Method for manufacturing current collector foil

Abstract

To provide a method for manufacturing a current collector foil which can reduce the number of pinholes in the current collector foil.SOLUTION: The present invention relates to a method for manufacturing a current collector foil which can provide a current collector foil for a liquid battery by attaching a first electrode foil with a pinhole and a second electrode foil on each other, one of the first electrode foil and the second electrode foil being a positive electrode foil and the other being a negative electrode foil. The method includes: an application step of applying an adhesive to the first electrode foil; a suction step of performing suction from a surface of the first electrode foil which is opposite to the surface on which the adhesive is applied and immersing the pinhole in the adhesive; a drying step of drying the adhesive; and a thermal welding step of attaching the second adhesive foil on the surface on which the adhesive of the first electrode foil is applied and performing a thermal welding.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a current collector foil. [Background technology]

[0002] Conventionally, a current collector foil for a liquid battery has been used in which a positive electrode foil and a negative electrode foil are bonded together.

[0003] For example, Patent Document 1 discloses a bipolar current collector having a positive electrode current collector with an aluminum layer, a negative electrode current collector with a copper layer, and an intermediate layer interposed between the aluminum layer and the copper layer, the copper layer having a thickness of 3 to 10 μm, and the intermediate layer having a porous anodized aluminum portion and a nickel portion present in the pores of the anodized aluminum portion.

[0004] Furthermore, Patent Document 2 discloses a stacked all-solid-state secondary battery in which a positive electrode, a solid electrolyte layer, and a negative electrode are stacked to form an electrical parallel connection within a parallel electrode body, and a plurality of parallel electrode bodies are electrically connected in series via a bipolar electrode, the bipolar electrode is disposed opposite a positive electrode and a negative electrode, and the bipolar electrode current collecting foil is separated from a positive electrode current collecting foil of a positive electrode and a negative electrode current collecting foil of a negative electrode disposed opposite the bipolar electrode. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-053669 A [Patent Document 2] JP 2018-037247 A Summary of the Invention [Problem to be solved by the invention]

[0006] Conventionally, current collector foils in which a positive electrode foil and a negative electrode foil are bonded together with an adhesive have been used as current collector foils for liquid batteries. However, metal foils used for the positive electrode foil and the negative electrode foil may have pinholes during the manufacturing process. When a current collector foil having a pinhole in at least one of the positive electrode foil and the negative electrode foil is used in a liquid battery, a through hole penetrating the positive electrode foil, the adhesive layer, and the negative electrode foil may be formed, and a liquid short circuit may occur through the through hole in the liquid battery.

[0007] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a manufacturing method for a current collecting foil that can reduce the number of pinholes in the current collecting foil. [Means for solving the problem]

[0008] Means for solving the above problems include the following aspects. <1> A method for producing a current collector foil for a liquid electrolyte battery, comprising bonding a first electrode foil having a pinhole and a second electrode foil, the method comprising the steps of: One of the first electrode foil and the second electrode foil is a positive electrode foil and the other is a negative electrode foil, a coating step of coating the first electrode foil with an adhesive; a suction step of suctioning the surface of the first electrode foil opposite to the surface on which the adhesive is applied, thereby impregnating the pinholes with the adhesive; a drying step of drying the adhesive; a thermal welding step of attaching the second electrode foil to the surface of the first electrode foil on which the adhesive is applied, and thermally welding the second electrode foil; The method for producing a current collecting foil comprising the steps of: <2> The suction step is a step of performing suction by bringing a suction member having a suction hole on a surface side of the first electrode foil opposite to the surface on which the adhesive is applied. <1> A method for producing the current collector foil according to claim 1. <3> The diameter of the suction hole is 0.5 mm or more and 15 mm or less. <2> A method for producing the current collector foil according to claim 1. <4> The spacing between the suction holes is 1.0 mm or more and 20 mm or less. <2> A method for producing the current collector foil according to claim 1. <5> The suction pressure from the suction hole is 5 kPa or more and 40 kPa or less. <2> A method for producing the current collector foil according to claim 1. Effect of the Invention

[0009] According to the present disclosure, there is provided a method for manufacturing a current collecting foil that can reduce the number of pinholes in the current collecting foil. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing a current collector foil manufacturing apparatus for implementing a current collector foil manufacturing method according to an embodiment of the present disclosure. [Diagram 2] 4 is a schematic cross-sectional view showing a state in which an adhesive is impregnated into a pinhole in a suction step in a manufacturing method for a battery negative electrode according to an embodiment of the present disclosure. FIG. [Diagram 3] 4 is a schematic cross-sectional view showing a state in which an adhesive is impregnated into a pinhole in a suction step in a manufacturing method for a battery negative electrode according to an embodiment of the present disclosure. FIG. [Figure 4] 4 is a schematic cross-sectional view showing a state in which an adhesive is impregnated into a pinhole in a suction step in a manufacturing method for a battery negative electrode according to an embodiment of the present disclosure. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment that is an example of the present disclosure will now be described. These descriptions and examples are merely illustrative of the embodiments and are not intended to limit the scope of the invention. In this specification, a numerical range expressed using "to" means a range that includes these numerical values ​​as the lower limit and upper limit. In the present specification, the upper limit of a certain numerical range may be replaced by the upper limit of another numerical range, or may be replaced by a value shown in an example. The lower limit of a certain numerical range may be replaced by the lower limit of another numerical range, or may be replaced by a value shown in an example. Furthermore, "%" for the content means "% by mass" unless otherwise specified.

[0012] Each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of those multiple substances present in the composition. The term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved.

[0013] <Manufacturing method of current collecting foil> The method for producing a current collector foil according to an embodiment of the present disclosure is a method for producing a current collector foil for a liquid-based battery (i.e., a battery having an electrolytic solution as an electrolyte) by bonding a first electrode foil having a pinhole and a second electrode foil together, where one of the first electrode foil and the second electrode foil is a positive electrode foil and the other is a negative electrode foil. The method for producing the current collector foil includes the following steps (1) to (4). (1) A coating process for applying adhesive to the first electrode foil (2) A suction process in which suction is applied from the side of the first electrode foil opposite to the side on which the adhesive is applied, so that the adhesive is impregnated into the pinholes. (3) Drying the adhesive (4) A thermal welding process in which the second electrode foil is attached to the adhesive-coated surface of the first electrode foil and thermally welded.

[0014] The method for producing a current collecting foil according to an embodiment of the present disclosure can reduce the number of pinholes in the current collecting foil by including a suction step between the coating step and the drying step as described above. As a result, when this current collecting foil is used in a liquid battery, the occurrence of through holes in the current collecting foil can be suppressed, and the occurrence of liquid short circuits in the liquid battery can be suppressed.

[0015] Conventionally, current collector foils have been used in which positive and negative foils are bonded together with an adhesive. However, the metal foils used for the positive and negative foils can have pinholes (small holes penetrating the metal foil) during the manufacturing process.

[0016] For example, when a positive electrode foil having a pinhole is used and a current collector foil obtained by bonding this positive electrode foil and negative electrode foil together with an adhesive is used in a liquid battery, a through hole may be formed at the pinhole in the positive electrode foil, penetrating through the positive electrode foil, adhesive layer, and negative electrode foil. Specifically, at the pinhole in the positive electrode foil, a hole may also be formed in the adhesive layer formed on the pinhole, meaning that the pinhole may not be blocked by the adhesive. When a current collector foil obtained by bonding a negative electrode foil to this positive electrode foil and adhesive layer is used in a liquid battery, the electrolyte penetrates into the hole penetrating the positive electrode foil and adhesive layer, and this electrolyte comes into contact with the negative electrode foil. When the battery is repeatedly charged and discharged in this state, a reaction with the electrolyte (for example, when copper foil is used as the negative electrode foil, Cu → Cu 2+ +2e - The negative foil may also be punctured by the reaction (reaction (a) of the positive and negative electrodes), resulting in a through hole that passes completely through the positive foil, the adhesive layer, and the negative foil. In addition, when a negative electrode foil having a pinhole is used and a current collector foil obtained by bonding the negative electrode foil and the positive electrode foil together with an adhesive is used in a liquid battery, a through hole may be formed at the pinhole in the positive electrode foil, penetrating the positive electrode foil, the adhesive layer, and the negative electrode foil. Specifically, at the pinhole in the negative electrode foil, a hole may also be formed in the adhesive layer formed on the pinhole, that is, the pinhole may not be blocked by the adhesive. When a current collector foil obtained by bonding a positive electrode foil to the negative electrode foil and the adhesive layer is used in a liquid battery, the electrolyte penetrates into the hole penetrating the negative electrode foil and the adhesive layer, and the electrolyte comes into contact with the positive electrode foil. When the battery is repeatedly charged and discharged in this state, the positive electrode foil may crack, and as a result, a through hole is formed that completely penetrates the negative electrode foil, the adhesive layer, and the positive electrode foil.

[0017] In a current collector foil having a through hole formed therein that penetrates the positive electrode foil, the adhesive layer, and the negative electrode foil, one side of the current collector foil communicates with the other side through the through hole, resulting in a liquid junction.

[0018] Therefore, in the current collector foil manufacturing method according to the embodiment of the present disclosure, a suction step is provided in which, after applying an adhesive to the first electrode foil and before drying the adhesive, suction is performed from the side of the first electrode foil opposite to the side to which the adhesive is applied. This suction step allows the adhesive before drying (i.e., liquid) to be impregnated into pinholes in the first electrode foil and fill the pinholes. This prevents electrolyte from penetrating into pinholes in the first electrode foil even when the current collector foil is used in a liquid battery, and prevents the formation of through holes that completely penetrate the positive electrode foil, adhesive layer, and negative electrode foil. As a result, the occurrence of liquid junctions in liquid batteries can be suppressed.

[0019] Here, one aspect of a method for producing a current collector foil according to an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0020] FIG. 1 is a schematic diagram showing a current collector foil manufacturing apparatus for carrying out a current collector foil manufacturing method according to an embodiment of the present disclosure. 1 has a positive electrode foil 12 (e.g., Al foil) as an example of a first electrode foil formed into a roll, and a negative electrode foil 14 (e.g., Cu foil) as an example of a second electrode foil formed into a roll. The positive electrode foil 12 is a metal foil having pinholes.

[0021] (1) Coating process First, the positive electrode foil 12 is conveyed to a roll pair consisting of a coating roll 22A (e.g., a gravure roll) and an opposing roll 22B. The coating roll 22A is partially immersed in an adhesive 40, and the adhesive 40 attached to the surface of the coating roll 22A is applied (e.g., gravure coated) from the coating roll 22A to one side of the positive electrode foil 12.

[0022] (2) Suction process Next, the positive electrode foil 12 having the adhesive 40 applied on one side is transported to a position where it contacts the suction roll 24, which is an example of a member having a suction mechanism (hereinafter also simply referred to as a "suction member"). The suction roll 24 is disposed at a position where it contacts the surface of the positive electrode foil 12 on which the adhesive 40 is not applied. Then, the suction roll 24 performs suction from the surface of the positive electrode foil 12 on which the adhesive 40 is not applied. This allows the adhesive 40 to be impregnated into the pinholes in the positive electrode foil 12.

[0023] More specifically, as shown in Fig. 2, at a location where a pinhole 120 is formed in the positive electrode foil 12, a hole may also be formed in the adhesive 40 applied on the pinhole 120. As shown in Fig. 3, the positive electrode foil 12 is sucked in the direction of arrow A by a suction roll 24 from the side of the positive electrode foil 12 on which the adhesive 40 is not applied, so that the inside of the pinhole 120 in the positive electrode foil 12 becomes negative pressure, and the adhesive 40 flows in the direction of arrow B. As a result, as shown in Fig. 4, the adhesive 40 permeates the pinhole 120, and the pinhole 120 is blocked.

[0024] Here, a suction member such as a suction roll will be described. A suction roll is a roll that can perform suction through suction holes provided on the surface. 1 shows a suction roll 24 as the suction member used in the suction step, but the present disclosure is not limited thereto. The suction member used in the embodiment of the present disclosure is not particularly limited as long as it is a member that can perform suction from the side opposite to the side on which the adhesive is applied in the first electrode foil. For example, a belt having suction holes on its surface (hereinafter referred to as a "suction belt") may be used.

[0025] The diameter of the suction holes (the arithmetic mean value of the diameters of 20 arbitrarily selected suction holes) provided on the surface of the suction member (suction roll 24 in FIG. 1) is preferably 0.5 mm or more and 15 mm or less, and more preferably 1.0 mm or more and 10 mm or less, from the viewpoint of making it easier to reduce the number of pinholes in the current collecting foil. The spacing between the suction holes (the distance between the center points of adjacent suction holes, the arithmetic mean value of the distances between the center points of 20 arbitrarily selected pairs of suction holes) on the surface of the suction member (suction roll 24 in FIG. 1) is preferably 1.0 mm or more and 20 mm or less, and more preferably 2.0 mm or more and 10 mm or less, from the viewpoint of making it easier to reduce the number of pinholes in the current collecting foil. The suction pressure from the suction holes in the suction member (suction roll 24 in FIG. 1) is preferably 5 kPa or more and 40 kPa or less, and more preferably 10 kPa or more and 30 kPa or less, from the viewpoint of making it easier to reduce the number of pinholes in the current collecting foil.

[0026] The suction member is preferably in the form of a roll (for example, suction roll 24 shown in Fig. 1). The wrap angle of this roll-shaped suction member (i.e., the angle between the traveling direction of the first electrode foil on the side entering the suction roll and the traveling direction of the first electrode foil on the side moving away from the suction roll) is preferably 40° or more and 100° or less, and more preferably 50° or more and 90° or less, from the viewpoint of making it easier to reduce the number of pinholes in the current collector foil.

[0027] The surface material of the suction member having a roll shape (for example, the suction roll 24 shown in FIG. 1) is preferably a metal, and particularly preferably SUS. The surface of the suction belt is preferably made of a resin or rubber.

[0028] (3) Drying process Next, as shown in FIG. 1, the positive electrode foil 12 that has been subjected to the suction step by the suction roll 24 is conveyed to a drying furnace 30, and the adhesive 40 on the positive electrode foil 12 is heated in the drying furnace 30 and dried.

[0029] The heating temperature in the drying step (the temperature inside drying oven 30 in FIG. 1) can be adjusted depending on the adhesive used, and is preferably, for example, 80° C. or higher and 200° C. or lower, and more preferably 100° C. or higher and 180° C. or lower.

[0030] (4) Heat welding process Next, the positive electrode foil 12 that has passed through the drying furnace 30 is transported via the transport roll 26 to a contact position with the pair of heated rolls 28A, 28B. In the nip portion of the pair of heated rolls 28A, 28B, the negative electrode foil 14 transported from another direction is bonded to the surface of the positive electrode foil 12 on which the adhesive 40 has been applied, and is heated and pressed by the pair of heated rolls 28A, 28B, whereby the positive electrode foil 12 and the negative electrode foil 14 are thermally welded together via the adhesive 40. Through these steps, the current collector foil 10 in which the positive electrode foil 12 and the negative electrode foil 14 are bonded together is manufactured.

[0031] The heating temperature in the heat welding step (the temperature of the pair of heated rolls 28A and 28B in FIG. 1) can be adjusted depending on the adhesive used, and is preferably, for example, 50°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. The pressure applied in the heat welding step (the nip pressure by the pair of heated rolls 28A and 28B in FIG. 1) is, for example, preferably from 0.20 MPa to 0.70 MPa, and more preferably from 0.30 MPa to 0.60 MPa.

[0032] 1, the manufacturing method is described in which adhesive 40 is applied to positive electrode foil 12 having a pinhole (application step), and then negative electrode foil 14 is attached and thermally welded (thermal welding step), but the present disclosure is not limited to this. That is, the manufacturing method may be such that adhesive is applied to negative electrode foil having a pinhole (application step), and then positive electrode foil is attached and thermally welded (thermal welding step).

[0033] In the method for producing a current collector foil according to the embodiment of the present disclosure, one of the first electrode foil and the second electrode foil is a positive electrode foil, and the other is a negative electrode foil.

[0034] The positive electrode foil used is preferably a conductive member made of a metal with good conductivity (e.g., aluminum). The thickness of the positive electrode foil is preferably, for example, 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 60 μm or less.

[0035] On the other hand, the negative electrode foil is preferably a conductive member made of a metal with good conductivity (for example, copper). The thickness of the negative electrode foil is preferably, for example, 1 μm or more and 20 μm or less, and more preferably 3 μm or more and 12 μm or less.

[0036] The adhesive used in the method for producing a current collector foil according to an embodiment of the present disclosure is not particularly limited as long as it is liquid before the drying step. For example, an adhesive in which a curing agent (e.g., an isocyanate-based curing agent) is added to a base agent (e.g., an olefin-based resin) is preferably used. A conductive assistant (e.g., particles with Ni plating on the surface) may also be added to the adhesive. The thickness of the adhesive layer formed by applying and drying the adhesive is preferably, for example, 0.5 μm to 15 μm, and more preferably 1.0 μm to 10 μm.

[0037] <Battery> Next, each component constituting a liquid battery using a current collector foil obtained by the current collector foil manufacturing method according to an embodiment of the present disclosure will be described.

[0038] (Cathode active material layer) The positive electrode mixture layer contains a positive electrode active material, and may further contain, for example, a binder. An example of a positive electrode active material is lithium nickel cobalt manganese composite oxide (hereinafter, simply referred to as "LNCM"). The simplest LNCM has the following general formula: LiNi x Co y Mn zIt is represented by O2 (where x, y, and z satisfy 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1). LNCM may contain, in addition to Li, Ni, Co, and Mn, other additive elements, such as transition metal elements other than Ni, Co, and Mn, and typical metal elements other than Li. LNCM has a layered crystal structure. LNCM may exceed 50% by mass of the entire cathode active material, for example, it may account for 80 to 100% by mass. The cathode active material may be composed of only LNCM. Examples of other cathode active materials include lithium nickel composite oxides, lithium cobalt composite oxides, lithium nickel manganese composite oxides, and the like.

[0039] Examples of the binder contained in the cathode composite layer include vinyl halide resins such as polyvinylidene fluoride (PVdF). The cathode composite layer may further contain other components, such as a conductive material. Examples of the conductive material include graphitized carbon, easily graphitizable carbon such as carbon black, and graphite.

[0040] (Negative electrode active layer) The aforementioned negative electrode active material layer is used for the negative electrode active layer. Since the details have already been described, they are omitted here.

[0041] (Separator) The separator is an electrically insulating porous membrane. The separator electrically isolates the positive electrode and the negative electrode. The separator may have a thickness of, for example, 5 to 30 μm. The separator may be composed of, for example, a porous polyethylene (PE) membrane, a porous polypropylene (PP) membrane, or the like. The separator may have a multilayer structure. For example, the separator may be composed of a porous PP membrane, a porous PE membrane, and a porous PP membrane laminated in this order. The separator may have a heat-resistant layer on its surface. The heat-resistant layer contains a heat-resistant material. Examples of the heat-resistant material include metal oxide particles such as alumina and high melting point resins such as polyimide.

[0042] (Electrolyte) The battery according to the embodiment of the present disclosure further comprises an electrolyte, and a non-aqueous electrolyte is particularly preferred.

[0043] ·solvent The non-aqueous electrolytic solution contains a solvent (non-aqueous solvent) and an electrolyte. Examples of the solvent (non-aqueous solvent) include N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(fluorosulfonyl)imide (DEME), 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMI), and 1-ethyl-2,3-dimethylimidazolium bis(fluorosulfonyl)imide (DEMI-FSI).

[0044] ·Electrolytes The electrolyte in the electrolytic solution may be, for example, a Li salt, such as lithium bis(fluorosulfonyl)imide (LiFSI), LiPF6 (lithium hexafluorophosphate), lithium tetrafluoroborate (LiBF4), or Li[N(CF3SO2)2]. The amount of the electrolyte may be, for example, 1.0 to 2.0 mol / L, and is preferably 1.0 to 1.5 mol / L.

[0045] The electrolytic solution may contain various additives, such as a thickener, a film-forming agent, a gas generating agent, etc., in addition to the solvent and the electrolyte. The electrolyte is typically a non-aqueous electrolytic solution that is liquid at room temperature (e.g., 25±10°C). The electrolytic solution is typically liquid in the environment in which the battery is used (e.g., a temperature environment of -20 to +60°C).

[0046] (Application) Applications of the batteries according to the embodiments of the present disclosure include, for example, power sources for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). EXAMPLES

[0047] The present disclosure will be described below based on examples, but the present disclosure is not limited to these examples in any way.

[0048] <Example> Preparation of adhesive Adhesive 1 was obtained by mixing an olefin resin as a base agent, an isocyanate curing agent, and Ni-plated particles as a conductive assistant.

[0049] -Preparation of current collecting foil 1, the adhesive 1 was used as the adhesive 40, an aluminum foil (Al foil) was used as the positive electrode foil 12, and a copper foil (Cu foil) was used as the negative electrode foil 14. The line speed (conveying speed) was 15 m / min.

[0050] The adhesive 1 was applied to one surface of the Al foil by gravure coating (coating step). A gravure roll (elongated, 75 lines) was used as the coating roll 22A.

[0051] Next, suction was performed by the suction roll 24 from the surface of the Al foil opposite to the surface on which the adhesive 1 was applied under the following conditions (suction step). (Suction roll conditions) Suction hole diameter: φ2mm Suction hole spacing (distance between the center points of the suction holes): 4mm Suction pressure: 20kPa Suction roll angle: 50°~90° Suction roll material: SUS

[0052] Next, the adhesive 1 was dried by passing through a drying oven 30 whose temperature was set at 150° C. (drying step). Thereafter, the Cu foil was attached to the surface of the Al foil that had been conveyed to the pair of heated rolls 28A and 28B on which the adhesive 1 had been applied, and the Cu foil was heat-welded (heat-welding step) to obtain a current collector foil of the embodiment. The conditions for the pair of heated rolls 28A and 28B were as follows. Heat roll temperature: 90℃ Heat roll nip pressure: 0.45MPa

[0053] <Comparative Example> A current collector foil of the comparative example was obtained in the same manner as in Example 1, except that the suction roll 24 in the current collector foil manufacturing apparatus 100 shown in FIG. 1 was changed to a SUS roll having no suction mechanism, i.e., the suction process was not performed.

[0054] [Evaluation test] Pinhole inspection The current collector foils obtained in the examples and comparative examples were inspected for the presence or absence of pinholes having a diameter of 0.5 mm or less using an inspection machine. The results are shown in Table 1 below.

[0055] [Table 1]

[0056] It can be seen that the current collecting foil of the example in which suction by suction roll 24 is performed after application of adhesive 1 has a reduced number of pinholes compared to the current collecting foil of the comparative example in which suction is not performed. [Explanation of symbols]

[0057] 10 current collector foil, 12 positive electrode foil, 14 negative electrode foil, 22A coating roll, 22B opposing roll, 24 suction roll, 26 transport roll, 28A, 28B pair of heat rolls, 30 drying furnace, 40 adhesive, 100 current collector foil manufacturing device, 120 pinhole

Claims

1. A method for producing a current collector foil for a liquid battery, comprising bonding a first electrode foil having a pinhole and a second electrode foil, the method comprising the steps of: One of the first electrode foil and the second electrode foil is a positive electrode foil and the other is a negative electrode foil, a coating step of coating the first electrode foil with an adhesive; a suction step of performing suction from a surface of the first electrode foil opposite to the surface on which the adhesive is applied, thereby impregnating the pinholes with the adhesive; a drying step of drying the adhesive; a thermal welding step of bonding the second electrode foil to the surface of the first electrode foil on which the adhesive is applied, and thermally welding the second electrode foil to the surface of the first electrode foil; The method for producing a current collecting foil comprising the steps of:

2. The method for producing a current collector foil according to claim 1 , wherein the suction step is a step of performing suction by bringing a suction member having suction holes on a surface thereof into contact with a surface of the first electrode foil opposite to the surface on which the adhesive is applied.

3. The method for producing a current collector foil according to claim 2 , wherein the suction hole has a diameter of 0.5 mm or more and 15 mm or less.

4. The method for producing a current collector foil according to claim 2 , wherein the spacing between the suction holes is 1.0 mm or more and 20 mm or less.

5. The method for producing a current collector foil according to claim 2 , wherein a suction pressure from the suction hole is 5 kPa or more and 40 kPa or less.

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