N-doped β”-AlON solid electrolyte powder and its preparation method

Abstract

This invention discloses a method for preparing N-doped β"-AlON solid electrolyte powder, which includes the following steps: (1) Slurry preparation: weigh anhydrous ethanol and dispersant, add the dispersant to anhydrous ethanol and stir evenly to obtain a mixed solution, then weigh aluminum source powder, lithium source powder, sodium source powder and nitrogen source powder to obtain a mixed powder, add the mixed powder to the mixed solution and stir thoroughly until the mixture is evenly mixed to obtain a mixed slurry; (2) Grinding to prepare precursor slurry: grind the mixed slurry thoroughly to obtain a precursor slurry; (3) Spray drying: spray dry the wet-ground precursor slurry to obtain spray-dried powder; (4) Calcination: calcine the spray-dried powder in a nitrogen atmosphere, and keep warm after calcination to obtain N-doped β"-AlON powder.

Description

Technical Field

[0001] This invention relates to the field of sodium salt battery technology, specifically to N-doped β”-AlON solid electrolyte powder and its preparation method. Background Technology

[0002] Sodium salt batteries are a type of high-temperature sodium battery. They are characterized by stable product properties, high safety, long service life, wide range of applications, readily available and non-toxic raw materials, and simple and pollution-free waste recycling process. After integration by GE's global R&D center, sodium salt battery technology has reached a relatively mature stage and has been applied in 25 countries around the world to build energy storage projects such as solar and wind power combinations, peak management, and communication base stations.

[0003] The electrolyte used in sodium salt batteries is β"-alumina ceramic. As the core material of sodium salt batteries, β"-alumina ceramic can provide strong support for sodium salt batteries, thereby ensuring their high performance and high safety. At the same time, due to the continuous expansion of the application fields of sodium energy storage batteries and the continuous innovation of technology, the importance of β"-alumina ceramic is becoming more and more obvious.

[0004] The electrolyte ceramics prepared from β"-alumina powder in the existing technology have the following technical problems: 1. Due to the inherent properties of β"-alumina, its resistivity is limited to 3.5-5 Ω·cm. The resistivity directly affects the battery's high-power output, continuous output capability, and charging speed; 2. The chemical bond of β"-alumina is Al-O, which has limited strength. Therefore, the strength that β"-alumina can achieve is 210-230 MPa. The strength affects the safety of the battery during later use. The electrolyte ceramic will break under thermal shock, vibration, etc., causing the entire battery to malfunction and reducing its lifespan.

[0005] Therefore, with the rapid development of the energy storage industry, higher requirements have been placed on sodium salt batteries, which need to have higher conductivity, higher structural strength and greater current carrying capacity. Therefore, it is crucial to prepare an electrolyte material with better performance. Summary of the Invention

[0006] The first objective of this invention is to provide a method for preparing N-doped β”-AlON solid electrolyte powder.

[0007] The second objective of this invention is to provide an N-doped β”-AlON solid electrolyte powder.

[0008] The first objective of this invention is achieved by the following technical solution: a method for preparing N-doped β"-AlON solid electrolyte powder, comprising the following steps:

[0009] (1) Slurry preparation: Weigh anhydrous ethanol and dispersant, add the dispersant to anhydrous ethanol and stir evenly to obtain a mixed solution, then weigh aluminum source powder, lithium source powder, sodium source powder and nitrogen source powder to obtain a mixed powder, add the mixed powder to the mixed solution and stir thoroughly until it is evenly mixed to obtain a mixed slurry. The role of adding nitrogen source is to increase the strength and conductivity of electrolyte ceramics prepared later.

[0010] (2) Grinding to prepare precursor slurry: Grind the mixed slurry thoroughly to obtain precursor slurry;

[0011] (3) Spray drying: The wet-milled precursor slurry is spray-dried to obtain spray-dried powder;

[0012] (4) Calcination: The spray-dried powder is calcined in a nitrogen atmosphere. After calcination, the temperature is maintained to obtain N-doped β"-AlON powder. Calcination improves the structural stability of the powder. The purpose of maintaining the temperature is to allow the high temperature to pass through the product and cook it, so that the sintering effect is better.

[0013] By selecting nitrogen source raw materials with fixed structure and content, nitrogen elements are inserted during the synthesis process under nitrogen protection to directionally synthesize β"-AlON powder with specific composition; in addition, by sand milling the raw materials, the original crystals of the powder reach 1-1.2μm, ensuring that the N element can be inserted uniformly and effectively to form a uniform solid solution structure.

[0014] The combination of wet milling and spray granulation results in good flowability of the granulated powder after calcination, which can be effectively filled into the sagger, solving the problems of voids and uneven accumulation of granulated powder. Selecting granulated materials within a certain particle size range for calcination ensures that the material is evenly filled into the sagger during the calcination process, with good dispersibility and uniform original crystals of powder, thereby obtaining β"-AlON with a stable crystal phase and fixed N content.

[0015] Furthermore, in step (1), the mixed powder is added to the mixed solution and stirred thoroughly, and the solid content and viscosity of the mixed slurry are controlled during the stirring process.

[0016] Furthermore, the solid content of the mixed slurry is 40%-50%, and the viscosity is 400-1500 cp.

[0017] Furthermore, in step (2), during the grinding process of the mixed slurry, it is necessary to control the solid content of the precursor slurry to be 40%-50%, the viscosity to be 400-1500cp, and the particle size D50 to be 1-1.2μm and D90 to be <3μm.

[0018] In steps (1) and (2), it is necessary to control the solid content and viscosity of the mixed slurry and the precursor slurry. Since the solid content affects the grinding effect, the solid content and viscosity are tested multiple times, and a small amount of anhydrous ethanol is added to fine-tune them to ensure the smooth progress of grinding. The purpose of testing the viscosity is to ensure the smooth progress of spray drying and reduce the energy consumption of the spray process. The lower the viscosity, the better.

[0019] Furthermore, in step (3), the particle size of the spray-dried powder is D50 > 40 μm.

[0020] Furthermore, in the calcination step, the calcination temperature is 1200-1280℃, the holding time is 2-4h, and the volume ratio of nitrogen atmosphere to air is nitrogen:air > 1:1. The nitrogen atmosphere has the function of preventing the diffusion of internal nitrogen sources and preventing oxidation.

[0021] Furthermore, the mixed powder comprises the following raw materials in parts by weight: 55-95 parts of aluminum source; 2-8 parts of lithium source; 5-20 parts of sodium source; and 1-20 parts of nitrogen source.

[0022] Furthermore, the aluminum source powder is γ-alumina or a calcined product of boehmite;

[0023] The lithium source powder is any one of lithium carbonate, lithium hydroxide monohydrate, or lithium acetate.

[0024] The sodium source powder is any one of sodium hydroxide, sodium carbonate, or sodium acetate.

[0025] The nitrogen source powder is any one of AlON, aluminum nitride, or magnesium nitride.

[0026] Furthermore, the dispersant is polyacrylamide, and the amount of the dispersant added accounts for 1%-3% of the mixed powder.

[0027] The second objective of this invention is achieved by the following technical solution: N-doped β"-AlON solid electrolyte powder prepared using the above-mentioned method for preparing N-doped β"-AlON solid electrolyte powder.

[0028] Advantages of this invention: It uses a special N-source material, inserting N atoms into the β"-alumina lattice through the introduction of N atoms, forming β"-AlON with superior performance. (See...) Figure 1In terms of the preparation process, the mixed slurry is ground to a particle size of D50 of 1-1.2 μm and D90 < 3 μm by wet milling, and then spray-dried to granulate to obtain a particle size of D50 > 40 μm. This ensures that the powder is uniformly filled into the sagger during the calcination process, thereby obtaining β"-AlON with a stable crystal phase and fixed N content. This avoids under-burning and over-burning caused by uneven filling, and ensures the stability and consistency of the product.

[0029] In this scheme, β"-AlON is formed by inserting a portion of N into β"-alumina, resulting in N with a negative trivalent oxidation state. 3- Replace part of O 2- The solid solution of β-AlON has excellent structural and functional properties. On the one hand, the Al-N bond has a higher strength than the Al-O bond, which makes the strength of β-AlON electrolyte higher than that of β-alumina, with a strength of over 280. This improves the battery's resistance to external impacts during use, enhances safety, extends battery life, and reduces usage costs.

[0030] On the other hand, N 3- O 2- The addition of an extra site for binding with Na+, where an N atom replaces an oxygen atom, increases the number of conductive sodium ions, thus increasing the sodium ion content in the electrolyte and lowering the resistivity to below 2.33. β"-AlON exhibits higher ionic conductivity, exceeding 0.429, which is beneficial for improving the battery's high-power output and continuous output capabilities, while also resulting in faster charging speeds. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 The process flow diagram for preparing N-doped β"-AlON solid electrolyte powder according to the present invention is shown below;

[0033] Figure 2 The XRD diffraction patterns are those of Example 3 and Comparative Example 4 of this invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1:

[0036] (1) Slurry preparation: Weigh 100g of anhydrous ethanol and 1g of dispersant and add them to a mixing tank. Stir for 10 minutes to obtain a mixed solution.

[0037] Weigh out 83.8g of γ-alumina, 2.3g of lithium carbonate, 10.6g of sodium hydroxide, and 3.2g of aluminum nitride to prepare a mixed powder. Add the mixed powder to the mixed solution in the mixing tank while stirring. After the addition is complete, stir for 30 minutes until the mixture is uniform and a mixed slurry is obtained. During the mixing process, a small amount of anhydrous alcohol can be added to make the viscosity of the mixed slurry 663cp.

[0038] (2) Grinding to prepare precursor slurry: Turn on the sand mill and grind the mixed slurry thoroughly to obtain precursor slurry. The precursor slurry is ground until the particle size D50 reaches 1.05μm. During the grinding process, a small amount of anhydrous alcohol can be added to make the viscosity of the precursor slurry 1265cp.

[0039] (3) Spray drying: The wet-milled precursor slurry is transferred to a spray drying tower for spray drying to obtain spray-dried powder with a particle size D50 of 47 μm, and anhydrous ethanol is recovered.

[0040] (4) Calcination: The spray-dried powder is filled into a sagger, covered and transferred to a pusher kiln. It is calcined at 1250°C under a nitrogen atmosphere. After calcination, it is kept at the temperature for 3 hours. After calcination, it is cooled, poured out of the sagger and sealed for storage to obtain N-doped β"-AlON powder.

[0041] Example 2:

[0042] (1) Slurry preparation: Weigh 100g of anhydrous ethanol and 1g of dispersant and add them to a mixing tank. Stir for 10 minutes to obtain a mixed solution.

[0043] Weigh out 67.5g of γ-alumina powder, 2.3g of lithium carbonate, 10.9g of sodium hydroxide, and 19.3g of aluminum oxynitride to prepare a mixed powder. Add the mixed powder to the mixed solution in the mixing tank while stirring. After adding, stir for 30 minutes until the mixture is uniform and a mixed slurry is obtained. During the mixing process, a small amount of anhydrous alcohol can be added to make the viscosity of the mixed slurry 617cp.

[0044] (2) Grinding to prepare precursor slurry: Turn on the sand mill and grind the mixed slurry thoroughly to obtain precursor slurry. The precursor slurry is ground until the particle size D50 reaches 1.12μm. During the grinding process, a small amount of anhydrous alcohol can be added to make the viscosity of the precursor slurry 1240cp.

[0045] (3) Spray drying: The wet-milled precursor slurry is transferred to a spray drying tower for spray drying to obtain spray-dried powder with a particle size D50 of 53 μm, and anhydrous ethanol is recovered.

[0046] (4) Calcination: The spray-dried powder is filled into a sagger, covered and transferred to a pusher kiln. It is calcined at 1280℃ under a nitrogen atmosphere. After calcination, it is kept at the temperature for 4 hours. After calcination, it is cooled, poured out of the sagger and sealed for storage to obtain N-doped β"-AlON powder.

[0047] Example 3:

[0048] (1) Slurry preparation: Weigh 100g of anhydrous ethanol and 1g of dispersant and add them to a mixing tank. Stir for 10 minutes to obtain a mixed solution.

[0049] Weigh out 82g of γ-alumina, 2.3g of lithium carbonate, 11.5g of sodium hydroxide and 4.1g of aluminum nitride to prepare a mixed powder. Add the mixed powder to the mixed solution in the mixing tank while stirring. After the addition is complete, stir for 30 minutes until the mixture is uniform and a mixed slurry is obtained. During the mixing process, a small amount of anhydrous alcohol can be added to make the viscosity of the mixed slurry 632cp.

[0050] (2) Grinding to prepare precursor slurry: Turn on the sand mill and grind the mixed slurry thoroughly to obtain precursor slurry. The precursor slurry is ground until the particle size D50 reaches 1.11μm. During the grinding process, a small amount of anhydrous alcohol can be added to make the viscosity of the precursor slurry 1202cp.

[0051] (3) Spray drying: The wet-milled precursor slurry is transferred to a spray drying tower for spray drying to obtain spray-dried powder with a particle size D50 of 58 μm, and anhydrous ethanol is recovered.

[0052] (4) Calcination: The spray-dried powder is filled into a sagger, covered and transferred to a pusher kiln. It is calcined at 1230°C under a nitrogen atmosphere. After calcination, it is kept at the temperature for 2 hours. After calcination, it is cooled, poured out of the sagger and sealed for storage to obtain N-doped β"-AlON powder.

[0053] Example 4:

[0054] (1) Slurry preparation: Weigh 100g of anhydrous ethanol and 1g of dispersant and add them to a mixing tank. Stir for 10 minutes to obtain a mixed solution.

[0055] Weigh out 82.7g of γ-alumina, 3.7g of lithium acetate, 10.4g of sodium hydroxide, and 3.3g of aluminum nitride to prepare a mixed powder. Add the mixed powder to the mixed solution in the mixing tank while stirring. After the addition is complete, stir for 30 minutes until the mixture is uniform and a mixed slurry is obtained. During the mixing process, a small amount of anhydrous alcohol can be added to make the viscosity of the mixed slurry 653cp.

[0056] (2) Grinding to prepare precursor slurry: Turn on the sand mill and grind the mixed slurry thoroughly to obtain precursor slurry. The precursor slurry is ground until the particle size D50 reaches 1.03μm. During the grinding process, a small amount of anhydrous alcohol can be added to make the viscosity of the precursor slurry 1299cp.

[0057] (3) Spray drying: The wet-milled precursor slurry is transferred to a spray drying tower for spray drying to obtain spray-dried powder with a particle size D50 of 61 μm, and anhydrous ethanol is recovered.

[0058] (4) Calcination: The spray-dried powder is filled into a sagger, covered and transferred to a pusher kiln. It is calcined at 1280℃ under a nitrogen atmosphere. After calcination, it is kept at the temperature for 4 hours. After calcination, it is cooled, poured out of the sagger and sealed for storage to obtain N-doped β"-AlON powder.

[0059] Comparative Example 1:

[0060] The difference from Example 3 is that there is no nitrogen source, but the composition of the raw materials remains unchanged;

[0061] (1) Slurry preparation: Weigh 100g of anhydrous ethanol and 1g of dispersant and add them to a mixing tank. Stir for 10 minutes to obtain a mixed solution.

[0062] Weigh out 82g of γ-alumina, 2.3g of lithium carbonate and 11.5g of sodium hydroxide to prepare a mixed powder. Add the mixed powder to the mixed solution in the mixing tank while stirring. After adding, stir for 30 minutes until the mixture is uniform and a mixed slurry is obtained. During the mixing process, a small amount of anhydrous alcohol can be added to make the viscosity of the mixed slurry 547cp.

[0063] (2) Grinding to prepare precursor slurry: Turn on the sand mill and grind the mixed slurry thoroughly to obtain precursor slurry. The precursor slurry is ground until the particle size D50 reaches 1.11μm. During the grinding process, a small amount of anhydrous alcohol can be added to make the viscosity of the precursor slurry 1338cp.

[0064] (3) Spray drying: The wet-milled precursor slurry is transferred to a spray drying tower for spray drying to obtain spray-dried powder with a particle size D50 of 58 μm, and anhydrous ethanol is recovered.

[0065] (4) Calcination: The spray-dried powder is filled into a sagger, covered and transferred to a pusher kiln. It is calcined at 1230°C under a nitrogen atmosphere. After calcination, it is kept at the temperature for 2 hours. After calcination, it is cooled, poured out of the sagger and sealed for storage to obtain N-doped β"-AlON powder.

[0066] Comparative Example 2:

[0067] The difference from Example 3 is that argon is used as the protective atmosphere;

[0068] (1) Slurry preparation: Weigh 100g of anhydrous ethanol and 1g of dispersant and add them to a mixing tank. Stir for 10 minutes to obtain a mixed solution.

[0069] Weigh out 82g of γ-alumina, 2.3g of lithium carbonate, 11.5g of sodium hydroxide and 4.1g of aluminum nitride to prepare a mixed powder. Add the mixed powder to the mixed solution in the mixing tank while stirring. After the addition is complete, stir for 30 minutes until the mixture is uniform and a mixed slurry is obtained. During the mixing process, a small amount of anhydrous alcohol can be added to make the viscosity of the mixed slurry 611cp.

[0070] (2) Grinding to prepare precursor slurry: Turn on the sand mill and grind the mixed slurry thoroughly to obtain precursor slurry. The precursor slurry is ground until the particle size D50 reaches 1.11μm. During the grinding process, a small amount of anhydrous alcohol can be added to make the viscosity of the precursor slurry 1307cp.

[0071] (3) Spray drying: The wet-milled precursor slurry is transferred to a spray drying tower for spray drying to obtain spray-dried powder with a particle size D50 of 58 μm, and anhydrous ethanol is recovered.

[0072] (4) Calcination: The spray-dried powder is filled into a sagger, covered and transferred to a pusher kiln. It is calcined at 1230°C under an argon atmosphere. After calcination, it is kept at the temperature for 2 hours. After calcination, it is cooled, poured out of the sagger and sealed for storage to obtain the powder.

[0073] Comparative Example 3:

[0074] The difference from Example 3 is that the nitrogen source used is not AlON, but aluminum nitride or magnesium nitride;

[0075] (1) Slurry preparation: Weigh 100g of anhydrous ethanol and 1g of dispersant and add them to a mixing tank. Stir for 10 minutes to obtain a mixed solution.

[0076] Weigh out 82g of γ-alumina, 2.3g of lithium carbonate, 11.5g of sodium hydroxide and 3.5g of silicon nitride to prepare a mixed powder. Add the mixed powder to the mixed solution in the mixing tank while stirring. After the addition is complete, stir for 30 minutes until the mixture is uniform and a mixed slurry is obtained. During the mixing process, a small amount of anhydrous alcohol can be added to make the viscosity of the mixed slurry 679cp.

[0077] (2) Grinding to prepare precursor slurry: Turn on the sand mill and grind the mixed slurry thoroughly to obtain precursor slurry. The precursor slurry is ground until the particle size D50 reaches 1.11μm. During the grinding process, a small amount of anhydrous alcohol can be added to make the viscosity of the precursor slurry 1391cp.

[0078] (3) Spray drying: The wet-milled precursor slurry is transferred to a spray drying tower for spray drying to obtain spray-dried powder with a particle size D50 of 58 μm, and anhydrous ethanol is recovered.

[0079] (4) Calcination: The spray-dried powder is filled into a sagger, covered and transferred to a pusher kiln. It is calcined at 1230°C under a nitrogen atmosphere. After calcination, it is kept at the temperature for 2 hours. After calcination, it is cooled, poured out of the sagger and sealed for storage to obtain N-doped β"-AlON powder.

[0080] Comparative Example 4:

[0081] Use existing methods for preparing β”-alumina powder;

[0082] (1) Sodium precursor powder preparation steps: Weigh Na2CO3 and α-Al2O3, mix them at a Na2O / Al2O3 mass ratio of 1:6, and add the weighed Na2CO3 and α-Al2O3 to deionized water for ball milling and mixing. During ball milling and mixing, add polymethyl methacrylate as a dispersant to obtain sodium precursor powder slurry. The mass ratio of the total mass of Na2CO3 and α-Al2O3 to the mass of deionized water is 1:1, and the mass ratio of polymethyl methacrylate to the total mass of Na2CO3 and α-Al2O3 is 0.001.

[0083] (2) Preparation steps of lithium precursor powder: Weigh Li2CO3 and α-Al2O3, mix them at a mass ratio of Li2O / Al2O3 of 1:4, and add the weighed Li2CO3 and α-Al2O3 to deionized water for ball milling and mixing. During ball milling and mixing, add polymethyl methacrylate as a dispersant to obtain lithium precursor powder slurry. The mass ratio of the total mass of Li2CO3 and α-Al2O3 to the mass of deionized water is 1:1, and the mass ratio of polymethyl methacrylate to the total mass of Li2CO3 and α-Al2O3 is 0.001.

[0084] (3) In the sodium precursor powder preparation step and the lithium precursor powder preparation step, a water-soluble polyacrylic acid type polyelectrolyte such as polymethacrylic acid is added;

[0085] (4) Preparation steps of β”-alumina powder: Sodium precursor powder and lithium precursor powder are added to anhydrous acetone at a mass ratio of 9:1, ball-milled and dried to obtain β”-alumina powder. β”-alumina powder is composed of 15wt.% Na2O, 2wt.% Li2O and 83wt.% Al2O3.

[0086] X-ray diffraction analysis was performed on the nitrogen-doped β"-AlON powder prepared in Example 3 and the β"-alumina powder prepared in Comparative Example 4. Figure 2 As shown in the figure, the diffraction patterns of the samples show that the first diffraction peak of β"-AlON at 8°-9° and the second diffraction peak at 15°-16° are right-biased. According to the diffraction data, these two peaks correspond to the (003) and (006) crystal planes. Under N doping, the C-axis of the β"-alumina lattice is elongated, and the diffraction angle of the corresponding crystal plane becomes larger and then right-biased, proving that N is effectively inserted into β"-alumina and causes changes in the lattice parameters.

[0087] Experimental subjects:

[0088] Experimental Example 1: Electrolyte ceramics prepared using the powder formulation of Example 1;

[0089] Experimental Example 2: Electrolyte ceramics prepared using the powder formulation of Example 2;

[0090] Experimental Example 3: Electrolyte ceramic prepared using the powder formulation of Example 3;

[0091] Experimental Example 4: Electrolyte ceramics prepared using the powder formulation of Example 4;

[0092] Experimental Example 5: Electrolyte ceramic prepared using powder technology from Comparative Example 1;

[0093] Experimental Example 6: Electrolyte ceramic prepared using powder technology as described in Comparative Example 2;

[0094] Experimental Example 7: Electrolyte ceramic prepared using powder technology as described in Comparative Example 3;

[0095] Experimental Example 8: Electrolyte ceramic prepared using powder technology as described in Comparative Example 4;

[0096] Specific preparation method of electrolyte ceramics: Electrolyte ceramics are prepared using the existing pressing and sintering process. A certain mass of electrolyte powder is weighed, granulated and pressed under the same environmental conditions, and then fired in a pusher kiln to form dense electrolyte ceramics at a firing temperature of 1600℃.

[0097] Specific experimental methods:

[0098] (1) According to the test method of axial resistivity of ceramic sample, specifically, a section of sample is cut from a uniform sample, placed under an AC voltage of 15kHz, and the resistivity of the sample is tested at a temperature of 350℃. The conductivity is calculated using the resistivity.

[0099] (2) According to the test method for bending strength of fine ceramics, specifically, a section of the sample is cut from a uniform sample and the ceramic strength test is carried out in accordance with the standard GB / T 6569-2006;

[0100] Experiments 1-7 were set up in triplicate, and the results of each experiment were averaged.

[0101] Table 1: Average values ​​of conductivity and intensity for test examples 1-7.

[0102]

[0103] As can be seen from the data in Table 1, compared with the electrolyte ceramics prepared in Experimental Examples 1-4 and Control Examples 1-4, the sodium ion electrolyte prepared by β”-AlON solid electrolyte powder has a strength of over 280, a resistivity of less than 2.33, and a conductivity of over 0.429 due to the special structure of β”-AlON solid electrolyte powder, thus exhibiting excellent functional properties.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing N-doped β"-AlON solid electrolyte powder, characterized in that, It includes the following steps: (1) Slurry preparation: Weigh anhydrous ethanol and dispersant, add the dispersant to anhydrous ethanol and stir evenly to obtain a mixed solution, then weigh aluminum source powder, lithium source powder, sodium source powder and nitrogen source powder to obtain a mixed powder, add the mixed powder to the mixed solution and stir thoroughly until evenly mixed to obtain a mixed slurry; The mixed powder comprises the following raw materials in parts by weight: 55-95 parts of aluminum source; 2-8 parts of lithium source; 5-20 parts of sodium source; and 1-20 parts of nitrogen source. The nitrogen source powder is any one of AlON, aluminum nitride, or magnesium nitride. (2) Grinding to prepare precursor slurry: Grind the mixed slurry thoroughly to obtain precursor slurry; (3) Spray drying: The wet-milled precursor slurry is spray-dried to obtain spray-dried powder; (4) Calcination: The spray-dried powder is calcined in a nitrogen atmosphere and kept at a constant temperature after calcination to obtain N-doped β"-AlON powder.

2. The method for preparing N-doped β"-AlON solid electrolyte powder according to claim 1, characterized in that, In step (1), the mixed powder is added to the mixed solution and stirred thoroughly. During the stirring process, the solid content and viscosity of the mixed slurry are controlled.

3. The method for preparing N-doped β"-AlON solid electrolyte powder according to claim 2, characterized in that, The solid content of the mixed slurry is 40%-50%, and the viscosity is 400-1500 cp.

4. The method for preparing N-doped β"-AlON solid electrolyte powder according to claim 1, characterized in that, In step (2), during the grinding process of the mixed slurry, it is necessary to control the solid content of the precursor slurry to be 40%-50%, the viscosity to be 400-1500cp, and the particle size D50 to be 1-1.2μm and D90 to be <3μm.

5. The method for preparing N-doped β"-AlON solid electrolyte powder according to claim 1, characterized in that, In step (3), the particle size of the spray-dried powder is D50>40μm.

6. The method for preparing N-doped β"-AlON solid electrolyte powder according to claim 1, characterized in that, In the calcination step, the calcination temperature is 1200-1280℃, and the holding time is 2-4h.

7. The method for preparing N-doped β"-AlON solid electrolyte powder according to claim 1, characterized in that, The aluminum source powder is γ-alumina or a calcined product of boehmite. The lithium source powder is any one of lithium carbonate, lithium hydroxide monohydrate, or lithium acetate. The sodium source powder is any one of sodium hydroxide, sodium carbonate, or sodium acetate.

8. The method for preparing N-doped β"-AlON solid electrolyte powder according to claim 7, characterized in that, The dispersant is polyacrylamide, and the amount of the dispersant added accounts for 1%-3% of the mixed powder.

9. N-doped β"-AlON solid electrolyte powder prepared by the method for preparing N-doped β"-AlON solid electrolyte powder according to any one of claims 1-8.

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