All-solid-state battery and manufacturing method therefor

Abstract

The present invention relates to an all-solid-state battery and, more specifically, to an all-solid-state battery comprising: a positive electrode layer comprising a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector; a negative electrode layer comprising a negative electrode current collector and a coating layer on the negative electrode current collector; a solid electrolyte layer between the positive electrode layer and the negative electrode layer; an elastic sheet on the positive electrode layer; and a packaging member on the elastic sheet, wherein the packaging member extends from one surface of the elastic sheet to a side surface of the positive electrode layer along a side surface of the elastic sheet, and the packaging member surrounds at least a part of the side surface of the positive electrode layer.

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]

[0003] 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.

[0004] Recently, all-solid-state batteries in which liquid electrolytes are replaced with solid electrolytes have been proposed. By not using flammable organic dispersion media, all-solid-state batteries can significantly reduce the likelihood of fire or explosion in the event of a short circuit. Therefore, these all-solid-state batteries can offer significantly higher safety compared to lithium-ion batteries that use liquid electrolytes.

[0005]

[0006] The problem that the present invention aims to solve is to provide an all-solid-state battery that has excellent capacity and can prevent electrical short circuits.

[0007] Another problem that the present invention aims to solve is to provide a method for manufacturing an all-solid-state battery having the above characteristics.

[0008]

[0009] A solid-state battery according to an embodiment of the present invention comprises: a positive electrode layer including a positive current collector and a positive active material layer on the positive current collector; a negative electrode layer including a negative current collector and a coating layer on the negative current collector; a solid electrolyte layer between the positive electrode layer and the negative electrode layer; an elastic sheet on the positive electrode layer; and a packaging member on the elastic sheet, wherein the packaging member extends from one side of the elastic sheet along the side of the elastic sheet to the side of the positive electrode layer, and the packaging member can wrap at least a portion of the side of the positive electrode layer.

[0010] A solid-state battery according to embodiments of the present invention comprises: a positive electrode layer comprising a positive current collector and a positive active material layer on the positive current collector; a negative electrode layer comprising a negative current collector and a coating layer on the negative current collector; a solid electrolyte layer between the positive electrode layer and the negative electrode layer; and an elastic sheet on the positive electrode layer, wherein the elastic sheet may comprise: a first sheet covering one side of the positive electrode layer; a second sheet covering at least a portion of the first side of the positive electrode layer; and a third sheet covering at least a portion of the second side of the positive electrode layer.

[0011] A solid-state battery according to further embodiments of the present invention comprises: an electrode laminate; and a packaging member, wherein the electrode laminate comprises: a first monocell comprising a first positive layer, a first solid electrolyte layer, a first negative layer, and a first elastic sheet; a unit cell located on the first monocell comprising a second positive layer, a third positive layer, a second solid electrolyte layer, a third solid electrolyte layer, a second negative layer, a third negative layer, and a second elastic sheet; and a second monocell comprising a fourth positive layer, a fourth solid electrolyte layer, a fourth negative layer, and a third elastic sheet, wherein the first elastic sheet is located at the bottom of the electrode laminate and the third elastic sheet is located at the top of the electrode laminate, and the packaging member may comprise: a first packaging member capping the bottom of the electrode laminate; and a second packaging member capping the top of the electrode laminate.

[0012]

[0013] An all-solid-state battery according to one embodiment of the present invention has excellent capacity and excellent energy density, and can have a long lifespan by preventing electrical short circuits.

[0014] 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 above characteristics and can reduce the production cost of the all-solid-state battery.

[0015]

[0016] FIG. 1 is a cross-sectional view of an all-solid-state battery according to embodiments of the present invention.

[0017] FIG. 2 is a cross-sectional view illustrating an all-solid-state battery according to one embodiment of the present invention.

[0018] FIG. 3 is a cross-sectional view of an all-solid-state battery having a laminated elastic sheet according to one embodiment of the present invention.

[0019] FIG. 4 is a cross-sectional view of an all-solid-state battery having an elastic sheet and a packaging member laminated according to one embodiment of the present invention.

[0020] FIGS. 5a to 5c are perspective views of a packaging member according to one embodiment of the present invention.

[0021] FIG. 6 is a cross-sectional view of an all-solid-state battery including an electrode laminate and a packaging member according to one embodiment of the present invention.

[0022] Figure 7 is a cross-sectional view of an all-solid-state battery in which an outer layer is covered over the electrode stack of Figure 6.

[0023] FIG. 8 is a cross-sectional view of an all-solid-state battery having an elastic sheet laminated according to embodiments of the present invention.

[0024] FIG. 9 is a cross-sectional view of an all-solid-state battery including a laminate and an elastic sheet according to embodiments of the present invention.

[0025]

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] In this specification, "combination of these" may mean a mixture of components, a laminate, a composite, a copolymer, an alloy, a blend, and a reaction product, etc.

[0031] Unless otherwise defined in this specification, the particle size may be the average particle size. Additionally, the particle size refers to the average particle size (D50), which means the diameter of the particle whose cumulative volume in the particle size distribution is 50% by volume. The average particle size (D50) may be measured by methods widely known to those skilled in the art, for example, by measuring with a particle size analyzer, or by measuring with a transmission electron microscope (TEM) image or a scanning electron microscope (SEM) image. Alternatively, the average particle size (D50) value may be obtained by measuring using a measuring device utilizing dynamic light-scattering, performing data analysis to count the number of particles for each particle size range, and then calculating from this. Alternatively, it may be measured using a laser diffraction method. When measuring by laser diffraction, more specifically, after dispersing the particles to be measured in a dispersion medium, they are introduced into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000) and irradiated with ultrasound of about 28 kHz at an output of 60 W, and then the average particle size (D50) at 50% of the particle size distribution in the measuring device can be calculated.

[0032] In this specification, each of the phrases such as “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B or C”, “at least one of A, B and C”, and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0033]

[0034] FIG. 1 is a cross-sectional view of an all-solid-state battery according to embodiments of the present invention. Referring to FIG. 1, 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).

[0035] 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.

[0036] 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.

[0037] To increase the bonding strength between the positive current collector (110) and the positive active material layer (120), a carbon-containing layer with a thickness of 0.1 μm to 4 μm, or 0.1 μm to 1 μm, may be further disposed between the positive current collector (110) and the positive active material layer (120). As an example, the carbon-containing layer may include a carbon-based material and a binder. For example, the carbon-based material may include at least one selected from the group consisting of graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes. For example, the binder may include at least one selected from the group consisting of polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, and polymethyl methacrylate. For example, the binder content may be 30% to 50% by weight relative to the total weight of the carbon-containing layer.

[0038] 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.

[0039] 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 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 Ni1-b-c Mn b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Nor 1-b-c Mn b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Nor b E c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Nor b Co c Mn d G e O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1), Li a NiG b O2(0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a MnG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a Mn2G b O4(0.90≤a≤1, 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3(0≤f≤2), Li 3-fIt 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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), and Li 7-x PS 6-x I x It may include at least one selected from (0≤x≤2).

[0045] Sulfide-based solid electrolytes are, for example, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x 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, and Li6PS5I.

[0046] 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 scandium (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.

[0047]

[0048] 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.

[0049] The solid electrolyte in the positive active material layer (120) may have a smaller average particle size compared to the solid electrolyte 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.

[0050] 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.

[0051] 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.

[0052] 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 75 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.

[0053] 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.

[0054] 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.

[0055] 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), aluminum (Al), silver (Ag), 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, more specifically 7 μm to 10 μm.

[0056] 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.

[0057] 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.

[0058] 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).

[0059] Carbon may originate from carbon assemblies added during the manufacture of the coating layer (220). The carbon assemblies may be secondary particles formed by the aggregation of primary particles. For example, the average particle size of the primary particles may be 20 nm to 100 nm, and the average particle size of the secondary particles may be 1 µm to 20 µm. The carbon in the coating layer (220) may mainly consist of primary particles.

[0060] 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.

[0061] 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.

[0062] 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).

[0063] 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).

[0064] The solid electrolyte in the solid electrolyte layer (300) may have particle shapes such as spheres or ellipsoids.

[0065] The solid electrolyte within the solid electrolyte layer (300) 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.

[0066] 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 x It 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.

[0067] 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.

[0068] 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.

[0069] The solid electrolyte layer (300) may further include a binder. The binder included in the solid electrolyte layer (300) is not limited to, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc. For example, the binder included in the solid electrolyte layer (300) may include at least one selected from the group consisting of styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, and polyacrylate. 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).

[0070] The solid electrolyte layer (300) may include a first sub-solid electrolyte layer (310) and a second sub-solid electrolyte layer (320). The first sub-solid electrolyte layer (310) may be adjacent to the anode layer (100), and the second sub-solid electrolyte layer (320) may be adjacent to the cathode layer (200).

[0071] The second sub-solid electrolyte layer (320) can be in direct contact with the coating layer (220). By doing so, the second sub-solid electrolyte layer (320) can suppress lithium dendrites formed between the coating layer (220) and the negative electrode current collector (210). The second sub-solid electrolyte layer (320) can effectively suppress negative electrode side reactions. By doing so, the cell performance of the all-solid-state battery according to the present invention can be improved.

[0072] The first sub-solid electrolyte layer (310) may have a first thickness (TK1), and the second sub-solid electrolyte layer (320) may have a second thickness (TK2). The first thickness (TK1) and the second thickness (TK2) may be the same or different from each other. In one embodiment, the first thickness (TK1) may be greater than the second thickness (TK2). In another example, the second thickness (TK2) may be equal to or greater than the first thickness (TK1).

[0073] The anode layer (100) and the first sub-solid electrolyte layer (310) can form an anode composite layer (CSH). The cathode layer (200) and the second sub-solid electrolyte layer (320) can form a cathode composite layer (ASH). An anode composite layer (CSH) can be laminated on the cathode composite layer (ASH).

[0074] The area of ​​the cathode composite layer (ASH) and the area of ​​the anode composite layer (CSH) may differ from each other. Specifically, the area of ​​the cathode composite layer (ASH) may be larger than the area of ​​the anode composite layer (CSH). The anode composite layer (CSH) may completely overlap within the cathode composite layer (ASH).

[0075] In one embodiment of the present invention, the first sub-solid electrolyte layer (310) may have substantially the same area as the anode layer (100). The second sub-solid electrolyte layer (320) may have substantially the same area as the cathode layer (200).

[0076] Specifically, the positive electrode composite layer (CSH) may have a first width (WI1) in a first direction (D1). The negative electrode composite layer (ASH) may have a second width (WI2) in a first direction (D1). The first width (WI1) may be smaller than the second width (WI2). The positive electrode composite layer (CSH) may have a third width (WI3) in a second direction (D2). The negative electrode composite layer (ASH) may have a fourth width (WI4) in a second direction (D2). The third width (WI3) may be smaller than the fourth width (WI4).

[0077] For example, the difference between the second width (WI2) and the first width (WI1) may be 10 mm or less. Specifically, the difference between the second width (WI2) and the first width (WI1) may be 8 mm or less, 5 mm or less, 3 mm or less, and 2 mm or less. The difference between the second width (WI2) and the first width (WI1) may be greater than 0 mm, greater than 0.1 mm, greater than 0.5 mm, and greater than 1 mm.

[0078] For example, the difference between the third width (WI3) and the fourth width (WI4) may be 10 mm or less. Specifically, the difference between the third width (WI3) and the fourth width (WI4) may be 8 mm or less, 5 mm or less, 3 mm or less, and 2 mm or less. The difference between the fourth width (WI4) and the third width (WI3) may be greater than 0 mm, greater than 0.1 mm, greater than 0.5 mm, and greater than 1 mm.

[0079] If the above numerical range is exceeded, the size of the anode layer (100) becomes relatively smaller, so the discharge capacity is lowered and the energy density of the all-solid-state battery may decrease. If the above numerical range is not met, it is difficult to suppress the formation of lithium dendrites in the cathode, so there may be a risk of a short circuit.

[0080] Referring to FIG. 1 and FIG. 8 to be described later, the positive current collector (110) may include a positive tab. The positive tab may be a protruding area of ​​the positive current collector (110). The positive tab may be an unprotected area. The positive tab may be an area not covered by the positive active material layer (120). A portion of the exposed positive tab may be electrically connected to a positive lead.

[0081] Additionally, the negative current collector (210) may include a negative tab. The negative tab may be a protruding area of ​​the negative current collector (210). The negative tab may be an undisturbed area. The negative tab may be an area not covered by the negative active material layer (220). A portion of the exposed negative tab may be electrically connected to a negative lead.

[0082]

[0083] FIG. 2 is a cross-sectional view of an all-solid-state battery according to embodiments of the present invention. Referring to FIG. 2, the negative electrode layer (200) of the unit cell (CEL) according to the present embodiment may further include a lithium metal layer (400) between the negative electrode current collector (210) and the coating layer (220). The lithium metal layer (400) may be formed during the charging of the unit cell (CEL), or its thickness may be further increased. The coating layer (220) serves as a protective layer for the lithium metal layer (400) and, at the same time, can suppress the growth of lithium dendrites from the lithium metal layer (400).

[0084] The lithium metal layer (400) may be a thin metal film containing lithium or a lithium alloy. The lithium alloy is not limited to, for example, Li-Al alloy, Li-Sn alloy, Li-In alloy, Li-Ag alloy, Li-Au alloy, Li-Zn alloy, Li-Ge alloy, Li-Si alloy, etc., and any alloy used as a lithium alloy is possible. The lithium metal layer (400) may contain one of these alloys or lithium. Alternatively, the lithium metal layer (400) may contain various types of alloys.

[0085] The lithium metal layer (400) may have a fifth width (WI5) in the first direction (D1). The fifth width (WI5) may be equal to or greater than the first width (WI1). The fifth width (WI5) may be equal to or smaller than the second width (WI2). For example, the fifth width (WI5) may be greater than the first width (WI1) and smaller than the second width (WI2).

[0086]

[0087] FIG. 3 is a cross-sectional view of an all-solid-state battery having a laminated elastic sheet according to one embodiment of the present invention. I will explain it mainly in terms of the differences compared with FIG. 1 and FIG. 2.

[0088] Referring to FIG. 4, an all-solid-state battery according to one embodiment of the present invention may include a positive electrode layer (100) comprising a positive electrode current collector (110) and a positive active material layer (120) on the positive electrode current collector (110), a negative electrode layer (200) comprising a negative electrode current collector (210) and a coating layer (220) on the negative electrode current collector (210), a solid electrolyte layer (300) between the positive electrode layer (100) and the negative electrode layer (200), and an elastic sheet (ELS) on the positive electrode current collector (110). The positive electrode current collector (110), the positive active material layer (120), the positive electrode layer (100), the negative electrode current collector (210), the coating layer (220), the negative electrode layer (200), and the solid electrolyte layer (300) may be substantially the same or similar as those described above in FIG. 1 and FIG. 2.

[0089] The elastic sheet (ELS) may be a polyurethane elastomer, an acrylic elastomer, or a silicone rubber. During charging and discharging of the all-solid-state battery, volume changes may occur due to the precipitation and dissociation of lithium (Li). The elastic sheet (ELS) can buffer the volume expansion of the all-solid-state battery or provide elasticity to restore the volume of the all-solid-state battery.

[0090] The elastic sheet (ELS) may include a first elastic sheet (ELS1) and a second elastic sheet (ELS2). Additionally, although not illustrated, a plurality of elastic sheets (ELS) may be further included between a plurality of unit cells described later.

[0091] As illustrated in FIG. 3, an all-solid-state battery according to one embodiment of the present invention may be stacked in the order of an elastic sheet (ELS), a positive electrode layer (100), a solid electrolyte layer (300), a negative electrode layer (200), a second negative electrode layer (201), a second solid electrolyte layer (301), a second positive electrode layer (101), and an elastic sheet (ELS) from the bottom.

[0092] More specifically, an all-solid-state battery according to one embodiment of the present invention may be stacked in the order of a first elastic sheet (ELS1), a positive current collector (110), a positive active material layer (120), a first sub-solid electrolyte layer (310), a second sub-solid electrolyte layer (320), a coating layer (210), a negative current collector (210), a second negative current collector (211), a second coating layer (221), a second-1 sub-solid electrolyte layer (321), a first-1 sub-solid electrolyte layer (311), a second positive active material layer (121), a second positive current collector (111), and a second elastic sheet (ELS2).

[0093] The anode layer (100), cathode layer (200), and solid electrolyte layer (300) described above may be substantially the same or similar to the first anode layer (100), the first cathode layer (200), and the first solid electrolyte layer (300) described later in FIGS. 6, 7, and 9.

[0094] Referring again to FIG. 3, an all-solid-state battery according to one embodiment of the present invention may have an elastic sheet (ELS) located at the outermost part. More specifically, a second elastic sheet (ELS2) may be located at the top of the all-solid-state battery. Additionally, a first elastic sheet (ELS1) may be located at the bottom of the all-solid-state battery. Furthermore, at least one of the first elastic sheet (ELS1) or the second elastic sheet (ELS2) may be located in an area adjacent to the outermost part of the all-solid-state battery. This may be so that the elastic sheet (ELS) protects the all-solid-state battery from external impact.

[0095] Referring again to FIG. 3, the anode layer (100), cathode layer (200), solid electrolyte layer (300), and elastic sheet (ELS) can form an electrode laminate (STC).

[0096]

[0097] FIG. 4 is a cross-sectional view of an all-solid-state battery in which an elastic sheet (ELS) and a packaging member (PCK) are laminated according to an embodiment of the present invention. I will explain the differences mainly in comparison with FIG. 3.

[0098] Referring to FIG. 4, a packaging member (PCK) may be positioned on at least one of the upper and lower portions of the electrode stack (STC). That is, the packaging member (PCK) may cap at least one of the upper and lower portions of the electrode stack (STC). The packaging member (PCK) can prevent the phenomenon of damage caused by stress being applied to the edges of the anode layer or the cathode layer.

[0099] Capping refers to the process of sealing or protecting the exterior of a battery. More specifically, capping can facilitate the formation of a sealed structure in all-solid-state batteries, maintain electrical connections and airtightness, provide mechanical protection, and enhance thermal stability.

[0100] The formation of a sealed structure through capping refers to the process of wrapping the exterior of a battery with a metal can, plastic film, or other sealed structure to protect it from the external environment. As a result, it can reduce performance degradation or the occurrence of degradation due to chemical reactions when the internal electrolyte and electrodes come into contact with external air.

[0101] Electrical connection and airtightness maintenance through capping may mean protecting external electrode terminals and stabilizing the electrical connection between the inside and outside so that the battery can operate safely.

[0102] Mechanical protection by capping refers to providing mechanical stability and preventing damage through capping, as all-solid-state batteries are vulnerable to mechanical stress such as shock, vibration, and external pressure.

[0103] Enhancement of thermal stability through capping means that, since the chemical reactivity of materials inside an all-solid-state battery can change in a high-temperature environment, capping can be used to protect the battery from such thermal and chemical stress.

[0104] Referring again to FIG. 4, a packaging member (PCK) may be located on the upper or lower portion of the electrode stack (STC). More specifically, a first packaging member (PCK1) may be located on the lower portion of the electrode stack (STC). Additionally, a second packaging member (PCK2) may be located on the lower portion of the electrode stack (STC).

[0105] The first packaging member (PCK1) may extend from one side of the first elastic sheet (ELS1) along the side of the first elastic sheet (ELS1) to the side of the anode layer (100). Additionally, the first packaging member (PCK1) may not wrap the cathode layer. That is, the first packaging member (PCK1) may wrap the first side (SD1), the second side (SD2), and the third side (SD3) of the first elastic sheet (ELS1). Additionally, the first packaging member (PCK1) may wrap the first side (SD1) and the third side (SD3) of the anode layer.

[0106] More specifically, the first wrapping member (PCK1) may include a first member (PCK-1) that wraps at least a portion of one side of the first elastic sheet (ELS1), a second member (PCK1-2) that wraps at least a portion of the first side of the anode layer (100), and a third member (PCK1-3) that wraps at least a portion of the second side (SD2) of the anode layer (100). Additionally, the second member (PCK1-2) and the third member (PCK1-3) may each wrap the first edge (CN1) and the second edge (CN2) of the first elastic sheet (ELS1). The description of the first member (PCK-1) to the third member (PCK1-3) will be explained in detail in FIGS. 5a to 5c.

[0107] The thickness of the first packaging member (PCK1) may be smaller than the thickness of the elastic sheet (ELS). That is, referring to FIG. 3 and FIG. 5a, the fourth thickness (TK4) may be smaller than the third thickness (TK3). This is because if the thickness of the packaging member (PCK) is greater than the thickness of the elastic sheet (ELS), a structural change in the electrode laminate (STC) may occur.

[0108] The packaging member (PCK) may include at least one of polyamideimide, polyimide, polysulfone, polyurethane, polycarbonate, epoxy resin, polysulfide, polybenzimidazole, or a combination thereof.

[0109] Referring again to FIG. 4, a packaging member (PCK) may be positioned on the upper portion of the electrode stack (STC). More specifically, a second packaging member (PCK2) may be positioned on the upper portion of the electrode stack (STC).

[0110] The second packaging member (PCK2) may extend from one side of the second elastic sheet (ELS2) along the side of the second elastic sheet (ELS2) to the side of the second anode layer (101). Additionally, the second packaging member (PCK2) may not wrap the second cathode layer (203). That is, the second packaging member (PCK2) may wrap the first side (SD1), the second side (SD2), and the third side (SD3) of the second elastic sheet (ELS2). Additionally, the second packaging member (PCK2) may wrap the first side (SD1) and the third side (SD3) of the second anode layer (103).

[0111] More specifically, the second wrapping member (PCK2) may include a fourth member (PCK2-1) that wraps at least a portion of one side of the second elastic sheet (ELS2), a fifth member (PCK2-2) that wraps at least a portion of the first side (SD1) of the second anode layer (101), and a sixth member (PCK2-3) that wraps at least a portion of the second side (SD2) of the second anode layer (100). Additionally, the fifth member (PCK2-2) and the sixth member (PCK2-3) may each wrap the corners of the second elastic sheet (ELS2). The description of the fourth member (PCK2-1) to the sixth member (PCK2-3) will be explained in detail in FIGS. 5a to 5c.

[0112] The thickness of the second packaging member (PCK2) may be smaller than the thickness of the elastic sheet (ELS). That is, referring to FIG. 3 and FIG. 5a, the fourth thickness (TK4) may be smaller than the third thickness (TK3). This is because if the thickness of the packaging member (PCK) is greater than the thickness of the elastic sheet (ELS), a structural change in the electrode laminate (STC) may occur.

[0113]

[0114] FIGS. 5a to 5c are perspective views of a packaging member (PCK) according to one embodiment of the present invention.

[0115] FIG. 5a is a perspective view of a packaging member (PCK). More specifically, FIG. 5a is a perspective view of a first packaging member (PCK1) or a second packaging member (PCK2).

[0116] Referring to FIG. 5a, a packaging member (PCK) according to one embodiment of the present invention may include a first-1 member (PK1), a second-1 member (PK2) to a second-6 member (PK7). More specifically, the first-1 member (PK1) may be a portion that contacts the packaging member (PCK) with an elastic sheet (ELS) or an electrode laminate (STC).

[0117] The second member (PCK1-2) may include the second-1 to second-6 members (PK2 to PK7). The second-1 member (PK2) and the second-2 member (PK3) may be located on the long axis of the packaging member (PCK). Additionally, the second-3 to second-6 members (PK4 to PK7) may be located on the short axis of the packaging member (PCK).

[0118] The 2-3 member (PK4) and the 2-4 member (PK5) may be spaced apart by a fifth width (WI5). This may be to allow air present inside to be expelled when the packaging member (PCK) wraps the elastic sheet (ELS). That is, internal air can be expelled through the gap opened by the fifth width (WI5).

[0119] Likewise, the 2-5 member (PK6) and the 2-6 member (PK7) may be spaced apart by the 5th width (WI5), but are not necessarily limited thereto.

[0120] Referring again to FIG. 5a, the packaging member (PCK) may include a third width (WI3) and a fourth width (WI4). The third width (WI3) may be substantially the same as or similar to the length of the short axis of the packaging member (PCK). Additionally, the fourth width (WI4) may be substantially the same as or similar to the length of the long axis of the packaging member (PCK).

[0121] The third width (WI3) and the fourth width (WI4) may each be equal to or greater than the lengths of the short and long axes of the elastic sheet (ELS) or the anode layer. This may be so that the packaging member (PCK) can wrap both the upper or lower surface and the side of the elastic sheet (ELS) or the anode layer.

[0122] FIG. 5b is a perspective view of a packaging member (PCK) according to embodiments of the present invention. I will explain it mainly in terms of the differences compared with FIG. 5a.

[0123] A packaging member (PCK) according to embodiments of the present invention may include a first-1' member (PK1') and second-1' to second-6' members (PK2' to PK7'). Each of the second-1' to second-6' members (PK2' to PK7') may be substantially identical or similar to the second-1 to second-6 members (PK2 to PK7) described above in FIG. 5a.

[0124] The 2-1' member (PK2') may have a centrally open shape. That is, the 2-1' member (PK2') may wrap a portion of one side of the elastic sheet (ELS) or the anode layer. Additionally, the elastic sheet (ELS) or the anode layer may be exposed through the opening of the 2-1' member (PK2').

[0125]

[0126] FIG. 5c is a perspective view of a packaging member (PCK) according to embodiments of the present invention. I will explain it mainly in terms of the differences compared with FIG. 5a and FIG. 5b.

[0127] A packaging member (PCK) according to embodiments of the present invention may include a plurality of horizontal members and a plurality of vertical members. More specifically, the plurality of horizontal members and the plurality of vertical members may each be located in the central part of the 2-1' member (PK2') of FIG. 5B. That is, the plurality of horizontal members and the plurality of vertical members may intersect each other in the open space to form a grid pattern.

[0128] For example, referring again to FIG. 5c, the first member (PCK-1) may include a first horizontal member to a seventh horizontal member (PL1 to PL7). Additionally, the first member (PCK-1) may include a first vertical member to a third vertical member (VT1 to VT3). The first horizontal member to the seventh horizontal member (PL1 to PL7) may each intersect with the first vertical member to the third vertical member (VT1 to VT3) to form a grid pattern.

[0129] The first to seventh horizontal members (PL1 to PL7) and the first vertical member (VT1) can come into contact with the elastic sheet (ELS) or the anode layer of the electrode laminate (STC). That is, a plurality of horizontal members and a plurality of vertical members can come into contact with the elastic sheet (ELS) or the anode layer. Additionally, the internal region of the grid structure formed by the plurality of horizontal members and the plurality of vertical members may have an open shape.

[0130] Referring again to FIG. 5c, a plurality of horizontal members may each be spaced apart by an eighth width (WI8). Additionally, a plurality of vertical members may each be spaced apart by a seventh width (WI7). The seventh width (WI7) and the eighth width (WI8) may be the same or different from each other and are not necessarily limited thereto.

[0131]

[0132] FIG. 6 is a cross-sectional view of an all-solid-state battery including an electrode stack (STC) and a packaging member (PCK) according to one embodiment of the present invention. I will explain it mainly in terms of the differences compared with FIG. 4.

[0133] Referring to FIG. 6, an electrode stack (STC) according to one embodiment of the present invention may include a first monocell (MNC1) comprising a first anode layer (100), a first solid electrolyte layer (300), a first cathode layer (200), and a first elastic sheet (ELS1). Additionally, the electrode stack (STC) may include a unit cell located on the first monocell (MNC1) comprising a second anode layer (101), a third anode layer (102), a second solid electrolyte layer (301), a third solid electrolyte layer (302), a second cathode layer (201), a third cathode layer (202), and a second elastic sheet (ELS2). Additionally, the electrode stack (STC) may include a second monocell (MNC2) comprising a fourth anode layer (103), a fourth solid electrolyte layer (303), a fourth cathode layer (203), and a third elastic sheet (ELS3).

[0134] That is, the electrode stack (STC) may include a first monocell (MNC1), a unit cell, and a second monocell (MNC2). Additionally, the electrode stack (STC) may have a plurality of unit cells stacked between the first monocell (MNC1) and the second monocell (MNC2). The plurality of unit cells may refer to a plurality of unit cells that are substantially identical or similar to the unit cell stacked together.

[0135] More specifically, referring to FIG. 6, in an electrode stack (STC) according to an embodiment of the present invention, a first anode layer (100) may be positioned on a first elastic sheet (ELS1). A first solid electrolyte layer (300) may be positioned on the first anode layer (100). A first cathode layer (200) may be positioned on the first solid electrolyte layer (300). A second cathode layer (201) may be positioned on the first cathode layer (200). A second solid electrolyte layer (301) may be positioned on the second cathode layer (201). A second elastic sheet (ELS2) may be positioned on the second solid electrolyte layer (301). A third anode layer (102) may be positioned on the second elastic sheet (ELS2). A third solid electrolyte layer (302) may be positioned on the third anode layer (102). A third cathode layer (202) may be located on the third solid electrolyte layer (302). A fourth cathode layer (203) may be located on the third cathode layer (202). A fourth solid electrolyte layer (303) may be located on the fourth cathode layer (203). A fourth anode layer (103) may be located on the fourth solid electrolyte layer (303). A third elastic sheet (ELS3) may be located on the fourth anode layer (103). A fifth anode layer (104) may be located on the third elastic sheet (ELS3). A fifth solid electrolyte layer (304) may be located on the fifth anode layer (104). A fifth cathode layer (204) may be located on the fifth solid electrolyte layer (304). A sixth cathode layer (205) may be located on the fifth cathode layer (204). A sixth solid electrolyte layer (305) may be located on the sixth cathode layer (205). A sixth anode layer (105) may be located on the sixth solid electrolyte layer (305). A fourth elastic sheet (ELS4) may be located on the sixth anode layer (105). Additionally, a second packaging member (PCK2) may be located on the fourth elastic sheet (ELS4).

[0136] To elaborate on the differences compared with FIG. 4, the second packaging member (PCK2) can be positioned on the fourth elastic sheet (ELS4). Thus, the second packaging member (PCK2) can wrap at least a portion of one side and side of the fourth elastic sheet (ELS4).

[0137]

[0138] Figure 7 is a cross-sectional view of an all-solid-state battery in which an outer layer is covered over the electrode stack (STC) of Figure 6.

[0139] The PCH can wrap the exterior of the all-solid-state battery laminate. The PCH can protect the internal materials of the all-solid-state battery from external shocks, vibrations, pressure, etc. In addition, the PCH can prevent degradation or performance deterioration of the battery materials.

[0140] The exterior material (PCH) may include aluminum foil (Al-foil), polyvinylidene chloride (PVDC), ethylene vinyl alcohol (EVOH), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), or at least one of these.

[0141] Referring to FIGS. 7 and 9, a packaging member (PCK) according to an embodiment of the present invention may be located between an electrode laminate (STC) and an outer layer (PCH). More specifically, a first packaging member (PCK1) may be located between an outer layer (PCH) and a third elastic sheet (ELS3). Additionally, the first packaging member (PCK1) may be located between an outer layer (PCH) and a first anode layer (100). A second packaging member (PCK2) may be located between an outer layer (PCH) and a fourth elastic sheet (ELS4). Additionally, the second packaging member (PCK2) may be located between an outer layer (PCH) and a sixth anode layer (105).

[0142]

[0143] FIG. 8 is a cross-sectional view of an all-solid-state battery having an elastic sheet (ELS) stacked according to embodiments of the present invention. I will explain it mainly in terms of differences compared with FIG. 4. Unlike FIG. 4, the elastic sheet (ELS) according to another embodiment of the present invention may include a first sheet (ELS1-1) covering one side of the positive layer, a second sheet (ELS1-2) covering at least a portion of the first side (SD1') of the positive layer, and a third sheet (ELS1-3) covering at least a portion of the second side (SD1') of the positive layer.

[0144] Additionally, an elastic sheet (ELS) according to another embodiment of the present invention may include a fourth sheet (ELS4-1) covering another side of the anode layer, a fifth sheet (ELS4-2) covering at least a portion of the first side (SD1') of the anode layer, and a sixth sheet (ELS4-3) covering at least a portion of the second side (SD1') of the anode layer.

[0145] The elastic sheet (ELS) according to the embodiments of the present invention may not wrap the cathode layer. Additionally, the second sheet (ELS1-2) and the third sheet (ELS1-3) according to the embodiments of the present invention may each wrap the first corner and the second corner of the anode layer. The first corner (CN1) and the second corner (CN2) may each be substantially the same or similar as described above in FIG. 4.

[0146] The structure of the first sheet (ELS1-1) to the third sheet (ELS1-3) may be substantially identical or similar to the first member (PCK-1) to the third member (PCK1-3) described above in FIGS. 5a to 5c.

[0147]

[0148] FIG. 9 is a cross-sectional view of an all-solid-state battery including a laminate and an elastic sheet (ELS) according to embodiments of the present invention. I will explain it mainly in terms of the differences compared with FIG. 7.

[0149] Referring to FIGS. 7 and FIGS. 9, the first elastic sheet (ELS1) may wrap a portion of the side of the first anode layer (100). Additionally, the fourth elastic sheet (ELS4) may wrap a portion of the side of the sixth anode layer (105). The remaining portion, excluding this, may be substantially the same or similar as described above in FIG. 7. Furthermore, as shown in FIG. 9, a separate packaging member (PCK) may not be included on the first elastic sheet (ELS1) and the fourth elastic sheet. However, it is not necessarily limited thereto.

[0150]

[0151] An all-solid-state battery according to one embodiment of the present invention may stack a plurality of unit cells and stack a monocell on the surface of the unit cell that contacts the outside. A packaging member may be attached to the corner portion where the monocell contacts the outside. As a result, an all-solid-state battery capable of having excellent capacity and preventing electrical short circuits can be provided.

[0152]

[0153] 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.

[0154]

[0155] Example 1

[0156] (Manufacturing of the anode layer)

[0157] A positive electrode active material layer slurry was applied onto a positive electrode current collector (aluminum (Al) foil, thickness = 13 μm) coated with a carbon-containing layer (carbon nanotubes and binder (PVDF-HFP), binder content = 40 wt%, thickness = 1 μm) on one side, vacuum dried at 40 ℃ for 8 hours, and then subjected to a pressurization process using a roll press. As the positive electrode active material, LiNi with a specific capacity of 200 mAh / g was used. 0.8 Co 0.15 Mn 0.05O2NCM was prepared, Li6PS5Cl (D50 = 0.5 μm, crystalline), an argyrodite-type crystal, as the solid electrolyte, carbon nanofibers (CNF) as the conductive material, and polytetrafluoroethylene (PTFE) as the binder. The cathode active material layer slurry was mixed with xylene solvent at a weight ratio of cathode active material : solid electrolyte : conductive material : binder = 85 : 11.5 : 3 : 1.5. The cathode active material layer slurry had a concentration of 25.4 mg / cm². 2 It was applied on the positive current collector (110) to have a loading level. The thickness of the positive active material layer was 107 μm, and the current density was 4.3 mAh / cm². 2 It was.

[0158] (Manufacturing of anode composite layer)

[0159] A mixture was prepared by adding a polyacrylate (SX-A334, Zeon) binder and a BYK dispersant to an argyrodite-type crystal Li6PS5Cl sulfide-based solid electrolyte (D50 = 3.0 μm, crystalline) (weight ratio of solid electrolyte : binder : dispersant = 94.4 : 5 : 0.6). A solid electrolyte layer slurry was prepared by stirring while adding octyl acetate to the prepared mixture.

[0160] The prepared solid electrolyte layer slurry was applied onto a temporary substrate (aluminum (Al) foil) using a blade coater and dried. After pressurization, the solid electrolyte layer had a thickness of 10 µm to 80 µm and a g / cm³ 3 A solid electrolyte layer was formed on a temporary substrate by performing a pressurization process using a roll press to have the density.

[0161] By the above process, a first solid electrolyte layer having substantially the same area as the anode layer and a second solid electrolyte layer having substantially the same area as the cathode layer were each prepared.

[0162] A first solid electrolyte layer and a temporary substrate were laminated on an anode layer so that the first solid electrolyte layer was in contact with the anode active material layer, and a pressurizing process was performed using a roll press to laminate the anode layer and the first solid electrolyte layer. Afterward, the temporary substrate was removed. In other words, the first solid electrolyte layer was transferred onto the anode active material layer. The pressurizing process was performed at a temperature of 120°C and a linear pressure of 3.5 ton / cm after preheating with infrared (IR) at a temperature of 140°C.

[0163] An elastic sheet was attached to the lower surface of the anode composite layer. The elastic sheet used was acrylic foam or polyurethane foam, and its thickness was 300 μm.

[0164] (Manufacturing of the cathode layer)

[0165] A coating layer slurry was applied onto a cathode current collector (Ni-plated Cu(Ni-Cu), thickness = 10 μm) using a bar coater, dried in air at 80°C for 10 minutes, dried under vacuum at 40°C for 10 hours, and then subjected to a pressurization process using a roll press. The coating layer slurry was prepared by placing 4 g of a mixed powder, consisting of silver (Ag) particles (average particle size 60 nm) and carbon black mixed in a weight ratio of 3:1, into a container, adding 4 g of an NMP solution containing 7 wt% PVDF binder (Kureha # 9300), and then stirring while gradually adding the NMP solution to the mixed solution. The coating layer slurry had a density of 0.8 mg / cm² 2 It was applied onto the cathode current collector to have a loading level. The pressurization process was performed at a temperature of 25°C with a linear pressure of 1.5 ton / cm to flatten the surface of the coating layer. The thickness of the coating layer was 7 μm. The area of ​​the coating layer was larger than the area of ​​the positive active material layer.

[0166] A second organic insulating layer was formed by applying and drying a second organic insulating layer slurry on one side of the coating layer. The second organic insulating layer contained polyamideimide.

[0167] (Manufacturing of cathode composite layer)

[0168] A second solid electrolyte layer and a temporary substrate were laminated on a cathode layer such that the exposed surface of the second solid electrolyte layer was in contact with a coating layer, and a pressurizing process was performed using a roll press to laminate the cathode layer and the second solid electrolyte layer. Afterward, the temporary substrate was removed. In other words, the second solid electrolyte layer was transferred onto the coating layer. The pressurizing process was performed at a temperature of 120°C and a linear pressure of 3.0 ton / cm after preheating with infrared (IR) at a temperature of 140°C.

[0169] An elastic sheet was attached to one side of the cathode composite layer. The elastic sheet used was acrylic foam or polyurethane foam, and its thickness was 300 μm.

[0170] (Manufacturing of all-solid-state batteries)

[0171] An anode composite layer was laminated on a cathode composite layer, and a pressurizing process was performed using a roll press. The pressurizing process was performed at a temperature of 160°C and a linear pressure of 0.5 ton / cm. Thus, an all-solid-state battery was manufactured.

[0172] The all-solid-state battery had a structure illustrated in FIG. 6 or FIG. 7. A first monocell, a plurality of unit cells, and a second monocell were stacked. Additionally, an elastic sheet was attached to the outer portions of the first monocell and the second monocell. Then, a packaging member was attached to each of the elastic sheets (ELS) located on the outer portions of the first monocell and the second monocell. The packaging member (PCK) used an Al sheet and had a thickness of 0.2 mm.

[0173]

[0174] Example 2

[0175] In Example 1, an all-solid-state battery was manufactured in the same manner as in Example 1, except that the central part of the packaging member has an open structure.

[0176]

[0177] Comparative Example 1

[0178] In Example 1, an all-solid-state battery was manufactured in the same manner as in Example 1, except that the packaging member was omitted.

[0179]

[0180] Experimental Example: Evaluation of Initial Capacity and Short Circuit Occurrence Time of All-Solid State Batteries

[0181] The initial capacity and the time of short circuit occurrence of the all-solid-state battery according to the examples and comparative examples were evaluated. The evaluation of the initial capacity and the time of short circuit occurrence was performed by placing elastic pads (polyurethane foam, thickness = 300 μm) having the same surface area as the all-solid-state battery on the upper and lower surfaces of the all-solid-state battery, respectively, placing them in a pouch, and sealing them. The evaluation of the initial capacity and the time of short circuit occurrence was performed by placing the all-solid-state battery in a constant temperature bath at 45°.

[0182] The initial capacity evaluation was performed as follows. The battery was charged with a constant current of 0.1C until the battery voltage reached 4.25V, and upon reaching 4.25V, constant voltage charging was performed at 4.25V under a 0.05C cut-off condition. Subsequently, the battery was discharged with a constant current of 1.0C until the battery voltage reached 2.5V. At this time, the discharge capacity was set as the initial capacity.

[0183] The short-circuit occurrence point evaluation was performed as follows. In the first cycle, the battery was charged with a constant current of 0.33C until the battery voltage reached 4.25V, and upon reaching 4.25V, constant voltage charging was performed at 4.25V under a 0.1C cut-off condition. Subsequently, the battery was discharged with a constant current of 0.33C until the battery voltage reached 2.5V. From the second cycle onwards, charging and discharging were performed for up to 350 cycles under the same conditions as the first cycle. This implies that the life characteristics improve as the number of cycles at which a short circuit occurs increases. A short circuit was confirmed to have occurred using the standard method (charge amount during life = discharge amount × 10%), and the number of cycles at that time was recorded.

[0184] The results are shown in Table 1.

[0185] Separate packaging component short circuit occurrence point (number of cycles) Example 1 Structure of Fig. 5a > 200 Example 2 Structure of Fig. 5b > 200 Comparative Example 1 Not applied < 50” > n” means that no short circuit occurs even after n cycle tests. <n”은, n회 사이클 시험 동안 단락이 발생함을 의미함.

[0186] Referring to Table 1, the all-solid-state batteries of Examples 1 and 2 had an improved initial capacity compared to the all-solid-state battery according to Comparative Example 1, and had a longer lifespan because the time of short circuit occurrence was later. The all-solid-state batteries according to Examples 1 and 2 had a longer lifespan because the time of short circuit occurrence was later than that of the all-solid-state battery according to Comparative Example 1. Thus, it was confirmed that the all-solid-state batteries according to Examples 1 and 2 can increase the initial capacity by using a packaging material. In addition, it was confirmed that the all-solid-state batteries according to Examples 1 and 2 have a long lifespan by preventing electrical short circuits through the packaging material.

[0187]

[0188] 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 an anode current collector and an anode active material layer on the anode current collector; A cathode layer comprising a cathode current collector and a coating layer on the cathode current collector; A solid electrolyte layer between the anode layer and the cathode layer; An elastic sheet on the anode layer above; and The packaging member on the elastic sheet above, comprising: The above packaging member extends from one side of the elastic sheet along the side of the elastic sheet to the side of the anode layer, and The above-described packaging member encloses at least a portion of the side of the above-described anode layer, in a solid-state battery.

2. In Paragraph 1, The above packaging member is an all-solid-state battery in which the negative electrode layer is not wrapped.

3. In Paragraph 1, The above packaging member is: A first member covering at least a portion of the surface of the elastic sheet; A second member covering at least a portion of the first side of the anode layer; and It includes a third member that surrounds at least a portion of the second side of the anode layer, and The above-mentioned second member and the above-mentioned third member each wrap around the first corner and the second corner of the elastic sheet, respectively, in an all-solid-state battery.

4. In Paragraph 3, The first member above includes a plurality of horizontal members and a plurality of vertical members, and A solid-state battery in which the plurality of horizontal members and the plurality of vertical members intersect each other to form a grid pattern.

5. In Paragraph 3, The first member wraps a portion of the one surface of the elastic sheet, and A solid-state battery, the remainder of the elastic sheet being exposed through the first member.

6. In Paragraph 1, A solid-state battery in which the thickness of the above-mentioned packaging member is smaller than the thickness of the above-mentioned elastic sheet.

7. In Paragraph 1, The above packaging member comprises at least one of polyamideimide, polyimide, polysulfone, polyurethane, polycarbonate, epoxy resin, polysulfide, polybenzimidazole, or a combination thereof, for an all-solid-state battery.

8. In Paragraph 1, The anode layer, the cathode layer, the solid electrolyte layer, and the elastic sheet constitute an electrode laminate, and The above packaging member caps at least one of the upper and lower parts of the electrode laminate, and The above-described all-solid-state battery further includes an outer material that encloses the electrode stack, wherein The above packaging member is a solid-state battery located between the exterior material and the elastic sheet.

9. In Paragraph 1, The solid electrolyte layer comprises a first sub-solid electrolyte layer adjacent to the anode layer and a second sub-solid electrolyte layer adjacent to the cathode layer, and The above anode layer and the above first sub-solid electrolyte layer constitute an anode composite layer, and The above cathode layer and the above second sub-solid electrolyte layer constitute a cathode composite layer, and When viewed in a planar view, the area of ​​the cathode composite layer is larger than the area of ​​the anode composite layer, All-solid-state battery.

10. An anode layer comprising an anode current collector and an anode active material layer on the anode current collector; A cathode layer comprising a cathode current collector and a coating layer on the cathode current collector; A solid electrolyte layer between the anode layer and the cathode layer; and The elastic sheet on the anode layer above, comprising: The above elastic sheet is: A first sheet covering one side of the anode layer; A second sheet covering at least a portion of the first side of the anode layer; and A solid-state battery comprising a third sheet covering at least a portion of the second side of the anode layer.

11. In Paragraph 10, The above elastic sheet is an all-solid-state battery in which the above negative electrode layer is not wrapped.

12. In Paragraph 10, The second sheet and the third sheet of the elastic sheet each wrap around the first corner and the second corner of the anode layer, respectively, in an all-solid-state battery.

13. Electrode laminate; and Including packaging members, The above electrode stack is: A first monocell comprising a first anode layer, a first solid electrolyte layer, a first cathode layer, and a first elastic sheet; A unit cell located on the first monocell and comprising a second anode layer, a third anode layer, a second solid electrolyte layer, a third solid electrolyte layer, a second cathode layer, a third cathode layer, and a second elastic sheet; and It includes a second monocell comprising a fourth anode layer, a fourth solid electrolyte layer, a fourth cathode layer, and a third elastic sheet, and The first elastic sheet is located at the bottom of the electrode laminate, and The third elastic sheet is located on the upper part of the electrode laminate, and The above packaging member is: A first packaging member for capping the lower portion of the electrode laminate; and All-solid-state battery comprising a second packaging member that caps the upper portion of the electrode laminate.

14. In Paragraph 13, The above first and second packaging members are an all-solid-state battery in which the first to fourth negative electrode layers are not wrapped.

15. In Paragraph 13, The above-mentioned first packaging member is: A first member covering at least a portion of one side of the first elastic sheet; A second member covering at least a portion of the first side of the first anode layer; and It includes a third member that surrounds at least a portion of the second side of the first anode layer, and The above-mentioned second member and the above-mentioned third member each wrap around the first corner and the second corner of the above-mentioned first elastic sheet, forming an all-solid-state battery.

16. In Paragraph 13, The above second packaging member is: A fourth member covering at least a portion of one side of the third elastic sheet; A fifth member covering at least a portion of the first side of the fourth anode layer; and It includes a sixth member that surrounds at least a portion of the second side of the fourth anode layer, and The above-mentioned fifth member and the above-mentioned sixth member each wrap around the first and second corners of the above-mentioned third elastic sheet, forming an all-solid-state battery.

17. In Paragraph 15, The first member wraps a portion of the surface of the first elastic sheet, and A solid-state battery in which the remaining portion of the first elastic sheet is exposed through the first member.

18. In Paragraph 16, The above-mentioned fourth member wraps a portion of the above-mentioned surface of the above-mentioned third elastic sheet, and The remaining portion of the third elastic sheet is exposed through the fourth member, in a solid-state battery.

19. In Paragraph 13, The above-described all-solid-state battery further includes an outer material that encloses the electrode stack, wherein The first packaging member is located between the exterior material and the first elastic sheet, and The above-mentioned second packaging member is a solid-state battery located between the above-mentioned exterior material and the above-mentioned third elastic sheet.

20. In Paragraph 13, A solid-state battery in which the thickness of the first and second packaging members is thinner than the thickness of the first to third elastic sheets.

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