阅读说明：本技术 一种孔径可控高比表面积电化学石墨电极的制备方法 (Preparation method of electrochemical graphite electrode with controllable aperture and high specific surface area ) 是由 吴沣 徐艳丽 杨家山 程雅琳 梁冉 姜鹏 李聃华 曹辉 刘巍 刘闪君 杜国强 于 2021-01-28 设计创作，主要内容包括：本发明公开了一种孔径可控高比表面积电化学石墨电极的制备方法,涉及石墨电极的制备技术领域,一种孔径可控高比表面积电化学石墨电极的制备方法,制备方法包括以下步骤：S1、对焦粉进行破碎,预筛分；S2、将焦粉过50-60目、170-175目或240-250目的筛子。该孔径可控高比表面积电化学石墨电极的制备方法,本发明通过堆积法制备多孔碳基材料,可达到孔径可控,可避免现有技术中制备电化学石墨电极时孔径单一问题,同时堆积法工艺简单,操作方便,成本低廉,能够大量减少腐蚀性药品的使用,适合大规模工业化生产。(The invention discloses a preparation method of an electrochemical graphite electrode with controllable aperture and high specific surface area, which relates to the technical field of graphite electrode preparation, and the preparation method of the electrochemical graphite electrode with controllable aperture and high specific surface area comprises the following steps: s1, crushing the coke powder, and pre-screening; s2, sieving the coke powder through a sieve with 50-60 meshes, 175 meshes at 170 and 250 meshes or 250 meshes at 240 and 250 meshes. According to the preparation method of the electrochemical graphite electrode with controllable aperture and high specific surface area, the porous carbon-based material is prepared by the stacking method, the aperture can be controlled, the problem of single aperture in the process of preparing the electrochemical graphite electrode in the prior art can be solved, and meanwhile, the stacking method is simple in process, convenient to operate, low in cost, capable of greatly reducing the use of corrosive medicines and suitable for large-scale industrial production.)

1. A preparation method of an electrochemical graphite electrode with controllable aperture and high specific surface area is characterized by comprising the following steps: the preparation method comprises the following steps:

s1, crushing the coke powder, and pre-screening;

s2, sieving the coke powder through a sieve with 50-60 meshes, 175 meshes in 170-plus-250 meshes or 250 meshes in 240-plus-250 meshes;

s3, respectively ultrasonically dispersing 50-60-mesh, 170-mesh and 175-mesh or 240-mesh and 250-mesh coke powder particles in a dispersion medium for 30min, selecting different medium ball grades according to different coke powder particle sizes for proportioning, then ball-milling for 3-4H, after the ball-milling is finished, performing suction filtration and low-temperature drying, and then measuring the particle size distribution of the coke powder by a laser particle size tester;

s4, mixing the ball-milled high-uniformity coke powder and the binder in a high-speed mixing mill, firstly mixing at a low rotating speed for 15min, and then mixing at a high rotating speed for 10 min;

s5, molding the mixed paste in a mold;

s6, roasting the sample molded in the S5 in a high-temperature nitrogen atmosphere furnace, graphitizing the sample, and obtaining the porous graphite electrode material with high bulk density at the graphitization temperature of 2700 ℃;

s7, finally, testing the specific surface area and the pore size of the obtained product material by using a specific surface area analyzer.

2. The method for preparing the electrochemical graphite electrode with controllable aperture and high specific surface area according to claim 1, wherein the method comprises the following steps: the pore diameter is formed by stacking particles with uniform particle size.

3. The method for preparing the electrochemical graphite electrode with controllable aperture and high specific surface area according to claim 1, wherein the method comprises the following steps: the dispersing medium in the S3 is ethanol.

4. The method for preparing the electrochemical graphite electrode with controllable aperture and high specific surface area according to claim 1, wherein the method comprises the following steps: the temperature of the low-temperature drying in the S3 is 40-60 ℃.

5. The method for preparing the electrochemical graphite electrode with controllable aperture and high specific surface area according to claim 1, wherein the method comprises the following steps: the medium ball in the S3 is zirconia, the ratio of the coke powder to the medium ball in the S3 is 10-20:1, and the rotating speed during ball milling is 300-400 r/min.

6. The method for preparing the electrochemical graphite electrode with controllable aperture and high specific surface area according to claim 1, wherein the method comprises the following steps: the ratio of the coke powder to the dispersion medium in the S3 is 200 g: 100 ml.

7. The method for preparing the electrochemical graphite electrode with controllable aperture and high specific surface area according to claim 1, wherein the method comprises the following steps: the binder used in the S4 is one or more of asphalt, polyvinyl alcohol, carboxymethyl cellulose and syrup, and the coke powder and the binder in the S4 comprise the following components in percentage by mass: 80-90% of coke powder and 5-30% of binder.

Technical Field

The invention relates to the technical field of preparation of graphite electrodes, in particular to a preparation method of an electrochemical graphite electrode with controllable aperture and high specific surface area.

Background

In the patent CN110540203A, a buckypan wood shell is used as a carbon source, and in the preparation method and application of the doped nano porous carbon material, a chemical activation method is used for preparing the porous carbon material, a large amount of corrosive medicines are consumed in the preparation process, and the obtained aperture is not controllable; in patent CN1753116A, a carbon material, a conductive agent, an organic monomer and a cross-linking agent are mixed into slurry, an initiator and a catalyst are added into the slurry for tape casting, and a porous electrode film is prepared after solidification, stripping and weak oxidation.

Therefore, a method for preparing an electrochemical graphite electrode with controllable pore size and high specific surface area is needed to solve the above problems.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a preparation method of an electrochemical graphite electrode with controllable aperture and high specific surface area, which solves the problems that the aperture is not controllable during the preparation of the electrochemical graphite electrode in the prior art, the preparation aperture of the electrochemical graphite electrode is single, the process is complicated, the preparation conditions are harsh, the cost is high, and the electrochemical graphite electrode is not suitable for large-scale industrial production.

(II) technical scheme

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows: a preparation method of an electrochemical graphite electrode with controllable aperture and high specific surface area comprises the following steps:

s1, crushing the coke powder, and pre-screening;

s2, sieving the coke powder through a sieve with 50-60 meshes, 175 meshes in 170-plus-250 meshes or 250 meshes in 240-plus-250 meshes;

s3, respectively ultrasonically dispersing 50-60-mesh, 170-mesh and 175-mesh or 240-mesh and 250-mesh coke powder particles in a dispersion medium for 30min, selecting different medium ball grades according to different coke powder particle sizes for proportioning, then ball-milling for 3-4H, after the ball-milling is finished, performing suction filtration and low-temperature drying, and then measuring the particle size distribution of the coke powder by a laser particle size tester;

s4, mixing the ball-milled high-uniformity coke powder and the binder in a high-speed mixing mill, firstly mixing at a low rotating speed for 15min, and then mixing at a high rotating speed for 10 min;

s5, molding the mixed paste in a mold;

s6, roasting the sample molded in the S5 in a high-temperature nitrogen atmosphere furnace, graphitizing the sample, and obtaining the porous graphite electrode material with high bulk density at the graphitization temperature of 2700 ℃;

s7, finally, testing the specific surface area and the pore size of the obtained product material by using a specific surface area analyzer.

Preferably, the pore diameter is formed by stacking particles having a uniform particle diameter.

Preferably, the dispersion medium in S3 is ethanol.

Preferably, the temperature for low-temperature drying in S3 is 40-60 ℃.

Preferably, the medium ball in the S3 is zirconia, the ratio of the coke powder to the medium ball in the S3 is 10-20:1, and the rotation speed during ball milling is 300-400 r/min.

Preferably, the ratio of the coke powder to the dispersion medium in the S3 is 200 g: 100 ml.

Preferably, the binder used in S4 is one or more of asphalt, polyvinyl alcohol, carboxymethyl cellulose, and syrup, and the coke powder and the binder in S4 comprise, by mass: 80-90% of coke powder and 5-30% of binder.

(III) advantageous effects

The invention has the beneficial effects that:

according to the preparation method of the electrochemical graphite electrode with controllable aperture and high specific surface area, the porous carbon-based material is prepared by the stacking method, the aperture can be controlled, the problem of single aperture in the process of preparing the electrochemical graphite electrode in the prior art can be solved, and meanwhile, the stacking method is simple in process, convenient to operate, low in cost, capable of greatly reducing the use of corrosive medicines and suitable for large-scale industrial production.

Drawings

FIG. 1 is a particle size distribution diagram according to an embodiment of the present invention;

FIG. 2 is a graph showing a distribution of particle sizes in accordance with example two of the present invention;

FIG. 3 is a distribution diagram of three particle sizes in accordance with an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-3, the present invention provides a technical solution: a preparation method of an electrochemical graphite electrode with controllable aperture and high specific surface area comprises the following steps:

s1, crushing the coke powder, and pre-screening;

s2, sieving the coke powder through a sieve with 50-60 meshes, 175 meshes in 170-plus-250 meshes or 250 meshes in 240-plus-250 meshes;

s3, respectively ultrasonically dispersing 50-60-mesh, 170-mesh and 175-mesh or 240-mesh and 250-mesh coke powder particles in a dispersion medium for 30min, selecting different medium ball grades according to different coke powder particle sizes for proportioning, then ball-milling for 3-4H, after the ball-milling is finished, performing suction filtration and low-temperature drying, and then measuring the particle size distribution of the coke powder by a laser particle size tester;

s4, mixing the ball-milled high-uniformity coke powder and the binder in a high-speed mixing mill, firstly mixing at a low rotating speed for 15min, and then mixing at a high rotating speed for 10 min;

s5, molding the mixed paste in a mold;

s6, roasting the sample molded in the S5 in a high-temperature nitrogen atmosphere furnace, graphitizing the sample, and obtaining the porous graphite electrode material with high bulk density at the graphitization temperature of 2700 ℃;

s7, finally, testing the specific surface area and the pore size of the obtained product material by using a specific surface area analyzer.

The pore diameter is formed by stacking particles with uniform particle size.

The dispersing medium in S3 is ethanol.

The temperature of the low-temperature drying in S3 is 40-60 ℃.

The medium ball in S3 is zirconia, the ratio of coke powder to the medium ball in S3 is 10-20:1, and the rotation speed during ball milling is 300-400 r/min.

In S3, the ratio of the coke powder to the dispersion medium is 200 g: 100 ml.

The binder used in S4 is one or more of asphalt, polyvinyl alcohol, carboxymethyl cellulose and syrup, and the coke powder and the binder in S4 comprise the following components in percentage by mass: 80-90% of coke powder and 5-30% of binder.

Example 1

Firstly, pre-crushing coke powder;

then passing the coke powder through a 50-60 mesh sieve (the particle size is 250-;

ultrasonically dispersing the coke powder particles with the particle size of 250-270 mu m in ethanol, wherein the ratio of the coke powder to the dispersion medium is as follows: 200g of coke powder/100 ml of ethanol, zirconia as a medium ball, a medium ball grade ratio of 8mm to 7mm to 5mm to 3 to 5 to 7, ball milling for 5-6h, a ball-material ratio of 10 to 1, a ball milling rotating speed: 300-400 r/min; after the ball milling is finished, carrying out suction filtration and low-temperature drying; measuring the particle size distribution of the coke powder by a laser particle size tester;

as shown in fig. 1, D90 ═ 74.25 μm, D50 ═ 62.23 μm, and D10 ═ 45.29 μm; adding 10% of carboxymethyl cellulose and distilled water into the ball-milled high-uniformity coke powder, firstly mixing for 15min at a low rotating speed in a high-speed mixing roll, then mixing for 10min at a high speed, and vibrating and molding the uniformly mixed paste in a mold;

roasting at 650 ℃ for 3h (10 ℃/minRT-250 ℃, 2 ℃/min250-550 ℃, 10 ℃/min550-650 ℃) in a nitrogen atmosphere furnace, and graphitizing at 2700 ℃ to obtain the high bulk density porous graphite electrode material.

Example 2

Firstly, pre-crushing coke powder;

then passing the coke powder through a 170-sand 175-mesh sieve (the particle size is 86-90 mu m), and ultrasonically dispersing the coke powder particles with the particle size of 86-90 mu m in ethanol, wherein the ratio of the coke powder to a dispersion medium is as follows: 200g of coke powder/100 ml of ethanol, zirconia as a medium ball, a medium ball grade ratio of 8mm to 7mm to 5mm to 3 to 5 to 7, ball milling for 5-6h, a ball-material ratio of 10 to 1, a ball milling rotating speed: 300-400 r/min. After the ball milling is finished, carrying out suction filtration and low-temperature drying; measuring the particle size distribution of the coke powder by a laser particle size tester;

as shown in fig. 2, D90 ═ 44.27 μm, D50 ═ 28.23 μm, and D10 ═ 22.33 μm; adding 10% of carboxymethyl cellulose and distilled water into the ball-milled high-uniformity coke powder, firstly mixing for 15min at a low rotating speed in a high-speed mixing roll, then mixing for 10min at a high speed, and vibrating and molding the uniformly mixed paste in a mold;

roasting at 650 ℃ for 3h (10 ℃/minRT-250 ℃, 2 ℃/min250-550 ℃, 10 ℃/min550-650 ℃) in a nitrogen atmosphere furnace, and graphitizing at 2700 ℃ to obtain the high bulk density porous graphite electrode material.

Example 3

Firstly, pre-crushing coke powder;

then passing the coke powder through a 240-sand 250-mesh sieve (with the particle size of 58-61 mu m), and ultrasonically dispersing the coke powder particles with the particle size of 58-61 mu m in ethanol, wherein the ratio of the coke powder to a dispersion medium is as follows: 200g of coke powder/100 ml of ethanol, zirconia as a medium ball, a medium ball grade ratio of 8mm to 7mm to 5mm to 3 to 5 to 7, ball milling for 5-6h, a ball-material ratio of 10 to 1, a ball milling rotating speed: 300-400 r/min; after the ball milling is finished, carrying out suction filtration and low-temperature drying; measuring the particle size distribution of the coke powder by a laser particle size tester;

as shown in fig. 3, D90 ═ 31.11 μm, D50 ═ 26.16 μm, and D10 ═ 22.64 μm. Adding 10% of carboxymethyl cellulose and distilled water into the ball-milled high-uniformity coke powder, firstly mixing for 15min at a low rotating speed in a high-speed mixing roll, then mixing for 10min at a high speed, and vibrating and molding the uniformly mixed paste in a mold;

roasting at 650 ℃ for 3h (10 ℃/minRT-250 ℃, 2 ℃/min250-550 ℃, 10 ℃/min550-650 ℃) in a nitrogen atmosphere furnace, and graphitizing at 2700 ℃ to obtain the high bulk density porous graphite electrode material.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.