All-solid-state battery and method for producing same

Abstract

The present invention relates to an all-solid-state battery and a method for producing same and, more specifically, to an all-solid-state battery comprising: a positive electrode layer including a positive electrode current collector and a positive electrode active material layer; a negative electrode layer including a negative electrode current collector and a negative electrode coating layer; a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer; and a positive electrode insulating film on one side surface of the positive electrode active material layer, wherein the positive electrode current collector includes an active portion and a tab portion, the tab portion includes an edge region adjacent to the active portion and an uncoated region extending from the edge region, the positive electrode insulating film includes: an adhesive layer in direct contact with the one side surface of the positive electrode active material layer; and an insulating layer on the adhesive layer, and the positive electrode insulating film may extend from a positive electrode protrusion of the positive electrode active material layer to the uncoated region.

Description

All-solid-state battery and method for manufacturing the same

[0001] The present invention relates to an all-solid-state battery.

[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] Recently, all-solid-state batteries have been proposed in which the liquid electrolyte of lithium-ion batteries is replaced with a solid electrolyte. By not using flammable organic dispersion media, all-solid-state batteries can significantly reduce the likelihood of fire or explosion in the event of a short circuit. Therefore, such all-solid-state batteries can possess excellent safety.

[0004] The problem that the present invention aims to solve is to provide an all-solid-state battery with excellent battery capacity, battery life, and stability.

[0005] Another problem that the present invention aims to solve is to provide a method for manufacturing an all-solid-state battery with excellent battery capacity, battery life, and stability.

[0006] A solid-state battery according to the concept of the present invention comprises: a positive electrode layer including a positive current collector and a positive active material layer; a negative electrode layer including a negative current collector and a negative coating layer; a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer; and a positive insulating film on one side of the positive active material layer, wherein the positive current collector includes an active portion and a tab portion, and the tab portion includes an edge region adjacent to the active portion and a non-existent region extending from the edge region, and the positive insulating film includes: an adhesive layer in direct contact with the one side of the positive active material layer; and an insulating layer on the adhesive layer, and the positive insulating film may extend from the positive protrusion of the positive active material layer onto the non-existent region.

[0007] A solid-state battery according to another concept of the present invention comprises: a first monocell; and a second monocell on the first monocell, wherein the second monocell is arranged vertically symmetrically with respect to the first monocell, and each of the first and second monocells comprises a positive layer including a positive current collector and a positive active material layer, a negative layer, a solid electrolyte layer disposed between the positive layer and the negative layer, and a positive insulating film on one side of the positive layer, wherein the positive insulating film is disposed extending from one side of the positive active material layer onto a non-positive region of the positive current collector, and the solid electrolyte layer comprises a first solid electrolyte layer adjacent to the positive layer and a second solid electrolyte layer adjacent to the negative layer, wherein the positive layer of the first monocell and the positive layer of the second monocell face each other, and the positive insulating film of the first monocell and the positive insulating film of the second monocell may face each other.

[0008] A method for manufacturing an all-solid-state battery according to another concept of the present invention comprises: stacking a positive electrode layer and a first solid electrolyte layer and then applying a first pressure to form a positive electrode stack; stacking a negative electrode layer and a second solid electrolyte layer and then applying a second pressure to form a negative electrode stack; transferring a positive electrode insulating film onto one side of the positive electrode stack; and bonding the first solid electrolyte layer and the second solid electrolyte layer to combine the positive electrode stack and the negative electrode stack, wherein transferring the positive electrode insulating film may include sequentially stacking an adhesive layer, an insulating layer, and an adhesive substrate layer on the positive electrode stack and removing the adhesive substrate layer.

[0009] An all-solid-state battery according to embodiments of the present invention may include an anode insulating film that protects one side of the anode active material layer. The anode insulating film can prevent the occurrence of physical defects that cause short circuits during the charging and discharging of the all-solid-state battery, thereby improving the stability of the all-solid-state battery.

[0010] An all-solid-state battery according to embodiments of the present invention may include a fixing layer that fixes the aforementioned positive insulating film and inert member. The fixing layer can prevent a short circuit of the all-solid-state battery together with the inert member. In addition, by including the fixing layer, uniform pressure can be applied during the cell pressurization step, thereby preventing the detachment or detachment of components of the all-solid-state battery. This can improve the battery capacity, battery life, and stability of the all-solid-state battery.

[0011] FIG. 1 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention.

[0012] FIG. 2 is a plan view of an all-solid-state battery according to one embodiment of the present invention.

[0013] FIG. 3 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0014] FIG. 4 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0015] FIG. 5 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0016] FIG. 6 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0017] FIG. 7a is a plan view illustrating an all-solid-state battery including an anode layer and a solid electrolyte layer according to another embodiment of the present invention, and FIG. 7b is a cross-sectional view along line I-I' of FIG. 7a.

[0018] Figures 8a and 8b are enlarged views showing the M region of Figure 7b.

[0019] FIG. 9 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0020] Figure 10 is an enlarged view showing the N region of Figure 9.

[0021] FIGS. 11 and FIGS. 12 are cross-sectional views of an all-solid-state battery according to other embodiments of the present invention.

[0022] FIGS. 13a to 13d, FIGS. 14a to 14c and FIG. 15 are conceptual diagrams for explaining a method for manufacturing an all-solid-state battery according to an embodiment of the present invention.

[0023] FIG. 16 is a conceptual diagram illustrating a method for manufacturing an all-solid-state battery according to another embodiment of the present invention.

[0024]

[0025] In order to fully understand the structure and effects of the present invention, preferred embodiments of the present invention are described with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and various modifications can be made. The description of these embodiments is provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention.

[0026] In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Additionally, in the drawings, the thicknesses of the components are exaggerated for the effective description of the technical content. Throughout the specification, parts indicated by the same reference numeral represent the same components.

[0027] The embodiments described herein will be described with reference to cross-sectional and / or plan views, which are exemplary illustrations of the invention. In the drawings, the thicknesses of films and regions are exaggerated for effective description of the technical content. Accordingly, the regions illustrated in the drawings are schematic in nature, and the shapes of the regions illustrated in the drawings are intended to illustrate specific forms of regions of the device and are not intended to limit the scope of the invention. Although terms such as first, second, third, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. The embodiments described and illustrated herein also include their complementary embodiments.

[0028] Unless otherwise specified in this specification, the singular form may also include the plural. Additionally, unless otherwise specified, "A or B" may mean "comprising A, comprising B, or comprising A and B." As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components to the mentioned components.

[0029] In this specification, "combination of these" may mean a mixture of components, a laminate, a composite, a copolymer, an alloy, a blend, and a reaction product, etc.

[0030] Unless otherwise defined in this specification, the particle size may be the average particle size. Additionally, the particle size refers to the average particle size (D50), which means the diameter of the particle whose cumulative volume in the particle size distribution is 50% by volume. The average particle size (D50) may be measured by methods widely known to those skilled in the art, for example, by measuring with a particle size analyzer, or by measuring with a transmission electron microscope (TEM) image or a scanning electron microscope (SEM) image. Alternatively, the average particle size (D50) value may be obtained by measuring using a measuring device utilizing dynamic light-scattering, performing data analysis to count the number of particles for each particle size range, and then calculating from this. Alternatively, it may be measured using a laser diffraction method. When measuring by laser diffraction, more specifically, after dispersing the particles to be measured in a dispersion medium, they are introduced into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000) and irradiated with ultrasound of about 28 kHz at an output of 60 W, and then the average particle size (D50) at 50% of the particle size distribution in the measuring device can be calculated.

[0031]

[0032] FIG. 1 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention. FIG. 2 is a plan view of an all-solid-state battery according to one embodiment of the present invention.

[0033] Referring to FIG. 1, an all-solid-state battery (10) according to one embodiment may include a positive electrode layer (100), a negative electrode layer (200) facing the positive electrode layer (100), and a solid electrolyte layer (300) disposed between the positive electrode layer (100) and the negative electrode layer (200). However, not limited thereto, the all-solid-state battery (10) may further include an additional functional layer, such as an adhesion-enhancing layer, disposed between the positive electrode layer (100) and the solid electrolyte layer (300) or between the negative electrode layer (200) and the solid electrolyte layer (300).

[0034] In one embodiment, the anode layer (100) may include an anode current collector (110) and an anode active material layer (120) disposed on the anode current collector (110). Although not illustrated, the anode active material layer (120) may include an anode active material, a solid electrolyte, a conductive material, and a binder.

[0035] The positive current collector (110) can provide a reference surface on which the positive active material layer (120) is placed. The positive current collector (110) may include, for example, a plate or foil comprising indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

[0036] Meanwhile, unlike as illustrated in FIG. 1, the positive current collector (110) may be omitted in one embodiment of the present invention. Although not illustrated, a carbon layer with a thickness of 0.1 μm to 4 μm may be further disposed between the positive current collector (110) and the positive active material layer (120) to increase the bonding strength between the positive current collector (110) and the positive active material layer (120).

[0037] The positive electrode active material may include a material capable of reversibly absorbing and desorbing lithium ions. The positive electrode active material may include a plurality of particles. The positive electrode active material may include, for example, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, but is not necessarily limited to these. Each positive electrode active material may be a single material or a mixture of two or more materials.

[0038] Lithium transition metal oxides are, for example, Li a A 1-b B b D2(0.90≤a≤1, 0≤b≤0.5), Li a E 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 Mn bB c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Nor 1-b-c Mn 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 Nor b E c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Nor b Co c Mn 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), Li a Mn2GbO4(0.90≤a≤1, 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3(0≤f≤2), Li 3-fIt is a compound represented by any one of Fe2(PO4)3 (0≤f≤2) or LiFePO4. In such compounds, the uppercase “ ” is Ni, Co, Mn, or a combination thereof; the uppercase “ ” is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; the uppercase “ ” is O, F, S, P, or a combination thereof; the uppercase “ ” is Co, Mn, or a combination thereof; the uppercase “ ” is F, S, P, or a combination thereof; the uppercase “ ” is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; the uppercase “ ” is Ti, Mo, Mn, or a combination thereof; the uppercase “ ” is Cr, V, Fe, Sc, Y, or a combination thereof; and the uppercase “ ” is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0039] The positive electrode active material may include, for example, a lithium salt of a transition metal oxide having a layered rock salt type structure among the lithium transition metal oxides described above. The "layered rock salt type structure" is, for example, a cubic rock salt type structure. <111> It is a structure in which oxygen and metal atomic layers are alternately and regularly arranged in a specific direction, thereby forming a two-dimensional plane for each atomic layer. The "cubic rock salt type structure" represents a sodium chloride (NaCl) type structure, which is a type of crystal structure; specifically, it exhibits a structure in which face-centered cubic lattices (fcc) formed by cations and anions, respectively, are offset from each other by half the ridge of the unit lattice. Lithium transition metal oxides having such a layered rock salt type structure are, for example, LiNi x Co y Al z O2(NCA) or LiNi x Co y Mn zO2(NCM) (0 <x<1,0<y<1, 0<z<1, x+y+z=1) 등의 삼원계 리튬전이금속산화물일 수 있다. 양극 활물질이 층상암염형 구조를 갖는 삼원계 리튬전이금속산화물을 포함하는 경우, 전고체 전지(10)의 에너지 밀도가 커지고 열안정성이 향상될 수 있다.

[0040] The aforementioned compound contained in the positive electrode active material may be covered by a coating layer (not shown). The positive electrode active material may also be a mixture of the aforementioned compound and the compound to which the coating layer is added. Meanwhile, the coating layer added to the surface of the positive electrode active material may include, for example, oxides, hydroxides, oxyhydroxides, oxycarbonates, or hydroxycarbonates of the following coating elements. The compounds forming this coating layer are amorphous or crystalline. The coating elements included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The coating layer may include, for example, Li2O-ZrO2 (LZO). The method for forming the coating layer is selected within a range that does not adversely affect the physical properties of the positive electrode active material. The method for forming the coating layer is, for example, spray coating or immersion.

[0041] When the positive electrode active material contains nickel (Ni) as a ternary lithium transition metal oxide such as NCA or NCM, for example, the capacity density of the all-solid-state battery (10) is increased, and the metal leaching of the positive electrode active material in the charged state can be reduced. As a result, the cycle characteristics of the all-solid-state battery (10) in the charged state are improved. Meanwhile, "cycle characteristics" is a characteristic that indicates the degree of deterioration of the all-solid-state battery (10) due to charging and discharging of the all-solid-state battery (10). An all-solid-state battery (10) with high cycle characteristics has a small degree of deterioration due to charging and discharging, while an all-solid-state battery (10) with low cycle characteristics may have a large degree of deterioration due to charging and discharging.

[0042] The positive active material may have a particle shape such as a sphere or an ellipsoid. The particle size and content of the positive active material are not particularly limited. In one embodiment, the positive active material is in the form of a polycrystalline structure and may include secondary particles formed by the aggregation of at least two primary particles. In other words, a single first particle may include a plurality of primary particles (NNP) aggregated together. The first particle may have a spherical or elliptical shape.

[0043] A solid electrolyte may be dispersed between the cathode active materials. The solid electrolyte dispersed between the cathode active materials may have a particulate form. The solid electrolyte dispersed between the cathode active materials may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. Sulfide-based solid electrolytes are, for example, 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, n are positive numbers, uppercase “ ” indicates one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are positive numbers, uppercase “” is one of P, Si, Ge, B, Al, Ga, In), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I xIt may include at least one selected from (0≤x≤2).

[0044] Sulfide-based solid electrolytes are, 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 It may be an argyrodite-type compound comprising one or more selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound comprising one or more selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I. The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. 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 defects such as penetration and short circuit of the solid electrolyte film due to lithium dendrite formation can be prevented. The elastic modulus of the solid electrolyte may be, for example, 15 GPa to 35 GPa.

[0045] The solid electrolyte in the positive active material layer (120) may have a smaller average particle size (D50) of intermediate particle size compared to the solid electrolyte in the solid electrolyte layer (300) described later. For example, the average particle size (D50) of the solid electrolyte included in the positive active material layer (120) may be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less of the average particle size (D50) of the solid electrolyte included in the solid electrolyte layer (300). Meanwhile, the average particle size (D50) may be a median diameter measured using a laser particle size distribution meter.

[0046] The positive active material layer (120) may include a conductive material. The conductive material may have conductivity without causing chemical changes in the all-solid-state battery (10), thereby increasing the conductivity of the positive active material and the solid electrolyte. The conductive material may include a carbon-based material. The conductive material may include, for example, one or more selected from graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0047] The positive active material layer (120) may further include a binder. The binder may bind the positive active material, solid electrolyte, and conductive material within the positive active material layer (120) together. The binder may include a material to improve the bonding strength between the positive active material layer (120) and the positive current collector (110). The binder may include, for example, polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, and polymethyl methacrylate.

[0048] Based on 100 parts by weight of the total positive active material, solid electrolyte, conductive material, and binder, the positive active material layer (120) may contain 85 parts by weight or more and 92 parts by weight or less of the positive active material. Based on 100 parts by weight of the total positive active material, solid electrolyte, conductive material, and binder, the positive active material layer (120) may contain 0.5 parts by weight or more and 1.5 parts by weight or less of the binder.

[0049] Based on 100 parts by weight of solid electrolyte within the positive active material layer (120), the positive active material layer (120) may contain 1 part by weight or more and 50 parts by weight or less of a conductive material. If the conductive material is included in the positive active material layer (120) in an amount less than 1 part by weight based on 100 parts by weight of solid electrolyte within the positive active material layer (120), the proportion of the conductive material decreases, and the electrical conductivity of the positive active material layer (120) may decrease. If the conductive material is included in the positive active material layer (120) in an amount exceeding 50 parts by weight based on 100 parts by weight of solid electrolyte within the positive active material layer (120), the proportion of the conductive material is excessively high, and a coating layer covering the surface of the solid electrolyte may not be properly formed.

[0050] The positive active material layer (120) may further include additives such as fillers, coating agents, dispersants, and ion conductivity aids in addition to the positive active material, solid electrolyte, conductive material, and binder described above.

[0051] The negative electrode layer (200) may include a negative electrode current collector (210) and a negative electrode coating layer (220) on the negative electrode current collector (210). The negative electrode current collector (210) may provide a reference surface on which the negative electrode coating layer (220) is placed. The negative electrode current collector (210) may include, for example, a material that does not react with lithium, that is, does not form any alloys or compounds with lithium. 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.

[0052] The negative current collector (210) may be composed of one of the metals described above, or may include an alloy of two or more metals or a coating material. The negative current collector (210) may, for example, have a plate-like or foil-like shape. Meanwhile, in one embodiment, the negative current collector (210) may be omitted.

[0053] The negative electrode coating layer (220) can allow lithium metal to grow between the all-solid-state battery (10) and the negative electrode current collector (210) during charging. The negative electrode coating layer (220) can serve as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites.

[0054] The cathode coating layer (220) may include metal and carbon. For example, the cathode coating layer (220) may include 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 cathode coating layer (220) may include at least one carbon selected from the group consisting of carbon black, acetylene black, furnace black, ketjen black, and graphene. In one embodiment, the cathode coating layer (220) may include a mixture of carbon black and silver (Ag).

[0055] The cathode coating layer (220) may further include other additives in addition to metal and carbon. The cathode coating layer (220) may further include at least one additive selected from the group consisting of, for example, binders, fillers, coating agents, dispersants, and ion-conducting aids.

[0056] The negative electrode coating layer (220) may have a smaller thickness compared to the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 1 µm to 20 µm, 2 µm to 10 µm, or 3 µm to 7 µm. If the thickness of the negative electrode coating layer (220) is excessively thin, lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210) may cause the negative electrode coating layer (220) to collapse, thereby degrading the cycle characteristics of the all-solid-state battery (10). If the thickness of the negative electrode coating layer (220) increases excessively, the energy density of the all-solid-state battery (10) decreases, and the internal resistance of the all-solid-state battery (10) due to the negative electrode coating layer (220) increases, which may degrade the cycle characteristics of the all-solid-state battery (10).

[0057] Meanwhile, although not illustrated, a carbon layer may be further included to improve adhesion between the cathode coating layer (220) and the solid electrolyte layer (300).

[0058] A solid electrolyte layer (300) may be provided between the anode layer (100) and the cathode layer (200). The solid electrolyte layer (300) may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. The solid electrolyte in the solid electrolyte layer (300) may be the same as or different from any one of the materials included in the solid electrolyte in the aforementioned anode active material layer (120).

[0059] The solid electrolyte layer (300) may include a first solid electrolyte layer (310) and a second solid electrolyte layer (320). The first solid electrolyte layer (310) may be adjacent to the anode layer (100), and the second solid electrolyte layer (320) may be adjacent to the cathode layer (200).

[0060] The second solid electrolyte layer (320) can be in direct contact with the negative electrode coating layer (220). By doing so, the second solid electrolyte layer (320) can suppress lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210). The second solid electrolyte layer (320) can effectively suppress negative side reactions. By doing so, the cell performance of the all-solid-state battery (10) according to the present invention can be improved.

[0061] The solid electrolyte in the solid electrolyte layer (300) may have particle shapes such as spheres or ellipsoids.

[0062] The solid electrolyte in the solid electrolyte layer (300) may include a sulfide-based solid electrolyte. The solid electrolyte in the solid electrolyte layer (300) may be amorphous, crystalline, or a mixture thereof. Additionally, the solid electrolyte may include sulfur (S), phosphorus (P), and lithium (Li) as at least constituent elements among the sulfide-based solid electrolyte materials described above, for example. For example, the solid electrolyte may be a material containing Li2S-P2S5. When using a sulfide-based solid electrolyte material containing Li2S-P2S5 to form the solid electrolyte, the molar ratio of Li2S and P2S5 is, for example, in the range of Li2S : P2S5 = 50 : 50 to 90 : 10.

[0063] In one embodiment, the solid electrolyte in the solid electrolyte layer (300) is Li 7-a M a PS 6-c X c It may be an argyrodite-type compound containing. Here, X may be Cl, Br, or a combination thereof. M may be Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, or a combination thereof. a and c may each be real numbers between 0 and 2.

[0064] The density of the azyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. By having a density of 1.5 g / cc or higher for the azyrodite-type solid electrolyte, the internal resistance of the all-solid-state battery is reduced, and defects such as penetration and short circuit of the solid electrolyte film due to lithium dendrite formation can be prevented. The elastic modulus of the solid electrolyte in the solid electrolyte layer (300) is, for example, 15 GPa to 35 GPa.

[0065] The solid electrolyte layer (300) may further include a binder. The binder included in the solid electrolyte layer (300) is, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited to these. The binder of the solid electrolyte layer (300) may be the same as or different from the binder included in the positive electrode active material layer (120) or the binder included in the negative electrode coating layer (220).

[0066] Referring again to FIG. 1, the first solid electrolyte layer (310) may have a first thickness (t1), and the second solid electrolyte layer (320) may have a second thickness (t2). The solid electrolyte layer (300) may have a third thickness (t3). The first thickness (t1) The second thickness (t2) may have different thicknesses. The second thickness (t2) may be larger than the first thickness (t1).

[0067] The thinner the thickness of the solid electrolyte layer (300), the higher the energy density, but on the other hand, it is difficult to suppress the formation of lithium dendrites in the negative electrode, so there is a possibility of a short circuit.

[0068] In solid electrolytes, voids can form at the interface between the electrode and the electrolyte, which act as interfacial resistance and can lead to battery performance degradation.

[0069] Interfacial resistance can be reduced by applying pressure to the electrode and the solid electrolyte layer together. In one embodiment, since the sulfide-based solid electrolyte has high ionic conductivity and is mechanically soft, an all-solid-state battery with improved interfacial resistance can be fabricated through pressure application.

[0070] In one embodiment of the present invention, the anode layer (120) and the cathode layer (220) may include a pressurization process in the manufacturing process. In one embodiment of the present invention, the pressurization process may be performed by applying different pressures to each of the anode layer (120) and the cathode layer (220). In one embodiment of the present invention, the anode layer (120) may be manufactured by applying a relatively higher pressure compared to the cathode layer (220). For example, applying nanoscale particles to the anode and cathode active materials can increase the contact area with the solid electrolyte and improve interfacial resistance. In one embodiment, the anode active material may be in a polycrystalline form for reasons such as improved adhesion to the electrode plate, capacity characteristics, and lifespan characteristics, and may include secondary particles formed by the aggregation of at least two primary particles. In this case, the interface resistance between the anode layer (120) and the first solid electrolyte layer (310) is observed to be greater than the interface resistance between the cathode layer (220) and the second solid electrolyte layer (320), so the anode laminate can be manufactured by applying a relatively higher pressure compared to the cathode laminate. However, this is not limited thereto, and the anode layer (120) and the cathode layer (220) can be manufactured through a pressurization process in which different pressures are applied to each for various reasons.

[0071] One embodiment of the present invention can solve process problems that may occur when the interfacial resistance between the anode layer (120) and the first solid electrolyte layer (310) is different from the interfacial resistance between the cathode layer (220) and the second solid electrolyte layer (320) by dividing the solid electrolyte (300) into a first solid electrolyte layer (310) and a second solid electrolyte layer (320). For example, an all-solid-state battery manufactured according to the all-solid-state battery manufacturing method described below can provide an all-solid-state battery manufactured by applying different pressures to the anode stack and the cathode stack, respectively.

[0072] One embodiment of the present invention divides the solid electrolyte layer (300) into a first solid electrolyte layer (310) and a second solid electrolyte layer (320) and adjusts the thickness of each differently, thereby increasing energy density while suppressing the formation of lithium dendrites in the negative electrode. This allows for the provision of an all-solid-state battery (10) with improved stability against short-circuit risk and shock and high energy density.

[0073] The ratio (t2 / t1) of the second thickness t2 to the first thickness t1 may be 1 to 20. Specifically, the ratio (t2 / t1) of the second thickness t2 to the first thickness t1 may be 2 to 15, 4 to 11, or 4.5 to 5.5. When the ratio (t2 / t1) of the second thickness t2 to the first thickness t1 is within the aforementioned numerical range, the formation of lithium dendrites in the negative electrode is suppressed while increasing energy density, thereby improving stability against short-circuit risk and shock, and providing an all-solid-state battery (10) with high energy density.

[0074] The first thickness (t1) may be 30 μm or less. Specifically, the first thickness (t1) may be 25 μm or less, 20 μm or less, 14 μm or less, or 10 μm or less. The first thickness (t1) may be 0.1 μm or more. Specifically, the first thickness (t1) may be 1 μm or more, 2 μm or more, 4 μm or more, or 5 μm or more. If the first thickness (t1) exceeds the numerical range mentioned above, the energy density of the all-solid-state battery (10) may decrease. If the first thickness (t1) does not fall within the numerical range mentioned above, the first thickness (t1) may not be sufficient to form an interface with respect to the diameter of the active material powder within the positive electrode.

[0075] The second thickness (t2) may be 30 μm or more. Specifically, it may be 35 μm or more, 40 μm or more, 45 μm or more, 50 μm or more, 55 μm or more, and 60 μm or more. The second thickness (t2) may be 120 μm or less. Specifically, the second thickness (t2) may be 90 μm or less and 60 μm or less. If the second thickness (t2) does not fall within the aforementioned numerical range, it may be difficult to suppress the formation of lithium dendrites within the negative electrode, and there may be a risk of a short circuit. If the second thickness (t2) exceeds the aforementioned numerical range, the energy density of the all-solid-state battery (10) may decrease.

[0076] The third thickness (t3) may be 120 μm or less. Specifically, the third thickness (t3) may be 90 μm or less and 60 μm or less. The third thickness (t3) may be 10 μm or more. Specifically, the third thickness (t3) may be 30 μm or more and 50 μm or more. If the third thickness (t3) exceeds the above numerical range, the energy density of the all-solid-state battery (10) may decrease.

[0077] Referring to FIGS. 1 and 2, the area of ​​the anode layer (100) and the area of ​​the cathode layer (200) may differ from each other. Specifically, the area of ​​the cathode layer (200) may be larger than the area of ​​the anode layer (100). The anode layer (100) may be completely superimposed within the cathode layer (200).

[0078] In one embodiment of the present invention, the first solid electrolyte layer (310) may have substantially the same area as the anode layer (100). The second solid electrolyte layer (320) may have substantially the same area as the cathode layer (200).

[0079] Referring to FIGS. 1 and 2, the first solid electrolyte layer (310) may have a first width (W1) in the first direction (D1). The second solid electrolyte layer (320) may have a second width (W2) in the first direction (D1). The first width (W1) may be smaller than the second width (W2).

[0080] The difference between the second width (W2) and the first width (W1) may be 10 mm or less. Specifically, the difference between the second width (W2) and the first width (W1) may be 8 mm or less, 5 mm or less, or 3 mm or less. The difference between the second width (W2) and the first width (W1) may be 0.1 mm or more, 0.5 mm or more, or 1 mm or more. If the above numerical range is exceeded, the size of the anode layer (100) becomes relatively smaller, so the discharge capacity is lowered and the energy density of the all-solid-state battery (10) may decrease. If the above numerical range is not met, it is difficult to suppress the formation of lithium dendrites in the negative electrode, and there may be a risk of a short circuit.

[0081] The ratio (W2 / W1) of the second width (W2) to the first width (W1) may be 1 to 1.6. Specifically, the ratio (W2 / W1) of the second width (W2) to the first width (W1) may be 1 to 1.5, 1 to 1.4, 1 to 1.3, 1 to 1.2, or 1 to 1.1.

[0082] If the ratio (W2 / W1) of the second width (W2) to the first width (W1) exceeds the numerical range, the energy density of the all-solid-state battery (10) is reduced.

[0083] Referring to FIGS. 1 and 2, the first solid electrolyte layer (310) may have a third width (W3) in the second direction (D2). The second solid electrolyte layer (320) may have a fourth width (W4) in the second direction (D2). The third width (W3) may be smaller than the fourth width (W4).

[0084] The difference between the third width (W3) and the fourth width (W4) may be 10 mm or less. Specifically, the difference between the third width (W3) and the fourth width (W4) may be 8 mm or less, 5 mm or less, or 3 mm or less. The difference between the fourth width (W4) and the third width (W3) may be 0.1 mm or more, 0.5 mm or more, or 1 mm or more. If the above numerical range is exceeded, the size of the anode layer (100) becomes relatively smaller, so the discharge capacity is lowered and the energy density of the all-solid-state battery (10) may decrease. If the above numerical range is not met, it is difficult to suppress the formation of lithium dendrites in the negative electrode, and there may be a risk of a short circuit.

[0085] The ratio (W4 / W3) of the fourth width (W4) to the third width (W3) may be 1 to 1.6. Specifically, the ratio (W4 / W3) of the fourth width (W4) to the third width (W3) may be 1 to 1.5, 1 to 1.4, 1 to 1.3, 1 to 1.2, or 1 to 1.1.

[0086] If the ratio (W4 / W3) of the fourth width (W4) to the third width (W3) exceeds the numerical range, the energy density of the all-solid-state battery (10) is reduced.

[0087]

[0088] FIG. 3 is a cross-sectional view illustrating an all-solid-state battery according to another embodiment of the present invention. In this embodiment, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 1 and FIG. 2 are omitted, and differences are described in detail.

[0089] Referring to FIG. 3, the negative electrode layer (200) of the all-solid-state battery (10) may further include a lithium metal layer (400) between the negative electrode current collector (210) and the negative electrode coating layer (220). The thickness of the lithium metal layer (400) may increase further during charging of the all-solid-state battery (10). The negative electrode coating layer (220) serves as a protective layer for the lithium metal layer (400) and, at the same time, can suppress the growth of lithium dendrites from the lithium metal layer (400).

[0090] The lithium metal layer (400) may be a thin metal film containing lithium or a lithium alloy. The lithium alloy is not limited to, for example, Li-Al alloy, Li-Sn alloy, Li-In alloy, Li-Ag alloy, Li-Au alloy, Li-Zn alloy, Li-Ge alloy, Li-Si alloy, etc., and any alloy used as a lithium alloy is possible. The lithium metal layer (400) may contain one of these alloys or lithium. Alternatively, the lithium metal layer (400) may contain various types of alloys.

[0091] The lithium metal layer (400) may have a fifth width (W5) in the first direction (D1). The fifth width (W5) may be equal to or greater than the first width (W1). The fifth width (W5) may be equal to or smaller than the second width (W2). For example, the fifth width (W5) may be greater than the first width (W1) and smaller than the second width (W2).

[0092] FIG. 4 is a cross-sectional view illustrating an all-solid-state battery according to another embodiment of the present invention. In this embodiment, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 1 to 3 are omitted, and differences are described in detail.

[0093] Referring to FIG. 4, the bi-cell all-solid-state battery (20) may include a first monocell (510) and a second monocell (520).

[0094] Each of the first and second monocells (510, 520) may include an anode layer (100), a cathode layer (200), and a solid electrolyte layer (300) disposed between the anode layer (100) and the cathode layer (200). The solid electrolyte layer (300) of each of the first and second monocells (510, 520) may include a first solid electrolyte layer (310) adjacent to the anode layer (100) and having a first width (W1) and a first thickness (t1), and a second solid electrolyte layer (320) adjacent to the cathode layer (200) and having a second width (W2) and a second thickness (t2). The second monocell (520) may be arranged vertically symmetrically with respect to the first monocell (510). The anode layer (100) of the first monocell (510) and the anode layer (100) of the second monocell (520) can face each other.

[0095] FIG. 5 is a cross-sectional view illustrating an all-solid-state battery according to another embodiment of the present invention. In this embodiment, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 1 to 4 are omitted, and differences are described in detail.

[0096] Referring to FIG. 5, the bi-cell all-solid-state battery (20) may further include an elastic member (ELP) disposed on one side of the negative electrode layer (200). The elastic member (ELP) is composed of members capable of absorbing volume changes (expansion) of the all-solid-state battery (20) due to charging and discharging, and is capable of elastic deformation; more specifically, it may be composed of a material having a lower elastic modulus than that of the positive current collector and the negative current collector. The material constituting the elastic member (ELP) may have a slope of the stress-displacement curve of 200 MPa or less at a displacement of 80% or less. Specifically, the material constituting the elastic member (ELP) may have a slope of the stress-displacement curve of 50 MPa or less at a displacement of 80% or less, and 10 MPa or less at a displacement of 50% or less.

[0097] Examples of materials for the above elastic member (ELP) include, but are not limited to, epoxy resin, acrylic resin, polyimide resin, polyester resin, polypropylene resin, polyamide resin, polystyrene resin, polyvinyl chloride resin, polycarbonate resin, fluoropolymer resin such as PTFE, silicone rubber, etc. Each elastic member (ELP) may be composed of a single material or may be composed of a combination of several materials. In addition, each elastic member (ELP) may include the same material or may include different materials. Furthermore, the elastic member (ELP) may include an insulating material and may insulate between each bicell all-solid-state battery (20). The insulating material has a surface resistance value of 1.0*10 17 Ω·cm 2 It may be the above, and specifically, it may be a fluoropolymer such as PTFE or silicone rubber, etc.

[0098] Since an elastic member (ELP) is disposed between each bicell all-solid-state battery (20), the pressure generated when the all-solid-state battery (20) is charged and expanded can be dispersed, thereby reducing the uneven distribution of pressure applied to each all-solid-state battery (20) due to charging and discharging. In addition, this can suppress cracking or deformation of the electrolyte layer that may occur as charging and discharging are repeated, and can suppress deterioration of battery characteristics such as cycle characteristics.

[0099] FIG. 6 is a cross-sectional view illustrating an all-solid-state battery according to another embodiment of the present invention. In this embodiment, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 1 to 5 are omitted, and differences are described in detail.

[0100] Referring to FIG. 6, the all-solid-state battery (20) may further include an inert member (INM) disposed on one side of the positive electrode layer (100) and the first solid electrolyte layer (310). By including the inert member (INM), cracking of the solid electrolyte layer (300) is prevented during manufacturing and / or charging and discharging of the all-solid-state battery (20), and consequently, the cycle characteristics of the all-solid-state battery (20) can be improved.

[0101] The inert member (INM) may include one or more selected from lithium-ion insulators and lithium-ion conductors. The inert member (INM) may be an electronic insulator; that is, the inert member (INM) may not be an electronic conductor. The inert member (INM) may be an ion insulator; that is, the inert member (INM) may not be an ion conductor. The inert member (INM) includes, for example, organic materials, inorganic materials, or organic-inorganic composite materials. Organic materials may be, for example, polymers. Inorganic materials may be ceramics, for example, metal oxides. Organic-inorganic composite materials may be a composite of a polymer and a metal oxide.

[0102] The above inert member (INM) may be disposed between the second solid electrolyte layer (320) of the first monocell (510) and the second solid electrolyte layer (320) of the second monocell (520). By including the inert member (INM), uniform pressure can be applied during the manufacturing process of the all-solid-state battery (20), thereby preventing cracking of the solid electrolyte layer (300) and consequently improving the cycle characteristics of the all-solid-state battery (20).

[0103] The thickness of the inert member (INM) may be equal to or less than the sum of the thickness (t1) of the first solid electrolyte layer (310) of the first monocell (510) and the thickness of the anode layer (100), and the thickness (t1) of the first solid electrolyte layer (310) of the second monocell (520) and the thickness of the anode layer (100). The thickness of the inert member (INM) may be greater than the thickness of the anode layer (100). If the thickness of the inert member (INM) is smaller than the thickness of the anode layer (100), appropriate pressure is not applied to the side of the second solid electrolyte layer (320), and cracks may occur in the solid electrolyte layer (300). If the thickness of the above inert member (INM) is greater than the sum of the thickness (t1) of the first solid electrolyte layer (310) of the first monocell (510) and the thickness of the anode layer (100), and the thickness (t1) of the first solid electrolyte layer (310) of the second monocell (520) and the thickness of the anode layer (100), the anode layer (100) and the first solid electrolyte layer (310) may not be sufficiently pressurized.

[0104]

[0105] FIG. 7a is a plan view illustrating an all-solid-state battery including an anode layer and a solid electrolyte layer according to another embodiment of the present invention, and FIG. 7b is a cross-sectional view along the line I-I' of FIG. 7a. FIG. 8a and FIG. 8b are enlarged views showing region M of FIG. 7b. In these embodiments, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 1 to 6 are omitted, and differences are described in detail.

[0106] Referring to FIGS. 7a, 7b and 8a, the positive current collector (110) may provide a reference surface on which the positive active material layer (120) is placed. The positive current collector (110) may include an active portion (AAP) and a tab portion (ATP). The positive active material layer (120) and the first solid electrolyte layer (310) may be sequentially placed on the active portion (AAP) of the positive current collector (110). The tab portion (ATP) of the positive current collector (110) may be a portion protruding from the active portion (AAP) in the first direction (D1). A protruding portion of the positive active material layer (120) and a positive insulating film (CIL) may be placed on the tab portion (ATP) of the positive current collector (110). The tab portion (ATP) of the positive current collector (100) may be a positive non-positive portion. Referring again to FIG. 8a, specifically, the tab portion (ATP) may include an edge region (ER) adjacent to the active portion (AAP) and a non-tabular region (PR) extending from the edge region (ER). The negative current collector (210) may provide a reference plane on which the negative coating layer (220) is placed. The negative current collector (210) may have a portion protruding from the negative coating layer (220) in the direction opposite to the first direction (D1). The protruding portion may be a tab of the negative.

[0107] The inert member (INM) may surround the side of the positive active material layer (120), the side of the first solid electrolyte layer (310), and one side of the positive insulating film (CIL) described later. The inert member (INM) may be disposed on the second solid electrolyte layer (320). Specifically, the inert member (INM) may include a first inert member (INM1) on the one side of the positive insulating film (CIL) and a second inert member (INM2) on the side of the positive active material layer (120) and the side of the first solid electrolyte layer (310).

[0108] The first inert member (INM1) may be separated from the anode active material layer (120) and the first solid electrolyte layer (310) by the anode insulating film (CIL) described later. As a result, the width of the first inert member (INM1) in the first direction (D1) may be smaller than the width of the second inert member (INM2) in the first direction (D1).

[0109] The positive active material layer (120) may extend from the active portion (AAP) to the edge region (ER) of the tab portion (ATP). That is, the positive active material layer (120) may include a positive protrusion (PRP) that protrudes in a first direction (D1) from the first solid electrolyte layer (310). By including the positive protrusion (PRP), the width of the positive active material layer (120) in the first direction (D1) may be greater than or equal to the width of the first solid electrolyte layer (310) in the first direction (D1). One side (120_S) of the positive active material layer (120) may be curved. One side (120_S) of the positive active material layer (120) may be closer to the first inert member (INM1) in the first direction (D1) than the side (310_S) of the first solid electrolyte layer (310). That is, one side (120_S) of the positive active material layer (120) and the side (310_S) of the first solid electrolyte layer (310) may not be vertically aligned.

[0110] The all-solid-state battery (10) may further include a positive insulating film (CIL) disposed on one side of the positive active material layer (120). Specifically, the positive insulating film (CIL) may be disposed between the positive active material layer (120) and the first inert member (INM1). The positive insulating film (CIL) may be disposed on the tab portion (ATP) of the positive current collector (110). Specifically, the positive insulating film (CIL) may be disposed extending from the edge region (ER) of the tab portion (ATP) to a portion of the non-positive region (PR). Specifically, the positive insulating film (CIL) may be disposed extending from the positive protrusion (PRP) of the positive active material layer (120) to the non-positive region (PR) of the positive current collector (110). The positive insulating film (CIL) may be disposed extending from one side (120_S) of the positive active material layer (120) to the non-positive region (PR) of the positive current collector (110). The positive insulating film (CIL) may have a curved surface corresponding to one side (120_S) of the positive active material layer (120).

[0111] The positive insulating film (CIL) can protect the side of the positive active material layer (120) protruding over the edge region (ER) of the tab portion (ATP). By including the positive insulating film (CIL), a short circuit or electrical short circuit of the positive layer (100) can be prevented during the manufacturing of the all-solid-state battery (10) and / or during charging and discharging, and consequently, the lifespan characteristics and cycle characteristics of the all-solid-state battery (10) can be improved. In addition, by having a curved surface corresponding to one side (120_S) of the positive active material layer (120) on which the positive insulating film (CIL) has a curved surface, the positive protrusion (PRP) of the positive active material layer (120) can be protected, thereby preventing a short circuit or electrical short circuit of the positive layer (100).

[0112] As the positive insulating film (CIL) is formed to be in contact with the positive active material layer (120) without contacting the first solid electrolyte layer (310), the all-solid-state battery (10) may further include an air gap (AGP) between the first solid electrolyte layer (310) and the first inert member (INM1). Specifically, the air gap (AGP) may be interposed between the positive insulating film (CIL), the first inert member (INM1), the second solid electrolyte layer (320), and the first solid electrolyte layer (310). For example, the air gap (AGP) may be a void or a seam.

[0113]

[0114] Referring to FIG. 8a, the positive insulating film (CIL) may include an adhesive layer (CHL) in direct contact with one side (120_S) of the positive active material layer (120) and an insulating layer (CPL) on the adhesive layer (CHL).

[0115] The adhesive layer (CHL) can be in direct contact with one side of the positive active material layer (120) and the lower surface of the positive current collector (110). That is, the adhesive layer (CHL) can extend from the lower surface of the positive current collector (110) onto the side surface of the positive active material layer (120). The adhesive layer (CHL) may include a binder. The binder may include a material for improving the bonding strength between the positive current collector (110) and the adhesive layer (CHL), and between the positive active material layer (120) and the adhesive layer (CHL). For example, the binder may include the same material as the binder included in the positive active material layer (120).

[0116] An insulating layer (CPL) may be placed on an adhesive layer (CHL). The insulating layer (CPL) may be spaced apart from the positive active material layer (120) due to the adhesive layer (CHL). The insulating layer (CPL) may include an organic material, an inorganic material, a binder, or a combination thereof. The average particle size (D50) of the insulating layer (CPL) may be 5 μm or less. The average particle size (D50) of the insulating layer (CPL) may be 4 μm or less, and may be 3 μm or less. The average particle size (D50) of the insulating layer (CPL) may be 1 μm or more.

[0117] For example, the insulating layer (CPL) may include titanium oxide (TiO2), magnesium carbonate (MgCO3), silicon dioxide (SiO2), alumina (Al2O3), etc. For example, the binder may include an acrylic adhesive. The binder may include the same material as the binder included in the adhesive layer (CHL).

[0118] The air gap (AGP) may be a void or a seam. The air gap (AGP) may be interposed between the adhesive layer (CHL), the insulating layer (CPL), the first inert member (INM1), the second solid electrolyte layer (320), and the first solid electrolyte layer (310). That is, the air gap (AGP) may be an empty space surrounded by the adhesive layer (CHL), the insulating layer (CPL), the first inert member (INM1), the second solid electrolyte layer (320), and the first solid electrolyte layer (310).

[0119] FIG. 8b is an enlarged view showing the M region of FIG. 7 as an embodiment different from the embodiment of FIG. 8a. The anode insulating film (CIL) may have a width (WD) in the first direction (D1) and a height (HG) in the third direction (D3). The width (WD) of the anode insulating film (CIL) may be defined as the horizontal distance in the first direction (D1) from one side to the other side. The height (HG) of the anode insulating film (CIL) may be defined as the vertical distance in the third direction (D3) from the lowest surface to the highest surface. The thickness (TH) of the anode insulating film (CIL) may be greater than or equal to the thickness of the anode active material layer (120). The thickness (TH) of the anode insulating film (CIL) may be less than the sum of the thickness of the anode active material layer (120) and the thickness of the first solid electrolyte layer (310).

[0120] The height (HG) of the positive insulating film (CIL) may be 200 μm or less. Specifically, the height (HG) of the positive insulating film (CIL) may be 180 μm or less, 175 μm or less, or 170 μm or less. The height (HG) of the positive insulating film (CIL) may be 10 μm or more. Specifically, the height (HG) of the positive insulating film (CIL) may be 100 μm or more, 130 μm or more, or 160 μm or more. The height (HG) of the positive insulating film (CIL) may be greater than or equal to the thickness of the positive active material layer (120).

[0121] The thickness (TH) of the positive insulating film (CIL) can be defined as the sum of the thickness of the adhesive layer (CHL) and the thickness of the insulating layer (CPL) described later. The thickness (TH) of the positive insulating film (CIL) may be, for example, 1 µm to 50 µm, more specifically 10 µm to 40 µm, and more specifically 20 µm to 30 µm. If the thickness (TH) of the positive insulating film (CIL) exceeds the aforementioned numerical range, excessive pressure may be applied during the manufacturing process of the all-solid-state battery (10), causing it to break. If the thickness (TH) of the positive insulating film (CIL) falls short of the aforementioned numerical range, the insulation properties of the all-solid-state battery (10) may deteriorate. That is, it may be difficult to protect the side of the positive active material layer (120), and there may be a risk of a short circuit.

[0122] The width (WD) of the anode insulating film (CIL) may be 5 mm or less. Specifically, the width (WD) of the anode insulating film (CIL) may be 3 mm or less and 2 mm or less. The width (WD) of the anode insulating film (CIL) may be 0.5 mm or more. Specifically, the width (WD) of the anode insulating film (CIL) may be 1 mm or more and 1.5 mm or more.

[0123] The height (HG), thickness (TH), and width (WD) of the aforementioned anode insulating film (CIL) can be applied in the same way to the embodiment of FIG. 8a.

[0124]

[0125] FIG. 9 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention, and FIG. 10 is an enlarged view showing region N of FIG. 9. In these embodiments, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 1 to FIG. 8b are omitted, and differences are described in detail.

[0126] Referring to FIGS. 9 and 10, an all-solid-state battery (10) according to one embodiment may further include a fixed layer (ADM) disposed between an inert member (INM) and a second solid electrolyte layer (320). By including the fixed layer (ADM), uniform pressure can be applied during the manufacturing of the all-solid-state battery (10) and residual moisture can be removed during charging and discharging, thereby improving the lifespan characteristics of the all-solid-state battery (10).

[0127] A fixed layer (ADM) may be disposed on a second solid electrolyte layer (320) and separated from the first solid electrolyte layer (310) by an air gap (AGP). The fixed layer (ADM) may comprise pulp fibers, glass fibers, aluminum hydroxide (Al(OH)3), a binder, or a combination thereof. The binder may comprise, for example, the same material as the binder contained in the second solid electrolyte layer (320).

[0128] By providing a fixing layer (ADM) on the second solid electrolyte layer (320), the inert member (INM) can be fixed without detaching from the fixing layer (ADM). For example, the adhesive strength of the fixing layer (ADM) may be 50 gf / 25 mm to 300 gf / 25 mm. If the adhesive strength of the fixing layer (ADM) exceeds the aforementioned numerical range, the inert member (INM) of the all-solid-state battery (10) may be deformed and a defect may occur. If the adhesive strength of the fixing layer (ADM) does not fall within the aforementioned numerical range, the inert member (INM) may easily detach.

[0129]

[0130] FIGS. 11 and 12 are cross-sectional views of all-solid-state batteries according to other embodiments of the present invention. In these embodiments, detailed descriptions of technical features that overlap with those previously described with reference to FIGS. 1 to 10 are omitted, and differences are described in detail.

[0131] Referring to FIG. 11, the bi-cell all-solid-state battery (20) may include a first monocell (510) and a second monocell (520).

[0132] Each of the first and second monocells (510, 520) may include an anode layer (100), a cathode layer (200), a solid electrolyte layer (300) disposed between the anode layer (100) and the cathode layer (200), and an anode insulating film (CIL) on one side of the anode active material layer (120).

[0133] Each of the first and second monocells (510, 520) may further include an inert member (INM) disposed on the second solid electrolyte layer (320) and an air gap (AGP) surrounded by the inert member (INM), the second solid electrolyte layer (320), and the first solid electrolyte layer (310), surrounding the side of the positive active material layer (120), the side of the first solid electrolyte layer (310), and one side of the positive insulating film (CIL). For example, the air gap (AGP) may be a void or a seam.

[0134] The solid electrolyte layer (300) of each of the first and second monocells (510, 520) may include a first solid electrolyte layer (310) adjacent to the anode layer (100) and having a first width and a first thickness, and a second solid electrolyte layer (320) adjacent to the cathode layer (200) and having a second width and a second thickness. The second monocell (520) may be arranged vertically symmetrically with respect to the first monocell (510). The anode layer (100) of the first monocell (510) and the anode layer (100) of the second monocell (520) may face each other.

[0135] Referring to FIG. 12, each of the first and second monocells (510, 520) may further include a fixed layer (ADM) disposed between an inert member (INM) and a second solid electrolyte layer (320).

[0136]

[0137] FIGS. 13a to 13d, FIGS. 14a to 14c and FIG. 15 are conceptual diagrams for explaining a method for manufacturing an all-solid-state battery according to an embodiment of the present invention.

[0138] Referring to FIGS. 13a to 13d and FIGS. 14a to 14c, an all-solid-state battery (10) according to one embodiment of the present invention can be manufactured by stacking a positive electrode layer (100) and a first solid electrolyte layer (310) and then applying a first pressure to form a positive electrode stack (12), and stacking a negative electrode layer (200) and the second solid electrolyte layer (320) and then applying a second pressure to form a negative electrode stack (14).

[0139] The present invention allows the first pressure and the second pressure to be controlled differently by manufacturing the anode laminate (12) and the cathode laminate (14) by applying an individual pressure method. Through this, a relatively low pressure can be applied to the laminate among the anode laminate (12) and the cathode laminate (14) that has weak mechanical strength or severe structural imbalance and may be damaged if pressure is applied at a high level. The first pressure may be greater than the second pressure.

[0140] Forming the anode laminate (12) and cathode laminate (14) may include a pressurizing process in which a roll press is applied. However, this method is not necessarily limited to this method, and any pressurizing process applicable in the relevant technical field may be applied. For example, pressurizing processes such as a hydraulic plate press and a warm isostatic press may be applied.

[0141] When a roll press is applied during the formation process of the anode laminate (12), the first pressure may be 1 ton / cm to 5 ton / cm, and more specifically, 1.5 ton / cm to 4.0 ton / cm or 2 ton / cm to 3.5 ton / cm. For example, the first pressure may be 3.5 ton / cm.

[0142] When a roll press is applied during the formation process of the above-mentioned cathode laminate (14), the second pressure may be 0.5 ton / cm to 4.5 ton / cm, and more specifically, 1.0 ton / cm to 3.5 ton / cm or 1.5 ton / cm to 3.0 ton / cm. As an example, the second pressure may be 1.5 ton / cm to 2.5 ton / cm.

[0143] The above pressurization process may be carried out at a relatively high temperature. Specifically, the above pressurization process may be carried out at 60 to 180 ℃, at 80 to 150 ℃, and at 100 to 130 ℃.

[0144] Forming the anode laminate (12) and cathode laminate (14) may include a preheating process prior to the pressurization process. Specifically, the anode laminate (12) and cathode laminate (14) may be preheated to ±10°C or ±5°C of the temperature at which the pressurization process is performed. The preheating process can prevent damage caused by rapid temperature changes in the anode laminate (12) and cathode laminate (14) during the high-temperature pressurization process.

[0145] Referring again to FIGS. 13a to 13d, in a method for manufacturing an all-solid-state battery according to another embodiment of the present invention, forming the positive electrode laminate (12) may include stacking a first functional layer (FNL1) on a first solid electrolyte layer before applying the first pressure, and forming the negative electrode laminate (14) may include stacking a second functional layer (FNL2) on a second solid electrolyte layer before applying the second pressure.

[0146] The method may further include removing the first functional layer (FNL1) and the second functional layer (FNL2) before combining the anode laminate (12) and the cathode laminate (14). The first functional layer (FNL1) and the second functional layer (FNL2) can prevent damage to the solid electrolyte by preventing the solid electrolyte layer from being directly exposed during the high-temperature pressurization process.

[0147] The first functional layer (FNL1), the second functional layer (FNL2), and the third functional layer (FNL3) may comprise a plate or foil comprising indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof. The first functional layer (FNL1), the second functional layer (FNL2), and the third functional layer (FNL3) may comprise polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI), or a mixture thereof.

[0148] Referring again to FIGS. 14a to 14c, the process may further include forming an anode insulating film (CIL) on the anode laminate (12) before combining the anode laminate (12) and the cathode laminate (14). The formation of the anode insulating film (CIL) may be performed through an anode insulating film (CIL) transfer method.

[0149] Specifically, the positive current collector (110) of the positive stack (12) may be formed larger in one direction than the positive active material layer (120) and the first solid electrolyte layer (310). The larger and protruding portion may be a tab of the positive stack (12). The larger and protruding portion may correspond to the tab portion (ATP) of FIG. 7A described above. A portion of the positive current collector (110) in which the positive active material layer (120) and the first solid electrolyte layer (310) are stacked may correspond to the active portion (AAP) of FIG. 7A described above.

[0150] In the pressurization process for forming the positive electrode laminate (12), since the roll press is applied only to the area corresponding to the aforementioned active portion (AAP in FIG. 7a) of the positive electrode current collector (110), the positive electrode active material layer (120) may be detached or removed onto the aforementioned tab portion (AAP in FIG. 7a) of the positive electrode current collector (110). A portion of the detached or removed positive electrode active material layer (120) may be formed into the aforementioned positive electrode protrusion (PRP in FIG. 8a). That is, forming the positive electrode insulating film (CIL) may involve transferring the positive electrode insulating film (CIL) onto the tab of the positive electrode laminate (12). Additionally, forming the positive electrode insulating film (CIL) may involve transferring the positive electrode insulating film (CIL) onto the positive electrode protrusion of the positive electrode active material layer (120) and onto the tab of the positive electrode laminate (12).

[0151] Transferring the anode insulating film (CIL) may include sequentially stacking an adhesive layer (CHL), an insulating layer (CPL), and an adhesive substrate layer (FNL3) on the anode laminate (12), and removing the adhesive substrate layer (FNL3). Sequentially stacking the adhesive layer (CHL), the insulating layer (CPL), and the adhesive substrate layer (FNL3) on the anode laminate (12) may involve sequentially stacking the adhesive layer (CHL), the insulating layer (CPL), and the adhesive substrate layer (FNL3) on the side surface of the anode active material layer (120). The adhesive layer (CHL), the insulating layer (CPL), and the adhesive substrate layer (FNL3) may not come into contact with the first solid electrolyte layer (310).

[0152] The adhesive substrate layer (FNL3) may be a release film suitable for a coating process or a transfer process. For example, the adhesive substrate layer (FNL3) may comprise a plate or foil comprising indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof. As another example, the adhesive substrate layer (FNL3) may comprise polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI), or a mixture thereof.

[0153] Referring to FIG. 15, an all-solid-state battery (10) according to one embodiment of the present invention can be manufactured by combining the positive electrode stack and the negative electrode stack so that the first solid electrolyte layer (310) and the second solid electrolyte layer (320) come into contact with each other, and applying the third pressure.

[0154] Forming the above-mentioned anode laminate and cathode laminate may include a pressurization process in which a hydraulic plate press is applied. However, it is not necessarily limited to this method, and any pressurization process applicable in the relevant technical field may be applied. For example, pressurization processes such as roll press and warm isostatic press may be applied.

[0155] When a roll press is applied during the formation process of the all-solid-state battery (10), the third pressure may be 0.1 ton / cm or more. Specifically, the third pressure may be 0.5 ton / cm or more and 1.0 ton / cm or more. The third pressure may be 2.0 ton / cm or less. Specifically, the third pressure may be 1.5 ton / cm or less.

[0156] FIG. 16 is a conceptual diagram illustrating a method for manufacturing an all-solid-state battery according to another embodiment of the present invention.

[0157] FIG. 16 is a conceptual diagram illustrating a method for manufacturing an all-solid-state battery according to another embodiment of the invention. In this embodiment, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 13a to 13d, FIG. 14a to 14c, and FIG. 15 are omitted, and the differences are described in detail.

[0158] An all-solid-state battery according to another embodiment of the present invention may include first and second monocells (510, 520). The second monocell (520) may be arranged vertically symmetrically with respect to the first monocell (510) and combined by applying pressure. Specifically, the all-solid-state battery may be manufactured by symmetrically arranging and combining the first monocell (510) and the second monocell (520) and applying pressure so that the positive layer (100) of each of the first and second monocells (510, 520) comes into contact with each other.

[0159]

[0160] The following describes embodiments and comparative examples of the present invention. However, the following embodiments are merely examples of the present invention, and the present invention is not limited to the following embodiments.

[0161]

[0162] Example 1

[0163] (Cathode layer manufacturing)

[0164] A Ni foil with a thickness of 10 μm was prepared as a negative electrode current collector. Additionally, carbon black (CB) with a primary particle size of approximately 30 nm and silver (Ag) particles with an average particle size (D50) of approximately 60 nm were prepared as negative electrode active materials. 4 g of a mixed powder, prepared by mixing carbon black (CB) and silver (Ag) particles in a weight ratio of 3:1, was placed in a container, and 4 g of an NMP solution containing 7 wt% of PVDF binder (Kureha # 9300) was added to prepare a mixed solution. Subsequently, a slurry was prepared by stirring the mixed solution while gradually adding NMP to it. The prepared slurry was applied to a Ni sheet using a bar coater and dried in air at 80°C for 10 minutes. The resulting laminate was vacuum dried at 40°C for 10 hours. The dried laminate was cold-roll-pressed at a pressure of 1.5 ton / cm to flatten the surface of the first cathode active material layer of the laminate. The cathode layer was fabricated by the above process. The thickness of the first cathode active material layer included in the cathode layer was approximately 7 μm. The area of ​​the first cathode active material layer and the cathode current collector were the same.

[0165]

[0166] (Anode layer manufacturing)

[0167] LiNi coated with Li2O-ZrO2 (LZO) as a positive electrode active material 0.8 Co 0.15 Mn 0.05O2(NCM) was prepared. The LZO-coated cathode active material was prepared according to the method disclosed in Korean Patent Publication No. 10-2016-0064942.

[0168] Li6PS5Cl, an argyrodite-type crystal (D50 = 0.5 μm, crystalline), was prepared as the solid electrolyte. Polytetrafluoroethylene (PTFE) binder was prepared as the binder. Carbon nanofiber (CNF) was prepared as the conductive agent. A slurry was formed by mixing these materials with xylene solvent in a weight ratio of positive active material : solid electrolyte : conductive agent : binder = 84 : 11.5 : 3 : 1.5, and then vacuum-dried at 40 °C for 8 hours to produce positive electrode sheets. The prepared positive electrode sheets were each placed on the cross-section of a positive electrode current collector, which consisted of a carbon-coated aluminum foil on one side. The total thickness of the positive electrode layer was approximately 120 μm. The thickness of the positive electrode active material layer was approximately 107 μm, and the thickness of the carbon-coated aluminum foil (thickness 1 mm) was approximately 13 μm. The area of ​​the positive active material layer and the positive current collector was the same.

[0169]

[0170] (Anode insulation film manufacturing, transfer)

[0171] An anode layer including an anode-free portion was prepared. The anode-free portion refers to a region of the anode current collector where the anode active material is not coated, and specifically includes a portion where an anode tab is formed that protrudes outwardly from the anode current collector.

[0172] An anode insulating film composite composed of an adhesive substrate layer, an insulating layer, and an adhesive layer was prepared. As the material for the adhesive substrate layer, a release film used for a coating process or a transfer process was prepared. For example, polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI), and a mixture thereof were prepared as the adhesive substrate layer. As the material for the insulating layer, a composite of an oxide and an organic material having insulating properties was prepared, and the insulating layer may include organic materials, inorganic materials, binders, or a combination thereof. For example, titanium oxide (TiO2), magnesium carbonate (MgCO3), silicon dioxide (SiO2), alumina (Al2O3), and a mixture thereof were prepared as the insulating layer. As the material for the adhesive layer, a binder material having the property of adhering the anode active material and the anode insulating film composite was prepared.

[0173] An anode insulating film composite, in which an adhesive substrate layer, an insulating layer, and an adhesive layer are sequentially applied and laminated, can be transferred in a form extending from the boundary of the anode active material layer toward the anode non-absorbent area. The ratio of the anode insulating film composite transferred onto the boundary of the anode active material layer to the ratio of the anode insulating film composite transferred onto the anode non-absorbent area can be 3:7 based on the total weight of the anode insulating film composite, and specifically, the ratio can be 4:6. After the anode insulating film composite is transferred, the adhesive substrate layer can be removed.

[0174] Based on the thickness direction of the anode current collector, the thickness of the anode insulating film transferred to the anode-free portion (the sum of the thickness of the adhesive layer and the thickness of the insulating layer) may be in the range of 1 μm to 50 μm, and more specifically, in the range of 10 μm to 40 μm. In this embodiment, the thickness of the anode insulating film may be 1 μm.

[0175] Based on the width direction of the positive current collector, the width of the positive insulating film transferred to the positive non-positive portion may be in the range of 0.5 mm to 5 mm, and more specifically, in the range of 1 mm to 2 mm. In this embodiment, the width of the positive insulating film may be 3 mm.

[0176]

[0177] (Preparation of solid electrolyte layer, dry method)

[0178] A mixture was prepared by adding 1 part by weight of a polytetrafluoroethylene (PTFE) first binder and 1 part by weight of a polyvinylidene fluoride (PVDF) second binder to an argyrodite-type crystal Li6PS5Cl sulfide-based solid electrolyte (D50 = 3 μm, crystalline) with respect to 98 parts by weight of the solid electrolyte into a grind mixer and mixing. A dough was prepared by adding the prepared mixture to a mortar heated to 80°C and stirring. The prepared dough was passed through a roller and formed into a sheet shape to prepare a solid electrolyte membrane of uniform thickness.

[0179] A solid electrolyte layer was prepared by the above process. The above solid electrolyte layer consisted of a first solid electrolyte layer having substantially the same area as the anode layer and a second solid electrolyte layer having substantially the same area as the cathode layer. The elastic modulus of the sulfide-based solid electrolyte was approximately 15 GPa to 30 GPa.

[0180]

[0181] (Manufacture of fixed layer, inert member (gasket))

[0182] A fixed layer was prepared to be disposed on a solid electrolyte layer adjacent to the cathode layer. An adsorption flame retardant film member was prepared as the material of the fixed layer. For example, pulp fibers, glass fibers, Al(OH)3, binders, and mixtures thereof were prepared as the fixed layer.

[0183] An inert member (gasket) is prepared to surround a solid electrolyte layer adjacent to an anode layer on a solid electrolyte layer adjacent to a cathode layer. By providing a fixing layer, the inert member can be fixed without detaching from the fixing layer. The adhesive strength of the fixing layer may be 50gf / 25mm to 300gf / 25mm, and specifically, the adhesive strength of the fixing layer may be 200gf / 25mm.

[0184]

[0185] (Manufacturing of all-solid-state batteries)

[0186] An anode layer and a first solid electrolyte layer were laminated and pressed using a roll press method. An anode laminate was manufactured by applying a linear pressure of 3.5 ton / cm at 120°C. A cathode layer and a second solid electrolyte layer were laminated and pressed using a roll press method. A cathode laminate was manufactured by applying a linear pressure of 3.0 ton / cm at 140°C. An all-solid-state battery was manufactured by combining the anode laminate and the cathode laminate.

[0187] Referring to FIG. 1, the second width (W2) of the second solid electrolyte layer was manufactured to be 4 mm larger than the first width (W1) of the first solid electrolyte layer. The thickness (t1) of the first solid electrolyte layer was 60 μm, and the thickness (t2) of the second solid electrolyte layer was manufactured to be 5 μm.

[0188]

[0189] Example 2

[0190] An all-solid-state battery was manufactured using the same method as in Example 1, except that the thickness of the anode insulating film was formed to 10 μm during the manufacturing and transfer of the anode insulating film.

[0191]

[0192] Example 3

[0193] An all-solid-state battery was manufactured using the same method as in Example 1, except that the thickness of the anode insulating film was formed to 20 μm during the manufacturing and transfer of the anode insulating film.

[0194]

[0195] Example 4

[0196] An all-solid-state battery was manufactured using the same method as in Example 1, except that the thickness of the anode insulating film was formed to 50 μm during the manufacturing and transfer of the anode insulating film.

[0197]

[0198] Example 5

[0199] An all-solid-state battery was manufactured using the same method as in Example 1, except that when manufacturing and transferring the positive insulating film, the thickness of the positive insulating film was formed to 20 μm and the width of the positive insulating film was formed to 0.5 mm.

[0200]

[0201] Example 6

[0202] An all-solid-state battery was manufactured using the same method as in Example 1, except that when manufacturing and transferring the positive insulating film, the thickness of the positive insulating film was formed to 20 μm and the width of the positive insulating film was formed to 1 mm.

[0203]

[0204] Example 7

[0205] An all-solid-state battery was manufactured using the same method as in Example 1, except that when manufacturing and transferring the positive insulating film, the thickness of the positive insulating film was formed to 20 μm and the width of the positive insulating film was formed to 2 mm.

[0206]

[0207] Example 8

[0208] An all-solid-state battery was manufactured using the same method as in Example 1, except that when manufacturing and transferring the positive insulating film, the thickness of the positive insulating film was formed to 20 μm and the width of the positive insulating film was formed to 5 mm.

[0209]

[0210] Example 9

[0211] An all-solid-state battery was manufactured using the same method as in Example 1, except that when manufacturing and transferring the positive insulating film, the thickness of the positive insulating film was formed to 20 μm and the width of the positive insulating film was formed to 10 mm.

[0212]

[0213] Example 10

[0214] An all-solid-state battery was manufactured using the same method as in Example 1, except that when manufacturing and transferring the positive insulating film, the thickness of the positive insulating film was formed to 20 μm, the width of the positive insulating film was formed to 2 mm, and the adhesion strength of the fixed layer was formed to 100 gf / 25 mm.

[0215]

[0216] Example 11

[0217] An all-solid-state battery was manufactured using the same method as in Example 1, except that when manufacturing and transferring the positive insulating film, the thickness of the positive insulating film was formed to 20 μm, the width of the positive insulating film was formed to 2 mm, and the adhesion strength of the fixed layer was formed to 300 gf / 25 mm.

[0218]

[0219]

[0220] Comparative Example 1

[0221] An all-solid-state battery identical to the one described above was manufactured, except that the transfer method used in Example 1 above for manufacturing the anode insulating film was omitted and a fixed layer was not formed.

[0222]

[0223] Comparative Example 2

[0224] An all-solid-state battery identical to the one described above was manufactured, except that the transfer method used in Example 1 above was omitted during the manufacture of the anode insulating film and the adhesion strength of the fixed layer was 0.

[0225]

[0226] Comparative Example 3

[0227] An all-solid-state battery identical to the one described above was manufactured, except that in Example 1 above, a tape method was applied when manufacturing the positive insulating film, a fixed layer was not formed, the thickness of the positive insulating film was formed to 15 μm, and the width of the positive insulating film was formed to 2 mm.

[0228]

[0229] Comparative Example 4

[0230] An all-solid-state battery identical to the one described above was manufactured, except that in Example 1 above, a tape method was applied when manufacturing the positive insulating film, the adhesive strength of the fixed layer was 0, the thickness of the positive insulating film was formed to 15 μm, and the width of the positive insulating film was formed to 2 mm.

[0231]

[0232] Evaluation Example 1: Good Product Rate (Mass Manufacturability)

[0233] The mass producibility of the all-solid-state batteries manufactured according to the examples and comparative examples was verified by conducting a yield rate test. The yield rate test evaluates the ratio of the number of good samples to the total number of samples produced; specifically, 100 samples were manufactured for each example and comparative example to conduct the test. The results of the yield rate experiment were classified as a percentage based on the number of good cells among the 100 samples. The classification results are shown in Table 1 below.

[0234]

[0235] Evaluation Example 2: OCV (Open-Circuit Voltage)

[0236] The charge / discharge life level of the all-solid-state batteries prepared by the examples and comparative examples was determined by checking the OCV (mV). OCV refers to the electromotive force applied to the all-solid-state battery when nothing is connected to it, and the results are shown in Table 1 below.

[0237]

[0238] Evaluation Example 3: Initial dosage

[0239] The all-solid-state batteries prepared according to the examples and comparative examples were evaluated by the following charge-discharge test. The charge-discharge test was performed by placing the all-solid-state batteries in a constant temperature bath at 45°C. In the first cycle, the battery was charged at a constant current of 0.1C until the battery voltage reached 4.25V, and upon reaching 4.25V, charging was performed at a constant voltage of 4.25V under a 0.05C cut-off condition. Subsequently, the battery was discharged at a constant current of 0.1C until the battery voltage reached 2.5V. The discharge capacity of the first cycle was set as the initial capacity. The results are shown in Table 1 below. The initial capacity was measured under standard method (first discharge amount) conditions and is shown in Table 1 below.

[0240]

[0241] Evaluation Example 4: Evaluation of Life Characteristics at the Time of Short Circuit Occurrence

[0242] The all-solid-state batteries prepared according to the examples and comparative examples were evaluated by the following charge-discharge test. The charge-discharge test was performed by placing the all-solid-state batteries in a constant temperature bath at 45°C. In the first cycle, the battery was charged with a constant current of 0.33C until the battery voltage reached 4.25V, and upon reaching 4.25V, constant voltage charging was performed at 4.25V under a 0.1C cut-off condition. Subsequently, the battery was discharged with a constant current of 0.33C until the battery voltage reached 2.5V. From the second cycle onwards, charging and discharging were performed up to 350 cycles under the same conditions as the first cycle. This implies that the life characteristics improve as the number of cycles at which a short circuit occurs increases. The results of the charge-discharge test are shown in Table 1 below. A short circuit was confirmed to have occurred using the standard method (charge amount during life = discharge amount * 10%), and the number of times the life had progressed up to that point was recorded and is shown in Table 1 below.

[0243]

[0244] Adhesion strength of anode insulating film fixing layer (gf / 25mm) Yield rate (%) OCV (mV) Initial capacity (mAh / g) Short circuit occurrence time Application method Thickness (㎛) Width (mm) Example 1 Transfer 13 200 < 10 100 190 < 50 Example 2 Transfer 10 3 200 < 20 100 195 < 100 Example 3 Transfer 20 3 200 > 99 200 200 > 200 Example 4 Transfer 50 3 200 > 50 150 195 < 100 Example 5 Transfer 200 5 200 < 10 50 185 < 50 Example 6 Transfer 20 1 200 < 50 100 185 < 100 Example 7 Transfer 20 2 200 > 90 200 190 > 200 Example 8 Transmission 205200〉80150180〈150 Example 9 Transmission 2010200〉50100170〈100 Example 10 Transmission 202100〈50100190〈100 Example 11 Transmission 202300〈50100190〈100 Comparative Example 1 Not Applied--Not Applied〈10-- Comparative Example 2 Not Applied--0〈10-- Comparative Example 3 Tape 152 Not Applied〈5〈100190〈1 Comparative Example 4 Tape 1520〈5200190〈1”>n” means that no short circuit occurs even after n cycle tests. <n”은, n회 사이클 시험 동안 단락이 발생함을 의미함.

[0245] Referring to Table 1, it can be confirmed that the all-solid-state batteries of Examples 1 to 11, in which a positive electrode insulating film is formed via a transfer method and a fixed layer is formed under an inert member, have a higher yield rate and superior initial capacity compared to the comparative examples. Additionally, it can be confirmed that the time at which a short circuit occurs is later than that of the comparative examples. Furthermore, the all-solid-state battery of Example 7, in which the positive electrode insulating film has a thickness of 20 μm and a width of 2 mm, and the adhesive strength of the fixed layer is 200 gf / 25 mm, has a yield rate of over 90% and does not experience a short circuit even after more than 200 cycle tests, thus confirming excellent mass producibility and lifespan characteristics. In addition, since the OCV value and initial capacity are high, lifespan characteristics during charging and discharging are improved, and it can be confirmed that the impact of physical defects in the all-solid-state battery is low.

[0246] On the other hand, in the all-solid-state batteries of Comparative Examples 1 to 4, where the positive electrode insulating film is not formed or is applied via a tape method, or where the fixed layer is not formed or the adhesive strength of the fixed layer is zero, it can be confirmed that the yield rate is lower than that of the Examples and that a short circuit occurs during the cycle test. In particular, in the all-solid-state battery of Comparative Example 2, where the positive electrode insulating film and the fixed layer are not formed, it can be confirmed that the initial capacity is small and the yield rate is also low. In the all-solid-state batteries of Comparative Examples 3 and 4, where the positive electrode insulating film is applied via a tape method rather than a transfer method, it can be confirmed that although the initial capacity is high, the yield rate is low at 5% or less and a short circuit occurs after only one cycle.

Claims

1. A positive electrode layer comprising a positive electrode current collector and a positive electrode active material layer; A cathode layer comprising a cathode current collector and a cathode coating layer; A solid electrolyte layer disposed between the anode layer and the cathode layer; and The anode insulating film on one side of the anode active material layer, wherein The above-mentioned positive current collector includes an active portion and a tab portion, the tab portion includes an edge region adjacent to the active portion and a non-active region extending from the edge region, and the positive insulating film is: An adhesive layer in direct contact with one side of the positive active material layer; and It includes an insulating layer on the adhesive layer above, and The above positive insulating film is an all-solid-state battery extending from the positive protrusion of the positive active material layer onto the uninsulated region.

2. In Paragraph 1, The above solid electrolyte layer is: A first solid electrolyte layer adjacent to the anode layer; and It includes a second solid electrolyte layer adjacent to the above-mentioned cathode layer, and An all-solid-state battery further comprising an inert member disposed on the second solid electrolyte layer, surrounding the side of the positive active material layer, the side of the first solid electrolyte layer, and the side of the positive insulating film.

3. In Paragraph 2, The above inert member is: A first inert member on the side of the anode insulating film; and It includes a second inert member on the side of the positive active material layer and the side of the first solid electrolyte layer, A solid-state battery in which the width of the first inert member is smaller than the width of the second inert member.

4. In Paragraph 2, An all-solid-state battery further comprising the anode insulating film, the inert member, the second solid electrolyte layer, and the first solid electrolyte layer interposed between them.

5. In Paragraph 4, The above air gap is a void or a seam in an all-solid-state battery.

6. In Paragraph 1, The above solid electrolyte layer is: A first solid electrolyte layer adjacent to the anode layer; and It includes a second solid electrolyte layer adjacent to the above-mentioned cathode layer, and The width of the positive active material layer is greater than or equal to the width of the first solid electrolyte layer in an all-solid-state battery.

7. In Paragraph 6, One side of the above positive active material layer includes a curved surface, and A solid-state battery having a side of the anode insulating film having a curved surface corresponding to the one side.

8. In Paragraph 2, An all-solid-state battery further comprising a fixed layer disposed between the inert member and the second solid electrolyte layer.

9. In Paragraph 1, A solid-state battery in which the height of the anode insulating film is greater than or equal to the thickness of the anode active material layer.

10. In Paragraph 9, The above solid electrolyte layer is: A first solid electrolyte layer adjacent to the anode layer; and It includes a second solid electrolyte layer adjacent to the above-mentioned cathode layer, and A solid-state battery in which the height of the anode insulating film is smaller than the sum of the thickness of the anode active material layer and the thickness of the first solid electrolyte layer.

11. In Paragraph 1, The above adhesive layer includes a binder, and The above insulating layer comprises an organic material, an inorganic material, a binder, or a combination thereof, in an all-solid-state battery.

12. In Paragraph 8, The above fixed layer comprises pulp fibers, glass fibers, a binder, aluminum hydroxide (Al(OH)3), or a combination thereof, in an all-solid-state battery.

13. First monocell; and Including a second monocell on the first monocell above, The second monocell is arranged vertically symmetrically with respect to the first monocell, and Each of the first and second monocells comprises an anode layer including an anode current collector and an anode active material layer, a cathode layer, a solid electrolyte layer disposed between the anode layer and the cathode layer, and an anode insulating film on one side of the anode layer. The above positive insulating film is disposed extending from one side of the positive active material layer onto the unprotected region of the positive current collector, and The above solid electrolyte layer includes a first solid electrolyte layer adjacent to the anode layer and a second solid electrolyte layer adjacent to the cathode layer, and A solid-state battery in which the positive layer of the first monocell and the positive layer of the second monocell face each other, and the positive insulating film of the first monocell and the positive insulating film of the second monocell face each other.

14. In Paragraph 13, Each of the above first and second monocells is: An inert member disposed on the second solid electrolyte layer, surrounding the side of the positive active material layer, the side of the first solid electrolyte layer, and the side of the positive insulating film; and The air gap surrounded by the anode insulating film, the inert member, the second solid electrolyte layer, and the first solid electrolyte layer is further included. The above air gap is a void or seam in an all-solid-state battery.

15. In Paragraph 14, Each of the first and second monocells further comprises a fixed layer disposed between the inert member and the second solid electrolyte layer, forming an all-solid-state battery.

16. In Paragraph 13, A solid-state battery in which the height of the anode insulating film is greater than the thickness of the anode active material layer and less than the sum of the thickness of the anode active material layer and the thickness of the first solid electrolyte layer.

17. In Paragraph 13, The above anode insulating film comprises an adhesive layer on one side of the anode active material layer and an insulating layer on the adhesive layer, and The above adhesive layer includes a binder, and The above insulating layer comprises an organic material, an inorganic material, a binder, or a combination thereof, in an all-solid-state battery.

18. In Paragraph 15, The above fixed layer comprises pulp fibers, glass fibers, a binder, aluminum hydroxide (Al(OH)3), or a combination thereof, and All-solid-state battery having an adhesive strength of the fixed layer of 50 gf / 25mm to 300 gf / 25mm.

19. Forming an anode laminate by laminating an anode layer and a first solid electrolyte layer and then applying a first pressure; A cathode layer and a second solid electrolyte layer are laminated, and then a second pressure is applied to form a cathode laminate; Transferring an anode insulating film onto one side of the anode laminate; and The method includes bonding the first solid electrolyte layer and the second solid electrolyte layer to combine the anode laminate and the cathode laminate, wherein A method for manufacturing an all-solid-state battery, wherein transferring the anode insulating film comprises sequentially laminating an adhesive layer, an insulating layer, and an adhesive substrate layer on the anode laminate and removing the adhesive substrate layer.

20. In Paragraph 19, Forming the anode laminate comprises laminating a first functional layer on the first solid electrolyte layer before applying the first pressure, and Forming the above cathode laminate includes laminating a second functional layer on the second solid electrolyte layer before applying the second pressure, and A method for manufacturing an all-solid-state battery, further comprising removing the first functional layer and the second functional layer before combining the positive electrode laminate and the negative electrode laminate.

Images