Pouch film comprising insulating layer, all-solid-state battery comprising same, and method for manufacturing same

Abstract

The present invention relates to an all-solid-state battery and a method for manufacturing same and, more specifically, to an all-solid-state battery comprising: an electrode assembly in which at least one unit cell is stacked; and a pouch for packaging the electrode assembly. The unit cell includes a positive electrode, a negative electrode, and a solid electrolyte between the positive electrode and the negative electrode, and the pouch includes an insulating layer and a metal layer on the insulating layer, the insulating layer containing a polymer resin and a heat absorbing material dispersed in the polymer resin, wherein the endothermic initiation temperature of the heat absorbing material is 170°C to 300°C.

Description

Pouch film including an insulating layer, all-solid-state battery including the same, 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] Recent industrial demands have led to the active development of batteries with high energy density and stability. 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.

[0003] Recently, all-solid-state batteries, which replace the electrolyte with a solid electrolyte, have been proposed. By eliminating the use of flammable organic dispersion media, 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.

[0004] Conventional pouch-type batteries are prone to thermal and mechanical damage. This can lead to short circuits, potentially resulting in fire or explosion.

[0005] The problem to be solved by the present invention is to provide a pouch-type all-solid-state battery with improved stability.

[0006] 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.

[0007] An 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; and a pouch for packaging the electrode assembly. The unit cell includes a positive electrode, a negative electrode, and a solid electrolyte between the positive electrode and the negative electrode, and the pouch includes an insulating layer and a metal layer on the insulating layer, and the insulating layer includes a polymer resin and a heat absorbing material dispersed within the polymer resin, and the heat absorbing material may have an absorption start temperature of 170°C to 300°C.

[0008] According to another concept of the present invention, an all-solid-state battery may include an electrode assembly in which at least one unit cell is stacked; a lead tab electrically connected to the unit cell; and a pouch for packaging the electrode assembly. The unit cell includes a first electrode, a second electrode having a different polarity from the first electrode, and a solid electrolyte between the first and second electrodes. The unit cell may further include a first substrate tab extending from the first electrode and a second substrate tab extending from the second electrode, and the lead tab may include a first lead tab connected to the first substrate tab and extending to the outside of the pouch, and a second lead tab connected to the second substrate tab and extending to the outside of the pouch. The pouch may include a metal layer and an insulating layer on the insulating layer, wherein the insulating layer includes a polymer resin, and the insulating layer may be in contact with the first lead tab in a first bonding region. In the first bonding region, the insulating layer further includes a heat absorbing material dispersed within the polymer resin, and in the first bonding region, the volume ratio of the heat absorbing material within the polymer resin may be 10% to 50%.

[0009] A method for manufacturing an 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 form a battery. The manufacturing of the pouch film may include: melting a polymer resin; adding a heat absorbing material to the molten polymer resin; forming an insulating layer with the polymer resin to which the heat absorbing material has been added; laminating the insulating layer on a metal layer; and laminating the metal layer and the insulating layer. An absorption initiation temperature of the heat absorbing material may be higher than a temperature of the molten polymer resin.

[0010] According to one embodiment of the present invention, an insulating layer is formed on a pouch film for an all-solid-state battery, thereby providing a pouch-type all-solid-state battery with improved stability.

[0011] According to one embodiment of the present invention, a method for manufacturing an all-solid-state battery with improved mass productivity and processability can be provided.

[0012] Figure 1 is a cross-sectional diagram schematically illustrating an all-solid-state battery.

[0013] Figure 2 is a plan view of an all-solid-state battery according to one embodiment.

[0014] Figure 3 is a cross-sectional view taken along line A-A' of Figure 2.

[0015] Figure 4 is a cross-sectional view of an all-solid-state battery unit cell according to one embodiment.

[0016] Figure 5 is a cross-sectional view of a pouch-type all-solid-state battery according to one embodiment.

[0017] Figure 6 is an enlarged view of area M of Figure 5.

[0018] Figure 7a is a schematic diagram for explaining the shape during operation of a comparative example in which a heat absorbing material (HAM) is not provided.

[0019] Figure 7b is an enlarged view of the N region of Figure 6.

[0020] Figure 8 is a cross-sectional view of a pouch-type all-solid-state battery according to one embodiment.

[0021] Figure 9a is an enlarged view of the X area of ​​Figure 8.

[0022] Figure 9b is an enlarged view of the Y region of Figure 8.

[0023] Figure 10 is a flowchart illustrating a method for manufacturing an all-solid-state battery according to embodiments of the present invention.

[0024] Figures 11 and 12 are schematic diagrams for explaining the third step of Figure 10.

[0025] Figure 13 is a perspective view of an all-solid-state battery according to one embodiment.

[0026] Figure 14 is an enlarged view of area O of Figure 13.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. Unless otherwise specified herein, the singular may also include the plural. Furthermore, unless otherwise specified, "A or B" may mean "including A, including B, or including A and B." As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components.

[0031] 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.

[0032] 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.

[0033] 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).

[0034] 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.

[0035] 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.

[0036] 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).

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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).

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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).

[0057] 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.

[0058] 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.

[0059] 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).

[0060] 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.

[0061] 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).

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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).

[0066] 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.

[0067] 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.

[0068] 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).

[0069] 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).

[0070] 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).

[0071] 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).

[0072] 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).

[0073] 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).

[0074] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

[0075] FIG. 5 is a cross-sectional view of a pouch-type all-solid-state battery (400) according to one embodiment of the present invention. Referring to FIG. 5, the pouch-type all-solid-state battery (400) may refer to a form in which an all-solid-state battery (10) is packaged in a pouch (PCH). More specifically, it may refer to a form in which an electrode assembly in which at least one unit cell is stacked is packaged in a pouch (PCH). In the present specification, a unit cell may refer to a basic unit including components constituting a cell. Referring to FIGS. 4 and 5, the 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 or / and a first electrode active material layer formed on the first electrode current collector (PLT1). In one embodiment, the unit cell may include a positive electrode, a negative electrode, and a solid electrolyte layer between the positive and negative electrodes. For example, it may be in the form of a sequentially stacked structure of a cathode, a solid electrolyte layer, an anode, a solid electrolyte layer, and a cathode.

[0076] 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). The lead tab (LTB) may be electrically connected to the substrate tab (TB) and may protrude outside the pouch. The lead tab (LTB) may be configured to electrically connect the electrode assembly (STC) to the outside of the pouch. The pouch (PCH) may package the electrode assembly and protect and shield the electrode assembly (STC) from the outside. An all-solid-state battery packaged in a pouch may be used as an independent unit battery. A plurality of pouch-type all-solid-state batteries (400) may be combined to form a battery module (Module). A plurality of battery modules (Modules) may be combined to form a battery pack (Pack). A pouch-type battery has a relatively simple configuration and can be reduced in volume and weight. In addition, it is flexible and can be manufactured in various shapes.

[0077] Fig. 6 is an enlarged view of the M region of Fig. 5. Referring to Fig. 6, an electrode current collector (PLT2) and a pouch (PCH) may be in contact. The pouch (PCH) may include a metal layer (MFL) and an insulating layer (ISL) formed on the metal layer (MFL). In one embodiment, the pouch (PCH) may include a metal layer (MFL) and an insulating layer (ISL) formed on one side of the metal layer (MFL) or on both sides of the metal layer (MFL).

[0078] Each of the metal layer (MFL) and the insulating layer (ISL) may have a certain thickness range. The thickness of the pouch (PCH) may refer to the thickness of the metal layer (MFL), the insulating layer (ISL), and the entire thickness of the insulating layer (ISL). In one embodiment, the thickness of the pouch (PCH) may be 50 μm to 300 μm.

[0079] The metal layer (MFL) may include a metal that maintains mechanical strength and has flexibility. For example, the metal layer (MFL) may include aluminum (Al). In addition to aluminum, 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 wt% to 99.9 wt% based on the total mass of the metal layer (MFL). A metal layer (MFL) having a thickness of 20 μm to 150 μm, or 30 μm to 120 μm, may be provided.

[0080] The insulating layer (ISL) may be a layer having a uniform thickness. In one embodiment, the thickness (STK) of the insulating layer (ISL) may be 10 μm to 150 μm. The insulating layer (ISL) may include a polymer resin (PMR) and a heat absorbing material (HAM) within the polymer resin (PMR).

[0081] Referring to FIG. 6, the insulating layer (ISL) may be in the form of a heat absorbing material (HAM) dispersed within a polymer resin (PMR). For example, the polymer resin (PMR) may include polypropylene. However, the present invention is not limited thereto, and the polymer resin (PMR) may include at least one polymer having insulating properties. For example, the polymer resin (PMR) 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. The melting point of the polymer resin (PMR) may be 170°C or lower.

[0082] Heat absorbing materials (HAM) are Al(OH)3, Mg5(CO3)4(OH)2·4H2O, NaAl(OH)2CO3, Mg(OH)2, MgO·CO 2(0.96) H2O (0.3) , AlO(OH), Ca(OH)2. The heat absorbent (HAM) may collectively refer to heat absorbent particles having a spherical, plate-like, and needle-like shape. However, the present invention is not limited thereto, and the type and shape of the material constituting the heat absorbent particles may not be limited to the above types. The average particle diameter (D50) of the heat absorbent (HAM) may be 0.1 μm to 10 μm. The volume ratio of the heat absorbent (HAM) within the polymer resin (PMR) may be 10% to 50%. In other words, the volume ratio of the heat absorbent (HAM) to the insulating layer (ISL) may be 10% to 50%.

[0083] The endothermic onset temperature of the heat absorbing material (HAM) may be higher than the melting point of the polymer resin (PMR). For example, the endothermic onset temperature of the heat absorbing material (HAM) may be 170°C to 300°C. As used herein, the endothermic onset temperature refers to the temperature at which the endothermic reaction of the heat absorbing material (HAM) begins to initiate, and the endothermic onset temperature can be measured by a method widely known to those skilled in the art. For example, the endothermic onset temperature may be an average value measured by differential scanning calorimetry (DSC).

[0084] Since the pouch (PCH) includes an insulating layer (ISL), the metal layer (MFL) can be prevented from being damaged by friction, impact, etc. from the outside. In addition, the insulating layer (ISL) can prevent the metal layer (MFL) from directly contacting the electrode assembly and can have insulating properties. The insulating layer (ISL) can be applied to both surfaces of the metal layer (MFL). For example, the pouch (PCH) can include a first insulating layer formed on a lower surface of the metal layer (MFL) and a second insulating layer formed on an upper surface of the metal layer (MFL). The material forming the first insulating layer can be the same as the material forming the second insulating layer. However, the present invention is not limited thereto, and the first and second insulating layers can include different polymer resins (PMR) and heat absorbing materials (HAM), respectively.

[0085] In addition, the heat absorbing material (HAM) may be provided only on the insulating layer (ISL) on either side of the metal layer (MFL). For example, the first insulating layer may include a polymer resin (PMR) and a heat absorbing material (HAM) within the polymer resin (PMR), and the second insulating layer may be formed only of the polymer resin (PMR). Hereinafter, for convenience of explanation, it is assumed that an insulating layer (ISL) formed of a polymer resin (PMR) including a heat absorbing material (HAM) is applied to both sides of the metal layer (MFL), and the first and second insulating layers are collectively referred to as insulating layers (ISL).

[0086] The heat absorbing material (HAM) can be dispersed within the polymer resin (PMR) to increase the melting point of the insulating layer (ISL) and enhance mechanical strength. The melting point of the insulating layer (ISL) can be 200°C or higher to ensure sufficient heat resistance. Since the insulating layer (ISL) has a high melting point due to the heat absorbing material (HAM), even when the battery is operated at a high temperature higher than the melting point of the polymer resin (PMR), the insulating layer (ISL) does not melt, and the insulating layer (ISL) can physically separate the metal layer (MFL) and the second electrode current collector (PLT2). Accordingly, 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.

[0087] Fig. 7a is a schematic diagram for explaining a phenomenon that may occur during operation of a pouch-type all-solid-state battery (400), and illustrates a comparative example in which a heat absorbing material (HAM) is not provided within the insulating layer (ISL) of the pouch (PCH). Fig. 7b is an enlarged view of the N region of Fig. 6 for explaining a phenomenon that may occur during operation of a pouch-type all-solid-state battery (400). It is a schematic diagram for explaining a phenomenon that may occur during operation of a pouch-type all-solid-state battery (400). Figs. 7a and 7b illustrate a state in which the internal temperature of the cell of the comparative example exceeds 170°C.

[0088] Although not shown, for the convenience of the following description, the insulating layer of the comparative example without the heat absorbing material (HAM) is referred to as a polymer layer (PML). The polymer layer (PML) may refer to a layer composed of a polymer resin (PMR) as described with reference to Fig. 6. In other words, the insulating layer (ISL) described with reference to Fig. 6 may be the same as one that does not include the heat absorbing material (HAM).

[0089] In the case of an all-solid-state battery, the internal temperature of the cell may be higher on average compared to a typical lithium-ion battery. For example, unlike a lithium-ion battery, the internal temperature of an all-solid-state battery may exceed 170°C. Even if the thermal stability of the cell is high, the temperature may exceed the melting point of the polymer layer (PML) within the pouch (PCH). That is, the polymer layer (PML) of the pouch (PCH) may melt. The polymer layer (PML) may melt and have fluidity. Accordingly, referring to FIG. 7a, the polymer layer (PML) may not exist between the metal layer (MFL) and the second electrode current collector (PLT2). For example, the molten polymer layer (PML) may flow from between the metal layer (MFL) and the second electrode current collector (PLT2) to the outside of the metal layer (MFL) or the second electrode current collector (PLT2). Accordingly, the metal layer (MFL) and the second electrode current collector (PLT2) may be electrically connected in some areas. For example, the metal layer (MFL) and the second electrode current collector (PLT2) may be in contact with each other in some areas.

[0090] The metal layer (MFL) of the pouch (PCH) and the second electrode current collector (PLT2) may be electrically connected to each other. The first lead tab (LTB1) illustrated in Fig. 5 may also be electrically connected to the metal layer (MFL) as the polymer layer (PML) melts. A short circuit may occur in which the first lead tab (LTB1) and the second electrode current collector (PLT2), which have different polarities, are connected to each other through the metal layer (MFL). Consequently, this may lead to accidents such as battery explosion and fire.

[0091] However, referring to FIG. 7b, the pouch (PCH) according to the present invention may include an insulating layer (ISL) that physically separates the metal layer (MFL) and the second electrode current collector (PLT2) even at high temperatures. For example, since the insulating layer (ISL) has a high melting point due to the heat absorbing material (HAM), the metal layer (MFL) and the second electrode current collector (PLT2) can be stably separated even when the battery is operated at a high temperature of 170°C or higher. Accordingly, 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.

[0092] Referring to FIG. 8, a pouch (PCH) according to embodiments of the present invention may be provided with an insulating layer (ISL) including a heat absorbing material (HAM) only in some areas. For example, in a pouch packaging an electrode assembly, the heat absorbing material (HAM) may be provided only in some areas where the stability of the insulating layer (ISL) is vulnerable. In one embodiment, the insulating layer (ISL) of the pouch (PCH) may locally include a heat absorbing material (HAM) only in a portion that contacts the lead tab (LTB).

[0093] The electrode assembly may include a second electrode disposed on the uppermost or lowermost layer and in contact with the pouch. That is, the second electrode 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 a positive electrode and the second electrode may be a negative electrode, but the present invention is not limited thereto. Each of the first electrode and the second electrode may include a substrate tab (TB) that is electrically connected and extends in one direction.

[0094] The substrate tab (TB) can be electrically connected to the lead tab (LTB). A single lead tab (LTB) can be electrically connected to multiple substrate tabs (TB). For example, the 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.

[0095] In order to make the welding between the electrode and the lead tab (LTB) more solid, a metal chip may be added between the electrode and the lead tab (LTB). The metal chip may be a thin piece of the same material as the substrate tab (TB). For example, the metal chip may be a metal foil, a metal mesh, etc. For example, the metal chip may be an aluminum foil, a copper foil, a SUS foil, etc. In other words, it may be the same material as the electrode current collector. The thickness of the metal chip may be, for example, 2 µm to 10 µm, 2 µm to 7 µm, or 4 µm to 6 µm. By having a thickness in this range, the connection with the lead tab (LTB) can be performed more easily.

[0096] 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).

[0097] The 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 to the first substrate tab (TB1) and may extend to the outside of the pouch (PCH) along a first direction. The second lead tab (LTB2) may be connected to the second substrate tab (TB2) and may extend to the outside of the pouch (PCH) along a direction opposite to the first direction. However, the present invention is not limited thereto, and the first substrate tab (TB1) and the second substrate tab (TB2) may extend in the same direction, and the first lead tab (LTB2) and the second lead tab (LTB2) may also extend in the same direction.

[0098] 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. In this specification, the area of ​​the pouch (PCH) that is in contact with the pouch (PCH) and the first lead tab (LTB1) may be referred to as the first bonding area (A1), and the area of ​​the pouch (PCH) that is in contact with the second lead tab (LTB2) may be referred to as the second bonding area (A2).

[0099] Fig. 9a is an enlarged view of the X region of Fig. 8, and Fig. 9b is an enlarged view of the Y region of Fig. 8. Referring to Fig. 9a, in the case of the X region in contact with the electrode assembly, the pouch (PCH) may not include a heat absorbing material (HAM). For example, in the X region, the pouch (PCH) may be provided with a polymer layer (PML) on both sides of the metal layer (MFL). In contrast, referring to Fig. 9b, in the case of the Y region in contact with the lead tab (LTB), the pouch (PCH) may include a heat absorbing material (HAM). For example, the insulating layer (ISL) of the pouch (PCH) in the Y region may be substantially the same as or similar to that described with reference to Fig. 6.

[0100] The pouch (PCH) may include a heat absorbing material (HAM) in at least one of the areas in contact with the first and second lead tabs (LTB1, LTB2). For example, although not shown, an insulating layer (ISL) may be provided on both sides of a metal layer (MFL) in a first bonding area (A1) in which the pouch (PCH) is in contact with the first lead tab (LTB1), whereas a polymer layer (PML) may be provided on both sides of the metal layer (MFL) in a second bonding area (A2) in contact with the second lead tab (LTB2). Referring to FIG. 8, the first lead tab (LTB1) and the second lead tab (LTB2) may be arranged in opposite directions. For example, when the first lead tab (LTB1) and the second lead tab (LTB2) are arranged in opposite directions, electrical contact can be prevented even if the insulating layer (ISL) includes the heat absorbing material (HAM) only in the area including the first bonding area (A1). Even if a part of the polymer layer (PML) of the pouch (PCH) is damaged, the insulating layer (ISL) including the heat absorbing material (HAM) is formed in the first bonding area (A1) that is electrically connected to the first electrode, thereby preventing a short circuit.

[0101] More specifically, even if the polymer layer (PML) is melted and the second electrode current collector (PLT2) and the metal layer (MFL) of the pouch (PCH) come into contact, the first lead tab (LTB1) connected to the first electrode inside the cell is in contact with the first junction area (A1) where the insulating layer (ISL) is formed, so that a short circuit can be prevented. By preventing the second electrode, which is arranged on the uppermost layer and / or the lowermost layer of the electrode assembly and is in direct contact with the pouch, the first electrode having the opposite polarity, and the metal layer (MFL) of the pouch (PCH) from being electrically connected, an electrical short circuit can be prevented. Therefore, unintended electrical connection can be prevented, so that the stability of the battery can be improved.

[0102] In addition, a pouch-type all-solid-state battery having high stability can be provided without reducing the adhesive strength of the pouch (PCH). Specifically, an insulating layer (ISL) including a heat absorbing material (HAM) may have lower adhesive strength than a polymer layer (PML) not including a heat absorbing material (HAM). For example, the heat absorbing material (HAM) may weaken the adhesive strength of the insulating layer (ISL) to the metal layer (MFL) or the adhesive strength between the insulating layers (ISL) and each other. Accordingly, when the insulating layer (ISL) is provided over the entire area of ​​the pouch (PCH), the adhesive strength between the lower pouch (LPCH) and the upper pouch (UPCH) may be reduced in the shaded area (see FIG. 13), which is the area where the lower pouch (LPCH) and the upper pouch (UPCH) are joined. However, according to one embodiment of the present invention, a heat absorbing material (HAM) is provided within the insulating layer (ISL) only in the first and / or second bonding areas (A1, A2) where electrodes of different polarities can be electrically connected, and a polymer layer (PML) can be provided on both sides of the metal layer (MFL) in other areas. Accordingly, a highly stable pouch can be provided without reducing the adhesive strength in the contact area between pouches (PCH).

[0103] The present invention is not limited to the above embodiments, and may include all embodiments that share the same problem-solving principle. For example, contrary to the above embodiments, it is also possible to provide the insulating layer (ISL) in an area excluding the first and second bonding areas (A1, A2) where the lead tab (LTB) and the pouch (PCH) are in contact. In addition, when the heat absorbing material (HAM) is provided in the entire area of ​​the pouch (PCH), the volume ratio of the heat absorbing material (HAM) may vary depending on the area. For example, the volume ratio of the heat absorbing material (HAM) in the first and / or second bonding areas (A1, A2) may be different from the volume ratio of the heat absorbing material (HAM) in an area excluding the first and / or second bonding areas (A1, A2). The volume ratio of the heat absorbing material (HAM) in each area may be 10% to 50%.

[0104] FIG. 10 is a flowchart illustrating a method for manufacturing an all-solid-state battery according to embodiments of the present invention. Referring to FIG. 10, the method for manufacturing an all-solid-state battery according to embodiments of the present invention may include a first step (S100) of manufacturing a pouch film, a second step (S200) of manufacturing an electrode assembly, and a third step (S300) of assembling a battery. Through the above-described manufacturing steps, a pouch-type all-solid-state battery with an improved stability structure can be manufactured. In addition, the mass productivity of the all-solid-state battery according to embodiments of the present invention can be further improved.

[0105] The step (S100) of manufacturing a pouch film may include a step of preparing each of a metal layer (MFL) and an insulating layer (ISL), and a step of laminating the insulating layer (ISL) on the metal layer (MFL).

[0106] Specifically, a metal layer (MFL) in a film form can be prepared to manufacture a battery pouch. The metal layer (MFL) can maintain mechanical strength and have flexibility. The metal layer (MFL) can include aluminum (Al). In addition to aluminum, the metal layer (MFL) 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 (MFL). A metal layer (MFL) having a constant width with respect to a first direction (D1) can be provided. The metal layer (MFL) having a constant width with respect to the first direction (D1) can be prepared in a long form of a roll. The width in the first direction (D1) can be adjusted according to the size of a pouch to be manufactured. The width in the first direction (D1) of the metal layer (MFL) may be the same as the width in the first direction (D1) of the manufactured pouch-type all-solid-state battery.

[0107] A roll-shaped metal layer (MFL) is positioned on a device that advances in one direction, and the wound metal layer (MFL) can be unwound. An insulating layer (ISL) in a film form can be prepared to manufacture a battery pouch. For example, a polymer resin (PMR) including at least one polymer having insulating properties can be prepared. For example, the polymer resin (PMR) can include polypropylene. The polymer resin (PMR) can be melted. An absorbent material (HAM) can be added to the molten polymer resin (PMR) at a temperature higher than the melting point of the polymer resin (PMR) and lower than the endothermic initiation temperature of the absorbent material (HAM). The absorbent material (HAM) can be Al(OH)3, Mg5(CO3)4(OH)2·4H2O, NaAl(OH)2CO3, Mg(OH)2, MgO·CO 2(0.96) H2O (0.3), AlO(OH), Ca(OH)2. The heat absorbent (HAM) can be impregnated and dispersed in the molten polymer resin (PMR). The volume ratio of the heat absorbent (HAM) in the polymer resin (PMR) can be 10% to 50%. The polymer resin (PMR) in which the heat absorbent (HAM) is dispersed can be formed into a film to form an insulating layer (ISL).

[0108] An insulating layer (ISL) formed in the form of a film can be laminated on an unwinding metal layer (MFL). The step of manufacturing a pouch film can include a step of disposing the insulating layer (ISL) on both sides or one side of the metal layer (MFL). The position and area of ​​the insulating layer (ISL) disposed on the metal layer (MFL) can vary. For example, a pouch can be manufactured in which the insulating layer (ISL) is formed only in the first bonding area (A1). The insulating layer (ISL) can be laminated on the metal layer (MFL) by a laminating method or a coating method.

[0109] Thereafter, a step (S200) of manufacturing an electrode assembly may be performed. The step (S200) of manufacturing an electrode assembly may include a step of manufacturing a unit cell, a step of stacking the unit cells, and a step of electrically connecting a substrate tab and a lead tab.

[0110] The step of manufacturing a unit cell may include a process of laminating an anode, a cathode, and a solid electrolyte layer between the anode and the cathode. In one embodiment, the unit cell may be in a form in which an anode, a solid electrolyte layer, and a cathode are sequentially laminated. In another embodiment, the unit cell may be in a form in which an anode (anode), a solid electrolyte layer, an anode (cathode), a solid electrolyte layer, and a cathode (cathode) are sequentially laminated. In this case, the anode, the cathode, and the solid electrolyte layer may be laminated with different areas, respectively.

[0111] 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).

[0112] The method may include connecting a plurality of positive electrode substrate tabs to positive lead tabs and connecting a plurality of negative electrode substrate tabs to negative lead tabs. Specifically, the electrodes and substrate tabs may be electrically connected by welding. For example, the electrical connection may be achieved by ultrasonic welding, laser welding, spot welding, or the like.

[0113] The lead tabs can be connected by extending in the direction in which the substrate tabs face. That is, the directions of the positive lead tab and the negative lead tab can be connected in the same way as the directions of the positive substrate tab and the negative substrate tab, respectively. An electrode assembly can be manufactured by stacking a plurality of unit cells manufactured as described above. An elastic layer can be additionally provided between the plurality of unit cells.

[0114] Thereafter, a step of assembling a battery (S300) may be performed. The step of assembling a battery may include a step of moving the manufactured electrode assembly onto a pouch and a step of packaging the electrode assembly into the pouch.

[0115] Referring to FIG. 11, electrode assemblies may be sequentially stacked on a manufactured pouch. More specifically, the electrode assemblies may be stacked on the pouch (PCH) at regular intervals while the manufactured pouch moves in the second direction (D2). Specifically, the electrode assemblies may be provided on the lower pouch (LPCH). In one embodiment, the first lead tab (LTB1) and the second lead tab (LTB2) of the electrode assembly may be arranged to face opposite directions with respect to the first direction (D1).

[0116] Referring to FIG. 12, when electrode assemblies are sequentially stacked and moved on a pouch, a step of the pouch covering the electrode assembly may be performed. Specifically, the upper pouch (UPCH) may be covered on the electrode assembly. The upper pouch (UPCH) and the lower pouch (LPCH) may be the same pouch manufactured in the step of manufacturing the pouch film (S100).

[0117] Fig. 13 is a perspective view illustrating a pouch-type battery manufactured according to one embodiment. Fig. 14 is an enlarged view of area O of Fig. 13. Referring to Figs. 13 and 14, the step of assembling the battery (S300) may include a step of cutting the pouch. The step of cutting the pouch may include cutting the pouch to fit the size of the battery. In other words, the step of cutting the pouch may include a step of packaging the electrode assembly according to the shape and size of the battery being manufactured.

[0118] After the upper and lower pouches are cut to fit the size of the battery being manufactured, a pouch sealing step may be performed. The sealing step may include a step of removing some of the generated gas or moisture. The sealing step may block the electrode assembly from external air or moisture. Through the above process, the electrode assembly may be packaged in a pouch. The pouch sealing may be performed by pressurizing the periphery of the pouch (PCH) at a high temperature. Through the sealing process, some areas of the first lead tab (LTB1) and the second lead tab (LTB2) may be in contact with the pouch (PCH). The area where a part of the first lead tab (LTB1) and the pouch (PCH) are in contact may be a first bonding area (A1). The area where a part of the second lead tab (LTB2) and the pouch (PCH) are in contact may be a second bonding area (A2). The lower pouch (LPCH) and the upper pouch (UPCH) can be in contact with each other at the periphery of the pouch (PCH) excluding the first bonding area (A1) and the second bonding area (A2).

[0119] The method for manufacturing an all-solid-state battery according to the present invention can be implemented in such a way that each step can be performed as a series of continuous processes. According to an embodiment of the present invention, by controlling the area of ​​the insulating layer (ISL) during the pouch manufacturing step, a pouch suitable for the shape and size of the battery can be manufactured. This allows the manufacture of a battery pouch that is suitable for the shape and size of the battery and has improved stability. Consequently, an effective manufacturing method capable of simultaneously achieving mass production and stability of pouch-type batteries can be provided.

Claims

1. An electrode assembly having at least one unit cell stacked thereon; and Including a pouch for packaging the above electrode assembly, The above unit cell includes a positive electrode, a negative electrode, and a solid electrolyte between the positive electrode and the negative electrode, The above pouch includes an insulating layer and a metal layer on the insulating layer, The above insulating layer comprises a polymer resin and a heat absorbing material dispersed within the polymer resin, The heat absorption initiation temperature of the above heat absorbing material is 170°C to 300°C. All-solid-state battery.

2. In paragraph 1, The above solid-state battery further includes a first lead tab electrically connected to the positive electrode and a second lead tab electrically connected to the negative electrode, The pouch includes a first bonding area in contact with the first lead tab and a second bonding area in contact with the second lead tab, The heat absorbing material is selectively provided in at least one of the first bonding area and the second bonding area of ​​the insulating layer. All-solid-state battery.

3. In paragraph 2, The above heat absorbing material is provided in the first bonding area of ​​the insulating layer, The second bonding area of ​​the insulating layer is not provided with the heat absorbing material. All-solid-state battery.

4. In paragraph 1, The average particle size of the above heat absorbing material is 0.1 μm to 10 μm. All-solid-state battery.

5. In paragraph 1, The volume ratio of the heat absorbing material in the polymer resin is 10% to 50%. All-solid-state battery.

6. In paragraph 1, The thickness of the above insulating layer is 10 μm to 150 μm, All-solid-state battery.

7. In paragraph 1, The polymer resin includes polypropylene, All-solid-state battery.

8. In paragraph 1, The above heat absorbents are Al(OH)3, Mg5(CO3)4(OH)2·4H2O, NaAl(OH)2CO3, Mg(OH)2, MgO·CO 2(0.96) H2O (0.3) , containing at least one of AlO(OH), Ca(OH)2, All-solid-state battery.

9. An electrode assembly having at least one unit cell stacked thereon; A lead tab electrically connected to the above unit cell; and An all-solid-state battery comprising a pouch for packaging the above electrode assembly: The unit cell includes a first electrode, a second electrode having a different polarity from the first electrode, and a solid electrolyte between the first and second electrodes, The unit cell further includes a first substrate tab extending from the first electrode, and a second substrate tab extending from the second electrode, The lead tab includes a first lead tab connected to the first substrate tab and extending to the outside of the pouch, and a second lead tab connected to the second substrate tab and extending to the outside of the pouch, The above pouch includes a metal layer and an insulating layer on the metal layer, The above insulating layer comprises a polymer resin, The insulating layer is in contact with the first lead tab in the first bonding area, In the first bonding region, the insulating layer further includes a heat absorbing material dispersed within the polymer resin, In the first bonding region, the volume ratio of the heat absorbing material in the polymer resin is 10% to 50%.

10. In paragraph 9, The second electrode is disposed on at least one of the uppermost and lowermost portions of the electrode assembly, The insulating layer further includes a second bonding region in contact with the second lead tab, In the second bonding area, the insulating layer does not include the heat absorbing material. All-solid-state battery.

11. In paragraph 9, In the remaining area except for the first bonding area, the insulating layer does not include the heat absorbing material. All-solid-state battery.

12. In paragraph 9, The heat absorption initiation temperature of the above heat absorbing material is 170°C to 300°C. All-solid-state battery.

13. In paragraph 9, The average particle size of the above heat absorbing material is 0.1 μm to 10 μm. All-solid-state battery.

14. In paragraph 9, The thickness of the above insulating layer is 10 μm to 150 μm, All-solid-state battery.

15. In paragraph 9, The polymer resin includes polypropylene, All-solid-state battery.

16. In paragraph 9, The above heat absorbents are Al(OH)3, Mg5(CO3)4(OH)2·4H2O, NaAl(OH)2CO3, Mg(OH)2, MgO·CO 2(0.96) H2O (0.3) , containing at least one of AlO(OH), Ca(OH)2, All-solid-state battery.

17. Manufacturing pouch film; Manufacturing an electrode assembly; and Comprising forming a battery by packaging the electrode assembly with the above pouch film, Manufacturing the above pouch film: Melting polymer resin; Adding a heat absorbent to the above molten polymer resin; Forming an insulating layer with a polymer resin to which the above heat absorbing material is added; Laminating the insulating layer on the metal layer; and Including laminating the metal layer and the insulating layer, The heat absorption initiation temperature of the above heat absorbing material is higher than the temperature of the molten polymer resin. Method for manufacturing an all-solid-state battery.

18. In paragraph 17, The volume ratio of the heat absorbing material to the insulating layer is 10% to 50%, Method for manufacturing an all-solid-state battery.

19. In paragraph 17, The above heat absorbents are Al(OH)3, Mg5(CO3)4(OH)2·4H2O, NaAl(OH)2CO3, Mg(OH)2, MgO·CO 2(0.96) H2O (0.3) , containing at least one of AlO(OH), Ca(OH)2, The average particle size of the above heat absorbing material is 0.1 μm to 10 μm. Method for manufacturing an all-solid-state battery.

20. In paragraph 17, The thickness of the above insulating layer is 10 μm to 150 μm, Method for manufacturing an all-solid-state battery.

Images