Method for making sulfide-based solid electrolyte for solid batteries

Abstract

The present invention discloses a method for manufacturing a solid electrolyte for an all-solid battery. The method may include: preparing a solvent mixture including a first polar organic solvent containing a cyano group and a second polar organic solvent containing a hydroxyl group; 2 S.P. 2 S 5 and LiCl are dissolved in a solvent mixture to prepare an electrolyte mixture; and a solid electrolyte is manufactured by stirring the electrolyte mixture. The method may also include: precipitating the solid electrolyte by evaporating the solvent mixture; and heat treating the precipitated solid electrolyte. Specifically, the solvent mixture may include a second polar organic solvent in an amount of about 0.01-0.03 wt % based on the total weight of the starting material.

Description

Field of the Invention

[0001] The present invention relates to a method for manufacturing a solid electrolyte for an all-solid-state battery, wherein the solid electrolyte can have high ionic conductivity and high chemical and electrochemical stability. Background Art

[0002] With the widespread use of smartphones and small electronic devices, the development of lithium secondary batteries as small power sources thereof has been increasing, and with the development of electric vehicles, the demand for lithium secondary batteries has further increased.

[0003] A lithium secondary battery includes a cathode and an anode that can send and receive lithium ions, and an electrolyte that is responsible for lithium ion transmission. A typical lithium secondary battery includes a liquid electrolyte that includes a lithium salt dissolved in an organic solvent and has a separator formed of organic fibers that is used to prevent physical contact between the cathode and the anode to prevent short circuits. Due to the use of flammable organic solvents as electrolyte solvents, fires and explosions are very likely to occur in the event of a short circuit caused by physical damage, and accidents occur frequently.

[0004] All-solid batteries include inorganic solid electrolytes that replace flammable liquid electrolytes. The materials of inorganic solid electrolytes are key elements of all-solid batteries, which mainly include oxides and sulfides. In particular, sulfide-based solid electrolytes have ionic conductivity as high as liquid electrolytes and can be the most promising solid electrolytes.

[0005] In recent years, a method has been designed to synthesize Li 2 S and P 2 S 5 A method for synthesizing a sulfide-based solid electrolyte by a reaction as a mass production process for synthesizing a sulfide-based solid electrolyte. For example, a sulfide-based solid electrolyte can be synthesized by dissolving and precipitating a starting material in a polar organic solvent. Although the performance of the solid electrolyte may deteriorate due to the residual organic solvent, a uniform and fine solid electrolyte can be obtained, and its large-scale production can be guaranteed.

[0006] However, there are problems with the solid electrolyte prepared by the above method. For example, since an excessive amount of Li 2 S, a large amount of Li remaining in the final product 2 S can react with water or its electrochemical stability with lithium can deteriorate. Dissolution precipitation may not be easily used to remove organic residues or Li with low solubility. 2 S impurities. Therefore, the ionic conductivity or chemical stability will be affected by the residual Li2 S amount decreases. Summary of the invention

[0007] In a preferred aspect, the present invention provides a method for making a sulfide-based solid electrolyte for an all-solid-state battery, the solid electrolyte having high ionic conductivity and high chemical and electrochemical stability.

[0008] For example, although the sulfide-based solid electrolyte of the present invention may include a residual amount of Li 2 S, Li with argyrodite structure in solid electrolyte 6 PS 5 X (X = Cl, Br, I) can have a very high lithium ion conductivity at room temperature. -2 Up to 10 -3 S cm -1 .

[0009] The present invention also includes the synthesis of solid electrolytes via a liquid phase process.

[0010] In one aspect, a method for manufacturing a solid electrolyte for an all-solid battery ("sulfide-based solid electrolyte") is provided. The method may include the following steps: preparing a solvent mixture including a first polar organic solvent and a second polar organic solvent; preparing a starting material such as Li 2 S.P. 2 S 5 and an electrolyte mixture of a solvent mixture; and preparing a solid electrolyte from the electrolyte mixture;

[0011] The above method may further include the steps of: precipitating the solid electrolyte; and heat-treating the precipitated solid electrolyte.

[0012] As used herein, the term "all-solid cell" or "all-solid battery" refers to a cell or battery that includes only solid or substantially solid components, such as solid electrodes (e.g., anodes and cathodes) and solid electrolytes. Thus, in preferred aspects, an all-solid cell will not include fluid and / or flowable electrolyte components as materials or components.

[0013] Preferably, the first polar organic solvent may include a compound containing a cyano group, and the second polar organic solvent may include a compound containing a hydroxyl group. Preferably, the first polar organic solvent may be different from the second polar organic solvent.

[0014] The solvent mixture may suitably include the second polar organic solvent in an amount of about 0.01-0.03 wt % based on the total weight of the starting materials.

[0015] The electrolyte mixture can be prepared by adding Li 2 S and P 2 S 5 Prepared by dissolving in a solvent mixture.

[0016] In the preparation of the solid electrolyte, the electrolyte mixture may be stirred.

[0017] The solid electrolyte may be precipitated by evaporating the solvent mixture. For example, the residual solvent mixture in the solid electrolyte may be less than about 10 wt%, less than about 9 wt%, less than about 8 wt%, less than about 7 wt%, less than about 6 wt%, less than about 5 wt%, less than about 4 wt%, less than about 3 wt%, less than about 2 wt%, less than about 1 wt%, less than about 0.5 wt%, or less than about 0.1 wt%.

[0018] The solid electrolyte can release about 0.25-0.4 cm 3 / g amount of H 2 S gas.

[0019] In the process of heat-treating the sulfide-based solid electrolyte, the sulfide-based solid electrolyte may have an amorphous structure or an argyrodite-type crystal structure.

[0020] As used herein, the term "argyrodite" or "argyrodite-type crystal structure" refers to a crystalline structure that is similar to naturally occurring Ag. 8 G JZ 6 (Argentumite) has an orthorhombic crystal structure similar to that of Argentumite. For example, Argentumite crystals may have a Pna2 1 The orthorhombic system of the space group has a unit cell of: a = 15.149, b = 7.476, Z = 4. Argentum crystals can also be determined empirically, for example, by observing peaks at approximately 2θ = 15.5 ± 1°, 18 ± 1°, 26 ± 1°, 30.5 ± 1°, and 32 ± 1° by X-ray diffraction spectroscopy.

[0021] During the heat treatment of the sulfide-based solid electrolyte, the sulfide-based solid electrolyte may include a metal oxide.

[0022] As used herein, "metal oxide" refers to a compound including at least one or more metal components (e.g., Li, Na, Mg, etc.) and oxygen atoms, and the metal components and oxygen atoms may be directly or indirectly bonded to each other. The metal oxide may also include other non-metal components, such as S, P, N, C, etc.

[0023] The first polar organic solvent may suitably include acetonitrile.The second polar organic solvent may suitably include one or more organic solvents selected from methanol, ethanol and 1-propanol.

[0024] The solvent mixture may be prepared by stirring at about 100-200 rpm for about 5-60 minutes.

[0025] The solid electrolyte may be prepared by stirring the electrolyte mixture at a temperature of about 30-60° C. for about 1 hour to 48 hours.

[0026] The above method may include the following steps in the preparation of the solid electrolyte: stirring the electrolyte mixture for the first time; and stirring the electrolyte mixture for the second time after the first stirring. For example, the first stirring may be performed at a rotation speed of about 100-150 rpm for about 5-10 minutes.

[0027] The secondary stirring may be performed at a rotation speed of about 250-300 rpm for about 18-36 hours.

[0028] The precipitation of the sulfide-based solid electrolyte may be performed by evaporating the solvent mixture by vacuum drying at a temperature ranging from room temperature to about 80° C. for about 1 hour to 24 hours.

[0029] In another aspect, a solid electrolyte is provided, which can be produced by the method described herein.

[0030] Also provided is an all-solid-state battery, which may include the solid electrolyte described herein.

[0031] Additionally provided is a vehicle that may include the all-solid-state battery described herein.

[0032] Other aspects of the invention are disclosed below.

[0033] According to various exemplary embodiments of the present invention, a method for manufacturing a sulfide-based solid electrolyte for an all-solid-state battery can provide a sulfide-based solid electrolyte for an all-solid-state battery having high ionic conductivity and high chemical and electrochemical stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a cross-sectional view schematically showing an all-solid-state battery;

[0035] Figure 2 The flowchart in schematically represents an exemplary method for manufacturing an exemplary sulfide-based solid electrolyte for an exemplary all-solid battery according to an exemplary embodiment of the present invention;

[0036] Figure 3A , 3B, 3C, 3D, 3E, 3F, 3G, 3H, 3I, 3J and 3K are graphs showing the XRD results of Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, Comparative Example 6, Comparative Example 7, Comparative Example 8 and Comparative Example 9, respectively;

[0037] Figure 4A The graph in Figure 2 shows the H measured in Example 1 and Comparative Example 6 when exposed to air. 2 The amount of S;

[0038] Figure 4B The graph in Figure 2 shows the H measured in Example 2 and Comparative Example 9 when exposed to air. 2 The amount of S;

[0039] Figure 5 is a graph showing a change in voltage depending on capacitance in Example 1; and

[0040] Figure 6 is a graph showing the results of cyclic voltammetry tests conducted on Example 1. DETAILED DESCRIPTION

[0041] The above and other aspects, features and advantages of the present invention will be more clearly understood from the following preferred embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed herein, but can be modified into different forms. These embodiments are provided to fully explain the present invention and fully convey the spirit of the present invention to those skilled in the art.

[0042] In all the accompanying drawings, the same reference numerals refer to the same or similar elements. For the purpose of making the present invention clear, the size of the structure is illustrated as being larger than its actual size. It should be understood that although terms such as "first", "second", etc. can be used in this article to illustrate different elements, these elements should not be limited by these terms. These terms are only used to distinguish elements from each other. For example, without departing from the scope of the present invention, the "first" element discussed below can be referred to as the "second" element. Similarly, the "second" element can also be referred to as the "first" element. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form.

[0043] It should be further understood that when used in this specification, the terms "comprising", "containing", "having", etc. indicate the presence of the stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof. In addition, it should be understood that when an element such as a layer, film, region, or sheet is referred to as being "on" another element, it may be directly on the other element, or there may be intervening elements therebetween. Conversely, when an element such as a layer, film, region, or sheet is referred to as being "under" another element, it may be directly under the other element, or there may be intervening elements therebetween.

[0044] In this specification, when the range of a parameter is described, it should be understood that the parameter includes all the values ​​including the endpoints described in the range. For example, the range "5-10" should be understood to include any sub-ranges, such as 6-10, 7-10, 6-9 and 7-9, etc., as well as individual values ​​5, 6, 7, 8, 9 and 10, and should also be understood to include any values ​​between the valid integers in the range, such as 5.5, 6.5, 7.5, 5.5-8.5 and 6.5-9, etc. In addition, for example, the range "10% to 30%" should be understood to include any sub-ranges, such as 10% to 15%, 12% to 18%, 20% to 30%, etc., and all integers including the values ​​10%, 11%, 12% and 13%, etc. up to 30%, and should also be understood to include any values ​​between the valid integers in the range, such as 10.5%, 15.5% and 25.5%, etc.

[0045] Moreover, unless expressly stated or obvious from the context, as used herein, the term "about" is understood to be within the normal tolerance range in the art, for example, within 2 standard deviations of the mean. "About" can be understood to be within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05% or 0.01% of the stated value. Unless otherwise obvious from the context, all numerical values ​​provided herein are modified by the term "about".

[0046] It should be understood that the term "vehicle" or "vehicle-borne" or other similar terms as used herein generally include motor vehicles such as passenger cars (including sport utility vehicles (SUVs), buses), trucks, various commercial vehicles, watercraft (including various ships and vessels), aircraft, etc., and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel (e.g., fuels derived from resources other than petroleum) vehicles. As mentioned herein, a hybrid vehicle is a vehicle having two or more power sources, for example, gasoline-powered and electric-powered vehicles.

[0047] Hereinafter, a method for manufacturing an exemplary sulfide-based solid electrolyte for an exemplary all-solid battery according to an exemplary embodiment of the present invention will be described in detail.

[0048] Figure 1 is a cross-sectional view schematically showing an all-solid-state battery.

[0049] like Figure 1 As shown, the all-solid battery (SC) includes a cathode 100, a solid electrolyte 200 and an anode 300. An electrochemical reaction occurs in an all-solid battery (SC). When an electrochemical reaction occurs on the electrode, lithium ions are transferred between the cathode and the anode through the electrolyte, and at the same time, electrons are transferred between the two electrodes through the wire. Here, the electrons are transferred along the external wire connecting the two electrodes. At the anode, electrochemical oxidation of the electrode material occurs during the discharge process of the battery, and the electrode is called an oxidation electrode. At the cathode, during the discharge process of the battery, electrons are transferred from the anode through an external circuit, and a reduction reaction of the electrode material occurs, and the electrode is called a reduction electrode. Here, the solid electrolyte plays the role of an ion conductor that transfers ions between the two electrodes, and only exhibits ionic conductivity, not electronic conductivity. The solid electrolyte 200 is disposed between the cathode 100 and the anode 300. The anode 300 is provided on the solid electrolyte 200. The solid electrolyte 200 is in contact with the cathode 100 and the anode 300.

[0050] All-solid batteries (SC) can be used as energy sources for the vehicles described above. For example, the term "vehicle" refers to a device for transporting goods, personnel, etc. Examples of vehicles include land vehicles, sea vehicles, and air vehicles. Land vehicles can include, for example, cars, including cars, vans, trucks, trailer trucks and sports cars, bicycles, motorcycles, trains, etc. Sea vehicles can include, for example, ships, submarines, etc. Air vehicles can include, for example, airplanes, hang gliders, hot air balloons, helicopters, and small aircraft, such as drones, etc.

[0051] The solid electrolyte can be a sulfide-based solid electrolyte. For example, “Li 2 SP 2 S 5 " can be included with Li 7 PS 6 The corresponding compound or a compound including derivatives such as LiCl, LiBr or LiI. The term "derivative" refers to a compound modified by the parent compound by introducing functional groups, oxidation, reduction, atom substitution, etc., within the scope of the structure and properties of the parent compound.

[0052] Figure 2The flowchart in FIG. 1 schematically represents an exemplary method for manufacturing a sulfide-based solid electrolyte for an all-solid-state battery according to an exemplary embodiment of the present invention.

[0053] The sulfide-based solid electrolyte obtained by the exemplary method for manufacturing a sulfide-based solid electrolyte for an all-solid battery according to an exemplary embodiment of the present invention can be used as Figure 1 Solid electrolyte 200 for all-solid-state batteries (SC).

[0054] like Figure 2 As shown, the method for manufacturing a sulfide-based solid electrolyte for an all-solid battery according to an embodiment of the present invention includes the following steps: preparing a solvent mixture by adding a first polar organic solvent and a second polar organic solvent (S100); 2 S and P 2 S 5 dissolving in a solvent mixture to form an electrolyte mixture (S200); and synthesizing a sulfide-based solid electrolyte by stirring the electrolyte mixture (S300); precipitating the sulfide-based solid electrolyte by evaporating the solvent mixture (S400); and heat-treating the precipitated sulfide-based solid electrolyte (S500).

[0055] A first polar organic solvent may be prepared that is a compound containing an amino group. The first polar organic solvent may include, for example, acetonitrile. The first polar organic solvent may be acetonitrile. The first polar organic solvent may be different from the second polar organic solvent.

[0056] By adding the first polar organic solvent and the second polar organic solvent, a solvent mixture including the first polar organic solvent and the second polar organic solvent can be prepared (S100). In the step of forming the solvent mixture (S100), the second polar organic solvent can be a compound containing a hydroxyl group, and can appropriately include one or more organic solvents selected from, for example, methanol, ethanol, and 1-propanol.

[0057] In the step of forming a solvent mixture (S100), the second polar organic solvent may be added in an amount of about 0.01-0.03 wt % based on the amount of the starting raw material. When the amount is less than about 0.01 wt %, the amount of the second polar organic solvent is reduced, so that the effect of adding it may not be significant. When the amount is greater than about 0.03 wt %, the sulfide-based solid electrolyte cannot sufficiently contain oxides, which may result in uneven mixing. When the second polar organic solvent is used as the main solvent instead of the first polar organic solvent, the second polar organic solvent may be mixed with the P 2 S 5The ions react to deteriorate the crystalline structure of the solid electrolyte, undesirably causing the ionic conductivity to deteriorate.

[0058] The step (S100) of forming a solvent mixture can be carried out by stirring the solvent mixture at a speed of about 100-200 rpm for about 5-60 minutes. When the step (S100) of forming a solvent mixture is carried out under the processing conditions lower than the respective lower limits of the above ranges, the first polar organic solvent and the second polar organic solvent will not be fully mixed. When the process is carried out under the processing conditions greater than the respective upper limits of the above ranges, uneven mixing will result.

[0059] By 2 S and P 2 S 5 Dissolved in a solvent mixture, it can form Li 2 S.P. 2 S 5 and a solvent mixture (S200). In the step of forming the electrolyte mixture (S200), a metal halide (e.g., LiBr, LiCl, etc.) may also be dissolved. For example, in the step of forming the electrolyte mixture (S200), when Li 2 S and P 2 S 5 When 70 mol% of Li 2 S and about 30 mol% P 2 S 5 When 70Li with an amorphous structure is obtained 2 S-30P 2 S 5 Solid electrolytes. Amorphous structures are non-crystalline or amorphous and can refer to structures in which the positions of atoms have no long-range order.

[0060] For example, in the step of forming an electrolyte mixture (S200), when dissolving Li 2 S.P. 2 S 5 When LiCl is added to the sulfide-based solid electrolyte, a argyrodite-type crystal structure may be obtained. Argentodite-type may refer to a crystalline phase. A sulfide-based solid electrolyte having an argyrodite-type crystal structure may typically include Li 6 PS 5 Cl and Li 7 PS 6 .

[0061] The sulfide-based solid electrolyte is synthesized by stirring the electrolyte mixture (S300). The step (S300) of synthesizing the sulfide-based solid electrolyte can be performed by stirring the electrolyte mixture at a temperature of about 30-80°C for about 1 hour to 48 hours. When the process is carried out under processing conditions lower than the respective lower limits of the above ranges, the sulfide-based solid electrolyte cannot be fully synthesized. When the process is carried out under processing conditions exceeding the respective upper limits of the above ranges, side reactions occur and it is impossible to obtain a solid electrolyte with high ionic conductivity.

[0062] The step (S300) of synthesizing a sulfide-based solid electrolyte may include first stirring the electrolyte mixture; and second stirring the first stirred electrolyte mixture. The first stirring may be performed at a rotation speed of about 100-150 rpm for about 5-10 minutes. When the process is performed under treatment conditions lower than the lower limits of the above ranges, it is difficult to convert Li 2 S and P 2 S 5 When the process is performed under treatment conditions exceeding the respective upper limits of the above ranges, the processing time of the prepared sulfide-based solid electrolyte increases, undesirably deteriorating mass production productivity.

[0063] The secondary stirring may be performed at a rotation speed of about 250-300 rpm for about 18-36 hours. When the process is performed under treatment conditions lower than the respective lower limits of the above ranges, the prepared sulfide-based solid electrolyte cannot be sufficiently synthesized. When the process is performed under treatment conditions exceeding the respective upper limits of the above ranges, side reactions may occur, and it is impossible to obtain a solid electrolyte having high ionic conductivity.

[0064] The sulfide-based solid electrolyte is precipitated (S400) by evaporating the solvent mixture. The step of precipitating the sulfide-based solid electrolyte (S400) can be performed by vacuum drying at room temperature (15-25° C.) to about 80° C. for about 1 hour to 24 hours to evaporate the solvent mixture. When the process is performed under treatment conditions lower than the respective lower limits of the above ranges, the solvent mixture cannot be fully evaporated. When the process is performed under treatment conditions exceeding the respective upper limits of the above ranges, the sulfide-based solid electrolyte will crack.

[0065] The precipitated sulfide-based solid electrolyte may be heat-treated (S500). In the step of heat-treating the sulfide-based solid electrolyte (S500), the sulfide-based solid electrolyte may have an amorphous structure or an argyrodite type crystal structure.

[0066] For example, when the sulfide-based solid electrolyte has an amorphous structure, the step of heat-treating the sulfide-based solid electrolyte (S500) may be performed at a temperature of about 200-300° C. for about 1-24 hours. When the process is performed under treatment conditions lower than the respective lower limits of the above ranges, the sulfide-based solid electrolyte does not have an amorphous structure. When the process is performed under treatment conditions exceeding the respective upper limits of the above ranges, side reactions occur and it is impossible to precipitate the desired crystalline phase.

[0067] For example, when the sulfide-based solid electrolyte has an argyrodite type crystal structure, the step of heat-treating the sulfide-based solid electrolyte (S500) may be performed at a temperature of about 300-550° C. for about 1-48 hours. When the process is performed under treatment conditions lower than the respective lower limits of the above ranges, the sulfide-based solid electrolyte does not have an argyrodite type crystal structure. When the process is performed under treatment conditions exceeding the respective upper limits of the above ranges, side reactions occur and it is impossible to precipitate the desired crystal phase.

[0068] Sulfide-based solid electrolytes can release about 0.25-0.4 cm 3 / g amount of H 2 When the amount of the released gas is less than the above lower limit, the ionic conductivity may decrease. When the amount thereof exceeds the above upper limit, the chemical stability of the sulfide-based solid electrolyte may decrease.

[0069] In the step of heat treating the sulfide-based solid electrolyte (S500), the sulfide-based solid electrolyte may include a metal oxide. The metal oxide may include, for example, Li 3 PO 4 The sulfide-based solid electrolyte may appropriately include a metal oxide, thereby having a low H 2 S gas content.

[0070] The sulfide-based solid electrolyte manufacturing method according to each exemplary embodiment of the present invention can provide a sulfide-based solid electrolyte for an all-solid-state battery. 2 The S gas content is low, the solid electrolyte has high ionic conductivity, and has high chemical and electrochemical stability, which is achieved by using the second polar organic solvent.

[0071] Example

[0072] The present invention will be better understood through the following examples, which are only used for illustration and should not be construed as limiting the scope of the present invention.

[0073] Example

[0074] Example 1

[0075] 200 ml of acetonitrile, a first polar organic solvent, was prepared. As a second polar organic solvent, ethanol was prepared and added in an amount of 0.025 wt % based on the amount of the starting material, thereby forming a solvent mixture. Then, Li 2 S.P. 2 S 5 The starting materials of LiCl and LiCl are dissolved in a solvent mixture to form an electrolyte mixture. The electrolyte mixture is stirred at a temperature of 30°C for 24 hours to synthesize a sulfide-based solid electrolyte. The synthesized sulfide-based solid electrolyte is first stirred at a rotation speed of 100 rpm for 5 minutes, and then stirred for a second time at a rotation speed of 280 rpm for 24 hours. The solvent mixture is evaporated for 12 hours by vacuum drying at room temperature to precipitate the sulfide-based solid electrolyte. The precipitated sulfide-based solid electrolyte is heat treated at a temperature of 550°C for 5 hours.

[0076] Example 2

[0077] This example was carried out in the same manner as Example 1 except that 70 mol% Li 2 S and 30 mol% P 2 S 5 , no LiCl was added, and the precipitated sulfide-based solid electrolyte was heat-treated at a temperature of 260 °C for 1 h.

[0078] Comparative Example 1

[0079] This example was performed in the same manner as Example 1 except that a second polar organic solvent was added in an amount of 0.05 wt % based on the amount of the starting material.

[0080] Comparative Example 2

[0081] This example was performed in the same manner as Example 1 except that a second polar organic solvent was added in an amount of 0.1 wt % based on the amount of the starting material.

[0082] Comparative Example 3

[0083] This example was performed in the same manner as Example 1 except that 1-propanol was used as the second polar organic solvent instead of ethanol.

[0084] Comparative Example 4

[0085] This example was performed in the same manner as Example 1 except that isopropanol was used as the second polar organic solvent instead of ethanol.

[0086] Comparative Example 5

[0087] This example was carried out in the same manner as Example 1 except that no second polar organic solvent was added.

[0088] Comparative Example 6

[0089] This example was performed in the same manner as Example 2 except that a second polar organic solvent was added in an amount of 0.1 wt % based on the amount of the starting material.

[0090] Comparative Example 7

[0091] This example was performed in the same manner as Example 2 except that 1-propanol was used as the second polar organic solvent instead of ethanol.

[0092] Comparative Example 8

[0093] This example was performed in the same manner as Example 2 except that isopropanol was used as the second polar organic solvent instead of ethanol.

[0094] Comparative Example 9

[0095] This example was carried out in the same manner as Example 2 except that no second polar organic solvent was added.

[0096] Characterization and Measurement Results

[0097] 1. Determination of crystal structure

[0098] The XRD (X-ray diffraction spectra) of the sulfide-based solid electrolytes precipitated in Examples 1 and 2 and Comparative Examples 1-9 were measured before and after heat treatment. The results are shown in Figures 3A to 3K The observed materials are shown in Table 1 below.

[0099] Table 1

[0100]

[0101] As shown in Table 1, Examples 1 and 2 contain oxide crystals such as Li 3 PO 4 Oxide crystals can reduce the H 2 The amount of S gas increases, thereby increasing the chemical stability of the solid electrolyte.

[0102] 2. Measure H 2 Amount of S gas

[0103] The H released when exposed to air in Examples 1 and 2 and Comparative Examples 1-9 was measured. 2 The results are shown in Table 2 below. In addition, the results of Example 1 and Comparative Example 6 are shown in Figure 4A The results of Example 2 and Comparative Example 9 are shown in Figure 4B middle.

[0104] Table 2

[0105]

[0106] As shown in Table 2 and Figure 4A and 4B As shown, H in Examples 1 and 2 2 The amount of S gas is smaller than that of Comparative Example 1-9.

[0107] 3. Measuring ionic conductivity

[0108] The ionic conductivity of Examples 1 and 2 and Comparative Examples 1 to 9 was measured. The results are shown in Table 3 below.

[0109] Table 3

[0110]

[0111] As shown in Tables 2 and 3, Examples 1 and 2 not only exhibit low H 2 S gas content, and exhibited excellent ionic conductivity. On the other hand, the ionic conductivity of Comparative Examples 1-9 was high, but H 2 The S gas content is also high, so it exhibits poor stability.

[0112] 4. Evaluation of charge / discharge

[0113] An all-solid-state battery was manufactured using Example 1 and its charge / discharge was evaluated. The results are shown in Figure 5 Reference Figure 5 , it can be confirmed that its charge / discharge capability is suitable for use in vehicles.

[0114] 5. Evaluation of electrochemical stability

[0115] Cyclic voltammetry was performed on Example 1. The results are shown in Figure 6 Since the Li interface is more stable, a clear graph without noise is presented. Example 1 shows a stable graph shape. Therefore, it can be confirmed that the electrolyte of Example 1 shows high Li metal stability.

[0116] Although the exemplary embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art will recognize that the present invention can be implemented in other specific forms without changing its technical spirit or basic characteristics. Therefore, the above embodiments should be understood to be non-limiting and illustrative.

Claims

1. A method for manufacturing a solid electrolyte for an all-solid battery, wherein The following steps are involved: preparing a solvent mixture including a first polar organic solvent and a second polar organic solvent; preparing an electrolyte mixture comprising starting materials and the solvent mixture; and preparing a solid electrolyte from the electrolyte mixture; Wherein, in the preparation of the solvent mixture, the first polar organic solvent includes a cyano group, the second polar organic solvent includes a hydroxyl group, and the first polar organic solvent is different from the second polar organic solvent, The starting material includes Li 2 S and P 2 S 5 ,and The solvent mixture includes the second polar organic solvent in an amount of 0.01 to 0.03 wt % based on the total weight of the starting materials.

2. The method according to claim 1, further comprising: The following steps are involved: precipitating the solid electrolyte; and The precipitated solid electrolyte is heat-treated.

3. The method according to claim 1, wherein the electrolyte mixture is prepared by mixing Li 2 S and P 2 S 5 Prepared by dissolving in the solvent mixture.

4. The method according to claim 1, wherein the electrolyte mixture is stirred for preparing the solid electrolyte.

5. The method of claim 2, wherein the solid electrolyte is precipitated by evaporating the solvent mixture.

6. The method according to claim 1, wherein the solid electrolyte emits 0.25-0.4 cm 3 / g amount of H 2 S gas.

7. The method according to claim 2, in, In the process of heat treating the solid electrolyte, the solid electrolyte has an amorphous structure or an argyrodite type crystal structure.

8. The method according to claim 2, in, During the heat treatment of the solid electrolyte, the solid electrolyte includes a metal oxide.

9. The method of claim 1, wherein the first polar organic solvent comprises acetonitrile.

10. The method of claim 1, wherein the second polar organic solvent comprises one or more organic solvents selected from methanol, ethanol and 1-propanol.

11. The method according to claim 1, wherein the solvent mixture is prepared by stirring at a rotation speed of 100-200 rpm for 5-60 minutes.

12. The method according to claim 4, wherein the solid electrolyte is prepared by stirring the electrolyte mixture at a temperature of 30-60°C for 1 hour to 48 hours.

13. The method according to claim 1, wherein in the preparation of the solid electrolyte The following steps are involved: subjecting the electrolyte mixture to a first stirring; and The electrolyte mixture stirred for the first time is stirred for the second time.

14. The method according to claim 13, wherein the first stirring is performed at a rotation speed of 100-150 rpm for 5-10 minutes.

15. The method according to claim 13, wherein the secondary stirring is carried out at a rotation speed of 250-300 rpm for 18-36 hours.

16. The method of claim 5, wherein the solid electrolyte is precipitated by evaporating the solvent mixture by vacuum drying at a temperature ranging from room temperature to 80°C for 1 hour to 24 hours.

17. A solid electrolyte produced by the method according to claim 1.

18. An all-solid-state battery comprising the solid electrolyte according to claim 17.

19. A vehicle comprising the all-solid-state battery according to claim 18.

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