Environment-friendly electrode material for electrolytic fluorination process and preparation method of environment-friendly electrode material

Abstract

The invention belongs to the technical field of electrode materials, and particularly relates to an environment-friendly electrode material for an electrolytic fluorination process and a preparation method thereof, and the preparation method comprises the following steps: (1) preparing pyrolyzed peanut shell powder; (2) grinding and cleaning to obtain cleaned pyrolyzed peanut shell powder; (3) ultrasonically dispersing the cleaned and pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then polymerizing polyaniline in situ; and (4) pyrolyzing the polyaniline modified pyrolyzed peanut shell powder again to obtain the electrode material. The environment-friendly electrode material adopts a two-step carbonization process. Wherein the primary low-temperature carbonization is used for obtaining a primary peanut shell carbon material with a complete structure and preventing collapse of a porous structure of a biological matrix in a one-step carbonization process, which is not beneficial to in-situ polymerization of polyaniline. The second carbonization process can promote further carbonization of the peanut shells and polyaniline, and the conductivity of the carbon material is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrode materials, and particularly relates to an environment-friendly electrode material for an electrolytic fluorination process and a preparation method thereof. Background Art

[0002] According to general physical and chemical properties, common chemical elements for constructing electrode materials can be roughly divided into three categories: (1) noble metals, such as gold (Au), silver (Ag), ruthenium (Ru), palladium (Pd), iridium (Ir), and platinum (Pt); (2) transition metals, such as iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo), and tungsten (W); (3) non-metals, such as boron (B), carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and selenium (Se). Based on this, electrode materials are classified into noble metal-based electrode materials, transition metal-based electrode materials, and non-metal-based electrode materials. Non-metal-based electrode materials, such as carbon materials, have low cost, good stability, and are multifunctional, and are considered to be one of the most promising alternative electrode materials. Various carbon materials, such as carbon nanotubes, graphene, carbon quantum dots, and heteroatom-doped carbon materials, etc., have been used as electrode materials. Among them, biomass carbon materials have been widely favored due to their low cost and high performance characteristics.

[0003] Biomass refers to various organisms produced through photosynthesis using the atmosphere, water, land, etc., that is, all living and growable organic substances are generally referred to as biomass. It includes animals, plants, and microorganisms. Its characteristics are renewable, widely distributed, and low in pollution. The main component of biomass is organic matter, and the main constituent element is carbon, which is a good carbon source for preparing carbon-based materials. Therefore, many activated carbons are derived from biomass, such as coconut shell activated carbon, straw activated carbon, etc. In addition, biomass has a wide source, low cost, and some biomass is even waste. Rational utilization can achieve waste resourceization, and there are already some high-performance self-doped carbon-based electrode materials prepared from biomass. The Chinese patent application with the publication number CN103971948A provides a method for preparing a supercapacitor carbon electrode material using pistachio shells. The method is to crush the dried pistachio shells, use a low dose of NaOH or KOH as the activator, carbonize, then wash with dilute hydrochloric acid and water in sequence until neutral, and finally dry to obtain the pistachio shell-based carbon electrode material. The raw material, pistachio shells, is renewable, rich in source, and low in cost. The activation process is simple, which is not only a high-value utilization of pistachio shells but also effectively reduces the cost of the supercapacitor carbon electrode material. The Chinese patent application with the publication number CN104085877A discloses a porous carbon electrode material based on chitosan and its derivatives, its preparation method, and uses. The porous carbon electrode material is prepared by a hard template carbonization method. Using hollow silica spheres as the template and chitosan and its derivatives as the carbon source precursors, through processes such as liquid-phase impregnation, high-temperature carbonization, and template removal, a porous carbon electrode material suitable for lithium-ion batteries and supercapacitors is obtained. The prepared porous carbon simultaneously has the characteristics of nitrogen doping and a hierarchical pore structure of macropores - mesopores - micropores, and the nitrogen doping content can be controlled by using different types of chitosan, and the hierarchical pore structure can be controlled by changing the particle size, wall thickness of the silica spheres, and adjusting the mass of the chitosan solution. The specific capacitance of the porous carbon electrode material obtained by this method is significantly increased compared with commercial graphite, and the rate performance remains good. However, the processes for preparing bio-based carbon materials in the prior art are complex, the specific surface area and conductivity are relatively low, making it difficult to promote their use and restricting the development of electrode materials. Summary of the Invention

[0004] The object of the present invention is to provide an environmentally friendly electrode material for the electrolytic fluorination process and its preparation method. Using peanut shells as the biomass raw material, a highly conductive environmentally friendly electrode material is prepared by a process of pre-calcination, polyaniline doping, and carbonization.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: A preparation method of an environmentally friendly electrode material for the electrolytic fluorination process, comprising the following steps: (1)The peanut shell powder is pyrolyzed in a muffle furnace under the protection of an inert gas to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 400 - 500 °C; Peanut shells are biomass materials with a wide range of sources. At the same time, essential nutrient elements for the growth and reproduction of organisms such as O, N, P, and S are evenly distributed inside the peanut shells. Carbonizing peanut shells can synthesize self-doped carbon materials, and this doped carbon has the advantage of uniform distribution of heteroelements. In addition, peanut shells have some special structures, which can also form special structures such as porous, flaky, reticular, or filamentous after carbonization. These structures can increase the specific surface area of the material, thereby improving the electrode performance.

[0006] First of all, it is necessary to pyrolyze the peanut shell powder at a relatively low temperature. This is because, compared with other biomass materials such as rice husks, straws, fruit peels, and nut shells, the coarse and fine fibers in peanut shells are crisscrossed. If the initial pyrolysis temperature is too high, the skeletal structure will collapse. Low-temperature pyrolysis can promote the preliminary carbonization of peanut shells without destroying the overall structure of peanut shells, preventing the collapse of the pore structure inside the shells, and facilitating the in-situ polymerization reaction of polyaniline subsequently.

[0007] (2)The pyrolyzed peanut shell powder is ground evenly, washed and dried to obtain washed pyrolyzed peanut shell powder; (3)First, the washed pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise under the condition of an ice-water bath. After the addition of aniline monomer is completed, ammonium persulfate solution is added dropwise while stirring. After the addition is completed, the reaction is carried out for a period of time; filtered, washed, and dried to obtain polyaniline-modified pyrolyzed peanut shell powder; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:(0.01 - 0.2); (4)The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under the protection of an inert gas and pyrolyzed again, washed and dried to obtain the electrode material.

[0008] The environmentally friendly electrode material of the present invention adopts a two-step carbonization process. Among them, the first low-temperature carbonization is to obtain a primary peanut shell carbon material with a complete structure, preventing the collapse of the porous structure of the biological matrix in the one-step carbonization process, which is not conducive to the in-situ polymerization of polyaniline. The high-temperature carbonization process can promote the further carbonization of peanut shells and polyaniline, improving the conductivity of the carbon material. During the carbonization process of in-situ polymerized polyaniline, the crystal structure of the peanut shell carbon material will not be damaged. Doping the peanut shell carbon material can increase the defects of the carbon material and improve its conductivity.

[0009] Specifically, the preparation process of the peanut shell powder in step (1) is as follows: Peanut shells are taken, washed clean, dried, ball-milled, and sieved to obtain peanut shell powder; the washing is carried out using deionized water; the drying is carried out in an oven, and the mesh number of sieving is 50 - 150 meshes.

[0010] Specifically, the inert gas in step (1) is one of nitrogen, helium, and argon.

[0011] Specifically, the pyrolysis time in step (1) is 1 - 2 h.

[0012] Specifically, in step (2), the cleaning is carried out by first soaking in an acidic solution and then washing until neutral; the acidic solution is one of hydrochloric acid solution, sulfuric acid solution, and nitric acid solution, with a concentration of 3 - 8 mol / L.

[0013] Specifically, the soaking time in step (2) is 5 - 10 h; the washing until neutral is carried out with deionized water.

[0014] Specifically, in step (3), the mass ratio of the cleaned pyrolyzed peanut shell powder to aniline monomer is 1:(0.1 - 0.6). Carbon materials have many advantages, making them widely used in many aspects. However, due to the relatively high crystallinity of pure carbon materials, the active sites of the materials are relatively few. Therefore, it is difficult for pure carbon materials to meet high requirements in terms of wettability and reactivity. Although peanut shells contain certain heteroelements such as nitrogen and sulfur, their content is low and the improvement effect is limited. In order to further improve the performance of peanut shell carbon materials, the present invention in - situ polymerizes polyaniline on the surface of pyrolyzed peanut shell powder. In - situ polymerization can better improve the uniform distribution of polyaniline on the peanut shell carbon surface and enhance the adhesion effect. Using polyaniline as the nitrogen - doping precursor, the six - membered ring structure on polyaniline is more likely to form a sp 2 carbonized structure during the carbonization process, which is beneficial to increasing conductivity; while the peanut shell carbon matrix has large pores and a high specific surface area, and the structure is stable after carbonization, which is beneficial to improving the performance of electrode materials. Further, the mass ratio of the cleaned pyrolyzed peanut shell powder to aniline monomer is 1:(0.2 - 0.4), and furthermore, the mass ratio of the cleaned pyrolyzed peanut shell powder to aniline monomer is 1:(0.3 - 0.4). By adjusting the amount of aniline monomer, polyaniline can be evenly loaded on the surface of peanut shell carbon materials, improving the doping effect.

[0015] Specifically, the reaction time in step (3) is 12 - 24 h; the molar ratio of aniline monomer to ammonium persulfate is 1:(0.7 - 1). There is no particular limitation on the type of polyethylene glycol, and polyethylene glycols with a molecular weight of 500 - 8000 commonly used in the art can be used. The surface of the peanut shell after low-temperature pyrolysis is rich in various oxygen-containing functional groups. Polyethylene glycol can not only improve the dispersion performance of the washed pyrolyzed peanut shell powder, but more importantly, on the one hand, polyethylene glycol can play a role in connecting the pyrolyzed peanut shell powder and aniline monomer; on the other hand, the hydroxyl groups and ether bonds contained in polyethylene glycol itself can form hydrogen bonds with aniline monomer, which can improve the adhesion of aniline monomer, enabling aniline monomer to polymerize with the washed pyrolyzed peanut shell powder as the matrix, and improving the adhesion of polyaniline. However, polyethylene glycol itself belongs to a polymer. When its addition amount is too large, it is not only easy to cause the washed pyrolyzed peanut shell powders to connect and agglomerate with each other, but also easy to block the porous structure of the pyrolyzed peanut shell powder, which is not conducive to the in-situ polymerization.

[0016] Specifically, the inert gas in step (4) is one of nitrogen, helium, and argon; the washing is to soak in an acidic solution first and then wash until neutral; the acidic solution is one of hydrochloric acid solution, sulfuric acid solution, and nitric acid solution; the temperature of the second pyrolysis is 900 - 1100 °C; the pyrolysis time is 3 - 4 h. High-temperature carbonization is beneficial to the formation of graphite structure and improves the conductivity. However, too high a temperature may cause the collapse of the porous structure of the carbon material, which is not conducive to improving its specific surface area. Specifically, the temperature of the second pyrolysis can be 900 °C, 920 °C, 950 °C, 980 °C, 1000 °C, 1030 °C, 1050 °C, 1080 °C, 1100 °C.

[0017] On the other hand, the present invention also provides an environmentally friendly electrode material for electrolytic fluorination process. The electrode material has a large specific surface area and high conductivity, improving the electrode performance.

[0018] Beneficial effects: The present invention provides an environmentally friendly electrode material for electrolytic fluorination process and its preparation method. Using peanut shell as a biomass raw material, a highly conductive environmentally friendly electrode material is prepared by pre-calcination, polyaniline doping, and carbonization processes. First, pyrolyzing the peanut shell powder at a relatively low temperature can promote the preliminary carbonization of the peanut shell without destroying the overall structure of the peanut shell and preventing the collapse of the pore structure inside the shell, facilitating the subsequent in-situ polymerization reaction of polyaniline. The subsequent high-temperature carbonization process can promote the further carbonization of the peanut shell and polyaniline, improving the conductivity of the carbon material. During the carbonization of the in-situ polymerized polyaniline, the crystal structure of the peanut shell carbon material will not be destroyed. Doping the peanut shell carbon material can increase the defects of the carbon material and improve its conductivity. Specific embodiments

[0019] To make the above objects, features, and advantages of the present application more apparent and understandable, a detailed description of the specific implementation manners of the present application is provided. Many specific details are set forth in the following description to facilitate a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application. Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in this application can be obtained through the market or can be prepared by existing methods.

[0021] In this application, the terms "multiple", "diverse", "multiple times", "pluralistic", etc., unless otherwise specified, refer to a quantity greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0022] Example 1 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill, and sieve them to obtain peanut shell powder; the washing is carried out using deionized water; the drying is carried out in an oven, and the mesh number of the sieving is 100 mesh; place the peanut shell powder in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 400 °C, and the pyrolysis time is 2 h; (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain washed pyrolyzed peanut shell powder; the washing is first to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 5 h, and then wash it with deionized water until neutral; (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under ice-water bath conditions, dropwise add aniline monomer; after the aniline monomer is added dropwise, while stirring, dropwise add ammonium persulfate solution, and react for 14 h after the addition is completed; filter, wash, and dry to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.04; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.2; the molar ratio of aniline monomer to ammonium persulfate is 1:0.7; (4) The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis again. After washing and drying, the electrode material is obtained. The temperature of the second pyrolysis is 900 °C, the pyrolysis time is 4 h, the washing is to soak in a hydrochloric acid solution with a concentration of 4 mol / L for 5 h first, and then wash with deionized water until neutral.

[0023] Example 2 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill and sieve them to obtain peanut shell powder. The washing is carried out with deionized water. The drying is carried out in an oven, and the mesh number of sieving is 100 mesh. The peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder. The pyrolysis temperature is 500 °C, and the pyrolysis time is 1 h. (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain washed pyrolyzed peanut shell powder. The washing is to soak in a hydrochloric acid solution with a concentration of 4 mol / L for 10 h first, and then wash with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under ice-water bath conditions, dropwise add aniline monomer. After the dropwise addition of aniline monomer, while stirring, dropwise add ammonium persulfate solution, and react for 24 h after the dropwise addition. Filter, wash and dry to obtain polyaniline-modified pyrolyzed peanut shell powder. The polyethylene glycol is PEG800. The mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.2. The mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.4. The molar ratio of aniline monomer to ammonium persulfate is 1:1. (4) The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis again. After washing and drying, the electrode material is obtained. The temperature of the second pyrolysis is 1030 °C, the pyrolysis time is 3 h, the washing is to soak in a hydrochloric acid solution with a concentration of 4 mol / L for 10 h first, and then wash with deionized water until neutral.

[0024] Example 3 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill and sieve them to obtain peanut shell powder. The washing is carried out with deionized water. The drying is carried out in an oven, and the mesh number of sieving is 100 mesh. The peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder. The pyrolysis temperature is 400 °C, and the pyrolysis time is 1.3 h. (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain the washed pyrolyzed peanut shell powder; the washing process is as follows: first soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 6 h, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice-water bath, dropwise add aniline monomer; after the addition of aniline monomer is complete, dropwise add ammonium persulfate solution while stirring, and react for 24 h after the addition is complete; filter, wash and dry to obtain the polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.2; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.2; the molar ratio of aniline monomer to ammonium persulfate is 1:1. (4) Place the polyaniline-modified pyrolyzed peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it again, wash and dry to obtain the electrode material; the temperature of the second pyrolysis is 900 °C; the pyrolysis time is 3 h; the washing process is as follows: first soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 10 h, and then wash it with deionized water until neutral.

[0025] Example 4 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill and sieve them to obtain peanut shell powder; the washing is carried out with deionized water; the drying is carried out in an oven, and the mesh number of sieving is 100 mesh; place the peanut shell powder in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 450 °C, and the pyrolysis time is 1.6 h. (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain the washed pyrolyzed peanut shell powder; the washing process is as follows: first soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice-water bath, dropwise add aniline monomer; after the addition of aniline monomer is complete, dropwise add ammonium persulfate solution while stirring, and react for 17 h after the addition is complete; filter, wash and dry to obtain the polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.1; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.1; the molar ratio of aniline monomer to ammonium persulfate is 1:0.8. (4) Pyrolyze the polyaniline-modified pyrolyzed peanut shell powder again in a muffle furnace under nitrogen gas protection, and obtain the electrode material after washing and drying; the temperature of the second pyrolysis is 980 °C; the pyrolysis time is 3.5 h; the washing is to soak in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash with deionized water until neutral.

[0026] Example 5 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill, and sieve to obtain peanut shell powder; the washing is carried out with deionized water; the drying is carried out in an oven, and the mesh number of the sieve is 100 mesh; place the peanut shell powder in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 460 °C, and the pyrolysis time is 1.6 h; (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry to obtain washed pyrolyzed peanut shell powder; the washing is to soak in a hydrochloric acid solution with a concentration of 4 mol / L for 9 h first, and then wash with deionized water until neutral; (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then dropwise add aniline monomer under ice-water bath conditions; after the dropwise addition of aniline monomer, dropwise add ammonium persulfate solution while stirring, and react for 16 h after the dropwise addition; filter, wash, and dry to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.08; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.33; the molar ratio of aniline monomer to ammonium persulfate is 1:0.8; (4) Pyrolyze the polyaniline-modified pyrolyzed peanut shell powder again in a muffle furnace under nitrogen gas protection, and obtain the electrode material after washing and drying; the temperature of the second pyrolysis is 990 °C; the pyrolysis time is 3.3 h; the washing is to soak in a hydrochloric acid solution with a concentration of 4 mol / L for 7.5 h first, and then wash with deionized water until neutral.

[0027] Example 6 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill, and sieve to obtain peanut shell powder; the washing is carried out with deionized water; the drying is carried out in an oven, and the mesh number of the sieve is 100 mesh; place the peanut shell powder in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 450 °C, and the pyrolysis time is 1.6 h; (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain the washed pyrolyzed peanut shell powder; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice-water bath, dropwise add aniline monomer; after the dropwise addition of aniline monomer is completed, dropwise add ammonium persulfate solution while stirring, and react for 17 h after the dropwise addition is completed; filter, wash and dry to obtain the polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.1; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.6; the molar ratio of aniline monomer to ammonium persulfate is 1:0.8. (4) Place the polyaniline-modified pyrolyzed peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it again, wash and dry it to obtain the electrode material; the temperature of the second pyrolysis is 980 °C; the pyrolysis time is 3.5 h; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral.

[0028] Example 7 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill and sieve them to obtain peanut shell powder; the washing is carried out with deionized water; the drying is carried out in an oven, and the mesh number of the sieving is 100 mesh; place the peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 490 °C, and the pyrolysis time is 1.3 h. (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain the washed pyrolyzed peanut shell powder; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 6 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice-water bath, dropwise add aniline monomer; after the dropwise addition of aniline monomer is completed, dropwise add ammonium persulfate solution while stirring, and react for 17 h after the dropwise addition is completed; filter, wash and dry to obtain the polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.17; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.36; the molar ratio of aniline monomer to ammonium persulfate is 1:0.8. (4) Place the polyaniline-modified pyrolyzed peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it again. After cleaning and drying, an electrode material is obtained. The temperature of the second pyrolysis is 920 °C, the pyrolysis time is 3.7 h. The cleaning process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 9 h first, and then wash it with deionized water until neutral.

[0029] Example 8 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, clean them, dry, ball-mill and sieve them to obtain peanut shell powder. The cleaning is carried out with deionized water. The drying is carried out in an oven, and the mesh number of sieving is 100 meshes. Place the peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it to obtain pyrolyzed peanut shell powder. The pyrolysis temperature is 450 °C, and the pyrolysis time is 1.6 h. (2) Grind the pyrolyzed peanut shell powder evenly, clean and dry it to obtain cleaned pyrolyzed peanut shell powder. The cleaning is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the cleaned pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then dropwise add aniline monomer under ice-water bath conditions. After the addition of aniline monomer is completed, dropwise add ammonium persulfate solution while stirring, and react for 17 h after the addition is completed. Filter, wash and dry to obtain polyaniline-modified pyrolyzed peanut shell powder. The polyethylene glycol is PEG800. The mass ratio of the cleaned pyrolyzed peanut shell powder to polyethylene glycol is 1:0.1. The mass ratio of the cleaned pyrolyzed peanut shell powder to aniline monomer is 1:0.32. The molar ratio of aniline monomer to ammonium persulfate is 1:0.8. (4) Place the polyaniline-modified pyrolyzed peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it again. After cleaning and drying, an electrode material is obtained. The temperature of the second pyrolysis is 1100 °C, the pyrolysis time is 3.5 h. The cleaning is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral.

[0030] Example 9 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, clean them, dry, ball-mill and sieve them to obtain peanut shell powder. The cleaning is carried out with deionized water. The drying is carried out in an oven, and the mesh number of sieving is 100 meshes. Place the peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it to obtain pyrolyzed peanut shell powder. The pyrolysis temperature is 420 °C, and the pyrolysis time is 1.8 h. (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain the washed pyrolyzed peanut shell powder; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 6 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice-water bath, dropwise add aniline monomer; after the addition of aniline monomer is completed, dropwise add ammonium persulfate solution while stirring, and react for 15 h after the addition is completed; filter, wash and dry to obtain the polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.09; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.25; the molar ratio of aniline monomer to ammonium persulfate is 1:0.8; (4) Place the polyaniline-modified pyrolyzed peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it again, wash and dry it to obtain the electrode material; the temperature of the second pyrolysis is 950 °C; the pyrolysis time is 3.8 h; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 6 h first, and then wash it with deionized water until neutral.

[0031] Example 10 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill and screen them to obtain peanut shell powder; the washing is carried out with deionized water; the drying is carried out in an oven, and the mesh number of the screening is 100 mesh; place the peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 480 °C, and the pyrolysis time is 1.2 h; (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain the washed pyrolyzed peanut shell powder; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 8 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice-water bath, dropwise add aniline monomer; after the addition of aniline monomer is completed, dropwise add ammonium persulfate solution while stirring, and react for 20 h after the addition is completed; filter, wash and dry to obtain the polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.18; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.37; the molar ratio of aniline monomer to ammonium persulfate is 1:0.9; (4) The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis again. After washing and drying, the electrode material is obtained. The temperature of the second pyrolysis is 1000 °C, the pyrolysis time is 3.3 h. The washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 8 h first, and then wash it with deionized water until neutral.

[0032] Example 11 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, clean them, dry, ball-mill and sieve them to obtain peanut shell powder. The cleaning is carried out with deionized water. The drying is carried out in an oven, and the mesh number of sieving is 100 meshes. The peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder. The pyrolysis temperature is 450 °C, and the pyrolysis time is 1.6 h. (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain washed pyrolyzed peanut shell powder. The washing is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then dropwise add aniline monomer under ice-water bath conditions. After the addition of aniline monomer is completed, dropwise add ammonium persulfate solution while stirring. After the addition is completed, react for 17 h. Filter, wash and dry to obtain polyaniline-modified pyrolyzed peanut shell powder. The polyethylene glycol is PEG800. The mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.1. The mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.32. The molar ratio of aniline monomer to ammonium persulfate is 1:0.8. (4) The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis again. After washing and drying, the electrode material is obtained. The temperature of the second pyrolysis is 980 °C, the pyrolysis time is 3.5 h. The washing is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral.

[0033] Comparative Example 1 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, clean them, dry, ball-mill and sieve them to obtain peanut shell powder. The cleaning is carried out with deionized water. The drying is carried out in an oven, and the mesh number of sieving is 100 meshes. The peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder. The pyrolysis temperature is 600 °C, and the pyrolysis time is 1.6 h. (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain the washed pyrolyzed peanut shell powder; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice-water bath, dropwise add aniline monomer; after the addition of aniline monomer is complete, dropwise add ammonium persulfate solution while stirring, and react for 17 h after the addition is complete; filter, wash and dry to obtain the polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.1; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.32; the molar ratio of aniline monomer to ammonium persulfate is 1:0.8. (4) Place the polyaniline-modified pyrolyzed peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it again, wash and dry it to obtain the electrode material; the temperature of the second pyrolysis is 980 °C; the pyrolysis time is 3.5 h; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral.

[0034] Comparative Example 2 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, wash them clean, dry, ball-mill and sieve them to obtain peanut shell powder; the washing is carried out with deionized water; the drying is carried out in an oven, and the mesh number of sieving is 100 mesh; place the peanut shell powder in a muffle furnace under nitrogen gas protection and pyrolyze it to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 450 °C, and the pyrolysis time is 1.6 h. (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain the washed pyrolyzed peanut shell powder; the washing process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice-water bath, dropwise add aniline monomer; after the addition of aniline monomer is complete, dropwise add ammonium persulfate solution while stirring, and react for 17 h after the addition is complete; filter, wash and dry to obtain the polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:0.4; the mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer is 1:0.32; the molar ratio of aniline monomer to ammonium persulfate is 1:0.8. (4) The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis again. After cleaning and drying, the electrode material is obtained. The temperature of the second pyrolysis is 980 °C, the pyrolysis time is 3.5 h. The cleaning process is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral.

[0035] Comparative Example 3 A preparation method of an environmentally friendly electrode material for an electrolytic fluorination process, comprising the following steps: (1) Take peanut shells, clean them, dry, ball-mill, and sieve them to obtain peanut shell powder. The cleaning is carried out with deionized water. The drying is carried out in an oven, and the mesh number of sieving is 100 mesh. The peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis to obtain pyrolyzed peanut shell powder. The pyrolysis temperature is 450 °C, and the pyrolysis time is 1.6 h. (2) Grind the pyrolyzed peanut shell powder evenly, clean and dry it to obtain cleaned pyrolyzed peanut shell powder. The cleaning is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral. (3) First, ultrasonically disperse the cleaned pyrolyzed peanut shell powder in deionized water, and then dropwise add aniline monomer under ice-water bath conditions. After the addition of aniline monomer is completed, dropwise add ammonium persulfate solution while stirring. After the addition is completed, react for 17 h. Filter, wash, and dry to obtain polyaniline-modified pyrolyzed peanut shell powder. The mass ratio of the cleaned pyrolyzed peanut shell powder to aniline monomer is 1:0.32. The molar ratio of aniline monomer to ammonium persulfate is 1:0.8. (4) The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under nitrogen gas protection for pyrolysis again. After cleaning and drying, the electrode material is obtained. The temperature of the second pyrolysis is 980 °C, the pyrolysis time is 3.5 h. The cleaning is to soak it in a hydrochloric acid solution with a concentration of 4 mol / L for 7 h first, and then wash it with deionized water until neutral.

[0036] Performance test: The specific surface area, pore volume, and conductivity of the environmentally friendly electrode materials for the electrolytic fluorination process prepared in the above examples and comparative examples are measured by a porosity analyzer and a four-probe tester respectively. The results are shown in Table 1-2.

[0037] Table 1 Performance of the electrode materials prepared in Examples 1-7

[0038] Table 2 Performance of the electrode materials prepared in Examples 8-11 and Comparative Examples 1-3

[0039] As can be seen from Table 1 and Table 2, the present invention uses peanut shells as biomass raw materials and prepares a highly conductive and environmentally friendly electrode material by means of pre-calcination, polyaniline doping, and carbonization processes. First, the peanut shell powder is pyrolyzed at a relatively low temperature, which can promote the initial carbonization of the peanut shells without destroying the overall structure of the peanut shells and preventing the collapse of the pore structure inside the shells, facilitating the subsequent in-situ polymerization reaction of polyaniline. The subsequent high-temperature carbonization process can promote the further carbonization of the peanut shells and polyaniline, improving the conductivity of the carbon material. During the carbonization of the in-situ polymerized polyaniline, the crystal structure of the peanut shell carbon material is not damaged. Doping the peanut shell carbon material can increase the defects of the carbon material and improve its conductivity: the introduction of nitrogen atoms will affect the spin density and charge distribution of carbon atoms by heteroatoms, resulting in an increase in the defects of the carbon material, creating more active sites, improving the reactivity of the material, and also improving the wettability and compatibility of the carbon material after doping. Compared with Example 11, in Comparative Example 1, the pyrolysis temperature in step (1) is too high, causing damage to the structure of the peanut shells and the collapse of the pore structure inside the shells, which is not conducive to the in-situ polymerization reaction of polyaniline and affects the formation of the conductive path. When the addition amount of polyethylene glycol in Comparative Example 2 is too much, it not only causes waste of polyethylene glycol but also easily blocks the porous structure of the pyrolyzed peanut shell powder, which is not conducive to the in-situ polymerization and leads to a decrease in the surface area. In Comparative Example 3, no polyethylene glycol is added, and the pyrolyzed peanut shell powder and the formed polyaniline have poor dispersibility, which is not conducive to the formation of the porous structure and also affects the formation of the conductive path.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A preparation method of an environment-friendly electrode material for an electrolytic fluorination process, characterized in that It includes the following steps: (1) Pyrolyze peanut shell powder in a muffle furnace under the protection of an inert gas to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 400 - 500 °C; (2) Grind the pyrolyzed peanut shell powder evenly, wash and dry it to obtain washed pyrolyzed peanut shell powder; (3) First, ultrasonically disperse the washed pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then, under the condition of an ice - water bath, dropwise add aniline monomer; after the addition of aniline monomer is complete, dropwise add ammonium persulfate solution while stirring, and react for a period of time after the addition is complete; Filter, wash and dry to obtain polyaniline - modified pyrolyzed peanut shell powder; the mass ratio of the washed pyrolyzed peanut shell powder to polyethylene glycol is 1:(0.01 - 0.2); (4) Place the polyaniline - modified pyrolyzed peanut shell powder in a muffle furnace under the protection of an inert gas for pyrolysis again, wash and dry it to obtain the electrode material.

2. The preparation method of an environmentally friendly electrode material for an electrolytic fluorination process according to claim 1, characterized in that, The preparation process of the peanut shell powder in step (1) is as follows: take peanut shells, wash them clean, dry, ball - mill and sieve them to obtain peanut shell powder; the washing is carried out with deionized water; the drying is carried out in an oven, and the mesh number of sieving is 50 - 150 meshes.

3. The preparation method of an environmentally friendly electrode material for an electrolytic fluorination process according to claim 1, characterized in that, The inert gas in step (1) is one of nitrogen, helium and argon.

4. The preparation method of an environmentally friendly electrode material for an electrolytic fluorination process according to claim 1, characterized in that, The pyrolysis time in step (1) is 1 - 2 h.

5. The preparation method of an environmentally friendly electrode material for an electrolytic fluorination process as described in claim 1, characterized in that, The washing in step (2) is as follows: first soak in an acidic solution, and then wash until neutral; The acidic solution is one of hydrochloric acid solution, sulfuric acid solution and nitric acid solution, and the concentration is 3 - 8 mol / L.

6. The preparation method of an environmentally friendly electrode material for an electrolytic fluorination process according to claim 5, characterized in that, The soaking time in step (2) is 5 - 10 h; the washing until neutral is carried out with deionized water.

7. The preparation method of an environmentally friendly electrode material for an electrolytic fluorination process according to claim 1, characterized in that, The mass ratio of the washed pyrolyzed peanut shell powder to aniline monomer in step (3) is 1:(0.1 - 0.6).

8. The preparation method of an environmentally friendly electrode material for an electrolytic fluorination process according to claim 1, characterized in that, The reaction time in step (3) is 12 - 24 h; the molar ratio of aniline monomer to ammonium persulfate is 1:(0.7 - 1).

9. The preparation method of an environmentally friendly electrode material for an electrolytic fluorination process according to claim 1, characterized in that, The inert gas in step (4) is one of nitrogen, helium and argon; the washing is first soaking in an acidic solution and then washing until neutral; The acidic solution is one of hydrochloric acid solution, sulfuric acid solution and nitric acid solution; the temperature of the second pyrolysis is 900 - 1100 °C; the pyrolysis time is 3 - 4 h.

10. An environmentally friendly electrode material for an electrolytic fluorination process, characterized in that: It is prepared by the preparation method of an environmentally friendly electrode material for an electrolytic fluorination process described in any one of claims 1 - 9.

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