Boehmite material with hollow structure as well as preparation method and application of boehmite material
Hollow-structure boehmite materials were prepared by using bacterial cellulose templates, which solved the problems of complex preparation process and high cost of boehmite, and achieved high energy density and low resistance energy storage battery performance, which has the potential for industrial application.
Patent Information
- Application Number
- CN202511322353.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-16
- Publication Date
- 2025-12-09
AI Technical Summary
Existing boehmite preparation methods suffer from problems such as strict process conditions, high cost, severe microstructure agglomeration, and difficulty in industrialization. Furthermore, the application of boehmite materials in energy storage batteries has not yet fully realized their potential for high energy density.
Using bacterial cellulose as a template for boehmite growth, a hollow boehmite material was prepared through high-temperature reaction, freeze-drying, and ball milling. Combined with steps such as alkali solution soaking, in-situ adsorption of aluminum alcohol solution, and high-temperature reaction with ammonia water, a boehmite material with high crystallinity and high specific surface area was formed.
The preparation process is simple and low-cost. The resulting boehmite material exhibits excellent energy density and low internal resistance in energy storage batteries, showing promising application prospects.
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Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of battery active materials, and particularly relates to a boehmite material with a hollow structure, its preparation method, and its application. Background Technology
[0002] Boehmite (AlOOH) is a precursor of γ-Al2O3. It has advantages such as zero point charge, high interfacial free energy, large specific surface area and good dispersibility. It is widely used in ceramic materials, composite materials, surface protective layer materials, optical materials, catalysts and support materials, semiconductor materials and coatings.
[0003] Currently, the main methods for preparing boehmite include hydrolysis, sol-gel, and hydrothermal methods. Hydrolysis involves hydrolyzing an aluminum-containing precursor in an aqueous solution to obtain boehmite, resulting in boehmite with high crystallinity. The sol-gel method involves generating a sol through hydrolysis and condensation reactions, then converting the sol into a gel state, followed by drying and heat treatment to obtain boehmite, resulting in boehmite with high purity and small particle size. The hydrothermal method utilizes high temperature and high pressure conditions to react the aluminum precursor to prepare boehmite, offering advantages such as high product purity and controllable microstructure and morphology.
[0004] However, the hydrolysis method has problems such as strict requirements for process conditions and severe agglomeration of the resulting boehmite microstructure. The sol-gel method has disadvantages such as complex preparation process, high production cost and difficulty in industrialization. The hydrothermal method has problems such as high production cost and difficulty in wastewater treatment, and has significant limitations. Summary of the Invention
[0005] The primary objective of this invention is to provide a method for preparing boehmite material. This method uses bacterial cellulose as a template for boehmite growth and involves steps such as high-temperature reaction, freeze-drying, sintering, and ball milling. It offers advantages such as simple preparation process, low production cost, and environmental friendliness, showing great promise for industrial application. Furthermore, the prepared boehmite material has a hollow structure and possesses both high crystallinity and high specific surface area. Using this boehmite material as a cathode material in energy storage batteries can effectively improve the energy density of the battery, demonstrating excellent application prospects.
[0006] A second objective of this invention is to provide a boehmite material.
[0007] A third objective of this invention is to provide the application of the aforementioned boehmite material in the preparation of energy storage batteries.
[0008] Specifically, the preparation method of boehmite material provided by the present invention includes: S1, soaking bacterial cellulose in an alkaline solution to obtain modified bacterial cellulose; S2, allowing the modified bacterial cellulose to adsorb aluminum alcohol solution in situ to obtain a first complex; S3, reacting the first complex with ammonia water at high temperature to obtain a second complex; S4, freeze-drying the second complex to obtain a freeze-dried powder; S5, sintering the freeze-dried powder and then ball-milling it to obtain the boehmite material; wherein, in step S1, the water content of the modified bacterial cellulose is not higher than 10%; in step S5, the sintering temperature is 200~400℃ and the time is 1~12h.
[0009] Further, in step S1, the OH content of the alkaline solution used in the alkaline solution soaking treatment is... - The concentration is 0.05~0.5mol / L.
[0010] Furthermore, in step S1, the soaking time in the alkaline solution is 1 to 120 hours.
[0011] Furthermore, step S1 includes repeated water washing, which includes: taking deionized water to wash the bacterial cellulose intervals that have been soaked in the alkaline solution multiple times, with the time interval between two adjacent water washing treatments being 3 to 24 hours, and the duration of repeated water washing being 1 to 7 days.
[0012] Further, in step S2, the aluminum alcohol solution comprises aluminum alkoxide, organic alcohol and water, wherein the concentration of the aluminum alkoxide is 0.1~0.5 g / mL and the volume ratio of the organic alcohol to water is 1:(1~19).
[0013] Further, in step S2, the aluminum alkoxide includes one or more of aluminum isobutoxide, aluminum isopropoxide, and aluminum sec-butoxide.
[0014] Further, in step S2, the organic alcohol includes one or more of isobutanol, isopropanol, and sec-butanol.
[0015] Further, in step S2, the amount of modified bacterial cellulose added is 1:(2~10) based on the volume of the aluminum alcohol solution.
[0016] Furthermore, in step S2, the in-situ adsorption treatment time is 12~72h.
[0017] Furthermore, in step S3, the concentration of the ammonia water is 20-30% (v / v).
[0018] Further, in step S3, the amount of ammonia added is 1~5% (v / v) based on the volume of the aluminum alcohol solution.
[0019] Furthermore, in step S3, the temperature of the high-temperature reaction is 120~300℃, and the time is 0.5~6h.
[0020] Furthermore, in step S4, the freeze-drying process is carried out at a temperature of -40℃ to -10℃ for a time of 6h to 24h.
[0021] Further, in step S5, the ball milling process includes: mixing the sintered product with composite grinding beads and ball milling at 100~200 r / min for 10~30 min to obtain the boehmite material.
[0022] Further, in step S5, the mixed grinding beads include large grinding beads, medium grinding beads and small grinding beads, the diameter ratio of the large grinding beads, medium grinding beads and small grinding beads is 1:0.5:(0.1~0.2), and the mass ratio of the large grinding beads, medium grinding beads and small grinding beads is (8~12):(78~82):10.
[0023] The boehmite material provided by this invention is prepared by the above-described method for preparing boehmite material.
[0024] This invention also provides the application of the above-mentioned boehmite material in the preparation of energy storage batteries.
[0025] Beneficial effects: In the boehmite preparation method provided by this invention, bacterial cellulose with abundant three-dimensional network structure and pores is used as a template. First, the bacterial cellulose is soaked in an alkaline solution to modify it while it absorbs water and swells. The resulting modified bacterial fibers, within a specific water content range, contain a large number of functional groups such as carboxyl and hydroxyl groups, exhibiting excellent adsorption capacity for aluminum alkoxides. Next, the modified bacterial cellulose is subjected to in-situ adsorption treatment with an aluminum alkoxide solution, allowing the aluminum alkoxide to adsorb onto the modified bacterial cellulose, yielding a first complex. Then, ammonia water is reacted with the first complex at high temperature, and the modified bacterial fibers serve as a supporting framework for the in-situ growth and crystal transformation of pseudoboehmite, yielding a second complex. Finally, the second complex is... The material is freeze-dried to effectively remove moisture while maintaining the three-dimensional structure of the second composite, resulting in freeze-dried powder. The freeze-dried powder is then sintered and ball-milled to form a hollow-structured nano-boehmite material. These steps work synergistically to form a cohesive whole, gradually creating a good three-dimensional structure through in-situ adsorption, high-temperature reaction, freeze-drying, sintering, and ball milling. The resulting boehmite material exhibits excellent particle size, specific surface area, and crystallinity, resulting in excellent energy density and ionic conductivity. Energy storage batteries prepared using this boehmite material as a cathode material demonstrate excellent energy density and low internal resistance, exhibiting superior performance and promising application prospects. Detailed Implementation
[0026] Based on a profound understanding of the problems existing in the preparation process of boehmite materials, the inventors of this invention have creatively discovered that bacterial cellulose can be used as a template for boehmite growth. Utilizing its rich three-dimensional network structure, porous structure, excellent swelling capacity, and abundant functional groups, it can achieve sufficient adsorption of aluminum alkoxides and provide an ideal structural basis for the formation of the microstructure of boehmite materials. Further research on the preparation process based on bacterial cellulose revealed that modifying bacterial cellulose by soaking in an alkaline solution can optimize its three-dimensional spatial structure while improving its adsorption capacity for aluminum alkoxides, resulting in modified bacterial cellulose. Subsequently, the modified cellulose undergoes in-situ adsorption treatment with aluminum alkoxide solution and high-temperature reaction with ammonia to achieve in-situ growth and crystal transformation of pseudo-boehmite on the modified bacterial fibers, obtaining a second composite. Finally, the second composite is subjected to freeze-drying, sintering, and ball milling. Throughout the entire preparation process, by effectively controlling the water content of the modified bacterial cellulose and the sintering conditions, boehmite materials with suitable particle size, specific surface area, and crystallinity can be prepared. Based on this, the technical solution of the present invention was obtained.
[0027] In this invention, the preparation method of the boehmite material specifically includes: S1, soaking bacterial cellulose in an alkaline solution to obtain modified bacterial cellulose; S2, allowing the modified bacterial cellulose to adsorb aluminum alcohol solution in situ to obtain a first complex; S3, reacting the first complex with ammonia at high temperature to obtain a second complex; S4, freeze-drying the second complex to obtain a freeze-dried powder; S5, sintering and then ball-milling the freeze-dried powder to obtain the boehmite material.
[0028] In this invention, the water content of the modified bacterial cellulose is specifically no higher than 10%; more preferably 2% to 6%. At this point, the modified bacterial cellulose has good swelling capacity for aluminum alcohol solutions and provides a structural basis for the formation of boehmite structures, so as to prepare boehmite materials with suitable particle size, specific surface area and crystallinity.
[0029] In this invention, in step S1, the OH content of the alkaline solution used in the alkaline solution soaking treatment is... - The preferred concentration is 0.05~0.5 mol / L, such as 0.1 mol / L, 0.13 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, or any value between them. In this case, the alkaline solution exhibits excellent modification effects on bacterial cellulose, and the resulting modified cellulose can better achieve adsorption of aluminum alkoxides.
[0030] In this invention, in step S1, the soaking time in the alkaline solution is preferably 1 to 120 hours, such as 1 hour, 12 hours, 24 hours, 60 hours, 80 hours, 100 hours, 120 hours, or any value between them. This allows for better modification of bacterial cellulose, resulting in modified cellulose with superior performance.
[0031] In this invention, step S1 preferably further includes repeated washing, which comprises: repeatedly washing the bacterial cellulose spacers that have been soaked in the alkaline solution with deionized water, wherein the time interval between two adjacent washing treatments is 3 to 24 hours, such as 3 hours, 6 hours, 12 hours, 18 hours, 24 hours, or any value between them; and the duration of the repeated washing treatment is 1 to 7 days, such as 1 day, 2.5 days, 4 days, 7 days, or any value between them. In this case, repeatedly washing the bacterial cellulose spacers not only thoroughly washes the bacterial cellulose but also acclimates it, improving its structural stability during subsequent in-situ adsorption treatment, high-temperature reaction, and freeze-drying treatment, which is beneficial for the formation of boehmite structures.
[0032] In this invention, in step S2, the aluminum alkoxide solution specifically comprises an aluminum alkoxide, an organic alcohol, and water. The aluminum alkoxide refers to a compound formed by aluminum ions and one or more alcohol molecules bonded together by chemical bonds, and specific examples include, but are not limited to, one or more of aluminum isobutoxide, aluminum isopropoxide, and aluminum sec-butoxide. The organic alcohol refers to an organic compound containing one or more hydroxyl functional groups, and specific examples include, but are not limited to, one or more of isobutanol, isopropanol, and sec-butanol.
[0033] In this invention, in step S2, the concentration of aluminum alkoxide in the aluminum alcohol solution is preferably 0.1~0.5 g / mL, such as 0.1 g / mL, 0.15 g / mL, 0.2 g / mL, 0.3 g / mL, 0.4 g / mL, 0.5 g / mL, or any value between them; the volume ratio of the organic alcohol to water is preferably 1:(1~19), such as 1:1, 1:3, 1:5, 1:10, 1:15, 1:19, or any value between them. At this point, the aluminum alkoxide concentration in the aluminum alcohol solution is suitable, and the solution exhibits a relatively ideal presence of complexes, which allows for better adsorption by modified bacterial cellulose, thus facilitating the in-situ growth of boehmite.
[0034] In this invention, in step S2, based on the volume of the aluminum alcohol solution, the amount of modified bacterial cellulose added is 1:(2~10), such as 1:2, 1:2.5, 1:2.8, 1:3, 1:4, 1:5, 1:7, 1:9, 1:10 or any value between them.
[0035] In this invention, the in-situ adsorption treatment time in step S2 is preferably 12~72h, such as 12h, 18h, 20h, 24h, 30h, 36h, 48h, 60h, 72h, or any value between them. At this time, the modified bacterial cellulose can achieve sufficient adsorption of aluminum alkoxides, which is beneficial to the in-situ growth of boehmite.
[0036] In this invention, in step S3, the concentration of the ammonia water is preferably 20-30% (v / v), such as 20% (v / v), 21% (v / v), 23% (v / v), 25% (v / v), 27.5% (v / v), 30% (v / v) or any value between them.
[0037] In this invention, in step S3, based on the volume of the aluminum alcohol solution, the amount of ammonia added is preferably 1 to 5% (v / v), such as 1% (v / v), 1.5% (v / v), 2% (v / v), 2.5% (v / v), 3% (v / v), 4% (v / v), 5% (v / v) or any value between them.
[0038] In this invention, in step S3, the conditions for the high-temperature reaction include a temperature preferably between 120 and 300°C, such as 120°C, 140°C, 180°C, 200°C, 240°C, 280°C, 300°C, or any value between them; and a time preferably between 0.5 and 6 hours, such as 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, or any value between them. At this time, the high-temperature reaction conditions can effectively achieve in-situ growth of pseudoboehmite on modified cellulose.
[0039] In this invention, in step S4, the freeze-drying conditions include a temperature preferably between -40°C and -10°C, such as -40°C, -38°C, -35°C, -32°C, -30°C, -28°C, -25°C, -20°C, -18°C, -15°C, -13°C, -10°C, or any value between them; and a time preferably between 6h and 24h, such as 6h, 7h, 8h, 12h, 14h, 16h, 20h, 22h, 24h, or any value between them.
[0040] In this invention, in step S5, the sintering conditions include a temperature of 200~400℃, such as 200℃, 230℃, 250℃, 300℃, 400℃, or any value between them; and a time of 1~12h, such as 1h, 4h, 10h, 12h, or any value between them. At this time, the sintering can effectively carbonize the bacterial cellulose contained within the material while ensuring that the material structure does not collapse, thereby preparing a boehmite material with an ideal structure.
[0041] In this invention, step S5 specifically includes: mixing the sintered product with composite grinding beads and ball milling to obtain the boehmite material.
[0042] In this invention, during the ball milling process in step S5, the mixed grinding beads specifically include large, medium, and small grinding beads, and the diameter ratio of the large, medium, and small grinding beads is preferably 1:0.5:(0.1~0.2), such as 1:0.5:0.1, 1:0.5:0.13, 1:0.5:0.15, 1:0.5:0.2, or any value between them; the mass ratio of the large, medium, and small grinding beads is preferably (8~12):(78~82):10, such as 8:82:10, 10:80:10, 11:79:10, 12:78:10, or any value between them. This allows for better ball milling of the sintered product, thereby obtaining boehmite material with a suitable particle size.
[0043] In this invention, during the ball milling process in step S5, the ball milling speed is preferably 100~200 r / min, such as 100 r / min, 110 r / min, 120 r / min, 130 r / min, 150 r / min, 180 r / min, 200 r / min or any value between them; the ball milling time is preferably 10~30 min, such as 10 min, 15 min, 20 min, 25 min, 30 min or any value between them.
[0044] The present invention also provides a boehmite material, which is prepared by the above-described method for preparing boehmite material.
[0045] In this invention, the boehmite material has excellent particle size, specific surface area and crystallinity, and can be well applied to the preparation of energy storage batteries, thereby obtaining battery products with both excellent energy density and low internal resistance.
[0046] Based on the excellent properties of the boehmite material, the present invention also provides the application of the boehmite material in the preparation of energy storage batteries.
[0047] The embodiments of the present invention are described in detail below. These embodiments are intended to explain the present invention and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.
[0048] Example 1 This embodiment illustrates a boehmite material and its preparation method. The preparation of the boehmite material specifically includes: S1. Take 100g of bacterial cellulose (Tianlu Nano, product number TL-009, hereinafter the same) and completely immerse it in 2000mL of sodium hydroxide solution (1wt%) for 48h. Then, wash the bacterial cellulose with deionized water every 12h, and repeat the washing treatment for 7 days to obtain modified bacterial cellulose. Cut the modified bacterial cellulose into squares of the same area, squeeze out the water with filter paper until the moisture content is 8%, and set aside for later use. The specific calculation of the moisture content of the modified bacterial cellulose is as follows: Bacterial cellulose water content = (m x -m0) / m0×100% m x The mass of bacterial cellulose after being squeezed through filter paper is given, and m0 is the initial weight of bacterial cellulose.
[0049] S2. Take 20 mL of isopropanol and 80 mL of deionized water, mix them evenly, add 10 g of aluminum isopropoxide to obtain an aluminum isopropoxide solution, add modified bacterial cellulose to the aluminum isopropoxide solution, and perform in-situ adsorption treatment for 24 h under magnetic stirring to obtain the first complex.
[0050] S3. Take 3 mL of 25% (v / v) ammonia solution and slowly add it dropwise to the first composite while stirring. After stirring for 10 min, place it in a reaction vessel with a polytetrafluoroethylene liner and carry out a high-pressure reaction at 180℃ for 1 h. After natural cooling, the second composite is obtained.
[0051] S4. After washing the second complex three times with deionized water, freeze-dry it at -40°C for 8 hours to obtain freeze-dried powder.
[0052] S5. Place the freeze-dried powder in a muffle furnace and sinter at 400℃ for 2 hours to obtain the sintered product. Use three types of grinding balls with a diameter ratio of 1:0.5:0.1 and a mass ratio of 12:78:10 (large, medium, and small) to ball mill the sintered product at 150 r / min for 20 minutes to obtain boehmite material with a yield of 3.21 g.
[0053] Example 2 This embodiment uses the method provided in Example 1 to prepare boehmite material. The difference is that in step S2, the amount of isopropanol added is 30 mL, the amount of deionized water added is 70 mL, and the amount of aluminum isopropoxide added is 5 g. That is, the volume ratio of organic alcohol to water is 3:7, and the amount of aluminum isopropoxide added is 0.05 g / mL. Other conditions are the same, and boehmite material with hollow structure is obtained with a yield of 2.83 g.
[0054] Example 3 This embodiment uses the method provided in Example 1 to prepare boehmite material. The difference is that the conditions used in the ball milling process in step S5 are different. Specifically, three types of grinding balls with a diameter ratio of 1:0.5:0.2 and a mass ratio of 8:82:10 (large, medium, and small) are used to ball mill the sintered product at 200 r / min for 30 min. Other conditions are the same, and boehmite material with a hollow structure is obtained with a yield of 3.19 g.
[0055] Example 4 This embodiment uses the method provided in Example 1 to prepare boehmite material. The difference is that in step S3, the in-situ adsorption treatment time is 12 hours, and other conditions are the same, resulting in boehmite material with a hollow structure and a yield of 2.90 g.
[0056] Example 5 This embodiment uses the method provided in Example 1 to prepare boehmite material. The difference is that in step S5, the sintering temperature is 230°C, and other conditions are the same, resulting in boehmite material with a hollow structure and a yield of 3.23g.
[0057] Comparative Example 1 This comparative example uses the method provided in Example 1 to prepare boehmite material. The difference is that in step S1, deionized water soaking treatment is used instead of alkaline solution soaking treatment. The deionized water soaking treatment specifically includes: taking 100g of bacterial cellulose and completely immersing it in 200mL of deionized water for 48h, with other conditions being the same, to obtain boehmite material with a yield of 1.98g.
[0058] Comparative Example 2 The comparative example uses the method provided in Example 1 to prepare boehmite material. The difference is that in step S1, the modified bacterial cellulose is not subjected to the operation of squeezing out water with filter paper. That is, in step S2, the water content of the modified bacterial cellulose added to the aluminum isopropoxide solution is 96%. Under the same conditions, boehmite material is obtained with a yield of 1.02g.
[0059] Comparative Example 3 The comparative example uses the method provided in Example 1 to prepare boehmite material. The difference is that in step S4, hot air drying is used instead of freeze drying. The hot air drying process specifically includes: rinsing the second composite with deionized water three times and then placing it in a forced-air drying oven for vacuum drying at 80°C for 5 hours. Other conditions are the same, and boehmite material is obtained with a yield of 3.18g.
[0060] Comparative Example 4 The comparative example uses the method provided in Example 1 to prepare boehmite material, except that in step S5, the sintering temperature is 120°C, and other conditions are the same, resulting in a boehmite material with a yield of 3.19g.
[0061] Test case This test example illustrates the relevant properties of the boehmite materials provided in the above embodiments and comparative examples. The tests specifically include: (1) D 50 The D of boehmite materials was determined using the method provided in GB / T 19077. 50 value; (2) Specific surface area and pore volume: The specific surface area and pore volume of boehmite materials were determined by the BET method; (3) Crystal structure characteristics: The L of boehmite material was determined by XRD. (020) And crystallinity; (4) Battery performance: Boehmite material and PVDF were mixed evenly at a mass ratio of 88:12 and coated onto the surface of the current collector together with the positive electrode slurry to obtain the positive electrode sheet. Then, it was assembled with the negative electrode sheet, electrolyte and PE separator to obtain a soft pack battery, and the following tests were performed: a. Capacity test: At 25℃, it was charged to 3.65V with a constant current and constant voltage of 0.5C, the cutoff current was 0.05C, and it was left to stand for 10min. Then, it was discharged to 2.5V with a constant current of 0.5C and left to stand for 10min. The cycle was repeated 3 times and the average value was recorded as C0; b. DCR test: At 25℃, it was discharged to 2.5V with a constant current of 0.5C and left to stand for 10min. Then, it was charged with a constant current of 0.5C0 for 30min and left to stand for 2h. Then, it was discharged with 1C0 for 10s. The DCR was calculated by the voltage change before and after discharge. The test results are shown in Table 1.
[0062] Table 1.
[0063] As shown in Table 1, the test results indicate that, compared to Comparative Examples 1-5, the boehmite material prepared by the method provided in Examples 1-5 of this invention has a higher specific surface area, pore volume, and crystallinity. When this boehmite material is used in the preparation of energy storage batteries, the prepared energy storage batteries exhibit better battery capacity and lower DCR values.
[0064] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.
Claims
1. A method for preparing boehmite material, characterized in that, The preparation method includes: S1. Bacterial cellulose is soaked in an alkaline solution to obtain modified bacterial cellulose; S2. The modified bacterial cellulose is adsorbed in situ into aluminum alcohol solution to obtain the first complex; S3. The first complex is reacted with ammonia water at high temperature to obtain the second complex; S4. The second complex is subjected to freeze-drying to obtain freeze-dried powder; S5. The freeze-dried powder is sintered and then ball-milled to obtain the boehmite material; In step S1, the moisture content of the modified bacterial cellulose is not higher than 10%; in step S5, the sintering temperature is 200~400℃ and the time is 1~12h.
2. The method for preparing boehmite material according to claim 1, characterized in that, In step S1, the OH content of the alkaline solution used in the alkaline solution soaking treatment is... - The concentration is 0.05~0.5 mol / L; Optionally, the immersion time in the alkaline solution is 1 to 120 hours; Optionally, step S1 includes repeated washing, which includes: taking deionized water to wash the bacterial cellulose intervals that have been soaked in the alkaline solution multiple times, with the time interval between two adjacent washing treatments being 3 to 24 hours, and the duration of repeated washing being 1 to 7 days.
3. The method for preparing boehmite material according to claim 1, characterized in that, In step S2, the aluminum alcohol solution comprises aluminum alkoxide, organic alcohol and water, wherein the concentration of the aluminum alkoxide is 0.1~0.5 g / mL and the volume ratio of the organic alcohol to water is 1:(1~19). Optionally, the aluminum alkoxide includes one or more of aluminum isobutoxide, aluminum isopropoxide, and aluminum sec-butoxide; Optionally, the organic alcohol includes one or more of isobutanol, isopropanol, and sec-butanol; Optionally, the amount of modified bacterial cellulose added is 1:(2~10) based on the volume of the aluminum alcohol solution.
4. The method for preparing boehmite material according to claim 1, characterized in that, In step S2, the in-situ adsorption treatment time is 12~72h.
5. The method for preparing boehmite material according to claim 1, characterized in that, In step S3, the concentration of the ammonia water is 20-30% (v / v); Optionally, the amount of ammonia added is 1 to 5% (v / v) based on the volume of the aluminum alcohol solution.
6. The method for preparing boehmite material according to claim 1, characterized in that, In step S3, the high-temperature reaction is carried out at a temperature of 120~300℃ for a time of 0.5~6h.
7. The method for preparing boehmite material according to claim 1, characterized in that, In step S4, the freeze-drying process is carried out at a temperature of -40℃ to -10℃ for a time of 6h to 24h.
8. The method for preparing boehmite material according to claim 1, characterized in that, In step S5, the ball milling process includes: mixing the sintered product with composite grinding beads and ball milling at 100~200 r / min for 10~30 min to obtain the boehmite material; Optionally, the mixed grinding beads include large grinding beads, medium grinding beads and small grinding beads, the diameter ratio of the large grinding beads, medium grinding beads and small grinding beads is 1:0.5:(0.1~0.2), and the mass ratio of the large grinding beads, medium grinding beads and small grinding beads is (8~12):(78~82):
10.
9. A boehmite material, characterized in that, The boehmite material is prepared by the boehmite material preparation method according to any one of claims 1 to 8.
10. The application of the boehmite material according to claim 9 in the preparation of energy storage batteries.