Environmentally friendly electrode material for electrolytic fluorination process and preparation method thereof

Abstract

The present invention belongs to the field of electrode material technology, and specifically relates to an environmentally friendly electrode material for electrolytic fluorination process and a preparation method thereof, comprising 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 pyrolyzed peanut shell powder and polyethylene glycol in deionized water, and then in-situ polymerizing polyaniline; (4) pyrolyzing the polyaniline-modified pyrolyzed peanut shell powder again to obtain an electrode material. The environmentally friendly electrode material of the present invention adopts a two-step carbonization process. The first low-temperature carbonization is to obtain a structurally complete primary peanut shell carbon material, thereby preventing the collapse of the porous structure of the biomatrix in the one-step carbonization process, which is not conducive to the in-situ polymerization of polyaniline. The second carbonization process can promote further carbonization of the peanut shell and polyaniline, thereby improving the conductivity of the carbon material.

Description

Technical Field

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

[0002] Based on their general physical and chemical properties, the chemical elements commonly used to construct electrode materials can be roughly divided into three categories: (1) precious 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); and (3) non-metals, such as boron (B), carbon (C), nitrogen (N), phosphorus (P), sulfur (S) and selenium (Se). Based on this, electrode materials are divided into precious 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 multifunctionality, and are considered to be one of the most promising alternative electrode materials. Various carbon materials, such as carbon nanotubes, graphene and carbon quantum dots and heteroatom-doped carbon materials, have been used as electrode materials. Among them, biomass carbon materials have been widely favored due to their low cost and high performance.

[0003] Biomass refers to various organisms produced through photosynthesis using the atmosphere, water, and land. In other words, all living, growing organic matter is generally referred to as biomass. It includes animals, plants, and microorganisms. Its characteristics are renewability, widespread distribution, and low pollution. Biomass is primarily composed of organic matter, with carbon being its primary element. It is a good carbon source for preparing carbon-based materials. Therefore, many activated carbons are derived from biomass, such as coconut shell activated carbon and straw activated carbon. Furthermore, biomass is widely available and inexpensive, and some biomass is even waste. Its rational utilization can achieve waste resource utilization, and several high-performance self-doped carbon-based electrode materials have been prepared using biomass. Chinese invention patent application publication number CN103971948A provides a method for preparing supercapacitor carbon electrode materials using pistachio shells. The method involves crushing dried pistachio shells, carbonizing them with a low dose of NaOH or KOH as an activator, then washing them with dilute hydrochloric acid and water until neutral, and finally drying them to obtain a pistachio shell-based carbon electrode material. The raw material pistachio shell is renewable, abundant in source, low in cost, and has a simple activation process. It is not only a high value-added utilization of pistachio shells, but also effectively reduces the cost of supercapacitor carbon electrode materials. The Chinese invention patent application with publication number CN104085877A discloses a porous carbon electrode material based on chitosan and its derivatives, its preparation method and use. The porous carbon electrode material adopts a hard template carbonization method, with hollow silica balls as templates and chitosan and its derivatives as carbon source precursors. Through liquid phase impregnation, high temperature carbonization and template removal, a porous carbon electrode material suitable for lithium-ion batteries and supercapacitors is obtained. The porous carbon obtained has the characteristics of nitrogen doping and macropore-mesopore-micropore hierarchical pore structure, 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 and wall thickness of the silica balls and adjusting the quality of the chitosan solution. The specific capacity 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 bio-based carbon materials prepared by existing technologies are complex processes, have low specific surface area and conductivity, and are difficult to promote and use, which limits the development of electrode materials. Summary of the Invention

[0004] The purpose of the present invention is to provide an environmentally friendly electrode material for electrolytic fluorination process and a preparation method thereof. Peanut shells are used as biomass raw materials, and a high-conductivity environmentally friendly electrode material is prepared by pre-calcination, polyaniline doping, and carbonization process.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0007] (1) Placing peanut shell powder in a muffle furnace under inert gas protection for pyrolysis to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 400-500°C;

[0008] Peanut shells are a widely available biomass material. Essential nutrients for biological growth and reproduction, such as O, N, P, and S, are evenly distributed within them. Carbonizing peanut shells can be used to synthesize self-doped carbon materials, which exhibit the advantage of uniform distribution of these elements. Furthermore, peanut shells possess unique structural properties, forming porous, flaky, mesh-like, or filamentous structures after carbonization. These structures can increase the specific surface area of the material, thereby improving electrode performance.

[0009] First, peanut shell powder needs to be pyrolyzed at a relatively low temperature. This is because, compared to other biomass materials such as rice husks, straw, fruit peels, and nut shells, peanut shells contain a crisscross pattern of coarse and fine fibers. If the initial pyrolysis temperature is too high, the skeleton structure will collapse. Low-temperature pyrolysis promotes initial carbonization of the peanut shells without disrupting their overall structure, preventing the collapse of the pore structure within the shells and facilitating the subsequent in-situ polymerization of polyaniline.

[0010] (2) grinding the pyrolyzed peanut shell powder uniformly, washing, and drying to obtain washed pyrolyzed peanut shell powder;

[0011] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the mixture is reacted for a period of time after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the mass ratio of the cleaned pyrolyzed peanut shell powder to polyethylene glycol is 1: (0.01-0.2);

[0012] (4) The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under inert gas protection for pyrolysis again, and then washed and dried to obtain the electrode material.

[0013] The environmentally friendly electrode material of the present invention utilizes a two-step carbonization process. The first low-temperature carbonization step is designed to obtain a structurally intact primary peanut shell carbon material, preventing the collapse of the porous structure of the biomatrix during the one-step carbonization process, which would hinder the in-situ polymerization of polyaniline. The high-temperature carbonization process can further carbonize the peanut shells and polyaniline, improving the conductivity of the carbon material. The in-situ carbonization of polyaniline does not destroy the crystalline structure of the peanut shell carbon material. Doping the peanut shell carbon material can also improve defects in the carbon material and enhance its conductivity.

[0014] In particular, the peanut shell powder preparation process in step (1) is as follows: clean the peanut shells, dry them, ball-mill them, and sieve them to obtain the peanut shell powder; the washing is performed using deionized water; the drying is performed in an oven, and the sieving mesh size is 50-150 meshes.

[0015] Particularly, the inert gas in step (1) is one of nitrogen, helium and argon.

[0016] In particular, the pyrolysis time in step (1) is 1-2 h.

[0017] In particular, the cleaning in step (2) is first soaking in an acidic solution and then washing to neutrality; the acidic solution is one of hydrochloric acid solution, sulfuric acid solution, and nitric acid solution, with a concentration of 3-8 mol / L.

[0018] Particularly, the soaking time in step (2) is 5-10 hours; and the washing to neutrality is performed with deionized water.

[0019] In particular, the mass ratio of the cleaned pyrolyzed peanut shell powder and the aniline monomer in step (3) is 1: (0.1-0.6). Carbon materials have many advantages, which makes 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, the wettability and reaction activity of pure carbon materials are difficult to meet high requirements. Although peanut shells contain certain nitrogen, sulfur and other miscellaneous elements, 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 improve the adhesion effect. Using polyaniline as a nitrogen-doped precursor, the six-membered ring structure on the polyaniline is more likely to form sp during the carbonization process. 2 The carbonized structure improves conductivity. The peanut shell carbon matrix, with its inherent macropores and high surface area, maintains a stable structure after carbonization, which improves electrode material performance. Furthermore, the mass ratio of cleaned pyrolyzed peanut shell powder to aniline monomer is 1:(0.2-0.4), and even further, the mass ratio of 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 onto the surface of the peanut shell carbon material, improving the doping effect.

[0020] In particular, the reaction time in step (3) is 12-24 hours; the molar ratio of aniline monomer to ammonium persulfate is 1:(0.7-1). The type of polyethylene glycol is not particularly limited, and polyethylene glycol with a molecular weight of 500-8000 commonly used in the art can be used. The surface of peanut shells after low-temperature pyrolysis is rich in various oxygen-containing functional groups. Polyethylene glycol can not only improve the dispersion performance of the cleaned pyrolyzed peanut shell powder, but more importantly, polyethylene glycol can play a role in connecting the pyrolyzed peanut shell powder and the aniline monomer; on the other hand, the hydroxyl groups and ether bonds contained in polyethylene glycol itself can form hydrogen bonds with the aniline monomer, which can improve the adhesion of the aniline monomer, so that the aniline monomer is polymerized with the cleaned pyrolyzed peanut shell powder as the matrix, thereby improving the adhesion of polyaniline. However, polyethylene glycol itself is a polymer. If it is added in excessive amounts, it will not only easily cause the cleaned pyrolyzed peanut shell powder to connect and agglomerate with each other, but also easily block the porous structure of the pyrolyzed peanut shell powder, which is not conducive to the in-situ polymerization.

[0021] In particular, the inert gas in step (4) is one of nitrogen, helium, and argon; the cleaning is performed 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; the temperature of the secondary pyrolysis is 900-1100°C; and the pyrolysis time is 3-4 hours. High-temperature carbonization is conducive to the formation of graphite structure and improves electrical conductivity. However, excessively high temperature may cause the collapse of the porous structure of the carbon material, which is not conducive to increasing its specific surface area. Specifically, the temperature of the secondary pyrolysis can be 900°C, 920°C, 950°C, 980°C, 1000°C, 1030°C, 1050°C, 1080°C, or 1100°C.

[0022] In another aspect, the present invention also provides an environmentally friendly electrode material for electrolytic fluorination processes. The electrode material has a large specific surface area and high electrical conductivity, thereby improving electrode performance.

[0023] Beneficial effects:

[0024] The present invention provides an environmentally friendly electrode material for an electrolytic fluorination process and a preparation method thereof. Peanut shells are used as biomass raw materials, and a high-conductivity environmentally friendly electrode material is prepared by 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, preventing the collapse of the pore structure within the shells, and facilitating the subsequent in-situ polymerization reaction of polyaniline. The subsequent high-temperature carbonization process can promote further carbonization of the peanut shells and polyaniline, thereby improving the conductivity of the carbon material. During the in-situ polymerization of polyaniline carbonization process, the crystalline 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. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotations of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art in the technical field of this application. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or can be prepared by existing methods.

[0027] In this application, "plurality", "multiple", "multiple times", "multiples", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0028] Example 1

[0029] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0030] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 2 hours;

[0031] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 5 h, and then washing it with deionized water until it is neutral;

[0032] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 14 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.04; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.2; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.7;

[0033] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 900 °C; the pyrolysis time was 4 h; and the cleaning was first soaked in a hydrochloric acid solution with a concentration of 4 mol / L for 5 h, and then washed with deionized water until neutral.

[0034] Example 2

[0035] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0036] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the washing is performed with deionized water; the drying is performed in an oven, and the sieving mesh size 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 hour;

[0037] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 10 h, and then washing it with deionized water until it is neutral;

[0038] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 24 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.2; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.4; the molar ratio of the aniline monomer to the ammonium persulfate is 1:1;

[0039] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 1030 °C; the pyrolysis time was 3 h; and the cleaning was first soaked in a hydrochloric acid solution with a concentration of 4 mol / L for 10 h, and then washed with deionized water until neutral.

[0040] Example 3

[0041] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0042] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 hours;

[0043] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 6 h, and then washing it with deionized water until it is neutral;

[0044] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 24 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.2; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.2; the molar ratio of the aniline monomer to the ammonium persulfate is 1:1;

[0045] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 900 °C; the pyrolysis time was 3 h; and the cleaning was first soaked in a hydrochloric acid solution with a concentration of 4 mol / L for 10 h, and then washed with deionized water until neutral.

[0046] Example 4

[0047] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0048] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 hours;

[0049] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 7 hours, and then washing it with deionized water until it is neutral;

[0050] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 17 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.1; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.1; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.8;

[0051] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 980 °C; the pyrolysis time was 3.5 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 7 h, and then washed with deionized water until neutral.

[0052] Example 5

[0053] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0054] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 460°C, and the pyrolysis time is 1.6 hours;

[0055] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 9 hours, and then washing it with deionized water until it is neutral;

[0056] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 16 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.08; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.33; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.8;

[0057] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 990 °C; the pyrolysis time was 3.3 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 7.5 h, and then washed with deionized water until neutral.

[0058] Example 6

[0059] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0060] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 hours;

[0061] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 7 hours, and then washing it with deionized water until it is neutral;

[0062] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 17 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.1; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.6; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.8;

[0063] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 980 °C; the pyrolysis time was 3.5 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 7 h, and then washed with deionized water until neutral.

[0064] Example 7

[0065] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0066] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 490°C, and the pyrolysis time is 1.3 hours;

[0067] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 6 h, and then washing it with deionized water until it is neutral;

[0068] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol were ultrasonically dispersed in deionized water, and then aniline monomer was added dropwise in an ice-water bath; after the aniline monomer was added dropwise, ammonium persulfate solution was added dropwise while stirring, and the reaction was carried out for 17 hours after the addition was completed; filtration, washing, and drying were performed to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol was PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol was 1:0.17; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer was 1:0.36; and the molar ratio of the aniline monomer to the ammonium persulfate was 1:0.8;

[0069] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 920 °C; the pyrolysis time was 3.7 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 9 h, and then washed with deionized water until neutral.

[0070] Example 8

[0071] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0072] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 hours;

[0073] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 7 hours, and then washing it with deionized water until it is neutral;

[0074] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 17 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.1; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.32; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.8;

[0075] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 1100 °C; the pyrolysis time was 3.5 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 7 h, and then washed with deionized water until neutral.

[0076] Example 9

[0077] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0078] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 420°C, and the pyrolysis time is 1.8 hours;

[0079] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 6 h, and then washing it with deionized water until it is neutral;

[0080] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 15 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.09; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.25; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.8;

[0081] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 950 °C; the pyrolysis time was 3.8 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 6 h, and then washed with deionized water until neutral.

[0082] Example 10

[0083] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0084] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 480°C, and the pyrolysis time is 1.2 hours;

[0085] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 8 h, and then washing it with deionized water until it is neutral;

[0086] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 20 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.18; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.37; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.9;

[0087] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 1000 °C; the pyrolysis time was 3.3 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 8 h, and then washed with deionized water until neutral.

[0088] Example 11

[0089] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0090] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 hours;

[0091] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 7 hours, and then washing it with deionized water until it is neutral;

[0092] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 17 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.1; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.32; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.8;

[0093] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 980 °C; the pyrolysis time was 3.5 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 7 h, and then washed with deionized water until neutral.

[0094] Comparative Example 1

[0095] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0096] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 600°C, and the pyrolysis time is 1.6 hours;

[0097] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 7 hours, and then washing it with deionized water until it is neutral;

[0098] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath; after the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is carried out for 17 hours after the addition is completed; filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol is PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol is 1:0.1; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer is 1:0.32; and the molar ratio of the aniline monomer to the ammonium persulfate is 1:0.8;

[0099] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 980 °C; the pyrolysis time was 3.5 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 7 h, and then washed with deionized water until neutral.

[0100] Comparative Example 2

[0101] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0102] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 hours;

[0103] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 7 hours, and then washing it with deionized water until it is neutral;

[0104] (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol were ultrasonically dispersed in deionized water, and then aniline monomer was added dropwise in an ice-water bath; after the aniline monomer was added dropwise, ammonium persulfate solution was added dropwise while stirring, and the reaction was carried out for 17 hours after the addition was completed; filtration, washing, and drying were performed to obtain polyaniline-modified pyrolyzed peanut shell powder; the polyethylene glycol was PEG800; the mass ratio of the cleaned pyrolyzed peanut shell powder to the polyethylene glycol was 1:0.4; the mass ratio of the cleaned pyrolyzed peanut shell powder to the aniline monomer was 1:0.32; and the molar ratio of the aniline monomer to the ammonium persulfate was 1:0.8;

[0105] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 980 °C; the pyrolysis time was 3.5 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 7 h, and then washed with deionized water until neutral.

[0106] Comparative Example 3

[0107] A method for preparing an environmentally friendly electrode material for an electrolytic fluorination process comprises the following steps:

[0108] (1) Cleaning peanut shells, drying, ball milling, and sieving to obtain peanut shell powder; the cleaning is performed using deionized water; the drying is performed in an oven, and the sieving mesh size 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 hours;

[0109] (2) Grinding the pyrolyzed peanut shell powder uniformly, washing and drying it to obtain washed pyrolyzed peanut shell powder; washing the powder is performed by first soaking it in a 4 mol / L hydrochloric acid solution for 7 hours, and then washing it with deionized water until it is neutral;

[0110] (3) First, the cleaned pyrolyzed peanut shell powder was ultrasonically dispersed in deionized water, and then aniline monomer was added dropwise in an ice-water bath. After the addition of aniline monomer, ammonium persulfate solution was added dropwise while stirring, and the reaction was carried out for 17 hours after the addition was completed. The polyaniline modified pyrolyzed peanut shell powder was obtained by filtration, washing, and drying. The mass ratio of cleaned pyrolyzed peanut shell powder to aniline monomer was 1:0.32; the molar ratio of aniline monomer to ammonium persulfate was 1:0.8.

[0111] (4) The polyaniline-modified pyrolyzed peanut shell powder was placed in a muffle furnace under nitrogen gas protection for pyrolysis again, and the electrode material was obtained after cleaning and drying; the temperature for the second pyrolysis was 980 °C; the pyrolysis time was 3.5 h; and the cleaning was first soaked in a 4 mol / L hydrochloric acid solution for 7 h, and then washed with deionized water until neutral.

[0112] Performance Testing: The specific surface area, pore volume, and electrical conductivity of the environmentally friendly electrode materials for electrolytic fluorination prepared in the above examples and comparative examples were measured using a porosity analyzer and a four-probe tester. The results are shown in Tables 1-2.

[0113] Table 1 Properties of electrode materials prepared in Examples 1-7

[0114]

[0115] Table 2 Properties of electrode materials prepared in Examples 8-11 and Comparative Examples 1-3

[0116]

[0117] As can be seen from Table 1 and Table 2, the present invention uses peanut shells as biomass raw materials, and adopts pre-calcination, polyaniline doping, and carbonization process to prepare high-conductivity environmentally friendly electrode materials. First, the peanut shell powder is pyrolyzed at a relatively low temperature, which can promote the initial carbonization of the peanut shell without destroying the overall structure of the peanut shell, preventing the collapse of the pore structure in the shell, and facilitating the subsequent in-situ polymerization reaction of polyaniline. The subsequent high-temperature carbonization process can promote further carbonization of peanut shells and polyaniline, and improve the conductivity of the carbon material. During the in-situ polymerization of polyaniline carbonization process, the crystalline 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: the introduction of nitrogen atoms will cause the spin density and charge distribution of carbon atoms to be affected by heteroatoms, resulting in an increase in the defects of the carbon material, creating more active sites, and improving the reactivity of the material. After doping, the wettability of the carbon material can also be improved, and the compatibility can be improved. Compared with Example 11, the pyrolysis temperature in step (1) of Comparative Example 1 was too high, resulting in the destruction of the peanut shell structure and the collapse of the pore structure within the shell, which was not conducive to the in-situ polymerization reaction of polyaniline and affected the formation of the conductive path. In Comparative Example 2, when too much polyethylene glycol was added, not only was polyethylene glycol wasted, but it also easily blocked the porous structure of the pyrolyzed peanut shell powder, which was not conducive to the in-situ polymerization and resulted in a reduction in surface area. In Comparative Example 3, no polyethylene glycol was added, and the pyrolyzed peanut shell powder and the resulting polyaniline had poor dispersibility, which was not conducive to the formation of a porous structure and affected the formation of the conductive path.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing an environmentally friendly electrode material for electrolytic fluorination process, characterized in that: The following steps are involved: (1) Placing peanut shell powder in a muffle furnace under inert gas protection for pyrolysis to obtain pyrolyzed peanut shell powder; the pyrolysis temperature is 400-500°C; (2) grinding the pyrolyzed peanut shell powder uniformly, washing, and drying to obtain washed pyrolyzed peanut shell powder; (3) First, the cleaned pyrolyzed peanut shell powder and polyethylene glycol are ultrasonically dispersed in deionized water, and then aniline monomer is added dropwise in an ice-water bath. After the aniline monomer is added dropwise, ammonium persulfate solution is added dropwise while stirring, and the reaction is continued for a period of time after the addition is completed; Filtering, washing, and drying to obtain polyaniline-modified pyrolyzed peanut shell powder; the mass ratio of the cleaned pyrolyzed peanut shell powder to polyethylene glycol is 1: (0.01-0.2); the mass ratio of the cleaned pyrolyzed peanut shell powder to aniline monomer is 1: (0.1-0.6); (4) The polyaniline-modified pyrolyzed peanut shell powder is placed in a muffle furnace under inert gas protection for pyrolysis again, and the electrode material is obtained after cleaning and drying; the temperature of the pyrolysis again is 900-1100°C.

2. The method for preparing an environmentally friendly electrode material for electrolytic fluorination process according to claim 1, characterized in that: The peanut shell powder preparation process in step (1) is as follows: peanut shells are taken and cleaned, dried, ball-milled, and sieved to obtain peanut shell powder; the washing is performed using deionized water; the drying is performed in an oven, and the sieving mesh size is 50-150 mesh.

3. The method for preparing an environmentally friendly electrode material for 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 method for preparing an environmentally friendly electrode material for electrolytic fluorination process according to claim 1, characterized in that: The pyrolysis time in step (1) is 1-2 hours.

5. The method for preparing an environmentally friendly electrode material for electrolytic fluorination process according to claim 1, characterized in that: The cleaning in step (2) is as follows: 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, and the concentration is 3-8 mol / L.

6. The method for preparing an environmentally friendly electrode material for electrolytic fluorination process according to claim 5, characterized in that: The soaking time in step (2) is 5-10 hours; the washing to neutrality is performed with deionized water.

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

8. The method for preparing an environmentally friendly electrode material for electrolytic fluorination process according to claim 1, characterized in that: In step (4), the inert gas is one of nitrogen, helium, and argon; the cleaning is performed by first soaking in an acidic solution and then washing to neutrality; The acidic solution is one of hydrochloric acid solution, sulfuric acid solution and nitric acid solution; and the pyrolysis time is 3-4 hours.

9. An environmentally friendly electrode material for electrolytic fluorination process, characterized by: The electrode material is prepared by the method for preparing an environmentally friendly electrode material for electrolytic fluorination process according to any one of claims 1 to 8.

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