KR102312990B1 - All solid secondary battery and method of manufacturing the same - Google Patents

Abstract

Disclosed are an all-solid-state secondary battery and a method for manufacturing the same. The all-solid-state secondary battery includes an anode layer; anode layer; and a solid electrolyte layer disposed between the negative electrode layer and the positive electrode layer, wherein the solid electrolyte layer includes a first solid electrolyte; and
a first bonding layer disposed between the positive electrode layer and the solid electrolyte layer; and a negative active material layer disposed on and wherein the second solid electrolyte may have a lower Young's modulus than that of the first solid electrolyte.

Description

All solid secondary battery and method of manufacturing the same

It relates to an all-solid-state secondary battery and a method for manufacturing the same.

All-solid-state secondary batteries have been manufactured by laminating electrode layers and solid electrolyte layers to realize the function of a large-capacity all-solid-state secondary battery, and then applying pressure with a warm isostatic press device. This type of all-solid-state secondary battery is not suitable for mass production and it may be difficult to form a close interface between the electrode layers and the solid electrolyte layer.

In order to solve this problem, there have been attempts in the art to manufacture an all-solid-state secondary battery by applying pressure with a roll press or hot press equipment. Even in the all-solid-state secondary battery manufactured by this method, it may be difficult to form a close interface between the electrode layers and the solid electrolyte layer, and thus the performance of the all-solid-state secondary battery may be deteriorated.

Therefore, there is still a need for a novel all-solid-state secondary battery and a method for manufacturing the all-solid-state secondary battery.

One aspect is to provide a novel all-solid-state secondary battery.

Another aspect is to provide a method for manufacturing the all-solid-state secondary battery.

According to one aspect,

cathode layer;

anode layer; and

a solid electrolyte layer disposed between the negative electrode layer and the positive electrode layer, wherein the solid electrolyte layer includes a first solid electrolyte; and

a first bonding layer disposed between the positive electrode layer and the solid electrolyte layer, wherein the first bonding layer includes a second solid electrolyte;

The negative electrode layer includes a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, and

The anode active material layer includes an anode active material that does not contain an alkali metal and a binder,

The positive electrode layer includes a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector,

The second solid electrolyte is an all-solid-state secondary battery having a lower Young's modulus than that of the first solid electrolyte.

According to the other aspect,

providing an anode layer;

forming a compressed anode layer by applying pressure to the anode layer;

providing a cathode layer;

providing a solid electrolyte layer;

forming a laminate by laminating the negative electrode layer on the solid electrolyte layer;

forming a compressed negative electrode layer and a solid electrolyte layer by applying pressure to the laminate;

interposing a first bonding layer between the compressed positive electrode layer and the compressed negative electrode layer and the solid electrolyte layer; and

There is provided a method of manufacturing an all-solid-state secondary battery comprising; manufacturing the above-described all-solid-state secondary battery by applying pressure to the compressed positive electrode layer, the first bonding layer, and the compressed negative electrode layer and the solid electrolyte layer. .

According to another aspect,

providing an anode layer;

forming an anode including a first bonding layer by disposing a first bonding layer on one surface of the anode layer;

providing a cathode layer;

providing a solid electrolyte layer;

forming a laminate by laminating the negative electrode layer on the solid electrolyte layer;

forming a compressed negative electrode layer and a solid electrolyte layer by applying pressure to the laminate;

laminating a positive electrode including the first bonding layer on the compressed negative electrode layer and the solid electrolyte layer; and

There is provided a method of manufacturing an all-solid-state secondary battery comprising; manufacturing the above-described all-solid-state secondary battery by applying pressure to the positive electrode including the first bonding layer, the compressed negative electrode layer, and the solid electrolyte layer.

An all-solid-state secondary battery and a method of manufacturing the same according to an aspect include a solid electrolyte layer disposed between a negative electrode layer and a positive electrode layer, wherein the solid electrolyte layer includes a first solid electrolyte, and the positive electrode layer and the solid electrolyte a first bonding layer disposed between the layers, wherein the first bonding layer includes a second solid electrolyte, wherein the second solid electrolyte has a lower Young's modulus than the first solid electrolyte; While reducing the interfacial resistance between the layer and the solid electrolyte layer, cell performance such as rate characteristics and lifespan characteristics can be improved.

1A to 1E are schematic views of a structure of an all-solid-state secondary battery according to an embodiment, respectively.
2 is a schematic diagram of a structure of an all-solid-state secondary battery according to an embodiment.
3 and 4 are schematic views of a method of manufacturing an all-solid-state secondary battery according to an embodiment, respectively.
5A and 5B are images of disassembling the all-solid-state secondary batteries according to Example 1 and Comparative Example 1, respectively, and observing the cross-section using a scanning electron microscope (SEM).
6 is a result of evaluating the initial impedance of the all-solid-state secondary batteries according to Example 1 and Comparative Example 1. Referring to FIG.
7A, 7B, and 7C show that the all-solid-state secondary batteries according to Examples 1, 4, and Comparative Example 1 were charged at 60°C at a rate of 0.1C (C-rate) and 0.2C, 0.33C, respectively. It is the result of evaluating the rate characteristics when discharging at a rate of , and 1.0C, respectively (voltage range of 2.5V to 4.25V).
8a is an evaluation of the lifespan characteristics when charging and discharging the all-solid-state secondary batteries according to Example 1 and Comparative Example 1 at a rate (C-rate) of 0.5C at 60°C (voltage range of 2.5V to 4.25V); It is the result.
8B is a graph showing the evaluation of lifespan characteristics when charging and discharging the all-solid-state secondary batteries according to Examples 1 to 3 at a rate (C-rate) of 0.5C at 60°C (voltage range of 2.5V to 4.25V) It is the result.

Hereinafter, an all-solid-state secondary battery and a manufacturing method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The following is presented by way of example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the claims to be described later.

As used herein, the term “included” means that other components may be further included, rather than excluding other components, unless otherwise stated.

As used herein, the term “and/or” is meant to include any and all combinations of one or more of the related listed items. As used herein, the term “or” means “and/or”. The expression “at least one” or “one or more” in front of a component in the present specification does not mean that it can supplement the entire list of components and can complement individual components of the description.

When it is referred to in this specification that one component is disposed “on” or “on” another component, one component may be disposed directly over the other component or a component interposed between the components. may exist. On the other hand, when it is stated that one element is disposed "directly on" or "directly on" another element, intervening elements may not be present.

As used herein, the term "combination" includes mixtures, alloys, reaction products, and the like, unless specifically stated otherwise.

In this specification, terms such as "first", "second", etc. do not indicate order, quantity, or importance, and are used to distinguish one element from another.

Unless otherwise indicated herein or otherwise clearly contradicted by context, it should be construed to include both the singular and the plural. "or" means "and/or" unless otherwise specified.

Throughout this specification, "one embodiment", "implementation", etc. indicates that a particular element described in connection with an embodiment is included in at least one embodiment described herein, and may or may not be present in another embodiment. means It should also be understood that the described elements may be combined in any suitable manner in the various embodiments.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. All patents, patent applications and other references cited are hereby incorporated by reference in their entirety. However, to the extent a term herein contradicts or conflicts with a term in the incorporated reference, the term from this specification takes precedence over the conflicting term in the incorporated reference. While specific embodiments and implementations have been described, alternatives, modifications, variations, improvements, and substantial equivalents, which are not presently anticipated or anticipated, may occur to applicants or persons skilled in the art. Accordingly, it is intended that the appended claims and amendments cover all such alternatives, modifications, improvements and substantial equivalents.

As used herein, the term "C-rate" is the discharge rate of the battery, and means a value obtained by dividing the total capacity of the battery by the total discharge time. For example, a cell with a discharge capacity of 1.6 ampere-hours would have a C-rate of 1.6 amperes.

In general, all-solid-state secondary batteries have been manufactured by stacking electrode layers and solid electrolyte layers for battery performance and applying pressure with a warm isostatic press device while vacuum-sealed in a pouch cell. The method of manufacturing an all-solid secondary battery using such isostatic press equipment is not suitable for mass production because the pressurization time is long and the pressurization tank volume is small. Therefore, in order to mass-produce an all-solid-state secondary battery, it is suitable to manufacture it using a roll press or hot press equipment. However, when the roll press or hot press equipment is used in this way, deformation may occur in the pouch cell. In addition, it may be difficult to apply pressure at the same time because there is a difference in pressurization conditions due to differences in physical properties between the electrode layers and the solid electrolyte layer. On the other hand, when the electrode layers and the solid electrolyte layer are respectively pressed and laminated to form a cell, the electrode layers and the solid electrolyte layer are compressed, making it difficult to form a close interface therebetween.

The inventors of the present invention intend to propose a novel all-solid-state secondary battery and a method for manufacturing the same based on this point.

1A to 1E are schematic views of a structure of an all-solid-state secondary battery according to an embodiment, respectively.

As shown in FIG. 1A , an all-solid-state secondary battery according to an embodiment includes an anode layer 20; anode layer 10; and a solid electrolyte layer 4 disposed between the negative electrode layer 20 and the positive electrode layer 10 . The solid electrolyte layer 4 includes a first solid electrolyte. The negative electrode layer includes a negative electrode current collector 6 and a negative electrode active material layer 5 disposed on the negative electrode current collector 6, and the negative electrode active material layer 5 includes an alkali metal-free negative electrode active material and Contains binder. The positive electrode layer 10 includes a positive electrode current collector 1 and a positive electrode active material layer 2 disposed on the positive electrode current collector 1 . In the all-solid-state secondary battery, a first bonding layer (3) is also disposed between the positive electrode active material layer (2) and the solid electrolyte layer (4), and the first bonding layer (3) is the solid The electrolyte layer 4 may include a second solid electrolyte having a lower Young's modulus than the first solid electrolyte.

The all-solid-state secondary battery according to an embodiment has a Young's modulus lower than that of the first solid electrolyte of the solid electrolyte layer 4 between the positive active material layer 2 of the positive electrode layer and the solid electrolyte layer 4 by at least 5 GPa. A first bonding layer 3 including a second solid electrolyte may be disposed. For example, the Young's modulus of the second solid electrolyte may be lower than that of the first solid electrolyte by at least 5 GPa, or at least 6 GPa, or at least 8 GPa, or at least 10 GPa. According to an embodiment, the Young's modulus of the second solid electrolyte may be 1 GPa to 10 GPa lower than that of the first solid electrolyte, 3 GPa to 10 GPa lower, or 5 GPa to 10 GPa lower. The first bonding layer 3 may include a second solid electrolyte softer than the first solid electrolyte of the solid electrolyte layer 4 . Since the solid electrolyte contains a powder (particle) material, the Young's modulus of the solid electrolyte is referred to as "powder modulus", for example, Young's modulus (elastic modulus) of the powder material. could be The Young's modulus (elastic modulus) or powder elastic modulus of the powder material of the solid electrolyte may be obtained by analyzing an indentation load-displacement curve obtained through nano-indenter measurement. The Young's modulus (elastic modulus) or powder elastic modulus of the powder material of the solid electrolyte may vary depending on the electrolyte type, such as a powder type, a pellet type, or a sheet type. Due to the disposition of the first bonding layer 3 , a close interface may be formed between the positive electrode layer 10 and the solid electrolyte layer 4 when an all-solid-state secondary battery is manufactured using roll press or hot press equipment. In the all-solid-state secondary battery, while reducing the interfacial resistance between the positive electrode layer and the solid electrolyte layer 4 , battery performance such as rate characteristics and lifespan characteristics may be improved.

For example, the first bonding layer 3 may be a layer interposed between the positive electrode active material layer 2 and the solid electrolyte layer 4 . For example, the first bonding layer 3 may be a layer disposed in contact with one surface of the positive active material layer 2 . The first bonding layer 3 disposed in contact is directly coated on one surface of the positive electrode active material layer 2 or separately to form the first bonding layer 3 and this is used as one surface of the positive electrode active material layer 2 . It can be manufactured through a transfer process.

The first bonding layer 3 may be a sulfide-based solid electrolyte, and may include a solid electrolyte represented by the following Chemical Formula 1:

[Formula 1]

Li _a M _b PS _c A _d

In Formula 1,

0<a≤6, 0≤b≤6, 0<c<6, 0≤d≤6;

M may be Ge, Sn, or Si;

A may be one or more halogen elements.

The solid electrolyte represented by Formula 1 has high ionic conductivity close to the ionic conductivity of the liquid electrolyte at room temperature, 10 ^-2 S/cm to 10 ^-3 S/cm, and thus does not cause a decrease in ionic conductivity. A tight interface may be formed between the layer 10 and the solid electrolyte layer 4 . In addition, the all-solid-state secondary battery including the solid electrolyte represented by Formula 1 may have improved battery performance such as rate characteristics and lifespan characteristics.

The first bonding layer 3 may include the second solid electrolyte represented by Chemical Formula 1, Li ₂ SP ₂ S ₅ , 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 (m, n is a positive number, Z is Ge, Zn or Ga), Li ₂ S-GeS ₂ , Li ₂ S-SiS ₂ -Li ₃ PO ₄ , Li ₂ S-SiS ₂ -Li _p MO _q (p, q is a positive number, M is P, Si , Ge, B, Al, or Ga In), Li ₇ P ₃ S ₁₁ , Li ₇ P _{1 . 4} S ₁₁ , Li ₁₀ GeP ₂ S ₁₂ , or a combination thereof may be further included.

The second solid electrolyte of the first bonding layer 3 may be a crystalline, amorphous solid electrolyte, or a combination thereof. For example, the second solid electrolyte of the first bonding layer 3 may be a mixed solid electrolyte in which a crystalline solid electrolyte and an amorphous solid electrolyte are mixed. For example, the second solid electrolyte of the first bonding layer 3 may be a crystalline solid electrolyte.

The second solid electrolyte of the first bonding layer 3 is in the form of particles and has an average particle diameter (D50) of 3 μm or less, 2.5 μm, or 2 μm. For example, the average particle diameter (D50) of the second solid electrolyte of the first bonding layer 3 may be 0.01 μm to 3 μm, or 0.05 μm to 3 μm, or 0.05 μm to 3 μm. can The second solid electrolyte of the first bonding layer 3 may form a close interface between the positive electrode layer 10 and the solid electrolyte layer 4 without causing a short circuit. Here, the average particle diameter (D50) means a value of the particle diameter corresponding to 50% from the smallest particle when the total number of particles is 100% in the distribution curve accumulated in the order of the smallest particle size to the largest particle size. . In addition, the particle size (D10) and the particle size (D95) mean values of particle diameters corresponding to 10% and 95% from the smallest particle when the total number of particles is 100% in the particle distribution curve, respectively.

The average particle size (D50), particle size (D10), and particle size (D95) may each be measured by methods well known to those skilled in the art, for example, measured with a particle size analyzer, or TEM photograph. Alternatively, it may be measured from an SEM photograph. As another method, it is measured using a measuring device using dynamic light-scattering, data analysis is performed, the number of particles is counted for each particle size range, and the average particle diameter is calculated from this. (D50) value, particle size (D10) value, and particle size (D95) value can be easily obtained.

The thickness of the first bonding layer 3 may be 30 μm or less. For example, the thickness of the first bonding layer 3 may be 10 μm or less. For example, the thickness of the first bonding layer 3 may be 5 μm or less. The first bonding layer 3 having the above thickness range may form a close interface between the positive electrode layer and the solid electrolyte layer 4 without impairing the performance of the battery.

The first solid electrolyte of the solid electrolyte layer 4 is Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -LiX (X is a halogen element), 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 (m, n is a positive number, Z is one of Ge, Zn or Ga), Li ₂ S-GeS ₂ , Li ₂ S-SiS ₂ -Li ₃ PO ₄ , Li ₂ S-SiS ₂ -Li _p MO _q (p, q is a positive number, M is One of P, Si, Ge, B, Al, Ga In), Li _x M' _y PS _z A _w (x, y, z, w are all 0 or more and 6 or less, M' is any of Ge, Sn, or Si one, A is one of F, Cl, Br, or I), or a mixture thereof.

The first solid electrolyte of the solid electrolyte layer 4 may be a sulfide-based solid electrolyte having the same or different composition as the second solid electrolyte of the first bonding layer 3 . For example, the first solid electrolyte of the solid electrolyte layer 4 may be a sulfide-based solid electrolyte having the same composition as the second solid electrolyte of the first bonding layer 3 .

The first solid electrolyte of the solid electrolyte layer 4 may be in the form of particles and have an average particle diameter (D50) of 1.0 μm to 3.5 μm. For example, the average particle diameter (D50) of the first solid electrolyte of the solid electrolyte layer 4 may be 1.0 μm to 3.4 μm, or 1.0 μm to 3.2 μm, or 1.0 μm to 3.1 μm. have. For example, the particle size D10 of the first solid electrolyte of the solid electrolyte layer 4 may be 0.1 μm to 2.0 μm, or 0.1 μm to 1.8 μm, or 0.2 μm to 1.5 μm, respectively. can For example, the particle size (D95) of the first solid electrolyte of the solid electrolyte layer 4 may be 7.0 μm to 11.0 μm, respectively, or 7.0 μm to 10.0 μm, or 8.0 μm to 10.0 μm. can The definition and measurement method of the average particle diameter (D50), the particle size (D10), and the particle size (D95) of the first solid electrolyte of the solid electrolyte layer (4) are the same as those described above, and thus a description thereof will be omitted.

For the first solid electrolyte of the solid electrolyte layer 4, a starting raw material (eg, Li ₂ S, P ₂ S _5, etc.) is treated by a melt quenching method or a mechanical milling method, and heat treatment is performed. can The first solid electrolyte of the solid electrolyte layer 4 may be crystalline or amorphous, and both may be mixed. For example, the first solid electrolyte of the solid electrolyte layer 4 may be a crystalline solid electrolyte.

When using a sulfide-based solid electrolyte material for forming the first solid electrolyte containing Li ₂ SP ₂ S ₅ , _{the mixing molar ratio of Li 2} S and P ₂ S ₅ is, for example, Li ₂ S: P ₂ S ₅ = 50:50 to 90:10, or 60:40 to 90:10, or 75:25 to 90:10. In addition, the solid electrolyte layer 4 may further include a binder. The binder included in the solid electrolyte layer 4 is, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene (PE) , polymethacraylate (PMA), polyacrylic acid (PAA), or a combination thereof, and the like. The binder of the solid electrolyte layer 4 may be the same as or different from the binder of the positive active material layer 2 and the negative active material layer 5 .

The thickness of the solid electrolyte layer 4 may be 10 μm to 150 μm, or 15 μm to 125 μm, or 20 μm to 100 μm.

As shown in FIG. 1B, in the all-solid-state secondary battery according to an embodiment, the second bonding layer 5a is in contact with the surface of the solid electrolyte layer 4 facing the negative active material layer 5 of the negative electrode layer. is disposed, and the second bonding layer 5a may include a third solid electrolyte having a lower Young's modulus than that of the first solid electrolyte of the solid electrolyte layer 4 . In the all-solid-state secondary battery according to an embodiment, the second bonding layer 5a is disposed between the negative electrode layer 20 and the solid electrolyte layer 4 to manufacture the battery using a roll press or hot press equipment. The adhesion between the layers may be improved, and thus a tight interface may be formed between the negative electrode layer 20 and the solid electrolyte layer 4 . In addition, the second bonding layer (5a) can secure high ionic conductivity at room temperature, so that the all-solid-state secondary battery including the same is not only the interfacial resistance between the positive electrode layer and the solid electrolyte layer (4), but also the negative electrode layer and the solid electrolyte layer ( 4) While reducing the interfacial resistance between the cells, at the same time, battery performance such as rate characteristics and lifespan characteristics can be further improved.

The second bonding layer 5a may include an amorphous sulfide-based solid electrolyte. The second bonding layer 5a may include a sulfide-based solid electrolyte having the same or different composition as that of the first bonding layer 5a. For example, the second bonding layer 5a may include Li ₂ SP ₂ S ₅ -LiX (X is a halogen element), Li ₇ P ₃ S ₁₁ , Li ₇ P _{1 . 4} S ₁₁ , Li ₁₀ GeP ₂ S ₁₂ , or a combination thereof.

Also, the second bonding layer 5a may be disposed between the positive electrode active material layer 2 of the positive electrode layer 10 and the solid electrolyte layer 4 together with or instead of the first bonding layer 3 . .

The solid electrolyte layer 4 may further include an alkali metal salt and/or an ionic liquid. For example, the solid electrolyte layer 4 may further include a lithium metal salt and/or an ionic liquid.

The content of the lithium salt in the solid electrolyte layer 4 may be 1M or more, or 2M or more, or 3M or more. For example, the content of the lithium salt in the solid electrolyte layer 4 may be 1M to 4M, or 1M to 3M, or 1M to 2M. The content of the lithium salt may improve ion conductivity by improving mobility of lithium ions in the solid electrolyte layer 4 .

The lithium salt is LiSCN, LiN(CN) ₂ , Li(CF ₃ SO ₂ ) ₃ C, LiC ₄ F ₉ SO ₃ , LiN(SO ₂ CF ₂ CF ₃ ) ₂ , LiCl, LiF, LiBr, LiI, LiB ( C ₂ O ₄ ) ₂ (lithium bis(oxalato) borate, LiBOB), LiBF ₄ , LiBF ₃ (C ₂ F ₅ ), lithium oxalyldifluoroborate (LIODFB), lithium difluoro (oxalato) ) borate (lithium difluoro(oxalato)borate, LiDFOB), lithium bis(trifluoro methanesulfonyl)imide, LiTFSI, LiN(SO ₂ CF ₃ ) ₂ ), lithium bis(fluoro Rosulfonyl)imide (lithium bis(fluorosulfonyl)imide, LiFSI, LiN(SO ₂ F) ₂ ), LiCF ₃ SO ₃ , LiAsF ₆ , LiSbF ₆ , LiClO _{4 ,} or a mixture thereof. For example, the lithium salt may be an imide-based lithium salt, for example, as the imide-based lithium salt, lithium bis(trifluoromethanesulfonyl)imide, LiTFSI, LiN(SO ₂ CF ₃ ) ₂ ), lithium bis(fluorosulfonyl)imide, LiFSI, LiN(SO ₂ F) ₂ ), or a combination thereof. The lithium salt may maintain or improve ionic conductivity by appropriately maintaining chemical reactivity with the ionic liquid.

The weight ratio of the first solid electrolyte and the ionic liquid in the solid electrolyte layer 4 may be 0.1:99.9 to 90:10. For example, the weight ratio of the first solid electrolyte to the ionic liquid may be 10:90 to 90:10. For example, the weight ratio of the first solid electrolyte to the ionic liquid may be 20:80 to 90:10. For example, the weight ratio of the first solid electrolyte to the ionic liquid may be 30:70 to 90:10. For example, the weight ratio of the first solid electrolyte to the ionic liquid may be 40:60 to 90:10. For example, the weight ratio of the first solid electrolyte to the ionic liquid may be 50:50 to 90:10. The solid electrolyte layer 4 having a weight ratio within the above range may maintain or improve ionic conductivity by improving the electrochemical contact area with the electrode. A battery including the same may have improved energy density, discharge capacity, and/or rate characteristics.

The positive electrode layer 10 may include a positive electrode current collector 1 and a positive electrode active material layer 2 disposed on the positive electrode current collector 1 .

The positive electrode current collector 1 is indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn) , aluminum (Al), germanium (Ge), lithium (Li), or a plate or foil made of an alloy thereof may be used. The positive electrode current collector 1 may be omitted.

The positive active material layer 2 may include a positive active material and a solid electrolyte. The solid electrolyte included in the positive electrode active material layer 2 is a first solid electrolyte included in the solid electrolyte layer 4 , a second solid electrolyte included in the first bonding layer 3 , and/or a second bonding layer The third solid electrolyte included in (5a) may be the same as or different from each other.

The positive electrode active material is a compound capable of insertion/desorption of an alkali metal, for example, lithium, and may be used without limitation as long as it is commonly used in the art.

Examples of the intercalation / deintercalation of the lithium compound is a _{Li a A 1 - b B '} b D' 2 ( in the above formula, 0.90≤a≤1.8, and 0≤b≤0.5); _{Li a E 1 - b B '} b O 2 - c D' c ( wherein, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05 a); _{LiE 2 - b B 'b O} 4 - c D' c ( wherein, 0≤b≤0.5, 0≤c≤0.05 a); Li _a Ni _1-bc Co _b B' _c D' _α (in the above formula, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); _{Li a Ni 1 -b- c Co b} B 'c O 2 - α F' α ( wherein, 0.90≤a≤1.8, 0≤b≤0.5, is 0≤c≤0.05, 0 <α <2) ; Li _a Ni _{1 -b- c} Mn _b B' _c D' _α (in the above formula, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); _{Li a Ni 1 -b- c Mn b} B 'c O 2 - α F' α ( wherein, 0.90≤a≤1.8, 0≤b≤0.5, is 0≤c≤0.05, 0 <α <2) ; Li _a Ni _b E _c G _d O ₂ (in the above formula, 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1); Li _a Ni _b Co _c Mn _d G _e O ₂ (in the above formula, 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1); Li _a NiG _b O ₂ (in the above formula, 0.90≤a≤1.8, 0.001≤b≤0.1); Li _a CoG _b O ₂ (in the above formula, 0.90≤a≤1.8, 0.001≤b≤0.1); Li _a MnG _b O ₂ (in the above formula, 0.90≤a≤1.8, 0.001≤b≤0.1); Li _a Mn ₂ G _b O ₄ (in the above formula, 0.90≤a≤1.8, 0.001≤b≤0.1); QO ₂ ; QS ₂ ; LiQS ₂ ; V ₂ O ₅ ; LiV ₂ O ₅ ; LiI'O ₂ ; LiNiVO ₄ ; Li _(3-f) J ₂ (PO ₄ ) ₃ (0≤f≤2); Li _(3-f) Fe ₂ (PO ₄ ) ₃ (0≤f≤2); A compound represented by any one of the chemical formulas of LiFePO _{4 may be used.}

In the above formula, A is Ni, Co, Mn, or a combination thereof; B' is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D' is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F' is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I' is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

Of course, a compound having a coating layer on the surface of the compound may be used, or a mixture of the compound and a compound having a coating layer may be used. The coating layer may include a coating element compound of oxide or hydroxide of the coating element, oxyhydroxide of the coating element, oxycarbonate of the coating element, or hydroxycarbonate of the coating element. The compound constituting these coating layers may be amorphous or crystalline. As the coating element included in the coating layer, Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or a mixture thereof may be used. In the coating layer forming process, any coating method may be used as long as it can be coated by a method that does not adversely affect the physical properties of the positive electrode active material by using these elements in the compound (eg, spray coating, dipping method, etc.). Since the content can be well understood by those engaged in the field, a detailed description thereof will be omitted.

The positive active material is, for example, LiNi _x Co _y Al _z O ₂ (NCA) or LiNi _x Co _y Mn _z O ₂ (NCM) having a layered rock salt structure (provided that 0 < x < 1, 0 < y < 1, 0 < z < 1, while x + y + z = 1) may be a ternary lithium transition metal oxide. The ternary lithium transition metal oxide having the layered rock salt structure may improve energy density and thermal stability of an all-solid-state secondary battery.

In addition, the positive active material may be a nickel-based composite oxide such as nickel cobalt manganate lithium or lithium nickel cobalt aluminum oxide containing nickel in 60 wt% or more, or 75 wt% or more, or 90 wt% or more. Since it is difficult to generate a resistance component between the sulfide-based solid electrolyte in such a positive active material including nickel, ionic conductivity can be easily secured.

In addition, as the positive active material, lithium cobalt oxide having a high true density and a high lithium ion diffusion rate may be used in addition to the nickel-based composite oxide. For example, the positive electrode active material may be a composite positive electrode active material coated with a nickel-based composite oxide, LiNbO ₂ , Li ₄ Ti ₅ O _{12 , or aluminum oxide on lithium cobalt oxide.}

As a shape of the said positive electrode active material, particle shapes, such as a true sphere or an elliptical sphere, are mentioned, for example. In addition, the particle diameter of the positive active material is not particularly limited, and may be within a range applicable to the positive active material of a typical all-solid secondary battery. In addition, the content of the positive electrode active material in the positive electrode layer is not particularly limited, and may be within a range applicable to the positive electrode layer of a typical all-solid-state secondary battery.

In addition to the above-described positive electrode active material and solid electrolyte, the positive electrode layer may further contain additives such as a conductive agent, a binder, a filler, a dispersant, or an ion conductive auxiliary agent as appropriate.

Examples of the conductive agent that can be blended into the positive electrode layer include graphite, carbon black, acetylene black, Ketjen black, carbon fiber, or metal powder. In addition, as a binder that can be blended into the positive electrode layer, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, or polyethylene may be mentioned. In addition, as a coating agent, a dispersing agent, or an ion conductive auxiliary agent that can be blended into the positive electrode layer, a known material commonly used for an electrode of an all-solid-state secondary battery may be used.

The negative electrode layer 20 may include a negative electrode current collector 6 and a negative electrode active material layer 5 disposed on the negative electrode current collector 6 .

The anode active material layer 5 may include an anode active material that does not contain an alkali metal and a binder. The anode active material layer 5 may be a layer in which alkali metal does not precipitate before charging of the all-solid-state secondary battery, or may be an alkali metal preliminary layer. The alkali metal may include, for example, lithium, sodium, or potassium.

The negative electrode current collector 6 may be made of a material that does not react with an alkali metal, for example, lithium metal, that is, does not form both an alloy and a compound. Examples of the material constituting the negative electrode current collector 6 include copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), or a combination thereof. have. The negative electrode current collector 6 may be made of one or two or more metal alloys or a coating material among the above metals. The negative electrode current collector 6 may be formed, for example, in a plate shape or a foil shape.

The negative active material may include amorphous carbon, gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof. The negative active material may include amorphous carbon, and may further include gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof. The amorphous carbon is, for example, carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), or Graphene etc. are mentioned. The mixing ratio (mass ratio) of a mixture of amorphous carbon and gold or the like may be, for example, 10:1 to 1:2, or 8:1 to 1:2, or 5:1 to 1:1. . By forming the anode active material of such a material, battery performance such as rate characteristics and lifespan characteristics of the all-solid-state secondary battery can be further improved.

Gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof used as the negative active material may have a particle shape and an average particle diameter (D50) of 4 μm or less, or 1 μm or less or 0.5 μm or less. The lower limit of the average particle diameter (D50) of the negative active material is not particularly limited, but may be about 10 nm. Since the definition and measurement method of the average particle diameter (D50) of the negative active material are the same as those described above, the following description will be omitted. An all-solid-state secondary battery including a negative active material having such an average particle diameter (D50) may have improved battery performance such as rate characteristics and lifespan characteristics.

Also, the negative active material may include a mixture of first particles formed of amorphous carbon and second particles formed of metal or semiconductor. The metal or semiconductor may include, for example, gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof. The content of the second particles may be about 8 to 60 wt%, for example, about 10 to 50 wt%, or about 15 to 45 wt%, based on the total weight of the negative active material. In this case, battery performance such as rate characteristics and lifespan characteristics of the all-solid-state secondary battery may be further improved.

When a binder is included in the anode active material layer 5 , the anode active material layer 5 may be stabilized on the anode current collector 6 . For example, when the anode active material layer 5 does not include a binder, the anode active material layer 5 may be easily separated from the anode current collector 6 . Since the anode current collector 6 is exposed at the portion where the anode active material layer 5 is separated from the anode current collector 6 , a short circuit may occur. The anode active material layer 5 may be formed by applying a slurry in which a material constituting the anode active material layer 5 is dispersed on the anode current collector 6 and drying the slurry. The binder may be included in the anode active material layer 5 to stably disperse the anode active material in the slurry. As a result, for example, when the slurry is applied on the negative electrode current collector 6 by a screen printing method, clogging of the screen (eg, clogging by the aggregate of the negative electrode active material) can be suppressed.

When a binder is included in the anode active material layer, the content of the binder may be about 0.3 to 15 wt%, or about 1 to 12.5 wt%, or about 2 to 10 wt%, based on the total weight of the anode active material. % by weight. When the content of the binder is less than 0.3% by weight, the strength of the film is not sufficient, properties may be deteriorated, and it may be difficult to process/handle. When the content of the binder exceeds 15% by weight, the performance of the all-solid-state secondary battery may be deteriorated.

The thickness of the negative active material layer is not particularly limited, but may be 1 μm to 20 μm, or 2 μm to 18 μm, or 5 μm to 15 μm. When the thickness of the anode active material layer is less than 1 μm, the performance of the all-solid-state secondary battery may not be sufficiently improved. When the thickness of the anode active material layer exceeds 20 μm, the resistance of the anode active material layer is high, and as a result, the performance of the all-solid-state secondary battery may not be sufficiently improved. When the above-described binder is used, the thickness of the anode active material layer 5 can be easily secured at an appropriate level.

In the negative active material layer, additives typically used in all-solid-state secondary batteries, for example, fillers, dispersants, or ion conductive agents, may be appropriately blended. The filler, dispersant, or ion conductive agent may be the same as or different from that used for the positive electrode active material layer.

As shown in FIG. 1C , the all-solid-state secondary battery may further include an alkali metal deposited layer 2a between the negative electrode current collector and the negative electrode active material layer during charging. The alkali metal deposited layer 2a may be a lithium metal deposited layer, a sodium metal deposited layer, or a potassium metal deposited layer. For example, the alkali metal precipitation layer may be a lithium metal precipitation layer.

In the all-solid-state secondary battery, an alkali metal, for example, lithium metal, is inserted into the anode active material layer 5 at the initial stage of charging. That is, the negative active material may form an alloy or compound with lithium ions that have migrated from the positive electrode layer. When charging exceeds the capacity of the anode active material layer 5, lithium is deposited on the back side of the anode active material layer 5, that is, between the anode current collector 6 and the anode active material layer 5, as shown in FIG. 1c, The metal layer 2a is formed by this lithium. This phenomenon may occur by forming the anode active material with a material that does not contain lithium metal but forms an alloy or compound with lithium. During discharge, lithium in the negative electrode active material layer 5 and the lithium metal precipitation layer 2a is ionized and moves toward the positive electrode layer. Therefore, lithium can be used as an anode active material in an all-solid-state secondary battery. In addition, since the anode active material layer 5 covers the lithium metal precipitation layer 2a, it can serve as a protective layer for the lithium metal precipitation layer 2a and suppress the precipitation growth of dendrites. As a result, it is possible to suppress a short circuit and a decrease in capacity of the all-solid-state secondary battery, and furthermore, it is possible to improve the performance of the all-solid-state secondary battery.

For example, in the all-solid-state secondary battery, the ratio of the charging capacity of the positive active material layer 2 and the charging capacity of the negative active material layer 5, that is, the capacity ratio, may satisfy the requirements of the following inequality (1). .

Inequality (1): 0.002 < b' / a' < 0.5

a': the charging capacity of the positive electrode active material layer (2) (mAh)

b': charging capacity (mAh) of the negative electrode active material layer (5)

Here, the charging capacity of the positive active material layer 2 is obtained by multiplying the specific charging capacity (mAh/g) of the positive active material by the mass of the positive active material in the positive active material layer 2 . When several types of positive electrode active materials are used, the specific charge capacity x mass value is calculated for each positive electrode active material, and what is necessary is just to set the sum total of these values as the charge capacity of the positive electrode active material layer 2 . The charging capacity of the anode active material layer 5 is calculated in the same way. That is, the charging capacity of the negative electrode active material layer 5 is obtained by multiplying the specific charge capacity (mAh/g) of the negative electrode active material by the mass of the negative electrode active material in the negative electrode active material layer 5 . When several types of negative electrode active materials are used, the specific charge capacity x mass value is calculated for each negative electrode active material, and what is necessary is just to make the sum total of these values into the charge capacity of the negative electrode active material layer 5 . Here, the charge specific capacity of the positive and negative electrode active materials is a capacity estimated using an all-solid half-cell in which lithium metal is applied to the counter electrode. The charging capacities of the positive electrode active material layer 2 and the negative electrode active material layer 5 are directly measured by measurement using an all-solid half-cell. When this charging capacity is divided by the mass of each active material, the charging specific capacity is calculated. The charging capacities of the positive active material layer 2 and the negative active material layer 5 may be initial charging capacities measured during the first cycle.

As shown in FIG. 1D , a thin film 5b may be additionally disposed between the negative electrode current collector 6 and the negative electrode active material layer 5 , and the thin film 5b is disposed on the negative electrode current collector 6 . It may include a material capable of forming an alloy or compound with an alkali metal.

The negative electrode current collector 6 does not react with alkali metal, but may make it difficult to deposit a smooth alkali metal layer, for example, a lithium metal layer thereon. The thin film 5b may be used as a wetting layer such that an alkali metal, for example, a lithium metal, is flatly deposited on the anode current collector 6 .

The material capable of forming an alloy with the alkali metal used in the thin film 5b may include silicon, magnesium, aluminum, lead, silver, tin, or a combination thereof. The material capable of forming a compound with the alkali metal used in the thin film 5b may include carbon, titanium sulfide, iron sulfide, or a combination thereof. The content of the material used in the thin film 5b may be small within a limit that does not affect the electrochemical properties of the electrode and/or the redox potential of the electrode. The thin film 5b may be applied flatly on the negative electrode current collector 6 to prevent cracking during the charging cycle of the all-solid-state secondary battery. For the application of the thin film 5b, a method such as physical vapor deposition such as evaporation or sputtering, chemical vapor deposition or plating method may be used.

The thickness of the thin film 5b may be 1 nm to 500 nm. The thickness of the thin film 5b may be, for example, 2 nm to 400 nm. The thickness of the thin film 5b may be, for example, 3 nm to 300 nm. The thickness of the thin film 5b may be, for example, 4 nm to 200 nm. The thickness of the thin film 5b may be, for example, 5 nm to 100 nm.

Also, as shown in FIG. 1D , in the all-solid-state secondary battery, alkali metal precipitates in at least one of the upper portion of the negative electrode active material layer 5 and the region between the negative electrode active material layer 5 and the negative electrode current collector 6 during charging. A deposited layer, for example, a lithium metal precipitated layer 2b may be further included.

The negative active material may include amorphous carbon and silver, and in the all-solid-state secondary battery, an alkali metal may be precipitated in the negative active material during charging to form an alloy with silver.

As shown in FIG. 1E , the all-solid-state secondary battery has a structure in which a lithium metal layer 22 and amorphous carbon 23 formed on the surface of the silicon negative active material 21 in the negative active material layer 5 region during charging are disposed am. This is because the lithium metal precipitation layer 22 is formed on the surface of the silicon anode active material 21 due to the large volume expansion rate of the silicon anode active material 21 to form an alloy.

2 is a schematic diagram of a structure of an all-solid-state secondary battery 30 according to an embodiment.

As shown in FIG. 2 , the all-solid-state secondary battery 30 includes a positive electrode 31 , a negative electrode 32 , and a battery can 34 accommodating them.

The anode 31 may be the aforementioned anode layer. The positive electrode layer may be formed by coating a positive electrode active material on the surface of a positive electrode current collector made of a material such as aluminum. Alternatively, the positive electrode layer may be prepared by casting/coating the positive electrode active material on a separate support and laminating the positive electrode active material film peeled from the support on the current collector.

The negative electrode 32 may be the above-described negative electrode layer. The above-described solid electrolyte layer may be included between the positive electrode 31 and the negative electrode 32 .

The all-solid-state secondary battery 30 is a unit cell having a structure of positive/separator/negative electrode, a bi-cell having a structure of positive/separator/negative electrode/separator/anode, or a stacked battery structure in which the structure of the unit cell is repeated. can do.

The shape of the all-solid-state secondary battery 30 is not particularly limited, and for example, a coin type, a button type, a sheet type, a stack type, a cylinder type, a flat type, a cone type, etc. may be exemplified. It can also be applied to large-sized batteries used in electric vehicles and the like. For example, the all-solid-state secondary battery 30 may also be used in a hybrid vehicle such as a plug-in hybrid electric vehicle (PHEV). In addition, it can be used in fields requiring a large amount of power storage. For example, it may be used for an electric bicycle or a power tool.

3 and 4 are schematic views of a method of manufacturing an all-solid-state secondary battery according to an embodiment, respectively.

As shown in FIG. 3 , a method of manufacturing an all-solid-state secondary battery 100 according to another embodiment includes providing a positive electrode layer; forming a compressed anode layer 40 by applying pressure to the anode layer; providing a cathode layer (50); providing a solid electrolyte layer (4); forming a laminate by laminating the negative electrode layer 50 on the solid electrolyte layer 4; forming a compressed negative electrode layer and a solid electrolyte layer 50 by applying pressure to the laminate; and interposing a first bonding layer (3) between the compressed positive electrode layer (40) and the compressed negative electrode layer and the solid electrolyte layer (50); and preparing the above-described all-solid-state secondary battery by applying pressure to the compressed positive electrode layer 40, the first bonding layer 3, and the compressed negative electrode layer and the solid electrolyte layer 50. can The positive electrode layer includes a positive electrode current collector (1) and a positive electrode active material layer (2) disposed on the positive electrode current collector (1), and the negative electrode layer includes a negative electrode current collector (6) and the negative electrode current collector (6) ) and an anode active material layer 5 disposed on it.

The step of applying pressure to the positive electrode layer, the step of applying pressure to the laminate, and the step of applying pressure to the compressed positive electrode layer, the first bonding layer, and the compressed negative electrode layer and the solid electrolyte layer are each a roll press , hot press, or a combination thereof.

In the case of a positive electrode or a negative electrode containing a part of a solid electrolyte, deformation of the electrode does not easily occur even after repeated rolling process, but in the case of a rolled solid electrolyte, repeated rolling may be difficult due to brittleness. In addition, when an all-solid-state secondary battery is manufactured by roll press or hot press, repeated rolling is required to increase the density of the electrode layers or the solid electrolyte layer. Therefore, the manufacturing method of the all-solid-state secondary battery separately comprising the step of forming the compressed positive electrode layer and the step of forming the compressed negative electrode layer and the solid electrolyte layer is easily performed between the electrode layers and the solid electrolyte layer when pressure is applied after lamination. A close interface can be formed. In addition, the manufacturing method of the all-solid-state secondary battery can improve battery performance such as rate characteristics and lifespan characteristics while reducing the interfacial resistance between the positive electrode layer and the solid electrolyte layer.

As shown in FIG. 4 , a method of manufacturing an all-solid-state secondary battery 100 according to another embodiment includes providing a positive electrode layer; disposing a first bonding layer (3) on one surface of the anode layer to form an anode including a first bonding layer; providing a cathode layer (50); providing a solid electrolyte layer (4); forming a laminate by laminating the negative electrode layer on the solid electrolyte layer (4); forming a compressed negative electrode layer and a solid electrolyte layer 50 by applying pressure to the laminate; laminating a positive electrode including the first bonding layer (3) on the compressed negative electrode layer and the solid electrolyte layer (50); and manufacturing the above-described all-solid-state secondary battery by applying pressure to the positive electrode including the first bonding layer 3 and the compressed negative electrode layer and the solid electrolyte layer 50 .

In the step of forming the positive electrode including the first bonding layer (bonding layer, 3), the first bonding layer (3) is coated on one surface of the positive electrode active material layer (2) or the first bonding layer (3) may include a process of transferring to one surface of the positive electrode active material layer (2).

The all-solid-state secondary battery in the step of manufacturing the all-solid-state secondary battery may be manufactured by applying pressure by roll press, hot press, or a combination thereof.

The manufacturing method of the all-solid-state secondary battery can be mass-produced, and when pressure is applied after lamination, a close interface can be formed between the electrode layers and the solid electrolyte layer. In addition, the manufacturing method of the all-solid-state secondary battery can improve battery performance such as rate characteristics and lifespan characteristics while reducing the interfacial resistance between the positive electrode layer and the solid electrolyte layer.

Hereinafter, Examples and Comparative Examples of the present invention will be described. However, the following examples are only examples of the present invention, and the present invention is not limited thereto.

[Example]

(Production of all-solid-state secondary battery)

Example One: all solid Production of secondary batteries

An all-solid-state secondary battery was manufactured under an argon gas atmosphere as follows.

Li ₂ S (Sigma Aldrich, 99%) powder, P ₂ S ₅ (Sigma Aldrich, 99%) powder, and LiCl (Acros Organic, 99%) powder were each mixed with Li _{5 . 75} PS _{4 . 75} Cl _{1 .25} were weighed in a stoichiometric molar ratio to obtain a sulfide solid electrolyte to form a mixture by mixing them. The mixture was mechanically milled using zirconia balls (diameter: 10 mm) and then a high energy ball mill was performed at a rotation speed of 600 rpm for about 45 hours to obtain a pulverized mixture. The pulverized mixture was put into absolute ethanol (Wako, 99.5%) at room temperature and stirred for 24 hours to obtain a homogeneous dark brown mixture. The mixture was dried at 80° C. for 3 hours under a vacuum atmosphere and pulverized to form a positive electrode layer Li _{5 . 75} PS _{4 . 75} Cl _{1 .25} sulfide solid electrolyte powder: to give the (D50 0.5 ㎛). In addition, prepared in the same manner as above, but Li _5.75 PS _4.75 Cl _1.25 sulfide solid electrolyte instead of Li _{5 . 5} PS _{4 . 5} Br _{0 . 75} Cl ₀ for _.75 sulfide solid were weighed in a molar ratio to the stoichiometric electrolyte obtained by forming a mixture by mixing them and milling the average particle diameter (D50) of the powder to the first joining layer 3 ㎛ form Li _{5. 5} PS _{4 . 5} Br _{0 . 75} Cl _{0 .75} sulfide solid electrolyte powder (D50: 3 ㎛) was obtained. Also, prepared in the same manner as above, but _{the average particle diameter (D50) of the Li 5.75} PS _4.75 Cl _1.25 sulfide solid electrolyte powder was pulverized to 3 μm to form Li _{5 . 75} PS _{4 . 75} Cl _{1 .25} sulfide solid electrolyte powder (D50: 3 ㎛) was obtained.

Separately, the positive active material LiN _{i0 . 9} Co _{0 . 07} Mn _{0 . 03} O ₂ , the Li _{5 . 75} PS _{4 . 75} Cl _{1 .25} sulfide solid electrolyte powder (D50: 0. 5㎛), re-conductive carbon nanofibers (Sigma Aldrich,> 98%) and carbon black (Super-P, Timcal Ltd.) , and a binder of polytetrafluoroethylene A positive electrode sheet was manufactured by greatly molding a mixture of roethylene (PTFE, Dupon) in a weight ratio of 87:10:1:1:1, respectively, in the form of a sheet. The positive electrode sheet was compressed on the positive electrode current collector of 18 μm thick aluminum foil, put in a batch type oil chamber, and a warm isostatic press process was performed to apply a pressure of 490 mPa to form a compressed positive electrode layer.

_{Separately, Li 5 for} the solid electrolyte layer _{. 75} PS _{4 . 75} Cl _{1 .25} sulfide solid electrolyte powder: the polyacrylic binder (Xeon Co., Ltd.) to (D50 3 ㎛) 99: was prepared a mixture by adding a weight ratio of 1. To the mixture, xylene and diethylbenzene were added and stirred to prepare a slurry for forming a solid electrolyte layer. The slurry for forming the solid electrolyte layer was applied on a nonwoven fabric using a blade coater, dried in air at a temperature of 40° C., and then vacuum dried at 40° C. for 12 hours to form a solid electrolyte layer.

Separately, a Ni foil (thickness: 10 μm) was prepared as a negative electrode current collector. As an anode active material, silver (primary particle diameter: 60 nm) and carbon black powder (primary particle diameter: 35 nm) were mixed in a weight ratio of 25:75 and prepared. In a container, 7 wt% of a polyvinylidene fluoride binder (# 9300, Kureha Co., Ltd.) along with the silver (primary particle diameter: 60 nm) and carbon black powder (primary particle diameter: 35 nm) was added as the negative electrode layer to N- It was put in methylpyrrolidone (NMP) and stirred to prepare a slurry for forming a negative electrode layer. The negative electrode layer forming slurry was applied to the Ni foil using a blade coater, dried in air at 80° C. for 20 minutes, and vacuum dried at 100° C. for 12 hours to prepare a negative electrode layer.

After laminating the solid electrolyte layer on the negative electrode layer, it was placed in a batch type oil chamber and subjected to a warm isostatic press process in which a pressure of 490 mPa was applied to form a compressed negative electrode layer and a solid electrolyte layer.

_{Separately, Li 5} for forming the first bonding layer _{. 5} PS _{4 . 5} Br _{0 . 75} Cl _{0 .75} sulfide solid electrolyte powder (D50: 3 ㎛) 30 g , polyacrylic binder (Xeon Co., Ltd.) 3.57 g, xylene, 4.2 g, and 5.0 g of diethyl benzene into the vessel at a rotation speed of about 2,000 rpm Mix twice for 1 minute. In addition, the zirconia balls were put into the container and mixed twice, but 2.0 g and 2.5 g of diethylbenzene were added and mixed instead of 5.0 g, respectively, and mixed in the same manner as above to form the first bonding layer A slurry was prepared. The slurry for forming the first bonding layer is applied on a polyethylene terephthalate film to which a nonwoven fabric is adhered by screen printing, dried in air at a temperature of 40° C., and then vacuum dried at 40° C. for 12 hours to form a first bonding layer. did.

The first bonding layer (thickness: about 10 μm) was interposed between the compressed positive electrode layer, the compressed negative electrode layer, and the solid electrolyte layer and roll press was performed at a pressure of 490 MPa to 2 cm x 2 cm An 18 mAh pouch-type all-solid-state secondary battery of the size was manufactured.

At this time, in the nano-indentation test according to ASTM E2546, the Li _5.5 PS _4.5 Br _0.75 Cl _0.75 sulfide solid electrolyte powder (D50: 3 μm) of the first bonding layer had a sheet-type Young’s modulus of about 12 GPa (a powder type of about 34 GPa). ), and the Li _5.75 PS _4.75 Cl _1.25 sulfide solid electrolyte powder (D50: 3 μm) of the solid electrolyte layer exhibited a sheet-type Young's modulus of about 17 GPa (a powder-type Young's modulus of about 24 GPa). . _{The Li 5.5} PS _4.5 Br _0.75 Cl _0.75 sulfide solid electrolyte powder of the first bonding layer has a sheet-type Young's modulus (about 10 GPa lower powder type) than _{the Li 5.75} PS _4.75 Cl _1.25 sulfide solid electrolyte powder of the solid electrolyte layer by about 5 GPa. of Young's modulus).

Example 2: all solid Production of secondary batteries

A first bonding layer was interposed between the compressed positive electrode layer, the compressed negative electrode layer, and the solid electrolyte layer, and roll press was performed at 400 MPa pressure instead of 490 Mpa pressure to have a size of 2 cm x 2 cm 18 mAh. A pouch-type all-solid-state secondary battery was manufactured.

Example 3: all solid Production of secondary batteries

A first bonding layer was interposed between the compressed positive electrode layer, the compressed negative electrode layer, and the solid electrolyte layer, and roll press was performed at 300 MPa pressure instead of 490 Mpa pressure to have a size of 2 cm x 2 cm 18 mAh A pouch-type all-solid-state secondary battery was manufactured.

Example 4: all solid Production of secondary batteries

An all-solid-state secondary battery was manufactured under an argon gas atmosphere as follows.

Li ₂ S (Sigma Aldrich, 99%) powder, P ₂ S ₅ (Sigma Aldrich, 99%) powder, and LiCl (Acros Organic, 99%) powder were each mixed with Li _{5 . 75} PS _{4 . 75} Cl _{1 .25} were weighed in a stoichiometric molar ratio to obtain a sulfide solid electrolyte to form a mixture by mixing them. The mixture was mechanically milled using zirconia balls (diameter: 10 mm) and then a high energy ball mill was performed at a rotation speed of 600 rpm for about 45 hours to obtain a pulverized mixture. The pulverized mixture was put into absolute ethanol (Wako, 99.5%) at room temperature and stirred for 24 hours to obtain a homogeneous dark brown mixture. The mixture was dried at 80° C. for 3 hours under a vacuum atmosphere and pulverized to form a positive electrode layer Li _{5 . 75} PS _{4 . 75} Cl _{1 .25} sulfide solid electrolyte powder: to give the (D50 0.5 ㎛). Also, prepared in the same manner as above, but Li _5.75 PS _4.75 Cl _1.25 sulfide solid electrolyte powder with an average particle diameter (D50) of 3 μm and pulverized to form a solid electrolyte layer Li _{5 . 75} PS _{4 . 75} Cl _{1 .25} sulfide solid electrolyte powder (D50: 3 ㎛) was obtained. Also prepared in the same manner as above, but Li _{5 . 75} PS _{4 . 75} Cl _{1 .25} sulfide solid electrolyte instead of Li _{5. 5} PS _{4 . 5} Br _{0 . 75} Cl ₀ for _.75 sulfide solid were weighed in a molar ratio to the stoichiometric electrolyte obtained by forming a mixture by mixing them and milling the average particle diameter (D50) of the powder to the first joining layer 3 ㎛ form Li _{5. 5} PS _{4 . 5} Br _{0 . 75} Cl _{0 .75} sulfide solid electrolyte powder (D50: 3 ㎛) was obtained.

_{Separately, Li 5} for forming the first bonding layer _{. 5} PS _{4 . 5} Br _{0 . 75} Cl _{0 .75} sulfide solid electrolyte powder (D50: 3 ㎛) 30 g , polyacrylic binder (Xeon Co., Ltd.) 3.57 g, xylene, 4.2 g, and 5.0 g of diethyl benzene into the vessel at a rotation speed of about 2,000 rpm Mix twice for 1 minute. In addition, the zirconia balls were put into the container and mixed twice, but 2.0 g and 2.5 g of diethylbenzene were added and mixed instead of 5.0 g, respectively, and mixed in the same manner as above to form the first bonding layer A slurry was prepared. The slurry for forming the first bonding layer is applied on a polyethylene terephthalate film to which a nonwoven fabric is adhered by screen printing, dried in air at a temperature of 40° C., and then vacuum dried at 40° C. for 12 hours to form a first bonding layer. did.

Separately, the positive active material LiN _{i0 . 9} Co _{0 . 07} Mn _{0 . 03} O ₂ , the Li _{5 . 75} PS _{4 . 75} Cl ₁ . ₂₅ Sulfide solid electrolyte powder (D50: 0.5 ㎛), conductive material carbon nanofiber (Sigma Aldrich, >98%) and carbon black (Super-P, Timcal Ltd.), and binder polytetrafluoroethylene (PTFE, Dupon) ), respectively, in a weight ratio of 87:10:1:1:1, and the mixture was largely molded into a sheet to prepare a positive electrode sheet. In addition, the positive electrode sheet was pressed against a positive electrode current collector made of 18 μm thick aluminum foil, and the first bonding layer was transferred onto the positive electrode sheet to prepare a positive electrode layer arranged in contact.

Separately, a Ni foil (thickness: 10 μm) was prepared as a negative electrode current collector. As an anode active material, silver (primary particle diameter: 60 nm) and carbon black powder (primary particle diameter: 35 nm) were mixed in a weight ratio of 25:75 and prepared. In a container, 7 wt% of a polyvinylidene fluoride binder (# 9300, Kureha Co., Ltd.) along with the silver (primary particle diameter: 60 nm) and carbon black powder (primary particle diameter: 35 nm) was added as the negative electrode layer to N- It was put in methylpyrrolidone (NMP) and stirred to prepare a slurry for forming a negative electrode layer. The negative electrode layer forming slurry was applied to the Ni foil using a blade coater, dried in air at 80° C. for 20 minutes, and vacuum dried at 100° C. for 12 hours to prepare a negative electrode layer.

_{Separately, Li 5 for} the solid electrolyte layer _{. 75} PS _{4 . 75} Cl _{1 .25} sulfide solid electrolyte powder: the polyacrylic binder (Xeon Co., Ltd.) to (D50 3 ㎛) 99: was prepared a mixture by adding a weight ratio of 1. To the mixture, xylene and diethylbenzene were added and stirred to prepare a slurry for forming a solid electrolyte layer. The slurry for forming the solid electrolyte layer was applied on a nonwoven fabric using a blade coater, dried in air at a temperature of 40° C., and then vacuum dried at 40° C. for 12 hours to form a solid electrolyte layer.

After laminating the solid electrolyte layer on the negative electrode layer, it was placed in a batch type oil chamber and subjected to a warm isostatic press process in which a pressure of 490 mPa was applied to form a compressed negative electrode layer and a solid electrolyte layer.

The first bonding layer (thickness: about 10 μm) was transferred and placed in contact with the positive electrode layer, the compressed negative electrode layer, and the solid electrolyte layer by roll pressing at a pressure of 490 MPa to have a size of 2 cm x 2 cm An 18 mAh pouch-type all-solid-state secondary battery was manufactured.

In this case, the first bonding layer is a sheet-type Young's modulus (about 34 GPa) of _{the Li 5.5} PS _4.5 Br _0.75 Cl _0.75 sulfide solid electrolyte powder (D50: 3 μm) of the first bonding layer during the nano-indentation test of about 12 GPa. powder type Young's modulus), and the Li _5.75 PS _4.75 Cl _1.25 sulfide solid electrolyte powder (D50: 3 μm) of the solid electrolyte layer exhibited a Young's modulus of about 17 GPa (a powder type Young's modulus of about 24 GPa). _{Li 5} of the first bonding layer _{. 5} PS _{4 . 5} Br _{0 . 75} Cl _{0 .75} sulfide solid electrolyte, the powder of the solid electrolyte layer _{5 Li. 75} PS _{4 . 75} Cl _{1 .25} shows a sulfide of about 5 GPa Young's modulus of the lower sheet-type (about 10 GPa Young's modulus of the low powder type) than the solid electrolyte powder.

comparative example One: all solid Production of secondary batteries

Between the compressed positive electrode layer, the compressed negative electrode layer, and the solid electrolyte layer, without interposing the first bonding layer, a roll press was performed at a pressure of 490 MPa to form an 18 mAh pouch with a size of 2 cm x 2 cm. of the all-solid-state secondary battery was manufactured.

Analysis example 1: SEM (Scanning Electron Microscope) picture

The all-solid-state secondary batteries according to Example 1 and Comparative Example 1 were disassembled and cross-sections thereof were observed with a scanning electron microscope (SEM). The results are shown in FIGS. 5A and 5B. S-5500 (Hitachi) was used for scanning electron microscope analysis.

Referring to FIG. 5A , in the all-solid-state secondary battery according to Example 1, it can be confirmed that a first bonding layer having a thickness of about 10 μm exists between the compressed positive electrode layer, the compressed negative electrode layer, and the solid electrolyte layer. Referring to FIG. 5B , in the all-solid-state secondary battery according to Comparative Example 1, it can be confirmed that the first bonding layer does not exist between the compressed positive electrode layer, the compressed negative electrode layer, and the solid electrolyte layer.

evaluation example 1: Initial impedance - interface resistance evaluation

The initial impedance of the all-solid-state secondary batteries according to Example 1 and Comparative Example 1 was evaluated.

The initial impedance is measured using an impedance analyzer (Solartron 1260A Impedance/Gain-Phase Analyzer) by applying a voltage bias of 10 mV in the frequency range of ^{25°C, 10 6 Hz to 0.1 MHz and measuring the resistance according to the 2-probe method.} By doing so, the initial impedance was evaluated. A Nyguist plot of these results is shown in FIG. 6 . 6 , the initial bulk resistance of the electrode is determined by the position, size, and slope of the semicircle after the semicircle, and the steeper the slope, the smaller the resistance.

Referring to FIG. 6 , it can be seen that the bulk resistance of the all-solid-state secondary battery according to Example 1 is reduced as compared to the all-solid-state secondary battery according to Comparative Example 1.

evaluation example 2: charging and discharging Experiment - Rate characteristics and life characteristics evaluation

The charging and discharging characteristics of the all-solid-state secondary batteries according to Examples 1 to 4 and Comparative Example 1 were evaluated using a charger (manufacturer: TOYO, model: TOYO-3100).

2-1. rate characteristic evaluation

The all-solid-state secondary batteries according to Examples 1, 4, and Comparative Example 1 were put in a constant temperature bath at 60° C., and then at a constant current at a rate of 0.1 C (C-rate) until the voltage became 4.25 V (vs. Li). After charging, the voltage was maintained until a current of 1/50C was reached. Then, it was discharged at a rate of 0.2C until the voltage reached 2.5V (vs. Li). Thereafter, it was rested for 10 minutes. Then, in the second and subsequent cycles, each of the all-solid-state secondary batteries is charged with a constant current at the same temperature at a rate of 0.1C until the voltage becomes 4.25V (vs. Li), and then reaches a current of 1/50C. The voltage was maintained until Then, it was discharged at a rate of 0.33C or 1.0C until the voltage reached 2.5V (vs. Li). The results are shown in FIGS. 7A, 7B, and 7C, respectively. At this time, the rate characteristics were evaluated according to the following [Equation 1].

[Equation 1]

Rate characteristic (%) = [(capacity when discharging at a rate of 1.0C)/(capacity when discharging at a rate of 0.33C)] X 100%

7A and 7B , the rate characteristic of the all-solid-state secondary batteries according to Examples 1 and 4 was 94%. Referring to FIG. 7C , the rate characteristic of the all-solid-state secondary battery according to Comparative Example 1 was 85%. From this, the all-solid-state secondary batteries according to Examples 1 and 4 have improved rate characteristics compared to the all-solid-state secondary batteries according to Comparative Example 1.

2-2. Life characteristics evaluation

All-solid-state secondary batteries according to Examples 1 to 3 and Comparative Example 1 were placed in a thermostat at 60° C. and charged at a rate of 0.1 C (C-rate) until the voltage became 4.25 V (vs. Li). After maintaining 4.25V (vs. Li), it was cut-off at a rate of 0.05C. Then, it was discharged at a rate (C-rate) of 0.1C until the voltage reached 2.5V (vs. Li) during discharge (Hwaseong step, 1 ^st cycle). This charging and discharging process was performed two more times to complete the formation process.

The all-solid-state secondary battery that has undergone the formation step is charged at the same temperature at a rate of 0.5 C until the voltage becomes 4.25 V (vs. Li), and then becomes 2.5 V (vs. Li) at a rate of 0.5 C. Discharge was performed until

The above-described charging/discharging process was repeatedly performed and performed a total of 70 times. Some results of the change in discharge capacity according to the number of cycles are shown in FIGS. 8A and 8B. At this time, life characteristics (ie, capacity retention rate) were evaluated according to the following [Equation 2].

[Equation 2]

Life characteristics (%) = [( ^{Capacity after 70 th} cycle)/( ^{Discharge capacity after 3 rd} cycle)] X 100%

Referring to FIG. 8A , the all-solid-state secondary battery according to Example 1 had a ^{lifespan characteristic after 70 th} cycle of 99.1%, and the all-solid-state secondary battery according to Comparative Example 1 had a life-span characteristic after ^{70 th cycle of 56.0%.} From this, the lifespan characteristics of the all-solid-state secondary battery according to Example 1 were significantly improved compared to the all-solid-state secondary battery according to Comparative Example 1.

Referring to FIG. 8B , the all-solid-state secondary battery according to Example 3 has somewhat decreased reversible capacity compared to the all-solid-state secondary battery according to Examples 1 and 2, but the lifespan characteristics are maintained to some extent until around ^{40 th cycle.} can be checked

However, when manufacturing an all-solid-state secondary battery, the first bonding layer (thickness: about 10 μm) is interposed between the compressed positive electrode layer, the compressed negative electrode layer, and the solid electrolyte layer and roll press with a pressure of less than 300 MPa. ), it is considered that a short circuit may occur.

1: positive electrode current collector, 2a, 2b: lithium metal deposited layer
2: cathode active material layer, 3: first bonding layer;
4: solid electrolyte layer, 5: anode active material layer,
5a: second bonding layer, 5b: thin film;
6: negative electrode current collector, 10: positive electrode layer,
20, 50: negative electrode layer, 21: silicon negative active material,
22: lithium metal layer, 23: amorphous carbon,
30, 100: all-solid-state secondary battery, 31: positive electrode,
32: negative electrode, 34: battery can
40: compressed anode layer

Claims (29)

cathode layer;
anode layer;
a solid electrolyte layer disposed between the negative electrode layer and the positive electrode layer, wherein the solid electrolyte layer includes a first solid electrolyte; and
a first bonding layer disposed between the positive electrode layer and the solid electrolyte layer, wherein the first bonding layer includes a second solid electrolyte;
The negative electrode layer includes a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, and
The anode active material layer includes an anode active material and a binder,
The positive electrode layer includes a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector,
The second solid electrolyte has a Young's modulus lower than that of the first solid electrolyte by 5 GPa to 10 GPa,
The second solid electrolyte is a sulfide-based solid electrolyte having a different composition from that of the first solid electrolyte, and an all-solid-state secondary battery [[.]] including a solid electrolyte represented by the following Chemical Formula 1:
[Formula 1]
Li _a M _b PS _c A _d
In Formula 1,
0<a≤6, 0≤b≤6, 0<c<6, 0≤d≤6;
M is Ge, Sn, or Si;
A is at least one halogen element. According to claim 1,
The anode active material layer is an all-solid-state secondary battery that does not contain an alkali metal. According to claim 1,
The first bonding layer is an all-solid-state secondary battery that is interposed between the positive electrode active material layer and the solid electrolyte layer. According to claim 1,
The first bonding layer is an all-solid-state secondary battery that is a layer disposed in contact with one surface of the positive electrode active material layer. delete According to claim 1,
The second solid electrolyte of the first bonding layer is a crystalline, amorphous solid electrolyte, or a combination thereof. According to claim 1,
The second solid electrolyte is in the form of particles and has an average particle diameter (D50) of 3 μm or less. According to claim 1,
An all-solid-state secondary battery having a thickness of the first bonding layer of 30 μm or less. According to claim 1,
The first solid electrolyte is Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -LiX (X is a halogen element), 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 (m, n is a positive number, Z is one of Ge, Zn or Ga ), Li ₂ S-GeS ₂ , Li ₂ S-SiS ₂ -Li ₃ PO ₄ , Li ₂ S-SiS ₂ -Li _p MO _q (p, q is a positive number, M is P, Si, Ge, B , Al, Ga In), Li _x M' _y PS _z A _w (x, y, z, w are all 0 or more and 6 or less, M' is one of Ge, Sn, or Si, A is F, Cl , Br, or one of I), or an all-solid-state secondary battery comprising a mixture thereof. According to claim 1,
The first solid electrolyte is in the form of particles and has an average particle diameter (D50) of 1.0 μm to 3.5 μm. According to claim 1,
An all-solid-state secondary battery having a thickness of the solid electrolyte layer of 10 μm to 150 μm. According to claim 1,
A second bonding layer is disposed in contact with the surface of the solid electrolyte layer facing the negative active material layer,
and the second bonding layer includes a third solid electrolyte having a Young's modulus lower than that of the first solid electrolyte. 13. The method of claim 12,
The second bonding layer is an all-solid-state secondary battery comprising an amorphous sulfide-based solid electrolyte. According to claim 1,
The anode active material is an all-solid-state secondary battery comprising amorphous carbon, gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof. According to claim 1,
The negative active material includes amorphous carbon,
An all-solid-state secondary battery further comprising gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof. According to claim 1,
The anode active material has a particle shape and has an average particle diameter (D50) of 4 μm or less. According to claim 1,
An all-solid-state secondary battery having a thickness of the anode active material layer of 1 μm to 20 μm. According to claim 1,
The all-solid-state secondary battery further includes an alkali metal deposited layer between the anode current collector and the anode active material layer during charging. According to claim 1,
A film is further disposed between the negative electrode current collector and the negative electrode active material layer,
The film is an all-solid-state secondary battery comprising a material capable of forming an alloy or compound with an alkali metal on the negative electrode current collector. 20. The method of claim 19,
The material capable of forming an alloy with the alkali metal is an all-solid-state secondary battery comprising silicon, magnesium, aluminum, lead, silver, tin, or a combination thereof. 20. The method of claim 19,
The material capable of forming a compound with the alkali metal is an all-solid-state secondary battery comprising carbon, titanium sulfide, iron sulfide, or a combination thereof. 20. The method of claim 19
An all-solid-state secondary battery having a thickness of 1 nm to 500 nm. 20. The method of claim 19,
The all-solid-state secondary battery further comprises an alkali metal deposited layer on an upper portion of the negative electrode active material layer, a region between the negative electrode active material layer and the negative electrode current collector, or a combination thereof. According to claim 1,
The negative active material includes amorphous carbon and silver,
The all-solid-state secondary battery is an all-solid-state secondary battery in which an alkali metal is precipitated in the negative active material during charging to form an alloy with silver. providing an anode layer;
forming a compressed anode layer by applying pressure to the anode layer;
providing a cathode layer;
providing a solid electrolyte layer;
forming a laminate by laminating the negative electrode layer on the solid electrolyte layer;
forming a compressed negative electrode layer and a solid electrolyte layer by applying pressure to the laminate;
interposing a first bonding layer between the compressed positive electrode layer and the compressed negative electrode layer and the solid electrolyte layer; and
The all-solid secondary according to any one of claims 1 to 4 and 6 to 24 by applying pressure to the compressed positive electrode layer, the first bonding layer, and the compressed negative electrode layer and the solid electrolyte layer. Manufacturing method of an all-solid-state secondary battery comprising; manufacturing a battery. 26. The method of claim 25,
The all-solid-state secondary battery in the step of manufacturing the all-solid-state secondary battery is a manufacturing method of an all-solid-state secondary battery produced by applying pressure by a roll press, hot press, or a combination thereof. providing an anode layer;
forming an anode including a first bonding layer by disposing a first bonding layer on one surface of the anode layer;
providing a cathode layer;
providing a solid electrolyte layer;
forming a laminate by laminating the negative electrode layer on the solid electrolyte layer;
forming a compressed negative electrode layer and a solid electrolyte layer by applying pressure to the laminate;
laminating a positive electrode including the first bonding layer on the compressed negative electrode layer and the solid electrolyte layer; and
The all-solid-state secondary battery according to any one of claims 1 to 4 and 6 to 24 is manufactured by applying pressure to the positive electrode including the first bonding layer and the compressed negative electrode layer and the solid electrolyte layer. A method of manufacturing an all-solid-state secondary battery comprising the; 28. The method of claim 27,
The step of disposing the first bonding layer (bonding layer) is
and coating the first bonding layer on one surface of the positive electrode active material layer or transferring the first bonding layer to one surface of the positive electrode active material layer. 29. The method of claim 28,
The step of applying pressure to the positive electrode including the first bonding layer and the compressed negative electrode layer and the solid electrolyte layer independently of each other is a method of manufacturing an all-solid-state secondary battery comprising a roll press, a hot press, or a combination thereof.

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