Laminating film for laminated battery and laminated battery

Abstract

To provide a novel laminating film, and a battery including such a laminating film.SOLUTION: A laminating film 10 for a laminated battery of the present disclosure includes a fusion resin layer 11, an aluminum layer 12 and an anodized aluminum layer 13, in this order. A laminated battery 1 of the present disclosure includes an electrode laminate 20 and the laminating film 10 of the present disclosure sealing the electrode laminate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a laminate film for a laminate battery and a laminate battery.

Background Art

[0002] A laminate battery (also called a pouch battery) including an electrode laminate and a laminate film that houses the electrode laminate is known.

[0003] For example, Patent Document 1 discloses a laminate battery including an electrode body (electrode laminate) and a laminate case (laminate film) that houses the electrode body, the laminate case having a multilayer structure including a sealant layer (fusion resin layer), an aluminum layer, and an outer layer (protective resin layer).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present disclosure is to provide a novel laminate film and a battery having such a laminate film.

Means for Solving the Problems

[0006] The present inventors have found that the above problems can be solved by the following means. <Aspect 1> A fusion resin layer, an aluminum layer, and an anodized aluminum layer A laminate film for a laminate battery having these in this order. <Aspect 2> The laminate film according to Embodiment 1, wherein the thermal conductivity of the anodized aluminum layer is 1 W / (m·K) or more. <Aspect 3> The electrode laminate, and The laminate film according to Embodiment 1 or 2 that seals the electrode laminate A laminate battery having the same. [Effect of the Invention]

[0007] According to the present disclosure, a novel laminate film and a laminate battery having such a laminate film can be provided. [Brief Description of the Drawings]

[0008]

Figure 1

Figure 2

Figure 3

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the following embodiments and can be variously modified and implemented within the scope of the gist of the disclosure. Also, the dimensional relationships in the drawings do not reflect actual dimensional relationships.

[0010] [Laminate Film for Laminate Battery] FIG. 1 is a schematic cross-sectional view showing an example of the laminate film of the present disclosure. As illustrated in FIG. 1, the laminate film 10 for a laminate battery of the present disclosure has a heat-sealing resin layer 11, an aluminum layer 12, and an anodized aluminum layer 13 in this order.

[0011] The laminate film 10 of the present disclosure may have an anodized aluminum layer 13 on both sides of the aluminum layer 12. In this case, the laminate film 10 may have a fusion resin layer 11, an anodized aluminum layer 13, an aluminum layer 12, and an anodized aluminum layer 13 in this order.

[0012] FIG. 3 is a schematic cross-sectional view showing an example of a laminate film according to the prior art. As shown in FIG. 3, the laminate film according to the prior art has a fusion resin layer 11, an aluminum layer 12, and a protective resin layer 14.

[0013] The laminate film of the present disclosure may further have a protective resin layer as an outer layer, or may not have a protective resin layer.

[0014] Even if the laminate film of the present disclosure does not have a protective resin layer, it has high strength and can sufficiently protect the electrode laminate from external impacts and the like. When the laminate film has a protective resin layer, the strength of the laminate film can be further improved.

[0015] The tensile strength of the laminate film of the present disclosure may be 50 MPa or more, 100 MPa or more, 150 MPa or more, 175 MPa or more, or 200 MPa or more, and may be 300 MPa or less, 250 MPa or less, or 200 MPa or less.

[0016] The thermal conductivity of the anodized aluminum layer may be 1 W / (m·K) or more. This thermal conductivity may be 10 W / (m·K) or more, 30 W / (m·K) or more, 50 W / (m·K) or more, or 70 W / (m·K) or more, and may be 100 W / (m·K) or less, 80 W / (m·K) or less, or 70 W / (m·K) or less. In particular, by subjecting the anodized aluminum layer to an electrolytic coloring treatment described later, the thermal conductivity of the anodized aluminum layer can be increased. The thermal conductivity of the anodized aluminum layer can be calculated, for example, by irradiating laser light onto the surface of the aluminum layer where the anodized aluminum layer is formed and analyzing the temperature rise curve of the other surface.

[0017] When the laminate film does not have a protective resin layer, the thermal conductivity of the laminate film is higher compared to the case where it has a protective resin layer. Therefore, when the laminate film is applied to a battery, the cooling performance of the battery can be improved.

[0018] The thickness of the anodized aluminum layer may be 1 μm or more, 5 μm or more, 10 μm or more, or 15 μm or more, and may be less than 20 μm, 18 μm or less, 16 μm or less, or 15 μm or less. With such a configuration, it can be made thinner than materials generally used as the protective resin layer as described later. Therefore, when the laminate film of the present disclosure does not have a protective resin layer, the structural efficiency of the battery can be improved.

[0019] The Vickers hardness of the anodized aluminum layer may be 300 Hv or more, 325 Hv or more, 350 Hv or more, or 400 Hv or more, and may be 500 Hv or less, 450 Hv or less, 400 Hv or less, or 350 Hv or less.

[0020] Examples of the material of the fusion resin layer include olefin resins such as polypropylene (PP) and polyethylene (PE). The thickness of the fusion resin layer may be, for example, 40 μm or more and 100 μm or less.

[0021] The thickness of the aluminum layer may be, for example, 30 μm or more and 60 μm or less.

[0022] Examples of the material of the protective resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the protective resin layer is, for example, 20 μm or more and 60 μm or less.

[0023] As described above, the laminate film of the present disclosure is high-strength, and has a high thermal conductivity when it does not have a protective resin layer as an outer layer. Further, in a laminate battery, it is desirable that the laminate film has high insulation in order to prevent a short circuit between the electrode laminate and, for example, conductive foreign matter or the like. However, the laminate film of the present disclosure has sufficient insulation to prevent such a short circuit.

[0024] The specific resistance of the anodic aluminum oxide layer in the laminate film of the present disclosure is 10 12 Ω·cm to 10 14 Ω·cm. This specific resistance can be used as an index of the insulation of the laminate film of the present disclosure.

[0025] 《Method for manufacturing a laminate film》 The method of the present disclosure for manufacturing a laminate film includes the following steps: (a) anodizing an aluminum layer to form an anodic aluminum oxide layer, and (b) laminating a fused resin layer and the anodic aluminum oxide layer.

[0026] As a method of forming an anodized aluminum layer by anodizing an aluminum layer, there is no particular limitation. For example, in a sulfuric acid solution, a direct current is passed with an aluminum foil as an anode, and oxygen generated by electrolysis of water is reacted with the aluminum foil to generate an anodized aluminum layer. By adjusting the treatment temperature, the magnitude of the current, the sulfuric acid concentration, the amount of dissolved aluminum, etc., the thickness of the anodized aluminum layer, the properties of the film, etc. can be controlled. When the aluminum foil is immersed in an acidic solution such as a sulfuric acid solution, by masking one surface of the aluminum foil, an anodized aluminum layer can be formed only on one side of the aluminum foil.

[0027] The method of the present disclosure may further include electrolytic coloring of the anodized aluminum layer after step (a) and before step (b). As a method of electrolytic coloring the anodized aluminum layer, there is no particular limitation. For example, a method of secondarily electrolyzing the anodized aluminum layer in an electrolytic solution to color it can be mentioned. As described above, by electrolytically coloring the anodized aluminum layer, the thermal conductivity of the anodized aluminum layer can be increased. Note that the color tone of the anodized aluminum without electrolytic coloring may be silver or gray, and the color tone of the anodized aluminum with electrolytic coloring may be black.

[0028] The method of the present disclosure may include treatments generally performed when forming an anodized film in addition to the above steps. That is, the method of the present disclosure may include, for example, each step of degreasing, etching, and neutralization before step (a), and may further include a washing step after step (a).

[0029] 《Laminated Battery》 As illustrated in FIG. 3, the laminated battery 1 of the present disclosure has an electrode laminate 20 and the laminated film 10 of the present disclosure that seals the electrode laminate.

[0030] The battery of the present disclosure may be a liquid battery or a solid battery. Regarding the present disclosure, "solid battery" means a battery using at least a solid electrolyte as an electrolyte. Therefore, the solid battery of the present disclosure may use a combination of a solid electrolyte and a liquid electrolyte as the electrolyte. Further, the solid battery of the present disclosure may be an all-solid battery, that is, a battery using only a solid electrolyte as the electrolyte.

[0031] The battery of the present disclosure may be, for example, a lithium-ion secondary battery. Examples of the uses of the battery include power sources for vehicles such as hybrid vehicles (HEV), plug-in hybrid vehicles (PHEV), battery electric vehicles (BEV), gasoline vehicles, and diesel vehicles. In particular, it is preferably used as a driving power source for a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), or a battery electric vehicle (BEV). Further, the battery in the present disclosure may be used as a power source for a moving body other than a vehicle (for example, railway, ship, aircraft), or may be used as a power source for an electric product such as an information processing device.

[0032] 〈Electrode laminate〉 The electrode laminate 20 functions as a power generation element of the laminated battery 1. The shape of the electrode laminate is not particularly limited. For example, it may have a top surface portion, a bottom surface portion facing the top surface portion, and four side surface portions connecting the top surface portion and the bottom surface portion. The shape of the top surface portion is not particularly limited. For example, quadrilaterals such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram can be mentioned. Further, the shape of the top surface portion may be a polygon other than a quadrilateral, or may be a shape having a curve such as a circle. Further, the shape of the bottom surface portion is the same as that of the top surface portion. The shape of the side surface portion is not particularly limited. For example, quadrilaterals such as a square, a rectangle, a rhombus, a trapezoid, and a parallelogram can be mentioned.

[0033] The electrode laminate may have a negative electrode current collector, a negative electrode active material layer, an electrolyte layer, a positive electrode active material layer, and a positive electrode current collector in this order.

[0034] 〈Laminated film〉 The laminate film 10 seals the electrode laminate 20. When the laminate battery 1 of the present disclosure has a current collecting terminal, the laminate film 10 may seal the electrode laminate 20 together with the current collecting terminal. Specifically, the laminate film may wind the electrode laminate and the current collecting terminal to seal the electrode laminate together with the current collecting terminal. Further, the laminate film may be composed of a first and a second film. In this case, the first and second films may sandwich the electrode laminate and the current collecting terminal from above and below in the stacking direction of the electrode laminate to seal the electrode laminate together with the current collecting terminal.

[0035] Regarding the configuration of the laminate film, reference can be made to the above description of the laminate film of the present disclosure.

[0036] <Other configurations> (Current collecting terminal) The laminate battery of the present disclosure may have a current collecting terminal 30 disposed on a side surface portion of the electrode laminate. The current collecting terminal may be disposed, for example, on a pair of opposing side surface portions of the electrode laminate. The material of the current collecting terminal is not particularly limited as long as it has a current collecting function. For example, it can be the same metal material as the positive electrode current collector and the negative electrode current collector. The size, shape, etc. of the current collecting terminal are not particularly limited.

[0037] (Current collecting portion) The laminate battery of the present disclosure may have a current collecting portion 40 that electrically connects the end portion of the electrode laminate and the end portion of the current collecting terminal. The current collecting portion may be a bundle of a portion of the positive electrode current collector in the electrode laminate where no other layers are stacked, and a portion of the negative electrode current collector in the electrode laminate where no other layers are stacked.

Description of reference numerals

[0038] 1 Laminate battery 10 Laminate film 11 Fused resin layer 12 Aluminum layer 13 Anodized aluminum layer 14 Protective resin layer 20 Electrode laminate 30 Current collector terminal 40 Current collection part

Claims

1. A fusion resin layer, an aluminum layer, and an anodized aluminum layer in this order, a laminate film for a laminated battery.

2. The laminate film according to claim 1, wherein the thermal conductivity of the anodized aluminum layer is 1 W / (m·K) or more.

3. The electrode laminate, and the laminate film according to claim 1 or 2 that seals the electrode laminate to have a laminated battery.

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