All-solid-state battery

Abstract

Provided is an all-solid-state battery comprising: a positive electrode layer comprising a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector; a negative electrode layer comprising a negative electrode current collector and a negative electrode coating layer on the negative electrode current collector; a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode coating layer and including a sulfide-based solid electrolyte; and an interlayer disposed on at least one surface of the solid electrolyte layer, wherein the interlayer contains a metal element (M1), and M1 includes at least one among molybdenum (Mo), titanium (Ti), zirconium (Zr), copper (Cu), and iron (Fe).

Description

All-solid-state battery

[0001] This is about all-solid-state batteries.

[0002] Recently, driven by industrial demands, the development of batteries with high energy density and safety is actively underway. For example, lithium batteries are being put into practical use not only in information and communication equipment sectors but also in the automotive sector. In the automotive field, safety is considered particularly important because it is directly related to human life.

[0003] Since lithium batteries use an electrolyte containing a flammable organic solvent, there is a possibility of overheating and fire if a short circuit occurs.

[0004] All-solid-state batteries using a solid electrolyte instead of a liquid electrolyte are being proposed.

[0005] By not using flammable organic solvents, all-solid-state batteries can significantly reduce the likelihood of fire or explosion in the event of a short circuit. These batteries can greatly enhance safety compared to lithium batteries that use liquid electrolytes.

[0006] Secondary batteries use sulfur-based materials as cathode active materials to increase capacity. Using sulfur-based materials allows for a higher theoretical energy capacity compared to lithium-ion batteries, and the low cost of sulfur-based materials can lower the manufacturing cost of secondary batteries.

[0007] One aspect is to provide all-solid-state batteries with improved lifespan characteristics.

[0008] According to one embodiment, the structure comprises: an anode layer comprising an anode current collector and an anode active material layer on the anode current collector; a cathode layer comprising a cathode current collector and a cathode coating layer on the cathode current collector; a solid electrolyte layer disposed between the anode active material layer and the cathode coating layer and comprising a sulfide-based solid electrolyte; and an interlayer disposed on at least one surface of the solid electrolyte layer, wherein the interlayer comprises a metal element (M 1Includes ), and M 1 An all-solid-state battery is provided that comprises at least one of molybdenum (Mo), titanium (Ti), zirconium (Zr), copper (Cu), or iron (Fe).

[0009] Depending on one aspect, metallic elements (M 1 By employing an intermediate layer containing ), it is possible to provide an all-solid-state battery with improved lifespan characteristics.

[0010] FIG. 1 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present disclosure.

[0011] FIG. 2 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present disclosure.

[0012] FIG. 3 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present disclosure.

[0013] FIGS. 4 and FIGS. 5 illustrate cross-sectional views of an all-solid-state battery according to another embodiment of the present disclosure.

[0014] 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.

[0015] 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. As used below, “ ” may be interpreted as “and” or “or” depending on the context.

[0016] 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.

[0017] 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.

[0018] In the present disclosure, “metal” includes both metals and metalloids such as silicon and germanium in an elemental or ionic state.

[0019] In this disclosure, “alloy” means a mixture of two or more metals.

[0020] In the present disclosure, “anode active material” refers to an anode material capable of undergoing lithiation and delithiation.

[0021] In the present disclosure, “anode active material” refers to an anode material capable of undergoing lithiation and delithiation.

[0022] 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.

[0023] 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.

[0024] In this disclosure, “charge” and “to charge” refer to the process of providing electrochemical energy to a battery.

[0025] In this disclosure, “anode” and “cathode” refer to electrodes where electrochemical reduction and lithiation occur during the discharge process.

[0026] In this disclosure, “cathode” and “anode” refer to electrodes where electrochemical oxidation and delithiation occur during the discharge process.

[0027] In the present disclosure, each of the phrases such as “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B or C”, “at least one of A, B and C”, and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0028] A solid-state battery (10) according to exemplary embodiments is described in more detail below.

[0029] FIG. 1 illustrates a cross-sectional view of an all-solid-state battery according to one embodiment of the present disclosure. Referring to FIG. 1, an all-solid-state battery according to one embodiment of the present disclosure comprises: a positive electrode layer comprising a positive current collector and a positive active material layer on the positive current collector; a negative electrode layer comprising a negative current collector and a negative coating layer on the negative current collector; a solid electrolyte layer disposed between the positive active material layer and the negative coating layer and comprising a sulfide-based solid electrolyte; and an interlayer disposed on at least one surface of the solid electrolyte layer, wherein the interlayer comprises a metal element (M 1 Includes ), and M 1 It contains at least one of molybdenum (Mo), titanium (Ti), zirconium (Zr), copper (Cu), or iron (Fe).

[0030] All-solid-state batteries, which use solid electrolytes instead of liquid electrolytes, exhibit excellent safety, energy density, and lifespan characteristics. Solid electrolytes offer high stability due to the relatively reduced risk of leakage and ignition, and their superior energy density can improve battery performance. In particular, the use of sulfide-based solid electrolytes can maximize battery performance by providing high ionic conductivity.

[0031] A solid-state battery (10) according to one embodiment includes a solid electrolyte layer (300) disposed between a positive electrode active material layer (120) and a negative electrode coating layer (220) and comprising a sulfide-based solid electrolyte.

[0032] Sulfide-based solid electrolytes are, for example, Li3PO4-Li2SO4, 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 (In the above formula, m and n are positive numbers, and Z is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (In the above formula, p and q are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, In), Li + 12-n-x A n+ X 2- 6-x Y - x (In the above formula, A is one of P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, or Ta, X is one of S, Se, or Te, Y is Cl, Br, I, F, CN, OCN, SCN, or N3, and 1≤n≤5, 0≤x≤2) Li 7-m M m PS 6-n X n(In the above formula, M is one of Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, Sc, Y, Ti, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Mn, Tc, Re, Bh, Ru, Os, Hs, Co, Rh, Ir, Mt, Ni, Pd, Pt, Ds, Au, Rg, Cd, Hg, or Cn, X is one of F, Cl, Br, or I, 0 <n≤2, 0<x≤2), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), or Li 7-x PS 6-x I x It may include at least one of (0≤x≤2) or any combination thereof.

[0033] Sulfide-based solid electrolytes can be manufactured by processing starting materials, such as Li2S or P2S5, using methods such as melt quenching or mechanical milling. Additionally, heat treatment may be performed after such processing. Sulfide-based solid electrolytes may be amorphous, crystalline, or a mixture thereof. Sulfide-based solid electrolytes may, for example, contain at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements. Sulfide-based solid electrolytes may, for example, contain Li2S-P2S5. When using a material containing Li2S-P2S5 as a sulfide-based solid electrolyte, the 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.

[0034] The sulfide-based solid electrolyte may be, for example, an argyrodite-type solid electrolyte. The density of the argyrodite-type solid electrolyte may be 1.5 to 2.0 g / cc. Since the argyrodite-type solid electrolyte has a density of 1.5 g / cc or higher, the internal resistance of the all-solid-state battery is reduced, and penetration of the solid electrolyte separator by lithium can be suppressed more effectively.

[0035] The solid electrolyte layer (300) may further include, for example, a binder. The binder included in the solid electrolyte layer (300) is, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited to these and any binder used in the art is acceptable. In another embodiment, the binder may be omitted.

[0036] The binder content included in the solid electrolyte layer (300) may be 0.1 to 10 wt% with respect to the total weight of the solid electrolyte layer (300).

[0037] Sulfide-based solid electrolytes are evaluated to possess high stability under typical operating environments for all-solid-state batteries. However, sulfide-based solid electrolytes may decompose under specific conditions (high voltage environments, high temperature environments, side reactions caused by additives, etc.), leading to the accumulation of sulfur (S) inside the cell. If a large amount of sulfur (S) accumulates inside the cell to form a sulfur layer, it can act as an insulating layer, thereby degrading lifespan characteristics.

[0038] A solid-state battery (10) according to one embodiment includes an intermediate layer (400) disposed on at least one surface of a solid electrolyte layer (300). The intermediate layer (400) is a metal element (M 1 Includes ), and M 1 It contains at least one of molybdenum (Mo), titanium (Ti), zirconium (Zr), copper (Cu), or iron (Fe).

[0039] Metal element (M 1 ) is sulfur (S), sulfide ions (S 2- ), disulfide ion (S2 2- ) Polysulfide ion (S x 2- , x reacts with 3 to 6) etc. to form metal sulfide (M 1 x S y ) can be formed. The intermediate layer (400) reacts with sulfur (S) inside the cell to form metal sulfide (M 1 x S y It can act as a metal sulfide-induced layer that induces ). Metal sulfide (M 1 x S y ) has ion conductivity, which can improve the lifespan characteristics of the all-solid-state battery (10).

[0040] According to one embodiment, the intermediate layer (400) is metal sulfide (M 1 x S y It may further include ). According to one embodiment, the metal sulfide (M) included in the intermediate layer (400) 1 x S y ) is a metal element (M) contained in the intermediate layer (400). 1 It may be formed by the reaction of ) and sulfur (S) inside the cell. According to another embodiment, the metal sulfide (M) contained in the intermediate layer (400) 1 x S y ) can be added from the time of manufacture of the intermediate layer (400).

[0041] Metal sulfide (M 1 x S y ) may include, for example, at least one of molybdenum disulfide (MoS2), dimolybdenum trisulfide (Mo2S3), titanium disulfide (TiS2), dititanium trisulfide (Ti2S3), zirconium disulfide (ZrS2), zirconium trisulfide (ZrS3), copper(I) sulfide (Cu2S), copper(II) sulfide (CuS), iron monosulfide (FeS), or iron disulfide (FeS2). metal sulfide (M 1 x S y ) has ion conductivity of its own, which can improve the lifespan characteristics of the all-solid-state battery (10).

[0042] According to one embodiment, the intermediate layer (400) is lithium metal sulfide (Li z M 1 x S y It may further include ). According to one embodiment, the intermediate layer (400) includes lithium metal sulfide (Li z M 1 x S y ) is the metal sulfide (M) contained in the intermediate layer (400). 1 x S y It may be formed by the reaction of ) and lithium (Li) inside the cell. According to another embodiment, the intermediate layer (400) contains lithium metal sulfide (Li z M 1 x S y ) can be added from the time of manufacture of the intermediate layer (400). Lithium metal sulfide (Li z M 1 x S y ) has good ion conductivity, which can improve the lifespan characteristics of the all-solid-state battery (10). Lithium metal sulfide (Li z M 1 x S y) can store lithium (Li), which can improve the energy density of the all-solid-state battery (10).

[0043] Lithium metal sulfide (Li z M 1 x S y ) may include, for example, at least one of lithium molybdenum tetrasulfide (Li2MoS4), lithium molybdenum disulfide (LiMoS2), lithium titanium disulfide (LiTiS2), lithium titanium trisulfide (Li2Ti2S3), lithium zirconium trisulfide (Li2ZrS3), lithium zirconium disulfide (LiZrS2), lithium copper sulfide (LiCuS), lithium copper trisulfide (Li2Cu2S3), lithium iron disulfide (LiFeS2), or lithium iron trisulfide (Li2FeS3).

[0044] According to one embodiment, an intermediate layer (400) may be disposed between a solid electrolyte layer (300) and a cathode coating layer (220). The intermediate layer (400) may be disposed between the solid electrolyte layer (300) and the cathode coating layer (220) to improve the interfacial stability and ion conductivity of the solid electrolyte layer (300). An all-solid-state battery in which the intermediate layer (400) is disposed between the solid electrolyte layer (300) and the cathode coating layer (220) may have improved lifespan characteristics and energy density.

[0045] According to one embodiment, the thickness of the intermediate layer (400) may be 0.1 μm to 10 μm. For example, the thickness of the intermediate layer (400) may be 0.5 μm to 10 μm, 1 μm to 10 μm, or 1 μm to 4 μm. If the thickness of the intermediate layer (400) exceeds the above range, the interfacial resistance of the solid electrolyte layer (300) may increase. If the thickness of the intermediate layer (400) is less than the above range, the lifespan characteristics of the all-solid-state battery (10) may be degraded.

[0046] A solid-state battery (10) according to one embodiment includes a negative electrode current collector (210) and a negative electrode coating layer (220) on the negative electrode current collector (210).

[0047] 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 12 μm. The negative current collector (210) may be composed of one of the metals described above, or may include an alloy or coating material of two or more metals. The negative current collector (210) is, for example, in the form of a plate or foil. In other embodiments, the negative current collector (210) may be omitted.

[0048] The cathode coating layer (220) may include a mixture of first particles containing a lithium-affinity metal and second particles containing a carbon element.

[0049] The lithium-affinity metal contained in the first particle is a material that can be lithiated and delithiated. The cathode coating layer (220) can be formed by introducing the lithium-affinity metal onto the cathode current collector (210) through nanoparticle casting. Nanoparticle casting can be performed, for example, by applying a slurry (dispersion) in which the first particle and the second particle are mixed and dispersed in a solvent onto the cathode current collector (210) using a doctor blade. When the cathode coating layer (220) is introduced onto the cathode current collector (210) through nanoparticle casting, lithium ions can pass through the cathode coating layer (220), and lithium metal can be formed between the cathode coating layer (220) and the cathode current collector (210). The first particle included in the cathode coating layer (220) may be a nanoparticle of the lithium-affinity metal. The average particle size of the first particle may be, for example, 10 nm to 4 µm, 10 nm to 1 µm, 10 nm to 500 nm, 10 nm to 100 nm, or 20 nm to 80 nm. Since the first particle has an average particle size within this range, reversible plating and / or dissolution of lithium during charging and discharging may be facilitated. Additionally, as the first particle has a nano-size, lithium ions may pass through the negative electrode coating layer (220) containing the first particle, and lithium metal may be deposited between the negative electrode current collector (210) and the negative electrode coating layer (220). The average particle size of the first particle is, for example, a median diameter (D50) measured using a laser particle size distribution meter.

[0050] Lithium-affinity metals may include, for example, at least one of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), or zinc (Zn), or any combination thereof.

[0051] The second particle can uniformly coat the first particle onto the negative current collector (210). The second particle containing a carbon element can uniformly coat the first particle onto the negative current collector (210), thereby uniformly coating the first particle onto the negative current collector (210). The uniformly coated first particle can uniformly precipitate lithium metal onto the negative current collector (210) to prevent the formation of lithium dendrites.

[0052] The second particle may include, for example, at least one of amorphous carbon or crystalline carbon, or any combination thereof.

[0053] Amorphous carbon may include, for example, at least one of carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), graphene, or carbon nanotubes (CNT), or any combination thereof. Amorphous carbon can be distinguished from crystalline carbon or graphite-based carbon as carbon that does not have crystallinity or has very low crystallinity.

[0054] The negative electrode coating layer (220) comprises, for example, a mixture of a first particle containing a lithium-affinity metal and a second particle containing a carbon element, so that the first particle is uniformly coated on the negative electrode current collector (210) through the second particle, and the first particle can uniformly deposit lithium metal between the negative electrode coating layer (220) and the negative electrode current collector (210). Accordingly, the formation of lithium dendrites is suppressed, and the lifespan characteristics of the all-solid-state battery (10) can be improved.

[0055] The mixing ratio of the mixture of the first particle and the second particle included in the cathode coating layer (220) may be, for example, 10:1 to 1:10, 1:1 to 1:10, 1:2 to 1:10, 1:1 to 1:5, or 1:2 to 1:5 by weight.

[0056] The cathode coating layer (220) may further include a binder. The binder included in the cathode coating layer (220) may be, for example, polyacrylic acid, carboxymethylcellulose (CMC), styrene-butadiene rubber (SBR), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene (PE), 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. The content of the binder included in the cathode coating layer (220) may be, for example, 55 weight% or less, 0.1 to 50 weight%, 0.1 to 20 weight%, or 0.1 to 10 weight% with respect to the total weight of the cathode coating layer (220).

[0057] The thickness of the negative electrode coating layer (220) may be, for example, 0.1 μm to 5 μm, 0.1 μm to 3 μm, or 0.5 μm to 5 μm, 0.5 μm to 3 μm, or 0.5 μm to 2 μm. If the thickness of the negative electrode coating layer (220) is less than the above range, lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210) may cause the negative electrode coating layer (220) to collapse, thereby degrading the cycle characteristics of the all-solid-state battery (10). If the thickness of the negative electrode coating layer (220) exceeds the above range, the energy density of the all-solid-state battery (10) may decrease.

[0058] According to one embodiment, the cathode layer (200) may further include a lithium metal layer (230) disposed between the cathode current collector (210) and the cathode coating layer (220).

[0059] 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.

[0060] A solid-state battery (10) according to one embodiment includes a positive current collector (110) and a positive active material layer (120) on the positive current collector (110), and a positive layer (100).

[0061] The positive current collector (110) may provide a reference surface on which the positive active material layer (120) is disposed. 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. The thickness of the positive current collector (110) may be, for example, 5 μm to 100 μm, 5 μm to 50 μm, or 8 μm to 25 μm. In another embodiment, the positive current collector (110) may be omitted. Although not illustrated, a carbon layer with a thickness of 10 nm 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 and the positive active material layer (120). The carbon layer may include amorphous carbon, crystalline carbon, etc.

[0062] The positive active material layer (120) may include a positive active material and a solid electrolyte.

[0063] The positive electrode active material is a lithium-containing metal oxide or lithium-containing sulfide-based positive electrode active material, and any material commonly used in the industry may be used without limitation.

[0064] The lithium-containing metal oxide may be one or more of the composite oxides of lithium and a metal selected from, for example, cobalt, manganese, nickel, and combinations thereof, and specific examples thereof include Li a A 1-b B b D2 (wherein 0.90≤a≤1, and 0≤b≤0.5); Li a E 1-b B b O 2-c D c (In the above formula, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05); LiE 2-b B bO 4-c D c (In the above formula, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b B c D α (In the above formula, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); Li a Ni 1-b-c Co b B c O 2-α F α (In the above formula, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); Li a Ni 1-b-c Co b B c O 2-α F2(wherein 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); Li a Ni 1-b-c Mn b B c D α (In the above equation, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); Li a Ni 1-b-c Mn b B c O 2-α F α (In the above formula, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); Li a Ni 1-b-c Mn b B c O 2-α F2(wherein 0.90≤a≤1, 0≤b ≤0.5, 0≤c≤0.05, 0<α<2); Li a Ni b E c G d O2(in the above equation, 0.90≤a≤1, 0≤b≤0.9, 0≤c ≤0.5, 0.001≤d≤0.1); Li a Ni b Co c Mn dGeO2(wherein the above formula, 0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1); Li a NiGbO2 (wherein the above formula, 0.90≤a≤1, 0.001≤b≤0.1); Li a CoGbO2(wherein the above formula, 0.90≤a≤1, 0.001≤b≤0.1); Li a MnGbO2(wherein the above formula, 0.90≤a≤1, 0.001≤b≤0.1); Li a Mn2GbO4 (wherein the above formula, 0.90≤a≤1, 0.001≤b≤0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiIO2; LiNiVO4; Li (3-f) J2(PO4)3(0≤f≤2); Li (3-f) Compounds represented by any one of the chemical formulas of Fe2(PO4)3(0≤f≤2); LiFePO4 can be used.

[0065] In the chemical formula representing the compound described above, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; and J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof. A compound having a coating layer added to the surface of the compound described above may also be used, and a mixture of the compound described above and the compound having a coating layer added may also be used. The coating layer applied to the surface of the aforementioned compound comprises, for example, a coating element compound of an oxide, hydroxide, oxyhydroxide, oxycarbonate, or hydroxycarbonate of a coating element. The compound forming this coating layer is amorphous or crystalline. The coating elements included in the coating layer are Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The method for forming the coating layer is selected within a range that does not adversely affect the physical properties of the cathode active material. The coating method is, for example, spray coating or immersion. Since specific coating methods are well understood by those skilled in the art, a detailed explanation will be omitted.

[0066] The positive active material is, for example, Li a Ni x Co y M z O 2-b A b(In the above equation, 1.0≤a≤1.2, 0≤b≤0.2, 0.8≤x<1, 0 <y≤0.3, 0<z≤0.3, 및 x+y+z=1이고, M은 망간(Mn), 니오븀(Nb), 바나듐(V), 마그네슘(Mg), 갈륨(Ga), 실리콘(Si), 텅스텐(W), 몰리브덴(Mo), 철(Fe), 크롬(Cr), 구리(Cu), 아연(Zn), 티타늄(Ti), 알루미늄(Al), 보론(B) 또는 이들의 조합이고, A는 F, S, Cl, Br 또는 이들의 조합), LiNi x Co y Mn z O2(wherein the above equation, 0.8≤x≤0.95, 0≤y≤0.2, 0 <z≤0.2 및 x+y+z=1), LiNi x Co y Al z O2(wherein the above equation, 0.8≤x≤0.95, 0≤y≤0.2, 0 <z≤0.2 및 x+y+z=1), LiNi x Co y Mn z Al w O2(wherein the above equation, 0.8≤x≤0.95, 0≤y≤0.2, 0 <z≤0.2, 0<w≤0.2, 및 x+y+z+w=1), Li a Co x M y O 2-b A b (In the above formula, 1.0≤a≤1.2, 0≤b≤0.2, 0.9≤x≤1, 0≤y≤0.1, and x+y=1, M is manganese (Mn), niobium (Nb), vanadium (V), magnesium (Mg), gallium (Ga), silicon (Si), tungsten (W), molybdenum (Mo), iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), titanium (Ti), aluminum (Al), boron (B) or a combination thereof, and A is F, S, Cl, Br or a combination thereof), Li a Ni x Mn y M' z O 2-b A b(In the above formula, 1.0≤a≤1.2, 0≤b≤0.2, 0 <x≤0.3, 0.5≤y<1, 0<z≤0.3, 및 x+y+z=1이고, M'는 코발트(Co), 니오븀(Nb), 바나듐(V), 마그네슘(Mg), 갈륨(Ga), 실리콘(Si), 텅스텐(W), 몰리브덴(Mo), 철(Fe), 크롬(Cr), 구리(Cu), 아연(Zn), 티타늄(Ti), 알루미늄(Al), 보론(B) 또는 이들의 조합이고, A는 F, S, Cl, Br 또는 이들의 조합), Li a M1 x M2 y PO 4-b X b (In the above equation, 0.90≤a≤1.1, 0≤x≤0.9, 0≤y≤0.5, 0.9 <x+y<1.1, 0≤b≤2 이며, M1이 크롬(Cr), 망간(Mn), 철(Fe), 코발트(Co), 니켈(Ni), 구리(Cu), 지르코늄(Zr) 또는 이들의 조합이며, M2가 마그네슘(Mg), 칼슘(Ca), 스트론튬(Sr), 바륨(Ba), 티탄(Ti), 아연(Zn), 보론(B), 니오븀(Nb), 갈륨(Ga), 인듐(In), 몰리브덴(Mo), 텅스텐(W), 알루미늄(Al), 실리콘(Si), 크롬(Cr), 바나듐(V), 스칸듐(Sc), 이트륨(Y) 또는 이들의 조합이며, X가 O, F, S, P 또는 이들의 조합), Li a M3 z PO4 (wherein 0.90≤a≤1.1, 0.9≤z≤1.1, and M3 is chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), or a combination thereof).

[0067] The cathode active material may be, for example, a lithium-containing sulfide-based cathode active material. The lithium-containing sulfide-based cathode active material may include, for example, Li2S, a Li2S-containing composite, or a combination thereof. By including Li2S, a Li2S-containing composite, or a combination thereof having high capacity as the lithium-containing sulfide-based cathode active material, the use of lithium metal may be omitted during the manufacture of the secondary battery. Since lithium metal has high reactivity and great ductility, it can reduce mass producibility during battery manufacturing. Therefore, if the use of lithium metal is omitted during the manufacture of the secondary battery, the mass producibility of the secondary battery may be improved.

[0068] A Li2S-containing composite is, for example, a composite of Li2S and a conductive material. The conductive material is, for example, an ionic conductive material, an electronic conductive material, or a combination thereof.

[0069] The ionic conductivity of an ion-conducting material is, for example, 1.0 × 10⁻⁶ at 25°C. -5 S / m or greater, 1.0×10 -4 S / m or more, or 1.0×10 -3 It is greater than S / m. The ion-conducting material may have pores. By having pores, Li2S can be contained within the pores, which can increase the contact area between Li2S and the ion-conducting material and increase the specific surface area of ​​Li2S. The form of the ion-conducting material may be, for example, particulate ion-conducting material, plate-shaped ion-conducting material, rod-shaped ion-conducting material, or a combination thereof, but is not necessarily limited to these.

[0070] An ion-conducting material according to one embodiment may include, for example, a metal salt compound. The metal salt compound may include a lithium salt compound. The lithium salt compound may include, for example, LiF, LiCl, LiBr, LiI, or a combination thereof. According to one embodiment, a Li2S-containing composite comprising a lithium salt compound may include, for example, Li2S-LiF, Li2S-LiCl, Li2S-LiBr, Li2S-LiI, or a combination thereof. The metal salt compound may further include a boron group metal halide salt. The boron group metal halide salt may include, for example, AlF3, AlCl3, AlBr3, AlI3GaF3, GaCl3, GaBr3, GaI3InF3, InCl3, InBr3, InI3T1F3, T1Cl3, T1Br3, T1I3, or a combination thereof. According to one embodiment, a Li2S-containing composite further comprising a boron group metal halide salt is, for example, 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, It may include 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.

[0071] The electronic conductivity of an electronically conductive material is, for example, 1.0 × 10⁻⁶ at 25°C. 3 S / m or greater, 1.0×10 4 S / m or more, or 1.0×10 5It is S / m or greater. The form of the electronically conductive material is, for example, particulate electronically conductive material, plate-shaped electronically conductive material, rod-shaped electronically conductive material, or a combination thereof, but is not necessarily limited to these. The electronically conductive material may be, for example, carbon, metal powder, metal compound, etc. When carbon is included as the electronically conductive material, a secondary battery having a high energy density per unit mass can be realized because carbon has high electronic conductivity and is lightweight. The electronically conductive material may have pores. By having pores in the electronically conductive material, Li2S can be contained within the pores, which can increase the contact area between Li2S and the electronically conductive material and increase the specific surface area of ​​Li2S. The pore capacity is, for example, 0.1 cc / g to 20.0 cc / g, 0.5 cc / g to 10 cc / g, or 0.5 cc / g to 5 cc / g. The average pore diameter is, for example, 1 nm to 100 nm, 1 nm to 50 nm, or 1 nm to 20 nm. The BET specific surface area of ​​the electron-conducting material having pores is 200 m² when the average pore diameter is 15 nm or less. 2 / g to 4500 m 2 / g, and if the average pore diameter is greater than 15 nm, 100 m 2 / g to 2500 m 2 It is / g. BET specific surface area, pore diameter, pore capacity, and average pore diameter can be obtained, for example, using the nitrogen adsorption method.

[0072] An electronically conductive material according to one embodiment may include, for example, carbon. Carbon may be any material containing carbon atoms, for example, used as a conductive material in the art. Carbon may be, for example, crystalline carbon, amorphous carbon, or a combination thereof. Carbon may be, for example, a calcined product of a carbon precursor. Carbon may be, for example, a carbon nanostructure. The carbon nanostructure may be, for example, a one-dimensional carbon nanostructure, a two-dimensional carbon nanostructure, a three-dimensional carbon nanostructure, or a combination thereof. The carbon nanostructure may be, for example, a carbon nanotube (CNT), a carbon nanofiber (CNF), a carbon nanobelt, a carbon nanorod, graphene, graphene oxide (GO), reduced graphene oxide (rGO), a graphene ball (GB), or a combination thereof. Carbon may be, for example, porous carbon or non-porous carbon. Porous carbon may include, for example, periodic and regular two-dimensional or three-dimensional pores. Porous carbon may be, for example, carbon black such as Ketjen black, acetylene black, Denka black, thermal black, Channel black; graphite, activated carbon, or a combination thereof. The form of carbon may be, for example, particle form, sheet form, flake form, etc., but is not limited thereto, and any form used as carbon in the relevant technical field is possible. The method of manufacturing a composite of Li2S or a Li2S-containing composite and carbon may be a dry method, a wet method, or a combination thereof, but is not limited thereto, and the method of manufacturing a composite of Li2S, a Li2S-containing composite and carbon in the relevant technical field may be, for example, milling, heat treatment, deposition, etc., but is not necessarily limited thereto, and any method used in the relevant technical field is possible. According to one embodiment, a Li2S-containing composite containing carbon may include, for example, Li2S-CNT, Li2S-CNF, or a combination thereof.

[0073] A Li2S-containing composite according to one embodiment may include a composite of Li2S, an ion-conducting material, and an electronically conductive material. According to one embodiment, a Li2S-containing composite comprising a composite of Li2S, an ion-conducting material, and an electron-conducting material is, for example, 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, 또는 Li2S-LiI-TlI3-CNF, 또는 이들의 임의의 조합을 포함할 수 있다.,

[0074] The positive active material layer (120) may include a solid electrolyte. The solid electrolyte included in the positive active material layer may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. The sulfide-based solid electrolyte may be the same as or different from the sulfide-based solid electrolyte included in the aforementioned solid electrolyte layer (300). A detailed description of the sulfide-based solid electrolyte is omitted below, as the content regarding the sulfide-based solid electrolyte included in the aforementioned solid electrolyte layer (300) can be applied as is.

[0075] The positive active material layer (120) may further include a conductive material. The conductive material may have conductivity without causing chemical changes in the all-solid-state battery (10), thereby increasing the conductivity of the positive active material and the solid electrolyte. The conductive material may include a carbon-based material. The conductive material may include, for example, at least one of graphite, carbon black, acetylene black, carbon nanofiber, or carbon nanotube. Meanwhile, the positive active material layer (120) may omit the conductive material.

[0076] The positive active material layer (120) may further include a binder. The binder included in the positive active material layer (120) 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 possible. In another embodiment, the binder may be omitted.

[0077] FIG. 2 illustrates a cross-sectional view of an all-solid-state battery (10) according to another embodiment of the present disclosure. Referring to FIG. 2, the negative electrode layer (200) of the all-solid-state battery (10) 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 metal layer comprising lithium or a lithium alloy. The lithium metal layer (230) may, for example, function as 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, etc., but is not limited to these, and any alloy used as a lithium alloy is possible. The lithium metal layer (230) may include one of these alloys or lithium, or may include various types of alloys.

[0078] The thickness of the lithium metal layer (230) is not particularly limited, but may be, for example, 1 μm to 1000 μm, 1 μm to 500 μm, 1 μm to 200 μm, 1 μm to 150 μm, 1 μm to 100 μm, or 1 μm to 50 μm. If the thickness of the lithium metal layer (230) is excessively thin, it is difficult for the lithium metal layer (230) to perform the role of a lithium reservoir. If the thickness of the lithium metal layer (230) is excessively thick, the mass and volume of the all-solid-state battery (10) increase, and the cycle characteristics of the all-solid-state battery (10) may deteriorate. The lithium metal layer (230) may be, for example, a metal foil having a thickness within this range.

[0079] A lithium metal layer (230) may be disposed between a negative current collector (210) and a negative coating layer (220), for example, before assembly of the all-solid-state battery (10). In one embodiment, the lithium metal layer (230) may be formed by precipitation between the negative current collector (210) and the negative coating layer (220) by charging after assembly of the all-solid-state battery (10). When the lithium metal layer (230) is disposed between the negative current collector (210) and the negative coating layer (220) before assembly of the all-solid-state battery (10), the lithium metal layer (230) may function as a lithium reservoir. Accordingly, the cycle characteristics of the all-solid-state battery (10) including the lithium metal layer (230) may be further improved.

[0080] FIG. 3 illustrates a cross-sectional view of an all-solid-state battery (10) according to another embodiment of the present disclosure. Referring to FIG. 3, the intermediate layer (400) of the all-solid-state battery (10) may further include an uneven surface formed on at least one surface. In one embodiment, the uneven surface may be formed on one surface of the intermediate layer (400) where the intermediate layer (400) and the solid electrolyte layer (300) come into contact. By including an uneven surface formed on at least one surface of the intermediate layer of the all-solid-state battery (10), the contact area between the solid electrolyte layer (300) and the intermediate layer (400) may be increased. The lifespan characteristics of the all-solid-state battery (10) may be further improved by including an intermediate layer (400) having an uneven surface formed on at least one surface.

[0081] FIGS. 4 and 5 illustrate cross-sectional views of an all-solid-state battery according to another embodiment of the present disclosure. Referring to FIGS. 4 and 5, the intermediate layer (400) of the all-solid-state battery (10) may include a plurality of through holes (h). Although not illustrated, a solid electrolyte layer (300) may extend to the intermediate layer (400) through the plurality of through holes (h). In other words, the interiors of the plurality of through holes (h) may be filled with a material having the same composition as the solid electrolyte layer (300). The plurality of through holes (h) may act as ion conduction channels within the intermediate layer (400). By including a plurality of through holes (h) in the intermediate layer (400) of the all-solid-state battery (10), the lifespan characteristics of the all-solid-state battery (10) may be improved. An intermediate layer including multiple through holes (h) can be formed through various methods such as drilling, laser processing, chemical etching, ultrasonic processing, and electrical discharge machining (EDM), and is not necessarily limited thereto, any processing method capable of forming through holes in the intermediate layer (400) can be applied.

[0082] A plurality of through holes (h) included in the intermediate layer (400) may have their bottom portions defined by the cathode coating layer (220). That is, the bottom portions of the plurality of through holes (h) may come into direct contact with one surface of the cathode coating layer (220). By the bottom portions of the through holes coming into direct contact with one surface of the cathode coating layer (220), ion conduction between the cathode layer (200) and the solid electrolyte layer (300) can be easily performed.

[0083] 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.

[0084] Example 1

[0085] (Cathode layer manufacturing)

[0086] A SUS foil with a thickness of 10 μm was prepared as a cathode current collector. In addition, 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 as the composition of the cathode coating layer.

[0087] 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 gradually adding NMP (N-methyl-2-pyrrolidone) to it. The prepared slurry was applied to a SUS sheet using a bar coater and dried in air at 80°C for 10 minutes to prepare a laminate. The prepared laminate was vacuum dried at 40°C for 10 hours. The dried laminate was cold-roll-pressed to flatten the surface of the cathode coating layer to fabricate the cathode layer. The thickness of the cathode coating layer was approximately 15 μm. The surface area of ​​the cathode coating layer and the cathode current collector were the same.

[0088] (Middle layer manufacturing)

[0089] A mixed solution was prepared by mixing a sufficient amount of molybdenum nanoparticles (Mo) with isopropyl alcohol (IPA) solvent. The prepared solution was treated with ultrasound to homogenize the particle distribution, and then sprayed onto the cathode coating layer at a constant speed using a spray coating device. After the coating process was completed, the solvent was evaporated by drying at 100°C for 5 minutes, and heat treatment was performed at 400°C for 1 minute. The thickness of the intermediate layer was adjusted to approximately 2 μm.

[0090] (Preparation of solid electrolyte layer)

[0091] A mixture was prepared by adding 1.5 parts by weight of an acrylic binder to 98.5 parts by weight of an argyrodite-type crystal Li6PS5Cl solid electrolyte (D50 = 3.0 μm, crystalline) to the solid electrolyte. 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 75 μm thick PET substrate, and dried in air at 80°C for 10 minutes to obtain a laminate. The obtained laminate was vacuum dried at 80°C for 2 hours. A solid electrolyte layer was prepared by the above process.

[0092] (Manufacturing of the anode layer)

[0093] A Li2S-LiI-AlI3-CNF composite was prepared as a cathode active material. The Li2S-LiI-AlI3-CNF composite was prepared as follows. 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 the Li2S-LiI-AlI3 composite. The milling conditions were 25 ℃ and 450 rpm for 10 hours. The milling energy applied to the sample during milling was 20 G. The Li2S-LiI-AlI3 composite thus prepared was mixed with carbon nanofiber (CNF) in a weight ratio of 60:10. The mixture was mechanically milled using a ball mill to prepare the Li2S-LiI-AlI3-CNF composite. The milling conditions were 25 ℃ and 450 rpm for 10 hours. The milling energy applied to the sample during milling was 20 G.

[0094] As a solid electrolyte, Li6PS5Cl solid electrolyte (D50 = 1.0 μm, crystalline), which is an argyrodite-type crystal, was prepared.

[0095] The positive active material and the solid electrolyte were prepared such that the weight ratio of the positive active material to the solid electrolyte was 70 to 30, respectively.

[0096] PTFE was prepared as a binder. An anode mixture was prepared by mixing the anode active material, solid electrolyte, and binder. The anode mixture was obtained by dry mixing using a mixer.

[0097] An anode composite was placed on one side of an anode current collector made of aluminum foil coated with carbon on one side, and an anode layer was prepared by plate pressing at a pressure of 200 MPa for 10 minutes. The thickness of the anode layer 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.

[0098] (Manufacturing of all-solid-state batteries)

[0099] Referring to FIG. 1, a cathode coating layer is placed on a cathode layer in contact with an intermediate layer, and the intermediate layer is placed in contact with a solid electrolyte layer. A cathode layer / intermediate layer / solid electrolyte layer laminate is prepared by applying heat and pressure.

[0100] An electrode assembly comprising a cathode layer / intermediate layer / solid electrolyte layer / anode layer was prepared by arranging the anode layer such that the solid electrolyte layer contacts one surface of the anode layer.

[0101] The prepared electrode assembly was subjected to plate press treatment. This pressurization process sintered the solid electrolyte layer, thereby improving battery characteristics. The thickness of the sintered solid electrolyte layer was approximately 45 μm. The sintered electrode assembly was placed in a pouch and sealed to prepare a sealed electrode assembly. Parts of the positive electrode current collector and the negative electrode current collector were protruded outside the sealed electrode assembly to be used as the positive layer terminal and the negative layer terminal.

[0102] An all-solid-state battery was manufactured by placing an electrode assembly between two pressure plates (not shown) and fastening the two pressure plates with screws, thereby applying constant pressure to both sides of the electrode assembly.

[0103] Example 2

[0104] An all-solid-state battery was prepared in the same manner as in Example 1, except that when preparing the mixed solution for the intermediate layer, molybdenum nanoparticles (Mo), MoS2 particles, and isopropyl alcohol solvent were mixed to prepare the intermediate layer. In the mixed solution, the mass ratio of molybdenum nanoparticles (Mo) to MoS2 particles was 2:1.

[0105] Example 3

[0106] An all-solid-state battery was prepared in the same manner as in Example 1, except that when preparing the mixed solution for the intermediate layer, molybdenum nanoparticles (Mo), LiMoS2 particles, and isopropyl alcohol solvent were mixed to prepare the intermediate layer. In the mixed solution, the mass ratio of molybdenum nanoparticles (Mo) to LiMoS2 particles was 2:1.

[0107] Example 4

[0108] When manufacturing the intermediate layer, a sandblasting method was applied to one surface to form an uneven surface. Referring to FIG. 3, a cathode coating layer on the cathode layer contacts the intermediate layer, and the surface of the intermediate layer with the uneven surface is contacted by the solid electrolyte layer. A cathode layer / intermediate layer / solid electrolyte layer is arranged such that the cathode layer / intermediate layer / solid electrolyte layer is contacted, and a cathode layer / intermediate layer / solid electrolyte layer laminate is prepared by heat and pressure. Except for this, an all-solid-state battery was manufactured in the same manner as in Example 1.

[0109] Example 5

[0110] Referring to Fig. 5, through holes were formed by applying a laser drilling method during the manufacturing of the intermediate layer. The through holes were formed evenly so that the total area of ​​the through holes was 20% of the total area of ​​the intermediate layer, and solid electrolyte was filled into the through holes. Referring to Fig. 4, a cathode coating layer on the cathode layer contacts the intermediate layer, and the intermediate layer with through holes contacts the solid electrolyte layer. A cathode layer / intermediate layer / solid electrolyte layer stack was prepared by heat and pressure, except that a cathode layer / intermediate layer / solid electrolyte layer stack was prepared.

[0111] Comparative Example 1

[0112] An all-solid-state battery was manufactured in the same manner as in Example 1, except that an intermediate layer was not included when forming the electrode assembly.

[0113] Evaluation Example: Charge / Discharge Test

[0114] The charge-discharge characteristics of the all-solid-state batteries prepared in Examples 1 to 5 and Comparative Example 1 were evaluated by the following charge-discharge test.

[0115] The charge-discharge test was performed by placing the all-solid-state battery in a constant temperature bath at 45°C. Charging was carried out in CC mode. The battery was charged at 0.05C until the voltage reached 2.8 V, and discharge was carried out in CC mode at 0.05C until it reached 1.0 V. The above charge-discharge test was repeated until the SOH reached 80%, and the battery life characteristics were evaluated by measuring the SOH after each cycle. The results of the charge-discharge test are summarized in Table 1 below.

[0116] Number of cycles [times, @SOH=80%] Example 1 220 Example 2 226 Example 3 282 Example 4 291 Example 5 305 Comparative Example 180

[0117] As shown in Table 1, the all-solid-state batteries of Examples 1 to 5 reached a SOH of 80% after multiple cycles. This indicates that the battery performance remains stable even after long-term charging and discharging. On the other hand, the all-solid-state battery of Comparative Example 1 dropped to an SOH of 80% after only 80 cycles. Through this, it can be confirmed that the Examples have superior lifespan characteristics compared to the Comparative Example.

[0118] 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

1. An anode layer comprising an anode current collector and an anode active material layer on the anode current collector; A cathode layer comprising a cathode current collector and a cathode coating layer on the cathode current collector; A solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode coating layer, comprising a sulfide-based solid electrolyte; and It includes an interlayer disposed on at least one surface of the solid electrolyte layer; The above intermediate layer is a metallic element (M 1 Includes ), and M 1 An all-solid-state battery comprising at least one of molybdenum (Mo), titanium (Ti), zirconium (Zr), copper (Cu), or iron (Fe).

2. In Paragraph 1, The above sulfide-based solid electrolyte is Li3PO4-Li2SO4, Li2S-P2S5, Li2S-P2S5-LiX (wherein 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 (In the above formula, m and n are positive numbers, and Z is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (In the above formula, p and q are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, In), Li + 12-n-x A n+ X 2- 6-x Y - x (In the above formula, A is one of P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, or Ta, X is one of S, Se, or Te, Y is Cl, Br, I, F, CN, OCN, SCN, or N3, and 1≤n≤5, 0≤x≤2) Li 7-m M m PS 6-n X n (In the above formula, M is one of Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, Sc, Y, Ti, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Mn, Tc, Re, Bh, Ru, Os, Hs, Co, Rh, Ir, Mt, Ni, Pd, Pt, Ds, Au, Rg, Cd, Hg, or Cn, X is one of F, Cl, Br, or I, 0 <n≤2, 0<x≤2), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), or Li 7-x PS 6-x I x A solid-state battery comprising at least one of (0≤x≤2) or any combination thereof.

3. In Paragraph 1, The above intermediate layer is metal sulfide (M 1 x S y All-solid-state battery including ) further.

4. In Paragraph 3, The above metal sulfide (M 1 x S y ) is an all-solid-state battery comprising at least one of molybdenum disulfide (MoS2), dimolybdenum trisulfide (Mo2S3), titanium disulfide (TiS2), dititanium trisulfide (Ti2S3), zirconium disulfide (ZrS2), zirconium trisulfide (ZrS3), copper(I) sulfide (Cu2S), copper(II) sulfide (CuS), iron monosulfide (FeS), or iron disulfide (FeS2).

5. In Paragraph 1, The above intermediate layer is lithium metal sulfide (Li z M 1 x S y All-solid-state battery including ) further.

6. In Paragraph 5, The above lithium metal sulfide (Li z M 1 x S y ) is an all-solid-state battery comprising at least one of lithium molybdenum tetrasulfide (Li2MoS4), lithium molybdenum disulfide (LiMoS2), lithium titanium disulfide (LiTiS2), lithium titanium trisulfide (Li2Ti2S3), lithium zirconium trisulfide (Li2ZrS3), lithium zirconium disulfide (LiZrS2), lithium copper sulfide (LiCuS), lithium copper trisulfide (Li2Cu2S3), lithium iron disulfide (LiFeS2), or lithium iron trisulfide (Li2FeS3).

7. In Paragraph 1, The above intermediate layer is an all-solid-state battery disposed between the solid electrolyte layer and the cathode coating layer.

8. In Paragraph 1, An all-solid-state battery having an intermediate layer thickness of 0.1 μm to 10 μm.

9. In Paragraph 1, The above-described cathode coating layer comprises a mixture of first particles containing a lithium-affinity metal and second particles containing a carbon element, in an all-solid-state battery.

10. In Paragraph 1, The above positive active material layer comprises a positive active material and a solid electrolyte, and The above positive active material is an all-solid-state battery comprising a lithium-containing metal oxide.

11. In Paragraph 1, The above positive active material layer comprises a positive active material and a solid electrolyte, and The above positive active material is an all-solid-state battery comprising a lithium-containing sulfide-based positive active material.

12. In Paragraph 11, The above lithium-containing sulfide-based cathode active material is an all-solid-state battery comprising Li2S, a Li2S-containing complex, or a combination thereof.

13. In Paragraph 12, The above Li2S-containing composite is a composite of Li2S and a conductive material, and The above conductive material includes an electronically conductive material, The above electronically conductive material is a carbon-containing all-solid-state battery.

14. In Paragraph 13, The above conductive material further includes an ion-conductive material, and The above ion-conducting material includes a metal salt compound, and The above metal salt compound is an all-solid-state battery comprising a lithium salt compound.

15. In Paragraph 14, The above metal salt compound is an all-solid-state battery further comprising a boron group metal halide salt.

16. In Paragraph 12, 상기 Li2S 함유 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, 또는 Li2S-LiI-TlI3-CNF, 또는 이들의 임의의 조합을 포함하는 전고체 전지., 17. In Paragraph 1, The above-described negative electrode layer further comprises a lithium metal layer disposed between the negative electrode current collector and the negative electrode coating layer in an all-solid-state battery.

18. In Paragraph 1, The above intermediate layer further comprises an uneven surface formed on at least one surface of an all-solid-state battery.

19. In Paragraph 1, The above intermediate layer is an all-solid-state battery comprising a plurality of through holes.

20. In Paragraph 19, The above solid electrolyte layer extends to the intermediate layer through the above plurality of through holes in an all-solid-state battery.

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