Solid electrolyte separator, all-solid-state battery comprising same, and method for manufacturing solid electrolyte separator

Abstract

Provided are a solid electrolyte separator, an all-solid-state battery comprising same, and a method for manufacturing the solid electrolyte separator, the solid electrolyte separator comprising: a first composite comprising Li2S and a first metal halide salt; and a first sulfide-based solid electrolyte, wherein the first metal halide salt comprises an alkali metal salt and a boron-group metal salt.

Description

Solid electrolyte separator, all-solid-state battery including the same, and method for manufacturing a solid electrolyte separator

[0001] The invention relates to a solid electrolyte separator, an all-solid-state battery including the same, and a method for manufacturing the solid electrolyte separator.

[0002] Recently, driven by industrial demands, the development of batteries with high energy density and safety is actively underway. For example, lithium batteries are used in a wide range of applications, including information devices, communication equipment, and automobiles. Since automobiles are a matter of life and death, safety is also critical.

[0003] Lithium batteries using liquid electrolytes may have an increased risk of fire and / or explosion in the event of a short circuit. All-solid-state batteries employing solid electrolytes instead of liquid electrolytes are being proposed. Solid electrolytes have a lower risk of ignition compared to liquid electrolytes.

[0004] All-solid-state batteries can reduce the possibility of fire or explosion by employing a solid electrolyte instead of a liquid electrolyte. All-solid-state batteries can provide enhanced safety.

[0005] One aspect is to provide a solid electrolyte separator with improved durability by including a complex of Li2S and a metal halide salt.

[0006] Another aspect is to provide an all-solid-state battery comprising the above-mentioned solid electrolyte separator.

[0007] Another aspect is to provide a method for manufacturing the above-mentioned solid electrolyte membrane.

[0008] According to one embodiment, a solid electrolyte separator is provided, comprising a first composite including Li2S and a first metal halide salt; and a first sulfide-based solid electrolyte, wherein the first metal halide salt includes an alkali metal salt and a boron group metal salt.

[0009] According to another embodiment, an all-solid-state battery is provided, comprising: an anode; a cathode; and a solid electrolyte layer disposed between the anode and the cathode, wherein the solid electrolyte layer comprises the solid electrolyte separator described above.

[0010] A method for manufacturing a solid electrolyte membrane is provided, comprising: providing a composite comprising Li2S and a metal halide salt according to another embodiment; providing a sulfide-based solid electrolyte; mixing the composite and the sulfide-based solid electrolyte to form a mixture; and molding the mixture to form a solid electrolyte membrane, wherein the metal halide salt comprises an alkali metal salt and a boron group metal salt.

[0011] According to one aspect, it is possible to provide an all-solid-state battery having improved cycle characteristics by employing a solid electrolyte separator comprising a complex of Li2S and a metal halide salt.

[0012] FIG. 1 is a cross-sectional view of an all-solid-state battery according to an exemplary embodiment.

[0013] Figure 2 is a schematic cross-sectional view showing an enlarged view of area A of Figure 1.

[0014] FIG. 3 is a cross-sectional view of an all-solid-state battery according to an exemplary embodiment.

[0015] Figure 4 is a graph showing the rapid charge / discharge characteristics of the all-solid-state battery of Example 5.

[0016] Figure 5 is a graph showing the rapid charge / discharge characteristics of the all-solid-state battery of Comparative Example 4.

[0017] The present inventive concept described below is subject to various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present inventive concept to specific embodiments and should be understood to include all modifications, equivalents, or substitutions that fall within the scope of the description of the present inventive concept.

[0018] The terms used below are used merely to describe specific embodiments and are not intended to limit the creative concept. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the following, terms such as “comprising” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, components, materials, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, components, materials, or combinations thereof. The “ / ” used below may be interpreted as “and” or “or” depending on the context.

[0019] In the drawings, thicknesses have been enlarged or reduced to clearly represent various layers and regions. Throughout the specification, the same reference numerals have been used for similar parts. Throughout the specification, when a part such as a layer, film, region, or plate is described as being “on” or “above” another part, this includes not only cases where it is directly above another part but also cases where there is another part in between. Throughout the specification, terms such as “first,” “second,” etc., may be used to describe various components, but the components should not be limited by these terms. In this specification and drawings, components having substantially the same functional configuration are referred to by the same reference numerals to avoid redundant descriptions.

[0020] In the present disclosure, the “size” of a particle is, for example, the “particle diameter” of the particle. The “particle diameter” of the particle represents the average diameter when the particle is spherical and represents the average major axis length when the particle is non-spherical. The particle diameter of the particle can be measured using a particle size analyzer (PSA). The “particle diameter” of the particle is, for example, the average particle diameter. The average particle diameter is, for example, the median particle diameter (D50). The median particle diameter (D50) is the particle size corresponding to the 50% cumulative volume calculated from the side of the particle having a small particle size in the particle size distribution measured, for example by laser diffraction.

[0021] In the present disclosure, “metal” includes both metals and metalloids such as silicon and germanium in an elemental or ionic state.

[0022] In this disclosure, “alloy” means a mixture of two or more metals.

[0023] In the present disclosure, “anode active material” refers to an anode material capable of undergoing lithiation and delithiation.

[0024] In the present disclosure, “anode active material” refers to an anode material capable of undergoing lithiation and delithiation.

[0025] In the present disclosure, “lithiation” and “to lithiate” refer to the process of adding lithium to a positive electrode active material or a negative electrode active material.

[0026] In the present disclosure, “delithiation” and “to delithiate” refer to the process of removing lithium from a positive electrode active material or a negative electrode active material.

[0027] In this disclosure, “charge” and “to charge” refer to the process of providing electrochemical energy to a battery.

[0028] In this disclosure, “anode” and “cathode” refer to electrodes where electrochemical reduction and lithiation occur during the discharge process.

[0029] In this disclosure, “cathode” and “anode” refer to electrodes where electrochemical oxidation and delithiation occur during the discharge process.

[0030] A solid electrolyte separator according to exemplary embodiments, an all-solid-state battery (10) including the same, and a method for manufacturing the solid electrolyte separator will be described in more detail below.

[0031] FIG. 1 is a cross-sectional view of an all-solid-state battery (10) according to an exemplary embodiment. Referring to FIG. 1, an all-solid-state battery (10) according to an embodiment may include a positive electrode (100), a negative electrode (200), and a solid electrolyte layer (300) disposed between the positive electrode (100) and the negative electrode (200). The solid electrolyte layer (300) may include a solid electrolyte separator.

[0032] [Solid Electrolyte Membrane]

[0033] [Solid Electrolyte Separator: First Complex]

[0034] FIG. 2 is a schematic cross-sectional view showing an enlarged view of area A of FIG. 1. Referring to FIG. 2, a solid electrolyte separator according to one embodiment comprises a first composite (composite, 1) comprising Li2S and a first metal halide salt; and a first sulfide-based solid electrolyte (2); wherein the first metal halide salt may include an alkali metal salt and a boron group metal salt.

[0035] A solid electrolyte separator can be manufactured, for example, using solid electrolyte particles. The solid electrolyte separator may include voids, such as pinholes, placed between the solid electrolyte particles. During the charging and discharging process of the all-solid-state battery (10), defects such as cracks in the solid electrolyte separator may occur as lithium dendrites grow through these pinholes. Through these defects, lithium dendrites may grow, causing a short circuit between the positive and negative electrodes. In this case, the cycle characteristics of the all-solid-state battery (10) may be degraded. Since the pinholes in the solid electrolyte separator act as insulators, they may increase the internal resistance of the solid electrolyte separator. In this case, the pinholes in the solid electrolyte separator may also increase the interface resistance between the solid electrolyte separator and the positive or negative electrode.

[0036] The durability of the solid electrolyte separator of the present disclosure can be improved by including a first composite (1) comprising Li2S and a first metal halide salt. The first composite (1) may have ductility, for example. The first composite (1) may act as a buffer material between sulfide-based solid electrolyte particles during the manufacturing process of the solid electrolyte separator. The first composite (1) may suppress the formation of additional cracks and voids in the sulfide-based solid electrolyte particles caused by collisions / friction between the sulfide-based solid electrolyte particles. The first composite (1) may be easily filled into the voids and / or interfaces between the sulfide-based solid electrolyte particles. In the solid electrolyte separator of the present disclosure, the formation of pores within the solid electrolyte separator is suppressed and the first composite (1) is easily disposed in the generated pores, thereby suppressing the formation of pinholes in the solid electrolyte separator and suppressing the growth of lithium dendrites through these pinholes, so the durability of the solid electrolyte separator can be improved.

[0037] Since the first composite (1) has ductility, it can be distinguished from oxide-based solid electrolytes that have brittleness, such as oxide-based solid electrolytes with a garnet structure. Since the first composite (1) has lithium ion conductivity, it can be distinguished from lithium-non-containing metal oxides that do not have lithium ion conductivity. The first composite (1) may be, for example, the result of mechanical milling of Li2S and the first metal halide salt. Since the first composite (1) is, for example, the result of a mechanochemical reaction of Li2S and the first metal halide salt, it can be distinguished from a simple mixture of Li2S and the first metal halide salt. A simple mixture of Li2S and the metal halide salt may provide high interfacial resistance by failing to maintain a dense interface between Li2S and the metal halide salt, and consequently increase the internal resistance of the solid electrolyte separator.

[0038] The first metal halide salt may include an alkali metal salt and a boron group metal salt. That is, the first complex (1) may be a complex of Li2S, an alkali metal salt, and a boron group metal salt.

[0039] The alkali metal salt according to one embodiment may be a lithium salt. The alkali metal salt may include, for example, LiF, LiCl, LiBr, LiI, or a combination thereof. The alkali metal salt may be, for example, a compound that does not contain sulfur (S). The ionic conductivity of the first complex (1) may be further improved by the first complex (1) including such an alkali metal salt.

[0040] A boron group metal salt according to one embodiment may be, for example, a binary compound composed of a boron group metal and one element selected from Group 17 of the periodic table. The boron group metal salt may include, for example, AlF3, AlCl3, AlBr3, AlI3, GaF3, GaCl3, GaBr3, GaI3, InF3, InCl3, lnBr3, lnI3, TlF3, TlCl3, TlBr3, TlI3, or a combination thereof. By including such a boron group metal salt, the first complex (1) can maintain its overall shape, easily form a solid solution, and lower interfacial resistance.

[0041] By including this first composite (1) in the solid electrolyte separator, the internal resistance of the solid electrolyte separator can be further reduced. As a result, the cycle characteristics of the all-solid-state battery (10) including this solid electrolyte separator can be further improved.

[0042] 제1 전이체(1)는 다이다, Li2S-LiF-AlF3, Li2S-LiF-AlCl3, Li2S-LiF-AlBr3, Li2S-LiF-AlI3, Li2S-LiF-GaF3, Li2S-LiF-GaCl3, Li2S-LiF-GaBr3, Li2S-LiF-GaI3, Li2S-LiF-InF3 Li2S-LiF-InCl3, Li2S-LiF-InBr3, Li2S-LiF-InI3, Li2S-LiF-TlF3, Li2S-LiF-TlCl3, Li2S-LiF-TlBr3, Li2S-LiF-TlI3, Li2S-LiCl-AlF3, Li2S-LiCl-AlCl3, Li2S-LiCl-AlBr3, Li2S-LiCl-AlI3, Li2S-LiCl-GaF3, Li2S-LiCl-GaCl3, Li2S-LiCl-GaBr3, Li2S-LiCl-GaI3, Li2S-LiCl-InF3, Li2S-LiCl-InCl3, Li2S-LiCl-InBr3, Li2S-LiCl-InI3, Li2S-LiCl-TlF3, Li2S-LiCl-TlCl3, Li2S-LiCl-TlBr3, Li2S-LiCl-TlI3, Li2S-LiBr-AlF3, Li2S-LiBr-AlCl3, Li2S-LiBr-AlBr3, Li2S-LiBr-AlI3, Li2S-LiBr-GaF3, Li2S-LiBr-GaCl3, Li2S-LiBr-GaBr3, Li2S-LiBr-GaI3, Li2S-LiBr-InF3, Li2S-LiBr-InCl3, Li2S-LiBr-InBr3, Li2S-LiBr-InI3, Li2S-LiBr-TlF3, Li2S-LiBr-TlCl3, Li2S-LiBr-TlBr3, Li2S-LiBr-TlI3, Li2S-LiI-AlF3, Li2S-LiI-AlCl3, Li2S-LiI-AlBr3, Li2S-LiI-AlI3, Li2S-LiI-GaF3, Li2S-LiI-GaCl3, Li2S-LiI-GaBr3, Li2S-LiI-GaI3, Li2S-LiI-InF3, Li2S-LiI-InCl3, Li2S-LiI-InBr3, Li2S-LiI-InI3, Li2S-LiI-TlF3,It may include Li2S-LiI-TlCl3, Li2S-LiI-TlBr3, Li2S-LiI-TlI3, or a combination thereof.

[0043] The first composite (1) may include, for example, a solid solution of Li2S and a first metal halide salt. By including the solid solution of Li2S and the first metal halide salt in the first composite (1), the ionic conductivity of the first composite (1) may be improved. For example, by including lithium ions disposed within the Li2S crystallites in the solid solution of Li2S and the first metal halide salt, the ionic conductivity of the solid solution of Li2S and the first metal halide salt may be improved compared to the ionic conductivity of Li2S. Consequently, the ionic conductivity of the first composite (1) may be improved, and the internal resistance of the Li2S and the first metal halide salt composite may be reduced. By including this first composite (1) in the solid electrolyte separator, the internal resistance of the solid electrolyte separator may be further reduced. Consequently, the cycle characteristics of the all-solid-state battery (10) including this solid electrolyte separator may be further improved.

[0044] The size of the Li2S crystallites obtained from the XRD spectrum of the first composite (1) may be, for example, 20 nm or less, 15 nm or less, or 10 nm or less. The size of the Li2S crystallites obtained from the XRD spectrum of the first composite (1) may be, for example, 1 to 20 nm, 1 to 15 nm, or 3 to 10 nm. As the size of the Li2S crystallites decreases, the contact area between Li2S and the first metal halide salt may be further increased. As the contact area between Li2S and the first metal halide salt is further increased, the ionic conductivity of the first composite (1) may be further increased. As the solid electrolyte separator includes this first composite (1), the internal resistance of the solid electrolyte separator may be further reduced. Consequently, the cycle characteristics of the all-solid-state battery (10) including this solid electrolyte separator may be further improved.

[0045] The Mohs hardness of the first composite (1) may be smaller than the Mohs hardness of the first metal halide salt. The first composite (1) may have improved ductility compared to the first metal halide salt. Since the first composite (1) has improved ductility, the formation of pinholes within the solid electrolyte membrane can be suppressed more effectively during the manufacture of the solid electrolyte membrane. Consequently, the durability of the solid electrolyte membrane containing this first composite (1) may be further improved. The Mohs hardness of the first composite (1) may be, for example, less than 2, 1.5 or less, 1 or less, or 0.7 or less. If the Mohs hardness of the first composite (1) increases excessively, it may be difficult to suppress the formation of pinholes within the solid electrolyte membrane due to the difficulty in providing ductility. The Mohs hardness of Li2S is, for example, 0.6. The Mohs hardness of the first metal halide salt may be 0.7 or higher, 0.8 or higher, 0.9 or higher, 1.0 or higher, 1.5 or higher, or 2.0 or higher. Since the first metal halide salt has a Mohs hardness within this range, the grinding of Li2S can be performed more easily during the milling process, and a solid solution of Li2S and the first metal halide salt can be formed more easily. The Mohs hardness of LiI is, for example, 2.0.

[0046] Since Li2S has relatively low ionic conductivity, a complex is formed with a first metal halide salt to improve ionic conductivity. The complex of Li2S and the first metal halide salt can provide improved ionic conductivity compared to Li2S alone. The content of Li2S in the first complex (1) may be 60 to 80 wt% or 65 to 75 wt% of the total weight of the first complex (1). By having a Li2S content within this range, the first complex (1) can simultaneously provide improved ionic conductivity and excellent ductility. Consequently, the durability of the solid electrolyte membrane containing the first complex (1) can be improved. The content of the first metal halide salt in the first complex (1) may be 20 to 40 wt% or 25 to 35 wt% of the total weight of the first complex (1). By having a first metal halide salt content within this range, the first composite (1) can simultaneously provide improved ionic conductivity and excellent ductility. Consequently, the durability of the solid electrolyte separator containing the first composite (1) can be improved.

[0047] According to one embodiment, the weight ratio of the alkali metal salt to the boron group metal salt in the first metal halide salt may be 5:1 to 1:20. For example, the weight ratio of the alkali metal salt to the boron group metal salt in the first metal halide salt may be 3:1 to 1:9, 1:1 to 1:9, or 1:2 to 1:9. When satisfying the above ranges, different types of metal halide salts can be included in appropriate proportions to maximize the effect of improving capacity characteristics.

[0048] The ionic conductivity of the first complex (1) is, for example, 1×10⁻⁶ at 45 ℃. -6 S / cm or more, 2×10 -6 S / cm or more, 4×10 -6 S / cm or more, or 5×10 -6It may be greater than S / cm. Ionic conductivity can be measured using, for example, electrochemical impedance spectrometry, DC polarization method, etc. As the first composite (1) has ionic conductivity in this range, the internal resistance of the solid electrolyte separator containing the first composite (1) can be further reduced. The cycle characteristics of the all-solid-state battery (10) containing the solid electrolyte separator can be improved.

[0049] The content of the first composite (1) in the solid electrolyte membrane may be, for example, 0.1 to 20 wt%, 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, or 1 to 5 wt% of the total weight of the first composite (1) and the first sulfide-based solid electrolyte (2). The content of the first composite (1) may be, for example, 0.1 to 20 wt%, 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, or 1 to 5 wt% of the total weight of the solid electrolyte membrane. By having the solid electrolyte membrane with a content of the first composite (1) within this range, the durability of the solid electrolyte membrane may be further improved and the internal resistance may be further reduced. If the content of the first composite (1) is excessively low, the effect may be negligible. If the content of the first complex (1) increases excessively, the internal resistance of the solid electrolyte membrane may increase.

[0050] The solid electrolyte separator may include, for example, particles of a first composite (1) and particles of a first sulfide-based solid electrolyte (2). The size of the particles of the first composite (1) may be, for example, smaller than the size of the particles of the first sulfide-based solid electrolyte (2). The size of the particles of the first composite (1) may be, for example, 90% or less, 80% or less, 60% or less, 40% or less, 20% or less, or 10% or less of the size of the particles of the first sulfide-based solid electrolyte (2). The particles of the first composite (1) may be placed, for example, in the voids between a plurality of first sulfide-based solid electrolytes (2). By placing the particles of the first composite (1) in the voids between a plurality of first sulfide-based solid electrolytes (2), the formation of pinholes within the solid electrolyte separator is suppressed, and the internal resistance of the solid electrolyte separator may be reduced. As a result, the durability of the solid electrolyte separator may be improved.

[0051] The size of the particles of the first sulfide-based solid electrolyte (2) may be, for example, 1 to 10 μm, 1 to 8 μm, 1 to 6 μm, 1 to 5 μm, or 1 to 3 μm. By having the particles of the first sulfide-based solid electrolyte (2) have a size within this range, the durability of the solid electrolyte separator can be further improved. The size of the particles of the first sulfide-based solid electrolyte (2) can be measured using, for example, laser diffraction, scanning electron microscopy, etc. The size of the particles of the first sulfide-based solid electrolyte (2) is, for example, the arithmetic mean value of the particle diameters of a plurality of particles measured using software in a scanning electron microscopy image.

[0052] The size of the particles of the first composite (1) may be, for example, 10 μm or less, 5 μm or less, or 3 μm or less. The size of the particles of the first composite (1) may be, for example, 0.1 to 10 μm, 0.1 to 5 μm, or 0.1 to 3 μm. By having the particles of the first composite (1) within this range of size, they can be more easily placed in the voids between multiple sulfide-based solid electrolytes, the formation of pinholes within the solid electrolyte membrane is suppressed, and the internal resistance of the solid electrolyte membrane can be reduced. Consequently, the durability of the solid electrolyte membrane can be improved. The size of the particles of the first composite (1) can be measured using, for example, laser diffraction, scanning electron microscopy, etc. The size of the particles of the first composite (1) is, for example, the arithmetic mean value of the particle diameters of multiple particles measured using software in a scanning electron microscopy image.

[0053] The ratio of the size of the first sulfide-based solid electrolyte (2) particles to the size of the first composite (1) particles may be, for example, 2:1 to 200:1, 2:1 to 100:1, or 2:1 to 50:1. By having the size of the first sulfide-based solid electrolyte (2) particles and the size of the first composite (1) particles within this range, the formation of defects in the solid electrolyte membrane is suppressed, and the durability of the solid electrolyte membrane can be further improved. If the ratio of the size of the first sulfide-based solid electrolyte (2) particles to the size of the first composite (1) particles is excessively small, the porosity of the solid electrolyte membrane increases excessively, which may reduce the durability of the solid electrolyte membrane. If the ratio of the size of the first sulfide-based solid electrolyte (2) particles to the size of the first composite (1) particles is excessively large, it may be difficult to achieve uniform dispersion of the first composite (1) particles within the solid electrolyte membrane.

[0054] The porosity of the solid electrolyte separator may be 8% or less, 7% or less, 5% or less, 3% or less, 2% or less, or 1% or less. The porosity of the solid electrolyte separator may be 0.01 to 8%, 0.05 to 7%, 0.1 to 5%, 0.1 to 3%, 0.1 to 2%, or 0.1 to 1%. By having a porosity of 10% or less, the internal resistance of the solid electrolyte separator is reduced, and the growth of lithium dendrites can be suppressed more effectively. As a result, the durability of the solid electrolyte separator can be improved. The porosity of the solid electrolyte separator can be measured, for example, by a method of calculating the pore area from a mapping image of the cross-section of the solid electrolyte separator through ultrasonic analysis, or by a method of calculating the pore area from an electron microscope image of the cross-section of the solid electrolyte separator.

[0055] [Solid Electrolyte Membrane: Primary Sulfide-based Solid Electrolyte]

[0056] The solid electrolyte separator comprises a first sulfide-based solid electrolyte (2). The first sulfide-based solid electrolyte (2) is, for example, Li2S-P2S5, Li2S-P2S5-LiX, where X is a halogen element, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n , m, n are positive numbers, Z is one of Ge, Zn, or Ga, Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q , p, q are positive numbers, M is one of P, Si, Ge, B, Al, Ga, In, Li 7-x PS 6-x Cl x(0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It is one or more selected from (0≤x≤2). The first sulfide-based solid electrolyte (2) can be manufactured by processing starting materials, such as Li2S, P2S5, etc., by a melt quenching method or a mechanical milling method. Additionally, heat treatment can be performed after such processing. The first sulfide-based solid electrolyte (2) may be amorphous, crystalline, or a mixture thereof. The first sulfide-based solid electrolyte (2) may include, for example, at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements. The first sulfide-based solid electrolyte (2) may include, for example, Li2S-P2S5. When using a material containing Li2S-P2S5 as the first sulfide-based solid electrolyte (2), the mixing molar ratio of Li2S and P2S5 is, for example, in the range of Li2S : P2S5 = 20 : 80 to 90 : 10, 25 : 75 to 90 : 10, 30 : 70 to 70 : 30, 40 : 60 to 60 : 40.

[0057] The first sulfide-based solid electrolyte (2) may include, for example, an argyrodite-type solid electrolyte represented by the following chemical formula 1:

[0058] <Chemical Formula 1>

[0059] Li + 12-n-x A n+ X 2- 6-x Y - x

[0060] In the above formula, A is P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, or Ta, X is S, Se, or Te, Y is Cl, Br, I, F, CN, OCN, SCN, or N3, and 1≤n≤5, 0≤x≤2. The first sulfide-based solid electrolyte (2) is, for example, Li 7-x PS 6-x Cl x , 0≤x≤2, Li 7-x PS 6-x Br x , 0≤x≤2, and Li 7-x PS 6-x I x It may be an argyrodite-type compound containing one or more selected from 0≤x≤2. The first sulfide-based solid electrolyte (2) may be an argyrodite-type compound containing one or more selected from, for example, Li6PS5Cl, Li6PS5Br, and Li6PS5I. The density of the argyrodite-type solid electrolyte may be 1.5 to 2.0 g / cc. By having a density of 1.5 g / cc or more for the argyrodite-type solid electrolyte, the internal resistance of the all-solid-state battery (10) is reduced, and penetration of the solid electrolyte separator by lithium can be suppressed more effectively.

[0061] The content of the first sulfide-based solid electrolyte (2) in the solid electrolyte separator may be, for example, 80 to 99.9 wt%, 80 to 99.5 wt%, 75 to 99.5 wt%, 90 to 99.5 wt%, or 95 to 99 wt% of the total weight of the first composite (1) and the first sulfide-based solid electrolyte (2). The content of the first sulfide-based solid electrolyte (2) may be, for example, 80 to 99.9 wt%, 80 to 99.5 wt%, 75 to 99.5 wt%, 90 to 99.5 wt%, or 95 to 99 wt% of the total weight of the solid electrolyte separator. By having the solid electrolyte membrane have a content of the first sulfide-based solid electrolyte (2) within this range, the ionic conductivity of the solid electrolyte membrane can be further improved and the internal resistance can be further reduced. If the content of the first sulfide-based solid electrolyte (2) is excessively low, the ionic conductivity may be lowered. If the content of the first sulfide-based solid electrolyte (2) increases excessively, the durability of the solid electrolyte membrane may decrease.

[0062] [Solid Electrolyte Separator: Binder]

[0063] The solid electrolyte membrane may further include a binder. The binder included in the solid electrolyte membrane is, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited to these, and any binder used in the relevant technical field is acceptable. The binder may be omitted.

[0064] A binder included in a solid electrolyte separator according to one embodiment may include an acrylic binder. The acrylic binder may include, for example, poly(methyl methacrylate) (PMMA), polyacrylonitrile (PAN), an ethylene-propylene-diene monomer (EPDM)-based acrylic copolymer, an acrylic-styrene copolymer, a poly(acrylic acid) (PAA), or a combination thereof.

[0065] The binder content included in the solid electrolyte membrane is, for example, 0.1 to 10 wt%, 0.1 to 5 wt%, 0.1 to 3 wt%, or 0.1 to 2 wt% based on the total weight of the solid electrolyte membrane.

[0066] [Solid Electrolyte Separator: Others]

[0067] The solid electrolyte separator may be free of carbon-based conductive materials. The solid electrolyte separator may not contain carbon-based conductive materials, such as graphite, carbon black, carbon nanotubes, or carbon nanofibers. By not containing carbon-based conductive materials, the solid electrolyte separator may provide high electronic insulation. By not containing carbon-based conductive materials, the possibility of a short circuit between the anode (100) and the cathode can be more effectively blocked. The solid electrolyte separator may also not contain metal-based conductive materials.

[0068] The solid electrolyte separator can be, for example, a self-standing film. The solid electrolyte separator can maintain a membrane shape without a support. The solid electrolyte separator can be, for example, in the form of a sheet. Since the solid electrolyte separator is a self-standing film, the assembly of an all-solid-state secondary battery equipped with the solid electrolyte separator can be performed more easily.

[0069] The solid electrolyte separator may have a curvature greater than zero, for example. The solid electrolyte separator may be bendable, for example. Since the solid electrolyte separator has ductility by including the first sulfide-based solid electrolyte (2) and the first composite (1), it can be bent or deformed. Therefore, during the charging and discharging process of the all-solid-state battery (10), volume changes of the positive electrode (100) and / or negative electrode can be effectively accommodated, and the formation of cracks, etc., in the solid electrolyte separator can be effectively prevented.

[0070] In contrast, a solid electrolyte separator made of an oxide-based solid electrolyte has brittleness, so it is difficult to bend and difficult to have a curvature greater than 0. A solid electrolyte separator made of an oxide-based solid electrolyte may not bend and may be cut by cracks due to uneven internal stress caused by volume changes of the positive electrode (100) and / or negative electrode during, for example, the charging and discharging process of an all-solid-state battery (10).

[0071] [All-solid-state battery]

[0072] A solid-state battery (10) according to another embodiment of the present disclosure comprises a positive electrode (100); a negative electrode; and a solid electrolyte layer disposed between the positive electrode (100) and the negative electrode; and the solid electrolyte layer may comprise the solid electrolyte separator described above.

[0073] [anode]

[0074] A positive electrode (100) according to one embodiment may include a positive electrode current collector (110) and a positive electrode active material layer (120) disposed on one or both sides of the positive electrode current collector (110).

[0075] [Polygon: Positive current collector]

[0076] The positive current collector (110) may provide a reference surface on which the positive active material layer (120) is placed. The positive current collector (110) may include, for example, a plate or foil comprising indium (In), copper (Cu), magnesium (Mg), stainless steel (SUS), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof. In another embodiment, the positive current collector (110) may be omitted. Although not illustrated, a carbon layer with a thickness of 0.1 μm to 4 μm may be further disposed between the positive current collector (110) and the positive active material layer (120) to increase the bonding strength between the positive current collector (110) and the positive active material layer (120). The carbon layer may include amorphous carbon, crystalline carbon, etc.

[0077] [Anode: Anode active material layer]

[0078] The positive active material layer (120) includes a positive active material. The positive active material is a positive active material capable of reversibly absorbing and desorbing lithium ions. The positive active material may include, for example, a sulfide-based positive active material, an oxide-based positive active material, or a combination thereof.

[0079] [Cathode active layer: Sulfide-based cathode active material + Secondary sulfide-based solid electrolyte]

[0080] The positive active material included in the positive active material layer (120) according to one embodiment may include a sulfide-based positive active material. When the positive active material according to one embodiment includes a sulfide-based positive active material, the positive active material layer (120) may include a second sulfide-based solid electrolyte.

[0081] The sulfide-based cathode active material may include a second composite comprising a sulfur-based material, a second metal halide salt, and a carbon-based conductive material. The second metal halide salt may include an alkali metal salt and a boron group metal salt.

[0082] The second composite may be, for example, the result of mechanical milling of a sulfur-based material, a second metal halide salt, and a carbon-based conductive material. Since the second composite is, for example, the result of a mechanochemical reaction of a sulfur-based material, a second metal halide salt, and a carbon-based conductive material, it can be distinguished from a simple mixture of a sulfur-based material, a second metal halide salt, and a carbon-based conductive material. A simple mixture of a sulfur-based material, a second metal halide salt, and a carbon-based conductive material may provide high interfacial resistance by failing to maintain a dense interface between the sulfur-based material, the second metal halide salt, and the carbon-based conductive material, and consequently increase the internal resistance of the positive active material layer (120).

[0083] Sulfur-based materials may contain elemental sulfur (S). Sulfur is attracting attention as a next-generation cathode material due to its high theoretical capacity (1,672 mAh / g), its abundance on Earth, and its relatively low cost. In one embodiment, the elemental sulfur (S) is S8 and Li2S nIt may exist in the form of a sulfur-based material containing at least one of (1 ≤ n ≤ 8, where n is an integer). A continuous oxidation / reduction reaction of sulfur and / or lithium sulfide proceeds in the sulfur-based material. For example, the reaction process of lithium polysulfide and lithium sulfide by the continuous reduction reaction of sulfur in the sulfur-based material can be expressed as S8→2S8→2S6→2S4→2S2→Li2S, etc. In this process, lithium ions move between the anode and cathode, and at the same time, electrons move through an external circuit to generate current. The capacity characteristics of the second composite may be further improved by the second composite containing such a sulfur-based material. Consequently, the energy density of the all-solid-state battery (10) containing such a second composite may be improved.

[0084] The second metal halide salt may include an alkali metal salt and a boron group metal salt. That is, the second composite may be a composite of a sulfur-based material, an alkali metal salt, a boron group metal salt, and a carbon-based conductive material.

[0085] The alkali metal salt according to one embodiment may be a lithium salt. The alkali metal salt may include, for example, LiF, LiCl, LiBr, LiI, or a combination thereof. The alkali metal salt may be, for example, a compound that does not contain sulfur (S). The ionic conductivity of the second complex may be further enhanced by the second complex including such an alkali metal salt.

[0086] A boron group metal salt according to one embodiment may be, for example, a binary compound composed of a boron group metal and one element selected from Group 17 of the periodic table. The boron group metal salt may include, for example, AlF3, AlCl3, AlBr3, AlI3, GaF3, GaCl3, GaBr3, GaI3, InF3, InCl3, lnBr3, lnI3, TlF3, TlCl3, TlBr3, TlI3, or a combination thereof. By including such a boron group metal salt in the second complex, the overall shape of the second complex can be maintained, allowing for the easy formation of a solid solution and lowering the interfacial resistance.

[0087] Carbon-based conductive materials may include, for example, any material containing carbon atoms that is used as a conductive material in the relevant technical field. Carbon-based conductive materials may include, for example, crystalline carbon, amorphous carbon, or a combination thereof. Carbon-based conductive materials may include, for example, a calcined product of a carbon precursor. Carbon-based conductive materials may be, for example, carbon nanostructures. Carbon nanostructures may include, for example, one-dimensional carbon nanostructures, two-dimensional carbon nanostructures, three-dimensional carbon nanostructures, or a combination thereof. Carbon nanostructures may include, for example, carbon nanotubes (CNT), carbon nanofibers (CNF), carbon nanobelts, carbon nanorods, graphene, or a combination thereof. Carbon-based conductive materials may be, for example, porous carbon-based materials or non-porous carbon-based materials. Porous carbon-based materials may include, for example, periodic and regular two-dimensional or three-dimensional pores. The porous carbon-based material may include, for example, carbon black such as Ketjen black, acetylene black, Denka black, thermal black, and channel black, graphite, activated carbon, or a combination thereof. The form of the carbon-based conductive material may be, for example, particle form, sheet form, flake form, etc., but is not limited thereto; any form used as a carbon-based conductive material in the relevant technical field is possible. The carbon-based conductive material according to one embodiment may include, for example, a fibrous carbon-based conductive material. The electron conductivity of the second composite may be further enhanced by the second composite including the fibrous carbon-based conductive material. Electron conduction from the surface to the interior of the second composite may be performed more easily by the second composite including the fibrous carbon-based conductive material.

[0088] By including this second composite in the positive active material layer (120), the internal resistance of the positive active material layer (120) can be further reduced. As a result, the cycle characteristics of the all-solid-state battery (10) including this positive active material layer (120) can be further improved.

[0089] 제2 복합체는 예를 들어, Li2S-LiF-CNT, Li2S-LiCl-CNT, Li2S-LiBr-CNT, Li2S-LiI-CNT, Li2S-LiF-CNF, Li2S-LiCl-CNF, Li2S-LiBr-CNF, Li2S-LiI-CNF, Li2S-LiF-AlF3-CNT, Li2S-LiF-AlCl3-CNT, Li2S-LiF-AlBr3-CNT, Li2S-LiF-AlI3-CNT, Li2S-LiF-GaF3-CNT, Li2S-LiF-GaCl3-CNT, Li2S-LiF-GaBr3-CNT, Li2S-LiF-GaI3-CNT, Li2S-LiF-InF3-CNT, Li2S-LiF-InCl3-CNT, Li2S-LiF-InBr3-CNT, Li2S-LiF-InI3-CNT, Li2S-LiF-TlF3-CNT, Li2S-LiF-TlCl3-CNT, Li2S-LiF-TlBr3-CNT, Li2S-LiF-TlI3-CNT, Li2S-LiCl-AlF3-CNT, Li2S-LiCl-AlCl3-CNT, Li2S-LiCl-AlBr3-CNT, Li2S-LiCl-AlI3-CNT, Li2S-LiCl-GaF3-CNT, Li2S-LiCl-GaCl3-CNT, Li2S-LiCl-GaBr3-CNT, Li2S-LiCl-GaI3-CNT, Li2S-LiCl-InF3-CNT, Li2S-LiCl-InCl3-CNT, Li2S-LiCl-InBr3-CNT, Li2S-LiCl-InI3-CNT, Li2S-LiCl-TlF3-CNT, Li2S-LiCl-TlCl3-CNT, Li2S-LiCl-TlBr3-CNT, Li2S-LiCl-TlI3-CNT, Li2S-LiBr-AlF3-CNT, Li2S-LiBr-AlCl3-CNT, Li2S-LiBr-AlBr3-CNT, Li2S-LiBr-AlI3-CNT, Li2S-LiBr-GaF3-CNT, Li2S-LiBr-GaCl3-CNT, Li2S-LiBr-GaBr3-CNT, Li2S-LiBr-GaI3-CNT, Li2S-LiBr-InF3-CNT, Li2S-LiBr-InCl3-CNT, Li2S-LiBr-InBr3-CNT,Li2S-LiBr-InI3-CNT, Li2S-LiBr-TlF3-CNT, Li2S-LiBr-TlCl3-CNT, Li2S-LiBr-TlBr3-CNT, Li2S-LiBr-TlI3-CNT, Li2S-LiI-AlF3-CNT, Li2S-LiI-AlCl3-CNT, Li2S-LiI-AlBr3-CNT, Li2S-LiI-AlI3-CNT, Li2S-LiI-GaF3-CNT, Li2S-LiI-GaCl3-CNT, Li2S-LiI-GaBr3-CNT, Li2S-LiI-GaI3-CNT, Li2S-LiI-InF3-CNT, Li2S-LiI-InCl3-CNT, Li2S-LiI-InBr3-CNT, Li2S-LiI-InI3-CNT, Li2S-LiI-TlF3-CNT, Li2S-LiI-TlCl3-CNT, Li2S-LiI-TlBr3-CNT, Li2S-LiI-TlI3-CNT, Li2S-LiF-AlF3-CNF, Li2S-LiF-AlCl3-CNF, Li2S-LiF-AlBr3-CNF, Li2S-LiF-AlI3-CNF, Li2S-LiF-GaF3-CNF, Li2S-LiF-GaCl3-CNF, Li2S-LiF-GaBr3-CNF, Li2S-LiF-GaI3-CNF, Li2S-LiF-InF3-CNF, Li2S-LiF-InCl3-CNF, Li2S-LiF-InBr3-CNF, Li2S-LiF-InI3-CNF, Li2S-LiF-TlF3-CNF, Li2S-LiF-TlCl3-CNF, Li2S-LiF-TlBr3-CNF, Li2S-LiF-TlI3-CNF, Li2S-LiCl-AlF3-CNF, Li2S-LiCl-AlCl3-CNF, Li2S-LiCl-AlBr3-CNF, Li2S-LiCl-AlI3-CNF, Li2S-LiCl-GaF3-CNF, Li2S-LiCl-GaCl3-CNF, Li2S-LiCl-GaBr3-CNF, Li2S-LiCl-GaI3-CNF, Li2S-LiCl-InF3-CNF, Li2S-LiCl-InCl3-CNF, Li2S-LiCl-InBr3-CNF, Li2S-LiCl-InI3-CNF, Li2S-LiCl-TlF3-CNF,Li2S-LiCl-TlCl3-CNF, Li2S-LiCl-TlBr3-CNF, Li2S-LiCl-TlI3-CNF, Li2S-LiBr-AlF3-CNF, Li2S-LiBr-AlCl3-CNF, Li2S-LiBr-AlBr3-CNF, Li2S-LiBr-AlI3-CNF, Li2S-LiBr-GaF3-CNF, Li2S-LiBr-GaCl3-CNF, Li2S-LiBr-GaBr3-CNF, Li2S-LiBr-GaI3-CNF, Li2S-LiBr-InF3-CNF, Li2S-LiBr-InCl3-CNF, Li2S-LiBr-InBr3-CNF, Li2S-LiBr-InI3-CNF, Li2S-LiBr-TlF3-CNF, Li2S-LiBr-TlCl3-CNF, Li2S-LiBr-TlBr3-CNF, Li2S-LiBr-TlI3-CNF, Li2S-LiI-AlF3-CNF, Li2S-LiI-AlCl3-CNF, Li2S-LiI-AlBr3-CNF, Li2S-LiI-AlI3-CNF, Li2S-LiI-GaF3-CNF, Li2S-LiI-GaCl3-CNF, Li2S-LiI-GaBr3-CNF, Li2S-LiI-GaI3-CNF, Li2S-LiI-InF3-CNF, Li2S-LiI-InCl3-CNF, Li2S-LiI-InBr3-CNF, Li2S-LiI-InI3-CNF, Li2S-LiI-TlF3-CNF, Li2S-LiI-TlCl3-CNF, Li2S-LiI-TlBr3-CNF, Li2S-LiI-TlI3-CNF 또는 이들의 조합을 포함할 수 있다.,

[0090] The second complex may include, for example, a solid solution of a sulfur-based material, a second metal halide salt, and a carbon-based conductive material. The ionic conductivity and electrical conductivity of the second complex may be enhanced by the second complex including the solid solution of the sulfur-based material, the second metal halide salt, and the carbon-based conductive material. For example, the ionic conductivity and electrical conductivity of the solid solution of the sulfur-based material, the second metal halide salt, and the carbon-based conductive material may be enhanced compared to the ionic conductivity and electrical conductivity of the sulfur-based material by including lithium ions disposed within the crystallites of the sulfur-based material. Consequently, the ionic conductivity and electrical conductivity of the second complex may be enhanced.

[0091] The size of the crystallites of Li2S contained in the sulfur-based material obtained from the XRD spectrum of the second complex may be, for example, 20 nm or less, 15 nm or less, or 10 nm or less. The size of the crystallites of Li2S contained in the sulfur-based material obtained from the XRD spectrum of the second complex may be, for example, 1 to 20 nm, 1 to 15 nm, or 3 to 10 nm. As the size of the Li2S crystallites decreases, the contact area between Li2S in the sulfur-based material and the second metal halide salt may be further increased. As the contact area between Li2S in the sulfur-based material and the second metal halide salt is further increased, the ionic conductivity of the second complex may be further increased. As the positive active material layer (120) includes such a second complex, the internal resistance of the positive active material layer (120) may be further reduced. As a result, the cycle characteristics of the all-solid-state battery (10) including this positive active material layer (120) can be further improved.

[0092] The Mohs hardness of the second composite may be lower than that of the second metal halide salt. The second composite may have improved ductility compared to the second metal halide salt. Since the second composite has improved ductility, the formation of pinholes within the solid electrolyte membrane can be suppressed more effectively during the manufacture of the solid electrolyte membrane. Consequently, the durability of the solid electrolyte membrane containing this second composite may be further improved. The Mohs hardness of the second composite may be, for example, less than 2, 1.5 or less, 1 or less, or 0.7 or less. If the Mohs hardness of the second composite increases excessively, it may be difficult to suppress the formation of pinholes within the solid electrolyte membrane due to the difficulty in providing ductility. The Mohs hardness of Li2S is, for example, 0.6. The Mohs hardness of the second metal halide salt may be 0.7 or higher, 0.8 or higher, 0.9 or higher, 1.0 or higher, 1.5 or higher, or 2.0 or higher. Since the second metal halide salt has a Mohs hardness within this range, the grinding of Li2S can be performed more easily during the milling process, and a solid solution of Li2S and the second metal halide salt can be formed more easily. The Mohs hardness of LiI is, for example, 2.0.

[0093] Since sulfur-based materials have relatively low ionic conductivity, a composite is formed with a second metal halide salt to improve ionic conductivity. The composite of the sulfur-based material, the second metal halide salt, and the carbon-based conductive material can provide improved ionic conductivity compared to the sulfur-based material alone. The content of the sulfur-based material in the second composite may be 50 to 80 wt%, 50 to 70 wt%, or 55 to 60 wt% of the total weight of the second composite. The second composite may provide improved ionic conductivity by having a content of the sulfur-based material within these ranges. The content of the second metal halide salt in the second composite may be 10 to 50 wt% or 20 to 50 wt% of the total weight of the second composite. The second composite may provide improved ionic conductivity by having a content of the second metal halide salt within these ranges. Consequently, the ionic conductivity of the positive active material layer (120) containing the second composite can be improved. The content of the alkali metal salt in the second metal halide salt may be 1 to 15 wt%, 3 to 10 wt%, or 5 to 10 wt% of the total weight of the second complex. The content of the boron group metal salt in the second metal halide salt may be 3 to 45 wt%, 9 to 30 wt%, or 15 to 30 wt% of the total weight of the second complex.

[0094] According to one embodiment, the weight ratio of the alkali metal salt to the boron group metal salt in the second metal halide salt may be 5:1 to 1:20. For example, the weight ratio of the alkali metal salt to the boron group metal salt in the second metal halide salt may be 3:1 to 1:9, 1:1 to 1:9, or 1:2 to 1:9. When satisfying the above ranges, different types of metal halide salts can be included in appropriate proportions to maximize the effect of improving capacity characteristics.

[0095] The ionic conductivity of the positive active material according to one embodiment is 3 x 10 at 25 ℃. -6It can be greater than S / cm. For example, the ionic conductivity of the positive active material is 3.5 x 10⁻⁶ -6 It may be greater than S / cm, and 4 x 10 -6 It may be greater than S / cm, and 5 x 10 -6 It may be greater than S / cm, and 6 x 10 -6 It may be greater than S / cm, and 6.75 x 10 -6 It may be greater than S / cm. The ionic conductivity of the positive active material according to one embodiment is 1 x 10 -4 It can be less than S / cm. Ionic conductivity can be measured using the DC polarization method. Alternatively, ionic conductivity can be measured using the complex impedance method.

[0096] Since sulfur-based materials have relatively low electronic conductivity, they form a composite with a carbon-based conductive material to improve electronic conductivity. A composite of a sulfur-based material, a second metal halide salt, and a carbon-based conductive material can provide improved electronic conductivity compared to the sulfur-based material alone. The content of the carbon-based conductive material in the second composite may be 1 to 30 wt%, 1 to 20 wt%, 5 to 20 wt%, or 10 to 20 wt% of the total weight of the second composite. The second composite can provide improved electronic conductivity by having a content of carbon-based conductive material within this range.

[0097] The electron conductivity of the positive active material according to one embodiment is 5 x 10 at 25 ℃. -3 It can be greater than S / cm. For example, the electron conductivity of the positive active material is 6.5 x 10⁻⁶ -3 It may be greater than S / cm, and 7 x 10 -3 It may be greater than S / cm, and 8 x 10 -3 It may be greater than S / cm. The electron conductivity of the positive active material according to one embodiment is 1 x 10 -1 It may be less than S / cm.

[0098] The second sulfide-based solid electrolyte is, for example, Li2S-P2S5, Li2S-P2S5-LiX, where X is a halogen element, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n , m, n are positive numbers, Z is one of Ge, Zn, or Ga, Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q , p, q are positive numbers, M is one of P, Si, Ge, B, Al, Ga, In, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I xIt is one or more selected from (0≤x≤2). The second sulfide-based solid electrolyte can be manufactured by processing starting materials, such as Li2S or P2S5, by methods such as melt quenching or mechanical milling. Additionally, heat treatment may be performed after such processing. The second sulfide-based solid electrolyte may be amorphous, crystalline, or a mixture thereof. The second sulfide-based solid electrolyte may, for example, contain at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements. The second sulfide-based solid electrolyte may, for example, contain Li2S-P2S5. When using a material containing Li2S-P2S5 as a second sulfide-based solid electrolyte, the mixed molar ratio of Li2S and P2S5 is, for example, in the range of Li2S : P2S5 = 20 : 80 to 90 : 10, 25 : 75 to 90 : 10, 30 : 70 to 70 : 30, and 40 : 60 to 60 : 40.

[0099] The second sulfide-based solid electrolyte may include, for example, an argyrodite-type solid electrolyte represented by the following chemical formula 1:

[0100] <Chemical Formula 1>

[0101] Li + 12-n-x A n+ X 2- 6-x Y - x

[0102] In the above formula, A is P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, or Ta, X is S, Se, or Te, Y is Cl, Br, I, F, CN, OCN, SCN, or N3, and 1≤n≤5, 0≤x≤2. The first sulfide-based solid electrolyte (2) is, for example, Li 7-x PS 6-x Cl x , 0≤x≤2, Li 7-x PS6-x Br x , 0≤x≤2, and Li 7-x PS 6-x I x It may be an argyrodite-type compound containing one or more selected from 0≤x≤2. The second sulfide-based solid electrolyte may be an argyrodite-type compound containing one or more selected from, for example, Li6PS5Cl, Li6PS5Br, and Li6PS5I. The density of the argyrodite-type solid electrolyte may be 1.5 to 2.0 g / cc. The internal resistance of the all-solid-state battery (10) may be reduced by the argyrodite-type solid electrolyte having a density of 1.5 g / cc or more.

[0103] The content of the second complex within the positive active material layer (120) may be, for example, 50 to 90 wt% or 60 to 80 wt% of the total weight of the second complex and the second sulfide-based solid electrolyte. By having the positive active material layer (120) have a second complex content within this range, the capacity of the positive active material layer (120) is further enhanced. Consequently, the capacity characteristics of the all-solid-state battery (10) including such a positive active material layer (120) can be improved.

[0104] The content of the second sulfide-based solid electrolyte in the positive active material layer (120) may be, for example, 10 to 50 wt% or 20 to 40 wt% of the total weight of the second composite and the second sulfide-based solid electrolyte. By having the positive active material layer (120) have a second sulfide-based solid electrolyte content within this range, the ionic conductivity of the positive active material layer (120) is further improved. Consequently, the cycle characteristics of the all-solid-state battery (10) including such a positive active material layer (120) can be improved.

[0105] [Cathode active material layer: Oxide-based cathode active material]

[0106] The positive active material included in the positive active material layer (120) according to another embodiment may include an oxide-based positive active material.

[0107] As an oxide-based cathode active material, a compound capable of reversible intercalation and deintercalation of lithium (a lithated intercalation compound) may be used. Specifically, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0108] The above composite oxide may be a lithium transition metal composite oxide, and specific examples include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0109] As an example, a compound represented by any one of the following chemical formulas may be used. Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d Ge O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3(0≤f≤2); Li a FePO4(0.90≤a≤1.8).

[0110] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X 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; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L 1 is Mn, Al, or a combination thereof.

[0111] For example, the above-mentioned positive electrode active material may be a high-nickel positive electrode active material in which the nickel content relative to 100 mol% of the metal excluding lithium in the lithium transition metal composite oxide is 80 mol% or more, 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more and 99 mol% or less. The high-nickel positive electrode active material can achieve high capacity and can be applied to high-capacity, high-density lithium secondary batteries.

[0112] [Anode Active Material Layer: Others]

[0113] The positive active material layer (120) may further include a binder and / or a conductive material.

[0114] For example, the positive active material layer (120) may further include an additive that can serve as a sacrificial positive.

[0115] The content of the binder and the conductive material may be 0.5% to 5% by weight each with respect to 100% by weight of the positive active material layer (120).

[0116] The binder serves to adhere the positive active material particles well to each other and also to adhere the positive active material well to the current collector. Representative examples of binders include, but are not limited to, polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, diacetylcellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, nylon, etc.

[0117] A conductive material is used to impart conductivity to an electrode, and any electronically conductive material that does not cause chemical changes can be used in the battery being constructed. Examples of conductive materials include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal-based materials in the form of metal powder or metal fibers containing copper, nickel, aluminum, silver, etc.; conductive polymers such as polyphenylene derivatives; or mixtures thereof. Meanwhile, when a sulfide-based cathode active material containing the second composite described above is applied as the cathode active material, a carbon-based conductive material is included within the second composite, so a separate conductive material may not be included. That is, the cathode active material layer (120) according to one embodiment may be free of conductive material.

[0118] [cathode]

[0119] A negative electrode (200) according to one embodiment may include a negative electrode current collector (210). In a negative electrode (200) according to one embodiment, lithium metal and / or a lithium alloy may be deposited on the negative electrode current collector (210) by charging. In this case, the lithium metal and / or lithium alloy may act as a lithium reservoir. That is, the all-solid-state battery (10) according to one embodiment may be a lithium metal battery.

[0120] The negative current collector (210) may provide a reference surface on which a lithium metal layer (230) or a negative coating layer (220) is disposed. The negative current collector (210) may include, for example, a material that does not react with lithium, that is, does not form any alloys or compounds with lithium. The material constituting the negative current collector (210) may include at least one metal selected from the group consisting of, for example, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). The thickness of the negative current collector (210) may be 1 to 20 μm, for example 5 to 15 μm, for example 7 to 10 μm.

[0121] The negative current collector (210) may be composed of one of the metals described above, or may include an alloy of two or more metals or a coating material. The negative current collector (210) is, for example, in the form of a plate or foil. In another embodiment, the negative current collector (210) may be omitted.

[0122] A solid-state battery (10) according to one embodiment may further include a negative coating layer (220) on a negative current collector (210). The negative coating layer (220) may be configured to allow lithium metal to grow between the negative current collector (210) and the negative coating layer (220) and / or within the negative coating layer (220) during charging of the solid-state battery (10). The negative coating layer (220) may serve as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites. The negative coating layer (220) may include, for example, a metal-carbon composite.

[0123] The metal-carbon composite included in the cathode coating layer (220) is a cathode material capable of forming an alloy or compound with, for example, lithium. The metal-carbon composite has, for example, a particle form. The average particle size of the metal-carbon composite having a particle form is, for example, 4 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, 500 nm or less, 300 nm or less, or 100 nm or less. The average particle size of the metal-carbon composite having a particle form is, for example, 10 nm to 4 μm, 10 nm to 3 μm, 10 nm to 2 μm, 10 nm to 1 μm, or 10 nm to 500 nm, 10 nm to 300 nm, or 10 nm to 100 nm. By having the average particle size of the metal-carbon composite within this range, the reversible absorption and / or desorption of lithium during charging and discharging may be more facilitated. The average particle size of the metal-carbon composite is, for example, the median diameter (D50) measured using a laser particle size distribution meter.

[0124] A metal-carbon composite may include, for example, metal particles and a carbonaceous material. The metal particles and the carbonaceous material may each have a particle form, for example. A metal-carbon composite may be, for example, a simple mixture of metal particles and a carbonaceous material. The metal particles within the metal-carbon composite may include at least one metal or metalloid selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). However, this is not limited thereto, and any metal or metalloid used in the art to form an alloy or compound with lithium is acceptable. The carbonaceous material within the metal-carbon composite may include, for example, amorphous carbon, crystalline carbon, porous carbon, or a combination thereof. The carbonaceous material within the metal-carbon composite may be amorphous carbon. The carbonaceous material within the metal-carbon composite may include, for example, carbon black, acetylene black, furnace black, Kettjen black, graphene, or a combination thereof. Amorphous carbon may be carbon that does not have crystallinity or has very low crystallinity. The carbonaceous material within the metal-carbon composite may be, for example, porous carbon. The pore volume contained in the porous carbon may be, for example, 0.1 cc / g to 10.0 cc / g, 0.5 cc / g to 5 cc / g, or 0.1 cc / g to 1 cc / g. The average pore diameter contained in the porous carbon may be, for example, 1 nm to 50 nm, 1 nm to 30 nm, or 1 nm to 10 nm. The BET specific surface area of ​​the porous carbon is, for example, 100 m² 2 / g to 3,000 m 2It can be / g. The BET specific surface area of ​​porous carbon can be measured, for example, according to ISO 9277:2022.

[0125] The mixing ratio of metal particles and carbon-based material included in the cathode coating layer (220) can be, for example, 1:10 to 2:1, 1:5 to 1:1, or 1:4 to 1:2 by weight.

[0126] The metal-carbon composite may be, for example, a composite of metal particles and a carbon-based material. The carbon-based material may be, for example, a carbon-based support. The metal-carbon composite may include, for example, a carbon-based support and metal particles supported on the carbon-based support. By having such a structure, the localization of metal particles within the cathode coating layer (220) is prevented and a uniform distribution can be obtained. Consequently, the cycle characteristics of the all-solid-state battery (10) including the cathode coating layer (220) can be further improved.

[0127] Metal particles supported on a carbon-based support may include, for example, a metal, a metal oxide, a composite of a metal and a metal oxide, or a combination thereof. The metal may include, for example, gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), tellurium (Te), and zinc (Zn). The metal oxide may include, for example, gold (Au) oxide, platinum (Pt) oxide, palladium (Pd) oxide, silicon (Si) oxide, silver (Ag) oxide, aluminum (Al) oxide, bismuth (Bi) oxide, tin (Sn) oxide, tellurium (Te) oxide, and zinc (Zn) oxide. The metal oxide may include, for example, Au x O y (0 <x≤2, 0<y≤3), Pt x O y (0 <x≤1, 0<y≤2), Pd x O y (0 <x≤1, 0<y≤1), Si xThe y (0 <x≤1, 0<y≤2), Ag x The y (0 <x≤2, 0<y≤1), Al x The y (0 <x≤2, 0<y≤3), Bi x The y (0 <x≤2, 0<y≤3), Sn x The y (0 <x≤1, 0<y≤2), Te x The y (0 <x≤1,0<y≤3), Zn x The y (0 <x≤1, 0<y≤1) 또는 이들의 조합을 포함할 수 있다. 금속과 금속 산화물의 복합체는 예를 들어 Au와 Au x The y (0 <x≤2, 0<y≤3)의 복합체, Pt와 Pt x The y (0 <x≤1, 0<y≤2)의 복합체, Pd와 Pd x The y (0 <x≤1, 0<y≤1)의 복합체, Si와 Si x The y (0 <x≤1, 0<y≤2)의 복합체, Ag 와 Ag x The y (0 <x≤2, 0<y≤1)의 복합체, Al과 Al x The y (0 <x≤2, 0<y≤3)의 복합체, Bi와 Bi x The y (0 <x≤2, 0<y≤3)의 복합체, Sn과 Sn x The y (0 <x≤1, 0<y≤2)의 복합체, Te과 Te x The y (0 <x≤1, 0<y≤3), Zn과 Zn x The y (0 <x≤1, 0<y≤1)의 복합체, 또는 이들의 조합을 포함할 수 있다.

[0128] A carbon-based support is, for example, amorphous carbon. Amorphous carbon is, for example, carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), graphene, activated carbon, carbon nanofiber (CNF), carbon nanotube (CNT), etc., but is not necessarily limited to these, and any carbon classified as amorphous carbon in the relevant technical field is acceptable. Amorphous carbon is carbon that does not have crystallinity or has very low crystallinity, and is distinguished from crystalline carbon or graphite-based carbon.

[0129] The binder included in the cathode coating layer (220) may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, etc., but is not necessarily limited to these and any binder used in the relevant technical field is possible. The binder may be composed of a single binder or a plurality of different binders.

[0130] The cathode coating layer (220) may further include other additives in addition to the metal-carbon composite. The cathode coating layer (220) may further include at least one additive selected from the group consisting of, for example, fillers, coating agents, dispersants, and ion-conducting aids.

[0131] The cathode coating layer (220) may further include a solid electrolyte. The solid electrolyte may be a material selected from, for example, a solid electrolyte included in a solid electrolyte separator. The solid electrolyte included in the cathode coating layer (220) may act as a reaction site where the formation of lithium metal begins within the cathode coating layer (220), act as a space where the formed lithium metal is stored, or act as a path for transporting lithium ions. The solid electrolyte may be omitted.

[0132] FIG. 3 is a cross-sectional view of an all-solid-state battery (10) according to an exemplary embodiment. Referring to FIG. 3, a negative electrode (200) according to another embodiment may further include a lithium metal layer (230) disposed between a negative electrode current collector (210) and a negative electrode coating layer (220). The lithium metal layer (230) may be a configuration formed by charging the all-solid-state battery (10). Although not shown in the drawing, the all-solid-state battery (10) may further include a lithium metal layer (230) disposed inside the negative electrode coating layer (220) by charging.

[0133] The lithium metal layer (230) may include lithium or a lithium alloy. Since the lithium metal layer (230) is a metal layer containing lithium, it may function as, for example, a lithium reservoir. The lithium alloy may be, for example, a Li-Al alloy, a Li-Sn alloy, a Li-In alloy, a Li-Ag alloy, a Li-Au alloy, a Li-Zn alloy, a Li-Ge alloy, a Li-Si alloy, but is not limited to these; any alloy used as a lithium alloy in the relevant technical field may be possible. The lithium metal layer (230) may be composed of one of these alloys or lithium, or may be composed of various types of alloys. The lithium metal layer (230) may be, for example, a plated layer. The lithium metal layer (230) may be deposited between the negative electrode coating layer (220) and the negative electrode current collector (210) during the charging process of the all-solid-state battery (10), for example.

[0134] In another embodiment, the lithium metal layer (230) in the negative electrode may be provided, for example, between the negative electrode current collector (210) and the negative electrode coating layer (220) before assembly of the all-solid-state battery (10). When the lithium metal layer (230) is placed between the negative electrode current collector (210) and the negative electrode coating layer (220) before assembly of the all-solid-state battery (10), the lithium metal layer (230) acts as a lithium reservoir because it is a metal layer containing lithium. For example, a lithium foil may be placed between the negative electrode current collector (210) and the negative electrode coating layer (220) before assembly of the all-solid-state battery (10).

[0135] When a lithium metal layer (230) is deposited by charging after assembly of the all-solid-state battery (10), the energy density of the all-solid-state battery (10) can be increased because the lithium metal layer (230) is not included during assembly of the all-solid-state battery (10). When charging the all-solid-state battery (10), it can be charged beyond the charging capacity of the negative electrode coating layer (220). That is, the negative electrode coating layer (220) can be overcharged. At the beginning of charging, lithium can be absorbed in the negative electrode coating layer (220). If charging is performed beyond the capacity of the negative electrode coating layer (220), lithium can be deposited, for example, between the negative electrode coating layer (220) and the negative electrode current collector (210). A lithium metal layer (230) can be formed by the deposited lithium.

[0136] The lithium metal layer (230) can be composed mainly of lithium (i.e., metallic lithium). During discharge, the lithium in the lithium metal layer (230) can be ionized and move to the positive electrode (100). In other words, lithium can be used as a negative electrode active material in the all-solid-state battery (10). In addition, since the negative electrode coating layer (220) covers the lithium metal layer (230), the negative electrode coating layer (220) can protect the lithium metal layer (230) and at the same time suppress the precipitation growth of lithium dendrites. Therefore, the negative electrode coating layer (220) can suppress short circuits and capacity degradation of the all-solid-state battery (10) and improve the cycle characteristics of the all-solid-state battery (10).

[0137] When a lithium metal layer (230) is formed by charging after assembly of the all-solid-state battery (10), the negative electrode, i.e., the negative electrode current collector (210) and the negative electrode coating layer (220) and the region between them may be a Li-free region that does not contain lithium (Li) in the initial state or after complete discharge of the all-solid-state battery (10).

[0138] [Method for manufacturing solid electrolyte membranes]

[0139] A method for manufacturing a solid electrolyte membrane according to another embodiment may include providing a composite comprising Li2S and a metal halide salt; providing a sulfide-based solid electrolyte; mixing the composite and the sulfide-based solid electrolyte to form a mixture; and molding the mixture to form a solid electrolyte membrane. The metal halide salt may include an alkali metal salt and a boron group metal salt. The composites are Li2S-LiF-AlF3, Li2S-LiF-AlCl3, Li2S-LiF-AlBr3, Li2S-LiF-AlI3, Li2S-LiF-GaF3, Li2S-LiF-GaCl3, Li2S-LiF-GaBr3, Li2S-LiF-GaI3, Li2S-LiF-InF3, Li2S-LiF-InCl3, Li2S-LiF-InBr3, Li2S-LiF-InI3, Li2S-LiF-TlF3, Li2S-LiF-TlCl3, Li2S-LiF-TlBr3, Li2S-LiF-TlI3, Li2S-LiCl-AlF3, Li2S-LiCl-AlCl3, Li2S-LiCl-AlBr3, Li2S-LiCl-AlI3, Li2S-LiCl-GaF3, Li2S-LiCl-GaCl3, Li2S-LiCl-GaBr3, Li2S-LiCl-GaI3, Li2S-LiCl-InF3, Li2S-LiCl-InCl3, Li2S-LiCl-InBr3, Li2S-LiCl-InI3, Li2S-LiCl-TlF3, Li2S-LiCl-TlCl3, Li2S-LiCl-TlBr3, Li2S-LiCl-TlI3, Li2S-LiBr-AlF3, Li2S-LiBr-AlCl3, Li2S-LiBr-AlBr3, Li2S-LiBr-AlI3, Li2S-LiBr-GaF3, Li2S-LiBr-GaCl3, Li2S-LiBr-GaBr3, Li2S-LiBr-GaI3, Li2S-LiBr-InF3, Li2S-LiBr-InCl3, Li2S-LiBr-InBr3, Li2S-LiBr-InI3, Li2S-LiBr-TlF3,It may include Li2S-LiBr-TlCl3, Li2S-LiBr-TlBr3, Li2S-LiBr-TlI3, Li2S-LiI-AlF3, Li2S-LiI-AlCl3, Li2S-LiI-AlBr3, Li2S-LiI-AlI3, Li2S-LiI-GaF3, Li2S-LiI-GaCl3, Li2S-LiI-GaBr3, Li2S-LiI-GaI3, Li2S-LiI-InF3, Li2S-LiI-InCl3, Li2S-LiI-InBr3, Li2S-LiI-InI3, Li2S-LiI-TlF3, Li2S-LiI-TlCl3, Li2S-LiI-TlBr3, Li2S-LiI-TlI3 or a combination thereof.

[0140] A complex comprising Li2S and a metal halide salt is provided.

[0141] A composite comprising Li2S and a metal halide salt can be prepared, for example, by mechanically milling Li2S, an alkali metal salt, and a boron group metal salt. The milling conditions are not particularly limited and any conditions capable of forming a composite of Li2S and a metal halide salt are possible. A composite of Li2S and a metal halide salt can be formed by introducing Li2S particles, an alkali metal salt, and a boron group metal salt into a ball mill and stirring at a speed of 100 to 1000 rpm for 1 to 20 hours. The mixing ratio of the Li2S particles and the metal halide salt introduced can be, for example, a weight ratio of 100:20 to 20:20, 80:20 to 20:20, or 60:20 to 20:20. The mixing ratio of the alkali metal salt and the boron group metal salt in the metal halide salt may be, for example, a weight ratio of 5:5 to 5:25, 5:10 to 5:25, or 5:10 to 5:20. Stirring may be performed one or more times.

[0142] A sulfide-based solid electrolyte is provided. The sulfide-based solid electrolyte refers to the solid electrolyte separator portion described above.

[0143] A mixture is formed by mixing the complex and the sulfide-based solid electrolyte.

[0144] The mixing ratio of the composite and the sulfide-based solid electrolyte may be, for example, a weight ratio of 50:50 to 95:5, 50:50 to 90:10, 50:50 to 80:20, or 50:50 to 70:30.

[0145] The mixture may additionally contain a process solvent. By additionally containing a process solvent, the mixture may have a slurry form. The solvent may be, for example, octyl acetate, but is not limited thereto, and any solvent used in the art is acceptable. Alternatively, the mixture may be prepared dry without containing a process solvent.

[0146] The formed mixture is molded to form a solid electrolyte separator.

[0147] For example, a sheet-shaped solid electrolyte separator can be manufactured by coating a wet mixture in the form of a slurry onto a substrate and drying it. The solid electrolyte separator can be formed by separating it from the substrate.

[0148] Alternatively, a sheet-shaped solid electrolyte separator can be manufactured by feeding a solvent-free dry mixture into an extruder and extruding it.

[0149] The creative idea is explained in more detail through the following examples and comparative examples. However, the examples are intended to illustrate the creative idea and do not limit the scope of the creative idea to these examples alone.

[0150] Example 1: [Solid electrolyte: Li2S-LiI-AlI3 complex = 99:1 weight ratio]

[0151] Preparation of Li2S-LiI-AlI3 complex

[0152] Li2S, LiI, and AlI3 were mixed in a weight ratio of 40:5:15. The mixture was mechanically milled using a ball mill to prepare a Li2S-LiI-AlI3 composite. The milling conditions were 25°C at 450 rpm for 10 hours.

[0153] To obtain a Li2S-LiI-AlI3 complex of 1 µm or less, after additional grinding at 300 rpm for 5 hours, large particles were filtered out using a 325 mesh with a mesh size of 45 µm.

[0154] The size of the obtained Li2S-LiI-AlI3 complex was less than 1 μm. The size of the Li2S-LiI-AlI3 complex was calculated by software from scanning electron microscope images of the Li2S-LiI-AlI3 complex powder. The size of the Li2S-LiI-AlI3 complex is the D50 average particle size.

[0155] solid electrolyte membrane manufacturing

[0156] A mixture was prepared by adding 1 part by weight of a Li2S-LiI-AlI3 composite and 1.5 parts by weight of a poly(methyl methacrylate) (PMMA) binder to 99 parts by weight of the solid electrolyte, in addition to the argyrodite-type crystal Li6PS5Cl solid electrolyte (D50=3.0 μm, crystalline). A slurry was prepared by stirring while adding octyl acetate to the prepared mixture. The prepared slurry was applied using a bar coater onto a 15 μm thick nonwoven fabric placed on a PET substrate, and a laminate was prepared by drying in air at 80 °C for 10 minutes. The prepared laminate was vacuum dried at 80 °C for 2 hours and then separated from the substrate to produce a solid electrolyte separator. The solid electrolyte separator is a self-standing film. The solid electrolyte membrane can be slightly bent when force is applied and can be restored to its original shape when the applied force is removed. The solid electrolyte membrane is used as is as a solid electrolyte layer.

[0157] Manufacturing of anodes

[0158] Li2S, LiI, AlI3, and CNF were mixed in a weight ratio of 57.1:7.14:21.4:14.3. The mixture was mechanically milled using a ball mill to prepare a Li2S-LiI-AlI3-CNF composite. The milling conditions were 25°C at 450 rpm for 10 hours.

[0159] A mixture was prepared by adding 70 parts by weight of a Li2S-LiI-AlI3-CNF composite to 30 parts by weight of a solid electrolyte (D50 = 3.0 μm, crystalline), which is an argyrodite-type crystal. PTFE was prepared as a binder. An anode composite was prepared by mixing these materials in a weight ratio of Li2S-LiI-AlI3-CNF composite : solid electrolyte : binder = 70 : 30 : 1.2. The anode composite was obtained by dry mixing using a ball mill.

[0160] An anode was prepared by placing the anode composite on one side of an anode current collector made of aluminum foil coated with carbon on one side and performing a plate press at a pressure of 200 MPa for 10 minutes. The thickness of the anode was approximately 120 μm. The thickness of the anode active material layer was approximately 100 μm, and the thickness of the carbon-coated aluminum foil was approximately 20 μm. The area of ​​the anode active material layer and the anode current collector were the same.

[0161] Manufacturing of the cathode

[0162] A SUS foil with a thickness of 10 μm was prepared as a cathode current collector. As a cathode coating layer, carbon black (CB) with a primary particle size of about 30 nm and silver (Ag) particles with an average particle diameter of about 60 nm were prepared. 4 g of a mixed powder, prepared by mixing carbon black (CB) and silver (Ag) particles in a weight ratio of 3:1, was placed in a container, and 4 g of an NMP solution containing 7 wt% of a PVDF binder (Kureha # 9300) was added to prepare a mixed solution. A slurry was prepared by stirring the mixed solution while adding NMP little by little to the prepared mixed solution. The prepared slurry was applied to a SUS sheet using a bar coater, dried in air at 80°C for 10 minutes, and then vacuum dried at 40°C for 10 hours to prepare a laminate.

[0163] A prepared laminate was cold-roll-pressed to flatten the surface, thereby preparing a cathode having a cathode coating layer / cathode current collector structure. The thickness of the cathode coating layer was approximately 15 μm. The area of ​​the cathode coating layer and the cathode current collector were the same.

[0164] Manufacturing of all-solid-state batteries

[0165] An electrode assembly was prepared by arranging the manufactured solid electrolyte separator so that a cathode coating layer contacts one side and an anode active material layer contacts the other side, with the electrode stacked in the order of cathode / solid electrolyte separator / anode.

[0166] The prepared electrode assembly was plate-pressed at 85 °C under a pressure of 500 MPa for 30 minutes. This pressurization process sintered the solid electrolyte separator, thereby improving battery characteristics. The thickness of the sintered solid electrolyte separator was approximately 45 μm. The density of the Li6PS5Cl solid electrolyte, an argyrodite-type crystal contained in the sintered solid electrolyte separator, was 1.6 g / cc. The area of ​​the solid electrolyte separator was equal to the area of ​​the negative electrode.

[0167] An all-solid-state battery was manufactured by placing a pressurized electrode assembly into a pouch and vacuum sealing it. Parts of the positive and negative current collectors were extended outside the sealed battery to serve as the positive and negative terminals.

[0168] Example 2: [Solid electrolyte: Li2S-LiI-AlI3 complex = 97:3 weight ratio]

[0169] A solid electrolyte separator and an all-solid-state battery were prepared in the same manner as in Example 1, except that 3 parts by weight of the Li2S-LiI-AlI3 composite prepared in the example and 1.5 parts by weight of poly(methyl methacrylate) (PMMA) binder were used for every 97 parts by weight of the solid electrolyte.

[0170] Example 3: [Solid electrolyte: Li2S-LiI-AlI3 complex = 95:5 weight ratio]

[0171] A solid electrolyte separator and an all-solid-state battery were prepared in the same manner as in Example 1, except that 5 parts by weight of the Li2S-LiI-AlI3 composite prepared in the example and 1.5 parts by weight of poly(methyl methacrylate) (PMMA) binder were used for every 95 parts by weight of the solid electrolyte.

[0172] Example 4: [Solid electrolyte: Li2S-LiI-AlI3 complex = 90:10 weight ratio]

[0173] A solid electrolyte separator and an all-solid-state battery were prepared in the same manner as in Example 1, except that 10 parts by weight of the Li2S-LiI-AlI3 composite prepared in the example and 1.5 parts by weight of poly(methyl methacrylate) (PMMA) binder were used for every 90 parts by weight of the solid electrolyte.

[0174] Example 5: Oxide-based cathode active material (NCA)

[0175] A solid electrolyte separator and an all-solid-state battery were manufactured in the same manner as in Example 1, except that a cathode manufactured by the cathode manufacturing method below was applied.

[0176] (Anode manufacturing)

[0177] LiNi coated with Li2O-ZrO2 (LZO) as a cathode active material 0.8 Co 0.15 Al 0.05 O2(NCA) was prepared. The LZO-coated cathode active material was prepared according to the method disclosed in Korean Patent Publication No. 10-2016-0064942. Li6PS5Cl, an argyrodite-type crystal (D50 = 0.5 μm, crystalline), was prepared as the solid electrolyte. Polytetrafluoroethylene (PTFE) binder was prepared as the binder. Carbon nanofiber (CNF) was prepared as the conductive agent. A slurry was formed by mixing these materials with a xylene solvent in a weight ratio of cathode active material: solid electrolyte: conductive agent: binder = 84: 11.5: 3: 1.5, and then vacuum-dried at 40°C for 8 hours to produce a cathode sheet. An anode sheet manufactured was placed on the carbon layer of an anode current collector made of aluminum foil coated with a carbon layer on one side, and an anode layer was manufactured by a heated roll press at 85°C. The total thickness of the anode layer was approximately 120 μm. The thickness of the anode active material layer was approximately 95 μm, and the thickness of the carbon-coated aluminum foil was approximately 25 μm.

[0178] Comparative Example 1: [Solid electrolyte alone]

[0179] A solid electrolyte separator and an all-solid-state battery were prepared in the same manner as in Example 1, except that 1.5 parts by weight of poly(methyl methacrylate) (PMMA) binder was used per 100 parts by weight of the solid electrolyte. A Li2S-LiI-AlI3 composite was not used.

[0180] Comparative Example 2: [Solid electrolyte: Li2S = 99:1 weight ratio]

[0181] A solid electrolyte separator and an all-solid-state battery were prepared in the same manner as in Example 1, except that Li2S was used instead of the Li2S-LiI-AlI3 complex.

[0182] Comparative Example 3: [Solid electrolyte: LiI = 99:1 weight ratio]

[0183] A solid electrolyte separator and an all-solid-state battery were prepared in the same manner as in Example 1, except that LiI was used instead of the Li2S-LiI-AlI3 complex.

[0184] Comparative Example 4: [Solid electrolyte alone, oxide-based cathode active material (NCA)]

[0185] An all-solid-state battery was manufactured in the same manner as in Example 1, except that the solid electrolyte separator of Comparative Example 1 and the anode of Example 5 were applied.

[0186] Evaluation Example 1: Porosity Measurement

[0187] The porosity of the solid electrolyte membranes prepared in Example 1 and Comparative Example 1 was measured, and the results are shown in Table 1 below.

[0188] The porosity of the solid electrolyte membrane was calculated through ultrasonic analysis. The solid electrolyte membrane was mapped using ultrasound, and an ultrasonic image of the membrane cross-section containing pores was obtained. The porosity was measured by calculating the pore area relative to the total cross-sectional area.

[0189] Porosity [%] Example 1 (Li2S-LiI-AlI31 wt%) 3.67 Comparative Example 1 (Li2S-LiI-AlI30 wt%) 8.7

[0190] As shown in Table 1, the porosity of the solid electrolyte membrane of Example 1 was reduced compared to the solid electrolyte membrane of Comparative Example 1.

[0191] Evaluation Example 2: Charge / Discharge Test - Sulfide-based Anode Active Material Anode

[0192] The charge-discharge characteristics of all-solid-state batteries employing the solid electrolyte separators prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated by the following charge-discharge test.

[0193] The charge / discharge test was performed by placing the all-solid-state battery in a constant temperature bath at 45°C.

[0194] The first cycle involved charging at a constant current of 0.1 C for 12.5 hours until the battery voltage reached 2.5 V to 2.8 V. Subsequently, discharging was performed at a constant current of 0.1 C for 12.5 hours until the battery voltage reached 0.3 V.

[0195] The discharge capacity of the first cycle was set as the standard capacity.

[0196] After the second cycle, the charge-discharge test was repeated under the same conditions as the first cycle until the SOH reached 80%, and the battery life characteristics were evaluated by measuring the SOH after each cycle. The measurement results are shown in Table 2 below.

[0197] The number of cycles refers to the number of cycles required to reduce the SOH to 80% after the second cycle. It was considered that the lifespan characteristics are superior as the number of cycles increases.

[0198] Cycle Count [Times] Example 1 (Li2S-LiI-AlI3 1 wt%, sulfide-based cathode active material) 253 Example 2 (Li2S-LiI-AlI3 3 wt%, sulfide-based cathode active material) 221 Example 3 (Li2S-LiI-AlI3 5 wt%, sulfide-based cathode active material) 204 Example 4 (Li2S-LiI-AlI3 10 wt%, sulfide-based cathode active material) 157 Comparative Example 1 (Li2S-LiI-AlI3 0 wt%, sulfide-based cathode active material) 50 Comparative Example 2 (Li2S alone 1 wt%, sulfide-based cathode active material) 35 Comparative Example 3 (LiI alone 1 wt%, sulfide-based cathode active material) 70

[0199] As shown in Table 2, the all-solid-state batteries of Examples 1 to 4 showed improved lifespan characteristics compared to the all-solid-state batteries of Comparative Examples 1 to 3. It was determined that this was because the durability of the solid electrolyte separator was improved by suppressing the formation of pinholes and suppressing defects such as short circuits caused by lithium dendrite growth through pinholes by including Li2S-LiI-AlI3 in the solid electrolyte separator employed in the all-solid-state batteries of Examples 1 to 4.

[0200] Evaluation Example 3: Charge / Discharge Test - Oxide-based Anode Active Material Anode

[0201] The charge-discharge characteristics of an all-solid-state battery employing the solid electrolyte separator prepared in Example 5 and Comparative Example 4 were evaluated by the following charge-discharge test. The charge-discharge test was performed by placing the all-solid-state secondary battery in a constant temperature bath at 45°C.

[0202] The first cycle is 0.6 mA / cm² until the battery voltage reaches 3.9V to 4.25V. 2 It was charged at a constant current of 0.6 mA / cm² for 12.5 hours. Subsequently, until the battery voltage reached 4.25V, it was charged at 0.6 mA / cm². 2 Discharge was performed for 12.5 hours with a constant current.

[0203] The discharge capacity of the first cycle was set as the standard capacity.

[0204] After the second cycle, the charge-discharge test was repeated under the same conditions as the first cycle until the SOH reached 80%, and the battery life characteristics were evaluated by measuring the SOH after each cycle. The measurement results are shown in Table 3 below.

[0205] The number of cycles refers to the number of cycles required to reduce the SOH to 80% after the second cycle. It was considered that the lifespan characteristics are superior as the number of cycles increases.

[0206] Number of cycles [times] Example 5 (Li2S-LiI-AlI31 wt%, oxide-based cathode active material) 456 Comparative Example 4 (Li2S-LiI-AlI30 wt%, oxide-based cathode active material) 350

[0207] As shown in Table 3, the all-solid-state battery of Example 5 showed improved lifespan characteristics compared to the all-solid-state battery of Comparative Example 4. It was determined that this was because the durability of the solid electrolyte separator was improved by suppressing the formation of pinholes and suppressing defects such as short circuits caused by lithium dendrite growth through pinholes by including Li2S-LiI-AlI3 in the solid electrolyte separator employed in the all-solid-state battery of Example 5.

[0208] Evaluation Example 4: Rate Characteristic Evaluation

[0209] The high-rate characteristics of the all-solid-state batteries of Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated by the following charge-discharge test. The charge-discharge test was performed by placing the all-solid-state secondary battery in a constant temperature bath at 45°C.

[0210] The all-solid-state batteries prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were charged at a constant current rate of 0.1 C at 45 °C until the voltage reached 2.5 V (vs. Li), and then cut off at a current rate of 0.05 C while maintaining 2.5 V in constant voltage mode. Subsequently, they were discharged at a constant current rate of 0.1 C until the voltage reached 0.3 V (vs. Li) during discharge (formation cycle).

[0211] The all-solid-state battery that has undergone the formation cycle was charged at a constant current rate of 0.2 C at 45 ℃ until the voltage reached 2.5 V (vs. Li). Subsequently, it was discharged at a constant current rate of 0.2 C until the voltage reached 0.3 V (vs. Li) during discharge (1st cycle).

[0212] The all-solid-state battery that had undergone the first cycle was charged at a constant current of 0.2 C rate at 45°C until the voltage reached 2.5 V (vs. Li). Subsequently, it was discharged at a constant current of 0.33 C rate until the voltage reached 0.3 V (vs. Li) during discharge (second cycle).

[0213] The all-solid-state battery that had undergone the second cycle was charged at a constant current rate of 0.2 C at 45°C until the voltage reached 2.5 V (vs. Li). Subsequently, it was discharged at a constant current rate of 0.5 C until the voltage reached 0.3 V (vs. Li) during discharge (third cycle).

[0214] The lithium battery that had undergone the third cycle was charged at a constant current rate of 0.2 C at 45°C until the voltage reached 2.5 V (vs. Li). Subsequently, it was discharged at a constant current rate of 1.0 C until the voltage reached 0.3 V (vs. Li) during discharge (fourth cycle).

[0215] In all charge / discharge cycles, a 10-minute pause was observed after each charge / discharge cycle. Some of the results of the room temperature charge / discharge experiments are shown in Table 3 below. The high-rate characteristic is defined by the following Equation 1.

[0216] <Mathematical Formula 1>

[0217] Rate Characteristic [%] = [Discharge Capacity in 4th Cycle / Discharge Capacity in 1st Cycle] × 100 (%)

[0218] Rate Characteristics (1C / 0.2C) [%] Example 1 (Li2S-LiI-AlI3 1 wt%, sulfide-based cathode active material) 88 Example 2 (Li2S-LiI-AlI3 3 wt%, sulfide-based cathode active material) 85 Example 3 (Li2S-LiI-AlI3 5 wt%, sulfide-based cathode active material) 83 Example 4 (Li2S-LiI-AlI3 10 wt%, sulfide-based cathode active material) 79 Comparative Example 1 (Li2S-LiI-AlI3 0 wt%, sulfide-based cathode active material) 70 Comparative Example 2 (Li2S alone 1 wt%, sulfide-based cathode active material) 65 Comparative Example 3 (LiI alone 1 wt%, sulfide-based cathode active material) 73

[0219] As shown in Table 4, the all-solid-state batteries of Examples 1 to 4 showed improved high-rate characteristics compared to the all-solid-state batteries of Comparative Examples 1 to 3.

[0220] Evaluation Example 5: Rapid Charging Evaluation

[0221] The all-solid-state batteries prepared according to Example 5 and Comparative Example 4 were subjected to 0.1C charging, 0.1C discharging once / 1.0C charging, 0.1C discharging once / 2.0C charging, 0.1C discharging once / 3.0C charging, 0.1C discharging once / 4.0C charging, and 0.1C discharging once. The results of Example 5 are shown in FIG. 4, and the results of Comparative Example 4 are shown in FIG. 5.

[0222] As shown in Fig. 4, the battery of Example 5 did not experience overcharging when charged at 1.0C to 4.0C. The respective charge capacities were 140mAh / g when charged at 1.0C to 3.0C and 133mAh / g when charged at 4.0C. Therefore, the charge amount decreased slightly compared to the charge amount of 151mAh / g when charged at 0.1C. The discharge capacity of Example 5 was also approximately 139mAh / g when charged at 1.0C to 4.0C, which is about 8% lower than the discharge capacity of 151mAh / g when charged and discharged at 0.1C. This rate of decrease can be judged as practically no decrease.

[0223] As shown in FIG. 5, the battery of Comparative Example 4 was overcharged (200 mAh / g) during 2.0 C charging, and the discharge capacity was approximately 120 mAh / g, which is about 20% lower than the discharge capacity (151 mAh / g) during 0.1 C charging / discharging. In addition, overcharged (240 mAh / g) occurred during 3.0 C and 4.0 C charging, and the discharge capacity was approximately 64 mAh / g, which is about 58% lower than the discharge capacity (151 mAh / g) during 0.1 C charging / discharging.

[0224] Although an exemplary embodiment has been described in detail above with reference to the attached drawings, the present creative idea is not limited to such examples. It is obvious that a person skilled in the art to which the present creative idea belongs can derive various variations or modifications within the scope of the technical idea described in the patent claims, and these also naturally fall within the technical scope of the present creative idea.

Claims

A first composite comprising Li2S and a first metal halide salt; and It includes a first sulfide-based solid electrolyte; A solid electrolyte separator, wherein the first metal halide salt comprises an alkali metal salt and a boron group metal salt. In paragraph 1, The above alkali metal salt is a lithium salt, a solid electrolyte separator. In paragraph 1, The above alkali metal salt comprises LiF, LiCl, LiBr, LiI, or a combination thereof, a solid electrolyte separator. In paragraph 1, The above boron group metal salt is a solid electrolyte separator, which is a binary compound composed of a boron group metal and one element selected from Group 17 of the periodic table. In paragraph 1, The above boron group metal salt comprises AlF3, AlCl3, AlBr3, AlI3, GaF3, GaCl3, GaBr3, GaI3, InF3, InCl3, lnBr3, lnI3, TlF3, TlCl3, TlBr3, TlI3, or a combination thereof, forming a solid electrolyte separator. In paragraph 1, The first complex is Li2S-LiF-AlF3, Li2S-LiF-AlCl3, Li2S-LiF-AlBr3, Li2S-LiF-AlI3, Li2S-LiF-GaF3, Li2S-LiF-GaCl3, Li2S-LiF-GaBr3, Li2S-LiF-GaI3, Li2S-LiF-InF3, Li2S-LiF-InCl3, Li2S-LiF-InBr3, Li2S-LiF-InI3, Li2S-LiF-TlF3, Li2S-LiF-TlCl3, Li2S-LiF-TlBr3, Li2S-LiF-TlI3, Li2S-LiCl-AlF3, Li2S-LiCl-AlCl3, Li2S-LiCl-AlBr3, Li2S-LiCl-AlI3, Li2S-LiCl-GaF3, Li2S-LiCl-GaCl3, Li2S-LiCl-GaBr3, Li2S-LiCl-GaI3, Li2S-LiCl-InF3, Li2S-LiCl-InCl3, Li2S-LiCl-InBr3, Li2S-LiCl-InI3, Li2S-LiCl-TlF3, Li2S-LiCl-TlCl3, Li2S-LiCl-TlBr3, Li2S-LiCl-TlI3, Li2S-LiBr-AlF3, Li2S-LiBr-AlCl3, Li2S-LiBr-AlBr3, Li2S-LiBr-AlI3, Li2S-LiBr-GaF3, Li2S-LiBr-GaCl3, Li2S-LiBr-GaBr3, Li2S-LiBr-GaI3, Li2S-LiBr-InF3, Li2S-LiBr-InCl3, Li2S-LiBr-InBr3, Li2S-LiBr-InI3, Li2S-LiBr-TlF3, Li2S-LiBr-TlCl3, Li2S-LiBr-TlBr3, Li2S-LiBr-TlI3, Li2S-LiI-AlF3, Li2S-LiI-AlCl3, Li2S-LiI-AlBr3, Li2S-LiI-AlI3, Li2S-LiI-GaF3, Li2S-LiI-GaCl3, Li2S-LiI-GaBr3, Li2S-LiI-GaI3, Li2S-LiI-InF3, Li2S-LiI-InCl3, Li2S-LiI-InBr3, Li2S-LiI-InI3, Li2S-LiI-TlF3,A solid electrolyte membrane comprising Li2S-LiI-TlCl3, Li2S-LiI-TlBr3, Li2S-LiI-TlI3, or a combination thereof. In paragraph 1, The first complex comprises a solid solution of Li2S and the first metal halide salt, and A solid electrolyte separator having a Li2S crystallite size of 20 nm or less obtained from the XRD spectrum of the first composite. In paragraph 1, A solid electrolyte separator, wherein the content of Li2S in the first composite is 60 to 80 wt% of the total weight of the first composite. In paragraph 1, A solid electrolyte separator, wherein the content of the first metal halide salt in the first composite is 20 to 40 wt% of the total weight of the first composite. In paragraph 1, A solid electrolyte separator having a weight ratio of the alkali metal salt and the boron group metal salt of 5:1 to 1:

20. In paragraph 1, A solid electrolyte separator, wherein the content of the first complex within the solid electrolyte separator is 0.1 to 20 wt% of the total weight of the first complex and the first sulfide-based solid electrolyte. In paragraph 1, The above-mentioned first complex comprises first complex particles, and The above-mentioned first sulfide-based solid electrolyte comprises first sulfide-based solid electrolyte particles, and The size of the first composite particle is smaller than the size of the first sulfide-based solid electrolyte particle, and A solid electrolyte separator in which the first composite particle is disposed within the void between the plurality of first sulfide-based solid electrolyte particles. In paragraph 1, A solid electrolyte separator having a porosity of 8% or less. In paragraph 1, The above first sulfide-based solid electrolyte is Li2S-P2S5, Li2S-P2S5-LiX, where X is a halogen element, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n , m, n are positive numbers, Z is one of Ge, Zn, or Ga, Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q , p, q are positive numbers, M is one of P, Si, Ge, B, Al, Ga, In, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x A solid electrolyte separator, one or more selected from (0≤x≤2). In claim 1, the solid electrolyte separator further comprises a binder, In the above solid electrolyte membrane, the carbon-based conductive material is free, and A solid electrolyte separator in which the above solid electrolyte separator is a self-standing film. anode; cathode; and It includes a solid electrolyte layer disposed between the anode and the cathode; An all-solid-state battery in which the above-mentioned solid electrolyte layer comprises a solid electrolyte separator according to claim 1. In Paragraph 16, The above anode further comprises an anode active material layer including a sulfide-based anode active material and a second sulfide-based solid electrolyte, and The above sulfide-based cathode active material is: A second composite comprising a sulfur-based material, a second metal halide salt, and a carbon-based conductive material, wherein The above-mentioned second metal halide salt comprises an alkali metal salt and a boron group metal salt, in an all-solid-state battery. In Paragraph 17, 상기 제2 복합체는 Li2S-LiF-CNT, Li2S-LiCl-CNT, Li2S-LiBr-CNT, Li2S-LiI-CNT, Li2S-LiF-CNF, Li2S-LiCl-CNF, Li2S-LiBr-CNF, Li2S-LiI-CNF, Li2S-LiF-AlF3-CNT, Li2S-LiF-AlCl3-CNT, Li2S-LiF-AlBr3-CNT, Li2S-LiF-AlI3-CNT, Li2S-LiF-GaF3-CNT, Li2S-LiF-GaCl3-CNT, Li2S-LiF-GaBr3-CNT, Li2S-LiF-GaI3-CNT, Li2S-LiF-InF3-CNT, Li2S-LiF-InCl3-CNT, Li2S-LiF-InBr3-CNT, Li2S-LiF-InI3-CNT, Li2S-LiF-TlF3-CNT, Li2S-LiF-TlCl3-CNT, Li2S-LiF-TlBr3-CNT, Li2S-LiF-TlI3-CNT, Li2S-LiCl-AlF3-CNT, Li2S-LiCl-AlCl3-CNT, Li2S-LiCl-AlBr3-CNT, Li2S-LiCl-AlI3-CNT, Li2S-LiCl-GaF3-CNT, Li2S-LiCl-GaCl3-CNT, Li2S-LiCl-GaBr3-CNT, Li2S-LiCl-GaI3-CNT, Li2S-LiCl-InF3-CNT, Li2S-LiCl-InCl3-CNT, Li2S-LiCl-InBr3-CNT, Li2S-LiCl-InI3-CNT, Li2S-LiCl-TlF3-CNT, Li2S-LiCl-TlCl3-CNT, Li2S-LiCl-TlBr3-CNT, Li2S-LiCl-TlI3-CNT, Li2S-LiBr-AlF3-CNT, Li2S-LiBr-AlCl3-CNT, Li2S-LiBr-AlBr3-CNT, Li2S-LiBr-AlI3-CNT, Li2S-LiBr-GaF3-CNT, Li2S-LiBr-GaCl3-CNT, Li2S-LiBr-GaBr3-CNT, Li2S-LiBr-GaI3-CNT, Li2S-LiBr-InF3-CNT, Li2S-LiBr-InCl3-CNT, Li2S-LiBr-InBr3-CNT,Li2S-LiBr-InI3-CNT, Li2S-LiBr-TlF3-CNT, Li2S-LiBr-TlCl3-CNT, Li2S-LiBr-TlBr3-CNT, Li2S-LiBr-TlI3-CNT, Li2S-LiI-AlF3-CNT, Li2S-LiI-AlCl3-CNT, Li2S-LiI-AlBr3-CNT, Li2S-LiI-AlI3-CNT, Li2S-LiI-GaF3-CNT, Li2S-LiI-GaCl3-CNT, Li2S-LiI-GaBr3-CNT, Li2S-LiI-GaI3-CNT, Li2S-LiI-InF3-CNT, Li2S-LiI-InCl3-CNT, Li2S-LiI-InBr3-CNT, Li2S-LiI-InI3-CNT, Li2S-LiI-TlF3-CNT, Li2S-LiI-TlCl3-CNT, Li2S-LiI-TlBr3-CNT, Li2S-LiI-TlI3-CNT, Li2S-LiF-AlF3-CNF, Li2S-LiF-AlCl3-CNF, Li2S-LiF-AlBr3-CNF, Li2S-LiF-AlI3-CNF, Li2S-LiF-GaF3-CNF, Li2S-LiF-GaCl3-CNF, Li2S-LiF-GaBr3-CNF, Li2S-LiF-GaI3-CNF, Li2S-LiF-InF3-CNF, Li2S-LiF-InCl3-CNF, Li2S-LiF-InBr3-CNF, Li2S-LiF-InI3-CNF, Li2S-LiF-TlF3-CNF, Li2S-LiF-TlCl3-CNF, Li2S-LiF-TlBr3-CNF, Li2S-LiF-TlI3-CNF, Li2S-LiCl-AlF3-CNF, Li2S-LiCl-AlCl3-CNF, Li2S-LiCl-AlBr3-CNF, Li2S-LiCl-AlI3-CNF, Li2S-LiCl-GaF3-CNF, Li2S-LiCl-GaCl3-CNF, Li2S-LiCl-GaBr3-CNF, Li2S-LiCl-GaI3-CNF, Li2S-LiCl-InF3-CNF, Li2S-LiCl-InCl3-CNF, Li2S-LiCl-InBr3-CNF, Li2S-LiCl-InI3-CNF, Li2S-LiCl-TlF3-CNF,Li2S-LiCl-TlCl3-CNF, Li2S-LiCl-TlBr3-CNF, Li2S-LiCl-TlI3-CNF, Li2S-LiBr-AlF3-CNF, Li2S-LiBr-AlCl3-CNF, Li2S-LiBr-AlBr3-CNF, Li2S-LiBr-AlI3-CNF, Li2S-LiBr-GaF3-CNF, Li2S-LiBr-GaCl3-CNF, Li2S-LiBr-GaBr3-CNF, Li2S-LiBr-GaI3-CNF, Li2S-LiBr-InF3-CNF, Li2S-LiBr-InCl3-CNF, Li2S-LiBr-InBr3-CNF, Li2S-LiBr-InI3-CNF, Li2S-LiBr-TlF3-CNF, Li2S-LiBr-TlCl3-CNF, Li2S-LiBr-TlBr3-CNF, Li2S-LiBr-TlI3-CNF, Li2S-LiI-AlF3-CNF, Li2S-LiI-AlCl3-CNF, Li2S-LiI-AlBr3-CNF, Li2S-LiI-AlI3-CNF, Li2S-LiI-GaF3-CNF, Li2S-LiI-GaCl3-CNF, Li2S-LiI-GaBr3-CNF, Li2S-LiI-GaI3-CNF, Li2S-LiI-InF3-CNF, Li2S-LiI-InCl3-CNF, Li2S-LiI-InBr3-CNF, Li2S-LiI-InI3-CNF, Li2S-LiI-TlF3-CNF, Li2S-LiI-TlCl3-CNF, Li2S-LiI-TlBr3-CNF, Li2S-LiI-TlI3-CNF 또는 이들의 조합을 포함하는, 전고체 전지., In Paragraph 16, The above anode further comprises an anode active material layer including an oxide-based anode active material, and The above oxide-based positive electrode active material comprises a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel-manganese-based oxide, or a combination thereof, in an all-solid-state battery. Providing a complex comprising Li2S and a metal halide salt; Providing sulfide-based solid electrolytes; Mixing the above complex and the above sulfide-based solid electrolyte to form a mixture; and The method includes forming the above mixture to form a solid electrolyte separator, A method for manufacturing a solid electrolyte separator, wherein the metal halide salt comprises an alkali metal salt and a boron group metal salt.

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