is a laminate film arranged on a part of the outer surface of a bipolar lithium ion battery.
• the laminate film of the present disclosure includes at least a barrier layer and a polyolefin layer provided on one side of the barrier layer.
• the polyolefin layer constitutes the surface on one side of the laminate film of the present disclosure.
• the laminate film of the present disclosure is arranged so as to straddle the ridge line portion from the main surface to the side of the outer surface of the bipolar lithium ion battery.
• the laminate film of the present disclosure has excellent formability, it can be suitably arranged so as to straddle the ridge line portion from the main surface to the side of the outer surface of the bipolar lithium ion battery.
• the laminate film of the present disclosure also has excellent electrolyte resistance, it is suitable as a laminate film arranged on a part of the outer surface of a bipolar lithium ion battery.
• the numerical ranges indicated with “ ⁇ " mean “greater than or equal to” or “less than or equal to”.
• the expression 2 to 15 mm means 2 mm or more and 15 mm or less.
• the 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 in stages.
• the upper limit and upper limit, the upper limit and lower limit, or the lower limit and lower limit 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 a value shown in the examples.
• the laminated film 10 of the present disclosure includes at least a barrier layer and a polyolefin layer provided on one side of the barrier layer, and the polyolefin layer constitutes the surface of one side of the laminated film.
• the laminated film 10 shown in FIG. 1 has a two-layer structure including a barrier layer 1 and a polyolefin layer 2 provided on one side of the barrier layer 1.
• the laminated film 10 shown in FIG. 2 has a three-layer structure including a barrier layer 1, a polyolefin layer 2 provided on one side of the barrier layer 1, and a resin layer 3 provided on the other side of the barrier layer 1.
• the laminated film 10 shown in FIG. 3 has a four-layer structure including a barrier layer 1, a polyolefin layer 2 provided on one side of the barrier layer 1, and a resin layer 3 provided on the other side of the barrier layer 1, and an adhesive layer 4 is disposed between the barrier layer 1 and the polyolefin layer 2.
• the laminated film 10 shown in FIG. 3 has a four-layer structure including a barrier layer 1, a polyolefin layer 2 provided on one side of the barrier layer 1, and a resin layer 3 provided on the other side of the barrier layer 1, and an adhesive layer 4 is disposed between the barrier layer 1 and the polyolefin layer 2.
• barrier layer 4 has a five-layer structure including a barrier layer 1, a polyolefin layer 2 provided on one side of the barrier layer 1, and a resin layer 3 provided on the other side of the barrier layer 1, with an adhesive layer 4 disposed between the barrier layer 1 and the polyolefin layer 2, and an adhesive layer 5 disposed between the barrier layer 1 and the resin layer 3.
• the laminate film 10 of the present disclosure is preferably made up of 2 to 6 layers, more preferably 2 to 5 layers, and even more preferably 3 to 5 layers.
• the polyolefin layer 2 can be disposed on the outer surface side of the bipolar lithium-ion battery 20 (i.e., the bipolar lithium-ion battery and the polyolefin layer 2 can be in contact with each other).
• the resin layer 3 can be disposed on the outer surface side of the bipolar lithium-ion battery 20 (i.e., the bipolar lithium-ion battery 20 and the resin layer 3 can be in contact with each other).
• the shape of the laminated film 10 of the present disclosure is not particularly limited, as long as it can be arranged so as to straddle the ridge line from the main surface to the side surface of the outer surface of the bipolar lithium ion battery.
• the laminated film 10 of the present disclosure can be rectangular and arranged so as to straddle the ridgeline 20c from the main surface 20a to the side surface 20b of the outer surface of the bipolar lithium-ion battery 20 (i.e., the laminated film 10 can be folded at the ridgeline 20c).
• the laminated film 10 of the present disclosure to protect the main surface 20a, side surface 20b, and ridgeline 20c of the outer surface of the bipolar lithium-ion battery 20.
• a plurality of laminate films 10 of the present disclosure may be arranged to straddle the ridge portion 20c from the main surface 20a to the side surface 20b of the outer surface of the bipolar lithium-ion battery 20.
• adjacent laminate films do not overlap at the four corners of the bipolar lithium-ion battery 20, but adjacent laminate films may be arranged to overlap at the corners, in which case the polyolefin layer on the outer surface of one laminate film and the polyolefin layer on the inner surface of the other laminate film can be heat-sealed at the overlapping portion.
• the laminated film 10 of the present disclosure may cover a part of the main surface 20a and the entire side surface 20b and ridge portion 20c. This allows the end collector 21 (electrode) located on the main surface 20a to be exposed, while the other parts of the outer surface of the bipolar lithium-ion battery 20 can be protected by the laminated film 10 of the present disclosure.
• Fig. 8 illustrates an embodiment in which one drawn laminated film 10 and one unformed laminated film 10 are applied to the outer surface of a bipolar lithium-ion battery.
• Fig. 9 illustrates an embodiment in which two drawn laminated films 10 are applied to the outer surface of a bipolar lithium-ion battery. The polyolefin layers 2 of the two laminated films 10 are heat-sealed to each other to achieve the arrangement shown in Figs. 8 and 9.
• the external shape of the bipolar lithium ion battery to which the laminated film 10 is applied is not particularly limited, and examples thereof include a rectangular parallelepiped shape (i.e., the main surface is rectangular in a plan view) and a cylindrical shape (i.e., the main surface is circular in a plan view).
• a rectangular parallelepiped shape and a planar rectangular shape include not only cases where the corners of the rectangular parallelepiped or rectangle are right angles, but also rounded shapes.
• the thickness of the laminate constituting laminate film 10 is not particularly limited, but from the viewpoint of optimally exerting the effects of the present disclosure, examples include approximately 210 ⁇ m or less, preferably approximately 190 ⁇ m or less, approximately 180 ⁇ m or less, approximately 155 ⁇ m or less, and approximately 120 ⁇ m or less. Furthermore, from the viewpoint of maintaining the function of the laminate film to protect the electricity storage device elements, the thickness of the laminate constituting laminate film 10 is preferably approximately 35 ⁇ m or more, approximately 45 ⁇ m or more, and approximately 60 ⁇ m or more.
• preferred ranges for the laminate constituting the laminate film 10 include, for example, about 35 to 210 ⁇ m, about 35 to 190 ⁇ m, about 35 to 180 ⁇ m, about 35 to 155 ⁇ m, about 35 to 120 ⁇ m, about 45 to 210 ⁇ m, about 45 to 190 ⁇ m, about 45 to 180 ⁇ m, about 45 to 155 ⁇ m, about 45 to 120 ⁇ m, about 60 to 210 ⁇ m, about 60 to 190 ⁇ m, about 60 to 180 ⁇ m, about 60 to 155 ⁇ m, and about 60 to 120 ⁇ m.
• about 60 to 155 ⁇ m is preferred, and when improving formability, about 155 to 190 ⁇ m is preferred.
• the ratio of the total thickness of the barrier layer 1, the polyolefin layer 2, the resin layer 3 provided as necessary, and the adhesive layers 4 and 5 to the thickness (total thickness) of the laminate constituting the laminate film 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
• the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the laminate film 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
• the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the laminate film 10 can be, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
• the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the laminate film 10 can be, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
• the layers constituting the laminate film 10 of the present disclosure are described in detail below.
• the barrier layer 1 is a layer that at least prevents the penetration of moisture.
• the barrier layer 1 may be, for example, a metal foil, a vapor deposition film, or a resin layer having barrier properties.
• the vapor deposition film include a metal vapor deposition film, an inorganic oxide vapor deposition film, and a carbon-containing inorganic oxide vapor deposition film.
• the resin layer include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, and ethylene-vinyl alcohol copolymers.
• the barrier layer 1 may also include a resin film having at least one of these vapor deposition films and resin layers.
• the barrier layer 1 may be provided in multiple layers. It is preferable that the barrier layer 1 includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 1 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, it is preferable that the barrier layer 1 includes at least one of aluminum alloy foil and stainless steel foil.
• the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy, and from the viewpoint of further improving the formability, it is preferably an aluminum alloy foil containing iron.
• the iron content is preferably about 0.1% by mass or more, more preferably about 0.5% by mass or more, even more preferably about 0.7% by mass or more, even more preferably about 0.9% by mass or more, even more preferably about 1.2% by mass or less, and also preferably about 9.0% by mass or less, more preferably about 2.0% by mass or less, even more preferably about 1.7% by mass or less, preferably about 1.3% by mass or less, and the preferred ranges are about 0.1 to 9.0% by mass, about 0.1 to 2.0% by mass, about 0.1 to 1.0% by mass, and about 0.1 to 1.0% by mass. .
• soft aluminum alloy foil examples include aluminum alloy foils having a composition specified in JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Silicon, magnesium, copper, manganese, etc. may also be added as necessary. Softening can be achieved by annealing or other treatments.
• the chemical composition of JIS A8021 is stipulated in the JIS standard (JIS H4160:2006) as follows: Si 0.15% by mass or less, Fe 1.2-1.7% by mass or less, Cu 0.05% by mass or less, other elements other than Al individually 0.05% by mass or less, the total of the other elements being 0.15% by mass or less, and the remainder being Al.
• the Si content in aluminum alloy foil that satisfies the chemical composition of JIS A8021 has usually been at least 0.10% by mass or more, and aluminum alloy foil with a Si content below this has not been used in practice.
• Aluminum alloy foil with a Si content of 0.10% by mass or more has also been used for electricity storage devices.
• aluminum alloy foils that meet the chemical composition of JIS A8021, aluminum alloy foils with an extremely low Si content of 0.08 mass% or less are used as battery packaging materials, which provides particularly excellent formability for laminates of different materials, at least aluminum alloy foil and a polyolefin layer or resin layer.
• the upper limit of the Si content in the aluminum alloy foil is preferably about 0.07% by mass or less, more preferably about 0.06% by mass or less, and the lower limit is, for example, about 0.02% by mass or more, preferably about 0.03% by mass or more, more preferably about 0.05% by mass or more.
• preferred ranges of the Si content in the aluminum alloy foil include about 0.02 to 0.08% by mass, about 0.03 to 0.08% by mass, about 0.05 to 0.08% by mass, about 0.02 to 0.07% by mass, about 0.03 to 0.07% by mass, about 0.05 to 0.07% by mass, about 0.02 to 0.06% by mass, about 0.03 to 0.06% by mass, and about 0.05 to 0.06% by mass.
• the upper limit of the Cu content in the aluminum alloy foil is preferably about 0.05% by mass or less, more preferably about 0.04% by mass or less, and the lower limit is, for example, 0.01% by mass or more, preferably about 0.02% by mass or more, more preferably about 0.03% by mass or more.
• preferred ranges of the Cu content in the aluminum alloy foil include about 0.01 to 0.05% by mass, about 0.01 to 0.04% by mass, about 0.02 to 0.05% by mass, about 0.02 to 0.04% by mass, about 0.03 to 0.05% by mass, and about 0.03 to 0.04% by mass.
• the upper limit of the Fe content in the aluminum alloy foil is preferably about 1.58% by mass or less, more preferably about 1.56% by mass or less, and the lower limit is preferably about 1.44% by mass or more, more preferably about 1.46% by mass or more.
• preferred ranges of the Fe content in the aluminum alloy foil include about 1.44 to 1.58% by mass, about 1.44 to 1.56% by mass, about 1.46 to 1.58% by mass, and about 1.46 to 1.56% by mass.
• the upper limit of the average crystal grain size of the aluminum alloy foil is preferably about 10.0 ⁇ m or less, more preferably 5.0 ⁇ m or less, and even more preferably 3.0 ⁇ m or less
• the lower limit is preferably about 1.0 ⁇ m or more, more preferably about 3.0 ⁇ m or more, and preferred ranges include about 1.0 to 10.0 ⁇ m, about 1.0 to 7.0 ⁇ m, about 1.0 to 5.0 ⁇ m, about 1.0 to 3.0 ⁇ m, about 3.0 to 10.0 ⁇ m, about 3.0 to 7.0 ⁇ m, and about 3.0 to 5.0 ⁇ m.
• the upper limit of the standard deviation of the average crystal grain size of the aluminum alloy foil is preferably about 6 ⁇ m or less, more preferably 5 ⁇ m or less, and even more preferably 4 ⁇ m or less, and the lower limit is preferably about 1 ⁇ m or more, more preferably about 2 ⁇ m or more, with preferred ranges being about 1 to 6 ⁇ m, about 1 to 5 ⁇ m, about 1 to 4 ⁇ m, about 2 to 6 ⁇ m, about 2 to 5 ⁇ m, and about 2 to 4 ⁇ m.
• the standard deviation of the average crystal grain size of the aluminum alloy foil is calculated from the grain size of 100 aluminum alloy crystal grains measured by cross-sectional observation as described below.
• the average crystal grain size in an aluminum alloy foil refers to the average value of the maximum diameters x of 100 aluminum alloy grains located within the field of view of a cross section of the aluminum alloy foil in the thickness direction, where the maximum diameter x is the diameter that maximizes the straight-line distance connecting one point on the periphery of a crystal grain to another point on the periphery of the same crystal grain.
• the average of the diameters y of the top 20 second phase particles in order of the largest straight-line distance connecting one point on the periphery of the second phase particle to another point on the periphery of the same second phase particle is preferably about 5.0 ⁇ m or less, more preferably about 1.0 to 4.0 ⁇ m, and even more preferably about 1.0 to 2.0 ⁇ m.
• the average crystal grain size in the aluminum alloy foil is 10.0 ⁇ m or less and the diameters of the second phase particles are in such a range, the formability of the laminate film 10 can be further improved.
• crystal grains When a cross section of aluminum alloy foil in the thickness direction is observed with a scanning electron microscope (SEM), crystal grains usually have boundaries where multiple crystals meet. In contrast, second-phase particles usually have boundaries that form a single crystal. In addition, because the crystal grains and second-phase particles are in different phases, they tend to have different colors on SEM images, with the second-phase particles often appearing white. Furthermore, when a cross section of aluminum alloy foil in the thickness direction is observed with an optical microscope, only the second-phase particles appear black due to the difference in phase between the crystal grains and second-phase particles, making observation easier.
• SEM scanning electron microscope
• the upper limit of the average area of the particles of the aluminum alloy foil in the cross section in the thickness direction of the laminate constituting the laminate film 10 is preferably about 40 ⁇ m 2 or less, more preferably 30 ⁇ m 2 or less, and even more preferably 25 ⁇ m 2 or less, and the lower limit is preferably about 4 ⁇ m 2 or more, more preferably about 5 ⁇ m 2 or more, and preferred ranges include about 4 to 40 ⁇ m 2 , about 4 to 30 ⁇ m 2 , about 4 to 25 ⁇ m 2 , about 5 to 40 ⁇ m 2 , about 5 to 30 ⁇ m 2 , and about 5 to 25 ⁇ m 2.
• the average area of the particles is measured as follows.
• the average crystal area of the grains is determined by observing a cross section of the aluminum alloy foil using a scanning electron microscope (SEM) EBSD (electron backscatter diffraction method, e.g., DVC5 manufactured by TSL Solutions) under the following conditions: acceleration voltage: 15 kV, working distance: 15 mm, tilt angle: 70 degrees, magnification: 2000 times, and calculating the average crystal area of the grains using the accompanying analysis software.
• SEM scanning electron microscope
• stainless steel foil examples include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. Furthermore, from the viewpoint of providing a laminated film with excellent formability, it is preferable that the stainless steel foil is made of austenitic stainless steel.
• austenitic stainless steels that make up the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.
• the thickness of the barrier layer 1 should at least function as a barrier layer that prevents moisture from penetrating, and may be, for example, about 9 to 200 ⁇ m.
• the thickness of the barrier layer 1 is preferably about 85 ⁇ m or less, more preferably about 50 ⁇ m or less, even more preferably about 40 ⁇ m or less, and particularly preferably about 35 ⁇ m or less.
• the thickness of the barrier layer 1 is preferably about 10 ⁇ m or more, even more preferably about 20 ⁇ m or more, and more preferably about 25 ⁇ m or more.
• the preferred ranges for the thickness of the barrier layer 1 include 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, about 20 to 35 ⁇ m, about 25 to 85 ⁇ m, about 25 to 50 ⁇ m, about 25 to 40 ⁇ m, and about 25 to 35 ⁇ m.
• the barrier layer 1 is made of an aluminum alloy foil, the above-mentioned range is particularly preferred.
• the thickness of the barrier layer 1 is preferably about 35 ⁇ m or more, more preferably about 45 ⁇ m or more, even more preferably about 50 ⁇ m or more, and even more preferably about 55 ⁇ m or more, and is preferably about 200 ⁇ m or less, more preferably about 85 ⁇ m or less, even more preferably about 75 ⁇ m or less, and even more preferably about 70 ⁇ m or less.
• suitable thickness ranges are about 35 to 200 ⁇ m, about 35 to 85 ⁇ m, about 35 to 75 ⁇ m, about 35 to 70 ⁇ m, about 45 to 200 ⁇ m, about 45 to 85 ⁇ m, about 45 to 75 ⁇ m, about 45 to 70 ⁇ m, about 50 to 200 ⁇ m, about 50 to 85 ⁇ m, about 50 to 75 ⁇ m, about 50 to 70 ⁇ m, about 55 to 200 ⁇ m, about 55 to 85 ⁇ m, about 55 to 75 ⁇ m, and about 55 to 70 ⁇ m.
• the high formability of the laminated film 10 facilitates deep drawing, which can contribute to the high capacity of the electric storage device.
• the thickness of the stainless steel foil is preferably about 60 ⁇ m or less, more preferably about 50 ⁇ m or less, even more preferably about 40 ⁇ m or less, even more preferably about 30 ⁇ m or less, and particularly preferably about 25 ⁇ m or less.
• the thickness of the stainless steel foil is preferably about 10 ⁇ m or more, more preferably about 15 ⁇ m or more.
• Preferred ranges for the thickness of the stainless steel foil include about 10 to 60 ⁇ m, about 10 to 50 ⁇ m, about 10 to 40 ⁇ m, about 10 to 30 ⁇ m, about 10 to 25 ⁇ m, about 15 to 60 ⁇ m, about 15 to 50 ⁇ m, about 15 to 40 ⁇ m, about 15 to 30 ⁇ m, and about 15 to 25 ⁇ m.
• the barrier layer 1 when the barrier layer 1 is a metal foil, it is preferable that at least one side of the barrier layer is provided with a corrosion-resistant film to prevent dissolution and corrosion.
• the barrier layer 1 may be provided with a corrosion-resistant film on both sides.
• the corrosion-resistant film refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) by performing, for example, hydrothermal transformation treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment with nickel or chromium, or corrosion prevention treatment by applying a coating agent on the surface of the barrier layer.
• the corrosion-resistant film means a film that improves the acid resistance of the barrier layer (acid-resistant film), a film that improves the alkali resistance of the barrier layer (alkali-resistant film), etc.
• the treatment for forming the corrosion-resistant film may be one type, or two or more types may be combined. In addition to one layer, multiple layers can be formed.
• the hydrothermal transformation treatment and the anodizing treatment are treatments in which the metal foil surface is dissolved by a treatment agent to form a metal compound with excellent corrosion resistance. These treatments may also be included in the definition of chemical conversion treatment. Also, if the barrier layer 1 has a corrosion-resistant coating, the corrosion-resistant coating is included in the barrier layer 1.
• the corrosion-resistant coating prevents delamination between the barrier layer 1 (e.g., aluminum alloy foil) and the polyolefin layer 2 during molding of the laminated film, prevents dissolution and corrosion of the barrier layer 1 surface due to hydrogen fluoride produced by the reaction of the electrolyte with water, and in particular prevents dissolution and corrosion of aluminum oxide present on the barrier layer surface when the barrier layer 1 is an aluminum alloy foil, and improves the adhesion (wettability) of the barrier layer 1 surface, preventing delamination between the polyolefin layer 2 and the barrier layer 1 during heat sealing and between the polyolefin layer 2 and the barrier layer 1 during molding.
• the barrier layer 1 e.g., aluminum alloy foil
• Various corrosion-resistant films formed by chemical conversion treatments are known, including mainly corrosion-resistant films containing at least one of phosphates, chromates, fluorides, triazine thiol compounds, and rare earth oxides.
• Chemical conversion treatments using phosphates and chromates include, for example, chromate chromate treatment, phosphoric acid chromate treatment, phosphoric acid-chromate treatment, and chromate treatment.
• chromium compounds used in these treatments include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromate acetyl acetate, chromium chloride, and potassium chromium sulfate.
• phosphorus compounds used in these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid.
• chromate treatments include etching chromate treatment, electrolytic chromate treatment, and coating-type chromate treatment, with coating-type chromate treatment being preferred.
• a barrier layer e.g., an aluminum alloy foil
• a known method such as an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or an acid activation method, and then a treatment liquid mainly composed of a metal phosphate such as Cr (chromium) phosphate, Ti (titanium) phosphate, Zr (zirconium) phosphate, or Zn (zinc) phosphate, or a mixture of these metal salts, or a treatment liquid mainly composed of a nonmetallic phosphate and a mixture of these nonmetallic salts, or a treatment liquid consisting of a mixture of these with a synthetic resin, or the like, is applied to the degreased surface by a known coating method such as a roll coating method, a gravure printing method, a dipping method, or the like, and then dried.
• a known coating method such as a roll coating method, a gravure printing method, a dipping method, or the like
• the treatment liquid various solvents such as water, alcohol-based solvents, hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, and ether-based solvents can be used, and water is preferred.
• the resin component used here may be a polymer such as a phenolic resin or an acrylic resin, and may be a chromate treatment using an aminated phenolic polymer having a repeating unit represented by the following general formulas (1) to (4).
• the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more.
• the acrylic resin is preferably polyacrylic acid, acrylic acid methacrylic acid ester copolymer, acrylic acid maleic acid copolymer, acrylic acid styrene copolymer, or a derivative thereof such as a sodium salt, an ammonium salt, or an amine salt.
• a derivative of polyacrylic acid such as an ammonium salt, a sodium salt, or an amine salt of polyacrylic acid is preferable.
• polyacrylic acid means a polymer of acrylic acid.
• the acrylic resin is also preferably a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic anhydride, and is also preferably an ammonium salt, a sodium salt, or an amine salt of a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic anhydride. Only one type of acrylic resin may be used, or two or more types may be mixed and used.
• X represents a hydrogen atom, a hydroxy group, an alkyl group, a hydroxyalkyl group, an allyl group, or a benzyl group.
• R 1 and R 2 may be the same or different and represent a hydroxy group, an alkyl group, or a hydroxyalkyl group.
• examples of the alkyl group represented by X, R 1 , and R 2 include linear or branched alkyl groups having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group.
• Examples of the hydroxyalkyl group represented by X, R 1 , and R 2 include linear or branched alkyl groups having 1 to 4 carbon atoms and substituted with one hydroxy group, such as a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, and a 4-hydroxybutyl group.
• the alkyl groups and hydroxyalkyl groups represented by X, R 1 , and R 2 may be the same or different.
• X is preferably a hydrogen atom, a hydroxy group, or a hydroxyalkyl group.
• the number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulae (1) to (4) is preferably about 500 to 1,000,000, and more preferably about 1,000 to 20,000.
• the aminated phenol polymer is produced, for example, by polycondensing a phenol compound or a naphthol compound with formaldehyde to produce a polymer consisting of the repeating units represented by the general formula (1) or (3), and then introducing a functional group (-CH 2 NR 1 R 2 ) into the polymer obtained above using formaldehyde and an amine (R 1 R 2 NH).
• the aminated phenol polymer may be used alone or in combination of two or more kinds.
• the rare earth element oxide contained in the corrosion-resistant film can be used alone or in combination of two or more types.
• liquid dispersion media for the rare earth element oxide sol include various solvents such as water, alcohol-based solvents, hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, and ether-based solvents, and water is preferred.
• the cationic polymer for example, polyethyleneimine, an ionic polymer complex consisting of a polymer having polyethyleneimine and a carboxylic acid, a primary amine grafted acrylic resin in which a primary amine is graft-polymerized to an acrylic main skeleton, polyallylamine or a derivative thereof, aminated phenol, etc. are preferable.
• the anionic polymer poly(meth)acrylic acid or a salt thereof, or a copolymer mainly composed of (meth)acrylic acid or a salt thereof is preferable.
• the crosslinking agent is at least one selected from the group consisting of a compound having any one of the functional groups of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, and a silane coupling agent.
• the phosphoric acid or the phosphoric acid salt is a condensed phosphoric acid or a condensed phosphate salt.
• a corrosion-resistant coating is one formed by applying a solution of fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, or barium sulfate dispersed in phosphoric acid to the surface of the barrier layer and then baking the coating at 150°C or higher.
• metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, or barium sulfate dispersed in phosphoric acid
• the corrosion-resistant coating may have a laminated structure in which at least one of a cationic polymer and an anionic polymer is further laminated.
• a cationic polymer and anionic polymer include those described above.
• composition of the corrosion-resistant coating can be analyzed, for example, using time-of-flight secondary ion mass spectrometry.
• the amount of the corrosion-resistant coating formed on the surface of the barrier layer 1 in the chemical conversion treatment is not particularly limited, but for example, in the case of a paint-type chromate treatment, it is desirable for the chromate compound to be contained in an amount, calculated as chromium, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, per 1 m2 of the surface of the barrier layer 1, of a phosphorus compound, calculated as phosphorus, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and of an aminated phenol polymer, calculated as phosphorus, of about 1.0 to 200 mg, preferably about 5.0 to 150 mg.
• the thickness of the corrosion-resistant film is not particularly limited, but is preferably about 1 nm to 20 ⁇ m, more preferably about 1 nm to 100 nm, and even more preferably about 1 nm to 50 nm, from the viewpoint of the cohesive force of the film and the adhesive force with the barrier layer or the polyolefin layer.
• the thickness of the corrosion-resistant film can be measured by observation with a transmission electron microscope, or a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron energy loss spectroscopy.
• peaks derived from secondary ions composed of Ce, P, and O for example, at least one of Ce 2 PO 4 + and CePO 4 -
• secondary ions composed of Cr, P, and O for example, at least one of CrPO 2 + and CrPO 4 -
• the chemical conversion treatment is carried out by applying a solution containing a compound used to form a corrosion-resistant film to the surface of the barrier layer by bar coating, roll coating, gravure coating, immersion, or other methods, and then heating the barrier layer to a temperature of about 70 to 200°C.
• the barrier layer may be subjected to a degreasing treatment by an alkali immersion method, electrolytic cleaning method, acid cleaning method, electrolytic acid cleaning method, or other method.
• an acid degreasing agent in which a fluorine-containing compound is dissolved in an inorganic acid for the degreasing treatment, it is possible to not only degrease the metal foil but also form a fluoride of the metal, which is in a passive state, and in such cases, only the degreasing treatment may be carried out.
• the polyolefin layer 2 is provided on one side of the barrier layer 1 and constitutes one surface of the laminate film 10.
• the laminate film 10 of the present disclosure can be used, for example, with the polyolefin layer 2 on the outer surface side of the bipolar lithium-ion battery 20.
• the polyolefin layer 2 preferably has thermal adhesion. Since the polyolefin layer 2 has thermal adhesion, the polyolefin layer 2 of the laminate film 10 of the present disclosure can be fixed to the outer surface of the bipolar lithium-ion battery 20 by thermal adhesion.
• the resin constituting the polyolefin layer 2 is not particularly limited, as long as it is a layer containing a polyolefin-based resin.
• the polyolefin-based resin is a resin containing a polyolefin skeleton, such as polyolefin or acid-modified polyolefin.
• the polyolefin layer 2 can be analyzed for its polyolefin skeleton by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like. It is also preferable that a peak derived from maleic anhydride is detected when the resin constituting the polyolefin layer 2 is analyzed by infrared spectroscopy.
• a peak derived from maleic anhydride is detected at a wave number of about 1760 cm -1 and a wave number of about 1780 cm -1 .
• the polyolefin layer 2 is a layer composed of maleic anhydride-modified polyolefin
• a peak derived from maleic anhydride is detected when measured by infrared spectroscopy.
• the degree of acid modification is low, the peak may be small and not detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.
• the polyolefin layer 2 preferably contains a polyolefin resin (a resin containing a polyolefin skeleton) as a main component, more preferably contains a polyolefin as a main component, and even more preferably contains polypropylene or polyethylene as a main component.
• the main component means that the content of the resin components contained in the polyolefin layer 2 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, even more preferably 99% by mass or more.
• the polyolefin layer 2 containing polypropylene as a main component means that the content of polypropylene among the resin components contained in the polyolefin layer 2 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, even more preferably 99% by mass or more.
• polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene- ⁇ -olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene- ⁇ -olefin copolymers; and ethylene-butene-propylene terpolymers.
• polypropylene is preferred.
• the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more types.
• the polyolefin may also be a cyclic polyolefin.
• Cyclic polyolefins are copolymers of olefins and cyclic monomers, and examples of olefins that are constituent monomers of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene.
• Examples of cyclic monomers that are constituent monomers of cyclic polyolefins include cyclic alkenes such as norbornene; and cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, cyclic alkenes are preferred, and norbornene is more preferred.
• the polyolefin may be an acid-modified polyolefin.
• An acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of a polyolefin with an acid component.
• the polyolefin to be acid-modified may be the above-mentioned polyolefin, a copolymer obtained by copolymerizing the above-mentioned polyolefin with a polar molecule such as acrylic acid or methacrylic acid, or a polymer such as a cross-linked polyolefin.
• the acid component used for the acid modification include carboxylic acids or anhydrides such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.
• the acid-modified polyolefin may be an acid-modified cyclic polyolefin.
• An acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by replacing it with an acid component, or by block polymerizing or graft polymerizing an acid component onto a cyclic polyolefin.
• the cyclic polyolefin to be acid-modified is the same as described above.
• the acid component used for the acid modification is the same as the acid component used for the modification of the polyolefin described above.
• Preferred acid-modified polyolefins include polyolefins modified with carboxylic acids or their anhydrides, polypropylenes modified with carboxylic acids or their anhydrides, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.
• the polyolefin layer 2 may be formed of one type of resin alone, or may be formed of a blend polymer of two or more types of resins. Furthermore, the polyolefin layer 2 may be formed of only one layer, or may be formed of two or more layers of the same or different resins.
• a preformed resin film may be used as the polyolefin layer 2.
• the heat-sealable resin that forms the polyolefin layer 2 may be formed into a film on the surface of the barrier layer 1 or the like by extrusion molding, coating, or the like, to form the polyolefin layer 2 from the resin film.
• the melting point of the polyolefin layer is preferably about 120°C or higher, more preferably about 125°C or higher, even more preferably 130°C or higher, and is preferably about 170°C or lower, more preferably about 165°C or lower, even more preferably 160°C or lower, with preferred ranges being about 120 to 170°C and about 130 to 160°C.
• the melting point is the melting peak temperature measured by a differential scanning calorimeter (DSC).
• the polyolefin layer 2 may also contain a lubricant, etc., if necessary. If the polyolefin layer 2 contains a lubricant, the formability of the laminated film can be improved. There are no particular limitations on the lubricant, and any known lubricant can be used.
• the lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of lubricants include those exemplified for the resin layer 3.
• the lubricant may be used alone or in combination of two or more types, and it is preferable to use a combination of two or more types.
• a lubricant is present on at least one of the surface and the inside of the polyolefin layer 2.
• the lubricant is not particularly limited, but preferably includes amide-based lubricants.
• Specific examples of amide-based lubricants include, for example, saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides.
• saturated fatty acid amides include lauric acid amides, palmitic acid amides, stearic acid amides, behenic acid amides, and hydroxystearic acid amides.
• unsaturated fatty acid amides include oleic acid amides and erucic acid amides.
• substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide.
• methylol amides include methylol stearic acid amide.
• saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide, etc.
• unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide, etc.
• fatty acid ester amides include stearamide ethyl stearate, etc.
• aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide.
• the lubricant may be used alone or in combination of two or more types, preferably in combination of two or more types.
• the amount thereof is not particularly limited, but from the viewpoint of improving the formability of the laminated film, it is preferably about 1 mg/m 2 or more, more preferably about 3 mg/m 2 or more, even more preferably about 5 mg/m 2 or more, even more preferably about 10 mg/m 2 or more, even more preferably about 15 mg/m 2 or more, and also preferably about 50 mg/m 2 or less, even more preferably about 40 mg/m 2 or less, and preferred ranges include about 1 to 50 mg/m 2 , about 1 to 40 mg/m 2 , about 3 to 50 mg/m 2 , about 3 to 40 mg/m 2 , about 5 to 50 mg/m 2 , about 5 to 40 mg/m 2 , about 10 to 50 mg/m 2 , about 10 to 40 mg/m 2 , about 15 to 50 mg/m 2 , and about 15 to 40 mg/m 2 .
• the amount present is not particularly limited, but from the viewpoint of improving the formability of the laminated film, it is preferably at least about 100 ppm, more preferably at least about 300 ppm, even more preferably at least about 500 ppm, and is preferably not more than about 3000 ppm, more preferably not more than about 2000 ppm, and preferred ranges include about 100 to 3000 ppm, about 100 to 2000 ppm, about 300 to 3000 ppm, about 300 to 2000 ppm, about 500 to 3000 ppm, and about 500 to 2000 ppm.
• the above amount of lubricant is the total amount of lubricant.
• the amount of the first type of lubricant is not particularly limited, but from the viewpoint of improving the formability of the laminated film, it is preferably about 100 ppm or more, more preferably about 300 ppm or more, even more preferably about 500 ppm or more, and is preferably about 3000 ppm or less, more preferably about 2000 ppm or less.
• the lubricant present on the surface of the polyolefin layer 2 may be a lubricant exuded from the resin that constitutes the polyolefin layer 2, or a lubricant applied to the surface of the polyolefin layer 2.
• the thickness of the polyolefin layer 2 is preferably about 15 ⁇ m or more, more preferably 30 ⁇ m or more, even more preferably 50 ⁇ m or more, even more preferably 60 ⁇ m or more, and is preferably about 150 ⁇ m or less, more preferably 120 ⁇ m or less, even more preferably 100 ⁇ m or less, with a preferred range being about 60 to 100 ⁇ m.
• the resin layer 3 is a layer that is provided as necessary on the side of the barrier layer 1 opposite to the polyolefin layer 2.
• the laminate film 10 of the present disclosure can be used, for example, with the resin layer 3 on the outer surface side of the bipolar lithium ion battery 20.
• the resin layer 3 of the laminate film 10 of the present disclosure can be fixed to the outer surface of the bipolar lithium ion battery 20 by thermal fusion.
• the resin layer 3 can be formed using a resin, which may contain additives as described below.
• the resin layer 3 can be formed, for example, from a resin film.
• a preformed resin film may be used as the resin layer 3 when the resin layer 3 is laminated with the barrier layer 1 or the like to manufacture the laminate film 10 of the present disclosure.
• the resin forming the resin layer 3 may be formed into a film on the surface of the barrier layer 1 or the like by extrusion molding or coating, and the resin layer 3 formed from the resin film may be used.
• the resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, and biaxially stretched films are preferred. Examples of stretching methods for forming a biaxially stretched film include sequential biaxial stretching, inflation, and simultaneous biaxial stretching. Examples of methods for applying the resin include roll coating, gravure coating, and extrusion coating.
• the resin that forms the resin layer 3 examples include resins such as polyester, polyamide, polyolefin resin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenol resin, as well as modified versions of these resins.
• the resin that forms the resin layer 3 may also be a copolymer of these resins, or a modified version of the copolymer. It may also be a mixture of these resins.
• the resin layer 3 containing polyolefin resin, polyester, or polyamide as the main component means that the content of polyolefin resin, polyester, or polyamide among the resin components contained in the resin layer 3 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.
• the resin that forms the resin layer 3 is a polyolefin resin, polyester, or polyamide.
• the resin layer 3 contains a polyolefin-based resin
• the resin layer 3 can be a layer similar to the polyolefin layer 2 described above.
• the resin layer 3 there are no particular limitations on the resin layer 3, as long as it is a layer containing a polyolefin-based resin.
• the polyolefin-based resin is a resin containing a polyolefin skeleton, such as the polyolefin or acid-modified polyolefin described above.
• polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters.
• copolymer polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit.
• polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate/isophthalate)), polyethylene (terephthalate/adipate), polyethylene (terephthalate/sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate), and polyethylene (terephthalate/decanedicarboxylate).
• polyethylene (terephthalate/isophthalate) polyethylene (terephthalate/adipate)
• polyethylene terephthalate/sodium sulfoisophthalate
• polyethylene terephthalate/sodium isophthalate
• polyethylene (terephthalate/phenyl-dicarboxylate) polyethylene (terephthalate/decanedicarboxylate).
• These polyesters may be used alone or in combination of two or
• polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) which contain structural units derived from terephthalic acid and/or isophthalic acid, and aromatic polyamides such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); polyamides copolymerized with lactam components or isocyanate components such as 4,4'-diphenylmethane diisocyanate; polyesteramide copolymers and polyetheresteramide copolymers which are copolymer,
• the resin layer 3 preferably includes at least one of a polyolefin film, a polyester film, a polyamide film, and a polyolefin film, preferably includes at least one of an unstretched polyolefin film, a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, more preferably includes at least one of an unstretched polyolefin film, a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film, and even more preferably includes at least one of an unstretched polyolefin film, a biaxially stretched polyethylene terephthalate film, a biaxially stretched polybutylene terephthalate film, a biaxially stretched nylon film, and a biaxially stretched polypropylene film.
• the resin layer 3 may be a single layer, or may be composed of two or more layers.
• the resin layer 3 may be a laminate in which resin films are laminated with an adhesive or the like, or a laminate of resin films in which resins are co-extruded into two or more layers.
• a laminate of resin films in which resins are co-extruded into two or more layers may be used as the resin layer 3 without being stretched, or may be uniaxially or biaxially stretched to form the resin layer 3.
• the resin layer 3 that is a laminate of two or more resin films include a laminate of a polyester film and a nylon film, a laminate of two or more nylon films, and a laminate of two or more polyester films.
• the laminate is a laminate of a stretched nylon film and a stretched polyester film, a laminate of two or more stretched nylon films, or a laminate of two or more stretched polyester films.
• the resin layer 3 is a laminate of two resin films, a laminate of a polyester resin film and a polyester resin film, a laminate of a polyamide resin film and a polyamide resin film, or a laminate of a polyester resin film and a polyamide resin film is preferred, and a laminate of a polyethylene terephthalate film and a polyethylene terephthalate film, a laminate of a nylon film and a nylon film, or a laminate of a polyethylene terephthalate film and a nylon film is more preferred.
• the polyester resin film is located as the outermost layer of the resin layer 3, because the polyester resin is less likely to discolor when, for example, an electrolyte is attached to the surface.
• the two or more layers of resin films may be laminated via an adhesive.
• Preferred adhesives include those similar to those exemplified for adhesive layers 4 and 5 described later.
• the method for laminating two or more layers of resin films is not particularly limited, and known methods can be used, such as dry lamination, sandwich lamination, extrusion lamination, and thermal lamination, and preferably dry lamination.
• a polyurethane adhesive as the adhesive.
• the thickness of the adhesive is, for example, about 2 to 5 ⁇ m.
• an anchor coat layer may be formed on the resin film and laminated.
• the anchor coat layer may be the same as those exemplified for adhesive layers 4 and 5 described later. In this case, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 ⁇ m.
• Additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be present on at least one of the surface and interior of the resin layer 3. Only one type of additive may be used, or two or more types may be mixed together.
• a lubricant is present on at least one of the surface and the inside of the resin layer 3.
• the lubricant is not particularly limited, but preferably includes amide-based lubricants.
• Specific examples of amide-based lubricants include, for example, saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides.
• saturated fatty acid amides include lauric acid amides, palmitic acid amides, stearic acid amides, behenic acid amides, and hydroxystearic acid amides.
• unsaturated fatty acid amides include oleic acid amides and erucic acid amides.
• substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide.
• methylol amides include methylol stearic acid amide.
• saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide, etc.
• unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide, etc.
• fatty acid ester amides include stearamide ethyl stearate, etc.
• aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide.
• the lubricant may be used alone or in combination of two or more types, preferably in combination of two or more types.
• the preferred range of the amount of the lubricant present on the surface of the resin layer 3 is about 3 to 15 mg/m2, about 3 to 14 mg/ m2 , about 3 to 10 mg/ m2 , about 4 to 15 mg/ m2 , about 4 to 14 mg/ m2 , about 4 to 10 mg/ m2 , about 5 to 15 mg/ m2 , about 5 to 14 mg/ m2 , or about 5 to 10 mg/ m2 .
• the thickness of the resin layer 3 is preferably about 15 ⁇ m or more, more preferably 30 ⁇ m or more, even more preferably 50 ⁇ m or more, and even more preferably 60 ⁇ m or more, and is preferably about 150 ⁇ m or less, more preferably 120 ⁇ m or less, and even more preferably 100 ⁇ m or less.
• Preferred ranges include about 15 to 150 ⁇ m, about 15 to 120 ⁇ m, about 15 to 100 ⁇ m, about 30 to 150 ⁇ m, about 30 to 120 ⁇ m, about 30 to 100 ⁇ m, about 50 to 150 ⁇ m, about 50 to 120 ⁇ m, about 50 to 100 ⁇ m, about 60 to 150 ⁇ m, about 60 to 120 ⁇ m, and about 60 to 100 ⁇ m.
• the adhesive layer 4 is a layer that is provided, as necessary, between the barrier layer 1 and the polyolefin layer 2 for the purpose of increasing the adhesion between them. Also, the adhesive layer 4 is a layer that is provided, as necessary, between the barrier layer 1 and the resin layer 3 for the purpose of increasing the adhesion between them.
• the adhesive layers 4 and 5 are formed from an adhesive capable of bonding the barrier layer 1 and the polyolefin layer 2, or the barrier layer 1 and the resin layer 3, respectively.
• the adhesive used to form the adhesive layers 4 and 5 may be any of a chemical reaction type, a solvent volatilization type, a hot melt type, a hot pressure type, etc. It may also be a two-component curing adhesive (two-component adhesive), a one-component curing adhesive (one-component adhesive), or a resin that does not involve a curing reaction.
• the adhesive layers 4 and 5 may be a single layer or multiple layers.
• adhesive components may be used alone or in combination of two or more.
• polyurethane adhesives are preferred.
• the adhesive strength of these adhesive component resins can be increased by using an appropriate curing agent in combination.
• the curing agent is selected from polyisocyanates, polyfunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, etc., depending on the functional groups of the adhesive components.
• the polyurethane adhesive may be, for example, a polyurethane adhesive containing a first agent containing a polyol compound and a second agent containing an isocyanate compound.
• a two-part curing polyurethane adhesive may preferably be used, in which a polyol such as polyester polyol, polyether polyol, or acrylic polyol is used as the first agent, and an aromatic or aliphatic polyisocyanate is used as the second agent.
• the polyurethane adhesive may be, for example, a polyurethane adhesive containing a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance, and an isocyanate compound.
• the polyurethane adhesive may be, for example, a polyurethane adhesive containing a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance, and a polyol compound.
• the polyurethane adhesive may be, for example, a polyurethane adhesive in which a polyurethane compound in which a polyol compound has been reacted with an isocyanate compound in advance is cured by reacting it with moisture in the air or the like.
• the polyol compound it is preferable to use a polyester polyol having a hydroxyl group on the side chain in addition to the hydroxyl group at the end of the repeating unit.
• the second agent may be an aliphatic, alicyclic, aromatic, or araliphatic isocyanate compound.
• isocyanate compound examples include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI).
• polyisocyanate compound examples include polyfunctional isocyanate modified compounds of one or more of these diisocyanates.
• a polymer e.g., a trimer
• examples of such polymers include adducts, biurets, and nurates.
• the adhesive layers 4 and 5 are made of polyurethane adhesive, which gives the laminated film excellent electrolyte resistance, and prevents the polyolefin layer 2 or resin layer 3 from peeling off from the barrier layer 1 even if electrolyte adheres to the side surface.
• the adhesive layers 4 and 5 may each contain other components, such as colorants, thermoplastic elastomers, tackifiers, and fillers, as long as they do not impair adhesion.
• colorants such as pigments and dyes can be used as colorants.
• only one type of colorant may be used, or two or more types may be mixed together.
• pigments there are no particular limitations on the type of pigment, so long as it does not impair the adhesive properties of the adhesive layers 4 and 5.
• organic pigments include azo, phthalocyanine, quinacridone, anthraquinone, dioxazine, indigothioindigo, perinone-perylene, isoindolenine, and benzimidazolone pigments
• inorganic pigments include carbon black, titanium oxide, cadmium, lead, chromium oxide, and iron pigments, as well as finely powdered mica and fish scale foil.
• carbon black is preferred, for example to give the laminated film a black appearance.
• the average particle size of the pigment is not particularly limited, and may be, for example, about 0.05 to 5 ⁇ m, and preferably about 0.08 to 2 ⁇ m.
• the average particle size of the pigment is the median size measured with a laser diffraction/scattering type particle size distribution measuring device.
• the pigment content in the adhesive layers 4 and 5 is not particularly limited as long as the laminated film is colored, and may be, for example, about 5 to 60% by weight, and preferably 10 to 40% by weight.
• the thickness of the adhesive layers 4 and 5 is not particularly limited as long as it can bond the barrier layer 1 and the polyolefin layer 2, or the barrier layer 1 and the resin layer 3, respectively, but is, for example, about 1 ⁇ m or more, about 2 ⁇ m or more.
• the thickness of the adhesive layers 4 and 5 is, for example, about 10 ⁇ m or less, about 5 ⁇ m or less. Preferred ranges for the thickness of the adhesive layers 4 and 5 include about 1 to 10 ⁇ m, about 1 to 5 ⁇ m, about 2 to 10 ⁇ m, and about 2 to 5 ⁇ m.
• the colored layer is a layer (not shown) that is provided between the barrier layer 1 and the adhesive layers 4, 5 as necessary.
• a colored layer may be provided between the polyolefin layer 2 and the adhesive layer 4, between the adhesive layer 4 and the barrier layer 1, between the barrier layer 1 and the adhesive layer 5, and between the adhesive layer 5 and the resin layer 3.
• a colored layer may also be provided on the outside of the resin layer 3.
• the colored layer can be formed, for example, by applying an ink containing a colorant to the surface of the polyolefin layer 2, the surface of the barrier layer 1, the surface of the resin layer 3, etc.
• a colorant such as pigments and dyes can be used as the colorant.
• only one type of colorant may be used, or two or more types may be mixed together.
• colorants contained in the colored layer include those exemplified in the section [Adhesive layers 4, 5].
• the laminated film of the present disclosure can be suitably used for applications in which it is disposed on the outer surface of a bipolar lithium ion battery.
• the lithium ion battery may be an all-solid-state battery, a semi-solid battery, or a clay battery.
• the bipolar lithium-ion battery 20 of the present disclosure is a bipolar lithium-ion battery 20 that utilizes the laminated film 10 of the present disclosure. That is, in the bipolar lithium-ion battery 20 of the present disclosure, the laminated film 10 of the present disclosure described above is disposed on a portion of the outer surface of the bipolar lithium-ion battery 20. The laminated film 10 of the present disclosure is disposed so as to straddle the ridge portion 20c from the main surface 20a to the side surface 20b of the outer surface of the bipolar lithium-ion battery 20.
• Figs. 5 to 9 show the laminated film 10 of the present disclosure disposed in a bipolar lithium-ion battery 20.
• the bipolar lithium-ion battery 20 shown in Figs. 5 to 9 has a rectangular parallelepiped outer shape and includes two opposing main surfaces 20a, four side surfaces 20b, and a ridge portion 20c located at the boundary between the main surfaces 20a and the side surfaces 20b.
• An end collector 21 i.e., an electrode
• Components included in a bipolar lithium-ion battery such as a collector 22, a positive electrode layer 23, a negative electrode layer 24, and an electrolyte 25, are disposed between the end collectors 21, and the battery functions as a bipolar lithium-ion battery.
• the external shape of the bipolar lithium-ion battery 20 is not particularly limited, and examples include a rectangular parallelepiped shape (i.e., the main surface is rectangular when viewed from above), a cylindrical shape (i.e., the main surface is circular when viewed from above), etc.
• the laminated film 10 is preferably heat-sealed to the outer surface of the bipolar lithium-ion battery 20.
• an adhesive film may be interposed between the laminated film 10 and the outer surface of the bipolar lithium-ion battery 20 for heat sealing.
• the adhesive film used may be, for example, a single layer film of acid-modified polyolefin, or a laminate of acid-modified polyolefin and polyolefin.
• FIG. 10 is a schematic cross-sectional view showing an example of an embodiment in which the laminated film 10 of the present disclosure is applied to the outer surface of a bipolar lithium-ion battery 20.
• FIG. 10 corresponds to the cross-sectional view of FIG. 7, and in FIG. 10, the spaces between the end collectors 21 and 22, and even between the collectors 22 themselves, are filled with a sealing member 26 to form side surface 20b, and the entire surface of side surface 20b is covered with laminated film 10.
• FIG. 7 is a perspective view of the bipolar lithium-ion battery 20 seen from above, so the bottom side is not shown, but the outer periphery of the end collector 21 on the bottom side is also covered with laminated film 10.
• Example 1 An aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 40 ⁇ m)) was prepared as the barrier layer. Two sheets of unstretched polypropylene film (CPP, thickness 70 ⁇ m, melting point 163° C.) were prepared as the polyolefin layer and the resin layer.
• CPP unstretched polypropylene film
• a two-liquid urethane adhesive (polyol compound and aromatic isocyanate compound) was used to laminate a polyolefin layer on both sides of the barrier layer, and aging treatment was performed to produce a laminated film for bipolar lithium ion batteries in which a polyolefin layer (CPP 70 ⁇ m)/adhesive layer (1.5 ⁇ m)/barrier layer (aluminum alloy foil 40 ⁇ m)/adhesive layer (1.5 ⁇ m)/resin layer (polyolefin layer CPP 70 ⁇ m) were laminated in this order.
• Example 2 A laminate film for bipolar lithium ion batteries was produced in the same manner as in Example 1, except that two sheets of unstretched polypropylene films (CPP, thickness 80 ⁇ m, melting point 163° C.) were used as the polyolefin layer and the resin layer, in which a polyolefin layer (CPP, 80 ⁇ m)/adhesive layer (1.5 ⁇ m)/barrier layer (aluminum alloy foil, 40 ⁇ m)/adhesive layer (1.5 ⁇ m)/resin layer (polyolefin layer, CPP, 80 ⁇ m) were laminated in this order.
• CPP unstretched polypropylene films
• Example 3 A laminate film for bipolar lithium ion batteries was produced in the same manner as in Example 1, except that two sheets of unstretched polypropylene films (CPP, thickness 100 ⁇ m, melting point 163° C.) were used as the polyolefin layer and the resin layer, in which a polyolefin layer (CPP, 100 ⁇ m)/adhesive layer (1.5 ⁇ m)/barrier layer (aluminum alloy foil, 40 ⁇ m)/adhesive layer (1.5 ⁇ m)/resin layer (polyolefin layer, CPP, 100 ⁇ m) were laminated in this order.
• CPP unstretched polypropylene films
• Example 4 An aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 40 ⁇ m)) was prepared as a barrier layer. A polyolefin layer and a resin layer were laminated on both sides of the barrier layer by melt extruding maleic anhydride modified polypropylene (melting point 160° C.), thereby producing a laminated film for bipolar lithium ion batteries in which a polyolefin layer (PPa 70 ⁇ m)/barrier layer (aluminum alloy foil 40 ⁇ m)/resin layer (polyolefin layer PPa 70 ⁇ m) were laminated in this order.
• a polyolefin layer PPa 70 ⁇ m
• barrier layer aluminum alloy foil 40 ⁇ m
• resin layer polyolefin layer PPa 70 ⁇ m
• Example 5 A laminate film for a bipolar lithium ion battery was produced in the same manner as in Example 1, except that two sheets of low-density polyethylene films (LDPE, thickness 70 ⁇ m) were used as the polyolefin layer and the resin layer, in which a polyolefin layer (LDPE, thickness 70 ⁇ m, melting point 130° C.)/adhesive layer (1.5 ⁇ m)/barrier layer (aluminum alloy foil, 40 ⁇ m)/adhesive layer (1.5 ⁇ m)/resin layer (polyolefin layer, LDPE, thickness 70 ⁇ m) were laminated in this order.
• LDPE low-density polyethylene films
• Example 6 A laminate film for bipolar lithium ion batteries was produced in the same manner as in Example 1, except that two high-density polyethylene films (HDPE, thickness 70 ⁇ m) were used as the polyolefin layer and the resin layer, in which a polyolefin layer (HDPE, thickness 70 ⁇ m, melting point 130° C.)/adhesive layer (1.5 ⁇ m)/barrier layer (aluminum alloy foil, 40 ⁇ m)/adhesive layer (1.5 ⁇ m)/resin layer (polyolefin layer, HDPE, thickness 70 ⁇ m) were laminated in this order.
• a polyolefin layer HDPE, thickness 70 ⁇ m, melting point 130° C.
• adhesive layer 1.5 ⁇ m
• resin layer polyolefin layer, HDPE, thickness 70 ⁇ m
• Example 7 An aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 60 ⁇ m)) was prepared as the barrier layer. Maleic anhydride modified polypropylene (melting point 160° C.) and polypropylene (melting point 140° C.) were prepared as resins for forming the polyolefin layer. As the resin layer, a film was prepared in which a polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and an oriented nylon (ONy) film (thickness 25 ⁇ m) were bonded with an adhesive (two-component urethane adhesive (polyol compound and aromatic isocyanate compound, thickness after curing is 3 ⁇ m).
• PET polyethylene terephthalate
• ONy oriented nylon
• Maleic anhydride-modified polypropylene and polypropylene were melt-extruded onto one side of the barrier layer to form a maleic anhydride-modified polypropylene layer (thickness 40 ⁇ m) and a polypropylene layer (thickness 40 ⁇ m) as polyolefin layers.
• the stretched nylon film side of the resin layer was bonded to one side of the barrier layer with an adhesive (two-component urethane adhesive (polyol compound and aromatic isocyanate compound, thickness after curing is 3 ⁇ m)) and aging treatment was performed to form a polyolefin layer (PP 40 ⁇ m/PPa 40 ⁇ m)/barrier layer (aluminum alloy foil).
• a laminated film for bipolar lithium ion batteries was produced in which a laminated film for bipolar lithium ion batteries was produced in which a laminated film (thickness 60 ⁇ m)/adhesive layer (3 ⁇ m)/resin layer (oriented nylon (ONy) film (thickness 25 ⁇ m)/adhesive (3 ⁇ m)/polyethylene terephthalate (PET) film (thickness 12 ⁇ m)) was laminated in this order.
• Example 8 A laminated film for bipolar lithium ion batteries was produced in the same manner as in Example 7, except that a film in which a polyethylene terephthalate (PET) film (thickness 25 ⁇ m) and a stretched nylon (ONy) film (thickness 25 ⁇ m) were bonded with an adhesive (two-component urethane adhesive (polyol compound and aromatic isocyanate compound, thickness after curing is 3 ⁇ m)) was used as the resin layer.
• PET polyethylene terephthalate
• ONy stretched nylon
• the laminated film was a polyolefin layer (PP 40 ⁇ m/PPa 40 ⁇ m)/barrier layer (aluminum alloy foil 60 ⁇ m)/adhesive layer (3 ⁇ m)/resin layer (stretched nylon (ONy) film (thickness 25 ⁇ m)/adhesive (3 ⁇ m)/polyethylene terephthalate (PET) film (thickness 25 ⁇ m)).
• Example 9 A laminated film for bipolar lithium ion batteries was produced in the same manner as in Example 8, except that an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 80 ⁇ m)) was used as the barrier layer, in which a polyolefin layer (PP 40 ⁇ m/PPa 40 ⁇ m)/barrier layer (aluminum alloy foil 80 ⁇ m)/adhesive layer (3 ⁇ m)/resin layer (oriented nylon (ONy) film (thickness 25 ⁇ m)/adhesive (3 ⁇ m)/polyethylene terephthalate (PET) film (thickness 25 ⁇ m)) was laminated in this order.
• a polyolefin layer PP 40 ⁇ m/PPa 40 ⁇ m
• barrier layer aluminum alloy foil 80 ⁇ m
• adhesive layer 3 ⁇ m
• resin layer oriented nylon (ONy) film (thickness 25 ⁇ m)/
• Example 10 A laminated film for bipolar lithium ion batteries was produced in the same manner as in Example 8, except that an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 60 ⁇ m)) having a Si content of 0.8 mass% or less was used as the barrier layer, in which a polyolefin layer (PP 40 ⁇ m/PPa 40 ⁇ m)/barrier layer (aluminum alloy foil 60 ⁇ m)/adhesive layer (3 ⁇ m)/resin layer (oriented nylon (ONy) film (thickness 25 ⁇ m)/adhesive (3 ⁇ m)/polyethylene terephthalate (PET) film (thickness 25 ⁇ m)) was laminated in this order.
• a polyolefin layer PP 40 ⁇ m/PPa 40 ⁇ m
• barrier layer aluminum alloy foil 60 ⁇ m
• adhesive layer 3 ⁇ m
• resin layer oriented nylon (ONy
• Example 11 A laminated film for bipolar lithium ion batteries was produced in the same manner as in Example 10, except that an unstretched polypropylene film (CPP, thickness 80 ⁇ m, melting point 163° C.) was used as the polyolefin layer, and an olefin-based adhesive (acid-modified polypropylene and epoxy compound, thickness after curing 3 ⁇ m) was used as the adhesive layer, in which a polyolefin layer (CPP 80 ⁇ m)/adhesive layer (3 ⁇ m)/barrier layer (aluminum alloy foil 60 ⁇ m)/adhesive layer (3 ⁇ m)/resin layer (oriented nylon (ONy) film (thickness 25 ⁇ m)/adhesive (3 ⁇ m)/polyethylene terephthalate (PET) film (thickness 25 ⁇ m)) was laminated in this order.
• CPP 80 ⁇ m unstretched polypropylene film
• Example 12 A laminated film for bipolar lithium ion batteries was produced in the same manner as in Example 1, except that an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 60 ⁇ m)) having a Si content of 0.8 mass % or less was used as the barrier layer, in which a polyolefin layer (PP 40 ⁇ m/PPa 40 ⁇ m)/barrier layer (aluminum alloy foil 60 ⁇ m)/adhesive layer (3 ⁇ m)/resin layer (oriented nylon (ONy) film (thickness 25 ⁇ m)/adhesive (3 ⁇ m)/polyethylene terephthalate (PET) film (thickness 12 ⁇ m)) was laminated in this order.
• a polyolefin layer PP 40 ⁇ m/PPa 40 ⁇ m
• barrier layer aluminum alloy foil 60 ⁇ m
• adhesive layer 3 ⁇ m
• resin layer oriented nylon (ON
• Example 13 A laminated film for bipolar lithium ion batteries was produced in the same manner as in Example 11, except that a film in which a polyethylene terephthalate (PET) film (thickness 12 ⁇ m) and a stretched nylon (ONy) film (thickness 25 ⁇ m) were bonded with an adhesive (two-component urethane adhesive (polyol compound and aromatic isocyanate compound, thickness after curing is 3 ⁇ m)) was used as the resin layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 60 ⁇ m)) having a Si content of 0.8 mass% or less was used as the barrier layer.
• PET polyethylene terephthalate
• ONy stretched nylon
• the laminated film was produced in the same manner as in Example 11, except that a polyolefin layer (CPP 80 ⁇ m)/adhesive layer (3 ⁇ m)/barrier layer (aluminum alloy foil 60 ⁇ m)/adhesive layer (3 ⁇ m)/resin layer (stretched nylon (ONy) film (thickness 25 ⁇ m)/adhesive (3 ⁇ m)/polyethylene terephthalate (PET) film (thickness 12 ⁇ m)) was laminated in this order.
• the glass bottle was sealed and stored in an oven at 85 ° C. for 24 hours.
• the bipolar lithium ion battery laminate film was taken out of the glass bottle, washed with water, wiped off, and a measurement sample was prepared by peeling between the aluminum alloy foil and the polyolefin layer at the end of each bipolar lithium ion battery laminate film.
• the aluminum alloy foil and the polyolefin layer were peeled off at 180 degrees, a tensile tester (manufactured by Shimadzu Corporation, AG-Xplus (trade name)) was used under conditions of 25°C, 50% RH atmosphere, 180° peeling, a tensile speed of 50 mm/min, and a gauge length of 50 mm, and the laminate strength (peel strength (N/15 mm)) was measured.
• the measurement conditions were 25°C, 50% RH atmosphere, 180° peeling, and a tensile speed of 50 mm/min.
• Each bipolar lithium-ion battery laminate film was cut into a rectangle with a length (MD) of 90 mm and a width (TD) of 150 mm to prepare a test sample.
• the MD of the bipolar lithium-ion battery laminate film corresponds to the rolling direction (RD) of the aluminum alloy foil
• the TD of the bipolar lithium-ion battery laminate film corresponds to the TD of the aluminum alloy foil.
• the maximum height roughness (nominal value of Rz) specified in Table 2 of the comparative surface roughness standard piece is 3.2 ⁇ m.
• the forming depth was changed in 0.5 mm increments from a forming depth of 0.5 mm at a pressing pressure (surface pressure) of 0.25 MPa, and cold forming (one-stage drawing) was performed on 10 samples each.
• the test sample was placed on the female mold so that the polyolefin layer side was located on the male mold side, and molding was performed.
• the clearance between the male mold and the female mold was 0.3 mm.
• the sample after cold forming was irradiated with light from a penlight in a dark room to confirm whether pinholes or cracks were generated in the aluminum alloy foil due to the transmission of light.
• the deepest forming depth at which no pinholes or cracks occurred in the aluminum alloy foil in any of the 10 samples was designated as A mm, and the number of samples at which pinholes or the like occurred in the aluminum alloy foil at the shallowest forming depth was designated as B.
• the value calculated by the following formula was rounded off to one decimal place to determine the limit forming depth of the laminated film.
• the evaluation criteria for limit formability are as follows. The results are shown in Table 1.
• the laminate films for bipolar lithium-ion batteries produced in Examples 1 to 13 have excellent electrolyte resistance and formability, and are suitable as laminate films to be placed on part of the outer surface of a bipolar lithium-ion battery.
• Item 1 A laminated film disposed on a portion of the outer surface of a bipolar lithium ion battery, The laminated film includes at least a barrier layer, a polyolefin layer provided on one side of the barrier layer, and It is equipped with The polyolefin layer constitutes one surface of the laminate film, The laminated film is arranged so as to straddle a ridge line portion from a main surface to a side surface of an outer surface of the bipolar lithium ion battery.
• Item 2 The laminate film for a bipolar lithium ion battery according to Item 1, wherein the polyolefin layer contains polypropylene.
• Item 4. The laminate film for bipolar lithium ion batteries according to any one of Items 1 to 3, wherein the polyolefin layer is formed of two or more layers of the same or different resins.
• Item 5. The laminate film for bipolar lithium ion batteries according to any one of Items 1 to 4, wherein the melting point of the polyolefin layer is 120° C. or higher and 165° C. or lower.
• Item 8 The laminate film for bipolar lithium ion batteries according to Item 7, wherein the aluminum alloy foil has an iron content of 0.1 mass % or more and 9.0 mass % or less.
• Item 9. The laminate film for bipolar lithium ion batteries according to any one of Items 1 to 8, wherein the barrier layer has a thickness of 35 ⁇ m or more.
• Item 10 The laminate film for bipolar lithium ion batteries according to any one of Items 1 to 9, further comprising an adhesive layer between the barrier layer and the polyolefin layer. Item 11.
• the laminate film for bipolar lithium ion batteries according to Item 10 wherein the adhesive layer is formed of an adhesive containing polyolefin.
• Item 12 The laminate film for bipolar lithium ion batteries according to any one of Items 1 to 11, wherein a plurality of the laminate films are disposed on a portion of an outer surface of the bipolar lithium ion battery.
• Item 13 The laminate film for bipolar lithium ion batteries according to any one of Items 1 to 12, further comprising at least one resin layer on the opposite side of the barrier layer from the polyolefin layer.
• Adhesive layer 10 Laminated film for bipolar lithium ion battery 10a Laminated film for bipolar lithium ion battery 10b Laminated film for bipolar lithium ion battery 10c Laminated film for bipolar lithium ion battery 10d Laminated film for bipolar lithium ion battery 20 Bipolar lithium ion battery 20a Main surface 20b Side surface 20c Ridge line portion 21 End collector 22 Collector 23 Positive electrode layer 24 Negative electrode layer 25 Electrolyte 26 Sealing member

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