Sulfide-based solid electrolyte and all-solid-state battery comprising same

Abstract

The present invention relates to a sulfide-based solid electrolyte containing lithium (Li), phosphorus (P), sulfur (S), boron (B), and a plurality of halogen elements and having an argyrodite-type crystal structure, wherein the sulfide-based solid electrolyte satisfies formula 1. [Formula 1] 3.6 ≤ (CxB) / A ≤ 5.5 In formula 1, A is Dmax measured by a laser diffraction and particle size distribution measurement method, B is D50, and C is an elastic modulus measured using an atomic force microscope (AFM).

Description

Sulfide-based solid electrolyte and all-solid-state battery containing the same

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

[0002] This application claims priority to Korean Patent Application No. 10-2024-0191513 filed on December 19, 2024, the entire contents of said prior application are incorporated herein by reference.

[0003] With the recent increase in demand for electric vehicles, the demand for lithium-ion batteries, which possess high energy and high power density, is also rising. Lithium-ion batteries have the advantage of higher energy density and greater capacity per unit area compared to nickel-manganese or nickel-cadmium batteries.

[0004] However, conventional lithium-ion batteries mainly use flammable organic liquid electrolytes as electrolytes, which causes safety issues such as overheating, so recently, all-solid-state batteries using non-flammable solid electrolytes are attracting attention.

[0005] In particular, among solid electrolytes, sulfides have high ionic conductivity and are relatively flexible, making it easy to form solid-solid interfaces. Furthermore, they are not only stable with respect to active materials but can also increase energy density during the manufacturing of all-solid-state batteries. To obtain good battery characteristics in an all-solid-state battery containing a sulfide-based solid electrolyte, it is desirable to uniformly distribute the sulfide-based solid electrolyte within the electrode by controlling its particle size.

[0006] However, although the particle size of sulfide-based solid electrolytes can be reduced by grinding, this grinding process may result in distorted particles or secondary particles formed by the aggregation of fine powder. Furthermore, when sulfide-based solid electrolytes react with moisture in the atmosphere, toxic hydrogen sulfide gas is generated, which can lead to a problem where ion conductivity decreases due to decomposition.

[0007] Accordingly, there is a need to develop technology for manufacturing sulfide-based solid electrolytes by controlling the particle size of the solid electrolyte during the grinding process.

[0008] One objective of the present invention is D 50 While raising D max We aim to provide a sulfide-based solid electrolyte with improved elastic modulus by lowering it.

[0009] Another objective of the present invention is to provide a method for manufacturing a sulfide-based solid electrolyte having the aforementioned characteristics by two-stage grinding during the solid electrolyte grinding process.

[0010] A sulfide-based solid electrolyte according to one embodiment of the present invention comprises a sulfide-based solid electrolyte having an agyrodite-type crystal structure containing lithium (Li), phosphorus (P), sulfur (S), boron (B), and a plurality of halogen elements, and the sulfide-based solid electrolyte satisfies the following Equation 1.

[0011] [Equation 1]

[0012] 3.6 ≤ (CxB) / A ≤ 5.5

[0013] In Equation 1 above, A is D measured by the laser diffraction scattering particle size distribution measurement method. max and, B is D 50 And, C is the elastic modulus measured by an atomic force microscope (AFM).

[0014] The above sulfide-based solid electrolyte can satisfy the following Equation 2.

[0015] [Equation 2]

[0016] 2 ≤ B / A ≤ 5.0

[0017] In the above Equation 2, A and B are as defined in the above Equation 1.

[0018] D of the above sulfide-based solid electrolyte max It can be 15μm or less.

[0019] D of the above sulfide-based solid electrolyte 50 It can be 3.15 μm or larger.

[0020] The elastic modulus of the above sulfide-based solid electrolyte may be 15 to 30 GPa.

[0021] The above sulfide-based solid electrolyte can be represented by the following chemical formula 1.

[0022] [Chemical Formula 1]

[0023] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab

[0024] In the above chemical formula 1, 1 ≤ x ≤ 2, 0.01 ≤ a ≤ 0.3, and 0.01 ≤ b ≤ 0.3.

[0025] The molar ratio of lithium (Li) to phosphorus (P) in the above sulfide-based solid electrolyte ([Li] / [P]) may be 5.5 to 6.5.

[0026] The molar ratio of boron (B) to phosphorus (P) in the above sulfide-based solid electrolyte ([B] / [P]) may be 0.03 to 0.08.

[0027] The molar ratio of sulfur (S) to phosphorus (P) in the above sulfide-based solid electrolyte ([S] / [P]) may be 4 to 5.5.

[0028] The molar ratio of oxygen (O) to phosphorus (P) in the above sulfide-based solid electrolyte ([O] / [P]) may be 0.05 to 0.12.

[0029] The molar ratio ([D] / [P]) of a plurality of halogen elements (D) to phosphorus (P) in the above sulfide-based solid electrolyte may be 0.5 to 1.5.

[0030] A method for manufacturing a sulfide-based solid electrolyte according to another embodiment of the present invention comprises the steps of: milling raw materials of lithium sulfide, a sulfur compound, a lithium compound, and a halogen compound including lithium fluoride to produce a mixture; heat-treating the mixture to produce a crystalline phase; first grinding the crystalline phase to obtain an intermediate; and second grinding the intermediate.

[0031] The above first grinding step may be ground using a bead mill.

[0032] The rotational speed of the above bead mill may be 500 to 3000 rpm, and the driving time may be 10 to 60 minutes.

[0033] The above secondary grinding step may be ground using a pin mill.

[0034] The rotational speed of the above pin mill may be 5,000 to 30,000 rpm.

[0035] The heat treatment temperature of the above mixture may be 300 to 600°C.

[0036] The above sulfide-based solid electrolyte has an agyrodite-type crystal structure and can be represented by the following chemical formula 1.

[0037] [Chemical Formula 1]

[0038] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab

[0039] In the above chemical formula 1, 1 ≤ x ≤ 2, 0.01 ≤ a ≤ 0.3, and 0.01 ≤ b ≤ 0.3.

[0040] A solid-state battery according to another embodiment of the present invention comprises a positive electrode layer; a negative electrode layer; and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, wherein one or more of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer comprises the aforementioned sulfide-based solid electrolyte.

[0041] A sulfide-based solid electrolyte according to one embodiment of the present invention controls the particle size during the grinding process, thereby D 50 Eun raise and D max It has the effect of improving elastic modulus by lowering it and enhancing lifespan characteristics when applied to all-solid-state batteries.

[0042] In this specification, terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited thereto. These terms are used solely to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, the first part, component, region, layer, or section described below may be referred to as the second part, component, region, layer, or section without departing from the scope of the invention.

[0043] The technical terms used herein are for the reference of specific embodiments only and are not intended to limit the invention. The singular forms used herein include plural forms unless phrases clearly indicate otherwise. As used in the specification, the meaning of "comprising" specifies certain characteristics, areas, integers, steps, actions, elements, and / or components, and does not exclude the presence or addition of other characteristics, areas, integers, steps, actions, elements, and / or components.

[0044] When it is stated that one part is "on" or "on" another part, it may be directly on or on the other part, or another part may be involved in between. In contrast, when it is stated that one part is "directly on" another part, no other part is interposed in between.

[0045] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined.

[0046] Also, unless otherwise specified, % means weight %, and 1 ppm is 0.0001 weight %.

[0047] In this specification, the term “combination(s) of these” described in the Markush-type expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expression, and means including any one or more selected from the group consisting of said components.

[0048] Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0049] Sulfide-based solid electrolytes

[0050] A sulfide-based solid electrolyte according to one embodiment of the present invention comprises a sulfide-based solid electrolyte having an agyrodite-type crystal structure containing lithium (Li), phosphorus (P), sulfur (S), boron (B) and a plurality of halogen elements, and the sulfide-based solid electrolyte satisfies the following Equation 1.

[0051] [Equation 1]

[0052] 3.6 ≤ (CxB) / A ≤ 5.5

[0053] In Equation 1 above, A is D measured by the laser diffraction scattering particle size distribution measurement method. max and, B is D 50 Equation 1 is the elastic modulus measured by an atomic force microscope (AFM). If Equation 1 satisfies the above range, the particle size distribution of the solid electrolyte is properly controlled, forming a uniform conduction path within the solid electrolyte, thereby reducing voltage drop and improving the performance of the all-solid-state battery. On the other hand, if Equation 1 is not met, the ionic conductivity of the solid electrolyte decreases and the strength of the solid electrolyte changes, which may cause problems that are difficult to control due to impact or pressure.

[0054] In one embodiment, the sulfide-based solid electrolyte may satisfy the following Equation 2.

[0055] [Equation 2]

[0056] 2 ≤ B / A ≤ 5.0

[0057] In Equation 2 above, A is D measured by the laser diffraction scattering particle size distribution measurement method. 50 and B is D maxIf Equation 2 satisfies the above range, the particle strength of the sulfide-based solid electrolyte is low, so the particles are easily crushed during the mixing or compression process, increasing the contact area between particles, which may have the advantage of improving the ion conduction path and reducing interfacial resistance. On the other hand, if Equation 2 falls outside the above range, the particle strength of the sulfide-based solid electrolyte is high, so it is not crushed during the process, which may result in a problem where the contact area decreases, increasing interfacial resistance and decreasing ion conductivity.

[0058] In one embodiment, D measured by the laser diffraction scattering particle size distribution measurement method max may be 15μm or less, specifically 10μm or more and 14.6μm or less. The above D max If the above range is satisfied, the particle size distribution is narrow, so the sulfide-based solid electrolyte of uniform particles is uniformly distributed within the all-solid-state battery, thereby improving the mechanical properties and ion conductivity of the all-solid-state battery. On the other hand, the above D max If it falls outside the above range, it may cause mechanical defects during the compression molding process of sulfide-based solid electrolytes.

[0059] In one embodiment, D measured by the laser diffraction scattering particle size distribution measurement method 50 The size may be 3.15 μm or larger, and specifically 3.16 to 4.0 μm. The above D 50 If the above range is satisfied, there is an advantage in that the charge density can be improved when manufacturing all-solid-state batteries. On the other hand, the above D 50 If the above range is exceeded, additional grinding or feeding processes are required to obtain the desired particle size, which may lead to problems that increase process time and energy consumption costs.

[0060] In one embodiment, the elastic modulus of the sulfide-based solid electrolyte may be 15 to 30 GPa, specifically 18 to 30 GPa, and more specifically 20 to 30 GPa. When the elastic modulus satisfies the above range, the particles are easily crushed during the mixing or compression process, increasing the contact area between particles, which may improve the ion conduction pathway and reduce interfacial resistance. On the other hand, when the elastic modulus falls outside the above range, the sulfide-based solid electrolyte is not crushed during the process, which may result in a decrease in the contact area, an increase in interfacial resistance, and a decrease in ion conductivity.

[0061] In one embodiment, the sulfide-based solid electrolyte may be represented by the following chemical formula 1.

[0062] [Chemical Formula 1]

[0063] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab

[0064] In the above Chemical Formula 1, 1 ≤ x ≤ 2, 0.01 ≤ a ≤ 0.3, and 0.01 ≤ b ≤ 0.3. When x, a, and b of the above Chemical Formula satisfy the above ranges, D of the sulfide-based solid electrolyte 50 Eun is high and D max Since is low, the sulfide-based particle size distribution is relatively narrow and formed around large particles, resulting in a uniform particle distribution; this may offer the advantage of improving mechanical properties and ion conductivity during the manufacture of all-solid-state batteries. On the other hand, if the above x, a, and b fall outside the above range, D of the sulfide-based solid electrolyte 50 This gets lower or D max Due to the high concentration of small particles, there are also excessively large particles, and as the particle size distribution widens, pores and defects within the electrolyte layer increase during the manufacturing of all-solid-state batteries, which may lead to a problem of reduced ion conductivity.

[0065] In one embodiment, the molar ratio of lithium (Li) to phosphorus (P) in the sulfide-based solid electrolyte ([Li] / [P]) may be 5.5 to 6.5, specifically 5.8 to 6.2. When the molar ratio of lithium (Li) to phosphorus (P) satisfies the above range, the ionic conductivity of the sulfide-based solid electrolyte is improved, which may have the advantage of improving electrochemical stability and increasing charge / discharge efficiency when manufacturing an all-solid-state battery. On the other hand, if the molar ratio of lithium (Li) to phosphorus (P) is too low, problems may arise such as a decrease in the ionic conductivity of the sulfide-based solid electrolyte and a reduction in the mobility of lithium ions. Furthermore, if the molar ratio of lithium (Li) to phosphorus (P) is too high, problems may arise such as reduced safety due to structural instability caused by excessive lithium and an increased possibility of electrolyte decomposition.

[0066] In one embodiment, the molar ratio of boron (B) to phosphorus (P) in the sulfide-based solid electrolyte ([B] / [P]) may be 0.03 to 0.08, specifically 0.045 to 0.075. If the molar ratio of boron (B) to phosphorus (P) satisfies the above range, the electrochemical stability of the solid electrolyte may be improved. On the other hand, if the molar ratio of boron (B) to phosphorus (P) is too small, the instability of the crystal structure of the sulfide-based solid electrolyte increases, which may reduce the safety of the battery. In addition, if the molar ratio of boron (B) to phosphorus (P) is too large, excessive doping of boron may cause problems such as reduced ionic conductivity of the solid electrolyte and increased side reactions.

[0067] In one embodiment, the molar ratio of sulfur (S) to phosphorus (P) of the sulfide-based solid electrolyte ([S] / [P]) may be 4 to 5.5, specifically 4.5 to 5.0. When the molar ratio of sulfur (S) to phosphorus (P) satisfies the above range, a stable crystal structure is formed, which may have the advantage of improving the stability of the sulfide-based solid electrolyte. On the other hand, if the molar ratio of sulfur (S) to phosphorus (P) is too low, the ionic conductivity of the sulfide-based solid electrolyte may decrease, and problems such as an unstable crystal structure may occur. In addition, if the molar ratio of sulfur (S) to phosphorus (P) is too high, problems such as reduced characteristics of the sulfide-based solid electrolyte and all-solid-state battery performance due to excessive sulfur content may occur.

[0068] In one embodiment, the molar ratio of oxygen (O) to phosphorus (P) in the sulfide-based solid electrolyte ([O] / [P]) may be 0.05 to 0.12, specifically 0.08 to 0.1. When the molar ratio of oxygen (O) to phosphorus (P) satisfies the above range, the electrochemical stability of the solid electrolyte is improved, and the interfacial resistance between the electrode and the electrolyte is lowered, thereby improving the performance of the battery. On the other hand, if the molar ratio of oxygen (O) to phosphorus (P) is too low, the stability of the solid electrolyte is reduced, and a problem of reduced ionic conductivity may occur. In addition, if the molar ratio of oxygen (O) to phosphorus (P) is too high, the structure of the electrolyte may be deformed due to excessive oxygen, and a self-discharge problem may occur due to increased electron conductivity.

[0069] In one embodiment, the molar ratio ([D] / [P]) of a plurality of halogen elements (D) to phosphorus (P) in the sulfide-based solid electrolyte may be 0.5 to 1.5, specifically 0.7 to 1.3. When the molar ratio of halogen elements (D) to phosphorus (P) satisfies the above range, the thermal stability of the solid electrolyte is improved and the interfacial resistance is reduced, thereby improving the performance of the all-solid-state battery. On the other hand, if the molar ratio of halogen elements (D) to phosphorus (P) is too low, the distribution of halogen elements within the sulfide-based solid electrolyte becomes uneven due to insufficient halogen doping, which may result in local performance differences. Additionally, if the molar ratio of halogen elements (D) to phosphorus (P) is too high, the halogen elements may be excessively doped, which may lower the structural stability of the solid electrolyte and cause a decrease in battery performance due to side reactions with the electrode material.

[0070] Method for manufacturing sulfide-based solid electrolytes

[0071] A method for manufacturing a sulfide-based solid electrolyte according to another embodiment of the present invention comprises the steps of: milling raw materials of a halogen compound including lithium sulfide, a sulfur compound, a lithium compound, and lithium fluoride to produce a mixture; heat-treating the mixture to produce a crystalline phase; first grinding the crystalline phase to obtain an intermediate; and second grinding the intermediate. If the crystalline phase is subjected to alternating second grinding after first grinding, there may be advantages in controlling the particle size of the sulfide-based solid electrolyte and reducing adverse reactions with moisture. Additionally, if a halogen compound including lithium fluoride is introduced, the particle strength of the sulfide-based solid electrolyte is lowered, allowing the particles to be easily crushed during mixing or compression processes, thereby forming a new surface and increasing the contact area between particles, which improves the ion conduction pathway and reduces interfacial resistance. The raw materials of the halogen compound may additionally include at least one compound selected from Cl, Br, and I.

[0072] In one embodiment, the first grinding step may be performed using a bead mill, but is not limited thereto, and any method capable of uniformly grinding the sulfide-based solid electrolyte may be used.

[0073] The rotational speed of the bead mill may be 500 to 3000 rpm, specifically 1,000 to 2,000 rpm. Additionally, the driving time of the bead mill may be 10 to 60 minutes, specifically 20 to 30 minutes. If the rotational speed and driving time of the bead mill satisfy the above ranges, a sulfide-based solid electrolyte with a uniform particle size distribution can be obtained. On the other hand, if the rotational speed and driving time of the bead mill fall outside the above ranges, a problem may arise in which a sulfide-based solid electrolyte containing a wide particle size distribution and excessive particles is manufactured.

[0074] In one embodiment, the secondary grinding step may be performed using a fin mill, but is not limited thereto, and any method capable of uniformly grinding the sulfide-based solid electrolyte may be used.

[0075] The rotational speed of the above fin mill may be 5,000 to 30,000 rpm, and specifically 10,000 to 20,000 rpm. When the rotational speed of the above fin mill satisfies the above range, D of the sulfide-based solid electrolyte max It can be lowered. On the other hand, if the rotational speed of the fin mill is outside the above range, a problem may occur in which a sulfide-based solid electrolyte containing a wide particle size distribution and excessive particles is manufactured.

[0076] In another embodiment, the heat treatment temperature of the mixture may be 300 to 600°C, specifically 400 to 500°C. If the heat treatment temperature satisfies the above range, there may be an advantage in that the ion conductivity is improved during the manufacture of an all-solid-state battery. On the other hand, if the heat treatment temperature is too low, impurities or residual solvent generated during the heat treatment process are not removed, which may cause a problem in which the electrochemical properties of the all-solid-state battery deteriorate. In addition, if the heat treatment temperature is too high, volatilization of sulfur (S) may occur, which may alter or decompose the composition of the sulfide-based solid electrolyte, and a sulfide-based solid electrolyte having an unstable crystal structure may be formed due to the high temperature.

[0077] In another embodiment, the sulfide-based solid electrolyte has an agyrodite-type crystal structure and can be represented by the following chemical formula 1.

[0078] [Chemical Formula 1]

[0079] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab

[0080] In the above Chemical Formula 1, 1 ≤ x ≤ 2, 0.01 ≤ a ≤ 0.3, and 0.01 ≤ b ≤ 0.3. When x, a, and b of the above Chemical Formula satisfy the above ranges, D of the sulfide-based solid electrolyte 50 Eun is high and D max Since is low, the sulfide-based particle size distribution is relatively narrow and formed around large particles, resulting in a uniform particle distribution; this may offer the advantage of improving mechanical properties and ion conductivity during the manufacture of all-solid-state batteries. On the other hand, if the above x, a, and b fall outside the above range, D of the sulfide-based solid electrolyte 50 This gets lower or D maxDue to the high concentration of small particles, there are also excessively large particles, and as the particle size distribution widens, pores and defects within the electrolyte layer increase during the manufacturing of all-solid-state batteries, which may lead to a problem of reduced ion conductivity.

[0081] In another embodiment, D of the sulfide-based solid electrolyte max may be 15μm or less, specifically 10μm or more and 14.6μm or less. The above D max If the above range is satisfied, the particle size distribution is narrow, allowing for the uniform distribution of uniform particles of the sulfide-based solid electrolyte within the all-solid-state battery, thereby improving the mechanical properties and ion conductivity of the all-solid-state battery. On the other hand, if the above Dmax falls outside the above range, it may cause mechanical defects during the compression molding process of the sulfide-based solid electrolyte.

[0082] In another embodiment, D of the sulfide-based solid electrolyte 50 It may be 3.15 μm or larger, and specifically, 3.16 μm or larger and 4.0 μm. The above D 50 If the above range is satisfied, there is an advantage in that the charge density can be improved when manufacturing all-solid-state batteries. On the other hand, the above D 50 If the above range is exceeded, additional grinding or feeding processes are required to obtain the desired particle size, which may lead to problems that increase process time and energy consumption costs.

[0083] In another embodiment, the elastic modulus of the sulfide-based solid electrolyte may be 15 to 30 GPa, specifically 18 to 30 GPa, and more specifically 20 to 30 GPa. If the elastic modulus satisfies the above range, the particles may be easily crushed during the mixing or compression process, increasing the contact area between particles, thereby improving the ion conduction pathway and reducing interfacial resistance. On the other hand, if the elastic modulus falls outside the above range, the sulfide-based solid electrolyte may not be crushed during the process, resulting in a decrease in the contact area, which may cause problems such as increased interfacial resistance and reduced ion conductivity.

[0084] All-solid-state battery

[0085] Another embodiment of the present invention provides an all-solid-state battery comprising: an anode layer; a cathode layer; and a solid electrolyte layer disposed between the anode layer and the cathode layer, wherein the solid electrolyte layer comprises the aforementioned sulfide-based solid electrolyte.

[0086] More specifically, the anode may include an anode current collector and an anode active material layer disposed on the anode current collector, and may include the aforementioned sulfide-based solid electrolyte and conductive material. Additionally, the anode active material layer may further include a binder.

[0087] At this time, the sulfide-based solid electrolyte described above may be, for example, a sulfide-based solid electrolyte with an azirodite-based crystal structure.

[0088] The above-mentioned sulfide-based solid electrolytes with an azirodite-based crystal structure are, for example, Li6PS5Cl, Li6PS5Br, Li6PS5I, Li 0.94 P 0.99 S 0.95 O 0.04 Cl 0.9801 F 0.01 , Li 0.7 P 0.7 S 0.6 O 1.2 Cl 0.49 F 0.21 , Li0.7875 P 0.85 S 0.7375 O 0.6 Cl 0.7225 F 0.1275 , Li 0.91 P 0.95 S 0.86 O 0.2 Cl 0.855 F 0.095 , Li 0.76 P 0.8 S 0.66 O 0.8 Cl 0.64 F 0.16 or a combination thereof, but not limited thereto.

[0089] The above sulfide-based solid electrolyte with an azirodite-based crystal structure may have at least a portion of the crystal structure doped with a doping element.

[0090] The above conductive material may be, for example, graphite, carbon black, acetylene black, ketjen black, carbon nanofibers, carbon nanotubes, or a combination thereof.

[0091] The binder may be, for example, polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, or a combination thereof.

[0092] The above-mentioned positive active material layer may further include additives such as fillers, coating agents, dispersants, and ion conductivity aids in addition to the aforementioned positive active material, solid electrolyte, binder, and conductive material.

[0093] Another embodiment of the present invention provides an all-solid-state battery comprising a positive electrode, a negative electrode, and a solid electrolyte layer disposed between them, wherein the positive electrode comprises a positive electrode active material for an all-solid-state battery.

[0094] The description of the anode above is omitted as it has been explained previously.

[0095] The above solid electrolyte layer may include the sulfide-based solid electrolyte described above.

[0096] The above sulfide-based solid electrolyte is, for example, Li 7-x PS 6-x Cl x , 0≤x≤2, Li 7-x PS 6-x Br x , 0≤x≤2, Li 7-x PS 6-x I x , 0≤x≤2, and Li(xy-x-5y+7)P (1-y) S (xy-x-5y+6) O 4y Cl(x-xy)(1-z)F z It may be an argyrodite-type compound containing one or more selected from , 1 ≤ x ≤ 2, 0.01 ≤ y ≤ 0.3, and 0.01 ≤ z ≤ 0.3. In particular, the sulfide-based solid electrolyte is Li6PS5Cl, Li6PS5Br, Li6PS5I, Li 0.94 P 0.99 S 0.95 O 0.04 Cl 0.9801 F 0.01 , Li 0.7 P 0.7 S 0.6 O 1.2 Cl 0.49 F 0.21 , Li 0.7875 P 0.85 S 0.7375 O 0.6 Cl 0.7225 F 0.1275 , Li 0.91 P 0.95 S 0.86 O 0.2 Cl 0.855 F 0.095 , Li 0.76 P 0.8 S 0.66 O 0.8 Cl 0.64 F 0.16It may be an azirodite-type compound comprising one or more selected from among. However, it is not limited thereto.

[0097] The above sulfide-based solid electrolyte may have at least a portion of the crystal structure of the aforementioned azirodite-type compound doped with a doping element.

[0098] The above solid electrolyte layer may further include a binder. The binder included in the solid electrolyte layer is, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited to these, and any binder used in the relevant technical field is possible. The binder of the solid electrolyte layer may be the same as or different from the binder included in the positive electrode active material layer and the negative electrode active material layer.

[0099] The above cathode may include a cathode current collector and a cathode active material layer disposed on the cathode current collector, and the cathode active material layer may include a cathode active material.

[0100] The above-mentioned negative electrode active material includes 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.

[0101] As a material capable of reversibly intercalating / deintercalating the above lithium ions, any carbon-based negative electrode active material commonly used in lithium-ion secondary batteries may be used, and representative examples include crystalline carbon, amorphous carbon, or a combination thereof. Examples of the above crystalline carbon include graphite such as amorphous, plate-like, flake-like, spherical, or fibrous natural graphite or artificial graphite, and examples of the above amorphous carbon include soft carbon (low-temperature calcined carbon) or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0102] As the above lithium metal alloy, an alloy of a metal selected from the group consisting of lithium, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn may be used.

[0103] Materials capable of doping and dedoping the above lithium include Si and SiO x Examples include (0 < x < 2), Si-Y alloy (wherein Y is an element selected from the group consisting of alkali metals, alkaline earth metals, group 13 elements, group 14 elements, transition metals, rare earth elements, and combinations thereof, and is not Si), Sn, SnO2, Sn-Y (wherein Y is an element selected from the group consisting of alkali metals, alkaline earth metals, group 13 elements, group 14 elements, transition metals, rare earth elements, and combinations thereof, and is not Sn), and at least one of these may also be mixed with SiO2. The above element Y may be selected from the group consisting of 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, Ti, Ge, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof.

[0104] Examples of the above transition metal oxides include vanadium oxide and lithium vanadium oxide.

[0105] The above-mentioned negative electrode active material layer also includes a binder and may optionally further include a conductive material.

[0106] 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. Representative examples include polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, etc., but are not limited thereto.

[0107] The above conductive material is used to impart conductivity to the electrode, and any electronically conductive material that does not cause chemical changes can be used in the battery being constructed. Examples include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, and carbon fibers; metal-based materials such as metal powders or metal fibers such as copper, nickel, aluminum, and silver; conductive polymer materials such as polyphenylene derivatives; or conductive materials including mixtures thereof.

[0108] As the above current collector, a material selected from the group consisting of copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof may be used.

[0109] Example 1

[0110] 1-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.96 F 0.0003 Method for manufacturing sulfide-based solid electrolytes

[0111] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3aCl(1-a)x(1-b)F ab In the solid electrolyte of applying x: 1.0, a: 0.03, b: 0.01, Li2S, P2S5, LiCl, B2O3, After quantifying LiF, the mixture was mixed at 300 rpm for about 8 hours using a planetary mill, then pellets were prepared at 300 MPa, and a crystalline phase was prepared by heat treatment at 430°C in an Ar atmosphere. Subsequently, the crystalline phase was fed into a bead mill and ground at 1,000 rpm for 30 minutes to prepare an intermediate, which was then fed into a fin mill and ground at 20,000 rpm to prepare a sulfide-based solid electrolyte.

[0112] 1-2. Method for manufacturing an all-solid-state battery

[0113] 75 wt% of cathode active material and the sulfide-based solid electrolyte with an Argyrodite crystal structure of Example 1-1 (Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.96 F 0.0003 ) 22wt%, Super C as a conductive agent 65 A mixed paste was prepared by thoroughly mixing 3 wt% with a solvent containing a small amount of dissolved binder. An electrode plate was manufactured using the mixed paste and dried to produce a composite electrode plate for the anode. First, an Argyrodite solid electrolyte (Li₂) functioning as a separator was placed in a jig for all-solid-state battery evaluation. 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.96 F 0.0003 100 mg of ) was loaded, and after applying pressure of 300 MPa or more to achieve a thickness of approximately 800 μm, a positive electrode plate was placed on one side and a secondary pressure was applied to fabricate the positive electrode. Subsequently, a Li-In alloy was placed on the other side and an appropriate pressure was applied to fabricate a battery for all-solid-state battery evaluation.

[0114] Example 2

[0115] 2-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.94 F 0.0009 Method for manufacturing sulfide-based solid electrolytes

[0116] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1.0, a: 0.03, and b: 0.03 were applied to the solid electrolyte.

[0117] 2-2. Method for Manufacturing All-Solid State Batteries

[0118] Sulfide-based solid electrolyte (Li of Example 2-1) 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.94 F 0.0009 It was prepared in the same manner as Example 1-2, except that ) was used.

[0119] Example 3

[0120] 3-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.92 F 0.0015 Method for manufacturing sulfide-based solid electrolytes

[0121] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1.0, a: 0.03, and b: 0.05 were applied to the solid electrolyte.

[0122] 3-2. Method for manufacturing all-solid-state batteries

[0123] Sulfide-based solid electrolyte (Li of Example 3-1) 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.92 F 0.0015 It was prepared in the same manner as Example 1-2, except that ) was used.

[0124] Example 4

[0125] 4-1. Li 5.335 P 0.97 B 0.06 S 4.85 O 0.09 Cl 1.411 F 0.0009 Method for manufacturing sulfide-based solid electrolytes

[0126] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1.5, a: 0.03, and b: 0.03 were applied to the solid electrolyte.

[0127] 4-2. Method for manufacturing all-solid-state batteries

[0128] Sulfide-based solid electrolyte (Li of Example 4-1) 5.335 P 0.97 B 0.06 S 4.85 O 0.09 Cl 1.411 F 0.0009 It was prepared in the same manner as Example 1-2, except that ) was used.

[0129] Example 5

[0130] 5-1. Li 4.2 P 0.7 B 0.6 S 3.5 O 0.9 Cl 0.63 F 0.03 Method for manufacturing sulfide-based solid electrolytes

[0131] Li(7-x)(1-a)P (1-a) B 2a S(6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1.0, a: 0.3, and b: 0.1 were applied to the solid electrolyte.

[0132] 5-2. Method for manufacturing all-solid-state batteries

[0133] Sulfide-based solid electrolyte (Li of Example 5-1) 4.2 P 0.7 B 0.6 S 3.5 O 0.9 Cl 0.63 F 0.03 It was prepared in the same manner as Example 1-2, except that ) was used.

[0134] Comparative Example 1

[0135] 1-1. Method for manufacturing Li6PS5Cl sulfide-based solid electrolyte

[0136] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1.0, a: 0.0, and b: 0.0 were applied to the solid electrolyte.

[0137] 1-2. Method for manufacturing an all-solid-state battery

[0138] It was prepared in the same manner as Example 1-2, except that the sulfide-based solid electrolyte (Li6PS5Cl) with an Argyrodite crystal structure of Comparative Example 1-1 was used.

[0139] Comparative Example 2

[0140] 2-1. Li 5.94 P 0.99 B 0.02 S 4.95 O 0.03 Cl 0.99 Method for manufacturing sulfide-based solid electrolytes

[0141] Li(7-x)(1-a)P (1-a) B 2a S(6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1, a: 0.01, and b: 0.0 were applied to the solid electrolyte.

[0142] 2-2. Method for Manufacturing All-Solid State Batteries

[0143] Sulfide-based solid electrolyte (Li of Comparative Example 2-1) 5.94 P 0.99 B 0.02 S 4.95 O 0.03 Cl 0.99 It was prepared in the same manner as Example 1-2, except that ) was used.

[0144] Comparative Example 3

[0145] 3-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.97 Method for manufacturing sulfide-based solid electrolytes

[0146] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Comparative Example 1-1, except that x: 1, a: 0.03, and b: 0.0 were applied to the solid electrolyte.

[0147] 3-2. Method for manufacturing all-solid-state batteries

[0148] Sulfide-based solid electrolyte (Li of Comparative Example 3-1) 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.97 It was prepared in the same manner as Example 1-2, except that ) was used.

[0149] Comparative Example 4

[0150] 4-1. Li 5.7 P 0.95 B 0.10 S4.75 O 0.15 Cl 0.95 Method for manufacturing sulfide-based solid electrolytes

[0151] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1, a: 0.05, and b: 0.0 were used in the solid electrolyte.

[0152] 4-2. Method for manufacturing all-solid-state batteries

[0153] Sulfide-based solid electrolyte (Li of Comparative Example 4-1) 5.7 P 0.95 B 0.10 S 4.75 O 0.15 Cl 0.95 It was prepared in the same manner as Example 1-2, except that ) was used.

[0154] Comparative Example 5

[0155] 5-1. Li 5.4 P 0.9 B 0.2 S 4.5 O 0.3 Cl 0.9 Method for manufacturing sulfide-based solid electrolytes

[0156] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1, a: 0.1, and b: 0.0 were applied to the solid electrolyte.

[0157] 5-2. Method for manufacturing all-solid-state batteries

[0158] Sulfide-based solid electrolyte (Li of Comparative Example 5-1) 5.4 P 0.9 B 0.2 S 4.5 O 0.3 Cl 0.9It was prepared in the same manner as Example 1-2, except that ) was used.

[0159] Comparative Example 6

[0160] 6-1. Li 4.2 P 0.7 B 0.6 S 3.5 O 0.6 Cl 0.63 F 0.03 Method for manufacturing sulfide-based solid electrolytes

[0161] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1, a: 0.3, and b: 0.1 were applied to the solid electrolyte.

[0162] 6-2. Method for Manufacturing All-Solid State Batteries

[0163] Sulfide-based solid electrolyte (Li of Comparative Example 6-1) 4.2 P 0.7 B 0.6 S 3.5 O 0.6 Cl 0.63 F 0.03 It was prepared in the same manner as Example 1-2, except that ) was used.

[0164] Comparative Example 7

[0165] 7-1. Li 4.2 P 0.7 B 0.6 S 3.5 O 0.9 Cl 0.49 F 0.09 Method for manufacturing sulfide-based solid electrolytes

[0166] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Example 1-1, except that x: 1.0, a: 0.3, and b: 0.3 were applied to the solid electrolyte.

[0167] 7-2. Method for manufacturing all-solid-state batteries

[0168] Sulfide-based solid electrolyte (Li of Comparative Example 7-1) 4.2 P 0.7 B 0.6 S 3.5 O 0.9 Cl 0.49 F 0.09 It was prepared in the same manner as Example 1-2, except that ) was used.

[0169] Comparative Example 8

[0170] 8-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.96 F 0.0003 Method for manufacturing sulfide-based solid electrolytes

[0171] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab In the solid electrolyte of applying x: 1, a: 0.03, b: 0.01, Li2S, P2S5, LiCl, B2O3, After quantifying LiF, the mixture was mixed at 300 rpm for about 8 hours using a planetary mill, then pellets were prepared at 300 MPa, and a crystalline phase was prepared by heat treatment at 430°C in an Ar atmosphere. Subsequently, the crystalline phase was fed into a bead mill and ground at 1,000 rpm for 30 minutes to prepare a sulfide-based solid electrolyte.

[0172] 8-2. Method for Manufacturing All-Solid State Batteries

[0173] Sulfide-based solid electrolyte (Li of Comparative Example 8-1) 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.96 F 0.0003 It was prepared in the same manner as Example 1-2, except that ) was used.

[0174] Comparative Example 9

[0175] 9-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.96 F 0.0003 Method for manufacturing sulfide-based solid electrolytes

[0176] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Comparative Example 7-1, except that x: 1, a: 0.03, and b: 0.03 were applied to the solid electrolyte.

[0177] 9-2. Method for Manufacturing All-Solid State Batteries

[0178] Sulfide-based solid electrolyte (Li of Comparative Example 9-1) 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.96 F 0.0003 It was prepared in the same manner as Example 1-2, except that ) was used.

[0179] Comparative Example 10

[0180] 10-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.92 F 0.0015 Method for manufacturing sulfide-based solid electrolytes

[0181] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Comparative Example 9-1, except that x: 1, a: 0.03, and b: 0.05 were applied to the solid electrolyte.

[0182] 10-2. Method for manufacturing all-solid-state batteries

[0183] Sulfide-based solid electrolyte (Li of Comparative Example 10-1) 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.92 F 0.0015 It was prepared in the same manner as Example 1-2, except that ) was used.

[0184] Comparative Example 11

[0185] 11-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.873 F 0.003 Method for manufacturing sulfide-based solid electrolytes

[0186] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Comparative Example 9-1, except that x: 1, a: 0.03, and b: 0.1 were applied to the solid electrolyte.

[0187] 11-2. Method for manufacturing all-solid-state batteries

[0188] Sulfide-based solid electrolyte (Li of Comparative Example 11-1) 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.873 F 0.003 It was prepared in the same manner as Example 1-2, except that ) was used.

[0189] Comparative Example 12

[0190] 12-1. Li 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.679 F 0.009 Method for manufacturing sulfide-based solid electrolytes

[0191] Li(7-x)(1-a)P (1-a) B 2a S(6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Comparative Example 9-1, except that x: 1, a: 0.03, and b: 0.3 were applied to the solid electrolyte.

[0192] 12-2. Method for Manufacturing All-Solid State Batteries

[0193] Sulfide-based solid electrolyte (Li of Comparative Example 12-1) 5.82 P 0.97 B 0.06 S 4.85 O 0.09 Cl 0.679 F 0.009 It was prepared in the same manner as Example 1-2, except that ) was used.

[0194] Comparative Example 13

[0195] 13-1. Li 5.335 P 0.97 B 0.06 S 4.365 O 0.09 Cl 1.41 F 0.0009 Method for manufacturing sulfide-based solid electrolytes

[0196] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab It was prepared in the same manner as Comparative Example 9-1, except that x: 1.5, a: 0.03, and b: 0.03 were applied to the solid electrolyte.

[0197] 13-2. Method for Manufacturing All-Solid State Batteries

[0198] Sulfide-based solid electrolyte (Li of Comparative Example 13-1) 5.335 P 0.97 B 0.06 S 4.365 O 0.09 Cl 1.41 F 0.0009 It was prepared in the same manner as Example 1-2, except that ) was used.

[0199] Experimental Example 1: Evaluation of Elastic Modulus

[0200] Force-distance curve measurements were performed on sulfide-based solid electrolytes according to one embodiment and comparative example of the present invention using an atomic force microscope (AFM, Bruker Dimension Icon), and the elastic modulus (Young's modulus) was calculated from the obtained force-distance curve.

[0201] A measurement sample was prepared by spreading and fixing the sample onto a silicon wafer thinly coated with epoxy resin inside a glove box in an inert gas atmosphere. The measurement conditions used were contact mode (force-distance curve measurement mode), and force-distance curves of 10 particles were measured for each sample. The solid electrolyte was measured after adjusting the measurement parameters to obtain a specified value using a known standard sample (glass: elastic modulus 72 GPa). The measurement environment was an Ar atmosphere (oxygen concentration < 0.1 ppm, moisture concentration < 0.1 ppm), 25°C, and a Bruker diamond probe (DNISP-HS) was used as the measurement probe. The obtained force-distance curve was fitted using the DMT model to derive the reduced modulus, and the elastic modulus of the solid electrolyte was derived by setting the Poisson's ratio to 0.3 from the relationship between the reduced modulus and the elastic modulus of the solid electrolyte, and the results are shown in Table 2.

[0202] Experimental Example 2: Evaluation of Ionic Conductivity at 30℃, 0.1C

[0203] The ionic conductivity of a sulfide-based solid electrolyte according to one embodiment and a comparative example of the present invention was evaluated. The sulfide-based solid electrolyte was introduced into a compaction cell and densified by applying a pressure of 300 MPa. Subsequently, the cell was closed using a SUS electrode at a pressure of 70 MPa, and the impedance was measured by applying 10 mV at 30°C, and the results are shown in Table 2.

[0204] Experimental Example 3: Evaluation of Electrochemical Properties

[0205] 3-1. Evaluation of Initial Discharge Capacity and Initial Efficiency

[0206] Charging was performed at room temperature (25℃) at 0.1C to 4.25V (vs. Li+ / Li), and the application of the charging current was terminated by setting the current amount to 0.02C at that voltage. Under the same conditions, at a current amount of 0.1C, 2.50V (vs. Li + After discharging to / Li), the initial discharge capacity was evaluated.

[0207] 3-2. Evaluation of Life Characteristics

[0208]

[0209] After preparing sulfide-based solid electrolyte pellets according to one embodiment and a comparative example of the present invention, the positive electrode was bonded to the top and the counter electrode to the bottom, and then the density was increased to 500 MPa. After assembling the all-solid-state battery cell, a formation cycle was performed at 0.1 C in a 30-degree chamber, and the life characteristics were evaluated at 0.5 C, and the results are shown in Table 2.

[0210] xabLiPBSOHa Grinding Method ClF (d) Comparative Example 1 1006 105010 Bead Mill, Fin Mill Comparative Example 2 10.0105.94 0.99 0.024.95 0.03 0.990 Bead Mill, Fin Mill Comparative Example 3 10.0305.82 0.97 0.064.85 0.09 0.970 Bead Mill, Fin Mill Comparative Example 4 10.0505.70.95 0.14.75 0.15 0.950 Bead Mill, Fin Mill Comparative Example 5 10.105.4 0.90.24.5 0.3 0.90 Bead Mill, Fin Mill Comparative Example 6 10.304.2 0.70.63.5 0.90.70 Bead Mill, Fin Mill Example 1 10.030.015.820.970.064.850.090.96030.0003 Bead mill, fin mill Example 2 10.030.035.820.970.064.850.090.94090.0009 Bead mill, fin mill Example 3 10.030.055.820.970.064.850.090.92150.0015 Bead mill, fin mill Example 4 1.50.030.035.3350.970.064.3650.091.411350.0009 Bead mill, fin mill Example 5 10.30.14.20.70.63.50.90.630.03 Bead Mill, Pin Mill Comparative Example 7 10.30.34.20.70.63.50.90.490.09 Bead Mill, Pin Mill Comparative Example 8 10.030.015.820.970.064.850.090.96030.0003 Bead Mill Comparative Example 9 10.030.035.820.970.064.850.090.94090.0009 Bead Mill Comparative Example 10 10.030 .055.820.970.064.850.090.92150.0015 Bead Mill Comparative Example 1110.030.15.820.970.064.850.090.8730.003 Bead Mill Comparative Example 1210.030.35.820.970.064.850.090.6790.009 Bead Mill Comparative Example 131.50.030.035.3350.970.064.3650.091.411350.0009 Bead Mill

[0211] Referring to Table 1, Li(xy-x-5y+7)P when preparing a sulfide-based solid electrolyte according to one embodiment and a comparative example of the present invention (1-y) S (xy-x-5y+6) O 4y Cl(x-xy)(1-z)F zThe molar ratios of x, a, and b applied to the composition and the grinding method can be verified.

[0212] Proposed Elastic modulus (GPa) Grinding application Particle size parameter Particle size and elastic modulus parameter Ion conductivity Discharge capacity 100 times D 50 D max D max / D 50 (Elastic modulus*D 50 ) / D max mS / cmmAh g -1 Lifespan Comparison Example 1 32.002.9016.605.725.592.120784 Comparison Example 2 32.802.9115.905.466.00220986 Comparison Example 3 33.103.0515.905.216.351.920886 Comparison Example 4 33.503.0115.805.256.381.720587 Comparison Example 5 34.903.2116.205. 056.911.5619985 Comparative Example 635.103.1016.605.356.551.119284 Example 128.103.2214.604.536.201.8021187 Example 223.203.3614.304.265.451.921387 Example 321.103.3314.504.354.851.921185 Example 4 20.603.1613.904.404.686.820881 Example 5 20.803.2114.404.494.641.520785 Comparative Example 7 20.103.2512.103.725.401.220189 Comparative Example 8 28.103.2219.606.094.622.2021187 Comparative Example 9 23.202.9018.806.483 .582.1121387 Comparative Example 1021.102.6018.407.082.981.9821185 Comparative Example 1120.802.4017.907.462.791.8420785 Comparative Example 1220.102.5020.408.162.461.6320189 Comparative Example 1320.602.6019.307.422.771.2220881

[0213] Referring to Table 2, even when bead milling and fin milling are performed stepwise during milling, it can be confirmed that when the halogen element in the sulfide-based solid electrolyte is included as a single element Cl, as in Comparative Examples 1 to 6, the discharge capacity is inferior and the elastic modulus is higher compared to Examples 1 to 5, which contain two types of halogen elements Cl and F, under the same process conditions. A high elastic modulus may imply that the particle strength is high, preventing fracture during the process, which reduces the contact area and may lead to an increase in interfacial resistance. Furthermore, Comparative Example 7 contains two types of halogen elements in the sulfide-based solid electrolyte and uses both a bead mill and a fin mill during solid electrolyte manufacturing; however, it can be confirmed that the ion conductivity and discharge capacity are lower compared to the examples due to the excessive input of B. Additionally, referring to Comparative Examples 8 to 13, although the sulfide-based solid electrolyte contains two types of halogen elements Cl and F, only bead milling was performed during milling, D max It can be confirmed that is inferior compared to Examples 1 to 5. Through this, it can be seen that when manufacturing a sulfide-based solid electrolyte containing two or more halogen elements, the two-step manufacturing process using a bead mill and a fin mill must be performed, and the doped boron content must be appropriate so that D does not decrease in ionic conductivity. 50 is large and D max It is possible to manufacture small sulfide-based solid electrolytes, and it can be confirmed that the electrochemical characteristics of the battery are excellent when an all-solid-state battery is manufactured using the said sulfide-based solid electrolyte. In addition, although the elastic modulus of Comparative Example 8 was similar to or slightly higher than that of Examples 1 to 5 due to the low input amount of F, D compared to Examples 1 to 5 was obtained by using only a bead mill when manufacturing the sulfide-based solid electrolyte. max It can be confirmed that it is inferior. Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and it is possible to implement it with various modifications within the scope of the claims, the detailed description of the invention, and the attached drawings, and it is obvious that such modifications also fall within the scope of the present invention.

[0214] Therefore, the substantive scope of the present invention shall be defined by the appended claims and their equivalents.

Claims

1. Containing lithium (Li), phosphorus (P), sulfur (S), boron (B) and a plurality of halogen elements It includes a sulfide-based solid electrolyte having an agyrodite-type crystal structure, The above sulfide-based solid electrolyte is a sulfide-based solid electrolyte satisfying the following Equation 1. [Equation 1] 3.6 ≤ (CxB) / A ≤ 5.5 In Equation 1 above, A is D measured by the laser diffraction scattering particle size distribution measurement method. max and, B is D 50 And, C is the elastic modulus measured by an atomic force microscope (AFM).

2. In Paragraph 1, The above sulfide-based solid electrolyte is a sulfide-based solid electrolyte satisfying the following Equation 2: [Equation 2] 2 ≤ B / A ≤ 5.0 In the above Equation 2, A and B are as defined in the above Equation 1.

3. In Paragraph 2, D of the above sulfide-based solid electrolyte max is 15μm or less, and D of the above sulfide-based solid electrolyte 50 A sulfide-based solid electrolyte with a particle size of 3.15 μm or larger.

4. In Paragraph 1, A sulfide-based solid electrolyte having an elastic modulus of 15 to 30 GPa.

5. In Paragraph 1, The above sulfide-based solid electrolyte is a sulfide-based solid electrolyte represented by the following chemical formula 1: [Chemical Formula 1] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab In the above chemical formula 1, 1 ≤ x ≤ 2, 0.01 ≤ a ≤ 0.3, and 0.01 ≤ b ≤ 0.

3.

6. In Paragraph 1, A sulfide-based solid electrolyte having a molar ratio of lithium (Li) to phosphorus (P) ([Li] / [P]) of 5.5 to 6.

5.

7. In Paragraph 1, A sulfide-based solid electrolyte in which the molar ratio of boron (B) to phosphorus (P) ([B] / [P]) of the above sulfide-based solid electrolyte is 0.03 to 0.

08.

8. In Paragraph 1, A sulfide-based solid electrolyte having a molar ratio of sulfur (S) to phosphorus (P) ([S] / [P]) of 4 to 5.

5.

9. In Paragraph 1, A sulfide-based solid electrolyte having a molar ratio of oxygen (O) to phosphorus (P) ([O] / [P]) of 0.05 to 0.

12.

10. In Paragraph 1, A sulfide-based solid electrolyte in which the molar ratio ([D] / [P]) of a plurality of halogen elements (D) to phosphorus (P) of the above sulfide-based solid electrolyte is 0.5 to 1.

5.

11. A step of preparing a mixture by milling raw materials of a halogen compound including lithium sulfide, a sulfur compound, a lithium compound, and lithium fluoride; A step of heat-treating the above mixture to produce a crystalline phase; A step of obtaining an intermediate by first crushing the above crystalline phase; and A method for manufacturing a sulfide-based solid electrolyte, comprising the step of secondarily grinding the above intermediate.

12. In Paragraph 11, The above first grinding step is performed by grinding with a bead mill, and A method for manufacturing a sulfide-based solid electrolyte, wherein the rotational speed of the bead mill is 500 to 3000 rpm and the driving time is 10 to 60 minutes.

13. In Paragraph 11, The above second grinding step is performed by grinding with a pin mill, and A method for manufacturing a sulfide-based solid electrolyte, wherein the rotational speed of the above-mentioned pin mill is 5,000 to 30,000 rpm.

14. In Paragraph 11, A method for manufacturing a sulfide-based solid electrolyte, wherein the heat treatment temperature of the above mixture is 300 to 600℃.

15. In Paragraph 11, A method for manufacturing a sulfide-based solid electrolyte, wherein the above sulfide-based solid electrolyte has an agyrodite-type crystal structure and is represented by the following chemical formula 1: [Chemical Formula 1] Li(7-x)(1-a)P (1-a) B 2a S (6-x)(1-a) O 3a Cl(1-a)x(1-b)F ab In the above chemical formula 1, 1 ≤ x ≤ 2, 0.01 ≤ a ≤ 0.3, and 0.01 ≤ b ≤ 0.3.