阅读说明：本技术 一种高比表面积、高比容的烧结阳极材料的制备方法 (Preparation method of sintered anode material with high specific surface area and high specific volume ) 是由 白光珠 张于胜 史瑞科 潘晓龙 王立强 王海丽 于 2021-09-02 设计创作，主要内容包括：本发明公开了一种高比表面积、高比容的烧结阳极材料的制备方法,包括以下步骤：一、将球状铝粉进行球磨处理,得到不规则状铝粉；二、将球状铝粉与不规则状铝粉进行混合,然后加入溶剂和粘结剂后进行搅拌,得到铝粉浆料；三、将铝粉浆料涂覆在铝箔基体表面,得到涂覆后铝箔基体；四、将涂覆后铝箔基体依次进行烧结、水煮和化成处理,得到铝电解电容器用阳极材料。本发明通过将球状铝粉与不规则状铝粉混合制备浆料,利用球状铝粉提供电解液进入阳极材料内部的孔隙,利用不规则状铝粉提供更高的比表面积,通过两者互相搭配,使阳极材料具有不同的比表面积和一定的孔隙率,保证了阳极材料能够提供更大的有效表面积,从而获得更大的比容。(The invention discloses a preparation method of a sintered anode material with high specific surface area and high specific volume, which comprises the following steps: firstly, ball milling spherical aluminum powder to obtain irregular aluminum powder; mixing spherical aluminum powder and irregular aluminum powder, adding a solvent and a binder, and stirring to obtain aluminum powder slurry; thirdly, coating the aluminum powder slurry on the surface of the aluminum foil substrate to obtain the coated aluminum foil substrate; and fourthly, sequentially sintering, boiling and forming the coated aluminum foil substrate to obtain the anode material for the aluminum electrolytic capacitor. According to the invention, the spherical aluminum powder and the irregular aluminum powder are mixed to prepare the slurry, the spherical aluminum powder is used for providing the electrolyte to enter the pores in the anode material, the irregular aluminum powder is used for providing a higher specific surface area, and the anode material has different specific surface areas and a certain porosity by matching the spherical aluminum powder and the irregular aluminum powder, so that the anode material can provide a larger effective surface area, and a larger specific volume is obtained.)

1. A preparation method of a sintered anode material with high specific surface area and high specific volume is characterized by comprising the following specific steps:

step one, ball milling treatment is carried out on spherical aluminum powder to obtain irregular aluminum powder;

step two, mixing spherical aluminum powder with the irregular aluminum powder obtained in the step one, adding a solvent and a binder, and stirring to obtain aluminum powder slurry;

step three, coating the aluminum powder slurry obtained in the step two on the surface of an aluminum foil substrate to obtain a coated aluminum foil substrate;

step four, sequentially sintering, water boiling and chemical treatment are carried out on the coated aluminum foil substrate obtained in the step three to obtain aluminum electrolysisAn anode material for a container; the specific surface area of the anode material for the aluminum electrolytic capacitor is more than 1200cm²/cm³Specific volume is more than 0.7 mu F/cm²。

2. The method for preparing the sintered anode material with high specific surface area and high specific volume according to claim 1, wherein the ball milling process in the first step is as follows: spherical aluminum powder, metal grinding balls and stearic acid are filled in a ball milling tank of a ball mill, then the ball milling tank is vacuumized and then argon is introduced, and the ball mill is opened for ball milling to obtain irregular aluminum powder.

3. The method for preparing the sintered anode material with high specific surface area and high specific volume according to claim 2, wherein in the ball milling process: the ball-material ratio is 10-30: 1, the ball-material filling ratio is 20-50%, the mass of stearic acid is 0.5-2% of the mass of spherical aluminum powder, the mass purity of the spherical aluminum powder is not less than 99.99%, the particle size is not more than 10 microns, the metal grinding ball is made of hard alloy, the diameter is 10mm, argon is high-purity argon with the mass purity of not less than 99.999%, the air pressure for introducing the argon is 0.01-0.1 MPa, the rotating speed of the ball mill is 300-500 rpm, the ball milling time is 2-24 h, and the ball milling mode is intermittent ball milling: stopping ball milling for 10-60 min after 5-15 min each time.

4. The method for preparing the sintered anode material with high specific volume and high specific surface area according to claim 1, wherein the irregular aluminum powder in the first step comprises a spindle shape, a strip shape, a fiber shape and a sheet shape, the particle size of the irregular aluminum powder is 10-20 μm, and the length-diameter ratio is 2-50: 1.

5. the method for preparing the sintered anode material with high specific surface area and high specific volume according to claim 1, wherein the mass ratio of the spherical aluminum powder to the irregular aluminum powder in the aluminum powder slurry in the second step is 1-99: 1 to 99.

6. The method for preparing a sintered anode material with high specific volume and high specific surface area according to claim 1, wherein the solvent in the second step is one or more selected from tributyl citrate, butyl carbitol, glycerol, ethylene glycol and terpineol, and the binder is one or more selected from ethyl cellulose, polyvinyl alcohol, polymethacrylate, carboxymethyl cellulose, polypropylene, polyethylene, polyisobutylene, ethylene-vinyl acetate resin, polyvinyl alcohol resin, polytetrafluoroethylene resin, acrylic resin, epoxy resin, urea-formaldehyde resin and phenol-formaldehyde resin.

7. The method for preparing the sintered anode material with high specific volume and high specific surface area according to claim 1, wherein the aluminum foil substrate is subjected to the de-oxidation treatment before coating in the third step, and the de-oxidation treatment is performed by soaking in a NaOH solution with a mass concentration of 0.1% -10%.

8. The method for preparing the sintered anode material with high specific volume and high specific surface area according to claim 1, wherein the thickness of the aluminum foil substrate in the third step is 30 to 60 μm, the thickness of the aluminum powder slurry in the coated aluminum foil substrate is 40 to 100 μm, and the coating is double-sided coating by using a scraper.

9. The method for preparing a sintered anode material with high specific volume and high specific surface area according to claim 1, wherein the sintering process in step four comprises: firstly, heating the coated aluminum foil substrate to 250-300 ℃ at a heating rate of 5-20 ℃/min, then preserving heat for 1-4 h, then heating to 350-500 ℃ at a heating rate of 5-20 ℃/min, then preserving heat for 2-8 h, then heating to 600-650 ℃ at a heating rate of 5-20 ℃/min, preserving heat for 1-24 h, and then cooling along with a furnace; and the atmosphere in the furnace in the sintering process is nitrogen, argon or vacuum.

10. The method for preparing a sintered anode material with high specific volume and high specific surface area according to claim 1, wherein the formation treatment in step four adopts a boric acid solution with a mass concentration of 0.5-20%, and the formation voltage is 520V.

Technical Field

The invention belongs to the technical field of aluminum electrolytic capacitors, and particularly relates to a preparation method of a sintered anode material with high specific surface area and high specific volume.

Background

Aluminum electrolytic capacitors have been widely used in the fields of industrial frequency conversion, inverters, power electronic circuits, and the like as important devices in the electronics industry. The anode foil is a key element of the aluminum electrolytic capacitor, and the quality of the anode foil is related to the service life of the capacitor, so that the service life of the whole electronic machine is directly influenced. At present, most anode foils of domestic high-voltage aluminum electrolytic capacitors adopt corrosion foils, the processing of the corrosion foils needs aluminum foils with high cubic texture content, then a sulfuric acid-hydrochloric acid system is used for electrochemical corrosion or chemical corrosion, high-density square tunnel holes are generated on the surfaces of the aluminum foils so as to increase the specific surface area, and then an aluminum oxide dielectric layer is formed after formation to form the final anode aluminum foils. The prior anode aluminum foil has long production time, high processing cost, strict requirements on processing and corrosion conditions, high maintenance cost of quality stability, and greater environmental protection pressure on the treatment of waste acid and waste oil generated in the processing and corrosion processes. Different from the high-purity aluminum corrosion surface expanding technology, the powder layer electronic aluminum foil technology is a technology for generating a porous structure with a high specific surface area by sintering aluminum powder on a core layer aluminum foil. The preparation of the powder layer electronic aluminum foil does not need a corrosion link, so that the manufacturing cost is greatly reduced, and the powder layer electronic aluminum foil is energy-saving, emission-reducing and environment-friendly.

Although the spherical aluminum powder with single particle size is stacked, the space can be fully utilized, and a natural porous structure is formed. However, due to the limitation of practical production technology, the aluminum powder with a single particle size is difficult to be classified and the production cost is high. Therefore, in the preparation process of the powder layer electronic aluminum foil, in order to reduce the cost, it is necessary to select aluminum powder with different particle sizes and shapes for mixing. The aluminum powder in various shapes can promote the electronic aluminum foil of the powder layer to form a communicated pore structure and provide a larger specific surface area, and the specific capacity is improved to a certain extent. For example, aluminum foil, also 120 μm thick, has now an area expansion ratio of less than 65 for the corrosion area expansion technique; and the core layer is a powder layer foil with the thickness of 30 mu m and the thickness of a single-side powder layer of 45 mu m, if 4 mu m spherical aluminum powder and 8 mu m irregular aluminum powder are matched, the surface expansion rate can reach 100, and the electric capacity of the anode aluminum foil can be greatly improved.

Therefore, it is desirable to provide a method for preparing a sintered anode material with high specific surface area and high specific volume.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a method for preparing a sintered anode material with high specific surface area and high specific volume, aiming at the defects of the prior art. According to the method, spherical aluminum powder and irregular aluminum powder are mixed to prepare slurry, the spherical aluminum powder is used for providing electrolyte to enter pores inside the anode material, the irregular aluminum powder is used for providing a higher specific surface area, the anode material has different specific surface areas and a certain porosity through mutual matching of the spherical aluminum powder and the irregular aluminum powder, the anode material is guaranteed to provide a larger effective surface area, and therefore a larger specific volume is obtained.

In order to solve the technical problems, the invention adopts the technical scheme that: a preparation method of a sintered anode material with high specific surface area and high specific volume is characterized by comprising the following specific steps:

step one, ball milling treatment is carried out on spherical aluminum powder to obtain irregular aluminum powder;

step two, mixing spherical aluminum powder with the irregular aluminum powder obtained in the step one, adding a solvent and a binder, and stirring to obtain aluminum powder slurry;

step three, coating the aluminum powder slurry obtained in the step two on the surface of an aluminum foil substrate to obtain a coated aluminum foil substrate;

step four, sequentially sintering, boiling and forming the coated aluminum foil substrate obtained in the step three to obtain an anode material for the aluminum electrolytic capacitor; the specific surface area of the anode material for the aluminum electrolytic capacitor is more than 1200cm²/cm³Specific volume is more than 0.7 mu F/cm²。

According to the invention, spherical aluminum powder is subjected to ball milling treatment to prepare irregular aluminum powder, and then the spherical aluminum powder and the irregular aluminum powder are mixed according to a certain proportion to prepare slurry, wherein the spherical aluminum powder aims at providing a hole for electrolyte to enter the interior of an anode material, and the irregular aluminum powder aims at providing a higher specific surface area; the invention removes the solvent and the binder through sintering, fully combines the spherical aluminum powder, the irregular aluminum powder and the aluminum foil matrix on the surface of the aluminum foil matrix, forms a hydration film on the surface of the anode material through water boiling, forms an oxidation film on the surface of the anode material through formation treatment, and improves the performance of the material.

The preparation method of the sintered anode material with high specific surface area and high specific volume is characterized in that the ball milling process in the first step is as follows: spherical aluminum powder, metal grinding balls and stearic acid are filled in a ball milling tank of a ball mill, then the ball milling tank is vacuumized and then argon is introduced, and the ball mill is opened for ball milling to obtain irregular aluminum powder. According to the invention, metal grinding balls are adopted to ball-mill spherical aluminum powder into various shapes to obtain irregular aluminum powder, stearic acid is added as a dispersing agent to prevent the aluminum powder from being welded with the steel balls and the ball-milling tank when the surface activity of the aluminum powder is higher, gas in the ball-milling tank is removed by vacuumizing, then argon is introduced to prevent the irregular aluminum powder from being oxidized, and the quality of the irregular aluminum powder is ensured.

The preparation method of the sintered anode material with high specific surface area and high specific volume is characterized in that in the ball milling process: the ball-material ratio is 10-30: 1, the ball-material filling ratio is 20-50%, the mass of stearic acid is 0.5-2% of the mass of spherical aluminum powder, the mass purity of the spherical aluminum powder is not less than 99.99%, the particle size is not more than 10 microns, the metal grinding ball is made of hard alloy, the diameter is 10mm, argon is high-purity argon with the mass purity of not less than 99.999%, the air pressure for introducing the argon is 0.01-0.1 MPa, the rotating speed of the ball mill is 300-500 rpm, the ball milling time is 2-24 h, and the ball milling mode is intermittent ball milling: stopping ball milling for 10-60 min after 5-15 min each time. According to the invention, collision energy can be fully utilized by controlling the ball-material ratio, irregular aluminum powder with proper particle size can be obtained, and when the ball-material ratio is high, namely, less aluminum powder is added, empty grinding is easy to generate, so that the energy utilization rate is low, and the ball-milling effect is influenced; when the ball-material ratio is low, namely more aluminum powder is added, because the added steel balls are definite, the effective crushing area is definite, so that in the ball milling process, a large amount of powder is pressed out, only a small part of raw materials are captured by the interfaces between the balls to be ground and crushed, other irregular aluminum powder obtained by ball milling has larger particle size due to the extension of shearing force and rubbing, the stearic acid with mass fraction can be effectively prevented from being welded with the steel balls and the ball milling tank when the surface activity of the aluminum powder is higher by controlling the mass of the stearic acid, the stearic acid with too little mass fraction cannot play a role, the stearic acid can react with the aluminum powder when the particle size is too large to generate aluminum stearate, the aluminum powder is prevented from being flaked, other impurities are not brought into the aluminum powder by controlling the mass purity of the spherical aluminum powder, the quality of the irregular aluminum powder is ensured, the particle size of the irregular aluminum powder after ball milling is controlled by controlling the particle size of the spherical aluminum powder, the particle size after ball milling is overlarge, the activity of the aluminum powder is reduced, the aluminum powder is difficult to combine with an aluminum matrix in the sintering process, a metal grinding ball with the diameter of 10mm is made of hard alloy, the metal grinding ball has high structural strength, can fully ball mill the spherical aluminum powder, and meanwhile, impurities can not be introduced, other impurities can not be introduced by controlling the purity and the air pressure of argon, irregular aluminum powder can be fully protected, the aluminum powder with different regular shapes and proper particle sizes can be obtained by ball milling under the parameters by controlling the rotating speed and the ball milling time of the ball mill, the aluminum powder is divided into 3 stages of cake forming, thinning and crushing in the ball milling process, and when the rotating speed is overlarge and the ball milling time is overlong, the aluminum powder can be crushed; when the rotating speed is too low and the ball milling time is too short, the aluminum powder is difficult to be ball milled into thin and even can not be cake-shaped, and the intermittent ball milling can prevent the oxidation, combustion and even explosion of the aluminum powder due to high activity.

The preparation method of the sintered anode material with the high specific surface area and the high specific volume is characterized in that in the step one, the irregular aluminum powder comprises a spindle shape, a strip shape, a fiber shape and a sheet shape, the particle size of the irregular aluminum powder is 10-20 microns, and the length-diameter ratio is 2-50: 1. the irregular aluminum powder is spindle-shaped, strip-shaped, fibrous and flaky and has a higher specific surface area, the particle size of the irregular aluminum powder is 10-20 microns, the irregular aluminum powder can provide a higher specific surface area and a certain porosity for an anode foil by matching with spherical aluminum powder, the electrical property is improved, and the length-diameter ratio is 2-50: 1, has high specific surface area, and when the length-diameter ratio exceeds a certain value, the aluminum powder can be crushed.

The preparation method of the sintered anode material with high specific surface area and high specific volume is characterized in that in the second step, the mass ratio of the spherical aluminum powder to the irregular aluminum powder in the aluminum powder slurry is 1-99: 1 to 99. According to the invention, by controlling the mass ratio of spherical aluminum powder to irregular aluminum powder, a higher specific surface area is obtained on the basis of ensuring that the anode foil has certain pores, the spherical aluminum powder is added for providing electrolyte to enter the pores in the anode material, the irregular aluminum powder is added for providing a higher specific surface area, and materials with different properties are prepared by mutually matching the spherical aluminum powder and the irregular aluminum powder.

The preparation method of the sintered anode material with high specific surface area and high specific volume is characterized in that in the second step, the solvent is one or more than two of tributyl citrate, butyl carbitol, glycerol, glycol and terpineol, and the binder is one or more than two of ethyl cellulose, polyvinyl alcohol, polymethacrylate, carboxymethyl cellulose, polypropylene, polyethylene, polyisobutylene, ethylene-vinyl acetate resin, polyvinyl alcohol resin, polytetrafluoroethylene resin, acrylic resin, epoxy resin, urea-formaldehyde resin and phenolic resin. The invention adopts the solvent to uniformly disperse irregular aluminum powder in the aluminum powder slurry, dissolves the binder, uniformly mixes the binder and the aluminum powder, simultaneously carries the aluminum powder, and controls the type of the solvent to uniformly disperse the aluminum powder, has high volatilization speed, low boiling point, small pollution and low price.

The preparation method of the sintered anode material with the high specific surface area and the high specific volume is characterized in that in the third step, the aluminum foil substrate is subjected to oxidation film removing treatment before coating, and the oxidation film removing treatment process is soaking in NaOH solution with the mass concentration of 0.1-10%. The oxide layer on the surface of the aluminum foil substrate is removed through oxide film removal treatment, the aluminum foil substrate has degreasing and dust removal effects, the coating layer is easy to combine, aluminum powder is better combined on the surface of the substrate in the sintering process, and the oxide layer is fully removed through soaking in NaOH solution with the mass concentration of 0.1% -10%.

The preparation method of the sintered anode material with the high specific surface area and the high specific volume is characterized in that in the third step, the thickness of the aluminum foil substrate is 30-60 mu m, the thickness of aluminum powder slurry in the coated aluminum foil substrate is 40-100 mu m, and the coating is double-sided coating by adopting a scraper. According to the invention, the thickness of the aluminum foil substrate is controlled, the thickness of the coating layer is increased, the use of the aluminum substrate is reduced, the cost is saved, the mechanical strength is influenced due to the thinness, the curling and winding of the anode foil in the later period are influenced, the specific capacitance of the anode foil is influenced due to the excessive thickness, the thickness of the prepared powder layer electronic aluminum foil is controlled to be 130-230 mu m by controlling the thickness of the aluminum powder slurry, the specific capacitance cannot be ensured when the thickness is too small, the later use cannot be ensured when the thickness is too large, the double-sided coating is carried out by adopting a scraper, the aluminum coating film with high smoothness and glossiness is obtained, and the adjustment precision is high compared with other coating modes.

The preparation method of the sintered anode material with high specific surface area and high specific volume is characterized in that the sintering treatment process in the fourth step is as follows: firstly, heating the coated aluminum foil substrate to 250-300 ℃ at a heating rate of 5-20 ℃/min, then preserving heat for 1-4 h, then heating to 350-500 ℃ at a heating rate of 5-20 ℃/min, then preserving heat for 2-8 h, then heating to 600-650 ℃ at a heating rate of 5-20 ℃/min, preserving heat for 1-24 h, and then cooling along with a furnace; and the atmosphere in the furnace in the sintering process is nitrogen, argon or vacuum. The invention carries out calcination by three-stage heating, removes the solvent and the binder by lower temperature in the first two stages, and fully combines spherical aluminum powder, irregular aluminum powder and the aluminum foil matrix together by higher temperature in the third stage, thereby enhancing the structural strength of the anode material.

The preparation method of the sintered anode material with the high specific surface area and the high specific volume is characterized in that boric acid solution with the mass concentration of 0.5-20% is adopted in the formation treatment in the fourth step, and the formation voltage is 520V. The invention forms an oxide film on the surface of the anode material through chemical conversion treatment, thereby improving the performance of the material.

Compared with the prior art, the invention has the following advantages:

1. according to the invention, the spherical aluminum powder and the irregular aluminum powder are mixed to prepare the slurry, the spherical aluminum powder is used for providing the electrolyte to enter the pores in the anode material, the irregular aluminum powder is used for providing a higher specific surface area, and the anode material has different specific surface areas and a certain porosity by matching the spherical aluminum powder and the irregular aluminum powder, so that the anode material can provide a larger effective surface area, and a larger specific volume is obtained.

2. The invention controls the length-diameter ratio of the irregular aluminum powder to ensure that the irregular aluminum powder has higher specific surface area and further increases the specific volume of the anode material.

3. The invention removes the solvent and the binder through sintering, fully combines the spherical aluminum powder, the irregular aluminum powder and the aluminum foil matrix on the surface of the aluminum foil matrix, forms a hydration film on the surface of the anode material through water boiling, forms an oxidation film on the surface of the anode material through formation treatment, and improves the performance of the material.

4. The thickness of the aluminum foil substrate is controlled, the thickness of the coating layer is increased, the use of the aluminum substrate is reduced, and the cost is saved; by performing double-sided coating with a doctor blade, an aluminum coating film of high smoothness and gloss is obtained, and the adjustment accuracy is high compared to other coating methods.

The technical solution of the present invention is further described in detail by examples below.

Detailed Description

Example 1

The embodiment comprises the following steps:

step one, ball milling treatment is carried out on spherical aluminum powder to obtain irregular aluminum powder; the ball milling process comprises the following steps: filling spherical aluminum powder, metal grinding balls and stearic acid into a ball milling tank of a ball mill, vacuumizing the ball milling tank, introducing argon, opening the ball mill for ball milling, and performing classification treatment on powder obtained by ball milling to obtain irregular aluminum powder; in the ball milling process: the ball-material ratio is 30:1, the ball-material filling ratio is 50%, the mass of stearic acid is 2% of that of spherical aluminum powder, the mass purity of the spherical aluminum powder is not less than 99.99%, the average particle size is 3-10 μm, the metal grinding ball is made of hard alloy, the diameter is 10mm, argon is high-purity argon with the mass purity of 99.999%, the pressure of argon introduced is 0.1MPa, the rotation speed of the ball mill is 500rpm, the ball milling time is 2h, and the ball milling mode is intermittent ball milling: ball milling for 5min, and stopping for 20 min; the irregular aluminum powder is flaky, and the particle size of the irregular aluminum powder is 10-20 microns;

step two, mixing spherical aluminum powder with the irregular aluminum powder obtained in the step one, adding a solvent and a binder, and stirring to obtain aluminum powder slurry; the mass ratio of the spherical aluminum powder to the irregular aluminum powder in the aluminum powder slurry is 99: 1; the solvent is tributyl citrate and terpineol, and the binder is carboxymethyl cellulose; the mass ratio of tributyl citrate, terpineol and carboxymethyl cellulose in the aluminum powder slurry is 20: 75: 5;

step three, coating the aluminum powder slurry obtained in the step two on the surface of an aluminum foil substrate to obtain a coated aluminum foil substrate; the aluminum foil substrate is subjected to oxidation film removing treatment before coating, wherein the oxidation film removing treatment process is to soak the aluminum foil substrate in NaOH solution with the mass concentration of 0.1%; the thickness of the aluminum foil substrate is 30 micrometers, the thickness of aluminum powder slurry in the coated aluminum foil substrate is 100 micrometers, and the coating is double-sided coating by adopting a scraper;

step four, sequentially sintering and forming the coated aluminum foil substrate obtained in the step three to obtain an anode material for the aluminum electrolytic capacitor; the sintering treatment process comprises the following steps: firstly, heating the coated aluminum foil substrate to 250 ℃ at a heating rate of 20 ℃/min, then preserving heat for 2h, then heating to 400 ℃ at a heating rate of 20 ℃/min, then preserving heat for 2h, then heating to 650 ℃ at a heating rate of 20 ℃/min, preserving heat for 8h, and then cooling along with a furnace; the atmosphere in the furnace in the sintering process is nitrogen; the formation treatment adopts a boric acid solution with the mass concentration of 10%, and the formation voltage is 520V.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 1.16 mu F/cm²The specific surface area is 1300cm²/cm³。

Example 2

The present embodiment is different from embodiment 1 in that: the length-diameter ratio of the irregular aluminum powder is 10: 1.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 1.32 mu F/cm²The specific surface area is 1500cm²/cm³。

Example 3

The embodiment comprises the following steps:

step one, ball milling treatment is carried out on spherical aluminum powder to obtain irregular aluminum powder; the ball milling process comprises the following steps: filling spherical aluminum powder, metal grinding balls and stearic acid into a ball milling tank of a ball mill, vacuumizing the ball milling tank, introducing argon, opening the ball mill for ball milling, and performing classification treatment on powder obtained by ball milling to obtain irregular aluminum powder; in the ball milling process: the ball-material ratio is 20:1, the ball-material filling ratio is 45%, the mass of stearic acid is 1.5% of that of spherical aluminum powder, the mass purity of the spherical aluminum powder is not less than 99.99%, the average particle size is 3-10 μm, the metal grinding ball is made of hard alloy, the diameter is 10mm, argon is high-purity argon with the mass purity of 99.999%, the pressure of argon introduced is 0.05MPa, the rotation speed of the ball mill is 400rpm, the ball milling time is 12h, and the ball milling mode is intermittent ball milling: ball milling for 10min, and stopping for 10 min; the irregular aluminum powder is strip-shaped and fibrous, and the particle size of the irregular aluminum powder is 10-20 microns;

step two, mixing spherical aluminum powder with the irregular aluminum powder obtained in the step one, adding a solvent and a binder, and stirring to obtain aluminum powder slurry; the mass ratio of the spherical aluminum powder to the irregular aluminum powder in the aluminum powder slurry is 98: 2, the mass ratio of the strip shapes to the fiber shapes in the irregular aluminum powder is 1: 1; the solvent is ethylene glycol and terpineol, and the binder is carboxymethyl cellulose; the mass ratio of ethylene glycol, terpineol and carboxymethyl cellulose in the aluminum powder slurry is 10: 85: 5;

step three, coating the aluminum powder slurry obtained in the step two on the surface of an aluminum foil substrate to obtain a coated aluminum foil substrate; the aluminum foil substrate is subjected to oxidation film removal treatment before coating, wherein the oxidation film removal treatment process is to soak the aluminum foil substrate in a NaOH solution with the mass concentration of 5%; the thickness of the aluminum foil substrate is 60 micrometers, the thickness of aluminum powder slurry in the coated aluminum foil substrate is 50 micrometers, and the coating is double-sided coating by adopting a scraper;

step four, sequentially sintering and forming the coated aluminum foil substrate obtained in the step three to obtain an anode material for the aluminum electrolytic capacitor; the sintering treatment process comprises the following steps: firstly, heating the coated aluminum foil substrate to 270 ℃ at a heating rate of 5 ℃/min, then preserving heat for 4h, then heating to 500 ℃ at a heating rate of 10 ℃/min, then preserving heat for 4h, then heating to 600 ℃ at a heating rate of 5 ℃/min, preserving heat for 24h, and then cooling along with a furnace; the furnace atmosphere in the sintering process is argon; the formation treatment adopts boric acid solution with mass concentration of 0.5%, and the formation voltage is 520V.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 0.96 mu F/cm²Specific surface area of 1400cm²/cm³。

Example 4

The present embodiment is different from embodiment 3 in that: the length-diameter ratio of the irregular aluminum powder is 5: 1.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 1.25 mu F/cm²Specific surface area of 1600cm²/cm³。

Example 5

The embodiment comprises the following steps:

step one, ball milling treatment is carried out on spherical aluminum powder to obtain irregular aluminum powder; the ball milling process comprises the following steps: filling spherical aluminum powder, metal grinding balls and stearic acid into a ball milling tank of a ball mill, vacuumizing the ball milling tank, introducing argon, opening the ball mill for ball milling, and performing classification treatment on powder obtained by ball milling to obtain irregular aluminum powder; in the ball milling process: the ball-material ratio is 10:1, the ball-material filling ratio is 20%, the mass of stearic acid is 0.5% of that of spherical aluminum powder, the mass purity of the spherical aluminum powder is not less than 99.99%, the average particle size is 3-10 μm, the metal grinding ball is made of hard alloy, the diameter is 10mm, argon is high-purity argon with the mass purity of 99.999%, the pressure of argon introduced is 0.01MPa, the rotation speed of the ball mill is 300rpm, the ball milling time is 24h, and the ball milling mode is intermittent ball milling: ball milling for 15min, and stopping for 60 min; the irregular aluminum powder is in a spindle shape, a strip shape, a fiber shape and a sheet shape, and the particle size of the irregular aluminum powder is 10-20 microns;

step two, mixing spherical aluminum powder with the irregular aluminum powder obtained in the step one, adding a solvent and a binder, and stirring to obtain aluminum powder slurry; the mass ratio of the spherical aluminum powder to the irregular aluminum powder in the aluminum powder slurry is 96: 4, the mass ratio of the spindle shape, the strip shape, the fiber shape and the sheet shape in the irregular aluminum powder is 1: 1: 1: 1; the solvent is ethylene glycol and terpineol, and the binder is carboxymethyl cellulose; the mass ratio of ethylene glycol, terpineol and carboxymethyl cellulose in the aluminum powder slurry is 20: 75: 5;

step three, coating the aluminum powder slurry obtained in the step two on the surface of an aluminum foil substrate to obtain a coated aluminum foil substrate; the aluminum foil substrate is subjected to oxidation film removal treatment before coating, wherein the oxidation film removal treatment process is to soak the aluminum foil substrate in a NaOH solution with the mass concentration of 10%; the thickness of the aluminum foil substrate is 40 micrometers, the thickness of aluminum powder slurry in the coated aluminum foil substrate is 40 micrometers, and the coating is double-sided coating by adopting a scraper;

step four, sequentially sintering and forming the coated aluminum foil substrate obtained in the step three to obtain an anode material for the aluminum electrolytic capacitor; the sintering treatment process comprises the following steps: firstly, heating the coated aluminum foil substrate to 300 ℃ at a heating rate of 10 ℃/min, then preserving heat for 1h, then heating to 350 ℃ at a heating rate of 5 ℃/min, then preserving heat for 8h, then heating to 630 ℃ at a heating rate of 10 ℃/min, preserving heat for 1h, and then cooling along with the furnace; the atmosphere in the furnace is vacuum in the sintering process; the formation treatment adopts a boric acid solution with the mass concentration of 20%, and the formation voltage is 520V.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 0.73 mu F/cm²Specific surface area of 1400cm²/cm³。

Example 6

This embodiment is different from embodiment 5 in that: the length-diameter ratio of the irregular aluminum powder is 2: 1.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 0.98 mu F/cm²Specific surface area of 1600cm²/cm³。

Example 7

The embodiment comprises the following steps:

step one, ball milling treatment is carried out on spherical aluminum powder to obtain irregular aluminum powder; the ball milling process comprises the following steps: filling spherical aluminum powder, metal grinding balls and stearic acid into a ball milling tank of a ball mill, vacuumizing the ball milling tank, introducing argon, opening the ball mill for ball milling, and performing classification treatment on powder obtained by ball milling to obtain irregular aluminum powder; in the ball milling process: the ball-material ratio is 15:1, the ball-material filling ratio is 30%, the mass of stearic acid is 0.5% of that of spherical aluminum powder, the mass purity of the spherical aluminum powder is not less than 99.99%, the average particle size is 3-10 μm, the metal grinding ball is made of hard alloy, the diameter is 10mm, argon is high-purity argon with the mass purity of 99.999%, the pressure of argon introduced is 0.01MPa, the rotation speed of the ball mill is 300rpm, the ball milling time is 24h, and the ball milling mode is intermittent ball milling: ball milling for 15min, and stopping for 60 min; the irregular aluminum powder is in a spindle shape, a strip shape, a fiber shape and a sheet shape, and the particle size of the irregular aluminum powder is 10-20 microns;

mixing spherical aluminum powder with the irregular aluminum powder obtained in the step one, adding a solvent and a binder, and stirring to obtain aluminum powder slurry; the mass ratio of the spherical aluminum powder to the irregular aluminum powder in the aluminum powder slurry is 1: 99, the mass ratio of the spindle shape, the strip shape, the fiber shape and the sheet shape in the irregular aluminum powder is 1: 1: 1: 1; the solvent is tributyl citrate and terpineol, and the binder is carboxymethyl cellulose and epoxy resin; the mass ratio of tributyl citrate, terpineol, carboxymethyl cellulose and epoxy resin in the aluminum powder slurry is 10: 80: 5: 5;

step three, coating the aluminum powder slurry obtained in the step two on the surface of an aluminum foil substrate to obtain a coated aluminum foil substrate; the aluminum foil substrate is subjected to oxidation film removal treatment before coating, wherein the oxidation film removal treatment process is to soak the aluminum foil substrate in a NaOH solution with the mass concentration of 4%; the thickness of the aluminum foil substrate is 50 micrometers, the thickness of aluminum powder slurry in the coated aluminum foil substrate is 80 micrometers, and the coating is double-sided coating by adopting a scraper;

step four, sequentially sintering and forming the coated aluminum foil substrate obtained in the step three to obtain an anode material for the aluminum electrolytic capacitor; the sintering treatment process comprises the following steps: firstly, heating the coated aluminum foil substrate to 280 ℃ at a heating rate of 15 ℃/min, then preserving heat for 3h, then heating to 450 ℃ at a heating rate of 8 ℃/min, then preserving heat for 6h, then heating to 620 ℃ at a heating rate of 15 ℃/min, preserving heat for 10h, and then cooling along with the furnace; the atmosphere in the furnace in the sintering process is nitrogen; the formation treatment adopts a boric acid solution with the mass concentration of 5%, and the formation voltage is 520V.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 0.92 mu F/cm²Specific surface area of 1400cm²/cm³。

Example 8

This embodiment is different from embodiment 7 in that: the length-diameter ratio of the irregular aluminum powder is 50: 1.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 1.25 mu F/cm²Specific surface area of 1600cm²/cm³。

Example 9

The embodiment comprises the following steps:

step one, ball milling treatment is carried out on spherical aluminum powder to obtain irregular aluminum powder; the ball milling process comprises the following steps: filling spherical aluminum powder, metal grinding balls and stearic acid into a ball milling tank of a ball mill, vacuumizing the ball milling tank, introducing argon, opening the ball mill for ball milling, and performing classification treatment on powder obtained by ball milling to obtain irregular aluminum powder; in the ball milling process: the ball-material ratio is 25:1, the ball-material filling ratio is 40%, the mass of stearic acid is 1% of that of spherical aluminum powder, the mass purity of the spherical aluminum powder is not less than 99.99%, the average particle size is 3-10 μm, the metal grinding ball is made of hard alloy, the diameter is 10mm, argon is high-purity argon with the mass purity of 99.999%, the pressure of argon introduced is 0.08MPa, the rotating speed of the ball mill is 350rpm, the ball milling time is 10h, and the ball milling mode is intermittent ball milling: ball milling for 8min, and stopping for 30 min; the irregular aluminum powder is in a spindle shape, a strip shape, a fiber shape and a sheet shape, and the particle size of the irregular aluminum powder is 10-20 microns;

step two, mixing spherical aluminum powder with the irregular aluminum powder obtained in the step one, adding a solvent and a binder, and stirring to obtain aluminum powder slurry; the mass ratio of the spherical aluminum powder to the irregular aluminum powder in the aluminum powder slurry is 50: 50, the mass ratio of the spindle shape, the strip shape, the fiber shape and the sheet shape in the irregular aluminum powder is 1: 1: 1: 1; the solvent is glycerol, and the binder is polypropylene and polyisobutylene; the mass ratio of the glycerol to the polypropylene to the polyisobutylene in the aluminum powder slurry is 90: 5: 5;

step three, coating the aluminum powder slurry obtained in the step two on the surface of an aluminum foil substrate to obtain a coated aluminum foil substrate; the aluminum foil substrate is subjected to oxidation film removal treatment before coating, wherein the oxidation film removal treatment process is to soak the aluminum foil substrate in a NaOH solution with the mass concentration of 1%; the thickness of the aluminum foil substrate is 45 micrometers, the thickness of aluminum powder slurry in the coated aluminum foil substrate is 60 micrometers, and the coating is double-sided coating by adopting a scraper;

step four, sequentially sintering and forming the coated aluminum foil substrate obtained in the step three to obtain an anode material for the aluminum electrolytic capacitor; the sintering treatment process comprises the following steps: firstly, heating the coated aluminum foil substrate to 290 ℃ at a heating rate of 8 ℃/min, then preserving heat for 2.5h, then heating to 430 ℃ at a heating rate of 15 ℃/min, then preserving heat for 6h, then heating to 640 ℃ at a heating rate of 8 ℃/min, preserving heat for 20h, and then cooling along with a furnace; the atmosphere in the furnace in the sintering process is nitrogen; the formation treatment adopts boric acid solution with the mass concentration of 15%, and the formation voltage is 520V.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 0.85 mu F/cm²Specific surface area of 1400cm²/cm³。

Example 10

The present embodiment is different from embodiment 9 in that: the length-diameter ratio of the irregular aluminum powder is 30: 1.

Through detection, the static specific capacity of the anode material prepared by the implementation reaches 1.12 mu F/cm²Specific surface area of 1600cm²/cm³。

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, change and equivalent changes of the above embodiments according to the technical essence of the invention are still within the protection scope of the technical solution of the invention.