Preparation method of sintered anode foil added with nano high-dielectric fiber

Abstract

The present invention discloses a preparation method of a sintered anode foil added with nano high-dielectric fibers, comprising the following steps: First, disperse the aggregated nano high-dielectric fibers in a solvent; Second, mix aluminum powder or aluminum alloy powder, the solvent-dispersed nano high-dielectric fibers and a binder; Third, coat the aluminum powder slurry on the surface of an aluminum foil substrate and then dry it; Fourth, sinter the sample; Fifth, boil and wash the sintered sample; Sixth, perform a forming treatment on the washed sample to obtain a sintered anode foil added with nano high-dielectric fibers. By dispersing the nano high-dielectric fibers in a solvent and uniformly mixing them with aluminum powder or aluminum alloy powder and a binder to prepare an anode material, the present invention utilizes the high strength characteristics and high specific surface area of the nano high-dielectric fibers to improve the bending performance and specific capacitance performance. Through the mutual cooperation of the nano high-dielectric fibers and aluminum powder, the anode foil meets the requirements of high specific capacitance and high strength for the electrode material of medium and high voltage aluminum electrolytic capacitors.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum electrolytic capacitors, and particularly relates to a preparation method of a sintered anode foil added with nano high-dielectric fibers. Background Art

[0002] Aluminum electrolytic capacitors are one of the very important basic electronic components. They can be used for filtering, bypassing in electronic circuits, and can also play roles such as coupling and decoupling. The high-voltage anode electronic aluminum foil is an important part of the aluminum electrolytic capacitor. It is a barrier-type oxide film grown on the surface of the aluminum electrode foil by anodic oxidation and is used as the dielectric layer of the aluminum electrolytic capacitor. At present, the high-voltage anode electronic aluminum foil is mainly obtained by electrochemically corroding or chemically corroding the surface of the aluminum foil with high cubic texture using sulfuric acid - hydrochloric acid. The corrosion process of the high-voltage anode electronic aluminum foil is generally relatively complex, mainly involving processes such as aluminum foil raw materials, aluminum foil pretreatment, the first stage (aluminum foil pore-forming stage), the second stage (aluminum foil pore-forming stage), post-treatment, cleaning and drying, etc. The above complex preparation process of the high-voltage anode electronic aluminum foil not only increases its processing cost, but also is difficult to reduce the cost of maintaining quality stability. At the same time, it is difficult to handle harmful substances such as waste acid and waste alkali generated during the preparation process of the high-voltage anode electronic aluminum foil. Different from the traditional corrosion process, currently, a method for preparing the high-voltage anode electronic aluminum foil of aluminum electrolytic capacitors by a sintering method (powder layer electronic aluminum foil technology) has emerged on the market. This method sinterizes aluminum powders on the surface of the aluminum matrix to form a sandwich structure with a porous structure. This method omits the traditional corrosion link and has the characteristics of simple process, low processing cost, and environmental friendliness.

[0003] Due to the advantages of low manufacturing cost and environmental friendliness of the powder layer electronic aluminum foil technology, medium and high-voltage anode foils with aluminum powders sinterized on the anode foil substrate have emerged on the market and have been patented. However, it can be found that although these powder layer electronic aluminum foils have high specific capacitance performance and can meet the electrical performance requirements for use in medium and high-voltage environments, their bending performance is difficult / hardly meets the requirements of the winding performance during the preparation of aluminum electrolytic capacitors. As a high-performance inorganic fiber, nano high-dielectric fiber has the advantages of high specific surface area, high strength, extraordinary heat resistance, and high-temperature oxidation resistance. It has high cost performance and commercial value and has been widely used in industrial, military, and civil composite material fields. Due to the high-strength advantage of the nano high-dielectric fiber, it is necessary to introduce it into the anode foil to improve the winding performance of the anode foil. In addition, the high specific surface area characteristic of the nano high-dielectric fiber itself can effectively improve the specific capacitance performance of the anode foil. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing a sintered anode foil added with nano high-dielectric fibers in view of the deficiencies of the above-mentioned prior art. This method disperses nano high-dielectric fibers in a solvent and uniformly mixes them with aluminum powder or aluminum alloy powder and a binder to prepare an anode material. Spherical aluminum powder is used to provide pores for the electrolyte to enter the interior of the anode material, and the high-strength characteristics and high specific surface area of the nano high-dielectric fibers are used to improve the bending performance and specific capacitance performance of the anode material. Through the mutual cooperation of the nano high-dielectric fibers and the spherical aluminum powder, the anode material meets the requirements of high specific capacitance and high strength for the electrode material of medium and high voltage aluminum electrolytic capacitors.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: a method for a sintered anode foil added with nano high-dielectric fibers, which is characterized by including the following steps.

[0006] Step 1: Use a high-speed disperser to uniformly disperse the agglomerated nano high-dielectric fibers in a solvent to obtain solvent-dispersed nano high-dielectric fibers.

[0007] Step 2: Mix aluminum powder or aluminum alloy powder, the solvent-dispersed nano high-dielectric fibers obtained in Step 1, and a binder to obtain an aluminum powder slurry.

[0008] Step 3: Coat the aluminum powder slurry obtained in Step 2 on the surface of an aluminum foil substrate, and then perform vacuum drying to obtain a sample.

[0009] Step 4: Subject the sample obtained in Step 3 to sintering treatment to obtain a sintered sample.

[0010] Step 5: Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample.

[0011] Step 6: Subject the washed sample obtained in Step 5 to forming treatment to obtain a sintered anode foil added with nano high-dielectric fibers.

[0012] By using a high-speed disperser to uniformly disperse the nano high-dielectric fibers in a solvent in the present invention, then mixing them with aluminum powder and a binder and uniformly coating them on the surface of the anode foil. The purpose of adding aluminum powder is to provide pores for the electrolyte to enter the interior of the anode material, and the purpose of adding nano high-dielectric fibers is to improve the winding performance of the anode foil and further provide a large effective specific surface area. Through the mutual cooperation of the nano high-dielectric fibers and the spherical aluminum powder, the high winding performance and high specific capacitance performance of the anode material are ensured; the nano high-dielectric fibers used in the process of preparing the sintered anode foil added with nano high-dielectric fibers in the present invention have the characteristics of low cost and no pollution, and the production process is simple and easy to operate, which can greatly reduce the production cost of the anode foil.

[0013] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that in step one, the diameter of the nano high-dielectric fibers is less than 1 μm, the length is less than 10 μm, and the mass purity is greater than 99.99%. The high-dielectric fibers are alumina fibers, titanium dioxide fibers, barium titanate fibers, strontium titanate fibers, calcium titanate fibers, sodium bismuth titanate fibers or potassium niobate fibers; the mass content of the high-dielectric fibers in the solvent-dispersed nano high-dielectric fibers is less than 20%. The present invention enhances the winding performance of the anode foil by controlling the size of the high-dielectric fibers, while providing a higher specific surface area for the anode foil, improving the electrical performance, and enabling the anode foil to maintain a high surface quality. By controlling the mass purity, impurities are prevented from being introduced. The winding performance of the anode foil is improved by utilizing the high-strength performance characteristics of the high-dielectric fibers, and the specific capacitance performance of the anode foil is enhanced by utilizing its high specific surface area characteristics. The present invention regulates the winding performance and surface quality of the anode foil by limiting the content of the high-dielectric fibers. When the content of the high-dielectric fibers is too high, it is not conducive to the coating of the slurry on the aluminum foil surface, and burrs will appear on the surface of the anode foil after drying, affecting the normal use of the anode foil.

[0014] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that in step one, the rate of the high-speed disperser for dispersing the nano high-dielectric fibers is 200 r / min to 6000 r / min. The present invention enables the high-dielectric fibers to be evenly dispersed in the slurry within this rate range and not to be broken by controlling the rotation speed of the high-speed disperser. When the rotation speed is too low, the high-dielectric fibers are difficult to be dispersed and tend to agglomerate; when the rotation speed is too high, the high-dielectric fibers are easily sheared and broken.

[0015] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that in step two, the particle size of the aluminum powder or aluminum alloy powder is less than 50 μm, and the mass purity of the aluminum powder and aluminum alloy powder is greater than 99.99%. The present invention limits the particle size, enabling the aluminum powder or aluminum alloy powder to have a relatively high specific surface area, which is beneficial to improving the capacitance of the anode foil of the aluminum electrolytic capacitor; by limiting the mass purity of the aluminum powder and aluminum alloy powder, the leakage current of the capacitance of the anode foil of the aluminum electrolytic capacitor is reduced.

[0016] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that, in step one, the solvent is one or more of tributyl citrate, butyl carbitol, glycerol, ethylene glycol, and terpineol; in step two, the binder is one or more of ethyl cellulose, polyvinyl alcohol, polymethacrylate, carboxymethyl cellulose, polypropylene, polyethylene, polyisobutene, vinyl acetate resin, vinyl alcohol resin, polyvinyl fluoride resin, propylene resin, epoxy resin, urea resin, and phenolic resin. In the present invention, a solvent is used to uniformly disperse aluminum powder or aluminum alloy powder in the aluminum powder slurry, and dissolve the binder, so that the binder is uniformly mixed with the aluminum raw material, and at the same time carries the aluminum raw material. By controlling the type of the solvent, the aluminum raw material is uniformly dispersed, has a fast evaporation rate, a low boiling point, little pollution, and a low price. In the present invention, a binder is used to bond the aluminum raw material to the aluminum foil substrate during the subsequent coating process, increase the viscosity of the aluminum raw material slurry, and facilitate the bonding between aluminum raw material particles. By controlling the type of the binder, it is easily soluble in the solvent, so that the aluminum raw material slurry has excellent rheological properties, is not easily stratified and precipitated in a short time, has a fast evaporation rate, a low boiling point, and a low price.

[0017] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that, in step three, the thickness of the aluminum foil substrate is 30 μm to 60 μm, and the single-sided thickness of the coating is 40 μm to 100 μm. In the present invention, by controlling the thickness of the aluminum foil substrate, the thickness of the coating layer is increased, the use of the aluminum substrate is reduced, and the cost is saved. If it is too thin, the mechanical strength will be affected, which will affect the curling and winding of the anode foil in the later stage. If it is too thick, the specific capacitance of the anode foil will be affected. In the present invention, when coating the slurry, double-sided coating is carried out on the sheet-shaped aluminum foil substrate. By controlling the single-sided thickness of the aluminum raw material slurry, it is ensured that the thickness of the sintered anode foil added with nano high-dielectric fibers prepared is controlled within 130 μm to 230 μm. If it is too small, the specific capacitance cannot be guaranteed. If it is too large, the later use cannot be guaranteed.

[0018] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that, in step three, the coating method of the aluminum powder slurry is blade coating; the temperature of the vacuum drying treatment is 40 °C to 200 °C. In the present invention, double-sided coating is carried out by using a blade to obtain an aluminum electrolytic capacitor anode foil with high smoothness and gloss, and the adjustment accuracy is higher than that of other coating methods. In the present invention, by controlling the drying conditions and temperature, other impurities are prevented from being introduced, and the solvent, binder, and dispersant in the aluminum raw material slurry are preliminarily removed to solidify the aluminum raw material slurry to form a sintered anode foil added with nano high-dielectric fibers, which facilitates the subsequent treatment.

[0019] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that the sintering process in step four is as follows: First, heat at a heating rate of 1 °C / min to 20 °C / min to 250 °C to 300 °C and hold for 1 h to 4 h, then heat at a heating rate of 1 °C / min to 20 °C / min to 350 °C to 500 °C and hold for 2 h to 8 h, and then heat at a heating rate of 1 °C / min to 20 °C / min to 600 °C to 650 °C and hold for 1 h to 24 h, and then cool with the furnace; nitrogen or argon is used as the protective gas during the sintering process, or a vacuum environment is adopted. The present invention performs calcination by three-stage heating. In the first two stages, the residual solvents, binders, and dispersants are removed at a relatively low temperature, and in the third stage, at a relatively high temperature, the slurry with added nano high-dielectric fibers on the surface of the aluminum foil substrate and the aluminum foil substrate are fully combined to enhance the structural strength of the anode foil.

[0020] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that both the water boiling and cleaning in step five are carried out with deionized water, and the water boiling is for 10 min to 20 min. The present invention prevents the introduction of other impurities by using deionized water, forms a hydration film with a suitable thickness on the surface of the anode foil by controlling the boiling time, and utilizes the forming treatment.

[0021] The above method for adding nano high-dielectric fibers to a sintered anode foil is characterized in that the forming treatment in step six adopts a boric acid solution with a mass concentration of 10%, and the forming voltage is 520 V. The present invention forms an oxide film on the surface of the anode material through the forming treatment to improve the performance of the material.

[0022] The present invention has the following advantages compared with the prior art:

[0023] 1. The present invention disperses nano high-dielectric fibers in a solvent, uniformly mixes them with aluminum powder or aluminum alloy powder and a binder to prepare an anode foil, uses the aluminum powder or aluminum alloy powder to provide pores for the electrolyte to enter the anode foil interior, and utilizes the high strength and high specific surface area characteristics of the nano high-dielectric fibers to improve the bending performance and specific capacitance performance of the anode foil. Through the mutual cooperation of the nano high-dielectric fibers and the aluminum powder or aluminum alloy powder, the sintered anode foil with added nano high-dielectric fibers meets the requirements of high specific capacitance and high strength for the electrode material of medium and high voltage aluminum electrolytic capacitors.

[0024] 2. Aiming at the disadvantage of poor winding performance of the anode foil for aluminum electrolytic capacitors, the present invention utilizes the high strength characteristic of nano high-dielectric fibers to add them to the aluminum-containing slurry and uniformly coat the nano high-dielectric fibers on the surface of the aluminum foil substrate to achieve the purpose of improving the winding performance of the sintered anode foil with added nano high-dielectric fibers for aluminum electrolytic capacitors.

[0025] 3. The present invention regulates the winding performance and surface quality of the anode foil by limiting the content of the high-dielectric fiber. When the content of the high-dielectric fiber is excessive, it is not conducive to the coating of the slurry on the surface of the aluminum foil, and burrs will appear on the surface of the anode foil after drying, affecting the normal use of the anode foil. By controlling the rotation speed of the high-speed disperser, the high-dielectric fiber can be evenly dispersed in the slurry within this speed range without being broken. When the rotation speed is too small, the high-dielectric fiber is difficult to be dispersed and prone to agglomeration. When the rotation speed is too large, the high-dielectric fiber is easily sheared and broken.

[0026] 4. The nano-high-dielectric fiber used in the process of preparing the sintered anode foil with added nano-high-dielectric fiber in the present invention has the characteristics of low cost and no pollution. The production process is simple and easy to operate, and can greatly reduce the production cost of the anode foil.

[0027] 5. The static specific capacitance of the sintered anode foil with added nano-high-dielectric fiber prepared by the present invention can reach up to 1.477 μF / cm 2 , and the maximum number of bending times can reach 198 times. The number of bending times is a parameter for examining the winding performance of the anode foil and is an index determining whether the anode foil can be used for winding the production of aluminum electrolytic capacitors. The number of bending times of the sintered anode foil with added nano-high-dielectric fiber of the present invention is much higher than that of similar products.

[0028] The technical solution of the present invention will be further described in detail below through examples. Specific Embodiments

[0029] Example 1

[0030] This example includes the following steps:

[0031] Step 1: Uniformly disperse the agglomerated nano-high-dielectric fiber in a solvent by using a high-speed disperser to obtain solvent-dispersed nano-high-dielectric fiber; the diameter of the nano-high-dielectric fiber is 15 nm, the length is 500 nm, the mass purity is greater than 99.99%, and the high-dielectric fiber is alumina fiber; the mass content of the high-dielectric fiber in the solvent-dispersed nano-high-dielectric fiber is 10%; the rate of the high-speed disperser for dispersing the nano-high-dielectric fiber is 2000 r / min;

[0032] Step 2: Mix aluminum powder with a particle size less than 20 μm and a mass purity greater than 99.99%, the solvent-dispersed nano-high-dielectric fiber obtained in Step 1, and a binder to obtain an aluminum powder slurry; the solvent is ethylene glycol and terpineol; the binder is ethyl cellulose and polypropylene, and the mass ratio of terpineol, ethylene glycol, ethyl cellulose, and polypropylene is 60:30:5:5;

[0033] Step 3: Coat the aluminum powder slurry obtained in Step 2 on the surface of the aluminum foil substrate, and then perform vacuum drying to obtain a sample; the thickness of the aluminum foil substrate is 40 μm, and the single-sided coating thickness is 100 μm; the coating method of the aluminum powder slurry is knife coating; the temperature of the vacuum drying treatment is 80 °C;

[0034] Step 4: Sinter the sample obtained in Step 3 to obtain a sintered sample; the process of the sintering treatment is as follows: First, heat it to 300 °C at a heating rate of 10 °C / min in a nitrogen atmosphere and hold for 1 h, then heat it to 350 °C at a heating rate of 10 °C / min and hold for 3 h, and then heat it to 630 °C at a heating rate of 10 °C / min and hold for 12 h, and then cool it with the furnace;

[0035] Step 5: Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample; both the boiling and washing are carried out with deionized water, and the boiling is for 18 min;

[0036] Step 6: Subject the washed sample obtained in Step 5 to forming treatment to obtain a sintered anode foil added with nano high-dielectric fibers; the forming treatment uses a boric acid solution with a mass concentration of 10%, and the forming voltage is 520 V.

[0037] After testing, the static specific capacitance of the sintered anode foil added with nano high-dielectric fibers prepared in this example is 1.477 μF / cm 2 , and the number of bending times is 164 times.

[0038] Comparative Example 1

[0039] This comparative example includes the following steps:

[0040] Step 1: Mix aluminum powder with a particle size less than 20 μm and a mass purity greater than 99.99%, a solvent, and a binder to obtain an aluminum powder slurry; the particle size of the aluminum powder is less than 50 μm and the mass purity is greater than 99.99%; the solvent is terpineol, and the binder is ethyl cellulose, where the mass ratio of terpineol to ethyl cellulose is 95:5;

[0041] Step 2: Coat the aluminum powder slurry obtained in Step 1 on the surface of the aluminum foil substrate, and then perform vacuum drying to obtain a sample; the thickness of the aluminum foil substrate is 30 μm, and the single-sided coating thickness is 80 μm; the coating method of the aluminum powder slurry is knife coating; the temperature of the vacuum drying treatment is 150 °C;

[0042] Step 3: Sinter the sample obtained in Step 2 to obtain a sintered sample; the process of the sintering treatment is as follows: First, heat it to 250°C at a heating rate of 20°C / min under argon protection and hold for 4 h, then heat it to 400°C at a heating rate of 20°C / min and hold for 5 h, and then heat it to 600°C at a heating rate of 20°C / min and hold for 24 h, and then cool it in the furnace;

[0043] Step 4: Boil and wash the sintered sample obtained in Step 3 in sequence to obtain a washed sample; both the boiling and washing are carried out with deionized water, and the boiling is for 15 min;

[0044] Step 5: Subject the washed sample obtained in Step 4 to formation treatment to obtain a sintered anode foil; the formation treatment is carried out with a boric acid solution having a mass concentration of 10%, and the formation voltage is 520 V.

[0045] After testing, the static specific capacitance of the sintered anode foil prepared in this comparative example is 0.909 μF / cm 2 and the number of bending times is 27 times.

[0046] It can be seen from the comparison between Comparative Example 1 and Example 1 that no nano-high dielectric fiber was added in Comparative Example 1, resulting in poor uniformity and uneven performance of the anode foil prepared in Comparative Example 1, so the static specific capacitance and the number of bending times are both low. In Example 1, by adding nano-high dielectric fiber, the static specific capacitance and the bending performance of the anode foil are ensured.

[0047] Example 2

[0048] This example includes the following steps:

[0049] Step 1: Uniformly disperse the agglomerated nano-high dielectric fibers in a solvent by a high-speed disperser to obtain solvent-dispersed nano-high dielectric fibers; the diameter of the nano-high dielectric fibers is 100 nm, the length is 800 nm, the mass purity is greater than 99.99%, and the high dielectric fibers are alumina fibers; the mass content of the high dielectric fibers in the solvent-dispersed nano-high dielectric fibers is 5%; the rate of the high-speed disperser for dispersing the nano-high dielectric fibers is 200 r / min;

[0050] Step 2: Mix aluminum powder with a particle size less than 20 μm and a mass purity greater than 99.99%, the solvent-dispersed nano-high dielectric fibers obtained in Step 1, and a binder to obtain an aluminum powder slurry; the particle size of the aluminum powder or aluminum alloy powder is less than 40 μm, and the mass purity of the aluminum powder and aluminum alloy powder is greater than 99.99%; the solvent is terpineol, and the binder is ethyl cellulose, where the mass ratio of terpineol to ethyl cellulose is 95:5;

[0051] Step 3: Coat the aluminum powder slurry obtained in Step 2 on the surface of the aluminum foil substrate, and then perform vacuum drying to obtain a sample; the thickness of the aluminum foil substrate is 30 μm, and the single-sided coating thickness is 70 μm; the coating method of the aluminum powder slurry is blade coating; the temperature of the vacuum drying treatment is 40°C;

[0052] Step 4: Sinter the sample obtained in Step 3 to obtain a sintered sample; the process of the sintering treatment is as follows: First, heat it to 260°C at a heating rate of 5°C / min under vacuum and hold for 2.5 h, then heat it to 380°C at a heating rate of 5°C / min and hold for 6 h, and then heat it to 620°C at a heating rate of 5°C / min and hold for 15 h, and cool it with the furnace;

[0053] Step 5: Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample; both the boiling and washing are carried out with deionized water, and the boiling is for 15 min;

[0054] Step 6: Subject the washed sample obtained in Step 5 to forming treatment to obtain a sintered anode foil added with nano high-dielectric fibers; the forming treatment uses a boric acid solution with a mass concentration of 10%, and the forming voltage is 520 V.

[0055] After testing, the static specific capacitance of the sintered anode foil added with nano high-dielectric fibers prepared in this example is 1.136 μF / cm 2 , and the number of bending times is 147 times.

[0056] Example 3

[0057] This example includes the following steps:

[0058] Step 1: Uniformly disperse the agglomerated nano high-dielectric fibers in a solvent by a high-speed disperser to obtain a solvent-dispersed nano high-dielectric fiber; the diameter of the nano high-dielectric fiber is 50 nm, the length is 600 nm, the mass purity is greater than 99.99%, and the high-dielectric fiber is alumina fiber; the mass content of the high-dielectric fiber in the solvent-dispersed nano high-dielectric fiber is 20%; the rate of the high-speed disperser for dispersing the nano high-dielectric fiber is 6000 r / min;

[0059] Step 2: Mix Al-Mg powder with a particle size less than 20 μm and a mass purity greater than 99.99%, the solvent-dispersed nano high-dielectric fiber obtained in Step 1, and a binder to obtain an aluminum powder slurry; the particle size of the aluminum powder or aluminum alloy powder is less than 50 μm, and the mass purity of the aluminum powder and aluminum alloy powder is greater than 99.99%; the solvent is ethylene glycol and terpineol; the binder is ethyl cellulose and polypropylene, and the mass ratio of terpineol, ethylene glycol, ethyl cellulose, and polypropylene is 60:30:5:5;

[0060] Step 3: Coat the aluminum powder slurry obtained in Step 2 on the surface of the aluminum foil substrate, and then perform vacuum drying to obtain a sample; the thickness of the aluminum foil substrate is 60 μm, and the single-sided coating thickness is 100 μm; the coating method of the aluminum powder slurry is blade coating; the temperature of the vacuum drying treatment is 200 °C;

[0061] Step 4: Sinter the sample obtained in Step 3 to obtain a sintered sample; the sintering process is as follows: first heat it to 290 °C at a heating rate of 8 °C / min under vacuum and hold for 1.5 h, then heat it to 450 °C at a heating rate of 8 °C / min and hold for 2 h, and then heat it to 610 °C at a heating rate of 8 °C / min and hold for 8 h, and cool it with the furnace;

[0062] Step 5: Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample; both the boiling and washing are carried out with deionized water, and the boiling is for 15 min;

[0063] Step 6: Subject the washed sample obtained in Step 5 to forming treatment to obtain a sintered anode foil added with nano high-dielectric fibers; the forming treatment uses a boric acid solution with a mass concentration of 10%, and the forming voltage is 520 V.

[0064] After testing, the static specific capacitance of the sintered anode foil added with nano high-dielectric fibers prepared in this example is 0.992 μF / cm 2 , and the number of bending times is 179 times.

[0065] Example 4

[0066] This example includes the following steps:

[0067] Step 1: Use a high-speed disperser to uniformly disperse the agglomerated nano high-dielectric fibers in a solvent to obtain solvent-dispersed nano high-dielectric fibers; the diameter of the nano high-dielectric fibers is 20 nm, the length is 500 nm, the mass purity is greater than 99.99%, and the high-dielectric fibers are alumina fibers; the mass content of the high-dielectric fibers in the solvent-dispersed nano high-dielectric fibers is 2%; the rate of the high-speed disperser for dispersing the nano high-dielectric fibers is 2000 r / min;

[0068] Step 2: Mix aluminum powder with a particle size less than 20 μm and a mass purity greater than 99.99%, the solvent-dispersed nano high-dielectric fibers obtained in Step 1, and a binder to obtain an aluminum powder slurry; the particle size of the aluminum powder is less than 30 μm, and the mass purity is greater than 99.99%; the solvent is terpineol, and the binder is ethyl cellulose, where the mass ratio of terpineol to ethyl cellulose is 95:5;

[0069] Step 3. Coat the aluminum powder slurry obtained in Step 2 on the surface of the aluminum foil substrate, and then perform vacuum drying to obtain a sample; the thickness of the aluminum foil substrate is 30 μm, and the single-sided coating thickness is 80 μm; the coating method of the aluminum powder slurry is blade coating; the temperature of the vacuum drying treatment is 150 °C;

[0070] Step 4. Sinter the sample obtained in Step 3 to obtain a sintered sample; the process of the sintering treatment is as follows: first, heat it to 250 °C at a heating rate of 20 °C / min under argon protection and hold for 4 h, then heat it to 400 °C at a heating rate of 20 °C / min and hold for 5 h, and then heat it to 600 °C at a heating rate of 20 °C / min and hold for 24 h, and then cool it with the furnace;

[0071] Step 5. Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample; both the boiling and washing are carried out with deionized water, and the boiling is for 15 min;

[0072] Step 6. Subject the washed sample obtained in Step 5 to forming treatment to obtain a sintered anode foil added with nano-high-dielectric fibers; the forming treatment uses a boric acid solution with a mass concentration of 10%, and the forming voltage is 520 V.

[0073] After testing, the static specific capacitance of the sintered anode foil added with nano-high-dielectric fibers prepared in this example is 1.089 μF / cm 2 , and the number of bending times is 142 times.

[0074] Example 5

[0075] This example includes the following steps:

[0076] Step 1. Use a high-speed disperser to uniformly disperse the agglomerated nano-high-dielectric fibers in a solvent to obtain solvent-dispersed nano-high-dielectric fibers; the diameter of the nano-high-dielectric fibers is 500 nm, the length is 5 μm, the mass purity is greater than 99.99%, the high-dielectric fibers are titanium dioxide fibers; the mass content of the high-dielectric fibers in the solvent-dispersed nano-high-dielectric fibers is 15%; the rate of the high-speed disperser for dispersing the nano-high-dielectric fibers is 3000 r / min;

[0077] Step 2: Mix the Al-Si-Cu-Mg powder with a particle size less than 20 μm and a mass purity greater than 99.99%, the solvent-dispersed nano-high dielectric fiber obtained in Step 1, and a binder to obtain an aluminum powder slurry; the particle size of the aluminum powder or aluminum alloy powder is less than 40 μm, and the mass purity of the aluminum powder and aluminum alloy powder is greater than 99.99%; the solvent is ethylene glycol and terpineol; the binder is ethyl cellulose and polypropylene, and the mass ratio of terpineol, ethylene glycol, ethyl cellulose, and polypropylene is 60:30:5:5;

[0078] Step 3: Coat the aluminum powder slurry obtained in Step 2 on the surface of an aluminum foil substrate, and then perform vacuum drying to obtain a sample; the thickness of the aluminum foil substrate is 60 μm, and the single-sided coating thickness is 40 μm; the coating method of the aluminum powder slurry is knife coating; the temperature of the vacuum drying treatment is 200 °C;

[0079] Step 4: Sinter the sample obtained in Step 3 to obtain a sintered sample; the sintering process is as follows: First, heat it to 300 °C at a heating rate of 20 °C / min under vacuum and hold for 1 h, then heat it to 500 °C at a heating rate of 20 °C / min and hold for 2 h, and then heat it to 650 °C at a heating rate of 20 °C / min and hold for 1 h, and then cool it with the furnace;

[0080] Step 5: Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample; both the boiling and washing are performed with deionized water, and the boiling is for 12 min;

[0081] Step 6: Subject the washed sample obtained in Step 5 to a formation treatment to obtain a sintered anode foil added with nano-high dielectric fiber; the formation treatment uses a boric acid solution with a mass concentration of 10%, and the formation voltage is 520 V.

[0082] After testing, the static specific capacitance of the sintered anode foil added with nano-high dielectric fiber prepared in this example is 1.430 μF / cm 2 , and the number of bending times is 198 times.

[0083] Example 6

[0084] This example includes the following steps:

[0085] Step 1: Uniformly disperse the agglomerated nano-high dielectric fiber in a solvent by a high-speed disperser to obtain a solvent-dispersed nano-high dielectric fiber; the diameter of the nano-high dielectric fiber is 700 nm, the length is 1 μm, the mass purity is greater than 99.99%, the high dielectric fiber is barium titanate fiber; the mass content of the high dielectric fiber in the solvent-dispersed nano-high dielectric fiber is 8%; the rate of the high-speed disperser for dispersing the nano-high dielectric fiber is 1000 r / min;

[0086] Step 2: Mix Al-Mg-Si powder with a particle size less than 20 μm and a mass purity greater than 99.99%, the solvent-dispersed nano high-dielectric fibers obtained in Step 1, and a binder to obtain an aluminum powder slurry; the particle size of the aluminum powder or aluminum alloy powder is less than 30 μm, and the mass purity of the aluminum powder and aluminum alloy powder is greater than 99.99%; the solvent is ethylene glycol and terpineol; the binder is ethyl cellulose and polypropylene, and the mass ratio of terpineol, ethylene glycol, ethyl cellulose, and polypropylene is 60:30:5:5;

[0087] Step 3: Coat the aluminum foil substrate surface with the aluminum powder slurry obtained in Step 2, and then perform vacuum drying to obtain a sample; the thickness of the aluminum foil substrate is 40 μm, and the single-sided coating thickness is 50 μm; the coating method of the aluminum powder slurry is knife coating; the temperature of the vacuum drying treatment is 100 °C;

[0088] Step 4: Sinter the sample obtained in Step 3 to obtain a sintered sample; the sintering process is as follows: first heat to 270 °C at a heating rate of 1 °C / min under vacuum and hold for 2 h, then heat to 350 °C at a heating rate of 1 °C / min and hold for 8 h, and then heat to 650 °C at a heating rate of 1 °C / min and hold for 1 h, and cool with the furnace;

[0089] Step 5: Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample; both the boiling and washing are performed with deionized water, and the boiling is for 10 min;

[0090] Step 6: Subject the washed sample obtained in Step 5 to forming treatment to obtain a sintered anode foil added with nano high-dielectric fibers; the forming treatment uses a boric acid solution with a mass concentration of 10%, and the forming voltage is 520 V.

[0091] After testing, the static specific capacitance of the sintered anode foil added with nano high-dielectric fibers prepared in this example is 1.128 μF / cm 2 , and the number of bending times is 171 times.

[0092] Example 7

[0093] This example includes the following steps:

[0094] Step 1: Use a high-speed disperser to evenly disperse the agglomerated nano-high dielectric fibers in a solvent to obtain solvent-dispersed nano-high dielectric fibers; the diameter of the nano-high dielectric fibers is 80 nm, the length is 700 nm, the mass purity is greater than 99.99%, and the high dielectric fibers are strontium titanate fibers; the mass content of the high dielectric fibers in the solvent-dispersed nano-high dielectric fibers is 12%; the rate of the high-speed disperser for dispersing the nano-high dielectric fibers is 5000 r / min;

[0095] Step 2: Mix aluminum powder with a particle size less than 20 μm and a mass purity greater than 99.99%, the solvent-dispersed nano-high dielectric fibers obtained in Step 1, and a binder to obtain an aluminum powder slurry; the particle size of the aluminum powder or aluminum alloy powder is less than 20 μm, and the mass purity of the aluminum powder and aluminum alloy powder is greater than 99.99%; the solvent is tributyl citrate, butyl carbitol, and ethylene glycol; the binder is carboxymethyl cellulose, and the mass ratio of tributyl citrate, butyl carbitol, ethylene glycol, and carboxymethyl cellulose is 45:30:20:5;

[0096] Step 3: Coat the aluminum powder slurry obtained in Step 2 on the surface of an aluminum foil substrate, and then perform vacuum drying to obtain a sample; the thickness of the aluminum foil substrate is 50 μm, and the single-sided coating thickness is 90 μm; the coating method of the aluminum powder slurry is knife coating; the temperature of the vacuum drying treatment is 120 °C;

[0097] Step 4: Sinter the sample obtained in Step 3 to obtain a sintered sample; the sintering process is as follows: First, heat it to 250 °C at a heating rate of 1 °C / min under vacuum and hold for 4 h, then heat it to 350 °C at a heating rate of 1 °C / min and hold for 8 h, and then heat it to 600 °C at a heating rate of 1 °C / min and hold for 20 h, and cool it with the furnace;

[0098] Step 5: Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample; both the boiling and washing are performed with deionized water, and the boiling is for 20 min;

[0099] Step 6: Perform formation treatment on the washed sample obtained in Step 5 to obtain a sintered anode foil added with nano-high dielectric fibers; the formation treatment uses a boric acid solution with a mass concentration of 10%, and the formation voltage is 520 V.

[0100] After testing, the static specific capacitance of the sintered anode foil added with nano-high dielectric fibers prepared in this example is 1.023 μF / cm 2 , and the number of bending times is 141 times.

[0101] The above are only the preferred embodiments of the present invention and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent variations made to the above embodiments based on the technical essence of the invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A preparation method of a sintered anode foil added with nano high-dielectric fibers, characterized in that, The method includes the following steps: Step 1: Uniformly disperse the agglomerated nano high-dielectric fibers in a solvent by using a high-speed disperser to obtain solvent-dispersed nano high-dielectric fibers; Step 2: Mix aluminum powder or aluminum alloy powder, the solvent-dispersed nano high-dielectric fibers obtained in Step 1, and a binder to obtain an aluminum powder slurry; Step 3: Coat the aluminum foil substrate surface with the aluminum powder slurry obtained in Step 2, and then perform vacuum drying to obtain a sample; Step 4: Perform sintering treatment on the sample obtained in Step 3 to obtain a sintered sample; Step 5: Boil and wash the sintered sample obtained in Step 4 in sequence to obtain a washed sample; Step 6: Perform forming treatment on the washed sample obtained in Step 5 to obtain a sintered anode foil added with nano high-dielectric fibers.

2. The preparation method of a sintered anode foil added with nano high-dielectric fibers according to claim 1, characterized in that In Step 1, the diameter of the nano high-dielectric fibers is less than 1 μm, the length is less than 10 μm, and the mass purity is greater than 99.99%. The high-dielectric fibers are alumina fibers, titanium dioxide fibers, barium titanate fibers, strontium titanate fibers, calcium titanate fibers, sodium bismuth titanate fibers, or potassium niobate fibers; the mass content of the high-dielectric fibers in the solvent-dispersed nano high-dielectric fibers is less than 20%.

3. The preparation method of a sintered anode foil added with nano high-dielectric fibers according to claim 1, characterized in that, In Step 1, the rate of the high-speed disperser for dispersing the nano high-dielectric fibers is 200 r / min to 6000 r / min.

4. The preparation method of a sintered anode foil added with nano high-dielectric fibers according to claim 1, characterized in that, In Step 2, the particle size of the aluminum powder or aluminum alloy powder is less than 50 μm, and the mass purity of the aluminum powder and aluminum alloy powder is greater than 99.99%.

5. The preparation method of a sintered anode foil adding nano high-dielectric fibers according to claim 1, characterized in that, In Step 1, the solvent is one or more of tributyl citrate, butyl carbitol, glycerol, ethylene glycol, and terpineol; in Step 2, the binder is one or more of ethyl cellulose, polyvinyl alcohol, polymethacrylate, carboxymethyl cellulose, polypropylene, polyethylene, polyisobutene, vinyl acetate resin, vinyl alcohol resin, polyvinyl fluoride resin, propylene resin, epoxy resin, urea resin, and phenolic resin.

6. The preparation method of a sintered anode foil adding nano high-dielectric fibers according to claim 1, characterized in that, In Step 3, the thickness of the aluminum foil substrate is 30 μm to 60 μm, and the single-sided coating thickness is 40 μm to 100 μm.

7. The preparation method of a sintered anode foil added with nano high-dielectric fibers according to claim 1, characterized in that In Step 3, the coating method of the aluminum powder slurry is blade coating; the temperature of the vacuum drying treatment is 40°C to 200°C.

8. The preparation method of a sintered anode foil adding nano high-dielectric fibers according to claim 1, characterized in that, The process of the sintering treatment in Step 4 is as follows: First, heat at a heating rate of 1°C / min to 20°C / min to 250°C to 300°C and keep warm for 1 h to 4 h, then heat at a heating rate of 1°C / min to 20°C / min to 350°C to 500°C and keep warm for 2 h to 8 h, and then heat at a heating rate of 1°C / min to 20°C / min to 600°C to 650°C and keep warm for 1 h to 24 h, and then cool with the furnace; nitrogen or argon is used as the protective gas during the sintering treatment process, or a vacuum environment is adopted.

9. The preparation method of a sintered anode foil added with nano high-dielectric fibers according to claim 1, characterized in that, In Step 5, both boiling and washing are performed with deionized water, and the boiling is for 10 min to 20 min.

10. The preparation method of a sintered anode foil added with nano high-dielectric fibers according to claim 1, characterized in that, In Step 6, the forming treatment is performed with a boric acid solution with a mass concentration of 10%, and the forming voltage is 520 V.