Solid electrolyte for all solid-state battery and all solid-state battery including same

Abstract

The present invention relates to a solid electrolyte for an all solid-state battery and an all solid-state battery including same, wherein the solid electrolyte for an all solid-state battery comprises a Zr element in an amount of 100 ppm to 1000 ppm, and comprises an argyrodite-based compound.

Description

Solid electrolyte for all-solid-state batteries and all-solid-state batteries containing the same

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

[0002] Recently, rapid developments have been made in electronic devices that use batteries, such as cell phones, laptop computers, and electric vehicles.

[0003] With these batteries, the development of all-solid-state batteries is underway. All-solid-state batteries are composed entirely of solid materials, specifically those that utilize solid electrolytes. Because the electrolyte is solid, all-solid-state batteries are structurally robust, reducing the risk of fire or explosion due to leakage from external impacts. Furthermore, all-solid-state batteries can be configured in a variety of shapes, making them useful in a variety of fields.

[0004] One embodiment provides a solid electrolyte for an all-solid-state battery having excellent ionic conductivity.

[0005] Another embodiment provides an all-solid-state battery comprising the solid electrolyte.

[0006] One embodiment provides a solid electrolyte for an all-solid-state battery comprising Zr element in an amount of 100 ppm to 1000 ppm and an argyrodite-based compound.

[0007] Another embodiment provides an all-solid-state battery comprising: a cathode; an anode; and a solid electrolyte layer positioned between the anode and the cathode, the solid electrolyte layer including the solid electrolyte.

[0008] A solid electrolyte for an all-solid-state battery according to one embodiment exhibits excellent ionic conductivity, and thus can provide an all-solid-state battery exhibiting excellent performance.

[0009] Figure 1 is a schematic diagram schematically showing an all-solid-state battery according to one embodiment.

[0010] Figure 2 is a schematic cross-sectional view schematically showing an all-solid-state battery according to another embodiment.

[0011] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention. The present invention is defined solely by the scope of the claims set forth below.

[0012] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0013] “Combination of these” means a mixture, laminate, composite, copolymer, alloy, blend, reaction product, etc. of the components.

[0014] It should be understood that the terms "include," "comprise," or "have" are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0015] Throughout this specification, when it is said that a part "includes" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0016] In addition, the terms "about", "substantially", etc. used throughout this specification are used in the sense of numerical values ​​or near numerical values ​​when manufacturing and material tolerances inherent to the meanings stated are presented, and are used to prevent unscrupulous infringers from unfairly exploiting disclosures that mention exact or absolute values ​​to aid understanding of this specification.

[0017] Throughout this specification, the description of “A and / or B” means “A or B or both.”

[0018] Unless otherwise specified herein, when a part such as a layer, film, region, or plate is said to be “on top of” another part, this includes not only cases where it is “directly on top of” the other part, but also cases where there is another part in between.

[0019] In the present invention, "particle size" or "particle diameter" may be an average particle diameter. In addition, the average particle diameter may be defined as the average particle diameter (D50) based on 50% of the cumulative volume in a particle diameter distribution curve. The particle diameter may be measured by a method 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, a scanning electron microscope, or a field emission scanning electron microscope (FE-SEM). Alternatively, the average particle diameter (D50) may be obtained by measuring with a measuring device that utilizes dynamic light-scattering, performing data analysis to count the number of particles for each particle size range, and calculating from this. Alternatively, the average particle diameter (D50) may be measured using a laser diffraction method. When measuring by laser diffraction, more specifically, after the particles to be measured are dispersed in a dispersion medium, they are introduced into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000) and irradiated with ultrasonic waves of about 28 kHz at an output of 60 W, and then the average particle diameter (D50) based on 50% of the particle size distribution in the measuring device can be calculated. Alternatively, the average particle diameter may be obtained by randomly measuring the sizes (diameter or length of the major axis) of about 20 particles in a scanning electron microscope image to obtain a particle size distribution, and taking the diameter (D50) of the particles having a cumulative volume of 50% by volume in the particle size distribution as the average particle diameter.

[0020] "Thickness" may be measured, for example, from photographs taken with an optical microscope such as a scanning electron microscope.

[0021] One embodiment relates to a solid electrolyte for an all-solid-state battery comprising Zr element in an amount of 100 ppm to 1000 ppm (e.g., by weight) and comprising an argyrodite-based compound.

[0022] In one embodiment, the azirodite compound can be represented by the following chemical formula 1.

[0023] [Chemical Formula 1]

[0024] Li a M b S c P d X e

[0025] In the above chemical formula 1, a, b, c, d, and e are all 0 or more and 12 or less. The a may be 4 to 8, or 5 to 7. The b may be 0 to 0.5, or 0 to 0.3. The c may be 4 to 6, or 4 to 5. The d may be 0.1 to 2, or 0.2 to 1.9. The e may be 0.1 to 2, or 0.1 to 1.9.

[0026] M is Ge, Sn, Si, Ag, Cu or a combination thereof, and may be Cu, Sn or a combination thereof.

[0027] X is one of F, Cl, Br, or I, and may be Cl, Br, or a combination thereof.

[0028] Specific examples of these argyrodite compounds are Li6PS5Cl, Li6PS5Br, Li 5.8 PS 4.8 Cl 1.2 , Li 6.2 PS 5.2 Br 0.8 , Li6PS5I, Li 5.75 PS 4.75 Cl 1.25 , (Li 5.69 Cu0.06 )PS 4.75 Cl 1.25 , (Li 5.72 Cu 0.03 )PS 4.75 Cl 1.25 , (Li 5.69 Cu 0.06 )P(S 4.70 (SO4) 0.05 )Cl 1.25 , (Li 5.69 Cu 0.06 )P(S 4.60 (SO4) 0.15 )Cl 1.25 , (Li 5.72 Cu 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 , (Li 5.72 Na 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 , Li 5.75 P(S 4.725 (SO4) 0.025 )Cl 1.25 , or a combination of these.

[0029] A solid electrolyte according to one embodiment may contain Zr element in an amount of 100 ppm to 1000 ppm, 100 ppm to 700 ppm, or 100 ppm to 600 ppm. In one embodiment, since Zr element is not present in a doped form in the argyrodite compound, Zr is not included in the above chemical formula 1. In addition, the solid electrolyte containing Zr element means that Zr element is present on the surface of the argyrodite compound or in a mixed state.

[0030] In one embodiment, the Zr element may be included in the form of Zr metal, Zr alloy, Li2O-ZrO2, Li2ZrO3, or a combination thereof. That is, the argyrodite compound according to one embodiment may be mixed with Zr particles (Zr metal particles) or a Zr alloy, or a compound including Zr may be mixed to form a solid electrolyte. The Zr alloy is an alloy of Zr metal and another metal, wherein the other metal can form an alloy with Zr, and any metal applicable to a solid electrolyte of an all-solid-state battery may be applied.

[0031] In one embodiment, the ionic conductivity of the solid electrolyte at room temperature (20°C to 27°C) may be 1 mS / cm to 10 mS / cm, or may be 1 mS / cm to 9 mS / cm. Since the solid electrolyte according to one embodiment exhibits such high ionic conductivity, it can be seen that it will exhibit excellent battery characteristics.

[0032] The average particle diameter (D50) of the solid electrolyte according to one embodiment may be 0.5 µm to 5 µm, and may also be 0.5 µm to 4 µm, 1 µm to 4 µm, or 1 µm to 3.5 µm.

[0033] The above solid electrolyte can be manufactured by the following method.

[0034] The azirodite compound of the above chemical formula 1 is mixed with zirconia. At this time, the content of the zirconia may be 0.001 wt% to 50 wt%, 0.01 wt% to 10 wt%, 0.01 wt% to 5 wt%, 0.01 wt% to 3 wt%, 0.01 wt% to 1 wt%, or 0.01 wt% to 0.1 wt% with respect to 100 wt% of the azirodite compound.

[0035] The obtained mixture is subjected to a firing process.

[0036] The above firing process can be carried out at a temperature of 300°C to 700°C, or 400°C to 600°C. In addition, the above firing process can be carried out for 1 hour to 24 hours, or 3 hours to 20 hours.

[0037] Next, the sintered product is pulverized to produce a solid electrolyte.

[0038] The above grinding process can be carried out at a rotation speed of 100 rpm to 800 rpm, and can also be carried out at a rotation speed of 100 rpm to 700 rpm, or 120 rpm to 700 rpm. In addition, the grinding process can be carried out for a period of time in which the average particle diameter (D50) of the grinding product becomes 0.5 ㎛ to 5 ㎛. For example, the process can be carried out for 1 hour to 24 hours.

[0039] The solid electrolyte manufactured according to the above process contains Zr element in an amount of 100 ppm to 1000 ppm and includes an argyrodite compound.

[0040] The composition of the solid electrolyte layer is described below.

[0041] Solid electrolyte layer

[0042] The solid electrolyte layer includes a solid electrolyte according to one embodiment.

[0043] In addition, the solid electrolyte layer may further include a binder. At this time, the binder may be styrene butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, an acrylate polymer, or a combination thereof, but is not limited thereto, and any binder used in the relevant technical field may be used. The acrylate polymer may be butyl acrylate, polyacrylate, polymethacrylate, or a combination thereof.

[0044] The above solid electrolyte layer can be formed by adding a solid electrolyte according to one embodiment to a binder solution, coating the same on a base film, and drying. The solvent of the binder solution may be isobutyryl isobutyrate, xylene, toluene, benzene, hexane, or a combination thereof. Since the solid electrolyte layer formation process is widely known in the art, a detailed description thereof will be omitted herein.

[0045] The thickness of the solid electrolyte layer may be, for example, 10 μm to 150 μm.

[0046] The solid electrolyte layer may further include an alkali metal salt, and / or an ionic liquid, and / or a conductive polymer.

[0047] The above alkali metal salt may be, for example, a lithium salt. The content of the lithium salt in the solid electrolyte layer may be 1 M or more, for example, 1 M to 4 M. In this case, the lithium salt may improve ion conductivity by enhancing the lithium ion mobility of the solid electrolyte layer.

[0048] The above lithium salts include, for example, LiSCN, LiN(CN)2, Li(CF3SO2)3C, LiC4F9SO3, LiN(SO2CF2CF3)2, LiCl, LiF, LiBr, LiI, LiB(C2O4)2, LiBF4, LiBF3(C2F5), lithium bis(oxalato)borate (LiBOB), lithium oxalyldifluoroborate (LIODFB), lithium difluoro(oxalato)borate (LiDFOB), lithium bis(trifluoro methanesulfonyl)imide (LiTFSI, LiN(SO2CF3)2), lithium bis(fluorosulfonyl)imide (LiFSI, It may include LiN(SO2F)2), LiCF3SO3, LiAsF6, LiSbF6, LiClO4 or mixtures thereof.

[0049] In addition, the lithium salt may be an imide-based one, and for example, the imide-based lithium salt may include lithium bis(trifluoro methanesulfonyl)imide (LiTFSI, LiN(SO2CF3)2), lithium bis(fluorosulfonyl)imide (LiFSI, LiN(SO2F)2). The lithium salt may maintain or improve ionic conductivity by appropriately maintaining chemical reactivity with an ionic liquid.

[0050] The above ionic liquid has a melting point below room temperature and is a salt or room-temperature molten salt that is liquid at room temperature and consists only of ions.

[0051] The above ionic liquid comprises a) one or more cations selected from ammonium, pyrrolidinium, pyridinium, pyrimidinium, imidazolium, piperidinium, pyrazolium, oxazolium, pyridazinium, phosphonium, sulfonium, triazolium, and mixtures thereof, and b) BF4. - , PF6 - , AsF6 - , SbF6 - , AlCl4 - , HSO4 - , ClO4 - , CH3SO3 - , CF3CO2 - , Cl - , Br - , I - , BF4 - , SO4 - , CF3SO3 - , (FSO2)2N - , (C2F5SO2)2N - , (C2F5SO2)(CF3SO2)N - , and (CF3SO2)2N - It may be a compound containing one or more anions selected from among.

[0052] The ionic liquid may be at least one selected from the group consisting of, for example, N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidinium bis(3-trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide.

[0053] In the above solid electrolyte layer, the weight ratio of the solid electrolyte and the ionic liquid may be 0.1:99.9 to 90:10, for example, 10:90 to 90:10, 20:80 to 90:10, 30:70 to 90:10, 40:60 to 90:10, or 50:50 to 90:10. A solid electrolyte layer satisfying the above range can maintain or improve ionic conductivity by improving the electrochemical contact area with the electrode. Accordingly, the energy density, discharge capacity, rate characteristics, etc. of the all-solid-state battery can be improved.

[0054] [All-solid-state battery]

[0055] Another embodiment provides an all-solid-state battery comprising the solid electrolyte. The all-solid-state battery comprises a positive electrode, a negative electrode, and a solid electrolyte layer positioned between the positive electrode and the negative electrode. The solid electrolyte layer comprises the solid electrolyte according to one embodiment.

[0056] Bipolar

[0057] The above positive electrode includes a positive electrode current collector and a positive electrode active material layer positioned on the positive electrode current collector.

[0058] The above-mentioned positive electrode active material layer may include a positive electrode active material and a sulfide-based solid electrolyte. In addition, the above-mentioned positive electrode active material layer may further include a binder and a conductive material.

[0059] The above positive electrode active material may be a positive electrode active material capable of reversibly absorbing and releasing lithium ions.

[0060] The above-mentioned positive electrode active material may be a positive electrode active material capable of reversibly absorbing and releasing lithium ions. For example, the positive electrode active material may use at least one of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof. Specific examples of the positive electrode active material include Li a A 1-b B 1 b D1 2(0.90≤a≤1.8, 0≤b≤0.5); Li a HAVE BEEN 1-b B 1 b O 2-c D 1 c (0.90≤a ≤1.8, 0 ≤b≤0.5, 0≤c≤0.5); Li a HAVE BEEN 2-b B 1 b O 4-c D 1 c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤05); Li a Ni 1-b-c Co b B 1 c D 1 α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α≤2); Li a Ni 1-b-c Co b B 1 c O 2-α F 1 α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Co b B 1 c O 2-α F 1 2(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mr b B 1 c D 1 α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α≤2); Li a Ni 1-b-c Mr b B 1 c O 2-α F 1 α(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b B 1 c O 2-α F 1 2(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b E c G d O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a MnG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiI 1 O2; LiNiVO4; Li (3-f) J2(PO4)3(0 ≤f≤2); Li (3-f) Fe2(PO4)3(0≤f≤2); or LiFePO4.

[0061] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; B 1 is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements or a combination thereof; D 1is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F 1 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 1 is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof; L 1 is Mn, Al or a combination thereof.

[0062] Of course, a compound having a coating layer on the surface of the compound may be used, or a compound having the compound and a coating layer may be mixed and used. The coating layer may include at least one coating element compound selected from the group consisting of an oxide of the coating element, a hydroxide of the coating element, an oxyhydroxide of the coating element, an oxycarbonate of the coating element, and a hydroxycarbonate of the coating element. The compounds forming these coating layers may be amorphous or crystalline. The coating elements included in the coating layer may include Li, Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or a combination thereof.

[0063] In addition, as the above coating layer, any known coating layer of the positive electrode active material of an all-solid-state battery can be applied, and examples thereof include Li2O-ZrO2 (LZO).

[0064] Furthermore, when the cathode active material is a ternary compound containing nickel, cobalt, and manganese, or nickel, cobalt, and aluminum, the capacity density of the all-solid-state battery can be further improved and metal dissolution from the cathode active material can be further reduced in a charged state. Consequently, the all-solid-state battery can exhibit improved long-term reliability and cycle performance in a charged state.

[0065] Here, the shape of the positive electrode active material may include, for example, a particle shape such as a sphere, an ellipsoid, a shape close to a sphere, a polyhedron, or an irregular shape.

[0066] In addition, the average particle diameter of the positive electrode active material is not particularly limited and may be within a range applicable to positive electrode active materials of existing all-solid-state secondary batteries. For example, the average particle diameter of the positive electrode active material may be 1 μm to 25 μm, for example, 4 μm to 25 μm, 5 μm to 20 μm, 8 μm to 20 μm, or 10 μm to 18 μm. A positive electrode active material having such a particle diameter range can be harmoniously mixed with other components within the positive electrode active material layer and can realize high capacity and high energy density.

[0067] The above positive electrode active material may be in the form of secondary particles formed by agglomeration of a plurality of primary particles, or may be in the form of a single crystal.

[0068] In addition, in the positive electrode active material layer, the content of the positive electrode active material is not particularly limited, but for example, with respect to 100 wt% of the entire positive electrode active material layer, the positive electrode active material may be included in an amount of 55 wt% to 99.7 wt%, for example, 74 wt% to 89.8 wt%. When included in the above range, the capacity of the all-solid-state battery can be maximized while further improving the life characteristics.

[0069] In one embodiment, the sulfide-based solid electrolyte is Li2S-P2S5, Li2S-P2S5-LiX (X is a halogen element, for example, I or Cl), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n (m and n are integers greater than or equal to 0 and less than or equal to 12, respectively, and Z is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p and q are integers greater than or equal to 0 and less than or equal to 12, respectively; M is one of P, Si, Ge, B, Al, Ga In), Li a M b P c S d A e (a, b, c, d and e are each integers greater than or equal to 0 and less than or equal to 12, M is Ge, Sn, Si or a combination thereof, and A is one of F, Cl, Br, or I). The sulfide-based solid electrolyte may be, for example, Li 7-x PS 6-x F x (0≤x≤2), Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2) or Li 7-x PS 6-x I x (0≤x≤2) can be. Also, specifically, Li3PS4, Li7P3S 11 , Li7PS6, Li6PS5Cl, Li6PS5Cl, Li6PS5I, Li6PS5Br, Li 5.8 PS 4.8 Cl1.2 , Li 6.2 PS 5.2 Br 0.8 It could be the back.

[0070] In one embodiment, the sulfide-based solid electrolyte may be an argyrodite-type sulfide-based solid electrolyte. The argyrodite-type sulfide-based solid electrolyte may be, for example, Li a M b P c S d A e (a, b, c, d, and e are all 0 or greater and 12 or less, M is Ge, Sn, Si, or a combination thereof, and A is one of F, Cl, Br, or I).

[0071] As specific examples, Li3PS4, Li7P3S 11 , Li7PS6, Li6PS5Cl, Li6PS5Br, Li 5.8 PS 4.8 Cl 1.2 , Li 6.2 PS 5.2 Br 0.8 , Li6PS5I, Li 5.75 PS 4.75 Cl 1.25 , (Li 5.69 Cu 0.06 )PS 4.75 Cl 1.25 , (Li 5.72 Cu 0.03 )PS 4.75 Cl 1.25 , (Li 5.69 Cu 0.06 )P(S 4.70 (SO4) 0.05 )Cl 1.25 , (Li 5.69 Cu 0.06 )P(S 4.60 (SO4) 0.15 )Cl 1.25 , (Li 5.72 Cu 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 , (Li 5.72 Na 0.03)P(S 4.725 (SO4) 0.025 )Cl 1.25 , Li 5.75 P(S 4.725 (SO4) 0.025 )Cl 1.25 , or combinations thereof, but are not limited thereto.

[0072] The sulfide-based solid electrolyte may be amorphous, crystalline, or a mixture thereof. For example, the sulfide-based solid electrolyte may be obtained by mixing Li2S and P2S5 in a molar ratio of 50:50 to 90:10, or in a molar ratio of 50:50 to 80:20. Within the above mixing ratio range, a sulfide-based solid electrolyte having excellent ionic conductivity can be produced. Here, the ionic conductivity can be further improved by further including other components such as SiS2, GeS2, and B2S3.

[0073] Methods for mixing sulfur-containing raw materials for manufacturing sulfide-based solid electrolytes include mechanical milling and solution methods. Mechanical milling involves placing the starting raw materials in a reactor and vigorously stirring them with a ball mill, thereby finely agitating the starting raw materials and mixing them. Using the solution method, the starting raw materials are mixed in a solvent to obtain a solid electrolyte as a precipitate. Furthermore, heat treatment after mixing can solidify the crystals of the solid electrolyte and improve ionic conductivity. For example, a sulfide-based solid electrolyte can be manufactured by mixing sulfur-containing raw materials and heat-treating them twice or more, in which case a sulfide-based solid electrolyte with high ionic conductivity and robustness can be manufactured.

[0074] Of course, a commercially available solid electrolyte can be used as the sulfide-based solid electrolyte.

[0075] With respect to the total weight of the positive electrode active material layer, the content of the solid electrolyte may be 0.1 wt% to 35 wt%, for example, 1 wt% to 35 wt%, 5 wt% to 30 wt%, 8 wt% to 25 wt%, or 10 wt% to 20 wt%. In addition, with respect to the total weight of the positive electrode active material and the solid electrolyte in the positive electrode active material layer, 65 wt% to 99 wt% of the positive electrode active material and 1 wt% to 35 wt% of the solid electrolyte may be included, for example, 80 wt% to 90 wt% of the positive electrode active material and 10 wt% to 20 wt% of the solid electrolyte may be included. When the solid electrolyte is included in the positive electrode in such an amount, the efficiency and life characteristics of the all-solid-state battery can be improved without reducing the capacity.

[0076] The above binder serves to adhere the positive electrode active material particles well to each other and also to adhere the positive electrode active material well to the current collector. Examples of the binder include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, etc.

[0077] The binder may be included in an amount of 0.1 wt% to 5 wt%, or 0.1 wt% to 3 wt%, based on 100 wt% of the total weight of the positive electrode active material layer. Within the above content range, the binder can sufficiently exhibit adhesive ability without degrading battery performance.

[0078] The conductive material is used to provide conductivity to the electrode, and any material that does not cause chemical changes and is electronically conductive can be used in the battery. Examples of the conductive material include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotubes; metal-based materials containing copper, nickel, aluminum, silver, etc. in the form of metal powder or metal fiber; conductive polymers such as polyphenylene derivatives; or conductive materials including mixtures thereof.

[0079] The conductive material may be included in an amount of 0.1 wt% to 5 wt%, or 0.1 wt% to 3 wt%, based on 100 wt% of the total weight of the positive electrode active material layer. Within the above content range, the conductive material can improve electrical conductivity without degrading battery performance.

[0080] The thickness of the positive electrode active material layer may be 90 μm to 200 μm. For example, the thickness of the positive electrode active material layer may be 90 μm or more, 100 μm or more, 110 μm or more, 120 μm or more, 130 μm or more, 140 μm or more, 150 μm or more, 160 μm or more, 170 μm or more, 180 μm or more, or 190 μm or more, and may be 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, 150 μm or less, 140 μm or less, 130 μm or less, 120 μm or less, or 110 μm or less.

[0081] The above anode current collector may include, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li) or an alloy thereof, and may be in the form of a foil or sheet.

[0082] <Cathode>

[0083] The above cathode includes a current collector and a cathode layer positioned on one surface of the current collector.

[0084] The above cathode layer may be a cathode coating layer, and the cathode coating layer may be a lithium electrodeposition induction layer or a cathode catalyst layer.

[0085] When the above-mentioned negative electrode layer is a negative electrode coating layer, it means that the negative electrode is a precipitation-type negative electrode. The precipitation-type negative electrode means a negative electrode that does not contain a negative electrode active material when the battery is assembled, but in which lithium metal or the like is precipitated when the battery is charged, and this acts as a negative electrode active material. In more detail, when the all-solid-state battery is charged, lithium ions are released from the positive electrode active material, pass through the solid electrolyte, and move toward the negative electrode, and are deposited on the negative electrode current collector, so that a lithium-containing layer, for example, a lithium precipitation layer, can be formed between the current collector and the negative electrode layer. A negative electrode having such a lithium-containing layer is called a precipitation-type negative electrode.

[0086] That is, a lithium-containing layer can be formed between the negative electrode current collector and the negative electrode layer.

[0087] The above charging process may be a chemical reaction process performed once to three times at 0.05C to 1C at about 25°C to 50°C.

[0088] The thickness of the lithium-containing layer may be 10 μm to 50 μm. For example, the thickness of the lithium-containing layer may be 10 μm or more, 20 μm or more, 30 μm or more, or 40 μm or more, or 50 μm or less, 40 μm or less, 30 μm or less, or 20 μm or less. When the thickness of the lithium-containing layer is within the above range, there may be an advantage in that lithium may be reversibly precipitated during charge / discharge, thereby further improving the lifespan.

[0089] The cathode coating layer may include a metal, a carbon material, or a combination thereof that acts as a catalyst. For example, the cathode coating layer may include a metal supported on a carbon material, or a mixture of the metal and the carbon material. In one embodiment, the cathode coating layer may include a metal and a carbon material.

[0090] The carbon material may be, for example, crystalline carbon, amorphous carbon, or a combination thereof, and may be amorphous carbon. The crystalline carbon may be, for example, natural graphite, artificial graphite, mesophase carbon microbeads, or a combination thereof.

[0091] The amorphous carbon may be, for example, carbon black, acetylene black, Denka black, Ketjen black, furnace black, activated carbon, graphene, or a combination thereof. An example of the carbon black is Super P (Timcal). The amorphous carbon is not limited thereto, and any amorphous carbon classified as such in the relevant field may be used.

[0092] The above amorphous carbon may be a single particle, may have the form of a secondary particle formed by agglomeration of multiple primary particles, or may be a combination thereof.

[0093] The particle size of the above single particle may be 10 nm to 60 mm. In addition, the particle size of the above primary particle may be 20 nm to 100 nm, and the particle size of the above secondary particle may be 1 μm to 20 μm.

[0094] In one embodiment, the particle size of the primary particles may be 20 nm or more, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, 70 nm or more, 80 nm or more, or 90 nm or more, and may be 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, or 30 nm or less.

[0095] In one embodiment, the particle size of the secondary particles may be 1 µm or more, 3 µm or more, 5 µm or more, 7 µm or more, 10 µm or more, or 15 µm or more, and may be 20 µm or less, 15 µm or less, 10 µm or less, 7 µm or less, 5 µm or less, or 3 µm or less.

[0096] The shape of the primary particles may be spherical, elliptical, plate-shaped, or a combination thereof, and in one embodiment, the shape of the primary particles may be spherical, elliptical, or a combination thereof.

[0097] The metal may be any one selected from Ag, Zn, Al, Sn, Mg, Ge, Cu, In, Ni, Bi, Au, Si, Pt, Pd, and combinations thereof, and in one embodiment may be Ag. When the cathode coating layer includes the metal particles, the electrical conductivity of the cathode may be improved.

[0098] The metal may be in the form of particles, and the metal particles may have a size of 5 nm to 800 nm. The size of the metal particles may be 5 nm or more, 50 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, 450 nm or more, 500 nm or more, 550 nm or more, 600 nm or more, 650 nm or more, 700 nm or more, or 750 nm or more. In addition, the size of the metal particles may be 800 nm or less, 750 nm or less, 700 nm or less, 650 nm or less, 600 nm or less, 550 nm or less, 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less. When the size of the metal particles is within the above range, the battery characteristics (e.g., life characteristics) of the all-solid-state battery can be improved.

[0099] When the cathode coating layer includes a carbon-based material and metal particles, the mixing ratio of the carbon-based material and the metal particles may be a weight ratio of 1:1 to 99:1. For example, the weight of the carbon-based material may be 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 10 or more, 15 or more, 20 or more, 25 or more, 30 or more, 35 or more, 40 or more, 45 or more, 50 or more, 55 or more, 60 or more, 65 or more, 70 or more, 75 or more, 80 or more, 85 or more, 90 or more or 95 or more, and may be 99 or less, 95 or less, 90 or less, 85 or less, 80 or less, 75 or less, 70 or less, 65 or less, 60 or less, 55 or less, 50 or less, 45 or less, 40 or less, 35 or less, 30 or less, 25 or less, 20 or less, 15 or less, 10 or less, 5 or less, 4 or less, 3 or less or 2 or less. For example, the weight ratio of the carbon-based material and the metal particles may be 1:1 to 5:1, 1:1 to 10:1, 1:1 to 20:1, 1:1 to 30:1, 1:1 to 40:1, 1:1 to 50:1, 1:1 to 60:1, 1:1 to 70:1, 1:1 to 80:1, or 1:1 to 90:1. When the carbon-based material and the metal particles are included in the weight ratio, the electrical conductivity of the negative electrode can be further improved.

[0100] When the above-mentioned cathode layer is a cathode coating layer, the cathode current collector may be, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li) or an alloy thereof, and may be in the form of a foil or sheet.

[0101] The above cathode coating layer may further include a solid electrolyte, and the solid electrolyte may be a sulfide-based solid electrolyte as described above for the anode. The solid electrolyte included in the cathode may be the same as or different from the solid electrolyte included in the anode.

[0102] The above-described cathode coating layer may further include additives such as fillers, dispersants, and ionic conductive agents. In addition, known materials generally used in all-solid-state batteries may be used as fillers, dispersants, and ionic conductive agents that can be included in the cathode coating layer.

[0103] The thickness of the cathode coating layer may be, for example, 1 µm to 500 µm, 1 µm to 200 µm, 1 µm to 100 µm, or 1 µm to 50 µm, but is not limited thereto.

[0104] In one embodiment, the negative electrode layer may be a negative electrode active material layer.

[0105] The above negative electrode active material layer includes a negative electrode active material, may include a binder, and may further include a conductive material.

[0106] The above negative electrode active material may include lithium metal. When the negative electrode active material includes lithium metal, it may include lithium metal itself or a lithium alloy. The lithium alloy may be, for example, 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, or a Li-Si alloy.

[0107] The above negative active material may include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0108] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite in an amorphous, plate-like, flake-like, spherical, or fibrous form, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0109] As the above lithium metal alloy, an alloy of lithium and one or more metals selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn can be used.

[0110] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used, and the Si-based negative electrode active material may be silicon, a silicon-carbon composite, or SiO. x(0 <x<2), Si-Q 합금(상기 Q는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 15족 원소, 16족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Si은 아님), 상기 Sn계 음극 활물질로는 Sn, SnO2, Sn-R 합금(상기 R은 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 15족 원소, 16족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Sn은 아님) 등을 들 수 있고, 또한 이들 중 적어도 하나와 SiO2를 혼합하여 사용할 수도 있다. 상기 원소 Q 및 R로는 Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, 및 이들의 조합으로 이루어진 군에서 선택되는 것을 사용할 수 있다.

[0111] The above silicon-carbon composite may be a composite of silicon and amorphous carbon. The average particle diameter (D) of the silicon-carbon composite particles 50 ) may be, for example, 0.5 μm to 20 μm. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles. For example, it may include secondary particles (cores) in which silicon primary particles are assembled and an amorphous carbon coating layer (shell) located on the surface of the secondary particles. The amorphous carbon may also be located between the silicon primary particles, so that, for example, the silicon primary particles may be coated with amorphous carbon. The secondary particles may be dispersed and present in an amorphous carbon matrix.

[0112] The silicon-carbon composite may further comprise crystalline carbon. For example, the silicon-carbon composite may comprise a core comprising crystalline carbon and silicon particles, and an amorphous carbon coating layer positioned on the surface of the core. The crystalline carbon may be artificial graphite, natural graphite, or a combination thereof. The amorphous carbon may include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0113] When the above silicon-carbon composite includes silicon and amorphous carbon, the content of silicon may be 10 wt% to 50 wt%, and the content of amorphous carbon may be 50 wt% to 90 wt%, based on 100 wt% of the silicon-carbon composite. In addition, when the composite includes silicon, amorphous carbon, and crystalline carbon, the content of silicon may be 10 wt% to 50 wt%, the content of crystalline carbon may be 10 wt% to 70 wt%, and the content of amorphous carbon may be 20 wt% to 40 wt%, based on 100 wt% of the silicon-carbon composite.

[0114] In addition, the thickness of the amorphous carbon coating layer may be 5 nm to 100 nm. The average particle diameter (D) of the silicon particles (primary particles) 50 ) may be 10 nm to 1 ㎛, or 10 nm to 200 nm. The silicon particles may exist as silicon alone, in the form of a silicon alloy, or in an oxidized form. The oxidized form of silicon is SiO x (0 <x<2)로 표시될 수 있다. 이때, 산화 정도를 나타내는 Si:O의 원자 함량 비율은 99:1 내지 33:67일 수 있다. 본 명세서에서, 별도의 정의가 없는 한, 평균 입경(D 50 ) means the diameter of the particle whose cumulative volume is 50% by volume in the particle size distribution.

[0115] The above Si-based negative electrode active material or Sn-based negative electrode active material can be used in combination with a carbon-based negative electrode active material. When the Si-based negative electrode active material or Sn-based negative electrode active material and the carbon-based negative electrode active material are used in combination, the mixing ratio can be 1:99 to 90:10 by weight.

[0116] The content of the negative active material in the above negative active material layer may be 95 wt% to 99 wt% with respect to the total weight of the negative active material layer.

[0117] The content of the binder in the negative electrode active material layer may be 1 wt% to 5 wt% based on the total weight of the negative electrode active material layer. In addition, when further including a conductive material, the negative electrode active material layer may include 90 wt% to 98 wt% of the negative electrode active material, 1 wt% to 5 wt% of the binder, and 1 wt% to 5 wt% of the conductive material.

[0118] The above binder serves to adhere the negative electrode active material particles well to each other and also to adhere the negative electrode active material well to the current collector. The binder may include a non-aqueous binder, an aqueous binder, or a combination thereof.

[0119] The non-aqueous binder may include, for example, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or combinations thereof.

[0120] The above-mentioned aqueous binder may include styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluoroelastomer, polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenol resin, epoxy resin, polyvinyl alcohol, or a combination thereof.

[0121] In addition, the negative electrode active material layer may include a cellulose-based compound. The cellulose-based compound may include carboxymethyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, an alkali metal salt thereof, or a combination thereof. Na, K, or Li may be used as the alkali metal. The cellulose-based compound may function as a binder or as a thickener that provides viscosity. Accordingly, the content of the cellulose-based compound need not be limited, but may be, for example, 0.1 to 3 parts by weight based on 100 parts by weight of the negative electrode active material.

[0122] When the above-mentioned negative electrode layer is a negative electrode active material layer, a current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0123] In one embodiment, the all-solid-state battery may further include a cushioning material, such as an elastic sheet, to cushion thickness changes that occur during charging and discharging. The cushioning material may be positioned on the outermost layer surface of the electrode assembly of the positive electrode, the solid electrolyte, and the negative electrode, or may be positioned, for example, between the negative electrode and the case. In the case of a battery in which one or more electrode assemblies are laminated, the cushioning material may be positioned between different electrode assemblies and / or on the outermost layer.

[0124] Considering that the thickness of the negative electrode, especially during charge and discharge, changes significantly due to reasons such as dendrite formation, the elastic sheet can buffer the problems caused by thickness changes by being positioned on the outside of the negative electrode, i.e., on the side opposite the side where the solid electrolyte layer is in contact with the negative electrode. Furthermore, by being positioned on the outside of the positive and / or negative electrode, the elastic sheet can prevent deterioration due to reaction with lithium, thereby increasing the Coulombic efficiency of the battery.

[0125] The above-mentioned cushioning material may be a material having an elastic recovery rate of 50% or more and an insulating function, and specifically, may be silicone rubber, acrylic rubber, fluorine rubber, urethane, nylon, synthetic rubber, or a combination thereof. The above-mentioned cushioning material may exist in the form of a polymer sheet.

[0126] According to one embodiment, an all-solid-state battery can be manufactured by sequentially stacking a positive electrode, a solid electrolyte, and a negative electrode to prepare a laminate, bonding an elastic sheet to the outer surface of the positive electrode and / or the negative electrode, and then applying pressure. The pressing can be performed at a temperature of, for example, 25°C to 90°C, and at a pressure of 550 MPa or less, or 500 MPa or less, for example, 1 MPa to 500 MPa. The pressing can be, for example, isostatic pressing, roll pressing, or plate pressing.

[0127] The above-mentioned all-solid-state battery may be a unit battery having a structure of positive electrode / solid electrolyte layer / negative electrode, a bi-cell having a structure of positive electrode / solid electrolyte layer / negative electrode / solid electrolyte layer / positive electrode, or a laminated battery in which the structure of the unit battery is repeated.

[0128] The shape of the above-mentioned all-solid-state battery is not particularly limited, and may be, for example, coin-shaped, button-shaped, sheet-shaped, stacked, cylindrical, flat, etc. In addition, the above-mentioned all-solid-state battery can be applied to medium- to large-sized batteries used in electric vehicles, etc. For example, the above-mentioned all-solid-state battery can be used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). In addition, it can be applied to energy storage systems (ESS) that require a large amount of power storage, and can also be applied to electric bicycles or power tools, etc.

[0129] FIG. 1 schematically illustrates an all-solid-state battery according to one embodiment, and the all-solid-state secondary battery (100) includes a positive electrode (200) including a positive electrode current collector (201) and a positive electrode active material layer (203), a negative electrode (400) including a negative electrode current collector (401), a negative electrode coating layer (403), and a solid electrolyte layer (300) disposed between the positive electrode layer (203) and the negative electrode coating layer (403).

[0130] Fig. 2 schematically illustrates an all-solid-state battery according to another embodiment. The all-solid-state battery (100) illustrated in Fig. 2 includes a positive electrode (200) including a positive electrode current collector (201) and a positive electrode active material layer (203), a negative electrode (400') including a negative electrode current collector (401'), a negative electrode coating layer (403'), and a battery case (500) positioned between the positive electrode (200) and the negative electrode (400') and containing a solid electrolyte layer (300), and further includes a lithium precipitation layer (405') between the negative electrode current collector (401') and the negative electrode coating layer (403'). When the all-solid-state battery is charged, the lithium precipitation layer can be formed by lithium ions being released from the positive electrode active material and deposited on the negative electrode current collector (401').

[0131] Hereinafter, examples and comparative examples of the present invention will be described. The following examples are merely exemplary of the present invention, and the present invention is not limited to the following examples.

[0132] (Example 1)

[0133] (1) Manufacturing of solid electrolyte layer

[0134] The azirodite compound of Li6PS5Cl and zirconia were mixed. At this time, the content of the zirconia was 0.07 wt% with respect to 100 wt% of the azirodite compound.

[0135] The above mixture was calcined at 510°C for 12 hours.

[0136] The obtained sintered product was subjected to a rotational speed of 150 rpm for 3 hours. The obtained solid electrolyte had an average particle diameter (D50) of 3.3 μm, contained 500.8 ppm of Zr element, and was an argyrodite-based solid electrolyte of Li6PS5Cl.

[0137] An isobutylyl isobutylate binder solution (solid content: 50 wt%) containing butyl acrylate, an acrylate polymer, was added to the manufactured solid electrolyte and mixed. At this time, the mixing ratio of the solid electrolyte and the binder was set to 98.7:1.3 by weight.

[0138] The above mixing process was performed using a sinky mixer. 2 mm zirconia balls were added to the resulting mixture and stirred again using the sinky mixer to produce a slurry. The slurry was cast onto a polytetrafluoroethylene film and dried at room temperature to produce a solid electrolyte with a solid electrolyte layer thickness of 100 μm.

[0139] (2) Manufacturing of cathode

[0140] A cathode coating layer slurry was prepared by mixing 92 wt% of carbon black having an average particle size (D50) of 30 nm, 3 wt% of Ag having an average particle size of 60 nm, 2 wt% of carboxymethyl cellulose, and 3 wt% of styrene-butadiene rubber in water.

[0141] After coating the above-mentioned negative electrode coating layer slurry on a stainless steel foil current collector with a thickness of 10 μm, vacuum drying was performed at 80°C to manufacture a negative electrode with a thickness of 2 μm.

[0142] (3) Manufacturing of anode

[0143] LiNi 0.8 Co 0.15 Mn 0.05 A cathode composition was prepared by mixing 85 wt% of O2 cathode active material, 13.5 wt% of lithium argyrodite-type solid electrolyte Li6PS5Cl, 1.0 wt% of polyvinylidene fluoride binder, and 0.5 wt% of Ketjen Black conductive material in an N-methyl pyrrolidone solvent.

[0144] The manufactured positive electrode composition was coated on an aluminum positive electrode current collector using a bar coater, dried, and rolled to manufacture a positive electrode.

[0145] (4) Manufacturing of all-solid-state batteries

[0146] The manufactured cathode, solid electrolyte, and anode were sequentially stacked, and pressure was applied at 500 MPa using a warm isostatic press (WIP) process to manufacture an all-solid-state.

[0147] (Example 2)

[0148] An all-solid-state battery was manufactured in the same manner as in Example 1, except that the content of zirconia was changed to 0.05 wt% based on 100 wt% of the above argyrodite compound, and an argyrodite-based solid electrolyte having an average particle diameter (D50) of 3.2 μm, containing 350.8 ppm of Zr element, and Li6PS5Cl was manufactured.

[0149] (Example 3)

[0150] An all-solid-state battery was manufactured in the same manner as in Example 1, except that the content of zirconia was changed to 0.03 wt% based on 100 wt% of the above argyrodite compound, and an argyrodite-based solid electrolyte having an average particle diameter (D50) of 3.5 μm, containing 265.4 ppm of Zr element, and Li6PS5Cl was manufactured.

[0151] (Example 4)

[0152] A solid electrolyte and an all-solid-state battery were manufactured in the same manner as in Example 1, except that the content of zirconia was changed to 0.01 wt% based on 100 wt% of the above argyrodite compound, and the grinding process was performed at a rotation speed of 150 rpm for 6 hours to manufacture an argyrodite-based solid electrolyte having an average particle diameter (D50) of 1.2 μm, containing 121.5 ppm of Zr element, and Li6PS5Cl.

[0153] (Example 5)

[0154] A solid electrolyte and an all-solid-state battery were manufactured in the same manner as in Example 1, except that the content of zirconia was changed to 0.008 wt% based on 100 wt% of the above argyrodite compound, and the grinding process was performed at a rotation speed of 150 rpm for 6 hours to manufacture an argyrodite-based solid electrolyte having an average particle diameter (D50) of 1.5 μm, containing 100 ppm of Zr element, and being Li6PS5Cl.

[0155] (Comparative Example 1)

[0156] An all-solid-state battery was manufactured in the same manner as in Example 1, except that the content of zirconia was changed to 0 wt% with respect to 100 wt% of the above azirodite compound, and an azirodite-based solid electrolyte of Li6PS5Cl having an average particle diameter (D50) of 3.6 μm was manufactured.

[0157] (Comparative Example 2)

[0158] A solid electrolyte and an all-solid-state battery were manufactured in the same manner as in Example 1, except that the content of zirconia was changed to 0.5 wt% based on 100 wt% of the above argyrodite compound, and the grinding process was performed at a rotation speed of 150 rpm for 6 hours to manufacture an argyrodite-based solid electrolyte having an average particle diameter (D50) of 1.3 μm, containing 2840.7 ppm of Zr element, and Li6PS5Cl.

[0159] (Comparative Example 3)

[0160] An all-solid-state battery was manufactured in the same manner as in Example 1, except that the content of zirconia was changed to 1 wt% based on 100 wt% of the above azirodite compound, and an azirodite-based solid electrolyte of Li6PS5Cl having an average particle diameter (D50) of 3.4 μm and containing 5420.3 ppm of Zr element was manufactured.

[0161] Experimental Example 1: Evaluation of Zr Element Content

[0162] The content of Zr element included in the solid electrolytes manufactured according to Examples 1 to 5 and Comparative Examples 1 to 3 was measured using XRF (X-ray fluorescence) equipment (manufacturer: Bruker Korea, product name: S8 Tiger Series2). The results are shown in Table 1 below.

[0163] Experimental Example 2: Ionic Conductivity Evaluation

[0164] The ionic conductivity of the solid electrolytes manufactured according to Examples 1 to 5 and Comparative Examples 1 to 3 was measured. The results are shown in Table 1 below.

[0165] Ionic conductivity was measured using an electric impedance spectroscopy meter at room temperature (25°C) with a torque of 10 Nm applied after sampling the solid electrolyte to 10Φ (diameter 10 mm). At this time, a frequency of 500 kHz to 50 mHz was scanned using an amplitude of 50 mV at an open circuit potential.

[0166] Zr content used (wt%)Crushing speed (rpm)Crushing time (hours)Solid electrolyte average particle size (D50, ㎛)Zr element content included in solid electrolyte (ppm)Ionic conductivity (mS / cm)Example 10.0715033.3500.83.5Example 20.0515033.2350.82.8Example 30.0315033.5265.42.1Example 40.0115061.2121.51.8Example 50.00815061.51002Comparative example 1015033.05.81.9Comparative example 20.515061.32840.71.3Comparative example 3115033.45420.31.9

[0167] In the above Table 1, the Zr content included in the solid electrolyte of Comparative Example 1 is the content included as an impurity.

[0168] It is appropriate to compare ionic conductivity between solid electrolytes having similar particle sizes. Accordingly, comparing Examples 1 to 3 with Comparative Examples 1 and 3, which have similar particle sizes, reveals that the ionic conductivity of Examples 1 to 3 is superior to that of Comparative Examples 1 and 3.

[0169] In addition, when comparing Examples 4 and 5 and Comparative Example 2, it can be seen that the ionic conductivity of Example 4 is superior to that of Comparative Example 2.

[0170] 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.

Claims

1. Containing Zr element in an amount of 100 ppm to 1000 ppm and containing an argyrodite compound. Solid electrolyte for all-solid-state batteries.

2. In paragraph 1, The above-mentioned azirodite compound is a solid electrolyte for an all-solid-state battery, which is represented by the following chemical formula 1. [Chemical Formula 1] Li a M b S c P d X e (In the above chemical formula 1, a, b, c, d and e are all 0 or more and 12 or less, M is Ge, Sn, Si, Ag, Cu or a combination thereof, X is one of F, Cl, Br, or I) 3. In paragraph 1, The above Zr element is Zr metal, Zr alloy, Li 2 O-ZrO 2 , Li 2 ZrO 3 , or a solid electrolyte for an all-solid-state battery comprising a combination thereof.

4. In paragraph 1, A solid electrolyte for an all-solid-state battery having a content of the Zr element of 100 ppm to 700 ppm.

5. In paragraph 2, The above a is a solid electrolyte for an all-solid-state battery having a number of 4 to 8.

6. In paragraph 2, A solid electrolyte for an all-solid-state battery wherein b is 0 to 0.

5.

7. In paragraph 2, The above c is a solid electrolyte for an all-solid-state battery having a number of 4 to 6.

8. In paragraph 2, A solid electrolyte for an all-solid-state battery wherein d is 0.1 to 2.

9. In paragraph 2, A solid electrolyte for an all-solid-state battery wherein e is 0.1 to 2.

10. In paragraph 2, The above M is a solid electrolyte for an all-solid-state battery, wherein M is Cu, Sn or a combination thereof.

11. In paragraph 2, A solid electrolyte for an all-solid-state battery, wherein X is Cl, Br or a combination thereof.

12. In paragraph 1, The above azirodite compound is Li 6 PS 5 Cl, Li 6 PS 5 Br, Li 5.8 PS 4.8 Cl 1.2 , Li 6.2 PS 5.2 Br 0.8 , Li 6 PS 5 I, Li 5.75 PS 4.75 Cl 1.25 , (Li 5.69 Cu 0.06 )PS 4.75 Cl 1.25 , (Li 5.72 Cu 0.03 )PS 4.75 Cl 1.25 , (Li 5.69 Cu 0.06 )P(S 4.70 (SO 4 ) 0.05 )Cl 1.25 , (Li 5.69 Cu 0.06 )P(S 4.60 (SO 4 ) 0.15 )Cl 1.25 , (Li 5.72 Cu 0.03 )P(S 4.725 (SO 4 ) 0.025 )Cl 1.25 , (Li 5.72 Na 0.03 )P(S 4.725 (SO 4 ) 0.025 )Cl 1.25 , Li 5.75 P(S 4.725 (SO 4 ) 0.025 )Cl 1.25 , or a solid electrolyte for an all-solid-state battery which is a combination thereof.

13. In paragraph 1, A solid electrolyte for an all-solid-state battery having an ionic conductivity of 1 mS / cm to 10 mS / cm at room temperature.

14. In paragraph 1, A solid electrolyte for an all-solid-state battery having an average particle diameter (D50) of 0.5 ㎛ to 5 ㎛.

15. Cathode; Bipolar; and A solid electrolyte layer positioned between the positive electrode and the negative electrode and including the solid electrolyte of any one of claims 1 to 14. An all-solid-state battery comprising:

16. In paragraph 15, An all-solid-state battery wherein the cathode comprises a metal and a carbon-based material.

17. In paragraph 15, An all-solid-state battery wherein the metal is one selected from Ag, Zn, Al, Sn, Mg, Ge, Cu, In, Ni, Bi, Au, Si, Pt, Pd and combinations thereof.

18. In paragraph 15, An all-solid-state battery wherein the carbon-based material is crystalline carbon, amorphous carbon or a combination thereof.

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