All-solid-state battery and manufacturing method thereof

Abstract

The present invention relates to an all-solid-state battery and a manufacturing method thereof and, more specifically, the all-solid-state battery comprises: a positive electrode layer including a current collector and a positive electrode active material layer, wherein the positive electrode active material layer includes a positive electrode active material and a sulfide-based solid electrolyte; a negative electrode layer including a current collector and a coating layer; and a solid electrolyte layer including a sulfide-based solid electrolyte and positioned between the positive electrode layer and the negative electrode layer, wherein the positive electrode active material layer includes a first active region and a first inactive region, the first inactive region is located on at least one side of the positive electrode active material layer, and the first inactive region is a region modified by a laser.

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

[0003] Recently, all-solid-state batteries 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.

[0004] The problem that the present invention aims to solve is to provide an all-solid-state battery that can prevent the occurrence of a short circuit during the charging and discharging process and has a long lifespan.

[0005] Another problem that the present invention aims to solve is to simplify the manufacturing process of an all-solid-state battery and to provide a method for manufacturing an all-solid-state battery that enables the all-solid-state battery to be manufactured more easily.

[0006] A solid-state battery according to one embodiment of the present invention comprises: a positive electrode layer including a current collector and a positive electrode active material layer, wherein the positive electrode active material layer includes a positive electrode active material and a sulfide-based solid electrolyte; a negative electrode layer including a current collector and a coating layer; and a solid electrolyte layer between the positive electrode layer and the negative electrode layer, wherein the positive electrode active material layer includes a first active region and a first inactive region, wherein the first inactive region is located on at least one side of the positive electrode active material layer, and the first inactive region may be a region modified by a laser.

[0007] A method for manufacturing an all-solid-state battery according to one embodiment of the present invention comprises: forming a positive electrode layer and a solid electrolyte layer sequentially stacked; performing a first pressurization process on the positive electrode layer and the solid electrolyte layer; and performing a cutting process using a laser together on the positive electrode layer and the solid electrolyte layer, wherein the cutting process may include modifying the cutting surface of the positive electrode layer with the laser to form a first inactive region.

[0008] A method for manufacturing an all-solid-state battery according to one embodiment of the present invention comprises: forming a negative electrode layer and a solid electrolyte layer stacked sequentially; performing a first pressurization process on the negative electrode layer and the solid electrolyte layer; performing a first cutting process on the negative electrode layer and the solid electrolyte layer together using a laser; performing a second cutting process on the positive electrode layer using a laser; and performing a second pressurization process on the positive electrode layer, the solid electrolyte layer, and the negative electrode layer, wherein the second cutting process may include modifying the cutting surface of the positive electrode layer with the laser to form a first inactive region.

[0009] An all-solid-state battery according to one embodiment of the present invention can prevent the occurrence of a short circuit during the charging and discharging process. In addition, an all-solid-state battery according to one embodiment of the present invention can have excellent lifespan characteristics.

[0010] A method for manufacturing an all-solid-state battery according to one embodiment of the present invention can manufacture an all-solid-state battery having the characteristics described above. In addition, a method for manufacturing an all-solid-state battery according to one embodiment of the present invention simplifies the manufacturing process and enables the all-solid-state battery to be manufactured more easily. As a result, the all-solid-state battery can be mass-produced.

[0011] FIG. 1 is a plan view of an all-solid-state battery according to embodiments of the present invention.

[0012] Figure 2 is a cross-sectional view along the line A-A' of Figure 1.

[0013] FIG. 3 is a perspective view illustrating an anode layer and a solid electrolyte layer according to one embodiment of the present invention.

[0014] FIG. 4 is a perspective view illustrating an anode layer and a solid electrolyte layer according to another embodiment of the present invention.

[0015] FIG. 5 is a perspective view illustrating an anode layer and a solid electrolyte layer according to another embodiment of the present invention.

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

[0017] FIG. 7 is a cross-sectional view for schematically explaining a method for manufacturing an all-solid-state battery according to one embodiment of the present invention.

[0018] FIGS. 8a and FIGS. 8b are cross-sectional views schematically illustrating a method for manufacturing an all-solid-state battery according to another embodiment of the present invention.

[0019] FIGS. 9a, 9b, and 9c are cross-sectional views schematically illustrating a method for manufacturing an all-solid-state battery according to another embodiment of the present invention.

[0020] FIGS. 10a and FIGS. 10b are scanning electron microscope images of the first inactive region of the positive electrode layer of an all-solid-state battery according to an embodiment.

[0021] Figures 11a and 11b are scanning electron microscope images of the side of the positive electrode layer of an all-solid-state battery according to a comparative example.

[0022] FIGS. 12a and 12b are drawings showing the results of Raman mapping and Raman spectrum for a first inactive region of the positive electrode layer of an all-solid-state battery according to an embodiment.

[0023] Figures 13a and 13b are drawings showing the results of Raman mapping and Raman spectrum for the side of the positive layer of an all-solid-state battery according to a comparative example.

[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] The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. 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]

[0029] All-solid-state battery

[0030] FIG. 1 is a plan view of an all-solid-state battery according to embodiments of the present invention. FIG. 2 is a cross-sectional view along line A-A' of FIG. 1. FIG. 3 is a perspective view for explaining a positive electrode layer and a solid electrolyte layer according to one embodiment of the present invention.

[0031] Referring to FIGS. 1 and 2, a unit cell (CEL) of an all-solid-state battery according to the present invention 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 unit cell (CEL) 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).

[0032] An anode layer (100) according to one embodiment of the present invention may include an anode current collector (110) and an anode active material layer (120) disposed on the anode current collector (110). The anode active material layer (120) may include an anode active material, a solid electrolyte, a conductive material, and a binder.

[0033] 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.

[0034] 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).

[0035] The positive active material of the positive active material layer (120) may include a material capable of reversibly absorbing and desorbing lithium ions. The positive active material may include a plurality of particles. The positive active material may include, for example, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, but is not necessarily limited to these. Each positive active material may be a single material or a mixture of two or more materials.

[0036] 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-cMn 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 Mn2GbO4(0.90≤a≤1, 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3(0≤f≤2), Li 3-fIt is a compound represented by any one of Fe2(PO4)3 (0≤f≤2) or LiFePO4. In such compounds, the uppercase “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.

[0037] The positive electrode active material may include, for example, a lithium salt of a transition metal oxide having a layered rock salt type structure among the lithium transition metal oxides described above. The "layered rock salt type structure" is, for example, a cubic rock salt type structure. <111> It is a structure in which oxygen and metal atomic layers are alternately and regularly arranged in a specific direction, thereby forming a two-dimensional plane for each atomic layer. The "cubic rock salt type structure" represents a sodium chloride (NaCl) type structure, which is a type of crystal structure; specifically, it exhibits a structure in which face-centered cubic lattices (fcc) formed by cations and anions, respectively, are offset from each other by half the ridge of the unit lattice. Lithium transition metal oxides having such a layered rock salt type structure are, for example, LiNi x Co y Al z O2(NCA) or LiNi x Co y Mn zO2(NCM) (0 <x<1,0<y<1, 0<z<1, x+y+z=1) 등의 삼원계 리튬전이금속산화물일 수 있다. 양극 활물질이 층상암염형 구조를 갖는 삼원계 리튬전이금속산화물을 포함하는 경우, 단위 셀(CEL)의 에너지 밀도가 커지고 열안정성이 향상될 수 있다.

[0038] 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.

[0039] When the cathode active material is a ternary lithium transition metal oxide, such as NCA or NCM, containing nickel (Ni), it is possible to increase the capacity density of the unit cell (CEL) and reduce the metal leaching of the cathode active material in the charged state. Consequently, the cycle characteristics of the unit cell (CEL) in the charged state are improved. Meanwhile, "cycle characteristics" refers to the degree of degradation of the unit cell (CEL) due to charging and discharging; a unit cell (CEL) with high cycle characteristics experiences less degradation due to charging and discharging, while a unit cell (CEL) with low cycle characteristics may experience greater degradation due to charging and discharging.

[0040] 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.

[0041] The solid electrolyte of the positive active material layer (120) may have a particle shape. The solid electrolyte may be dispersed among the positive active materials. The solid electrolyte 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, 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), or Li 7-x PS 6-x I x It may include at least one of (0≤x≤2).

[0042] 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), or Li 7-x PS6-x I x It may be an argyrodite-type compound comprising at least one of (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound comprising at least one of Li6PS5Cl, Li6PS5Br, or Li6PS5I.

[0043] Alternatively, sulfide-based solid electrolytes are Li 7-a M a PS 6-c X c It may be an argyrodite-type compound containing (0≤a≤2, 0≤c≤2). Here, X may be F, Br, Cl, I, or a combination thereof. M may be candium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), or a combination thereof.

[0044] 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 may be, for example, 15 GPa to 35 GPa.

[0045] The solid electrolyte in the positive active material layer (120) may have a smaller average particle size compared to the first and second solid electrolytes in the solid electrolyte layer (300) described later. For example, the average particle size of the solid electrolyte 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 of the solid electrolyte in the solid electrolyte layer (300). Meanwhile, the average particle size may be the median diameter measured using a laser particle size distribution meter.

[0046] The positive active material layer (120) may include a conductive material. The conductive material may have conductivity without causing chemical changes in the unit cell (CEL), 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, at least one of graphite, carbon black, acetylene black, carbon nanofiber, or carbon nanotube.

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

[0048] Based on 100 parts by weight of the total positive active material, solid electrolyte, conductive material, and binder, the positive active material layer (120) may contain 78 parts by weight or more and 92 parts by weight or less of the positive active material. Based on 100 parts by weight of the total positive active material, solid electrolyte, conductive material, and binder, the positive active material layer (120) may contain 0.5 parts by weight or more and 1.5 parts by weight or less of the binder.

[0049] Based on 100 parts by weight of solid electrolyte, 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, 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, the proportion of the conductive material is excessively high, and a coating layer covering the surface of the solid electrolyte may not be properly formed.

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

[0051] The negative electrode layer (200) may include a negative electrode current collector (210) and a coating layer (220) on the negative electrode current collector (210). The negative electrode current collector (210) may provide a reference surface on which the 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 of copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), or an alloy thereof. The thickness of the negative electrode current collector (210) may be 1 μm to 20 μm, more specifically 5 μm to 15 μm, and more specifically 7 μm to 10 μm.

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

[0053] The coating layer (220) can allow lithium metal to grow between the unit cell (CEL) and the negative current collector (210) during charging. The coating layer (220) can serve as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites.

[0054] The coating layer (220) may include metal and carbon. For example, the 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 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 coating layer (220) may include a mixture (or composite) of carbon black and silver (Ag).

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

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

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

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

[0059] The solid electrolyte layer (300) may include a solid electrolyte. The solid electrolyte may have a particle shape such as a sphere or an ellipsoid. The solid electrolyte may include a sulfide-based solid electrolyte. The solid electrolyte 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.

[0060] In one embodiment, the solid electrolyte is Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), or Li 7-x PS 6-x I xIt may include an argyrodite-type compound comprising at least one of (0≤x≤2). The solid electrolyte may include an argyrodite-type compound comprising at least one of Li6PS5Cl, Li6PS5Br, or Li6PS5I.

[0061] In another embodiment, the solid electrolyte is Li 7-a M a PS 6-c X c It may include an argyrodite-type compound comprising. Here, X may be Cl, Br, or a combination thereof. M may be Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, or a combination thereof. a and c may each be real numbers between 0 and 2.

[0062] The density of the azyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. Since the azyrodite-type solid electrolyte has a density of 1.5 g / cc or higher, 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 is, for example, 15 GPa to 35 GPa.

[0063] 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 active material layer (120) or the binder included in the coating layer (220).

[0064] In one embodiment of the present invention, the area of ​​the anode layer (100) and the area of ​​the cathode layer (200) may be substantially the same as each other. A substantially the same area may be defined as a difference in area of ​​within 10%.

[0065] Specifically, the anode layer (100) may have a first width (WI1) in a first direction (D1). The cathode layer (200) may have a second width (WI2) in a first direction (D1). The first width (WI1) and the second width (WI2) may be substantially the same. The anode layer (100) may have a third width (WI3) in a second direction (D2). The cathode layer (200) may have a fourth width (WI4) in a second direction (D2). The third width (WI3) and the fourth width (WI4) may be substantially the same. A substantially the same width may be defined as a difference in width within 10%.

[0066] In one embodiment of the present invention, the area of ​​the anode layer (100) and the area of ​​the solid electrolyte layer (300) may be substantially the same. Specifically, the solid electrolyte layer (300) may have a fifth width (WI5) in the first direction (D1). The fifth width (WI5) may be substantially the same as the first width (WI1). The solid electrolyte layer (300) may have a sixth width (WI6) in the second direction (D2). The sixth width (WI6) may be substantially the same as the third width (WI3).

[0067] In one embodiment of the present invention, the area of ​​the cathode layer (200) and the area of ​​the solid electrolyte layer (300) may be substantially the same as each other. Specifically, the fifth width (WI5) may be substantially the same as the second width (WI2). The sixth width (WI4) may be substantially the same as the third width (WI4).

[0068] The positive current collector (110) may include a positive tab (CTB). The positive tab (CTB) may be a protruding area of ​​the positive current collector (110). The positive tab (CTB) may protrude in a second direction (D2).

[0069] The negative current collector (210) may include a negative tab (ATB). The negative tab (ATB) may be a protruding area of ​​the negative current collector (210). The negative tab (ATB) may protrude in a second direction (D2). For example, the negative tab (ATB) may protrude in the opposite direction to the positive tab (CTB).

[0070]

[0071] Referring to FIG. 2, the positive active material layer (120) may include a first active region (ATP1) and a first inactive region (DAP1). The first inactive region (DAP1) may be located on at least one side of the positive active material layer (120). At least one side of the positive active material layer (120) may be located between the positive current collector (110) and the solid electrolyte layer (300) and may be a side exposed from the unit cell (CEL) of the all-solid-state battery. The first inactive region (DAP1) may be a region of the positive active material layer (120) that has been denatured by heat.

[0072] On the surface of the first inactive region (DAP1), a shape formed by melting and adhering due to heat may be observed. As will be described later, for example, the heat may originate from a laser cutting process during the manufacturing process of the all-solid-state battery. In the cutting process, the material constituting the anode layer (100) may be melted by heat and adher to the side of the anode active material layer (120). The material constituting the anode layer (100) may not only be melted by heat but may also undergo chemical changes. For example, chemical changes may include thermal decomposition, the formation of byproducts, etc.

[0073] The first inactive region (DAP1) may contain a thermally decomposed solid electrolyte. The solid electrolyte within the first inactive region (DAP1) may have a state in which the bonding structure has been altered as chemical bonds within the electrolyte are broken due to exposure to high temperatures. The solid electrolyte within the first inactive region (DAP1) may be in a state in which it has lost its original function due to thermal decomposition.

[0074] The first inactive region (DAP1) may be in a carbonized state. The first inactive region (DAP1) may be an area where the positive active material layer (120) is partially carbonized. For example, the first inactive region (DAP1) may appear black due to carbonization. The first inactive region (DAP1) may have relatively weak physical strength.

[0075] The first inactive region (DAP1) may include a solid electrolyte with a modified crystal structure. The first inactive region (DAP1) may be in a state where mechanical strength, flexibility, and durability are reduced compared to the positive active material layer (120). The first inactive region (DAP1) may be in a state where it is partially melted or shrunken.

[0076] The first inactive region (DAP1) may contain microcracks. The first inactive region (DAP1) may be in a state where physical damage has occurred due to thermal expansion and contraction caused by heat.

[0077] As will be described later, the first inactive region (DAP1) may include a plurality of first inactive regions. The plurality of first inactive regions may be arranged at a predetermined pitch or arranged adjacent to each other.

[0078] The first active region (ATP1) may be the remaining region of the anode active material layer (120) excluding the first inactive region (DAP1). The first active region (ATP1) may be a region not exposed to high temperatures. The first active region (ATP1) may be a region not carbonized. The first active region (ATP1) and the first inactive region (DAP1) may be in contact with each other. For example, at least one side of the first active region (ATP1) may be exposed.

[0079] The first inactive region (DAP1) may have a relatively very low ionic conductivity. In the case of the first inactive region (DAP1), the crystal structure of the solid electrolyte may be deformed or phase changes may hinder the movement of ions. The ionic conductivity of the first inactive region (DAP1) may be lower than that of the first active region (ATP1). For example, the ionic conductivity of the first inactive region (DAP1) is 10 -8 S / cm to 10 -6 S / cm, or 10 -8 S / cm to 10 -7 It can be S / cm. On the other hand, the ionic conductivity of the first active region (ATP1) is 10 -8 S / cm to 10 -6 It can be S / cm.

[0080] When a laser cutting process is performed on the positive active material layer (120), the content of the components constituting the positive active material layer (120) may change due to melting of the positive current collector (110), modification of the positive active material, thermal decomposition of the solid electrolyte, etc.

[0081] The first inactive region (DAP1) may contain a relatively large amount of aluminum (Al). For example, the aluminum (Al) may be derived mainly from the positive current collector (110) and / or the positive active material layer (120). The content of aluminum (Al) in the first inactive region (DAP1) may be greater than the content of aluminum (Al) in the first active region (ATP1). If a laser cutting process is performed on the positive active material layer (120), a first inactive region (DAP1) with a higher content of aluminum (Al) than the first active region (ATP1) may be formed. For example, when the total content of nickel (Ni), cobalt (Co), and aluminum (Al) is 100 at%, the content of aluminum (Al) in the first inactive region (DAP1) may be 4 at% to 50 at% or 10 at% to 50 at%, and the content of aluminum (Al) in the first active region (ATP1) may be less than 10 at% or 3 at% to 8 at%. For example, when the total content of sulfur (S), carbon (C), nickel (Ni), and aluminum (Al) is 100 at%, the content of aluminum (Al) in the first inactive region (DAP1) may be 30 at% to 40 at%.

[0082] The content of nickel (Ni) in the first inactive region (DAP1) may be less than the content of nickel (Ni) in the first active region (ATP1). For example, when the total content of nickel (Ni), cobalt (Co), and aluminum (Al) is 100 at%, the content of nickel (Ni) in the first inactive region (DAP1) may be 50 at% to 90 at%, and the content of nickel (Ni) in the first active region (ATP1) may be 80 at% to 95 at%. For example, when the total content of sulfur (S), carbon (C), nickel (Ni), and aluminum (Al) is 100 at%, the content of nickel (Ni) in the first inactive region (DAP1) may be 45 at% to 55 at%, and the content of nickel (Ni) in the first active region (ATP1) may be 50 at% to 94 at%, or 50 at% to 60 at%.

[0083] The content of cobalt (Co) in the first inactive region (DAP1) may be less than the content of cobalt (Co) in the first active region (ATP1). For example, when the total content of nickel (Ni), cobalt (Co), and aluminum (Al) is 100 at%, the content of cobalt (Co) in the first inactive region (DAP1) may be 4 at% to 7 at%, and the content of cobalt (Co) in the first active region (ATP1) may be 5 at% to 10 at%.

[0084] The content ratio of nickel (Ni) to cobalt (Co) in the first inactive region (DAP1) (Ni / Co) may be greater than the content ratio of nickel (Ni) to cobalt (Co) in the first active region (ATP1) (Ni / Co). For example, the content ratio of nickel (Ni) to cobalt (Co) in the first inactive region (DAP1) (Ni / Co) may be 12 to 20, and the content ratio of nickel (Ni) to cobalt (Co) in the first active region (ATP1) (Ni / Co) may be 8 to 20, or 8 to 12.

[0085] Due to the thermal decomposition of the solid electrolyte, the sulfur (S) content in the first inactive region (DAP1) may be less than the sulfur (S) content in the first active region (ATP1). For example, when the total content of sulfur (S), carbon (C), nickel (Ni), and aluminum (Al) is 100 at%, the sulfur (S) content in the first inactive region (DAP1) may be 5 at% to 10 at%, and the sulfur (S) content in the first active region (ATP1) may be 30 at% to 50 at%.

[0086] The ratio of nickel (Ni) to sulfur (S) in the first inactive region (DAP1) (Ni / S) may be greater than the ratio of nickel (Ni) to sulfur (S) in the first active region (ATP1). For example, the ratio of nickel (Ni) to sulfur (S) in the first inactive region (DAP1) (Ni / S) may be 5 to 10, and the ratio of nickel (Ni) to sulfur (S) in the first active region (ATP1) (Ni / S) may be 1 to 2.

[0087] The ratio of aluminum (Al) to sulfur (S) in the first inactive region (DAP1) (Al / S) may be greater than the ratio of aluminum (Al) to sulfur (S) in the first active region (ATP1). For example, the ratio of aluminum (Al) to sulfur (S) in the first inactive region (DAP1) (Al / S) may be 5 to 10. The ratio of aluminum (Al) to sulfur (S) in the first active region (ATP1) (Al / S) may be less than 0.05.

[0088] The ratio of carbon (C) to sulfur (S) in the first inactive region (DAP1) (C / S) may be greater than the ratio of carbon (C) to sulfur (S) in the first active region (ATP1). For example, the ratio of carbon (C) to sulfur (S) in the first inactive region (DAP1) (C / S) may be 0.5 to 2, and the ratio of carbon (C) to sulfur (S) in the first active region (ATP1) (C / S) may be 0.1 to 0.5.

[0089] If the content of sulfur (S), aluminum (Al), nickel (Ni), and carbon (C) within the first inactive region (DAP1) satisfies the range described above, the first inactive region (DAP1) may have a relatively very low ionic conductivity.

[0090] In the Raman spectrum for the first inactive region (DAP1), a peak corresponding to aluminum can be observed. The peak corresponding to aluminum is at 1000 cm⁻¹. -1 up to 1300cm -1 It can be observed in. For example, aluminum may include forms of its compounds. For example, aluminum compounds may include its oxides, alloys with other metals, etc. On the other hand, in the Raman spectrum for the first active region (ATP1), the peak corresponding to aluminum may be small or hardly observed.

[0091] For example, the thickness (TKD1) in the first direction (D1) of the first inactive region (DAP1) may be within about 1 mm.

[0092] For example, the thickness of the first inactive region (DAP1) in the third direction (D3) may be substantially the same as the thickness of the first active region (ATP1) in the third direction (D3). That is, the thickness of the positive active material layer (120) may have a substantially uniform thickness from its interior to its sides. A substantially uniform thickness may mean that the difference in thickness is 10% or less. Thus, the density within the positive active material layer (120) may be uniform. In other words, the density within the positive active material layer (120) may not be higher near the sides than in its interior.

[0093] Referring to FIG. 3, the first inactive region (DAP1) may be located on two sides facing each other among the sides of the positive active material layer (120). The first inactive region (DAP1) may include two first inactive regions (DAP1). The first inactive region (DAP1) may include two first inactive regions (DAP1) formed along two sides facing each other of the positive active material layer (120). The two first inactive regions (DAP1) may be arranged along a second direction (D2) at a predetermined pitch. The two first inactive regions (DAP1) may be spaced apart from each other in a first direction (D1). The first inactive regions (DAP1) may be in contact with two different sides among the four sides of the first active region (ATP1).

[0094] The remaining two sides of the first active region (ATP1) may be exposed. The two exposed sides may be sides that are not in contact with the first inactive region (DAP1). One of the exposed sides may be the side facing the direction in which the anode tab (CTB) protrudes. The other side may be opposite to said side.

[0095] Although not illustrated, as an example, the unit cell (CEL) may further include a functional layer on at least one exposed side of the first active region (ATP1). For example, the functional layer may include an insulating material, a polymer, etc. The functional layer may cover at least one exposed side of the first active region (ATP1). The functional layer may prevent a short circuit between the positive layer (100) and the negative layer (200) due to the growth of lithium on the side of the all-solid-state battery during the charging and discharging process on at least one exposed side of the first active region (ATP1).

[0096] FIGS. 4 and FIGS. 5 are perspective views illustrating an anode layer and a solid electrolyte layer according to different embodiments of the present invention. In the embodiments described below, detailed descriptions of technical features that overlap with those previously described with reference to FIGS. 1 to 3 are omitted, and differences are described in detail.

[0097] Referring to FIG. 4, the first inactive region (DAP1) may be located on three adjacent sides of the positive active material layer (120). The first inactive region (DAP1) may be in contact with three different sides of the four sides of the first active region (ATP1).

[0098] The remaining side of the first active region (ATP1) may be exposed. The exposed side may be the side not in contact with the first inactive region (DAP1). The exposed side may be the side in the direction in which the positive tab (CTB) protrudes.

[0099] Referring to FIG. 5, the first inactive region (DAP1) may be located on the four sides of the positive active material layer (120). The first inactive region (DAP1) may be in contact with the four sides of the first active region (ATP1). The first active region (ATP1) may be surrounded by the first inactive region (DAP1). The present embodiment may be formed by forming the first inactive region (DAP1) through a cutting process and then separately attaching a positive tab (CTB) to the positive current collector (110).

[0100]

[0101] Referring again to FIG. 2, the solid electrolyte layer (300) may include a second active region (ATP2) and a second inactive region (DAP2). The second inactive region (DAP2) may be located on at least one side of the solid electrolyte layer (300). At least one side of the solid electrolyte layer (300) may be located between the positive active material layer (120) and the coating layer (220) and may be a side exposed from the unit cell (CEL) of the all-solid-state battery. The second inactive region (DAP2) may be a region of the solid electrolyte layer (300) that has been altered by heat.

[0102] On the surface of the second inactive region (DAP2), a shape formed by melting and adhering due to heat may be observed. As will be described later, for example, the heat may originate from a laser cutting process during the manufacturing process of the all-solid-state battery. In the cutting process, the material constituting the solid electrolyte layer (300) may be melted by heat and adher to the side of the solid electrolyte layer (300). Additionally, if the solid electrolyte layer (300) is formed on the anode layer (100) or the cathode layer (200) and then cut, the material constituting the anode layer (100) or the cathode layer (200) may be melted by heat and adher to the side of the solid electrolyte layer (300) during the cutting process. The material constituting the solid electrolyte layer (300), the anode layer (100), or the cathode layer (200) may not only be melted by heat but may also undergo chemical changes. For example, chemical changes may include thermal decomposition, the formation of by-products, etc.

[0103] The second inactive region (DAP2) may contain a thermally decomposed solid electrolyte. The solid electrolyte within the second inactive region (DAP2) may have a state in which the bonding structure has been altered as chemical bonds within the electrolyte are broken due to exposure to high temperatures. The solid electrolyte within the second inactive region (DAP2) may have lost its original function due to thermal decomposition.

[0104] The second inactive region (DAP2) may be in a carbonized state. The second inactive region (DAP2) may be a region where the solid electrolyte layer (300) is partially carbonized. For example, the second inactive region (DAP2) may appear black due to carbonization. The second inactive region (DAP2) may have relatively weak physical strength.

[0105] The second inactive region (DAP2) may include a solid electrolyte with a modified crystal structure. The second inactive region (DAP2) may be in a state where mechanical strength, flexibility, and durability are reduced compared to the solid electrolyte layer (300). The second inactive region (DAP2) may be in a state where it is partially melted or shrunken.

[0106] The second inactive region (DAP2) may contain microcracks. The second inactive region (DAP2) may be in a state where physical damage has occurred due to thermal expansion and contraction caused by heat.

[0107] As will be described later, the second inactive region (DAP2) may include a plurality of second inactive regions. The plurality of second inactive regions may be arranged at a predetermined pitch or arranged adjacent to each other.

[0108] The second active region (ATP2) may be the remaining region of the solid electrolyte layer (300) excluding the second inactive region (DAP2). The second active region (ATP2) may be a region not exposed to high temperatures. The second active region (ATP2) may be a region not carbonized. The second active region (ATP2) and the second inactive region (DAP2) may be in contact with each other. For example, at least one side of the second active region (ATP2) may be exposed.

[0109] The second inactive region (DAP2) may have a relatively very low ionic conductivity. In the case of the second inactive region (DAP2), the crystal structure of the solid electrolyte may be deformed or phase changes may hinder the movement of ions. The ionic conductivity of the second inactive region (DAP2) may be lower than that of the second active region (ATP2). For example, the ionic conductivity of the second inactive region (DAP2) is 10 -8 S / cm to 10 -6 S / cm, or 10 -8 S / cm to 10 -7 It can be S / cm. On the other hand, the ionic conductivity of the second active region (ATP2) is 10 -5 It can be from S / cm to 10 S / cm.

[0110] Due to the thermal decomposition of the solid electrolyte, the sulfur (S) content in the second inactive region (DAP2) may be less than the sulfur (S) content in the second active region (ATP2).

[0111] For example, the second inactive region (DAP2) may contain aluminum (Al). For example, the aluminum (Al) may be derived primarily from the positive current collector (110) and / or the positive active material layer (120). The content of aluminum (Al) in the second inactive region (DAP2) may be greater than the content of aluminum (Al) in the second active region (ATP2). When a laser cutting process is performed on the positive active material layer (120) and the solid electrolyte layer (300), a second inactive region (DAP2) with a higher content of aluminum (Al) than the second active region (ATP2) may be formed. For example, during the laser cutting process, due to melting of the positive current collector (110), a second inactive region (DAP2) with a higher content of aluminum (Al) than the second active region (ATP2) may be formed. The second active region (ATP2) may not substantially contain aluminum (Al). For example, the aluminum (Al) content in the second active region (ATP2) may be less than 2 at%.

[0112] The ratio of aluminum (Al) to sulfur (S) in the second inactive region (DAP2) (Al / S) may be greater than the ratio of aluminum (Al) to sulfur (S) in the second active region (ATP2) (Al / S).

[0113] If the content of sulfur (S) and aluminum (Al) within the second inactive region (DAP2) satisfies the range described above, the second inactive region (DAP2) may have a relatively very low ionic conductivity.

[0114] For example, the thickness (TKD2) of the second inactive region (DAP2) in the first direction (D1) may be within about 1 mm.

[0115] For example, the thickness of the second inactive region (DAP2) in the third direction (D3) may be substantially the same as the thickness of the second active region (ATP2) in the third direction (D3). That is, the thickness of the solid electrolyte layer (300) may have a substantially uniform thickness from its interior to its sides. Thus, the density within the solid electrolyte layer (300) may be uniform. In other words, the density within the solid electrolyte layer (300) may not be higher near its sides than in its interior.

[0116] Referring again to FIG. 3, the second inactive region (DAP2) may be located on two sides facing each other among the sides of the solid electrolyte layer (300). The second inactive region (DAP2) may include two second inactive regions (DAP2). The second inactive region (DAP2) may include two second inactive regions (DAP2) formed along two sides facing each other of the solid electrolyte layer (300). The two second inactive regions (DAP2) may be arranged along the second direction (D2) at a predetermined pitch. The two second inactive regions (DAP2) may be spaced apart from each other in the first direction (D1). The second inactive regions (DAP2) may be in contact with two different sides among the four sides of the second active region (ATP2).

[0117] The remaining two sides of the second active region (ATP1) may be exposed. The two exposed sides may be sides that do not come into contact with the second inactive region (DAP1). One of the exposed sides may be the side facing the direction in which the anode tab (CTB) protrudes. The other side may be opposite to said side.

[0118] The second inactive region (DAP2) can be vertically overlapped with the first inactive region (DAP1).

[0119] Although not illustrated, as an example, the unit cell (CEL) may further include a functional layer on at least one side where the second active region (ATP2) is exposed. The description of the functional layer is as described above.

[0120] As another example, referring to FIG. 4, the second inactive region (DAP2) may be located on three adjacent sides of the solid electrolyte layer (300). The second inactive region (DAP2) may be in contact with three different sides of the four sides of the second active region (ATP2).

[0121] The remaining side of the second active region (ATP2) may be exposed. The exposed side may be the side that is not in contact with the second inactive region (DAP2).

[0122] For example, the exposed side may be the side in the direction in which the positive tab (CTB) protrudes. The second inactive area (DAP2) may overlap vertically with the first inactive area (DAP1).

[0123] Alternatively, as another example, unlike what is described, the exposed side may be the side in the direction in which the cathode tab (ATB) protrudes. The second inactive region (DAP2) may only partially overlap the first inactive region (DAP1) perpendicularly.

[0124] As another example, referring to FIG. 5, the second inactive region (DAP2) may be located on the four sides of the solid electrolyte layer (300). The second inactive region (DAP2) may be in contact with the four sides of the second active region (ATP2). The second active region (ATP2) may be surrounded by the second inactive region (DAP2). The second inactive region (DAP2) may be vertically overlapped with the first inactive region (DAP1). The present embodiment may be formed by forming the second inactive region (DAP2) through a cutting process, and then separately attaching a positive tab (CTB) to the positive current collector (110) or a negative tab (ATB) to the negative current collector (210).

[0125]

[0126] Although not illustrated, the coating layer (220) of the unit cell (CEL) of the all-solid-state battery according to another embodiment of the present invention may further include the sulfide-based solid electrolyte described above, in addition to metal and carbon. In this case, the coating layer (220) may include a third active region and a third inactive region. The third inactive region may be located on at least one side of the coating layer. At least one side of the coating layer may be located between the negative electrode current collector (210) and the solid electrolyte layer (300) and may be a side exposed from the unit cell (CEL) of the all-solid-state battery. The third inactive region may be a region of the coating layer that has been altered by heat.

[0127] On the surface of the third inactive region, a shape formed by melting and adhering due to heat can be observed. In the coating process, the material constituting the cathode layer (200) may be melted by heat and adher to the side of the coating layer (220). The material constituting the cathode layer (200) may not only be melted by heat but may also undergo chemical changes. For example, chemical changes may include thermal decomposition, the formation of byproducts, etc.

[0128] The third inactive region may include a thermally decomposed solid electrolyte. The third inactive region may be in a carbonized state. The third inactive region may include a solid electrolyte with a modified crystal structure. The third inactive region may include microcracks.

[0129] The third inactive region may include a plurality of third inactive regions. The plurality of third inactive regions may be arranged at a predetermined pitch or arranged adjacent to each other.

[0130] The third inactive region may have a relatively very low ionic conductivity. The ionic conductivity of the third inactive region may be lower than that of the third active region.

[0131] Due to the thermal decomposition of the solid electrolyte, the sulfur (S) content in the third inactive region may be less than the sulfur (S) content in the third active region.

[0132] For example, the thickness of the third inactive region in the first direction (D1) may be within about 1 mm.

[0133] For example, the thickness of the third inactive region in the third direction (D3) may be substantially the same as the thickness of the third active region in the third direction (D3). That is, the thickness of the coating layer (220) may have a substantially uniform thickness from its interior to its sides. Thus, the density within the coating layer (220) may be uniform. In other words, the density within the coating layer (220) may not be higher near the sides than in its interior.

[0134] All or part of the third inactive region (DAP3) may vertically overlap with the second inactive region (DAP2).

[0135]

[0136] A unit cell (CEL) of an all-solid-state battery according to embodiments of the present invention may not include a gasket. That is, the unit cell (CEL) may have a structure in which a gasket is omitted. Since the areas of the positive electrode layer (100), the solid electrolyte layer (300), and the negative electrode layer (200) are substantially the same, the unit cell (CEL) according to embodiments of the present invention may not have a step on its side. By forming the side of the unit cell (CEL) including a first inactive region (DAP1) and / or a second inactive region (DAP2) according to the manufacturing method of the all-solid-state battery described below, the unit cell (CEL) according to the present invention may not have a step on its side. In other words, the unit cell (CEL) of an all-solid-state battery according to embodiments of the present invention may omit a gasket by including a first inactive region (DAP1) and / or a second inactive region (DAP2).

[0137] In addition, the first inactive region (DAP1) and the second inactive region (DAP2) may be regions where there is substantially little movement of ions during the operation of the all-solid-state battery and where the battery does not perform its function. The first inactive region (DAP1) and the second inactive region (DAP2) may substantially function as an insulating layer. Therefore, since they have the same or similar function and structure as a gasket, which is an insulating structure, the unit cell (CEL) of the all-solid-state battery according to the embodiments of the present invention may omit the gasket.

[0138] The all-solid-state battery according to the embodiments of the present invention includes a first inactive region (DAP1) and a second inactive region (DAP2), thereby lowering the ion conductivity on the side of the all-solid-state battery. This effectively prevents a short circuit between the positive electrode layer (100) and the negative electrode layer (200) caused by lithium growth on the side of the all-solid-state battery during the charging and discharging process.

[0139] Specifically, FIG. 6 is a cross-sectional view of an all-solid-state battery during charging and discharging according to an embodiment of the present invention. Referring to FIG. 6, a unit cell (CEL) of an all-solid-state battery according to embodiments of the present invention may include a lithium electrodeposition layer (LDL) between a negative electrode current collector (210) and a coating layer (220). The width (WIL) of the lithium electrodeposition layer (LDL) may be equal to or smaller than the width (WID1) of a first active region (DAP1). The width (WIL) of the lithium electrodeposition layer (LDL) may be equal to or smaller than the width (WID2) of a second active region (DAP2). The lithium electrodeposition layer (LDL) may not be formed below the first inactive region (DAP1) and the second inactive region (DAP2). Since the first inactive region (DAP1) and the second inactive region (DAP2) are inactive regions with low ion conductivity, the lithium electrodeposition layer (LDL) is not formed overlapping with them, thereby preventing defects caused by lithium growth and / or electrodeposition on the side of the unit cell (CLE) of the all-solid-state battery. Accordingly, the all-solid-state battery according to the embodiments of the present invention can improve the all-solid-state battery life characteristics.

[0140] In addition, since the density within the positive active material layer (120), the solid electrolyte layer (300), or the negative electrode layer (200) of the all-solid-state battery according to the embodiments of the present invention is uniform, problems such as localized growth of lithium or formation of lithium dendrites in specific parts of the all-solid-state battery (e.g., sides, or near sides such as first and second inactive regions) during the charging and discharging process can be prevented. Therefore, the all-solid-state battery according to the embodiments of the present invention can improve the all-solid-state battery life characteristics.

[0141]

[0142] Method for manufacturing an all-solid-state battery

[0143] FIG. 7 is a cross-sectional view schematically illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. FIG. 8a and FIG. 8b are cross-sectional views schematically illustrating a method for manufacturing an all-solid-state battery according to another embodiment of the present invention. FIG. 9a, FIG. 9b and FIG. 9c are cross-sectional views schematically illustrating a method for manufacturing an all-solid-state battery according to another embodiment of the present invention.

[0144] Referring to FIG. 7, a method for manufacturing an all-solid-state battery according to one embodiment of the present invention may include forming a positive electrode layer (100), a solid electrolyte layer (300), and a negative electrode layer (200); performing a first pressurization process on the positive electrode layer (100), the solid electrolyte layer (300), and the negative electrode layer (200); and performing a cutting process using a laser on the positive electrode layer (100), the solid electrolyte layer (300), and the negative electrode layer (200).

[0145] The positive layer (100) may include a positive current collector (110) and a positive active material layer (120) that are sequentially stacked. Preparing the positive layer (100) may include forming a positive active material layer (120) on a positive current collector (110). Forming the positive active material layer (120) may include coating a positive active material slurry on a positive current collector (110) and drying the coated positive active material slurry. In another embodiment of the present invention, forming the positive active material layer (120) may include forming the positive active material layer (120) by a dry process and stacking the dry-manufactured positive active material layer (120) on a positive current collector (110).

[0146] The cathode layer (200) may include a cathode current collector (210) and a coating layer (220) that are sequentially stacked. Forming the cathode layer (200) may include coating a coating layer slurry on the cathode current collector (210) and drying the coated coating layer slurry.

[0147] Forming the solid electrolyte layer (300) may include coating a solid electrolyte slurry on a substrate and drying the coated solid electrolyte slurry. As an example, the substrate may be a metal substrate. For example, the metal substrate 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 metal substrate may be removed.

[0148] As another example, the substrate may be an anode layer (100) or a cathode layer (200). That is, a solid electrolyte slurry may be directly coated and dried on the anode layer (100) or the cathode layer (200). If the substrate is an anode layer (100), the solid electrolyte layer (300) may form an anode substrate (CSS) together with the anode layer (100). If the substrate is a cathode layer (200), the solid electrolyte layer (300) may form a cathode substrate (ASS) together with the cathode layer (200).

[0149] In another embodiment of the present invention, forming the solid electrolyte layer (300) may include forming the solid electrolyte layer by a dry process.

[0150] For example, the anode layer (100), solid electrolyte layer (300), and cathode layer (200) can each be provided on different reels and can be stacked sequentially in a third direction (D3).

[0151] As another example, the positive electrode substrate (CSS) and the negative electrode layer (200) may each be provided on different reels and may be stacked in a third direction (D3). Alternatively, the negative electrode substrate (ASS) and the positive electrode layer (100) may each be provided on different reels and may be stacked in a third direction (D3).

[0152] A first pressurization process can be performed on the anode layer (100), the solid electrolyte layer (300), and the cathode layer (200). The anode layer (100), the solid electrolyte layer (300), and the cathode layer (200) can be pressurized together. The first pressurization process may include a roll press. The roll press may be performed using a pair of rollers (R). The pair of rollers (R) may be configured to press the anode layer (100), the solid electrolyte layer (300), and the cathode layer (200).

[0153] For example, the roll press of the first pressing process can be performed at 0.1 ton / cm to 10 ton / cm. For example, the first pressing process can be performed at 60°C to 180°C.

[0154] A cutting process can be performed on the anode layer (100), solid electrolyte layer (300), and cathode layer (200). The anode layer (100), solid electrolyte layer (300), and cathode layer (200) can be cut together. The cutting process can be performed using a laser generator (LGH). A laser (LSR) emitted from the laser generator (LGH) can penetrate the anode layer (100), solid electrolyte layer (300), and cathode layer (200), and the anode layer (100), solid electrolyte layer (300), and cathode layer (200) can be cut. By using the laser (LSR), the cut side can be formed perpendicularly along a third direction (D3) with respect to a horizontal plane defined by a first direction (D1) and a second direction (D2). When using a laser (LSR), the cut side of the positive active material layer (120), the cut side of the solid electrolyte layer (300), and the cut side of the coating layer (220) can be formed perpendicularly along the third direction (D3). That is, when using a laser (LSR), the sides of the positive active material layer (120), the solid electrolyte layer (300), and the coating layer (220) may not be cut at an angle.

[0155] By using a laser (LSR), the thickness of the positive active material layer (120) can be substantially uniform from its interior to the cut side. By using a laser (LSR), the thickness of the solid electrolyte layer (300) can be substantially uniform from its interior to the cut side. By using a laser (LSR), the thickness of the coating layer (220) can be substantially uniform from its interior to the cut side.

[0156] A laser (LSR) can be irradiated from a laser generator (LGH) with sufficient intensity to cut the anode layer (100), solid electrolyte layer (300), and cathode layer (200).

[0157] As the laser (LSR) penetrates the anode layer (100) and the solid electrolyte layer (300), a first inactive region (DAP1) may be formed within the anode active material layer (120), and a second inactive region (DAP2) may be formed within the solid electrolyte layer (300). The first inactive region (DAP1) and the second inactive region (DAP2) may be regions where the anode layer (100), the solid electrolyte layer (300), and the cathode layer (200) are melted or chemically altered by the laser (LSR) (i.e., heat). The first inactive region (DAP1) and the second inactive region (DAP2) may be parts where the anode active material layer (120) and the solid electrolyte layer (300) are modified by the laser (LSR) (i.e., heat). As previously explained, the first inactive region (DAP1) and the second inactive region (DAP2) may contain a structurally modified solid electrolyte. The first inactive region (DAP1) and the second inactive region (DAP2) may contain microcracks. The ionic conductivity of the first inactive region (DAP1) and the second inactive region (DAP2) may be very low. The sulfur (S) content within the first inactive region (DAP1) and the second inactive region (DAP2) may be very low. Due to melting of the anode current collector (110), etc., the aluminum (Al) content within the first inactive region (DAP1) and the second inactive region (DAP2) may be relatively high. The nickel (Ni) content ratio (Ni / S) to sulfur (S) and the carbon (C) content ratio (C / S) to sulfur (S) within the first inactive region (DAP1) may be relatively high.

[0158] For example, the laser (LSR) can be irradiated onto the positive current collector (110). Or, as illustrated, for another example, the laser (LSR) can be irradiated onto the negative current collector (210).

[0159] By using the method for manufacturing an all-solid-state battery according to the embodiments of the present invention, an all-solid-state battery described with reference to FIGS. 1 to 6 can be manufactured. In addition, by cutting using a laser, the method for manufacturing an all-solid-state battery according to the embodiments of the present invention can simplify the manufacturing process of the all-solid-state battery by omitting processes such as alignment between the positive electrode layer (100), the solid electrolyte layer (300), or the negative electrode layer (200), thereby making it easier to manufacture the all-solid-state battery and enabling mass production.

[0160]

[0161] In the embodiments described below, detailed descriptions of technical features that overlap with those previously described with reference to FIG. 7 are omitted, and differences are described in detail.

[0162] Referring to FIG. 8a and FIG. 8b, a method for manufacturing an all-solid-state battery according to one embodiment of the present invention may include forming a positive electrode layer (100) and a solid electrolyte layer (300); performing a first pressurization process on the positive electrode layer (100) and the solid electrolyte layer (300); performing a cutting process using a laser on the positive electrode layer (100) and the solid electrolyte layer (300); forming a negative electrode layer (200) on the solid electrolyte layer (300); and performing a second pressurization process on the positive electrode layer (100), the solid electrolyte layer (300), and the negative electrode layer (200).

[0163] The anode substrate (CSS) may include an anode layer (100) and a solid electrolyte layer (300). For example, the anode layer (100) and the solid electrolyte layer (300) may each be provided on different reels and stacked in a third direction (D3) to form the anode substrate (CSS). For another example, the anode substrate (CSS) may be formed by directly coating and drying a solid electrolyte slurry on the anode layer (100).

[0164] A first pressurization process can be performed on the anode substrate (CSS). The anode layer (100) and the solid electrolyte layer (300) can be pressurized together. A pair of rollers (R) can be configured to pressurize the anode layer (100) and the solid electrolyte layer (300).

[0165] A cutting process can be performed on the anode layer (100) and the solid electrolyte layer (300). The anode layer (100) and the solid electrolyte layer (300) can be cut together. The cutting process can be performed using a laser generator (LGH). A laser (LSR) emitted from the laser generator (LGH) can penetrate the anode layer (100) and the solid electrolyte layer (300), and the anode layer (100) and the solid electrolyte layer (300) can be cut. By using the laser (LSR), the cut side can be formed perpendicularly along the third direction (D3) with respect to a horizontal plane defined by the first direction (D1) and the second direction (D2). By using the laser (LSR), the cut side of the anode active material layer (120) and the cut side of the solid electrolyte layer (300) can be formed perpendicularly along the third direction (D3). That is, by using a laser (LSR), the sides of the positive active material layer (120) and the solid electrolyte layer (300) may not be cut at an angle.

[0166] By using a laser (LSR), the thickness of the positive active material layer (120) can be substantially uniform from its interior to the cut side. By using a laser (LSR), the thickness of the solid electrolyte layer (300) can be substantially uniform from its interior to the cut side.

[0167] As the laser (LSR) penetrates the anode layer (100) and the solid electrolyte layer (300), a first inactive region (DAP1) may be formed within the anode active material layer (120), and a second inactive region (DAP2) may be formed within the solid electrolyte layer (300).

[0168] For example, the laser (LSR) can be irradiated onto the solid electrolyte layer (300). Or, as shown, in another example, the laser (LSR) can be irradiated onto the positive current collector (110).

[0169] A cathode layer (200) may be formed on a solid electrolyte layer (300). The cathode layer (200) may be formed on the solid electrolyte layer (300) so that the solid electrolyte layer (300) is disposed between the cathode layer (200) and the anode layer (100). For example, the cathode layer (200) may be cut. For example, the cutting may be performed by the laser generator (LGH) described above. The cut cathode layer (200) may be aligned on the solid electrolyte layer (300).

[0170] A second pressurization process may be performed on the anode layer (100), the solid electrolyte layer (300), and the cathode layer (200). The anode layer (100), the solid electrolyte layer (300), and the cathode layer (200) may be pressurized together. The second pressurization process may include a roll press. The roll press may be performed using a pair of rollers (R). The pair of rollers (R) may be configured to press the anode layer (100), the solid electrolyte layer (300), and the cathode layer (200).

[0171] For example, the roll press of the second pressing process can be performed at 0.1 ton / cm to 10 ton / cm. For example, the second pressing process can be performed at 60°C to 180°C.

[0172] Referring to FIGS. 9a to 9c, a method for manufacturing an all-solid-state battery according to one embodiment of the present invention may include forming a negative electrode layer (200) and a solid electrolyte layer (300); performing a third pressurization process on the negative electrode layer (200) and the solid electrolyte layer (300); performing a first cutting process on the negative electrode layer (200) and the solid electrolyte layer (300) together using a laser; performing a second cutting process on the positive electrode layer (100) using a laser; and performing a fourth pressurization process on the positive electrode layer (100), the solid electrolyte layer (300), and the negative electrode layer (200).

[0173] The cathode substrate (ASS) may include a cathode layer (200) and a solid electrolyte layer (300). For example, the cathode layer (200) and the solid electrolyte layer (300) may each be provided on different reels and stacked in a third direction (D3) to form the cathode substrate (ASS). For another example, the cathode substrate (ASS) may be formed by directly coating and drying a solid electrolyte slurry on the cathode layer (200).

[0174] A third pressurization process can be performed on the cathode substrate (ASS). The cathode layer (200) and the solid electrolyte layer (300) can be pressurized together. The third pressurization process may include a roll press. The roll press may be performed using a pair of rollers (R). The pair of rollers (R) may be configured to press the solid electrolyte layer (300) and the cathode layer (200).

[0175] For example, the roll press of the third pressing process can be performed at 0.1 ton / cm to 10 ton / cm. For example, the third pressing process can be performed at 60°C to 180°C.

[0176] A first cutting process can be performed on the cathode layer (200) and the solid electrolyte layer (300). The cathode layer (200) and the solid electrolyte layer (300) can be cut together. The cutting process can be performed with a laser generator (LGH). A laser (LSR) emitted from the laser generator (LGH) can penetrate the solid electrolyte layer (300) and the cathode layer (200), and the solid electrolyte layer (300) and the cathode layer (200) can be cut. By using the laser (LSR), the cut side can be formed perpendicularly along the third direction (D3) with respect to a horizontal plane defined by the first direction (D1) and the second direction (D2). By using the laser (LSR), the cut side of the solid electrolyte layer (300) and the cut side of the coating layer (220) can be formed perpendicularly along the third direction (D3). That is, by using a laser (LSR), the sides of the solid electrolyte layer (300) and the coating layer (220) may not be cut at an angle.

[0177] By using a laser (LSR), the thickness of the solid electrolyte layer (300) can be substantially uniform from its interior to the cut side. By using a laser (LSR), the thickness of the coating layer (220) can be substantially uniform from its interior to the cut side.

[0178] As the laser (LSR) penetrates the solid electrolyte layer (300), a second inactive region (DAP2) can be formed within the solid electrolyte layer (300).

[0179] For example, the laser (LSR) can be irradiated onto the solid electrolyte layer (300). Unlike what is illustrated, in another example, the laser (LSR) can be irradiated onto the cathode current collector (210).

[0180] A second cutting process can be performed on the anode layer (100). The cutting process can be performed using a laser generator (LGH). A laser (LSR) emitted from the laser generator (LGH) can penetrate the anode layer (100), and the anode layer (100) can be cut. When using the laser (LSR), the cut side can be formed perpendicularly along the third direction (D3) with respect to a horizontal plane defined by the first direction (D1) and the second direction (D2). When using the laser (LSR), the cut side of the anode active material layer (120) can be formed perpendicularly along the third direction (D3). That is, when using the laser (LSR), the side of the anode active material layer (120) may not be cut at an angle.

[0181] By using a laser (LSR), the thickness of the positive active material layer (120) can have a substantially uniform thickness from the inside to the cut side.

[0182] As the laser (LSR) penetrates the anode layer (100), a first inactive region (DAP1) can be formed within the anode active material layer (120).

[0183] For example, a laser (LSR) can be irradiated onto the positive active material layer (120). Unlike what is illustrated, in another example, the laser (LSR) can be irradiated onto the positive current collector (110).

[0184] The anode layer (100) can be formed on the solid electrolyte layer (300) so that the solid electrolyte layer (300) is disposed between the cathode layer (200) and the anode layer (100). The cut anode layer (100) can be aligned on the solid electrolyte layer (300).

[0185] A fourth pressurization process may be performed on the anode layer (100), the solid electrolyte layer (300), and the cathode layer (200). The anode layer (100), the solid electrolyte layer (300), and the cathode layer (200) may be pressurized together. The fourth pressurization process may include a roll press. The roll press may be performed using a pair of rollers (R). The pair of rollers (R) may be configured to press the anode layer (100), the solid electrolyte layer (300), and the cathode layer (200).

[0186] For example, the roll press of the fourth pressing process can be performed at 0.1 ton / cm to 10 ton / cm. For example, the fourth pressing process can be performed at 60°C to 180°C.

[0187]

[0188] Although not illustrated, if the coating layer (220) further comprises the aforementioned sulfide-based solid electrolyte in addition to metal and carbon, a third inactive region may be formed within the coating layer (220) as the laser (LSR) penetrates the cathode layer (200) during the cutting process.

[0189]

[0190] 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.

[0191]

[0192] Examples

[0193] (Manufacturing of the anode layer)

[0194] An anode layer comprising an anode active material layer on an anode current collector was prepared. An aluminum foil with a thickness of approximately 13 μm was prepared as the anode current collector. For the anode active material layer, LiNi was used as the anode active material. 0.90 Co 0.05 Al 0.05O2 (NCA), Li6PS5Cl (D50 = 0.5 μm, crystalline), an argyrodite-type crystal, as a solid electrolyte, carbon nanotubes (CNT) as a conductive material, and polyvinylidene fluoride (PVDF) as a binder were included in a weight ratio of 84:11.5:3:1.5. The thickness of the positive active material layer was approximately 70 μm.

[0195]

[0196] (Manufacturing of the cathode layer)

[0197] A cathode layer including a coating layer on a cathode current collector was prepared. As the cathode current collector, a Ni-plated Cu substrate (i.e., a Ni-Cu substrate) with a thickness of about 10 μm was prepared. The coating layer contained carbon black (CB) with a primary particle size of about 30 nm and silver (Ag) particles with an average particle size (D50) of about 60 nm in a weight ratio of 3:1. The thickness of the coating layer was about 7 μm.

[0198]

[0199] (Preparation of solid electrolyte layer, dry method)

[0200] A mixture was prepared by mixing polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) with an argyrodite-type crystal Li6PS5Cl sulfide-based solid electrolyte (D50 = 3 μm, crystalline). The mixture was stirred to prepare a dough, and then the prepared dough was passed through a roller to form a sheet. The thickness of the solid electrolyte layer was approximately 70 μm.

[0201]

[0202] (Manufacturing of all-solid-state batteries)

[0203] A battery cell was manufactured by sequentially stacking an anode layer, a solid electrolyte layer, and a cathode layer, and applying pressure using a roll press method. The pressure was applied at a temperature of 140 ℃ with a linear pressure of 1.0 ton / cm.

[0204] A laser was irradiated onto the positive current collector of a pressurized battery cell to cut the battery cell and form an inactive region on the side of the battery cell. A first inactive region was formed on the side of the positive active material layer, and a second inactive region was formed on the side of the solid electrolyte layer.

[0205]

[0206] Comparative example

[0207] The battery cell was manufactured using the same method as in the example, except that a Thomson jig was used instead of a laser when cutting the battery cell. No inactive region was formed on the side of the battery cell.

[0208]

[0209] Evaluation Example 1: Cross-sectional analysis of an all-solid-state battery (1)

[0210] FIGS. 10a and 10b are scanning electron microscope images of the first inactive region of the positive electrode layer of an all-solid-state battery according to an embodiment. FIGS. 11a and 11b are scanning electron microscope images of the side of the positive electrode layer of an all-solid-state battery according to a comparative example. Referring to FIGS. 10a, 10b, 11a, and 11b, a shape formed by melting and sticking due to heat was observed on the surface of the first inactive region.

[0211] Table 1 shows the results of EDS analysis of the nickel (Ni), cobalt (Co), and aluminum (Al) components in the first inactive region of the anode layer of the all-solid-state battery according to the example, and in the side of the anode layer of the all-solid-state battery according to the comparative example. Table 1 is the average of the results obtained from five regions. Meanwhile, the content of nickel (Ni), cobalt (Co), and aluminum (Al) in the comparative example was the same as the content of nickel (Ni), cobalt (Co), and aluminum (Al) in the first active region of the example.

[0212]

[0213] Classification Ni content (at%) Co content (at%) Al content (at%) Example 7 4.0 25.4 42 0.5 4 Comparative Example 8 7.3 87.5 45.0 8

[0214]

[0215] Referring to Table 1, the content of nickel (Ni), cobalt (Co), and aluminum (Al) in the first inactive region of the example and in the comparative example were different. The Ni / Co content ratio of the example was greater than the Ni / Co content ratio of the comparative example. The content of nickel (Ni), cobalt (Co), and aluminum (Al) in the first inactive region and in the first active region of the example were different. The Ni / Co content ratio of the first inactive region was greater than the Ni / Co content ratio of the first active region.

[0216] In addition, in the case of the first inactive region of the example, regions with very high aluminum (Al) content were partially observed, and accordingly, the average aluminum (Al) content was much higher than that of the comparative example and the first active region of the example.

[0217]

[0218] Table 2 shows the results of EDS analysis of the sulfur (S), carbon (C), nickel (Ni), and aluminum (Al) components in the first inactive region of the anode layer of the all-solid-state battery according to the example, and in the side of the anode layer of the all-solid-state battery according to the comparative example. Table 2 is the average of the results obtained from five regions. Meanwhile, the content of sulfur (S), carbon (C), nickel (Ni), and aluminum (Al) in the comparative example was the same as the content of sulfur (S), carbon (C), nickel (Ni), and aluminum (Al) in the first active region of the example.

[0219]

[0220] Classification Content of C (at%) Content of S (at%) Content of Ni (at%) Content of Al (at%) C / S Content Ratio Ni / S Content Ratio Al / S Content Ratio Example 6.6 6.3 4 9.9 3 7.2 1.0 5 7.9 2 5.9 0 Comparative Example 8.3 3 7.9 5 3.8 ≈ 0 0.2 2 1.4 2 ≈ 0

[0221]

[0222] Referring to Table 2, the sulfur (S) content in the first inactive region of the example was less than the sulfur (S) content in the side of the comparative example. The sulfur (S) content in the first inactive region of the example was less than the sulfur (S) content in the first active region of the example.

[0223] The aluminum (Al) content in the first inactive region of the example was greater than the aluminum (Al) content in the side of the comparative example. The aluminum (Al) content in the first inactive region of the example was greater than the aluminum (Al) content in the first active region of the example.

[0224] The C / S content ratio, Ni / S content ratio, and Al / S content ratio within the first inactive region of the example were greater than the C / S content ratio, Ni / S content ratio, and Al / S content ratio within the side of the comparative example. The C / S content ratio, Ni / S content ratio, and Al / S content ratio within the first inactive region of the example were greater than the C / S content ratio, Ni / S content ratio, and Al / S content ratio within the first active region of the example.

[0225]

[0226] Evaluation Example 2: Cross-sectional analysis of an all-solid-state battery (2)

[0227] FIGS. 12a and 12b are figures showing the results of Raman mapping and Raman spectrum for the first inactive region of the anode layer of an all-solid-state battery according to an example. Referring to FIGS. 12a and 12b, it was confirmed that the first inactive region of the example contains an aluminum compound. The aluminum compound was mainly formed in the middle part of the first inactive region of the example.

[0228] FIGS. 13a and 13b are drawings showing the results of Raman mapping and Raman spectrum for the side of the anode layer of an all-solid-state battery according to a comparative example. Referring to FIGS. 13a and 13b, it was confirmed that the side of the comparative example contains almost no aluminum.

[0229]

[0230] Evaluation Example 3: Lifespan evaluation of all-solid-state batteries

[0231] The lifespan of all-solid-state batteries according to the examples and comparative examples was evaluated. The lifespan evaluation was performed by placing the all-solid-state batteries in a constant temperature chamber at 45°C.

[0232] The all-solid-state battery according to the example and comparative example was initially charged to 4.25V under a constant current (0.1C) condition, and when it reached 4.25V, constant voltage charging was performed at 4.25V under a 0.05C cut-off condition. Subsequently, it was discharged to 2.5V under a constant current (0.1C) condition. The charging and discharging cycles were repeated n times under the 0.33C / 0.33C condition. The number of cycles at which the capacity retention rate (ratio of the discharge capacity of 100 cycles to the initial discharge capacity) of the all-solid-state battery reached 80% was determined, and the results are shown in Table 3.

[0233]

[0234] Classification Lifespan of all-solid-state battery (number of cycles at which capacity retention reaches 80%) Example 200 Comparative Example < 10

[0235]

[0236] Referring to Table 3, the all-solid-state battery according to the comparative example showed that lithium grew on the side due to repeated charging and discharging, causing a short circuit. On the other hand, it was confirmed that the all-solid-state battery according to the example has a long lifespan as it includes a first inactive region and a second inactive region.

[0237]

[0238] 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. An anode layer comprising a current collector and an anode active material layer, wherein the anode active material layer comprises an anode active material and a sulfide-based solid electrolyte; A cathode layer including a current collector and a coating layer; and It includes a sulfide-based solid electrolyte and a solid electrolyte layer between the anode layer and the cathode layer, wherein The above positive active material layer includes a first active region and a first inactive region, and The first inactive region is located on at least one side of the positive active material layer, and The above first inactive region is a region altered by a laser, All-solid-state battery.

2. In Paragraph 1, The sulfur content in the first inactive region is less than the sulfur content in the first active region. All-solid-state battery.

3. In Paragraph 1, The first inactive region above includes aluminum, and The aluminum content in the first inactive region is greater than the aluminum content in the first active region. All-solid-state battery.

4. In Paragraph 1, The nickel content in the first inactive region is less than the nickel content in the first active region. All-solid-state battery.

5. In Paragraph 1, The ion conductivity of the first inactive region is lower than the ion conductivity of the first active region. All-solid-state battery.

6. In Paragraph 1, The first inactive region is located on two sides facing each other among the sides of the positive active material layer, All-solid-state battery.

7. In Paragraph 1, The first inactive region is located on three adjacent sides among the sides of the positive active material layer, All-solid-state battery.

8. In Paragraph 1, At least one side of the first active region is exposed, All-solid-state battery.

9. In Paragraph 1, The above solid electrolyte layer includes a second active region and a second inactive region, and The second inactive region is located on at least one side of the solid electrolyte layer, All-solid-state battery.

10. In Paragraph 9, The sulfur content in the second inactive region is less than the sulfur content in the second active region. All-solid-state battery.

11. In Paragraph 9, The above second inactive region includes aluminum, and The aluminum content in the second inactive region is greater than the aluminum content in the second active region. All-solid-state battery.

12. In Paragraph 9, The ion conductivity of the second inactive region is lower than the ion conductivity of the second active region. All-solid-state battery.

13. In Paragraph 9, The first inactive region and the second inactive region are vertically overlapping each other. All-solid-state battery.

14. In Paragraph 1, The above coating layer comprises metal, carbon, and sulfide-based solid electrolytes, and The coating layer comprises a third active region and a third inactive region, All-solid-state battery.

15. Forming sequentially stacked anode layers and solid electrolyte layers; Performing a first pressurization process on the anode layer and the solid electrolyte layer; and The method includes performing a cutting process using a laser together with the anode layer and the solid electrolyte layer, wherein The above cutting process includes modifying the cutting surface of the anode layer with the laser to form a first inactive region. Method for manufacturing an all-solid-state battery.

16. In Paragraph 15, The above cutting process further comprises forming a second inactive region by modifying the cutting surface of the solid electrolyte layer with the laser. Method for manufacturing an all-solid-state battery.

17. In Paragraph 15, Before performing the first pressurization process above, it further includes forming a cathode layer, and The above first pressurization process includes pressurizing the cathode layer on the solid electrolyte layer together, and The above cutting process includes cutting the cathode layer together. Method for manufacturing an all-solid-state battery.

18. In Paragraph 15, After the above cutting process, forming a cathode layer on the solid electrolyte layer; and A method further comprising performing a second pressurization process on the anode layer, the solid electrolyte layer, and the cathode layer. Method for manufacturing an all-solid-state battery.

19. Forming sequentially stacked cathode layers and solid electrolyte layers; Performing a first pressurization process on the above cathode layer and the above solid electrolyte layer; Performing a first cutting process using a laser together with the above cathode layer and the above solid electrolyte layer; Performing a second cutting process on the anode layer using a laser; and The method includes performing a second pressurization process on the anode layer, the solid electrolyte layer, and the cathode layer, wherein The second cutting process described above includes modifying the cutting surface of the anode layer with the laser to form a first inactive region. Method for manufacturing an all-solid-state battery.

20. In Paragraph 19, The first cutting process described above includes modifying the cutting surface of the solid electrolyte layer with the laser to form a second inactive region. Method for manufacturing an all-solid-state battery.

Images