High-performance sodium-electricity solid electrolyte as well as preparation method and application thereof

Abstract

The invention discloses a high-performance sodium battery solid electrolyte and a preparation method and application thereof, and belongs to the technical field of battery materials, the preparation method of the high-performance sodium battery solid electrolyte comprises the following steps: A1, pretreating NZSP-based ceramic powder to obtain pretreated ceramic powder, and grinding a polymer matrix into powder to obtain polymer powder; a2, adding the polymer powder into an organic solvent to obtain a polymer solution; a3, adding a sodium salt additive into an organic solvent to obtain a sodium salt additive solution; a4, adding the pretreated ceramic powder into a polymer solution, then adding a sodium salt additive solution, continuously stirring, taking out, and carrying out ball milling in a ball mill to obtain electrolyte slurry; and A5, performing hot press molding on the electrolyte slurry, and performing annealing treatment to obtain the solid electrolyte membrane. The solid electrolyte prepared by the method has excellent electrochemical performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery materials, and in particular relates to a high-performance sodium battery solid electrolyte and a preparation method and application thereof. Background Art

[0002] As the global demand for renewable energy continues to grow and portable electronic devices develop rapidly, sodium-ion batteries have become a hot research topic due to their abundant sodium resources, low cost, and similar working principles to lithium-ion batteries. As the core component of sodium-ion batteries, electrolyte plays a decisive role in the overall performance of the battery. It not only directly affects the battery's ion transfer efficiency, but also affects the battery's cycle life, rate performance, and safety performance.

[0003] Traditional liquid electrolytes have safety hazards such as easy leakage and flammability, while solid electrolytes are expected to overcome these problems. However, the existing solid electrolyte materials still face many challenges in terms of ionic conductivity, electrochemical stability, interfacial compatibility with electrodes, and preparation costs. For example, although some inorganic solid electrolytes have high ionic conductivity, they are brittle and have poor interfacial contact; although organic solid electrolytes have good flexibility and interfacial compatibility, their ionic conductivity is relatively low and their thermal stability is insufficient. Therefore, the development of a sodium-based solid electrolyte with excellent comprehensive performance is of extremely important practical significance. Summary of the invention

[0004] In order to solve the problem in the background technology that some inorganic solid electrolytes in the prior art have high ionic conductivity but high brittleness and poor interface contact; and organic solid electrolytes have good flexibility and interface compatibility but relatively low ionic conductivity and insufficient thermal stability, the purpose of the present invention is to provide a high-performance sodium battery solid electrolyte and its preparation method and application.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a high-performance sodium solid electrolyte, comprising the following steps:

[0007] A1: NZSP (Na3Zr2S i2PO 12 )-based ceramic powder is pretreated to obtain pretreated ceramic powder, and the polymer matrix is ​​ground into powder to obtain polymer powder;

[0008] NZSP-based ceramic powder is the core skeleton of ion conduction, providing a fast transmission channel for sodium ions. NZSP has high ionic conductivity and excellent electrochemical stability. The purpose of pretreatment is to remove impurities adsorbed on the surface of NZSP-based ceramic powder and improve its purity and activity. The purpose of grinding the polymer matrix into powder is to ensure that the polymer matrix has uniform particle size, which is conducive to the subsequent uniform mixing of the polymer matrix with other ingredients.

[0009] A2: Add the polymer powder into an organic solvent, stir and dissolve, and obtain a polymer solution;

[0010] The usage ratio of polymer powder to organic solvent is 0.5 g:10 mL.

[0011] A3: adding the sodium salt additive to the organic solvent and stirring to obtain a sodium salt additive solution;

[0012] A4: Add the pretreated ceramic powder to the polymer solution, stir, then add the sodium salt additive solution, continue stirring for 2-4 hours, take it out, and ball mill it in a ball mill to obtain an electrolyte slurry;

[0013] The dosage ratio of the pretreated ceramic powder, the polymer solution and the sodium salt additive solution is 10 g: 25 mL: 10 mL.

[0014] A5: The electrolyte slurry is hot-pressed and then annealed to obtain a solid electrolyte membrane.

[0015] During the hot pressing process, the polymer matrix softens and fills between the ceramic powders to form a tightly bound structure, while removing bubbles from the slurry and improving the density of the electrolyte membrane. Annealing can eliminate internal stress, further stabilize the structure of the electrolyte, and improve its electrochemical performance.

[0016] Furthermore, in step A1, the particle size of the NZSP-based ceramic powder is 1-20 μm.

[0017] Within the above-mentioned particle size range, NZSP particles can form a tightly packed structure, which is conducive to the rapid migration of sodium ions and maintains good mechanical strength.

[0018] Furthermore, in step A1, the pretreatment environment is a vacuum environment, the temperature is 200-300° C., and the time is 2-4 hours.

[0019] Furthermore, in step A1, the polymer matrix is ​​a copolymer of polyvinylidene fluoride-hexafluoropropylene and polyethylene oxide, and the mass ratio of polyvinylidene fluoride-hexafluoropropylene to polyethylene oxide in the copolymer is (1-3):1.

[0020] The above copolymers not only impart a certain degree of flexibility, but also can be closely combined with ceramic powder and sodium salt additives, thereby improving the overall performance of the electrolyte.

[0021] Furthermore, in step A1, the specific steps of grinding are: grinding the polymer matrix into fine powder under the protection of dry nitrogen gas, and passing through a 200-400 mesh sieve.

[0022] Furthermore, in step A2 and step A3, the organic solvent is a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate is (1-3):1.

[0023] Furthermore, in step A2, the stirring temperature is 30-50° C., the speed is 500-1000 rpm, and the time is 2-4 h.

[0024] Furthermore, in step A3, the sodium salt additive is a mixture of NaTFS I and NaFS I, and the molar ratio of NaTFS I to NaFS I is 1:1; the concentration of the sodium salt additive solution is 0.5-1.5 mol / L.

[0025] Furthermore, in step A4, the stirring speed is 100-300 rpm.

[0026] Furthermore, in step A4, the ball milling medium is selected as zirconium oxide balls, the mass ratio of balls to materials is (5-10):1, the ball milling speed is 300-500rpm, and the ball milling time is 4-8h.

[0027] Ball milling can further refine the particles, promote uniform mixing between the components, and improve the performance uniformity of the electrolyte.

[0028] Furthermore, in step A5, the temperature of hot pressing is 120-160° C., the pressure is 5-10 MPa, and the time is 1-3 h.

[0029] Furthermore, in step A5, the annealing treatment is performed in a vacuum environment at a temperature of 80-120° C. for 2-4 hours.

[0030] In a second aspect, the present invention provides a high-performance sodium battery solid electrolyte, which is prepared by the preparation method of the high-performance sodium battery solid electrolyte described in any one of the above contents.

[0031] In a third aspect, the present invention provides an application of the high-performance sodium-ion solid electrolyte described above in a sodium-ion battery.

[0032] Beneficial effects of the present invention:

[0033] 1. The present invention successfully achieves comprehensive improvement in ionic conductivity, electrochemical stability, interface compatibility and mechanical properties by optimizing the composition and preparation process of solid electrolytes. The rational combination of NZSP-based ceramic powder, polymer matrix and sodium salt additives constructs a stable and efficient ion transmission channel, effectively improving the ion conduction efficiency.

[0034] 2. The present invention precisely controls the particle size, proportion and preparation process parameters of each component, such as the particle size of the ceramic powder, the composition of the polymer matrix, hot pressing and annealing conditions, so that the solid electrolyte membrane has a good microstructure and uniformity, thereby ensuring excellent electrochemical performance.

[0035] 3. The present invention not only significantly improves the ionic conductivity, but also improves the electrochemical stability and reduces the interface impedance by reasonably selecting the sodium salt additive and accurately controlling the addition amount of the sodium salt additive, thereby further enhancing the cycle stability and safety of the battery.

[0036] 4. The preparation method of the present invention is simple, easy to operate, and highly operable, and is suitable for large-scale industrial production. The prepared solid-state battery has high energy density, long cycle life, and good safety performance, and has broad application prospects in the field of sodium ion batteries, and can be widely used in electric vehicles, energy storage systems, and other fields. DETAILED DESCRIPTION

[0037] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Example 1

[0039] A method for preparing a high-performance sodium solid electrolyte comprises the following steps:

[0040] A1: Weigh NZSP-based ceramic powder with a particle size distribution of 10-20 μm, pretreat it at 250°C for 3 h in a vacuum environment to obtain pretreated ceramic powder, grind the polymer matrix (the polymer matrix is ​​a copolymer of polyvinylidene fluoride-hexafluoropropylene and polyethylene oxide, and the mass ratio of polyvinylidene fluoride-hexafluoropropylene to polyethylene oxide in the copolymer is 2:1) into fine powder under the protection of dry nitrogen gas, and pass it through a 300-mesh sieve to obtain polymer powder;

[0041] A2: 0.5 g of polymer powder was added into 10 mL of organic solvent (the organic solvent was a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate was 1:1), and the mixture was stirred and dissolved at 800 rpm at 40° C. for 3 hours to obtain a polymer solution;

[0042] A3: Weigh 0.5 mol NaTFS I and 0.5 mol NaFS I respectively, dissolve in an organic solvent (the organic solvent is a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate is 1:1), stir to obtain a 1 mol / L sodium salt additive solution;

[0043] A4: 10 g of pretreated ceramic powder was added to 25 mL of polymer solution and stirred. Then, 10 mL of sodium salt additive solution was added and stirred for 3 h. Then, the mixture was taken out and transferred to a planetary ball mill for ball milling. Zirconia balls were used as the ball milling medium. The ball-to-material ratio was 8:1. The ball milling speed was 400 rpm and the ball milling time was 6 h to obtain an electrolyte slurry.

[0044] A5: Pour the electrolyte slurry into a mold, hot-press it at 140°C and 8 MPa for 2 hours, and then anneal it at 100°C for 3 hours under a vacuum environment to obtain a solid electrolyte membrane.

[0045] Example 2

[0046] A method for preparing a high-performance sodium solid electrolyte comprises the following steps:

[0047] A1: Weigh NZSP-based ceramic powder with a particle size distribution of 1-10 μm, pretreat it at 250°C for 2 h in a vacuum environment to obtain pretreated ceramic powder, grind the polymer matrix (the polymer matrix is ​​a copolymer of polyvinylidene fluoride-hexafluoropropylene and polyethylene oxide, and the mass ratio of polyvinylidene fluoride-hexafluoropropylene to polyethylene oxide in the copolymer is 2:1) into fine powder under the protection of dry nitrogen gas, and pass it through a 200-mesh sieve to obtain polymer powder;

[0048] A2: 0.5 g of polymer powder was added into 10 mL of organic solvent (the organic solvent was a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate was 1:1), and the mixture was stirred and dissolved at 500 rpm at 30° C. for 4 hours to obtain a polymer solution;

[0049] A3: Weigh 0.5 mol NaTFS I and 0.5 mol NaFS I respectively, dissolve in an organic solvent (the organic solvent is a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate is 1:1), stir to obtain a 1 mol / L sodium salt additive solution;

[0050] A4: 10 g of pretreated ceramic powder was added to 25 mL of polymer solution and stirred. Then, 10 mL of sodium salt additive solution was added and stirred for 3 h. Then, the mixture was taken out and transferred to a planetary ball mill for ball milling. Zirconia balls were used as the ball milling medium. The ball-to-material ratio was 5:1. The ball milling speed was 300 rpm and the ball milling time was 6 h to obtain an electrolyte slurry.

[0051] A5: Pour the electrolyte slurry into a mold, hot-press it at 120°C and 5 MPa for 1 hour, and then anneal it at 80°C for 2 hours under a vacuum environment to obtain a solid electrolyte membrane.

[0052] Example 3

[0053] A method for preparing a high-performance sodium solid electrolyte comprises the following steps:

[0054] A1: Weigh NZSP-based ceramic powder with a particle size distribution of 10-20 μm, pretreat it at 250°C for 4 h in a vacuum environment to obtain pretreated ceramic powder, grind the polymer matrix (the polymer matrix is ​​a copolymer of polyvinylidene fluoride-hexafluoropropylene and polyethylene oxide, and the mass ratio of polyvinylidene fluoride-hexafluoropropylene to polyethylene oxide in the copolymer is 1:1) into fine powder under the protection of dry nitrogen gas, and pass it through a 400-mesh sieve to obtain polymer powder;

[0055] A2: 0.5 g of polymer powder was added into 10 mL of organic solvent (the organic solvent was a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate was 1:1), and the mixture was stirred and dissolved at 50° C. at a speed of 1000 rpm for 2 hours to obtain a polymer solution;

[0056] A3: Weigh 0.5 mol NaTFS I and 0.5 mol NaFS I respectively, dissolve in an organic solvent (the organic solvent is a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate is 1:1), stir to obtain a 1 mol / L sodium salt additive solution;

[0057] A4: 10 g of pretreated ceramic powder was added to 25 mL of polymer solution and stirred. Then, 10 mL of sodium salt additive solution was added and stirred for 3 h. Then, the mixture was taken out and transferred to a planetary ball mill for ball milling. Zirconia balls were used as the ball milling medium. The ball-to-material ratio was 10:1. The ball milling speed was 500 rpm and the ball milling time was 4 h to obtain an electrolyte slurry.

[0058] A5: Pour the electrolyte slurry into a mold, hot-press it at 160°C and 10 MPa for 3 hours, and then anneal it at 120°C for 4 hours under a vacuum environment to obtain a solid electrolyte membrane.

[0059] Example 4

[0060] The difference between this embodiment and embodiment 1 is that:

[0061] 0.25 mol NaTFS I and 0.25 mol NaFS I were weighed separately and dissolved in an organic solvent (the organic solvent was a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate was 1:1), and stirred to obtain a 0.5 mol / L sodium salt additive solution.

[0062] The remaining materials and steps are the same as in Example 1.

[0063] Example 5

[0064] The difference between this embodiment and embodiment 1 is that:

[0065] 0.75 mol NaTFS I and 0.75 mol NaFS I were weighed separately and dissolved in an organic solvent (the organic solvent was a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate was 1:1), and stirred to obtain a 1.5 mol / L sodium salt additive solution.

[0066] The remaining materials and steps are the same as in Example 1.

[0067] Comparative Example 1

[0068] Compared with Example 1, this comparative example is different only in that:

[0069] No sodium salt additive was added, and the remaining raw materials and steps were the same as in Example 1.

[0070] Comparative Example 2

[0071] Compared with Example 1, this comparative example is different only in that:

[0072] The sodium salt additive was only 1 mol of NaTFS I, and the other raw materials and steps were the same as in Example 1.

[0073] Comparative Example 3

[0074] This comparative example is different from Example 4 only in that:

[0075] The concentration of the sodium salt additive solution is 0.4 mol / L, and the remaining raw materials and steps are the same as in Example 4.

[0076] Comparative Example 4

[0077] This comparative example is different from Example 5 only in that:

[0078] The concentration of the sodium salt additive solution is 1.6 mol / L, and the remaining raw materials and steps are the same as in Example 5.

[0079] In a glove box filled with argon (water and oxygen content is less than 0.1 ppm), the solid electrolyte membranes prepared in Examples 1 to 5 and Comparative Examples 1 to 4 were sandwiched between the positive electrode sheet and the negative electrode sheet, and a laminated structure was used to assemble a solid-state battery. A layer of Celgard 2400 diaphragm was placed between the battery components. The assembled battery was encapsulated with an aluminum-plastic film and then heat-sealed on a hot press at a heat sealing temperature of 160° C., a pressure of 0.4 MPa, and a time of 8 seconds. The preparation process of the positive electrode sheet is as follows: NaN i 0.5 Mn 0.5 O2, acetylene black and PVDF are mixed in a mass ratio of 8:1:1, stirred and dispersed in NMP solvent, coated on aluminum foil, dried, compacted and cut into circular pole pieces with a diameter of 14 mm. The preparation process of the negative electrode is as follows: hard carbon, graphite and CMC are mixed in a mass ratio of 7:2:1, dispersed in deionized water, coated on copper foil, dried, compacted and cut into circular pole pieces with a diameter of 14 mm. The performance of the assembled battery and solid electrolyte membrane was tested. The test items are as follows, and the results are shown in Table 1:

[0080] 1. Ionic conductivity test: The ionic conductivity of the solid electrolyte was tested by electrochemical impedance spectroscopy (EIS). The solid electrolyte membrane was sandwiched between two stainless steel electrodes and assembled into a symmetrical battery. The test was performed using an electrochemical workstation HI 660E with a frequency range of 1Hz-1 MHz and an amplitude of 5mV. Based on the impedance spectrum obtained from the test, the ionic conductivity was calculated by equivalent circuit fitting.

[0081] 2. Electrochemical window test: Stainless steel is used as the working electrode, lithium sheet is used as the counter electrode and reference electrode, and solid electrolyte membrane is used as the electrolyte to assemble a three-electrode system. Linear sweep voltammetry (LSV) test is performed on the electrochemical workstation with a scan rate of 0.1mV / s and a scan range of 0-6V. The electrochemical window is determined by observing the voltage value when the current begins to rise sharply.

[0082] 3. After assembling the solid-state battery, perform AC impedance test in open circuit state. The test frequency range is 100kHz-0.1Hz, and the amplitude is 5mV. By analyzing the impedance spectrum, the interface impedance between the electrolyte and the electrode is obtained.

[0083] 4. Perform charge and discharge cycle tests on solid-state batteries on the battery test system LAND CT2001A. The charge cut-off voltage is determined according to the positive electrode material, the discharge cut-off voltage is 0.01-1V, and the current density is 0.5C-2C. Record the capacity retention rate of the battery during the cycle process to evaluate the cycle stability of the battery.

[0084] Table 1

[0085]

[0086] It can be seen from Table 1 that the comprehensive performance of the electrolytes and batteries prepared in Examples 1 to 5 is significantly better than that of Comparative Examples 1 to 4.

[0087] Compared with Example 1, Example 2 is different in that the particle size of the NZSP-based ceramic powder in Example 2 is 1-10 μm, which is smaller than that in Example 1. Its ionic conductivity, interface impedance and capacity retention rate are all better than those in Example 1, indicating that ceramic powder with small particle size is beneficial to improving the ionic conductivity of the solid electrolyte and the interface impedance and capacity retention rate of the battery.

[0088] Compared with Example 1, Example 3 is different in that the mass ratio of polyvinylidene fluoride-hexafluoropropylene and polyethylene oxide in the copolymer of Example 3 is 1:1, and its comprehensive performance is lower than that of Example 1, indicating that the mass ratio of polyvinylidene fluoride-hexafluoropropylene and polyethylene oxide in the copolymer is 2:1, which is the optimal amount.

[0089] Compared with Example 1, Examples 4 and 5 differ in that the concentrations of the sodium salt additive solution are lower and higher than those of Example 1, respectively. The results show that the comprehensive performance of Example 4 is lower than that of Example 1, and the comprehensive performance of Example 5 is higher than that of Example 1, indicating that the sodium salt additive is beneficial to improving the ionic conductivity, improving the electrochemical stability and reducing the interface impedance, and further enhancing the cycle stability and safety of the battery.

[0090] Compared with Example 1, the difference between Comparative Example 1 and Example 1 is that no sodium salt additive is added in Comparative Example 1, and its comprehensive performance is significantly reduced compared with Example 1; only one sodium salt additive is added in Comparative Example 2, and its comprehensive performance is also reduced compared with Example 1, indicating that the present invention adopts a compound of two sodium salt additives to significantly improve the comprehensive performance of solid electrolytes and batteries.

[0091] Compared with Example 4 and Example 5, the concentration of the sodium salt additive solution in Comparative Example 3 and Comparative Example 4 is lower than that in Example 4, and its comprehensive performance is lower than that in Example 4; the concentration of the sodium salt additive solution in Comparative Example 4 is higher than that in Example 5, and its comprehensive performance is lower than that in Example 5, indicating that too much or too little sodium salt additive will affect the comprehensive performance of the battery, and the amount of sodium salt additive used in the present invention is the optimal amount.

[0092] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0093] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a high-performance sodium solid electrolyte, characterized in that: The following steps are involved: A1: pre-treating NZSP-based ceramic powder to obtain pre-treated ceramic powder, grinding the polymer matrix into powder to obtain polymer powder; A2: Add the polymer powder into an organic solvent, stir and dissolve, and obtain a polymer solution; A3: adding the sodium salt additive to the organic solvent and stirring to obtain a sodium salt additive solution; A4: Add the pretreated ceramic powder to the polymer solution, stir, then add the sodium salt additive solution, continue stirring for 2-4 hours, take it out, and ball mill it in a ball mill to obtain an electrolyte slurry; A5: The electrolyte slurry is hot-pressed and then annealed to obtain a solid electrolyte membrane.

2. The method for preparing a high-performance sodium solid electrolyte according to claim 1, characterized in that: In step A1, the particle size of the NZSP-based ceramic powder is 1-20 μm.

3. The method for preparing a high-performance sodium solid electrolyte according to claim 1, characterized in that: In step A1, the pretreatment environment is a vacuum environment, the temperature is 200-300° C., and the time is 2-4 hours; the polymer matrix is ​​a copolymer of polyvinylidene fluoride-hexafluoropropylene and polyethylene oxide, and the mass ratio of polyvinylidene fluoride-hexafluoropropylene and polyethylene oxide in the copolymer is (1-3):1; the specific steps of grinding are: grinding the polymer matrix into fine powder under the protection of dry nitrogen gas, and passing through a 200-400 mesh sieve.

4. The method for preparing a high-performance sodium solid electrolyte according to claim 1, characterized in that: In step A2 and step A3, the organic solvent is a mixed solvent of dimethyl carbonate and ethyl methyl carbonate, and the volume ratio of dimethyl carbonate to ethyl methyl carbonate is (1-3):

1.

5. The method for preparing a high-performance sodium solid electrolyte according to claim 1, characterized in that: In step A2, the stirring temperature is 30-50° C., the speed is 500-1000 rpm, and the time is 2-4 h; the amount ratio of polymer powder to organic solvent is 0.5 g:10 mL.

6. The method for preparing a high-performance sodium solid electrolyte according to claim 1, characterized in that: In step A3, the sodium salt additive is a mixture of NaTFS I and NaFS I, and the molar ratio of NaTFS I to NaFS I is 1:1; the concentration of the sodium salt additive solution is 0.5-1.5 mol / L.

7. The method for preparing a high-performance sodium solid electrolyte according to claim 1, characterized in that: In step A4, the stirring speed is 100-300rpm; the ball milling medium is selected as zirconium oxide balls, the mass ratio of balls to materials is (5-10):1, the ball milling speed is 300-500rpm, and the ball milling time is 4-8h; the amount ratio of pretreated ceramic powder, polymer solution, and sodium salt additive solution is 10g:25mL:10mL.

8. The method for preparing a high-performance sodium solid electrolyte according to claim 1, characterized in that: In step A5, the temperature of hot pressing is 120-160° C., the pressure is 5-10 MPa, and the time is 1-3 h; the annealing treatment is carried out in a vacuum environment at a temperature of 80-120° C. and the time is 2-4 h.

9. A high-performance sodium solid electrolyte, characterized in that: The high-performance sodium solid electrolyte is prepared by the preparation method of any one of claims 1 to 8.

10. Use of the high-performance sodium-ion solid electrolyte according to claim 9 in sodium-ion batteries.

Images