Method for manufacturing bipolar all-solid-state battery and bipolar all-solid-state battery manufactured thereby

Abstract

A method for manufacturing a bipolar all-solid-state battery is provided. The method comprises: forming a coating layer on the entirety of a first surface of a current collector having the first surface and a second surface opposite to the first surface; forming a first solid electrolyte layer on the coating layer; forming, on the second surface, a plurality of positive electrode active material layers spaced apart from each other at predetermined intervals; forming a second solid electrolyte layer on each of the plurality of positive electrode active material layers to form a bipolar all-solid-state electrode; forming a plurality of unit electrode assemblies by punching the second surface such that cut portions are positioned between adjacent ones of the plurality of positive electrode active material layers; and stacking the plurality of unit electrode assemblies such that the first solid electrolyte layer and the second solid electrolyte layer are in contact with each other.

Description

Method for manufacturing a bipolar all-solid-state battery and a bipolar all-solid-state battery manufactured thereby

[0001] This invention relates to a method for manufacturing a bipolar all-solid-state battery and a bipolar all-solid-state battery manufactured thereby.

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

[0003] Currently commercially available lithium-ion batteries use electrolytes containing flammable organic solvents, so there is a possibility of overheating and fire if a short circuit occurs. In response to this, all-solid-state secondary batteries using solid electrolytes instead of liquid electrolytes are being proposed.

[0004] By not using flammable organic solvents, all-solid-state rechargeable batteries can significantly reduce the likelihood of fire or explosion in the event of a short circuit. Therefore, these all-solid-state batteries can offer significantly higher safety compared to lithium-ion batteries that use liquid electrolytes.

[0005] In addition, one of the characteristics of all-solid-state secondary batteries is that, unlike conventional lithium-ion batteries, a bipolar structure can be easily constructed, which has the advantage of reducing the number of components and allowing high current to flow easily, thereby enabling the development of high-output, high-energy-density cells with high voltage.

[0006] One aspect is to provide a method for manufacturing a bipolar all-solid-state battery with improved processability.

[0007] Another aspect is to provide an all-solid-state battery produced through a manufacturing method for a bipolar all-solid-state battery with improved processability.

[0008] A method for manufacturing a bipolar all-solid-state battery is provided, comprising: a current collector having a first surface and a second surface opposite to the first surface according to one embodiment; forming a coating layer on the front surface of the first surface; forming a first solid electrolyte layer on the coating layer; forming a plurality of positive active material layers spaced apart at a certain interval on the second surface; forming a second solid electrolyte layer on each of the plurality of positive active material layers to form a bipolar all-solid-state electrode; forming a plurality of unit electrode assemblies on the second surface by punching such that a cut portion is positioned between adjacent positive active material layers among the plurality of positive active material layers; and stacking the plurality of unit electrode assemblies so that the first solid electrolyte layer and the second solid electrolyte layer come into contact with each other.

[0009] According to another embodiment, a bipolar all-solid-state battery is provided, comprising: a positive electrode assembly; a negative electrode assembly; and at least one unit electrode assembly interposed between the positive electrode assembly and the negative electrode assembly and manufactured by the manufacturing method described above.

[0010] According to one aspect, by employing a method of manufacturing multiple bipolar all-solid-state electrodes in succession in batches, it is possible to provide a bipolar all-solid-state battery with improved processability.

[0011] FIG. 1 is a schematic process diagram for explaining a method for manufacturing a bipolar all-solid-state battery according to an exemplary embodiment.

[0012] FIG. 2 is a schematic cross-sectional view of a bipolar all-solid-state battery manufactured by a method for manufacturing a bipolar all-solid-state battery according to an exemplary embodiment.

[0013] Figure 3 is a plan view illustrating the positional relationship between the second solid electrolyte layer and the current collector in the bipolar all-solid-state battery of Figure 2.

[0014] FIG. 4 is a schematic process diagram for explaining a method for manufacturing a bipolar all-solid-state battery according to another exemplary embodiment.

[0015] FIG. 5 is a schematic process diagram for explaining a method for manufacturing a bipolar all-solid-state battery according to another exemplary embodiment.

[0016] FIG. 6 is a schematic cross-sectional view of a bipolar all-solid-state battery manufactured by a method for manufacturing a bipolar all-solid-state battery according to another exemplary embodiment.

[0017] Figure 7 is a plan view illustrating the positional relationship between the second solid electrolyte layer and the current collector in the bipolar all-solid-state battery of Figure 6.

[0018] The present inventive concept described below is subject to various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present inventive concept to specific embodiments and should be understood to include all modifications, equivalents, or substitutions that fall within the scope of the description of the present inventive concept.

[0019] The terms used below are used merely to describe specific embodiments and are not intended to limit the creative concept. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the following, terms such as “comprising” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, components, materials, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, components, materials, or combinations thereof. The “ / ” used below may be interpreted as “and” or “or” depending on the context.

[0020] In the drawings, thicknesses have been enlarged or reduced to clearly represent various layers and regions. Throughout the specification, the same reference numerals have been used for similar parts. Throughout the specification, when a part such as a layer, film, region, or plate is described as being “on” or “above” another part, this includes not only cases where it is directly above another part but also cases where there is another part in between. Throughout the specification, terms such as “first,” “second,” etc., may be used to describe various components, but the components should not be limited by these terms. In this specification and drawings, components having substantially the same functional configuration are referred to by the same reference numerals to avoid redundant descriptions.

[0021] In the present disclosure, the “size” of a particle is, for example, the “particle diameter” of the particle. The “particle diameter” of the particle represents the average diameter when the particle is spherical and represents the average major axis length when the particle is non-spherical. The particle diameter of the particle can be measured using a particle size analyzer (PSA). The “particle diameter” of the particle is, for example, the average particle diameter. The average particle diameter is, for example, the median particle diameter (D50). The median particle diameter (D50) is the particle size corresponding to the 50% cumulative volume calculated from the side of the particle having a small particle size in the particle size distribution measured, for example by laser diffraction.

[0022] In the present disclosure, “metal” includes both metals and metalloids such as silicon and germanium in an elemental or ionic state.

[0023] In this disclosure, “alloy” means a mixture of two or more metals.

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

[0025] In the present disclosure, “anode active material” refers to an anode material capable of undergoing lithiation and delithiation.

[0026] In the present disclosure, “lithiation” and “to lithiate” refer to the process of adding lithium to a positive electrode active material or a negative electrode active material.

[0027] In the present disclosure, “delithiation” and “to delithiate” refer to the process of removing lithium from a positive electrode active material or a negative electrode active material.

[0028] In this disclosure, “charge” and “to charge” refer to the process of providing electrochemical energy to a battery.

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

[0030] In this disclosure, “cathode” and “anode” refer to electrodes where electrochemical oxidation and delithiation occur during the discharge process.

[0031] In the present disclosure, each of the phrases such as “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B or C”, “at least one of A, B and C”, and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0032] The present disclosure relates to a method for manufacturing a bipolar all-solid-state battery by manufacturing a plurality of bipolar unit electrode assemblies in succession and stacking them.

[0033] A method for manufacturing a bipolar all-solid-state battery according to one embodiment may include: a current collector having a first surface and a second surface opposite to the first surface; forming a coating layer on the front surface of the first surface; forming a first solid electrolyte layer on the coating layer; forming a plurality of positive active material layers spaced apart at a certain interval on the second surface; forming a bipolar all-solid-state electrode by forming a second solid electrolyte layer on each of the plurality of positive active material layers; forming a plurality of unit electrode assemblies on the second surface by punching such that a cut portion is positioned between adjacent positive active material layers among the plurality of positive active material layers; and stacking the plurality of unit electrode assemblies so that the first solid electrolyte layer and the second solid electrolyte layer come into contact with each other.

[0034] Referring to FIG. 1, a current collector (COL) having a first surface and a second surface opposite to the first surface is prepared. In this specification, the first surface and the second surface of the current collector do not refer to a specific location or direction, but rather refer to one of the main surfaces of the current collector and another surface distinct from it, and should be interpreted not to be limited to the terms themselves.

[0035] A current collector (COL) with a wide withstand voltage range may be used. The withstand voltage range of the current collector (COL) may be, for example, -1 to 5.5 V or -0.5 to 5.5 V. Within the above range, it can be appropriately used as a current collector (COL) for a bipolar all-solid-state battery. The current collector (COL) is composed of a material that does not react with lithium, for example, that is, does not form either an alloy or a compound. The material constituting the current collector (COL) may be, for example, stainless steel, aluminum (Al), copper (Cu), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), alloys thereof, and clads thereof, but is not necessarily limited to these; any material used as an electrode current collector for a bipolar battery in the relevant technical field is acceptable. The current collector (COL) may be composed of one of the metals described above, or may be composed of an alloy or coating material of two or more metals. According to one embodiment, the current collector (COL) may be made of stainless steel. Stainless steel has a wide withstand voltage range of -0.5 to 5.5V, so it can be suitably used as a current collector (COL) for a bipolar battery. According to one embodiment, an alloy such as Al-Cu clad, which can withstand potential over a wide range, can also be suitably used as a current collector (COL). The thickness of the current collector (COL) may be, for example, 1 μm to 200 μm, 1 μm to 100 μm, 10 μm to 100 μm, or 10 μm to 50 μm. If the thickness of the current collector (COL) exceeds the above range, the energy density of the bipolar all-solid-state battery may decrease, and if it is below the above range, a short circuit may occur due to insufficient mechanical strength of the current collector (COL).

[0036] Referring to FIG. 1, a coating layer (AE) is formed on the front surface of the first surface of the current collector (COL). The process of forming the coating layer (AE) can be carried out as a wet process and / or a dry process.

[0037] In the process of forming a coating layer (AE) according to one embodiment, a coating layer composition is prepared. The coating layer composition can be prepared by mixing metal particles, a carbon-based material, a binder, and a solvent. In one embodiment, the process can proceed as a dry process without mixing a solvent.

[0038] The metal particles may include, for example, gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn) and zinc (Zn), or a combination thereof.

[0039] Carbon-based materials may include, for example, amorphous carbon, crystalline carbon, porous carbon, or a combination thereof. Carbon-based materials may include, for example, carbon black, acetylene black, furnace black, Kettjen black, graphene, or a combination thereof. The mixing ratio of carbon-based materials and metal particles in the coating layer composition may be, for example, 10:1 to 1:2, 5:1 to 1:1, or 4:1 to 2:1 by weight.

[0040] The binder may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, etc., but is not necessarily limited to these, and any binder used in the relevant technical field may be used. The binder may be composed of a single binder or a plurality of different binders.

[0041] The solvent may include organic solvents and / or inorganic solvents. Organic solvents may include, but are not limited to, NMP, acetone, dichloromethane, toluene, hexane, ethanol, or combinations thereof, and any solvent used as an organic solvent in the art is acceptable. Inorganic solvents may include, but are not limited to, water, liquid ammonia, sulfur dioxide, hydrogen fluoride, or combinations thereof, and any solvent used as an organic solvent in the art is acceptable. As described above, when the coating layer (AE) formation process is carried out as a dry process, the coating layer composition may not contain a solvent.

[0042] In the process of forming a coating layer (AE) according to one embodiment, the coating layer composition is applied to the entire surface of the first surface of the current collector (COL). In one embodiment, the coating layer composition containing a solvent can be uniformly applied to the current collector and dried to form the coating layer (AE). As an application method, the doctor blade coating method, slot die coating method, gravure coating method, etc., can be applied, but is not limited thereto; any method used as a wet coating method in the relevant technical field is possible. In another embodiment, the coating layer composition in powder form that does not contain a solvent can be directly applied to the current collector, and the coating layer (AE) can be formed through a heat treatment and / or pressurization process. As an application method, the powder compression method, electrostatic coating method, etc., can be applied, but is not limited thereto; any method used as a dry coating method in the relevant technical field is possible.

[0043] A coating layer (AE) can be formed by applying a coating layer composition to the entire surface of the first side of the current collector (COL) and then applying pressure (e.g., pressure using hydrostatic pressure). The pressure application process may be omitted.

[0044] Referring to FIG. 1, a first solid electrolyte layer (SE1) is formed on a coating layer (AE). The process of forming the first solid electrolyte layer (SE1) can be carried out as a wet process and / or a dry process.

[0045] In the process of forming the first solid electrolyte layer (SE1) according to one embodiment, a first solid electrolyte layer composition is prepared. The first solid electrolyte layer composition can be prepared by mixing a solid electrolyte, a binder, an additive, and a solvent. In one embodiment, the process may proceed as a dry process without mixing a solvent. In one embodiment, the binder and the additive may be omitted.

[0046] The solid electrolyte may include, for example, a sulfide-based solid electrolyte. Sulfide-based solid electrolytes include, for example, Li3PO4-Li2SO4, Li2S-P2S5, Li2S-P2S5-LiX (wherein X is a halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n (In the above formula, m and n are positive numbers, and Z is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (In the above formula, p and q are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, and In), Li + 12-n-x A n+ X 2- 6-x Y - x(In the above formula, A is one of P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, or Ta, X is one of S, Se, or Te, Y is Cl, Br, I, F, CN, OCN, SCN, or N3, and 1≤n≤5, 0≤x≤2) Li 7-m M m PS 6-n X n (In the above formula, M is one of Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, Sc, Y, Ti, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Mn, Tc, Re, Bh, Ru, Os, Hs, Co, Rh, Ir, Mt, Ni, Pd, Pt, Ds, Au, Rg, Cd, Hg, or Cn, X is one of F, Cl, Br, or I, 0 <n≤2, 0<x≤2), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), Li 7-x PS 6-x I xIt may include (0≤x≤2) or a combination thereof. Sulfide-based solid electrolytes can be produced by processing starting materials, such as Li2S or P2S5, by methods such as melt quenching or mechanical milling. Additionally, heat treatment may be performed after such processing. Sulfide-based solid electrolytes may be amorphous, crystalline, or a mixture thereof. Sulfide-based solid electrolytes may include, for example, at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements. Sulfide-based solid electrolytes may include, for example, Li2S-P2S5. When using a material containing Li2S-P2S5 as a sulfide-based solid electrolyte, the mixed molar ratio of Li2S and P2S5 is, for example, in the range of Li2S : P2S5 = 20 : 80 to 90 : 10, 25 : 75 to 90 : 10, 30 : 70 to 70 : 30, and 40 : 60 to 60 : 40. The sulfide-based solid electrolyte may be, for example, an argyrodite-type solid electrolyte. The density of the argyrodite-type solid electrolyte may be 1.5 to 2.0 g / cc. By having a density of 1.5 g / cc or higher for the argyrodite-type solid electrolyte, the internal resistance of the all-solid-state battery is reduced, and penetration of the solid electrolyte separator by lithium can be suppressed more effectively.

[0047] Solid electrolytes may include, for example, oxide-based solid electrolytes. Oxide-based solid electrolytes are, for example, Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (0 <x<2, 0≤y<3), BaTiO3, Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti yO3(PLZT)(0 <x<1, 0<y<1), PB(Mg3Nb 2 / 3 )O3-PbTiO3(PMN-PT), HfO2, SrTiO3, SnO2, CeO2, Na2O, MgO, NiO, CaO, BaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiO2, Li3PO4, Li x Ti y (PO4)3(0 <x≤2, 0<y≤3), Li x Al y Ti z (PO4)3(0 <x≤2, 0<y≤1, 0<z≤3), Li 1+x+y (Al, Ga) x (Ti, Ge) 2-x Si y P 3-y O 12 (0≤x≤1, 0≤y≤1), Li x La y TiO3(0 <x≤2, 0<y≤3), Li2O, LiOH, Li2CO3, LiAlO2, Li2O-Al2O3-SiO2-P2O5-TiO2-GeO2, Li 3+x La3M2O 12 (M = Te, Nb, or Zr, 0≤x≤10), or a combination thereof. Oxide-based solid electrolytes are produced, for example, by sintering methods. Oxide-based solid electrolytes are, for example, Li7La3Zr2O 12 (LLZO) and Li 3+x La3Zr 2-a M a O 12 (M-doped LLZO, M=Ga, W, Nb, Ta, or Al(0 <a<2, 0≤x≤10) 중에서 선택된 가넷계(Garnet-type) 고체 전해질이다.

[0048] The solid electrolyte may include, for example, a polymeric solid electrolyte. The polymeric solid electrolyte may include, for example, a mixture of a lithium salt and a polymer, or a polymer having ion-conducting functional groups. The polymeric solid electrolyte may be, for example, a polymeric electrolyte that is in a solid state at 25°C and 1 atm. The polymeric solid electrolyte may not include, for example, a liquid.The polymeric solid electrolyte comprises a polymer, wherein the polymer is, for example, polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyethylene oxide (PEO), poly(styrene-b-ethylene oxide) block copolymer (PS-PEO), poly(styrene-butadiene), poly(styrene-isoprene-styrene), poly(styrene-b-divinylbenzene) block copolymer, poly(styrene-ethylene oxide-styrene) block copolymer, polystyrene sulfonate (PSS), polyvinyl fluoride (PVF), poly(methylmethacrylate) (PMMA), polyethylene glycol (PEG), polyacrylonitrile (PAN), polytetrafluoroethylene (PTFE), polyethylenedioxythiophene (PEDOT), polypyrrole (PPY), polyacrylonitrile (PAN), Polyaniline, Polyacetylene, Nafion, Aquivion, Flemion, Gore, Aciplex, Morgane ADP, Sulfonated poly(ether ether ketone) (SPEEK), Sulfonated poly(arylene ether ketone ketone sulfone) (SPAEKKS), Sulfonated poly(arylether ketone) (SPAEK), Poly[bis(benzimidazobenzisoquinolinones)] (SPBIBI), Poly(styrene sulfonate) (PSS), Lithium 9,10-Diphenylanthracene-2-sulfonate (lithium 9,10-diphenylanthracene-2-sulfonate, DPASLi. +It may be ) or a combination thereof, but is not limited thereto, and any that are used in polymer electrolytes in the relevant technical field are permitted. Any lithium salt that can be used as a lithium salt in the relevant technical field is permitted. Examples of lithium salts include LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, Li(CF3SO2)2N, LiC4F9SO3, LiAlO2, LiAlCl4, LiN(C x F2 x+1 SO2)(C y F 2y+1 The polymer may be SO2)(x and y are each 1 to 20), LiCl, LiI, or a mixture thereof. The polymer included in the polymer solid electrolyte may be, for example, a compound containing 10 or more, 20 or more, 50 or more, or 100 or more repeating units. The weight-average molecular weight of the polymer included in the polymer solid electrolyte may be, for example, 1,000 Dalton or more, 10,000 Dalton or more, 100,000 Dalton or more, or 1,000,000 Dalton or more.

[0049] Gel electrolytes are, for example, polymeric gel electrolytes. Gel electrolytes can have a gel state without, for example, containing polymers.

[0050] Polymer gel electrolytes may, for example, comprise a liquid electrolyte and a polymer, or comprise an organic solvent and a polymer having ion-conducting functional groups. Polymer gel electrolytes may, for example, be polymer electrolytes in a gel state at 25°C and 1 atm. Polymer gel electrolytes may, for example, have a gel state without containing a liquid. The liquid electrolyte used in the polymer gel electrolyte may be, for example, an ionic liquid, a mixture of a lithium salt and an organic solvent; a mixture of a lithium salt and an organic solvent; a mixture of an ionic liquid and an organic solvent; or a mixture of a lithium salt, an ionic liquid, and an organic solvent. The polymer used in the polymer gel electrolyte may be selected from the polymers used in solid polymer electrolytes. The organic solvent may be selected from the organic solvents used in liquid electrolytes. The lithium salt may be selected from the lithium salts used in solid polymer electrolytes. An ionic liquid refers to a salt or a room-temperature molten salt that has a melting point below room temperature, consists solely of ions, and is in a liquid state at room temperature. The ionic liquid comprises, for example, a) one or more cations selected from ammonium, pyrrolidinium, pyridinium, pyrimidinium, imidazolium, piperidinium, pyrazolium, oxazolium, pyridazinium, phosphonium, sulfonium, triazolium, and mixtures thereof, and b) BF4 - , PF6 - , AsF6 - , SbF6 - , AlCl4 - , HSO4 - , ClO4 - , CH3SO3 - , CF3CO2 - , Cl - , Br - , I - , BF4 - , SO4 - , CF3SO3 - , (FSO2)2N - , (C2F5SO2)2N - , (C2F5SO2)(CF3SO2)N - , and (CF3SO2)2N -It may include one or more compounds selected from those containing one or more anions selected from among. The polymer solid electrolyte may form a polymer gel electrolyte by impregnating it into a liquid electrolyte in a secondary battery, for example. The polymer gel electrolyte may further include inorganic particles. The polymer included in the polymer gel electrolyte may be a compound containing, for example, 10 or more, 20 or more, 50 or more, or 100 or more repeating units. The weight-average molecular weight of the polymer included in the polymer gel electrolyte may be, for example, 500 Dalton or more, 1000 Dalton or more, 10,000 Dalton or more, 100,000 Dalton or more, or 1,000,000 Dalton or more.

[0051] The binder may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited to these; any binder used in the relevant technical field is acceptable. The binder of the first solid electrolyte layer (SE1) may be the same as or different from the binder included in the coating layer (AE) described above. The binder may be omitted.

[0052] Additives are not limited to, for example, antioxidants and stabilizers, but any additive used in the relevant technical field to improve the mechanical or chemical properties of a solid electrolyte layer is acceptable. Additives may be omitted.

[0053] In the process of forming the first solid electrolyte layer (SE1) according to one embodiment, the first solid electrolyte layer composition is applied onto the coating layer (AE). In one embodiment, the first solid electrolyte layer composition containing a solvent can be uniformly applied onto the coating layer (AE) and dried to form the first solid electrolyte layer (SE1). As an application method, dip coating, spray coating, doctor blade coating, slot die coating, gravure coating, etc., may be applied, but is not limited thereto; any method used as a wet coating method in the relevant technical field is possible. In another embodiment, the first solid electrolyte layer composition in powder form that does not contain a solvent may be directly applied onto the coating layer (AE), and the first solid electrolyte layer (SE1) may be formed through a heat treatment and / or pressurization process. As an application method, powder compression, electrostatic coating, etc., may be applied, but is not limited thereto; any method used as a dry coating method in the relevant technical field is possible.

[0054] The thickness of the first solid electrolyte layer (SE1) may be, for example, 1 μm to 200 μm, 1 μm to 100 μm, 1 μm to 50 μm, or 10 μm to 50 μm. If the thickness of the first solid electrolyte layer (SE1) exceeds the above range, the energy density of the bipolar all-solid-state battery may decrease, and if it is less than the above range, there may be a risk of short circuit.

[0055] Referring to FIG. 1, a plurality of positive active material layers (CE) are formed spaced apart at regular intervals on the second surface of a current collector (COL). The process of forming the positive active material layers (CE) can be carried out as a wet process and / or a dry process.

[0056] In the process of forming the positive active material layer (CE) according to one embodiment, a positive active material composition is prepared. The positive active material composition can be prepared by mixing a positive active material, a solid electrolyte, a conductive material, a binder, and a solvent. In one embodiment, the process may proceed as a dry process without mixing a solvent.

[0057] The cathode active material may be, for example, a lithium-containing sulfide-based cathode active material. The lithium-containing sulfide-based cathode active material may include, for example, Li2S, a Li2S-containing composite, or a combination thereof. By including Li2S, a Li2S-containing composite, or a combination thereof having high capacity as the lithium-containing sulfide-based cathode active material, the use of lithium metal may be omitted during the manufacture of the secondary battery. Since lithium metal has high reactivity and great ductility, it can reduce mass producibility during battery manufacturing. Therefore, if the use of lithium metal is omitted during the manufacture of the secondary battery, the mass producibility of the secondary battery may be improved.

[0058] A Li2S-containing composite is, for example, a composite of Li2S and a conductive material. The conductive material is, for example, an ionic conductive material, an electronic conductive material, or a combination thereof.

[0059] The ionic conductivity of an ion-conducting material is, for example, 1.0 × 10⁻⁶ at 25°C. -5 S / m or greater, 1.0×10 -4 S / m or more, or 1.0×10 -3 It is greater than S / m. The ion-conducting material may have pores. By having pores, Li2S can be contained within the pores, which can increase the contact area between Li2S and the ion-conducting material and increase the specific surface area of ​​Li2S. The form of the ion-conducting material may be, for example, particulate ion-conducting material, plate-shaped ion-conducting material, rod-shaped ion-conducting material, or a combination thereof, but is not necessarily limited to these.

[0060] An ion-conducting material according to one embodiment may include, for example, a metal salt compound. The metal salt compound may include a lithium salt compound. The lithium salt compound may include, for example, LiF, LiCl, LiBr, LiI, or a combination thereof. According to one embodiment, a Li2S-containing composite comprising a lithium salt compound may include, for example, Li2S-LiF, Li2S-LiCl, Li2S-LiBr, Li2S-LiI, or a combination thereof. The metal salt compound may further include a boron group metal halide salt. The boron group metal halide salt may include, for example, AlF3, AlCl3, AlBr3, AlI3GaF3, GaCl3, GaBr3, GaI3InF3, InCl3, InBr3, InI3T1F3, T1Cl3, T1Br3, T1I3, or a combination thereof. According to one embodiment, a Li2S-containing composite further comprising a boron group metal halide salt is, for example, Li2S-LiF-AlF3, Li2S-LiF-AlCl3, Li2S-LiF-AlBr3, Li2S-LiF-AlI3, Li2S-LiF-GaF3, Li2S-LiF-GaCl3, Li2S-LiF-GaBr3, Li2S-LiF-GaI3, Li2S-LiF-InF3, Li2S-LiF-InCl3, Li2S-LiF-InBr3, Li2S-LiF-InI3, Li2S-LiF-TlF3, Li2S-LiF-TlCl3, Li2S-LiF-TlBr3, Li2S-LiF-TlI3, Li2S-LiCl-AlF3, Li2S-LiCl-AlCl3, Li2S-LiCl-AlBr3, Li2S-LiCl-AlI3, Li2S-LiCl-GaF3, Li2S-LiCl-GaCl3, Li2S-LiCl-GaBr3, Li2S-LiCl-GaI3, Li2S-LiCl-InF3, Li2S-LiCl-InCl3, Li2S-LiCl-InBr3, Li2S-LiCl-InI3, Li2S-LiCl-TlF3, Li2S-LiCl-TlCl3, Li2S-LiCl-TlBr3, Li2S-LiCl-TlI3, Li2S-LiBr-AlF3,Li2S-LiBr-AlCl3, Li2S-LiBr-AlBr3, Li2S-LiBr-AlI3, Li2S-LiBr-GaF3, Li2S-LiBr-GaCl3, Li2S-LiBr-GaBr3, Li2S-LiBr-GaI3, Li2S-LiBr-InF3, Li2S-LiBr-InCl3, Li2S-LiBr-InBr3, Li2S-LiBr-InI3, Li2S-LiBr-TlF3, Li2S-LiBr-TlCl3, Li2S-LiBr-TlBr3, Li2S-LiBr-TlI3, Li2S-LiI-AlF3, Li2S-LiI-AlCl3, Li2S-LiI-AlBr3, Li2S-LiI-AlI3, Li2S-LiI-GaF3, Li2S-LiI-GaCl3, Li2S-LiI-GaBr3, It may include Li2S-LiI-GaI3, Li2S-LiI-InF3, Li2S-LiI-InCl3, Li2S-LiI-InBr3, Li2S-LiI-InI3, Li2S-LiI-TlF3, Li2S-LiI-TlCl3, Li2S-LiI-TlBr3, Li2S-LiI-TlI3 or a combination thereof.

[0061] The electronic conductivity of an electronically conductive material is, for example, 1.0 × 10⁻⁶ at 25°C. 3 S / m or greater, 1.0×10 4 S / m or more, or 1.0×10 5It is S / m or greater. The form of the electronically conductive material is, for example, particulate electronically conductive material, plate-shaped electronically conductive material, rod-shaped electronically conductive material, or a combination thereof, but is not necessarily limited to these. The electronically conductive material may be, for example, carbon, metal powder, metal compound, etc. When carbon is included as the electronically conductive material, a secondary battery having a high energy density per unit mass can be realized because carbon has high electronic conductivity and is lightweight. The electronically conductive material may have pores. By having pores in the electronically conductive material, Li2S can be contained within the pores, which can increase the contact area between Li2S and the electronically conductive material and increase the specific surface area of ​​Li2S. The pore capacity is, for example, 0.1 cc / g to 20.0 cc / g, 0.5 cc / g to 10 cc / g, or 0.5 cc / g to 5 cc / g. The average pore diameter is, for example, 1 nm to 100 nm, 1 nm to 50 nm, or 1 nm to 20 nm. The BET specific surface area of ​​the electron-conducting material having pores is 200 m² when the average pore diameter is 15 nm or less. 2 / g to 4500 m 2 / g, and if the average pore diameter is greater than 15 nm, 100 m 2 / g to 2500 m 2 It is / g. BET specific surface area, pore diameter, pore capacity, and average pore diameter can be obtained, for example, using the nitrogen adsorption method.

[0062] An electronically conductive material according to one embodiment may include, for example, carbon. Carbon may be any material containing carbon atoms, for example, used as a conductive material in the art. Carbon may be, for example, crystalline carbon, amorphous carbon, or a combination thereof. Carbon may be, for example, a calcined product of a carbon precursor. Carbon may be, for example, a carbon nanostructure. The carbon nanostructure may be, for example, a one-dimensional carbon nanostructure, a two-dimensional carbon nanostructure, a three-dimensional carbon nanostructure, or a combination thereof. The carbon nanostructure may be, for example, a carbon nanotube (CNT), a carbon nanofiber (CNF), a carbon nanobelt, a carbon nanorod, graphene, graphene oxide (GO), reduced graphene oxide (rGO), a graphene ball (GB), or a combination thereof. Carbon may be, for example, porous carbon or non-porous carbon. Porous carbon may include, for example, periodic and regular two-dimensional or three-dimensional pores. Porous carbon may be, for example, carbon black such as Ketjen black, acetylene black, Denka black, thermal black, Channel black; graphite, activated carbon, or a combination thereof. The form of carbon may be, for example, particle form, sheet form, flake form, etc., but is not limited thereto, and any form used as carbon in the relevant technical field is possible. The method of manufacturing a composite of Li2S or a Li2S-containing composite and carbon may be a dry method, a wet method, or a combination thereof, but is not limited thereto, and the method of manufacturing a composite of Li2S, a Li2S-containing composite and carbon in the relevant technical field may be, for example, milling, heat treatment, deposition, etc., but is not necessarily limited thereto, and any method used in the relevant technical field is possible. According to one embodiment, a Li2S-containing composite containing carbon may include, for example, Li2S-CNT, Li2S-CNF, or a combination thereof.

[0063] A Li2S-containing composite according to one embodiment may include a composite of Li2S, an ion-conducting material, and an electronically conductive material. According to one embodiment, a Li2S-containing composite comprising a composite of Li2S, an ion-conducting material, and an electron-conducting material is, for example, Li2S-LiF-CNT, Li2S-LiCl-CNT, Li2S-LiBr-CNT, Li2S-LiI-CNT, Li2S-LiF-CNF, Li2S-LiCl-CNF, Li2S-LiBr-CNF, Li2S-LiI-CNF, Li2S-LiF-AlF3-CNT, Li2S-LiF-AlCl3-CNT, Li2S-LiF-AlBr3-CNT, Li2S-LiF-AlI3-CNT, Li2S-LiF-GaF3-CNT, Li2S-LiF-GaCl3-CNT, Li2S-LiF-GaBr3-CNT, Li2S-LiF-GaI3-CNT, Li2S-LiF-InF3-CNT, Li2S-LiF-InCl3-CNT, Li2S-LiF-InBr3-CNT, Li2S-LiF-InI3-CNT, Li2S-LiF-TlF3-CNT, Li2S-LiF-TlCl3-CNT, Li2S-LiF-TlBr3-CNT, Li2S-LiF-TlI3-CNT, Li2S-LiCl-AlF3-CNT, Li2S-LiCl-AlCl3-CNT, Li2S-LiCl-AlBr3-CNT, Li2S-LiCl-AlI3-CNT, Li2S-LiCl-GaF3-CNT, Li2S-LiCl-GaCl3-CNT, Li2S-LiCl-GaBr3-CNT, Li2S-LiCl-GaI3-CNT, Li2S-LiCl-InF3-CNT, Li2S-LiCl-InCl3-CNT, Li2S-LiCl-InBr3-CNT, Li2S-LiCl-InI3-CNT, Li2S-LiCl-TlF3-CNT, Li2S-LiCl-TlCl3-CNT, Li2S-LiCl-TlBr3-CNT, Li2S-LiCl-TlI3-CNT, Li2S-LiBr-AlF3-CNT, Li2S-LiBr-AlCl3-CNT, Li2S-LiBr-AlBr3-CNT, Li2S-LiBr-AlI3-CNT, Li2S-LiBr-GaF3-CNT,Li2S-LiBr-GaCl3-CNT, Li2S-LiBr-GaBr3-CNT, Li2S-LiBr-GaI3-CNT, Li2S-LiBr-InF3-CNT, Li2S-LiBr-InCl3-CNT, Li2S-LiBr-InBr3-CNT, Li2S-LiBr-InI3-CNT, Li2S-LiBr-TlF3-CNT, Li2S-LiBr-TlCl3-CNT, Li2S-LiBr-TlBr3-CNT, Li2S-LiBr-TlI3-CNT, Li2S-LiI-AlF3-CNT, Li2S-LiI-AlCl3-CNT, Li2S-LiI-AlBr3-CNT, Li2S-LiI-AlI3-CNT, Li2S-LiI-GaF3-CNT, Li2S-LiI-GaCl3-CNT, Li2S-LiI-GaBr3-CNT, Li2S-LiI-GaI3-CNT, Li2S-LiI-InF3-CNT, Li2S-LiI-InCl3-CNT, Li2S-LiI-InBr3-CNT, Li2S-LiI-InI3-CNT, Li2S-LiI-TlF3-CNT, Li2S-LiI-TlCl3-CNT, Li2S-LiI-TlBr3-CNT, Li2S-LiI-TlI3-CNT, Li2S-LiF-AlF3-CNF, Li2S-LiF-AlCl3-CNF, Li2S-LiF-AlBr3-CNF, Li2S-LiF-AlI3-CNF, Li2S-LiF-GaF3-CNF, Li2S-LiF-GaCl3-CNF, Li2S-LiF-GaBr3-CNF, Li2S-LiF-GaI3-CNF, Li2S-LiF-InF3-CNF, Li2S-LiF-InCl3-CNF, Li2S-LiF-InBr3-CNF, Li2S-LiF-InI3-CNF, Li2S-LiF-TlF3-CNF, Li2S-LiF-TlCl3-CNF, Li2S-LiF-TlBr3-CNF, Li2S-LiF-TlI3-CNF, Li2S-LiCl-AlF3-CNF, Li2S-LiCl-AlCl3-CNF, Li2S-LiCl-AlBr3-CNF, Li2S-LiCl-AlI3-CNF, Li2S-LiCl-GaF3-CNF, Li2S-LiCl-GaCl3-CNF, Li2S-LiCl-GaBr3-CNF,Li2S-LiCl-GaI3-CNF, Li2S-LiCl-InF3-CNF, Li2S-LiCl-InCl3-CNF, Li2S-LiCl-InBr3-CNF, Li2S-LiCl-InI3-CNF, Li2S-LiCl-TlF3-CNF, Li2S-LiCl-TlCl3-CNF, Li2S-LiCl-TlBr3-CNF, Li2S-LiCl-TlI3-CNF, Li2S-LiBr-AlF3-CNF, Li2S-LiBr-AlCl3-CNF, Li2S-LiBr-AlBr3-CNF, Li2S-LiBr-AlI3-CNF, Li2S-LiBr-GaF3-CNF, Li2S-LiBr-GaCl3-CNF, Li2S-LiBr-GaBr3-CNF, Li2S-LiBr-GaI3-CNF, Li2S-LiBr-InF3-CNF, Li2S-LiBr-InCl3-CNF, Li2S-LiBr-InBr3-CNF, Li2S-LiBr-InI3-CNF, Li2S-LiBr-TlF3-CNF, Li2S-LiBr-TlCl3-CNF, Li2S-LiBr-TlBr3-CNF, Li2S-LiBr-TlI3-CNF, Li2S-LiI-AlF3-CNF, Li2S-LiI-AlCl3-CNF, Li2S-LiI-AlBr3-CNF, Li2S-LiI-AlI3-CNF, Li2S-LiI-GaF3-CNF, Li2S-LiI-GaCl3-CNF, Li2S-LiI-GaBr3-CNF, Li2S-LiI-GaI3-CNF, Li2S-LiI-InF3-CNF, It may include Li2S-LiI-InCl3-CNF, Li2S-LiI-InBr3-CNF, Li2S-LiI-InI3-CNF, Li2S-LiI-TlF3-CNF, Li2S-LiI-TlCl3-CNF, Li2S-LiI-TlBr3-CNF, Li2S-LiI-TlI3-CNF, or a combination thereof.

[0064] The content of the positive active material in the positive active material composition may be 50 to 95 wt%, 50 to 90 wt%, 50 to 80 wt%, or 60 to 80 wt% of the total weight of the positive active material composition.

[0065] The solid electrolyte may include, for example, a sulfide-based solid electrolyte, an oxide-based solid electrolyte, a polymeric solid electrolyte, or a combination thereof. The solid electrolyte included in the positive electrode active material layer (AE) may include components that are the same as or different from the solid electrolyte included in the first solid electrolyte layer (SE1). Since the details regarding the solid electrolyte can be applied as described above for the first solid electrolyte layer (SE1), a detailed explanation is omitted.

[0066] The content of the solid electrolyte in the positive electrode active material composition may be 5 to 50 wt%, 10 to 50 wt%, 20 to 50 wt%, or 20 to 40 wt% of the total weight of the positive electrode active material composition.

[0067] The cathode active material composition may further include a conductive material. The conductive material may be, for example, a carbon-based conductive material, a metal-based conductive material, or a combination thereof. The carbon-based conductive material may be, for example, graphite, carbon black, acetylene black, Ketjen black, carbon fiber, or a combination thereof, but is not limited thereto, and any material used as a carbon-based conductive material in the relevant technical field is acceptable. The metal-based conductive material may be metal powder, metal fiber, or a combination thereof, but is not limited thereto, and any material used as a metal-based conductive material in the relevant technical field is acceptable. In one embodiment, the conductive material may be omitted.

[0068] The content of the conductive material in the positive electrode active material composition may be 1 to 30 wt%, 1 to 20 wt%, or 1 to 10 wt% of the total weight of the positive electrode active material composition.

[0069] The cathode active material composition may further include a binder. The binder may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, etc., but is not necessarily limited to these, and any binder used in the relevant technical field may be used. The binder may be composed of a single binder or a plurality of different binders.

[0070] The content of the binder in the positive active material composition may be 1 to 30 wt%, 1 to 20 wt%, or 1 to 10 wt% of the total weight of the positive active material composition.

[0071] Referring to FIG. 1, in the process of forming a positive active material layer (CE) according to one embodiment, the positive active material composition is partially applied at regular intervals to the second surface of a current collector (COL). In one embodiment, the positive active material layer (CE) can be formed by applying the positive active material composition containing a solvent to the current collector and drying it. As a coating method, a masking coating method may be applied, but is not limited thereto; any method used as a wet coating method in the relevant technical field is possible. In another embodiment, the positive active material layer (CE) can be formed by applying a coating layer composition in powder form that does not contain a solvent by quantitatively spraying it at a specific location on the current collector and through a heat treatment and / or pressurization process. As a coating method, a powder compression method, an electrostatic coating method, etc., may be applied, but is not limited thereto; any method used as a dry coating method in the relevant technical field is possible.

[0072] The thickness of the positive active material layer (CE) may be, for example, 1 μm to 500 μm, 1 μm to 300 μm, 1 μm to 200 μm, or 100 μm to 200 μm. If the thickness of the positive active material layer (CE) exceeds the above range, the ionic conductivity of the positive active material layer (CE) may decrease, and if it is less than the above range, the energy density of the bipolar all-solid-state battery may decrease.

[0073] Referring to FIG. 1, a second solid electrolyte layer (SE2) is formed on each of the plurality of positive active material layers (CE) to form a bipolar all-solid electrode. The process of forming the second solid electrolyte layer (SE2) can be carried out as a wet process and / or a dry process. In the process of forming the second solid electrolyte layer (SE2) according to one embodiment, a second solid electrolyte layer composition is prepared. The second solid electrolyte layer composition can be prepared by mixing a solid electrolyte, a binder, an additive, and a solvent. In one embodiment, the process can be carried out as a dry process without mixing a solvent. The composition of the second solid electrolyte layer composition may be the same as or different from that of the first solid electrolyte layer composition. Since the details regarding the solid electrolyte, binder, additive, and solvent included in the second solid electrolyte layer composition can be applied as is to the solid electrolyte, binder, additive, and solvent included in the first solid electrolyte layer composition described above, a detailed description below will be omitted.

[0074] The thickness of the second solid electrolyte layer (SE2) may be, for example, 1 μm to 200 μm, 1 μm to 100 μm, 1 μm to 50 μm, or 10 μm to 50 μm. If the thickness of the second solid electrolyte layer (SE2) exceeds the above range, the energy density of the bipolar all-solid-state battery may decrease, and if it is less than the above range, there may be a risk of short circuit.

[0075] Referring to FIG. 1, a plurality of unit electrode assemblies (UEA1, UEA2, UEA3…) are formed by punching a second surface of a current collector (COL) in a bipolar all-solid-state electrode such that a cut portion is positioned between adjacent ones of the plurality of positive active material layers (AE) and / or second solid electrolyte layers (SE2). The punching method may be, for example, mechanical punching, ultrasonic punching, laser punching, etc., but is not necessarily limited to these methods; any method used for punching electrodes in the relevant technical field is possible.

[0076] Referring to FIGS. 1 and 2, a bipolar all-solid-state battery is manufactured by stacking the plurality of unit electrode assemblies (UEA1, UEA2, UEA3…) so that the first solid electrolyte layer (SE1) and the second solid electrolyte layer (SE2) are in contact with each other.

[0077] Referring to FIG. 2, a bipolar all-solid-state battery according to an embodiment includes a bipolar all-solid-state electrode in which a positive active material layer (CE) and a coating layer (AE) are formed on both sides of a current collector (COL). A bipolar all-solid-state battery formed by sequentially stacking a plurality of bipolar all-solid-state electrodes is connected in series without connectors between the plurality of unit electrode assemblies, thereby simplifying the structure and enabling voltage superposition. That is, it is easy to implement a high-voltage cell, high output power is achieved through high voltage, and resistance can be reduced by shortening the electron transport path between the positive and negative electrodes. The coating layer (AE) functions as an electrodeposition inducing layer that induces the deposition of a lithium metal layer on the current collector (COL). The bipolar all-solid-state battery according to this embodiment does not include a negative active material layer, and by including the coating layer (AE) as an electrodeposition inducing layer, the lithium metal layer formed on the current collector functions similarly to a negative electrode, and can be included in the category of a lithium metal battery. The theoretical electric capacity of lithium metal is approximately 3,860 mAh / g, which is larger than that of graphite. The coating layer (AE) can suppress the formation of dendrites on the surface of the lithium metal. Consequently, a bipolar all-solid-state battery comprising the coating layer (AE) manufactured according to the present embodiment has a high energy density and can suppress dendrite formation.

[0078] A method for manufacturing a bipolar all-solid-state battery according to one embodiment of the present disclosure can improve processability by manufacturing a plurality of bipolar all-solid-state electrodes in a batch and stacking them to manufacture a battery, while simultaneously enabling large-area, standardized, and mass production of the battery. In addition, it is possible to manufacture a bipolar all-solid-state battery capable of effectively preventing short circuits in the battery caused by contact between the positive and negative electrodes.

[0079] Referring to FIGS. 1 and 2, a negative electrode assembly (AEA) may be disposed on the uppermost part of a bipolar all-solid-state battery. Referring to FIGS. 1 and 2, the negative electrode assembly (AEA) may include a current collector (COL); a coating layer (AE) on the current collector (COL); and a first solid electrolyte layer (SE1) on the coating layer. Since the above descriptions regarding the current collector (COL), the coating layer (AE), and the first solid electrolyte layer (SE1) can be applied as is, a detailed description thereof will be omitted below. Referring to FIGS. 1 and 2, the second solid electrolyte layer (SE2) of the unit electrode assembly (UEA1, UEA2, UEA3…) and the first solid electrolyte layer (SE1) of the negative electrode assembly (AEA) may be disposed to be in contact with each other. Consequently, a current collector (COL) may be disposed on the uppermost part of the bipolar all-solid-state battery.

[0080] Referring to FIGS. 1 and 2, a positive electrode assembly (CEA) may be disposed in the lowest layer of a bipolar all-solid-state battery. Referring to FIGS. 1 and 2, the positive electrode assembly (CEA) may include a current collector (COL); a positive electrode active material layer (CE) on the current collector (COL); and a second solid electrolyte layer (SE2) on the positive electrode active material layer. Since the above descriptions regarding the current collector (COL), the positive electrode active material layer (CE), and the second solid electrolyte layer (SE2) can be applied as is, a detailed description thereof will be omitted below. Referring to FIGS. 1 and 2, the first solid electrolyte layer (SE1) of the unit electrode assembly (UEA1, UEA2, UEA3…) and the second solid electrolyte layer (SE2) of the positive electrode assembly (CEA) may be disposed to be in contact with each other. Consequently, a current collector (COL) may be disposed in the lowest layer of the bipolar all-solid-state battery.

[0081] Referring to FIGS. 2 and 3, the area of ​​the positive active material layer (CE) in the positive assembly (CEA) is smaller than the area where the positive active material layer (CE) contacts the current collector (COL). The area of ​​the second solid electrolyte layer (SE2) in the positive assembly (CEA) is smaller than the area where the positive active material layer (CE) contacts the current collector (COL). The area of ​​the positive active material layer (CE) and the area of ​​the second solid electrolyte layer (SE2) in the positive assembly (CEA) are substantially the same. The above-described details regarding the areas of the positive active material layer (CE) and the second solid electrolyte layer (SE2) in the positive assembly (CEA) can be applied as is to the unit electrode assembly (UEA).

[0082] Referring to FIG. 4 and FIG. 7, a method for manufacturing a bipolar all-solid-state battery according to another embodiment of the present disclosure may further include forming an inert member (IAM) on one side of a positive active material layer (CE) and a second solid electrolyte layer (SE2). The inert member may be, for example, a flame-retardant inert member. The flame-retardant inert member may include, for example, a matrix and a filler. The matrix may include, for example, a substrate and a reinforcing material. The matrix may include, for example, a fibrous substrate and a fibrous reinforcing material. By including a substrate, the matrix may have elasticity. Thus, the matrix can effectively accommodate volume changes during charging and discharging of the bipolar all-solid-state battery. The fibrous substrate may include, for example, pulp fibers, insulating polymer fibers, ion-conducting polymer fibers, or a combination thereof. The filler is, for example, an inorganic material. The filler included in the flame-retardant inert member may be, for example, a moisture adsorbent. The filler may be, for example, a metal hydroxide having moisture adsorption properties. The metal hydroxide contained in the filler may include, for example, Mg(OH)2, Fe(OH)3, Sb(OH)3, Sn(OH)4, TI(OH)3, Zr(OH)4, Al(OH)3, or a combination thereof.

[0083] Referring to FIG. 4, an inert member (IAM) is formed on a current collector (COL). The thickness of the inert member (IAM) formed on the current collector (COL) can be formed to be substantially the same as the thickness from the second surface of the current collector (COL) to the end portion of the second solid electrolyte layer (SE2). By including the inert member (IAM) in the bipolar all-solid-state battery, damage to the first solid electrolyte layer (SE1) and the current collector (COL) caused by the pressure difference during the pressing process in the current collector (COL) and the first solid electrolyte layer (SE1) that do not come into contact with the positive active material layer (CE) and the second solid electrolyte layer (SE2) can be effectively suppressed.

[0084] Referring to FIG. 5 and FIG. 7, a method for manufacturing a bipolar all-solid-state battery according to another embodiment of the present disclosure may further include cutting a bipolar all-solid-state electrode in a substantially horizontal direction. According to one embodiment, the method for manufacturing a bipolar all-solid-state battery may have a cutting surface having a third thickness (d3) in a first direction (D1) from a current collector. According to one embodiment, the thickness (d1) on which an inert member (IAM) is formed on a current collector (COL) may be greater than the thickness (d2) from a second surface of the current collector (COL) to the end portion of a second solid electrolyte layer (SE2). In this specification, the 'end portion of the second solid electrolyte layer (SE2)' is defined as the portion of a plurality of second solid electrolyte layers (SE2) that is the longest from the current collector. According to one embodiment, the third thickness (d3) may be smaller than the thickness (d2) from the second surface of the current collector (COL) to the end portion of the second solid electrolyte layer (SE2). By further including the method of manufacturing the bipolar all-solid-state battery in the horizontal direction cutting the bipolar all-solid-state electrode, it may be relatively easy to flatten the thickness of the second solid electrolyte layer (SE2) and the inert member (IAM).

[0085] Although exemplary embodiments have been described in detail with reference to the attached drawings, the present creative idea is not limited to such examples. It is obvious that a person skilled in the art to which the present creative idea belongs can derive various variations or modifications within the scope of the technical idea described in the patent claims, and these also naturally fall within the technical scope of the present creative idea.

Claims

1. A current collector having a first surface and a second surface opposite to the first surface: Forming a coating layer on the front surface of the first surface; Forming a first solid electrolyte layer on the above coating layer; Forming a plurality of positive active material layers spaced apart at regular intervals on the second surface; Forming a bipolar all-solid electrode by forming a second solid electrolyte layer on each of the aforementioned plurality of positive active material layers; Forming a plurality of unit electrode assemblies by punching on the second surface such that a cut portion is positioned between adjacent of the plurality of positive active material layers; and Stacking the plurality of unit electrode assemblies so that the first solid electrolyte layer and the second solid electrolyte layer are in contact with each other; A method for manufacturing a bipolar all-solid-state battery comprising 2. In Paragraph 1, A method for manufacturing a bipolar all-solid-state battery, wherein the uppermost part of the above bipolar all-solid-state battery has a negative electrode assembly disposed thereon.

3. In Paragraph 1, A method for manufacturing a bipolar all-solid-state battery, wherein the bottom layer of the above-mentioned bipolar all-solid-state battery has a positive electrode assembly disposed therein.

4. In Paragraph 1, A method for manufacturing a bipolar all-solid-state battery, further comprising forming an inert member on one side of the positive active material layer and the second solid electrolyte layer.

5. In Paragraph 4, A method for manufacturing a bipolar all-solid-state battery, wherein the thickness of the inert member formed on the current collector is substantially the same as the thickness from the second surface to the end portion of the second solid electrolyte layer.

6. In Paragraph 4, A method for manufacturing a bipolar all-solid-state battery, wherein the thickness of the inert member formed from the second surface is greater than the thickness from the second surface to the end portion of the second solid electrolyte layer.

7. In Paragraph 4, A method for manufacturing a bipolar all-solid-state battery, further comprising cutting the above-mentioned bipolar all-solid-state electrode in a horizontal direction.

8. In Paragraph 6, A method for manufacturing a bipolar all-solid-state battery, wherein the above-mentioned bipolar all-solid-state electrode has a cutting surface having a certain thickness in a first direction from the second surface.

9. In Paragraph 1, A method for manufacturing a bipolar all-solid-state battery, wherein the positive active material layer comprises a lithium-containing sulfide-based positive active material.

10. In Paragraph 9, A method for manufacturing a bipolar all-solid-state battery, wherein the above lithium-containing sulfide-based cathode active material comprises a Li2S-containing composite.

11. In Paragraph 10, A method for manufacturing a bipolar all-solid-state battery, wherein the above Li2S-containing composite comprises an ion-conducting material comprising a metal salt compound and an electron-conducting material comprising carbon.

12. In Paragraph 11, A method for manufacturing a bipolar all-solid-state battery, wherein the above-mentioned ion-conducting material comprises a lithium salt compound.

13. In Paragraph 12, A method for manufacturing a bipolar all-solid-state battery, wherein the above ion-conducting material further comprises a boron group metal halide salt.

14. In Paragraph 10, The above Li2S-containing composite is a bipolar all-solid body comprising Li2S-LiI-AlF3-CNF, Li2S-LiI-AlCl3-CNF, Li2S-LiI-AlBr3-CNF, Li2S-LiI-AlI3-CNF, Li2S-LiI-GaF3-CNF, Li2S-LiI-GaCl3-CNF, Li2S-LiI-GaBr3-CNF, Li2S-LiI-GaI3-CNF, Li2S-LiI-InF3-CNF, Li2S-LiI-InCl3-CNF, Li2S-LiI-InBr3-CNF, Li2S-LiI-InI3-CNF, Li2S-LiI-TlF3-CNF, Li2S-LiI-TlCl3-CNF, Li2S-LiI-TlBr3-CNF, Li2S-LiI-TlI3-CNF, or a combination thereof. Method for manufacturing a battery.

15. In Paragraph 1, A method for manufacturing a bipolar all-solid-state battery, wherein the coating layer comprises metal particles and a carbon-based material.

16. In Paragraph 1, A method for manufacturing a bipolar all-solid-state battery, wherein forming the positive electrode active material layer comprises a dry process.

17. In Paragraph 1, The thickness of the first solid electrolyte layer is 1 μm to 200 μm, and A method for manufacturing a bipolar all-solid-state battery, wherein the thickness of the second solid electrolyte layer is 1 μm to 200 μm.

18. In Paragraph 1, A method for manufacturing a bipolar all-solid-state battery in which the composition of the first solid electrolyte layer and the composition of the second solid electrolyte layer are the same or different from each other.

19. In Paragraph 1, The first solid electrolyte layer and the second solid electrolyte layer comprise a sulfide-based solid electrolyte, The above sulfide-based solid electrolyte is Li3PO4-Li2SO4, Li2S-P2S5, Li2S-P2S5-LiX (where X is a halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n (In the above formula, m and n are positive numbers, and Z is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (In the above formula, p and q are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, and In), Li + 12-n-x A n+ X 2- 6-x Y - x (In the above formula, A is one of P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, or Ta, X is one of S, Se, or Te, Y is Cl, Br, I, F, CN, OCN, SCN, or N3, and 1≤n≤5, 0≤x≤2) Li 7-m M m PS 6-n X n (In the above formula, M is one of Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, Sc, Y, Ti, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Mn, Tc, Re, Bh, Ru, Os, Hs, Co, Rh, Ir, Mt, Ni, Pd, Pt, Ds, Au, Rg, Cd, Hg, or Cn, X is one of F, Cl, Br, or I, 0 <n≤2, 0<x≤2), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), Li 7-x PS 6-x I x A method for manufacturing a bipolar all-solid-state battery comprising (0≤x≤2) or a combination thereof.

20. Anode assembly; cathode assembly; and At least one unit electrode assembly interposed between the anode assembly and the cathode assembly, manufactured by the manufacturing method according to claim 1; A bipolar all-solid-state battery including

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