Pouch film comprising support 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, the pouch includes a polymer layer, a metal layer, and a support layer between the polymer layer and the metal layer, the support layer has a porous structure including a plurality of pores, the melting point of the polymer layer is lower than 170°C, and the melting point of the support layer is higher than 200°C.

Description

A pouch film including a support layer, an all-solid-state battery including the same, and a 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] Recently, driven by industrial demands, the development of batteries with high energy density and stability is actively underway. For example, lithium-ion batteries are being commercialized not only in the fields of information and communication devices but also in the automotive sector. In the automotive sector, safety is considered particularly important because it is directly related to human life.

[0003] Recently, all-solid-state batteries in which liquid electrolytes are replaced with solid electrolytes have been proposed. By not using flammable organic dispersion media, all-solid-state batteries can significantly reduce the likelihood of fire or explosion in the event of a short circuit. Therefore, these all-solid-state batteries can offer significantly higher safety compared to lithium-ion batteries that use liquid electrolytes.

[0004] In pouch-type batteries, conventional pouches have a problem with thermal and mechanical damage. This can lead to short circuits, which may result in fire or explosion.

[0005] The problem that the present invention aims to solve is to provide a pouch-type all-solid-state battery with improved stability.

[0006] Another problem that the present invention aims to solve is to provide a method for manufacturing a pouch-type all-solid-state battery with improved stability.

[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 packing the electrode assembly. The unit cell comprises a positive electrode, a negative electrode, and a solid electrolyte between the positive electrode and the negative electrode, and the pouch comprises a polymer layer, a metal layer, and a support layer between the polymer layer and the metal layer, wherein the support layer has a porous structure comprising a plurality of pores, the melting point of the polymer layer may be less than 170°C, and the melting point of the support layer may be greater than 200°C.

[0008] An all-solid-state battery according to another concept of the present invention may comprise 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 packing the electrode assembly. The unit cell comprises a first electrode, a second electrode having a polarity opposite to that of the first electrode, and a solid electrolyte between the first and second electrodes. The unit cell further comprises a first substrate tab extending from the first electrode and a second substrate tab extending from the second electrode. The lead tab may comprise 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 comprise a first bonding portion in contact with the first lead tab, wherein the first bonding portion may comprise a metal layer, a first polymer layer in contact with the first lead tab, and a first support layer between the metal layer and the first polymer layer. The first support layer has a porous structure including a plurality of pores, and the melting point of the first support layer may be higher than the melting point of the first polymer layer.

[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. Manufacturing the pouch film may include: sequentially laminating a metal layer, a support layer, and a polymer layer; and laminating the metal layer, the support layer, and the polymer layer. The support layer may have a porous structure including a plurality of pores. The melting point of the polymer layer may be less than 170°C, and the melting point of the support layer may be greater than 200°C.

[0010] According to one embodiment of the present invention, a pouch-type all-solid-state battery with improved stability can be provided by forming a support layer on a pouch film for an all-solid-state battery.

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

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

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

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

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

[0016] FIG. 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 the M region of Figure 5.

[0018] Figures 7a and 7b are enlarged views of the N1 region of Figure 6.

[0019] FIG. 7c is a schematic diagram illustrating the shape during operation of an all-solid-state battery in which a support layer (SL) is not provided.

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

[0021] Figure 9 is an enlarged view of the N2 region of Figure 8.

[0022] FIG. 10 is a cross-sectional view of a pouch-type all-solid-state battery according to one embodiment.

[0023] Fig. 11a is an enlarged view of the X-region of Fig. 10.

[0024] Fig. 11b is an enlarged view of the Y region of Fig. 10.

[0025] FIG. 12 is a flowchart illustrating a method for manufacturing an all-solid-state battery according to embodiments of the present invention.

[0026] FIGS. 13 and FIGS. 14 are schematic diagrams for explaining the third step of FIG. 12.

[0027] FIG. 15 is a perspective view of an all-solid-state battery according to one embodiment.

[0028] Figure 16 is an enlarged view of the O area of ​​Figure 15.

[0029] In order to fully understand the structure and effects of the present invention, preferred embodiments of the present invention are described with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and various modifications can be made. The description of these embodiments is provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention.

[0030] In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Additionally, in the drawings, the thicknesses of the components are exaggerated for the effective description of the technical content. Throughout the specification, parts indicated by the same reference numeral represent the same components.

[0031] The embodiments described herein will be described with reference to cross-sectional and / or plan views, which are exemplary illustrations of the invention. In the drawings, the thicknesses of films and regions are exaggerated for effective description of the technical content. Accordingly, the regions illustrated in the drawings are schematic in nature, and the shapes of the regions illustrated in the drawings are intended to illustrate specific forms of regions of the device and are not intended to limit the scope of the invention. Although terms such as first, second, third, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. The embodiments described and illustrated herein also include their complementary embodiments.

[0032] The terms used herein are for describing the embodiments and are not intended to limit the invention. Unless otherwise specified herein, singular forms may also include plural forms. Additionally, unless otherwise specified, "A or B" may mean "comprising A, comprising B, or comprising A and B." As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components to the mentioned components.

[0033] Unless otherwise defined in this specification, the particle size may be the average particle size. Additionally, the particle size refers to the average particle size (D50), which means the diameter of the particle whose cumulative volume in the particle size distribution is 50% by volume. The average particle size (D50) may be measured by methods widely known to those skilled in the art, for example, by measuring with a particle size analyzer, or by measuring with a transmission electron microscope (TEM) image or a scanning electron microscope (SEM) image. Alternatively, the average particle size (D50) value may be obtained by measuring using a measuring device utilizing dynamic light scattering, performing data analysis to count the number of particles for each particle size range, and then calculating from this. Alternatively, it may be measured using a laser diffraction method. When measuring by laser diffraction, more specifically, after dispersing the particles to be measured in a dispersion medium, they are introduced into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000) and irradiated with ultrasound of about 28 kHz at an output of 60 W, and then the average particle size (D50) at 50% of the particle size distribution in the measuring device can be calculated.

[0034] In this specification, the term "melting point" may refer to the temperature at which a substance undergoes a state change from solid to liquid. Specifically, the melting point of a polymer may refer to the temperature at which a polymer sample receives sufficient thermal energy and transitions its crystalline regions to an amorphous state. In the case of polymers, the melting point can be clearly defined only when they possess a crystalline structure. In this case, the melting point of the polymer may represent the temperature at which polymer crystals begin to decompose and arrange themselves randomly. However, polymers may possess a partially crystalline (semicrystalline) structure. Accordingly, the melting point of a polymer may have a melting range rather than a specific temperature. That is, the melting range may refer to the temperature range at which the crystalline regions within the polymer melt and completely transition to an amorphous state, and in this specification, the melting point of a material containing a polymer may encompass the meaning of the melting range.

[0035] Unless otherwise defined, the melting point may be measured by methods widely known to those skilled in the art. For example, it may be measured using a melting point apparatus, a digital thermal analyzer, or differential scanning calorimetry (DSC). Alternatively, it may be measured using hot-stage optical microscopy or thermo-mechanical analysis (TMA).

[0036] More specifically, a differential scanning calorimeter may refer to a thermal analysis device that quantitatively compares the difference in heat between two substances by heating or cooling a sample to be measured at a constant rate under the same conditions as a reference substance. Through this process, changes in the heat absorbed or released by the sample can be measured to obtain a graph of the sample's endothermic / exothermic amounts as a function of temperature. From the graph, the melting point of the sample can be determined by analyzing the endothermic peak resulting from the phase transition from solid to liquid. For example, an endothermic peak may appear in a specific temperature range due to the heat absorbed when a polymer melts, and the temperature range where this peak is located may represent the melting point (melting range) of the polymer.

[0037] More specifically, thermomechanical analysis refers to an analytical method in which the temperature is increased while applying physical deformation to a sample to be measured, and the resulting physical changes in the sample are measured. Through the above process, a graph measuring the deformation of the sample according to the applied load can be obtained. At the melting point, the sample may undergo abrupt changes in volume or mechanical properties. Accordingly, the point in the above graph where abrupt changes in the properties of the sample occur can be assumed to be the melting point.

[0038] As such, melting points can be accurately measured through various experimental methods. The measured value can play an important role in understanding and applying the physical properties of a specific material. For example, the melting point of a material containing a polymer can be a critical physical property that determines the temperature range in which the material can be used. Accordingly, accurately measuring the melting point of such a material can be essential in product design. For instance, the higher the melting point of a polymer, the more stably the material can be used at high temperatures, which can be a significant factor in determining heat resistance and the range of applicable applications.

[0039] 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 along the line A-A' of FIG. 2.

[0040] Referring to FIG. 1, an all-solid-state battery (10) according to one embodiment includes a positive electrode layer (100), a negative electrode layer (200) facing the positive electrode layer (100), and a solid electrolyte layer (300) disposed between the positive electrode layer (100) and the negative electrode layer (200). However, the all-solid-state battery (10) may further include an additional functional layer, such as an adhesion-enhancing layer, disposed between the positive electrode layer (100) and the solid electrolyte layer (300) or between the negative electrode layer (200) and the solid electrolyte layer (300).

[0041] An anode layer (100) of one embodiment includes an anode current collector (110) and an anode active material layer (120) disposed on the anode current collector (110). The anode active material layer (120) may include an anode active material, a solid electrolyte, a conductive material, and a binder.

[0042] The positive current collector (110) can provide a reference surface on which the positive active material layer (120) is placed. The positive current collector (110) may include, for example, a plate or foil comprising indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

[0043] Meanwhile, unlike as illustrated in FIG. 1, the positive current collector (110) may be omitted in one embodiment of the present invention. Although not illustrated, a carbon layer with a thickness of 0.1 μm to 4 μm may be further disposed between the positive current collector (110) and the positive active material layer (120) to increase the bonding strength between the positive current collector (110) and the positive active material layer (120).

[0044] The positive electrode active material is a material capable of reversibly absorbing and desorbing lithium ions. The positive electrode active material may include, for example, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, as well as nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, but is not necessarily limited to these. The positive electrode active material may be a single material or a mixture of two or more materials.

[0045] Lithium transition metal oxides are, for example, Li a A 1-b B b D2(0.90≤a≤1, 0≤b≤0.5), Li a E 1-b B b O 2-c D c (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05), LiE 2-b B b O 4-c D c (0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Co b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Mn b B c D α(0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Nor 1-b-c Mn b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Nor b E c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Nor b Co c Mn d GeO2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1), Li a NiG b O2(0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a MnG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a Mn2GbO4(0.90≤a≤1, 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3(0≤f≤2), Li 3-fIt is a compound represented by any one of Fe2(PO4)3 (0≤f≤2) or LiFePO4. In such compounds, the uppercase “A” is Ni, Co, Mn, or a combination thereof; the uppercase “B” is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; the uppercase “D” is O, F, S, P, or a combination thereof; the uppercase “E” is Co, Mn, or a combination thereof; the uppercase “F” is F, S, P, or a combination thereof; the uppercase “G” is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; the uppercase “Q” is Ti, Mo, Mn, or a combination thereof; the uppercase “I” is Cr, V, Fe, Sc, Y, or a combination thereof; and the uppercase “J” is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0046] The positive electrode active material may include, for example, a lithium salt of a transition metal oxide having a layered rock salt type structure among the lithium transition metal oxides described above. The "layered rock salt type structure" is, for example, a cubic rock salt type structure. <111> It is a structure in which oxygen and metal atomic layers are alternately and regularly arranged in a specific direction, thereby forming a two-dimensional plane for each atomic layer. The "cubic rock salt type structure" represents a sodium chloride (NaCl type) structure, which is a type of crystal structure; specifically, it exhibits a structure in which face-centered cubic lattices (fcc) formed by cations and anions, respectively, are offset from each other by half the ridge of the unit lattice. Lithium transition metal oxides having such a layered rock salt type structure are, for example, LiNi x Co y Al z O2(NCA) or LiNi x Co y Mn zO2(NCM) (0 <x<1,0<y<1, 0<z<1, x+y+z=1) 등의 삼원계 리튬전이금속산화물일 수 있다. 양극활물질이 층상암염형 구조를 갖는 삼원계 리튬전이금속산화물을 포함하는 경우, 전고체 전지(10)의 에너지 밀도가 커지고 열안정성이 향상될 수 있다.

[0047] The aforementioned compound contained in the positive electrode active material may be covered by a coating layer (not shown). The positive electrode active material may also be a mixture of the aforementioned compound and the compound to which the coating layer is added. Meanwhile, the coating layer added to the surface of the positive electrode active material may include, for example, oxides, hydroxides, oxyhydroxides, oxycarbonates, or hydroxycarbonates of the following coating elements. The compounds forming this coating layer are amorphous or crystalline. The coating elements included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The coating layer may include, for example, Li2O-ZrO2 (LZO). The method for forming the coating layer is selected within a range that does not adversely affect the physical properties of the positive electrode active material. The method for forming the coating layer is, for example, spray coating or immersion.

[0048] When the positive electrode active material contains 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) is increased, and the metal leaching of the positive electrode active material in the charged state can be reduced. As a result, the cycle characteristics of the all-solid-state battery (10) in the charged state are improved. Meanwhile, “cycle characteristics” is a characteristic that indicates the degree of deterioration of the all-solid-state battery (10) due to charging and discharging of the all-solid-state battery (10). An all-solid-state battery (10) with high cycle characteristics has a small degree of deterioration due to charging and discharging, while an all-solid-state battery (10) with low cycle characteristics may have a large degree of deterioration due to charging and discharging.

[0049] The shape of the positive electrode active material may include particle shapes such as spheres or ellipsoids. The particle size and content of the positive electrode active material are not particularly limited.

[0050] The solid electrolyte may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. Sulfide-based solid electrolytes include, for example, Li2S-P2S5, Li2S-P2S5-LiX (where X is a halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, and Li2S-P2S5-Z m S n (m, n are positive numbers, uppercase “Z” is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are positive numbers, uppercase “M” is one of P, Si, Ge, B, Al, Ga, In), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It may include at least one selected from (0≤x≤2).

[0051] Sulfide-based solid electrolytes are, for example, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I xIt may be an argyrodite-type compound comprising one or more selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound comprising one or more selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0052] Alternatively, sulfide-based solid electrolytes are Li 7-a M a PS 6-c X c It may be an argyrodite-type compound containing (0≤a≤2, (0≤c≤2)). Here, X may be F, Br, Cl, or a combination thereof. M can be candium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), or a combination thereof. there is.

[0053] The density of the azyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. By having a density of 1.5 g / cc or higher for the azyrodite-type solid electrolyte, the internal resistance of the all-solid-state battery is reduced, and defects such as penetration and short circuit of the solid electrolyte film due to lithium dendrite formation can be prevented. The elastic modulus of the solid electrolyte may be, for example, 15 GPa to 35 GPa.

[0054] The solid electrolyte included in the positive electrode active material layer (120) may have a smaller average particle size (D50) compared to the solid electrolyte included in the solid electrolyte layer (300). For example, the average particle size (D50) of the solid electrolyte included in the positive electrode active material layer (120) may be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less of the average particle size (D50) of the solid electrolyte included in the solid electrolyte layer (300). Meanwhile, the average particle size (D50) may be the median diameter measured using a laser particle size distribution meter.

[0055] The positive active material layer (120) may include a conductive material. The conductive material may have conductivity without causing chemical changes in the all-solid-state battery (10), thereby increasing the conductivity of the positive active material and the solid electrolyte. The conductive material may include a carbon-based material. The conductive material may include, for example, one or more selected from graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0056] The positive active material layer (120) may further include a binder. The binder may include a material for bonding the positive active material, solid electrolyte, and conductive material included in the positive active material layer (120), and for improving the bonding strength with the positive current collector (110). The binder may include, for example, polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, and polymethyl methacrylate.

[0057] Based on 100 parts by weight of the total positive active material, solid electrolyte, conductive material, and binder, the positive active material layer (120) may contain 85 parts by weight or more and 92 parts by weight or less of the positive active material. Based on 100 parts by weight of the total positive active material, solid electrolyte, conductive material, and binder, the positive active material layer (120) may contain 0.5 parts by weight or more and 1.5 parts by weight or less of the binder.

[0058] Based on 100 parts by weight of solid electrolyte, the positive active material layer (120) may contain 1 part by weight or more and 50 parts by weight or less of a conductive material. If the conductive material is included in the positive active material layer (120) in an amount less than 1 part by weight based on 100 parts by weight of solid electrolyte, the proportion of the conductive material decreases, and the electrical conductivity of the positive active material layer (120) may decrease. If the conductive material is included in the positive active material layer (120) in an amount exceeding 50 parts by weight based on 100 parts by weight of solid electrolyte, the proportion of the conductive material is excessively high, and a coating layer covering the surface of the solid electrolyte may not be properly formed.

[0059] The positive active material layer (120) may further include additives such as fillers, coating agents, dispersants, and ion conductivity aids in addition to the positive active material, solid electrolyte, conductive material, and binder described above.

[0060] The negative electrode layer (200) may include a negative electrode current collector (210) and a negative electrode coating layer (220) on the negative electrode current collector (210). The negative electrode current collector (210) may provide a reference surface on which the negative electrode coating layer (220) is placed. The negative electrode current collector (210) may include, for example, a material that does not react with lithium, that is, does not form any alloys or compounds with lithium. For example, the negative electrode current collector (210) may include at least one metal selected from the group consisting of copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). The thickness of the negative electrode current collector (210) may be 1 μm to 20 μm, more specifically 5 μm to 15 μm, and more specifically 7 μm to 10 μm.

[0061] The negative current collector (210) may be composed of one of the metals described above, or may include an alloy of two or more metals or a coating material. The negative current collector (210) may, for example, have a plate-like or foil-like shape. Meanwhile, in one embodiment, the negative current collector (210) may be omitted.

[0062] The negative electrode coating layer (220) can allow lithium metal to grow between the all-solid-state battery (10) and the negative electrode current collector (210) during charging. The negative electrode coating layer (220) can serve as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites.

[0063] The cathode coating layer (220) may include metal and carbon. For example, the cathode coating layer (220) may include at least one metal selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The cathode coating layer (220) may include at least one carbon selected from the group consisting of carbon black, acetylene black, furnace black, ketjen black, and graphene. In one embodiment, the cathode coating layer (220) may include a mixture of carbon black and silver (Ag).

[0064] The cathode coating layer (220) may further include other additives in addition to metal and carbon. The cathode coating layer (220) may further include at least one additive selected from the group consisting of, for example, binders, fillers, coating agents, dispersants, and ion-conducting aids.

[0065] The negative electrode coating layer (220) may have a smaller thickness compared to the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 1 µm to 20 µm, 2 µm to 10 µm, or 3 µm to 7 µm. If the thickness of the negative electrode coating layer (220) is excessively thin, lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210) may cause the negative electrode coating layer (220) to collapse, thereby degrading the cycle characteristics of the all-solid-state battery (10). If the thickness of the negative electrode coating layer (220) increases excessively, the energy density of the all-solid-state battery (10) decreases, and the internal resistance of the all-solid-state battery (10) due to the negative electrode coating layer (220) increases, which may degrade the cycle characteristics of the cell.

[0066] 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).

[0067] A solid electrolyte layer (300) may be provided between the anode layer (100) and the cathode layer (200). The solid electrolyte layer (300) may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics. The solid electrolyte in the solid electrolyte layer (300) may be the same as or different from any one of the materials included in the solid electrolyte in the aforementioned anode active material layer (120).

[0068] Referring to FIG. 3, the solid electrolyte layer (300) may include a first solid electrolyte layer (310) and a second solid electrolyte layer (320). The first solid electrolyte layer (310) may be adjacent to the anode layer (100), and the second solid electrolyte layer (320) may be adjacent to the cathode layer (200).

[0069] The first solid electrolyte layer (310) may include a first solid electrolyte. The first solid electrolyte may have a particle shape such as a sphere or an ellipsoid. The first solid electrolyte may include a sulfide-based solid electrolyte. The first solid electrolyte may be amorphous, crystalline, or a mixture thereof. Additionally, the solid electrolyte may include sulfur (S), phosphorus (P), and lithium (Li) as at least constituent elements among the sulfide-based solid electrolyte materials described above, for example. For example, the solid electrolyte may be a material containing Li2S-P2S5. When using a sulfide-based solid electrolyte material containing Li2S-P2S5 to form the solid electrolyte, the molar ratio of Li2S and P2S5 is, for example, in the range of Li2S : P2S5 = 50 : 50 to 90 : 10.

[0070] In one embodiment, the first solid electrolyte is Li 7-a M a PS6-c X c It may be an argyrodite-type compound containing. Here, X may be Cl, Br, or a combination thereof. M may be Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, or a combination thereof. a and c may each be a real number between 0 and 2.

[0071] The density of the azyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. Since the azyrodite-type solid electrolyte has a density of 1.5 g / cc or higher, the internal resistance of the all-solid-state battery is reduced, and defects such as penetration and short circuit of the solid electrolyte film due to lithium dendrite formation can be prevented. The elastic modulus of the first solid electrolyte is, for example, 15 GPa to 35 GPa.

[0072] The first solid electrolyte layer (310) may further include a binder. The binder included in the solid electrolyte layer (300) is, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited to these. The binder of the first solid electrolyte layer (310) may be the same as or different from the binder included in the positive electrode active material layer (120) or the binder included in the negative electrode coating layer (220).

[0073] The second solid electrolyte layer (320) may include a second solid electrolyte. The second solid electrolyte may have a particle shape such as a sphere or an ellipsoid. The second solid electrolyte may include a sulfide-based solid electrolyte. The description of the second solid electrolyte may be the same or similar as that described above for the first solid electrolyte. In one embodiment, the second solid electrolyte may have substantially the same composition as the first solid electrolyte. In another embodiment, the second solid electrolyte may have a composition similar to that of the first solid electrolyte.

[0074] The second solid electrolyte can come into direct contact with the negative electrode coating layer (220). By doing so, the second solid electrolyte can suppress lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210). The second solid electrolyte can effectively suppress negative side reactions. By doing so, the cell performance of the all-solid-state battery (10) according to the present invention can be improved.

[0075] The first solid electrolyte layer (310) may have a first thickness (TK1), and the second solid electrolyte layer (320) may have a second thickness (TK2). The first thickness (TK1) and the second thickness (TK2) may be the same or different from each other. In one embodiment, the first thickness (TK1) may be greater than the second thickness (TK2). For example, the first thickness (TK1) may be 1.1 to 5 times the second thickness (TK2).

[0076] Referring again to FIGS. 2 and FIGS. 3, the anode layer (100) and the first solid electrolyte layer (310) can form an anode composite layer (CSH). The cathode layer (200) and the second solid electrolyte layer (320) can form a cathode composite layer (ASH). An anode composite layer (CSH) can be laminated on the cathode composite layer (ASH).

[0077] The area of ​​the cathode composite layer (ASH) and the area of ​​the anode composite layer (CSH) may differ from each other. Specifically, the area of ​​the cathode composite layer (ASH) may be larger than the area of ​​the anode composite layer (CSH). The anode composite layer (CSH) may completely overlap within the cathode composite layer (ASH).

[0078] In one embodiment of the present invention, the first solid electrolyte layer (310) may have substantially the same area as the anode layer (100). The second solid electrolyte layer (320) may have substantially the same area as the cathode layer (200).

[0079] Specifically, the positive composite layer (CSH) may have a first width (WI1) in a first direction (D1). The negative composite layer (ASH) may have a second width (WI2) in a first direction (D1). The first width (WI1) may be smaller than the second width (WI2). The positive composite layer (CSH) may have a third width (WI3) in a second direction (D2). The negative composite layer (ASH) may have a fourth width (WI4) in a second direction (D2). The third width (WI3) may be smaller than the fourth width (WI4).

[0080] 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).

[0081] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

[0082] FIG. 5 is a cross-sectional view of a pouch-type all-solid-state battery (400) according to an 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 an electrode assembly in which at least one unit cell is stacked and packaged in a pouch (PCH). In this specification, a unit cell may refer to a basic unit containing components that constitute a cell. Referring to FIG. 4 and FIG. 5, the unit cell may include a first electrode, a second electrode having 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 a stacked form in the order of a cathode, a solid electrolyte layer, an anode, a solid electrolyte layer, and a cathode.

[0083] 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 protrude outside the pouch. The lead tab (LTB) may be configured so that the electrode assembly (STC) is electrically connected to the outside of the pouch. The pouch (PCH) may package the electrode assembly to protect and shield the electrode assembly (STC) from the outside. An all-solid-state battery packaged in a pouch may be used as a single independent unit battery. Multiple pouch-type all-solid-state batteries (400) may be combined to form a battery module. Multiple battery modules may be combined to form a battery pack. Pouch-type batteries have a relatively simple configuration and can reduce volume and weight. Additionally, they can be manufactured in flexible and various shapes.

[0084] FIG. 6 is an enlarged view of the M region of FIG. 5. Referring to FIG. 6, it can be seen that the electrode current collector (PLT2) and the pouch (PCH) are in contact. The pouch (PCH) may include a metal layer (MFL), a support layer (SL) formed on the metal layer (MFL), and a polymer layer (PML) formed on the support layer (SL). In one embodiment, the pouch (PCH) may include a metal layer (MFL), a support layer (SL) formed on both sides of the metal layer (MFL), and a polymer layer (PML) formed on each of the support layers (SL) formed on both sides.

[0085] For example, the pouch (PCH) may include a first support layer formed on the lower surface of the metal layer (MFL), a first polymer layer formed on the lower surface of the first support layer, a second support layer formed on the upper surface of the metal layer (MFL), and a second polymer layer formed on the upper surface of the second support layer. The material forming the first support layer may be the same as the material forming the second support layer. The first and second support layers may be collectively referred to as support layers (SL), and the first and second polymer layers may be collectively referred to as polymer layers (PML). However, the present invention is not limited thereto, and the support layer (SL) and the polymer layer (PML) may be formed on only one side of the metal layer (MFL). For example, the pouch (PCH) may include one support layer (SL) and one polymer layer (PML), each disposed on the lower surface of the metal layer (MFL).

[0086] Each of the metal layer (MFL), support layer (SL), and polymer layer (PML) may have a constant thickness range. The thickness of the pouch (PCH) may refer to the total thickness of the metal layer (MFL), support layer (SL), and polymer layer (PML). In one embodiment, the thickness of the pouch (PCH) may be 50 μm to 500 μm.

[0087] The metal layer (MFL) may comprise a metal that maintains mechanical strength and flexibility. For example, the metal layer (MFL) may comprise aluminum (Al). In addition to aluminum, the metal layer (MFL) may comprise one or more metals selected from the group consisting of iron (Fe), carbon (C), chromium (Cr), manganese (Mn), and nickel (Ni). Aluminum (Al) may be included in an amount of 90% to 99.9% by weight relative to the total mass of the metal layer (MFL). A metal layer (MFL) having a thickness of 20 μm to 300 μm, or 30 μm to 40 μm, may be provided.

[0088] The polymer layer (PML) may include an insulating material. For example, the polymer layer (PML) may have a single membrane structure made of any one material selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, polyparaphenylenebenzobisoxazole, polyarylate, Teflon, and glass fiber, or a composite membrane structure made of two or more materials. As an example, the polymer layer (PML) may include a polymer having a melting point of 140°C to 160°C, but the present invention is not limited thereto. By including the polymer layer (PML) in the pouch (PCH), the metal layer (MFL) can be prevented from being damaged by friction, impact, etc. In addition, the polymer layer (PML) prevents the metal layer (MFL) from coming into direct contact with the electrode assembly and can provide insulation.

[0089] A polymer layer (PML) may be applied to one or both sides of a metal layer (MFL). When a polymer layer (PML) is provided on both sides of a metal layer (MFL), a polymer layer (PML) containing different polymer resins may be formed on each side of the metal layer (MFL). The thickness of the polymer layer (PML) formed on one side of the metal layer (MFL) may be 30 μm to 300 μm. The melting point of the polymer layer (PML) may be about 180°C or lower, specifically about 170°C or lower, more specifically about 165°C or lower.

[0090] FIG. 7a is an enlarged view of the N1 region of FIG. 6. In one embodiment, the support layer (SL) may be a layer having a uniform thickness. In one embodiment, the thickness (STK) of the support layer (SL) may be about 1 μm to about 200 μm. The support layer (SL) may be a porous structure containing a plurality of pores. For example, the support layer (SL) may comprise a sheet or nonwoven fabric made of at least one selected from the group comprising an olefinic porous substrate and heat-resistant fibers or polyethylene. For example, the support layer (SL) may be a sheet comprising a resin such as a polyolefin-based (polyethylene, polypropylene, polybutene, polyvinyl chloride) and a mixture or copolymer thereof, or a resin such as polyethylene terephthalate, polycycloolefin, polyethersulfone, polyamide, polyimide, polyimideamide, polyaramid, polycycloolefin, nylon, polytetrafluoroethylene, etc.

[0091] Alternatively, the support layer (SL) may be a sheet containing heat-resistant fibers. The heat-resistant fibers may refer to at least one of aramid fibers, polyphenylene sulfide (PPS) fibers, oxidized polyacrylonitrile (OXI-PAN) fibers, polyimide (PI) fibers, polybenzimidazole (PBI) fibers, polybenzoxazole (PBO) fibers, polytetrafluoroethylene (PTFE) fibers, polyketone (PK) fibers, metal fibers, carbon fibers, glass fibers, basalt fibers, silica fibers, and ceramic fibers. The support layer (SL) may be a nonwoven fabric having a heat-resistant fiber content of about 30% by weight to 100% by weight.

[0092] The support layer (SL) may be formed by stacking the above sheets in one or more layers. If the support layer (SL) has two or more layers, each layer of the porous support layer may be made of a different material, or each layer of the porous support layer may be made of the same material. However, the present invention is not limited thereto, and the support layer (SL) may have a single layer.

[0093] The average diameter of the pores of the support layer (SL) may be about 0.01 μm to 60 μm. The average thickness of the pores may be about 0.01 μm to about 60 μm. Although FIG. 7a is illustrated as having the same diameter and completely penetrating the support layer (SL), the present invention is not limited thereto. The diameters and thicknesses of the pores may differ from each other and may not completely penetrate the support layer (SL). The porosity of the support layer (SL) may be about 30% to about 90%.

[0094] The melting point of the support layer (SL) may be greater than the melting point of the polymer layer (PML). The melting point of the support layer (SL) may be greater than approximately 170°C. Specifically, the melting point of the support layer (SL) may be approximately 200°C or higher, more specifically approximately 300°C or higher.

[0095] In FIG. 7a, the melting points of the support layer (SL) and the polymer layer (PML) may represent the melting range as described above and may be measured using the methods exemplified in the description above. For example, the melting points of the support layer (SL) and the polymer layer (PML) may be measured using a differential scanning calorimeter. Differential scanning calorimetry may be performed by preparing a sample of the support layer (SL) and the polymer layer (PML). Accordingly, a graph of the endothermic / exothermic amounts of the support layer (SL) and the polymer layer (PML) according to temperature can be obtained. In the graph, the melting range or melting point of the support layer (SL) and the polymer layer (PML) may be measured by analyzing the position of the endothermic peak measured by the heat absorbed as the support layer (SL) and the polymer layer (PML) melts. However, the present invention is not limited thereto, and the melting points of the support layer (SL) and the polymer layer (PML) may be measured through other methods.

[0096] In the case of a pouch (PCH) with a multi-layered structure as in the present invention, the relationship and role with adjacent layers can be determined according to the melting point of each layer. For example, a support layer (SL) having a higher melting point than a polymer layer (PML) can maintain stability even at the temperature at which the polymer layer (PML) melts. Accordingly, the support layer (SL) can play the role of absorbing the molten polymer layer (PML). Hereinafter, the relationship between the support layer (SL) and the polymer layer (PML) according to the operation of the pouch-type all-solid-state battery (400) will be explained in detail with reference to FIGS. 7b and 7c, which will be described later.

[0097] FIG. 7b is an enlarged view of the N1 region of FIG. 6 and is a schematic diagram for explaining phenomena that may occur during the operation of a pouch-type all-solid-state battery (400). Specifically, FIG. 7b illustrates a state in which the internal cell temperature of the pouch-type all-solid-state battery (400) exceeds 170°C.

[0098] In the case of all-solid-state batteries, the internal cell temperature may be higher on average compared to conventional lithium-ion batteries. For example, unlike lithium-ion batteries, the internal cell temperature of an all-solid-state battery may exceed 170°C. Even if the thermal stability of the cell is high, the melting point of the polymer layer (PML) within the pouch (PCH) may be exceeded. That is, the polymer layer (PML) of the pouch (PCH) may melt. The polymer layer (PML) may melt and become fluid. Since the support layer (SL) contains empty spaces that can accommodate the molten polymer layer (PML), the molten polymer layer (PML) may be impregnated into the support layer (SL). Specifically, the molten polymer layer (PML) may fill the interior of the pores of the support layer (SL).

[0099] FIG. 7c is a schematic diagram for explaining phenomena that may occur during the operation of a pouch-type all-solid-state battery (400), illustrating a comparative example in which a support layer (SL) according to an embodiment of the present invention is not provided within the pouch. Specifically, FIG. 7c illustrates a state in which the internal temperature of the cell of the comparative example exceeds 170°C.

[0100] As the melting point of the polymer layer (PML) is approximately 170°C or lower, the polymer layer (PML) may be melted. The melted polymer layer (PML) has fluidity and, accordingly, may not exist between the metal layer (MFL) and the second electrode current collector (PLT2). For example, the melted 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, unlike in FIG. 7b, 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 come into contact with each other in some areas.

[0101] The metal layer (MFL) of the pouch (PCH) and the second electrode current collector (PLT2) can be electrically connected to each other. The first lead tab (LTB1) shown in FIG. 5 can 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), having different polarities, are connected to each other through the metal layer (MFL). Consequently, this may lead to accidents such as the explosion and fire of the battery.

[0102] Alternatively, defects may occur in corners or other areas that undergo significant elongation during the packaging process of the electrode assembly by the pouch (PCH) due to mechanical weakness. For example, defects may occur in corners surrounding a stacked electrode assembly or corners surrounding an externally protruding lead tab. If the polymer layer (PML) of the pouch (PCH) is mechanically or thermally damaged, the metal layer (MFL) may be exposed to the outside. This may result in the aforementioned short circuit.

[0103] Referring to FIGS. 7b and 7c, the pouch (PCH) according to the present invention includes a support layer (SL) that physically separates the metal layer (MFL) and the second electrode current collector (PLT2), thereby maintaining stability even in the event of damage to the polymer layer (PML). For example, since the support layer (SL) has a high melting point, it can stably separate the metal layer (MFL) and the second electrode current collector (PLT2) even when the battery is operated at a high temperature of about 170°C or higher. In addition, since the support layer (SL) has a porous structure, the molten polymer layer (PML) can be absorbed into the pores of the support layer (SL). Accordingly, the operation of the all-solid-state battery at high temperatures can be facilitated, and a pouch-type all-solid-state battery with improved stability can be provided.

[0104] FIG. 8 is a cross-sectional view of a pouch-type all-solid-state battery (400) according to one embodiment of the present invention, showing an enlarged view of the M region of FIG. 5. FIG. 9 is an enlarged view of the N2 region of FIG. 8.

[0105] Referring to FIGS. 8 and 9, in one embodiment, the support layer (SL) may be in the form of inorganic particles (IOP) dispersed within a polymer adhesive layer (PAL). The inorganic particles (IOP) may include aluminum oxide (Al2O3) and silicon dioxide (SiO2). However, the present invention is not limited thereto, and the inorganic particles (IOP) may include, for example, SiO2, Al2O3, MgO, TiO2, ZrO2, CaO, Y2O3, etc. The polymer adhesive layer (PAL) may include an organic polymer. For example, the polymer adhesive layer (PAL) may include polyester resin, polyurethane resin, polyimide resin, polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polypropylene, polyimide resin, aramid, polyvinylidene fluoride, polyvinyl alcohol, cellulose resin, styrene butadiene rubber, fluororubber, etc.

[0106] However, the present invention is not limited thereto, and the support layer (SL) may be in the form in which inorganic particles (IOP) are dispersed in a sheet described with reference to FIG. 7a. For example, it may be in the form in which inorganic particles (IOP) are dispersed within the pores of a porous structure sheet described with reference to FIG. 7a.

[0107] Inorganic particles (IOP) are dispersed within the polymer adhesive layer (PAL) to increase the melting point of the support layer (SL) and enhance mechanical strength. The melting point of the support layer (SL) may be approximately 200°C or higher to ensure sufficient heat resistance. For example, the melting point of the support layer (SL) may be approximately 350°C to approximately 450°C. Since the support layer (SL) has a higher melting point than the polymer layer (PML), even if the polymer layer (PML) melts when the battery is operated at a high temperature above the melting point of the polymer layer (PML), the support layer (SL) can physically separate the metal layer (MFL) from the second electrode current collector (PLT2). Accordingly, the operation of the all-solid-state battery at high temperatures can be facilitated, and a pouch-type all-solid-state battery with improved stability can be provided.

[0108] Referring to FIG. 10, a pouch (PCH) according to embodiments of the present invention may be provided with a support layer (SL) only in a portion of the area. For example, in a pouch for packaging an electrode assembly, the support layer (SL) may be included only in a portion where stability is weak. In one embodiment, the pouch (PCH) may locally include a support layer (SL) only in the portion that contacts the lead tab (LTB).

[0109] The electrode assembly may include a second electrode disposed on the top or bottom layer and in contact with the pouch. That is, it 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 the first electrode. For example, the first electrode may be the positive electrode and the second electrode may be the negative electrode, but the present invention is not limited thereto. Each of the first electrode and the second electrode may include a substrate tab (TB) that is electrically connected and extends in one direction.

[0110] A substrate tab (TB) can be electrically connected to a lead tab (LTB). A single lead tab (LTB) can be electrically connected to multiple substrate tabs (TB). For example, they can be connected by welding. More specifically, the lead tab (LTB) can be welded to the substrate tab (TB) or electrode layer by ultrasonic welding, laser welding, spot welding, etc.

[0111] To make the welding between the electrode and the lead tab (LTB) more robust, a metal chip may be added between the electrode and the lead tab (LTB). The metal chip may be a thin sheet 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. That is, 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 within this range, the connection with the lead tab (LTB) can be performed more easily.

[0112] A substrate tab (TB) may refer to a portion of the uncoated portion of an electrode current collector. The uncoated portion may refer to an area excluding the region where a coating layer or / and an active material layer exists on the electrode current collector. 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).

[0113] A lead tab (LTB) may include a first lead tab (LTB1) connected to a plurality of first electrodes and a second lead tab (LTB2) connected to a plurality of second electrodes. The first lead tab (LTB1) may be electrically connected to at least one first substrate tab (TB1). The second lead tab (LTB2) may be electrically connected to at least one second substrate tab (TB2). That is, the first lead tab (LTB1) may be connected only to the first electrode, and the second lead tab (LTB2) may be connected only to the second electrode. In this specification, the area of ​​the pouch (PCH) in contact with the first lead tab (LTB1) may be referred to as a first joint (A1), and the area of ​​the pouch (PCH) in contact with the second lead tab (LTB2) may be referred to as a second joint (A2).

[0114] FIG. 11a is an enlarged view of the X region of FIG. 10, and FIG. 11b is an enlarged view of the Y region of FIG. 10. Referring to FIG. 11a, in the case of the X region in contact with the electrode assembly, the pouch (PCH) may not include a support layer (SL). In contrast, referring to FIG. 11b, in the case of the Y region in contact with the lead tab (LTB), the pouch (PCH) may include a support layer (SL).

[0115] However, the present invention is not limited thereto, and the pouch (PCH) may include a support layer (SL) in only one of the regions in contact with the first and second lead tabs (LTB1, LTB2). For example, although not illustrated, the pouch (PCH) may include a support layer (SL) in the first joint (A1) in contact with the first lead tab (LTB1), but may not include a support layer (SL) in the second joint (A2) in contact with the second lead tab (LTB2). Referring to FIG. 10, 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 support layer (SL) is provided only in the region containing the first joint (A1). Even if a portion of the polymer layer (PML) of the pouch (PCH) is damaged, a support layer (SL) is formed at the first junction (A1) electrically connected to the first electrode, so that a short circuit can be prevented.

[0116] More specifically, even if the polymer layer (PML) is melted / damaged and the second electrode current collector (PLT2) comes into contact with the metal layer (MFL) of the pouch (PCH), the first lead tab (LTB1) connected to the first electrode inside the cell comes into contact with the first junction (A1) on which the support layer (SL) is formed, thereby preventing a short circuit. By ensuring that the second electrode, which is placed on the uppermost and / or lowermost layer of the electrode assembly and is in direct contact with the pouch, the first electrode of opposite polarity, and the metal layer (MFL) of the pouch (PCH) are not electrically connected, an electrical short circuit can be prevented. Therefore, the stability of the battery can be improved by preventing unintended electrical connections. The above embodiment is not limited to the above example and may include all embodiments that share the same principle of solving the problem. For example, contrary to the above example, it is also possible to include a support layer in the portion excluding the first and second junctions (A1, A2) where the lead tab (LTB) and the pouch (PCH) come into contact.

[0117] FIG. 12 is a flowchart illustrating a method for manufacturing an all-solid-state battery according to embodiments of the present invention.

[0118] Referring to FIG. 12, a 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 such manufacturing steps, a pouch-type all-solid-state battery with a structure having improved stability can be manufactured. In addition, the mass producibility of the all-solid-state battery according to embodiments of the present invention may be further improved.

[0119] The step of manufacturing a pouch film (S100) may include the step of preparing a metal layer (MFL), the step of laminating a support layer (SL) on the metal layer (MFL), and the step of laminating a polymer layer (PML) on the support layer (SL).

[0120] Specifically, a metal layer (MFL) in the form of a film may be prepared to manufacture a pouch for a battery. The metal layer (MFL) may maintain mechanical strength and have flexibility. 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% to 99.9% by weight relative to the total mass of the metal layer (MFL). A metal layer (MFL) having a constant width with respect to a first direction (D1) may be provided. A metal layer (MFL) having a constant width with respect to the first direction (D1) may be extended and prepared in a roll form. The width of the first direction (D1) may be adjusted to match the size of the 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 pouch-type all-solid-state battery being manufactured.

[0121] A metal layer (MFL) in the form of a roll can be positioned on equipment that moves in one direction, allowing the metal layer (MFL) that was wound to be unwound. A step of forming a support layer (SL) can be performed on the unwound metal layer (MFL). For example, the support layer (SL) may comprise a sheet or nonwoven fabric made of at least one selected from the group comprising an olefin-based porous substrate and heat-resistant fibers or polyethylene. For example, the support layer (SL) may be a sheet comprising a resin such as a polyolefin-based (polyethylene, polypropylene, polybutene, polyvinyl chloride) and a mixture or copolymer thereof, or a resin such as polyethylene terephthalate, polycycloolefin, polyethersulfone, polyamide, polyimide, polyimideamide, polyaramid, polycycloolefin, nylon, or polytetrafluoroethylene. The support layer (SL) may be laminated on the metal layer (MFL). The step of manufacturing a pouch film may include the step of forming a support layer (SL) on both sides or on one side of a metal layer (MFL). The location and area where the support layer (SL) is formed on the metal layer (MFL) may vary. For example, a pouch may be manufactured in which the support layer (SL) is formed only on the first bonding portion (A1).

[0122] A step of forming a polymer layer (PML) on a support layer (SL) may be performed. The polymer layer (PML) may comprise one or more polymer resins selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, polyarylate, and Teflon. In particular, polyolefin resins such as polypropylene (PP) or polyethylene (PE) may be used. The polymer layer (PML) may be formed by a laminating method by applying a polymer resin onto the support layer (SL). Alternatively, it may be formed by a coating method.

[0123] Subsequently, a step (S200) for manufacturing an electrode assembly may be performed. The step (S200) for 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 the substrate tab and the lead tab.

[0124] The step of manufacturing a unit cell may include a process of stacking an anode, a cathode, and a solid electrolyte layer between the anode and the cathode. In one embodiment, the unit cell may be in the form of an anode, a solid electrolyte layer, and a cathode stacked sequentially. In another embodiment, the unit cell may be in the form of a cathode (anode), a solid electrolyte layer, an anode (cathode), a solid electrolyte layer, and a cathode (cathode) stacked sequentially. In this case, the anode, the cathode, and the solid electrolyte layer may be stacked with different areas.

[0125] In the process of stacking the positive and negative electrodes, the direction of the substrate tabs connected to each electrode can be set. For example, the positive substrate tab and the negative substrate tab can be stacked so that their directions face opposite directions with respect to the first direction (D1). As another example, the positive substrate tab and the negative substrate tab can be stacked so that their directions are the same with respect to the first direction (D1).

[0126] The process may include connecting a plurality of positive substrate tabs to positive lead tabs and connecting a plurality of negative substrate tabs to negative lead tabs. Specifically, the electrodes and substrate tabs may be electrically connected through welding. For example, they may be electrically connected by ultrasonic welding, laser welding, spot welding, etc.

[0127] The lead tabs can be extended and connected in the direction facing the substrate tabs. That is, the directions of the positive lead tab and the negative lead tab can be connected such that they are identical to 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.

[0128] Afterwards, a step of assembling the battery (S300) may be performed. The step of assembling the 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.

[0129] Referring to FIG. 13, electrode assemblies can be sequentially stacked on a manufactured pouch. More specifically, electrode assemblies can be stacked on a pouch (PCH) at regular intervals while the manufactured pouch moves in a second direction (D2). Specifically, electrode assemblies can be provided on a lower pouch (LPCH). In one embodiment, the first lead tab (LTB1) and the second lead tab (LTB2) of the electrode assembly can be arranged to face opposite directions with respect to the first direction (D1).

[0130] Referring to FIG. 14, as electrode assemblies are sequentially stacked and moved on a pouch, a step in which the pouch covers the electrode assembly may proceed. Specifically, an upper pouch (UPCH) may cover the electrode assembly. The upper pouch (UPCH) and the lower pouch (LPCH) may be the same pouch manufactured in the step of manufacturing a pouch film (S100).

[0131] FIG. 15 is a perspective view illustrating a pouch-type battery manufactured according to one embodiment. FIG. 16 is an enlarged view of the O area of ​​FIG. 15. Referring to FIG. 15 and FIG. 16, the step of assembling the battery (S300) may include the step of cutting the pouch. The step of cutting the pouch may include cutting the pouch to fit the size of the battery. That is, the step of cutting the pouch may include the step of packaging the electrode assembly to fit the shape and size of the battery being manufactured.

[0132] 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 to remove some generated gas or moisture. Through the sealing step, the electrode assembly can be blocked from external air or moisture. Through the above process, the electrode assembly can be packaged into a pouch. Pouch sealing may be performed by applying pressure to the periphery of the pouch (PCH) at a high temperature. Due to the sealing process, a portion of the first lead tab (LTB1) and the second lead tab (LTB2) may come into contact with the pouch (PCH). The area where a portion of the first lead tab (LTB1) comes into contact with the pouch (PCH) may be the first joint (A1). The area where a portion of the second lead tab (LTB2) comes into contact with the pouch (PCH) may be the second joint (A2).

[0133] In the method for manufacturing an all-solid-state battery according to the present invention, each step can proceed as a series of continuous processes. According to an embodiment of the present invention, by controlling the area of ​​the support layer (SL) in the pouch manufacturing step, a pouch suitable for the shape or size of the battery can be manufactured. A battery pouch suitable for the shape and size of the battery and having improved stability can be manufactured. Consequently, an effective manufacturing method can be provided that simultaneously addresses mass production and stability of a pouch-type battery.

Claims

1. An electrode assembly having at least one stacked unit cell; and A pouch for packing the above electrode assembly, comprising: The above unit cell includes an anode, a cathode, and a solid electrolyte between the anode and the cathode, and The above pouch comprises a polymer layer, a metal layer, and a support layer between the polymer layer and the metal layer, and The above support layer has a porous structure including a plurality of pores, and The melting point of the above polymer layer is less than 170℃, and The melting point of the above support layer is greater than 200℃, All-solid-state battery.

2. In Paragraph 1, The above-described all-solid-state battery further comprises a first lead tab electrically connected to the positive electrode and a second lead tab electrically connected to the negative electrode, and The above pouch includes a first joint portion in contact with the first lead tab and a second joint portion in contact with the second lead tab, and The support layer is optionally provided on at least one of the first joint and the second joint, All-solid-state battery.

3. In Paragraph 2, The above support layer is provided at the first joint, and The support layer is omitted in the second joint above, All-solid-state battery.

4. In Paragraph 1, Even at a temperature higher than 170°C, the support layer is configured such that at least one lead tab among the anode and the cathode and the metal layer do not come into contact with each other. All-solid-state battery.

5. In Paragraph 4, The above polymer layer comprises a polymer having a melting point of 140°C to 160°C, All-solid-state battery.

6. In Paragraph 1, The thickness of the above support layer is 1 μm to 200 μm, All-solid-state battery.

7. In Paragraph 1, The pores of the support layer include empty spaces capable of accommodating the molten polymer of the polymer layer. All-solid-state battery.

8. In Paragraph 1, The above solid electrolyte is a sulfide-based solid electrolyte, All-solid-state battery.

9. In Paragraph 1, The above support layer comprises at least one of polyolefin resin, polyethylene terephthalate, polycycloolefin, polyethersulfone, polyamide, polyimide, polyimideamide, polyaramid, polycycloolefin, nylon, polytetrafluoroethylene resin, and heat-resistant fiber. All-solid-state battery.

10. An electrode assembly having at least one stacked unit cell; A lead tab electrically connected to the above unit cell; and All-solid-state battery comprising a pouch for packing the above electrode assembly: The above unit cell comprises a first electrode, a second electrode having a polarity different from that of the first electrode, and a solid electrolyte between the first and second electrodes, and The above unit cell further includes a first substrate tab extending from the first electrode and a second substrate tab extending from the second electrode, and The above lead tab includes a first lead tab connected to the first material tab and extending to the outside of the pouch, and a second lead tab connected to the second material tab and extending to the outside of the pouch. The above pouch includes a first joint portion that contacts the first lead tab, wherein The first joint comprises a metal layer, a first polymer layer in contact with the first lead tab, and a first support layer between the metal layer and the first polymer layer. The first support layer has a porous structure including a plurality of pores, and The melting point of the first support layer is higher than the melting point of the first polymer layer.

11. In Paragraph 10, The second electrode is disposed on at least one of the uppermost and lowermost parts of the electrode assembly, and The above pouch further includes a second joint that contacts the second lead tab, wherein The first support layer is omitted in the second joint above. All-solid-state battery.

12. In Paragraph 10, The first support layer is omitted in the remaining part of the pouch excluding the first joint, All-solid-state battery.

13. In Paragraph 10, The first support layer has a melting point of 200℃ or higher, All-solid-state battery.

14. In Paragraph 10, The first polymer layer comprises a polymer having a melting point of 140°C to 160°C, All-solid-state battery.

15. In Paragraph 10, The thickness of the first support layer is 1 μm to 200 μm, All-solid-state battery.

16. In Paragraph 10, The first joint further comprises a second polymer layer disposed on the metal layer facing the first polymer layer and a second support layer between the metal layer and the second polymer layer. The second support layer above includes a porous structure having a plurality of pores, and The material constituting the second support layer is the same as the material constituting the first support layer. All-solid-state battery.

17. In Paragraph 10, The pores of the first support layer include empty spaces capable of accommodating the molten polymer of the polymer layer. All-solid-state battery.

18. Manufacturing pouch film; Manufacturing an electrode assembly; and The method includes packaging the electrode assembly with the above pouch film to form a battery, wherein Manufacturing the above pouch film is: Sequentially stacking a metal layer, a support layer, and a polymer layer; and The method includes laminating the metal layer, the support layer, and the polymer layer. The above support layer has a porous structure including a plurality of pores, and The melting point of the above polymer layer is less than 170℃, and The melting point of the above support layer is greater than 200℃, Method for manufacturing an all-solid-state battery.

19. In Paragraph 18, The pores of the support layer include empty spaces capable of accommodating the molten polymer of the polymer layer. Method for manufacturing an all-solid-state battery.

20. In Paragraph 18, The thickness of the above support layer is 1 μm to 200 μm, Method for manufacturing an all-solid-state battery.

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