Deposition method for laminate film

Abstract

To provide a deposition method for a laminate film capable of uniformly pressurizing a deposition portion of a laminate film in irradiation with a laser.SOLUTION: A method for mutually depositing a laminate film 10 includes the following steps of: pressing a peripheral edge 10y of a deposition portion 10x of the mutually laminated laminate film 10 with a pressing member 2 comprising a laser permeable part 2a, thereby forming a sealed space 6, which covers the deposition portion 10x, consisting of the laser permeable part 2a, the pressing member 2 and the laminate film 10; injecting a gas into the sealed space 6 and pressurizing the deposition portion 10x; and irradiating the pressurized deposition portion 10x with a laser beam 4 through the laser permeable part 2a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method for welding a laminate film and a method for manufacturing a laminate battery using this welding method. [Background technology]

[0002] A laminate battery is a battery in which a battery laminate having, for example, a positive electrode current collector layer, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer is covered with a laminate film and sealed.

[0003] As a method for covering and sealing a battery stack with a laminate film, for example, Patent Document 1 discloses a method for manufacturing a laminated secondary battery in which the peripheral edges of two laminate exterior bodies sandwiching a power generating element are overlapped and then heat-welded to seal the sandwiched edges while applying pressure to the sandwiched edges, the method comprising: a heating step in which at least one surface of the peripheral edges is sandwiched between laser-transparent members and the peripheral edges are melted by irradiating the laser light through the laser-transparent members; and a cooling step in which the peripheral edges are cooled by continuing to be sandwiched between the laser-transparent members after the heating step. The manufacturing method in Patent Document 1 is said to be able to shorten the cooling time, i.e., shorten the manufacturing time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2006-004687 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, in the above-described method for welding a laminate film, when at least one surface around the welded portion of the laminate film is pressed down with a laser-transparent member, it is necessary to further press down the laser-transparent member with a pressing member while avoiding blocking the path of the laser.

[0006] For example, it is conceivable to place a laser-transmitting member on the welded portion of the laminate film, and press the peripheral edge of the laser-transmitting member with a presser member.

[0007] In this case, the laser-transmitting member may bend convexly in the direction opposite to the surface of the laminate film, which may prevent uniform pressure from being applied to the welded portion of the laminate film, making it difficult to ensure adhesion of the laminate film. Therefore, improvements are needed.

[0008] Therefore, an object of the present disclosure is to provide a method for welding a laminate film that can apply uniform pressure to the welded portion of the laminate film during laser irradiation. [Means for solving the problem]

[0009] The present disclosure achieves the above object by the following procedures.

[0010] (Aspect 1) 1. A method for welding laminate films together, comprising the steps of: pressing the periphery of the welded portion of the laminate films stacked together with a pressing member having a laser-transparent portion, thereby forming a sealed space that covers the welded portion; injecting gas into the sealed space to pressurize the welded portion; and Irradiating the pressurized welded portion with laser light through the laser transparent portion. (Aspect 2) A method for manufacturing a laminated battery, comprising the steps of: sandwiching the battery stack between the laminate films; and The laminate films are welded together by the method of aspect 1 to seal the battery stack with the laminate films. [Effects of the Invention]

[0011] According to the method of the present disclosure, pressure can be applied evenly to the welded portion of the laminate film. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram illustrating a step of pressing the periphery of the welded portion of the laminate film to form an enclosed space in the method for welding the laminate film of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram illustrating the step of applying pressure to the welded portion in the method for welding a laminate film according to the present disclosure. [Figure 3] FIG. 3 is a schematic diagram illustrating the step of irradiating laser light in the method for welding a laminate film according to the present disclosure. [Figure 4] FIG. 4 is a schematic diagram for explaining a conventional method for welding a laminate film. [Figure 5] FIG. 5 is a schematic diagram for explaining the method for manufacturing a laminate battery according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] <<How to weld laminate film>> The disclosed method for welding a laminate film comprises: pressing the periphery of the welded portion of the laminate films stacked together with a pressing member having a laser-transparent portion, thereby forming a sealed space that covers the welded portion; injecting gas into the sealed space to pressurize the welded portion; and irradiating the pressurized welded portion with laser light through the laser transparent portion; Includes.

[0014] According to the above-described method for welding a laminate film, the welded portion of the laminate film can be uniformly pressurized.

[0015] In a conventional laminate film welding method (FIG. 4(a)), a laser-transparent member 1 is placed on a laminate film 10, and a pressing member 2 is placed around the periphery of the laser-transparent member 1. When the pressing member 2 presses the laser-transparent member 1 to apply pressure to the welded portion 10x of the laminate film 10, the laser-transparent member 1 curves convexly on the side opposite to the side on which the laminate film 10 is located, which can make it difficult to apply uniform pressure to the welded portion 10x of the laminate film 10 (FIG. 4(b)).

[0016] In contrast, according to the present disclosure, pressure can be applied evenly to the welded portion of the laminate film.

[0017] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present disclosure. In addition, in the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions will be omitted.

[0018] (Sealing process) In the method of the present disclosure, first, the periphery of the welded portion of the laminate films that are stacked together is pressed down with a pressing member having a laser-transparent portion, thereby forming a sealed space that covers the welded portion.

[0019] FIG. 1(a) is a cross-sectional view of a welding portion 10x of a laminate film 10 used in the method of this embodiment and a structure used for welding. The laminate film 10 in FIG. 1(a) has a fusion layer 10a, a metal layer 10b, and a resin layer 10c, but this is not limited to this. Two laminate films 10 are in contact with each other, with the fusion layer 10a as the contact surface. A presser member 2 is installed at the peripheral edge 10y of the welding portion 10x of the laminate film 10, and the laser-transparent portion 2a is fixed to the top of the laminate film 10 without contacting the laminate film 10. In this configuration, a sealed space 6 is formed, with the laminate film 10 at the bottom, the presser member 2 at the side, and the laser-transparent portion 2a at the top. The presser member 2 has a gas injection conduit 3. In FIG. 1(a), the gas injection conduit 3 is attached to the presser member 2, but this is not limited to this.

[0020] 1(b) is a top view of the structure shown in FIG. 1(a). In FIG. 1(b), the laser transparent portion 2a and the pressing member 2 have rectangular shapes, but this is not limited to this. Also, in FIG. 1(a) and FIG. 1(b), the sealed space 6 has a cubic shape, but this is not limited to this. For example, the fixing portion of the laser transparent portion 2a and the pressing member 2 does not have to be at a right angle.

[0021] (Pressure process) The method of the present disclosure then involves injecting gas into the sealed space to pressurize the welded portion.

[0022] In Fig. 2, gas is injected into the sealed space 6 through the gas injection conduit 3. The gas injection increases the air pressure inside the sealed space 6, making it possible to uniformly pressurize the welded portion 10x of the laminate film 10.

[0023] (Welding process) In the method of the present disclosure, laser light is then irradiated onto the pressurized welded portion through the laser transparent portion.

[0024] In Fig. 3, the pressed welded portion 10x is irradiated with laser light 4. The irradiated laser light 4 passes through the laser transparent portion 2a and reaches the laminate film 10. The irradiation of the laser light 4 heats the irradiated welded portion 10x of the laminate film 10, and the laminate film 10 is welded to each other.

[0025] (laminating film) The laminate film 10 has a fusion layer 10a and a metal layer 10b. The laminate film is not particularly limited, but may have the fusion layer 10a, the metal layer 10b, and the resin layer 10c in this order.

[0026] (fusion layer) The material of the fusion layer is not particularly limited, but examples thereof include polyolefin resins. Examples of polyolefin resins include polypropylene (PP) and polyethylene (PE). The thickness of the adhesive layer is not particularly limited, but may be 3 It may be 100 μm or more, 40 μm or more, or 50 μm or more, and may be 110 μm or less, 100 It may be 90 μm or less.

[0027] (metal layer) Examples of materials for the metal layer include aluminum, aluminum alloys, and stainless steel. The thickness of the metal layer is not particularly limited, but may be 20 It may be 70 μm or less, 60 μm or less, 30 μm or more, or 40 μm or more. It may be 50 μm or less.

[0028] (resin layer) Examples of materials for the resin layer include polyethylene terephthalate and nylon. The thickness of the resin layer is not particularly limited, but is preferably 70 μm or more. , 80 μm or more, or 90 μm or more, 270 μm or less, 250 μm or less, Alternatively, it may be 230 μm or less.

[0029] <Laminate battery manufacturing method> The disclosed method for manufacturing a laminate battery includes: sandwiching the battery stack with laminate films; and welding the laminate films together by the method described above to seal the battery stack with the laminate films; Includes.

[0030] (Clamping process) The disclosed method for manufacturing a laminated battery begins by sandwiching a battery stack between laminate films.

[0031] In the present disclosure, the battery stack may be a liquid-based battery stack or a solid-state battery stack. In the context of the present disclosure, a "solid-state battery" refers to a battery that uses at least a solid electrolyte as the electrolyte. Therefore, a solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as the electrolyte. The solid-state battery of the present disclosure may also be an all-solid-state battery, i.e., a battery that uses only a solid electrolyte as the electrolyte.

[0032] In the present disclosure, the battery stack is not particularly limited, but may include at least a positive electrode current collector layer, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer, in this order. Fig. 5(a) shows an example of a battery stack 20 used in the method of this embodiment. The battery stack 20 includes a negative electrode current collector layer 20a, a negative electrode active material layer 20b, an electrolyte layer 20c, a positive electrode active material layer 20d, and a positive electrode current collector layer 20e stacked in this order, with the negative electrode current collector layer 20a and the positive electrode current collector layer 20e shared.

[0033] Figure 5(b) shows the battery stack 20 sandwiched between laminate films 10. Figure 5(b) shows the battery stack 20 sandwiched between one laminate film 10, but this is not limited to this. For example, the battery stack 20 may be sandwiched between multiple laminate films 10.

[0034] (Sealing process) The method of the present disclosure then involves welding the laminate films together by the method described above to seal the battery stack with the laminate films.

[0035] FIG. 5(c) shows the laminate film 10 welded and sealed to the battery stack 20 using the above method. In FIG. 5(c), the laminate film 10 and the battery stack 20 are not in close contact, but this is not limited to this. Also, in FIG. 5(c), the corners of the laminate film 10 after sealing have rounded curves, but this is not limited to this.

[0036] 5(c), the welded portion 10x of the laminate film 10 is part of the periphery of the battery stack 20, but this is not limited to this. For example, if the battery stack 20 is sandwiched between two laminate films 10, the welded portion of the laminate film 10 can be the entire periphery of the battery stack 20. [Explanation of symbols]

[0037] 1 Laser-transparent material 2. Retaining member 2a Laser-transmitting part 3 Gas injection conduit 4. Laser light 10. Laminating film 10a Fusion layer 10b metal layer 10c resin layer 10x welded parts 10y Periphery of the welded part 20 Battery stack 20a Negative electrode current collector layer 20b Negative electrode active material layer 20c electrolyte layer 20d Cathode active material layer 20e Positive electrode current collector layer

Claims

1. 1. A method for welding laminate films together, comprising the steps of: pressing the periphery of the welded portion of the laminate films stacked together with a pressing member having a laser-transparent portion, thereby forming a sealed space that covers the welded portion; injecting gas into the sealed space to pressurize the welded portion; and Irradiating the pressurized welded portion with laser light through the laser transparent portion.

2. A method for manufacturing a laminate battery, comprising the steps of: sandwiching the battery stack between the laminate films; and The method of claim 1, wherein the laminate films are welded together to seal the battery stack with the laminate films.

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