KR20200056039A - Graphite-free composite anode for all-solid state battery and process for preparing thereof - Google Patents

Abstract

The present invention relates to a graphite-free composite negative electrode for an all-solid battery and a manufacturing method thereof. More specifically, by forming a composite negative electrode capable of storing lithium ions in a minimum volume and weight by using a carbon material such as a carbon nanotube (CNT) without using graphite functioning as a negative electrode active material, it is possible to dramatically reduce the energy density per weight and energy density per volume of the all-solid battery.

Description

Graphite-free composite anode for all-solid state battery and process for preparing thereof

The present invention relates to a composite anode for an all-solid-state battery that does not contain graphite and a method for manufacturing the same. Specifically, instead of using graphite as a negative electrode active material, instead of using a carbon material such as carbon nanotubes (CNTs), a composite negative electrode capable of storing lithium ions in a minimum volume and weight is realized, thereby It is characterized by a significant improvement in energy density per weight and energy density per volume.

Secondary batteries that can be charged and discharged are used not only in small electronic devices such as mobile phones and laptops, but also in large vehicles such as hybrid vehicles and electric vehicles. Accordingly, there is a need to develop a secondary battery having higher stability and energy density.

Most of the existing secondary batteries constitute a cell based on an organic solvent (organic liquid electrolyte), and thus show limitations in improving stability and energy density.

On the other hand, all-solid-state batteries using inorganic solid electrolytes have recently been in the spotlight because they can manufacture cells in a safer and simpler form based on technology excluding organic solvents.

However, the all-solid-state battery has a limitation that the energy density and output performance are less than that of a lithium-ion battery using a conventional liquid electrolyte, and studies have been actively conducted to improve the electrode of the all-solid-state battery to solve this.

Particularly, graphite is mainly used as a negative electrode of an all-solid-state battery. In this case, energy density per weight is significantly lower than that of a lithium-ion battery because ionic conductivity can be ensured only when a large amount of solid electrolyte with graphite is added in excess. In addition, when using lithium metal as the negative electrode, there are technical limitations such as price competitiveness and large area.

Japanese Registered Patent No. 5662318 Korean Patent Publication No. 10-2016-0127652 U.S. Patent No. 9,525,192

The present invention is to solve the above problems, the specific purpose is as follows.

An object of the present invention is to provide a composite negative electrode for an all-solid-state battery and an all-solid-state battery including the same while minimizing the volume and weight while being able to exert the original function of a rechargeable battery capable of charging and discharging.

An object of the present invention is to provide an all-solid-state battery having a significantly improved energy density per weight and energy density per volume.

The object of the present invention is not limited to the object mentioned above. The object of the present invention will be more apparent from the following description, and will be realized by means described in the claims and combinations thereof.

The composite negative electrode for an all-solid-state battery according to an embodiment of the present invention includes a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector, and the negative electrode active material layer includes a carbon material and a solid electrolyte.

The negative active material layer may further include a binder.

The negative active material layer may not include graphite and silicon-based compounds.

The carbon material may be selected from the group consisting of carbon nanotubes (CNT), carbon nanofibers (CNF), vapor-grown carbon fibers (VGCF), and combinations thereof.

The carbon material may have an average length of 1 to 300 μm and an average diameter of 1 to 100 nm.

The solid electrolyte may be a sulfide-based solid electrolyte.

The negative active material layer may include a carbon material and a solid electrolyte in a mass ratio of 2: 8 to 8: 2.

The negative active material layer is 80 to 99.9% by weight of a mixture of a carbon material and a solid electrolyte; And 0.1 to 20% by weight of the binder.

The anode active material layer may have a porosity of 0.1 to 70%.

The negative active material layer may have a thickness of 1 to 300 μm.

The negative electrode current collector may be a metal substrate including one selected from the group consisting of nickel (Ni), copper (Cu), and combinations thereof.

The negative electrode current collector has a sheet shape, and includes coating layers formed on both sides, and the coating layers are soft carbon, hard carbon, carbon nanotubes (CNT), carbon nanofibers (CNF), vapor-grown carbon fibers (VGCF) and their It may include those selected from the group consisting of combinations.

The coating layer may have a thickness of 1 to 15㎛.

An all-solid-state battery according to an embodiment of the present invention includes the composite anode, the composite anode, and a solid electrolyte layer positioned between the composite anode and the composite anode.

A method of manufacturing a composite negative electrode for an all-solid-state battery according to an embodiment of the present invention comprises preparing a slurry comprising a carbon material, a solid electrolyte, a binder, and a solvent, and applying the slurry on the negative electrode current collector to form a layer of a predetermined thickness. And forming a negative electrode active material layer having a thickness of 1 to 300 μm and a porosity of 0.1 to 70% by pressing the layer.

According to the present invention, by using a carbon material and a solid electrolyte as a composite negative electrode for an all-solid-state battery, and by having the composite negative electrode having a porosity of a certain ratio, it is possible to implement the function of the negative electrode as before, even in the absence of the negative electrode active material. Volume and weight can be minimized.

According to the present invention, the energy density per weight and the energy density per volume of the all-solid-state battery can be greatly improved.

According to the present invention, since the composite negative electrode does not contain graphite, there is no volume expansion of the negative electrode due to charging and discharging, so that the life of the all-solid-state battery can be greatly increased.

The effects of the present invention are not limited to the effects mentioned above. It should be understood that the effects of the present invention include all effects that can be deduced from the following description.

1 is a cross-sectional view schematically showing a conventional all-solid-state battery.
2 is a cross-sectional view schematically showing an all-solid-state battery according to the present invention.
3 is a cross-sectional view schematically showing a composite negative electrode for an all-solid-state battery according to the present invention.
FIG. 4 is an enlarged view of part A of FIG. 3.
5 shows a method of manufacturing a composite negative electrode for an all-solid-state battery according to the present invention.
6 is a graph showing the results of an experimental example of the present invention.

The above objects, other objects, features and advantages of the present invention will be readily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed contents are thorough and complete and that the spirit of the present invention is sufficiently conveyed to those skilled in the art.

In this specification, the terms "include" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts or combinations thereof described herein, one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, actions, components, parts or combinations thereof are not excluded in advance. In addition, when a part such as a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case of being "directly above" the other part but also another part in the middle. Conversely, when a portion of a layer, film, region, plate, or the like is said to be “under” another portion, this includes not only the case “underneath” another portion, but also another portion in the middle.

Unless otherwise specified, all numbers, values, and / or expressions expressing the amounts of ingredients, reaction conditions, polymer compositions, and blends used herein are those numbers that occur in obtaining these values, among other things. As these are approximations that reflect the various uncertainties of the measurement, it should be understood that in all cases they are modified by the term "about". It will also be understood that when a range is described for a variable, the variable includes all values within the stated range, including the described endpoints of the range. For example, a range of “5 to 10” includes values of 5, 6, 7, 8, 9, and 10, as well as any subrange of 6 to 10, 7 to 10, 6 to 9, 7 to 9, and the like. It will be understood to include, and include any value between integers pertinent to the stated range of ranges such as 5.5, 6.5, 7.5, 5.5 to 8.5 and 6.5 to 9, and the like. Also, for example, the range of “10% to 30%” is 10% to 15%, 12% to 10%, 11%, 12%, 13%, etc., and all integers including up to 30%. It will be understood that it includes any subranges such as 18%, 20% to 30%, etc., and also includes any value between valid integers within the scope of the stated range, such as 10.5%, 15.5%, 25.5%, and the like.

1 is a cross-sectional view schematically showing a conventional all-solid-state battery. Referring to this, the all-solid-state battery includes a negative electrode 70, a positive electrode 80, and a solid electrolyte layer 90 interposed between the negative electrode 70 and the positive electrode 80. The negative electrode 70 includes a negative electrode current collector 71 and a negative electrode active material layer 73, and the positive electrode 80 includes a positive electrode current collector 81 and a positive electrode active material layer 83.

In a conventional all-solid-state battery, the negative active material layer 73 contains graphite as a negative active material. In addition, an excessive amount of solid electrolyte is added together to secure ion conductivity inside the negative electrode active material layer 73. As a result, the volume and weight of the cathode 70 increase, and thus there is a disadvantage in that the energy density is lowered.

In addition, since the negative electrode active material graphite has a large degree of volume expansion and contraction due to charging and discharging of the battery, a short circuit occurs inside the negative electrode active material layer 73 to increase resistance, thereby shortening the life of the battery.

Lithium metal is also used as the negative electrode 70 of the all-solid-state battery. Lithium metal is expensive and has a slow reaction rate. In addition, there is a problem such as disadvantages of short-circuit and large area due to dendrite growth.

The present invention has been devised to solve the above-described conventional problems, and the composite anode for an all-solid-state battery according to the present invention will be described in detail below.

2 is a cross-sectional view schematically showing an all-solid-state battery according to the present invention. Referring to this, the all-solid-state battery includes a composite cathode 10, a composite anode 20, and a solid electrolyte layer 30 positioned between the composite cathode 10 and the composite anode 20.

Composite cathode

3 is a cross-sectional view schematically showing the composite cathode 10. Referring to this, the composite negative electrode 10 includes a negative electrode current collector 11 and a negative electrode active material layer 13 formed on the negative electrode current collector 11.

The negative electrode current collector 11 may include a metal substrate 111 including one selected from the group consisting of nickel (Ni), copper (Cu), and combinations thereof. For example, it may be a nickel mesh, a copper foil, or the like.

The negative electrode current collector 11 has a sheet shape, and may include a coating layer 113 on both sides.

The coating layer 113 is made of soft carbon, hard carbon, carbon nanotube (CNT), carbon nanofiber (CNF), vapor grown carbon fiber (VGCF), and combinations thereof. It may include those selected from the group.

The coating layer 113 may have a thickness of about 1 to 15㎛. The thickness of the coating layer 113 can be measured, for example, by observation by a transmission electron microscope (TEM).

By forming the coating layer 113 of the above material and thickness on the metal substrate 111, it is possible to maintain the potential of the all-solid-state battery.

FIG. 4 is an enlarged view of a portion A of the negative electrode active material layer 13 illustrated in FIG. 3. Referring to this, the negative active material layer 13 includes a carbon material 131 and a solid electrolyte 133.

The negative active material layer 13 does not include negative active materials such as graphite and silicon compounds.

The carbon material 131 may be selected from the group consisting of carbon nanotubes (CNT), carbon nanofibers (CNF), vapor-grown carbon fibers (VGCF), and combinations thereof. For example, carbon nanotubes (CNT) can be used. The carbon nanotube (CNT) may be a single-wall carbon nanotube (SWCNT), a multi-wall carbon nanotube (MWCNT), or the like.

Since the carbon material 131 as described above has many sites capable of binding lithium ions, similarly to graphite, it is possible to store the lithium ions moved to the composite cathode 10 by charging the battery while maintaining the potential of the battery. have.

The carbon material 131 may have an average length of about 1 to 300 μm, an average diameter of about 1 to 100 nm, and an aspect ratio (average length / average particle diameter) of about 10,000 or more. The average length and average diameter of the carbon material 131 are measured by using a commercially available measuring device, or the length and diameter of a predetermined number of carbon materials 131 randomly extracted from an electron micrograph are calculated and then the average value is determined. can do.

The solid electrolyte 133 is a component responsible for conducting lithium ions in the negative electrode active material layer 13, and may be an oxide-based solid electrolyte or a sulfide-based solid electrolyte. However, it is preferable to use a sulfide-based solid electrolyte having high lithium ion conductivity.

The sulfide-based solid electrolyte is Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -LiI, Li ₂ SP ₂ S ₅ -LiCl, Li ₂ SP ₂ S ₅ -LiBr, Li ₂ SP ₂ S ₅ -Li ₂ O , Li ₂ SP ₂ S ₅ -Li ₂ O-LiI, Li ₂ S-SiS ₂ , Li ₂ S-SiS ₂ -LiI, Li ₂ S-SiS ₂ -LiBr, Li ₂ S-SiS ₂ -LiCl, Li ₂ S-SiS ₂ -B ₂ S ₃ -LiI, Li ₂ S-SiS ₂ -P ₂ S ₅ -LiI, Li ₂ SB ₂ S ₃ , Li ₂ SP ₂ S ₅ -Z _m S _n (however, m, n Is a positive number, Z is one of Ge, Zn, Ga), Li ₂ S-GeS ₂ , Li ₂ S-SiS ₂ -Li ₃ PO ₄ , Li ₂ S-SiS ₂ -Li _x MO _y (However, x , y is a positive number, M is one of P, Si, Ge, B, Al, Ga, In), Li ₁₀ GeP ₂ S ₁₂ , and the like.

The sulfide-based solid electrolyte may have an average particle diameter (D50) of 0.1 to 10㎛.

The sulfide-based solid electrolyte is preferably a lithium ion conductivity of 1x10 ^-4 S / cm or more.

The solid electrolyte 133 is mixed with the carbon material 131 in a powder form to constitute a negative electrode active material layer 13. Therefore, an empty space between particles of the solid electrolyte 133 may be formed. In this specification, the empty space formed as above is called a void (B). This will be described later.

The negative active material layer 13 may include a carbon material 131 and a solid electrolyte 133 in a mass ratio of 2: 8 to 8: 2. When the content of the carbon material 131 is less than the above value range, there is insufficient space to store lithium ions in the negative electrode 10, so that the negative electrode 10 cannot function properly, and when it exceeds the above value range, it is relatively solid. The content of the electrolyte 133 decreases, and the lithium ion conductivity in the negative electrode 10 decreases.

The negative active material layer 13 may further include a binder (not shown). The binder may be BR (Butadiene rubber), NBR (Nitrile butadiene rubber), HNBR (Hydrogenated nitrile butadiene rubber), PVDF (polyvinylidene difluoride), PTFE (polytetrafluoroethylene), CMC (carboxymethylcellulose), and the like.

The negative active material layer 13 may include 80 to 99.9% by weight of the mixture of the carbon material 131 and the solid electrolyte 133, and 0.1 to 20% by weight of the binder. When the content of the binder exceeds 20% by weight, the amount of the mixture is too small, so that the negative electrode 10 cannot function properly, and the binder acts as a resistance in the negative electrode 10 to degrade the performance of the battery.

As described above, the negative electrode active material layer 13 includes voids B. When the cathode active material layer is implemented to have a specific range of porosity in a state in which the carbon material 131 is evenly distributed in a powder in a state in which a large number of particles of the solid electrolyte 133 are aggregated, lithium ions in the cathode 10 are generated. Since the space that can be stored can be secured, the negative electrode 10 can function even if there is no negative electrode active material such as graphite.

Specifically, the porosity of the negative electrode active material layer 13 may be 0.1 to 70%. In this specification, the porosity is the ratio of the pores (B) included in the unit volume of the negative electrode active material layer (13). Without being limited thereto, the porosity may be measured as follows.

First, the true density of the negative electrode active material layer 13 is measured using a gas phase displacement method (Pickometer method) or a liquid phase method (Archimedes method), and the thin film density is calculated by the following equation.

Thin film density = thin film weight / (thin film thickness x area)

The porosity is calculated using the true density and thin film density.

Porosity = (true density-thin film density) / true density x 100

The negative active material layer 13 may have a thickness of 1 to 300 μm. If the thickness exceeds 300 μm, the volume of the battery may be too large, and thus the degree of improvement in energy density per volume may not be significant.

The porosity and thickness of the negative electrode active material layer 13 can be adjusted in the manufacturing process, which will be described later.

Composite anode

The composite positive electrode 20 includes a positive electrode current collector 21 and a positive electrode active material layer 23.

The positive electrode current collector 21 may be an aluminum foil or the like.

The positive electrode active material layer 23 may include a positive electrode active material, a solid electrolyte, a conductive material, a binder, and the like.

The positive electrode active material may be an oxide active material or a sulfide active material.

The oxide active material is _{LiCoO 2, LiMnO 2, LiNiO 2} , LiVO 2, Li 1 + x Ni amyeomcheung type active materials such as a _{1/3 Co 1/3 Mn} 1/3 O 2, LiMn 2 O 4, Li (Ni 0. ₅ Mn _{1 .5)} O ₄ spinel and so on of the active material, LiNiVO _4, LiCoVO ₄ including the inversed-spinel type active _{material, LiFePO 4, LiMnPO 4, LiCoPO} 4, LiNiPO 4 olivine active material such as a, Li ₂ FeSiO _4, Li ₂ silicon-containing active material, such as _{MnSiO 4, LiNi 0 .8 Co (} 0.2-x) Al x O 2 (0 <x <0.2) and as Shaped substituted amyeomcheung a portion of the transition metal in different metal electrode active material, Li _{1 + x} Mn _2-xy M _y O ₄ (M is at least one of Al, Mg, Co, Fe, Ni, and Zn and is a spinel-type active material in which a part of the transition metal is replaced with a dissimilar metal, such as 0 <x + y <2), Li Lithium titanate, such as ₄ Ti ₅ O ₁₂ .

The sulfide active material may be copper chevrel, iron sulfide, cobalt sulfide, nickel sulfide, or the like.

The solid electrolyte may be an oxide solid electrolyte or a sulfide solid electrolyte, and may be the same as or different from the solid electrolyte included in the negative active material layer 13.

The conductive material may be carbon black, conductive graphite, ethylene black, graphene, or the like.

The binder may be BR (Butadiene rubber), NBR (Nitrile butadiene rubber), HNBR (Hydrogenated nitrile butadiene rubber), PVDF (polyvinylidene difluoride), PTFE (polytetrafluoroethylene), CMC (carboxymethylcellulose), etc., the negative electrode active material layer (13) It may be the same as or different from the binder included.

Solid electrolyte layer

The solid electrolyte layer 30 is interposed between the composite anode 10 and the composite anode 20 to allow lithium ions to move both electrodes.

The solid electrolyte layer 30 may include an oxide-based solid electrolyte or a sulfide-based solid electrolyte. At this time, the solid electrolyte may be the same as or different from the solid electrolyte included in the composite cathode 10.

5 shows a method of manufacturing a composite negative electrode for an all-solid-state battery according to the present invention. The manufacturing method comprises preparing a slurry containing a carbon material, a solid electrolyte, a binder, and a solvent (S1), applying the slurry on a negative electrode current collector to form a layer having a predetermined thickness (S2) and the layer. And pressing (S3) to form a negative electrode active material layer having a thickness of 1 to 300 μm and a porosity of 0.1 to 70% by pressing.

Since the carbon material, solid electrolyte, and binder of the slurry preparation step (S1) are as described above, detailed descriptions thereof will be omitted.

The solvent of the slurry preparation step (S1) is not particularly limited, but a non-polar solvent that is not reactive with sulfur may be used. For example, aromatic hydrocarbon-based non-polar solvents such as xylene, toluene, ethylbenzene, or aliphatic hydrocarbon-based pentane, hexane, heptane, etc. Can be used.

The slurry application step (S2) is a step of forming a layer by applying the prepared slurry on the negative electrode current collector to a predetermined thickness. The coating method is not particularly limited. For example, it can be applied by a method such as a screen printing method, a spray coating method, a coating method using a doctor blade, a gravure coating method, a dip coating method, a slot die method, or the like.

The layer formed in the slurry application step (S2) may be preferably applied with a somewhat thicker thickness than the desired composite active material layer.

The pressing step (S3) is a step of pressing the layer to form a negative electrode active material layer having a specific range of thickness and porosity. Specifically, a negative electrode active material layer having a thickness of 1 to 300 μm and a porosity of 0.1 to 70% is formed by adjusting the pressurization conditions.

Hereinafter, the present invention will be described in more detail through specific examples. The following examples are only examples for helping the understanding of the present invention, and the scope of the present invention is not limited thereto.

Example 1  To 3

A slurry comprising a carbon material, a solid electrolyte, a binder, and a solvent was prepared. As the carbon material, a carbon nanotube (CNT) having an average length of about 100 μm and an average diameter of about 10 nm was used. As the solid electrolyte, a sulfide represented by Li ₆ PS ₅ Cl having an azirodite type crystal structure was used. Based solid electrolyte was used. As the binder, BR (Butadiene rubber) was used.

A slurry was prepared by adding 95% by weight of a mixture of the carbon material and the solid electrolyte and 5% by weight of a binder to a solvent. At this time, the mass ratio of the carbon material and the solid electrolyte was adjusted to 8: 2 (Example 1), 5: 5 (Example 2), and 2: 8 (Example 3).

The slurry was applied on a negative electrode current collector to form a layer having a predetermined thickness. As the negative electrode current collector, a copper thin plate having a coating layer having a thickness of about 2 μm on both sides was used.

The layer was roll-pressed to complete a negative electrode active material layer having a porosity of about 30% and a composite negative electrode comprising the same.

Experimental Example

After constructing the all-solid-state battery comprising the composite anode according to Examples 1 to 3, charge and discharge evaluation of the all-solid-state battery was performed. The results are shown in FIG. 6.

Referring to this, it can be seen that all of Examples 1 to 3 show equivalent or higher capacity than the conventional all-solid-state battery. Among them, the capacity of Example 2, in which the carbon material and the solid electrolyte were mixed at a mass ratio of 5: 5, was measured to be the highest.

Through this, it can be seen that the use of the composite negative electrode proposed in the present invention enables the implementation of an all-solid-state battery having the same or higher performance than the conventional one without using graphite or silicon-based chemicals as the negative electrode active material. It can be seen that the energy density per volume and the energy density per weight can be greatly improved by minimizing the volume and weight.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the present invention to its technical spirit or essential features. You will understand that there is. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

10: composite negative electrode 11: negative electrode current collector 13: negative electrode active material layer
111: metal substrate 113: coating layer
20: composite positive electrode 21: positive electrode current collector 23: positive electrode active material layer
30: solid electrolyte layer

Claims (15)

Cathode current collector; And
It includes a negative electrode active material layer formed on the negative electrode current collector,
The negative active material layer
Carbon material; And
A composite negative electrode for a solid-state battery comprising a solid electrolyte. According to claim 1,
The negative electrode active material layer is a composite negative electrode for an all-solid-state battery further comprising a binder. According to claim 1,
The negative electrode active material layer is a composite negative electrode for a solid-state battery that does not contain a graphite and silicon-based compounds. According to claim 1,
The carbon material is a composite anode for an all-solid-state battery that is selected from the group consisting of carbon nanotubes (CNT), carbon nanofibers (CNF), vapor phase growth carbon fibers (VGCF), and combinations thereof. According to claim 1,
The carbon material is a composite negative electrode for an all-solid-state battery having an average length of 1 to 300 μm and an average diameter of 1 to 100 nm. According to claim 1,
The solid electrolyte is a sulfide-based solid electrolyte composite negative electrode for an all-solid-state battery. According to claim 1,
The negative active material layer is a composite negative electrode for an all-solid-state battery comprising a carbon material and a solid electrolyte in a mass ratio of 2: 8 to 8: 2. According to claim 2,
The negative active material layer is 80 to 99.9% by weight of a mixture of a carbon material and a solid electrolyte; And 0.1 to 20% by weight of a binder. According to claim 1,
The negative electrode active material layer is a composite negative electrode for an all-solid-state battery having a porosity of 0.1 to 70%. According to claim 1,
The negative electrode active material layer is a composite negative electrode for an all-solid-state battery having a thickness of 1 to 300㎛. According to claim 1,
The negative electrode current collector is a composite negative electrode for an all-solid-state battery comprising a metal selected from the group consisting of nickel (Ni), copper (Cu), and combinations thereof. According to claim 1,
The negative electrode current collector has a sheet shape, and includes a coating layer formed on both sides,
The coating layer is a soft carbon, hard carbon, carbon nanotubes (CNT), carbon nanofibers (CNF), vapor-grown carbon fibers (VGCF), and a composite negative electrode for a solid-state battery comprising a combination of these. The method of claim 12,
The coating layer is a composite negative electrode for an all-solid-state battery having a thickness of 1 to 15㎛. The composite anode of any one of claims 1 to 13;
Composite anodes; And
An all-solid-state battery comprising a solid electrolyte layer positioned between the composite anode and the composite anode. A method for producing a composite negative electrode for an all-solid-state battery according to any one of claims 1 to 13,
Preparing a slurry comprising a carbon material, a solid electrolyte, a binder, and a solvent;
Forming a layer having a predetermined thickness by applying the slurry on a negative electrode current collector; And
A method of manufacturing a composite negative electrode for an all-solid-state battery comprising pressing the layer to form a negative electrode active material layer having a thickness of 1 to 300 μm and a porosity of 0.1 to 70%.

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