Oxide, solid electrolyte comprising the oxide, Preparation method thereof, and electrochemical device comprising the oxide

Abstract

Oxides according to various embodiments of the present invention may include compounds represented by the following chemical formula 1. [Chemical Formula 1] Ba7+xNb4-yAyMo1-zBzO20 where A is at least one selected from the group consisting of Ta, As, Sb, Nb and V, and B is at least one selected from the group consisting of W and Cr, and 0≤x≤0.5, 0≤y≤4, 0≤z≤1. A solid electrolyte according to various embodiments of the present invention may include the oxide. Electrochemical elements according to various embodiments of the present invention may include the oxide. A method for manufacturing a solid electrolyte according to various embodiments of the present invention may include the step of mixing at least one of BaCO3, Nb2O5, Ta2O5, WO3, and MoO3 in proportion to the stoichiometric ratio of Formula 1; the step of drying and calcining the powder mixed in the mixing step; and the step of manufacturing an electrolyte using the powder calcined in the calcining step.

Description

Technology Field

[0001] The present invention relates to an oxide, a solid electrolyte containing the same, a method for manufacturing the same, and an electrochemical device. Specifically, various embodiments of the present invention relate to an oxide with improved sinterability through isovalent doping, a solid electrolyte containing the same, a method for manufacturing the same, and an electrochemical device. Background Technology

[0002] Solid oxide electrochemical cells (SOFCs) are devices that convert the chemical energy of fuel into electrical energy or convert electrical energy into chemical fuel. Due to their high conversion efficiency and environmentally friendly characteristics, they are regarded as a future energy source to replace conventional internal combustion engines and as one of the green hydrogen production technologies. These solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs) have the highest theoretical efficiency among related technologies and offer the advantage of not requiring precious metal catalysts due to their high operating temperatures.

[0003] However, the most widely used solid oxide fuel cells (SOFC) and solid oxide water electrolysis cells (SOEC) currently use oxygen ion conductors such as Yttria-stabilized Zirconia (YSZ) as electrolyte materials, which requires a very high operating temperature, leading to increased system costs and issues with durability and reliability. Accordingly, research has recently been actively conducted to lower their operating temperatures to a medium-low temperature range of 650 degrees or less.

[0004] As a result, protonic ceramic fuel cells (PCFCs) and protonic ceramic electrolysis cells (PCECs) were developed using hydrogen ion-conducting oxides as electrolytes, which possess excellent ionic conductivity in the medium-to-low temperature range and can have lower ion transport activation energy compared to oxygen ions.

[0005] Proton-conducting oxide fuel cells and water electrolysis cells share a common structure in which porous electrodes (anodes and cathodes) are positioned on opposite sides of a dense electrolyte layer that prevents gas penetration. In this context, the electrolyte material must provide high conductivity, and during device fabrication, it must be dense enough to effectively prevent crossover of hydrogen and air flowing between the two electrodes separated by the electrolyte. In the case of proton-conducting oxide fuel cells, fuel such as hydrogen is supplied to the anode and electrochemically oxidized to separate into hydrogen ions (protons) and electrons. Electrons flow into an external circuit and move to the anode, while protons pass through the electrolyte layer to reach the anode. These supplied protons and electrons react with oxygen at the anode to produce water, and electrical energy is generated using the potential difference between the anode and cathode created during this process. Therefore, manufacturing an electrolyte that is structurally very dense and possesses high proton conductivity is critical for the high-efficiency operation of the device.

[0006] Ba7Nb4MoO 20 (hereinafter BNM) oxides in a humidified environment oxygen ions (O 2- ) not only conductivity but also protons (H +A material that simultaneously possesses conductivity and is characterized by incorporating the advantages of the proton-conducting oxide described above, thereby making it possible to lower the conventional SOFC / SOEC operating temperature to 600°C or lower. This reduction in operating temperature lowers the degradation rate caused by high temperatures and provides a wider range of material choices, which can contribute to reducing manufacturing costs.

[0007] Meanwhile, BNM is a material with excellent bulk ion conductivity because it contains specific crystal planes that can rapidly transport oxygen and hydrogen ions within its crystal structure, but it has a limitation in that its overall conductivity is low when used as an electrolyte for polycrystalline SOFC / SOEC and PCFC / PCEC, as the grain boundary resistance is relatively high at temperatures below 600°C.

[0008] To overcome this, the general method is to reduce grain boundary density by sintering at high temperatures, but BNM Ba5Nb4O at temperatures above 1100℃ 15 It has the problem that a secondary phase similar to an insulator is formed, which actually reduces the bulk conductivity within the crystal. The problem to be solved

[0009] The present invention is derived to solve the aforementioned problems and aims to provide an oxide that can obtain a dense electrolyte at low temperatures with improved sinterability and reduce grain boundary density and grain boundary resistance, a solid electrolyte containing the same, a method for manufacturing the same, and an electrochemical device. means of solving the problem

[0010] Oxides according to various embodiments of the present invention may include compounds represented by the following chemical formula 1.

[0011] [Chemical Formula 1]

[0012] Ba 7+x Nb 4-y A y Mo1-z B z O 20

[0013] Here, A is at least one selected from the group consisting of Ta, As, Sb, Nb and V, and ,

[0014] B is at least one selected from the group consisting of W and Cr, and ,

[0015] 0≤x≤0.5, 0≤y≤4, 0≤z≤1.

[0016] A solid electrolyte according to various embodiments of the present invention may include the oxide.

[0017] Electrochemical elements according to various embodiments of the present invention may include the oxide.

[0018] A method for manufacturing a solid electrolyte according to various embodiments of the present invention may include the step of mixing at least one of BaCO3, Nb2O5, Ta2O5, WO3, and MoO3 in proportion to the stoichiometric ratio of Formula 1; the step of drying and calcining the powder mixed in the mixing step; and the step of manufacturing an electrolyte using the powder calcined in the calcining step. Effects of the invention

[0019] The present invention provides an oxide with improved sinterability through isovalent doping, a solid electrolyte containing the same, a method for manufacturing the same, and an electrochemical device.

[0020] Specifically, the present invention relates to Ba through equivalent heteroelement substitution. 7-x Nb4MoO 20+α Sinterability can be improved without significantly damaging the crystal structure or the conductivity properties within the crystal. Therefore, sinterability is improved, allowing for the production of a dense electrolyte at low temperatures and reducing grain boundary density and grain boundary resistance. Brief explanation of the drawing

[0021] Figure 1 is the result of confirming the purity of the powder obtained according to Example 1 using X-ray diffraction (XRD). Figure 2 is a graph comparing the theoretical calculated value and the actual measured value of the electrolyte density obtained according to Example 1. Figure 3 shows the density of the electrolyte obtained according to Example 1. Figure 4 is a graph comparing the theoretical calculated value and the actual measured value of the electrolyte density obtained according to Example 2. Figure 5 shows the density of the electrolyte obtained according to Example 2. Figure 6 shows photographs confirming the microstructures of the examples and comparative examples. Figure 7 shows the results of confirming the ion conductivity characteristics of the examples and comparative examples. Specific details for implementing the invention

[0022] Hereinafter, various embodiments of this document are described with reference to the accompanying drawings. The embodiments and the terms used therein are not intended to limit the technology described in this document to specific embodiments and should be understood to include various modifications, equivalents, and / or substitutions of said embodiments.

[0024] Oxides according to various embodiments of the present invention may include compounds represented by the following chemical formula 1.

[0025] [Chemical Formula 1]

[0026] Ba 7+x Nb 4-y A y Mo 1-z B z O 20

[0027] Here, A is at least one selected from the group consisting of Ta, As, Sb, Nb and V, and , B is at least one selected from the group consisting of W and Cr, and , 0≤x≤0.5, 0≤y≤4, 0≤z≤1. A is Nb5+ It is the element being substituted instead, and B is Mo 6+ It is an element that is substituted instead.

[0028] Specifically, A is Ta and B is W, and 0≤y≤0.3 and 0.01≤z≤0.1 may be true. That is, the compound of the present invention is Ba 7+x Nb 4-y A y Mo 1-z B z O 20 from Nb 5+ Instead Ta 5+ Replaced by, or Mo 6+ Instead of W 6+ It can be replaced with, or both can be replaced simultaneously.

[0029] Generally Ba7Nb4MoO 20 Synthesis is difficult due to its unique crystal structure, and there is a problem in that a large amount of secondary phases are formed under the same synthesis conditions, particularly when heterogeneous elements are substituted. Therefore, in the present invention, Ba 7+x Nb4MoO 20 It is characterized by doping with an isovalent dopant having an ionic valence that can improve sinterability without significantly damaging the crystal structure or conductivity properties within the crystal.

[0030] Ba 7+x Nb 4-y A y Mo 1-z B z O 20 In Ta 5+ A substitution of within 20% may be appropriate. More specifically, substitution within 5% is advantageous for securing a single phase. In addition, Ba 7-x Nb4MoO 20+α In W 6+ Substitution within 20% may be appropriate. More specifically, substitution within 5% may be advantageous for securing a single phase.

[0031] Specifically, the compound of the present invention is Ba 7+x Nb 4-y Ay Mo 1-z B z O 20 In this, Ta may be substituted for Nb in 1, 2, or 5 mol%, or W may be substituted for Mo in 1, 2, or 5 mol%. More specifically, the compound of the present invention is Ba7Nb 3.96 Ta 0.04 MoO 20 , Ba7Nb 3.92 Ta 0.08 MoO 20 , Ba7Nb 3.8 Ta 0.2 MoO 20 , Ba7Nb4Mo 0.99 W 0.01 O 20 , Ba7Nb4Mo 0.98 W 0.02 O 20 , and Ba7Nb4Mo 0.95 W 0.05 O 20 It can be at least one selected from the group consisting of

[0033] Meanwhile, the present invention may provide a solid electrolyte comprising the oxide described above. Additionally, the present invention may provide an electrochemical device comprising the oxide described above. In this case, the electrochemical device may be at least one of a solid oxide fuel cell (SOFC), a protonic ceramic fuel cell (PCFC), a solid oxide electrolysis cell (SOEC), and a protonic ceramic electrolysis cell (PECE).

[0036] A method for manufacturing a solid electrolyte according to various embodiments of the present invention may include the steps of mixing powders; drying and calcining the mixed powders; and pressurizing and sintering.

[0037] First, in the step of mixing the powder, the starting materials can be mixed by weighing them according to the stoichiometric ratio of Chemical Formula 1 described above. For example, ball milling can be performed after preparing at least one of BaCO3, Nb2O5, Ta2O5, WO3, and MoO3 as the starting materials.

[0038] Subsequently, the mixed powder may be subjected to drying and calcination steps. At this time, the pellets obtained by uniaxial pressing the dried powder may be calcined. Uniaxial pressing can be performed, for example, at a pressure of 300 kgf to 700 kgf for about 30 seconds to 5 minutes. Calcining such pressurized pellets may be advantageous for securing a single phase.

[0039] Meanwhile, in the calcination step, these pellets can be calcined at a temperature of 900 to 1200 ℃. Specifically, in the calcination step, calcination can be performed at 1050 ℃ for 48 hours. Meanwhile, after calcination, the pellets can be crushed, ball-milled, and then sieved to obtain a single-phase powder of uniform size.

[0040] Next, in the pressurization and sintering step, an electrolyte can be manufactured using the calcined powder. More specifically, an electrolyte can be manufactured by pressurizing or tape-casting the calcined powder and then sintering it.

[0041] For example, an electrolyte green body can be obtained by uniaxially pressing the calcined powder and performing cold isostatic pressing. Next, the compressed electrolyte specimen can be placed in a crucible, positioned inside a furnace, and sintered to obtain a high-density specimen.

[0042] Alternatively, the calcined powder can be mixed into a tape casting slurry, and tape casting can be performed to obtain an electrolyte green sheet. Next, several to tens of green sheets can be stacked, and then warm isostatic pressing (WIP) can be performed to obtain an electrolyte manufacturing sheet of a desired thickness. Next, the sheet can be cut to a desired shape and size, placed inside a sintering furnace with a setter, and sintered to obtain a high-density thick film electrolyte.

[0043] At this time, the sintering can be carried out in a first sintering process at a temperature of 1300 to 1500 ℃ for 30 minutes to 7 hours, and a second annealing process at a temperature of 900 to 1200 ℃ for 40 to 60 hours after cooling. Through this two-stage stepwise sintering, a high-density specimen can be finally obtained, and the conductivity improvement effect of the electrolyte can be optimized by removing the secondary phase with low conductivity formed in the first sintering stage.

[0044] The first sintering temperature may be 1300 ℃ to 1500 ℃. Preferably, the first sintering temperature may be 1350 ℃ to 1400 ℃. The first sintering time may be 30 minutes to 7 hours. Preferably, it may be 1 hour to 5 hours.

[0045] The second annealing temperature may be 900 to 1200 ℃. Preferably, the second sintering temperature may be 1050 to 1100 ℃. The second annealing time may be 40 to 60 hours. Preferably, it may be 30 to 50 hours. If the annealing time is insufficient, there is a risk that the formation of a secondary phase affecting the degradation of conductivity properties may be excessive.

[0046] The ramping rate for reaching the sintering temperature may be 2 ℃ / min to 10 ℃ / min. Preferably, it may be 5 ℃ / min or higher. In addition, by varying the ramping time for each temperature range, a dense electrolyte with minimized breakage or deformation can be obtained.

[0047] In the present invention, even for materials where it is difficult to obtain a single-phase composition, a secondary phase can be effectively suppressed to produce a solid electrolyte of high purity and high density. That is, the secondary phase of the electrolyte can be effectively removed, and a high-purity and high-density electrolyte can be produced. Specifically, in the present invention, a solid electrolyte with a sintering density of 90% or more can be produced.

[0048] The present invention can produce a solid electrolyte comprising a compound having the composition of the following chemical formula 1 described above through this method.

[0049] [Chemical Formula 1]

[0050] Ba 7+x Nb 4-y A y Mo 1-z B z O 20

[0051] Here, A is at least one selected from the group consisting of Ta, As, Sb, Nb and V, and , B is at least one selected from the group consisting of W and Cr, and , 0≤x≤0.5, 0≤y≤4, 0≤z≤1. A is Nb 5+ It is the element being substituted instead, and B is Mo 6+ It is an element that is substituted instead.

[0052] Meanwhile, the manufacturing method of the present invention can improve sinterability without significantly damaging the crystal structure or conductivity characteristics within the crystal of the material. In addition, a dense electrolyte can be obtained at a low temperature.

[0054] The present invention will be described in detail below through specific embodiments.

[0055] However, the following examples are merely for illustrating the present invention and the present invention is not limited by the following examples.

[0057] Example 1: Synthesis of Powder and Preparation of Electrolyte

[0058] First, BaCO3, Nb2O5Ta2O5, WO3, and MoO3 powders were prepared as Ba7Nb 3.96 Ta 0.04 MoO 20 , Ba7Nb 3.92 Ta 0.08 MoO 20 , Ba7Nb 3.8 Ta 0.2 MoO 20 , Ba7Nb4Mo 0.99 W 0.01 O 20 , Ba7Nb4Mo 0.98 W 0.02 O 20 , and Ba7Nb4Mo 0.95 W 0.05 O 20 It was weighed and mixed according to the stoichiometric ratio. That is, Ba7Nb4MoO 20 at Nb 5+ Instead Ta 5+ Ba7Nb substituted at 1, 2, and 5 mol%, respectively 3.96 Ta 0.04 MoO 20 , Ba7Nb 3.92 Ta 0.08 MoO 20 , and Ba7Nb 3.8 Ta 0.2 MoO 20 It was prepared to match the stoichiometric ratio of. In addition, Ba7Nb4MoO 20 at Mo 6+ Instead of W 6+ Ba7Nb4Mo substituted at 1, 2, and 5 mol%, respectively 0.99 W 0.01 O 20 , Ba7Nb4Mo 0.98 W 0.02 O 20 , and Ba7Nb4Mo0.95 W 0.05 O 20 It was prepared to match the stoichiometric ratio.

[0059] Each precursor was placed in a Nalsen bottle, 1 / 3 volume of zirconia balls were added, and then anhydrous ethanol was filled and ball-milled for 24 hours.

[0060] The mixed powder was uniaxially pressed at 500 kgf for 1 minute to prepare a pellet, and calcined at 1050°C for 48 hours at a heating and cooling rate of 5°C per minute. Although a rapid decrease in purity is observed when the concentration of the substituted element is higher than 5 mol%, it is possible to obtain a completely single-phase powder by repeating the above process.

[0061] The calcined powder was subjected to uniaxial pressure of 500 kgf for 1 minute, followed by cold isotropic pressure of 200 MPa for 10 minutes. Subsequently, the electrolyte was prepared by first sintering at 1350°C for 1 hour at a heating and cooling rate of 5°C per minute, followed by cooling to 1050°C and performing a second annealing step for 48 hours.

[0062] Example 2: Preparation of electrolytes with different sintering times

[0063] An electrolyte sample was also prepared in the same manner as in Example 1, except that a first sintering step was performed at 1400°C for 1 hour at a heating and cooling rate of 5°C per minute, followed by a second annealing step in which the temperature was lowered to 1050°C and maintained for 48 hours.

[0064] Comparative Example 1: Synthesis of Powder and Preparation of Electrolyte

[0065] Ta 5+ or W 6+ Ba7Nb4MoO is identical to Example 1 except that is not substituted 20 The powder was synthesized and the electrolyte was prepared.

[0066] Comparative Example 2: Preparation of electrolytes with different sintering times

[0067] Ta 5+ or W 6+Ba7Nb4MoO is identical to Example 1, except that no substitution was performed and the first sintering was carried out at 1400°C for 1 hour. 20 I prepared an electrolyte.

[0069] Experimental Example 1: Confirmation of whether substitution composition powder was synthesized

[0070] The purity of the powder obtained according to Example 1 was confirmed by X-ray diffraction (XRD). As a result, referring to Fig. 1, 1, 2, and 5 mol% Ta and W were all Ba7Nb4MoO 20 It was confirmed that it exhibits a pattern consistent with the XRD pattern of the composition. W 6+ In the case of substitution, a small amount of secondary phase observed (Ba5Nb4O 15 ) did not exceed 3wt%.

[0071] Experimental Example 2: Verification of Sintering Density

[0072] The sintered density of the electrolyte obtained according to Example 1 was verified. As a result, referring to Fig. 2, a significant increase in density was observed for both Ta and W compared to the theoretical density increase expected due to the substituent elements. In particular, referring to Fig. 3, it can be seen that high-density electrolytes can be obtained for both Ta and W when the concentration of the substituent element is 5 mol%. That is, Ba7Nb 3.8 Ta 0.2 MoO 20 and Ba7Nb4Mo 0.95 W 0.05 O 20 The density was the highest. In addition, when the concentration of the substituent element was 5 mol%, Ta-substituted Ba7Nb 3.8 Ta 0.2 MoO 20 The density of was higher.

[0073] Meanwhile, the sintered density of the electrolyte obtained according to Example 2 was verified. As a result, referring to Fig. 4, a significant increase in density was observed for both Ta and W compared to the theoretical density increase expected due to the substituent elements, similar to Fig. 2. Likewise, referring to Fig. 5, it can be seen that high-density electrolytes can be obtained for both Ta and W when the concentration of the substituent element is 5 mol%. Furthermore, when the concentration of the substituent element is 5 mol%, Ba7Nb4Mo substituted with W 0.95 W 0.05 O 20 The density of was higher.

[0074] From the results of Figures 2 to 5, it can be seen that the sintering time must be varied depending on the type of substituent element to obtain a high-density electrolyte.

[0075] Experimental Example 3: Confirmation of Electrolyte Microstructure

[0076] Ba7Nb4MoO obtained from Comparative Example 2 20 Ba7Nb4Mo among the electrolyte and the electrolyte obtained from Example 2 0.98 W 0.02 O 20 The microstructure was examined. To confirm the grain boundary microstructure, surface polishing was performed, followed by thermal etching at 1050°C for 10 minutes, and then a scanning electron microscope was used. As a result, referring to Figure 6, a reduction in micropores observed in the electrolyte was confirmed as Ta and W were substituted, and it was confirmed that this effect was more pronounced in W than in Ta. This is consistent with the density values ​​measured when referring to Figure 4. In addition, while generally non-uniform grain boundary sizes were observed in all electrolytes, large grain boundaries with sizes ranging from 3 μm to 5 μm were observed more frequently in the electrolytes substituted with Ta and W. Based on this, it was confirmed that the improved sinterability achieved by substituting Ta and W promoted grain boundary growth within the electrolyte.

[0077] Experimental Example 4: Confirmation of Ionic Conductivity Characteristics

[0078] Ba7Nb4MoO obtained from Comparative Example 1 20 Ba7Nb4Mo among the electrolyte and the electrolyte obtained from Example 1 0.98 W 0.02 O 20 The ionic conductivity characteristics were verified. To this end, Pt paste was applied to both sides of each electrolyte and heat-treated at 900°C for 10 minutes. The ionic conductivity characteristics were measured using AC impedance spectroscopy at various temperatures under a 3% humidified air atmosphere. As a result, referring to Fig. 7, the electrolyte substituted with 2 mol% W showed lower grain boundary resistance (R). GB It can be seen that ) is observed. In other words, reduced grain boundary resistance characteristics due to increased sintering density were confirmed.

[0080] The features, structures, effects, etc. described in the above-described embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified and implemented in other embodiments by a person skilled in the art to which the embodiments belong. Therefore, details regarding such combinations and modifications should be interpreted as being included within the scope of the present invention.

[0081] Furthermore, although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

Claim 1 Ba7Nb4MoO 20 at Nb 5+ Instead Ta 5+ Ba7Nb formed by substituting an equivalent heterogeneous element 3.96 Ta 0.04 MoO 20 , Ba7Nb 3.92 Ta 0.08 MoO 20 , and Ba7Nb 3.8 Ta 0.2 MoO 20 ; and Ba7Nb4MoO 20 at Mo 6+ Instead of W 6+ Ba7Nb4Mo formed by substituting an equivalent heterogeneous element 0.99 W 0.01 O 20 , Ba7Nb4Mo 0.98 W 0.02 O 20 , and Ba7Nb4Mo 0.95 W 0.05 O 20 An oxide comprising at least one compound selected from the group consisting of Claim 2 delete Claim 3 delete Claim 4 A solid electrolyte comprising the oxide of claim 1. Claim 5 Electrochemical device comprising the oxide of claim 1. Claim 6 In claim 5, the electrochemical device is characterized in that the electrochemical device is at least one of a solid oxide fuel cell (SOFC), a protonic ceramic fuel cell (PCFC), a solid oxide electrolysis cell (SOEC), and a protonic ceramic electrolysis cell (PECE). Claim 7 At least one of BaCO3, Nb2O5, Ta2O5, WO3, and MoO3 is Ba7Nb 3.96 Ta 0.04 MoO 20 , Ba7Nb 3.92 Ta 0.08 MoO 20 , Ba7Nb 3.8 Ta 0.2 MoO 20 , Ba7Nb4Mo 0.99 W 0.01 O 20 , Ba7Nb4Mo 0.98 W 0.02 O 20 , and Ba7Nb4Mo 0.95 W 0.05 O 20 The method comprises the steps of: weighing and mixing according to a stoichiometric ratio selected from a group consisting of; drying and calcining the powder mixed in the mixing step; and manufacturing an electrolyte using the powder calcined in the calcination step, wherein Ba7Nb 3.96 Ta 0.04 MoO 20 , Ba7Nb 3.92 Ta 0.08 MoO 20 , and Ba7Nb 3.8 Ta 0.2 MoO 20 is Ba7Nb4MoO 20 at Nb 5+ Instead Ta 5+ It is characterized by being formed by substituting an equivalent heterogeneous element, and the above Ba7Nb4Mo 0.99 W 0.01 O 20 , Ba7Nb4Mo 0.98 W 0.02 O 20 , and Ba7Nb4Mo 0.95 W 0.05 O 20 Is Ba7Nb4MoO 20 at Mo 6+ Instead of W 6+ A method for manufacturing a solid electrolyte characterized by being formed by substituting an equivalent heterogeneous element. Claim 8 delete Claim 9 delete Claim 10 A method for manufacturing a solid electrolyte according to claim 7, characterized in that the calcination step is carried out at a temperature of 900 to 1200 ℃. Claim 11 A method for manufacturing a solid electrolyte according to claim 7, wherein the step of manufacturing the electrolyte comprises a step of pressurizing or a step of tape-casting. Claim 12 A method for manufacturing a solid electrolyte according to claim 11, wherein the above-mentioned pressurization is uniaxial pressurization. Claim 13 A method for manufacturing a solid electrolyte according to claim 11, further comprising a sintering step after the pressurizing step or tape-casting step, wherein the sintering is characterized by a first sintering performed at a temperature of 1300 to 1500 ℃ for 30 minutes to 7 hours and a second annealing performed at a temperature of 900 to 1200 ℃ for 40 hours to 60 hours.

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