Solid electrolyte, method for preparing same, and all-solid-state battery comprising same

Abstract

The present invention relates to a sulfide-based solid electrolyte that includes a compound containing lithium (Li), phosphorus (P), sulfur (S), and chlorine (Cl) and having an argyrodite-based crystal structure, wherein at least a portion of the crystal structure is doped with a Group 13 element, a Group 14 element, and oxygen (O), and the compound is represented by chemical formula 1. [Chemical formula 1] Li6(1-x-y)A2xByP(1-x-y)S5.0(1-x-y)O3xCl(1-x-y)+4y In chemical formula 1, 0.01 ≤ x ≤ 0.08, 0.03 ≤ y ≤ 0.45, element A is the Group 13 element, and element B is the Group 14 element.

Description

Solid electrolyte, method for manufacturing the same, and all-solid-state battery including the same

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

[0002] This application claims priority to Korean Patent Application No. 10-2024-0190716, filed on December 19, 2024, the entire contents of which are incorporated herein by reference.

[0003] Recently, the demand for high-performance batteries has been rapidly increasing in application fields such as IT mobile devices, small power drive systems (e-bikes, small EVs, etc.), and energy storage systems (ESS). Due to this growing demand, higher capacity and output power of energy storage devices are becoming essential, and ensuring safety and reliability has emerged as a critical issue. While conventional lithium-ion rechargeable batteries have been commercialized based on their high energy density and excellent cycle life, there are limitations in ensuring safety due to issues such as the flammability of liquid electrolytes and thermal runaway caused by internal short circuits.

[0004] To address these issues, all-solid-state batteries are attracting attention as promising next-generation energy storage devices. By replacing liquid electrolytes with solid electrolytes, all-solid-state batteries offer high safety and stability while possessing the potential to maximize energy density. In particular, solid electrolytes have high electrochemical stability and can be combined with lithium metal anodes, offering the advantage of theoretically enabling higher capacity and energy density.

[0005] Among solid electrolytes, Li6PS5Cl-based sulfide-based solid electrolytes having an argyrodite structure have excellent ionic conductivity (10 -3 ~ 10 -2It is evaluated as a candidate material with high commercialization potential due to its relatively low synthesis temperature and simplified manufacturing process, along with its S / cm level. Such electrolytes support the rapid movement of lithium ions and exhibit characteristics favorable for improving interfacial stability with electrodes. Accordingly, active research and development on Li6PS5Cl and its modified compositions is being conducted by various research groups.

[0006] However, sulfide-based solid electrolytes are sensitive to moisture, posing a problem of causing side reactions that generate toxic gases such as H2S under normal atmospheric conditions. This characteristic necessitates strict environmental control during manufacturing and handling processes, acting as a major constraint on commercialization. Therefore, research into compositional modifications to improve the moisture stability of sulfide-based solid electrolytes, the development of surface coating technologies, and manufacturing processes that optimize environmental conditions are emerging as critical tasks.

[0007] The objective of the present invention is to solve the problems of the aforementioned prior art by providing a sulfide-based solid electrolyte having excellent moisture safety and excellent ion conductivity, a method for manufacturing the same, and an all-solid-state battery including the same.

[0008] A sulfide-based solid electrolyte according to one embodiment of the present invention comprises a compound having an argyrodite-based crystal structure containing lithium (Li), phosphorus (P), sulfur (S), and chlorine (Cl), wherein at least a portion of the crystal structure is doped with a Group 13 element, a Group 14 element, and oxygen (O), and the compound can be represented by the following chemical formula 1.

[0009] [Chemical Formula 1]

[0010] Li 6(1-x-y) A 2x B y P (1-x-y) S 5.0(1-x-y) O 3x Cl(1-xy)+4y

[0011] In the above chemical formula 1, 0.01 ≤ x ≤ 0.08, 0.03 ≤ y ≤ 0.45, element A is a group 13 element, and element B is a group 14 element.

[0012] Group 13 elements can be boron (B).

[0013] Group 14 elements can be silicon (Si).

[0014] In Chemical Formula 1, 0.015 ≤ x ≤ 0.035 and 0.05 ≤ y ≤ 0.2 may be possible.

[0015] In Chemical Formula 1, 0.015 ≤ x ≤ 0.025 and 0.05 ≤ y ≤ 0.2 may be possible.

[0016] In Chemical Formula 1, 0.02 ≤ x ≤ 0.035 and 0.05 ≤ y ≤ 0.15 may be possible.

[0017] When analyzing the X-ray diffraction (XRD) pattern, the compound may exhibit a peak in the range of 30.2˚≤2θ≤30.3˚.

[0018] A method for manufacturing a sulfide-based solid electrolyte according to another embodiment of the present invention comprises the steps of: mixing a lithium (Li) raw material, a first phosphorus (P) raw material, a second phosphorus (P) raw material, a chlorine (Cl) raw material, and a doping raw material to form a mixture; and heat-treating the mixture to form a sulfide-based solid electrolyte having an argyrodite-based crystal structure, wherein the doping raw material includes a boron (B) compound and a silicon (Si) compound, the first phosphorus (P) raw material and the second phosphorus (P) raw material are heterogeneous, and at least one of the first phosphorus (P) raw material or the second phosphorus (P) raw material may contain oxygen (O).

[0019] The first phosphorus (P) raw material contains oxygen (O), and the second phosphorus (P) raw material may not contain oxygen (O).

[0020] The boron (B) compound can be BCl3.

[0021] The silicon (Si) compound can be SiCl4.

[0022] The amount of boron (B) compound added may be 0.01 to 0.08 mol% based on the total moles of the mixture.

[0023] The amount of silicon (Si) compound added may be 0.03 to 0.045 mol% based on the total moles of the mixture.

[0024] In another embodiment of the present invention, another all-solid-state battery comprises a positive electrode layer; a negative electrode layer and a solid electrolyte layer located between the positive electrode layer and the negative electrode layer, and at least one of the positive electrode layer, the negative electrode layer and the solid electrolyte layer may comprise the aforementioned solid electrolyte.

[0025] A sulfide-based solid electrolyte according to one embodiment of the present invention can provide an electrolyte with excellent moisture safety and improved ion conductivity.

[0026] Figure 1 is a graph of the X-ray diffraction pattern analysis results of solid electrolytes prepared according to Example 1 and Comparative Example 1.

[0027] 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 present invention.

[0028] 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.

[0029] When it is stated that one part is "above" or "on" another part, it may be directly above or on the other part, or other parts may be involved in between. In contrast, when it is stated that one part is "directly above" another part, no other parts are interposed in between.

[0030] 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.

[0031] Also, unless otherwise specified, % means weight %, and 1 ppm is 0.0001 weight %.

[0032] 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.

[0033] 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.

[0034]

[0035] 1. Solid electrolyte

[0036] A sulfide-based solid electrolyte according to one embodiment of the present invention may include a compound having an argyrodite-based crystal structure containing lithium (Li), phosphorus (P), sulfur (S), and chlorine (Cl). Specifically, the compound may be Li6PS5Cl.

[0037] In this case, the sulfide-based solid electrolyte may be doped with at least a portion of the azirodite-based crystal structure with a Group 13 element, a Group 14 element, and oxygen (O).

[0038] By doping a sulfide-based solid electrolyte with an azirodite crystal structure with Group 13 and Group 14 elements, the lithium ion concentration is optimized, the mobile pathways for lithium ions are increased, and the interaction between anions and lithium ions is weakened, thereby improving ionic conductivity. Furthermore, defects within the crystal structure are controlled, the activation energy of lithium ion movement is lowered, and structural flexibility is provided to maximize lithium ion mobility. Additionally, intergranular connectivity is improved and interfacial resistance is reduced, thereby enhancing overall conductivity performance. In other words, by doping a sulfide-based solid electrolyte with an azirodite crystal structure with Group 13 and Group 14 elements, the ionic conductivity of the electrolyte can be improved due to the aforementioned structural and electrochemical changes.

[0039] Group 13 elements may be boron (B), aluminum (Al), gallium (Ga), indium (In), or a combination thereof. Specifically, Group 13 elements may be boron (B).

[0040] When boron (B) is doped into an azirodite-based sulfide solid electrolyte, boron increases the stability of the crystal structure through its small atomic size and strong BS bonds, and improves ionic conductivity by optimizing the lithium ion transport pathway. In addition, it improves moisture stability by suppressing moisture reactivity and provides long-term performance stability by reducing reactions at the electrode-electrolyte interface.

[0041] When aluminum (Al) is doped into azirodite-based sulfide solid electrolytes, it not only increases ionic conductivity by adjusting structural defects and optimizing lithium ion concentration, but also enhances stability under high-voltage conditions and provides long-term stability by suppressing electrode-electrolyte interfacial reactions. Additionally, it improves handling characteristics during the manufacturing process by increasing mechanical strength.

[0042] When gallium (Ga) is doped into azirodite-based sulfide solid electrolytes, it provides structural flexibility and improves ionic conductivity by expanding lithium ion migration pathways. Furthermore, it enhances oxidation stability to improve compatibility with high-voltage electrodes and stabilizes electrolyte performance by maintaining thermal stability even in high-temperature environments.

[0043] When indium (In) is doped into azirodite-based sulfide solid electrolytes, stability is enhanced to maintain electrolyte performance in high-temperature environments, and ionic conductivity is increased by expanding lithium ion migration pathways. Additionally, it reduces side reactions at the electrode-electrolyte interface and extends battery life by providing long-term chemical stability.

[0044] Group 14 elements may be silicon (Si), germanium (Ge), tin (Sn), or a combination thereof. Specifically, Group 14 elements may be silicon (Si).

[0045] When silicon (Si) is doped into azirodite-based sulfide solid electrolytes, structural stability is enhanced through strong Si-S bonding, and moisture stability is improved by reducing reactivity with water. Additionally, ionic conductivity is increased by optimizing lithium ion migration pathways, and compatibility with high-voltage electrodes is improved due to enhanced oxidation stability.

[0046] When germanium (Ge) is doped into an azirodite-based sulfide solid electrolyte, [GeS4] 4- It forms units to significantly expand the lithium ion transport pathway, providing excellent ionic conductivity; enhances crystal structure stability by maintaining structural symmetry and controlling defects; and improves ionic conductivity by increasing interfacial stability and reducing activation energy.

[0047] When tin (Sn) is doped into azirodite-based sulfide solid electrolytes, it provides cost-effectiveness while increasing mechanical flexibility, improves compatibility with high-voltage anodes through high oxidation stability, and enhances long-term stability through increased ionic conductivity and suppression of interfacial reactions.

[0048] By doping oxygen (O) into an azirodite-based sulfide solid electrolyte, reactivity with water is reduced due to the strong electronegativity and bonding strength of oxygen (O), and chemical stability is increased as oxygen (O) is introduced instead of sulfur (S). Furthermore, the crystal structure is made denser and stronger to inhibit the penetration of water molecules and reduce defect formation, thereby lowering reactivity with moisture. Additionally, surface chemical properties are altered to lower the affinity for water and improve the long-term stability and durability of the electrolyte. In other words, by doping oxygen (O) into a sulfide-based solid electrolyte with an azirodite crystal structure, the moisture stability of the electrolyte is improved through the aforementioned methods, which can also improve handling performance and lifespan.

[0049] The compound can be represented by the following chemical formula 1:

[0050] [Chemical Formula 1]

[0051] Li 6(1-x-y) A 2x B y P (1-x-y) S 5.0(1-x-y) O 3x Cl(1-xy)+4y

[0052] In Chemical Formula 1, 0.01 ≤ x ≤ 0.08 and 0.03 ≤ y ≤ 0.45, and element A is a Group 13 element and element B is a Group 14 element. Since the doping effects of Group 13 and Group 14 elements have been discussed previously, they will be omitted below to avoid duplication.

[0053] Meanwhile, in the sulfide-based solid electrolyte according to the present invention, the doping amounts of Group 13 and Group 14 elements can be controlled independently of each other. In other words, the doping amounts of Group 13 and Group 14 elements do not have a constant correlation with each other and can be randomly controlled to independent doping amounts. Accordingly, the effect of improving the ion conductivity of the aforementioned solid electrolyte can be preferably maximized.

[0054] Specifically, in Chemical Formula 1, 0.015 ≤ x ≤ 0.05 and 0.05 ≤ y ≤ 0.4 may be true. Specifically, 0.015 ≤ x ≤ 0.035 and 0.05 ≤ y ≤ 0.2 may be true. Specifically, 0.015 ≤ x ≤ 0.025 and 0.05 ≤ y ≤ 0.2 may be true. Specifically, 0.02 ≤ x ≤ 0.035 and 0.05 ≤ y ≤ 0.15 may be true.

[0055] In Chemical Formula 1, if the value of x or y is too small, the doping amount of the Group 13 or Group 14 element is too low, so the effect of improving the ionic conductivity of the aforementioned solid electrolyte may be negligible. On the other hand, if the value of x or y is too large, the azirodite crystal structure is significantly deformed due to excessive doping, which hinders the smooth movement of lithium ions. Furthermore, the Group 13 or Group 14 element fails to form the azirodite crystal structure and exists as an impurity, which may actually lower the ionic conductivity of the solid electrolyte. Therefore, the effect of improving the ionic conductivity of the solid electrolyte can be preferably realized when x and y satisfy the above range.

[0056] Sulfide-based solid electrolytes can be in the form of particles or powder, and can be crystalline or amorphous.

[0057] When analyzing the X-ray diffraction (XRD) pattern, the compound may exhibit peaks in the range of 30.2˚ ≤ 2θ ≤ 30.3˚. Peaks in the above range indicate an azirodite-based crystalline phase, and by including said crystalline phase, the ionic conductivity and electrochemical properties of the solid electrolyte can be preferably realized.

[0058]

[0059] 2. Method for manufacturing solid electrolyte

[0060] A method for manufacturing a sulfide-based solid electrolyte according to another embodiment of the present invention comprises the steps of: mixing a lithium (Li) raw material, a first phosphorus (P) raw material, a second phosphorus (P) raw material, a chlorine (Cl) raw material, and a doping raw material to form a mixture; and heat-treating the mixture to form a sulfide-based solid electrolyte having an argyrodite-based crystal structure, wherein the doping raw material comprises a boron (B) compound and a silicon (Si) compound, and the first phosphorus (P) raw material and the second phosphorus (P) raw material are heterogeneous, and at least one of the first phosphorus (P) raw material or the second phosphorus (P) raw material may contain oxygen (O).

[0061] In this specification, the term 'heterogeneous' means different kind.

[0062] Hereinafter, a method for manufacturing a sulfide-based solid electrolyte according to another embodiment of the present invention will be described step by step.

[0063] First, a lithium (Li) raw material, a first phosphorus (P) raw material, a second phosphorus (P) raw material, a chlorine (Cl) raw material, and a doping raw material are mixed to form a mixture.

[0064] The lithium (Li) source material may be, for example, Li2S, Li2S2, or a combination thereof, but is not necessarily limited thereto. Specifically, the lithium (Li) source material may be Li2S.

[0065] The first phosphorus (P) raw material and the second phosphorus (P) raw material are P2S5, P2O5, Li3P, and PS4, respectively. 3- It may be PCl3, PCl5, or a combination thereof, but is not necessarily limited thereto. However, the first phosphorus (P) raw material and the second phosphorus (P) raw material are different types, and at least one of the first phosphorus (P) raw material or the second phosphorus (P) raw material may contain oxygen (O).

[0066] Specifically, the first phosphorus (P) raw material contains oxygen (O), and the second phosphorus (P) raw material may not contain oxygen (O). More specifically, the first phosphorus (P) raw material may be P2O5. More specifically, the second phosphorus (P) raw material may be P2S5.

[0067] The chlorine (Cl) source material may be, for example, LiCl, PCl3, PCl5, SCl2, S2Cl2, or a combination thereof, but is not necessarily limited thereto. Specifically, the chlorine (Cl) source material may be LiCl.

[0068] The boron (B) compound is not particularly limited as long as it is a compound containing boron (B), and may be, for example, B2S3, LiBH4, BCl3, B2O3, Li2B4O7 or a combination thereof.

[0069] The boron (B) compound can be, more specifically, BCl3. By using BCl3 as the boron (B) compound, there is an advantage in being able to design a composition rich in chlorine (Cl) content while simultaneously doping with boron (B).

[0070] The silicon (Si) compound is not particularly limited as long as it is a compound containing silicon (Si), and may be, for example, SiS2, SiO2, Li2SiO3, Li4SiO4, SiCl4, or a combination thereof.

[0071] The silicon (Si) compound can be, more specifically, SiCl4. By using SiCl4 as the silicon (Si) compound, there is an advantage in being able to design a composition rich in chlorine (Cl) content while simultaneously doping silicon (Si).

[0072] The amount of boron (B) compound added may be 00 to 00 mol% based on the total molar amount of the mixture, and more specifically, 00 to 00 mol%. When the amount of boron (B) compound added satisfies the above range, the boron (B) doping amount is doped to the aforementioned range, so that the ionic conductivity of the electrolyte and the electrochemical properties of the battery can be preferably realized.

[0073] The amount of silicon (Si) compound added may be 00 to 00 mol% based on the total molar amount of the mixture, and more specifically, 00 to 00 mol%. When the amount of silicon (Si) compound added satisfies the above range, the silicon (Si) doping amount is doped to the aforementioned range, so that the ionic conductivity of the electrolyte and the electrochemical properties of the battery can be preferably realized.

[0074] The mixing of raw materials can be carried out by mechanical mixing or chemical mixing.

[0075] Mechanical mixing can be performed using methods such as a planetary mill, paint shaker, ball mill, bead mill, homogenizer, hammer mill, turbo mill, disc mill, planetary mill, mechanofusion, etc.

[0076] Chemical mixing can be performed, for example, by melt quenching.

[0077] Mixing can be performed for 4 to 12 hours, specifically 6 to 10 hours, and more specifically 7 to 9 hours. If the mixing time is too short, a problem may arise where mixing is insufficient. If the mixing time is too long, mixing may be fully completed after a certain period, and even if mixing is continued, the mixing state will remain the same, which may cause problems in terms of process efficiency.

[0078] Mixing can be performed at a rotational speed of 100 to 500 rpm, specifically at 150 to 450 rpm, and more specifically at 200 to 400 rpm. If the rotational speed is too slow, the balls may not penetrate into the powder, resulting in less overall mixing of the powder particles or lower energy, which may lead to insufficient atomization of the powder particles. On the other hand, if the rotational speed is too fast, the powder particles may become concentrated in one area, resulting in less even mixing.

[0079] Next, optionally as needed, after the step of forming the mixture, a step of compressing the mixture to form pellets may be further included.

[0080] At this time, compression can be performed at a pressure of 100 to 500 MPa, specifically 150 to 450 MPa, and more specifically 200 to 400 MPa. If the pressure is too low, a problem may arise where interfacial resistance increases due to insufficient binding between powder particles. On the other hand, if the pressure is too high, the binding between powder particles is already established, so the binding state does not change even if additional pressure is applied, which may cause problems in terms of process efficiency. Therefore, forming pellets at an appropriate pressure is desirable in terms of productivity.

[0081] Next, the mixture is heat-treated to form a sulfide-based solid electrolyte with an argyrodite-based crystal structure.

[0082] At this time, the heat treatment can be performed at a temperature of 400 to 700°C, and more specifically at 500 to 600°C. If the heat treatment temperature is too low, the synthesis of the solid electrolyte with an azirodite crystal structure may not occur sufficiently, or it may be synthesized into an amorphous crystal structure, which may result in a decrease in the ionic conductivity of the solid electrolyte. If the heat treatment temperature is too high, the elements constituting the solid electrolyte may vaporize, causing the solid electrolyte to be lost, or impurity phases may be generated, which may result in a decrease in the ionic conductivity of the solid electrolyte.

[0083] In addition, the heat treatment can be performed for 2 to 8 hours, and more specifically, for 3 to 5 hours. If the heat treatment time is too short, the synthesis of the solid electrolyte with an azirodite crystal structure may not occur sufficiently, or it may be synthesized into an amorphous crystal structure, which may result in a decrease in the ionic conductivity of the solid electrolyte. If the heat treatment time is too long, the elements constituting the solid electrolyte may vaporize, causing the solid electrolyte to be lost, or impurity phases may be generated, which may result in a decrease in the ionic conductivity of the solid electrolyte.

[0084] In addition, the heat treatment may be performed in an inert gas atmosphere. Since the heat treatment is performed in an inert gas atmosphere, there may be an advantage in that contact with atmospheric moisture can be blocked. The inert gas atmosphere may be, for example, an Ar, N2, H2, or He atmosphere, and more specifically, an Ar atmosphere.

[0085]

[0086] 3. All-solid-state battery

[0087] 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 located between the positive electrode layer and the negative electrode layer, and at least one of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer may comprise the aforementioned solid electrolyte.

[0088]

[0089] (Bipolar layer)

[0090] More specifically, the anode layer may include an anode current collector and an anode active material layer disposed on the anode current collector.

[0091] The positive active material layer may further include, for example, a positive active material and, optionally, a solid electrolyte. The solid electrolyte included in the positive active material layer may be the same as or different from the solid electrolyte according to one embodiment of the present invention, and may be the same as or different from the solid electrolyte included in the solid electrolyte layer.

[0092] The cathode active material is a material capable of reversibly absorbing and desorbing lithium ions. The cathode active material may be, for example, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, but is not necessarily limited to these; any material used as a cathode active material in the relevant technical field is acceptable. The cathode active material may be a single material or a mixture of two or more materials.

[0093] Lithium transition metal oxides are, for example, Li a A 1-b B b D2(wherein 0.90 ≤ a ≤ 1, and 0 ≤ b ≤ 0.5); Li a E 1-b B b O 2-c D c (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); LiE 2-b B b O 4-c D c (In the above equation, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li a Ni 1-b-c Co b B c D α (In the above equation, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α ≤ 2); Li a Ni 1-b-c Co b B c O 2-α F α(In the above equation, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni 1-b-c Co b B c O 2-α F2(wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni 1-b-c Mn b B c D α (In the above equation, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α ≤ 2); Li a Ni 1-b-c Mn b B c O 2-α F α (In the above equation, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni 1-b-c Mn b B c O 2-α F2(wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni b E c G d O2(wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0.001 ≤ d ≤ 0.1); Li a Ni b Co c Mn d GeO2(wherein the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0.001 ≤ e ≤ 0.1); Li a NiG b O2(in the above equation, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a CoGb O2(in the above equation, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a MnG b O2(in the above equation, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a Mn2G b O4(wherein 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiIO2; LiNiVO4; Li (3-f) J2(PO4)3(0 ≤ f ≤ 2); Li (3-f)Fe2(PO4)3(0 ≤ f ≤ 2); a compound represented by any one of the chemical formulas of LiFePO4. In such a compound, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; and J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof. A compound having a coating layer added to the surface of such a compound may also be used, and a mixture of the compound described above and a compound having a coating layer added may also be used. The coating layer applied to the surface of such a compound comprises, for example, a coating element compound of an oxide, hydroxide, oxyhydroxide, oxycarbonate, or hydroxycarbonate of a coating element. The compound forming this coating layer is amorphous or crystalline. The coating elements included in the coating layer are Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The method for forming the coating layer is selected within a range that does not adversely affect the physical properties of the cathode active material. The coating method is, for example, spray coating or immersion. Since specific coating methods are well understood by those skilled in the art, a detailed explanation will be omitted.

[0094] The positive active material layer may include, for example, a binder. The binder may be, 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 acceptable.

[0095] The positive active material layer may include, for example, a conductive material. The conductive material may include, for example, graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, etc., but is not limited to these, and any material used as a conductive material in the relevant technical field is acceptable.

[0096] The positive active material layer may further include additives such as fillers, coating agents, dispersants, and ion conductivity aids in addition to the positive active material, solid electrolyte, binder, and conductive material described above, for example.

[0097] As fillers, coating agents, dispersants, ion conductivity aids, etc. that may be included in the positive electrode active material layer, known materials generally used in electrodes of all-solid-state secondary batteries can be used.

[0098] The positive current collector may be a plate or foil made of, 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 alloys thereof. The thickness of the positive current collector may be, for example, 1 µm to 100 µm, 1 µm to 50 µm, 5 µm to 25 µm, or 10 µm to 20 µm.

[0099]

[0100] (Cathode layer)

[0101] More specifically, the cathode layer may include a cathode current collector and a cathode active material layer disposed on the cathode current collector.

[0102] The negative electrode active material layer may include, for example, a negative electrode active material and a binder, and may optionally further include a solid electrolyte as needed.

[0103] The negative electrode active material may include, for example, a carbon-based negative electrode active material, a metal / metallic negative electrode active material, or a combination thereof.

[0104] The carbon-based cathode active material may be amorphous carbon, crystalline carbon, or a mixture or composite thereof. The amorphous carbon may be, for example, carbon black (CB), acetylene black (AB), furnace black (FB), Kettjen black (KB), graphene, etc., but is not necessarily limited to these; any material classified as amorphous carbon in the relevant technical field is acceptable. Amorphous carbon is carbon that does not have crystallinity or has very low crystallinity, and is distinguished from crystalline carbon or graphite-based carbon. The crystalline carbon may be, for example, natural graphite, artificial graphite, or a combination thereof.

[0105] The metal / metallic anode active material comprises one or more selected from the group consisting of lithium (Li), gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn), but is not necessarily limited to these, and any metal anode active material or metallic anode active material that forms an alloy or compound with lithium in the relevant technical field is acceptable.

[0106] The binder included in the negative electrode active material layer may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, etc., but is not necessarily limited to these, and any binder used in the relevant technical field is acceptable. The binder may be composed of a single binder or a plurality of different binders.

[0107] The cathode active material layer is stabilized on the cathode current collector by including a binder. In addition, cracking of the cathode active material layer is suppressed despite volume changes and / or relative positional changes of the cathode active material layer during the charging and discharging process.

[0108] The negative electrode active material layer may further include additives used in conventional all-solid-state batteries, such as fillers, coating agents, dispersants, ion conductivity aids, etc.

[0109] The all-solid-state battery may further include a second negative electrode active material layer disposed between the negative electrode current collector and the negative electrode active material layer upon charging. The second negative electrode active material layer may be deposited between the negative electrode current collector and the negative electrode current collector during the charging process, or may be further disposed on the negative electrode active material layer during electrode assembly. This second negative electrode active material layer may be a metal layer comprising lithium 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, a Li-Si alloy, but is not limited thereto; any alloy used as a lithium alloy in the relevant technical field is acceptable. The second negative electrode active material layer may be composed of one of these alloys and / or lithium, or may be composed of various types of alloys and / or lithium.

[0110] The negative electrode current collector may be composed of, for example, a material that does not react with lithium, that is, does not form either an alloy or a compound. The negative electrode current collector may include, for example, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni), but is not necessarily limited to these; any material used as an electrode current collector in the relevant technical field is acceptable. The negative electrode current collector may be composed of one of the metals described above, or may be composed of an alloy or coating material of two or more metals. The negative electrode current collector may be, for example, in the form of a plate or a foil.

[0111] When the negative electrode active material layer includes a solid electrolyte, the solid electrolyte included in the negative electrode active material layer may be the same as or different from the solid electrolyte according to one embodiment of the present invention, and may be the same as or different from the solid electrolyte included in the solid electrolyte layer.

[0112]

[0113] (Solid electrolyte layer)

[0114] The solid electrolyte layer can be manufactured by mixing and drying the aforementioned solid electrolyte and binder, or by rolling the aforementioned solid electrolyte powder into a specific shape under a pressure of 1 ton to 10 ton.

[0115] In this case, the solid electrolyte may be in the form of a powder or a molded article. The solid electrolyte in the form of a molded article may be, for example, in the form of pellets, sheets, or thin films, but is not necessarily limited to these and may have various forms depending on the application.

[0116] If necessary, the solid electrolyte layer may further include a solid electrolyte, such as a conventional sulfide-based solid electrolyte and / or an oxide-based solid electrolyte, in addition to the aforementioned solid electrolyte.

[0117] The binder may be, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polyvinyl alcohol, etc., but is not limited to these; any binder used in the relevant technical field may be used. The binder of the solid electrolyte layer may be of the same type as or different from the binders of the anode layer and the cathode layer.

[0118]

[0119] An electric vehicle according to another embodiment of the present invention may include the aforementioned all-solid-state battery.

[0120] The embodiments of the present invention will be described in more detail below through examples. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited by the following examples.

[0121]

[0122] Preparation Example: Li6PS 5.0 Preparation of Cl solid electrolyte

[0123] The final product is Li 6(1-x-y) B 2x Si y P (1-x-y) S 5.0(1-x-y) O 3x In the Cl(1-xy)+4y solid electrolyte, the reactants Li2S, P2S5, and LiCl were mixed at 300 rpm for about 8 hours using a planetary mill to form a mixture such that x=0 and y=0.

[0124] Next, a pressure of 300 MPa was applied to the above mixture to form pellets.

[0125] Next, the above pellets are heat-treated at 550°C for 4 hours in an argon (Ar) atmosphere to produce Li6PS 5.0 A Cl solid electrolyte was prepared.

[0126]

[0127] Example 1: Li 5.58 B 0.04 Si 0.05 P 0.93 S 4.65 O 0.06 Cl 1.13 Preparation of solid electrolytes

[0128] The final product is Li 6(1-x-y) B 2x Si y P (1-x-y) S 5.0(1-x-y) O 3x In the Cl(1-xy)+4y solid electrolyte, the reactants Li2S and P2S are used such that x=0.02 and y=0.05. 5, P2O5, LiCl, BCl3, and SiCl4 were quantified so that BCl3 was 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was 0.05 mol% based on 100 mol% of the total reactants, and a mixture was formed by mixing at 300 rpm for about 8 hours using a planetary mill.

[0129] Next, a pressure of 300 MPa was applied to the above mixture to form pellets.

[0130] Next, the above pellets are heat-treated at 550°C in an argon (Ar) atmosphere for about 4 hours to Li 5.58 B 0.04 Si 0.05 P 0.93 S 4.65 O 0.06 Cl 1.13 A solid electrolyte was manufactured.

[0131]

[0132] Example 2: Li 5.28 B 0.04 Si 0.1 P 0.88 S 4.4 O 0.06 Cl 1.28 Preparation of solid electrolytes

[0133] The reactants Li2S and P2S are set so that x=0.02 and y=0.1 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, and Li 5.28 B 0.04 Si 0.1 P 0.88 S 4.4 O 0.06 Cl 1.28 A solid electrolyte was manufactured.

[0134]

[0135] Example 3: Li 4.98 B 0.04 Si 0.15 P 0.83 S 4.15 O 0.06 Cl 1.43 Preparation of solid electrolytes

[0136] The reactants Li2S and P2S are set so that x=0.02 and y=0.15 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.15 mol% based on 100 mol% of the total reactants, and Li 4.98 B 0.04 Si 0.15 P 0.83 S 4.15 O 0.06 Cl 1.43 A solid electrolyte was manufactured.

[0137]

[0138] Example 4: Li 4.68 B 0.04 Si 0.2 P 0.78 S 3.9 O 0.06 Cl 1.58 Preparation of solid electrolytes

[0139] The reactants Li2S and P2S are set so that x=0.02 and y=0.2 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.2 mol% based on 100 mol% of the total reactants, thereby Li 4.68 B 0.04 Si 0.2 P 0.78 S 3.9 O 0.06 Cl 1.58 A solid electrolyte was manufactured.

[0140]

[0141] Example 5: Li 4.08 B 0.04 Si 0.3 P 0.68 S 3.4 O 0.06 Cl 1.88 Preparation of solid electrolytes

[0142] The reactants Li2S and P2S are set so that x=0.02 and y=0.3 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.3 mol% based on 100 mol% of the total reactants, thereby Li 4.08 B 0.04 Si 0.3 P 0.68 S 3.4 O 0.06 Cl 1.88 A solid electrolyte was manufactured.

[0143]

[0144] Example 6: Li 3.48 B 0.04 Si 0.4 P 0.58 S 2.9 O 0.06 Cl2.18 Preparation of solid electrolytes

[0145] The reactants Li2S and P2S are set so that x=0.02 and y=0.4 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.4 mol% based on 100 mol% of the total reactants, and Li 3.48 B 0.04 Si 0.4 P 0.58 S 2.9 O 0.06 Cl 2.18 A solid electrolyte was manufactured.

[0146]

[0147] Example 7: Li 5.31 B 0.03 Si 0.1 P 0.885 S 4.425 O 0.045 Cl 1.285 Preparation of solid electrolytes

[0148] The reactants Li2S and P2S are set so that x=0.015 and y=0.1 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.015 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, and Li 5.31 B 0.015 Si 0.1 P 0.885 S 3.825 O 0. Cl 1.33 A solid electrolyte was manufactured.

[0149]

[0150] Example 8: Li 5.25 B 0.05 Si 0.1 P 0.875 S4.375 O 0.075 Cl 1.275 Preparation of solid electrolytes

[0151] The reactants Li2S and P2S are set so that x=0.025 and y=0.1 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.025 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, and Li 5.25 B 0.05 Si 0.1 P 0.875 S 4.375 O 0.075 Cl 1.275 A solid electrolyte was manufactured.

[0152]

[0153] Example 9: Li 5.22 B 0.06 Si 0.1 P 0.87 S 4.35 O 0.09 Cl 1.27 Preparation of solid electrolytes

[0154] The reactants Li2S and P2S are set so that x=0.03 and y=0.1 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.03 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, and Li 5.22 B 0.06 Si 0.1 P 0.87 S 4.35 O 0.09 Cl 1.27 A solid electrolyte was manufactured.

[0155]

[0156] Example 10: Li 5.16 B 0.08 Si0.1 P 0.86 S 4.3 O 0.12 Cl 1.26 Preparation of solid electrolytes

[0157] The reactants Li2S and P2S are set so that x=0.04 and y=0.1 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.04 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, thereby Li 5.16 B 0.08 Si 0.1 P 0.86 S 4.3 O 0.12 Cl 1.26 A solid electrolyte was manufactured.

[0158]

[0159] Example 11: Li 5.1 B 0.1 Si 0.1 P 0.85 S 4.25 O 0.15 Cl 1.25 Preparation of solid electrolytes

[0160] The reactants Li2S and P2S are set so that x=0.05 and y=0.1 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.05 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, and Li 5.1 B 0.1 Si 0.1 P 0.85 S 4.25 O 0.15 Cl 1.25 A solid electrolyte was manufactured.

[0161]

[0162] Comparative Example 1: Li5.58 B 0.04 P 0.98 S 4.9 O 0.06 Cl 0.98 Preparation of solid electrolytes

[0163] Reactants Li2S and P2S such that x=0.02 and y=0 5, P2O5, LiCl, and BCl3 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants, and Li 5.58 B 0.04 P 0.98 S 4.9 O 0.06 Cl 0.98 A solid electrolyte was manufactured.

[0164]

[0165] Comparative Example 2: Li 5.4 Si 0.1 P 0.9 S 4.5 Cl 1.3 Preparation of solid electrolytes

[0166] The reactants Li2S and P2S are set so that x=0 and y=0.1 5, LiCl and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, and Li 5.4 Si 0.1 P 0.9 S 4.5 Cl 1.3 A solid electrolyte was manufactured.

[0167]

[0168] Comparative Example 3: Li 2.88 B 0.04 Si 0.5 P 0.48 S 2.4 O 0.06 Cl 2.48 Preparation of solid electrolytes

[0169] The reactants Li2S and P2S are set so that x=0.02 and y=0.5 5,P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.5 mol% based on 100 mol% of the total reactants, and Li 2.88 B 0.04 Si 0.5 P 0.48 S 2.4 O 0.06 Cl 2.48 A solid electrolyte was manufactured.

[0170]

[0171] Comparative Example 4: Li 5.82 B 0.04 Si 0.01 P 0.97 S 4.85 O 0.06 Cl 1.01 Preparation of solid electrolytes

[0172] The reactants Li2S and P2S are adjusted so that x=0.02 and y=greater than 0.01. 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.01 mol% based on 100 mol% of the total reactants, thereby Li 5.82 B 0.04 Si 0.01 P 0.97 S 4.85 O 0.06 Cl 1.01 A solid electrolyte was manufactured.

[0173]

[0174] Comparative Example 5: Li 4.8 B 0.2 Si 0.1 P 0.8 S 4.0 O 0.3 Cl 1.2 Preparation of solid electrolytes

[0175] The reactants Li2S and P2S such that x=0.1 and y=0.1 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.1 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, and Li 4.8 B 0.2 Si 0.1 P 0.8 S 4.0 O 0.3 Cl 1.2 A solid electrolyte was manufactured.

[0176]

[0177] Comparative Example 6: Li 5.76 B 0.04 Si 0.02 P 0.96 S 4.8 O 0.06 Cl 1.04 Solid Electrolyte Manufacturing

[0178] The reactants Li2S and P2S are set so that x=0.02 and y=0.02. 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.02 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.02 mol% based on 100 mol% of the total reactants, and Li 5.76 B 0.04 Si 0.02 P 0.96 S 4.8 O 0.06 Cl 1.04 A solid electrolyte was manufactured.

[0179]

[0180] Comparative Example 7: Li 5.37 B 0.01 Si 0.1 P 0.895 S 4.475 O 0.015 Cl 1.295 Preparation of solid electrolytes

[0181] The reactants Li2S and P2S are set so that x=0.005 and y=0.1 5, P2O5, LiCl, BCl3, and SiCl4 were quantified, and the procedure was carried out in the same manner as Example 1, except that BCl3 was set to 0.005 mol% based on 100 mol% of the total reactants and SiCl4 was set to 0.1 mol% based on 100 mol% of the total reactants, and Li 5.37 B 0.01 Si 0.1 P 0.895 S 4.475 O 0.015 Cl 1.295 A solid electrolyte was manufactured.

[0182]

[0183] Table 1 below summarizes the moles of B2O3 and SiCl4 added to the preparation example, example, and comparative example, and Table 2 below summarizes the composition and content of the solid electrolyte of the preparation example, comparative example, and example, and the experimental results according to Experimental Example 1 described below.

[0184]

[0185] X mol%B2O3Y mol%SiCl4 Preparation Example--Comparative Example 10.02-Comparative Example 2-0.1 Comparative Example 30.020.5 Comparative Example 40.020.01 Comparative Example 50.10.1 Comparative Example 60.020.02 Comparative Example 70.0050.1 Example 10.020.05 Example 20.020.1 Example 30.020.15 Example 40.020.2 Example 50.020.3 Example 60.020.4 Example 70.0150.1 Example 80.0250.1 Example 90.0300.1 Example 100.040.1 Example 110.050.1

[0186] Li a P b S c Cl d B e Si f O gLi[a]P[b]S[c]Cl[d]B[e]Si[f]O[g]Ionic Conductivity[mS / cm] Preparation Example 6 15.01---2.9 Comparative Example 15.880.9804.90.980.0400.061.3 Comparative Example 25.40.9004.51.3-0.1-1.6 Comparative Example 32.880.4802.42.480.040.50.062.6 Comparative Example 45.820.9704.851.010.040.010.061.81 Comparative Example 54.80.80041.20.20.10.31.9 Comparative Example 65.760.9604.81.040.040.020.062.1 Comparative Example 75.370.8954.4751.2950.010.10.0151.8 Example 15.580.9304.651.130.040.050.063.3 Example 25.280.8804.41.280.040.10.064.2 Example 34.980.8304.151.430.040.150.064.1 Example 44.680.7803.91.580.040.20.063.9 Example 54.080.6803.41.880.040.30.063.5 Example 63.480.5802.92.180.040.40.063.3 Example 75.310.8854.4251.2850.030.10.0453.7 Example 85.250.8754.3751.2750.050.10.0754.4 Example 95.220.8704.351.270.060.10.094.5 Example 105.160.8604.31.260.080.10.123.8 Example 115.10.8504.251.250.10.10.153.2

[0187] Experimental Example 1: Analysis of Solid Electrolyte Composition and Evaluation of Ionic Conductivity

[0188] (1) Composition analysis

[0189] The composition of the solid electrolyte was measured using an ICP (Inductively Coupled Plasma Emission Spectrometry) instrument. More specifically, all synthesized solid electrolyte samples were dissolved in HNO3 solvent, diluted with DI water, and the elemental content was measured using an ICP instrument.

[0190] (2) Ionic conductivity evaluation (30℃, 0.1C)

[0191] An experiment to evaluate the ionic conductivity of a solid electrolyte was conducted using a pressure powder cell. Specifically, the synthesized solid electrolyte was ground and then formed into pellets under a pressure of 300 MPa. Subsequently, a cell was fabricated using SUS as the working electrode under a pressure of 70 MPa. Then, the impedance was measured by applying a voltage of 10 mV at 30°C.

[0192]

[0193] Referring to Table 2, it was confirmed that the solid electrolyte of Comparative Example 1, which is doped only with boron (B) and oxygen (O) and not with silicon (Si), actually has lower ionic conductivity compared to the solid electrolyte of the preparation example, which has a basic azirodite crystal structure. In addition, it was confirmed that the solid electrolyte of Comparative Example 2, which is not doped with boron (B) and is doped only with silicon (Si) and oxygen (O), also has lower ionic conductivity compared to the preparation example.

[0194] In addition, in the case of additional Comparative Examples 3 to 7, in which boron (B), silicon (Si), and oxygen (O) were all doped but the ranges of x and y were not properly controlled, it was confirmed that the ionic conductivity was lower compared to the preparation example.

[0195] On the other hand, it was confirmed that the solid electrolytes of the examples in which boron (B), silicon (Si), and oxygen (O) are all doped and the ranges of x and y are appropriately controlled showed significantly improved ionic conductivity compared to the preparation example and comparative example.

[0196]

[0197] Experimental Example 2: XRD Diffraction Analysis Experiment

[0198] X-ray diffraction (XRD) analysis experiments were conducted on the solid electrolyte prepared according to Preparation Example and Example 9, and the results are shown in Figure 1.

[0199] Referring to Fig. 1, the solid electrolyte prepared according to Preparation Example and Example 9 exhibited a peak in the range of 30.2˚ ≤ 2θ ≤ 30.3˚ when analyzed by X-ray diffraction (XRD) pattern analysis. Through this, it was confirmed that the solid electrolyte of Preparation Example and Example 9 has an azirodite-based crystal structure.

[0200]

[0201] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto and can be implemented 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.

[0202] Therefore, the substantive scope of the present invention shall be defined by the appended claims and their equivalents.

Claims

1. A compound containing lithium (Li), phosphorus (P), sulfur (S), and chlorine (Cl) and having an argyrodite-based crystal structure, At least a portion of the above crystal structure is doped with a Group 13 element, a Group 14 element, and oxygen (O), and The above compound is a sulfide-based solid electrolyte represented by the following chemical formula 1: [Chemical Formula 1] Li 6(1-x-y) A 2x B y P (1-x-y) S 5.0(1-x-y) O 3x Cl(1-x-y)+4y In the above chemical formula 1, 0.01 ≤ x ≤ 0.08, 0.03 ≤ y ≤ 0.45, element A is a group 13 element, and element B is a group 14 element.

2. In Paragraph 1, The above-mentioned Group 13 element is boron (B), a sulfide-based solid electrolyte.

3. In Paragraph 1, A sulfide-based solid electrolyte in which the above Group 14 element is silicon (Si).

4. In Paragraph 1, A sulfide-based solid electrolyte in the above chemical formula 1, wherein 0.015 ≤ x ≤ 0.035 and 0.05 ≤ y ≤ 0.

2.

5. In Paragraph 1, A sulfide-based solid electrolyte in the above chemical formula 1, wherein 0.015 ≤ x ≤ 0.025 and 0.05 ≤ y ≤ 0.

2.

6. In Paragraph 1, A sulfide-based solid electrolyte in the above chemical formula 1, wherein 0.02 ≤ x ≤ 0.035 and 0.05 ≤ y ≤ 0.

15.

7. In Paragraph 1, The above compound is a sulfide-based solid electrolyte that exhibits a peak in the range of 30.2˚≤2θ≤30.3˚ when analyzed by X-ray diffraction (XRD) pattern analysis.

8. A step of forming a mixture by mixing a lithium (Li) raw material, a first phosphorus (P) raw material, a second phosphorus (P) raw material, a chlorine (Cl) raw material, and a doping raw material; and The method includes the step of heat-treating the above mixture to form a sulfide-based solid electrolyte with an argyrodite-based crystal structure, and The above doping raw material includes a boron (B) compound and a silicon (Si) compound, and The above first phosphorus (P) raw material and second phosphorus (P) raw material are heterogeneous, and A method for manufacturing a sulfide-based solid electrolyte, wherein at least one of the first phosphorus (P) raw material or the second phosphorus (P) raw material contains oxygen (O).

9. In Paragraph 8, A sulfide-based solid electrolyte in which the first phosphorus (P) raw material contains oxygen (O), and the second phosphorus (P) raw material does not contain oxygen (O):

10. In Paragraph 8, The above boron (B) compound is a sulfide-based solid electrolyte, BCl3.

11. In Paragraph 8, The above silicon (Si) compound is a sulfide-based solid electrolyte, SiCl4.

12. In Paragraph 10, A sulfide-based solid electrolyte in which the amount of the boron (B) compound added is 0.01 to 0.08 mol% based on the total molar amount of the mixture.

13. In Paragraph 11, A sulfide-based solid electrolyte in which the amount of the silicon (Si) compound added is 0.03 to 0.045 mol% based on the total molar amount of the mixture.

14. Anode layer; cathode layer and a solid electrolyte layer located between the anode layer and the cathode layer, and An all-solid-state battery in which at least one of the anode layer, cathode layer, and solid electrolyte layer comprises a solid electrolyte according to claim 1.

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