Pouch-type all-solid-state battery and manufacturing method therefor

Abstract

The present invention relates to a pouch-type all-solid-state battery and, more specifically, comprises: an electrode assembly in which one or more unit cells are stacked; a substrate tab extending from each unit cell; a lead tab electrically connected to the substrate tab; a pouch for packing the electrode assembly; and an insulating layer provided between the pouch and the substrate tab. The pouch includes a metal layer and a polymer layer on the metal layer, the insulating layer includes ceramic having a melting point higher than 200 °C, and the polymer layer has a melting point of 170 °C or lower.

Description

Pouch-type all-solid-state battery and method for manufacturing the same

[0001] The present invention relates to a pouch-type 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 stability 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] In pouch-type batteries, conventional pouches have a problem with thermal and mechanical damage. This can lead to short circuits, which may result in fire or explosion.

[0006]

[0007] The problem that the present invention aims to solve is to provide a pouch-type all-solid-state battery with improved stability.

[0008] Another problem that the present invention aims to solve is to provide a method for manufacturing a pouch-type all-solid-state battery with improved stability.

[0009]

[0010] A pouch-type all-solid-state battery according to the concept of the present invention may include: an electrode assembly in which at least one unit cell is stacked; a substrate tab extending from the unit cell; a lead tab electrically connected to the substrate tab; a pouch for packing the electrode assembly; and an insulating layer provided between the pouch and the substrate tab. The lead tab extends from the substrate tab to the outside of the pouch, and the pouch comprises a metal layer and a polymer layer on the metal layer, and the insulating layer comprises a ceramic having a melting point higher than 200°C, and the melting point of the polymer layer may be 170°C or lower.

[0011] A pouch-type all-solid-state battery according to another concept of the present invention may comprise: an electrode assembly having at least one unit cell stacked therein; a substrate tab extending from the unit cell; a lead tab electrically connected to the substrate tab; a pouch packing the electrode assembly; and an insulating layer optionally provided on a region of the inner surface of the pouch that contacts the substrate tab. The pouch may comprise a metal layer and a polymer layer on the metal layer, and the insulating layer may be configured to keep the substrate tab separated from the metal layer even at a temperature of 170°C or higher.

[0012] A method for manufacturing a pouch-type all-solid-state battery according to another concept of the present invention may include manufacturing a pouch film; manufacturing an electrode assembly; and packaging the electrode assembly with the pouch film to assemble the battery. Manufacturing the pouch film may include laminating a metal layer and a polymer layer on the metal layer; and coating an insulating layer on at least one region of the polymer layer, wherein the insulating layer is optionally formed in a region in contact with a substrate tab extending from the electrode assembly, and the melting point of the polymer layer may be less than 170°C and the melting point of the insulating layer may be greater than 200°C.

[0013]

[0014] According to one embodiment of the present invention, by forming an insulating layer on a region of the inner surface of the pouch that contacts the substrate tab, a short circuit between the pouch and the substrate tab can be completely prevented. This allows for the provision of a pouch-type all-solid-state battery with improved stability.

[0015]

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

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

[0018] Figure 3 is a cross-sectional view along the line A-A' of Figure 2.

[0019] FIG. 4 is a cross-sectional view of an all-solid-state battery unit cell according to one embodiment of the present invention.

[0020] FIG. 5 is a schematic diagram illustrating a pouch-type all-solid-state battery according to one embodiment of the present invention.

[0021] FIG. 6 is a cross-sectional view of a pouch-type all-solid-state battery according to one embodiment of the present invention.

[0022] Figure 7 is an enlarged view of the X-region of Figure 6.

[0023] Figure 8 is an enlarged view of the Y-region of Figure 6.

[0024] FIG. 9 is a top-view perspective of a pouch-type all-solid-state battery according to one embodiment of the present invention.

[0025] FIG. 10 is a schematic diagram showing an insulating layer selectively formed on the inner surface of a pouch according to one embodiment of the present invention.

[0026] FIG. 11 is a schematic diagram illustrating the state in which a lead tab and a substrate tab are electrically connected in a pouch-type all-solid-state battery according to one embodiment of the present invention.

[0027] FIG. 12 is a flowchart illustrating a method for manufacturing a pouch-type all-solid-state battery according to one embodiment of the present invention.

[0028] Figures 13 and 14 are schematic diagrams illustrating step S200 of Figure 12, respectively.

[0029] Figure 15 is a schematic diagram illustrating step S300 of Figure 12.

[0030]

[0031] In order to fully understand the structure and effects of the present invention, preferred embodiments of the present invention are described with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and various modifications can be made. The description of these embodiments is provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention.

[0032] In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Additionally, in the drawings, the thicknesses of the components are exaggerated for the effective description of the technical content. Throughout the specification, parts indicated by the same reference numeral represent the same components.

[0033] 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.

[0034] The terms used herein are for describing the embodiments and are not intended to limit the invention. Unless otherwise specified herein, singular forms may also include plural forms. Additionally, unless otherwise specified, "A or B" may mean "comprising A, comprising B, or comprising A and B." As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components to the mentioned components.

[0035] 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.

[0036]

[0037] FIG. 1 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention. FIG. 2 is a plan view of an all-solid-state battery according to one embodiment of the present invention. FIG. 3 is a cross-sectional view along line A-A' of FIG. 2.

[0038] Referring to FIG. 1, an all-solid-state battery (10) according to one embodiment includes 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, the all-solid-state battery (10) may further include an additional functional layer, such as an adhesion-enhancing layer, disposed between the positive electrode layer (100) and the solid electrolyte layer (300) or between the negative electrode layer (200) and the solid electrolyte layer (300).

[0039] An anode layer (100) of one embodiment includes 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.

[0040] 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.

[0041] 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).

[0042] The positive electrode active material is a material capable of reversibly absorbing and desorbing lithium ions. The positive electrode active material may include, for example, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, as well as nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, but is not necessarily limited to these. The positive electrode active material may be a single material or a mixture of two or more materials.

[0043] Lithium transition metal oxides are, for example, Li a A 1-b B b D2(0.90≤a≤1, 0≤b≤0.5), Li a E 1-b B b O 2-c D c (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05), LiE 2-b B b O 4-c D c (0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Co b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Mn b B c D α(0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Nor 1-b-c Mn b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Nor b E c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Nor b Co c Mn d GeO2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1), Li a NiG b O2(0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a MnG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a 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.

[0044] 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. 양극활물질이 층상암염형 구조를 갖는 삼원계 리튬전이금속산화물을 포함하는 경우, 전고체 전지(10)의 에너지 밀도가 커지고 열안정성이 향상될 수 있다.

[0045] 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.

[0046] When the positive electrode active material is a ternary lithium transition metal oxide such as NCA or NCM and contains nickel (Ni), the capacity density of the all-solid-state battery (10) is increased, and the metal leaching of the positive electrode active material in the charged state can be reduced. As a result, the cycle characteristics of the all-solid-state battery (10) in the charged state are improved. Meanwhile, “cycle characteristics” is a characteristic that indicates the degree of deterioration of the all-solid-state battery (10) due to charging and discharging of the all-solid-state battery (10). An all-solid-state battery (10) with high cycle characteristics has a small degree of deterioration due to charging and discharging, while an all-solid-state battery (10) with low cycle characteristics may have a large degree of deterioration due to charging and discharging.

[0047] The shape of the positive electrode active material may include particle shapes such as spheres or ellipsoids. The particle size and content of the positive electrode active material are not particularly limited.

[0048] The solid electrolyte may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. Sulfide-based solid electrolytes include, for example, Li2S-P2S5, Li2S-P2S5-LiX (where X is a halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, and Li2S-P2S5-Z m S n (m, n are positive numbers, uppercase “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).

[0049] Sulfide-based solid electrolytes are, for example, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I xIt may be an argyrodite-type compound comprising one or more selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound comprising one or more selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0050] 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, or a combination thereof. M can 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. there is.

[0051] 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.

[0052] The solid electrolyte included in the positive electrode active material layer (120) may have a smaller average particle size (D50) compared to the solid electrolyte included in the solid electrolyte layer (300). For example, the average particle size (D50) of the solid electrolyte included in the positive electrode active material layer (120) may be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less of the average particle size (D50) of the solid electrolyte included in the solid electrolyte layer (300). Meanwhile, the average particle size (D50) may be the median diameter measured using a laser particle size distribution meter.

[0053] The positive active material layer (120) may include a conductive material. The conductive material may have conductivity without causing chemical changes in the all-solid-state battery (10), thereby increasing the conductivity of the positive active material and the solid electrolyte. The conductive material may include a carbon-based material. The conductive material may include, for example, one or more selected from graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0054] The positive active material layer (120) may further include a binder. The binder may include a material for bonding the positive active material, solid electrolyte, and conductive material included in the positive active material layer (120), and for improving the bonding strength with the positive current collector (110). The binder may include, for example, polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, and polymethyl methacrylate.

[0055] Based on 100 parts by weight of the total positive active material, solid electrolyte, conductive material, and binder, the positive active material layer (120) may contain 85 parts by weight or more and 92 parts by weight or less of the positive active material. Based on 100 parts by weight of the total positive active material, solid electrolyte, conductive material, and binder, the positive active material layer (120) may contain 0.5 parts by weight or more and 1.5 parts by weight or less of the binder.

[0056] 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.

[0057] 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.

[0058] The negative electrode layer (200) may include a negative electrode current collector (210) and a negative electrode coating layer (220) on the negative electrode current collector (210). The negative electrode current collector (210) may provide a reference surface on which the negative electrode coating layer (220) is placed. The negative electrode current collector (210) may include, for example, a material that does not react with lithium, that is, does not form any alloys or compounds with lithium. For example, the negative electrode current collector (210) may include at least one metal selected from the group consisting of copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). The thickness of the negative electrode current collector (210) may be 1 μm to 20 μm, more specifically 5 μm to 15 μm, and more specifically 7 μm to 10 μm.

[0059] 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.

[0060] The negative electrode coating layer (220) can allow lithium metal to grow between the all-solid-state battery (10) and the negative electrode current collector (210) during charging. The negative electrode coating layer (220) can serve as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites.

[0061] The cathode coating layer (220) may include metal and carbon. For example, the cathode coating layer (220) may include at least one metal selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The cathode coating layer (220) may include at least one carbon selected from the group consisting of carbon black, acetylene black, furnace black, ketjen black, and graphene. In one embodiment, the cathode coating layer (220) may include a mixture of carbon black and silver (Ag).

[0062] The cathode coating layer (220) may further include other additives in addition to metal and carbon. The cathode coating layer (220) may further include at least one additive selected from the group consisting of, for example, binders, fillers, coating agents, dispersants, and ion-conducting aids.

[0063] The negative electrode coating layer (220) may have a smaller thickness compared to the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 1 µm to 20 µm, 2 µm to 10 µm, or 3 µm to 7 µm. If the thickness of the negative electrode coating layer (220) is excessively thin, lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210) may cause the negative electrode coating layer (220) to collapse, thereby degrading the cycle characteristics of the all-solid-state battery (10). If the thickness of the negative electrode coating layer (220) increases excessively, the energy density of the all-solid-state battery (10) decreases, and the internal resistance of the all-solid-state battery (10) due to the negative electrode coating layer (220) increases, which may degrade the cycle characteristics of the cell.

[0064] Meanwhile, although not illustrated, a carbon layer may be further included to improve adhesion between the cathode coating layer (220) and the solid electrolyte layer (300).

[0065] 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).

[0066] Referring to FIG. 3, the solid electrolyte layer (300) may include a first solid electrolyte layer (310) and a second solid electrolyte layer (320). The first solid electrolyte layer (310) may be adjacent to the anode layer (100), and the second solid electrolyte layer (320) may be adjacent to the cathode layer (200).

[0067] The first solid electrolyte layer (310) may include a first solid electrolyte. The first solid electrolyte may have a particle shape such as a sphere or an ellipsoid. The first solid electrolyte may include a sulfide-based solid electrolyte. The first 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.

[0068] In one embodiment, the first solid electrolyte is Li 7-a M a PS6-c X c It may be an argyrodite-type compound containing. Here, X may be Cl, Br, or a combination thereof. M may be Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, or a combination thereof. a and c may each be real numbers between 0 and 2.

[0069] 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 first solid electrolyte is, for example, 15 GPa to 35 GPa.

[0070] The first solid electrolyte layer (310) 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 first solid electrolyte layer (310) may be the same as or different from the binder included in the positive electrode active material layer (120) or the binder included in the negative electrode coating layer (220).

[0071] The second solid electrolyte layer (320) may include a second solid electrolyte. The second solid electrolyte may have a particle shape such as a sphere or an ellipsoid. The second solid electrolyte may include a sulfide-based solid electrolyte. The description of the second solid electrolyte may be the same or similar as that described above for the first solid electrolyte. In one embodiment, the second solid electrolyte may have substantially the same composition as the first solid electrolyte. In another embodiment, the second solid electrolyte may have a composition similar to that of the first solid electrolyte.

[0072] The second solid electrolyte can come into direct contact with the negative electrode coating layer (220). By doing so, the second solid electrolyte can suppress lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210). The second solid electrolyte can effectively suppress negative side reactions. By doing so, the cell performance of the all-solid-state battery (10) according to the present invention can be improved.

[0073] The first solid electrolyte layer (310) may have a first thickness (TK1), and the second 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). For example, the first thickness (TK1) may be 1.1 to 5 times the second thickness (TK2).

[0074] Referring again to FIGS. 2 and FIGS. 3, the anode layer (100) and the first solid electrolyte layer (310) can form an anode composite layer (CSH). The cathode layer (200) and the second 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).

[0075] 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).

[0076] In one embodiment of the present invention, the first solid electrolyte layer (310) may have substantially the same area as the anode layer (100). The second solid electrolyte layer (320) may have substantially the same area as the cathode layer (200).

[0077] 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).

[0078] A solid-state battery (10) according to one embodiment of the present invention can be manufactured by forming a negative electrode composite layer (ASH) on a first carrier film and forming a positive electrode composite layer (CSH) on a second carrier film, and then laminating the negative electrode composite layer (ASH) and the positive electrode composite layer (CSH).

[0079]

[0080] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

[0081] FIG. 4 is a cross-sectional view of a unit cell of an all-solid-state battery according to one embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a pouch-type all-solid-state battery according to one embodiment of the present invention. FIG. 6 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention.

[0082] Referring to FIGS. 5 and 6, a pouch-type all-solid-state battery (400) according to one embodiment of the present invention may include an electrode assembly (STC) in which at least one unit cell is stacked, a substrate tab (TB) extending from the unit cell, a lead tab (LTB) electrically connected to the substrate tab (TB), and a pouch (PCH) for packing the electrode assembly (STC).

[0083] A pouch-type all-solid-state battery (400) according to one embodiment of the present invention may refer to a form in which the aforementioned all-solid-state battery (10) is packaged in a pouch (PCH). Specifically, it may be a form in which an electrode assembly (STC) having at least one unit cell stacked is packaged in a pouch (PCH).

[0084] In this specification, the term "unit cell" may refer to a basic unit comprising components that constitute a cell. A unit cell may include a first electrode, a second electrode having polarity opposite to that of the first electrode, and a solid electrolyte layer between the first and second electrodes. The first electrode may include a first electrode current collector (PLT1) and a first electrode coating layer or / and a first electrode active material layer formed on the first electrode current collector (PLT1). The second electrode may include a second electrode current collector (PLT2) and a second electrode coating layer and / or a second electrode active material layer formed on the second electrode current collector (PLT2).

[0085] The unit cell may include an anode layer, a cathode layer, and a solid electrolyte layer between the anode and cathode layers. In one embodiment, as shown in FIG. 4, the unit cell may be in the form of sequentially stacked in the order of a cathode layer (200), a solid electrolyte layer (300), an anode layer (100), a solid electrolyte layer (300), and a cathode layer (200).

[0086] The electrode assembly (STC) may include a stack cell in which at least one unit cell is stacked. It may further include an elastic layer (ELS) between the plurality of unit cells.

[0087] The electrode assembly (STC) may include a second electrode disposed on the top or bottom layer and facing the pouch (PCH). That is, it may include a second electrode in which the second electrode current collector (PLT2) and the pouch (PCH) face each other. Conversely, an electrode having an electrically opposite polarity to the second electrode and not in contact with the pouch (PCH) may be referred to as the first electrode. For example, the first electrode may be the positive electrode and the second electrode may be the negative electrode, but the present invention is not limited thereto.

[0088] A substrate tab (TB) may be extended from an electrode assembly (STC) and electrically connected to a unit cell. The substrate tab (TB) may refer to a portion of the uncoated portion of the electrode current collectors (PLT1, PLT2). The uncoated portion may refer to an area excluding the region where a coating layer or / and an active material layer exists on the electrode current collectors (PLT1, PLT2). The substrate tab (TB) may include a first substrate tab (TB1) extended from a first electrode current collector (plt1) and a second substrate tab (TB2) extended from a second electrode current collector (PLT2).

[0089] The lead tab (LTB) can be electrically connected to the substrate tab (TB). One end of the lead tab (LTB) is connected to the substrate tab (TB), and the other end can protrude outside the pouch (PCH).

[0090] One end of the lead tab (LTB) can be electrically connected to a plurality of substrate tabs (TB). The method of electrical connection is not particularly limited, and methods widely known in the field, such as welding, soldering, and brazing, may be used. For example, the lead tab (LTB) can be connected to a plurality of substrate tabs (TB) by a welding method. Specifically, the lead tab (LTB) can be welded to the substrate tabs (TB) by ultrasonic welding, laser welding, spot welding, etc.

[0091] For example, as shown in FIG. 6, the lead tab (LTB) may be welded to the lower part of the substrate tab (TB). However, the present invention is not limited thereto, and the lead tab (LTB) may be welded to the upper part of the substrate tab (TB).

[0092] The other end of the lead tab (LTB) protrudes partially outside the pouch (PCH) and can serve as an electrode terminal to electrically connect with the outside.

[0093] A lead tab (LTB) may include a first lead tab (LTB1) connected to a plurality of first electrodes and a second lead tab (LTB2) connected to a plurality of second electrodes. The first lead tab (LTB1) may be electrically connected to at least one first substrate tab (TB1). The second lead tab (LTB2) may be electrically connected to at least one second substrate tab (TB2). That is, the first lead tab (LTB1) may be connected only to the first electrode, and the second lead tab (LTB2) may be connected only to the second electrode.

[0094] The first lead tab (LTB1) may be connected to the first substrate tab (TB1) and extend outward from the pouch (PCH) along the first direction (D1). The second lead tab (LTB2) may be connected to the second substrate tab (TB2) and extend outward from the pouch (PCH) along the opposite direction of the first direction (D1). However, the present invention is not limited thereto, and the direction in which the first lead tab (LTB1) extends and the direction in which the second lead tab (LTB2) extends may be the same.

[0095] The pouch (PCH) can package the electrode assembly (STC) to protect and block the electrode assembly (STC) from the outside. The all-solid-state battery (400) packaged in the pouch (PCH) can be used as a single independent unit battery.

[0096] The pouch (PCH) may include a first pouch (PCH1) located at the upper side of one side of the electrode assembly (STC) to package the electrode assembly (STC), and a second pouch (PCH2) located at the lower side of one side of the electrode assembly (STC) to package the electrode assembly (STC).

[0097] The pouch (PCH) can be sealed by bringing the first pouch (upper pouch, PCH1) and the second pouch (lower pouch, PCH2) into contact and applying pressure at a high temperature while the pouch (PCH) accommodates the electrode assembly (STC). The pouch (PCH) may include a sealing portion (SL, see FIG. 5) along the edge of the pouch (PCH) where the first pouch (PCH1) and the second pouch (PCH2) are sealed. The sealing portion (SL) may be the area where the first pouch (PCH1) and the second pouch (PCH2) come into contact, that is, the edge of the pouch (PCH).

[0098] The pouch-type all-solid-state battery (400) may further include a lead film (LDF) surrounding a lead tab (LTB).

[0099] The lead film (LDF) can be heat-fused with the pouch (PCH) during the sealing process to provide high adhesion between the lead tab (LTB) and the pouch (PCH). The lead film (LDF) can prevent short circuits between the pouch (PCH) and the lead tab (LTB). That is, the lead film (LDF) can be formed in the form of a film having insulating and heat-fusion properties. For example, the lead film (LDF) may include at least one of PET, PVC, HDPE, and epoxy resin.

[0100] A lead film (LDF) may be provided corresponding to a position where the lead tab (LTB) contacts the sealing portion (SL) of the pouch (PCH). The lead film (LDF) may be provided to surround the outer surface of the lead tab (LTB) located at the sealing portion (SL).

[0101] The lead film (LDF) may include a first lead film (LDF1) surrounding a first lead tab (LTB1) and a second lead film (LDF2) surrounding a second lead tab (LTB2). The first lead film (LDF1) may be provided in an area where the sealing portion (SL) of the pouch (PCH) and the first lead tab (LTB1) come into contact. The second lead film (LDF2) may be provided in an area where the sealing portion (SL) of the pouch (PCH) and the second lead tab (LTB2) come into contact.

[0102]

[0103] Fig. 7 is an enlarged view of the X-region of Fig. 6. Fig. 8 is an enlarged view of the Y-region of Fig. 6.

[0104] Referring to FIG. 7, the pouch (PCH) may include a metal layer (MFL) and a polymer layer (PML) formed on the metal layer (MFL). The pouch (PCH) may include a metal layer (MFL) and a polymer layer (PML) formed on one or both sides of the metal layer (MFL). In one embodiment, the pouch (PCH) may include a metal layer (MFL) and a polymer layer (PML) formed on both sides of the metal layer (MFL).

[0105] Each of the metal layer (MFL) and the polymer layer (PML) may have a certain thickness range. The thickness of the pouch may refer to the total thickness of the metal layer (MFL) and the polymer layer (PML). In one embodiment, the thickness of the pouch (PCH) may be 50 μm to 300 μm.

[0106] The metal layer (MFL) may include a metal that maintains mechanical strength and flexibility. For example, the metal layer (MFL) may include aluminum (Al). In addition to aluminum (Al), the metal layer (MFL) may include one or more metals selected from the group consisting of iron (Fe), carbon (C), chromium (Cr), manganese (Mn), and nickel (Ni). Aluminum (Al) may be included in an amount of 90% to 99.9% by weight relative to the total mass of the metal layer (MFL). The thickness of the metal layer (MFL) may be 30μm to 150μm.

[0107] The polymer layer (PML) may include at least one polymer resin having insulating properties. For example, the polymer layer (PML) may have a single membrane structure made of any one material selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, polyparaphenylenebenzobisoxazole, polyarylate, Teflon, and glass fiber, or a composite membrane structure made of two or more materials.

[0108] The polymer layer (PML) can prevent the metal layer (MFL) from being damaged by external friction, impact, etc. In addition, the polymer layer (PML) can prevent the metal layer (MFL) from coming into direct contact with the electrode assembly (STC).

[0109] A polymer layer (PML) may be applied to one or both sides of a metal layer (MFL). When a polymer layer (PML) is provided on both sides of a metal layer (MFL), a polymer layer (PML) comprising the same or different polymer resins may be formed on each side of the metal layer (MFL). The thickness of the polymer layer (PML) formed on one side of the metal layer (MFL) may be 10 μm to 150 μm.

[0110] The melting point of the polymer layer (PML) may be about 170°C or lower. For example, the melting point of the polymer layer (PML) may be 140°C to 170°C, 140°C to 160°C, or 150°C to 160°C. The polymer layer (PML) may include a polymer resin having a melting point of about 200°C or lower. The melting point of the polymer resin included in the polymer layer (PML) may be, for example, 140°C to 200°C, 150°C to 180°C, or 170°C to 190°C.

[0111] The melting point of a polymer layer (PML) can refer to the temperature at which the polymer layer (PML) in a solid state changes into a polymer layer (PML) in a liquid state. The melting point of the polymer layer (PML) may occur within a specific temperature range. For example, if the polymer layer (PML) contains only polymers, the melting point of the polymer layer (PML) may be the same as the melting point of the polymer resin. As another example, if the polymer layer (PML) contains additives other than the polymer resin, the melting point of the polymer layer (PML) may be lower or higher than the melting point of the polymer resin. The melting points of the polymer layer (PML) and the polymer resin can be measured, for example, by Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), or optical methods.

[0112] In the case of all-solid-state batteries, the internal cell temperature can be higher on average compared to conventional lithium-ion batteries. For example, unlike lithium-ion batteries, the internal cell temperature of an all-solid-state battery can exceed 170°C. The following problems may occur in all-solid-state batteries at high temperatures above 170°C.

[0113] Defects may occur during the packaging process of the electrode assembly (STC) because the pouch (PCH) undergoes relatively high stretching. In particular, significant thermal deformation of the pouch (PCH) can occur at the points where the pouch (PCH) contacts the substrate tab (TB) or where the pouch (PCH) contacts the lead tab (LTB). Consequently, the polymer layer (PML) may melt in some areas of the pouch (PCH) at high temperatures, thereby exposing the metal layer (MFL).

[0114] In other words, the polymer layer (PML) may not exist between the metal layer (MFL) and the first substrate tab (TB1). Accordingly, the metal layer (MFL) and the first substrate tab (TB1) may come into contact with each other in some areas. That is, the metal layer (MFL) and the first substrate tab (TB1) may be electrically connected in some areas.

[0115] The second lead tab (LTB2) can also become electrically connected to the metal layer (MFL) as the polymer layer (PML) melts in some areas. Consequently, a short circuit may occur in which the first substrate tab (TB1) and the second lead tab (LTB2), having different polarities, are connected to each other through the metal layer (MFL). As a result, this can lead to accidents such as battery explosion and fire.

[0116] According to one embodiment of the present invention, as shown in FIGS. 6 and 8, by forming an insulating layer (ISL) locally in the area where the pouch (PCH) and the substrate tab (TB) come into contact, the occurrence of a short circuit between the pouch (PCH) and the substrate tab (TB) is fundamentally blocked even if the polymer layer (PML) is damaged, thereby ensuring the stability of the battery.

[0117] A pouch-type all-solid-state battery (400) according to one embodiment of the present invention may include an insulating layer (ISL) that physically separates a metal layer (MFL) from a substrate tab (TB). That is, the insulating layer (ISL) may be configured to separate the substrate tab (TB) from the metal layer (MFL) even at a high temperature of 170°C or higher. A detailed description of the insulating layer (ISL) will be provided later with reference to FIGS. 9 to 11.

[0118]

[0119] FIG. 9 is a top-view perspective of a pouch-type all-solid-state battery according to one embodiment of the present invention.

[0120] Referring to FIG. 9, an insulating layer (ISL) may be provided on a portion of the inner surface of the pouch (PCH) that contacts the substrate tab (TB). For example, in a pouch (PCH) packaging an electrode assembly (STC), the insulating layer (ISL) may be provided only in a portion of the area where the stability of the polymer layer (PML) is relatively weak. In one embodiment, the insulating layer (ISL) may be selectively provided only in the area where the substrate tab (TB) and the pouch (PCH) contact.

[0121] The insulating layer (ISL) may include a first insulating layer (ISL1) provided on at least a portion of the inner surface of the pouch (PCH) along a first direction (D1); and a second insulating layer (ISL2) provided on at least a portion of the inner surface of the pouch (PCH) along a direction opposite to the first direction (D1).

[0122] The first insulating layer (ISL1) may be provided between the pouch (PCH) and the first substrate tab (TB1). Specifically, it may be optionally provided on a region of the inner surface of the pouch (PCH) that contacts the first substrate tab (TB1).

[0123] The second insulating layer (ISL2) may be provided between the pouch (PCH) and the second substrate tab (TB2). Specifically, it may be optionally provided on one area of ​​the inner surface of the pouch (PCH) that contacts the second substrate tab (TB2).

[0124] According to one embodiment of the present invention, as illustrated in FIG. 9, a pouch-type all-solid-state battery (400) may include a first region (RG1), a second region (RG2), and a third region (RG3) arranged sequentially in one direction. The second region (RG2) may include a pair of second regions (RG2) that are symmetrical to each other with respect to the first region (RG1). The third region (RG3) may include a pair of third regions (RG3) that are symmetrical to each other with respect to the first region (RG1).

[0125] The first region (RG1) may be an area within the internal space (S) of the pouch (PCH) where the electrode assembly (STC) is accommodated. The internal space (S) may refer to an empty space excluding the sealing portion (SL), i.e., the edge area where the pouch (PCH) is sealed.

[0126] The second region (RG2) may be an area within the internal space (S) of the pouch (PCH) excluding the first region (RG1). The second region (RG2) may be an area where the pouch (PCH) and the substrate tab (TB) face each other. The substrate tab (TB) and the lead tab (LTB) may be welded in the second region (RG2). That is, one end of the lead tab (LTB) may be located within the second region (RG2), and the other end of the lead tab (LTB) may protrude beyond the third region (RG3) to the outside of the pouch (PCH). The second region (RG2) may be an area where at least a portion of the inner surface of the pouch (PCH) comes into contact with the substrate tab (TB) when the shape of the pouch (PCH) is deformed due to external force, etc.

[0127] The third region (RG3) may be a region where at least a portion of the sealing portion (SL) of the pouch (PCH) contacts the lead tab (LTB).

[0128] Hereinafter, with reference to FIGS. 10 and FIGS. 11, we will examine the area where the insulating layer is provided in more detail.

[0129] FIG. 10 is a schematic diagram showing an insulating layer selectively provided on the inner surface of a pouch according to one embodiment of the present invention. FIG. 11 is a schematic diagram for explaining the state in which a lead tab and a substrate tab are electrically connected in a pouch-type all-solid-state battery according to one embodiment of the present invention.

[0130] In FIGS. 10 and 11, the first insulating layer is exemplarily shown being provided on the inner surface of the pouch (PCH), but the present invention is not limited thereto and can be applied in the same way to the second insulating layer. Hereinafter, for convenience of explanation, the first and second insulating layers (ISL1, ISL2) will be collectively referred to as insulating layers (ISL).

[0131] Referring to FIG. 10, an insulating layer (ISL) according to one embodiment of the present invention may be provided along the inner surface of a pouch (PCH) in a second region (RG2). The insulating layer (ISL) may be provided in a shape symmetrical to each other with respect to a first region (RG1).

[0132] An insulating layer (ISL) may not be provided in the third region (RG3). This is because, as previously explained, sealing is achieved in the third region (RG3) through thermal fusion between the lead film (LDF) and the polymer layer (PML) of the pouch (PCH). Therefore, it is not desirable to provide an insulating layer (ISL) on the inner surface of the pouch (PCH) in the third region (RG3).

[0133] In addition, if the insulating layer (ISL) is provided directly on the lead tab (LTB), this case is also undesirable because the insulating layer (ISL) may be damaged during the sealing process of the pouch (PCH) or during the welding process between the lead tab (LTB) and the substrate tab (TB).

[0134] Referring to FIG. 11, one end of the insulating layer (ISL) may be formed to extend and surround the weld (WD). The weld (WD) may be an area where the substrate tab (TB) and the lead tab (LTB) come into contact with each other. That is, the insulating layer (ISL) may be formed to cover the weld (WD) by positioning it on the upper and lower surfaces of the weld (WD) respectively, facing each other. By doing so, the insulating layer (ISL) prevents the pouch (PCH) from coming into direct contact with the weld (WD), thereby preventing a short circuit through the weld (WD).

[0135] The insulating layer (ISL) may have a width (WI5) in the second direction (D2). The substrate tab (TB) may have a width (WI6) in the second direction (D2). The width (WI5) of the insulating layer (ISL) may be greater than the width (WI6) of the substrate tab (TB). Alternatively, the width (WI5) of the insulating layer (ISL) may be the same as the width (WI6) of the substrate tab (TB). If the width (WI5) of the insulating layer (ISL) is smaller than the width (WI6) of the substrate tab (TB), it is undesirable because the metal layer (MFL) exposed to the outside as the polymer layer (PML) melts may come into contact with the substrate tab (TB).

[0136] The present invention is not limited to the above embodiments and may include all embodiments that share the same principle of solving the problem. For example, in another embodiment, the insulating layer may be provided on the inner surface of the pouch (PCH) by appropriately adjusting the width in the first direction (D1) at a specific area where the stability of the pouch (PCH) is weak. In yet another embodiment, the insulating layer may also be additionally provided in the first region (RG1) described above.

[0137] The insulating layer (ISL) may include a ceramic having insulating and heat dissipation properties. For example, the ceramic may include at least one of h-BN (Hexagonal boron nitride), c-BN (Cubic boron nitride), Si3N4 (Silicon nitride), SiC (Silicon carbide), AlN (Aluminum nitride), and BeO (Berylium oxide).

[0138] The insulating layer (ISL) may include a ceramic having a melting point of 200°C or higher. The melting point of the ceramic included in the insulating layer (ISL) may be, for example, 500°C or higher, 1000°C or higher, 1500°C or higher, or 2000°C or higher. The melting point of the ceramic may refer to the temperature at which the ceramic changes from a solid state to a liquid state. The melting point of the ceramic may refer to the decomposition temperature or glass transition temperature at which the material substantially undergoes a thermal change. The melting point of the ceramic may be measured, for example, by Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA), high-temperature microscopy, etc.

[0139] The melting point of the insulating layer (ISL) containing the ceramic may be approximately 200°C or higher to ensure sufficient heat resistance. Since the insulating layer (ISL) has a higher melting point than the polymer layer (PML), the insulating layer (ISL) does not melt even when the battery is operated at a high temperature above the melting point of the polymer layer (PML) (approximately 170°C), and the insulating layer (ISL) can physically separate the metal layer (MFL) and the substrate tab (TB). As a result, the operation of the all-solid-state battery at high temperatures can be facilitated, and a pouch-type all-solid-state battery with improved stability can be provided.

[0140] The resistivity of the above ceramic is 106 Ω·cm to 10 17 It can be Ω·cm. For example, the resistivity of the ceramic is 10 6 Ω·cm to 10 10 Ω·cm, 10 11 Ω·cm to 10 15 Ω·cm, 10 13 Ω·cm to 10 15 Ω·cm, or 10⁻⁶ 15 Ω·cm to 10 17 It can be Ω·cm. The resistivity of a ceramic is a physical quantity representing the degree to which a material impedes the flow of current, and it can refer to the resistance value per unit length and unit area. For example, the resistivity of a ceramic can be measured by the 4-Point Probe method. Specifically, four probes are placed in a straight line at regular intervals on the surface of a ceramic sample, current is applied to the two outermost probes, and the voltage drop between the two middle probes is measured; the resistivity can then be calculated using the measured current and voltage. The method for measuring the resistivity of a ceramic is not particularly limited and can be measured according to various domestic and international standards and experimental methods, including ASTM A717, ASTM D257, KS L1619, KS L 1620, KS L 2109, KS C IECTS62607-4-3, etc.

[0141] The insulating layer (ISL) can possess excellent insulating properties by including a ceramic with high resistivity. As a result, even though the metal layer (MFL) is exposed as the polymer layer (PML) of the pouch (PCH) melts at high temperatures, the short circuit between the substrate tab (TB) and the metal layer (MFL) can be fundamentally blocked through the insulating layer (ISL).

[0142] The thermal conductivity of the ceramic may be 100 W / m·K to 800 W / m·K. For example, the thermal conductivity of the ceramic may be 100 W / m·K to 400 W / m·K, 200 W / m·K to 500 W / m·K, 300 W / m·K to 600 W / m·K, 400 W / m·K to 700 W / m·K, or 500 W / m·K to 800 W / m·K. The thermal conductivity of the ceramic may refer to the ability of a material to transfer thermal energy from one location in space to another. As an example, the thermal conductivity of the ceramic may be measured by the laser flash method. Specifically, heat may be generated by irradiating a laser pulse onto one side of a ceramic sample, and the thermal conductivity may be calculated by measuring the temperature change over time on the opposite side. The method for measuring the thermal conductivity of ceramics is not particularly limited and can be measured according to various domestic and international standards and experimental methods, including ISO 8301, ISO 8302, ASTM C518, ASTM C1113, KS L 1604, etc.

[0143] The insulating layer (ISL) can possess excellent heat dissipation characteristics by including a ceramic with high thermal conductivity. Consequently, even if the internal cell temperature rises abnormally due to reasons such as an internal short circuit, thermal energy can be rapidly dissipated to the outside to lower the internal cell temperature and prevent it from reaching the ignition point. As a result, thermal runaway caused by internal short circuits can be prevented, thereby ensuring the stability of the battery.

[0144] The thickness of the insulating layer (ISL) may be 10 µm to 100 µm. For example, it may be 10 µm to 40 µm, 30 µm to 60 µm, 50 µm to 80 µm, or 70 µm to 100 µm. If the thickness of the insulating layer (ISL) satisfies the range described above, the occurrence of a short circuit between the pouch (PCH) and the substrate tab (TB) through the insulating layer (ISL) can be more effectively blocked. The thickness of the insulating layer (ISL) may be measured, for example, through a photograph taken with an optical microscope such as a scanning electron microscope.

[0145]

[0146] Hereinafter, with reference to the drawings, a method for manufacturing a pouch-type all-solid-state battery according to one embodiment of the present invention will be examined.

[0147] FIG. 12 is a flowchart illustrating a method for manufacturing a pouch-type all-solid-state battery according to one embodiment of the present invention.

[0148] Referring to FIG. 12, a method for manufacturing a pouch-type all-solid-state battery according to one embodiment of the present invention may include manufacturing a pouch film (S100); manufacturing an electrode assembly (S200); and assembling a battery by packaging the electrode assembly with the pouch film (S300). Through such manufacturing steps, a pouch-type all-solid-state battery with a structure having improved stability can be manufactured.

[0149] Manufacturing the above pouch film (S100) may include laminating a metal layer and a polymer layer on the metal layer; and coating an insulating layer on at least one region of the polymer layer.

[0150] Specifically, a metal layer in the form of a film may be prepared to manufacture a pouch for a battery. The metal layer may maintain mechanical strength and possess flexibility. The metal layer may include aluminum (Al). In addition to aluminum (Al), the metal layer may include one or more metals selected from the group consisting of iron (Fe), carbon (C), chromium (Cr), manganese (Mn), and nickel (Ni). Aluminum (Al) may be included in an amount of 90% to 99.9% by weight relative to the total mass of the metal layer. A metal layer having a constant width with respect to a first direction (D1) may be provided. A metal layer having a constant width with respect to the first direction (D1) may be prepared in a roll form by extending it lengthwise. The width in the first direction (D1) may be adjusted to match the size of the pouch to be manufactured. The width of the metal layer in the first direction (D1) may be the same as the width in the first direction (D1) of the pouch-type all-solid-state battery being manufactured (see FIG. 6).

[0151] A metal layer in the form of a roll can be positioned on equipment moving in one direction to unwind the wound metal layer. A step of forming a polymer layer on the unwinded metal layer can be performed.

[0152] The polymer layer may include at least one polymer resin having insulating properties. The polymer layer may include one or more polymer resins selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, polyarylate, and Teflon. Preferably, a polyolefin resin such as polypropylene (PP) or polyethylene (PE) may be used. The melting point of the polymer layer may be less than 170°C.

[0153] The polymer layer can be laminated onto the metal layer by lamination or coating. The polymer layer can be laminated on both sides or on either side of the metal layer. In one embodiment, the polymer layer can be laminated on both sides of the metal layer.

[0154] Subsequently, an insulating layer may be formed in at least one region on the polymer layer. The placement position, width, and thickness of the insulating layer may be varied and controlled. In other words, during the pouch film manufacturing process, the pouch film may be manufactured by appropriately controlling the position where the insulating layer is formed, the width and thickness of the insulating layer, etc. For example, the width of the insulating layer may be equal to or greater than the width of the substrate tab. The insulating layer may be provided on the inner surface of the pouch that does not overlap with the aforementioned sealing portion. The insulating layer may be optionally provided in the region in contact with the substrate tab extending from the electrode assembly. The insulating layer may be formed with a thickness of about 10 μm to 100 μm.

[0155] For example, an insulating layer can be formed on at least one region of a polymer layer through a coating method. The coating method is not particularly limited and can be performed by knife coating, air knife coating, roll coating, spray coating, etc.

[0156] Specifically, the insulating layer can be formed by dispersing ceramic powder in a solvent to prepare a slurry, then applying the slurry to a region on the polymer layer and drying it. The slurry may also be prepared by adding a binder as needed.

[0157] The insulating layer may include a ceramic having insulating and heat dissipation properties. For example, the ceramic may include at least one of h-BN (Hexagonal boron nitride), c-BN (Cubic boron nitride), Si3N4 (Silicon nitride), SiC (Silicon carbide), AlN (Aluminum nitride), and BeO (Berylium oxide). The melting point of the insulating layer may be greater than 200°C.

[0158] Figures 13 and 14 are schematic diagrams illustrating step S200 of Figure 12, respectively.

[0159] After manufacturing the pouch film (S100), manufacturing the electrode assembly (S200) may proceed.

[0160] Manufacturing the above electrode assembly (S200) may include stacking at least one unit cell comprising an anode layer, a solid electrolyte layer, and a cathode layer; gathering substrate tabs (TB) extending from the unit cell to form a tab stack; and electrically connecting the tab stack and a lead tab (LTB).

[0161] Stacking unit cells may include stacking an anode layer, a cathode layer, and a solid electrolyte layer between the anode layer and the cathode layer. In one embodiment, the unit cell may be in the form of a mono-cell in which an anode layer, a solid electrolyte layer, and a cathode layer are stacked sequentially. In another embodiment, the unit cell may be in the form of a bi-cell in which a cathode layer (anode layer), a solid electrolyte layer, an anode layer (cathode layer), a solid electrolyte layer, and a cathode layer (anode layer) are stacked sequentially. In this case, the anode layer, the cathode layer, and the solid electrolyte layer may be stacked with different areas for each. At least one of the unit cells may be stacked to form an electrode assembly (STC) comprising a plurality of unit cells. An elastic layer may be interposed between the plurality of unit cells.

[0162] In the process of stacking the positive electrode layer and the negative electrode layer, the direction of the substrate tab (TB) connected to each electrode can be set. For example, the positive electrode substrate tab and the negative electrode substrate tab can be stacked so that their directions face opposite directions with respect to the first direction (D1). As another example, the positive electrode substrate tab and the negative electrode substrate tab can be stacked so that their directions face the same with respect to the first direction (D1).

[0163] Referring to FIG. 13, a tab stack can be formed by gathering substrate tabs (TB) extending from a unit cell. Forming the tab stack may include gathering a plurality of substrate tabs (TB) extending from the unit cell by pressing them together, and then joining them together. Specifically, forming the tab stack may include joining a plurality of cathode substrate tabs together to form a cathode tab stack, and joining a plurality of anode substrate tabs together to form an anode tab stack. In one embodiment, a plurality of substrate tabs (TB) can be joined together through welding. The welding method is not particularly limited and can be performed by ultrasonic welding, laser welding, spot welding, etc. Thus, a tab stack formed by gathering the plurality of substrate tabs (TB) can be formed.

[0164] Referring to FIG. 14, the tab stack and the lead tab (LTB) can be electrically connected. Specifically, electrically connecting the tab stack and the lead tab (LTB) may include connecting the positive tab stack to the positive lead tab and connecting the negative tab stack to the negative lead tab. In one embodiment, the tab stack and the lead tab (LTB) can be electrically connected through welding. The welding method is not particularly limited and can be performed by ultrasonic welding, laser welding, spot welding, etc.

[0165] The lead tab (LTB) can be extended and connected in the direction in which the substrate tab (TB) faces. That is, the direction of the positive lead tab and the negative lead tab can be connected such that they are the same as the direction of the positive substrate tab and the negative substrate tab, respectively.

[0166] Figure 15 is a schematic diagram illustrating step S300 of Figure 12.

[0167] After manufacturing the electrode assembly (S200), the electrode assembly can be packaged with a pouch film to assemble the battery (S300).

[0168] Assembling the above battery (S300) may include accommodating an electrode assembly inside a pouch film; and sealing the pouch film along the edge of the pouch film.

[0169] Sealing the pouch film may include sealing by applying pressure at a high temperature while bringing the upper pouch (PCH1) and the lower pouch (PCH2) into mutual contact with each other while the electrode assembly is contained.

[0170] A lead tab (LTB) may be interposed in a portion of the area where the upper pouch (PCH1) and the lower pouch (PCH2) come into contact. At this time, a lead film (LDF) surrounding the lead tab (LTB) may be provided on the lead tab (LTB). That is, the lead film (LDF) may be heat-fused with the pouch (PCH) during the sealing process to provide high adhesion between the lead tab (LTB) and the pouch (PCH). For example, the lead film (LDF) may include at least one of PET, PVC, HDPE, and epoxy resin.

[0171] In a method for manufacturing an all-solid-state battery according to one embodiment of the present invention, each step may proceed as a series of continuous processes. According to an embodiment of the present invention, by controlling the placement position of the insulating layer during the pouch manufacturing step, short circuits between the pouch and the substrate tab can be fundamentally prevented, thereby enabling the manufacture of a battery pouch with improved stability. Furthermore, the mass producibility of the pouch-type all-solid-state battery according to an embodiment of the present invention can be further improved.

[0172] According to one embodiment of the present invention, after the manufacturing process of a pouch film in which an insulating layer is coated on at least a portion of the inner surface of the pouch, a welding process between a substrate tab and a lead tab and a sealing process of the pouch may be carried out.

[0173] In other words, in the present invention, as described above, since the insulating layer is coated on a region of the inner surface of the pouch that contacts the substrate tab rather than being directly provided on the lead tab or including the insulating layer in the pouch itself, the problem of the insulating layer being destroyed during the welding process between the substrate tab and the lead tab or during the sealing process of the pouch can be prevented. As a result, a pouch-type all-solid-state battery with improved stability can be manufactured.

[0174] The present invention can fundamentally prevent the occurrence of a short circuit between the pouch and the substrate tab by forming an insulating layer in the area where the pouch and the substrate tab come into contact. That is, even if the metal layer is exposed to the outside as the polymer layer melts at high temperatures, the stability of the battery can be ensured by blocking an internal short circuit of the battery through the insulating layer.

[0175]

[0176] The present invention may include not only the embodiments described above, but also embodiments that can be simply modified or easily modified. Furthermore, the present invention may include technologies that can be easily modified and implemented using the embodiments. Accordingly, the scope of the present invention should not be limited to the embodiments described above, but should be defined by the claims set forth below as well as equivalents.

Claims

1. An electrode assembly having at least one stacked unit cell; A recording tab extending from the above unit cell; A lead tab electrically connected to the above-mentioned tab; A pouch for packing the above electrode assembly; and It includes an insulating layer provided between the above pouch and the above substrate tab, The above pouch comprises a metal layer and a polymer layer on the metal layer, and The above insulating layer comprises a ceramic with a melting point higher than 200℃, and The melting point of the above polymer layer is 170℃ or lower, Pouch-type solid-state battery.

2. In Paragraph 1, The above-described all-solid-state battery includes a first region, a second region, and a third region arranged sequentially in one direction, and The insulating layer is provided along the inner surface of the pouch in the second region, Pouch-type solid-state battery.

3. In Paragraph 2, The insulating layer is optionally provided on one region of the inner surface of the pouch that contacts the substrate tab, Pouch-type solid-state battery.

4. In Paragraph 1, The width of the insulating layer is equal to or wider than the width of the substrate tab. Pouch-type solid-state battery.

5. In Paragraph 1, The ceramic comprises at least one of h-BN, c-BN, Si3N4, SiC, AlN, and BeO. Pouch-type solid-state battery.

6. In Paragraph 1, The resistivity of the above ceramic is 10 6 Ω·cm to 10 17 It is Ω·cm, and The thermal conductivity of the ceramic is 100 W / m·K to 800 W / m·K, Pouch-type solid-state battery.

7. In Paragraph 1, The thickness of the insulating layer is 10 μm to 100 μm, Pouch-type solid-state battery.

8. In Paragraph 1, The above-described all-solid-state battery further comprises a lead film surrounding the lead tab, Pouch-type solid-state battery.

9. An electrode assembly having at least one stacked unit cell; A recording tab extending from the above unit cell; A lead tab electrically connected to the above-mentioned tab; A pouch for packing the above electrode assembly; and It includes an insulating layer optionally provided on one region of the inner surface of the pouch that contacts the substrate tab, wherein The above pouch comprises a metal layer and a polymer layer on the metal layer, and The above insulating layer is configured to separate the substrate tab from the metal layer even at a temperature of 170°C or higher. Pouch-type solid-state battery.

10. In Paragraph 9, The above pouch-type all-solid-state battery includes a first region, a second region, and a third region arranged sequentially in a unidirectional direction, and The insulating layer is provided along the inner surface of the pouch in the second region, Pouch-type solid-state battery.

11. In Paragraph 9, The width of the insulating layer is equal to or wider than the width of the substrate tab. Pouch-type solid-state battery.

12. In Paragraph 9, The above insulating layer comprises a ceramic having a melting point higher than 200°C, Pouch-type solid-state battery.

13. In Paragraph 12, The ceramic comprises at least one of h-BN, c-BN, Si3N4, SiC, AlN, and BeO. Pouch-type solid-state battery.

14. In Paragraph 12, The resistivity of the above ceramic is 10 6 Ω·cm to 10 17 It is Ω·cm, and The thermal conductivity of the ceramic is 100 W / m·K to 800 W / m·K, Pouch-type solid-state battery.

15. In Paragraph 9, The thickness of the insulating layer is 10 μm to 100 μm, Pouch-type solid-state battery.

16. In Paragraph 9, The above pouch-type all-solid-state battery further comprises a lead film surrounding the lead tab, Pouch-type solid-state battery.

17. Manufacturing pouch film; Manufacturing an electrode assembly; and The method includes assembling a battery by packaging the electrode assembly with the above pouch film, Manufacturing the above pouch film is, Laminating a metal layer and a polymer layer stacked on the metal layer; and It includes coating an insulating layer on at least one region of the polymer layer, and The insulating layer is optionally formed in the region in contact with the substrate tab extending from the electrode assembly, and The melting point of the above polymer layer is less than 170℃, and The melting point of the above insulating layer is greater than 200℃, Method for manufacturing a pouch-type all-solid-state battery.

18. In Paragraph 17, Manufacturing the above electrode assembly is, Stacking at least one unit cell comprising an anode layer, a solid electrolyte layer, and a cathode layer; Forming a tab stack by gathering the material tabs extending from the above unit cell; and including electrically connecting the above tab stack and the lead tab, Method for manufacturing a pouch-type all-solid-state battery.

19. In Paragraph 17, Assembling the above battery is, accommodating the electrode assembly inside the pouch film; and including sealing the pouch film along the edge of the pouch film. Method for manufacturing a pouch-type all-solid-state battery.

20. In Paragraph 17, The above insulating layer includes ceramic, and The ceramic comprises at least one of h-BN, c-BN, Si3N4, SiC, AlN, and BeO. Method for manufacturing a pouch-type all-solid-state battery.

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