JP2020082082A - Cutting method of laminate and cutting device of laminate - Google Patents

Abstract

To reduce thermal effect of a laser beam on a laminate in cutting the laminate such as an electrode sheet.SOLUTION: A cutting method of a laminate includes: an irradiation process of irradiating with a plurality of laser beams from upper and lower directions respectively along a lamination direction of the laminate and superimposing at least a part of the respective laser beams on a side surface of the laminate; and a moving process of moving a superimposed part of the respective laser beams along a cutting direction orthogonal to the lamination direction of the laminate while maintaining a superimposed state of the respective laser beams.SELECTED DRAWING: Figure 2

Description

The present invention relates to a laminated material cutting method and a laminated material cutting device.

A technique of cutting a laminated material (for example, an electrode sheet) in which different materials are laminated with a laser beam is known (for example, refer to Patent Document 1). Patent Document 1 discloses a technique in which an electrode sheet having active material layers formed on both sides of a metal foil is irradiated with laser light from both sides in the stacking direction to cut the electrode sheet. Of the two laser beams emitted from both sides, the intensity of one of the laser beams is set to the intensity that can cut only the active material layer, and the intensity of the other laser beam can cut the active material layer and the metal foil. It is set to strength.

JP, 2017-84691, A

In the technique described in Patent Document 1, the intensity of one laser beam may be an intensity that can cut the metal foil and the active material layer on one side. Therefore, the intensity of each laser beam emitted from both sides of the laminated material can be made smaller than the intensity of the laser beam when the electrode sheet and the active material layers on both sides are cut by a single laser beam. However, the one-sided active material layer, which is irradiated with laser light capable of cutting the metal foil, is irradiated with laser light having a higher intensity than the other laser light, which may cause thermal influence on the active material layer. .. On the other hand, if the two laser beams are set to have the same intensity, the heat absorbed from both sides of the metal foil from each laser beam diffuses to the surroundings, so that the intensity of each laser beam can be adjusted by one laser beam. It must be greater than half the strength at which the sheet can be cut. That is, the intensity of the laser light is increased, and the thermal effect on the active material layer is increased.

The present invention has been made to solve the above-mentioned problems, and provides a method for cutting a laminated material and a cutting device for the laminated material, which reduce the thermal effect of laser light on the laminated material when cutting the laminated material such as an electrode sheet. The purpose is to provide.

The present invention has been made to solve the above problems, and can be implemented as the following modes.

(1) According to one aspect of the present invention, a method for cutting a laminated material is provided. This cutting method is a step of irradiating a plurality of laser beams from respective upper and lower directions along the laminating direction of the laminated material to overlap at least a part of each laser beam on the side surface of the laminated material, A moving step of moving the overlapping portion of each laser light along a cutting direction orthogonal to the stacking direction while maintaining the overlapping state of the laser light.

According to this configuration, the side surface of the laminated material is irradiated with the overlapping portion where the plurality of laser lights are overlapped and the intensity of the laser lights is high. When the overlapping portion moves along the cutting direction while maintaining the overlapping state of each laser beam, each layer of the laminated material is cut by the laser beam. Here, the side surface of the laminated material with which the overlapping portion is irradiated is irradiated with the highest intensity laser light in which a plurality of laser lights overlap. By placing the overlapping portion on the side surface of the layer that must be irradiated with the highest intensity laser light for cutting, the other layer can be applied to the laminated material from the upper side or the lower side along the laminating direction. Only the laser light that is emitted is emitted. With this, only a part of the laser light is irradiated to the layer that does not need to be irradiated with the high-intensity laser light, so that the thermal effect generated on the laminated material by the laser light can be reduced.

(2) In the cutting method according to the above-described embodiment, in the moving step, the laser light of each of the laser beams is maintained while maintaining the superposed state of each of the laser beams and maintaining the angle of each of the laser beams with respect to the cutting direction. The overlapping portion may be moved along the cutting direction.
According to this configuration, since the angle of each laser beam with which the side surface of the laminated material is irradiated, that is, the incident angle to the side surface is maintained, the intensity and the irradiation width of the overlapping portion are kept constant. As a result, the laminated material can be stably cut by the laser light having a constant intensity.

(3) In the cutting method according to the above aspect, the plurality of laser lights are first laser light emitted from an upper side in the stacking direction toward a side surface of the multilayer material, and the plurality of laser lights from a lower side in the stacking direction. And a second laser beam emitted toward the side surface of the second laser beam, the angle formed by the first laser beam with respect to the cutting direction, and the angle formed by the second laser beam with respect to the cutting direction, They may be substantially the same.
With this configuration, it is easy to adjust the intensity and irradiation width of the overlapping portion and change the position of the overlapping portion with respect to the laminated material while maintaining the overlapping state.

(4) In the cutting method of the above aspect, each of the laser beams may be P-polarized light parallel to a plane including an optical axis of each of the laser beams.
According to this configuration, compared with the case of the P-polarized light in which the first laser light and the second laser light are not parallel to the plane including the optical axis of the first laser light and the optical axis of the second laser, the overlapping portion The absorption rate and intensity of the laser light absorbed by the laminated material irradiated with are increased. This makes it possible to maintain the intensity of the laser light in the overlapping portion with which the laminated material is irradiated and at the same time reduce the intensity of the laser light itself to be irradiated.

(5) In the method of the above aspect, the laminated material is an electrode sheet in which an active material layer is formed on at least one surface of a metal foil, and in the irradiation step, the laser light on each side surface of the metal foil is used. At least a part of them may be overlapped with each other, and the cutting direction may be a normal direction of a side surface of the metal foil irradiated with the laser light.
The metal foil included in the electrode sheet needs to be irradiated with laser light having a higher intensity than the active material layer in order to be cut. On the other hand, when the active material layer is irradiated with high-intensity laser light, the active material layer is deteriorated by the heat of the laser light. According to this configuration, the overlapping portion exists on the side surface of the metal foil, and the overlapping portion moves along the normal line direction of the side surface of the metal foil irradiated with the laser light. Therefore, the metal foil is cut by the high-intensity laser light, and the active material layer is cut by the weak laser light which does not overlap with other laser light. As a result, an electrode sheet in which deterioration of the active material layer is suppressed is manufactured.

(6) According to another aspect of the present invention, there is provided a laminated material cutting device. This cutting device has a fixing portion for fixing the laminated material, and a side surface of the laminated material fixed to the fixing portion, and at least a part of laser beams from respective upper and lower directions along the laminating direction of the laminated material. And a plurality of emission ports for overlapping and irradiating, and a superposed portion of each laser beam along a cutting direction orthogonal to the stacking direction while maintaining a superposed state of each laser beam emitted from the plurality of emission ports. And a control unit that moves the.
With this configuration, the side surface of the laminated material is irradiated with the superposed portion where the intensity of the laser light is high. The control unit moves the laser light overlapping portion along the cutting direction while maintaining the laser light overlapping state. In this case, the overlapping portion is arranged on the side surface of the layer that must be irradiated with the highest intensity laser light for cutting, so that other layers are irradiated from the upper side or the lower side along the stacking direction. Only the irradiated laser light is irradiated. With this, only a part of the laser light is irradiated to the layer that does not need to be irradiated with the high-intensity laser light, so that the thermal effect generated on the laminated material by the laser light can be reduced.

The present invention can be realized in various modes, for example, a cutting device and a cutting method for a laminated material, a manufacturing method for a laminated material, a computer program for executing these devices and methods, and this computer program. And a non-transitory storage medium storing a computer program.

It is a schematic diagram showing a cutting device of an electrode sheet in a 1st embodiment. It is the schematic sectional drawing which expanded the side surface of the electrode sheet by which a laser beam is irradiated. It is a graph which shows the relationship between the incident angle of a laser beam, and the absorptance of P polarized light and S polarized light with respect to a metal foil. It is a graph which shows the relationship between the incident angle of a laser beam, and the intensity ratio (%) of the laser beam per unit area in an overlapping part. It is a flowchart of a cutting process of an electrode sheet. It is a schematic diagram of an electrode sheet cut by laser light. It is a schematic diagram of an electrode sheet after being cut by laser light. It is the schematic sectional drawing which expanded the side surface of the electrode sheet by which the laser beam in 2nd Embodiment is irradiated.

<First Embodiment>
FIG. 1 is a schematic view showing a cutting device 1 for an electrode sheet 90 according to the first embodiment. The cutting device 1 is a device that cuts a laminated material (for example, an electrode sheet 90) in which a plurality of layers are laminated by laser light. As shown in FIG. 1, the cutting device 1 includes a stage that fixes two laser devices 30a and 30b that irradiate the electrode sheet 90 with laser light, and the electrode sheet 90 and the emission ports 32a and 32b that irradiate laser light. A device 20 and a control device (control unit) 10 that controls the laser devices 30 a and 30 b and the stage device 20 are provided.

The control device 10 is a personal computer. The control device 10 includes a monitor that displays an image, a ROM (Read Only Memory), a RAM (Random Access Memory), a CPU (Central Prcessing Unit), and a keyboard (not shown). The keyboard receives user operations. The CPU executes the functions of various programs by expanding the programs stored in the ROM into the RAM based on the operation received by the operation unit. The monitor displays various images according to the program executed by the CPU. The control device 10 transmits a control signal to the laser devices 30a and 30b and the stage device 20 based on the operation received by the keyboard and the program executed by the CPU.

The laser devices 30a and 30b output laser light. As shown in FIG. 1, the laser devices 30a and 30b emit the first laser light LAa and the second laser light LAb based on the emission ports 32a and 32b and the control signal transmitted from the control device 10. The laser light adjusting units 31a and 31b for adjusting the intensities of the first laser light LAa and the second laser light LAb emitted from the outlets 32a and 32b, and the laser light adjusting units 31a and 31b to the emission ports 32a and 32b are connected. The optical fibers 33a and 33b are provided. The laser device 30a and the laser device 30b are synchronized so that laser light can be emitted at the same timing. Note that, hereinafter, the first laser light LAa and the second laser light LAb are collectively referred to simply as “laser light LAa, LAb”.

As shown in FIG. 1, the stage device 20 fixes the positions of the electrode sheet 90 with respect to the electric stages 21a and 21b that movably support the ejection openings 32a and 32b and the electric stages 21a and 21b. And a stage adjusting unit 23 that moves the ejection ports 32a and 32b with respect to the electric stages 21a and 21b based on a control signal transmitted from the control device 10. Each of the electric stages 21a and 21b movably supports the ejection ports 32a and 32b along a parallel movement direction (cutting direction) CS1. Each of the electric stages 21a and 21b moves along the movement direction CS1 while maintaining the postures of the ejection openings 32a and 32b and maintaining the relative positions of the ejection openings 32a and 32b. Therefore, as shown in FIG. 1, the laser beams LAa and LAb emitted from the emission ports 32a and 32b overlap each other in a part of the overlapping portion and keep the overlapping portion unchanged.

FIG. 2 is an enlarged schematic cross-sectional view of the side surface of the electrode sheet 90 irradiated with the laser beams LAa and LAb. The side surface in the present embodiment refers to a surface of the laminated material other than the laminated surface orthogonal to the laminating direction. In the present embodiment, the electrode sheet 90 cut by the cutting device 1 is a sheet material that is a source of an electrode used in a lithium ion secondary battery.

As shown in FIG. 2, the electrode sheet 90 of the present embodiment is a laminated material in which active material layers 92a and 92b are formed on both surfaces of a metal foil 91. The thickness of the metal foil is about 10 micrometers (μm) to 30 μm. The thickness of the active material layers 92a and 92b is about 100 μm. The metal foil for the positive electrode is made of aluminum, and the active material layer for the positive electrode is made of a metal oxide containing lithium. The metal foil for the negative electrode is made of copper, and the active material layer for the negative electrode is made of conductive graphite. In FIG. 2, the positive electrode and the negative electrode of the metal foil 91 are shown without being distinguished. When the electrode sheet 90 is cut by laser light, the metal foil 91 needs to be irradiated with laser light having a higher intensity than the active material layers 92a and 92b.

As shown in FIG. 2, the laser light LAa, LAb emitted to the electrode sheet 90 from each of the emission ports 32a, 32b is emitted to the side surface of the metal foil 91. The respective angles of incidence of the laser beams LAa and LAb on the side surfaces of the metal foil 91 are incident angles α1 and α2. The incident angle α1 and the incident angle α2 of this embodiment are set to the same 45°. The beam diameters of the laser lights LAa and LAb are the width RL. The irradiation width with which the side surfaces of the metal foil 91 are irradiated with the laser lights LAa and LAb is a width RI. Since the incident angles α1 and α2 are 45°, the irradiation width RI is about 1.41 times the width RL of the beam diameter. The incident angles α1 and α2 in the present embodiment can be rephrased as the angles formed by the laser beams LAa and LAb with respect to the moving direction CS1.

As shown in FIG. 2, the overlapping portions AR where the side surfaces of the electrode sheet 90 are overlapped by being irradiated with the laser beams LAa and LAb are the side surfaces of the metal foil 91 and not the side surfaces of the active material layers 92a and 92b. .. The laser beams LAa and LAb are superposed on the superposed portion AR. Therefore, the overlapping portion AR is irradiated with laser light having a higher intensity than the laser light LAa and the laser light LAb, respectively.

The respective optical axes of the laser beams LAa and LAb and the normal to the side surface of the electrode sheet 90 are included in the same plane. The laser beams LAa and LAb of this embodiment are P-polarized light (P-wave) parallel to the plane. FIG. 3 is a graph showing the relationship between the incident angles α1 and α2 of the laser beams LAa and LAb and the absorptance (%) of P-polarized light and S-polarized light (S-wave) with respect to the metal foil 91. As an example, FIG. 3 shows the relationship when the metal foil 91 is made of copper. As shown in FIG. 3, the absorptance LS of S-polarized light monotonically decreases as the incident angles α1 and α2 increase. The absorptance LP of P-polarized light is higher than that of S-polarized light at any of the incident angles α1 and α2. The absorptance LP of P-polarized light becomes maximum when the incident angles α1 and α2 are around 81°. However, as the incident angles α1 and α2 increase, the area of the overlapping portion AR increases. Therefore, when the incident angles α1 and α2 increase, the intensity of the laser light per unit area in the overlapping portion AR decreases.

FIG. 4 is a graph showing the relationship between the incident angles α1 and α2 of the laser beams LAa and LAb and the intensity ratio (%) of the laser beam per unit area in the overlapping portion AR. The intensity ratio on the vertical axis shown in FIG. 4 is a value normalized with the intensity when the incident angles α1 and α2 are 0° as 100%. As shown in FIG. 4, the intensity ratio of the P-polarized light and the S-polarized light monotonically decreases as the incident angles α1 and α2 increase. The intensity ratio IP of P-polarized light is higher than the intensity ratio IS of S-polarized light at any of the incident angles α1 and α2. Considering the intensity ratio in the overlapping portion AR and the area of the overlapping portion AR, the incident angles α1 and α2 are preferably 45° or less.

FIG. 5 is a flowchart of the cutting process of the electrode sheet 90. In the cutting process of the electrode sheet 90, the electrode sheet 90 is first fixed to the fixing portion 22 (step S1). The electrode sheet 90 is fixed so that the normal line direction of the side surface of the metal foil 91 of the electrode sheet 90 irradiated with the laser beams LAa and LAb and the moving direction CS1 of the emission openings 32a and 32b are parallel to each other. After fixing the electrode sheet 90, laser beams LAa and LAb are emitted from the emission ports 32a and 32b so that the overlapping portion AR is arranged on the side surface of the metal foil 91 (step S2). Incident angles α1 and α2 are set by changing the postures of the ejection openings 32a and 32b with respect to the electric stages 21a and 21b. The wavelengths and pulse widths of the laser lights LAa and LAb are set by the laser light adjusting units 31a and 31b.

After the irradiation of the laser beams LAa and LAb, the control device 10 moves the laser beams LAa and LAb by moving the emission ports 32a and 32b along the moving direction CS1 while maintaining the size of the overlapping portion AR. It is moved along the direction CS1 (step S3). FIG. 6 is a schematic view of the electrode sheet 90 cut by the laser beams LAa and LAb. FIG. 7 is a schematic view of the electrode sheet 90 after being cut by the laser beams LAa and LAb. 6 and 7, only the vicinity of the ejection openings 32a and 32b and the electrode sheet 90 are shown. In the process of step S3, the injection ports 32a and 32b move from the state shown in FIG. 1 along the movement direction CS1 to the state shown in FIG. 7 through the state shown in FIG. Then, the electrode sheet 90 is cut by the laser beams LAa and LAb, and the cutting process (FIG. 5) of the electrode sheet 90 ends. In the state shown in FIG. 7, the laser beams LAa and LAb are shown to overlap the fixed portion 22, but the laser beams LAa and LAb and the fixed portion 22 are different from each other in the direction of penetrating the plane of the drawing. The fixed portions 22 are not irradiated with the laser beams LAa and LAb.

As described above, in the present embodiment, the laser beams LAa and LAb emitted from each of the up and down directions along the stacking direction are emitted to the side surface of the electrode sheet 90 in a state of being overlapped at the overlapping portion AR. The superposed portion AR moves along the movement direction CS1 orthogonal to the stacking direction while maintaining the superposed state of the laser lights LAa and LAb. Therefore, a plurality of laser lights LAa and LAb are overlapped with each other, and a superposed portion AR having a high laser light intensity is applied to the side surface of the metal foil 91 in the electrode sheet 90. When the laser beams LAa and LAb move along the movement direction CS1 while maintaining the overlapping portion AR, the overlapping portion AR is always present on the side surface of the metal foil 91 during the movement. On the other hand, the active material layers 92a and 92b in the electrode sheet 90 are irradiated with only one of the laser beams LAa and LAb. That is, only the metal foil 91 that needs to be irradiated with the high-intensity laser beam for cutting is irradiated with the laser beams LAa and LAb in a superimposed manner, and the active material layers 92a and 92b are irradiated to the metal foil 91. Laser light having a weaker intensity than that of the laser light is emitted. This prevents the active material layers 92a and 92b from being irradiated with a laser beam having a higher intensity than necessary, so that the thermal effect generated on the active material layers 92a and 92b can be reduced.

Further, in the present embodiment, the overlapping portion AR moves along the movement direction CS1 while maintaining the incident angles α1 and α2 of the laser beams LAa and LAb on the side surface of the electrode sheet 90. Further, the incident angle α1 of the first laser light LAa on the electrode sheet 90 and the incident angle α2 of the second laser light LAb on the electrode sheet 90 are the same angle. Therefore, the overlapping portion AR having a constant intensity and a constant irradiation width RI is applied to the side surface of the metal foil 91. Thereby, the metal foil 91 can be stably cut. The difference between the incident angle α1 and the incident angle α2 is preferably within 5°, and the smaller the difference, the better.

In addition, in the present embodiment, the laser lights LAa and LAb are P-polarized light parallel to a plane including the optical axis of the first laser light LAa and the optical axis of the second laser light LAb. Therefore, the absorption rate and the intensity of the laser beams LAa and LAb absorbed by the metal foil 91 with which the overlapping portion AR is irradiated are increased. This makes it possible to reduce the respective intensities of the laser beams LAa and LAb while maintaining the intensities of the laser beams LAa and LAb in the overlapping portion AR. Further, in addition to the respective optical axes of the laser lights LAa and LAb, the normal line on the side surface of the metal foil 91 is also on the same plane, and therefore the absorption rate and the intensity of the laser lights LAa and LAb absorbed by the metal foil 91 are shown. Can be even higher.

<Second Embodiment>
FIG. 8 is an enlarged schematic cross-sectional view of the side surface of the electrode sheet 90 irradiated with the laser beams LAaa and LAba in the second embodiment. As shown in FIG. 8, in the second embodiment, as compared with the first embodiment, the width RLa of the beam diameter of the laser beams LAaa and LAba irradiated from the emission ports 32a and 32b to the electrode sheet 90 and the irradiation. The width RIa is different, and the other configurations are the same. Therefore, in the second embodiment, laser lights LAaa and LAba different from those in the first embodiment will be described, and other description will be omitted.

As shown in FIG. 8, the beam diameter width RLa and the irradiation width RIa of the laser beams LAaa and LAba of the second embodiment are larger than the beam diameter width RL and the irradiation width RI of the first embodiment. On the other hand, the positions of the emission openings 32a and 32b are set so that the overlapping portions AR on which the laser lights LAaa and LAba are overlapped are the same as in the first embodiment. In the first embodiment, the laser lights LAa and LAb are completely overlapped on the metal foil 91, but in the second embodiment, the laser lights LAaa and LAba are not completely overlapped. Therefore, as shown in FIG. 8, one of the laser beams LAaa and LAba is irradiated to the metal foil 91 and part of the active material layers 92a and 92b before the metal foil 91 is cut. ..

In the second embodiment, the laser beams LAaa and LAba do not have to overlap with each other over the entire irradiation width RIa of the laser beams LAaa and LAba. As shown in FIG. 6, it suffices that the overlapping portion AR be about the thickness of the metal foil 91, and when the incident angles α1 and α2 are 45°, the irradiation width RIa of the laser beams LAaa and LAba is the metal foil. About twice the thickness of 91 is preferable.
<Modification of this embodiment>
The present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the scope of the invention, and the following modifications are possible, for example.

[Modification]
In the first and second embodiments described above, the two laser beams are overlapped to form the overlapping portion AR, but the overlapping portion AR may be formed by overlapping three or more laser lights. The width of the beam diameter, the irradiation width, the wavelength, the incident angle, the type of laser light, and the like in the plurality of laser lights can be variously modified. For example, the width of the beam diameter of each of the plurality of laser lights may be different. For example, the incident angle α1 of the first laser light LAa and the incident angle α2 of the second laser light LAb in the first embodiment may be different. As a result, the reflected light of the laser light LAa, LAb reflected on the side surface of the metal foil 91 does not enter the emission ports 32a, 32b. Moreover, the respective optical axes of the plurality of laser beams may not be on the same plane. The optical axes of the plurality of laser beams may be on the same plane, and the normal to the side surface of the electrode sheet 90 may not be on the plane. The plurality of laser beams need not be P-polarized light parallel to the plane, but may be S-polarized light.

The wavelengths of the laser lights LAa and LAb may be 1 μm band and may be shorter. A nonlinear optical crystal arranged inside the emission ports 32a and 32b may convert the wavelength of 1 μm into a shorter wavelength. When the wavelengths of the laser beams LAa and LAb are short, the absorption rate of the laser beams LAa and LAb in the metal foil 91 of the electrode sheet 90 is high, and the metal foil 91 can be cut with the low intensity laser beams LAa and LAb. The form of oscillation of the laser beams LAa and LAb is preferably a pulse, and particularly, the pulse time width is preferably in the nanosecond (ns) region.

In the above-described first embodiment, the laser light LAa, LAb is irradiated to the electrode sheet 90 from the respective emission openings 32a, 32b of the laser devices 30a, 30b, but the laser light is branched from the emission opening of one laser device. Laser light may be superimposed. The ejection openings 32a and 32b are preferably small.

In the above-described first embodiment, the laser light LAa, LAb with which the electrode sheet 90 is irradiated is moved by the stage device 20, but the positions and postures of the emission openings 32a, 32b are changed by controlling the galvanomirror. Alternatively, the laser beams LAa and LAb may change. As the fixing portion 22, a well-known holder or the like can be adopted, and it may be replaced depending on the size of the electrode sheet 90, or a well-known technique can be applied.

In the first embodiment, the electrode sheet 90 is given as an example of the laminated material cut by the laser beams LAa and LAb, but the laminated material can be variously modified. One of the active material layers 92a and 92b in the electrode sheet 90 may not be formed, or the other layer may be formed. The side surface of the electrode sheet 90 may be formed obliquely at a predetermined angle with respect to the stacking surface without being orthogonal to the stacking direction. In this case, the moving direction CS1 is a direction included in a plane including the normal line of the side surface of the electrode sheet 90 irradiated with the laser beams LAa and LAb and the laminating direction, and included in a plane direction orthogonal to the laminating direction. It may be. The laminated material may be a laminated material that is completely different from the electrode used in the lithium-ion secondary battery, and may be, for example, a printed board or a laminated steel plate. By appropriately changing the stage device 20 and the laser devices 30a and 30b, it is possible to cope with a change in the size of the laminated material.

Although the present aspect has been described above based on the embodiment and the modified examples, the embodiment of the aspect described above is for facilitating the understanding of the present aspect and does not limit the present aspect. The present embodiment can be modified and improved without departing from the spirit and scope of the claims, and the present embodiment includes the equivalents thereof. If the technical features are not described as essential in this specification, they can be deleted as appropriate.

1... Cutting device 10... Control device (control unit)
20... Stage device 21a, 21b... Electric stage 22... Fixed part 23... Stage adjustment part 30a, 30b... Laser device 31a, 32a... Ejection port 33a, 33b... Optical fiber 90... Electrode sheet 91... Metal foil 92a, 92b... Live Material layer AR... Superposed portion CS1... Moving direction LAa, LAaa... First laser light LAb, LAba... Second laser light RI, RIa... Irradiation width RL, RLa... Beam diameter width S1... Irradiation step S2... Moving step α1, α2... Incident angle

Claims (6)

A method of cutting a laminated material,
An irradiation step of irradiating a plurality of laser beams from each of the upper and lower directions along the laminating direction of the laminated material, and superimposing at least a part of each laser beam on the side surface of the laminated material,
And a moving step of moving the overlapped portion of each laser beam along a cutting direction orthogonal to the stacking direction while maintaining the overlapped state of each laser beam. The cutting method according to claim 1, wherein
In the moving step, the superposed state of the laser beams is maintained, and the superposed portions of the laser beams are moved along the cutting direction while maintaining the angles of the laser beams with respect to the cutting direction. , Cutting method. The cutting method according to claim 1 or 2, wherein
The plurality of laser lights,
A first laser beam emitted from the upper side in the stacking direction toward the side surface of the stack material;
A second laser beam emitted from a lower side in the stacking direction toward a side surface of the stack material,
A cutting method in which an angle formed by the first laser light with respect to the cutting direction and an angle formed by the second laser light with respect to the cutting direction are substantially the same. The cutting method according to any one of claims 1 to 3,
The cutting method, wherein each of the laser beams is P-polarized light parallel to a plane including an optical axis of each of the laser beams. The cutting method according to any one of claims 1 to 4,
The laminated material is an electrode sheet having an active material layer formed on at least one surface of a metal foil,
In the irradiation step, at least a portion of each of the laser light is superposed on the side surface of the metal foil,
The cutting method is a normal direction of a side surface of the metal foil irradiated with the laser light. A cutting device for laminated materials,
A fixing portion for fixing the laminated material,
On the side surface of the laminated material fixed to the fixing portion, laser light from each of the upper and lower directions along the laminating direction of the laminated material, a plurality of emission ports for irradiating at least a portion of each other by overlapping.
A cutting device, comprising: a controller that moves the overlapping portion of each laser beam along a cutting direction orthogonal to the stacking direction while maintaining the overlapping state of each laser light emitted from the plurality of emission ports. ..

Images