All-solid-state battery and method of manufacturing same

Abstract

An all-solid-state battery and a method of manufacturing the same are disclosed. The method of manufacturing an all-solid-state battery includes the steps of: preparing a first substrate and a second substrate; preparing a first electrode plate by forming a first mixture layer on the first substrate; preparing a second electrode plate by forming a second mixture layer on a second substrate; forming a first electrode by transferring the second mixture layer of the second electrode plate to the first mixture layer of the first electrode plate; and performing a post-pressurization step to pressurize the first electrode. The step of forming the first electrode includes performing a pre-pressurization step in which the first electrode plate and the second electrode plate are pressurized while facing each other. The post-pressurization step further includes cooling the second electrode plate.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2024-0154347, filed on November 4, 2024, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to an all-solid-state battery and a method for manufacturing the all-solid-state battery. Background Technology

[0003] Recently, with the rapid proliferation of battery-powered electronic devices such as mobile phones, laptops, and electric vehicles, the demand for rechargeable lithium batteries with high energy density and high capacity has increased rapidly. Therefore, extensive research has been conducted to improve the performance of rechargeable lithium batteries.

[0004] A rechargeable lithium battery includes a positive electrode, a negative electrode, and an electrolyte. The positive and negative electrodes include active materials that can insert and deintercalate lithium ions, and generate electrical energy through oxidation and reduction reactions when lithium ions are inserted and deintercalated.

[0005] Among rechargeable lithium batteries, all-solid-state batteries are those in which all materials are solid, especially those using solid electrolytes. These all-solid-state batteries exhibit excellent safety due to the absence of electrolyte leakage risk and are easy to manufacture in thin layers.

[0006] Various methods for increasing the capacity of all-solid-state batteries are being investigated, and one method to increase capacity within a limited volume is to fabricate electrode plates with high current density. Summary of the Invention

[0007] Embodiments of this disclosure provide an all-solid-state battery with high current density and a method for manufacturing the all-solid-state battery.

[0008] Embodiments of this disclosure provide an all-solid-state battery with a large amount of active material coating and a method for manufacturing the all-solid-state battery.

[0009] According to embodiments of this disclosure, a method for manufacturing an all-solid-state battery may include the following steps: preparing a first substrate and a second substrate; preparing a first electrode plate by forming a first mixture layer on the first substrate; preparing a second electrode plate by forming a second mixture layer on the second substrate; forming a first electrode by transferring the second mixture layer of the second electrode plate to the first mixture layer of the first electrode plate; and performing a post-pressurization step to pressurize the first electrode. The step of forming the first electrode may include performing a pre-pressurization step, in which the first electrode plate and the second electrode plate are pressurized while facing each other. The post-pressurization step may further include cooling the second electrode plate.

[0010] According to embodiments of this disclosure, an all-solid-state battery may include: a positive electrode, comprising a positive electrode current collector, a first mixture layer on the positive electrode current collector, and a second mixture layer on the first mixture layer; a solid electrolyte layer on the second mixture layer; and a negative electrode layer on the solid electrolyte layer. The first mixture layer may include a first positive electrode active material and a first solid electrolyte. The second mixture layer may include a second positive electrode active material and a second solid electrolyte. The weight ratio of the first solid electrolyte in the first mixture layer may be less than the weight ratio of the second solid electrolyte in the second mixture layer. Attached Figure Description

[0011] Figure 1 A cross-sectional view of an all-solid-state battery according to an embodiment of the present disclosure is shown.

[0012] Figure 2A and Figure 2B A flowchart illustrating a method for manufacturing an all-solid-state battery according to an embodiment of the present disclosure is shown.

[0013] Figures 3 to 7 A cross-sectional view is shown illustrating a method for manufacturing an all-solid-state battery according to an embodiment of the present disclosure. Detailed Implementation

[0014] To fully understand the structure and effects of this disclosure, some embodiments of the disclosure will be described with reference to the accompanying drawings. However, it should be noted that this disclosure is not limited to the following exemplary embodiments and can be implemented in various forms. Rather, exemplary embodiments are provided merely to disclose the disclosure and to give those skilled in the art a full understanding of its scope.

[0015] In this specification, it will be understood that when an element is referred to as being on another element, the element may be directly on the other element, or an intervening element may exist between them. In the accompanying drawings, the thickness of some components is exaggerated for the purpose of effectively explaining the technical content. Throughout the specification, the same reference numerals refer to the same elements.

[0016] Unless otherwise specified in this specification, singular expressions may include plural expressions. Additionally, unless otherwise specified, the phrase "A or B" may indicate "A but not B", "B but not A", and "A and B". The terms "including / comprise" and / or variations thereof as used in this specification do not exclude the presence or addition of one or more other components.

[0017] In this specification, the term "combination thereof" may refer to mixtures, stacks, complexes, copolymers, alloys, blends, or reaction products.

[0018] In all-solid-state battery electrodes that include current collectors, methods for increasing battery capacity within a limited volume by design considerations may include increasing the amount of active material coating on the substrate to manufacture an electrode plate with high current density.

[0019] The all-solid-state battery and the method of manufacturing the all-solid-state battery according to embodiments of the present disclosure can be used to increase the coating amount of battery active material to achieve the desired thickness and quality of uniformity and improve the current density performance of the battery.

[0020] Figure 1 An all-solid-state battery according to an embodiment of the present disclosure is shown.

[0021] Figure 1 This is a cross-sectional view of an all-solid-state battery 1000 according to an embodiment of the present disclosure.

[0022] Reference Figure 1 The all-solid-state battery 1000 according to an embodiment may include a positive electrode layer 100, a negative electrode layer 200 opposite to 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, this disclosure is not limited thereto, and the all-solid-state battery 1000 may also include additional functional layers (such as adhesion enhancement layers) 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.

[0023] According to an embodiment, the positive electrode layer 100 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.

[0024] The positive electrode current collector 110 can provide a reference surface on which the positive electrode active material layer 120 is disposed. The positive electrode current collector 110 may include a plate or foil, which may include, 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 alloys thereof.

[0025] Although not shown, in order to increase the adhesion between the positive electrode current collector 110 and the positive electrode active material layer 120, a carbon layer with a thickness of about 0.1 μm to about 4 μm may be provided between the positive electrode current collector 110 and the positive electrode active material layer 120.

[0026] The positive electrode active material can be an active material capable of reversibly absorbing and releasing lithium ions. The positive electrode active material may include lithium transition metal oxides (e.g., lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganese oxide, or lithium iron phosphate), nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, but this disclosure is not limited thereto. The positive electrode active material may be used alone or in a mixture of two or more substances.

[0027] The positive electrode active material can be spherical. The positive electrode active material can be elliptical. There are no restrictions on the shape of the positive electrode active material.

[0028] Lithium transition metal oxides can be, for example, made of Li a A 1-b B b D2 (where 0.90≤a≤1 and 0≤b≤0.5), Li a E 1-b B b O 2-c D c (where 0.90≤a≤1, 0≤b≤0.5 and 0≤c≤0.05), LiE 2-b B b O 4-c D c (where 0 ≤ b ≤ 0.5 and 0 ≤ c ≤ 0.05), Li a Ni 1-b-c Co b B c D α (where 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α<2), Li a Ni 1-b-c Co b B c O 2-α F α (where 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α<2), Li a Ni 1-b-c Mn b B c D α (where 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α≤2), Li a Ni 1-b-c Mn b B c O 2-α F α (where 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α<2), Lia Ni b E c G d O2 (where 0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5 and 0.001≤d≤0.1), Li a Ni b Co c Mn d G e O2 (where 0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5 and 0.001≤e≤0.1), Li a NiG b O2 (where 0.9 ≤ a ≤ 1 and 0.001 ≤ b ≤ 0.1), Li a CoG b O2 (where 0.90≤a≤1 and 0.001≤b≤0.1), Li a MnG b O2 (where 0.90≤a≤1 and 0.001≤b≤0.1), Li a Mn2G b O4 (where 0.90≤a≤1 and 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3 (where 0≤f≤2), Li 3-f The compounds represented by Fe2(PO4)3 (where 0≤f≤2) and LiFePO4. In the above compounds, "A" can be Ni, Co, Mn or a combination thereof; "B" can be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements or a combination thereof; "D" can be O, F, S, P or a combination thereof; "E" can be Co, Mn or a combination thereof; "F" can be F, S, P or a combination thereof; "G" can be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; "Q" can be Ti, Mo, Mn or a combination thereof; "I" can be Cr, V, Fe, Sc, Y or a combination thereof; and "J" can be V, Cr, Mn, Co, Ni, Cu or a combination thereof.

[0029] The positive electrode 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 discussed above. The term "layered rock salt-type structure" may refer to a structure in which oxygen atom layers and metal atom layers are alternately and regularly arranged in the <111> direction of the cubic rock salt-type structure, where each atom layer forms a two-dimensional plane. The term "cubic rock salt-type structure" may refer to the sodium chloride (NaCl)-type structure, which is a crystal structure and, for example, has a face-centered cubic lattice (FCC) formed by cations and anions that are offset by 1 / 2 of the ridge of the unit lattice from each other. The lithium transition metal oxide having a layered rock salt-type structure may be a ternary lithium transition metal oxide, such as LiNi x Co y Al z O2 (NCA) or LiNi x Co y Mn z O2 (NCM) (where 0 < x < 1, 0 < y < 1, 0 < z < 1 and x + y + z = 1). When the positive electrode active material includes a ternary lithium transition metal oxide having a layered rock salt-type structure, the all-solid-state battery 1000 may have an increased energy density and improved thermal stability.

[0030] The compound included in the positive electrode active material may be covered with a coating layer (not shown). The positive electrode active material may be used in the form of a mixture of the compound and the compound with the coating layer added. The coating layer added to the surface of the positive electrode active material may include, for example, oxides, hydroxides, hydroxyoxides, carbonate oxy salts, or bicarbonate salts of the coating elements discussed below. The compound constituting the coating layer may be 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 a mixture thereof. The coating layer may include, for example, Li2O-ZrO2 (LZO). The method for forming the coating layer may be selected within any method that does not adversely affect the physical properties of the positive electrode active material. The method for forming the coating layer may include, for example, spraying or dipping.

[0031] When a ternary lithium transition metal oxide such as NCA or NCM including nickel (Ni) is used as the positive electrode active material, the capacity density of the all-solid-state battery 1000 may increase to reduce the departure of metal from the positive electrode active material in the charged state. Therefore, the all-solid-state battery 1000 may improve the cycling characteristics in the charged state. The term "cycling characteristics" may refer to the property indicating the degree of deterioration of the all-solid-state battery 1000 due to charging and discharging. For example, the all-solid-state battery 1000 having high cycling characteristics may deteriorate less due to charging and discharging, while the all-solid-state battery 1000 having low cycling characteristics may deteriorate more due to charging and discharging.

[0032] The positive electrode active material can have, for example, spherical or elliptical particle shapes. There are no restrictions on the particle size and amount of the positive electrode active material.

[0033] The solid electrolyte in the positive electrode active material layer 120 may include a sulfide-based solid electrolyte with excellent lithium-ion conductivity. The sulfide-based solid electrolyte may include, for example, selected from 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-ZmSn (where m and n are positive integers, and "Z" is one of Ge, Zn, and Ga), Li₂S-GeS₂, Li₂S-SiS₂-Li₃PO₄, Li₂S-SiS₂-Li p MO q (Where p and q are both positive integers, and "M" is one of P, Si, Ge, B, Al, Ga, and In), Li 7-x PS 6- x Cl x (where 0≤x≤2), Li 7-x PS 6-x Br x (where 0≤x≤2), and Li 7-x PS 6-x I x At least one of the following (where 0 ≤ x ≤ 2).

[0034] Sulfide solid electrolytes can include, for example, those selected from Li 7-x PS 6-x Cl x (where 0≤x≤2), Li 7-x PS 6- x Br x (where 0≤x≤2), and Li 7-x PS 6-x I x (where 0 ≤ x ≤ 2) is at least one of the following silver-germanium sulfide compounds. For example, sulfide solid electrolytes may be silver-germanium sulfide compounds including at least one of Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0035] Optionally, the sulfide-based solid electrolyte can be, for example, Li. 7-a M a PS 6-c X c (Where 0≤a≤2 and 0≤c≤2) are sulfosilver-germanium ore-type compounds. In the above chemical formulas, X can be F, Br, Cl, or a combination thereof. M can be scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), or a combination thereof.

[0036] The sulfide-germanium ore type solid electrolyte can have a density of about 1.5 g / cc to about 2.0 g / cc. Because the sulfide-germanium ore type solid electrolyte has a density equal to or greater than about 1.5 g / cc, the internal resistance of the all-solid-state battery can be reduced, and short circuits and penetration of the solid electrolyte layer due to lithium dendrite formation can be prevented. The solid electrolyte can have an elastic modulus, for example, from about 15 GPa to about 35 GPa.

[0037] Conductive materials can be conductive without causing chemical changes in the all-solid-state battery 1000, thereby increasing the conductivity of the positive electrode active material and the solid electrolyte. Conductive materials can include carbon-based materials. Conductive materials can include one or more of, for example, graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0038] The binder may include materials that allow the positive electrode active material, solid electrolyte, and conductive material to adhere to each other and improve adhesion to the first substrate (see [link to binder]). Figure 3 The adhesive is an adhesive material (PRL1). The adhesive may include, for example, polyvinylidene fluoride, styrene-butadiene rubber (SBR), polytetrafluoroethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate or butyl acrylate polymers.

[0039] A solid electrolyte layer 300 may be disposed between the positive electrode layer 100 and the negative electrode layer 200, and may include a sulfide-based solid electrolyte with excellent lithium-ion conductivity. The solid electrolyte included in the solid electrolyte layer 300 may be made of the same or different material as the solid electrolyte included in the positive electrode active material layer 120.

[0040] The solid electrolyte layer 300 may also include a binder. The binder included in the solid electrolyte layer 300 may include, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, or polyethylene, but this disclosure is not limited thereto. The binder of the solid electrolyte layer 300 may be the same as or different from the binder of the positive electrode active material layer 120 or the binder of the coating layer 220, which will be discussed below.

[0041] The negative electrode layer 200 may include a negative electrode current collector 210 and a coating layer 220 on the negative electrode current collector 210. The negative electrode current collector 210 may provide a reference surface on which the coating layer 220 is disposed. The negative electrode current collector 210 may include a material that does not react with lithium, for example, a material that does not form an alloy or compound with lithium. For example, the negative electrode current collector 210 may include at least one metal selected from copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). For example, the thickness of the negative electrode current collector 210 may be in the range of about 1 μm to about 20 μm, about 5 μm to about 15 μm, or about 7 μm to about 10 μm.

[0042] The negative electrode current collector 210 may be formed from one of the aforementioned metals, an alloy of two or more of the aforementioned metals, or a coating material. The negative electrode current collector 210 may have, for example, a plate or foil shape. In embodiments, the negative electrode current collector 210 may not be provided.

[0043] When the all-solid-state battery 1000 is charged, the coating layer 220 can induce the growth of lithium metal between the coating layer 220 and the negative electrode current collector 210. The coating layer 220 can serve as a protective layer for lithium metal, while also suppressing the precipitation and growth of lithium dendrites.

[0044] The coating layer 220 may include metals and carbon. For example, the coating layer 220 may include at least one metal selected from gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The coating layer 220 may include at least one carbon selected from carbon black, acetylene black, furnace black, Ketjen black, and graphene. In an embodiment, the coating layer 220 may include a mixture of carbon black and silver (Ag).

[0045] In addition to metals and carbon, coating layer 220 may also include additives. Coating layer 220 may include at least one additive selected from, for example, binders, fillers, coating agents, dispersants, and ionic conductive agents.

[0046] The coating layer 220 can have a thickness smaller than that of the positive electrode active material layer 120. For example, the coating layer 220 can have a thickness equal to or less than about 50%, 40%, 30%, 20%, 10%, or 5% of the thickness of the positive electrode active material layer 120. The thickness of the coating layer 220 can be in the range of, for example, about 1 μm to about 20 μm, about 2 μm to about 10 μm, or about 3 μm to about 7 μm. When the coating layer 220 has too small a thickness, lithium dendrites formed between the coating layer 220 and the negative electrode current collector 210 may cause the coating layer 220 to disintegrate, thereby reducing the cycle characteristics of the all-solid-state battery 1000. When the coating layer 220 has too large a thickness, the all-solid-state battery 1000 may have a reduced energy density, and the internal resistance of the all-solid-state battery 1000 may increase due to the coating layer 220, thereby reducing the cycle characteristics of the all-solid-state battery 1000.

[0047] Although not shown, a carbon layer may also be included to increase the adhesion between the coating layer 220 and the solid electrolyte layer 300.

[0048] In this embodiment, the solid electrolyte layer 300 may include a positive electrode solid electrolyte layer and a negative electrode solid electrolyte layer. The positive electrode solid electrolyte layer may be adjacent to the positive electrode layer 100, and the negative electrode solid electrolyte layer may be adjacent to the negative electrode layer 200. Each of the positive electrode solid electrolyte layer and the negative electrode solid electrolyte layer may include the solid electrolyte discussed above.

[0049] Figure 2A A flowchart illustrating a method for manufacturing an all-solid-state battery according to an embodiment of the present disclosure is shown. Figure 2B A flowchart illustrating a method for manufacturing an all-solid-state battery according to an embodiment of the present disclosure is shown. Figures 3 to 7 A cross-sectional view is shown illustrating a method for manufacturing an all-solid-state battery according to an embodiment of the present disclosure.

[0050] Reference Figure 2A The method for manufacturing an all-solid-state battery according to the present disclosure may include: preparing a first substrate and a second substrate (S11); forming a first electrode plate (S12); forming a second electrode plate (S13); disposing the second electrode plate on the first electrode plate to form a first electrode (S14); and performing a post-pressurization step to pressurize the first electrode (S15).

[0051] Reference Figure 2BThe method for manufacturing an all-solid-state battery according to the present disclosure may include: preparing a first substrate and a second substrate (S11); forming a first electrode plate (S12); forming a second electrode plate (S13); performing an initial pressurization step on the first electrode plate (S121); performing an initial pressurization step on the second electrode plate (S131); placing the second electrode plate on the first electrode plate to form a first electrode (S14); and performing a post-pressurization step to pressurize the first electrode (S15).

[0052] The following will refer to Figures 3 to 7 Provide a detailed explanation.

[0053] Reference Figure 3 A first substrate PRL1 can be prepared. A first mixture layer 121 can be formed on the first substrate PRL1. The first mixture layer 121 can be formed on the first substrate PRL1 to form a first electrode plate 1. For example, a first positive electrode paste can be coated on the first substrate PRL1 and dried to form the first mixture layer 121. Therefore, a first electrode plate 1 including the first substrate PRL1 and the first mixture layer 121 can be formed.

[0054] A second substrate PRL2 can be prepared to face the first substrate PRL1. A second mixture layer 122 can be formed on the second substrate PRL2. The second mixture layer 122 can be formed on the second substrate PRL2 to form a second electrode plate 2. For example, a second positive electrode paste can be coated on the second substrate PRL2 and dried to form the second mixture layer 122. Therefore, a second electrode plate 2 including the second substrate PRL2 and the second mixture layer 122 can be formed.

[0055] The first substrate PRL1 may be a current collector. The first substrate PRL1 may include, 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 alloys thereof.

[0056] The first mixture layer 121 may include a positive electrode active material, a first solid electrolyte, a conductive material, and a binder.

[0057] Based on a total of 100 parts by weight of the positive electrode active material, the first solid electrolyte, the conductive material, and the binder, the positive electrode active material may be included in the first mixture layer 121 in an amount of about 83 parts by weight to about 89 parts by weight.

[0058] Based on a total of 100 parts by weight of the positive electrode active material, the first solid electrolyte, the conductive material, and the binder, the weight percentage of the first solid electrolyte can be in the range of about 10 wt% to about 18 wt%. For example, in the first mixture layer 121, the weight percentage of the first solid electrolyte can be equal to or less than about 15 parts by weight.

[0059] Based on a total of 100 parts by weight of the positive electrode active material, the first solid electrolyte, the conductive material and the binder, the binder may be included in the first mixture layer 121 in an amount of about 0.5 parts by weight to about 1.5 parts by weight.

[0060] Based on a total of 100 parts by weight of the positive electrode active material, the first solid electrolyte, the conductive material, and the binder, the conductive material may be included in the first mixture layer 121 in an amount of about 0.5 parts by weight to about 10 parts by weight. When the amount of conductive material included is equal to or less than about 0.5 parts by weight, the proportion of conductive material may be reduced, thereby reducing the conductivity of the first mixture layer 121. When the amount of conductive material included is equal to or greater than about 10 parts by weight, the proportion of conductive material may be excessively increased, resulting in incomplete formation of the coating covering the surface of the first solid electrolyte.

[0061] In addition to the positive electrode active material, the first solid electrolyte, the conductive material, and the binder, the first mixture layer 121 may also include additives such as fillers, coating agents, dispersants, and ionic conductive agents.

[0062] The second substrate PRL2 may be the same as the first substrate PRL1. The second mixture layer 122 may include a positive electrode active material, a second solid electrolyte, a conductive material, and a binder. The positive electrode active material may be included in the second mixture layer 122 in an amount of about 65 parts by weight to about 79 parts by weight, and the second mixture layer 122 may be the same as the first mixture layer 121, except that the weight proportion of the second solid electrolyte in the second mixture layer 122 is about 20 wt% to about 40 wt%. The weight proportion of the first solid electrolyte in the first electrode plate 1 may be less than the weight proportion of the second solid electrolyte in the second electrode plate 2.

[0063] Return to reference Figure 3 The first substrate PRL1 may have an untreated first substrate thickness T41. The untreated first substrate thickness T41 of the first substrate PRL1 can be defined as the thickness when no pressure is applied to the first substrate PRL1.

[0064] The first substrate PRL1 may have a first mixture layer 121 having an untreated first mixture layer thickness T51 thereon. The untreated first mixture layer thickness T51 may be defined as the thickness of the first mixture layer 121 without pressure being applied.

[0065] The first electrode plate 1 may have an untreated first electrode plate thickness T61. The untreated first electrode plate thickness T61 can be defined as the thickness of the first electrode plate 1 without pressure applied. The untreated first electrode plate thickness T61 of the first electrode plate 1 may be substantially the same as the sum of the untreated first mixture layer thickness T51 and the untreated first substrate thickness T41. In this specification, the phrase "substantially the same" may indicate an average error range of approximately 5%.

[0066] The second substrate PRL2 may have an untreated second substrate thickness T11. The untreated second substrate thickness T11 of the second substrate PRL2 can be defined as the thickness when no pressure is applied to the second substrate PRL2.

[0067] The second substrate PRL2 may have a second mixture layer 122 having an untreated second mixture layer thickness T21 thereon. The untreated second mixture layer thickness T21 may be defined as the thickness of the second mixture layer 122 without pressure being applied.

[0068] The second electrode plate 2 may have an untreated second electrode plate thickness T31. The untreated second electrode plate thickness T31 can be defined as the thickness of the second electrode plate 2 without pressure applied. The untreated second electrode plate thickness T31 of the second electrode plate 2 may be substantially the same as the sum of the untreated second mixture layer thickness T21 and the untreated second substrate thickness T11. In this specification, the phrase "substantially the same" may indicate an average error range of approximately 5%.

[0069] The first electrode plate 1 may include a carbon-containing coating. An additional coating may be provided on the first mixture layer 121. In this case, the first electrode plate 1 may include a first substrate PRL1, the first mixture layer 121, and the coating. The thickness of the coating may be equal to or less than about 3 μm.

[0070] Reference Figure 4 The initial pressurization step S121 can be performed to pressurize the first electrode plate 1. After the first mixture layer 121 is disposed on the first substrate PRL1 to form the first electrode plate 1, the first electrode plate 1 can be pressurized in the initial pressurization step S121. The initial pressurization step S121 may include pressurizing the first electrode plate 1 at a pressure of about 0.1 tons / cm to about 0.3 tons / cm. After performing the initial pressurization step S121 on the first electrode plate 1, the first substrate PRL1, the first mixture layer 121, and the first electrode plate 1 may have their reduced thicknesses.

[0071] After the initial pressurization step S121, the first substrate PRL1 may have a first substrate thickness T42 after the initial pressurization treatment. The processed first substrate thickness T42 may be less than the unprocessed first substrate thickness T41.

[0072] After the initial pressurization step S121, the first mixture layer 121 may have a first mixture layer thickness T52 after the initial pressurization treatment. The treated first mixture layer thickness T52 may be less than the untreated first mixture layer thickness T51.

[0073] After the initial pressurization step S121, the first electrode plate 1 may have a first electrode plate thickness T62 after the initial pressurization treatment. The treated first electrode plate thickness T62 may be less than the untreated first electrode plate thickness T61.

[0074] The initial pressurization step S131 can be performed on the second electrode plate 2 simultaneously with the initial pressurization step S121, or it can be performed sequentially after the initial pressurization step S121. In the initial pressurization step S131, the second electrode plate 2 can be pressurized. After the second mixture layer 122 is formed on the second base PRL2 to create the second electrode plate 2, the second electrode plate 2 can be pressurized in the initial pressurization step S131. The initial pressurization step S131 of the second electrode plate 2 can include pressurizing the second electrode plate 2 at a pressure of about 0.1 tons / cm to about 0.3 tons / cm. After performing the initial pressurization step S131 on the second electrode plate 2, the second substrate PRL2, the second mixture layer 122, and the second electrode plate 2 can have their reduced thicknesses.

[0075] After the initial pressurization step S131, the second substrate PRL2 may have a second substrate thickness T12 after the initial pressurization treatment. The treated second substrate thickness T12 may be less than the untreated second substrate thickness T11.

[0076] After the initial pressurization step S131, the second mixture layer 122 may have a second mixture layer thickness T22 after the initial pressurization treatment. The treated second mixture layer thickness T22 may be less than the untreated second mixture layer thickness T21.

[0077] After the initial pressurization step S131, the second electrode plate 2 may have a second electrode plate thickness T32 after the initial pressurization treatment. The treated second electrode plate thickness T32 may be less than the untreated second electrode plate thickness T31.

[0078] The thickness T62 of the first electrode plate after treatment can be substantially the same as the sum of the thickness T52 of the first mixed layer after treatment and the thickness T42 of the first substrate after treatment.

[0079] The thickness T32 of the processed second electrode plate can be substantially the same as the sum of the thickness T22 of the processed second mixture layer and the thickness T12 of the processed second substrate.

[0080] Reference Figure 5 Step S14 can be performed to transfer the second electrode plate 2 to the first electrode plate 1 to form the first electrode 10. Step S14 of forming the first electrode 10 may include bringing the second mixture layer 122 of the second electrode plate 2 into face-to-face contact with the first mixture layer 121 of the first electrode plate 1.

[0081] Step S14, which forms the first electrode 10, may include a pre-pressurization step of pressurizing the first electrode plate 1 and the second electrode plate 2 while they are facing each other. In this case, the pre-pressurization step may include pressurizing the first electrode plate 1 and the second electrode plate 2 at a pressure of about 0.3 tons / cm to about 0.5 tons / cm.

[0082] Since step S14 includes bringing the first electrode plate 1 and the second electrode plate 2 face each other and applying pressure, each of the first electrode plate 1 and the second electrode plate 2 can have a reduced thickness. For example, the thickness T63 of the first electrode plate 1 of the first electrode 10 can be less than the processed first electrode plate thickness T62. The thickness T33 of the second electrode plate 2 of the first electrode 10 can be less than the processed second electrode plate thickness T32.

[0083] The thickness T7 of the first electrode 10 can be the sum of the thickness T63 of the first electrode plate 1 and the thickness T33 of the second electrode plate 2. The thickness T7 of the first electrode 10 can be less than the sum of the processed thickness T62 of the first electrode plate and the processed thickness T32 of the second electrode plate.

[0084] The thickness T43 of the first substrate PRL1 of the first electrode 10 can be less than the thickness T42 of the processed first substrate. The thickness T53 of the first mixture layer 121 of the first electrode 10 can be less than the thickness T52 of the processed first mixture layer.

[0085] The thickness T13 of the second substrate PRL2 of the first electrode 10 can be less than the thickness T12 of the processed second substrate. The thickness T23 of the second mixture layer 122 of the first electrode 10 can be less than the thickness T22 of the processed second mixture layer.

[0086] Reference Figure 6The post-pressurization step S15 can be performed to pressurize the first electrode 10. The first electrode 10 can be post-pressurized to form a first pressurized electrode 11. The post-pressurization step S15 may also include cooling the second electrode plate 2. The cooling step of the second electrode plate 2 may include cooling the second electrode plate 2 using liquid nitrogen. The post-pressurization step S15 may include pressurizing the first electrode plate 1 and the second electrode plate 2 at a pressure of about 2.0 tons / cm to about 2.5 tons / cm.

[0087] The cooling step of the second electrode plate 2 may include, for example, treating the first electrode 10 in a liquid nitrogen atmosphere at a temperature of about -200°C to about -196°C for about 10 minutes to about 20 minutes.

[0088] The first pressurized electrode 11 can be formed by cooling the second electrode plate 2 of the first electrode and pressurizing the first electrode 10.

[0089] The thickness T8 of the first pressurized electrode 11 can be less than the thickness T7 of the first electrode 10. The thickness T64 of the first electrode plate 1 of the first pressurized electrode 11 can be less than the thickness T63 of the first electrode plate 1 of the first electrode 10. The thickness T34 of the second electrode plate 2 of the first pressurized electrode 11 can be less than the thickness T33 of the second electrode plate 2 of the first electrode 10. The thickness T44 of the first substrate PRL1 of the first pressurized electrode 11 can be less than the thickness T43 of the first substrate PRL1 of the first electrode 10. The thickness T14 of the second substrate PRL2 of the first pressurized electrode 11 can be less than the thickness T13 of the second substrate PRL2 of the first electrode 10. The thickness T54 of the first mixture layer 121 of the first pressurized electrode 11 can be less than the thickness T53 of the first mixture layer 121 of the first electrode 10. The thickness T24 of the second mixture layer 122 of the first pressurized electrode 11 can be less than the thickness T23 of the second mixture layer 122 of the first electrode 10.

[0090] Reference Figure 7 After the post-pressurization step S15, the step of removing the cooled second substrate PRL2 can be performed. Since the second electrode plate 2 is cooled in the post-pressurization step S15, the second substrate PRL2 can be removed more easily than when the second substrate PRL2 is not cooled.

[0091] In the second electrode plate 2, where the first pressurized electrode 11 is cooled under a liquid nitrogen atmosphere, the second substrate PRL2 of the second electrode plate 2 can be removed. The second substrate PRL2 can be cooled as discussed above, thus making it easier to remove.

[0092] A solid electrolyte layer and a negative electrode plate can be stacked on the second mixture layer 122 exposed by the removal of the second substrate PRL2. Therefore, an all-solid-state battery can be manufactured.

[0093] In an embodiment of the all-solid-state battery manufactured using the method discussed above, based on the positive electrode active material layer 120 located on one side of the positive electrode current collector 110, the positive electrode active material layer 120 can have a concentration of approximately 15 mg / cm³. 2 Approximately 60 mg / cm 2 The loading level. For example, the positive electrode active material layer 120 located on one side of the positive electrode current collector 110 can have a loading level of approximately 15 mg / cm³. 2 Approximately 60 mg / cm 2 The loading level. Optionally, when the positive electrode active material layer 120 is coated on the opposite side of the positive electrode current collector 110, the positive electrode active material layer 120 may have a loading level of approximately 30 mg / cm³. 2 Approximately 120 mg / cm 2 The total load level. In this specification, the term "load level of the positive electrode active material layer" may refer to the weight of the positive electrode material per unit area of ​​the positive electrode active material layer.

[0094] The second electrode plate 2 of the all-solid-state battery manufactured by the method discussed above can be treated with liquid nitrogen. One side surface of the second electrode plate 2 can contact the first electrode plate 1, and the other side surface of the second electrode plate 2 can contact the solid electrolyte layer.

[0095] Example 1 (Manufacturing of the positive electrode) Preparing LiNi 0.8 Co 0.15 Mn 0.05 O2 (NCM) powder was used as the positive electrode active material. An average particle size (D) was prepared. 50 The first solid electrolyte particles (Li6PS5Cl) of 1 μm sulfide-germanium ore type were used as the solid electrolyte, polyvinylidene fluoride (PVdF) was used as the binder, and carbon nanofibers (CNF) were used as the conductive material.

[0096] A first positive electrode slurry was prepared by mixing the positive electrode active material, solid electrolyte, conductive material, and binder in an octyl acetate solvent at a weight ratio of 85:13.5:0.5:1. The first positive electrode slurry was coated onto an aluminum positive electrode current collector, then dried and pressed to manufacture a first electrode plate.

[0097] Preparing LiNi 0.8 Co 0.15 Mn 0.05 O2 (NCM) powder was used as the positive electrode active material. Particles with an average particle size (D) of 1 μm were prepared. 50The second solid electrolyte particles (Li6PS5Cl) of sulfosilgermanium ore type are used as solid electrolytes, polyvinylidene fluoride (PVdF) is used as binder, and carbon nanofibers (CNF) are used as conductive materials.

[0098] A second positive electrode slurry was prepared by mixing the positive electrode active material, solid electrolyte, conductive material, and binder in an N-methylpyrrolidone solvent at a weight ratio of 78.5:20:0.5:1. The second positive electrode slurry was then coated onto an aluminum substrate, dried, and pressed to fabricate a second electrode plate.

[0099] The first and second electrode plates were brought into face-to-face contact and then cooled at -196°C for 15 minutes in a liquid nitrogen atmosphere while being pressurized at 2.5 tons / cm.

[0100] Next, the aluminum substrate of the second electrode plate is removed.

[0101] (Manufacturing of solid electrolyte layer) With an average particle size of 3 μm (D 50 Third solid electrolyte particles of the sulfide-germanium type (Li6PS5Cl) were added to an isobutyl isobutyrate binder solution containing butyl acrylate polymers to prepare a solid electrolyte slurry (the solid electrolyte and binder were mixed at a weight ratio of 98.7:1.3). The prepared solid electrolyte slurry was coated onto a release polytetrafluoroethylene membrane and dried at 60°C for 2 hours to produce a solid electrolyte layer with a thickness of 100 μm.

[0102] (Manufacturing of the negative electrode) 90wt% Ag nanoparticles (D 50 A negative electrode coating slurry was prepared by mixing 60 nm and 10 wt% carbon black in an aqueous solvent. A mixture of primary and secondary particles with a particle size of 38 nm was used as the carbon black, the secondary particles consisting of primary particles with a particle size of 76 nm and a total particle size of 275 nm. The slurry was coated onto a stainless steel foil serving as a current collector and then dried to fabricate a negative electrode comprising a 12 μm thick negative electrode coating and a 10 μm thick current collector.

[0103] (Fabrication of all-solid-state batteries) A solid-state battery is fabricated by stacking a positive electrode, a solid electrolyte layer, and a negative electrode, and then performing isostatic pressing at 85°C for about 30 minutes under a pressure of 500 MPa.

[0104] Example 2 Except that when preparing the first positive electrode slurry during the manufacture of the first electrode plate, the positive electrode active material, solid electrolyte, conductive material and binder are mixed in a weight ratio of 87:11.5:0.5:1, the all-solid-state battery is manufactured in the same manner as in Example 1.

[0105] Example 3 Except that when preparing the first positive electrode slurry during the manufacture of the first electrode plate, the positive electrode active material, solid electrolyte, conductive material and binder are mixed in a weight ratio of 83:15.5:0.5:1, the all-solid-state battery is manufactured in the same manner as in Example 1.

[0106] Example 4 Except that when preparing the second positive electrode slurry during the manufacture of the second electrode plate, the positive electrode active material, solid electrolyte, conductive material and binder are mixed in a weight ratio of 73.5:25:0.5:1, the all-solid-state battery is manufactured in the same manner as in Example 1.

[0107] Example 5 Except that when preparing the second positive electrode slurry during the manufacture of the second electrode plate, the positive electrode active material, solid electrolyte, conductive material and binder are mixed in a weight ratio of 68.5:30:0.5:1, the all-solid-state battery is manufactured in the same manner as in Example 1.

[0108] Comparative Example 1 (Manufacturing of the positive electrode) Preparing LiNi 0.8 Co 0.15 Mn 0.05 O2 (NCM) powder was used as the positive electrode active material. An average particle size (D) was prepared. 50 A first solid electrolyte slurry was prepared by using 1 μm steric sulfide-germanium ore type first solid electrolyte particles (Li6PS5Cl) as the solid electrolyte, polyvinylidene fluoride (PVdF) as the binder, and carbon nanofibers (CNF) as the conductive material. The positive electrode active material, solid electrolyte, conductive material, and binder were mixed in N-methylpyrrolidone solvent at a weight ratio of 85:13.5:0.5:1 to prepare the first positive electrode slurry.

[0109] Preparing LiNi 0.8 Co 0.15 Mn 0.05 O2 (NCM) powder was used as the positive electrode active material. An average particle size (D) was prepared. 50A second solid electrolyte slurry was prepared by using 1 μm steric sulfide-germanium ore type second solid electrolyte particles (Li6PS5Cl) as the solid electrolyte, polyvinylidene fluoride (PVdF) as the binder, and carbon nanofibers (CNF) as the conductive material. The positive electrode active material, solid electrolyte, conductive material, and binder were mixed in N-methylpyrrolidone solvent at a weight ratio of 78.5:20:0.5:1 to prepare the second positive electrode slurry.

[0110] The first positive electrode paste and the second positive electrode paste are sequentially coated onto the aluminum positive electrode current collector, then dried and pressed to manufacture the first positive electrode plate.

[0111] (Manufacturing of solid electrolyte layer) Average particle size (D) 50 3 μm sterhenite-type third solid electrolyte particles (Li6PS5Cl) were added to an isobutyl isobutyrate binder solution containing butyl acrylate polymers to prepare a solid electrolyte slurry (the solid electrolyte and binder were mixed at a weight ratio of 98.7:1.3). The prepared solid electrolyte slurry was coated onto a release PTFE membrane and dried at 60 °C for 2 hours to produce a solid electrolyte layer with a thickness of 100 μm.

[0112] (Manufacturing of the negative electrode) 90wt% Ag nanoparticles (D 50 A negative electrode coating slurry was prepared by mixing 60 nm and 10 wt% carbon black in an aqueous solvent. A mixture of primary and secondary particles with a particle size of 38 nm was used as the carbon black, the secondary particles consisting of primary particles with a particle size of 76 nm and a total particle size of 275 nm. The slurry was coated onto a stainless steel foil serving as a current collector and then dried to fabricate a negative electrode comprising a 12 μm thick negative electrode coating and a 10 μm thick current collector.

[0113] (Fabrication of all-solid-state batteries) A solid-state battery is fabricated by stacking a positive electrode, a solid electrolyte layer, and a negative electrode, and then performing isostatic pressing at 85°C for about 30 minutes under a pressure of 500 MPa.

[0114] Comparative Example 2 Except that when preparing the second positive electrode slurry, the positive electrode active material, solid electrolyte, conductive material and binder are mixed in a weight ratio of 85:13.5:0.5:1, the positive electrode, solid electrolyte layer, negative electrode and all-solid-state battery are manufactured in the same manner as in Example 1.

[0115] Comparative Example 3 Except that when preparing the first positive electrode slurry, the positive electrode active material, solid electrolyte, conductive material and binder are mixed in a weight ratio of 81:17.5:0.5:1, the positive electrode, solid electrolyte layer, negative electrode and all-solid-state battery are manufactured in the same manner as in Example 1.

[0116] Evaluation 1: Ionic conductivity of the positive electrode The ionic conductivity of batteries according to several examples and comparative examples was measured using the following method. Each positive electrode in Examples 1 to 5 and Comparative Examples 1 to 3 was sampled with a thickness of 150 μm and a diameter of 12 mm. Impedance was measured using a Solartron 1260A impedance / gain phase analyzer according to the two-probe method, and Nyquist plots were obtained (25°C, frequency range: 500 kHz to 50 mHz, amplitude voltage: 50 mV). Based on the measured Nyquist plot results, an equivalent circuit model was applied for fitting to calculate the electronic and ionic conductivity of the batteries. The results are listed in Table 1.

[0117] [Table 1]

[0118] Referring to Table 1, it can be observed that the ionic conductivity and electronic conductivity of the positive electrode according to Example 1 are higher than those of the positive electrodes according to Comparative Examples 1 to 3. The low ionic conductivity of Comparative Example 1 and the low electronic conductivity of Comparative Example 3 cause high resistance during battery operation, thus limiting the output. It can be determined that, in the case of the examples, both ionic conductivity and electronic conductivity are excellent.

[0119] Evaluation 2: Lifetime Characteristics The all-solid-state batteries according to Examples 1 to 5 and Comparative Examples 1 to 3 were charged and discharged. The first charge and discharge cycle was performed at 45°C under the following conditions: charging (0.33C, CC / CV charging, 4.25V, 0.05C cutoff) and discharging (0.33C, CC discharging, 3.0V cutoff). The second and subsequent charge and discharge cycles were performed under the following conditions: charging (1.0C, CC / CV charging, 4.25V, 0.05C cutoff) and discharging (0.5C, CC discharging, 3.0V cutoff). The cycle count (cyc) at which the capacity retention (SOH) reaches 80% after repeated charge and discharge cycles was defined as the lifetime characteristic. The charge retention rate for the Nth cycle was calculated according to Equation 1.

[0120] [Equation 1] Capacity retention rate [%] = (Discharge capacity in the Nth cycle / Discharge capacity in the first cycle) × 100% [Table 2]

[0121] As shown in Table 2, it can be observed that the lifetime characteristics of Examples 1 to 5 are better than those of Comparative Examples 1 to 3.

[0122] According to the all-solid-state battery and its manufacturing method disclosed herein, the coating amount of the active material layer can be increased to manufacture an electrode plate with high current density.

[0123] According to the method for manufacturing all-solid-state batteries disclosed herein, all-solid-state batteries can be easily manufactured and the method is suitable for mass production.

[0124] While this disclosure has been described in conjunction with what is now considered a preferred embodiment, it will be understood that this disclosure is not limited to the disclosed embodiments and is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the foregoing embodiments should be understood as exemplary and not as limiting this disclosure in any way.

Claims

1. A method for manufacturing an all-solid-state battery, the method comprising the following steps: Fabrication of the first substrate and the second substrate; The first electrode plate is prepared by forming a first mixture layer on the first substrate; The second electrode plate is prepared by forming a second mixture layer on the second substrate; The first electrode is formed by transferring the second mixture layer of the second electrode plate to the first mixture layer of the first electrode plate; as well as The subsequent pressurization step applies pressure to the first electrode. The step of forming the first electrode includes performing a pre-pressurization step, in which the first electrode plate and the second electrode plate are pressurized while facing each other, and The post-pressurization step further includes cooling the second electrode plate.

2. The method according to claim 1, wherein, The step of forming the first mixture layer includes coating a first positive electrode paste onto the first substrate, and The step of forming the second mixture layer includes coating a second positive electrode paste onto the second substrate.

3. The method of claim 1, further comprising the step of transferring the second mixture layer to the first mixture layer prior to the following steps: Perform the initial pressurization step to pressurize the first electrode plate; as well as Perform the initial pressurization step to pressurize the second electrode plate.

4. The method according to claim 3, wherein, The initial pressurization step of the first electrode plate is performed, such that the first electrode plate is pressurized at a rate of 0.1 tons / cm to 0.3 tons / cm, and The initial pressurization step of the second electrode plate is performed, such that the second electrode plate is pressurized at a rate of 0.1 tons / cm to 0.3 tons / cm.

5. The method of claim 1, further comprising removing the cooled second substrate after the post-pressurization step.

6. The method according to claim 1, wherein, The first substrate and the second substrate comprise aluminum.

7. The method according to claim 1, wherein, The post-pressurization step includes pressurizing the first electrode at a rate of 2.0 tons / cm to 2.5 tons / cm.

8. The method according to claim 1, wherein, The pre-pressurization step includes bringing the first electrode plate and the second electrode plate face each other and applying pressure at 0.3 tons / cm to 0.5 tons / cm.

9. The method according to claim 1, wherein, The first mixture layer includes a first solid electrolyte. The second mixture layer includes a second solid electrolyte. The weight percentage of the first solid electrolyte in the first mixture layer is 10 wt% to 18 wt%, and The weight ratio of the second solid electrolyte in the second mixture layer is 20 wt% to 40 wt%.

10. The method according to claim 1, wherein, The second electrode plate was cooled using liquid nitrogen.

11. An all-solid-state battery, the all-solid-state battery comprising: A positive electrode, the positive electrode comprising a positive electrode current collector, a first mixture layer on the positive electrode current collector, and a second mixture layer on the first mixture layer; A solid electrolyte layer is placed on the second mixture layer; as well as The negative electrode layer is located on the solid electrolyte layer. The first mixture layer comprises a first positive electrode active material and a first solid electrolyte. The second mixture layer comprises a second positive electrode active material and a second solid electrolyte, and Wherein, the weight ratio of the first solid electrolyte in the first mixture layer is less than the weight ratio of the second solid electrolyte in the second mixture layer.

12. The all-solid-state battery according to claim 11, wherein, The weight percentage of the first solid electrolyte in the first mixture layer is 10 wt% to 18 wt%, and The weight ratio of the second solid electrolyte in the second mixture layer is 20 wt% to 40 wt%.

13. The all-solid-state battery of claim 11, further comprising a coating between the first mixture layer and the second mixture layer, the coating comprising carbon.

14. The all-solid-state battery according to claim 13, wherein, The thickness of the coating is equal to or less than 3 μm.

15. The all-solid-state battery according to claim 11, wherein, The loading level of the mixture layer, including the first mixture layer and the second mixture layer, on the side of the positive electrode current collector is 15 mg / cm². 2 Up to 60 mg / cm 2 .

16. The all-solid-state battery according to claim 11, wherein, The positive electrode current collector comprises aluminum.

17. The all-solid-state battery according to claim 16, wherein, The first solid electrolyte includes sulfide solid electrolytes.

18. The all-solid-state battery according to claim 17, wherein, The first solid electrolyte and the second solid electrolyte include sulfide solid electrolytes.

19. The all-solid-state battery according to claim 11, wherein, The second mixture layer was treated with liquid nitrogen.

20. The all-solid-state battery according to claim 11, wherein, One side surface of the second mixture layer is in contact with the first mixture layer, and The other side surface of the second mixture layer is in contact with the solid electrolyte layer.

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