Polymer electrolyte containing oxygen vacancy vanadium-based filler, and preparation method and application thereof

Abstract

The application discloses a kind of polymer electrolyte of oxygen vacancy vanadium-based filler and its preparation method and application, it is related to battery material technical field, wherein preparation method includes the following steps: (1) preparation deep eutectic solution;(2) mixing;(3) preparation precursor solution;(4) preparation polymer electrolyte film.Polymer electrolyte is obtained by the preparation method described above.Polymer electrolyte is applied in solid-state sodium metal battery described above.Effect: the application discloses a kind of preparation method of polymer electrolyte of oxygen vacancy vanadium-based filler, raw material cost is low, industrialization is strong, process is environmental protection high efficiency, can realize continuous production.Polymer electrolyte wide voltage window, adaptation high voltage positive pole, high ion conduction efficiency, adaptation room temperature application, effectively reduce the concentration difference polarization in ion transmission process, improve battery charge-discharge efficiency.Solid-state sodium metal battery has high power potential, adaptation high current discharge, long cycle stability, life is significantly extended.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery materials, in particular to a polymer electrolyte containing oxygen vacancy vanadium-based fillers, a preparation method and application thereof. BACKGROUND

[0002] The growing demand for wearable electronic devices has accelerated the development of efficient and flexible energy storage solutions. Among these batteries, all-solid-state sodium metal batteries have great potential for development, and the key component is the solid-state electrolyte. Solid-state electrolytes can be broadly divided into inorganic solid electrolytes and polymer solid electrolytes. Although inorganic solid electrolytes have excellent ionic conductivity and a wide voltage window, their inherent brittleness, limited thermodynamic stability, sensitivity to moisture, and requirement for high-pressure treatment hinder their application in flexible devices.

[0003] Ethoxylated trimethylolpropane triacrylate has become a very valuable polymer electrolyte monomer due to its light-curable, stable three-dimensional network-forming, ion conduction-promoting, and good mechanical properties. It has shown potential in improving battery energy density, cycle life, and safety. However, limited sodium salt dissociation and low Na + transportation, resulting in low reduced ionic conductivity, limiting its widespread application. To solve these problems, the main modification methods can be divided into the following categories: copolymerization, crosslinking, or adding plasticizers, etc. Among them, the introduction of inorganic fillers is a multifunctional and synergistic strategy for preparing composite polymer electrolytes. It not only significantly improves the ionic conductivity and mechanical strength, but also brings unique benefits such as stable interface and improved safety, and is considered one of the key technical paths to realize the industrialization of high-energy-density all-solid-state batteries. The patent with application number CN202510937319.5 discloses a preparation method for lithium metal batteries based on two-dimensional inorganic filler polymer electrolytes. By preparing a polymer electrolyte based on two-dimensional inorganic fillers, the problems of low ionic conductivity and insufficient mechanical strength of the polymer electrolyte are solved, and a high-safety, high-performance lithium metal battery is achieved. However, there are still the following problems: 1. Two-dimensional inorganic fillers (nanometer molybdenum disulfide, graphene, Ti3C2T x x, etc.) are high-end nanomaterials with high purchase cost and poor industrial adaptability; 2. The use of two-dimensional fillers to improve ion conduction relies only on interlayer confinement transmission to improve conduction, without solving the problem of ion disorder migration, thus the upper limit of ion conduction performance is low; 3. Solution casting method is used to prepare electrolyte: two-dimensional fillers, polymers, and lithium salts need to be dissolved in toxic solvents such as N-methyl pyrrolidone (NMP) and N,N-dimethylformamide (DMF), and the solvent needs to be evaporated at 60-80°C. Therefore, not only does the solvent volatilization easily cause environmental pollution (additional waste gas treatment is required), but also the electrolyte purity is easily reduced due to residual solvent.

[0004] In summary, in the current field of polymer electrolytes for all-solid-state metal batteries, there is an urgent need to develop a polymer electrolyte based on oxygen vacancy-containing vanadium-based fillers with low raw material cost, simple and environmentally friendly preparation process, and controllable performance, which simultaneously solves the core problems of "low room temperature ionic conductivity and low cation transfer number", especially to adapt to the transmission characteristics of sodium ion batteries, to provide a feasible technical path for the industrialization of high-energy density and high-safety all-solid-state sodium metal batteries. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a polymer electrolyte containing oxygen vacancy vanadium-based fillers and its preparation method and application. The preparation method provided by the present application has low raw material cost, strong industrial adaptability, environmentally friendly and efficient process, and can realize continuous production. The polymer electrolyte has a wide voltage window, adapts to high-voltage cathodes, has high ion conduction efficiency, adapts to room temperature applications, effectively reduces the concentration polarization in the ion transmission process, and improves the battery charge and discharge efficiency. The solid-state sodium metal battery has high power potential, adapts to high-current discharge, has long cycle stability, and significantly prolongs the service life.

[0006] The technical scheme of the present application discloses a preparation method of a polymer electrolyte containing oxygen vacancy vanadium-based fillers, which comprises the following steps:

[0007] (1) Prepare a deep eutectic solution: uniformly mix succinonitrile (SN) and sodium salt according to a mass ratio of 2-2.5:1 to obtain a clear and transparent deep eutectic solution; the deep eutectic structure can significantly improve the dissociation efficiency of the sodium salt, laying a foundation for subsequent ion conduction.

[0008] (2) Mixing: uniformly mix the deep eutectic solution in step (1) with ethoxylated trimethylolpropane triacrylate (ETPTA) and fluoroethylene carbonate (FEC) according to a mass ratio of 1:0.3-0.5:0.05-0.1 to obtain a mixed solution; wherein ETPTA is a photocurable polymer monomer that can form a three-dimensional network structure to ensure the mechanical strength of the electrolyte; FEC is a plasticizer that can reduce the crystallinity of the polymer and accelerate the transmission of Na⁺.

[0009] (3) Prepare a precursor solution: uniformly mix the mixed solution in step (2) with vanadium-based inorganic fillers according to a mass ratio of 1:0.05-0.1 to form a precursor solution; wherein the oxygen vacancies in the vanadium-based inorganic fillers can anchor the anions generated by the dissociation of sodium salt, promote the directional transmission of Na⁺. + Directional transmission.

[0010] (4) Preparation of polymer electrolyte membrane: The precursor solution and initiator in step (3) are mixed evenly at a mass ratio of 1:0.005-0.01, and then dropped onto the glass fiber membrane to completely wet the glass fiber membrane. Then, the membrane is irradiated with an ultraviolet lamp for 10-30 min to induce photopolymerization of ETPTA and obtain the polymer electrolyte membrane.

[0011] Furthermore, the sodium salt in step (1) is sodium bis(trifluoromethanesulfonyl)imide.

[0012] Furthermore, the preparation method of the vanadium-based inorganic filler in step (3) includes the following steps: placing vanadium pentoxide powder in a reducing gas and calcining it at a temperature of 350-400℃ for 1-2 hours to obtain vanadium-based inorganic filler containing oxygen vacancies.

[0013] The specific reaction formula is as follows:

[0014]

[0015] In the hydrogen-argon mixture, argon isolates the V2O5 from air to prevent re-oxidation; the temperature of 350~400℃ provides kinetic energy for hydrogen (H2), causing it to adsorb onto the surface / defect sites of V2O5, and then dissociate into reducing hydrogen protons (H). + Vanadium pentoxide provides active species for the reduction reaction with free electrons (e⁻). Vanadium in vanadium pentoxide is reduced from a high valence state to a low valence state, resulting in a decrease in the positive charge of vanadium and a partial charge imbalance (positive charge deficiency) in the crystal lattice. To maintain electroneutrality, the negative charge needs to be eliminated through oxygen atom desorption; that is, the charge imbalance drives the oxygen ions (O⁻) in the crystal lattice to dissipate. 2- ) and H + The reaction produces water molecules (H2O), which desorb in a gaseous state; O 2- The detached lattice sites form oxygen vacancies, which are mainly distributed on the surface / near surface of V2O5, in the form of single vacancies / double vacancies (non-aggregated state); at 350~400℃, which is below the melting point of V2O5 (690℃), only the surface / near surface is reduced, and the main [VO5] structure is not destroyed, providing support for oxygen vacancies.

[0016] Furthermore, the reducing gas is a hydrogen-argon mixture, wherein hydrogen accounts for 3-5% of the mass of the hydrogen-argon mixture.

[0017] Furthermore, the initiator in step (4) is 2-hydroxy-2-methylacetone.

[0018] Furthermore, steps (1)-(4) are carried out under an argon protective atmosphere.

[0019] On the other hand, a polymer electrolyte containing oxygen-vacancy vanadium-based filler is disclosed, which is prepared into a polymer electrolyte membrane using the above-mentioned preparation method.

[0020] Further, the thickness of the polymer electrolyte film is 800-980 mu m, which balances ion conduction efficiency and mechanical support performance.

[0021] In another aspect, the application discloses application of the polymer electrolyte containing oxygen vacancy vanadium-based fillers in a solid-state sodium metal battery.

[0022] Advantages of the application:

[0023] 1. The application discloses a preparation method of a polymer electrolyte containing oxygen vacancy vanadium-based fillers, wherein the fillers are conventional vanadium pentoxide subjected to reduction treatment, and the fillers are not high-end nanomaterials (such as graphene, Ti3C2T x ), and the purchase cost is significantly reduced; other raw materials (succinonitrile, fluoroethylene carbonate, ethoxylated trimethylolpropane triacrylate) are common chemicals in the battery field, which are easy to obtain and stable in price, thereby avoiding dependence on scarce or high-priced raw materials, and the raw material cost is low, and the industrialization adaptability is strong.

[0024] 2. The application discloses a preparation method of a polymer electrolyte containing oxygen vacancy vanadium-based fillers, and the process is environmentally friendly and efficient, that is, no toxic organic solvents such as NMP and DMF are needed in the whole process, environmental pollution caused by solvent volatilization (no additional waste gas treatment is needed) is avoided, and the problem of electrolyte purity reduction caused by solvent residue is eliminated; and by adjusting the calcination temperature (350-400 DEG C) and time (1-2 h) of V2O5, the oxygen vacancy concentration can be accurately controlled, and the problems of structure collapse due to too many vacancies and insufficient performance due to too few vacancies can be avoided; the polymer curing is performed by ultraviolet light irradiation for 10-30 min, and the photo-curing efficiency is much higher than that of traditional thermal curing, and continuous production can be realized.

[0025] 3. The application discloses a polymer electrolyte containing oxygen vacancy vanadium-based fillers, which has a wide voltage window and is suitable for high-voltage positive electrodes, that is, the voltage window is widened to 5.5 V at most, which is much higher than that of electrolyte without fillers, and can match high-voltage materials such as sodium vanadium phosphate and nickel-based sodium-rich positive electrodes, thereby significantly widening the selection range of battery positive electrode materials and laying a foundation for high-energy-density batteries; the polymer electrolyte has high ion conduction efficiency and is suitable for room-temperature applications, that is, the room-temperature ion conductivity reaches 2.98 mS / cm and 3.13 mS / cm, which is much higher than that of electrolyte without fillers, and the sodium ion transfer number reaches 0.322, thereby effectively reducing the concentration polarization in the ion transfer process and improving the battery charge and discharge efficiency. +

[0026] 4. The application discloses application of the polymer electrolyte containing oxygen vacancy vanadium-based fillers in a solid-state sodium metal battery, and the solid-state sodium metal battery has high power potential and is suitable for high-current discharge, that is, the critical current density of the application reaches 2.6 mA / cm 2 ​, is 2 times of the no-filler solid-state sodium metal battery, can withstand higher charge and discharge current, meets the high power demand of wearable devices, portable energy storage and other scenes; long cycle stability, life is significantly prolonged, that is, after 200 cycles at 0.5C rate, the capacity retention rate of the battery of the application is up to 98% or more, and the polarization voltage is stable; while the no-filler solid-state sodium metal battery starts to significantly decay after 100 cycles, and the retention rate is less than 80% after 200 cycles. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0028] Figure 1 X-ray diffraction pattern of the vanadium-based inorganic filler in the present application embodiment 1.

[0029] Figure 2 X-ray diffraction pattern of the polymer electrolyte membrane in the present application embodiment 1.

[0030] Figure 3 Voltage window comparison chart of the solid-state sodium metal battery of the present application embodiments 4-7 and comparative example 1.

[0031] Figure 4 Electrochemical impedance spectrogram of the solid-state sodium metal battery of the present application embodiments 4-7 and comparative example 1.

[0032] Figure 5 Chronoamperometry curve (I-t) and impedance chart before and after polarization of the solid-state sodium metal battery of comparative example 1.

[0033] Figure 6 Chronoamperometry curve (I-t) and impedance chart before and after polarization of the solid-state sodium metal battery of the present application embodiment 4.

[0034] Figure 7 Critical current density comparison curve chart of the solid-state sodium metal battery of the present application embodiment 4 and comparative example 1.

[0035] Figure 8 Voltage-time curve chart of the solid-state sodium metal battery of the present application embodiment 4 and comparative example 1 at 0.1 mA / cm 2 Current density.

[0036] Figure 9 Long cycle capacity comparison chart of the solid-state sodium metal battery of the present application embodiment 4 and comparative example 1 at 0.5C rate. Detailed Implementation

[0037] The present invention will be further described in detail below through embodiments.

[0038] Example 1:

[0039] 1. Preparation of vanadium-based inorganic fillers containing oxygen vacancies

[0040] Vanadium pentoxide powder was placed in a hydrogen-argon mixture atmosphere with a hydrogen mass ratio of 5%, heated to 350℃, and calcined for 2 hours. After natural cooling, vanadium-based inorganic filler containing oxygen vacancies was obtained. X-ray diffraction (XRD) analysis was performed (see...). Figure 1 The characteristic peaks of this filler are slightly shifted compared to pure V2O5, indicating lattice expansion and proving the introduction of oxygen vacancies.

[0041] 2. Preparation of polymer electrolyte membrane

[0042] (1) In an argon glove box (ambient temperature 25℃), 1.0g of succinate and 0.4g of sodium bis(trifluoromethanesulfonyl)imide were mixed and stirred at room temperature for 30 minutes to form a clear and transparent deep eutectic solution.

[0043] (2) Add 0.3g of ethoxylated trimethylolpropane triacrylate and 0.05g of fluoroethylene carbonate to the above deep eutectic solution, stir at room temperature for 2.5 hours to obtain a homogeneous mixture;

[0044] (3) Add 0.1g of the vanadium-based inorganic filler prepared above to the mixture and stir at room temperature for 1 hour to form a uniformly dispersed precursor solution;

[0045] (4) Add 0.01 g of 2-hydroxy-2-methylphenylacetone to the precursor solution, stir for 10 minutes to mix evenly, then drop it onto the glass fiber membrane, ensuring the membrane is completely wetted; irradiate with a 365 nm UV lamp for 20 minutes to obtain a polymer electrolyte membrane (approximately 950 μm thick); analyze by XRD (see... Figure 2 The characteristic diffraction peaks of V2O5 can be clearly observed in the XRD pattern of the composite electrolyte, indicating that V2O5 was successfully retained and introduced into the polymer matrix during the composite process. The reduced intensity of the polymer characteristic peaks in the membrane proves that the filler effectively reduced the crystallinity of the polymer.

[0046] Example 2: The overall method is the same as that of Example 1, except that in the preparation of the polymer electrolyte film, the addition amount of each component is succinonitrile: 1.0 g, sodium bis(trifluoromethanesulfonyl)imide: 0.5 g, ethoxylated trimethylolpropane triacrylate: 0.5 g, fluoroethylene carbonate: 0.1 g, vanadium-based inorganic filler: 0.05 g, 2-hydroxy-2-methylpropiophenone: 0.005 g; a polymer electrolyte film (thickness about 830 microns) is obtained.

[0047] Example 3: The overall method is the same as that of Example 1, except that in the preparation of the polymer electrolyte film, the addition amount of each component is succinonitrile: 1.0 g, sodium bis(trifluoromethanesulfonyl)imide: 0.45 g, ethoxylated trimethylolpropane triacrylate: 0.4 g, fluoroethylene carbonate: 0.07 g, vanadium-based inorganic filler: 0.07 g, 2-hydroxy-2-methylpropiophenone: 0.007 g; a polymer electrolyte film (thickness about 970 microns) is obtained.

[0048] Example 4: A solid-state sodium metal battery is prepared using the polymer electrolyte film prepared in Example 1, specifically comprising the following steps:

[0049] (1) Positive electrode preparation: sodium vanadium phosphate, acetylene black, and polyvinylidene fluoride are mixed and ground in a mass ratio of 7:2:1, and are dispersed in N-methylpyrrolidone to form a film solution; the film solution is coated on an aluminum foil (coating thickness about 100 microns), and is vacuum dried at 120°C for 12 hours to obtain a sodium vanadium phosphate positive electrode (diameter 14 mm);

[0050] (2) Battery assembly: in an argon glove box, a metal sodium negative electrode (diameter 14 mm, thickness 0.5 mm), the polymer electrolyte film prepared in Example 1, and the sodium vanadium phosphate positive electrode are sequentially stacked, and are placed in a CR2032 type battery shell, which is then sealed with a battery sealing machine to obtain a solid-state sodium metal battery.

[0051] Example 5: The overall method is the same as that of Example 4, except that in the preparation of the vanadium-based inorganic filler with oxygen vacancies as a raw material, the calcination is carried out at a temperature of 350°C for 1 hour.

[0052] Example 6: The overall method is the same as that of Example 4, except that in the preparation of the vanadium-based inorganic filler with oxygen vacancies as a raw material, the calcination is carried out at a temperature of 400°C for 1 hour.

[0053] Example 7: The overall method is the same as that of Example 4, except that in the preparation of the vanadium-based inorganic filler with oxygen vacancies as a raw material, the calcination is carried out at a temperature of 400°C for 2 hours.

[0054] Comparative Example 1: The overall method is the same as that of Example 4, except that no vanadium-based inorganic filler is added in the process of preparing the polymer electrolyte film.

[0055] Performance test and result analysis:

[0056] The solid-state sodium metal batteries of Examples 4-7 and Comparative Example 1 were subjected to performance tests, and the results are as follows:

[0057] 1. Electrochemical window test

[0058] The solid-state sodium metal batteries of Examples 4-7 and Comparative Example 1 were tested by linear sweep voltammetry (LSV), and the results of the tested voltage window are shown in Figure 3 and Table 1:

[0059] Table 1 Voltage window of different electrolytes

[0060]

[0061] As can be seen from Figure 3 and Table 1, the voltage window of the electrolyte prepared in Examples 4-7 is significantly widened to above 5.0 V, while the voltage window of the electrolyte prepared in Comparative Example 1 without vanadium-based inorganic filler is only 4.7 V, wherein the voltage window of the electrolyte prepared in Example 4 is significantly widened to 5.5 V, which can match high-voltage positive electrode materials, proving that the vanadium-based inorganic filler containing oxygen vacancies can effectively improve the oxidation stability of the electrolyte.

[0062] 2. Room temperature ionic conductivity test

[0063] The bulk impedance R of the solid-state sodium metal batteries of Examples 4-7 and Comparative Example 1 was tested by electrochemical impedance spectroscopy (EIS), and the ionic conductivity (σ) was calculated according to the formula σ = L / (R×S) (σ is the ionic conductivity, L is the film thickness, and S is the steel sheet area), and the results of the tested and calculated ionic conductivity are shown in Figure 4 and Table 2:

[0064] Table 2 Room temperature ionic conductivity of different electrolytes

[0065]

[0066] As can be seen from Figure 4 and Table 2, the room temperature ionic conductivities of the electrolytes prepared in Examples 4-7 are all higher than that of Comparative Example 1; wherein the room temperature ionic conductivities of Examples 4 and 5 are 2.98 mS / cm and 3.13 mS / cm, which are much higher than that of Comparative Example 1 (1.58 mS / cm), proving that the vanadium-based inorganic filler in the present application can effectively accelerate the Na + transport.

[0067] 3. Sodium ion transfer number test

[0068] The sodium ion transfer numbers of the solid sodium metal batteries in Example 4 and Comparative Example 1 were tested using the chronoamperometry (CA) method. The results of the sodium ion transfer numbers are shown in [the table below]. Figure 5 , 6 :

[0069] from Figure 5 As can be seen, the sodium ion transfer number in the solid-state sodium metal battery of Comparative Example 1 is 0.288; from Figure 6 As can be seen, the sodium ion transfer number in the solid sodium metal battery of Example 4 is 0.322; the results show that the oxygen vacancies of the vanadium-based inorganic filler can anchor TFSI⁻ anions, reduce anion migration, thereby increasing the sodium ion transfer number and reducing concentration polarization.

[0070] 4. Critical Current Density Test

[0071] The critical current density of the solid sodium metal battery in Example 4 and Comparative Example 1 was tested by gradually increasing the current density. The results of the critical current density test are shown in Figure 7.

[0072] In Example 4, the critical current density of the solid sodium metal battery was 2.6 mA / cm². 2 The critical current density of the solid sodium metal battery in Comparative Example 1 is approximately 1.3 mA / cm². 2 The results show that the electrolyte of the solid sodium metal battery in Example 4 can withstand higher current density and has better high-power discharge potential.

[0073] 5. Long-cycle stability test

[0074] The cycle performance of the solid sodium metal batteries of Example 4 and Comparative Example 1 was tested at a 0.5C rate, and the results are shown in [Figure Number]. Figure 8 , 9 :

[0075] The solid sodium metal battery in Example 4 maintained a capacity retention of over 98% after 200 cycles, and its polarization voltage remained stable. In contrast, the solid sodium metal battery in Comparative Example 1 began to show significant capacity decay after 100 cycles, and its capacity retention was less than 80% after 200 cycles. The results indicate that vanadium-based inorganic fillers can stabilize the electrode-electrolyte interface and inhibit sodium dendrite growth, thereby improving the long-cycle stability of the battery.

[0076] The above are preferred embodiments of the present invention. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing an oxygen-vacancy-containing vanadium-based filler-containing polymer electrolyte, characterized by, It comprises the following steps: (1) preparing a deep eutectic solution: uniformly mixing succinonitrile and sodium salt according to a mass ratio of 2-2.5:1 to obtain a clear and transparent deep eutectic solution; (2) mixing: uniformly mixing the deep eutectic solution in step (1) with ethoxylated trimethylolpropane triacrylate and fluoroethylene carbonate according to a mass ratio of 1:0.3-0.5:0.05-0.1 to obtain a mixed solution; (3) preparing a precursor solution: uniformly mixing the mixed solution in step (2) with a vanadium-based inorganic filler according to a mass ratio of 1:0.05-0.1 to form a precursor solution; wherein the preparation method of the vanadium-based inorganic filler comprises the following steps: placing vanadium pentoxide powder in a reducing gas, calcining at a temperature of 350-400℃ for 1-2h to obtain a vanadium-based inorganic filler containing oxygen vacancies; (4) preparing a polymer electrolyte membrane: uniformly mixing the precursor solution in step (3) with an initiator according to a mass ratio of 1:0.005-0.01, then dropping onto a glass fiber separator, making the glass fiber separator completely wet, then irradiating with an ultraviolet lamp for 10-30 min to obtain a polymer electrolyte membrane.

2. The method for preparing a polymer electrolyte with oxygen-vacancy vanadium-based filler according to claim 1, characterized in that, The sodium salt in step (1) is sodium bistrifluoromethanesulfonimide.

3. The method for preparing a polymer electrolyte with oxygen-vacancy vanadium-based filler according to claim 1, characterized in that, The reducing gas in step (3) is hydrogen-argon mixed gas, wherein the hydrogen gas is 3-5% of the mass of the hydrogen-argon mixed gas.

4. The method for preparing a polymer electrolyte with oxygen-vacancy vanadium-based filler according to claim 1, characterized in that, The initiator in step (4) is 2-hydroxy-2-methylpropiophenone.

5. The method of claim 1, wherein the method is characterized by: Steps (1)-(4) are carried out under an argon protective atmosphere.

6. A polymer electrolyte containing an oxygen-vacancy vanadium-based filler, characterized in that, It adopts the preparation method of any one of claims 1-5 to prepare a polymer electrolyte membrane.

7. The polymer electrolyte containing oxygen-vacancy vanadium-based filler according to claim 6, characterized in that, The thickness of the polymer electrolyte membrane is 800-980μm.

8. Application of the polymer electrolyte containing oxygen vacancy vanadium-based filler of claim 7 in a solid-state sodium metal battery.

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