All-solid-state battery and method for manufacturing an all-solid-state battery

Abstract

The present invention provides an all-solid-state battery having a high current density and a method for manufacturing the same. [Solution] The present invention is a method for manufacturing an all-solid-state battery, comprising the steps of preparing a first substrate and a second substrate, forming a first electrode plate, forming a second electrode plate, transferring the second electrode plate onto the first electrode plate to form a first electrode, and pressurizing the first electrode, wherein the step of forming the first electrode includes a pre-pressurizing step of pressing the first electrode plate and the second electrode plate facing each other, and the post-pressurizing step further includes a step of cooling the second electrode plate.

Description

[Technical Field]

[0001] This invention relates to an all-solid-state battery and a method for manufacturing the same. [Background technology]

[0002] Recently, with the rapid proliferation of electronic devices that use batteries, such as mobile phones, laptops, and electric vehicles, the demand for rechargeable batteries with high energy density and high capacity has been rapidly increasing. Therefore, research and development to improve the performance of lithium-ion rechargeable batteries is actively underway.

[0003] A lithium secondary battery is a battery that includes a positive electrode and a negative electrode containing an active material that allows for the insertion and deintercalation of lithium ions, and an electrolyte. It produces electrical energy through oxidation and reduction reactions that occur when lithium ions are inserted / deintercalated at the positive and negative electrodes.

[0004] Among lithium-ion secondary batteries, all-solid-state batteries are batteries in which all materials are solid, and in particular, batteries that use a solid electrolyte. Such all-solid-state batteries have the advantage of being highly safe because there is no risk of electrolyte leakage, and they are easy to manufacture in a thin form.

[0005] Various methods are being considered to increase the battery capacity of all-solid-state batteries, and one method that can increase capacity within a limited volume is the fabrication of high-current-density electrodes. [Overview of the project] [Problems that the invention aims to solve]

[0006] The problem that this invention aims to solve is to provide an all-solid-state battery having a high current density and a method for manufacturing the same.

[0007] The problem that this invention aims to solve is to provide an all-solid-state battery with a large amount of coating on the active material layer and a method for manufacturing the same. [Means for solving the problem]

[0008] A method for manufacturing an all-solid-state battery according to an embodiment of the present invention includes the steps of preparing a first substrate and a second substrate, preparing a first electrode plate by forming a first mixed layer on the first substrate, preparing a second electrode plate by forming a second mixed layer on the second substrate, forming a first electrode by transferring the second mixed layer of the second electrode plate onto the first mixed layer of the first electrode plate, and a post-pressure step of pressurizing the first electrode, wherein the step of forming the first electrode includes a pre-pressure step of pressing the first electrode plate and the second electrode plate facing each other, and the post-pressure step may further include a step of cooling the second electrode plate.

[0009] An all-solid-state battery according to an embodiment of the present invention includes a positive electrode layer comprising a positive electrode current collector, a first mixed layer on the positive electrode current collector, and a second mixed layer on the first mixed layer, a solid electrolyte membrane on the second mixed layer, and a negative electrode layer on the solid electrolyte membrane, wherein the first mixed layer comprises a first positive electrode active material and a first solid electrolyte, and the second mixed layer comprises a second positive electrode active material and a second solid electrolyte, and the weight ratio of the first solid electrolyte in the first mixed layer can be smaller than the weight ratio of the second solid electrolyte in the second mixed layer. [Effects of the Invention]

[0010] According to the all-solid-state battery manufacturing method and all-solid-state battery according to the embodiments of the present invention, the amount of coating in the active material layer can be increased, making it possible to manufacture electrode plates with high current density.

[0011] According to the all-solid-state battery manufacturing method of the embodiment of the present invention, it is easy to manufacture and may be possible to mass-produce. [Brief explanation of the drawing]

[0012] [Figure 1] This is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention. [Figure 2A] This is a flowchart illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. [Figure 2B] This is a flowchart illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. [Figure 3] This is a diagram illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. [Figure 4] This is a diagram illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. [Figure 5] This is a diagram illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. [Figure 6] This is a diagram illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. [Figure 7] This is a diagram illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. [Modes for carrying out the invention]

[0013] To fully understand the structure and effects of the present invention, preferred embodiments will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be embodied in various forms and modified in various ways. However, this description of the embodiments is provided to ensure that the disclosure of the present invention is complete and to fully inform a person with ordinary skill in the art of which the invention pertains.

[0014] In this specification, when a given component is referred to as being on another component, it means that it can be formed directly on the other component, or that a third component may be interposed between them. Furthermore, in the drawings, the thickness of components is exaggerated for the sake of efficient illustration of the technical content. Parts indicated by the same reference number throughout the specification represent the same component.

[0015] Unless otherwise specified herein, singular designations may also include plural designations. Furthermore, unless otherwise specified, “A or B” may mean “including A, including B, or including A and B.” As used in this specification, “comprises” and / or “comprising” do not preclude the presence or addition of one or more other components by which the referred component is located.

[0016] In this specification, “these combinations” may mean mixtures, laminates, composites, copolymers, alloys, blends, and reaction products of the constituents.

[0017] In an electrode for an all-solid-state battery, which includes a current collector, an active material layer on the current collector, and a solid electrolyte layer on the active material layer, one design for producing a high-current-density electrode plate is to increase the amount of coating on the active material layer on the substrate, in a way that can increase the battery capacity within a limited volume while considering the design.

[0018] By utilizing an all-solid-state battery and a method for manufacturing an all-solid-state battery according to one embodiment of the present invention, the amount of active material coating on the battery can be increased, the desired thickness and quality can be made uniform, and the current density performance of the battery can be increased.

[0019] Figure 1 shows an all-solid-state battery according to one embodiment of the present invention.

[0020] Figure 1 is a cross-sectional view of an all-solid-state battery 10 according to one embodiment of the present invention.

[0021] Referring to Figure 1, an all-solid-state battery 10 according to one embodiment includes 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 all-solid-state battery 10 is not limited thereto and may further include additional functional layers, such as adhesion-enhancing 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.

[0022] In one embodiment, the positive electrode layer 100 includes 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.

[0023] The positive electrode current collector 110 can provide a reference surface on which the positive electrode active material layer 120 is placed. The positive electrode current collector 110 may include a plate or foil containing, 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.

[0024] Although not shown in the diagram, a carbon layer with a thickness of 0.1 μm to 4 μm may be further placed between the positive electrode current collector 110 and the positive electrode active material layer 120 to enhance the adhesion between the positive electrode current collector 110 and the positive electrode active material layer 120.

[0025] The positive electrode active material may be an active material capable of reversibly absorbing and releasing lithium ions. The positive electrode active material may include, but is not 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 manganese oxide, lithium iron phosphate oxide, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide. Each positive electrode active material may be a single material or a mixture of two or more materials.

[0026] The positive electrode active material may be spherical. The positive electrode active material may be elliptical. The shape of the positive electrode active material is not limited.

[0027] Lithium transition metal oxides include, for example, Li a A 1-b B b D2(0.90≦a≦1, 0≦b≦0.5), Li aHAVE BEEN 1-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 b O2(0.90≦a≦1、0.001≦b≦0.1)、Lia 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 This is a compound that can be represented by one of the following: Fe2(PO4)3 (0≦f≦2) or LiFePO4. In such a compound, uppercase "A" represents Ni, Co, Mn, or a combination thereof; uppercase "B" represents Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; uppercase "D" represents O, F, S, P, or a combination thereof; uppercase "E" represents Co, Mn, or a combination thereof; uppercase "F" represents F, S, P, or a combination thereof; uppercase "G" represents Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; uppercase "Q" represents Ti, Mo, Mn, or a combination thereof; uppercase "I" represents Cr, V, Fe, Sc, Y, or a combination thereof; and uppercase "J" represents V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0028] The positive electrode active material may include, for example, lithium salts of transition metal oxides having a layered rock salt type structure among the lithium transition metal oxides mentioned above. The “layered rock salt type structure” is, for example, a cubic rock salt type structure. <111> This structure consists of alternating, regular arrangements of oxygen and metal atomic layers in a directional pattern, where each atomic layer forms a two-dimensional plane. The "cubic rock salt structure" is a type of crystalline structure, specifically a sodium chloride type structure, in which the face-centered cubic lattices (fcc) formed by the cations and anions are offset from each other by approximately half the ridge of the unit cell. Lithium transition metals and oxides having such a layered rock salt structure include, for example, LiNi x Co y Al z O2(NCA) or LiNi x Co y Mn zIt can be a ternary lithium transition metal oxide such as O2(NCM) (0 < x < 1, 0 < y < 1, 0 < z < 1, x + y + z = 1). When the positive electrode active material includes a ternary lithium transition metal oxide having a layered rock salt structure, the energy density of the all-solid-state battery 10 can be increased and the thermal stability can be improved.

[0029] The above-described compound contained in the positive electrode active material can be covered by a coating layer (not shown). The positive electrode active material can also be used as a mixture of the above-described compound and the compound with the coating layer added. On the other hand, the coating layer added to the surface of the positive electrode active material can contain, for example, oxides, hydroxides, oxyhydroxides, oxycarbonates, or hydroxycarbonates of the following coating elements. The compound forming such a coating layer is amorphous or crystalline. The coating elements contained in the coating layer can include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or a mixture thereof. The coating layer can include, for example, Li2O-ZrO2 (LZO), etc. The coating layer formation method is selected within a range that does not adversely affect the physical properties of the positive electrode active material. The coating layer formation method is, for example, spray coating, dipping method, etc.

[0030] When the positive electrode active material contains nickel (Ni) as a ternary lithium transition metal oxide such as NCA or NCM, for example, it is possible to increase the capacity density of the all-solid-state battery 10 and reduce the metal elution of the positive electrode active material in the charged state. As a result, the cycle characteristics of the all-solid-state battery 10 in the charged state are improved. On the other hand, "cycle characteristics" is a characteristic indicating the degree to which the all-solid-state battery 10 deteriorates due to charge / discharge of the all-solid-state battery 10. An all-solid-state battery 10 with high cycle characteristics has a small degree of deterioration of the all-solid-state battery 10 due to charge / discharge, and an all-solid-state battery 10 with low cycle characteristics may have a large degree of deterioration of the all-solid-state battery 10 due to charge / discharge.

[0031] The shape of the positive electrode active material can include particle shapes such as spheres, ellipsoids, etc. The particle size and content of the positive electrode active material are not particularly limited.

[0032] The solid electrolyte in the positive electrode active material layer 120 may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. Examples of sulfide-based solid electrolytes include 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, and Li2S-P2S5-Z. m S n (m and n are positive numbers, and the uppercase letter "Z" is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p and q are positive numbers, and the uppercase letter "M" is one of P, Si, Ge, B, Al, or Gain), 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 can include at least one selected from (0 ≤ x ≤ 2).

[0033] 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 The compound may be an argyrodite-type compound containing one or more selected values ​​from (0 ≤ x ≤ 2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound containing one or more selected values ​​from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0034] Alternatively, a sulfide-based solid electrolyte is Li 7-a MaPS 6-c X c The compound may be an argyrodite-type compound containing (0≦a≦2, (0≦c≦2)), where X may be F, Br, Cl, or a combination thereof. M may 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), or 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 combinations thereof.

[0035] The density of the algyrodite-type solid electrolyte can be 1.5 g / cc to 2.0 g / cc. Having a density of 1.5 g / cc or higher for the algyrodite-type solid electrolyte reduces the internal resistance of the all-solid-state battery, preventing defects such as penetration and short circuits of the solid electrolyte membrane due to lithium dendrite formation. The elastic modulus of the solid electrolyte can be, for example, 15 GPa to 35 GPa.

[0036] The conductive material may enhance the conductivity of the positive electrode active material and solid electrolyte without causing any chemical changes in the all-solid-state battery. The conductive material may include carbon-based materials. The conductive material may include one or more selected from, for example, graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0037] The binder may include substances that bind the positive electrode active material, solid electrolyte, and conductive material, and improve the bonding strength with the first substrate PRL1. Examples of binders include polyvinylidene fluoride, styrene-styrene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, and polymethyl methacrylate.

[0038] The solid electrolyte layer 300 is positioned between the positive electrode layer 100 and the negative electrode layer 200 and may contain a sulfide-based solid electrolyte with excellent lithium-ion conductivity characteristics. The solid electrolyte contained in the solid electrolyte layer 300 may be identical to or different from any of the materials that may be contained in the solid electrolyte contained in the positive electrode active material layer 120, which will be described later.

[0039] The solid electrolyte layer 300 may further contain a binder. The binder in the solid electrolyte layer 300 may be, but is not limited to, styrene-styrene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc. The binder in the solid electrolyte layer 300 may be the same as, or different from, the binder contained in the positive electrode active material layer 120 or the binder contained in the coating layer 220.

[0040] 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 can provide a reference surface on which the coating layer 220 is placed. The negative electrode current collector 210 may include a material that does not react with lithium, i.e., does not form any alloys or compounds 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.

[0041] The negative electrode current collector 210 may be composed of one of the above-mentioned 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. On the other hand, in one embodiment, the negative electrode current collector 210 may be omitted.

[0042] The coating layer 220 allows lithium metal to grow between the all-solid-state battery 10 and the negative electrode current collector 210 during charging. The coating layer 220 acts as a protective layer for the lithium metal and at the same time can suppress the deposition and growth of lithium dendrites.

[0043] The coating layer 220 may contain metals and carbon. For example, the coating layer 220 may contain at least one metal selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The coating layer 220 may contain at least one carbon selected from the group consisting of carbon black, acetylene black, furnace black, Ketzen black, and graphene. In one embodiment, the coating layer 220 may contain a mixture of carbon black and silver (Ag).

[0044] The coating layer 220 may further contain other additives in addition to metal and carbon. The coating layer 220 may further contain at least one additive selected from the group consisting of, for example, binders, fillers, coating agents, dispersants, and ion conductivity enhancers.

[0045] The coating layer 220 may be thinner than the positive electrode active material layer 120. The thickness of the 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 coating layer 220 may be, for example, 1 μm to 20 μm, 2 μm to 10 μm, or 3 μm to 7 μm. If the thickness of the coating layer 220 is excessively thin, lithium dendrites formed between the coating layer 220 and the negative electrode current collector 210 may cause the coating layer 220 to break down, degrading the cycle characteristics of the all-solid-state battery 10. If the thickness of the coating layer 220 is excessively increased, the energy density of the all-solid-state battery 10 may decrease, and the internal resistance of the all-solid-state battery 10 due to the coating layer 220 may increase, degrading the cycle characteristics of the all-solid-state battery 10.

[0046] On the other hand, although not shown, a carbon layer may be further included between the coating layer 220 and the solid electrolyte layer 300 to improve adhesion.

[0047] In one 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 contain the solid electrolyte described above.

[0048] Figure 2A is a flowchart illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. Figure 2B is a flowchart illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. Figures 3 to 7 are drawings illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention.

[0049] Referring to Figure 2A, the method for manufacturing an all-solid-state battery according to the present invention may include the steps of preparing a first substrate and a second substrate (S11), forming a first electrode plate (S12), forming a second electrode plate (S13), providing the second electrode plate on the first electrode plate to form a first electrode (S14), and pressurizing the first electrode (S15).

[0050] Referring to Figure 2B, the method for manufacturing an all-solid-state battery according to the present invention may include the steps of preparing a first substrate and a second substrate (S11), forming a first electrode plate (S12), forming a second electrode plate (S13), applying primary pressure to the first electrode plate (S121), applying primary pressure to the second electrode plate (S131), providing the second electrode plate on the first electrode plate to form a first electrode (S14), and applying post-pressure to the first electrode (S15).

[0051] Please refer to Figures 3 to 7 below for a more detailed explanation.

[0052] Referring to Figure 3, a first substrate PRL1 can be prepared. A first mixed layer 121 can be provided on the first substrate PRL1. A first electrode plate 1 can be formed by providing the first mixed layer 121 on the first substrate PRL1. For example, the first mixed layer 121 can be formed by coating and drying a first positive electrode slurry on the first substrate PRL1. Through this, a first electrode plate 1 including the first substrate PRL1 and the first mixed layer can be formed.

[0053] A second substrate PRL2 may be prepared facing the first substrate PRL1. A second mixed layer 122 may be provided on the second substrate PRL2. A second electrode plate 2 may be formed by providing the second mixed layer on the second substrate PRL2. For example, a second positive electrode slurry can be applied to and dried on the second substrate PRL2 to form the second mixed layer 122. Through this, a second electrode plate 2 including the second substrate PRL2 and the second mixed layer 122 may be formed.

[0054] The first base material PRL1 can be a current collector. The first base material 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.

[0055] The first mixed layer 121 may include a positive electrode active material, a first solid electrolyte, a conductive material, and a binder.

[0056] When the total weight of the positive electrode active material, first solid electrolyte, conductive material, and binder is 100 parts by weight, the first mixed layer 121 may contain 83 parts by weight or more and 92 parts by weight or less of positive electrode active material.

[0057] When the total weight of the positive electrode active material, first solid electrolyte, conductive material, and binder is based on 100 parts by weight, the weight ratio of the first solid electrolyte may be 15 parts by weight or less. That is, in the first mixed layer 121, the weight ratio of the first solid electrolyte may be 10% by weight or more and 18% by weight or less.

[0058] When the total weight of the positive electrode active material, first solid electrolyte, conductive material, and binder is 100 parts by weight, the first mixed layer 121 may contain 0.5 parts by weight or more and 1.5 parts by weight or less of binder.

[0059] When the first solid electrolyte is based on 100 parts by weight, the first mixed layer 121 may contain 1 to 10 parts by weight of conductive material. If the conductive material is included in the first mixed layer 121 in an amount of 1 part by weight or less per 100 parts by weight of the first solid electrolyte, the ratio of conductive material may decrease, and the electrical conductivity of the first mixed layer 121 may decrease. If the conductive material is included in the first mixed layer 121 in an amount of 10 parts by weight or more per 100 parts by weight of the first solid electrolyte, the ratio of conductive material is excessively high, which may prevent the coating layer covering the surface of the solid electrolyte from being properly formed.

[0060] In addition to the positive electrode active material, first solid electrolyte, conductive material, and binder described above, the first mixed layer 121 may further contain additives such as fillers, coating agents, dispersants, and ion conductivity enhancers.

[0061] The second substrate PRL2 may be the same as the first substrate PRL1. The second mixed layer 122 may contain a positive electrode active material, a second solid electrolyte, a conductive material, and a binder. The second mixed layer 122 may contain 65 parts by weight or more and 90 parts by weight or less of positive electrode active material, and the weight ratio of the second solid electrolyte in the second mixed layer 122 may be 20% by weight or more and 40% by weight or less, except that the second mixed layer 122 may contain 65 parts by weight or more and 90 parts by weight or less. The weight ratio of the first solid electrolyte in the first electrode plate 1 may be smaller than the weight ratio of the second solid electrolyte in the second electrode plate 2.

[0062] Referring again to 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.

[0063] The first mixed layer 121 may be provided on the first substrate PRL1 with an untreated thickness T51 of the first mixed layer. The thickness T51 of the untreated first mixed layer can be defined as the thickness when no pressure is applied to the first mixed layer 121.

[0064] The first electrode plate 1 may have an untreated thickness T61. The untreated thickness T61 of the first electrode plate can be defined as the thickness when no pressure is applied to the first electrode plate 1. The untreated thickness T61 of the first electrode plate 1 may be substantially the same as the sum of the thickness T51 of the untreated first mixed layer and the thickness T41 of the untreated first substrate. In this specification, substantially the same may mean an average error range of about 5%.

[0065] The second substrate PRL2 may have an untreated thickness T11. The untreated thickness T11 of the second substrate PRL2 can be defined as the thickness when no pressure is applied to the second substrate PRL2.

[0066] The second mixed layer 122 may be provided on the second substrate PRL2 with an untreated second mixed layer thickness T21. The untreated second mixed layer thickness T21 can be defined as the thickness when no pressure is applied to the second mixed layer 122.

[0067] 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 when no pressure is applied to the second electrode plate 2. The untreated second electrode plate thickness T31 of the second electrode plate 2 may be substantially identical to the sum of the thickness T21 of the untreated second mixed layer and the thickness T11 of the untreated second substrate. In this specification, substantially identical may mean an average error range of about 5%.

[0068] The first electrode plate 1 may include a carbon-containing coating film. An additional coating film may be provided on the first mixed layer 121. In this case, the first electrode plate 1 may include the first substrate PRL1, the first mixed layer 121, and the coating film. The thickness of the coating film may be 3 μm or less.

[0069] Referring to Figure 4, a Primary Pressurization Stage (S121) may be performed on the first electrode plate 1, in which the first electrode plate 1 is pressurized. After the first mixed layer 121 is provided on the first substrate PRL1 to form the first electrode plate 1, pressure can be applied to the first electrode plate 1 in the Primary Pressurization Stage (S121). The Primary Pressurization Stage (S121) may include pressurizing the first electrode plate 1 to 0.1 ton / cm or more and 0.3 ton / cm or less. After the Primary Pressurization Stage (S121) is performed on the first electrode plate, the thickness of the first substrate PRL1, the first mixed layer 121, and the first electrode plate 1 may decrease.

[0070] The first substrate PRL1 may have a primary pressure-treated thickness T42 after the primary pressure step (S121) on the first electrode plate. The primary pressure-treated thickness T42 of the first substrate may be smaller than the thickness T41 of the untreated first substrate.

[0071] The first mixed layer 121 may have a thickness T52 of the primary pressurized first mixed layer after the primary pressurizing step (S121) on the first electrode plate. The thickness T52 of the primary pressurized first mixed layer may be smaller than the thickness T51 of the untreated first mixed layer.

[0072] The first electrode plate 1 may have a thickness T62 after the primary pressurization step (S121) applied to the first electrode plate. The thickness T62 of the primary pressurized first electrode plate may be smaller than the thickness T61 of the untreated first electrode plate.

[0073] The primary pressurization step (S131) ​​for the second electrode plate may be performed simultaneously with or sequentially to the primary pressurization step (S121) for the first electrode plate. The second electrode plate 2 may be pressurized in the primary pressurization step (S131) ​​for the second electrode plate. After the second mixed layer 122 is provided on the second substrate PRL2 to form the second electrode plate 2, pressure can be applied to the second electrode plate 2 in the primary pressurization step (S131) ​​for the second electrode plate. The primary pressurization step (S131) ​​for the second electrode plate may include pressurizing the second electrode plate 2 to 0.1 ton / cm or more and 0.3 ton / cm or less. After the primary pressurization step (S131) ​​for the second electrode plate has been performed, the thicknesses of the second substrate PRL2, the second mixed layer 122, and the second electrode plate 2 may be reduced.

[0074] The second substrate PRL2 may have a primary pressure-treated thickness T12 after the primary pressure step (S131) ​​on the second electrode plate. The primary pressure-treated thickness T12 of the second substrate may be smaller than the untreated thickness T11 of the second substrate.

[0075] The second mixed layer 122 may have a thickness T22 of the primary pressurized second mixed layer after the primary pressurizing step (S131) ​​on the second electrode plate. The thickness T22 of the primary pressurized second mixed layer may be smaller than the thickness T21 of the untreated second mixed layer.

[0076] The second electrode plate 2 may have a thickness T32 of the primary pressure-treated second electrode plate after the primary pressure step (S131) ​​applied to the second electrode plate. The thickness T32 of the primary pressure-treated second electrode plate may be smaller than the thickness T31 of the untreated second electrode plate.

[0077] The thickness T62 of the first electrode plate that has been subjected to primary pressure treatment may be substantially the same as the sum of the thickness T52 of the first mixed layer that has been subjected to primary pressure treatment and the thickness T42 of the first substrate that has been subjected to primary pressure treatment.

[0078] The thickness T32 of the primary pressure-treated second electrode plate may be substantially the same as the sum of the thickness T22 of the primary pressure-treated second mixed layer and the thickness T12 of the primary pressure-treated second substrate.

[0079] Referring to Figure 5, the step (S14) of transferring the second electrode plate 2 onto the first electrode plate 1 to form the first electrode may proceed. The step (S14) of transferring the second electrode plate 2 onto the first electrode plate 1 to form the first electrode may include the step of bringing the second mixed layer 122 of the second electrode plate 2 and the first mixed layer 121 of the first electrode plate 1 into face-to-face contact.

[0080] The step of transferring the second electrode plate 2 onto the first electrode plate 1 to form the first electrode (S14) may include a pre-pressure step in which the first electrode plate 1 and the second electrode plate 2 are brought into contact and pressurized. In this case, the pre-pressure step may include pressurizing to 0.3 ton / cm or more and 0.5 ton / cm or less.

[0081] As described above, the step of forming the first electrode (S14) includes the step of facing the first electrode plate 1 and the second electrode plate 2 and applying pressure, so the thickness of each of the first electrode plate 1 and the second electrode plate 2 can be reduced. In other words, the thickness T63 of the first electrode plate 1 can be smaller than the thickness T62 of the first electrode plate after primary pressure treatment. The thickness T33 of the second electrode plate 2 can be smaller than the thickness T32 of the second electrode plate after primary pressure treatment.

[0082] The thickness T7 of the first electrode 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 can be less than the sum of the thickness T62 of the first electrode plate that has been subjected to primary pressure treatment and the thickness T32 of the second electrode plate that has been subjected to primary pressure treatment.

[0083] The thickness T43 of the first substrate PRL1 of the first electrode may be smaller than the thickness T42 of the first substrate after primary pressure treatment. The thickness T53 of the first mixed layer 121 of the first electrode may be smaller than the thickness T52 of the first mixed layer 121 after primary pressure treatment.

[0084] The thickness T13 of the second substrate PRL2 of the first electrode may be less than the thickness T12 of the second substrate after primary pressure treatment. The thickness T23 of the second mixed layer 122 of the first electrode may be less than the thickness T22 of the second mixed layer 122 after primary pressure treatment.

[0085] Referring to Figure 6, a post-pressurization step (S15) may be performed in which the first electrode is pressurized. The first electrode may be post-pressurized to form the first pressurized electrode 11. The post-pressurization step may further include a step of cooling the second electrode plate 2. The step of cooling the second electrode plate 2 may include a step of cooling the second electrode plate 2 using liquid nitrogen. The post-pressurization step may include pressurizing the first electrode to 2.0 ton / cm or more and 2.5 ton / cm or less.

[0086] The step of cooling the second electrode plate 2 may, for example, include treating the first electrode under liquid nitrogen in an atmosphere of -200°C to -196°C for 10 to 20 minutes.

[0087] The first pressurized electrode 11 can be formed by cooling the second electrode plate 2 of the first electrode and pressurizing the first electrode.

[0088] The thickness T8 of the first pressure electrode 11 may be less than the thickness T7 of the first electrode. The thickness T64 of the first electrode plate of the first pressure electrode 11 may be less than the thickness T63 of the first electrode plate. The thickness T34 of the second electrode plate of the first pressure electrode 11 may be less than the thickness T33 of the second electrode plate. The thickness T44 of the first substrate of the first pressure electrode 11 may be less than the thickness T43 of the first substrate of the first electrode. The thickness T14 of the second substrate of the first pressure electrode 11 may be less than the thickness T13 of the second substrate of the first electrode.

[0089] Referring to Figure 7, after the post-pressurization step (S15), a step may be performed to remove the cooled second substrate PRL2. Since the second electrode plate 2 was cooled during the post-pressurization step, the second substrate PRL2 can be removed more easily than if it had not been cooled.

[0090] The second electrode plate 2, which has been treated and cooled under liquid nitrogen, can have the second substrate PRL2 on it removed. The second substrate PRL2 can be removed more easily by cooling it as described above.

[0091] A solid electrolyte layer and a negative electrode plate can be laminated onto the second mixed layer 122, which is exposed after the second substrate PRL2 is removed. Through this, an all-solid-state battery can be manufactured.

[0092] As one embodiment of an all-solid-state battery formed by the manufacturing method described above, the loading level of the positive electrode active material layer 120 is 15 mg / cm² relative to the positive electrode active material layer 120 located on one side of the positive electrode current collector 110. 2 More than 60mg / cm 2 The following is possible. For example, the loading level of the positive electrode active material layer 120 located on one surface of the positive electrode current collector 110 is 15 mg / cm². 2 More than 60mg / cm 2 The following is possible. As another example, if the positive electrode active material layer 120 is coated on both sides of the positive electrode current collector 110, the total loading level of the positive electrode active material layer 120 is 30 mg / cm². 2 More than 120mg / cm 2The following may be applicable. In this specification, the "loading level of the positive electrode active material layer" means the weight of the positive electrode active material per unit area of the positive electrode active material layer.

[0093] The second electrode plate 2 of the all-solid-state battery formed through the manufacturing method described above can be treated with liquid nitrogen. One side surface of the second electrode plate 2 can be in contact with the first electrode plate 1, and the other side surface of the second electrode plate 2 can be adjacent to the solid electrolyte layer.

[0094] Example 1 (Positive electrode manufacturing) LiNi 0.8 Co 0.15 Mn 0.05 O2 (NCM) powder was prepared. As the solid electrolyte, argillodite-based first solid electrolyte particles (Li6PS5Cl) with an average particle diameter (D50) of 1 μm were prepared, as the binder, a polyvinylidene fluoride (PVdF) binder was prepared, and as the conductive material, carbon nanofibers (CNF) were prepared.

[0095] Such materials were mixed in an octyl acetate solvent at a weight ratio of positive electrode active material: solid electrolyte: conductive material: binder = 85:13.5:0.5:1 to produce a first positive electrode slurry. The first positive electrode slurry was coated on an aluminum positive electrode current collector, dried, and rolled to produce a first electrode plate.

[0096] LiNi 0.8 Co 0.15 Mn 0.05 O2 (NCM) powder was prepared. As the solid electrolyte, argillodite-based second solid electrolyte particles (Li6PS5Cl) with an average particle diameter (D50) of 1 μm were prepared, as the binder, a polyvinylidene fluoride (PVdF) binder was prepared, and as the conductive material, carbon nanofibers (CNF) were prepared.

[0097] These materials were mixed in an N-methylpyrrolidone solvent in a weight ratio of positive electrode active material:solid electrolyte:conductive material:binder = 78.5:20:0.5:1 to produce a second positive electrode slurry. The second positive electrode slurry was coated onto an aluminum substrate, dried, and rolled (pressed) to produce a second electrode plate.

[0098] The first and second electrodes were placed facing each other and in contact, then pressurized at 2.5 ton / cm while simultaneously being cooled under liquid nitrogen at -196°C for 15 minutes.

[0099] Subsequently, the aluminum substrate was removed from the second positive electrode slurry.

[0100] (Solid electrolyte layer manufacturing) A solid electrolyte slurry was prepared by adding argyrodite-based third solid electrolyte particles (Li6PS5Cl) with an average particle size (D50) of 3 μm to an isobutylyl isobutylate binder solution to which a butyl acrylate polymer had been added (the mixing ratio of solid electrolyte to binder was 98.7:1.3 by weight). The prepared solid electrolyte slurry was coated onto a release polytetrafluoroethylene film and dried at 60°C for 2 hours to produce a solid electrolyte layer with a thickness of 100 μm.

[0101] (Negative electrode manufacturing) A negative electrode coating layer slurry was prepared by mixing 90 wt% Ag nanoparticles (D50: 60 nm) and 10 wt% carbon black in an aqueous solvent. The carbon black consisted of a mixture of single particles with a particle size of 38 nm and secondary particles, with the secondary particles being assembled from primary particles with a particle size of 76 nm and secondary particles with a particle size of 275 nm. After coating a stainless steel foil current collector with the slurry, it was dried to produce a negative electrode containing a 12 μm thick negative electrode coating layer and a 10 μm thick current collector.

[0102] (All-solid-state battery) The positive electrode, solid electrolyte layer, and negative electrode manufactured as described above were laminated, and an isostatic press was performed at 85 °C and a pressure of 500 MPa for about 30 minutes to manufacture an all-solid-state battery.

[0103] Example 2 In the manufacture of the first electrode plate, an all-solid-state battery was manufactured in the same manner as in Example 1, except that when manufacturing the first positive electrode slurry, the positive electrode active material: solid electrolyte: conductive material: binder was mixed at a weight ratio of 87:11.5:0.5:1.

[0104] Example 3 In the manufacture of the first electrode plate, an all-solid-state battery was manufactured in the same manner as in Example 1, except that when manufacturing the first positive electrode slurry, the positive electrode active material: solid electrolyte: conductive material: binder was mixed at a weight ratio of 83:15.5:0.5:1.

[0105] Example 4 In the manufacture of the second electrode plate, an all-solid-state battery was manufactured in the same manner as in Example 1, except that when manufacturing the second positive electrode slurry, the positive electrode active material: solid electrolyte: conductive material: binder was mixed at a weight ratio of 73.5:25:0.5:1.

[0106] Example 5 In the manufacture of the second electrode plate, an all-solid-state battery was manufactured in the same manner as in Example 1, except that when manufacturing the second positive electrode slurry, the positive electrode active material: solid electrolyte: conductive material: binder was mixed at a weight ratio of 68.5:30:0.5:1.

[0107] Comparative Example 1 (Manufacture of Positive Electrode) LiNi as the positive electrode active material ) 0.8 Co 0.15 Mn 0.05O2(NCM) powder was prepared. As a solid electrolyte, algyrodite-based first solid electrolyte particles (Li6PS5Cl) with an average particle size (D50) of 1 μm were prepared, as a binder, polyvinylidene fluoride (PVdF) binder was prepared, and as a conductive material, carbon nanofibers (CNF) were prepared. These materials were mixed in N-methylpyrrolidone solvent in a weight ratio of positive electrode active material:solid electrolyte:conductive material:binder = 85:13.5:0.5:1 to produce a first positive electrode slurry.

[0108] LiNi 0.8 Co 0.15 Mn 0.05 O2(NCM) powder was prepared. As the solid electrolyte, algyrodite-based second solid electrolyte particles (Li6PS5Cl) with an average particle size (D50) of 1 μm were prepared, as the binder, polyvinylidene fluoride (PVdF) binder was prepared, and as the conductive material, carbon nanofiber (CNF) was prepared. These materials were mixed in N-methylpyrrolidone solvent in a weight ratio of positive electrode active material:solid electrolyte:conductive material:binder = 78.5:20:0.5:1 to produce a second positive electrode slurry.

[0109] The first positive electrode slurry and the second positive electrode slurry were sequentially coated onto an aluminum positive electrode current collector, and the primary positive electrode plate was manufactured by drying and rolling (pressing).

[0110] (Solid electrolyte layer manufacturing) A solid electrolyte slurry was prepared by adding argyrodite-based third solid electrolyte particles (Li6PS5Cl) with an average particle size (D50) of 3 μm to an isobutylyl isobutylate binder solution to which a butyl acrylate polymer had been added (the mixing ratio of solid electrolyte to binder was 98.7:1.3 by weight). The prepared solid electrolyte slurry was coated onto a release polytetrafluoroethylene film and dried at 60°C for 2 hours to produce a solid electrolyte layer with a thickness of 100 μm.

[0111] (Negative electrode manufacturing) A negative electrode coating layer slurry was prepared by mixing 90 wt% Ag nanoparticles (D50: 60 nm) and 10 wt% carbon black in an aqueous solvent. The carbon black consisted of a mixture of single particles with a particle size of 38 nm and secondary particles, with the secondary particles being assembled from primary particles with a particle size of 76 nm and secondary particles with a particle size of 275 nm. After coating a stainless steel foil current collector with the slurry, it was dried to produce a negative electrode containing a 12 μm thick negative electrode coating layer and a 10 μm thick current collector.

[0112] (All-solid-state battery) As described above, the positive electrode, solid electrolyte layer, and negative electrode were stacked, and an isohydrostatic press was performed at 85°C and 500 MPa pressure for approximately 30 minutes to manufacture an all-solid-state battery.

[0113] Comparative Example 2 The positive electrode, solid electrolyte layer, negative electrode, and all-solid-state battery were manufactured in the same manner as in Example 1, except that the second positive electrode slurry was prepared by mixing the positive electrode active material, solid electrolyte, conductive material, and binder in a weight ratio of 85:13.5:0.5:1.

[0114] Comparative Example 3 The positive electrode, solid electrolyte layer, negative electrode, and all-solid-state battery were manufactured in the same manner as in Example 1, except that the first positive electrode slurry was prepared by mixing the positive electrode active material, solid electrolyte, conductive material, and binder in a weight ratio of 81:17.5:0.5:1.

[0115] Evaluation Example 1: Evaluation of positive electrode ion conductivity The ionic conductivity of the cells in the examples and comparative examples was measured by the following method. First, the positive electrodes of each example from Examples 1 to 5 and Comparative Examples 1 to 3 were sampled with a thickness of 150 μm and a diameter of 12 mm. The impedance was measured using a two-probe method with an impedance analyzer (Solartron 1260A Impedance / Gain-Phase Analyzer) to obtain a Nyquist plot (25°C, frequency range: 500 kHz to 50 mHz, amplitude voltage: 50 mV). An equivalent circuit model was applied and fitted based on the measured Nyquist plot results, and the electronic conductivity and ionic conductivity of the cells were calculated through this process. The results are shown in Table 1.

[0116] [Table 1]

[0117] Referring to Table 1, it can be confirmed that the ionic conductivity and electronic conductivity of the positive electrode in Example 1 have lower ionic resistance than the positive electrodes in Comparative Examples 1 to 3. In the case of Comparative Example 1, the low ionic conductivity results in high resistance during battery operation, limiting the output. In the case of Comparative Examples 2 and 3, the low electronic conductivity results in high resistance. In the case of Example, it can be confirmed that both the ionic conductivity and electronic conductivity are excellent.

[0118] Evaluation Example 2: Lifetime Characteristics Evaluation The all-solid-state batteries were charged and discharged according to Examples 1-5 and Comparative Examples 1-3. The first charge and discharge was performed at 45° under the following conditions: charging (0.33C CC / CV charge 4.25V 0.05C cut) and discharging (0.33C CC discharge 3.0V cut). From the second charge and discharge onward, the following conditions were observed: charging (1.0C CC / CV charge 4.25V 0.05C cut) and discharging (0.5C CC discharge 3.0V cut). After subsequent charge and discharge cycles, the number of cycles (cyc) at which the State of Health (SOH) reached 80% was defined as the lifespan characteristic. The SOH at the Nth cycle was calculated using Equation 2 below. [Formula 2] Capacity retention rate [%] = [Discharge capacity in the Nth cycle / Discharge capacity in the 1st cycle] × 100

[0119] [Table 2]

[0120] As can be seen in Table 2, the lifespan characteristics of Examples 1 to 5 are superior to those of Comparative Examples 1 to 3.

[0121] While preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and can be implemented in various ways within the scope of the claims, the detailed description of the invention, and the attached drawings, which naturally also fall within the scope of the present invention. [Explanation of Symbols]

[0122] 10 All-solid-state battery 100 Positive electrode layer 110 Positive electrode current collector 120 Cathode active material layer 121 1st mixed layer 122 2nd mixed layer 200 Negative electrode layer 210 Negative electrode current collector 220 Coating layer 300 solid electrolyte layer 310 Positive Electrolyte Layer 320 Negative Electrolyte Solid Layer PRL1 First Substrate PRL2 Second Substrate

Claims

1. The steps include preparing the first substrate and the second substrate, The steps include: preparing a first electrode plate by forming a first mixed layer on the first substrate; The steps include: preparing a second electrode plate by forming a second mixed layer on the second substrate; The steps include transferring the second mixed layer of the second electrode plate onto the first mixed layer of the first electrode plate to form the first electrode, The step includes a post-pressurization step of pressurizing the first electrode, The step of forming the first electrode includes a pre-pressure step of pressing the first electrode plate and the second electrode plate facing each other, A method for manufacturing an all-solid-state battery, wherein the post-pressurization step further includes a step of cooling the second electrode plate.

2. Forming the first mixed layer includes applying the first positive electrode slurry onto the first substrate, The method for manufacturing an all-solid-state battery according to claim 1, wherein forming the second mixed layer includes applying a second positive electrode slurry onto the second substrate.

3. Before the aforementioned transcription, A primary pressurization step for the first electrode plate, in which the first electrode plate is pressurized, The method for manufacturing an all-solid-state battery according to claim 1, further comprising a primary pressurization step of pressurizing the second electrode plate.

4. The primary pressurization step for the first electrode plate involves pressurizing the first electrode plate to 0.1 ton / cm or more and 0.3 ton / cm or less. The method for manufacturing an all-solid-state battery according to claim 3, wherein the primary pressurization step for the second electrode plate is to pressurize the second electrode plate to 0.1 ton / cm or more and 0.3 ton / cm or less.

5. The method for manufacturing an all-solid-state battery according to claim 1, further comprising the step of removing the cooled second substrate after the post-pressurization step.

6. The method for manufacturing an all-solid-state battery according to claim 1, wherein the first substrate and the second substrate include aluminum.

7. The method for manufacturing an all-solid-state battery according to claim 1, wherein the post-pressurization step includes pressurizing the first electrode to 2.0 ton / cm or more and 2.5 ton / cm or less.

8. The method for manufacturing an all-solid-state battery according to claim 1, wherein the pre-pressurization step includes a step of facing the first electrode plate and the second electrode plate and pressurizing them to 0.3 ton / cm or more and 0.5 ton / cm or less.

9. The first mixed layer contains a first solid electrolyte, The aforementioned second mixed layer contains a second solid electrolyte, In the first mixed layer, the weight ratio of the first solid electrolyte is 10% by weight or more and 18% by weight or less. The method for manufacturing an all-solid-state battery according to claim 1, wherein the weight ratio of the second solid electrolyte in the second mixed layer is 20% by weight or more and 40% by weight or less.

10. The method for manufacturing an all-solid-state battery according to claim 1, wherein the step of cooling the second electrode plate is performed using liquid nitrogen.

11. The positive electrode layer, The positive electrode layer includes a positive electrode current collector, a first mixed layer on the positive electrode current collector, and a second mixed layer on the first mixed layer. A solid electrolyte membrane on the preceding second mixed layer, The negative electrode layer on the solid electrolyte membrane, The first mixed layer comprises a first positive electrode active material and a first solid electrolyte, The second mixed layer comprises a second positive electrode active material and a second solid electrolyte. An all-solid-state battery in which the weight ratio of the first solid electrolyte in the first mixed layer is smaller than the weight ratio of the second solid electrolyte in the second mixed layer.

12. In the first mixed layer, the weight ratio of the first solid electrolyte is 10% by weight or more and 18% by weight or less. The all-solid-state battery according to claim 11, wherein the weight ratio of the second solid electrolyte in the second mixed layer is 20% by weight or more and 40% by weight or less.

13. The all-solid-state battery according to claim 11, further comprising a carbon-containing coating film interposed between the first mixed layer and the second mixed layer.

14. The all-solid-state battery according to claim 13, wherein the thickness of the coating film is 0 μm or more and 3 μm or less.

15. The sum of the loading levels of the mixed layer, including the first and second mixed layers, is 30 mg / cm² on a cross-sectional basis. 2 35mg / cm or more 2 The all-solid-state battery according to claim 11, which is as follows:

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

17. The all-solid-state battery according to claim 16, wherein the first solid electrolyte is a sulfide-based solid electrolyte.

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

19. The all-solid-state battery according to claim 11, wherein the second mixed layer is subjected to liquid nitrogen treatment.

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

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