Solid electrolyte sheet and all-solid-state battery comprising same

Abstract

The present invention relates to a solid electrolyte sheet comprising: a porous support composed of glass fibers; and a solid electrolyte filled in all or at least some pores of the porous support, wherein the glass fibers have a weight per bundle of glass fiber yarn of 3.5-8.5 g / 1 km.

Description

Solid electrolyte sheet and all-solid-state battery comprising the same

[0001] The present invention relates to a solid electrolyte sheet and an all-solid-state battery including the same.

[0002] Research on the safety and energy density of high-capacity batteries is gaining attention, and all-solid-state batteries are gaining attention as next-generation batteries. These all-solid-state batteries replace liquid electrolytes, which can be prone to explosion, with solid electrolytes. This eliminates the use of flammable solvents within the battery, eliminating the risk of ignition or explosion caused by reactions like the decomposition of conventional electrolytes. This ensures battery safety.

[0003] In addition, since lithium metal or a lithium alloy can be used as the negative electrode material, the energy density in relation to the mass and volume of the battery can be improved. The solid electrolyte used in the above-mentioned all-solid-state battery is generally an inorganic solid electrolyte, and various studies are being conducted on a sulfide-based solid electrolyte having a composition such as Li6PS5Cl, which has an argyrodite structure among the above-mentioned all-solid-state batteries.

[0004] The practical application of all-solid-state batteries requires the production of large-area batteries. This necessitates the manufacture of thin sheet-type electrodes, separators (solid electrolyte layers), and cathodes, similar to those used in conventional lithium-ion batteries. In particular, the separator in all-solid-state batteries consists of a solid electrolyte and a binder, and its properties (ionic conductivity, electrochemical stability, and chemical stability) vary depending on the manufacturing method and selected solid electrolyte material.

[0005] However, as the thickness of the solid electrolyte layer decreases, cracks and pinholes are more likely to occur due to the ceramic properties (brittleness) of the solid electrolyte. These cracks and pinholes within the solid electrolyte layer cause microscopic short circuits within the battery, thereby reducing cell performance.

[0006] Meanwhile, for large-area all-solid-state batteries, the mechanical properties of the solid electrolyte layer itself are crucial for facilitating the stacking of solid electrolytes during battery manufacturing. Therefore, a self-contained solid electrolyte layer is required for application in the stacking process of existing lithium-ion batteries.

[0007]

[0008] One object of the present invention is to provide a solid electrolyte sheet that has excellent mechanical properties and can be applied in the form of a self-standing membrane, has high ionic conductivity, and can exhibit excellent capacity and lifespan characteristics without causing a short circuit when applied to a battery.

[0009]

[0010] This application claims priority to Republic of Korea Patent Application No. 10-2024-0109952, filed August 16, 2024, the entire contents of which are incorporated herein by reference.

[0011] One embodiment of the present invention provides a solid electrolyte sheet comprising a porous support composed of glass fibers and a solid electrolyte filled in all or at least a portion of the pores of the porous support, wherein the glass fibers have a weight of 3.5 to 8.5 g / 1km per bundle of glass fiber yarns.

[0012] The above glass fiber may have a diameter of one strand of glass fiber yarn of 0.8 to 5.5 μm.

[0013] The porous support has a mass per unit area of ​​14.5 to 23.5 g / m 2 It could be.

[0014] The above solid electrolyte may have an average particle diameter (D50) of 1.5 to 4.5 μm.

[0015] The above glass fibers may have a yarn strand concentration of 5 to 26 per bundle of glass yarns.

[0016] The above solid electrolyte may be a sulfide compound, a halide compound, or a combination thereof.

[0017] The above solid electrolyte may be a sulfide compound having an argyrodite crystal structure.

[0018] The above sulfide compound can be represented by the following chemical formula 1.

[0019] [Chemical Formula 1]

[0020] Li x1 P y1 S z1 D w1 M1 a1 M2 a2

[0021] In the above chemical formula 1, D is a halogen element such as F, Cl, Br, I or a combination thereof, M1 is B, Al, Si, Ge, Ga, In, Sn or a combination thereof, M2 is O, N, Se, As, Se, Sb, Sn or a combination thereof, and 4≤x1≤8, 0.5≤y1≤1.5, 3≤z1≤7, 0≤a1≤2, 0≤a2≤2.

[0022] The above halide compound can be represented by the following chemical formula 2.

[0023] [Chemical Formula 2]

[0024] Li x2 M3 y2 A z2

[0025] In the above chemical formula 2, M3 is Sc, In, Zr, Lu, Er, Y, Ho or a combination thereof, A is a halogen element such as F, Cl, Br, I or a combination thereof, and 1.5≤x2≤3.5, 0.5≤y2≤1.5, 5≤z2≤7.

[0026] The content of the solid electrolyte may be 1 to 5 wt% based on the total weight of the porous support.

[0027] The above solid electrolyte sheet may have a thickness of 80 μm or less.

[0028] The above solid electrolyte sheet has a tensile strength of 50 kgf / cm. 2 It could be strange.

[0029] The above solid electrolyte sheet may have a bending strength of 80 MPa or more.

[0030] The above solid electrolyte sheet may have an ionic conductivity of 0.1 mS / cm or more at 30°C.

[0031] The above solid electrolyte sheet may further include a binder selected from the group consisting of nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), styrene-butadiene-styrene copolymer, acrylic resin, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, or a combination thereof.

[0032] The content of the above binder may be 1 to 5 wt% based on the total weight of the solid electrolyte.

[0033]

[0034] Another embodiment of the present invention provides an all-solid-state battery comprising: a positive electrode layer; a negative electrode layer; and a solid electrolyte layer positioned between the positive electrode layer and the negative electrode layer, the solid electrolyte layer including the aforementioned solid electrolyte sheet.

[0035]

[0036] A solid electrolyte sheet according to one embodiment of the present invention uses glass fibers as a support, and by controlling physical properties such as the weight of the glass fiber bundle, the solid electrolyte sheet can be provided in the form of a self-standing membrane with improved mechanical properties. This can improve the convenience of processes such as stacking processes for cell production.

[0037] In addition, the solid electrolyte sheet according to one embodiment of the present invention has high ionic conductivity, and when applied to a battery, it can simultaneously achieve good capacity and life characteristics without causing a short circuit.

[0038]

[0039] Figure 1 is a schematic diagram of a glass fiber according to the present invention.

[0040] Figure 2 is a photograph of a solid electrolyte sheet manufactured according to Example 3.

[0041] Figure 3 is a conceptual diagram for measuring the tensile strength of a solid electrolyte sheet.

[0042] Figure 4 is a conceptual diagram of a method for measuring the bending strength of a solid electrolyte sheet.

[0043] Figure 5 is a graph showing the results of evaluating the tensile strength of a solid electrolyte sheet manufactured according to Example 3.

[0044] Figure 6 is a graph showing the results of evaluating the bending strength of a solid electrolyte sheet manufactured according to Example 3.

[0045] The terms first, second, and third, etc., are used to describe, but are not limited to, various parts, components, regions, layers, and / or sections. These terms are used only to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention.

[0046] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used herein, the singular forms "singular" and "comprising" include plural forms as well, unless the context clearly dictates otherwise. The word "comprising" as used herein specifies a particular feature, region, integer, step, operation, element, and / or component, but does not exclude the presence or addition of other features, regions, integers, steps, operations, elements, and / or components.

[0047] When a part is referred to as being "on" or "over" another part, it can be directly on or over the other part, or there may be other parts intervening. Conversely, when a part is referred to as being "directly on" another part, there are no other parts intervening.

[0048] Although not defined otherwise, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or overly formal unless otherwise defined.

[0049] Also, unless otherwise stated, % means weight%, and 1 ppm is 0.0001 weight%.

[0050] In this specification, the term "combination(s) thereof" described in the expression in the Makushi format means one or more mixtures or combinations selected from the group consisting of the components described in the expression in the Makushi format, and means including any one or more selected from the group consisting of said components.

[0051] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0052]

[0053] 1. Solid electrolyte sheet

[0054] A solid electrolyte sheet according to one embodiment of the present invention can be applied to a solid electrolyte layer in an all-solid-state battery.

[0055] According to one embodiment of the present invention, a solid electrolyte sheet includes a porous support made of glass fibers and a solid electrolyte filled in all or at least a portion of the pores of the porous support. Glass fibers have excellent mechanical strength, and when applied as a support for a solid electrolyte sheet, they can improve mechanical properties such as tensile strength and bending strength of the solid electrolyte sheet. Accordingly, the solid electrolyte sheet according to the present invention can be provided in the form of a self-standing membrane, and the convenience of processes such as a stacking process for cell production can be improved. In particular, glass fibers are more suitable as a support for a solid electrolyte sheet in the form of a self-standing membrane because they have excellent mechanical strength compared to polymer non-woven fabrics commonly used as conventional supports.

[0056] However, the mechanical properties (tensile strength, bending strength) and electrochemical properties (ionic conductivity, capacity characteristics when applied to a battery, life characteristics) of the solid electrolyte sheet may vary sharply depending on the change in physical properties according to the processing form of the glass fiber support, even if glass fiber material of the same composition is used.

[0057] Accordingly, the inventors of the present invention completed the present invention by studying the properties of a glass fiber support to simultaneously achieve excellent mechanical and electrochemical properties of a solid electrolyte sheet to which a glass fiber support is applied.

[0058] Figure 1 is a schematic diagram of a glass fiber according to the present invention.

[0059] Referring to FIG. 1, the glass fiber according to the present invention may be formed as a glass fiber bundle in which individual strands of glass fiber yarn are bundled together in groups of several to several dozen. In addition, the porous support according to the present invention may be formed by weaving glass fiber bundles into a mesh shape, thereby forming a porous structure having a plurality of internal pores.

[0060] At this time, the glass fiber according to the present invention may have a weight per bundle of glass fiber yarn of 3.5 to 8.5 g / 1km, and more specifically, 4.5 to 7.5 g / 1km or 5.5 to 6.5 g / 1km. When the weight per bundle of glass fiber yarn is too small, the number of yarn strands forming the yarn bundle may be too small, thereby deteriorating the mechanical properties of the solid electrolyte sheet, which may cause numerous cracks, pinholes, etc., which may cause a battery short circuit. When the weight per bundle of glass fiber yarn is too large, the ratio of glass fiber bundles among the solid electrolyte powders may be too high, thereby hindering lithium ion conduction, causing current concentration due to narrowing of some movement paths, which may cause a battery short circuit. In addition, when the weight per bundle of glass fiber yarn satisfies the above range, the ion conductivity of the solid electrolyte sheet, the capacity, and the lifespan characteristics of the battery can be more desirably implemented.

[0061] In addition, the glass fiber according to the present invention may have a diameter of one glass fiber yarn of 0.8 to 5.5 μm, more specifically, 1.5 to 4.5 μm or 2.5 to 3.5 μm. When the diameter of one glass fiber yarn is too small, the strength of the glass fiber yarn may be weakened, which may deteriorate the mechanical properties of the solid electrolyte sheet, which may cause numerous cracks, pinholes, etc., which may cause a battery short circuit. When the diameter of one glass fiber yarn is too large, it is difficult for the solid electrolyte to fill the pores in the support, and the pores may remain unfilled, which may cause a battery short circuit. In addition, when the diameter of one glass fiber yarn satisfies the above range, the ionic conductivity of the solid electrolyte sheet, the capacity of the battery, and the lifespan characteristics can be more preferably implemented.

[0062] In addition, the porous support of the present invention has a mass per unit area of ​​14.5 to 23.5 g / m 2 may be, more specifically, 16 to 22 g / m 2 or 18 to 20 g / m 2 It can be. The mass per unit area of ​​the porous support can increase or decrease depending on the degree of dense weaving of the glass fibers. At this time, if the mass per unit area of ​​the porous support is too small, the density of the glass fibers may decrease, which may deteriorate the mechanical properties of the solid electrolyte sheet, which may cause numerous cracks, pinholes, etc., which may cause a battery short circuit. If the mass per unit area of ​​the porous support is too large, the density of the glass fibers may become excessively high, making it difficult for the solid electrolyte to fill the pores in the support, and the pores may remain unfilled, which may cause a battery short circuit. In addition, when the mass per unit area of ​​the porous support satisfies the above range, the ionic conductivity of the solid electrolyte sheet, the capacity of the battery, and the lifespan characteristics can be more preferably implemented.

[0063] In addition, the glass fiber according to the present invention may have a yarn strand concentration number of 5 to 60 per bundle of glass fiber yarns, and more specifically, 5 to 26. When the yarn strand concentration number per bundle of glass fiber yarns satisfies the above range, the effects of improving the mechanical properties and ionic conductivity of the solid electrolyte sheet, suppressing the occurrence of battery short circuits, and improving battery capacity and life characteristics can be more preferably implemented.

[0064] In addition, the solid electrolyte according to the present invention may have an average particle diameter (D50) of 1.5 to 4.5 μm, and more specifically, 2.5 to 3.5 μm. If the average particle diameter (D50) of the solid electrolyte is too small, the solid electrolyte may not be densely positioned within the pores of the porous support, which may deteriorate the mechanical properties of the solid electrolyte sheet and cause a battery short circuit. In addition, the interfacial area may increase due to small particles, which may lower the ionic conductivity of the membrane. If the average particle diameter (D50) of the solid electrolyte is too large, the pore structure of the porous support may be destroyed, or the solid electrolyte may not be filled into the pores but be exposed outside the support, which may deteriorate the mechanical properties or cause a battery short circuit. In addition, when the average particle diameter (D50) of the solid electrolyte satisfies the above range, the ionic conductivity of the solid electrolyte sheet, the capacity of the battery, and the lifespan characteristics can be more preferably implemented.

[0065] In this specification, the average particle diameter (D50) can be defined as the particle diameter corresponding to 50% of the volume accumulation amount in the particle diameter distribution curve. The average particle diameter (D50) can be measured using, for example, the laser diffraction method.

[0066]

[0067]

[0068] *62In addition, the content of the solid electrolyte may be 1 to 5 wt% based on the total weight of the porous support. If the content of the solid electrolyte is too low, the solid electrolyte may not be densely positioned within the pores of the porous support, which may deteriorate the mechanical properties of the solid electrolyte sheet and deteriorate the ionic conductivity of the solid electrolyte sheet. If the content of the solid electrolyte is too high, the pore structure of the porous support may be destroyed due to an excessive amount of solid electrolyte, or an appropriate amount of solid electrolyte may be exposed outside the support, which may deteriorate the mechanical properties or cause a battery short circuit. In addition, when the content of the solid electrolyte satisfies the above range, the ionic conductivity of the solid electrolyte sheet, the capacity of the battery, and the lifespan characteristics can be more preferably implemented.

[0069] Meanwhile, the solid electrolyte may be a sulfide compound, a halide compound, or a combination thereof. When the solid electrolyte is a sulfide compound or a halide compound, it has good compatibility with the porous support according to the present invention, and thus, short-circuiting during battery operation is suppressed, and capacity or life characteristics can be preferably implemented.

[0070] The above 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, Li2S-P2S5-Z m S n (wherein m, n are positive numbers, and Z is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q(where p and q are positive numbers, and M is one of P, Si, Ge, B, Al, Ga In), Li3PS4, Li7P3S 11 , Li 7-x PS 6-x Cl x (However, 0≤x≤2), Li 7-x PS 6-x Br x (where 0≤x≤2), and Li 7-x PS 6-x I x (However, there can be one or more selected from 0≤x≤2).

[0071] The above sulfide-based solid electrolyte is manufactured by treating starting materials such as Li2S and P2S5 by a melting rapid cooling method or a mechanical milling method. In addition, a heat treatment may be performed after the treatment. The solid electrolyte may be amorphous, crystalline, or a mixture thereof. In addition, the solid electrolyte may be, for example, one of the above-described sulfide-based solid electrolyte materials that contains at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements. For example, the solid electrolyte may be a material containing Li2S-P2S5.

[0072] From the perspective of more desirable implementation of ionic conductivity, the sulfide-based solid electrolyte may have an argyrodite-based crystal structure.

[0073] A sulfide-based solid electrolyte having an argyrodite crystal structure may contain, for example, Li, P, S, and halogen elements, and may further contain other doping elements as needed. By further including other doping elements in the argyrodite crystal structure, the moisture stability of the solid electrolyte may be improved, or the electrochemical properties, such as the capacity of the battery, may be more preferably realized.

[0074] The above sulfide compound can be more specifically represented by the following chemical formula 1.

[0075] [Chemical Formula 1]

[0076] Li x1 P y1 S z1 D w1 M1 a1 M2 a2

[0077] In the above chemical formula 1, D is a halogen element such as F, Cl, Br, I or a combination thereof, M1 is B, Al, Si, Ge, Ga, In, Sn or a combination thereof, M2 is O, N, Se, As, Se, Sb, Sn or a combination thereof, and 4≤x1≤8, 0.5≤y1≤1.5, 3≤z1≤7, 0≤a1≤2, 0≤a2≤2.

[0078] The above halide compound can be more specifically represented by the following chemical formula 2.

[0079] [Chemical Formula 2]

[0080] Li x2 M3 y2 A z2

[0081] In the above chemical formula 2, M3 is Sc, In, Zr, Lu, Er, Y, Ho or a combination thereof, A is a halogen element such as F, Cl, Br, I or a combination thereof, and 1.5≤x2≤3.5, 0.5≤y2≤1.5, 5≤z2≤7.

[0082]

[0083] Meanwhile, the solid electrolyte sheet according to the present invention may have a thickness of 80 μm or less. As the thickness of the solid electrolyte sheet decreases, the battery energy density can be improved.

[0084]

[0085] In addition, the solid electrolyte sheet according to the present invention has improved mechanical properties as the properties of the glass fiber support, the average particle diameter (D50) of the solid electrolyte, etc. are controlled within the range according to the present invention, and the tensile strength is 50 kgf / cm. 2 It can be more than 60 kgf / cm, more specifically2 , 70 kgf / cm 2 , 80 kgf / cm 2 , 90 kgf / cm 2 or 100 kgf / cm 2 It could be strange.

[0086] In addition, the solid electrolyte sheet according to the present invention can have improved mechanical properties such that the bending strength can be 80 MPa or more, and more specifically, 85 MPa, 90 MPa, 95 MPa, or 100 MPa or more, as the physical properties of the glass fiber support, the average particle diameter (D50) of the solid electrolyte, etc. are controlled within the ranges according to the present invention.

[0087] Meanwhile, in this specification, the tensile strength of the solid electrolyte sheet is measured by pulling the solid electrolyte sheet sample up and down at a speed of 5 mm / min in a dry room atmosphere with moisture removed using UTM, universal testing machine equipment, and the value of the force measured when the sample breaks (kgf / cm 2 ) can be obtained by measuring it. At this time, the sample can be punched and measured so that a tensile force can be applied to a certain area. More specifically, referring to Fig. 3, the total length of the solid electrolyte sheet sample to be stretched can be measured as 100 mm, the width as 25 mm, the length of the concave portion that becomes concave due to stretching as 23 mm, and the width of the concave portion as 5.2 mm.

[0088] In addition, the bending strength of the solid electrolyte sheet can be measured in a dry room atmosphere with moisture removed using a UTM, universal testing machine_model Zwick RoellZ2.5 TS_ Instron 2810 SERIES MICRO 3-POINT BEND FIXTURE(2810-411)_3-point bending strength equipment. Specifically, referring to Fig. 4, the bottom of the solid electrolyte sheet sample is supported by two supports (fulcrums), and a sharp pressure part is lowered from the top to apply force to the center of the sample and measure the force until the sample breaks. At this time, the solid electrolyte sheet sample size (Sample size), the lowering speed of the pressure part (Measurement speed), and the distance between the supports (Distance between fulcrums) can be performed as follows.

[0089] - Sample size: 10mm (length) x 5mm (width)

[0090] - Measurement speed: 1.2mm / min

[0091] - Distance between fulcrums: 3mm

[0092]

[0093] All samples for bending strength were subjected to a warm isostatic press at 80°C, 4,900 kgf for 30 minutes. This is because the excellent bending strength of the solid electrolyte sheet is the rigidity required to withstand the stress as a separator within a rolled cell without breaking.

[0094]

[0095] In addition, the solid electrolyte sheet according to the present invention has improved ionic conductivity as the properties of the glass fiber support, the average particle diameter (D50) of the solid electrolyte, etc. are controlled within the ranges according to the present invention, so that the ionic conductivity at 30°C can be 0.1 mS / cm or more, and more specifically, 0.2 mS / cm, 0.5 mS / cm, 0.7 mS / cm, 0.9 mS / cm, or 1.0 mS / cm or more.

[0096] Meanwhile, the solid electrolyte sheet according to the present invention may further include a binder selected from the group consisting of nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), styrene-butadiene-styrene copolymer, acrylic resin, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, or a combination thereof.

[0097] At this time, the content of the binder may be 1 to 5 wt% based on the total weight of the solid electrolyte. If the content of the binder is too low, the binding between the porous support and the solid electrolyte or between the solid electrolyte particles may not be properly performed, so that the internal voids in the sheet may increase, which may deteriorate the mechanical strength and cause a battery short circuit. If the content of the binder is too high, the cohesion between the solid electrolyte particles may occur too strongly, so that the internal voids in the sheet may increase, which may deteriorate the mechanical strength and cause a battery short circuit. In addition, the internal resistance may increase, which may lower the ionic conductivity of the solid electrolyte membrane. In addition, when the content of the binder satisfies the above range, the ionic conductivity of the solid electrolyte sheet, the capacity of the battery, and the lifespan characteristics can be more preferably implemented.

[0098]

[0099] Meanwhile, the solid electrolyte sheet according to the present invention can be manufactured according to the following manufacturing method, which will be described below.

[0100] First, a solid electrolyte composition is formed.

[0101] The above solid electrolyte composition may include a solvent along with the solid electrolyte and binder according to the present invention described above. Since the solid electrolyte and binder have been described in detail above, a detailed description thereof will be omitted.

[0102] The solvent may be, for example, a non-polar solvent such as xylene, toluene, an ester solvent, isobutyl isobutyrate, or a combination thereof, but is not necessarily limited thereto, and any solvent used in the relevant technical field may be used.

[0103] The above solid electrolyte composition may further include a dispersant that can improve the dispersibility of the solid content in the solid electrolyte composition, and may further include other additives as needed.

[0104]

[0105] Next, the solid electrolyte composition is applied and impregnated onto the prepared porous support.

[0106] The material (glass fiber) and properties of the porous support are the same as those described above, so they are omitted.

[0107] The above application is not particularly limited as long as it is commonly used in the relevant technical field, but may be performed by, for example, a slurry casting method.

[0108]

[0109] Next, the solid electrolyte composition applied on the porous support is dried to remove the solvent in the solid electrolyte composition, thereby forming a solid electrolyte sheet.

[0110] The drying can be performed, for example, at a temperature of about 20 to 120°C.

[0111]

[0112] 2. All-solid-state battery

[0113] Another embodiment of the present invention provides an all-solid-state battery comprising: a positive electrode layer; a negative electrode layer; and a solid electrolyte layer positioned between the positive electrode layer and the negative electrode layer, the solid electrolyte layer including the aforementioned solid electrolyte sheet.

[0114] More specifically, the above positive electrode layer may include a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector.

[0115] The above-mentioned positive electrode active material layer may include, for example, a positive electrode active material and a solid electrolyte. The solid electrolyte included in the positive electrode active material layer may be the same as or different from the solid electrolyte included in the solid electrolyte sheet.

[0116] A cathode active material is a material that can reversibly absorb and desorb lithium ions. Examples of cathode active materials include, but are not 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; and the like. Any material used as a cathode active material in the relevant technical field may be used. The cathode active materials may be singly or as a mixture of two or more.

[0117] The above lithium transition metal oxide is, for example, Li a A 1-b B b D2 (in the above formula, 0.90 ≤ a ≤ 1, and 0 ≤ b ≤ 0.5); Li a E 1-b B b O 2-c D c(In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); LiE 2-b B b O 4-c D c (In the above formula, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li a Ni 1-b-c Co b B c D α (In the above equation, 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 (In the above equation, 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 F2 (in the above formula, 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 (In the above equation, 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 O 2-α F α (In the above equation, 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 O 2-αF2 (in the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni b E c G d O2 (in the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0.001 ≤ d ≤ 0.1); Li a Ni b Co c Mn d GeO2 (in the above formula, 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 (in the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a CoG b O2 (in the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a MnG b O2 (in the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a Mn2G b O4 (wherein 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-f)Fe2(PO4)3(0 ≤ f ≤ 2); A compound represented by any one of the chemical formulas of LiFePO4. In this compound, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof. It is also possible to use a compound having a coating layer added to the surface of this compound, and it is also possible to use a mixture of the above-mentioned compound and the compound having a coating layer added. The coating layer added to the surface of these compounds includes a coating element compound of, for example, an oxide, a hydroxide, an oxyhydroxide of the coating element, an oxycarbonate of the coating element, or a hydroxycarbonate of the coating element of the coating element. The compound forming the coating layer is amorphous or crystalline. The coating elements included in the coating layer are Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or a mixture thereof. 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 coating method includes, for example, spray coating and dipping. Since the specific coating method is well understood by those working in the relevant field, a detailed description thereof will be omitted.

[0118] The positive electrode active material layer may include, for example, a solid electrolyte. The solid electrolyte included in the positive electrode layer may be the same as or different from the solid electrolyte included in the solid electrolyte layer.

[0119] The positive electrode active material layer may include, for example, a binder. The binder may include, but is not limited to, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, and the like, and any binder used in the art may be used.

[0120] The positive electrode active material layer may include, for example, a conductive material. The conductive material may include, but is not limited to, graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, etc., and any conductive material used in the relevant technical field may be used.

[0121] The positive electrode active material layer may further include, for example, additives such as fillers, coating agents, dispersants, and ion conductive aids in addition to the above-described positive electrode active material, solid electrolyte, binder, and conductive agent.

[0122] As fillers, coating agents, dispersants, ion conductive aids, etc. that the positive electrode active material layer may include, known materials generally used in electrodes of all-solid-state secondary batteries can be used.

[0123] The positive electrode collector may be, for example, a plate or foil made of 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. The thickness of the positive electrode collector may be, for example, 1 um to 100 um, 1 um to 50 um, 5 um to 25 um, or 10 um to 20 um.

[0124]

[0125] The above negative electrode layer may more specifically include a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector.

[0126] The above negative electrode active material layer may include, for example, a negative electrode active material and a binder.

[0127] The above negative electrode active material may include, for example, a carbon-based negative electrode active material, a metal / metalloid negative electrode active material, or a combination thereof.

[0128] The above carbon-based negative electrode active material may be amorphous carbon. The amorphous carbon may include, but is not limited to, carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), graphene, etc., and any material classified as amorphous carbon in the relevant technical field may be used. Amorphous carbon is carbon that has no crystallinity or very low crystallinity, and is distinguished from crystalline carbon or graphite-based carbon.

[0129] The metal / metalloid negative electrode active material includes at least one selected from the group consisting of lithium (Li), gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn), but is not necessarily limited thereto, and any metal negative electrode active material or metalloid negative electrode active material that forms an alloy or compound with lithium in the relevant technical field may be used.

[0130] The binder included in the negative electrode active material layer may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, etc., but is not necessarily limited thereto, and any binder used in the relevant technical field may be used. The binder may be composed of a single binder or a plurality of different binders.

[0131] By including a binder in the negative electrode active material layer, the negative electrode active material layer is stabilized on the negative electrode current collector. Furthermore, cracking of the negative electrode active material layer is suppressed despite changes in volume and / or relative position of the negative electrode active material layer during the charge / discharge process.

[0132] The negative active material layer may further include additives used in conventional all-solid-state batteries, such as fillers, coating agents, dispersants, and ion conductive aids.

[0133] The all-solid-state battery may further include a second negative electrode active material layer disposed between the negative electrode current collector and the negative electrode active material layer during charging. The second negative electrode active material layer may be deposited between the negative electrode current collector and the negative electrode current collector during the charging process, or may be further disposed on the negative electrode active material layer during electrode assembly. The second negative electrode active material layer may be a metal layer containing lithium or a lithium alloy. The lithium alloy includes, but is not limited to, a Li-Al alloy, a Li-Sn alloy, a Li-In alloy, a Li-Ag alloy, a Li-Au alloy, a Li-Zn alloy, a Li-Ge alloy, a Li-Si alloy, and the like, and any lithium alloy used in the art may be used. The second negative electrode active material layer may be made of one of these alloys and / or lithium, or may be made of multiple types of alloys and / or lithium.

[0134] The negative electrode current collector may be composed of, for example, a material that does not react with lithium, i.e., does not form an alloy or compound. The negative electrode current collector may include, but is not limited to, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni), and any material that is used as an electrode current collector in the art may be used. The negative electrode current collector may be composed of one of the above-described metals, or may be composed of an alloy or a coating material of two or more metals. The negative electrode current collector may be, for example, in the form of a plate or foil.

[0135]

[0136] Hereinafter, embodiments of the present invention will be described in more detail through examples. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0137]

[0138] Example 1

[0139] (1) Preparation of 3μm Li6PS5Cl argyrodite solid electrolyte

[0140] Li6PS5Cl was synthesized via a dry method. Specifically, Li2S, P2S5, and LiCl were weighed according to their compositions, mixed in a high-viscosity mill (Planetary Mill) at 300 rpm for 8 hours, and pellets were manufactured at 300 MPa. These pellets were heat-treated at 550°C in an argon (Ar) atmosphere to synthesize a Li6PS5Cl argyrodite-based solid electrolyte. The synthesized solid electrolyte was then ball milled to a pulverized particle size (D50) of 3 μm.

[0141] (2) Manufacturing of solid electrolyte sheets

[0142] (Preparation of a porous support) A porous support composed of glass fiber was prepared. The porous support was processed into a form in which a bundle of glass fiber yarns, each of which was made up of dozens of individual glass fiber yarn strands, was woven to have a large number of internal pores. The diameter of each glass fiber strand was 3 μm, the weight per glass fiber bundle was 8 g / km, and the mass per unit area of ​​the porous support was 19 g / m. 2 It was processed to become .

[0143] (Preparation of solid electrolyte composition) Afterwards, the solid electrolyte prepared above was mixed with a xylene solvent in which 2 wt% of NBR binder was dissolved to form a solid electrolyte composition (slurry). At this time, the content of the NBR binder was set to 2 wt% based on the total weight of the solid electrolyte. In addition, the content of the solid electrolyte in the solid electrolyte composition was set to 2 wt% based on the total weight of the prepared glass fiber porous support.

[0144] (Coating and impregnation) After that, the solid electrolyte composition (slurry) was coated and impregnated on the glass fiber porous support by blade coating.

[0145] (After drying), the solid electrolyte composition (slurry) applied and impregnated on the porous support was dried at 50°C to remove the solvent, thereby manufacturing a final solid electrolyte sheet.

[0146] (3) All-solid-state battery manufacturing

[0147] The above-mentioned manufactured solid electrolyte sheet is 0.785 cm 2 After punching out the area and placing it in the pressure cell, the composite electrode was loaded on top. The composite electrode was made by mixing the cathode slurry, which was a cathode active material (NCM811): solid electrolyte (Li6PS5Cl): conductive material (denka black) in a weight ratio of 70:29:1, and loading it with a thickness of 0.785 cm. 2It was manufactured by loading 20.0 mg on the area and densifying to 300 MPa. Afterwards, the In-Li counter electrode was bonded at 50 MPa as the cathode, and the cell was fastened at the same pressure.

[0148]

[0149] Other Examples, Comparative Examples, and Reference Examples

[0150] As shown in Table 1 below, when preparing a porous support, the weight per bundle of glass fiber yarn, the diameter of one strand of glass fiber yarn, and the mass per unit area of ​​the porous support were processed differently, and when preparing a solid electrolyte, the average particle size (D50) was varied, and a solid electrolyte sheet and an all-solid-state battery were manufactured in the same manner as in Example 1.

[0151] (Example 3 is described repeatedly in Tables 1 and 2 below. This is to more easily compare the correlation between the mechanical properties and electrochemical properties of the solid electrolyte sheet according to the control of various properties of the glass fiber.)

[0152] Glass fiber solid electrolyte yarn bundle weight (g / 1km) yarn strand diameter (μm) support unit area mass (g / m) 2) Number of yarn strands per bundle Average particle diameter (D50) (μm) Comparative example 19319103 Example 18319103 Example 27319103 Example 36319103 Example 45319103 Example 54319103 Comparative example 23319103 Reference example 16619103 Example 66519103 Example 76419103 Example 36319103 Example 86219103 Example 96119103 Reference example 260.519103 Reference example 36324103 Example 106323103 Example 116321103 Example 36319103 Example 126317103 Example 136315103 Reference Example 46314103 Reference Example 56319101 Example 146319102 Example 36319103 Example 156319104 Reference Example 66319105 Reference Example 7631923 Example 36319103 Example 166319203 Reference Example 86319303

[0153] Table 2 below is a table summarizing the results of evaluating the mechanical and electrochemical properties of the solid electrolyte sheet according to Experimental Examples 2 to 4 described below.

[0154] Mechanical propertiesElectrochemical propertiesTensile strength (Kgf / cm) 2) Bending strength (MPa) Ionic conductivity (mS / cm) Initial discharge capacity (mAh / g) Life characteristics (%) Comparative example 11081250.02 Paragraph Paragraph Example 11051200.216582 Example 21031150.817892 Example 377.81091.118297 Example 465950.717687 Example 555870.216582 Comparative example 252740.06 Paragraph Paragraph Reference example 1721020.08 Paragraph Paragraph Example 61071180.415281 Example 71041120.617794 Example 377.81091.118297 Example 863920.317488 Example 951830.215281 Reference Example 2821130.7 Paragraph Paragraph Reference Example 3821200.05 Paragraph Paragraph Example 101091190.616687 Example 111071110.717995 Example 377.81091.118297 Example 1267950.317681 Example 1359820.215479 Reference Example 448751.2 Paragraph Paragraph Reference Example 565970.115875 Example 1472920.617280 Example 377.81091.118297 Example 15781111.218095Reference Example 6791121.5 Paragraph Paragraph Reference Example 738621.3 Paragraph Paragraph Example 377.81091.118297Example 16921150.717581Reference Example 81201260.5 Paragraph Paragraph

[0155] Experimental Example 1: Evaluation of Self-Standing Properties of Solid Electrolyte Sheets

[0156] An image of a solid electrolyte sheet manufactured according to Example 3 is shown in Fig. 2.

[0157] Referring to FIG. 2, the solid electrolyte sheet of the embodiment is well equipped with a self-standing membrane form, and thus, convenience of processes such as a stacking process for cell production is expected.

[0158]

[0159] Experimental Example 2: Evaluation of the mechanical properties of solid electrolyte sheets

[0160] (1) Tensile strength evaluation

[0161] The tensile strength of the solid electrolyte sheet was measured by pulling the solid electrolyte sheet sample up and down at a speed of 5 mm / min in a dry room atmosphere with moisture removed using UTM, a universal testing machine, and the value of the force measured when the sample breaks (kgf / cm 2 ) was measured and obtained. At this time, the sample was punched and measured so that a tensile force could be applied to a certain area. More specifically, referring to Fig. 3, the total length of the solid electrolyte sheet sample being stretched was 100 mm, the width was 25 mm, the length of the concave portion that became concave due to stretching was 23 mm, and the width of the concave portion was 5.2 mm.

[0162] Figure 5 is a graph showing the results of evaluating the tensile strength of a solid electrolyte sheet manufactured according to Example 3.

[0163] (2) Bending strength evaluation

[0164] The bending strength of the solid electrolyte sheet was measured in a dry room atmosphere with moisture removed using a UTM, universal testing machine_model Zwick RoellZ2.5 TS_ Instron 2810 SERIES MICRO 3-POINT BEND FIXTURE(2810-411)_3-point bending strength equipment. Specifically, referring to Fig. 4, the bottom of the solid electrolyte sheet sample was supported by two supports (fulcrums), and a sharp pressure part was lowered from the top to apply force to the center of the sample, and the force until the sample broke was measured. At this time, the solid electrolyte sheet sample size (Sample size), the lowering speed of the pressure part (Measurement speed), and the distance between the supports (Distance between fulcrums) were as follows.

[0165] - Sample size: 10mm (length) x 5mm (width)

[0166] - Measurement speed: 1.2mm / min

[0167] - Distance between fulcrums: 3mm

[0168] Figure 6 is a graph showing the results of evaluating the bending strength of a solid electrolyte sheet manufactured according to Example 3.

[0169]

[0170] Experimental Example 3: Evaluation of the ionic conductivity of solid electrolyte sheets

[0171] The solid electrolyte sheet manufactured according to the examples and comparative examples was used as a working electrode and the cell was fastened at a pressure of 70 MPa using SUS, and then the impedance was measured by applying a voltage of 10 mV at 30°C.

[0172]

[0173] Experimental Example 4: Evaluation of the Electrochemical Characteristics of All-Solid-State Battery

[0174] (1) Initial discharge capacity evaluation

[0175] After fabricating the all-solid-state battery, it was aged at 25°C for 12 hours and then subjected to a charge-discharge test at 30°C. To evaluate the initial capacity, 200 mAh / g was used as the reference capacity, and the battery was charged to 4.25 V at a constant current of 0.1 C. Then, the battery was switched to a constant voltage and charged until the end current reached 0.05 C. After a 10-minute rest period after charging, the battery was discharged to 2.5 V at a constant current of 0.1 C, using 200 mAh / g as the reference capacity.

[0176] (2) Life characteristics evaluation (30℃, 50 cycles)

[0177] After fabricating the all-solid-state battery, it was charged to 4.25 V at a constant current of 0.5 C at 30 °C, then switched to a constant voltage and charged until the end current reached 0.05 C. After a 10-minute rest period after charging, it was discharged at a constant current of 1.0 C until the voltage reached 2.5 V. Under these charge-discharge cycle conditions, 50 charge-discharge cycles were performed, and the capacity retention rate of the 50th cycle was calculated compared to the first cycle.

[0178]

[0179] Referring to Tables 1 and 2, in the case of Examples 1 to 16 in which all properties, including the weight per bundle of glass fiber yarn, satisfied the range according to the present invention, it was confirmed that mechanical properties (solid electrolyte sheet tensile strength, bending strength) and electrochemical properties (solid electrolyte sheet ionic conductivity, battery capacity, and lifespan) were equally excellently implemented.

[0180] On the other hand, in the case of Comparative Example 1, it was confirmed that the weight per bundle of glass fiber yarn was too large, resulting in excessive deterioration of the ionic conductivity of the solid electrolyte sheet and occurrence of a battery short circuit.

[0181] In the case of Comparative Example 2, it was confirmed that the weight per bundle of glass fiber yarn was too small, resulting in excessive deterioration of the bending strength and ionic conductivity of the solid electrolyte sheet, and occurrence of a battery short circuit.

[0182] In the case of Reference Example 1, it was confirmed that the diameter of one strand of glass fiber yarn was too large, resulting in excessive deterioration of the ionic conductivity of the solid electrolyte sheet and occurrence of a battery short circuit.

[0183] In the case of Reference Example 2, it was confirmed that a battery short circuit occurred as a result of the diameter of one strand of glass fiber yarn being too small.

[0184] In the case of Reference Example 3, it was confirmed that the mass per unit area of ​​the support was too large, resulting in excessive deterioration of the ionic conductivity of the solid electrolyte sheet and occurrence of a battery short circuit.

[0185] In the case of Reference Example 4, the mass per unit area of ​​the support was too small, resulting in excessive deterioration of the mechanical properties (tensile strength, bending strength) of the solid electrolyte sheet, and although the ionic conductivity increased, the glass fiber occupancy ratio inside the sheet decreased, resulting in deterioration of the mechanical rigidity and occurrence of a battery short circuit.

[0186] In the case of Reference Example 5, it was confirmed that the average particle diameter (D50) of the solid electrolyte was too small, resulting in the ionic conductivity of the solid electrolyte sheet being too deteriorated and the battery life characteristics being too deteriorated.

[0187] In the case of Reference Example 6, it was confirmed that a battery short circuit occurred because the average particle diameter (D50) of the solid electrolyte was too large.

[0188] In the case of Reference Example 7, it was confirmed that the number of yarn strands per bundle of glass fiber yarn was too small, resulting in excessive deterioration of the mechanical properties (tensile strength, bending strength) of the solid electrolyte sheet and occurrence of a battery short circuit.

[0189] In the case of Reference Example 8, it was confirmed that a short circuit occurred in the battery as the number of yarn strands per bundle of glass fiber yarn was too large.

[0190] Meanwhile, when comparing the examples, it was confirmed that in the case of Examples 2 to 4, 7 to 8, and 11 to 12, in which the weight per bundle of glass fiber yarn and other properties were more appropriately controlled, the mechanical properties (solid electrolyte sheet tensile strength, bending strength) and electrochemical properties (solid electrolyte sheet ionic conductivity, battery capacity, and lifespan) were comprehensively more preferably implemented than in the other examples.

[0191]

[0192] Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the patent claims, the detailed description of the invention, and the attached drawings, and it is obvious that this also falls within the scope of the present invention.

[0193] Accordingly, the actual scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A porous support composed of glass fibers and a solid electrolyte filled in all or at least part of the pores of the porous support, The above glass fiber is a solid electrolyte sheet having a weight per bundle of glass fiber yarn of 3.5 to 8.5 g / 1km.

2. In paragraph 1, The above glass fiber is a solid electrolyte sheet having a diameter of one strand of glass fiber yarn of 0.8 to 5.5 μm.

3. In paragraph 1, The porous support has a mass per unit area of ​​14.5 to 23.5 g / m 2 A solid electrolyte sheet.

4. In paragraph 1, The above solid electrolyte is a solid electrolyte sheet having an average particle diameter (D50) of 1.5 to 4.5 μm.

5. In paragraph 1, The above glass fiber is a solid electrolyte sheet having a yarn strand concentration of 5 to 26 per glass yarn bundle.

6. In paragraph 1, The above solid electrolyte is a solid electrolyte sheet comprising a sulfide compound, a halide compound, or a combination thereof.

7. In paragraph 1, The above solid electrolyte is a solid electrolyte sheet which is a sulfide compound with an argyrodite crystal structure.

8. In paragraph 6, The above sulfide compound is a solid electrolyte sheet represented by the following chemical formula 1: [Chemical Formula 1] The x1 P y1 S z1 D w1 M1 a1 M2 a2 In the above chemical formula 1, D is a halogen element such as F, Cl, Br, I or a combination thereof, M1 is B, Al, Si, Ge, Ga, In, Sn or a combination thereof, M2 is O, N, Se, As, Se, Sb, Sn or a combination thereof, and 4≤x1≤8, 0.5≤y1≤1.5, 3≤z1≤7, 0≤a1≤2, 0≤a2≤2.

9. In paragraph 6, The above halide compound is a solid electrolyte sheet represented by the following chemical formula 2: [Chemical Formula 2] Li x2 M3 y2 A z2 In the above chemical formula 2, M3 is Sc, In, Zr, Lu, Er, Y, Ho or a combination thereof, A is a halogen element such as F, Cl, Br, I or a combination thereof, and 1.5≤x2≤3.5, 0.5≤y2≤1.5, 5≤z2≤7.

10. In paragraph 1, A solid electrolyte sheet having a content of the solid electrolyte of 1 to 5 wt% based on the total weight of the porous support.

11. In paragraph 1, A solid electrolyte sheet having a thickness of 80 μm or less.

12. In paragraph 1, Tensile strength is 50 kgf / cm 2 Ideal solid electrolyte sheet.

13. In paragraph 1, A solid electrolyte sheet having a bending strength of 80 MPa or more.

14. In paragraph 1, A solid electrolyte sheet having an ionic conductivity of 0.1 mS / cm or more at 30°C.

15. An all-solid-state battery comprising a positive electrode layer; a negative electrode layer; and a solid electrolyte layer positioned between the positive electrode layer and the negative electrode layer, the solid electrolyte layer including the solid electrolyte sheet of claim 1.

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