All-solid-state battery and manufacturing method therefor

Abstract

The present invention relates to a method for manufacturing an all-solid-state battery and an all-solid-state battery manufactured thereby. More specifically, the method for manufacturing an all-solid-state battery of the present invention includes laminating an electrode laminate including a first electrode and a second electrode in a first direction. The laminating includes: aligning the electrode laminate such that a first tab portion protruding to a front side portion of the electrode laminate faces the first direction; disposing a first stress relief member adjacent to at least one side of the first tab portion; and passing the electrode laminate and the first stress relief member through a pressing roller in the first direction.

Description

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

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

[0002] Recently, accompanied by the rapid proliferation of battery-powered electronic devices such as mobile phones, laptop computers, and electric vehicles, the demand for high-energy-density, high-capacity rechargeable batteries is rapidly increasing. Accordingly, research and development to improve the performance of lithium-ion batteries is actively underway.

[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 a method for manufacturing an all-solid-state battery capable of applying uniform pressure to an electrode laminate during a lamination process.

[0005] Another problem that the present invention aims to solve is to provide a method for manufacturing an all-solid-state battery that can prevent damage to the electrode tab during the lamination process.

[0006] Another problem that the present invention aims to solve is to provide an all-solid-state battery with excellent interfacial resistance and an undamaged electrode tab.

[0007] A method for manufacturing an all-solid-state battery according to the concept of the present invention may include laminating an electrode stack comprising a first electrode and a second electrode in a first direction. The lamination may include: aligning the electrode stack such that a first tab portion protruding from the front side of the electrode stack faces the first direction; arranging a first stress relief member adjacent to at least one side of the first tab portion; and passing the electrode stack and the first stress relief member through a pressure roller in the first direction.

[0008] An all-solid-state battery according to another concept of the present invention may include a positive electrode layer; a negative electrode layer; a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer; and an inert member surrounding the side of the positive electrode layer. The inert member includes a side portion extending in a first direction, a front side portion extending in a second direction intersecting the first direction, and a corner defined where the front side portion and the side portion meet, and the corner of the inert member may include a recess region.

[0009] Through the manufacturing method according to the embodiments of the present invention, uniform pressure can be applied to the electrode laminate during the lamination process, and damage to the electrode tab can be prevented. In addition, the adhesion between interfaces of the manufactured all-solid-state battery can be improved, and the interfacial resistance can be improved.

[0010] FIG. 1 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention.

[0011] FIG. 2 is a plan view of an all-solid-state battery according to one embodiment of the present invention.

[0012] FIG. 3 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0013] FIG. 4 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0014] FIG. 5 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0015] FIG. 6 is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0016] FIG. 7a is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0017] FIG. 7b is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0018] FIG. 8a is a plan view illustrating a lamination process according to a comparative example. FIG. 8b is a cross-sectional view illustrating a lamination process according to a comparative example.

[0019] FIG. 9a is a plan view illustrating a lamination process according to one embodiment. FIG. 9b is a cross-sectional view illustrating a lamination process according to one embodiment.

[0020] FIG. 10 is a plan view for explaining a method for manufacturing an all-solid-state battery according to one embodiment.

[0021] FIG. 11a is a plan view illustrating a method for manufacturing an all-solid-state battery according to one embodiment. FIG. 11b is an enlarged view of FIG. 11a illustrating a stress relief member according to one embodiment. FIG. 11c is a right side view of FIG. 11a illustrating a stress relief member according to one embodiment. FIG. 11d is a plan view illustrating a stress relief member according to an embodiment different from FIG. 11a.

[0022] FIG. 12 is a plan view for explaining a method for manufacturing an all-solid-state battery according to one embodiment.

[0023] FIGS. 13a and 13b are plan views illustrating structural changes in an inert member that occur when an electrode stack passes through a pressure roller and an all-solid-state battery including the same. FIG. 13c is a plan view illustrating an inert member with recessed corners.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029]

[0030] All-solid-state battery

[0031] 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.

[0032] 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).

[0033] 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.

[0034] 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.

[0035] 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).

[0036] 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 oxIED), lithium nickel cobalt oxide (Lithium nickel cobalt oxIED), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganese oxide (Lithium manganate), and lithium iron phosphate, as well as nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide (vanadium oxIED), 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.

[0037] 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 E1-b B b O 2-c D c (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05), LiE 2-b B b O 4-c D c (0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Co b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Mr b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Ni 1-b-c Mr b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni b HAVE BEEN c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Ni b Co c Mr d GeO2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1), Li a NiG b O2(0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a MnG bO2(0.90≤a≤1, 0.001≤b≤0.1), Li a Mn2GbO4(0.90≤a≤1, 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3(0≤f≤2), Li 3-f It is a compound represented by any one of Fe2(PO4)3 (0≤f≤2) or LiFePO4. In such compounds, the uppercase “A” is Ni, Co, Mn, or a combination thereof; the uppercase “B” is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; the uppercase “D” is O, F, S, P, or a combination thereof; the uppercase “E” is Co, Mn, or a combination thereof; the uppercase “F” is F, S, P, or a combination thereof; the uppercase “G” is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; the uppercase “Q” is Ti, Mo, Mn, or a combination thereof; the uppercase “I” is Cr, V, Fe, Sc, Y, or a combination thereof; and the uppercase “J” is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0038] 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 z O2(NCM) (0 <x<1,0<y<1, 0<z<1, x+y+z=1) 등의 삼원계 리튬전이금속산화물일 수 있다. 양극 활물질이 층상암염형 구조를 갖는 삼원계 리튬전이금속산화물을 포함하는 경우, 전고체 전지(10)의 에너지 밀도가 커지고 열안정성이 향상될 수 있다.

[0039] 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.

[0040] 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.

[0041] The positive active material may have particle shapes such as, for example, spheres or ellipsoids. The particle size and content of the positive active material are not particularly limited.

[0042] 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 “Z” is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are positive numbers, uppercase “M” is one of P, Si, Ge, B, Al, Ga, In), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It may include at least one selected from (0≤x≤2).

[0043] 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 xIt 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] 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).

[0056] Meanwhile, although not shown, a carbon layer may be further included to improve adhesion between the cathode coating layer (220) and the solid electrolyte layer (300).

[0057] 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).

[0058] The solid electrolyte layer (300) may include an anode solid electrolyte layer (310) and a cathode solid electrolyte layer (320). The anode solid electrolyte layer (310) may be adjacent to the anode layer (100), and the cathode solid electrolyte layer (320) may be adjacent to the cathode layer (200).

[0059] The negative solid electrolyte layer (320) can be in direct contact with the negative coating layer (220). By doing so, the negative solid electrolyte layer (320) can suppress lithium dendrites formed between the negative coating layer (220) and the negative current collector (210). The negative 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.

[0060] The solid electrolyte in the solid electrolyte layer (300) may have particle shapes such as spheres or ellipsoids.

[0061] 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.

[0062] 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 a real number between 0 and 2.

[0063] 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.

[0064] 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).

[0065] Referring again to FIG. 1, the anode solid electrolyte layer (310) may have a first thickness (t1), and the cathode 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) and the second thickness (t2) may have different thicknesses. The second thickness (t2) may be greater than the first thickness (t1).

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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 anode solid electrolyte layer (310) is observed to be greater than the interface resistance between the cathode layer (220) and the cathode 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.

[0070] One embodiment of the present invention can solve process problems that may occur when the interfacial resistance between the anode layer (120) and the anode solid electrolyte layer (310) is different from the interfacial resistance between the cathode layer (220) and the cathode solid electrolyte layer (320) by dividing the solid electrolyte (300) into an anode solid electrolyte layer (310) and a cathode 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.

[0071] One embodiment of the present invention divides the solid electrolyte layer (300) into a positive electrode solid electrolyte layer (310) and a negative electrode 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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).

[0077] In one embodiment of the present invention, the anode solid electrolyte layer (310) may have substantially the same area as the anode layer (100). The cathode solid electrolyte layer (320) may have substantially the same area as the cathode layer (200).

[0078] Referring to FIGS. 1 and 2, the anode solid electrolyte layer (310) may have a first width (W1) in a first direction (D1). The cathode solid electrolyte layer (320) may have a second width (W2) in a first direction (D1). The first width (W1) may be smaller than the second width (W2).

[0079] 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.

[0080] 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.

[0081] 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.

[0082] Referring to FIGS. 1 and 2, the anode solid electrolyte layer (310) may have a third width (W3) in the second direction (D2). The cathode 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).

[0083] 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.

[0084] 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.

[0085] 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.

[0086]

[0087] 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.

[0088] 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) acts 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).

[0089] 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.

[0090] 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).

[0091] 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.

[0092] Referring to FIG. 4, the bi-cell all-solid-state battery (20) may include a first monocell (510) and a second monocell (520).

[0093] 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 an anode solid electrolyte layer (310) adjacent to the anode layer (100) and having a first width (W1) and a first thickness (t1), and a cathode 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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 positive electrode 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.

[0100] 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.

[0101] The above inert member (INM) may be disposed between the negative solid electrolyte layer (320) of the first monocell (510) and the negative 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).

[0102] The thickness of the inert member (INM) may be equal to or smaller 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 anode 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 cathode 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 anode solid electrolyte layer (310) of the second monocell (520) and the thickness of the anode layer (100), the anode layer (100) and the anode solid electrolyte layer (310) may not be sufficiently pressurized.

[0103]

[0104] FIG. 7a is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention. Detailed descriptions of technical features that overlap with those previously described with reference to FIG. 1 to 6 are omitted, and the differences are described in detail.

[0105] Referring to FIG. 7a, 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 have a portion protruding from the positive active material layer (120) in a first direction (D1). The protruding portion may be a positive non-positive portion. The protruding portion may be a tab of the positive. The negative current collector (210) may provide a reference surface 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 opposite direction of the first direction (D1). The protruding portion may be a tab of the negative.

[0106] The inert member (INM) may surround the side of the positive active material layer (120), the side of the positive solid electrolyte layer (310), and one side of the positive insulating film (CIL) described later. The inert member (INM) may be placed on the negative solid electrolyte layer (320).

[0107] In one embodiment, the inert member (INM) may be separated from the anode active material layer (120) and the anode solid electrolyte layer (310) by the anode insulating film (CIL) described later.

[0108] 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 an inert member (INM). The positive insulating film (CIL) may be provided on the boundary between the tab of the positive current collector (110) and the positive active material layer (120). The positive insulating film (CIL) may protect the side of the positive active material layer (120) adjacent to the tab of the positive. By including the positive insulating film (CIL), short circuits or electrical short circuits of the positive layer (100) are prevented during manufacturing and / or charging and discharging of the all-solid-state battery (10), and consequently, the lifespan characteristics and cycle characteristics of the all-solid-state battery (10) may be improved.

[0109] As the positive insulating film (CIL) is formed to be in contact with the positive active material layer (120) without contacting the positive solid electrolyte layer (310), the all-solid-state battery (10) may further include an air gap (AGP) between the positive solid electrolyte layer (310) and the inert member (INM). Specifically, the air gap (AGP) may be interposed between the positive insulating film (CIL), the inert member (INM), the negative solid electrolyte layer (320), and the positive solid electrolyte layer (310). For example, the air gap (AGP) may be a void or a seam.

[0110]

[0111] FIG. 7b is a cross-sectional view of an all-solid-state battery according to another embodiment of the present invention.

[0112] Referring to FIG. 7b, the bi-cell all-solid-state battery (20) may include a first monocell (510) and a second monocell (520).

[0113] 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).

[0114] Each of the first and second monocells (510, 520) may further include an inert member (INM) disposed on the cathode solid electrolyte layer (320) and an air gap (AGP) surrounded by the inert member (INM), the cathode solid electrolyte layer (320), and the anode solid electrolyte layer (310), surrounding the side of the positive active material layer (120), the side of the positive 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.

[0115] The solid electrolyte layer (300) of each of the first and second monocells (510, 520) may include an anode solid electrolyte layer (310) adjacent to the anode layer (100) and having a first width and a first thickness, and a cathode 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.

[0116]

[0117] Hereinafter, a method for manufacturing an all-solid-state battery according to the embodiments is described in detail.

[0118] Method for manufacturing all-solid-state batteries

[0119] A method for manufacturing an all-solid-state battery according to embodiments of the present invention includes laminating an electrode stack by applying a stress-relieving member.

[0120] FIG. 8a is a plan view illustrating a lamination process according to a comparative example. FIG. 8b is a cross-sectional view illustrating a lamination process according to a comparative example. Referring to FIG. 8a and FIG. 8b, when a heating roll press is performed using a pressure roller (ROL) in the process of laminating an electrode laminate (ETS), the upper roller (URO) and the lower roller (LRO) may become thicker in the center than at both ends due to thermal expansion. As a result, uneven pressure may be applied to the electrode laminate (ETS), such as high pressure being applied to the center of the electrode laminate (ETS) and low pressure being applied to both ends. Consequently, bonding defects may occur at both ends of the electrode laminate where low pressure is applied, and brittleness may worsen in the center where high pressure is applied.

[0121] Meanwhile, FIG. 9a is a plan view illustrating a lamination process according to one embodiment. FIG. 9b is a cross-sectional view illustrating a lamination process according to one embodiment. Referring to FIG. 9a and FIG. 9b, the method for manufacturing an all-solid-state battery according to embodiments of the present invention can improve the pressure difference applied to the center and both ends of an electrode stack by aligning the electrode stack vertically in the lamination direction, i.e., the MD direction (machine direction), and roll pressing. In other words, by minimizing the width of the electrode stack (ETS) passing through the pressure roller, uniform pressure can be applied to the electrode stack (ETS).

[0122] Furthermore, by placing a stress relief member adjacent to at least one side of the tab portion (TAB) and performing roll pressing, the stress applied to the tab portion (TAB) of the electrode laminate (ETS) can be relieved, and consequently, the tab portion (TAB) can be protected. Hereinafter, a method for manufacturing an all-solid-state battery according to embodiments will be described in more detail with reference to FIGS. 10 to 12.

[0123] FIGS. 10 to 12 are plan views for explaining a method for manufacturing an all-solid-state battery according to embodiments of the present invention.

[0124] Referring to FIG. 10, a method for manufacturing an all-solid-state battery according to embodiments of the present invention may include aligning electrode stacks (ETS).

[0125] In one embodiment, the electrode laminate (ETS) may be aligned such that the length (LN) of the electrode laminate (ETS) laminated along the first direction (D1) is greater than the width (WI) of the electrode laminate (ETS) laminated in the second direction (D2). As a result, the distance between the two ends of the electrode laminate (ETS) is shortened, and consequently, uniform pressure can be applied to the electrode laminate (ETS) during roll pressing. As an example, the electrode laminate (ETS) may be aligned on a driving material (DRM).

[0126] In one embodiment, the electrode stack (ETS) may include a first electrode and a second electrode. The first electrode may include either an anode layer or a cathode layer, and the second electrode may include the other of the anode layer and the cathode layer. In one embodiment, each of the first electrode and the second electrode may further include a solid electrolyte layer. For example, the first electrode may include a cathode layer and a cathode solid electrolyte layer, and the second electrode may include an anode layer and an anode solid electrolyte layer. Each of the anode layer, cathode layer, solid electrolyte layer, and inert member may be the same as those described above with reference to FIGS. 1 to 7.

[0127] In one embodiment, the area of ​​the first electrode and the area of ​​the second electrode may be different. The electrode stack (ETS) may include an inert member that compensates for the difference in area between the first electrode and the second electrode. As an example, the electrode stack (ETS) may have a structure in which the second electrode is stacked on the first electrode. The area of ​​the second electrode is smaller than the area of ​​the first electrode, and an inert member (INM) to compensate for the area difference may be disposed on the side of the first electrode.

[0128] In one embodiment, the electrode stack (ETS) may include first and second tab portions (TAB1, TAB2). The first tab portion (TAB1) may be either an anode tab or a cathode tab, and the second tab portion (TAB2) may be the other of an anode tab and a cathode tab.

[0129] The electrode stack (ETS) may include a front side (FSD), a rear side (RSD), and a side (SID). The side (SID) may include a left side (LSD) and a right side (RSD). A first tab portion (TAB1) may protrude to the front side (FSD) of the electrode stack (ETS). A second tab portion (TAB2) may protrude to the rear side (RSD) of the electrode stack (ETS).

[0130] In one embodiment, the lengths of the front side (FSD) and rear side (BSD) of the electrode stack (ETS) may each correspond to the width (WI) of the electrode stack (ETS). The length of the side (SID) of the electrode stack (ETS) may correspond to the length (LN) of the electrode stack (ETS). That is, the lengths of the left side (LSD) and right side (WSD) may each correspond to the length (LN) of the electrode stack (ETS). The length of the front side (FSD) of the electrode stack (ETS) may be greater than the lengths of the left side (LSD) and right side (RSD), respectively. Additionally, it may be greater than the length of the side (SID) of the electrode stack (ETS). A first tab portion (TAB1) and a second tab portion (TAB2) may protrude from the front side (FSD) and rear side (BSD), respectively, which are relatively shorter in length.

[0131] In one embodiment, the first tab portion (TAB1) and the second tab portion (TAB2) may be aligned along the first direction (D1).

[0132] Referring again to FIG. 10, in one embodiment, aligning the electrode stack (ETS) may include aligning the electrode stack (ETS) such that a first tab portion (TAB1) protruding from the front side (FSD) of the electrode stack (ETS) faces a first direction (D1). Through this, a second tab portion (TAB2) protruding from the rear side (BSD) of the electrode stack (ETS) may be aligned to face the opposite direction of the first direction (D1). The electrode stack (ETS) may then be laminated along the first direction (D1). Specifically, the electrode stack (ETS) may be roll-pressed along the first direction (D1). As an example, the electrode stack (ETS) may be heat-roll-pressed.

[0133] In one embodiment, a method for manufacturing an all-solid-state battery may include manufacturing a first electrode and a second electrode. Specifically, it may include manufacturing a first electrode by applying a first pressure after stacking a negative electrode layer and a negative electrode solid electrolyte layer; and manufacturing a second electrode by applying a second pressure after stacking an anode layer and a positive electrode solid electrolyte layer. The first pressure may be greater than the second pressure.

[0134] In one embodiment, the first 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 first pressure may be 3.0 ton / cm.

[0135] In one embodiment, the second 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. As an example, the second pressure may be 3.5 ton / cm.

[0136] A method for manufacturing an all-solid-state battery according to embodiments of the present invention may include placing a stress relief member (SRM).

[0137] FIG. 11a is a plan view illustrating the arrangement of a stress relief member according to one embodiment. FIG. 11b is an enlarged view of FIG. 11a illustrating a stress relief member according to one embodiment.

[0138] Referring to FIG. 11a, in one embodiment, a first stress relief member (SRM1) may be positioned adjacent to at least one side of the first tab portion (TAB1). As an example, first stress relief members (SRM1a, SRM1b) may be positioned on each of both sides of the first tab portion (TAB1).

[0139] Additionally, a second stress relief member (SRM2) may be positioned adjacent to at least one side of the second tab portion (TAB2). For example, second stress relief members (SRM2a, SRM2b) may be positioned on each of the two sides of the second tab portion (TAB2).

[0140] In one embodiment, the first and second stress relief members (SRM1, SRM2) may be disposed on a driving substrate (DRM) together with an electrode laminate (ETS).

[0141] In one embodiment, the stress relief member (SRM) may have a shape that wraps around the side edges of the electrode laminate (ETS).

[0142] In one embodiment, the first stress relief member (SRM1) may have a shape that wraps around the corner formed by the meeting of the side (SID) and the front side (FSD) of the electrode laminate (ETS). The first stress relief member (SRM1) may have a shape that wraps around the corner formed by the meeting of the front side (FSD) and either the left side (LSD) or the right side (RSD) of the electrode laminate (ETS).

[0143] In one embodiment, the first stress relief member (SRM1) may include a first part (PAR1a) that guards the front side (FSD) of the electrode stack (ETS); and a second part (PAR2a) that guards the side (SID) of the electrode stack (ETS). The first stress relief member (SRM1) may further include a connecting part (COPa) that connects the first part (PAR1a) and the second part (PAR2a). The first part (PAR1) and the second part (PAR2) may be connected to each other to surround the corner formed where the side (SID) and the front side (FSD) of the stack (ETS) meet.

[0144] In one embodiment, the second stress relief member (SRM2) may have a shape that wraps around the corner formed by the meeting of the side (SID) and the rear side (BSD) of the electrode stack (ETS). The second stress relief member (SRM2) may have a shape that wraps around the corner formed by the meeting of either the left side (LSD) or the right side (RSD) of the electrode stack (ETS) and the rear side (BSD) of the electrode stack (ETS).

[0145] In one embodiment, the second stress relief member (SRM2) may include a first part (PAR1b) that guards the rear side (BSD) of the electrode stack (ETS); and a second part (PAR2b) that guards the side (SID) of the electrode stack (ETS). The second stress relief member (SRM2) may further include a connecting part (COPb) that connects the first part (PAR1b) and the second part (PAR2b). The first part (PAR1) and the second part (PAR2) may be connected to each other to surround the corner formed where the side (SID) and the rear side (BSD) of the stack (ETS) meet.

[0146] The stress relief member (SRM) can maintain the alignment of the electrode laminate (ETS) during the lamination process by having the shape described above.

[0147] In one embodiment, the stress relief member (SRM) may comprise at least one of porous pulp and a porous polymer film. The porous polymer film may comprise at least one of a polyethylene terephthalate (PET) film, a polyethylene (PE) film, and a polytetrafluoroethylene (PTFE) film.

[0148] For example, the stress relief member (SRM) may be porous pulp. By using porous pulp, pressure deformation of the stress relief member (SRM) can be minimized, and consequently, tab damage can be prevented.

[0149] In one embodiment, the second portion (PAR2a) of the first stress relief member (SRM1) may include a rear portion (SRS1). The electrode laminate (ETS) may include a positive active material layer (PML) inside. The positive active material layer (PML) may be any one of the positive active material layers (120) described above with reference to FIGS. 1 to 7b.

[0150] In one embodiment, the rear portion (SRS1) of the second portion (PAR2a) of the first stress relief member (SRM1) can be aligned with the front portion (PRS) of the positive active material layer (PML) in the second direction (D2).

[0151] In one embodiment, the rear portion (SRS1) of the second portion (PAR2a) of the first stress relief member (SRM1) may be aligned further forward in the first direction (D1) than the front portion (PRS) of the positive active material layer (PML). When the rear portion (SRS1) of the second portion (PAR2a) of the first stress relief member (SRM1) is aligned further back than the front portion (PRS) of the positive active material layer (PML), the first stress relief member (SRM1) and the positive active material layer (PML) may be pressed together, which may result in a bonding defect. Specifically, a bonding defect between the interfaces of the electrode stack (ETS) may occur, and the interfacial resistance may increase.

[0152] In one embodiment, the second portion (PAR2b) of the second stress relief member (SRM2) may include a front portion (SFS2). The front portion (SFS2) of the second portion (PAR2b) of the second stress relief member (SRM2) may be aligned with the rear portion (BRS) of the positive active material layer (PML) in a second direction (D2).

[0153] In one embodiment, the rear portion (BRS) of the positive active material layer (PML) may be aligned further forward in the first direction (D1) than the front portions (SFS2) of the second portion (PAR2b) of the second stress relief member (SRM2). When the rear portion (BRS) of the positive active material layer (PML) is aligned further back than the front portion (SFS2) of the second portion (PAR2b) of the second stress relief member (SRM2), the second stress relief member (SRM2) and the positive active material layer (PML) may be pressed together, which may result in a bonding defect. Specifically, a bonding defect between the interfaces of the electrode stack (ETS) may occur, and the interfacial resistance may increase.

[0154] In other words, by positioning the stress relief member (SRM) so that the stress relief member (SRM) and the positive active material layer (PML) have a predetermined gap in the first direction (D1), the stress relief member (SRM) and the positive active material layer (PML) can be prevented from being pressed together by the pressure roller (ROL). Through this, the bonding strength between the interfaces of the electrode stack (ETS) can be improved and the interfacial resistance can be improved. Meanwhile, the stress relief member (SRM) and the tab portion (TAB) can be pressed together by the pressure roller (ROL) to disperse the stress applied to the tab portion (TAB).

[0155] Referring to FIG. 11a and FIG. 11b, in one embodiment, a first portion (PAR1a) of a first stress relief member (SRM1) may have a first gap (GP1) in a first direction from a front portion (FDS) of an electrode stack (ETS). Specifically, the front portion (FDS) of the electrode stack (ETS) may include a first region (RG1) in which a first tab portion (TAB1) protrudes, and a second region (RG2) which is a region excluding the first region (RG1). The first portion (PAR1a) of the first stress relief member (SRM1) may have a first gap (GP1) in a first direction from the second region (RG2) of the front portion (FDS) of the electrode stack (ETS).

[0156] In another embodiment, although not illustrated, a first portion (PAR1a) of the first stress relief member (SRM1) may be in contact with the front side (FDS) of the electrode laminate (ETS). Specifically, the first portion (PAR1a) of the first stress relief member (SRM1) may be in contact with a second region (RG2) of the front side (FDS).

[0157] In one embodiment, the pressure roller (ROL) may include an area where the upper roller (URO) and the lower roller (LRO) come into contact. The first gap (GP1) may be smaller than the length in the first direction of the area where the upper roller (URO) and the lower roller (LRO) of the pressure roller (ROL) come into contact. Otherwise, a section may occur where the pressure roller (ROL) presses only the tab portion (TAB) of the electrode laminate (ETS) without a stress relief member, and the tab portion (TAB) may be damaged. Specifically, the first gap (GP1) may be 3 mm or less. As an example, the first gap (GP1) may be 0 mm to 3 mm or 0.1 mm to 3 mm.

[0158] Referring again to FIG. 11a, in one embodiment, a first portion (PAR1a) of a first stress relief member (SRM1) may have a first length (L1) in a first direction (D1).

[0159] The first tab portion (TAB1) may have a second length (L2) in the first direction (D1).

[0160] In one embodiment, the ratio (L1 / L2) of the first length (L1) to the second length (L2) may be 1 or more, specifically 1 to 3, 1 to 2, or 1 to 1.5.

[0161] In one embodiment, the first length (L1) may be 5 mm to 30 mm, 10 mm to 30 mm, or 15 mm to 25 mm.

[0162] In one embodiment, the length of the second part (PAR2a) in the first direction (D1) may be 5 mm to 30 mm, 10 mm to 30 mm, or 15 mm to 25 mm.

[0163] In one embodiment, the sum of the first length (L1) and the first gap (GP1) of the first stress relief member (SRM1) may be equal to or greater than the second length (L2) of the first tab portion (TAB1). By doing so, the first tab portion (TAB1) is first inserted into the pressure roller, thereby preventing it from being pressed alone without the stress relief member.

[0164] In one embodiment, a first portion (PAR1a) of the first stress relief member (SRM1) may have a first width (WD1) in the second direction (D2). A second portion (PAR2a) of the first stress relief member (SRM1) may have a third width (WD3) in the second direction (D2). A first tab portion (TAB1) may have a second width (WD2) in the second direction (D2).

[0165] In one embodiment, the ratio of the sum of the first width (WD1) and the third width (WD3) of the first stress relief member (SRM1) to the second width (WD2) of the first tab portion (TAB1) ((WD1+WD3) / WD2) may be 0.2 to 3, 0.4 to 1, or 0.4 to 0.6. If the above range is exceeded, process efficiency may decrease due to equipment expansion.

[0166] In one embodiment, the sum of the first width (WD1) and the third width (WD3) (WD1+WD3) may be 5 mm to 40 mm, 10 mm to 30 mm, or 15 mm to 25 mm.

[0167] In one embodiment, the first width (WD1) of the first part (PAR2a) may be 5 mm to 40 mm, or 10 mm to 30 mm.

[0168] In one embodiment, the third width (WD3) of the second part (PAR2a) may be 1 mm or more, 5 mm or more, or 10 mm or more. Specifically, it may be 1 mm to 25 mm, 5 mm to 25, or 10 mm to 25 mm.

[0169] FIG. 11c is a right-side view of FIG. 11a to illustrate a stress-relieving member.

[0170] Referring to FIG. 11c, in one embodiment, the stress relief member (SRM) may have a first thickness (TK1) in the third direction (D3). The electrode laminate (ETS) may have a second thickness (TK2) in the third direction (D3).

[0171] Referring to FIG. 11a and FIG. 11c, in one embodiment, the ratio (TK1 / TK2) of the first thickness (TK1) of the stress relief member (SRM) to the second thickness (TK2) of the electrode laminate (ETS) may be 1 to 2. Specifically, the ratio (TK1 / TK2) of the first thickness (TK1) of the stress relief member (SRM) to the second thickness of the electrode laminate (ETS) may be 1.3 to 1.5. If the ratio of the first thickness (TK1) to the second thickness (TK2) is smaller than the above range, a high linear pressure is applied to the tab portion (TAB), and cutting may occur. If the ratio of the first thickness (TK1) to the second thickness (TK2) is larger than the above range, damage to the electrode laminate (ETS) may occur due to an increase in the step difference between the stress relief member (SRM) and the electrode laminate (ETS).

[0172]

[0173] FIG. 11d is a plan view illustrating a stress relief member (SRM) according to another embodiment. In this embodiment, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 11a to 11c are omitted, and the differences are described in detail.

[0174] Referring to FIG. 11d, the first stress relief member (SRM1) may include a first part (PAR1a) that guards the front side (FSD) of the electrode stack (ETS). Specifically, the first stress relief member (SRM1) may be composed of a first part (PAR1a) that guards the front side (FSD) of the electrode stack (ETS).

[0175] The first tab portion (TAB1) and the first stress relief members (SRM1a, SRM1b) can be aligned along the second direction (D2).

[0176] The first stress relief member (SRM1) may have a first gap (GP1') in a first direction from the front side (FDS) of the electrode laminate (ETS). Specifically, the front side (FDS) of the electrode laminate (ETS) may include a first region (RG1) in which a first tab portion (TAB1) protrudes, and a second region (RG2) which is a region excluding the first region (RG2). The first stress relief member (SRM1) may have a first gap (GP1') in a first direction from the second region (RG2) of the front side (FDS) of the laminate (ETS).

[0177] In another embodiment, although not illustrated, the first stress relief member (SRM1) may be in contact with the front side (FDS) of the electrode laminate (ETS). Specifically, the first stress relief member (SRM1) may be in contact with the second region (RG2) of the front side (FDS).

[0178] In one embodiment, the first gap (GP1') may be smaller than the length in the first direction of the contact area between the upper roller (URO) and the lower roller (LRO) of the pressure roller (ROL). Otherwise, a section may occur where the pressure roller (ROL) presses only the tab portion (TAB) of the electrode laminate (ETS) without a stress relief member, and the tab portion (TAB) may be damaged. Specifically, the first gap (GP1') may be 3 mm or less. As an example, the first gap (GP1) may be 0 mm to 3 mm or 0.1 mm to 3 mm.

[0179] Referring again to FIG. 11d, in one embodiment, the first stress relief member (SRM) may have a first length (L1) in a first direction (D1). The first tab portion (TAB1) may have a second length (L2) in the first direction (D1).

[0180] In one embodiment, the sum of the first length (L1) and the first gap (GP1) of the first stress relief member (SRM) may be equal to or greater than the second length (L2) of the first tab portion (TAB1). By doing so, the first tab portion (TAB1) can enter the pressure roller first, thereby preventing it from being pressed alone without the stress relief member.

[0181] In one embodiment, the ratio (L1 / L2) of the first length (L1) to the second length (L2) may be 1 or more, specifically 1 to 3, 1 to 2, or 1 to 1.5.

[0182] In one embodiment, the first length (L1) may be 5 mm to 30 mm, 10 mm to 30 mm, or 15 mm to 25 mm.

[0183] In one embodiment, the first stress relief member (SRM) may have a first width (WD1) in the second direction (D2). The first tab portion (TAB1) may have a second width (WD2) in the second direction (D2).

[0184] In one embodiment, the ratio (WD1 / WD2) of the first width (WD1) of the first stress relief member (SRM1) to the second width (W2) of the first tab portion (TAB1) may be 0.2 to 3, 0.4 to 1, or 0.4 to 0.6. If the above range is exceeded, process efficiency may decrease due to equipment expansion.

[0185] In one embodiment, the first width (WD1) may be 5 mm to 30 mm, 10 mm to 30 mm, or 15 mm to 25 mm.

[0186] Referring to FIG. 12, a method for manufacturing an all-solid-state battery according to embodiments of the present invention may include passing an electrode stack (ETS) and a stress relief member (SRM) together through a pressure roller (ROL). In one embodiment, the electrode stack (ETS) and the stress relief member (SRM) may be driven in a first direction (D1) and passed through the pressure roller (ROL).

[0187] The pressure roller (ROL) can apply a third pressure to the passing electrode laminate (ETS). In one embodiment, the third pressure may be 0.01 ton / cm to 1 ton / cm, or 0.1 ton / cm to 1 ton / cm.

[0188] A first stress relief member (SRM1) positioned adjacent to the side of the first tab portion (TAB1) can relieve stress applied to the first tab portion (TAB1).

[0189] A second stress relief member (SRM2) positioned adjacent to the side of the second tab portion (TAB2) can relieve stress applied to the second tab portion (TAB2).

[0190] In one embodiment, the stress relief member (SRM) can maintain the alignment of the electrode laminate (ETS) while passing through the pressure roller (ROL). In one example, the stress relief member (SRM) can be attached and fixed to the driving material (DRM).

[0191]

[0192] FIGS. 13a and 13b are plan views illustrating structural changes in an inert member that occur when an electrode stack passes through a pressure roller and an all-solid-state battery including the same. FIG. 13c is a plan view of an inert member inside an all-solid-state battery. FIG. 13c is a plan view illustrating an inert member (INM) with recessed corners.

[0193] Referring to FIGS. 13a and 13b, in one embodiment, as the electrode stack (ETS) passes through a pressure roller (ROL), the inert member (INM) may be stretched. The stretched inert member may collide with a stress relief member, and as a result, the side edges of the inert member may be recessed.

[0194] In one embodiment, the inert member (NM) may be an organic material, an inorganic material, or an organic-inorganic composite material. The organic material may be, for example, a polymer. The inorganic material may be a ceramic, for example, a metal oxide. The organic-inorganic composite material may be a composite of a polymer and a metal oxide. The inert member (400) may include one or more selected from, for example, an insulating polymer, an ion-conducting polymer, an insulating inorganic material, an oxide-based solid electrolyte, and a sulfide-based solid electrolyte. The inert member may be an olefin-based polymer, for example, polypropylene (PP) or polyethylene (PE). The inert member has excellent ductility by including the above-mentioned organic material.

[0195] Referring to FIG. 13c, the inert member (INM) may include a side portion (ISD) extending in a first direction (D1) and a front portion (IFD) extending in a second direction (D2). The inert member (INM) may include a rear portion (IBD) extending in a second direction (D2). The front portion (IFD) and the rear portion (IBD) of the inert member (INM) may be spaced apart from each other in the second direction (D1).

[0196] In one embodiment, the inert member (INM) may include an edge (IED) defined by the meeting of either the front side (IFD) or the rear side (IBD) and the side (ISD). As an example, the inert member (INM) may include a first edge (IED1) defined by the meeting of the front side (IFD) and the side (ISD). Additionally, the inert member (INM) may include a second edge (IED2) ​​defined by the meeting of the rear side (IBD) and the side (ISD).

[0197] In one embodiment, an edge (IED) of an inert member (INM) may include a recess area (RER). Specifically, a first edge (IED1) may include a first recess area (RER1). A second edge (IED2) ​​may include a second recess area (RER2).

[0198] In one embodiment, the first recess region (RER1) may be located on the front side (IFD) of the inert member (INM).

[0199] In one embodiment, the second recess region (RER2) may be located at the rear side (IBD) of the inert member (INM).

[0200] Referring again to FIG. 13b and FIG. 13c, the inert member (INM) may include a hollow portion (HOL). In one embodiment, a positive active material layer (PML) may be disposed within the hollow portion (HOL).

[0201] In one embodiment, referring to FIG. 13b and FIG. 13c, when viewed in a planar view, the rear portion (RBS) of the first recess region (RER1) may be located in a first direction ahead of the front portion (PRS) of the positive active material layer (PML). In other words, in an all-solid-state battery (CEL), the first recess region (RER1) of the inert member (INM) may have a predetermined gap along the first direction (D1) with the positive active material layer (PML) region. Alternatively, when viewed in a planar view, the rear portion (RBS) of the first recess region (RER1) may be aligned with the front portion (PRS) of the positive active material layer (PML) in a second direction (D2).

[0202] In one embodiment, referring to FIG. 13b and FIG. 13c, when viewed in a planar view, the front portion (RFS) of the second recess region (RER2) may be located behind the rear portion (BRS) of the positive active material layer (PML) in a first direction. In other words, in an all-solid-state battery (CEL), the second recess region (RER2) of the inert member (INM) may have a predetermined gap along the first direction (D1) with the positive active material layer (PML) region. Alternatively, when viewed in a planar view, the front portion (RFS) of the second recess region (RER2) may be aligned with the rear portion (BRS) of the positive active material layer (PML) in a second direction (D2).

[0203] By doing so, it is possible to prevent the stress relief member (SRM) and the positive active material layer (PML) from being simultaneously pressurized. The positive active material layer (PML) may be one of the positive active material layers (120) described above with reference to FIGS. 1 to 6, FIG. 7a, and FIG. 7b.

[0204] In one embodiment, the first tab portion (TAB1) and the second tab portion (TAB2) of the electrode stack (ETS) may be aligned along a first direction (D1). The first tab portion (TAB1) may be either an anode tab or a cathode tab, and the second tab portion (TAB2) may be the other of an anode tab and a cathode tab.

[0205] The electrode stack (ETS) is laminated while passing through a pressure roller (ROL), thereby allowing the manufacture of a solid-state cell (CEL). In one embodiment, the solid-state cell (CEL) manufactured may be one of the solid-state cells described with reference to FIGS. 1 to 6, FIG. 7a, and FIG. 7b.

[0206]

[0207] Hereinafter, embodiments and comparative examples of the present invention are described. However, the following embodiments are merely examples of the present invention, and the present invention is not limited to the following embodiments.

[0208] Example 1

[0209] (Cathode layer manufacturing)

[0210] A Ni foil with a thickness of 10 μm was prepared as a cathode 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 cathode coating layer 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 cathode coating layer of the laminate. The cathode layer was fabricated by the above process. The thickness of the cathode coating layer included in the cathode layer was approximately 10 μm. The area of ​​the cathode coating layer and the cathode current collector were the same. A cathode tab was formed on the cathode current collector with a width of 40 mm in the second direction and a length of 20 mm in the first direction.

[0211] (Anode layer manufacturing)

[0212] LiNi coated with Li2O-ZrO2 (LZO) as a positive electrode active material 0.8 Co 0.15 Mn 0.05 O2(NCM) was prepared. The LZO-coated cathode active material was prepared according to the method disclosed in Korean Patent Publication No. 10-2016-0064942.

[0213] 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. An anode tab was formed on the anode current collector, having a width of 40 mm in the second direction and a length of 20 mm in the first direction.

[0214] (Preparation of solid electrolyte layer)

[0215] 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.

[0216] A solid electrolyte layer was prepared by the above process. The above solid electrolyte layer was prepared by preparing an anode solid electrolyte layer having substantially the same area as the anode layer and a cathode solid electrolyte layer having substantially the same area as the cathode layer. The elastic modulus of the sulfide-based solid electrolyte was about 15 GPa to 30 GPa.

[0217] (Inert component)

[0218] 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.

[0219] An inert member (gasket) was prepared to surround the anode solid electrolyte layer and the anode active material layer adjacent to the anode layer on the solid electrolyte layer adjacent to the cathode layer.

[0220] (Electrode stack)

[0221] An anode layer and an anode 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 130°C. A cathode layer and a cathode 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 anode laminate was laminated on the cathode laminate so that the cathode tab and the anode tab were aligned in the first direction. Then, an inert member was placed on the side of the anode laminate to prepare an electrode laminate (thickness: 200 μm).

[0222] (Stress relief member)

[0223] A stress-relieving member having the shape described with reference to FIG. 11a was prepared. Four porous pulps were prepared, each having a maximum length in the first direction and a maximum width in the second direction of 40 mm, a maximum length in the first direction and a maximum width in the second direction of 20 mm, and a thickness of 250 μm.

[0224] (Lamination, solid-state battery manufacturing)

[0225] An electrode stack was positioned on a driving substrate such that the negative tab of the electrode stack prepared thereon was located on the front side in the driving direction. Then, stress relief members prepared thereon were placed on both sides of the negative tab and the positive tab of the electrode stack. An all-solid-state battery was manufactured by passing the electrode stack and the stress relief members through a pressure roller and performing lamination at a pressure of 0.5 ton / cm.

[0226]

[0227] Example 2

[0228] An all-solid-state battery was manufactured in the same manner as in Example 1, except that a porous pulp with a constant length and width, as described with reference to FIG. 11d, was used as the stress-relieving member. That is, four porous pulps were prepared as the stress-relieving members, each having a length in the first direction and a width in the second direction of 20 mm and a thickness of 250 μm.

[0229]

[0230] Example 3

[0231] An all-solid-state battery was manufactured in the same manner as in Example 2, except that the thickness of the stress-relaxing member was 200 μm.

[0232]

[0233] Example 4

[0234] An all-solid-state battery was manufactured in the same manner as in Example 2, except that the thickness of the stress-relaxing member was 150 μm.

[0235]

[0236] Example 5

[0237] An all-solid-state battery was manufactured in the same manner as in Example 2, except that the thickness of the stress-relaxing member was 100 μm.

[0238]

[0239] Example 6

[0240] An all-solid-state battery was manufactured in the same manner as in Example 2, except that a porous pulp having a length in the first direction and a width in the second direction of 10 mm and a thickness of 250 μm was used as a stress-relieving member.

[0241]

[0242] Example 7

[0243] An all-solid-state battery was manufactured in the same manner as in Example 2, except that a PET film with a thickness of 250 μm was used as a stress-relieving member.

[0244]

[0245] Example 8

[0246] An all-solid-state battery was manufactured in the same manner as in Example 2, except that a PE film with a thickness of 250 μm was used as a stress-relieving member.

[0247]

[0248] Example 9

[0249] An all-solid-state battery was manufactured in the same manner as in Example 2, except that a PTFE film with a thickness of 250 μm was used as a stress-relieving member.

[0250]

[0251] Comparative Example 1

[0252] An all-solid-state battery was manufactured by passing the electrode laminate of Example 1 alone through a pressure roller without using a stress-relieving member and performing lamination at a pressure of 0.5 ton / cm.

[0253]

[0254] Evaluation Example 1. Evaluation of whether the anode tab is damaged

[0255] Ten all-solid-state batteries were manufactured according to Examples 1 to 9 and Comparative Example 1, respectively, and then the tab breakage was evaluated.

[0256] Stress-relieving member Anode tab Number of broken cells Material Second direction width (mm) First direction length (mm) Ratio of the thickness of the stress-relieving member to the electrode laminate (TK1 / TK2) Example 1 Porous pulp First part width: 20 Second part width: 20 First part length: 20 Second part length: 20 1.250 Example 2 Porous pulp 20 20 1.250 Example 3 Porous pulp 20 20 12 Example 4 Porous pulp 20 20 0.753 Example 5 Porous pulp 20 20 0.54 Example 6 Porous pulp 10 10 1.252 Example 7 Porous polymer film (PET) 20 20 1.255 Example 8 Porous polymer film (PE) 20 20 1.255 Example 9 Porous polymer Film (PEFT) 20201.255 Comparative Example 1 ----10

[0257] Referring to Table 1, it can be seen that in Comparative Example 1, which does not have a stress-relieving member, all 10 positive electrode tabs were damaged. On the other hand, referring to Examples 1 to 9, it can be seen that the stress-relieving member can prevent damage to the electrode tabs. In particular, referring to Examples 1, 2, 7, 8, and 9, it can be seen that the effect of preventing tab damage is even better when porous pulp is used as the stress-relieving member.

Claims

1. A method for manufacturing an all-solid-state battery comprising laminating an electrode stack including a first electrode and a second electrode in a first direction: The above lamination is: Aligning the electrode stack so that a first tab portion protruding from the front side of the electrode stack faces the first direction; Deploying a first stress relief member adjacent to at least one side of the first tab portion; and It includes passing the electrode laminate and the first stress relief member through a pressure roller in the first direction.

2. In Paragraph 1, The above electrode stack includes a second tab portion protruding toward the rear side, and A method for manufacturing an all-solid-state battery, wherein the lamination further comprises placing a second stress relief member on at least one side of the second tab portion.

3. In Paragraph 1, A method for manufacturing an all-solid-state battery in which the length of the front portion is smaller than the length of the side portion of the electrode stack.

4. In Paragraph 1, A method for manufacturing an all-solid-state battery, wherein the ratio of the thickness of the first stress relief member in the third direction to the thickness of the electrode laminate in the third direction is 1 to 2.

5. In Paragraph 1, The above front portion includes a first area in which the first tab portion protrudes and a second area excluding the first area, and The above-mentioned pressure roller includes an area where the upper roller and the lower roller come into contact, and A method for manufacturing an all-solid-state battery, wherein the gap in the first direction between the first stress relief member and the second region is smaller than the length in the first direction of the region of the pressure roller.

6. In Paragraph 5, A method for manufacturing an all-solid-state battery in which the above gap is 3 mm or less.

7. In Paragraph 1, A method for manufacturing an all-solid-state battery, wherein the ratio of the length of the first stress relief member in the first direction to the length of the first tab portion in the first direction is 1 to 3.

8. In Paragraph 1, A method for manufacturing an all-solid-state battery, wherein the first stress-relieving member comprises at least one of porous pulp and a porous polymer film.

9. In Paragraph 1, The first stress-relieving member above is: A first portion guarding the front side of the electrode stack; and It includes a second part that guards the side of the electrode stack, and The electrode stack includes a corner formed where the front side and the side meet each other, and A method for manufacturing an all-solid-state battery, wherein the first part and the second part are connected to each other and wrap around the corner.

10. In Paragraph 9, The above electrode laminate includes a positive active material layer, and The first stress relief member is positioned such that the rear portion of the second portion is aligned with the front portion of the positive active material layer in a second direction, and A method for manufacturing an all-solid-state battery, wherein the second direction is a direction intersecting the first direction.

11. In Paragraph 9, The above electrode laminate includes a positive active material layer, and A method for manufacturing an all-solid-state battery, wherein the first stress relief member is positioned such that the rear portion of the second portion is located further forward in the first direction than the front portion of the positive active material layer.

12. In Paragraph 1, Manufacturing a first electrode by applying a first pressure after stacking a cathode layer and a cathode solid electrolyte layer; and The method further includes manufacturing a second electrode by applying a second pressure after stacking an anode layer and an anode solid electrolyte layer. A method for manufacturing an all-solid-state battery in which the second pressure is greater than the first pressure.

13. In Paragraph 11, The first pressure is 0.5 ton / cm to 4.5 ton / cm, and A method for manufacturing an all-solid-state battery, wherein the second pressure is 1 ton / cm to 5 ton / cm.

14. In Paragraph 1, The area of ​​the second electrode is smaller than that of the first electrode, and A method for manufacturing an all-solid-state battery, wherein the electrode laminate comprises an inert member surrounding the side of the second electrode.

15. In Paragraph 1, A method for manufacturing an all-solid-state battery, wherein after the lamination, at least one corner of the inert member includes a recessed area.

16. Anode layer; cathode layer; solid electrolyte layer disposed between the anode layer and the cathode layer; and an inert member surrounding the side of the anode layer, wherein The above-mentioned inert member comprises a side extending in a first direction, a front side extending in a second direction intersecting the first direction, and a corner defined where the front side and the side meet. The corner of the above-mentioned inert member includes a recess region, in a solid-state battery.

17. In Paragraph 16, The above recess region is located on the front side of the above inert member, and The above anode layer includes an anode current collector and an anode active material layer, and A solid-state battery in which, when viewed in a planar view, the rear portion of the recess region is aligned with the front portion of the positive active material layer in the second direction.

18. In Paragraph 16, The above recess region is located on the front side of the above inert member, and The above anode layer includes an anode current collector and an anode active material layer, and A solid-state battery in which, when viewed in a planar view, the rear portion of the recess region is located further forward in the first direction than the front portion of the positive active material layer.

19. In Paragraph 16, The above-described all-solid-state battery includes a positive electrode tab and a negative electrode tab, and The above positive electrode tab and the above negative electrode tab are aligned along a first direction, in an all-solid-state battery.

20. In Paragraph 16, The above solid electrolyte layer includes an anode solid electrolyte layer and a cathode solid electrolyte layer, and The above anode solid electrolyte layer is adjacent to the above anode layer, and The above-mentioned cathode solid electrolyte layer is an all-solid-state battery adjacent to the above-mentioned cathode layer.

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