Negative electrode for all-solid-state battery, all-solid-state battery comprising same, and method for manufacturing all-solid-state battery

Abstract

The present invention relates to a negative electrode for an all-solid-state battery. More specifically, the negative electrode for an all-solid-state battery comprises: a negative electrode current collector, wherein the negative electrode current collector includes a first side portion and a second side portion extending parallel to each other in a first direction, and the first side portion and the second side portion are located opposite to each other in a second direction; a binder coating layer located on at least one of the first side portion and the second side portion of the negative electrode current collector and including a binder; a negative electrode coating layer on the negative electrode current collector and the binder coating layer; and a solid electrolyte layer on the negative electrode coating layer.

Description

A negative electrode for an all-solid-state battery, an all-solid-state battery including the same, and a method for manufacturing an all-solid-state battery

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

[0002]

[0003] 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.

[0004] Recently, all-solid-state batteries in which liquid electrolytes are replaced with solid electrolytes have been proposed. 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, these all-solid-state batteries can offer significantly higher safety compared to lithium-ion batteries that use liquid electrolytes.

[0005]

[0006] The problem to be solved by the present invention is to provide a negative electrode for an all-solid-state battery that prevents delamination of the negative electrode layer while having excellent electrical conductivity by reducing the binder content in the negative electrode plate.

[0007] Another problem that the present invention aims to solve is to provide an all-solid-state battery with uniform thickness and quality, resulting in a long lifespan and high efficiency.

[0008] Another problem that the present invention aims to solve is to provide a method for manufacturing a negative electrode for an all-solid-state battery that has low manufacturing difficulty and enables mass production.

[0009]

[0010] A negative electrode for an all-solid-state battery according to an embodiment of the present invention may comprise: a negative electrode current collector, wherein the negative electrode current collector includes a first side portion and a second side portion extending parallel to each other in a first direction, and the first side portion and the second side portion are located opposite each other in a second direction; a binder coating layer comprising a binder located on at least one of the first side portion or the second side portion of the negative electrode current collector; a negative electrode coating layer on the negative electrode current collector and the binder coating layer; and a solid electrolyte layer on the negative electrode coating layer.

[0011] A solid-state battery according to another embodiment of the present invention comprises: a positive electrode layer; a negative electrode layer; a solid electrolyte layer between the positive electrode layer and the negative electrode layer; and an inert member provided around the positive electrode layer to compensate for the difference in area between the positive electrode layer and the negative electrode layer, wherein the negative electrode layer comprises a negative electrode current collector, a negative electrode coating layer, and a binder coating layer located between the negative electrode current collector and the negative electrode coating layer, and the binder coating layer may be vertically superimposed with the solid electrolyte layer.

[0012] A method for manufacturing an all-solid-state battery according to another embodiment of the present invention comprises: providing a positive electrode layer; providing a solid electrolyte layer; providing a negative electrode layer; sequentially stacking the positive electrode layer, the solid electrolyte layer, and the negative electrode layer to form a cell stack; and pressing the cell stack, wherein providing the negative electrode layer may include: forming a binder coating layer on at least one of a first side portion or a second side portion of a negative electrode current collector; and forming a negative electrode coating layer on the negative electrode current collector and the binder coating layer.

[0013]

[0014] A negative electrode for an all-solid-state battery according to the concept of the present invention can prevent the phenomenon of unbonded delamination of the negative electrode substrate by increasing the bonding force between the negative electrode current collector and the negative electrode coating layer.

[0015] An all-solid-state battery according to another concept of the present invention can improve electrical conductivity by reducing the binder content of the negative electrode layer.

[0016] A method for manufacturing an all-solid-state battery according to another concept of the present invention has low manufacturing difficulty and enables mass production.

[0017]

[0018] FIG. 1 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention.

[0019] FIG. 2 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention.

[0020] FIGS. 3 and FIGS. 4 are a plan view and a cross-sectional view, respectively, of an all-solid-state battery according to an embodiment of the present invention.

[0021] FIG. 5 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention.

[0022] FIG. 6 is a cross-sectional view of an all-solid-state battery including a gasket structure according to one embodiment of the present invention.

[0023] FIGS. 7a to 8 are cross-sectional views of an all-solid-state battery including a binder coating layer according to one embodiment of the present invention.

[0024] FIGS. 9a to 9c are plan views of a negative current collector (210) according to one embodiment of the present invention.

[0025] Figures 10a and 10b are cross-sectional views of BB' of Figures 9a and 9b.

[0026] FIG. 11 is an enlarged view of a binder coating layer according to one embodiment of the present invention.

[0027] FIGS. 12 to 13c are plan views of a negative electrode for an all-solid-state battery according to one embodiment of the present invention.

[0028] FIGS. 14 to 16 are conceptual diagrams showing a step-by-step method for manufacturing an all-solid-state battery according to one embodiment of the present invention.

[0029] FIG. 17 is a flowchart showing the sequence of a method for manufacturing an all-solid-state battery according to one embodiment of the present invention.

[0030]

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035]

[0036] FIG. 1 is a cross-sectional view of an all-solid-state battery (10) according to one embodiment of the present invention.

[0037] Referring to FIG. 1, the all-solid-state battery (10) may include a positive electrode (100), a negative electrode (200) facing the positive electrode (100), and a solid electrolyte layer (300) disposed between the positive electrode (100) and the negative electrode (200). However, the all-solid-state battery (10) may further include an additional functional layer, such as an adhesion-enhancing layer, disposed between the positive electrode (100) and the solid electrolyte layer (300) or between the negative electrode (200) and the solid electrolyte layer (300).

[0038] The positive electrode (100) may include a positive electrode current collector (110) and a positive electrode active material layer (120) disposed on the positive electrode current collector (110). The positive electrode active material layer (120) may include a positive electrode active material, a solid electrolyte, a conductive material, and a binder.

[0039] 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 have a plate or foil form. For example, the positive current collector (110) may include indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof. The positive current collector (110) of FIG. 1 may be substantially the same or similar to the positive current collector (COL1) of FIG. 5, which will be described later.

[0040] Unlike as illustrated in FIG. 1, in one embodiment of the present invention, the positive current collector (110) may be omitted. 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).

[0041] The positive electrode active material may be a material capable of reversibly absorbing and desorbing lithium ions. For example, the positive electrode active material may include lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, but is not limited thereto. The positive electrode active material may be a single material or a mixture of two or more materials.

[0042] Lithium transition metal oxides are, for example, Li a A 1-b B b D2(0.90≤a≤1, 0≤b≤0.5), Li a E 1-b B b O 2-c D c (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05), LiE 2-b B b O 4-c D c (0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Co b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Mn b B c D α(0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Nor 1-b-c Mn b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Nor b E c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Nor b Co c Mn d GeO2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1), Li a NiG b O2(0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a MnG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a Mn2G b O4(0.90≤a≤1, 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3(0≤f≤2), Li 3-fIt may be a compound represented by any one of Fe2(PO4)3 (0≤f≤2) or LiFePO4. In such a compound, 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.

[0043] 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 Mnz 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.

[0044] 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 may be amorphous or crystalline. The coating elements included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The coating layer may include, for example, Li2O-ZrO2 (LZO). The method for forming the coating layer may be 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 may include, for example, spray coating or immersion methods.

[0045] When the positive electrode active material is a ternary lithium transition metal oxide such as NCA or NCM and contains nickel (Ni), the capacity density of the all-solid-state battery (10) can be 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 can be 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.

[0046] The shape of the positive electrode active material may include particle shapes such as spheres or ellipsoids. The particle size and content of the positive electrode active material are not particularly limited.

[0047] The solid electrolyte may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. Sulfide-based solid electrolytes include, for example, Li2S-P2S5, Li2S-P2S5-LiX (where X is a halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, and Li2S-P2S5-Z m S n (m, n are positive numbers, uppercase “ ” indicates one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are positive numbers, uppercase “” is one of P, Si, Ge, B, Al, Ga, In), Li 7-x PS 6-x Cl x(0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It may include at least one selected from (0≤x≤2).

[0048] Sulfide-based solid electrolytes are, for example, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It may be an argyrodite-type compound comprising one or more selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound comprising one or more selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I. The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. By having a density of 1.5 g / cc or higher for the argyrodite-type solid electrolyte, the internal resistance of the all-solid-state battery is reduced, and defects such as penetration and short circuit of the solid electrolyte film due to lithium dendrite formation can be prevented. The elastic modulus of the solid electrolyte may be, for example, 15 GPa to 35 GPa.

[0049] The solid electrolyte included in the positive electrode active material layer (120) may have a smaller average particle size (D50) compared to the solid electrolyte included in the solid electrolyte layer (300). For example, the average particle size (D50) of the solid electrolyte included in the positive electrode 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.

[0050] 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.

[0051] The positive active material layer (120) may further include a binder. The binder may include a material for bonding the positive active material, solid electrolyte, and conductive material included in the positive active material layer (120), and for improving the bonding strength with the positive current collector (110). For example, the binder may include polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, or polymethyl methacrylate.

[0052] When the total of the positive active material, solid electrolyte, conductive material, and binder is 100 parts by weight, the positive active material layer (120) may include 78 to 92 parts by weight of the positive active material. The positive active material layer (120) may include 0.5 to 1.5 parts by weight of the binder.

[0053] In the positive electrode active material layer (120), the conductive material may have 1 to 50 parts by weight per 100 parts by weight of solid electrolyte. If the conductive material is less than 1 part by weight per 100 parts by weight of solid electrolyte, the electrical conductivity of the positive electrode active material layer (120) may be reduced. If the conductive material is more than 50 parts by weight per 100 parts by weight of solid electrolyte, the ratio of the conductive material is excessively high, so a coating layer covering the surface of the solid electrolyte may not be properly formed.

[0054] According to the embodiments, the positive active material layer (120) may further include at least one additive selected from the group consisting of a filler, a coating agent, a dispersant, and an ion-conducting aid, in addition to the positive active material, solid electrolyte, conductive material, and binder described above.

[0055] The solid electrolyte layer (300) is disposed between the positive electrode (100) and the negative electrode (200) and may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. The solid electrolyte included in the solid electrolyte layer (300) may be the same as or different from any one of the materials that may be included in the solid electrolyte included in the aforementioned positive electrode active material layer (120).

[0056] The solid electrolyte layer (300) may further include a binder. The binder 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).

[0057] The cathode (200) may include a cathode current collector (210) and a cathode coating layer (220) on the cathode current collector (210). The cathode current collector (210) may provide a reference surface on which the cathode coating layer (220) is placed. The cathode 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 cathode 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 cathode 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.

[0058] 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.

[0059] 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.

[0060] 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-based material 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).

[0061] 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.

[0062] 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).

[0063] Meanwhile, although not illustrated, a carbon layer may be further included to improve adhesion between the cathode coating layer (220) and the solid electrolyte layer (300).

[0064]

[0065] FIG. 2 is a cross-sectional view of an all-solid-state battery (10) according to another embodiment of the present invention.

[0066] Referring to FIG. 2, 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 (100), and the cathode solid electrolyte layer (320) may be adjacent to the cathode (200). Each of the anode solid electrolyte layer (310) and the cathode solid electrolyte layer (320) may include the solid electrolyte (SE) described above.

[0067] The positive solid electrolyte layer (310) and the negative solid electrolyte layer (320) may have different thicknesses. The positive solid electrolyte layer (310) may have a first thickness (TK1), and the negative solid electrolyte layer (320) may have a second thickness (TK2). The second thickness (TK2) may be greater than the first thickness (TK1). For example, the second thickness (TK2) may be 2 to 100 times the first thickness (TK1).

[0068]

[0069] FIG. 3 is a plan view of an all-solid-state battery (10) according to another embodiment of the present invention. FIG. 4 is a cross-sectional view along the line A-A' of FIG. 3. 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.

[0070] Referring to FIGS. 3 and 4, the area of ​​the anode (100) and the area of ​​the cathode (200) may differ from each other. Specifically, the area of ​​the cathode (200) may be larger than the area of ​​the anode (100). The anode (100) may be completely superimposed within the cathode (200).

[0071] In one embodiment of the present invention, the anode solid electrolyte layer (310) may have substantially the same area as the anode (100). The cathode solid electrolyte layer (320) may have substantially the same area as the cathode (200).

[0072] Specifically, the anode solid electrolyte layer (310) may have a first width (WI1) in a first direction (D1). The cathode solid electrolyte layer (320) may have a second width (WI2) in a first direction (D1). The first width (WI1) may be smaller than the second width (WI2). The anode solid electrolyte layer (310) may have a third width (WI3) in a second direction (D2). The cathode solid electrolyte layer (320) may have a fourth width (WI4) in a second direction (D2). The third width (WI3) may be smaller than the fourth width (WI4).

[0073] The all-solid-state battery (10) according to the present embodiment can be manufactured by forming a first stack of a positive electrode (100) and a positive electrode solid electrolyte layer (310), forming a second stack of a negative electrode (200) and a negative electrode solid electrolyte layer (320), and then laminating the first stack and the second stack.

[0074]

[0075] FIG. 5 is a cross-sectional view along line A-A' of FIG. 3, intended to illustrate an all-solid-state battery according to another embodiment of the present invention. Referring to FIG. 5, the negative electrode layer (200) of the all-solid-state battery (10) may further include a lithium metal layer (400) between the negative electrode current collector (210) and the negative electrode coating layer (220). The thickness of the lithium metal layer (400) may increase further during charging of the all-solid-state battery (10). The negative electrode coating layer (220) serves as a protective layer for the lithium metal layer (400) and, at the same time, can suppress the growth of lithium dendrites from the lithium metal layer (400).

[0076] 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.

[0077] The lithium metal layer (400) may have a fifth width (WI5) in the first direction (D1). The fifth width (WI5) may be equal to or greater than the first width (WI1). The fifth width (WI5) may be equal to or smaller than the second width (WI2). For example, the fifth width (WI5) may be greater than the first width (WI1) and smaller than the second width (WI2).

[0078]

[0079] FIG. 6 is a cross-sectional view illustrating an all-solid-state battery according to another embodiment of the present invention. Referring to FIG. 6, the all-solid-state battery (10) may include a gasket structure (500). The gasket structure (500) can fill the step difference on the side of the all-solid-state battery (10) caused by the difference in area between the first laminate and the second laminate. The gasket structure (500) can surround the sides of the first laminate of the all-solid-state battery (10) along the first and second directions (D2) (D1, D2). For example, the thickness of the gasket structure (500) may be substantially the same as the thickness of the first laminate. Thus, even if the first laminate and the second laminate, which have different areas, are laminated and pressed, damage to the step difference on the side of the all-solid-state battery can be prevented. 'Substantially identical thickness' can be defined as a thickness sufficient to prevent damage to the step difference on the side of the all-solid-state battery even when the first and second laminates with different areas are laminated and pressed.

[0080]

[0081] FIGS. 7a to 8 are cross-sectional views of an all-solid-state battery including a binder coating layer according to an embodiment of the present invention. Referring to FIG. 7a, in an all-solid-state battery according to an embodiment of the present invention, a binder coating layer (BCL1, BCL2) and a negative electrode coating layer (220) may be located on a negative electrode current collector (210). A second solid electrolyte layer (320) may be located on the negative electrode coating layer (220). A first solid electrolyte layer (310) and a positive electrode layer (100) may be located on the second solid electrolyte layer (320). Additionally, an inert member (INM) may be located on the outer periphery of the first solid electrolyte layer and the positive electrode active material layer (120). Hereinafter, the differences will be explained mainly in comparison with the descriptions in FIGS. 1 to 6.

[0082] Referring to FIG. 7a, an all-solid-state battery according to one embodiment of the present invention may include a binder coating layer. The binder coating layer (BCL1, BCL2) may perform the role of increasing the bonding strength between the negative electrode current collector (210) and the negative electrode coating layer. The binder coating layer (BCL1, BCL2) may perform the role of preventing delamination between the negative electrode current collector (210) and the negative electrode coating layer (220). In addition, the binder coating layer (BCL1, BCL2) may suppress delamination between the negative electrode current collector (210) and the negative electrode coating layer (220) after the pressurization process during the manufacturing of the all-solid-state battery. If delamination occurs between the negative electrode current collector (210) and the negative electrode coating layer (220), the manufacturing efficiency of the all-solid-state battery may decrease.

[0083] The binder coating layer may include a first binder coating layer (BCL1) and a second binder coating layer (BCL2).

[0084] The first binder coating layer (BCL1) may be located on the first side portion (SD1) of the negative current collector (210). Additionally, the second binder coating layer (BCL2) may be located on the second side portion (SD2) of the negative current collector (210). The first side portion (SD1) and the second side portion (SD2) will be described later in FIG. 9a.

[0085] The binder coating layer (BCL1, BCL2) may include a binder mixture. Additionally, the binder coating layer may include a binder and a colored inorganic material. The binder may be substantially the same or similar as the binder described above in FIG. 1. Additionally, the binder may include at least one of polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, or a combination thereof.

[0086] The colored inorganic material can serve the role of enabling the binder coating layer to be identifiable. The colored inorganic material can impart a color that is visually identifiable to the binder coating layer (BCL1, BCL2). The colored inorganic material can serve the role of facilitating the manufacturing method of an all-solid-state battery according to one embodiment of the present invention. In addition, the colored inorganic material can serve the role of facilitating the coating of the negative electrode coating layer (220) on the negative electrode current collector (210).

[0087] Colored inorganic materials may include dyes. Additionally, colored inorganic materials may include materials with low electrical conductivity. Dyes are inorganic compounds that can display color by absorbing or reflecting specific wavelengths of light. Dyes may include metal oxides or sulfides. More specifically, colored inorganic materials may include at least one of TiO₂, ZnS, Cr₂O₃, CoAl₂O₄, MnO₂, Fe₂O₃, Fe₃O₄, BaSO₄, or a combination thereof.

[0088] The weight of the inorganic material relative to the total weight of the binder coating layer may be about 0.1% to about 60%, about 1% to about 50%, or 5% to about 3%.

[0089] The binder coating layer may not be transparent. This may be due to inorganic materials contained in the binder coating layer. That is, the transmittance of the binder coating layer may be about 20% to about 50%.

[0090] Transmittance refers to the ratio representing the amount of light passing through a material. Transmittance can be expressed as a percentage of the ratio of incident light to transmitted light. In other words, transmittance can be expressed as (intensity of transmitted light / intensity of incident light) x 100. Transmittance can have a value between 0% and 100%. If the transmittance is 0%, the material may not allow any light to pass through. Also, if the transmittance is 100%, the material may allow all light to pass through.

[0091] Transmittance can be measured by quantitatively evaluating the amount of light passing through a specific material. More specifically, transmittance can be measured using a spectrophotometer. First, the spectrophotometer is preheated to ensure the stability of the light source. After ensuring the stability of the light source, the intensity of the reference incident light (I0) is measured. Then, a target wavelength is set, and the sample is mounted in the sample holder of the spectrophotometer to measure the intensity (I) of the light passing through the sample. The transmittance (T) can be calculated by comparing the measured transmitted light (I) with the incident light (I0). If necessary, the above process can be repeated at various wavelengths to obtain the transmission spectrum of the sample and analyze the optical properties of the sample. Additionally, the transmittance can be adjusted based on the recognition range of the coater's vision camera.

[0092]

[0093] Referring again to FIG. 7a, an all-solid-state battery according to one embodiment of the present invention may include an inert member (INM).

[0094] An inert member (INM) is provided around the anode layer and can serve to compensate for the difference in area between the anode layer and the cathode layer. The inert member (INM) may be substantially identical or similar to the gasket structure (500) described above in FIG. 6. More specifically, the inert member (INM) may be substantially the same as the thickness of the anode layer. The anode layer may include an anode active material layer (120) and a first solid electrolyte layer (310). For example, the thickness of the inert member (INM) may be 50 μm to 180 μm. As an example, the inert member (INM) may be a non-woven sheet. The inert member (INM) may have a sixth width. Referring to FIG. 7a and FIG. 11 to be described later, the sixth width (WI6) may be larger than the seventh width (WI7), which is the width of the first binder coating layer (BCL1).

[0095] Referring to FIG. 7a, a binder coating layer of an all-solid-state battery according to one embodiment of the present invention may be vertically overlapped with an inert member (INM). Additionally, the binder coating layer (BCL1, BCL2) may be vertically overlapped with a solid electrolyte layer (300).

[0096] Vertical overlap means that an inert member (INM) may be located in the third direction (D3) of the binder coating layers (BCL1, BCL2). Additionally, a binder coating layer may be located in a direction opposite to the third direction (D3) of all or part of the inert member (INM). More specifically, an inert member (INM) may be located on the extension line of the third direction (D3) of the first binder coating layer (BCL1). Additionally, an inert member (INM) may be located on the extension line of the third direction (D3) of the second binder coating layer (BCL2).

[0097] Referring to FIG. 7a and FIG. 11, the width (WI6) of the inert member may be greater than the width (WI7) of the binder coating layer. When the width (WI7) of the binder coating layer is greater than the width (WI6) of the inert member, the content of the binder included in the cathode layer may increase. When the content of the binder included in the cathode layer increases, the electrical conductivity of the all-solid-state battery may decrease. Additionally, when the content of the binder included in the cathode layer increases, the ionic conductivity of the all-solid-state battery may decrease.

[0098] FIG. 7b shows a cross-sectional view of an all-solid-state battery according to an embodiment of the present invention. Referring to FIG. 7b, the all-solid-state battery according to an embodiment of the present invention may include a lithium metal layer (400). The lithium metal layer (400) may be substantially the same or similar to the lithium metal layer (400) described above in FIG. 5. To explain the differences, referring to FIG. 7b and FIG. 11, the thickness of the lithium metal layer (400) according to an embodiment of the present invention may be smaller than the thickness (TK3) of the binder coating layer. That is, the lithium metal precipitated in the lithium metal layer (400) may not be formed to a thickness greater than the thickness (TK3) of the binder coating layer. The thickness of the lithium metal layer (400) may be about 0.01 mm to about 0.06 mm, about 0.01 mm to about 0.05 mm, or about 0.01 mm to about 0.04 mm.

[0099] Additionally, a lithium metal layer (400) may be formed between the first binder coating layer (BCL1) and the second binder coating layer (BCL2). The binder coating layers (BCL1, BCL2) can prevent the negative coating layer (220) from detaching from the negative current collector (210) even when the lithium metal layer (400) is formed. The binder coating layers (BCL1, BCL2) can prevent the negative coating layer (220) from detaching from the negative current collector (210) by lithium dendrites.

[0100]

[0101] FIG. 8 is a cross-sectional view of an all-solid-state battery according to an embodiment of the present invention. Referring to FIG. 8, the first binder coating layer (BCL1) may include a first-1 binder coating layer (BCL1-1) and a first-2 binder coating layer (BCL1-2). Referring to FIG. 8, the first-1 binder coating layer (BCL1-1) may be located on the tab portion of the negative electrode current collector (210). This will be explained in detail in FIG. 13c.

[0102]

[0103] FIGS. 9a to 9c are plan views of a negative current collector (210) according to an embodiment of the present invention. As shown in FIGS. 9a to 9c, the negative current collector (210) may be formed long in a first direction (D1) so as to be wound onto a roll. That is, the negative current collector (210) may exist in a web form. The negative current collector (210) shown in FIG. 9a may be a negative current collector (210) before being cut into a unit sheet. Additionally, the negative current collector (210) may include a plurality of unit negative current collectors (210). A unit negative current collector (210) may refer to a negative current collector (210) included in a single cell stack.

[0104] Referring to FIG. 9a, the negative current collector (210) may include a first side portion (SD1) and a second side portion (SD2). Additionally, the binder coating layer may include a first binder coating layer (BCL1) and a second binder coating layer (BCL2).

[0105] The first side portion (SD1) may be a region of the negative current collector (210). More specifically, the first side portion (SD1) may be a region extended in the first direction (D1) of the negative current collector (210). Referring to FIG. 9a, the first side portion (SD1) may be located in a direction opposite to the second direction (D2) of the negative current collector (210). A first binder coating layer (BCL1) may be located in the first side portion (SD1). Additionally, the first side portion (SD1) may be a portion where the negative current collector (210) and the negative coating layer come into contact. The first binder coating layer (BCL1) can prevent the negative current collector (210) and the negative coating layer from separating in the first side portion (SD1). Additionally, the first binder coating layer (BCL1) can prevent delamination in the first side portion (SD1).

[0106] The second side portion (SD2) may be another region of the negative current collector (210). More specifically, the second side portion (SD2) may be a region extended in the first direction (D1) of the negative current collector (210). Referring to FIG. 9a, the second side portion (SD2) may be located in the second direction (D2) of the negative current collector (210). A second binder coating layer (BCL2) may be located on the second side portion (SD2). Additionally, the second side portion (SD2) may be a portion where the negative current collector (210) and the negative coating layer (220) come into contact. The second binder coating layer (BCL2) can prevent the negative current collector (210) and the negative coating layer (220) from separating at the second side portion (SD2). In addition, the first binder coating layer (BCL1) can prevent delamination at the first side portion (SD1).

[0107]

[0108] Referring to FIG. 9a, the first side portion (SD1) and the second side portion (SD2) may be located opposite each other in the second direction (D2). That is, the first side portion (SD1) and the second side portion (SD2) may represent the left and right regions of the negative current collector (210). A first binder coating layer (BCL1) may be located on the first side portion (SD1). Additionally, a second binder coating layer (BCL2) may be located on the second side portion (SD2).

[0109] As illustrated in FIG. 9a, the binder coating layer may be colored so as to be distinguishable from the cathode current collector (210). This may be due to the colored inorganic material included in the binder coating layer. If the binder coating layer (BCL1, BCL2) is colorless, it may not be easy to identify the location when coating the binder coating layer (BCL1, BCL2) on the cathode current collector (210). Referring to FIG. 9a and FIG. 12, a cathode coating layer (220) can be formed on the cathode current collector (210) based on the colored binder coating layer (BCL1, BCL2).

[0110]

[0111] FIG. 9b is a plan view showing a negative current collector (210) coated with a binder coating layer (BCL1) according to an embodiment of the present invention. Referring to FIG. 9b, the binder coating layer may be located on a first side portion (SD1) of the negative current collector (210). Referring to FIG. 9a and FIG. 9b, the binder coating layer may be located in at least one of the first side or the second side.

[0112] FIG. 9c is a plan view showing a binder coating layer according to an embodiment of the present invention. Referring to FIG. 9c, the binder coating layer may be in the form of a pattern including an opening. Additionally, the binder coating layer may be in the form of a pattern including a plurality of openings. Referring to FIG. 9c, a binder coating layer including a plurality of openings (OHP1 to OHP3) may be positioned on a cathode current collector (210). The binder coating layer may include a first pattern layer (PT1), a second pattern layer (PT2), and a third pattern layer (PT3). Additionally, each of the first pattern layer (PT1) to the third pattern layer (PT3) may include a first opening (OHP1) to a third opening (OHP3). That is, each pattern layer may include an opening. Additionally, the pattern layer may include a cutting line. The cutting line formed on the cathode current collector (210) may be any line. That is, the cutting line may refer to a line in which a web-shaped negative current collector (210) is cut into a unit negative current collector (210). Referring to FIG. 9c, a first cutting line (L1) may be located between the first pattern layer (PT1) and the second pattern layer (PT2). Additionally, a second cutting line (L2) may be located between the second pattern layer (PT2) and the third pattern layer (PT3). The negative electrode for an all-solid-state battery manufactured with the binder pattern layer shown in FIG. 9c will be described later in FIG. 13b.

[0113]

[0114] Figures 10a and 10b are cross-sectional views of BB' of Figures 9a and 9b.

[0115] Referring to FIGS. 10a and 10b, a binder coating layer may be located on a negative current collector (210). More specifically, a first binder coating layer (BCL1) may be located on the negative current collector (210). The first binder coating layer (BCL1) may be located on a first side portion (SD1) of the negative current collector (210). A second binder coating layer (BCL2) may be located on the negative current collector (210). The second binder coating layer (BCL2) may be located on a second side portion (SD2) of the negative current collector (210). Additionally, a binder coating layer may be located on either the first side portion (SD1) or the second side portion (SD2) of the negative coating layer. As shown in FIG. 10b, the binder coating layer (BCL1) may be located only on the first side portion (SD1).

[0116]

[0117] FIG. 11 is an enlarged view of a binder coating layer according to an embodiment of the present invention. That is, FIG. 11 may be an enlarged view of a first side portion (SD1). Also, FIG. 11 may be an enlarged view of a second side portion (SD2). Referring to FIG. 11, the first binder coating layer (BCL1) may have a third thickness (TK3). The third thickness (TK3) may be about 0.0001 mm to about 0.005 mm, 0.0005 mm to about 0.003 mm, or 0.001 mm to about 0.002 mm. If the third thickness (TK3) is smaller than about 0.0001 mm, it may not be able to perform the function of a binder coating layer. That is, if the third thickness (TK3) is smaller than approximately 0.0001 mm, the bonding force between the negative current collector (210) and the negative coating layer (220) may decrease. On the other hand, if the third thickness (TK3) is larger than approximately 0.005 mm, the thickness may cause substrate breakage or curling during coating, and the thickness difference with the solid electrolyte layer may increase, making it difficult to manufacture a uniform cell. The description of the lithium metal layer may be as described above in FIG. 7b.

[0118] Referring again to FIG. 11, the first binder coating layer (BCL1) may include a seventh width (WI7). The seventh width (WI7) may be about 0.1 mm to about 7.0 mm, about 0.15 mm to about 6.0 mm, or about 0.2 mm to about 5.0 mm. If the seventh width (WI7) is smaller than about 0.2 mm, it may not function as a binder coating layer. That is, if the seventh width (WI7) is smaller than about 0.2 mm, the bonding force between the negative electrode current collector (210) and the negative electrode coating layer may decrease. On the other hand, if the seventh width (WI7) is larger than about 5.0 mm, the electrical resistance may increase. An increase in electrical resistance may lead to a decrease in the performance of the all-solid-state battery.

[0119] FIGS. 12 to 13c are plan views of a negative electrode for an all-solid-state battery according to one embodiment of the present invention.

[0120] Referring to FIG. 12, a binder coating layer may be formed on a cathode current collector (210), and then a cathode coating layer (CTL) may be formed on the cathode current collector (210) and the binder coating layer. The cathode layer may be manufactured by forming a cathode coating layer (CTL) on the cathode current collector (210) and the binder coating layer. FIG. 12 shows a plan view of the cathode layer. More specifically, a cathode coating layer (CTL) may be formed after a first binder coating layer (BCL1) and a second binder coating layer (BCL2) are coated on the cathode current collector (210). Referring again to FIG. 12, the cathode coating layer (CTL) may be located on the cathode current collector (210) and the binder coating layer. There may also be areas of the cathode current collector (210) where the cathode coating layer (CTL) is not formed. Referring to FIG. 12, the non-block portion (NCL) may be an area of ​​the negative current collector (210) where the negative coating layer ((CTL)) is not formed. The non-block portion (NCL) may be an area where a tab portion is subsequently formed. The non-block portion (NCL) may be an area of ​​the negative current collector (210) where the binder coating layer and the negative coating layer (CTL) are not located. The negative coating layer (CTL) may be substantially the same or similar to the negative coating layer (220) described above in FIG. 1 to 9a.

[0121] Although not shown in FIG. 12, the cathode coating layer (CTL) may be located on the cathode current collector (210) and the first binder coating layer (BCL1). Additionally, as shown in FIG. 12, the cathode coating layer (CTL) may be located on the cathode current collector (210), the first binder coating layer (BCL1), and the second binder coating layer (BCL2).

[0122] FIGS. 13a to 13c are plan views showing the cathode layer described in detail in FIG. 12 after a tab portion has been formed. The tab portion may be formed on the unlined portion (NCL) described in detail in FIG. 12. The tab portion may be formed by a notching process. FIG. 13a may be a drawing after the cathode layer of FIG. 12 has been cut into a plurality of unit cathode layers. A unit cathode layer may be formed by cutting a web-shaped cathode layer to a certain length. Therefore, when the cathode layer of FIG. 12 is cut, a plurality of unit cathode layers shown in FIG. 13a may be formed. The web-shaped cathode layer and the unit cathode layer may differ only in size, and other than size, may be substantially identical or similar. FIG. 13b and FIG. 13c may also be formed substantially identically or similarly to this.

[0123] Referring to FIG. 13a, the cathode layer may include a cathode current collector (210), a first tab portion (TB1), a first binder coating layer (BCL1), a second binder coating layer (BCL2), and a cathode coating layer (CTL). The unit cathode layer may also be substantially identical or similar to the cathode layer described above. Referring to FIG. 13a, the first tab portion (TB1) may be located adjacent to the first binder coating layer (BCL1). Additionally, the first tab portion (TB1) may be located in a direction opposite to the second direction (D2) of the first side portion (SD1). Additionally, the first tab portion (TB1) may be located adjacent to the first side portion (SD1). The binder coating layer may be located in either the first side portion (SD1) or the second side portion (SD2). The binder coating layer may be located on the first side portion (SD1). That is, the binder coating layer can be located in an area adjacent to the first tab portion (TB1). That is, the first binder coating layer (BCL1) can be located in an area adjacent to the first tab portion (TB1).

[0124] FIG. 13b is a plan view of a cathode layer including the pattern layer described in FIG. 9c. I will explain it mainly in terms of differences compared with FIG. 13a. The cathode layer may include a first side portion (SD1), a second side portion (SD2), a third side portion (SD3), and a fourth side portion (SD4). The first side portion (SD1) and the second side portion (SD2) may be substantially the same or similar as those described in FIG. 7a and FIG. 9a.

[0125] The third side portion (SD3) may be an area extended in the second direction (D2) of the negative current collector (210). Referring to FIG. 13b, a third binder coating layer (BCL3) may be located in the third side portion (SD3).

[0126] The fourth side portion (SD4) may be an area extended in the second direction (D2) of the negative current collector (210). Referring to FIG. 13b, a fourth binder coating layer (BCL4) may be located on the fourth side portion (SD4).

[0127] The third side portion (SD3) and the fourth side portion (SD4) may be located opposite each other in the first direction (D1). That is, the third side portion (SD3) and the fourth side portion (SD4) may represent the upper and lower regions of the negative current collector (210). Referring to FIG. 13b, the first to fourth side portions (SD4) of the negative current collector (210) may be located in the border region. Additionally, the first to fourth binder coating layers (BCL4) may be located on each of the first to fourth side portions (SD4).

[0128] Referring to FIG. 9c and FIG. 13b, the first to fourth side portions (SD4) may be the border regions of the negative current collector (210). That is, the first to fourth side portions (SD4) may be regions of the binder pattern layer excluding the openings.

[0129] FIG. 13c is a plan view of a negative electrode for an all-solid-state battery according to an embodiment of the present invention. To explain the differences, the negative electrode layer of FIG. 13c may have a binder coating layer partially located on the first tab portion (TB1). That is, a first-1 binder coating layer (BCL1-1) may be located on the first tab portion (TB1). The first binder coating layer (BCL1) may include a first-1 binder coating layer (BCL1-1) and a first-2 binder coating layer (BCL1-2). The first-1 binder coating layer (BCL1-1) may be formed by performing a notching process on a part of the first binder coating layer (BCL1). That is, a notching process for forming the first tab portion (TB1) may be performed on the uncoated portion (NCL) and the first binder coating layer (BCL1) described above in FIG. 12. If the notching process is performed only on the unmarked portion (NCL), the first-1 binder coating layer (BCL1-1) may not be formed. The first-1 binder coating layer (BCL1-1) can increase the bonding strength between the negative current collector (210) and the negative coating layer by being located on the first tab portion (TB1). Additionally, the first-1 binder coating layer (BCL1-1) can serve to prevent electrical short circuits by being located on the first tab portion (TB1).

[0130]

[0131] FIGS. 14 to 16 are conceptual diagrams illustrating, in steps, a method for manufacturing an all-solid-state battery according to an embodiment of the present invention. Referring to FIGS. 14 and 15, a solid electrolyte layer may be formed on a negative electrode coating layer (220). The solid electrolyte layer may be substantially identical or similar to the second solid electrolyte layer (320) described above in FIGS. 1 and 2. Referring to FIGS. 14 and 15, a negative electrode layer may be formed by forming a solid electrolyte layer on the negative electrode coating layer (220). The negative electrode layer according to an embodiment of the present invention may include the second solid electrolyte layer (320) described above in FIGS. 1 and 2.

[0132] FIG. 16 is a conceptual diagram showing the formation of a cell stack by stacking an anode layer (100, 310) on a negative electrode layer for an all-solid-state battery according to an embodiment of the present invention. The anode layer of FIG. 16 may be substantially identical or similar to the anode layer described above in FIG. 1 and FIG. 2. The anode layer of FIG. 16 may include an anode current collector (110), an anode active material layer (120), and a first solid electrolyte layer (310). Additionally, the anode layer (100) may include an anode current collector (110) and an anode active material layer (120). The cell stack formed as shown in FIG. 16 may be substantially identical or similar to the all-solid-state battery described above in FIG. 1 to 6. However, the all-solid-state battery according to an embodiment of the present invention shown in FIG. 16 may further include a binder coating layer.

[0133]

[0134] FIG. 17 is a flowchart showing the sequence of a method for manufacturing an all-solid-state battery according to an embodiment of the present invention. A method for manufacturing an all-solid-state battery according to an embodiment of the present invention may include providing a positive electrode layer, providing a solid electrolyte layer, providing a negative electrode layer, sequentially stacking the positive electrode layer, the solid electrolyte layer, and the negative electrode layer to form a cell stack (S400), and pressing the cell stack (S500). Providing the negative electrode layer may include, as shown in FIG. 17, providing a negative electrode current collector (210) (S100), forming a binder coating layer on at least one of a first side portion (SD1) or a second side portion (SD2) of the negative electrode current collector (210) (S200), and forming a negative electrode layer by forming a negative electrode coating layer on the negative electrode current collector (210) and the binder coating layer (S300).

[0135] Providing a negative current collector (210) (S100) may be providing the negative current collector (210) described above in FIG. 1 and FIG. 2.

[0136] Forming a binder coating layer (S200) on at least one of the first side portion (SD1) or the second side portion (SD2) of the negative current collector (210) may be substantially the same or similar as described above in FIGS. 9a to 11.

[0137] Forming a cathode layer (S300) by forming a cathode coating layer on a cathode current collector (210) and a binder coating layer may be substantially the same or similar as described above in FIGS. 12 to 13c.

[0138] Providing an anode layer, providing a solid electrolyte layer, providing a cathode layer, and sequentially stacking the anode layer, solid electrolyte layer, and cathode layer to form a cell stack (S400) may be substantially the same or similar as described above in FIGS. 14 to 16.

[0139] Pressing the cell stack (S500) may include roll pressing the cell stack. Additionally, pressing the cell stack (S500) may include any method of pressing the cell stack. The pressure range for pressing may be about 0.1 ton / cm to about 2.0 ton / cm, about 0.3 ton / cm to about 2.0 ton / cm, or about 0.3 ton / cm to about 1.0 ton / cm.

[0140]

[0141] The negative electrode for an all-solid-state battery according to the embodiments of the present invention includes a binder coating layer, which can prevent delamination between the negative electrode current collector (210) and the negative electrode coating layer during the manufacture of the all-solid-state battery. In addition, the negative electrode for an all-solid-state battery according to the embodiments of the present invention can have excellent electrical conductivity by reducing the binder content.

[0142] In addition, the method for manufacturing an all-solid-state battery according to the embodiments of the present invention can have a low manufacturing difficulty and enable mass production by using a colored binder coating layer.

[0143]

[0144] The present invention will be explained in more detail below through examples. However, these examples are intended to illustrate the invention and the scope of the invention is not limited to these examples.

[0145] Example 1

[0146] (Cathode layer manufacturing)

[0147] A Ni-plated Cu foil with a thickness of 10 μm was prepared as a cathode current collector. A mixture of PVDF binder and TiO2 was coated to a thickness of 3.0 mm on each of the edge portions located on both sides of the 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 active materials. 4 g of a mixed powder, prepared by mixing carbon black (CB) and silver (Ag) particles in a weight ratio of 3:1, was placed in a container, and 4 g of an NMP solution containing 7 wt% of PVDF binder (Kureha # 9300) was added to prepare a mixed solution. The binder content in the mixed solution was 4% by weight. 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 to flatten the surface of the negative active material layer of the laminate. A negative electrode layer was fabricated through the above process. The thickness of the negative active material layer contained in the negative electrode layer was approximately 7 μm. The area of ​​the negative active material layer and the negative current collector were the same.

[0148]

[0149] (Preparation of solid electrolyte layer)

[0150] 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 crystalline Li6PS5Cl sulfide-based solid electrolyte (D50 = 10 μm, crystalline) with respect to 98 parts by weight of the solid electrolyte into a grind mixer and mixing. The prepared mixture was added to a mortar heated to 80°C and stirred to prepare a dough. The prepared dough was passed through a roller and formed into a sheet shape to prepare a solid electrolyte film of a uniform thickness. A solid electrolyte layer was manufactured by the above process. A second solid electrolyte layer having substantially the same area as the above-mentioned cathode layer was prepared from the solid electrolyte layer. The elastic modulus of the sulfide-based solid electrolyte was approximately 15 GPa to 30 GPa.

[0151]

[0152] (Manufacture of cathode semi-finished products)

[0153] The cathode layer and the second solid electrolyte layer were laminated and pressed using a roll press method. A cathode laminate was manufactured by applying a linear pressure of 3.0 ton / cm at 120°C. At this time, the thickness of the second solid electrolyte layer was 55.1 μm.

[0154]

[0155] Example 2

[0156] In Example 1, when manufacturing the cathode layer, a binder coating layer was formed on only one side of the cathode current collector. Except for this, a cathode semi-finished product was manufactured in the same manner as in Example 1.

[0157]

[0158] Example 3

[0159] In Example 1, a cathode semi-finished product was prepared in the same manner as in Example 1, except that the thickness of the second solid electrolyte layer was 56.0 μm.

[0160]

[0161] Comparative example

[0162] In Example 1, the cathode layer was prepared excluding the binder coating layer during the preparation of the cathode layer. The remaining parts, excluding the binder coating layer, were prepared as a cathode semi-finished product in the same manner as in Example 1.

[0163]

[0164] Evaluation Preliminary Semi-finished Product Press Test

[0165] Examples 1 to 3 and Comparative Example were roll-pressed at 3.0 ton / cm, and the presence or absence of peeling was tested to measure the yield rate.

[0166] The measured values ​​are as shown in Table 1 below.

[0167] Speed ​​(m / min) Solid Electrolyte Layer Thickness (㎛) Presence or Absence of Peeling Good Product Rate (%) Example 1 455.1X100 Example 2 455.1X100 Example 3 2056.0X>90 Comparative Example 455.1O0

[0168] Referring to Table 1, when comparing Examples 1 to 3 with the Comparative Example, it can be seen that the delamination between the cathode current collector and the cathode coating layer is suppressed in the cathode semi-finished product containing the binder coating layer. As a result, it can be seen that the yield rate also increases.

[0169]

[0170] Although embodiments of the present invention have been described above with reference to the attached drawings, the present invention may be implemented in other specific forms without altering its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A negative current collector, wherein the negative current collector includes a first side portion and a second side portion extending parallel to each other in a first direction, and the first side portion and the second side portion are located on opposite sides of each other in a second direction; A binder coating layer comprising a binder, positioned on at least one of the first side portion or the second side portion of the above-mentioned negative electrode current collector; The above-mentioned cathode current collector and the above-mentioned cathode coating layer on the binder coating layer; and A cathode for an all-solid-state battery comprising a solid electrolyte layer on the above-mentioned cathode coating layer.

2. In Paragraph 1, The above-mentioned first side portion includes a first tab portion, and A negative electrode for an all-solid-state battery, wherein the binder coating layer is located on one region of the first tab portion.

3. In Paragraph 1, The above binder comprises at least one of polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, or a combination thereof, for a negative electrode for an all-solid-state battery.

4. In Paragraph 1, A negative electrode for an all-solid-state battery, wherein the thickness of the binder coating layer is 0.0001 mm to 0.5 mm.

5. In Paragraph 1, A negative electrode for an all-solid-state battery, wherein the width of the binder coating layer is 0.2 mm to 5.0 mm.

6. In Paragraph 1, The above binder coating layer includes colored inorganic materials, and A negative electrode for an all-solid-state battery, wherein the weight of the inorganic material relative to the total weight of the binder coating layer is 0.1% to 60%.

7. In Paragraph 1, The above binder coating layer is a negative electrode for an all-solid-state battery having a transmittance of 20% to 50%.

8. In Paragraph 1, The above-mentioned negative current collector further includes a third side portion and a fourth side portion extending parallel to each other in the second direction, and The third side portion and the fourth side portion are located on opposite sides of each other in the first direction, and The above binder coating layer is a negative electrode for an all-solid-state battery located on the first to fourth side portions.

9. In Paragraph 8, The above binder coating layer is a negative electrode for an all-solid-state battery having a width of 0.2 mm to 5.0 mm.

10. Bipolar layer; cathode layer; A solid electrolyte layer between the anode layer and the cathode layer; and It includes an inert member provided around the anode layer to compensate for the area difference between the anode layer and the cathode layer, The above cathode layer comprises a cathode current collector, a cathode coating layer, and a binder coating layer located between the cathode current collector and the cathode coating layer. The above binder coating layer is vertically superimposed with the above solid electrolyte layer, in an all-solid-state battery.

11. In Paragraph 10, The above-mentioned negative current collector includes a first side portion and a second side portion extending parallel to each other in a first direction, and a third side portion and a fourth side portion extending parallel to each other in a second direction. The first side portion and the second side portion are located opposite each other in the second direction, and the third side portion and the fourth side portion are located opposite each other in the first direction. The binder coating layer is located on at least one of the first side portion, the second side portion, the third side portion, or the fourth side portion, in an all-solid-state battery.

12. In Paragraph 10, The above-mentioned negative current collector includes a tab portion, and The above binder coating layer is located on one region of the above tab portion, in an all-solid-state battery.

13. In Paragraph 10, A solid-state battery in which the width of the binder coating layer is smaller than the width of the inert member.

14. In Paragraph 10, An all-solid-state battery having a binder coating layer thickness of 0.0001 mm to 0.5 mm.

15. In Paragraph 10, The above binder coating layer is an all-solid-state battery having a transmittance of 20% to 50%.

16. Providing a bipolar layer; Providing a solid electrolyte layer; Providing a cathode layer; Forming a cell stack by sequentially stacking the anode layer, the solid electrolyte layer, and the cathode layer; and The method includes pressing the cell stack, Providing the above cathode layer is: Forming a binder coating layer on at least one of the first side portion or the second side portion of the negative current collector; and A method for manufacturing an all-solid-state battery, comprising forming a negative electrode coating layer on the negative electrode current collector and the binder coating layer.

17. In Paragraph 16, A method for manufacturing an all-solid-state battery in which the binder coating layer comprises a colored inorganic material.

18. In Paragraph 16, The above-mentioned negative current collector includes a third side portion and a fourth side portion, and A method for manufacturing an all-solid-state battery, comprising forming a binder coating layer on at least one of the first side portion, the second side portion, the third side portion, or the fourth side portion.

19. In Paragraph 18, A method for manufacturing an all-solid-state battery, comprising performing a notching process for forming a tab portion in a non-solid portion adjacent to the first side portion of the negative current collector.

20. In Paragraph 16, Forming the above binder coating layer is, A method for manufacturing an all-solid-state battery, wherein the binder coating layer is coated on the negative current collector in the form of a pattern including an opening.

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