JP2020061267A - Manufacturing method of all-solid-state battery - Google Patents

Abstract

To provide a manufacturing method of an all-solid-state battery which can suppress chipping at a cut end, dropout of a constituent material, and the like, and can suppress peeling of a solid electrolyte layer.SOLUTION: A manufacturing method of an all-solid-state battery includes a step of preparing a laminate in which a solid electrolyte layer is laminated on an active material layer, and a step of irradiating the laminate with a laser beam having a wavelength at which the solid electrolyte layer has an absorptivity of 50% or more in the laminating direction of the laminate, and cutting the laminate.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a method of manufacturing an all-solid-state battery.

In recent years, the demand for a laminated battery having a battery structural member (electrode sheet) for an all-solid battery having a positive electrode layer or a negative electrode layer and a solid electrolyte layer is increasing, and a large number of laminated batteries can be efficiently manufactured in a short time. A method is needed.
For example, in Patent Document 1, a laminated body having at least a positive electrode, a solid electrolyte and a negative electrode is manufactured between a first and a second collector foil, and the laminated body is arranged on the positive electrode side and the negative electrode side. Disclosed is a method for manufacturing a solid electrolyte battery, in which a battery structure is obtained by cutting by engaging two cutting blades.
However, when a laminated body having such a positive electrode layer or a negative electrode layer and a solid electrolyte layer, or a laminated structure in which these are laminated is cut by a cutting blade as described in Patent Document 1, a cutting portion There is a problem that chipping and the falling of constituent materials are likely to occur at the end portion (hereinafter, referred to as a cut end).
On the other hand, Patent Document 2 discloses that as a cutting method for a laminate having a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, cutting by a blade, polishing, cutting by laser, ultrasonic wave, or the like can be adopted. Has been done.

JP, 2014-127260, A JP, 2005-103432, A

As described above, when the laminate including the positive electrode layer or the negative electrode layer and the solid electrolyte layer or the laminated structure in which these are laminated is cut by laser irradiation, the constitution of the positive electrode layer or the negative electrode layer by the irradiation heat at the time of laser irradiation. Since the material is melted and each melted material is solidified at the cut end, there is an advantage that the above-described problems such as chipping at the cut end and dropping of constituent materials are suppressed.
On the other hand, when the above-described laminated body including the positive electrode layer or the negative electrode layer and the solid electrolyte layer or the laminated structure in which the laminated body is laminated is cut with a laser beam, a phenomenon in which a part of the solid electrolyte layer peels easily occurs. There was a problem.
The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing an all-solid-state battery that can suppress chipping at a cut end, dropping of constituent materials, and the like, and can suppress peeling of a solid electrolyte layer.

  The method for manufacturing an all-solid-state battery of the present disclosure includes a step of preparing a laminate in which a solid electrolyte layer is laminated on an active material layer, and a laser beam having a wavelength at which the absorption rate of the solid electrolyte layer is 50% or more. Irradiating in the laminating direction of the laminated body to cut the laminated body.

  According to the present disclosure, it is possible to provide a method for manufacturing an all-solid-state battery that can suppress chipping at a cut end, dropping of constituent materials, and the like, and can suppress peeling of a solid electrolyte layer.

FIG. 3 is a cross-sectional view conceptually showing each step of the manufacturing method of the all-solid-state battery of the present disclosure. FIG. 3 is a cross-sectional view conceptually showing each step of the manufacturing method of the all-solid-state battery of the present disclosure. FIG. 6 is a cross-sectional view conceptually showing a cutting step in the method for manufacturing the all-solid-state battery of the present disclosure. It is a figure which shows the result of the model experiment for confirming the difference of the wavelength dependence of the absorptivity of a laser beam of the active material layer 1 and the solid electrolyte layer 2. In Comparative Example 1, it is a diagram showing an observation image obtained by observing the surface of the solid electrolyte layer side after cutting the laminate 1 by laser irradiation with an SEM. It is sectional drawing which shows notionally each process of the manufacturing method of the conventional all-solid-state battery. It is sectional drawing which shows notionally each process of the manufacturing method of the conventional all-solid-state battery. In Example 1, it is a figure which shows the observation image which observed the surface by the side of a solid electrolyte layer after cutting the laminated body 1 by laser irradiation by SEM.

Below, the manufacturing method of the all-solid-state battery of this indication is demonstrated.
In the present disclosure, a layer containing a solid electrolyte interposed between a positive electrode and a negative electrode is called a solid electrolyte layer, and a layer containing an active material is called an active material layer.

Conventionally, the laminated body 106 in which the active material layer 1 and the solid electrolyte layer 2 are laminated on the electrode current collector 4 is arranged so that the surface on the solid electrolyte layer 2 side is the upper surface side, and the solid electrolyte layer 2 When the cutting step of cutting the laminated body 106 by irradiating the laser light L from the side (see FIG. 6A) is performed, a part of the solid electrolyte layer 2 is formed in the irradiation portion of the laser light L or a region in the vicinity thereof. However, the peeled portion 21 (see FIG. 6C) due to the interlayer peeling at the interface with other layers such as the active material layer 1 was likely to occur. Therefore, when the active material layer 3 on the counter electrode side is further stacked on the solid electrolyte layer 2a of the laminated body 106a after the cutting step, the active material on the counter electrode side is located at a position including the peeled portion 21 of the solid electrolyte layer 2a. The layer 3 may be stacked (see FIG. 6D), and in the obtained all-solid-state battery, there is a problem that the insulating property between the pair of active material layers 1 a and 3 (between the positive electrode and the negative electrode) is reduced. there were.
On the other hand, in order to suppress such a decrease in the insulation between the pair of active material layers (between the positive electrode and the negative electrode) in the all-solid-state battery, the peeling portion 21 of the solid electrolyte layer 2 is avoided to avoid the active material layer on the counter electrode side. 3 had to be stacked (see FIG. 6 (e)). In this case, the active material layer 11 immediately below the peeled portion 21 of the solid electrolyte layer 2 is often removed after the cutting step in order to prevent a short circuit, and accordingly, the loss of the active material layer 1 increases. There was a problem. Even when the active material layer 11 existing immediately below the peeled portion 21 of the solid electrolyte layer 2 is not removed after the cutting step, the active material layer 3 on the counter electrode side is the peeled portion of the solid electrolyte layer 2 as described above. Since it is necessary to avoid the layer 21 and stack the layers (see FIG. 1E), the area balance between the active material layer 1a and the active material layer 3 on the counter electrode side becomes poor. Therefore, the active material layer 11 existing immediately below the peeled portion 21 is not fully utilized during charge / discharge of the all-solid-state battery, resulting in a large loss of the active material layer 1.

In addition, on the solid electrolyte layer 2 of the laminated body in which the active material layer 1 and the solid electrolyte layer 2 are laminated on the electrode current collector 4, the active material layer 3 on the counter electrode side on the side opposite to the active material layer 1 is formed. When the laminated body 107 in which the layers are laminated is cut by the laser beam L (see FIG. 7A), the peeled portion 21 caused by the interlayer peeling of a part of the solid electrolyte layer 2 as described above is the counter electrode side. The active material layer 3 may be expanded to the laminated position (see FIG. 7C), and in the obtained all-solid-state battery, the insulating property between the pair of active material layers 1a and 3 (between the positive electrode and the negative electrode) is deteriorated. There was a problem of doing.
On the other hand, in order to prevent the region 21 ′ where the separation of the solid electrolyte is expected to occur due to laser irradiation from overlapping with the formation region of the active material layer 3 on the counter electrode side, the irradiation position of the laser light L is set to the counter electrode. It was necessary to set a position separated from the end portion 31 of the active material layer 3 on the side by a predetermined distance to widen the margin 32 of the cut portion (see FIG. 7D). in this case,
In the laminated body after cutting, the active material layer 12 existing immediately below the region 21 'where the separation of the solid electrolyte is expected to occur is often removed after the cutting step in order to prevent a short circuit. However, there is a problem that the loss of the active material layer 1 becomes large.

It is considered that such a peeling phenomenon of the solid electrolyte occurs by the following mechanism.
For example, in the case of cutting the laminated bodies 106 and 107 having the active material layer 1 and the solid electrolyte layer 2 using the laser light L as shown in FIGS. 6 and 7, from the viewpoint of versatility, high output, and cost, Generally, the most popular laser light having an infrared wavelength has been used. As described above, when the laminate is cut using the laser light having the infrared wavelength, the solid electrolyte layer 2 which is the upper layer of the active material layer 1 is relatively difficult to cut.
Therefore, when the laser light L having such a wavelength is applied to the above-mentioned stacked bodies 106 and 107 from the side having the solid electrolyte layer 2, the active material layer generally has a comparison for any wavelength. Since the laser light L has a relatively high absorptance, the laser light L passes through the solid electrolyte layer 2 and is absorbed in the active material layer 1 (see FIGS. 6A and 7A). The active material layer 1 is cut by the constituent materials being vaporized by the energy of the absorbed laser light L. The jet gas G generated by the vaporization of the constituent material of the active material layer 1 is confined inside the stacked bodies 106 and 107 by the solid electrolyte layer 2 and the free passage is blocked (FIG. 6 (a)). ), See FIG. 7 (a). Therefore, the jetted gas G trapped inside the stacked bodies 106 and 107 has no escape area, so that part of the solid electrolyte layer 2 peels off (see FIGS. 6B and 7B), It is considered that the peeled portion 21 occurs (see FIGS. 6C and 7C).

FIG. 4 is a diagram showing the results of a model experiment for confirming the difference in the wavelength dependence of the absorptance of laser light between the active material layer 1 and the solid electrolyte layer 2. In FIG. 4, a curve (a) is a graph showing the wavelength dependence of the absorptance of laser light of a Si particle layer made of Si particles, which is a material generally used as a negative electrode active material, and FIG. medium curve (b) is a material which is generally used as a solid electrolyte, the wavelength of the laser light absorptance of _LiI-Li 2 _S-P 2 consists _{S 5 LiI-Li 2 S-} P 2 S 5 layers It is a graph which shows dependence.
As shown by the curve (a) in FIG. 4, the Si particle layer has an absorptance of 50% or more for laser light having a wavelength near 1070 nm. On the other hand, as shown by the curve (b) in FIG. 4, the LiI-Li ₂ S-P ₂ S ₅ layer has only about 20% absorptance with respect to laser light having a wavelength near 1070 nm.

Such a laser beam having a wavelength in the vicinity of 1070 nm is applied to a laminated body of a Si particle layer (active material layer model layer) and a LiI-Li ₂ S-P ₂ S ₅ layer (solid electrolyte layer model layer). in contrast, was irradiated from _{LiI-Li 2 S-P 2} S 5 -layer side, the phenomenon in which a part of _{LiI-Li 2 S-P 2} S 5 -layer is peeled off from the Si particles layer has occurred.
This is in _{LiI-Li 2 S-P 2} S 5 layers and Si particles layer, respectively showing the absorption rate as described above, a laser beam having a wavelength of 1070nm vicinity, a _{LiI-Li 2 S-P 2} S 5 layers It is considered that this is because the light was transmitted and absorbed in the Si particle layer.

The graph shown in FIG. 4 is specifically obtained by the following method using a spectroscopic measurement device (UV-260, manufactured by Shimadzu Corporation).
That is, the Si particles or _{LiI-Li 2 S-P 2} S 5 powder to be measured, respectively, in the recess portion of the measuring portion (a depth of about 3mm spectrometric instrument, the barium sulfate to a depth about 2mm on the filled layer filled with Si particles or _{LiI-Li 2 S-P 2} S 5 powder to be measured, compacted and put into to form a thick layer) of about 1 mm, the measurement The reflectance was measured by irradiating from the upper surface side of the part while sequentially changing the wavelength of light, and the absorptance calculated from the reflectance was plotted against the wavelength of light.

In contrast to such a conventional manufacturing method, the manufacturing method of the all-solid-state battery of the present disclosure has the following features.
The method for manufacturing an all-solid-state battery of the present disclosure includes a step of preparing a laminate in which a solid electrolyte layer is laminated on an active material layer, and a laser beam having a wavelength at which the absorption rate of the solid electrolyte layer is 50% or more. Irradiating in the laminating direction of the laminated body to cut the laminated body.

  According to the manufacturing method of the present disclosure, by using laser light for cutting a laminate in which a solid electrolyte layer is laminated on an active material layer, the active material layer and the solid electrolyte layer are formed by irradiation heat during laser irradiation. Since the respective materials to be melted are melted and the melted materials are solidified at the cutting end, it is possible to suppress the occurrence of defects such as chipping at the cutting end and dropping of constituent materials.

Further, according to the present disclosure, by using a laser beam having a wavelength at which the absorptance of the solid electrolyte layer is 50% or more, for cutting the laminate having a solid electrolyte layer laminated on an active material layer, the laminate It is possible to suppress the phenomenon that a part of the solid electrolyte layer peels off during the cutting.
According to the manufacturing method of the present disclosure, since it is possible to suppress the phenomenon that a part of the solid electrolyte layer peels off during cutting of the laminated body in this way, without increasing the loss of the active material layer, in the all solid state battery, It is possible to secure insulation between the active material layers (negative electrode layer-positive electrode layer).

It is considered that this is due to the following mechanism.
That is, as shown in FIGS. 1 and 2, the laminate having the active material layer 1 and the solid electrolyte layer 2 was irradiated with laser light L having a wavelength at which the absorption rate of the solid electrolyte layer 2 was 50% or more. In this case, the laser light L is absorbed by both the active material layer 1 and the solid electrolyte layer 2 (see FIGS. 1B and 2B).
Therefore, the active material layer 1 and the solid electrolyte layer 2 are cut by the vaporization of their constituent materials by the energy of the absorbed laser light (see FIGS. 1C and 2C). Therefore, the ejected gas G generated by the vaporization of the constituent materials of the active material layer 1 and the solid electrolyte layer 2 is released to the outside through the gas free passage formed in the cutting portion 22 of the solid electrolyte layer 2. (See FIG. 1C and FIG. 2C). Therefore, it is considered that the laminated body can be cut in a state in which the phenomenon that a part of the solid electrolyte layer 2 is separated due to the pressure of the jetted gas G is suppressed.

  In the present disclosure, the absorptance of light is obtained by subtracting, from the irradiation amount of light having a certain wavelength, the amount of the light reflected by the irradiation target and the amount of the light passing through the irradiation target. The value obtained by obtaining the absorption amount and dividing this absorption amount by the irradiation amount of the light of the above wavelength.

As shown in the curves (a) and (b) of FIG. 4 described above, the Si particle layer and the LiI-Li ₂ S-P ₂ S ₅ layer are both 50% for laser light having a wavelength near 470 nm. It has an absorption rate of not less than%.

Such a laser beam having a wavelength of 470nm near, Si particles layer laminate of the (active material layer model layer) and _{LiI-Li 2 S-P 2} S 5 -layer (Model layer of the solid electrolyte layer) in contrast, the case of irradiating from _{LiI-Li 2 S-P 2} S 5 -layer side, without causing a phenomenon in which part of which peeling of _{LiI-Li 2 S-P 2} S 5 -layer, was able to cut the laminate.
This, _LiI-Li in 2 _S-P 2 _{S 5} layers and Si particles layer, respectively showing the absorption rate as described above, the laser light having a wavelength of 470nm near, Si particle layer and _{LiI-Li 2 S-P} 2 It is absorbed in both of the S ₅ layers, and not only the Si particle layer but also the LiI-Li ₂ S-P ₂ S ₅ layer is cut, so that a free passage of gas to the LiI-Li ₂ S-P ₂ S ₅ layer is obtained. It is considered that this is due to the formation of

Hereinafter, a method for manufacturing the electrode member for an all-solid battery of the present disclosure will be described in detail.
1. Method for manufacturing all-solid-state battery (1-1)
1 (a) to 1 (e) are diagrams conceptually showing one embodiment of a method for manufacturing an all-solid-state battery of the present disclosure.
First, as shown in FIG. 1A, the active material layer 1 is stacked on the electrode current collector 4, and the solid electrolyte layer 2 is stacked on the active material layer 1 to prepare a first stacked body 101. Perform the preparation process.
Next, as shown in FIGS. 1B to 1C, a laser beam L having a wavelength at which the absorptance of the solid electrolyte layer 2 is 50% or more is applied to the first laminate 101. A cutting step of irradiating from the layer 2 side in the stacking direction of the first stacked body 101 to cut the first stacked body 101 is performed.
As a result, the first intermediate laminate 101a (electrode current collector 4a-active material layer 1a-solid electrolyte layer 2a) in which the solid electrolyte layer 2a after cutting is laminated on the active material layer 1a after cutting is obtained. To obtain (see FIG. 1 (d)).
The active material layer 3 on the counter electrode side is laminated on the solid electrolyte layer 2a of the first intermediate laminate 101a (electrode current collector 4a-active material layer 1a-solid electrolyte layer 2a) thus obtained. Thus, the all-solid-state battery 201 is obtained (see FIG. 1 (e)).

(1-2)
2A to 2D are views conceptually showing another embodiment of the method for manufacturing an all-solid-state battery of the present disclosure.
First, as shown in FIG. 2A, the active material layer 1 is stacked on the electrode current collector 4, the solid electrolyte layer 2 is stacked on the active material layer 1, and the active material of the solid electrolyte layer 2 is stacked. A preparation step of preparing a second laminated body 102 in which the active material layer 3 on the counter electrode side is laminated on the side opposite to the layer 1 is performed.
Next, as shown in FIGS. 2B to 2C, a laser beam L having a wavelength at which the absorptance of the solid electrolyte layer 2 is 50% or more is applied to the second stacked body 102. From the layer 2 side, irradiation is performed in the stacking direction of the second stacked body 102 to perform a cutting step of cutting the second stacked body 102. Thus, the cut solid electrolyte layer 2a is laminated on the cut active material layer 1a, and the cut solid electrolyte layer 2a is opposite to the cut active material layer 1a on the opposite electrode side. An all-solid-state battery 202 (electrode current collector 4a-active material layer 1a-solid electrolyte layer 2a-counter electrode active material layer 3) in which the layers 3 are stacked is obtained (see FIG. 2D).

  Hereinafter, the manufacturing method of the present disclosure will be described in detail by taking the embodiment described in (1-1) (FIG. 1A to FIG. 1E) as an example.

A-1. Preparation Step First, a preparation step of preparing the first laminate 101 in which the active material layer 1 is laminated on the electrode current collector 4 and the solid electrolyte layer 2 is laminated on the active material layer 1 is performed (see FIG. See a)).
(1) Active Material Layer In the manufacturing method of the present disclosure, the active material layer 1 may be a negative electrode active material layer containing a negative electrode active material or a positive electrode active material layer containing a positive electrode active material.

(1-a) Negative Electrode Active Material Layer The negative electrode active material layer contains at least a negative electrode active material and, if necessary, a solid electrolyte, a conductive material, and other components such as a binder.

Examples of the negative electrode active material include a carbon active material (carbon material), an oxide active material, and a metal active material.
Examples of the carbon active material (carbon material) include mesocarbon microbeads (MCMB), graphite such as highly oriented graphite (HOPG), hard carbon, and soft carbon.
Examples of the oxide active material include Nb ₂ O ₅ , Li ₄ Ti ₅ O ₁₂ and SiO. Examples of the metal active material include In, Al, Si and Sn.
Si may be a simple substance of Si or a Si alloy.

Examples of the shape of the negative electrode active material include a particulate shape.
The average particle diameter (D50) of the particles of the negative electrode active material is usually in the range of 1 nm to 100 μm, and further in the range of 10 nm to 30 μm. If the average particle size of the particles is too small, the handleability may deteriorate, and if the average particle size of the particles is too large, it may be difficult to obtain a flat negative electrode active material layer.

  The ratio of the negative electrode active material in the negative electrode active material layer is not particularly limited, but is, for example, 40% by mass or more and 99% by mass or less, preferably 60% by mass or more and 80% by mass or less. .

  The solid electrolyte in the negative electrode active material layer may be any of a crystalline solid electrolyte, an amorphous solid electrolyte, and a solid electrolyte glass ceramic, and is the same as the solid electrolyte used in the solid electrolyte layer 2 described later. Can be used.

  The negative electrode active material layer may include a conductive material as another component. Examples of the conductive material include carbon materials such as acetylene black (AB), Ketjen black (KB), carbon nanotube (CNT), and carbon fiber (CNF). More specifically, as the carbon material, vapor grown carbon fiber (VGCF) can be mentioned.

  The negative electrode active material layer may contain a binder as another component. As the binder, for example, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), butylene rubber (BR), styrene-butadiene rubber (SBR), polyvinyl butyral (PVB), acrylic resin or the like may be used. it can.

(1-b) Positive Electrode Active Material Layer The positive electrode active material layer contains at least a positive electrode active material, and if necessary, a solid electrolyte, a conductive material, and other components such as a binder. In addition to the above, the positive electrode active material layer may contain a thickener.

A conventionally known material can be used as the positive electrode active material. When the all-solid-state battery is a lithium battery, examples of the positive electrode active material include lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), Li _{1 + x} Ni _1/3 Mn _1/3 Co _{1 / 3} O ₂ , composition represented by lithium manganate (LiMn ₂ O ₄ ), Li _{1 + x} Mn _{2−x− y My} O ₄ (M is one or more selected from Al, Mg, Co, Fe, Ni, Zn) Different element substitution Li—Mn spinel, lithium titanate (Li _x TiO _y ), lithium metal phosphate (LiMPO ₄ , M = Fe, Mn, Co, Ni) and the like.
The shape of the positive electrode active material is not particularly limited, and may be a film shape or a particle shape.

The positive electrode active material may have a coating layer in which the surface of the positive electrode active material is coated with a solid electrolyte.
The method of coating the surface of the positive electrode active material with the solid electrolyte is not particularly limited, and for example, using a rolling fluid type coating device (manufactured by Paulec Co., Ltd.), the positive electrode active material is coated with a solid electrolyte such as LiNbO ₃ in an atmospheric environment. Examples include a method of coating and firing in an atmospheric environment. Further, for example, a sputtering method, a sol-gel method, an electrostatic spraying method, a ball milling method and the like can be mentioned.
It is sufficient that the coating layer contains a substance that has lithium ion conductivity, does not flow even when brought into contact with the active material or the solid electrolyte, and can maintain the form of the coating layer. Specific examples of the solid electrolyte that constitutes the coating layer include solid electrolytes such as LiNbO ₃ , Li ₄ Ti ₅ O ₁₂ , and Li ₃ PO ₄ .

  When the positive electrode active material is particles, the average particle diameter (D50) is usually in the range of 1 nm to 100 μm, and further in the range of 10 nm to 30 μm.

  The proportion of the positive electrode active material in the positive electrode active material layer is not particularly limited, but is, for example, 40% by mass or more and 99% by mass or less, preferably 60% by mass or more and 90% by mass or less. .

  In addition, as the binder, the solid electrolyte, and the conductive material, the same materials as those used for the negative electrode material portion can be used.

As a method of forming the active material layer 1, a material for forming the negative electrode active material layer (a powder of a negative electrode material containing a negative electrode active material and, if necessary, other components. This is also referred to as a negative electrode mixture. ) Or a material for forming a positive electrode active material layer (a powder of a positive electrode material containing a positive electrode active material and optionally other components; this is also referred to as a positive electrode mixture), and a removable binder. A method of forming the active material layer 1 by forming a coating film by applying the dispersion liquid containing the agent on the electrode current collector 4 and then removing the binder from the coating film can be mentioned.
In addition, as another method, a coating liquid is prepared by applying a dispersion liquid containing a negative electrode mixture material or a positive electrode mixture material and a removable binder onto a support other than the electrode current collector 4. After forming the active material layer 1 by removing the binder from the coating film, the active material layer 1 is peeled from the support, and the peeled active material layer 1 is placed on the electrode current collector 4. You may make it laminate | stack.

When the active material layer 1 is a negative electrode active material layer, the active material layer 1 may be formed on the negative electrode current collector.
Examples of the material of the negative electrode current collector include copper and copper alloys, nickel and nickel alloys, and the like. Copper, Ni, Cr, C, etc. plated and evaporated, nickel, Cr, C, etc. plated, evaporated You can also use the ones. In addition, examples of the shape of the negative electrode current collector include a foil shape, a plate shape, and a mesh shape.

When the active material layer 1 is a positive electrode active material layer, the active material layer 1 may be formed on the positive electrode current collector.
Examples of the material of the positive electrode current collector include metal materials such as SUS, Ni, Cr, Au, Pt, Al, Fe, Ti, Zn and Cu. A material obtained by plating or vapor depositing Ni, Cr, C or the like on each of these materials can also be used. Moreover, examples of the shape of the positive electrode current collector include a foil shape, a plate shape, and a mesh shape.

Further, as another method, there is a method in which a negative electrode composite material or a positive electrode composite material is subjected to pressure molding by applying a predetermined press pressure.
Further, as another method, after the negative electrode composite material or the positive electrode composite material, and a powder containing a removable binder is compression molded into a shape of the negative electrode active material layer or the positive electrode active material layer, You may form by the method of heating a molded object and removing a binder from a coating film.

(2) Solid Electrolyte Layer The solid electrolyte layer 2 contains a solid electrolyte and, if necessary, other components such as a binder.
A conventionally known material can be used as the solid electrolyte. As the solid electrolyte, an oxide solid electrolyte and a sulfide solid electrolyte having high Li ion conductivity are preferably used.
Examples of the oxide-based solid electrolyte include Li _6.25 La ₃ Zr ₂ Al _0.25 O ₁₂ , Li ₃ PO ₄ , and LiPON.
In addition, other oxide-based solid electrolytes include insulating ceramics such as alumina and zirconia, or oxide-based amorphous materials such as Li ₂ O—B ₂ O ₃ —P ₂ O ₅ and Li ₂ O—SiO _2. solid _{electrolyte, LiI, Li 3 N, Li} 5 La 3 Ta 2 O 12, Li 7 La 3 Zr 2 O 12, Li 6 BaLa 2 Ta 2 O 12, Li 3 PO (4-3 / 2w) Nw (w < _{1), Li 3.6 Si 0.6 P} 0.4 O 4 oxide crystalline solid electrolyte oxynitride crystalline solid electrolyte such as and the like.
Examples of the sulfide-based solid electrolyte, for _{example, Li 2 S-SiS 2,} LiI-Li 2 S-SiS 2, LiI-Li 2 S-P 2 S 5, LiI-Li 2 S-P 2 O 5, LiI _{-Li 3 PO 4 -P 2 S 5} , Li 2 S-P 2 S sulfide such as ₅ amorphous solid _{electrolyte, Li 7 P 3 S 11,} Li 3.25 P 0.75 glass S ₄ such Examples thereof include ceramics and sulfide-based crystalline solid electrolytes such as thio-LISIO-based crystals such as Li _3.24 P _0.24 Ge _0.76 S ₄ .

  As the solid electrolyte for forming the solid electrolyte layer 2, a powdery solid electrolyte may be used. In that case, the average particle diameter (D50) of the solid electrolyte particles constituting the powder is, for example, in the range of 1 nm to 100 μm, and further in the range of 10 nm to 30 μm.

  As the binder used for the solid electrolyte layer 2, the same binder as used for the negative electrode active material layer described above can be used.

The solid electrolyte may be used alone or in combination of two or more. When using two or more kinds of solid electrolytes, two or more kinds of solid electrolytes may be mixed, or two or more solid electrolyte layers may be formed to form a multilayer structure.
When the solid electrolyte layer 2 has a two-layer structure, for example, a sulfide solid electrolyte may be arranged on the active material layer 1 side, and an oxide solid electrolyte may be arranged on the counter electrode side active material layer 3 side, which will be described later, You may arrange in the reverse order. Any arrangement order may be adopted as long as the arrangement corresponds to the potential window of the solid electrolyte.

The proportion of the solid electrolyte in the solid electrolyte layer 2 is not particularly limited, but is, for example, 50 mass% or more, preferably in the range of 60 mass% or more and 100 mass% or less, and 70 mass% or more. It is more preferably within the range of 100% by mass or less, and particularly preferably 100% by mass.
Examples of other components contained in the solid electrolyte layer 2 include a binder, a plasticizer and a dispersant.

  Examples of the method of forming the solid electrolyte layer 2 include the same method as the method of forming the active material layer 1.

When each layer constituting the first laminate 101 is formed by pressure molding, the negative electrode mixture material or the positive electrode mixture material is pressure formed to form the active material layer 1, and then the active material layer is formed. 1, a solid electrolyte powder and a powder of a solid electrolyte material containing other components as necessary are deposited on one surface side of the solid electrolyte layer 1 and pressure-molded to form a solid electrolyte layer 2 to produce a first laminate 101. You may do it.
In addition, as another method, a negative electrode mixture material or a positive electrode mixture material is charged into a pressure cylinder of powder pressure molding and deposited to a uniform thickness to form a negative electrode mixture layer or a positive electrode mixture layer. On the negative electrode mixture layer or the positive electrode mixture layer, the solid electrolyte material powder is charged and deposited to a uniform thickness to form a solid electrolyte material powder layer. The first stacked body 101 may be manufactured by press-molding a powder deposit having two powder deposit layers at a time.

B-1. Cutting Step Next, laser light L having a wavelength at which the absorptance of the solid electrolyte layer 2 is 50% or more is applied to the first laminate 101 from the solid electrolyte layer 2 side. And a cutting step of cutting the first stacked body 101 is performed by irradiating in the stacking direction (see FIGS. 1B to 1C). As a result, the first intermediate laminate 101a (electrode current collector 4a-active material layer 1a-solid electrolyte layer 2a) in which the solid electrolyte layer 2a after cutting is laminated on the active material layer 1a after cutting is obtained. To obtain (see FIG. 1 (d)). In the present disclosure, since the laser light L having a wavelength at which the absorptance of the solid electrolyte layer 2 is 50% or more is used as the laser light applied when the first laminate 101 is cut, the active material layer 1 and The jet gas G generated by the vaporization of the constituent material of the solid electrolyte layer 2 is released to the outside through the gas free passage formed in the cutting portion 22 of the solid electrolyte layer 2 (see FIG. 1C). . Therefore, in the first intermediate laminate 101a obtained after cutting, the phenomenon that part of the solid electrolyte layer 2 is peeled off is suppressed.

Next, the active material layer 3 on the counter electrode side is laminated on the solid electrolyte layer 2a of the first intermediate laminate 101a (electrode current collector 4a-active material layer 1a-solid electrolyte layer 2a) (Fig. 1 ( See e)).
The active material layer 3 on the counter electrode side is laminated so that the active material layer 3 on the counter electrode side is formed within the region where the solid electrolyte layer 2a after cutting is formed.

  As a method of forming the active material layer 3 on the counter electrode side, the same method as the method of forming the active material layer 1 can be mentioned.

As described above, in the manufacturing method of the present disclosure, in the cutting step, since the laser light L having a wavelength at which the absorption rate of the solid electrolyte layer 2 is 50% or more is used, the first intermediate obtained after cutting is used. In the laminated body 101a, the phenomenon that a part of the solid electrolyte layer 2 is peeled off is suppressed. Therefore, as shown in FIG. 1 (e), when the active material layer 3 on the counter electrode side is stacked on the first intermediate laminate 101a, the end portion 31 of the active material layer 3 on the counter electrode side is It can be arranged at a position close to the cut end 101E by laser irradiation in the first intermediate laminate 101a.
Therefore, it is possible to secure the insulation between the active material layer 1a and the active material layer 3 on the counter electrode side in the obtained all-solid-state battery 201 without increasing the loss of the active material layer 1.

  In the example shown in FIG. 1, the laser light L is irradiated to the first laminated body 101 in which the active material layer 1 and the solid electrolyte layer 2 are laminated in this order on one surface of the electrode current collector 4. Although the cutting process is performed by the above, the active material layers 1 and 1 ′ are laminated on both surfaces of the electrode current collector 4 as shown in, for example, FIG. The laser light L having a wavelength at which the absorption rate of the solid electrolyte layers 2 and 2'is 50% or more is applied to the third laminate 103 in which the solid electrolyte layers 2 and 2'are laminated on the surfaces of the solid electrolyte layers 2 and 2 ', respectively. You may do it.

  Next, the manufacturing method of the present disclosure will be described in detail by taking the embodiment described in (1-2) (FIG. 2A to FIG. 2D) as an example.

A-2. Preparation Step First, as shown in FIG. 2A, the active material layer 1 is laminated on the electrode current collector 4, the solid electrolyte layer 2 is laminated on the active material layer 1, and the solid electrolyte layer 2 A preparatory step of preparing a second laminated body 102 in which the counter electrode side active material layer 3 is laminated on the side opposite to the active material layer 1 is performed.

  The active material layer 1, the solid electrolyte layer 2, and the active material layer 3 on the counter electrode side are all formed in the same manner as described in the above embodiment (1-1) as an example. it can.

B-2. Cutting Step Next, as shown in FIG. 2B, a laser beam L having a wavelength at which the absorption rate of the solid electrolyte layer 2 is 50% or more is applied to the second stacked body 102. From the side, a cutting step of irradiating in the stacking direction of the second stacked body 102 and cutting the second stacked body 102 is performed (see FIGS. 2B to 2C).
Thereby, the solid electrolyte layer 2a after cutting is laminated on the active material layer 1a after cutting, and the active material layer on the opposite side to the opposite side of the active material layer 1a after cutting of the solid electrolyte layer 2a after cutting. An all-solid-state battery 202 (electrode current collector 4a-active material layer 1a-solid electrolyte layer 2a-counter electrode-side active material layer 3) in which 3 is stacked is obtained.
In the manufacturing method of the present disclosure, as described above, the laser light L having a wavelength at which the absorptance of the solid electrolyte layer 2 is 50% or more is used as the laser light applied when the second stacked body 102 is cut. Therefore, the jet gas G generated by the vaporization of the constituent materials of the active material layer 1 and the solid electrolyte layer 2 is released to the outside through the free passage of the gas formed in the cutting portion 22 of the solid electrolyte layer 2. (See FIG. 2 (c)). For this reason, the phenomenon that a part of the solid electrolyte layer 2 after cutting is peeled off is suppressed.
Therefore, when the second laminated body 102 is irradiated with the laser beam, as shown in FIG. 2B, when the laser beam L is irradiated to a position near the end 31 of the active material layer 3 on the counter electrode side. However, it is possible to prevent the peeled portion of the solid electrolyte layer 2a from expanding to the laminated position of the active material layer 3 on the counter electrode side.
Therefore, the insulating property between the active material layer 1a in the all-solid-state battery 202 and the active material layer 3 on the counter electrode side can be ensured without increasing the loss of the active material layer 1.

  In the example shown in FIG. 2, the active material layer 1, the solid electrolyte layer 2, and the active material layer 3 on the counter electrode side are laminated in this order on one surface of the electrode current collector 4 to form a second laminate 102. On the other hand, an example in which the cutting step is performed by irradiating with a laser beam is shown. For example, as shown in FIG. 3B, active material layers 1 and 1 ′ are laminated on both surfaces of the electrode current collector 4, The solid electrolyte layers 2, 2 ′ are laminated on the surfaces of the active material layers 1, 1 ′, and the counter electrode side active material layers 3, 3 ′ are laminated on the surfaces of the solid electrolyte layers 2, 2 ′. The laser light L having a wavelength at which the absorptance of the solid electrolyte layers 2 and 2 ′ is 50% or more may be applied to the fourth laminated body 104.

2. All-solid-state battery 201 In the all-solid-state battery 201, an electrode current collector 4a, an active material layer 1a, a solid electrolyte layer 2a, and a counter electrode-side active material layer 3 are arranged in this order, and these are directly or other materials. Are joined through the part consisting of. Further, in the all-solid-state battery 202, the electrode current collector 4a, the active material layer 1a, the solid electrolyte layer 2a, and the counter electrode-side active material layer 3 are arranged in this order, and these are arranged directly or from another material. It is joined through the part.
Electrode current collector-active material layer-solid electrolyte layer-counter electrode active material layer, the active material layer and the counter electrode side active material layer, the thickness of each is usually about 0.1μm or more 200μm or less, solid electrolyte The thickness of the layer is usually about 0.1 μm or more and 300 μm or less.
Note that other members such as an outer package may be attached to the all-solid-state battery 201 and the all-solid-state battery 202, respectively.

  Hereinafter, the present disclosure will be described more specifically with reference to examples, but the present disclosure is not limited to the examples.

1. Production of laminated body [Production Example 1]
(1) Negative Electrode Material Part Formation Step The following negative electrode raw material was added to a polypropylene container.
Negative electrode active material particles: Single crystal Si (manufactured by Kojundo Chemical Co., Ltd.) (average particle size 5 μm) 2.0 g
-Sulfide-based solid electrolyte: Li ₂ S-P ₂ S ₅ -based glass ceramics containing LiI (average particle size 1.5 μm) 1.5 g
Binder: 10% by mass PVdF binder in butyl butyrate solution 0.4 g
・ Dispersion medium: Butyl butyrate 2.1 g
・ Conductivity aid: VGCF 0.1 g
The mixture in the container was stirred for 30 seconds by an ultrasonic dispersion device (UH-50, manufactured by SMT). Next, the container was shaken with a shaker (TTM-1 manufactured by Shibata Scientific Co., Ltd.) for 30 minutes to prepare a raw material for negative electrode mixture.
The raw material for negative electrode mixture was applied onto one surface of a copper foil (negative electrode current collector, manufactured by UACJ Foil Co., Ltd.) by a blade method using an applicator. This raw material for negative electrode mixture was dried on a hot plate at 100 ° C. for 30 minutes to form a negative electrode active material layer.

(2) Solid Electrolyte Material Part Formation Step The following raw material for solid electrolyte layer was added to a polypropylene container.
· Sulfide-based solid _{electrolyte: Li 2 S-P 2 S} 5 -based glass ceramic (average particle diameter 2.0 [mu] m) containing LiI 1 g
-Binder: 0.1% of 5% by mass butyl butyrate solution of PVdF binder
・ Dispersion medium: Butyl butyrate 1.5 g
The mixture in the container was stirred for 30 seconds by an ultrasonic dispersion device (UH-50, manufactured by SMT). Next, the container was shaken with a shaker (TTM-1 manufactured by Shibata Scientific Co., Ltd.) for 30 minutes to prepare a raw material for a solid electrolyte layer.
The solid electrolyte layer raw material was applied onto a release sheet (Al foil) by a blade method using an applicator to form a solid electrolyte layer. This solid electrolyte layer was dried on a hot plate at 100 ° C. for 30 minutes.

  (2) The solid electrolyte layer-side surface of the laminate of the solid electrolyte layer-release sheet (Al foil) obtained in the solid electrolyte material part forming step is the copper obtained in the (1) negative electrode material part forming step. The negative electrode active material layer is laminated on the negative electrode active material layer-side surface of the laminate of the foil (negative electrode current collector) -negative electrode active material layer, and then the release sheet (Al foil) is peeled from the solid electrolyte layer to obtain the negative electrode active material. The solid electrolyte layer was transferred onto the material layer. Thereby, a laminate 1 (negative electrode current collector (copper foil) -negative electrode active material layer-solid electrolyte layer) was obtained.

2. Cutting of laminate [Example 1]
The laminate 1 produced in Production Example 1 was irradiated with laser light having a wavelength of 0.5 μm from the solid electrolyte layer side in the stacking direction of the negative electrode current collector (copper foil) -negative electrode active material layer-solid electrolyte layer. Then, the laminate 1 was cut.
The solid electrolyte layer of the laminate 1 has an absorptance of laser light having a wavelength of 0.5 μm of 50%.

[Comparative Example 1]
The laminate 1 produced in Production Example 1 was irradiated with laser light having a wavelength of 1 μm from the solid electrolyte layer side in the lamination direction of the negative electrode current collector (copper foil) -negative electrode active material layer-solid electrolyte layer, The laminate 1 was cut.
The absorption rate of the laser beam having a wavelength of 1 μm in the solid electrolyte layer of the laminated body 1 is 20%.

3. Evaluation (1) Observation of laminate after cutting In Example 1 and Comparative Example 1, the surface of the laminate 1 after cutting by laser irradiation on the solid electrolyte layer side was observed by SEM. The observed images are shown in FIGS. 5 and 8.

4. Consideration In Comparative Example 1, the surface of the laminated body 1 after irradiation with a laser having a wavelength of 1 μm in the laminating direction of the laminated body 1 and cutting was about 0 with the laser light irradiation line at the center, as shown in FIG. With the width D of 0.37 mm, peeling of the solid electrolyte layer occurred.
On the other hand, in Example 1, the surface of the laminated body 1 after irradiation with a laser beam having a wavelength of 0.5 μm in the laminating direction of the laminated body 1 and cutting, as shown in FIG. The laminate 1 could be cut without peeling the solid electrolyte layer.

1, 1 ', 1a Active material layer 11 Active material layer 12 immediately below peeled portion 21 Active material layer 2, 2', 2a immediately below region 21 'Solid electrolyte layer 21 Stripped portion 21' Expected region 22 Cutting part 3 of solid electrolyte layer 2, 3'Active material layer 31 on the counter electrode side End part 32 of active material layer 3 on the counter electrode side Margin 4, 4a Electrode current collector 101 First lamination Body 101a First intermediate laminate 101E Cut end 102 Second laminate 103 Third laminate 104 Fourth laminate 106, 106a, 107 Laminate 201, 202 All-solid-state battery L Laser light G Jet gas

Claims (1)

A step of preparing a laminate in which a solid electrolyte layer is laminated on the active material layer,
A step of irradiating a laser beam having a wavelength at which the absorptance of the solid electrolyte layer is 50% or more in a stacking direction of the stack to cut the stack, the all-solid-state battery Manufacturing method.