CN112279645A

CN112279645A - Preparation method of rod-shaped carbon anode material

Info

Publication number: CN112279645A
Application number: CN202011235059.0A
Authority: CN
Inventors: 赵伟
Original assignee: Individual
Current assignee: Quzhou Qufarui New Energy Materials Co ltd
Priority date: 2020-11-08
Filing date: 2020-11-08
Publication date: 2021-01-29
Anticipated expiration: 2040-11-08
Also published as: CN112279645B

Abstract

The invention provides a preparation method of a rodlike carbon anode material, wherein the size, the size and the shape of a carbon rod carbon raw material are almost consistent, the obtained carbon fiber anode material has high mechanical strength, good corrosion resistance, good uniformity and long service life, and the breaking strength of the carbon fiber anode material is 950 +/-10 kg/cm²Mean deviation of breaking strength 5.52, coefficient of variation of breaking strength 5.7 x 10^‑3And the high-temperature use condition has no swelling and no fracture.

Description

Preparation method of rod-shaped carbon anode material

Technical Field

The invention relates to the technical field of a preparation method of an inert anode material for nonferrous metal electrolytic refining.

Background

The electrode plays a very important role in the electrolysis industry, the insoluble anode material for extracting nonferrous metals at present mainly comprises a lead alloy (mainly Pb-Ag alloy) electrode and a titanium-based coating electrode, but the lead alloy has high density, low strength and easy dissolution, and the lead alloy is adopted as the anode material, so that the lead content in an electrolysis product is increased; in the latter, although the titanium-based noble metal (iridium, ruthenium, tantalum) oxide coating electrode has been successfully applied to the chlor-alkali industry, the titanium-based noble metal oxide coating electrode is not suitable for being used in an oxygen evolution type sulfuric acid electrolyte, and the problem that the titanium internal resistance is too large is unavoidable.

To overcome the deficiencies of lead electrodes, researchers have mainly focused on two areas: on one hand, the silver content in the Pb-Ag alloy is reduced, and simultaneously, other alloy elements (Sr, Sn, Bi, Sb and the like) and rare earth elements (Ce, Tb, Yb and the like) are added for multi-element alloying so as to improve the alloy strength and corrosion resistance and reduce the cell voltage; on the other hand, a layer of electrocatalytic activator and a reinforcing agent, such as IrO2, RuO2, PbO2, MnO2 and the like, is electrodeposited or coated on the surface of the lead electrode by means of electrochemical deposition, coating and the like, so that the conductivity and the stability of the electrode are improved, and the adhesion of a surface coating is enhanced. However, various treatments to the lead alloy anode, or the addition of other elements to the alloy, or the activation and enhancement treatments to the lead alloy anode can not always solve the problem of dissolution of the lead matrix in the electrochemical corrosion process.

Carbon materials, such as carbon fibers, have a series of excellent mechanical properties such as high specific modulus and specific strength, corrosion resistance, fatigue resistance, wear resistance, light specific gravity and the like, and meanwhile, the carbon materials have the advantages of good conductivity, strong corrosion resistance, high strength, easiness in processing, long service life, low preparation cost and high electrode catalytic activity, and are suitable for being used for nonferrous metal electrorefining inert anodes.

At present, carbon materials mainly focus on porous carbon materials with high specific surface area and small internal resistance, modification studies on carbon-based materials, and the like. Commonly used carbon materials are: activated carbon, carbon black, carbon nanofibers, glassy carbon, carbon nanotubes, carbon aerogels, network-structured activated carbon, and carbonization products of certain organic substances, and the like.

For example, CN 105386087A discloses a preparation method of a carbon fiber anode material for electrolysis, which comprises the following steps of mixing carbon fiber powder and a binder according to a mass ratio of 9: 1-3: 2, uniformly mixing to form a prefabricated ingredient; placing the prefabricated ingredients in a ball mill for ball milling and then screening to obtain ball grinding materials; placing the ball-milled material in a molding device for cold press molding to obtain a molding material; placing the molding material in nitrogen or inert atmosphere or vacuum high-temperature atmosphere for oxygen-free sintering molding, and cooling to obtain a carbon fiber anode material, wherein the carbon fiber anode has good conductivity, mechanical strength, corrosion resistance and chemical stability; simultaneously effectively reduces the impurity content in the deposited metal and greatly improves the purity of the cathode product.

However, the same problem exists in the electrodes made of any kind of activated carbon, carbon black, carbon nanofibers, glassy carbon, carbon nanotubes, carbon aerogel, activated carbon with a network structure, and carbonization products of some organic substances, that is, the mechanical strength of the electrode, such as the breaking strength, is not uniform, and it often happens that the breaking strength at a certain position is too low, and the mechanical property of the whole electrode material is reduced, which is mainly caused by the non-uniform size of the raw materials of the activated carbon, carbon black, and carbon nanofibers.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provides a preparation method of a rod-shaped carbon anode material, wherein the size, the dimension and the shape of a carbon rod raw material are almost consistent, the obtained carbon fiber anode material has high mechanical strength, good corrosion resistance, good uniformity and long service life, and the breaking strength of the carbon fiber anode material is 950 +/-10 kg/cm²Mean deviation of breaking strength 5.52, coefficient of variation of breaking strength 5.7 x 10^-3And the high-temperature use condition has no swelling and no fracture.

A preparation method of a rod-shaped carbon anode material comprises the following steps:

(1) uniformly mixing the rod-shaped carbon and a binder according to the mass ratio of (7-8) to 1, wherein the binder is resin or asphalt;

(2) and (3) pressure forming: at a pressure of 800-²Pre-pressing to form with density of 1.2-1.3g/cm³；

(3) Vacuum carbonization: vacuum degree of 250-: by 5^oThe temperature rises to 450 ℃ at a rate of C/h^oC, keeping the temperature for 1h by 2^oThe temperature rises to 550 ℃ at the rate of C/h^oC, keeping the temperature for 2 hours, and then adding 1^oThe temperature rises to 920 at the rate of C/h^oC, preserving the heat for 5 hours to obtain a carbon pre-sintering blank;

(4) high-temperature graphitization: placing the graphite powder in a nitrogen high-temperature graphitization furnace to obtain a graphite powder with the temperature of 15 DEG C^oThe temperature rises to 2400 ℃ at the rate of C/h^oC, preserving heat for 8 hours; the obtained rod-shaped carbon anode material has a density of 1.85-1.89^oC; the breaking strength of the anode is 950 +/-10 kg/cm²Mean deviation of breaking strength 5.52, coefficient of variation of breaking strength 5.7 x 10^-3,

Wherein the preparation process of the rod-shaped carbon comprises the following steps:

(1) forming a porous oxide film on the surface of an aluminum material by using the aluminum material as a base material through an electrochemical method;

(2) repeatedly filling the carbon source in the oxide film pore canal for multiple times by taking the porous oxide film as a hard template and the pitch resin polymer as the carbon source;

(3) mechanically polishing the material obtained in the step (2);

(4) corroding the material obtained in the step (3) by using strong acid, and removing the hard template;

(5) and washing and drying to obtain rod-shaped carbon.

Further, the substrate is pretreated: degreasing-washing-pickling-washing-alkaline etching-washing-brightening-washing, wherein the degreasing solution: 45 g/L sodium bicarbonate, 45 g/L sodium carbonate, 40 deg.C^oC; acid washing solution: hydrofluoric acid 0.02g/L, sulfuric acid 4 g/L, surfactant 1 g/L, temperature room temperature, alkaline etching solution: 45 g/L of sodium hydroxide, 1 g/L of sodium gluconate and 40 ℃ of temperature^oC, the time is 2-3 min; brightening liquid: 350g/L nitric acid solution for 2-3 min.

Further, the process of step (1) is as follows: the pretreated aluminum material is taken as an anode, an inert lead material is taken as a cathode, a 10-20wt.% sulfuric acid aqueous solution is taken as electrolyte, and the current density is 1-2A/dm²The time is 30-100min, and the temperature is 20-30^oAnd C, obtaining the anodic oxidation film aluminum material.

Further, the obtained anodized aluminum material was coated at 35 deg.C^oAnd C, expanding the pores by using 5-7wt.% phosphoric acid for 40-50min, and carrying out vacuum drying.

Further, the preparation method of the pitch resin polymer in the step (2) is as follows: placing benzaldehyde, anthracene and concentrated sulfuric acid into a three-neck bottle, evacuating with nitrogen, and introducing at 135 deg.C^oC, obtaining a black asphalt resin product under the condition of continuous stirring, repeatedly washing with propanol, filtering and drying to obtain a light yellow powder solid, dissolving the light yellow powder in tetrahydrofuran, stirring for 30min, adding the hole-expanded aluminum oxide film obtained in the step (1), continuously stirring, performing auxiliary vacuum pumping, filling for 12-24h, performing rotary evaporation to obtain the light yellow aluminum oxide film, and further performing 800-step nitrogen atmosphere^oAnd C, carbonizing for 4 hours.

Further, the vacuum degree of the vacuumizing is 10-20 Pa.

Further, the repeated filling is performed for 1 to 2 times.

Further, the mechanical polishing is polishing wheel grinding and is used for removing non-porous carbon materials on the porous layer of the anodic oxide film.

Further, the strong acid is 15wt.% of H₂SO₄And 10wt.% HNO₃Volume ratio of VH₂SO₄:VHNO₃1:1, under stirring at 100^oC, refluxing for 3 h.

Further, the washing is repeated washing by using deionized water until the solution is neutral, then filtering is carried out, and the drying is 60^oAnd C, blowing and drying for 12 hours.

Regarding the preparation method:

(a) after the electrode raw material carbon is determined, certain small-amount binder substances are added according to the physical and chemical properties of the forming main material so as to improve the powder adhesion and the cohesiveness of the forming main material and achieve a satisfactory forming effect. After the main molding material is determined, different molding binders are selected to greatly influence the physical properties of the product. In order to improve the performance of the product and the performance of the molding process, a proper amount of molding binder is added according to the physical properties of the molding main material.

The invention selects resin or asphalt as the binder, and the product is not hoped to be polluted by the binder in the electrode forming process, the resin or asphalt can be decomposed in the roasting process, the obtained decomposed product is bonded with the rod-shaped carbon to play a certain skeleton role, so that the dispersed rod-shaped carbon is combined into a firm integral electrode, and the integral electrode is graphitized under vacuum and high temperature to finally become the high-density and high-strength carbon anode material.

(b) Pressure molding, in a cold press at a pressure of 800-²Pre-pressing to form with density of 1.2-1.3g/cm³；

For initially increasing the density of the carbonaceous material, as shown in fig. 8.

(c) Vacuum carbonization: through the test of carbon material in TGA/DTA curve, it can be found that the TGA/DTA curve is 400^oAbout C has a small thermal weight loss and thermal decompositionThe dissolved small molecules begin to volatilize at 400-^oC has no obvious thermal weight loss, and when the temperature is increased to 550^OC undergoes intense thermal decomposition and dehydrogenation reactions and generates a large amount of gas, during which the volume shrinks, the shrinkage rate is about 9.78%, the weight loss is 11.32%, and the density is 1.62 g/cm³This process requires at 450^oC and 550^oThe C two temperature points are fully reacted, which is beneficial to the growth of high-density carbon materials, specifically the vacuum degree of 250-: by 5^oThe temperature rises to 450 ℃ at a rate of C/h^oC, keeping the temperature for 1h by 2^oThe temperature rises to 550 ℃ at the rate of C/h^oC, keeping the temperature for 2 hours, and then adding 1^oThe temperature rises to 920 at the rate of C/h^oAnd C, preserving the heat for 5 hours to obtain the carbon pre-sintering blank.

(d) High-temperature graphitization: : placing the graphite powder in a nitrogen high-temperature graphitization furnace to obtain a graphite powder with the temperature of 15 DEG C^oThe temperature rises to 2400 ℃ at the rate of C/h^oC, preserving heat for 8 hours; further reducing volatile matters in the rod-shaped carbon, improving the heat conductivity of the anode, and reducing the phenomenon of carbonization cracking caused by thermal stress generated by low heat conductivity coefficient and large shrinkage, wherein the shrinkage of the carbon anode in the process is about 3.2%, the weight loss is 1.9%, and the density is 1.85-1.89g/cm³

(1) The aluminum material used in the present application should be pretreated before anodizing regardless of the surface treatment process, so as to obtain a good effect, and cleaning the surface is the primary condition, and the present application expects to obtain an anodized film having uniform nanopores and uniform thickness, so that the pretreatment is the basis for obtaining an isotropic uniform oxidized film, and the base material of the present invention is pretreated: degreasing, washing with water, pickling, washing with water, alkaline etching, washing with water, brightening and washing with water.

Wherein the degreasing solution: 45 g/L sodium bicarbonate, 45 g/L sodium carbonate, 40 deg.C^oAnd C, before the surface of the workpiece is treated, oil stains on the surface must be removed firstly to ensure the bonding strength of the conversion coating and the matrix metal, ensure the chemical reaction of the conversion coating to be smoothly carried out and obtain the conversion coating with qualified quality.

Acid washing solution: 0.02g/L of hydrofluoric acid, 4 g/L of sulfuric acid, 1 g/L of surfactant, room temperature, and acid cleaning to remove dirt and oxide on the surface without hydrogen embrittlement, wherein the acid degreasing mechanism of the aluminum alloy is as follows: oxides on the surface of the aluminum are dissolved to loosen the oil stains, and the oil stains are separated from the metal surface by utilizing the action of water flow.

Alkaline etching solution: 45 g/L of sodium hydroxide, 1 g/L of sodium gluconate and 40 ℃ of temperature^oC, the time is 2-3min, the aluminum alloy workpiece can not be subjected to conversion film treatment after a degreasing process, the surface generally has defects of a natural oxide film, processing stripes and the like, and the natural oxide film needs to be removed by corrosion treatment to activate the surface. The alkaline etching is the most common etching process, the main component is NaOH solution, the cost is low, the maintenance and the management are easy, and the alkaline etching is used for removing the oxide film which can not be removed by acid cleaning.

Brightening liquid: 350g/L nitric acid solution for 2-3 min. The surface of the workpiece corroded by acid and alkali is often dark, because the surface of the aluminum alloy containing high copper content has copper oxide, and black hanging ash is formed. In order to brighten the surface of the workpiece, the polishing treatment is usually performed in a nitric acid solution.

(2) Regarding anodic oxidation: adopting 10-20wt.% sulfuric acid aqueous solution as electrolyte, and having current density of 1-2A/dm²The time is 30-100min, and the temperature is 20-30^oC, the thickness of the obtained anodic oxide film aluminum material is 10-20 microns, the pore diameter is concentrated below 500nm and is small, as shown in figure 5, the pore diameter is not beneficial to subsequent filling of carbon precursors, and therefore the obtained anodic oxide film aluminum material is 35 DEG^oAnd C, reaming the hole by using 5-7wt.% phosphoric acid for 40-50min, and performing vacuum drying to complete reaming of the anode oxide film pore canal, so that the carbon precursor is favorably filled, the thickness is not obviously reduced or is not obviously reduced in the reaming process, the pore diameter is enlarged to 0.5-0.7 mu m, as shown in figure 6, the hard template is an anode oxide film pore canal hard template for reaming for 20min, as shown in figure 7, the hard template is an anode oxide film hard template for reaming for 45 min.

(3) Regarding the preparation of the precursor: the carbon precursor is selected according to the principle that the molecular size is suitable for entering the pore channel of the anodic oxide film template, the compatibility (wettability and hydrophilicity) with the pore wall is good, and the polymer substance separated or further polymerized in the pore has higher carbonization yield and the like. At present, carbon precursors mainly comprise sucrose, xylose, glucose, furfuryl alcohol resin, phenolic resin, mesophase pitch, anthracene, phenanthrene, divinylbenzene and some organic solvents such as ethanol, methanol, toluene and the like. There are also a number of ways to introduce different precursors into the channels of the hard template, the most common being mainly solution impregnation, the type of carbon precursor also having a large influence on the structure of the final carbon material. The furfuryl alcohol is used as a carbon precursor, and mesoporous carbon with good order can be easily prepared; when the mesophase pitch is used as the carbon precursor, the microporosity of the material can be obviously reduced, and the carbon yield is high; in addition, the type of the carbon precursor has a very important influence on the graphitization degree of the finally obtained carbon material, and the precursor (such as phenolic resin) with a loose molecular structure and high oxygen content can obtain a hard carbon material containing a large amount of micropores and high oxygen content after carbonization, and the hard carbon material is difficult to graphitize. The precursor (such as anthracene) containing no oxygen and having a condensed ring structure can be carbonized to obtain a mesoporous carbon material with higher graphitization degree.

The preparation method comprises the following steps: placing benzaldehyde, anthracene and concentrated sulfuric acid into a three-neck bottle, evacuating with nitrogen, and introducing at 135 deg.C^oC, obtaining a black asphalt resin product under the condition of continuous stirring, repeatedly washing with propanol, filtering and drying to obtain a light yellow powder solid, dissolving the light yellow powder in tetrahydrofuran, stirring for 30min, adding the hole-expanded aluminum oxide film obtained in the step (1), continuously stirring, performing auxiliary vacuum pumping, filling for 12-24h, performing rotary evaporation to obtain the light yellow aluminum oxide film, and further performing 800-step nitrogen atmosphere^oAnd C, carbonizing for 4 hours.

In the process, attention needs to be paid to (a) temperature and moisture in the filling process, so that the water-based hole sealing phenomenon of an anodic oxide film is avoided, and the filling of the carbon precursor liquid is obviously reduced due to the sealing of holes; (b) stirring and vacuumizing are necessary means, and due to the viscosity of the asphalt polymer and the difficulty in the filling process, the asphalt polymer must be stirred constantly and vacuumized, and the auxiliary carbon precursor enters a pore channel and then is subjected to evaporation, drying and carbonization processes; (c) the number of filling times is determined as needed, and the more the better, the more the filling is sufficient.

In addition, the quality of the hard template of the anodic oxidation porous membrane, the filling amount of the carbon precursor and the carbonization process all influence the mesostructure of the carbon nano-rod to a great extent. Of particular importance is the choice of carbon precursor. The carbon precursor molecules can interact with the template molecules to form an ordered mesostructure. Secondly, precursor molecules must be capable of being crosslinked with each other to form a thermosetting polymer network, and deformation caused by skeleton shrinkage in the process of high-temperature carbonization and template removal can be guaranteed to be resisted in the template removal engineering through the formation of the polymer network. In addition, different carbon precursors can undergo different carbonization processes, and further, the mesostructure of the carbon rod can be influenced, and the microstructure such as graphitization degree can also be influenced. Therefore, the carbon precursor molecule is required to have the characteristics of proper size, good thermal stability, abundant warp groups, high residual carbon content of the polymer, and the like.

(4) Regarding the grinding: mechanical polishing is a key step for controlling morphology, when the carbon precursor is excessively filled as shown in figure 1, carbon materials are attached to the surface of the anodic oxide film, polishing is needed to remove the non-pore carbon materials on the porous layer of the anodic oxide film, one end of the finally obtained carbon rod is a semi-arc section at the position of the barrier layer of the anodic oxide film, and the other end of the carbon rod is a mechanically polished flat line end, as shown in figure 2, one end of the carbon rod is arc-shaped, and the other end of the carbon rod is a flat line end.

(5) Regarding corrosion, for anodized aluminum, the base materials are aluminum oxide and aluminum material, and due to the amphoteric property of aluminum material, the corrosion can be performed by using acid solution or alkaline solution, but the alkaline corrosion is abandoned in the application, and the invention needs to introduce a large amount of hydrophilic free radicals such as hydroxyl, oxygen and the like on the surface of carbon material besides removing aluminum material template, and the alkaline corrosion is not enough, so that 15wt.% of H is used as strong acid₂SO₄And 10wt.% HNO₃Volume ratio of VH₂SO₄:VHNO₃1:1, under stirring at 100^oC, refluxing for 3 h, introducing hydroxyl through strong acid corrosion and refluxing, so that the water solubility of the carbon material is improved, and under an ethanol and water solution system, as shown in an SEM (scanning electron microscope) shown in an attached figure 2, the carbon rod disclosed by the invention is uniformly dispersed and low in polymerization, and the application field of the carbon rod is remarkably widened due to the existence of the dispersed state.

As shown in the attached FIG. 3 and FIG. 4, the top view and the side view of the structured carbon rod material obtained after the structured carbon rod material is directly corroded without being ground.

The scheme of the invention has the following beneficial effects:

(1) the carbon rods prepared by the template method are almost consistent in size, size and shape, and the finally obtained carbon material is good in uniformity.

(2) The obtained carbon fiber anode material has high mechanical strength, good corrosion resistance, good uniformity and long service life,

(3) the breaking strength of the anode material is 950 +/-10 kg/cm²Mean deviation of breaking strength 5.52, coefficient of variation of breaking strength 5.7 x 10^-3And the high-temperature use condition has no swelling and no fracture.

Drawings

FIG. 1 is a schematic view of a method for preparing a carbon nanorod according to the present invention.

FIG. 2 is a TEM image of the carbon nanorods of the invention under water-ethanol conditions.

Fig. 3 is a SEM top view of the nano rod-shaped carbon material without being polished according to the present invention.

Fig. 4 is a side view of the nano rod-shaped carbon material without being ground according to the present invention.

Fig. 5 is an SEM image of the non-reamed channels of the anodized film of the present invention.

FIG. 6 is an SEM image of the anode oxide film pore canals reamed for 20 min.

FIG. 7 is an SEM image of the anodic oxide film pore canals reamed for 45 min.

Fig. 8 is an SEM image of the anode material obtained by press molding according to the present invention.

Detailed Description

Example 1

A preparation method of a rod-shaped carbon anode material is characterized by comprising the following steps:

(a) uniformly mixing rod-shaped carbon and a binder according to a mass ratio of 7:1, wherein the binder is resin or asphalt;

(b) and (3) pressure forming: at a pressure of 800kg/cm in a cold press²Pre-pressing and forming;

(c) vacuum carbonization: vacuum degree of 250toor, temperature programmed parameter: by 5^oThe temperature rises to 450 ℃ at a rate of C/h^oC, keeping the temperature for 1h by 2^oThe temperature rises to 550 ℃ at the rate of C/h^oC, keeping the temperature for 2 hours, and then adding 1^oThe temperature rises to 920 at the rate of C/h^oC, preserving the heat for 5 hours to obtain a carbon pre-sintering blank;

(d) high-temperature graphitization: placing the graphite powder in a nitrogen high-temperature graphitization furnace to obtain a graphite powder with the temperature of 15 DEG C^oThe temperature rises to 2400 ℃ at the rate of C/h^oC, preserving heat for 8 hours;

wherein the preparation process of the rod-shaped carbon comprises the following steps: (1) pre-treatment, degreasing, washing with water, acid washing, washing with water, alkaline etching, washing with water, brightening, washing with water, wherein the degreasing solution: 45 g/L sodium bicarbonate, 45 g/L sodium carbonate, 40 deg.C^oC; acid washing solution: hydrofluoric acid 0.02g/L, sulfuric acid 4 g/L, surfactant 1 g/L, temperature room temperature, alkaline etching solution: 45 g/L of sodium hydroxide, 1 g/L of sodium gluconate and 40 ℃ of temperature^oC, the time is 2 min; brightening liquid: 350g/L nitric acid solution for 2 min.

(2) Forming a porous oxide film on the surface of an aluminum material by using the aluminum material as a base material through an electrochemical method; the method is characterized in that aluminum or aluminum alloy is used as a base material, an inert lead material is used as a cathode, a 10wt.% sulfuric acid aqueous solution is used as electrolyte, and the current density is 1A/dm²Time 30min, temperature 20^oC, obtaining an anodized aluminum material, and putting the obtained anodized aluminum material at 35 DEG^oAnd C, expanding the pores by using 5wt.% phosphoric acid for 40min, and performing vacuum drying.

(3) And repeatedly filling the carbon source in the pore canal of the oxide film for many times by taking the porous oxide film as a hard template and the pitch resin polymer as the carbon source, wherein the preparation method of the pitch resin polymer comprises the following steps: placing benzaldehyde, anthracene and concentrated sulfuric acid into a three-neck bottle, and adding nitrogenAir evacuation at 135^oC, obtaining a black asphalt resin product under the condition of continuous stirring, repeatedly washing with propanol, filtering and drying to obtain a light yellow powder solid, dissolving the light yellow powder in tetrahydrofuran, stirring for 30min, adding the hole-expanded aluminum oxide film obtained in the step (1), continuously stirring, performing auxiliary vacuum pumping, filling for 12h, performing rotary evaporation to obtain the light yellow aluminum oxide film, further reacting with nitrogen atmosphere, and performing 800^oAnd C, carbonizing for 4 hours under the condition of vacuum degree of 10-20Pa, and filling twice.

(4) Mechanical polishing step materials: the mechanical polishing is polishing by a polishing wheel and is used for removing non-porous carbon materials on the porous layer of the anodic oxide film.

(5) Removing the hard template by strong acid corrosion: the strong acid is 15wt.% of H₂SO₄And 10wt.% HNO₃Volume ratio of VH₂SO₄:VHNO₃1:1, under stirring at 100^oC, refluxing for 3 h.

(6) Washing, drying, washing with deionized water for several times to neutral, filtering, and drying to 60%^oAnd C, blowing and drying for 12 hours.

Example 2

(a) uniformly mixing rod-shaped carbon and a binder according to a mass ratio of 7.5:1, wherein the binder is resin or asphalt;

(b) and (3) pressure forming: at a pressure of 800-²Pre-pressing and forming;

(c) vacuum carbonization: vacuum degree 300toor, temperature programmed parameter: by 5^oThe temperature rises to 450 ℃ at a rate of C/h^oC, keeping the temperature for 1h by 2^oThe temperature rises to 550 ℃ at the rate of C/h^oC, keeping the temperature for 2 hours, and then adding 1^oThe temperature rises to 920 at the rate of C/h^oC, preserving the heat for 5 hours to obtain a carbon pre-sintering blank;

(d) high-temperature graphitization: placing the graphite powder in a nitrogen high-temperature graphitization furnace to obtain a graphite powder with the temperature of 15 DEG C^oThe temperature rises to 2400 ℃ at the rate of C/h^oC, preserving heat for 8 hours; breaking strength of the anodeIs 950 +/-10 kg/cm²Mean deviation of breaking strength 5.52, coefficient of variation of breaking strength 5.7 x 10^-3,

(1) pre-treatment, degreasing, washing with water, acid washing, washing with water, alkaline etching, washing with water, brightening, washing with water, wherein the degreasing solution: 45 g/L sodium bicarbonate, 45 g/L sodium carbonate, 40 deg.C^oC; acid washing solution: hydrofluoric acid 0.02g/L, sulfuric acid 4 g/L, surfactant 1 g/L, temperature room temperature, alkaline etching solution: 45 g/L of sodium hydroxide, 1 g/L of sodium gluconate and 40 ℃ of temperature^oC, the time is 2.5 min; brightening liquid: 350g/L nitric acid solution for 2.5 min.

(2) Forming a porous oxide film on the surface of an aluminum material by using the aluminum material as a base material through an electrochemical method; the method is characterized in that aluminum or aluminum alloy is used as a base material, an inert lead material is used as a cathode, a 15wt.% sulfuric acid aqueous solution is used as electrolyte, and the current density is 1.5A/dm²Time 60min, temperature 25^oC, obtaining an anodized aluminum material, and putting the obtained anodized aluminum material at 35 DEG^oUnder C, 6wt.% phosphoric acid is used for reaming for 45min, and vacuum drying is carried out.

(3) And repeatedly filling the carbon source in the pore canal of the oxide film for many times by taking the porous oxide film as a hard template and the pitch resin polymer as the carbon source, wherein the preparation method of the pitch resin polymer comprises the following steps: placing benzaldehyde, anthracene and concentrated sulfuric acid into a three-neck bottle, evacuating with nitrogen, and introducing at 135 deg.C^oC, obtaining a black asphalt resin product under the condition of continuous stirring, repeatedly washing with propanol, filtering and drying to obtain a light yellow powder solid, dissolving the light yellow powder in tetrahydrofuran, stirring for 30min, adding the hole-expanded aluminum oxide film obtained in the step (1), continuously stirring, performing auxiliary vacuum pumping, filling for 18h, performing rotary evaporation to obtain the light yellow aluminum oxide film, further reacting with nitrogen atmosphere, and performing 800 h^oAnd C, carbonizing for 4 hours under the condition of vacuum degree of 10-20Pa, and filling twice.

（5）Removing the hard template by strong acid corrosion: the strong acid is 15wt.% of H₂SO₄And 10wt.% HNO₃Volume ratio of VH₂SO₄:VHNO₃1:1, under stirring at 100^oC, refluxing for 3 h.

Example 3

(a) uniformly mixing rod-shaped carbon and a binder according to a mass ratio of 8:1, wherein the binder is resin or asphalt;

(b) and (3) pressure forming: in a cold press at a pressure of 850kg/cm²Pre-pressing and forming;

(1) pre-treatment, degreasing, washing with water, acid washing, washing with water, alkaline etching, washing with water, brightening, washing with water, wherein the degreasing solution: 45 g/L sodium bicarbonate, 45 g/L sodium carbonate, 40 deg.C^oC; acid washing solution: hydrofluoric acid 0.02g/L, sulfuric acid 4 g/L, surfactant 1 g/L, temperature room temperature, alkaline etching solution: 45 g/L of sodium hydroxide, 1 g/L of sodium gluconate and 40 ℃ of temperature^oC, the time is 3 min; brightening liquid: 350g/L nitric acid solution for 3 min.

(2) Forming a porous oxide film on the surface of an aluminum material by using the aluminum material as a base material through an electrochemical method; the method is characterized in that aluminum or aluminum alloy is used as a base material, an inert lead material is used as a cathode, a 20wt.% sulfuric acid aqueous solution is used as electrolyte, and the current density is 2A/dm²Time 100min, temperature 30^oC, obtaining an anodized aluminum material, and putting the obtained anodized aluminum material at 35 DEG^oAnd C, expanding the pores by using 7wt.% phosphoric acid for 50min, and performing vacuum drying.

(3) And repeatedly filling the carbon source in the pore canal of the oxide film for many times by taking the porous oxide film as a hard template and the pitch resin polymer as the carbon source, wherein the preparation method of the pitch resin polymer comprises the following steps: placing benzaldehyde, anthracene and concentrated sulfuric acid into a three-neck bottle, evacuating with nitrogen, and introducing at 135 deg.C^oC, obtaining a black asphalt resin product under the condition of continuous stirring, repeatedly washing with propanol, filtering and drying to obtain a light yellow powder solid, dissolving the light yellow powder in tetrahydrofuran, stirring for 30min, adding the hole-expanded aluminum oxide film obtained in the step (1), continuously stirring, performing auxiliary vacuum pumping, filling for 24h, performing rotary evaporation to obtain the light yellow aluminum oxide film, further reacting with nitrogen atmosphere, and performing 800^oAnd C, carbonizing for 4 hours under the condition of vacuum degree of 10-20Pa, and filling twice.

Using the procedure of example 2, 20 samples were prepared and measured for breaking strength using an ST-5E Strength tester, the breaking strength being 957 kg/cm each²；953 kg/cm²；955 kg/cm²；959 kg/cm²；956 kg/cm²；956 kg/cm²；954 kg/cm²；955 kg/cm²；956 kg/cm²；949 kg/cm²；952 kg/cm²；950 kg/cm²；961 kg/cm²；943 kg/cm²；957 kg/cm²；947 kg/cm²；949 kg/cm²；960 kg/cm²；942 kg/cm²；945 kg/cm²(ii) a The density of the obtained anode material is 1.85-1.89 by calculation^oC; the breaking strength of the anode is 950 +/-10 kg/cm²Mean deviation of breaking strength 5.52, coefficient of variation of breaking strength 5.7 x 10^-3The stability and breaking strength of the anode far exceed those of similar products.

Although the present invention has been described above by way of examples of preferred embodiments, the present invention is not limited to the specific embodiments, and can be modified as appropriate within the scope of the present invention.

Claims

1. A preparation method of a rod-shaped carbon anode material is characterized by comprising the following steps:

(a) uniformly mixing the rod-shaped carbon and a binder according to the mass ratio of (7-8) to 1, wherein the binder is resin or asphalt;

(b) and (3) pressure forming: at a pressure of 800-²Pre-pressing to form with density of 1.2-1.3g/cm³；

(c) Vacuum carbonization: vacuum degree of 250-: by 5^oThe temperature rises to 450 ℃ at a rate of C/h^oC, keeping the temperature for 1h by 2^oThe temperature rises to 550 ℃ at the rate of C/h^oC, keeping the temperature for 2 hours, and then adding 1^oThe temperature rises to 920 at the rate of C/h^oC, preserving the heat for 5 hours to obtain a carbon pre-sintering blank;

(d) high-temperature graphitization: placing the graphite powder in a nitrogen high-temperature graphitization furnace to obtain a graphite powder with the temperature of 15 DEG C^oThe temperature rises to 2400 ℃ at the rate of C/h^oC, preserving heat for 8 hours; the obtained rod-shaped carbon anode material has a density of 1.85-1.89^oC; the breaking strength of the anode is 950 +/-10 kg/cm²Mean deviation of breaking strength 5.52, coefficient of variation of breaking strength 5.7 x 10^-3,

(3) mechanically polishing the material obtained in the step (2);

(5) and washing and drying to obtain rod-shaped carbon.

2. The method for preparing a rod-shaped carbon anode material according to claim 1, wherein the base material is pretreated by: degreasing-washing-pickling-washing-alkaline etching-washing-brightening-washing, wherein the degreasing solution: 45 g/L sodium bicarbonate, 45 g/L sodium carbonate, 40 deg.C^oC; acid washing solution: hydrofluoric acid 0.02g/L, sulfuric acid 4 g/L, surfactant 1 g/L, temperature room temperature, alkaline etching solution: 45 g/L of sodium hydroxide, 1 g/L of sodium gluconate and 40 ℃ of temperature^oC, the time is 2-3 min; brightening liquid: 350g/L nitric acid solution for 2-3 min.

3. The method for preparing a rod-shaped carbon anode material according to claim 1, wherein the process of the step (1) is as follows: the pretreated aluminum material is taken as an anode, an inert lead material is taken as a cathode, a 10-20wt.% sulfuric acid aqueous solution is taken as electrolyte, and the current density is 1-2A/dm²The time is 30-100min, and the temperature is 20-30^oAnd C, obtaining the anodic oxidation film aluminum material.

4. The method for producing a rod-like carbon anode material according to claim 3, wherein the obtained anodized aluminum material is coated at 35 ℃ to obtain a rod-like carbon anode material^oAnd C, expanding the pores by using 5-7wt.% phosphoric acid for 40-50min, and carrying out vacuum drying.

5. The method for preparing a rod-shaped carbon anode material according to claim 1, wherein the pitch resin polymer in the step (2) is prepared by: placing benzaldehyde, anthracene and concentrated sulfuric acid into a three-neck bottleEvacuation with nitrogen at 135^oC, obtaining a black asphalt resin product under the condition of continuous stirring, repeatedly washing with propanol, filtering and drying to obtain a light yellow powder solid, dissolving the light yellow powder in tetrahydrofuran, stirring for 30min, adding the hole-expanded aluminum oxide film obtained in the step (1), continuously stirring, performing auxiliary vacuum pumping, filling for 12-24h, performing rotary evaporation to obtain the light yellow aluminum oxide film, and further performing 800-step nitrogen atmosphere^oAnd C, carbonizing for 4 hours.

6. The method for preparing a rod-like carbon anode material according to claim 5, wherein the degree of vacuum of said evacuation is 10 to 20 Pa.

7. The method for preparing a rod-shaped carbon anode material according to claim 1, wherein the repeated filling is performed 1 to 2 times.

8. The method according to claim 1, wherein the mechanical polishing is buff polishing for removing the non-porous carbonaceous material on the porous layer of the anodic oxide film.

9. The method according to claim 1, wherein the strong acid is 15wt.% of H₂SO₄And 10wt.% HNO₃Volume ratio of VH₂SO₄:VHNO₃1:1, under stirring at 100^oC, refluxing for 3 h.

10. The method for preparing a rod-shaped carbon anode material according to claim 1, wherein the washing is repeated several times by using deionized water until the rod-shaped carbon anode material becomes neutral, then the rod-shaped carbon anode material is filtered and dried to 60 degrees^oAnd C, blowing and drying for 12 hours.