Sulfide-based solid electrolyte and method for producing same

Abstract

The present invention provides a sulfide-based solid electrolyte comprising an argyrodite crystal structure and satisfying expression 1 below. [Expression 1] 1 ≤ I2 / I1 ≤ 1.3 (in expression 1, I1 refers to an ionic conductivity value measured immediately after production, I2 refers to an ionic conductivity value measured after exposure to the atmosphere under a predetermined condition).

Description

Sulfide-based solid electrolyte and method for manufacturing the same

[0001] The present invention relates to a sulfide-based solid electrolyte, and more specifically, to a sulfide-based solid electrolyte containing oxygen in a certain proportion and a method for manufacturing the same.

[0002] The present invention claims priority based on Korean Patent Application No. 10-2024-0190804 filed on December 19, 2024, the entire contents of said application incorporated herein by reference.

[0003] All-solid-state batteries, which do not use liquid electrolytes, are gaining attention as battery systems for next-generation electric vehicles due to their high safety and the potential to achieve high energy density. In particular, sulfide-based solid electrolytes possess high ionic conductivity, making them highly promising for applications such as electric vehicles requiring high power output, leading to ongoing research and development in various forms.

[0004] However, sulfide-based solid electrolytes have poor moisture and electrochemical stability compared to their high ionic conductivity, and their commercialization is difficult due to the high cost of raw materials.

[0005] The objective of the present invention is to provide a sulfide-based solid electrolyte having excellent moisture stability and electrochemical stability, and also securing high ionic conductivity.

[0006] Another objective of the present invention is to provide a method for manufacturing a sulfide-based solid electrolyte having the aforementioned advantages.

[0007] One embodiment of the present invention provides a sulfide-based solid electrolyte comprising an argyrodite crystal structure and satisfying Formula 1 below.

[0008] [Equation 1]

[0009] 1 ≤ I2 / I1 ≤ 1.3

[0010] (In the above Equation 1, I1 represents the ionic conductivity value measured immediately after manufacturing, and I2 represents the ionic conductivity value measured after exposure to the atmosphere under predetermined conditions.)

[0011] The above solid electrolyte contains sulfur and oxygen, and the number of moles of oxygen relative to the sulfur may be 0.25 to 4.

[0012] The above solid electrolyte may contain halogen elements.

[0013] The above halogen element may be Cl.

[0014] The above solid electrolyte can be represented by the following chemical formula 1.

[0015] [Chemical Formula 1]

[0016] Li 6-a PS 5-a-b X a O b

[0017] (In the above Chemical Formula 1, X comprises F, Cl, Br, I, or a combination thereof, and 0 < a ≤ 1, 2 ≤ b < 5.)

[0018] In the above chemical formula 1, b / (5-a) may be 0.2 or more and less than 1.

[0019] Another embodiment of the present invention provides a method for manufacturing a solid electrolyte by mixing a Li precursor, a P precursor, and a halogen element precursor to form a precursor mixture and then heat-treating the mixture, wherein the Li precursor contains 0.2 to 0.9 mol% of Li2O and the P precursor contains 0.2 to 0.9 mol% of P2O5, and the mol% of Li2O in the Li precursor and the mol% of P2O5 in the P precursor are the same.

[0020] The above Li precursor includes Li2S and Li2O, and the number of moles of Li2O relative to Li2S may be 0.25 to 4.

[0021] The above P precursor is P2S5 and P2O 5- It includes, and the number of moles of P2O5 relative to P2S5 may be 0.25 to 4.

[0022] The above halogen element precursor may include LiCl.

[0023] The above precursor mixture can be heat-treated after producing precursor pellets at a pressure of 100 to 500 MPa.

[0024] The above heat treatment can be carried out at a temperature of 400 to 700°C.

[0025] A sulfide-based solid electrolyte according to one embodiment of the present invention has an argyrodite crystal structure and, by replacing some of the sulfur with oxygen while controlling the molar ratio of oxygen to sulfur, it has excellent moisture stability and electrochemical stability and can secure high ionic conductivity.

[0026] A method for manufacturing a sulfide-based solid electrolyte according to another embodiment of the present invention can manufacture a solid electrolyte having the aforementioned advantages in an economical manner.

[0027] Figure 1 is an XRD (x-ray diffraction) graph of an example and a comparative example.

[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]

[0032] Sulfide-based solid electrolytes

[0033] In one embodiment of the present invention, a sulfide-based solid electrolyte is provided having an argyrodite crystal structure, which has excellent moisture stability and electrochemical stability and secures high ionic conductivity by replacing some of the sulfur with oxygen while controlling the molar ratio of oxygen to sulfur.

[0034] In one embodiment, the sulfide-based solid electrolyte includes an argyrodite crystal structure and can satisfy Formula 1 below.

[0035] [Equation 1]

[0036] 1 ≤ I2 / I1 ≤ 1.3

[0037] In the above Equation 1, I1 represents the ionic conductivity value measured immediately after manufacturing, and I2 represents the ionic conductivity value measured after exposure to the atmosphere under predetermined conditions. The predetermined conditions are left for about 12 hours in a dry environment at -50 to -40°C, and may be conditions for evaluating the moisture stability of the sulfide-based solid electrolyte.

[0038] The above Equation 1 may be 1 to 1.3, specifically 1 to 1.27, 1 to 1.24, 1 to 1.21, or 1 to 1.8. By satisfying the above range, the above solid electrolyte can maintain an ionic conductivity above a certain level even when exposed to the atmosphere, thereby ensuring electrochemical stability and maintaining electrical performance. If the above Equation 1 deviates from the upper limit of the above range, the difference in ionic conductivity before and after exposure to the atmosphere increases, which may lead to a decrease in battery performance due to insufficient moisture stability. Furthermore, if it deviates from 1, which is the lower limit of the above range, it implies that ionic conductivity improves after exposure to the atmosphere, which is not theoretically valid.

[0039] In one embodiment, the sulfide-based solid electrolyte comprises sulfur and oxygen, and the number of moles of oxygen relative to sulfur may be 0.25 to 4. Specifically, the number of moles of oxygen relative to sulfur may be 0.5 to 4, 0.5 to 3.5, 0.5 to 3, 1 to 4, 1 to 3.5, 1 to 3, 1.25 to 4, 1.25 to 3.5, 1.25 to 3, 1.5 to 4, 1.5 to 3.5, or 1.5 to 3. By satisfying the aforementioned ranges for the number of moles of oxygen, a certain number of sulfur molecules within the azirodite crystal structure may be replaced by oxygen, thereby preventing a decrease in ionic conductivity even with exposure to moisture, and preventing the reaction of the solid electrolyte in redox reactions during the charging and discharging processes of the battery. If the number of moles of oxygen exceeds the upper limit of the aforementioned range, the number of moles of oxygen relative to sulfur is excessively insufficient, making it impossible to exhibit the aforementioned advantages. Furthermore, if the number of moles of oxygen exceeds the lower limit of the aforementioned range, the number of moles of oxygen relative to sulfur becomes excessively large, which may result in a problem where the ionic conductivity of the solid electrolyte becomes very low.

[0040] In one embodiment, the sulfide-based solid electrolyte can be represented by the following chemical formula 1.

[0041] [Chemical Formula 1]

[0042] Li 6-a PS 5-a-b X a O b

[0043] In the above chemical formula 1, X comprises F, Cl, Br, I, or a combination thereof, and 0 < a ≤ 1, 2 ≤ b < 5.

[0044] In the above chemical formula 1, a represents the ratio in which X replaces the Li element, and may be 0 < a ≤ 1. If a is 0, it does not contain a halogen element, so the effect of improving ionic conductivity through the halogen element cannot be enjoyed. In addition, if a exceeds 1, the ionic conductivity of the solid electrolyte improves, but problems such as reduced moisture stability and battery capacity characteristics may occur.

[0045] The above X may include F, Cl, Br, I, or a combination thereof. More specifically, from the perspective of structural stabilization of the solid electrolyte, ease of synthesis, and reduction of process costs, X may be Cl. Additionally, from the perspective of a more desirable implementation of ionic conductivity, the above X may further include one or more elements selected from Br and I in addition to Cl, and more specifically, the above X may include Cl and Br.

[0046] In the above chemical formula 1, b represents the molar ratio of O, and may be 2 ≤ b < 5. Specifically, b may be 2 to 4.75, 2 to 4.5, 2 to 4.25, 2.25 to less than 5, 2.25 or more to 4.75, 2.25 to 4.5, 2.25 to 4.25, 2.5 or more to less than 5, 2.5 to 4.75, 2.5 to 4.5, or 2.5 to 4.25. If b deviates from the upper limit of the aforementioned range, moisture stability is improved, but the ionic conductivity of the solid electrolyte itself may become excessively low. Furthermore, if b deviates from the lower limit of the aforementioned range, ionic conductivity is improved, but the moisture stability and electrochemical stability obtained by including oxygen may be reduced.

[0047] In one embodiment, in the sulfide-based solid electrolyte, b / (5-a) in Formula 1 may be 0.2 or more to less than 1, 0.2 to 0.9, 0.2 to 0.8, 0.3 or more to less than 1, 0.3 to 0.9, 0.3 to 0.8, 0.4 or more to less than 1, 0.4 to 0.9, or 0.4 to 0.8. By satisfying the aforementioned ranges, the ionic conductivity and moisture stability of the solid electrolyte can be simultaneously secured at high performance. If b / (5-a) deviates from the upper limit of the aforementioned range, moisture stability is improved, but the ionic conductivity of the solid electrolyte itself may become excessively low. Furthermore, if it deviates from the lower limit of the aforementioned range, ionic conductivity is improved, but the moisture stability and electrochemical stability obtained by including oxygen may be reduced.

[0048]

[0049] Method for manufacturing sulfide-based solid electrolytes

[0050] In another embodiment of the present invention, a method for manufacturing an economical sulfide-based solid electrolyte having the aforementioned advantages is provided.

[0051] In one embodiment, a method for manufacturing a sulfide-based solid electrolyte is a method of manufacturing a solid electrolyte by mixing a Li precursor, a P precursor, and a halogen element precursor and then heat-treating the mixture, wherein the Li precursor contains 0.2 to 0.9 mol% of Li2O and the P precursor contains 0.2 to 0.9 mol% of P2O5, and the mol% of Li2O in the Li precursor and the mol% of P2O5 in the P precursor may be the same.

[0052] The above Li precursor may be, for example, Li2S, Li2S2, Li2O, or a combination thereof, and the above P precursor may be, for example, P2S5, P2O5, or a combination thereof, but is not necessarily limited thereto.

[0053] The above Li precursor may contain 0.2 to 0.9 mol% of Li2O, and specifically, may be 0.2 to 0.8 mol%, 0.2 to 0.7 mol%, 0.25 to 0.9 mol%, 0.25 to 0.8 mol%, 0.25 to 0.7 mol%, 0.3 to 0.9 mol%, 0.3 to 0.8 mol%, or 0.3 to 0.7 mol%. In addition, the P precursor may contain 0.2 to 0.9 mol% of P2O5, specifically 0.2 to 0.8 mol%, 0.2 to 0.7 mol%, 0.25 to 0.9 mol%, 0.25 to 0.8 mol%, 0.25 to 0.7 mol%, 0.3 to 0.9 mol%, 0.3 to 0.8 mol%, and 0.3 to 0.7 mol%. The mol% of Li2O in the Li precursor and the mol% of P2O5 in the P precursor may be the same.

[0054] This is intended to replace sulfur with oxygen while maintaining the azirodite crystal structure; by satisfying the aforementioned range, moisture stability and ionic conductivity are secured, and manufacturing costs can be reduced by using Li2O instead of Li2S, which has a high production cost. If the value falls outside the upper limit of the aforementioned range, a problem may arise where the ionic conductivity becomes excessively low because the solid electrolyte does not contain sulfur. Furthermore, if the value falls outside the lower limit of the aforementioned range, the number of moles of oxygen replacing sulfur is excessively small, making it impossible to realize the aforementioned advantages.

[0055] The above halogen element precursor may be, for example, LiF, LiCl, LiBr, LiI, or a combination thereof, but is not necessarily limited thereto. More specifically, the above halogen element raw material may be LiCl.

[0056] In one embodiment, the Li precursor comprises Li2S and Li2O, and the molar number of Li2O relative to Li2S may be 0.25 to 4. Specifically, it may be 0.5 to 4, 0.5 to 3.5, 0.5 to 3, 1 to 4, 1 to 3.5, 1 to 3, 1.25 to 4, 1.25 to 3.5, 1.25 to 3, 1.5 to 4, 1.5 to 3.5, or 1.5 to 3. Additionally, the P precursor comprises P2S5 and P2O 5- It includes, and the moles of P2O5 relative to P2S5 may be 0.25 to 4. Specifically, it may be 0.5 to 4, 0.5 to 3.5, 0.5 to 3, 1 to 4, 1 to 3.5, 1 to 3, 1.25 to 4, 1.25 to 3.5, 1.25 to 3, 1.5 to 4, 1.5 to 3.5, or 1.5 to 3.

[0057] This is intended to replace sulfur with oxygen while maintaining the azirodite crystal structure; by satisfying the aforementioned range, moisture stability and ionic conductivity are secured, and manufacturing costs can be reduced by using Li2O instead of Li2S, which has a high production cost. If the value falls outside the upper limit of the aforementioned range, a problem may arise where the ionic conductivity becomes excessively low because the solid electrolyte does not contain sulfur. Furthermore, if the value falls outside the lower limit of the aforementioned range, the number of moles of oxygen replacing sulfur is excessively small, making it impossible to realize the aforementioned advantages.

[0058] In one embodiment, the method for manufacturing a sulfide-based solid electrolyte may be carried out by mechanical mixing or chemical mixing during the process of mixing the precursor. The mechanical mixing may be carried out, for example, by a planetary mill, paint shaker, ball mill, bead mill, homogenizer, hammer mill, turbo mill, disc mill, planetary mill, mechanofusion, etc. The chemical mixing may be carried out, for example, by a melt quenching method.

[0059] The above 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 is completed after a certain period, and even if mixing is continued, the mixing state remains the same, which may cause problems in terms of process efficiency.

[0060] The above 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.

[0061] In one embodiment, a method for manufacturing a sulfide-based solid electrolyte may involve preparing precursor pellets from the precursor mixture at a pressure of 100 to 500 MPa and then heat-treating them. At this time, the compression may be performed at a pressure of 100 to 500 MPa, and specifically at a pressure of 150 to 450 MPa or 200 to 400 MPa.

[0062] If the pressure is too low, insufficient binding between powder particles may lead to problems such as increased interfacial resistance. Conversely, if the pressure is too high, the particles are already bound, so applying further pressure does not alter the binding state, which can cause issues in terms of process efficiency. Therefore, forming pellets at an appropriate pressure is desirable for productivity.

[0063] In one embodiment, the method for manufacturing a sulfide-based solid electrolyte may perform the heat treatment at a temperature of 400 to 700°C, and specifically at 500 to 600°C.

[0064] 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 can lead to 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, resulting in a loss of the solid electrolyte or the generation of impurity phases, which can also lead to a decrease in the ionic conductivity of the solid electrolyte.

[0065] In addition, the heat treatment may be performed for 2 to 8 hours, specifically 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.

[0066] 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 moisture in the atmosphere can be blocked. The inert gas atmosphere may be, for example, an Ar, N2, H2, or He atmosphere, and more specifically, an Ar atmosphere.

[0067]

[0068] Preferred embodiments and comparative examples of the present invention are described below. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0069]

[0070] Examples

[0071] Example 1

[0072] The composition of the solid electrolyte is Li6PS 2.5 ClO 2.5Precursors Li2S, Li2O, P2S5, P2O5, and LiCl were introduced into a planetary mill. After mixing at 300 rpm for about 8 hours, a pressure of 300 MPa was applied to form pellets. Subsequently, a sulfide-based solid electrolyte was prepared by heat treatment at 550 °C for 6 hours under an Ar atmosphere.

[0073]

[0074] Example 2

[0075] The composition of the solid electrolyte is Li6PS 3.25 ClO 1.75 It was manufactured in the same manner as Example 1, except that the precursor was added to make it so.

[0076]

[0077] Comparative example

[0078] Comparative Example 1

[0079] It was prepared in the same manner as in Example 1, except that precursors Li2S, Li2O, P2S5, P2O5, and LiCl were added so that the composition of the solid electrolyte became Li6PS5Cl.

[0080]

[0081] Comparative Example 2 and Comparative Example 3

[0082] The composition of the solid electrolyte is Li6PS, respectively. 4.25 ClO 0.75 and Li6PS 4.75 ClO 0.25 It was manufactured in the same manner as Example 1, except that the precursor was added to make it so.

[0083]

[0084] Experimental Example

[0085] (1) XRD measurement

[0086] Figure 1 is an XRD (x-ray diffraction) graph of an example and a comparative example.

[0087] As shown in Figure 1, XRD analysis was performed on the above examples and comparative examples, and it can be confirmed that peaks corresponding to 29.8±0.5˚, 25.3±0.5˚, and 31.2±0.5˚ with respect to 2θ were observed for both the examples and comparative examples. In other words, it can be seen that both the examples and comparative examples have an argyrodite crystal structure.

[0088]

[0089] (2) Ionic conductivity measurement

[0090] After grinding the solid electrolytes of the above examples and comparative examples, 100 mg of the powder was pressurized to 200 MPa, and the ionic conductivity was measured by applying a 50 mV AC signal in the 1 MHz to 1 Hz range using a potentiostat at 25 ℃, and the results are shown in Table 1 below. Through this, it can be confirmed that the ionic conductivity decreases as the number of moles of oxygen increases. However, in the case of Examples 1 and 2, the ionic conductivity was 1 to 1.5 mS / cm, which can be considered to have secured an ionic conductivity sufficient for commercialization without difficulty.

[0091]

[0092] (3) Moisture stability evaluation; measurement of ion conductivity and discharge capacity before and after atmospheric exposure

[0093] After leaving the above examples and comparative examples in a dry environment of -50 to -40°C for about 12 hours, the ion conductivity was measured after exposure to the atmosphere using the same method as described above and is shown in Table 1 below.

[0094] In addition, the above examples and comparative examples were used as solid electrolytes, and batteries were manufactured using an NCM 811-based anode and a lithium cathode. At this time, identical half-cells were manufactured using the solid electrolytes of the examples and comparative examples, which were exposed to the atmosphere in the same manner as described above. Subsequently, the discharge capacity was measured by charging to 4.25 V (vs. Li+ / Li) at 0.1 C at 25°C and then discharging to 2.5 V (vs. Li+ / Li), and the results are shown in Table 2 below.

[0095] Looking at Tables 1 and 2 below, it can be confirmed that the changes in ion conductivity and discharge capacity before and after exposure to the atmosphere in the Examples are smaller compared to the Comparative Examples. In other words, even if the ion conductivity before exposure to the atmosphere is lower than that of the Comparative Examples, it can be seen that including a certain amount of oxygen as in the Examples ensures both moisture stability and electrochemical stability. Accordingly, the Examples of the present invention can be seen as having a composition capable of maintaining an appropriate range of ion conductivity, moisture stability, and electrochemical stability.

[0096] Ion conductivity before atmospheric exposure (mS / cm) Ion conductivity after atmospheric exposure (mS / cm) Equation 1 (I2 / I1) Example 1 1.05 0.89 31.18 Example 2 1.53 1.24 1.24 Comparative Example 12.18 1.66 1.32 Comparative Example 22.60 1.90 1.37 Comparative Example 32.80 1.99 1.41

[0097] Standby Exposure Front Total Capacity (mAh / g) Standby Exposure Rear Total Capacity (mAh / g) Standby Exposure After / Before Example 1 203.1178.750.88 Example 2 203.2172.730.85 Comparative Example 1 203.06168.950.83 Comparative Example 2 204.1163.290.80 Comparative Example 3 203.8148.540.73

[0098] The present invention is not limited to the above embodiments and can be manufactured in various different forms, and those skilled in the art will understand that the invention can be implemented in other specific forms without changing the technical concept or essential features of the invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

It includes an argyrodite crystal structure, Satisfying Equation 1 below, Sulfide-based solid electrolyte. [Equation 1] 1 ≤ I2 / I1 ≤ 1.3 (In the above Equation 1, I1 represents the ionic conductivity value measured immediately after manufacturing, and I2 represents the ionic conductivity value measured after exposure to the atmosphere under predetermined conditions.) In paragraph 1, The above solid electrolyte contains sulfur and oxygen, and The number of moles of oxygen relative to the sulfur is 0.25 to 4, Sulfide-based solid electrolyte. In paragraph 1, The above solid electrolyte contains a halogen element, Sulfide-based solid electrolyte. In paragraph 3, The above halogen element is Cl, Sulfide-based solid electrolyte. In paragraph 1, Represented by the following chemical formula 1, Sulfide-based solid electrolyte. [Chemical Formula 1] Li 6-a P.S. 5-a-b X a About b (In the above Chemical Formula 1, X comprises F, Cl, Br, I, or a combination thereof, and 0 < a ≤ 1, 2 ≤ b < 5.) In paragraph 5, In the above chemical formula 1, b / (5-a) is 0.2 or more and less than 1, Sulfide-based solid electrolyte. A method for manufacturing a solid electrolyte by mixing a Li precursor, a P precursor, and a halogen element precursor to form a precursor mixture, and then heat-treating the mixture. The above Li precursor contains 0.2 to 0.9 mol% of Li2O, and The above P precursor contains 0.2 to 0.9 mol% of P2O5, and The mol% of Li2O in the above Li precursor and the mol% of P2O5 in the above P precursor are the same, Method for manufacturing a sulfide-based solid electrolyte. In Paragraph 7, The above Li precursor includes Li2S and Li2O, and The number of moles of Li2O relative to Li2S is 0.25 to 4, Method for manufacturing a sulfide-based solid electrolyte. In Paragraph 7, The above P precursor is P2S5 and P2O 5- Includes, The number of moles of P2O5 relative to P2S5 is 0.25 to 4, Method for manufacturing a sulfide-based solid electrolyte. In Paragraph 7, The above halogen element precursor includes LiCl, Method for manufacturing a sulfide-based solid electrolyte. In Paragraph 7, Preparing precursor pellets from the above precursor mixture under a pressure of 100 to 500 MPa and then heat-treating, Method for manufacturing a sulfide-based solid electrolyte. In Paragraph 7, The above heat treatment is performed at a temperature of 400 to 700℃, Method for manufacturing a sulfide-based solid electrolyte. In Paragraph 7, The above solid electrolyte is represented by the following chemical formula 1, Method for manufacturing a sulfide-based solid electrolyte. [Chemical Formula 1] Li 6-a P.S. 5-a-b X a About b (In the above Chemical Formula 1, X comprises F, Cl, Br, I, or a combination thereof, and 0 < a ≤ 1, 2 ≤ b < 5.)

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