Disposing method of metal foil

Abstract

To provide a disposing method of metal foil that reduces waste.SOLUTION: A disposing method of metal foil includes: winding up a long piece of metal foil that is left unused during electrode production while being suctioned to a winding core equipped with an air suction mechanism; and then stopping the suction to separate the metal foil from the winding core and recover the metal foil.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for disposing of metal foil. [Background technology]

[0002] For example, in the electrodes of a lithium-ion secondary battery, a laminated foil in which, for example, a metal foil is laminated is used as a current collector.

[0003] Patent Document 1 discloses "a bipolar battery electrode comprising: a current collector including a positive electrode-side metal layer, a negative electrode-side metal layer, and an intermediate layer disposed between the positive electrode-side metal layer and the negative electrode-side metal layer and having a Young's modulus that is 1 / 100,000 to 1 / 2 of that of the positive electrode-side metal layer and that of the negative electrode-side metal layer; a positive electrode electrically coupled to the positive electrode-side metal layer side of the current collector; and a negative electrode electrically coupled to the negative electrode-side metal layer side of the current collector." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-140552 Summary of the Invention [Problem to be solved by the invention]

[0005] When manufacturing current collectors in which positive and negative electrode metal foils are bonded together during the electrode manufacturing process, the roll core with the remaining unnecessary current collector foil is reused, and the unnecessary current collector foil is unwound, cut into sheets, and discarded, resulting in a lot of waste.

[0006] A problem to be solved by one embodiment of the present disclosure is to provide a method for disposing of metal foil that reduces waste. [Means for solving the problem]

[0007] The means for solving the above problems include the following aspects. <1> A method for disposing of metal foil, comprising: winding a long metal foil produced during electrode manufacturing while adsorbing it onto a winding core equipped with an air suction mechanism; and then stopping the suction to separate the metal foil from the winding core and recover the metal foil. [Effects of the Invention]

[0008] According to one embodiment of the present disclosure, a method for disposing of metal foil that reduces waste is provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic perspective view showing an example of a winding core and a metal foil wound around the winding core, which are used in the disposal method of the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of the structure of a winding core used in the disposal method of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] The disposal method of the present disclosure will be described below with reference to the drawings.

[0011] The disposal method of the present disclosure includes, in an electrode manufacturing process, winding up an unnecessary long metal foil while suctioning it onto a winding core equipped with an air suction mechanism, and then stopping the suction to separate the metal foil from the winding core and recover the metal foil. By including such a process, it is possible to reduce waste.

[0012] The metal foil may be made of metal such as aluminum (Al), stainless steel (SUS), nickel (Ni), copper (Cu), or a conductive resin. The metal foil may be a substrate having a surface coated with aluminum, copper, or the like, or may be a substrate having a carbon coating. Examples of unnecessary long metal foil in the electrode manufacturing process include, for example, Al foil that remains unused on the Al foil unwinding roll during the process of laminating Al foil and Cu foil to produce a laminated foil.

[0013] Fig. 1 is a schematic perspective view showing an example of a winding core used in the disposal method of the present disclosure and a metal foil wound around the winding core. The disposal method of the present disclosure can be performed using the winding core 30 shown in Fig. 1 (air suction mechanism not shown). As shown in Fig. 1, the winding core 30 has a plurality of holes H in the circumferential direction.

[0014] An example of the structure of the winding core 30 shown in Fig. 1 is shown more specifically in Fig. 2. Fig. 2 is a schematic cross-sectional view showing an example of the structure of a winding core used in the disposal method of the present disclosure. As shown in Figure 2, the winding core 30 has a core material 32 with a hollow portion, an inner tube 34 provided on the outside of the core material 32, and an outer tube 36 provided on the outside of the inner tube 34, and an air suction mechanism 38 is provided in the hollow portion of the core material 32.

[0015] The core material 32, the inner tube 34, and the outer tube 36 may each be made of, for example, stainless steel, which has excellent corrosion resistance. The core material 32, the inner tube 34, and the outer tube 36 may be subjected to an antistatic treatment to prevent unintended adhesion due to static electricity of the metal foil wound around the winding core.

[0016] The core 32 is a hollow shaft member. The core 32 is disposed along the central axis of the winding core 30 and is supported by a support member (not shown) that supports the winding core 30.

[0017] The inner cylinder 34 is a cylindrical member. Both ends of the inner cylinder 34 may be fitted into spacers (not shown) and fixed to the core material 32.

[0018] The outer cylinder 36 is a cylindrical member having an inner diameter larger than the outer diameter of the inner cylinder 34. The outer cylinder 36 is provided on the outside of the inner cylinder 34. The outer cylinder 36 may rotate via a bearing (not shown) attached to the core material 32.

[0019] 2, the outer cylinder 36 has a plurality of holes H over the entire circumferential area. The inner cylinder 34 has a plurality of holes H in one circumferential area. The core material 32 has one hole H in one circumferential area.

[0020] As described above, the hollow portion of the core material 32 is provided with an air suction mechanism 38. By using this air suction mechanism 38, air A can be sucked from the outside through a plurality of holes H provided in the outer cylinder 36. The air suction mechanism 38 is not particularly limited and may be, for example, a vacuum pump. The vacuum pump may be a diaphragm type or a oscillating piston type.

[0021] Additionally, core material 32 is provided with a valve V adjacent to one of holes H on the hollow portion side for closing hole H. Valve V is configured to open when the pressure in the hollow portion of core material 32 is lower than the external pressure, and to close when the pressure in the hollow portion of core material 32 is higher than the external pressure. The core material 32 is also provided with an air A exhaust section (not shown) that communicates with the outside and exhausts the air A sucked in from the outside. The exhaust section is provided with a valve that opens when the pressure in the hollow space of the core material 32 is higher than the outside pressure and closes when the pressure in the hollow space of the core material 32 is lower than the outside pressure.

[0022] The winding core 30 has an air suction mechanism 38 that makes the pressure in the hollow portion of the core material 32 lower than the external pressure. This allows air A to be sucked in through the multiple holes H in the outer tube 36, so that the winding core 30 has an adhesive force around the entire circumferential direction of the outer tube 36. Therefore, the wound metal foil 20 is adsorbed to the winding core.

[0023] Furthermore, the above-described configuration of the winding core 30 increases the suction force compared to when the multiple holes H in the inner tube 34 are provided over the entire circumferential area. Therefore, the metal foil 20 can be wound while being more stably suctioned onto the winding core. The suction force can be further increased by adjusting the function of the air suction mechanism 38.

[0024] Meanwhile, the suction of the metal foil can be stopped as appropriate by adjusting the air suction mechanism 38. By stopping the suction, the adhesive force of the winding core on the metal foil disappears, so the current collecting roll can be separated from the winding core and the current collecting roll can be easily recovered.

[0025] This method eliminates the need to cut the current collector into sheets for disposal when it becomes unnecessary during the battery manufacturing process, and allows the current collector to be reused without being discarded together with the winding core to which the adhesive tape for temporarily fixing the current collector is attached, thereby reducing waste. [Explanation of symbols]

[0026] 18 Winding section, 20 Metal foil, 30 Winding core, 32 Core material, 34 Inner cylinder, 36 Outer cylinder, 38 Air suction mechanism, H hole, A Air, V valve

Claims

[Claim 1] A method for disposing of metal foil, comprising: winding a long metal foil produced during electrode manufacturing while adsorbing it onto a winding core equipped with an air suction mechanism; and then stopping the suction to separate the metal foil from the winding core and recover the metal foil.

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