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

Abstract

The present invention relates to a pouch-type all-solid-state battery comprising: an assembly comprising a positive electrode a solid electrolyte layer and a negative electrode; a first substrate tab protruding from the positive electrode; a second substrate tab protruding from the negative electrode; a first lead tab electrically connected to the first substrate tab; a second lead tab electrically connected to the second substrate tab; a bonding portion provided in the space between the first base tab and the first lead tab and / or the space between the second base tab and the second lead tab; and a pouch case accommodating the assembly. The first and second lead tabs are exposed to the outside of the pouch case, and the bonding portion includes a metal having a melting point lower than 250 °C.

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] Recent industrial demands have led to the active development of batteries with high energy density and safety. For example, lithium-ion batteries are being used not only in information and communication devices, but also in the automotive sector. Safety is particularly important in the automotive sector, as it is directly related to life.

[0004] Meanwhile, lithium-ion batteries currently on the market contain electrolytes containing flammable organic dispersions, which pose a risk of overheating and fire in the event of a short circuit. Considering these issues, all-solid-state batteries, which replace the electrolyte with a solid electrolyte, are being proposed. By eliminating flammable organic dispersions, all-solid-state batteries significantly reduce the risk of fire or explosion in the event of a short circuit. Therefore, these all-solid-state batteries can significantly improve safety compared to lithium-ion batteries that use electrolytes.

[0005]

[0006] The problem to be solved by the present invention is to provide a pouch-type all-solid-state battery with improved stability.

[0007] Another problem to be solved by the present invention is to provide a method for manufacturing a pouch-type all-solid-state battery with improved stability.

[0008]

[0009] According to the concept of the present invention, an all-solid-state battery comprises: an assembly including a positive electrode, a solid electrolyte layer, and a negative electrode; a first substrate tab protruding from the positive electrode; a second substrate tab protruding from the negative electrode; a first lead tab electrically connected to the first substrate tab; a second lead tab electrically connected to the second substrate tab; a coupling portion provided between the first substrate tab and the first lead tab and between the second substrate tab and the second lead tab; and a pouch outer case for accommodating the assembly, wherein the first and second lead tabs are exposed to the outside of the pouch outer case, and the coupling portion may include a metal having a melting point lower than 250° C.

[0010] An all-solid-state battery according to the concept of the present invention comprises: an assembly including a positive electrode, a solid electrolyte layer, and a negative electrode; a first substrate tab protruding from the positive electrode; a second substrate tab protruding from the negative electrode; a first lead tab directly connected to the first substrate tab; a second lead tab electrically connected to the second substrate tab; a joint formed between the second substrate tab and the first lead tab; and a pouch outer case accommodating the assembly, wherein the joint may be configured to disconnect the electrical connection between the second substrate tab and the second lead tab at a temperature between 120° C. and 250° C.

[0011] According to the concept of the present invention, a method for manufacturing an all-solid-state battery comprises: manufacturing a pouch film; manufacturing an electrode assembly; and packaging the electrode assembly with the pouch film to form an all-solid-state battery; wherein manufacturing the electrode assembly comprises: forming a unit cell by laminating a positive electrode, a solid electrolyte layer, and a negative electrode; providing a joint between a substrate tab and a lead tab of the negative electrode; and electrically connecting the substrate tab and the lead tab by welding the substrate tab and the lead tab, wherein the joint may include a metal having a melting point lower than 250°C.

[0012]

[0013] According to one embodiment of the present invention, a pouch-type all-solid-state battery with improved stability can be provided by arranging a bonding portion including a metal having a low melting point between an electrode substrate tab and a lead tab.

[0014]

[0015] Figure 1 is a cross-sectional diagram schematically illustrating an all-solid-state battery.

[0016] Figure 2 is a plan view of an all-solid-state battery according to one embodiment.

[0017] Figure 3 is a cross-sectional view taken along line A-A' of Figure 2.

[0018] Figure 4 is a cross-sectional view of an all-solid-state battery unit cell according to one embodiment.

[0019] FIG. 5 is a schematic diagram illustrating a pouch-type all-solid-state battery according to one embodiment.

[0020] Figure 6 is a cross-sectional view of a pouch-type all-solid-state battery according to one embodiment.

[0021] Figures 7a and 7b are enlarged views of area M of Figure 6.

[0022] Figure 8 is a plan view of area M of Figure 6.

[0023] Figure 9 is a flowchart illustrating a method for manufacturing an all-solid-state battery according to embodiments of the present invention.

[0024]

[0025] To fully understand the structure and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and subject to various modifications. However, the description of these embodiments is provided solely to ensure a complete disclosure of the present invention and to fully inform those skilled in the art of the invention of the scope of the invention.

[0026] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. Furthermore, in the drawings, the thicknesses of the components are exaggerated for the sake of clarity. Parts designated by the same reference numerals throughout the specification represent the same components.

[0027] Embodiments described herein will be described with reference to cross-sectional and / or plan views, which are ideal illustrations of the present invention. In the drawings, the thicknesses of films and regions are exaggerated for the purpose of effectively explaining the technical contents. Accordingly, the regions illustrated in the drawings have a schematic nature, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of regions of the device and are not intended to limit the scope of the invention. Although terms such as first, second, and third are used to describe various components in various embodiments of the present specification, these components should not be limited by such terms. These terms are used only to distinguish one component from another. The embodiments described and illustrated herein also include complementary embodiments thereof.

[0028] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the words "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components.

[0029] Unless otherwise defined herein, the particle size may be the average particle size. In addition, the particle size refers to the average particle size (D50), which means the diameter of particles with a cumulative volume of 50% by volume in a particle size distribution. The average particle size (D50) can be measured by a method well 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) photograph or a scanning electron microscope (SEM) photograph. Alternatively, the average particle size (D50) value can be obtained by measuring with a measuring device that utilizes dynamic light-scattering, performing data analysis to count the number of particles for each particle size range, and calculating from the counted number. Alternatively, the average particle size (D50) value can be obtained by measuring with a laser diffraction method. When measuring by laser diffraction, more specifically, after the particles to be measured are dispersed 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 ultrasonic waves of approximately 28 kHz at an output of 60 W, and the average particle size (D50) based on 50% of the particle size distribution in the measuring device can be calculated.

[0030] Fig. 1 is a cross-sectional view of an all-solid-state battery (10) according to one embodiment of the present invention. Fig. 2 is a plan view of an all-solid-state battery (10) according to one embodiment of the present invention. Fig. 3 is a cross-sectional view taken along line A-A' of Fig. 2.

[0031] 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 present invention is not limited thereto, and 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).

[0032] The positive electrode layer (100) of one embodiment includes a positive electrode current collector (110) and a positive electrode active material layer (120) disposed on the positive electrode current collector (110). The positive electrode active material layer (120) may include a positive electrode active material, a solid electrolyte, a conductive material, and a binder.

[0033] The positive electrode current collector (110) can provide a reference surface on which the positive electrode active material layer (120) is arranged. The positive electrode current collector (110) can include a plate or foil including, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

[0034] Meanwhile, unlike that illustrated in FIG. 1, in one embodiment of the present invention, the positive electrode current collector (110) may be omitted. Although not illustrated, a carbon layer having a thickness of 0.1 μm to 4 μm may be additionally disposed between the positive electrode current collector (110) and the positive electrode active material layer (120) to increase the bonding strength between the positive electrode current collector (110) and the positive electrode active material layer (120).

[0035] The cathode active material is a material that can reversibly absorb and desorb lithium ions. The cathode active material may include, but is not necessarily limited to, 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. The cathode active materials may be used alone or as a mixture of two or more.

[0036] Lithium transition metal oxides include, 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-fA compound represented by any one of Fe2(PO4)3(0≤f≤2), LiFePO4. In these compounds, the capital letter “A” is Ni, Co, Mn, or a combination thereof, the capital letter “B” is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof, the capital letter “D” is O, F, S, P, or a combination thereof, the capital letter “E” is Co, Mn, or a combination thereof, the capital letter “F” is F, S, P, or a combination thereof, the capital letter “G” is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof, the capital letter “Q” is Ti, Mo, Mn, or a combination thereof, the capital letter “I” is Cr, V, Fe, Sc, Y, or a combination thereof, and the capital letter “J” is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0037] The cathode 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 atomic layers and metal atomic layers are alternately and regularly arranged in a direction, and thereby each atomic layer forms a two-dimensional plane. The "cubic rock salt structure" refers to the sodium chloride type (NaCl type) structure, which is a type of crystal structure, and specifically refers to a structure in which the face-centered cubic lattice (fcc) formed by each cation and anion is arranged with a displacement of half of the ridge of the unit lattice. Lithium transition metal oxides having this layered rock salt structure include, 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.

[0038] The above-described compound included 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 above-described compound and a compound to which a coating layer is added. Meanwhile, the coating layer added to the surface of the positive electrode active material may include, for example, an oxide, a hydroxide, an oxyhydroxide, an oxycarbonate, or a hydroxycarbonate of the coating elements below. The compound forming the coating layer is 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 includes, for example, spray coating, dipping, etc.

[0039] When the positive electrode active material includes nickel (Ni) as a ternary lithium transition metal oxide such as NCA or NCM, for example, the capacity density of the all-solid-state battery (10) can be increased, thereby reducing metal dissolution of the positive electrode active material in a charged state. As a result, the cycle characteristics of the all-solid-state battery (10) in a charged state are improved. Meanwhile, the “cycle characteristics” are characteristics indicating the degree to which the all-solid-state battery (10) is deteriorated by charge / discharge of the all-solid-state battery (10). An all-solid-state battery (10) with high cycle characteristics may have a small degree of deterioration of the all-solid-state battery (10) due to charge / discharge, and an all-solid-state battery (10) with low cycle characteristics may have a large degree of deterioration of the all-solid-state battery (10) due to charge / discharge.

[0040] The shape of the positive electrode active material may include particle shapes such as a sphere or an ellipsoid, for example. The particle size and content of the positive electrode active material are not particularly limited.

[0041] The solid electrolyte may include a sulfide-based solid electrolyte having excellent lithium ion conductivity characteristics. Examples of the sulfide-based solid electrolyte include Li2S-P2S5, Li2S-P2S5-LiX (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, capital letter “Z” represents Ge, Zn or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are positive numbers, capital letter “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).

[0042] Sulfide-based solid electrolytes include, 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 including at least one selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0043] Alternatively, the sulfide-based solid electrolyte is Li 7-a M a PS 6-c X c It may be an argyrodite-type compound containing (0≤a≤2, (0≤c≤2)), where X may be F, Br, Cl, or a combination thereof. M is 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 their It could be a combination.

[0044] The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. Since the argyrodite-type solid electrolyte has a density of 1.5 g / cc or more, the internal resistance of the all-solid-state battery is reduced, and the defect of the solid electrolyte membrane being penetrated and short-circuited due to the formation of lithium dendrites can be prevented. The elastic modulus of the solid electrolyte may be, for example, 15 GPa to 35 GPa.

[0045] The solid electrolyte included in the positive electrode active material layer (120) may have a smaller average particle diameter (D50) than the solid electrolyte included in the solid electrolyte layer (300). For example, the average particle diameter (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 diameter (D50) of the solid electrolyte included in the solid electrolyte layer (300). Meanwhile, the average particle diameter (D50) may be a median diameter measured using a laser particle size distribution meter.

[0046] The positive electrode active material layer (120) may include a conductive material. The conductive material may have conductivity without causing a chemical change in the all-solid-state battery (10), thereby increasing the conductivity of the positive electrode 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.

[0047] The positive electrode active material layer (120) may further include a binder. The binder may include a material for binding the positive electrode active material, solid electrolyte, and conductive material included in the positive electrode active material layer (120) and improving bonding strength with the positive electrode 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.

[0048] Based on 100 parts by weight of the total of the positive electrode active material, the solid electrolyte, the conductive material, and the binder, the positive electrode active material layer (120) may include 85 parts by weight or more and 92 parts by weight or less of the positive electrode active material. Based on 100 parts by weight of the total of the positive electrode active material, the solid electrolyte, the conductive material, and the binder, the positive electrode active material layer (120) may include 0.5 parts by weight or more and 1.5 parts by weight or less of the binder.

[0049] Based on 100 parts by weight of the solid electrolyte, the positive electrode active material layer (120) may include 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 electrode active material layer (120) in an amount of less than 1 part by weight based on 100 parts by weight of the solid electrolyte, the proportion of the conductive material may decrease, thereby lowering the electrical conductivity of the positive electrode active material layer (120). If the conductive material is included in the positive electrode active material layer (120) in an amount of more than 50 parts by weight based on 100 parts by weight of the solid electrolyte, the proportion of the conductive material may be excessively high, so that a covering layer covering the surface of the solid electrolyte may not be properly formed.

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

[0051] 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 disposed. The negative electrode current collector (210) may include, for example, a material that does not react with lithium, i.e., does not form an alloy or a compound 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.

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

[0053] The negative electrode coating layer (220) can allow lithium metal to grow between it and the negative electrode current collector (210) when the all-solid-state battery (10) is charged. The negative electrode coating layer (220) can act as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites.

[0054] The cathode coating layer (220) may include a 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).

[0055] The cathode coating layer (220) may further include additives other than metal and carbon. The cathode coating layer (220) may further include, for example, at least one additive selected from the group consisting of a binder, a filler, a coating agent, a dispersant, and an ion conductive additive.

[0056] The negative electrode coating layer (220) may have a smaller thickness than 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 um to 20 um, 2 um to 10 um, or 3 um to 7 um. If the thickness of the negative electrode coating layer (220) is too 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 deteriorating the cycle characteristics of the all-solid-state battery (10). If the thickness of the cathode coating layer (220) increases excessively, the energy density of the all-solid-state battery (10) may decrease and the internal resistance of the all-solid-state battery (10) due to the cathode coating layer (220) may increase, thereby deteriorating the cycle characteristics of the cell.

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

[0058] A solid electrolyte layer (300) may be provided between the positive electrode layer (100) and the negative electrode layer (200). The solid electrolyte layer (300) may include a sulfide-based solid electrolyte having 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 positive electrode active material layer (120) described above.

[0059] 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 positive electrode layer (100), and the second solid electrolyte layer (320) may be adjacent to the negative electrode layer (200).

[0060] 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. In addition, the solid electrolyte may include, for example, at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements among the above-described sulfide-based solid electrolyte materials. For example, the solid electrolyte may be a material including Li2S-P2S5. When using a sulfide-based solid electrolyte material including Li2S-P2S5 to form the solid electrolyte, the mixing molar ratio of Li2S and P2S5 is, for example, in the range of Li2S:P2S5=50:50 to 90:10.

[0061] 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, where 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. Each of a and c may be a real number between 0 and 2.

[0062] The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. When the argyrodite-type solid electrolyte has a density of 1.5 g / cc or more, the internal resistance of the all-solid-state battery is reduced, and the defect of the solid electrolyte membrane being penetrated and short-circuited due to the formation of lithium dendrites can be prevented. The elastic modulus of the first solid electrolyte is, for example, 15 GPa to 35 GPa.

[0063] The first solid electrolyte layer (310) may further include a binder. The binder included in the solid electrolyte layer (300) may be, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited thereto. 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).

[0064] 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 as or similar to 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 similar composition as the first solid electrolyte.

[0065] The second solid electrolyte can be in direct contact with the negative electrode coating layer (220). As a result, 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 electrode side reactions. As a result, the cell performance of the all-solid-state battery (10) according to the present invention can be improved.

[0066] 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. 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).

[0067] Referring again to FIGS. 2 and 3, the positive electrode layer (100) and the first solid electrolyte layer (310) may form a positive electrode composite layer (CSH). The negative electrode layer (200) and the second solid electrolyte layer (320) may form a negative electrode composite layer (ASH). The positive electrode composite layer (CSH) may be laminated on the negative electrode composite layer (ASH).

[0068] The area of ​​the cathode composite layer (ASH) and the area of ​​the cathode composite layer (CSH) may be different. Specifically, the area of ​​the cathode composite layer (ASH) may be larger than that of the cathode composite layer (CSH). The cathode composite layer (CSH) may be completely overlapped within the cathode composite layer (ASH).

[0069] In one embodiment of the present invention, the first solid electrolyte layer (310) may have substantially the same area as the positive electrode layer (100). The second solid electrolyte layer (320) may have substantially the same area as the negative electrode layer (200).

[0070] 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 the 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 the second direction (D2). The negative electrode composite layer (ASH) may have a fourth width (WI4) in the second direction (D2). The third width (WI3) may be smaller than the fourth width (WI4).

[0071] The all-solid-state battery (10) according to the present embodiment can be manufactured by forming a negative electrode composite layer (ASH) on a first carrier film, 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).

[0072] FIG. 4 is a cross-sectional view illustrating an all-solid-state battery according to another embodiment of the present invention.

[0073] Referring to FIG. 4, the all-solid-state battery (10) may have a bi-cell structure. The bi-cell structure may be a structure in which a solid electrolyte layer (SEL) and a second electrode (ETD2) are symmetrically arranged to face each other with a first electrode (ETD1) as the center. In one embodiment, the all-solid-state battery having a bi-cell structure may have a form in which a negative electrode, a solid electrolyte layer, a positive electrode, a solid electrolyte layer, and a negative electrode are sequentially stacked in that order. In another embodiment, the all-solid-state battery having a bi-cell structure may have a form in which a positive electrode, a solid electrolyte layer, a negative electrode, a solid electrolyte layer, and a positive electrode are sequentially stacked in that order.

[0074]

[0075] Hereinafter, an all-solid-state battery according to embodiments of the present invention will be described in more detail.

[0076] FIG. 5 is a schematic diagram of an all-solid-state battery (400) according to one embodiment of the present invention, and FIG. 6 is a cross-sectional diagram of an all-solid-state battery (400) according to one embodiment of the present invention.

[0077] Referring to FIGS. 5 and 6, the pouch-type all-solid-state battery (400) may refer to a form in which the all-solid-state battery (400) is packaged in the form of a pouch (PCH). More specifically, the pouch-type all-solid-state battery (400) may be a form in which an electrode assembly in which at least one unit cell is stacked is packaged in a pouch (PCH).

[0078] In this specification, a unit cell may mean a basic unit including components constituting a cell. For example, a unit cell may include a first electrode, a second electrode having an opposite polarity to 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 and / or a first electrode active material layer formed on the first electrode current collector (PLT1), and 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). In one embodiment, the unit cell may include a positive electrode, a negative electrode, and a solid electrolyte layer between the positive electrode and the negative electrode.

[0079] The electrode assembly may include a unit cell, a substrate tab (TB) electrically connected to the unit cell, and a lead tab (LTB) connected to the substrate tab (TB). In one embodiment, the first substrate tab (TB1) may be electrically connected to the first electrode current collector (PLT1), and the second substrate tab (TB2) may be electrically connected to the second electrode current collector (PLT2). The lead tab (LTB) may be connected to the substrate tab (TB) and protrude outside the pouch. In other words, the lead tab (LTB) may be configured such that the electrode assembly is connected to the outside of the pouch.

[0080] The substrate tab (TB) can be electrically connected to the lead tab (LTB). One lead tab (LTB) can be electrically connected to multiple substrate tabs (TB). The electrical connection method is not particularly limited, and methods such as welding, soldering, and brazing can be used. For example, the electrical connection can be made by welding. More specifically, the lead tab (LTB) can be welded to the substrate tab (TB) or the electrode layer by ultrasonic welding, laser welding, spot welding, or the like.

[0081] The substrate tab (TB) and lead tab (LTB) can be directly connected, or can be connected via a joint between the substrate tab (TB) and lead tab (LTB). The joint (BDL) may include a metal with a low melting point and low resistivity. The joint (BDL) will be described below with reference to FIGS. 7a and 7b.

[0082] The substrate tab (TB) may refer to a portion of the uncoated portion of the electrode current collector. The uncoated portion may refer to an area excluding an area on the electrode current collector where a coating layer and / or an active material layer exist. The substrate tab (TB) may include a first substrate tab (TB1) extending from a first electrode current collector (PLT1) and a second substrate tab (TB2) extending from a second electrode current collector (PLT2).

[0083] 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). 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.

[0084] The electrode assembly may include a second electrode disposed on the uppermost or lowermost layer and in contact with the pouch. That is, the electrode assembly may include a second electrode in which the second electrode current collector (PLT2) and the pouch (PCH) are in contact. 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 a first electrode. For example, the first electrode may be an anode, and the second electrode may be a cathode, but the present invention is not limited thereto.

[0085] The pouch (PCH) can package the electrode assembly and 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 an independent unit battery. Multiple pouch-type all-solid-state batteries (400) can be combined to form a battery module. Multiple battery modules can be combined to form a battery pack. The pouch-type battery has a relatively simple structure and can be reduced in volume and weight. In addition, it can be manufactured in a flexible and diverse form.

[0086] The pouch (PCH) may include a metal layer and a polymer layer formed on the metal layer. In one embodiment, the pouch (PCH) may include a metal layer and a polymer layer formed on both sides of the metal layer.

[0087] For example, the pouch (PCH) may include a first polymer layer formed on a lower surface of a metal layer, and a second polymer layer formed on an upper surface of the metal layer. The first and second polymer layers may be collectively referred to as polymer layers. In another embodiment of the present invention, the polymer layer may be formed on only one surface of the metal layer. For example, the pouch (PCH) may include only a polymer layer formed on a lower surface of the metal layer.

[0088] The metal layer may include a metal that maintains mechanical strength and has flexibility. For example, the metal layer may include aluminum (Al). In addition to aluminum, 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 wt% to 99.9 wt% based on the total mass of the metal layer. The thickness of the metal layer may be 20 μm to 150 μm, or 30 μm to 120 μm.

[0089] The polymer layer may include an insulating material. For example, the polymer layer may have a single film structure made of any one material selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, polyparaphenylenebenzobisoxazole, polyarylate, Teflon, and glass fiber, or a composite film structure made of two or more materials. Since the pouch (PCH) includes the polymer layer, the metal layer can be prevented from being damaged by friction or impact with the outside. In addition, the polymer layer can prevent the metal layer from directly contacting the electrode assembly.

[0090] The polymer layer may be applied to one or both sides of the metal layer. When the polymer layer is provided on both sides of the metal layer, polymer layers containing different polymer resins may be formed on each side of the metal layer. The thickness of the polymer layer formed on either side of the metal layer may be 10 μm to 150 μm.

[0091] The polymer layer may include a polymer having a melting point of about 200°C or lower. For example, the melting point of the polymer included in the polymer layer may be 140°C to 200°C, 140°C to 180°C, or 140°C to 160°C. The melting point of a polymer may refer to the temperature at which a polymer having a crystalline structure changes from a solid state to a liquid state. If the polymer does not have a perfect crystalline structure, the melting point may appear within a certain temperature range. The melting point of a polymer may be measured, for example, by DSC (Differential Scanning Calorimetry), TGA (Thermogravimetric Analysis), or optical methods.

[0092] The melting point of the polymer layer may be about 170°C or lower. The melting point of the polymer layer may be, for example, 140°C to 200°C, 140°C to 180°C, 140°C to 160°C, or 150°C to 160°C. The melting point of the polymer layer may refer to the temperature at which the solid polymer layer changes into a liquid polymer layer. The polymer layer, like the polymer itself, may have a melting point within a certain temperature range. The melting point of the polymer layer may be the same as or similar to the melting point of the polymer contained in the polymer layer. In one embodiment, when the polymer layer contains only a polymer, the melting point of the polymer layer may be the same as the melting point of the polymer. In another embodiment, when the polymer layer contains a separate additive in addition to the polymer, the melting point of the polymer layer may be lower or higher than the melting point of the polymer. In one embodiment, the melting point of the polymer layer may be measured by Differential Scanning Calorimetry (DSC).

[0093] Figure 7a is an enlarged view of area M of Figure 6, showing an all-solid-state battery at room temperature. Figure 7b is an enlarged view of area M of Figure 6, showing an all-solid-state battery after a temperature increase. Figure 8 is a plan view of area M of Figure 6.

[0094] Referring to FIGS. 7A and 8, a coupling portion (BDL) may be provided between a substrate tab (TB) and a lead tab (LTB) to electrically connect the substrate tab (TB) and the lead tab (LTB). In one embodiment, the coupling portion (BDL) may have the same width as the lead tab (LTB) in a second direction (D2) and may be narrower than the substrate tab (TB) in the second direction (D2). Although not shown, in another embodiment, the coupling portion (BDL) may have the same width as the substrate tab (TB) in the second direction (D2) and may be narrower than the lead tab (LTB) in the second direction (D2). In yet another embodiment, the width of the coupling portion in the second direction (D2) may be narrower than the lead tab and the substrate tab.

[0095] The bonding layer (BDL) may include a metal having a low melting point and low resistivity. For example, the bonding layer may include at least one metal selected from the group consisting of indium (In) and tin (Sn). When the bonding layer (BDL) includes a metal having low resistivity, the bonding layer (BDL) has excellent electrical conductivity, thereby enabling the substrate tab (TB) and the lead tab (LTB) to be connected without impeding the current flow of the all-solid-state battery.

[0096] In one embodiment, the resistivity of the metal included in the bonding portion (BDL) may have a value similar to the resistivity of the substrate tab (TB) and / or the lead tab (LTB). In another embodiment, the resistivity of the metal may be smaller than the resistivity of the substrate tab (TB) and larger than the resistivity of the lead tab (LTB). For example, the resistivity of the metal may be 30 nΩ·m to 300 nΩ·m, 40 nΩ·m to 200 nΩ·m, or 50 nΩ·m to 150 nΩ·m. The resistivity of the metal may refer to the resistance value of the metal that appears in unit length and unit area.

[0097] In one embodiment, the resistivity of a metal can be measured using the 4-point probe method. Specifically, four probes are placed on the metal in a straight line at regular intervals, current is applied to the two outermost probes, and the voltage drop between the two middle probes is measured. The measured current and voltage can then be used to calculate the resistivity.

[0098] Referring to Fig. 7b, when the bonding portion (BDL) includes a metal with a low melting point, when the temperature of the battery rises abnormally, the bonding portion (BDL) can cut the connection between the substrate tab (TB) and the lead tab (LTB), thereby blocking the current. This can ensure the stability of the battery.

[0099] Meanwhile, in the case of all-solid-state batteries, since the internal temperature of the cell may be higher on average compared to a typical lithium-ion battery, the melting point of the metal should not be excessively low and must have a melting point above a certain temperature. For example, the melting point of the metal included in the bonding layer (BDL) may be 120°C to 250°C, 140°C to 240°C, or 150°C to 200°C. The melting point of a metal may refer to a specific temperature at which the metal begins to change from a solid state to a liquid state. For example, the melting point of a metal can be measured by thermal analysis methods such as Differential Scanning Calorimetry (DSC) and Microscopic Thermal Analysis.

[0100] When the melting point of the metal satisfies the above-described range, the bonding layer (BDL) can interrupt the current inside the battery before the polymer layer of the pouch (PCH) melts at high temperatures and a short circuit occurs, while not interfering with the operation of the battery at normal battery operating temperatures.

[0101] As described above, all-solid-state batteries can have higher internal cell temperatures than lithium-ion batteries, exceeding 170°C. In this case, even if the thermal stability of the cell itself is high, the polymer layer of the pouch (PCH) can melt, which can cause problems.

[0102] Specifically, the molten polymer layer may have fluidity, and thus, no polymer layer may exist between the metal layer and the second electrode current collector (PLT2). For example, the molten polymer layer may flow from between the metal layer and the second electrode current collector (PLT2) to the outside of the metal layer or the second electrode current collector (PLT2). Accordingly, the metal layer and the second electrode current collector (PLT2) may be electrically connected in some areas. In other words, the metal layer and the second electrode current collector (PLT2) may come into contact with each other in some areas and be electrically connected to each other.

[0103] The first lead tab (LTB1) illustrated in Fig. 6 may also become electrically connected to the metal layer as the polymer layer melts. This may result in a short circuit between the first lead tab (LTB1) and the second electrode current collector (PLT2), which have different polarities, through the metal layer. Consequently, this could lead to accidents such as battery explosion or fire.

[0104] If a low-melting-point bonding layer (BDL) is formed between the substrate tab (TB) and the lead tab (LTB), the BDL may cause a short circuit inside the battery before the polymer layer of the pouch (PCH) melts. In other words, the BDL can ensure battery stability by interrupting current inside the battery before the polymer layer melts and a short circuit occurs.

[0105] The bonding layer (BDL) must interrupt the current before a short circuit occurs, but the melting point of the metal included in the bonding layer does not necessarily need to be lower than the melting point of the polymer layer. This is because the polymer layer is composed of a polymer with low thermal conductivity and does not immediately melt at temperatures above 170°C, whereas the bonding layer (BDL) contains a metal with high thermal conductivity and can immediately undergo a phase change to a liquid state at temperatures above its melting point. The heat transfer rate of the polymer layer can vary depending on the type of cell, output, etc. Therefore, by considering the above factors, a metal with an appropriate melting point can be selected so that the bonding layer can melt before the polymer layer is completely melted.

[0106] In one embodiment, the thickness of the bonding portion (BDL) may be 10 μm to 500 μm, 50 μm to 300 μm, or 50 μm to 200 μm. When the thickness of the bonding portion (BDL) satisfies the above-described range, the bonding portion (BDL) can sufficiently block current without interfering with the current flow of the battery.

[0107] The bonding portion can be formed, in particular, between the negative electrode substrate tab and the negative electrode lead tab. In an all-solid-state battery, stainless steel (SUS), which has low reactivity with solid electrolytes, can be used as the negative electrode current collector and negative electrode substrate tab, but stainless steel has high electrical resistance. Therefore, when stainless steel is used as the negative electrode substrate tab, the negative electrode substrate tab can have higher resistance than the materials of the positive electrode substrate tab, positive lead tab, and negative electrode lead tab.

[0108] When stainless steel is used as the negative substrate tab, a significant resistance deviation can occur at the interface between the negative substrate tab and the negative lead tab. In this case, if a large current flows within the battery within a short period of time due to an external short circuit, nail penetration, or local crush, the current can become a bottleneck between the negative substrate tab and the negative lead tab, causing a rapid change in resistance. This can lead to localized heating, which can lead to excessive battery temperature rises and even ignition.

[0109] The pouch-type all-solid-state battery according to the present invention can prevent localized heating, such as the above, by arranging a low-melting-point joint between the negative electrode substrate tab and the negative electrode lead tab. In other words, the joint can ensure battery safety by interrupting current before the heating between the negative electrode substrate tab and the negative electrode lead tab becomes severe, leading to ignition or damage to the pouch.

[0110]

[0111] Figure 9 is a flowchart illustrating a method for manufacturing an all-solid-state battery according to embodiments of the present invention. Hereinafter, a method for manufacturing an all-solid-state battery according to embodiments of the present invention will be described with reference to Figure 9.

[0112] A method for manufacturing a pouch-type all-solid-state battery may include forming a pouch film (S100); forming an electrode assembly (S200); and packaging the electrode assembly with the pouch film to form a battery (S300).

[0113] The step of forming a pouch film (S100) may include a step of preparing a metal layer and a step of laminating a polymer layer on the metal layer.

[0114] Specifically, a metal layer in the form of a film can be prepared to manufacture a pouch for a battery. The metal layer can maintain mechanical strength and have flexibility. The metal layer can include aluminum (Al). In addition to aluminum, the metal layer can include one or more metals selected from the group consisting of iron (Fe), carbon (C), chromium (Cr), manganese (Mn), and nickel (Ni). Aluminum (Al) can be included in an amount of 90 wt% to 99.9 wt% based on the total mass of the metal layer. A metal layer having a constant width in a first direction (D1) can be provided. The metal layer having a constant width in the first direction (D1) can be prepared in a long form in a roll shape. The width in the first direction (d1) can be adjusted according to the size of a pouch to be manufactured. The width of the metal layer in the first direction (d1) can be the same as the width of the pouch-type all-solid-state battery to be manufactured in the first direction (d1).

[0115] A roll-shaped metal layer is positioned on equipment that advances in one direction, and the wound metal layer can be unwound. A step of forming a polymer layer on the unwinding metal layer can be performed. The polymer layer can include one or more polymer resins selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, polyarylate, and Teflon. In particular, a polyolefin resin such as polypropylene (PP) or polyethylene (PE) can be used. The polymer layer can be formed by laminating by applying the polymer resin on the metal layer. Or, it can be formed by coating.

[0116]

[0117] Thereafter, a step (s200) of manufacturing an electrode assembly may be performed. The step (s200) of manufacturing an electrode assembly may include: forming a unit cell by stacking a positive electrode, a solid electrolyte layer, and a negative electrode; providing a joint between a substrate tab and a lead tab of the negative electrode; and electrically connecting the substrate tab and the lead tab by welding the substrate tab and the lead tab.

[0118] The step of manufacturing a unit cell may include a process of laminating a positive electrode, a negative electrode, and a solid electrolyte layer between the positive electrode and the negative electrode. In one embodiment, the unit cell may be in a form in which a positive electrode, a solid electrolyte layer, and a negative electrode are sequentially laminated. In another embodiment, the unit cell may be in a form in which a negative electrode (positive electrode), a solid electrolyte layer, a positive electrode (negative electrode), a solid electrolyte layer, and a negative electrode (negative electrode) are sequentially laminated. In this case, the positive electrode, the negative electrode, and the solid electrolyte layer may be laminated with different areas. By laminating the above-described unit cells, an electrode assembly including a plurality of unit cells can be formed.

[0119] During the process of laminating the positive and negative electrodes, the direction of the substrate tabs connected to each electrode can be set. For example, the positive and negative substrate tabs can be laminated so that they face opposite directions relative to the first direction (d1). As another example, the positive and negative substrate tabs can be laminated so that they face the same direction relative to the first direction (d1).

[0120] A joint including a metal may be provided between a negative electrode substrate tab and a negative electrode lead tab. The joint may include a metal having a low melting point and a low resistivity. In one embodiment, the melting point of the metal may be 120°C to 250°C, 140°C to 240°C, or 150°C to 200°C, and the resistivity of the metal may be 30 nΩ·m to 300 nΩ·m, 40 nΩ·m to 200 nΩ·m, or 50 nΩ·m to 150 nΩ·m. For example, the metal included in the joint may be indium (In) and / or tin (Sn).

[0121] The negative electrode base tab and the negative electrode lead tab can then be electrically connected by welding. The welding method is not particularly limited, and methods such as ultrasonic welding, laser welding, and spot welding can be used.

[0122] Separately from the cathode, multiple anode substrate tabs can be electrically connected by welding them to the anode lead tab. Similar to the cathode, the welding method can include ultrasonic welding, laser welding, and spot welding.

[0123] Finally, a battery assembly step (S300) may be performed. The battery assembly step may include a step of moving the manufactured electrode assembly onto a pouch and a step of packaging the electrode assembly into the pouch.

[0124]

[0125] The present invention may encompass not only the embodiments described above, but also embodiments that are simply designed or easily modified. Furthermore, the present invention may encompass techniques that can be easily modified and implemented using the embodiments described above. Therefore, the scope of the present invention should not be limited to the embodiments described above, but should be defined not only by the following claims but also by their equivalents.

Claims

1. An assembly comprising a positive electrode, a solid electrolyte layer, and a negative electrode; A first substrate tab protruding from the above anode; A second substrate tab protruding from the above cathode; A first lead tab electrically connected to the first substrate tab; A second lead tab electrically connected to the second substrate tab; A connecting portion provided between the first substrate tab and the first lead tab, and between the second substrate tab and the second lead tab; and Including a pouch outer material accommodating the above assembly, The first and second lead tabs are exposed to the outside of the pouch outer material, The above-mentioned bonding part is an all-solid-state battery including a metal having a melting point lower than 250°C.

2. In paragraph 1, All-solid-state battery with a melting point of the above metal higher than 120°C 3. In paragraph 1, An all-solid-state battery having a resistivity of the above metal of 50 nΩ·m to 150 nΩ·m.

4. In paragraph 1, An all-solid-state battery wherein the metal comprises at least one of indium (In) and tin (Sn).

5. In paragraph 1, An all-solid-state battery wherein the thickness of the above-mentioned joint is 10㎛ to 500㎛.

6. In paragraph 1, The above pouch outer material includes a polymer layer and a metal layer, An all-solid-state battery having a melting point of the polymer layer lower than 200°C.

7. In paragraph 6, An all-solid-state battery wherein the polymer layer comprises a polymer having a melting point of 140°C to 160°C.

8. In paragraph 1, An all-solid-state battery in which the connecting portion is provided between the second substrate tab and the second lead tab.

9. In paragraph 8, The above second substrate tab comprises stainless steel (SUS), An all-solid-state battery, wherein the second lead tab comprises a metal having a lower resistivity than the stainless steel.

10. An assembly comprising a positive electrode, a solid electrolyte layer, and a negative electrode; A first substrate tab protruding from the above anode; A second substrate tab protruding from the above cathode; A first lead tab directly connected to the first substrate tab; A second lead tab electrically connected to the second substrate tab; A joint formed between the second substrate tab and the second lead tab; and Including a pouch outer material accommodating the above assembly, An all-solid-state battery, wherein the above-mentioned joint is configured to disconnect the electrical connection between the second substrate tab and the second lead tab at a temperature between 120°C and 250°C.

11. In paragraph 10, The above-mentioned bonding member is an all-solid-state battery comprising a metal having a melting point of 150°C to 240°C.

12. In paragraph 10, An all-solid-state battery wherein the above bonding member comprises at least one of indium (In) and tin (Sn).

13. In paragraph 10, An all-solid-state battery having a resistivity of the above-mentioned joint of 50 nΩ·m to 150 nΩ·m.

14. In paragraph 10, An all-solid-state battery wherein the thickness of the above-mentioned joint is 10 ㎛ to 500 ㎛.

15. In paragraph 10, The above pouch outer material includes a polymer layer and a metal layer, An all-solid-state battery having a melting point of the polymer layer lower than 200°C.

16. In paragraph 15, An all-solid-state battery wherein the polymer layer comprises a polymer having a melting point of 140°C to 160°C.

17. Manufacturing pouch film; Manufacturing an electrode assembly; and Comprising packaging the electrode assembly with the above pouch film to form an all-solid-state battery, Manufacturing the above electrode assembly: Forming a unit cell by laminating an anode, a solid electrolyte layer, and a cathode; Providing a joint between the substrate tab and the lead tab of the above cathode; and Including electrically connecting the substrate tab and the lead tab by welding the substrate tab and the lead tab, A method for manufacturing an all-solid-state battery, wherein the above-mentioned bonding part includes a metal having a melting point lower than 250°C.

18. In paragraph 17, A method for manufacturing an all-solid-state battery wherein the resistivity of the above metal is 50 nΩ·m to 150 nΩ·m.

19. In paragraph 17, A method for manufacturing an all-solid-state battery, wherein the metal comprises at least one of indium (In) and tin (Sn).

20. In paragraph 17, The above-described tab is a method for manufacturing an all-solid-state battery including stainless steel (SUS).

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