All-solid-state battery

Abstract

The present invention relates to an all-solid-state battery and, more particularly, to a all-solid-state battery comprising a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, wherein the negative electrode layer comprises: a negative electrode current collector; a negative electrode coating layer disposed on the negative electrode current collector and including a first metal and a first carbon; and a lithium-deposited buffer layer disposed between the negative electrode current collector and the negative electrode coating layer and including a second metal and a second carbon, wherein the Gibbs free energy of the chemical reaction between the first metal and molten lithium at 250°C is △G1, and the Gibbs free energy of the chemical reaction between the second metal and molten lithium at 250°C is △G2, wherein △G2 is greater than △G1.

Description

All-solid-state batteries

[0001] The present invention relates to an all-solid-state battery, and more particularly, to an all-solid-state battery including a lithium deposition buffer layer.

[0002] Recent industrial demands have led to the active development of batteries with high energy density and safety. For example, lithium-ion batteries are being used not only in information and communication devices, but also in the automotive sector. Safety is particularly important in the automotive sector, as it is directly related to life.

[0003] Recently, all-solid-state batteries, which replace the electrolyte with a solid electrolyte, have been proposed. By eliminating the use of flammable organic dispersion media, all-solid-state batteries significantly reduce the risk of fire or explosion in the event of a short circuit. Therefore, these all-solid-state batteries can significantly improve safety compared to lithium-ion batteries that use electrolytes.

[0004] The problem to be solved by the present invention is to provide an all-solid-state battery with an extended lifespan.

[0005] According to one embodiment of the present invention, an all-solid-state battery includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, wherein the negative electrode layer includes: a negative electrode current collector; a negative electrode coating layer disposed on the negative electrode current collector and including a first metal and a first carbon; and a lithium deposition buffer layer disposed between the negative electrode current collector and the negative electrode coating layer and including a second metal and a second carbon; wherein a Gibbs free energy of a chemical reaction of the first metal with molten lithium at 250°C is △G1, and a Gibbs free energy of a chemical reaction of the second metal with molten lithium at 250°C is △G2, and △G2 may be greater than △G1.

[0006] According to another embodiment of the present invention, an all-solid-state battery includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, wherein the negative electrode layer includes: a negative electrode current collector; a negative electrode coating layer disposed on the negative electrode current collector and including a first metal and a first carbon; a lithium deposition buffer layer disposed between the negative electrode current collector and the negative electrode coating layer and including a second metal and a second carbon; and a lithium deposition layer disposed between the lithium deposition buffer layer and the negative electrode coating layer; wherein the content of the first metal is 3 wt% to 50 wt% based on the total weight of the negative electrode coating layer, and the content of the second metal is 30 wt% to 90 wt% based on the total weight of the lithium deposition buffer layer, and the content of the first metal may be less than the content of the second metal.

[0007] An all-solid-state battery according to one embodiment of the present invention can have excellent lifespan characteristics.

[0008] FIGS. 1 to 3 are each cross-sectional views of an all-solid-state battery according to embodiments of the present invention.

[0009] Figure 4 is a cross-sectional view of an all-solid-state battery during charging according to one embodiment of the present invention.

[0010] To fully understand the structure and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and subject to various modifications. However, the description of these embodiments is provided solely to ensure a complete disclosure of the present invention and to fully inform those skilled in the art of the invention of the scope of the invention.

[0011] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. Furthermore, in the drawings, the thicknesses of the components are exaggerated for the sake of clarity. Parts designated by the same reference numerals throughout the specification represent the same components.

[0012] Embodiments described herein will be described with reference to cross-sectional and / or plan views, which are ideal illustrations of the present invention. In the drawings, the thicknesses of films and regions are exaggerated for the purpose of effectively explaining the technical contents. Accordingly, the regions illustrated in the drawings have a schematic nature, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of regions of the device and are not intended to limit the scope of the invention. Although terms such as first, second, and third are used to describe various components in various embodiments of the present specification, these components should not be limited by such terms. These terms are used only to distinguish one component from another. The embodiments described and illustrated herein also include complementary embodiments thereof.

[0013] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the words "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components.

[0014] The method for measuring the content of elements according to embodiments of the present invention was obtained through quantitative analysis by performing scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) on the surface of particles. In addition to SEM-EDS, inductively coupled plasma-mass spectrometry (ICP-MS) or inductively coupled plasma-optical emission spectroscopy (ICP-OES) can also be used as a method for measuring the content of elements.

[0015]

[0016] Figure 1 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention.

[0017] Referring to FIG. 1, an all-solid-state battery (CEL1) according to one embodiment may include a positive electrode layer (100), a negative electrode layer (200) facing the positive electrode layer (100), and a solid electrolyte layer (300) disposed between the positive electrode layer (100) and the negative electrode layer (200). However, the present invention is not limited thereto, and the all-solid-state battery (CEL1) may further include an additional functional layer, such as an adhesion enhancing layer, disposed between the positive electrode layer (100) and the solid electrolyte layer (300) or between the negative electrode layer (200) and the solid electrolyte layer (300).

[0018] The positive electrode layer (100) of one embodiment may include a positive electrode current collector (110) and a positive electrode active material layer (120) disposed on the positive electrode current collector (110). The positive electrode active material layer (120) may include a positive electrode active material, a solid electrolyte, a conductive material, and a binder.

[0019] The positive electrode current collector (110) can provide a reference surface on which the positive electrode active material layer (120) is arranged. The positive electrode current collector (110) can include a plate or foil including, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

[0020] Meanwhile, unlike that illustrated in FIG. 1, in one embodiment of the present invention, the positive electrode current collector (110) may be omitted. Although not illustrated, a carbon layer having a thickness of 0.1 μm to 4 μm may be additionally disposed between the positive electrode current collector (110) and the positive electrode active material layer (120) to increase the bonding strength between the positive electrode current collector (110) and the positive electrode active material layer (120).

[0021] The cathode active material may include a material that can reversibly absorb and desorb lithium ions. The cathode active material may include a plurality of particles. The cathode active material may include, but is not necessarily limited to, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide. The cathode active materials may be used alone or as a mixture of two or more.

[0022] Lithium transition metal oxides include, for example, Li a A 1-b B b D2(0.90≤a≤1, 0≤b≤0.5), Li a E1-b B b O 2-c D c (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05), LiE 2-b B b O 4-c D c (0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b B c D α (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 (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Mr b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Ni 1-b-c Mr b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni b HAVE BEEN c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Ni b Co c Mr d GeO2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1), Li a NiG b O2(0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a MnG bO2(0.90≤a≤1, 0.001≤b≤0.1), Li a Mn2GbO4(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 A compound represented by any one of Fe2(PO4)3(0≤f≤2), LiFePO4. In these compounds, the capital letter “A” is Ni, Co, Mn, or a combination thereof, the capital letter “B” is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof, the capital letter “D” is O, F, S, P, or a combination thereof, the capital letter “E” is Co, Mn, or a combination thereof, the capital letter “F” is F, S, P, or a combination thereof, the capital letter “G” is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof, the capital letter “Q” is Ti, Mo, Mn, or a combination thereof, the capital letter “I” is Cr, V, Fe, Sc, Y, or a combination thereof, and the capital letter “J” is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0023] The cathode active material may include, for example, a lithium salt of a transition metal oxide having a layered rock salt type structure among the lithium transition metal oxides described above. The "layered rock salt type structure" is, for example, a cubic rock salt type structure. <111> It is a structure in which oxygen atomic layers and metal atomic layers are alternately and regularly arranged in a direction, and thereby each atomic layer forms a two-dimensional plane. The "cubic rock salt structure" refers to the sodium chloride type (NaCl type) structure, which is a type of crystal structure, and specifically refers to a structure in which the face-centered cubic lattice (fcc) formed by each cation and anion is arranged with a displacement of half of the ridge of the unit lattice. Lithium transition metal oxides having this layered rock salt structure include, for example, LiNi x Co y Al z O2(NCA) or LiNi x Co y Mn z O2(NCM) (0 <x<1,0<y<1, 0<z<1, x+y+z=1) 등의 삼원계 리튬전이금속산화물일 수 있다. 양극 활물질이 층상암염형 구조를 갖는 삼원계 리튬전이금속산화물을 포함하는 경우, 전고체 전지(CEL1)의 에너지 밀도가 커지고 열안정성이 향상될 수 있다.

[0024] The above-described compound included in the positive electrode active material may be covered by a coating layer (not shown). The positive electrode active material may also be a mixture of the above-described compound and a compound to which a coating layer is added. Meanwhile, the coating layer added to the surface of the positive electrode active material (PAM) may include, for example, an oxide, a hydroxide, an oxyhydroxide, an oxycarbonate, or a hydroxycarbonate of the coating elements below. The compound forming the coating layer is amorphous or crystalline. The coating elements included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The coating layer may include, for example, Li2O-ZrO2 (LZO). The method of forming the coating layer is selected within a range that does not adversely affect the physical properties of the positive electrode active material. The method of forming the coating layer includes, for example, spray coating, dipping, etc.

[0025] When the positive electrode active material is a ternary lithium transition metal oxide such as NCA or NCM and contains nickel (Ni), the capacity density of the all-solid-state battery (CEL1) can be increased, thereby reducing metal dissolution of the positive electrode active material in a charged state. As a result, the cycle characteristics of the all-solid-state battery (CEL1) in a charged state are improved. Meanwhile, the "cycle characteristics" are characteristics indicating the degree to which the all-solid-state battery (CEL1) is deteriorated due to charge / discharge of the all-solid-state battery (CEL1). An all-solid-state battery (CEL1) with high cycle characteristics may have a small degree of deterioration of the all-solid-state battery (CEL1) due to charge / discharge, and an all-solid-state battery (CEL1) with low cycle characteristics may have a large degree of deterioration of the all-solid-state battery (CEL1) due to charge / discharge.

[0026] The positive electrode active material may have a particle shape such as a sphere or an ellipsoid, for example. The particle size and content of the positive electrode active material are not particularly limited.

[0027] The solid electrolyte may include a sulfide-based solid electrolyte having excellent lithium ion conductivity characteristics. Examples of the sulfide-based solid electrolyte include Li2S-P2S5, Li2S-P2S5-LiX (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, capital letter “Z” represents Ge, Zn or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are positive numbers, capital letter “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 may include at least one selected from (0≤x≤2).

[0028] Sulfide-based solid electrolytes include, 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(0≤x≤2) may be an argyrodite-type compound including at least one selected from. In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I. The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. Since the argyrodite-type solid electrolyte has a density of 1.5 g / cc or more, the internal resistance of the all-solid-state battery is reduced, and the defect of the solid electrolyte membrane being penetrated and short-circuited due to the formation of lithium dendrites can be prevented. The elastic modulus of the solid electrolyte may be, for example, 15 GPa to 35 GPa.

[0029] The solid electrolyte in the positive electrode active material layer (120) may have a smaller median particle size average particle diameter (D50) than the first and second solid electrolytes (SE1, SE2) in the solid electrolyte layer (300) to be described later. For example, the median particle size average particle diameter (D50) of the solid electrolyte included in the positive electrode active material layer (120) may be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less of the median particle size average particle diameter (D50) of the solid electrolyte included in the solid electrolyte layer (300). Meanwhile, the median particle size average particle diameter (D50) may be a median diameter measured using a laser particle size distribution meter.

[0030] The positive electrode active material layer (120) may include a conductive material. The conductive material may have conductivity without causing chemical changes in the all-solid-state battery (CEL1), thereby increasing the conductivity of the positive electrode active material and the solid electrolyte. The conductive material may include a carbon-based material. For example, the conductive material may include one or more selected from graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0031] The positive electrode active material layer (120) may further include a binder. The binder may bind the positive electrode active material, the solid electrolyte, and the conductive material within the positive electrode active material layer (120) to each other. The binder may include a material for improving the bonding strength between the positive electrode active material layer (120) and the positive electrode current collector (110). The binder may include, for example, polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, and polymethyl methacrylate.

[0032] Based on 100 parts by weight of the total of the positive electrode active material, the solid electrolyte, the conductive material, and the binder, the positive electrode active material layer (120) may include 85 parts by weight or more and 92 parts by weight or less of the positive electrode active material. Based on 100 parts by weight of the total of the positive electrode active material, the solid electrolyte, the conductive material, and the binder, the positive electrode active material layer (120) may include 0.5 parts by weight or more and 1.5 parts by weight or less of the binder.

[0033] Based on 100 parts by weight of the solid electrolyte, the positive electrode active material layer (120) may include 1 part by weight or more and 50 parts by weight or less of a conductive material. If the conductive material is included in the positive electrode active material layer (120) in an amount of less than 1 part by weight based on 100 parts by weight of the solid electrolyte, the proportion of the conductive material may decrease, thereby lowering the electrical conductivity of the positive electrode active material layer (120). If the conductive material is included in the positive electrode active material layer (120) in an amount of more than 50 parts by weight based on 100 parts by weight of the solid electrolyte, the proportion of the conductive material may be excessively high, so that a covering layer covering the surface of the solid electrolyte may not be properly formed.

[0034] The positive electrode active material layer (120) may further include additives such as fillers, coating agents, dispersants, and ion conductive aids in addition to the above-described positive electrode active material, solid electrolyte, conductive agent, and binder.

[0035] Referring to FIG. 1, a solid electrolyte layer (300) may be provided between the positive electrode layer (100) and the negative electrode layer (200). The solid electrolyte layer (300) may include a sulfide-based solid electrolyte having excellent lithium ion conductivity characteristics. The solid electrolyte in the solid electrolyte layer (300) may be the same as or different from any one of the materials included in the solid electrolyte in the positive electrode active material layer (120) described above.

[0036] The solid electrolyte layer (300) of one embodiment may include a sulfide-based solid electrolyte. The sulfide-based solid electrolyte may be manufactured by treating starting materials such as Li2S and P2S5 by a melting rapid cooling method or a mechanical milling method. In addition, a heat treatment may be performed after the treatment. The solid electrolyte may be amorphous, crystalline, or a mixture thereof. In addition, the solid electrolyte may include, for example, at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements among the above-described sulfide-based solid electrolyte materials. For example, the solid electrolyte may be a material including Li2S-P2S5. When using a sulfide-based solid electrolyte material including Li2S-P2S5 to form the solid electrolyte, the mixing molar ratio of Li2S and P2S5 is, for example, in the range of Li2S:P2S5=50:50 to 90:10.

[0037] Sulfide-based solid electrolytes include, 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 PS6-x I x (0≤x≤2) may be an argyrodite-type compound including at least one selected from. In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I. The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. Since the argyrodite-type solid electrolyte has a density of 1.5 g / cc or more, the internal resistance of the all-solid-state battery is reduced, and the defect of the solid electrolyte membrane being penetrated and short-circuited due to the formation of lithium dendrites can be prevented. The elastic modulus of the solid electrolyte is, for example, 15 GPa to 35 GPa.

[0038] The solid electrolyte layer (300) may further include a binder. The binder included in the solid electrolyte layer (300) may be, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited thereto. The binder of the solid electrolyte layer (300) may be the same as or different from the binder (124) included in the positive electrode active material layer (120) or the binder included in the negative electrode coating layer (220).

[0039] Referring to FIG. 1, the negative electrode layer (200) may include a negative electrode current collector (210) and a negative electrode coating layer (220) on the negative electrode current collector (210). The negative electrode current collector (210) may provide a reference surface on which the negative electrode coating layer (220) is disposed. The negative electrode current collector (210) may include, for example, a material that does not react with lithium, i.e., does not form an alloy or a compound with lithium. For example, the negative electrode current collector (210) may include at least one metal selected from the group consisting of copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). The thickness of the negative electrode current collector (210) may be 1 μm to 20 μm, more specifically, 5 μm to 15 μm, and more specifically, 7 μm to 10 μm.

[0040] The negative electrode current collector (210) may be composed of one of the above-described metals, or may include an alloy or coating material of two or more metals. The negative electrode current collector (210) may have, for example, a plate shape or a foil shape. Meanwhile, in one embodiment, the negative electrode current collector (210) may be omitted.

[0041] The negative electrode coating layer (220) can allow lithium metal to grow between the negative electrode current collector (210) and the solid-state battery (CEL1) when charging. The negative electrode coating layer (220) can act as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites.

[0042] The cathode coating layer (220) may include a first metal and a first carbon. For example, the cathode coating layer (220) may include at least one first metal selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), zinc (Zn), magnesium (Mg), indium (In), and zinc oxide (ZnO).

[0043] The cathode coating layer (220) may include at least one first carbon selected from the group consisting of carbon black, carbon nanotubes, acetylene black, furnace black, ketjen black, and graphene. In one embodiment, the cathode coating layer (220) may include a mixture of carbon black and silver (Ag). The porosity of the first carbon may be 20% to 90%.

[0044] The cathode coating layer (220) may further include additives other than the first metal and the first carbon. The cathode coating layer (220) may further include, for example, at least one additive selected from the group consisting of a binder, a filler, a coating agent, a dispersant, and an ion conductive additive.

[0045] The negative electrode coating layer (220) may have a smaller thickness than the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 1 um to 20 um, 2 um to 10 um, or 3 um to 7 um. If the thickness of the negative electrode coating layer (220) is too thin, 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 deteriorating the cycle characteristics of the all-solid-state battery (CEL1). If the thickness of the cathode coating layer (220) increases excessively, the energy density of the all-solid-state battery (CEL1) may decrease and the internal resistance of the all-solid-state battery (CEL1) due to the cathode coating layer (220) may increase, thereby deteriorating the cycle characteristics of the cell.

[0046] Meanwhile, although not shown, a carbon layer may be further included to improve adhesion between the cathode coating layer (220) and the solid electrolyte layer (300).

[0047]

[0048] Figures 2 and 3 are cross-sectional views illustrating an all-solid-state battery according to embodiments of the present invention. For convenience of explanation, the same details as those described with reference to Figure 1 will be omitted below, and differences will be described in detail.

[0049] Referring to FIG. 2, the negative electrode layer (200) of the all-solid-state battery (CEL1) may further include a lithium deposition buffer layer (LBL). The lithium deposition buffer layer (LBL) may be disposed between the negative electrode current collector (210) and the negative electrode coating layer (220).

[0050] A lithium deposition buffer layer (LBL) can suppress the precipitation and growth of lithium dendrites between the negative electrode coating layer (220) and the negative electrode current collector (210) during charging of an all-solid-state battery (CEL1). The lithium deposition buffer layer (LBL) can prevent the occurrence of voids at the interface between the negative electrode coating layer (220) and the negative electrode current collector (210), irreversible deformation of the negative electrode current collector (210), and the generation of dead lithium.

[0051] The lithium deposition buffer layer (LBL) may include a second metal and a second carbon. By including the second metal and the second carbon together in the lithium deposition buffer layer (LBL), the lifespan of the all-solid-state battery can be extended.

[0052] For example, the lithium deposition buffer layer (LBL) may include at least one second metal selected from the group consisting of beryllium (Be), boron (B), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), hafnium (Hf), tantalum (Ta), tungsten (W), lithium (Re), and osmium (Os).

[0053] For example, the lithium deposition buffer layer (LBL) may include at least one secondary carbon selected from the group consisting of carbon black, carbon nanotubes, acetylene black, furnace black, ketjen black, and graphene.

[0054] The second carbon can strengthen the cohesion between the negative electrode coating layer (220) and the lithium deposition buffer layer (LBL). The second carbon can prevent unevenness at the interface between the negative electrode coating layer (220) and the lithium deposition buffer layer (LBL) during charge and discharge of the all-solid-state battery (CEL1).

[0055] The porosity of the second carbon may be 30% to 70%. The second carbon can mitigate volume expansion caused by lithium deposition during charging of the all-solid-state battery (CEL1).

[0056] The Gibbs free energy of the first metal included in the cathode coating layer (220) with molten lithium may be △G1.

[0057] The Gibbs free energy (△G1) of the first metal with molten lithium can be defined as the Gibbs free energy expressed by Equation 1 below.

[0058] [Formula 1]

[0059] △G1=△H1 523.15K -T△S1 523.15K

[0060] That is, △G1 can be defined as the Gibbs formation energy of the chemical reaction between the first metal and molten lithium at 250℃.

[0061] The first metal may include a lithiophilic metal. Specific examples of the first metal may be as described above. For example, △G1 may be ≤ 0 kJ / mol. Alternatively, -1500 kJ / mol < △G1 ≤ 0 kJ / mol. When △G1 satisfies the above-described range, a Li-first metal alloy reaction may occur. Accordingly, the first metal may induce lithium deposition during charge / discharge of the all-solid-state battery. For example, the charge / discharge temperature of the all-solid-state battery may be 25°C to 90°C.

[0062] The Gibbs free energy of the second metal contained in the lithium-deposited buffer layer (LBL) with molten lithium may be △G2.

[0063] The Gibbs free energy (△G2) of the second metal with molten lithium can be defined as the Gibbs free energy expressed by Equation 2 below.

[0064] [Formula 2]

[0065] △G2=△H2 523.15K -T△S2 523.15K

[0066] That is, △G2 can be defined as the Gibbs formation energy of the chemical reaction between the second metal and molten lithium at 250℃.

[0067] The second metal may include a lithium non-affinity metal (lithiophobic metal). △G2 may be greater than △G1. For example, △G2 may be > 0 kJ / mol. Alternatively, 0 kJ / mol < △G2 < 1000 kJ / mol. When △G2 satisfies the above-described range, an alloying reaction of Li-the second metal may not occur. The second metal may lower lithium ion conductivity. Accordingly, lithium may be deposited on the lithium deposition buffer layer (LBL) during charge and discharge of the all-solid-state battery.

[0068] For example, the content of the first metal may be less than the content of the second metal. For example, the content of the first metal may be 3 wt% to 50 wt% relative to the total weight of the cathode coating layer. For example, the content of the second metal may be 30 wt% to 90 wt% relative to the total weight of the lithium-deposited buffer layer.

[0069] The second metal can have high electrical conductivity. This allows the lithium-deposited buffer layer (LBL) to easily transport electrons. For example, the electrical conductivity of the second metal is 1 at 20°C. 10 6 S / m or more. Alternatively, the electrical conductivity of the second metal may be 1 10 6 S / m to 1 10 5 It could be S / m.

[0070] For example, the thickness of the negative electrode coating layer (220) may be thicker than the thickness of the lithium deposition buffer layer (LBL). For example, the thickness of the negative electrode coating layer (220) may be 5 μm to 15 μm. For example, the thickness of the lithium deposition buffer layer (LBL) may be 1 μm to 10 μm. When the thickness of the negative electrode coating layer (220) and the thickness of the lithium deposition buffer layer (LBL) each satisfy the ranges described above, the lifespan of the all-solid-state battery can be extended. In particular, when the thickness of the negative electrode coating layer (220) is thinner than the range described above, lithium may penetrate through the negative electrode coating layer (220) and be precipitated, and dendrite may be formed in the direction of the solid electrolyte layer (300). On the other hand, when the thickness of the negative electrode coating layer (220) is thicker than the range described above, lithium may be precipitated inside the negative electrode coating layer (220). If the thickness of the lithium deposition buffer layer (LBL) is thinner than the range described above, lithium cannot be evenly deposited on the lithium deposition buffer layer (LBL), dendrites are formed, and the buffer layer cannot function. On the other hand, if the thickness of the lithium deposition buffer layer (LBL) is thicker than the range described above, the energy density of the all-solid-state battery may decrease.

[0071] For example, a lithium deposition buffer layer (LBL) can be manufactured by coating a slurry containing the second metal and the second carbon described above on a negative electrode current collector (210). For example, a lithium deposition buffer layer (LBL) can be manufactured by bar coating a slurry containing the second metal and the second carbon described above on a negative electrode current collector (210).

[0072] Referring to FIG. 3, the negative electrode layer (200) of the all-solid-state battery (CEL1) may further include a lithium deposition layer (LDL). The lithium deposition layer (LDL) may include lithium precipitated during charging of the all-solid-state battery (CEL1).

[0073] A lithium deposition layer (LDL) may be disposed between a lithium deposition buffer layer (LBL) and a cathode coating layer (220). The lithium deposition layer (LDL) may be formed thinly on the lithium deposition buffer layer (LBL) when charging the all-solid-state battery (CEL1).

[0074] The thickness of the lithium deposition layer (LDL) may be uniform. The lithium deposition layer (LDL) may not include lithium dendrites. For example, when an all-solid-state battery (CEL1) is charged with a constant current (CC) of 0.33 C up to 4.25 V and then charged with a constant voltage (CV) of 4.25 V down to 0.1 C, the thickness of the lithium deposition layer (LDL) may be 500 nm to 30 μm.

[0075]

[0076] Hereinafter, the present invention will be described in more detail through examples. However, these examples are intended to exemplify the present invention and the scope of the present invention is not limited to these examples.

[0077]

[0078] Example 1

[0079] A negative electrode layer (200) including a lithium deposition buffer layer (LBL) disposed between a negative electrode current collector (210) and a negative electrode coating layer (220) was prepared. The negative electrode coating layer (220) contained silver (Ag) as a first metal, and the content of silver (Ag) was 15 wt% based on the total weight of the negative electrode coating layer. The thickness of the negative electrode coating layer (220) was 15 μm. The lithium deposition buffer layer (LBL) contained iron (Fe) as a second metal, and the content of iron (Fe) was 32 wt% based on the total weight of the lithium deposition buffer layer. The thickness of the lithium deposition buffer layer (LBL) was 10 μm. The negative electrode layer (200) was prepared by the following method.

[0080] A 10 μm thick nickel thin film was prepared as a negative electrode current collector. To form a lithium deposition buffer layer, a lithium deposition buffer layer slurry was prepared by mixing second metal particles, second carbon (carbon black), PVDF (Polyvinylidene fluoride) binder (# S5130 from Solvay), and NMP (N-Methyl Pyrrolidone) solvent. The prepared lithium deposition buffer layer slurry was applied to the nickel thin film using a bar coater, and dried in a convection oven at 80°C for 10 minutes to form a laminate of the negative electrode current collector and the lithium deposition buffer layer. To form the negative electrode coating layer, a negative electrode coating layer slurry was prepared by mixing first metal particles, first carbon (carbon black), PVDF binder, and NMP solvent. The manufactured negative electrode coating layer slurry was applied to the lithium deposition buffer layer using a bar coater and dried in a convection oven at 80°C for 10 minutes to form a laminate of the negative electrode current collector, the lithium deposition buffer layer, and the negative electrode coating layer. Through the above process, a negative electrode layer laminated in the order of the negative electrode current collector, the lithium deposition buffer layer, and the negative electrode coating layer was manufactured.

[0081]

[0082] Example 2

[0083] The cathode coating layer (220) includes silver (Ag) as the first metal in an amount of 5 wt% relative to the total weight of the cathode coating layer, the thickness of the cathode coating layer (220) is 13 μm, and the lithium deposition buffer layer (LBL) includes iron (Fe) as the second metal in an amount of 55 wt% relative to the total weight of the lithium deposition buffer layer, and the thickness of the lithium deposition buffer layer (LBL) is 5 μm, except that the method was the same as Example 1.

[0084]

[0085] Example 3

[0086] The cathode coating layer (220) includes silver (Ag) as the first metal in an amount of 25 wt% relative to the total weight of the cathode coating layer, the thickness of the cathode coating layer (220) is 10 μm, and the lithium deposition buffer layer (LBL) includes copper (Cu) as the second metal in an amount of 64 wt% relative to the total weight of the lithium deposition buffer layer, and the thickness of the lithium deposition buffer layer (LBL) is 8 μm, except that the same method as in Example 1 was used for preparation.

[0087]

[0088] Example 4

[0089] The cathode coating layer (220) includes 40 wt% of zinc (Zn) as the first metal relative to the total weight of the cathode coating layer, the thickness of the cathode coating layer (220) is 10 μm, and the lithium deposition buffer layer (LBL) includes 62 wt% of iron (Fe) as the second metal relative to the total weight of the lithium deposition buffer layer, and the thickness of the lithium deposition buffer layer (LBL) is 3 μm, except that the same method as Example 1 was used for preparation.

[0090]

[0091] Example 5

[0092] The cathode coating layer (220) includes zinc oxide (ZnO) as the first metal in an amount of 30 wt% relative to the total weight of the cathode coating layer, the thickness of the cathode coating layer (220) is 11 μm, and the lithium deposition buffer layer (LBL) includes iron (Fe) as the second metal in an amount of 70 wt% relative to the total weight of the lithium deposition buffer layer, and the thickness of the lithium deposition buffer layer (LBL) is 2 μm, except that the same method as Example 1 was used for preparation.

[0093]

[0094] Example 6

[0095] The cathode coating layer (220) includes silver (Ag) as the first metal in an amount of 44 wt% relative to the total weight of the cathode coating layer, the thickness of the cathode coating layer (220) is 8 μm, and the lithium deposition buffer layer (LBL) includes nickel (Ni) as the second metal in an amount of 53 wt% relative to the total weight of the lithium deposition buffer layer, and the thickness of the lithium deposition buffer layer (LBL) is 3 μm, except that the cathode coating layer (220) was prepared in the same manner as Example 1.

[0096]

[0097] Example 7

[0098] The cathode coating layer (220) includes 49 wt% of zinc (Zn) as the first metal relative to the total weight of the cathode coating layer, the thickness of the cathode coating layer (220) is 5 μm, and the lithium deposition buffer layer (LBL) includes 77 wt% of iron (Fe) as the second metal relative to the total weight of the lithium deposition buffer layer, and the thickness of the lithium deposition buffer layer (LBL) is 1 μm, except that the same method as Example 1 was used for preparation.

[0099]

[0100] Comparative Example 1

[0101] The cathode coating layer (220) was prepared in the same manner as Example 1, except that it did not include the first metal and the lithium deposition buffer layer (LBL) did not include the second metal.

[0102]

[0103] Comparative Example 2

[0104] The lithium deposition buffer layer (LBL) was prepared in the same manner as in Example 1, except that it did not contain a second metal.

[0105]

[0106] Comparative Example 3

[0107] The cathode coating layer (220) was prepared in the same manner as Example 1, except that it did not contain the first metal.

[0108]

[0109] Comparative Example 4

[0110] It was prepared in the same manner as Example 1, except that the thickness of the lithium deposition buffer layer (LBL) was 13 μm.

[0111]

[0112] Comparative Example 5

[0113] It was prepared in the same manner as Example 1, except that the thickness of the cathode coating layer (220) was 18 μm.

[0114]

[0115] Comparative Example 6

[0116] It was prepared in the same manner as Example 1, except that the lithium deposition buffer layer (LBL) was not included at all.

[0117]

[0118] Comparative Example 7

[0119] The lithium-deposited buffer layer (LBL) was prepared in the same manner as in Example 1, except that it did not contain any secondary carbon.

[0120]

[0121] Comparative Example 8

[0122] It was prepared in the same manner as Example 1, except that the thickness of the cathode coating layer (220) was 3 μm.

[0123]

[0124] Distinction cathode coating layer (220) Lithium deposition buffer layer (LBL) First metal Metal content (wt%) Thickness (㎛) Second metal Metal content (wt%) Thickness (㎛) Example 1 Ag1515Fe3210 Example 2 Ag513Fe555 Example 3 Ag2510Cu648 Example 4 Zn4010Fe623 Example 5 ZnO3011Fe702 Example 6 Ag448Ni533 Example 7 Zn495Fe771 Comparative Example 1-012-08 Comparative Example 2 Ag2512-08 Comparative Example 3-015Fe505 Comparative Example 4 Ag1010Fe3213 Comparative Example 5 Ag1018Fe505 Comparative Example 6 Ag1515---Comparative Example 7Ag1515Fe9310 Comparative Example 8Ag153Fe3210

[0125] Manufacturing example: Manufacturing of all-solid-state batteries

[0126] (positive electrode active material)

[0127] Cathode active material LiNi0.8Co0. 15 Mn0. 05 O2 (NCM) powder was prepared.

[0128] (bipolar layer)

[0129] LiNi0.8Co0 as the positive electrode active material described above. 15 Mn0. 05 O2 (NCM) powder was prepared. A crystalline argyrodite-based solid electrolyte (Li6PS5Cl) was prepared as a solid electrolyte. A polytetrafluoroethylene (PTFE) binder (Teflon binder from DuPont) was prepared as a binder. Carbon nanofibers (CNF) were prepared as a conductive material. These materials were mixed in a weight ratio of positive electrode active material: solid electrolyte: conductive material: binder = 84.2:11.5:2.9:1.4, and the mixture was formed into a large sheet shape to manufacture a positive electrode sheet. The manufactured positive electrode sheet was pressed onto a positive electrode current collector made of 18 μm thick carbon-coated aluminum foil to manufacture a positive electrode layer. The thickness of the positive electrode active material layer included in the positive electrode layer was approximately 100 μm.

[0130] (cathode layer)

[0131] The cathode layer described above was prepared.

[0132] (solid electrolyte layer)

[0133] A solid electrolyte solution was prepared by adding argyrodite-type solid electrolyte Li6PS5Cl to an isobutylyl isobutylate binder solution containing an acrylate polymer (solid content: 50 wt%, mixing ratio of the solid electrolyte and binder: 98.7:1.3 wt ratio).

[0134] The above solid electrolyte solution was applied to a heterogeneous polytetrafluoroethylene film and dried at 60°C for 2 hours to produce a solid electrolyte layer having a thickness of 100 μm.

[0135] (Manufacturing of all-solid-state batteries)

[0136] The prepared cathode layer, solid electrolyte layer, and anode layer were sequentially laminated. The prepared laminate was plate pressed at 25°C and 100 MPa for 10 minutes to manufacture an all-solid-state battery.

[0137]

[0138] Experimental Example 1: Cross-sectional Analysis of an All-Solid-State Battery

[0139] When the all-solid-state battery manufactured in Example 1 was charged, an SEM image of the cross-section of the all-solid-state battery is shown in Fig. 4. The all-solid-state battery was charged at a constant current (CC) of 0.33 C up to 4.25 V, and then at a constant voltage (CV) of 4.25 V down to 0.1 C. A cross-section of the charged all-solid-state battery was prepared using an ion beam cross-section polisher. Each layer constituting the cross-section was distinguished through EDS analysis.

[0140] Referring to FIG. 4, it can be confirmed that a lithium deposition buffer layer (LBL) existed between the negative electrode current collector (210) and the negative electrode coating layer (220), and that a lithium deposition layer (LDL) was formed on the lithium deposition buffer layer (LBL). The lithium deposition layer (LDL) did not contain any lithium dendrites. The thickness of the lithium deposition layer (LDL) was 500 nm to 10 μm. The thickness of the lithium deposition layer (LDL) was thin and uniform. Meanwhile, referring to FIG. 4, one layer was observed between the lithium deposition layer (LDL) and the negative electrode coating layer (220), but this was confirmed to be a layer (etched residue layer; re-deposition layer) generated when cutting a cross-section of the all-solid-state battery.

[0141]

[0142] Experimental Example 2: Life Evaluation of All-Solid-State Battery

[0143] The lifespan of all-solid-state batteries manufactured using the cathode layers of Examples 1 to 7 and Comparative Examples 1 to 8 was evaluated. The lifespan was evaluated by repeating charge and discharge 100 times at a constant current of 0.33 C. That is, the lifespan evaluation was performed by charging at a constant current of 0.33 C until the voltage of the all-solid-state battery reached 4.25 V, then charging at a constant voltage (CV) of 4.25 V until it reached 0.1 C, and then repeatedly discharging at 0.33 C until the voltage of the all-solid-state battery reached 2.5 V. The lifespan (charge and discharge efficiency) was calculated according to Equation 1 below. The lifespan characteristics were evaluated as A, B, and C according to the calculated results. The lifespan evaluation results are shown in Table 2 below.

[0144]

[0145] [Formula 1]

[0146] Lifespan = (100 discharge capacity / initial discharge capacity) x 100

[0147]

[0148] A: If the lifespan is 85% or more

[0149] B: If the lifespan is 75% or more but less than 85%

[0150] C: If the lifespan is less than 75%

[0151]

[0152] Lifespan Evaluation (%)Example 1AExample 2AExample 3AExample 4AExample 5AExample 6AExample 7AComparative Example 1CComparative Example 2BComparative Example 3BComparative Example 4CComparative Example 5BComparative Example 6BComparative Example 7BComparative Example 8C

[0153] Referring to Table 2, the life characteristics of the all-solid-state batteries according to Examples 1 to 7 were superior to the life characteristics of the all-solid-state batteries according to Comparative Examples 1 to 7.

[0154] Specifically, the life characteristics of the all-solid-state batteries according to Examples 1 to 7 were superior to the life characteristics of the all-solid-state battery according to Comparative Example 6. Thus, it was confirmed that the life of the all-solid-state battery can be extended by the presence of a lithium deposition buffer layer.

[0155] The life characteristics of the all-solid-state batteries according to Examples 1 to 7 were superior to those of the all-solid-state batteries according to Comparative Examples 1 to 3 and 7. Accordingly, it was confirmed that the lifespan of the all-solid-state battery could be further extended when the lithium-deposited buffer layer contained both the second metal and the second carbon. In addition, the life characteristics of the all-solid-state battery were the best when the negative electrode coating layer also contained both the first metal and the first carbon.

[0156] The lifespan characteristics of the all-solid-state batteries according to Examples 1 to 7 were superior to those of the all-solid-state batteries according to Comparative Examples 4 to 6 and 8. Accordingly, it was confirmed that the lifespan of the all-solid-state battery can be extended only when each of the negative electrode coating layer and the lithium deposition buffer layer satisfies the target thickness range.

[0157]

[0158] While embodiments of the present invention have been described with reference to the attached drawings, the present invention may be implemented in other specific forms without altering the technical spirit or essential features thereof. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

Claims

1. Including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, The above cathode layer: negative current collector; A negative electrode coating layer disposed on the negative electrode current collector and including a first metal and a first carbon; and A lithium deposition buffer layer disposed between the negative electrode current collector and the negative electrode coating layer, and including a second metal and a second carbon; The Gibbs free energy of the chemical reaction of the first metal with molten lithium at 250°C is △G1, The Gibbs free energy of the chemical reaction of the second metal with molten lithium at 250°C is △G2. The above △G2 is greater than the above △G1, All-solid-state battery.

2. In paragraph 1, The above △G1 ≤ 0kJ / mol, The above △G2 > 0kJ / mol, All-solid-state battery.

3. In paragraph 1, The electrical conductivity of the second metal is 1 at 20°C. 10 6 S / m or larger, All-solid-state battery.

4. In paragraph 1, The first metal comprises at least one selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), zinc (Zn), magnesium (Mg), indium (In), and zinc oxide (ZnO). All-solid-state battery.

5. In paragraph 1, The second metal comprises at least one selected from the group consisting of beryllium (Be), boron (B), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), hafnium (Hf), tantalum (Ta), tungsten (W), lithium (Re), and osmium (Os). All-solid-state battery.

6. In paragraph 1, The porosity of the first carbon is 20% to 90%, The porosity of the second carbon is 30% to 70%, All-solid-state battery.

7. In paragraph 1, The first carbon comprises at least one selected from the group consisting of carbon black, carbon nanotubes, acetylene black, furnace black, ketgen black, and graphene, The second carbon comprises at least one selected from the group consisting of carbon black, carbon nanotubes, acetylene black, furnace black, ketgen black, and graphene. All-solid-state battery.

8. In paragraph 1, The thickness of the above cathode coating layer is thicker than the thickness of the lithium deposition buffer layer. All-solid-state battery.

9. In paragraph 1, The thickness of the above cathode coating layer is 5㎛ to 15㎛, The thickness of the lithium deposition buffer layer is 1 ㎛ to 10 ㎛, All-solid-state battery.

10. In paragraph 1, The content of the first metal is 3 wt% to 50 wt% based on the total weight of the cathode coating layer, The content of the second metal is 30% to 90% by weight relative to the total weight of the lithium deposition buffer layer, The content of the first metal is less than the content of the second metal, All-solid-state battery.

11. Including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, The above cathode layer: negative current collector; A cathode coating layer disposed on the cathode current collector and including a first metal and a first carbon; A lithium deposition buffer layer disposed between the negative electrode current collector and the negative electrode coating layer, the buffer layer including a second metal and a second carbon; and A lithium deposition layer disposed between the lithium deposition buffer layer and the cathode coating layer; The content of the first metal is 3 wt% to 50 wt% based on the total weight of the cathode coating layer, The content of the second metal is 30% to 90% by weight relative to the total weight of the lithium deposition buffer layer, The content of the first metal is less than the content of the second metal, All-solid-state battery.

12. In paragraph 11, The Gibbs free energy of the chemical reaction of the first metal with molten lithium at 250°C is △G1, The Gibbs free energy of the chemical reaction of the second metal with molten lithium at 250°C is △G2. The above △G2 is greater than the above △G1, All-solid-state battery.

13. In paragraph 12, The above △G1 ≤ 0kJ / mol, The above △G2 > 0kJ / mol, All-solid-state battery.

14. In paragraph 11, The electrical conductivity of the second metal is 1 at 20°C. 10 6 S / m or larger, All-solid-state battery.

15. In paragraph 11, The first metal comprises at least one selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), zinc (Zn), magnesium (Mg), indium (In), and zinc oxide (ZnO). All-solid-state battery.

16. In paragraph 11, The second metal comprises at least one selected from the group consisting of beryllium (Be), boron (B), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), hafnium (Hf), tantalum (Ta), tungsten (W), lithium (Re), and osmium (Os). All-solid-state battery.

17. In paragraph 11, The porosity of the first carbon is 20% to 90%, The porosity of the second carbon is 30% to 70%, All-solid-state battery.

18. In paragraph 11, The first carbon comprises at least one selected from the group consisting of carbon black, carbon nanotubes, acetylene black, furnace black, ketgen black, and graphene, The second carbon comprises at least one selected from the group consisting of carbon black, carbon nanotubes, acetylene black, furnace black, ketgen black, and graphene. All-solid-state battery.

19. In paragraph 11, The thickness of the above cathode coating layer is thicker than the thickness of the lithium deposition buffer layer, The thickness of the above cathode coating layer is 5㎛ to 15㎛, The thickness of the lithium deposition buffer layer is 1 ㎛ to 10 ㎛, All-solid-state battery.

20. In paragraph 11, The thickness of the lithium deposition layer is 500 nm to 10 μm, All-solid-state battery.

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