JP2021034243A - Cutting device for electrode of all-solid-state battery - Google Patents

Abstract

To provide a cutting device for an electrode of an all-solid-state battery capable of suppressing the generation of a foreign matter caused by electrode cutting.SOLUTION: A cutting device 100 for an electrode 60 of an all-solid-state battery includes a laser beam irradiation unit 10 that irradiates the electrode 60 with a laser beam 12 to soften the electrode 60, a blade cutting unit 20 that cuts the electrode 60 with a cutting tool 22, and a control unit 30 that controls to cut the softened electrode 60 with the cutting tool 22.SELECTED DRAWING: Figure 1

Description

The present invention relates to an all-solid-state battery electrode cutting device.

In recent years, secondary batteries such as lithium secondary batteries have been used as portable power sources for personal computers, mobile terminals, etc., and vehicle drive power sources for electric vehicles (EV), hybrid vehicles (HV), plug-in hybrid vehicles (PHV), etc. It is preferably used.

With the widespread use of secondary batteries, further improvement in performance is desired. As a high-performance secondary battery, an all-solid-state battery in which an electrolytic solution is replaced with a solid electrolyte is drawing attention. In the manufacture of an all-solid-state battery, the electrodes are generally cut to a predetermined size.

For example, Patent Document 1 discloses a technique of irradiating a battery laminate provided with a current collector layer and an active material layer with laser light from a laser light source to cut the battery laminate. Further, Patent Document 2 discloses a technique for cutting an electrode body including a positive electrode, a solid electrolyte, and a negative electrode by engaging two cutting blades arranged on the positive electrode side and the negative electrode side.

Japanese Unexamined Patent Publication No. 2016-219348 Japanese Unexamined Patent Publication No. 2014-127260

However, as a result of diligent studies by the present inventor, when the electrode is cut with a laser as in the above-mentioned prior art, foreign matter is generated due to bumping or the like caused by the momentary high temperature of the electrode material, and this foreign matter is short-circuited. As a result, it has been found that there is a problem that the battery performance is lowered.
Further, when the electrode is cut by a cutting blade as in the above-mentioned conventional technique, the electrode material is hard but brittle, so that the electrode material is cracked at the cut portion, and the cracked electrode material falls off from the cut portion and is a foreign substance. Therefore, it was found that this foreign substance also causes a short circuit or the like, and as a result, there is a problem that the battery performance is deteriorated.

Therefore, an object of the present invention is to provide an electrode cutting device for an all-solid-state battery capable of suppressing the generation of foreign matter due to electrode cutting.

The electrode cutting device of the all-solid-state battery disclosed herein includes a laser beam irradiation unit that irradiates the electrode with laser light to soften the electrode, a blade cutting unit that cuts the electrode with a cutting tool, and the electrode softens. It is provided with a control unit that controls cutting by the cutting tool in the state of being cut.
According to such a configuration, an electrode cutting device for an all-solid-state battery capable of suppressing the generation of foreign matter due to the cutting of the electrodes is provided.

It is a schematic diagram which shows an example of the electrode cutting apparatus of the all-solid-state battery which concerns on one Embodiment of this invention.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. It should be noted that matters other than those specifically mentioned in the present specification and necessary for carrying out the present invention (for example, general configurations and manufactures of electrode cutting devices for all-solid-state batteries that do not characterize the present invention). The process) can be grasped as a design matter of a person skilled in the art based on the prior art in the art. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the art. Further, in the following drawings, members / parts having the same action are described with the same reference numerals. Further, the dimensional relations (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relations.

FIG. 1 schematically shows an example of an electrode cutting device for an all-solid-state battery according to the present embodiment. The cutting device 100 shown in FIG. 1 includes a laser beam irradiation unit 10, a blade cutting unit 20, and a control unit 30. As shown, the cutting device 100 may include a movable stage 40. The cutting device 100 may include a support 50.

The laser light irradiation unit 10 is configured so that the electrode 60 of the all-solid-state battery arranged on the movable stage 40 can be irradiated with the laser light 12 to soften the electrode 60. Although the laser light irradiation unit 10 is fixed to the cutting device 100, its position can be corrected.
As the laser light irradiating unit 10, a laser output having a constant laser output and having a laser output suitable for softening the electrode 60 may be used, or a laser output capable of changing the laser output and softening the electrode 60. You may use the one that can be adjusted to.
A fiber laser is adopted for the laser light irradiating unit 10, so that the laser irradiating unit 10 is configured as a fiber laser irradiator. However, the laser of the laser light irradiation unit 10 is not limited to the fiber laser, and the type is not limited as long as the electrode 60 can be softened. Lasers, for example, a solid-state laser (e.g., YAG laser, a glass laser, a ruby laser, etc.), liquid lasers (e.g., dye laser, etc.), gas lasers (e.g., CO ₂ laser or the like), a semiconductor laser, free electron lasers, chemical It may be a laser or the like.

The blade cutting portion 20 includes a cutting tool 22, and is configured so that the electrode 60 can be cut by the cutting tool 22. Although the blade cutting portion 20 is fixed to the cutting device 100, its position can be corrected.
In the illustrated example, the blade cutting portion 20 is an ultrasonic cutter provided with a blade tool 22 that vibrates ultrasonically. The type of the blade cutting portion 20 is not limited to this, and other cutting machines (eg, a slitter having a rotary blade, a cutter having a cutting blade movable in the vertical direction, etc.) can be used as the blade cutting portion 20.

The control unit 30 is configured to control cutting by the blade tool 22 of the blade cutting unit 20 in a state where the electrode 60 is softened.
The control unit 30 is an NC control device or a computer connected to the cutting device 100. However, the above control is not limited to this as long as possible. The computer may include a central processing unit (CPU), a ROM in which a program executed by the CPU and the like are stored, a RAM, and the like. According to the program, the cutting device 100 can be controlled so that the electrode 60 is softened and then cut by the cutting tool 22 of the blade cutting portion 20. Such control may be performed by software installed on the computer.
The control unit 30 is connected to the laser light irradiation unit 10, the blade cutting unit 20, and the support base 50. However, as long as the above control is possible, the portion connected to the control unit 30 is not limited to this.
In the above control, for example, the output of the laser light 12 from the laser light irradiation unit 10 and the irradiation point of the laser light 12 are set so that the cutting is performed by the cutting tool 22 of the blade cutting portion 20 in the softened state of the electrode 60. The distance of the blade cutting portion 20 to the cutting edge (the position of the laser light irradiation portion 10 and the position of the blade cutting portion), the moving speed of the movable stage, and the like are adjusted.

An electrode 60 is installed on the movable stage 40 provided on the support base 50, and the electrode is cut on the movable stage 40.
The movable stage 40 is configured to be movable in the horizontal direction, particularly in the linear direction, on the support base 50.
The support base 50 is a base for supporting the movable stage 40. Inside the support base 50, a mechanism (eg, a motor or the like) for moving the movable stage 40 is provided. The moving speed of the movable stage 40 can be controlled by the control unit 30.

The configuration of the cutting device 100 is not limited to the above example.
For example, in the cutting device 100, the stage is fixed so as not to move, and the laser light irradiation unit 10 and the blade cutting unit 20 can be configured to be movable.

Further, the cutting device 100 may include a temperature sensor (not shown). The temperature sensor is, for example, a non-contact temperature sensor installed above the movable stage 40, and is configured to measure the temperature of the upper surface of the electrode 60 irradiated with the laser beam. Alternatively, the temperature sensor is, for example, a contact-type temperature sensor installed in the movable stage 40, and is configured to measure the temperature of the lower surface of the electrode 60 irradiated with the laser beam. In the present specification, one main surface of the electrode 60 in contact with the movable stage 40 is referred to as a "lower surface", and the other main surface facing the lower surface is referred to as an "upper surface".
The temperature of the temperature sensor is output to the control unit 30, and in response to this, the control unit 30 outputs the laser light 12 from the laser light irradiation unit 10, and the distance between the irradiation point of the laser light 12 and the cutting edge of the blade cutting unit 20. (The position of the laser beam irradiation unit 10 and the position of the blade cutting portion), the moving speed of the movable stage, and the like may be adjusted.

It is the electrode 60 of the all-solid-state battery that is cut by the cutting device 100. Hereinafter, the electrode 60 will be described. The electrode 60 is not a component of the cutting device 100.
The electrode 60 typically comprises an active material layer.
The electrode 60 may further include a current collector. When the electrode includes a current collector, the active material layer may be provided on one side of the current collector or on both sides.
The electrode 60 may further include a release base material. The electrode 60 provided with the release base material can be used, for example, to transfer the electrode 60 to another electrode to prepare an electrode body.
The electrode 60 may further include a solid electrolyte layer.

When the electrode 60 is a positive electrode, the active material layer (that is, the positive electrode active material layer) contains the positive electrode active material.
As the positive electrode active material, those used in known all-solid-state batteries may be used. Examples of positive electrode active materials include lithium nickel-based composite oxides, lithium cobalt-based composite oxides, lithium manganese-based composite oxides, lithium nickel cobalt-based composite oxides, lithium nickel-manganese-based composite oxides, and lithium nickel cobalt manganese-based composite oxides. Lithium transition metal composite oxides such as composite oxides; lithium composite compounds having an olivine structure such as _{LiFePO 4 and the like can be mentioned.}
The average particle size of the positive electrode active material is not particularly limited, but is, for example, 0.5 μm to 20 μm, preferably 1 μm to 10 μm.
Unless otherwise specified, the "average particle size" in the present specification corresponds to a cumulative 50% from the particle size side in the volume-based particle size distribution measured by particle size distribution measurement based on the laser diffraction / light scattering method. It refers to the particle diameter of the (D ₅₀ particle size, also called median diameter) of.

The positive electrode active material layer may further contain a solid electrolyte.
As the solid electrolyte, those used in known all-solid-state batteries may be used. Examples of the materials constituting the solid electrolyte include sulfide solid electrolyte materials, oxide solid electrolyte materials, nitride solid electrolyte materials, halide solid electrolyte materials and the like. As the sulfide solid electrolyte material, Li ₂ S-P ₂ S ₅ system material, Li ₂ S-GeS ₂ system material, Li ₂ S-GeS ₂ -P ₂ S ₅ system material, Li ₂ S-SiS ₂ system material _{, Li 2 S-B 2 S} 3 type _material, sulfide material such as Li ₃ PO 4 _-P 2 _{S 5} based material is exemplified. Further, a halogen-added sulfide material obtained by adding a halogen element to the sulfide material can also be used. Examples of the oxide solid electrolyte material include lithium lanthanum zirconium-containing composite oxide (LLZO), Al-doped-LLZO, lithium lanthanum titanium-containing composite oxide (LLTO), Al-doped-LLTO, lithium oxynitride phosphate (LIPON), and the like. Is exemplified.
The average particle size of the solid electrolyte is not particularly limited, but is, for example, 0.5 μm to 10 μm, preferably 1 μm to 5 μm.

The positive electrode active material layer is, if necessary, a conductive material (eg, carbon black such as acetylene black, graphite, carbon nanotubes, etc.), a binder (eg, polyvinylidene fluoride (PVDF), polyethylene terephthalate (PTFE), or the like, and a fluorine-based binder. , A rubber-based binder such as styrene-butadiene rubber (SBR), etc.) may be further contained.

When the electrode is a positive electrode, the current collector (ie, the positive electrode current collector) is typically composed of a metal with good conductivity (eg, aluminum, nickel, titanium, stainless steel, etc.) and is suitable. Is made of aluminum. The positive electrode current collector is preferably a foil-like body. Aluminum foil is particularly preferable as the positive electrode current collector.
The thickness of the positive electrode current collector is not particularly limited, but is preferably 5 μm to 50 μm, more preferably 8 μm to 30 μm, in view of the balance between the capacity density of the battery and the strength of the current collector.

When the electrode 60 is a negative electrode, the active material layer (that is, the negative electrode active material layer) contains the negative electrode active material.
As the negative electrode active material, those used in known all-solid-state batteries may be used. Examples of negative electrode active materials include carbon-based negative electrode active materials such as graphite, hard carbon, soft carbon, and carbon nanotubes; Si-based negative electrode active materials such as Si, silicon oxide, silicon carbide, and silicon nitride; tin, tin oxide, and the like. Examples thereof include Sn-based negative electrode active materials such as tin nitride and tin-containing alloys.
The average particle size of the negative electrode active material is not particularly limited, but is, for example, 1 μm to 20 μm, preferably 2 μm to 10 μm.
The negative electrode active material layer may further contain a solid electrolyte. Examples of the solid electrolyte include the same ones contained in the positive electrode active material layer.
The negative electrode active material layer may be a conductive material (eg, carbon black such as acetylene black, carbon material such as vapor phase carbon fiber, etc.), a binder (eg, a fluorine-based binder such as PVDF, PTFE, SBR, etc.), if necessary. (Rubber-based binder, etc.) may be further contained.
The thickness of the negative electrode active material layer is not particularly limited, but is, for example, 10 μm to 500 μm.

When the electrode 60 is a negative electrode, the current collector (ie, the negative electrode current collector) is typically a metal (eg, copper, copper alloy, nickel) that is difficult to alloy with Li and has good conductivity. Etc.), preferably made of copper. The negative electrode current collector is preferably a foil-like body. Copper foil is particularly preferable as the negative electrode current collector.
The thickness of the negative electrode current collector is not particularly limited, but is preferably 5 μm to 50 μm, more preferably 8 μm to 40 μm, in view of the balance between the capacity density of the battery and the strength of the current collector.

The solid electrolyte layer contains a solid electrolyte. Examples of the solid electrolyte include the same ones contained in the positive electrode active material layer.
The solid electrolyte layer may further contain a binder (eg, a fluorine-based binder such as PVDF or PTFE, a rubber-based binder such as SBR, etc.).
The thickness of the solid electrolyte layer is not particularly limited, but is, for example, 0.1 μm to 500 μm.

Examples of the release base material include aluminum foil and the like.

The electrode 60 may be in the form of an electrode body including a positive electrode, a negative electrode, and a solid electrolyte layer.

Next, the operation when the electrode 60 is cut by the cutting device 100 will be described.
The electrode 60 is arranged on the movable stage 40 on the support base 50. The movable stage 40 can move in the direction of the arrow S. Therefore, the electrode 60 is arranged so that the cutting direction coincides with the direction of the arrow S.

On the other hand, information about the electrode 60 is input to the computer which is the control unit 30, and the moving speed of the movable stage 40 and the distance (offset distance) D between the laser beam irradiation point and the cutting edge of the blade cutting unit 20 are obtained. To determine. Specifically, for example, the offset distance D is determined by multiplying the heating time (s) required for softening the electrode 60 by the moving speed (m / s) of the movable stage 40. According to this determination, the position of the blade cutting portion 20 is corrected.

The upper surface of the electrode 60 is irradiated with the laser beam 12 from the laser beam irradiation unit 10. At this time, the movable stage 40 moves in the direction S of the arrow at the above-determined moving speed. The electrode 60 is locally heated and softened by irradiation with the laser beam 12. At the irradiation point of the laser beam 12, it is preferable to soften the entire electrode 60 in the thickness direction.
Next, cutting is performed by the blade cutting portion 20. Here, since the moving speed of the movable stage 40 and the offset distance D are appropriately adjusted by the control unit 30, cutting is performed by the blade cutting unit 20 while the electrode 60 is softened.

As described above, according to the cutting device 100, cracking of the electrode material can be suppressed by cutting the electrode 60 with the blade cutting portion 20 in a state of being softened by locally heating with a laser beam. Therefore, it is possible to suppress the generation of foreign matter due to cracking of the electrode material when the electrode is cut by the cutting blade. In addition, the temperature at which the electrode 60 is heated is sufficiently lower than the temperature at which the electrode material causes bumping or the like (for example, it may be about 80 ° C.), which is caused by bumping or the like when the electrode is cut by a laser. The generation of foreign matter can be suppressed. That is, according to the cutting device 100, it is possible to suppress the generation of foreign matter due to the cutting of the electrodes.

Further, from another side, by cutting the electrode with a cutting tool in a state of being softened by heating with a laser, it is possible to suppress the generation of foreign matter caused by the cutting of the electrode, so that the foreign matter caused by the cutting of the electrode can be suppressed. Provided is a method for manufacturing an electrode of an all-solid-state battery, which can suppress the occurrence of.

The method for manufacturing the electrode of the all-solid-state battery includes a step of irradiating a sheet for an electrode which is made of the same material as the electrode and has a size larger than the electrode with laser light to soften the sheet for the electrode and the softening of the sheet. It includes a step of cutting the electrode sheet with a cutting tool while it is softened.

The larger the area of the electrode 60 cut by the cutting device 100 (that is, the longer the cutting distance), the greater the advantage of suppressing the generation of foreign matter due to the cutting of the electrode. Therefore, it is preferable that the electrode is an all-solid-state battery used as a driving power source mounted on a vehicle such as an electric vehicle (EV), a hybrid vehicle (HV), or a plug-in hybrid vehicle (PHV). Further, the electrode 60 is preferably an electrode of an all-solid-state lithium secondary battery.

Hereinafter, examples relating to the present invention will be described, but the present invention is not intended to be limited to those shown in such examples.

〔Example〕
Electrodes for an all-solid-state lithium secondary battery in which active material layers were formed on both sides of the current collector were prepared. The dimensions of this electrode were 75 mm in length × 43 mm in width × 0.3 mm in thickness.
In addition, a cutting device having the configuration shown in FIG. 1 was prepared. The cutting device was equipped with a fiber laser, an ultrasonic cutter, a computer, and a linear slider. The ultrasonic cutter was placed at a predetermined distance (offset distance) from the irradiation point of the fiber laser.
The electrodes were set on the linear slider and irradiated with laser light from a fiber laser to soften the electrodes. At this time, the linear slider was moved at a speed of 1 m / s. The conditions for this laser irradiation were as follows.
Laser: IPG Photonics fiber laser "YLR-150 / 1500-QCW-MM-AC"
Beam diameter: φ1 mm
Laser output: 50W

Subsequently, the electrodes were cut with an ultrasonic cutter. The conditions for this cutting were as follows.
Ultrasonic cutter: Sonotec oscillator: SF-3441
Output: 300W
Frequency: 22kHz
Blade material: Carbide Blade thickness: 0.4 mm

A dust sensor ("SN-DSTH01" manufactured by SNC) was used to check the cut electrodes for the presence or absence of dust. As a result, the linear slider was moved at a speed of 1 m / s and an offset distance of 2 to 6 mm. It was confirmed that no dust (foreign matter) having a particle size of 30 μm or more was generated.
Further, from this, it can be seen that 2 ms is required as the heating time. Regarding this, when the temperature distribution of the laser irradiation point of the electrode was measured, it was observed that the temperature was 80 ° C. or higher in all the regions of the front surface, the central portion and the back surface of the electrode after 2 ms had passed at the laser irradiation point. Was done. Therefore, in this example, it was found that cutting should be performed while the temperature of the electrode is 80 ° C. or higher.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.

10 Laser light irradiation unit 12 Laser light 20 Blade cutting unit 22 Blade tool 30 Control unit 40 Movable stage 50 Support base 60 Electrode 100 Cutting device

Claims (1)

A laser beam irradiation unit that irradiates the electrodes with laser light to soften the electrodes,
A blade cutting portion that cuts the electrode with a cutting tool,
A control unit that controls cutting with the cutting tool in a softened state,
An all-solid-state battery electrode cutting device comprising.

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