CN110880599A - A kind of preparation method of high performance fluorinated peanut shell hard carbon electrode material - Google Patents

Abstract

The invention discloses a preparation method of a high-performance fluorinated peanut shell hard carbon electrode material, which comprises the steps of crushing peanut shells, cleaning the crushed peanut shells with deionized water once, and removing water-soluble impurities; soaking in a KOH solution for activation, drying, pyrolyzing at high temperature for 4-6 hours under the protection of inert gas, and cooling to room temperature after pyrolysis is finished to obtain a pyrolytic carbon material; washing to be neutral, drying, grinding into powder, fluorinating the pyrolytic carbon material obtained after the step 4 by adopting a gas phase fluorination method, wherein the fluorination gas is a mixed gas of fluorine gas and nitrogen, the fluorination temperature is 200-300 ℃, the heat preservation time is 3-5 hours, and cooling is carried out after the fluorination is finished to obtain the pyrolytic carbon material; uniformly mixing the carbon fluoride material, carbon black and a binder in proportion, uniformly coating the mixture on an aluminum foil by utilizing NMP (N-methyl pyrrolidone), and drying to obtain the high-performance fluorinated peanut shell hard carbon electrode material. The carbon fluoride material with high energy density can be obtained by the method and used for the lithium primary battery, and the specific capacity of the battery can be obviously improved.

Description

A kind of preparation method of high performance fluorinated peanut shell hard carbon electrode material

technical field

The invention belongs to the technical field of carbon composite materials, and in particular relates to a preparation method of a high-performance fluorinated peanut shell hard carbon electrode material.

Background technique

In recent years, energy storage technologies for rechargeable batteries for electric vehicles, portable electronics, and large-scale electrical energy storage have attracted much attention due to the global demand for clean and sustainable energy. Rechargeable lithium-ion batteries (LIBs) dominate the following fields. Handheld electronic devices are considered to be the preferred candidates for electric vehicle energy supply. However, LIBs are not suitable for large-scale electrical energy storage due to limited mineral reserves and high cost of lithium-based compounds. To address this issue, rechargeable sodium-ion batteries (NIBs) have recently attracted the attention of researchers due to their low cost, abundant sodium resources. Various carbonaceous materials such as graphitic carbon, amorphous carbon (hard and soft carbon, etc., nanostructured carbon, graphene, and carbon nanotubes, etc.) have been widely used in NIBs due to the similar intercalation chemistry of lithium and sodium ions application. Among these carbonaceous materials, hard carbons (non-graphitized carbons) with large interlayer distances and disordered orientations attract a large number of carbonaceous materials due to their benefits for Li ⁺ /Na ⁺ intercalation-extraction, high-capacity It has received great attention due to its advantages and fast rate capability, however its rate performance is not satisfactory. In addition, hard carbon is usually obtained by the pyrolysis of important industrial products such as sucrose, glucose, polyvinyl chloride (PVC). Researchers have sought and sought appropriate pyrolysis processes to improve cycle performance.

In recent years, biomass waste as a carbon source has attracted much attention due to its abundance, low cost and sustainability. Carbonaceous materials made from bamboo, peat moss, banana peels, and pomelo peels have been shown to be excellent electrode materials for LIB and/or NIB applications. As one of the important biomass waste products, about 6 million tons of peanut shells are produced worldwide each year, most of which are underutilized. The pyrolysis of peanut shells for LIB applications has been studied previously, and the obtained carbon was found to have a specific capacity of over 380 mAh g ^-1 under 70 cycles.

One-dimensional (1D) nanostructures provide a direct pathway for efficient charge transport along their microscale axes, while the two extremely small nanoscale dimensions greatly reduce the ion diffusion length. Due to their unique advantages, 1D nanostructures have fast rate capability and have been intensively studied for use in electrochemical energy storage devices. Carbon nanotubes (CNTs) have unique structural and electronic properties, such as good electrical conductivity and high surface area-to-weight ratio and the ability to form three-dimensional conductive networks. The potential use of fluorinated carbon nanotubes (F-CNTs) as high-energy-density cathode materials for Li/CFx batteries can be expected, especially for deeply fluorinated batteries. F-CNTs have been demonstrated to exhibit stable operating potential and Faradaic yield at low discharge rates. However, carbon nanotubes are expensive and not suitable for large-scale use. The preparation of hard carbon from a wide range of biomass has become the research focus of many scientists.

The above-mentioned prior art has the following disadvantages:

1. Poor rate performance;

2. High production cost;

3. Small capacity.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the deficiencies of the prior art and provide a preparation method of a high-performance fluorinated peanut shell hard carbon electrode material. Density of carbon fluoride as a positive electrode material for lithium primary batteries.

The present invention is achieved through the following technical solutions:

A preparation method of a high-performance fluorinated peanut shell hard carbon electrode material, comprising the following steps:

Step 1, crushing the peanut shells, crushing the peanut shells to less than 5 mm, and washing the crushed peanut shells with deionized water to remove some water-soluble impurities;

Step 2, activation, soaking the peanut shells obtained in step 1 in a 5-7wt% KOH solution for activation, and then drying, and the amount of the KOH solution is 2-4 times the mass of the peanut shells;

Step 3, pyrolysis, the peanut shells obtained in step 2 are pyrolyzed at 700 to 900 degrees Celsius for 4 to 6 hours under the protection of an inert gas, and after the pyrolysis is completed, the temperature is lowered to room temperature to obtain a pyrolytic carbon material;

Step 4, washing and drying, washing the pyrolytic carbon material with deionized water to neutrality, and grinding into powder after drying;

Step 5, fluorination, adopt the gas phase fluorination method to fluorinate the pyrolytic carbon material obtained after the completion of step 4, the fluorinated gas is a mixed gas of fluorine gas and nitrogen gas, and the volume fraction of fluorine gas in the mixed gas is 15 ～20vol%, the fluorination temperature is 200～300 degrees Celsius, the holding time is 3～5 hours, and the temperature is lowered to room temperature after the fluorination is completed to obtain the carbon fluoride material;

Step 6, electrode preparation, the carbon fluoride material, carbon black, and binder are uniformly mixed in a ratio of 7-8:1:1 by mass, and evenly coated on aluminum foil with N-methylpyrrolidone (NMP) Then, drying in a vacuum drying oven for 10 to 12 hours, the relative vacuum degree is -110 to -90KPa, and the temperature is 90 to 110 degrees Celsius to obtain a high-performance fluorinated peanut shell hard carbon electrode material.

In the above technical solution, in the step 1, peanut shells are pulverized, the peanut shells are pulverized to 2-4 mm, and the pulverized peanut shells are soaked in deionized water for 2-3 hours to remove some water-soluble impurities.

In the above technical solution, in the step 2, activation, the peanut shells obtained by completing the step 1 are soaked in a 7wt% KOH solution for 1.5-3 hours, and then placed in a 50-80 ℃ oven for 2-3 hours. , the dosage of the KOH solution is 2 to 4 times the mass of the peanut shell;

In the above technical solution, in the step 3, the peanut shells obtained by completing the step 2 are pyrolyzed at 700-900 degrees Celsius for 4-6 hours under the protection of argon, the heating rate is 5-10 degrees Celsius/min, and the temperature is naturally lowered after the pyrolysis is completed. to room temperature to obtain a pyrolytic carbon material.

In the above technical solution, in step 4, the pyrolytic carbon material is washed with deionized water until neutral, dried at 50-80 degrees Celsius for 2-3 hours, and ground into powder after drying.

In the above technical solution, in step 5, the pyrolytic carbon material obtained after step 4 is placed into a fluorination furnace, the pressure in the fluorination furnace is reduced to a relative vacuum of -0.10 to -0.12MPa, and the temperature is increased to 200 to 300 degrees Celsius, the heating rate is 5 to 10 degrees Celsius/min. After the heating is completed, the fluorination furnace is evacuated again to a relative vacuum of -0.1 to -0.12MPa to remove gas impurities such as water vapor, and fluorinated gas is introduced to fluorine. The pressure in the furnace rises to one atmospheric pressure, the fluorinated gas is a mixed gas of fluorine gas and nitrogen gas, the volume fraction of fluorine gas in the mixed gas is 15-20 vol%, the holding time is 3-5 hours, and the fluorination is completed. Then, the temperature is lowered to room temperature to obtain a carbon fluoride material.

In the above technical solution, in the step 6, the binder is an aqueous solution of polyvinylidene fluoride, and the concentration of the aqueous solution of polyvinylidene fluoride is 0.1-0.2 g/ml.

In the above technical solution, in the step 6, electrode preparation, the carbon fluoride material, carbon black, and an aqueous solution of 0.1 g/ml polyvinylidene fluoride are uniformly mixed in a mass ratio of 8:1:1, using N-methylpyrrolidone (NMP) was evenly coated on the aluminum foil, dried in a vacuum drying oven for 12 hours, the relative vacuum degree was -0.1MPa, and the temperature was 110 degrees Celsius to obtain a high-performance fluorinated peanut shell hard carbon electrode material.

A preparation method of a high-performance fluorinated peanut shell hard carbon electrode material, comprising the following steps:

Step 1, crushing the peanut shells, crushing the peanut shells to less than 3 mm, and soaking the crushed peanut shells in deionized water for 2 hours to remove some water-soluble impurities;

Step 2, activation, soak the peanut shells obtained in step 1 in a 7wt% KOH solution for 2 hours, then place them in an oven at 80°C for 2 hours, and the amount of the KOH solution is 2% of the quality of the peanut shells. ~4 times;

Step 3, pyrolysis, the peanut shells obtained in step 2 are pyrolyzed at 800 degrees Celsius for 5 hours under the protection of an inert gas, and the heating rate is 5-10 degrees Celsius/min, and after the pyrolysis is completed, the temperature is lowered to room temperature to obtain a pyrolytic carbon material;

Step 4, washing and drying, washing the pyrolytic carbon material with deionized water to neutrality, drying at 80 degrees Celsius for 3 hours, and grinding into powder after drying;

Step 5, fluorination, put the pyrolytic carbon material obtained after the completion of step 4 into a fluorination furnace, reduce the pressure in the fluorination furnace to a relative vacuum of -0.1MPa, heat up to 300 degrees Celsius, and heat up at a rate of 10 degrees Celsius/ minutes, after the temperature rise is completed, the fluorination furnace is evacuated to a relative vacuum degree of -0.1MPa again to remove gas impurities such as water vapor, and the fluorinated gas is introduced to the pressure in the fluorination furnace to rise to an atmospheric pressure, and the fluorinated gas It is a mixed gas of fluorine gas and nitrogen gas, the volume fraction of fluorine gas in the mixed gas is 15-20 vol%, the holding time is 4 hours, and after the fluorination is completed, it is lowered to room temperature to obtain a fluorocarbon material;

Step 6, electrode preparation, mix the carbon fluoride material, carbon black, and an aqueous solution of polyvinylidene fluoride with a concentration of 0.1 g/ml uniformly in a ratio of 8:1:1 by mass, using N-methylpyrrolidone (NMP) was evenly coated on the aluminum foil, dried in a vacuum drying oven for 12 hours, the relative vacuum degree was -0.1MPa, and the temperature was 110 degrees Celsius to obtain a high-performance fluorinated peanut shell hard carbon electrode material.

A high-performance fluorinated peanut shell hard carbon electrode material prepared according to the above-mentioned preparation method of the high-performance fluorinated peanut shell hard carbon electrode material.

The advantages and beneficial effects of the invention are: high capacity and low cost.

Description of drawings

FIG. 1 is a cyclic voltammetry characteristic curve of Example 1 of the present invention.

The solid line, the dashed-dotted line and the dashed line represent the 1st, 2nd, and 3rd cyclic voltammetry characteristic curves, respectively. The upper three curves represent reduction peaks, and the lower three curves represent oxidation peaks.

FIG. 2 is a constant current charge-discharge curve of Example 1 of the present invention.

The charging curves correspond to the 1st charging curve, the 2nd charging curve, the 3rd charging curve, the 5th charging curve and the 10th charging curve from right to left.

For those of ordinary skill in the art, other related drawings can be obtained from the above drawings without any creative effort.

Detailed ways

In order to make those skilled in the art better understand the solutions of the present invention, the technical solutions of the present invention are further described below with reference to specific embodiments.

Example 1

A preparation method of a high-performance fluorinated peanut shell hard carbon electrode material, comprising the following steps:

Step 1, crushing the peanut shells, crushing the peanut shells to less than 3 mm, and soaking the crushed peanut shells in deionized water for 2 hours to remove some water-soluble impurities;

Step 2, activation, soak the peanut shells obtained in step 1 in a 7wt% KOH solution for 2 hours, then place them in an oven at 80°C for 2 hours, and the amount of the KOH solution is 3% of the mass of the peanut shells. times;

Step 3, pyrolysis, the peanut shells obtained in step 2 are pyrolyzed at 800 degrees Celsius for 5 hours under the protection of argon gas, and after the pyrolysis is completed, the temperature is lowered to room temperature to obtain a pyrolysis carbon material;

Step 4, washing and drying, washing the pyrolytic carbon material with deionized water to neutrality, drying at 80 degrees Celsius for 3 hours, and grinding into powder after drying;

Step 5, fluorination, put the pyrolytic carbon material obtained after the completion of step 4 into a fluorination furnace, reduce the pressure in the fluorination furnace to a relative vacuum of -0.1MPa, heat up to 300 degrees Celsius, and heat up at a rate of 10 degrees Celsius/ minutes, after the temperature rise is completed, the fluorination furnace is evacuated to a relative vacuum degree of -0.1MPa again to remove gas impurities such as water vapor, and the fluorinated gas is introduced to the pressure in the fluorination furnace to rise to an atmospheric pressure, and the fluorinated gas It is a mixed gas of fluorine gas and nitrogen gas, the volume fraction of fluorine gas in the mixed gas is 15vol%, the holding time is 4 hours, and after the fluorination is completed, it is lowered to room temperature to obtain a fluorocarbon material;

Step 6, electrode preparation, 80 mg of the carbon fluoride material and 10 mg of carbon black are placed in a mortar and fully ground, and then a few drops of N-methylpyrrolidone (NMP) are added dropwise to form a viscous slurry. Add 100 microliters of 0.1 g/ml polyvinylidene fluoride aqueous solution with a pipette gun, continue grinding, pour the slurry on aluminum foil, put a plastic membrane on it, and use a rolling pin to roll out the electrode slurry. It was dried in a vacuum drying oven for 12 hours, the relative vacuum degree was -0.1 MPa, and the temperature was 110 degrees Celsius to obtain a high-performance fluorinated peanut shell hard carbon electrode material.

Cut the high-performance fluorinated peanut shell hard carbon electrode material obtained in step 6 into a 12mm disc, and assemble it into a button battery. The battery consists of positive and negative electrode cover, lithium sheet, separator, positive electrode sheet (high-performance fluorinated peanut shell hard carbon electrode material disc), electrolyte (LiPF6 as solute, solvent is diethyl carbonate: dimethyl carbonate = 1: 1 volume ratio), assemble the battery for testing.

From the cyclic voltammetry characteristic curve in Figure 1, it can be seen that:

The solid line is the first scan. From the convex part of the oxidation peak curve, it can be known that the SEI (solid electrolyte membrane) film is formed. In the subsequent cycles, the smooth curve indicates that the electrode reaction proceeds normally and the cycle performance is stable.

It can be seen from the constant current charge-discharge curve in Figure 2 that:

It can be seen from the first cycle of discharge that the capacity reaches 350mAh/g, which indicates that the fluorinated peanut shell pyrolysis hard carbon has a high specific capacity. In the subsequent discharge tests, the capacity is maintained at about 200mAh/g. It may be caused by the decrease in the number of active sites for lithium ion insertion due to the lattice distortion of the carbon fluoride.

The advantage of this embodiment is mainly that a carbon fluoride material with high energy density can be obtained, and the carbon fluoride material is used in a lithium primary battery, which can significantly improve the specific capacity of the battery.

Example 2

A preparation method of a high-performance fluorinated peanut shell hard carbon electrode material, comprising the following steps:

Step 1, crushing the peanut shells, crushing the peanut shells to less than 5 mm, and soaking the crushed peanut shells in deionized water for 3 hours to remove some water-soluble impurities;

Step 2, activation, soak the peanut shells obtained in step 1 in a 7wt% KOH solution for 3 hours, then place them in a 70° C. oven to dry for 3 hours, and the amount of the KOH solution is 4% of the mass of the peanut shells. times;

Step 3, pyrolysis, the peanut shells obtained in step 2 are pyrolyzed at 700 degrees Celsius for 6 hours under the protection of argon, and the heating rate is 10 degrees Celsius/min, and after the pyrolysis is completed, the temperature is lowered to room temperature to obtain a pyrolytic carbon material;

Step 4, washing and drying, washing the pyrolytic carbon material with deionized water until neutral, drying at 60 degrees Celsius for 3 hours, and grinding into powder after drying;

Step 5, fluorination, put the pyrolytic carbon material obtained after the completion of step 4 into a fluorination furnace, reduce the pressure in the fluorination furnace to a relative vacuum of -0.12MPa, heat up to 300 degrees Celsius, and heat up at a rate of 10 degrees Celsius/ 10 minutes, the fluorination furnace is evacuated to relative vacuum degree-0.12MPa again after the temperature rise is completed, to remove gas impurities such as water vapor, and the pressure in the fluorination furnace is fed into the fluorination furnace to an atmospheric pressure, and the fluorinated gas is It is a mixed gas of fluorine gas and nitrogen gas, the volume fraction of fluorine gas in the mixed gas is 20 vol%, the holding time is 5 hours, and after the fluorination is completed, it is lowered to room temperature to obtain a fluorocarbon material;

Step 6, electrode preparation, 80 mg of the carbon fluoride material and 10 mg of carbon black are placed in a mortar and fully ground, and then a few drops of N-methylpyrrolidone (NMP) are added dropwise to form a viscous slurry. Add 100 microliters of 0.1 g/ml polyvinylidene fluoride aqueous solution with a pipette gun, continue grinding, pour the slurry on aluminum foil, put a plastic membrane on it, and use a rolling pin to roll out the electrode slurry. It was dried in a vacuum drying oven for 12 hours, the relative vacuum degree was -0.1 MPa, and the temperature was 110 degrees Celsius to obtain a high-performance fluorinated peanut shell hard carbon electrode material.

Cut the high-performance fluorinated peanut shell hard carbon electrode material obtained in step 6 into a 12mm disc, and assemble it into a button battery. The battery consists of positive and negative electrode caps, lithium sheets, separators, positive electrode sheets (12mm disc of high-performance fluorinated peanut shell hard carbon electrode material), electrolyte (LiPF6 as a solute, and the solvent is diethyl carbonate: dimethyl carbonate = 1:1 volume ratio), assemble the battery for testing.

Example 3

A preparation method of a high-performance fluorinated peanut shell hard carbon electrode material, comprising the following steps:

Step 1, crushing the peanut shells, crushing the peanut shells to less than 2 mm, and soaking the crushed peanut shells in deionized water for 3 hours to remove some water-soluble impurities;

Step 2, activation, soak the peanut shells obtained in step 1 in a 7wt% KOH solution for 3 hours, then place them in an oven at 80°C for 3 hours, and the amount of the KOH solution is 2% of the mass of the peanut shells. times;

Step 3, pyrolysis, the peanut shells obtained in step 2 are pyrolyzed at 750 degrees Celsius for 6 hours under the protection of an inert gas, and the heating rate is 8 degrees Celsius/min, and after the pyrolysis is completed, the temperature is lowered to room temperature to obtain a pyrolytic carbon material;

Step 4, washing and drying, washing the pyrolytic carbon material with deionized water until neutral, drying at 70 degrees Celsius for 3 hours, and grinding into powder after drying;

Step 5, fluorination, put the pyrolytic carbon material obtained after the completion of step 4 into a fluorination furnace, reduce the pressure in the fluorination furnace to a relative vacuum of -0.10MPa, heat up to 300 degrees Celsius, and heat up at a rate of 10 degrees Celsius/ 10 minutes, the fluorination furnace is evacuated to relative vacuum degree-0.10MPa again after the temperature rise is completed, to remove gas impurities such as water vapor, and the pressure in the fluorination furnace is fed into the fluorination furnace to an atmospheric pressure, and the fluorinated gas is It is a mixed gas of fluorine gas and nitrogen gas, the volume fraction of fluorine gas in the mixed gas is 18vol%, the holding time is 3.5 hours, and after the fluorination is completed, it is lowered to room temperature to obtain a fluorocarbon material;

Step 6, electrode preparation, 80 mg of the carbon fluoride material and 10 mg of carbon black are placed in a mortar and fully ground, and then a few drops of N-methylpyrrolidone (NMP) are added dropwise to form a viscous slurry. Add 100 microliters of 0.1 g/ml polyvinylidene fluoride aqueous solution with a pipette gun, continue grinding, pour the slurry on aluminum foil, put a plastic membrane on it, and use a rolling pin to roll out the electrode slurry. It was dried in a vacuum drying oven for 12 hours, the relative vacuum degree was -0.1 MPa, and the temperature was 110 degrees Celsius to obtain a high-performance fluorinated peanut shell hard carbon electrode material.

Cut the high-performance fluorinated peanut shell hard carbon electrode material obtained in step 6 into a 12mm disc, and assemble it into a button battery. The battery consists of positive and negative electrode caps, lithium sheets, separators, positive electrode sheets (12mm disc of high-performance fluorinated peanut shell hard carbon electrode material), electrolyte (LiPF6 as a solute, and the solvent is diethyl carbonate: dimethyl carbonate = 1:1 volume ratio), assemble the battery for testing.

The present invention has been exemplarily described above. It should be noted that, without departing from the core of the present invention, any simple deformation, modification, or other equivalent replacements that can be performed by those skilled in the art without any creative effort fall into the scope of the present invention. the scope of protection of the invention.

Claims (10)

1. A preparation method of a high-performance fluorinated peanut shell hard carbon electrode material is characterized by comprising the following steps:

step 1, crushing peanut shells, namely crushing the peanut shells to be less than 5mm, and cleaning the crushed peanut shells once by using deionized water to remove part of water-soluble impurities;

step 2, activating, namely soaking the peanut shells obtained in the step 1 in a 5-7 wt% KOH solution for activation, and then drying, wherein the using amount of the KOH solution is 2-4 times of the mass of the peanut shells;

step 3, performing pyrolysis, namely pyrolyzing the peanut shells obtained in the step 2 for 4-6 hours at 700-900 ℃ under the protection of inert gas, and cooling to room temperature after pyrolysis is completed to obtain a pyrolytic carbon material;

step 4, washing and drying, washing the pyrolytic carbon material to be neutral by deionized water, drying and grinding into powder;

step 5, fluorination, namely, carrying out fluorination on the pyrolytic carbon material obtained after the step 4 by adopting a gas phase fluorination method, wherein the fluorinated gas is a mixed gas of fluorine gas and nitrogen gas, the volume fraction of the fluorine gas in the mixed gas is 15-20 vol%, the fluorination temperature is 200-300 ℃, the heat preservation time is 3-5 hours, and cooling to room temperature after the fluorination is finished to obtain the fluorinated carbon material;

and 6, preparing an electrode, namely uniformly mixing the carbon fluoride material, carbon black and a binder according to the mass ratio of 7-8: 1:1, uniformly coating the mixture on an aluminum foil by using N-methylpyrrolidone (NMP), drying the aluminum foil for 10-12 hours in a vacuum drying oven, wherein the relative vacuum degree is-110 to-90 KPa, and the temperature is 90-110 ℃, so as to obtain the high-performance fluorinated peanut shell hard carbon electrode material.

2. The method for preparing the high-performance fluorinated peanut shell hard carbon electrode material as claimed in claim 1, wherein in the step 1, the peanut shell is crushed to 2-4 mm, and the crushed peanut shell is soaked in deionized water for 2-3 hours to remove part of water-soluble impurities.

3. The preparation method of the high-performance fluorinated peanut shell hard carbon electrode material as claimed in claim 1, wherein in the step 2, activation, the peanut shell obtained in the step 1 is soaked in 7 wt% KOH solution for activation for 1.5-3 hours, and then is dried in an oven at 50-80 ℃ for 2-3 hours, and the amount of the KOH solution is 2-4 times of the mass of the peanut shell.

4. The preparation method of the high-performance fluorinated peanut shell hard carbon electrode material as claimed in claim 1, wherein in the step 3, the peanut shell obtained in the step 2 is pyrolyzed at 700-900 ℃ for 4-6 hours under the protection of argon gas, the temperature rise rate is 5-10 ℃ per minute, and the pyrolyzed carbon material is obtained by naturally cooling to room temperature after pyrolysis.

5. The method for preparing the high-performance fluorinated peanut shell hard carbon electrode material as claimed in claim 1, wherein in the step 4, the pyrolytic carbon material is washed to be neutral by deionized water, dried for 2-3 hours at 50-80 ℃, and ground into powder after being dried.

6. The method for preparing a high-performance fluorinated peanut shell hard carbon electrode material as claimed in claim 1, wherein in the step 5, the pyrolytic carbon material obtained after the step 4 is completed is placed into a fluorination furnace, the pressure in the fluorination furnace is reduced to a relative vacuum degree of-0.10 to-0.12 MPa, the temperature is raised to 200 to 300 ℃, the temperature raising rate is 5 to 10 ℃ per minute, the fluorination furnace is vacuumized again to a relative vacuum degree of-0.1 to-0.12 MPa after the temperature raising is finished, gas impurities such as water vapor and the like are removed, the pressure in the fluorination furnace is increased to one atmosphere by introducing fluorinated gas, the fluorinated gas is a mixed gas of fluorine gas and nitrogen gas, the volume fraction of the fluorine gas in the mixed gas is 15 to 20 vol%, the heat preservation time is 3 to 5 hours, and the temperature is reduced to room temperature after the fluorination is finished, so that the fluorinated carbon material is obtained.

7. The method for preparing the high-performance fluorinated peanut shell hard carbon electrode material as claimed in claim 1, wherein in the step 6, the binder is an aqueous solution of polyvinylidene fluoride, and the concentration of the aqueous solution of polyvinylidene fluoride is 0.1-0.2 g/ml.

8. The preparation method of the high-performance fluorinated peanut shell hard carbon electrode material as claimed in claim 1, wherein in the step 6, the electrode is prepared by uniformly mixing the carbon fluoride material, carbon black and 0.1 g/ml polyvinylidene fluoride aqueous solution according to a mass ratio of 8:1:1, uniformly coating the mixture on an aluminum foil by using N-methylpyrrolidone (NMP), and drying the mixture in a vacuum drying oven for 12 hours at a relative vacuum degree of-0.1 MPa and a temperature of 110 ℃ to obtain the high-performance fluorinated peanut shell hard carbon electrode material.

9. A preparation method of a high-performance fluorinated peanut shell hard carbon electrode material is characterized by comprising the following steps:

step 1, crushing peanut shells, namely crushing the peanut shells to be less than 3mm, and soaking the crushed peanut shells in deionized water for 2 hours to remove part of water-soluble impurities;

step 2, activating, namely soaking the peanut shells obtained in the step 1 in a 7 wt% KOH solution for 2 hours, and then drying the peanut shells in an oven at 80 ℃ for 2 hours, wherein the using amount of the KOH solution is 2-4 times of the mass of the peanut shells;

step 3, performing pyrolysis, namely pyrolyzing the peanut shells obtained in the step 2 for 5 hours at 800 ℃ under the protection of inert gas, wherein the heating rate is 5-10 ℃ per minute, and cooling to room temperature after pyrolysis is completed to obtain a pyrolytic carbon material;

step 4, washing and drying, namely washing the pyrolytic carbon material to be neutral by using deionized water, drying for 3 hours at 80 ℃, and grinding into powder after drying;

step 5, fluorination, namely putting the pyrolytic carbon material obtained after the completion of the step 4 into a fluorination furnace, reducing the pressure in the fluorination furnace to-0.1 MPa of relative vacuum degree, heating to 300 ℃, heating at a heating rate of 10 ℃ per minute, vacuumizing the fluorination furnace again to-0.1 MPa of relative vacuum degree after the heating is finished so as to remove gas impurities such as water vapor, introducing a fluorinated gas until the pressure in the fluorination furnace is increased to one atmospheric pressure, wherein the fluorinated gas is a mixed gas of fluorine gas and nitrogen gas, the volume fraction of the fluorine gas in the mixed gas is 15-20 vol%, keeping the temperature for 4 hours, and reducing the temperature to room temperature after the fluorination is finished so as to obtain the fluorinated carbon material;

and 6, preparing an electrode, namely uniformly mixing the carbon fluoride material with carbon black and a polyvinylidene fluoride aqueous solution with the concentration of 0.1 g/ml according to the mass ratio of 8:1:1, uniformly coating the mixture on an aluminum foil by utilizing N-methylpyrrolidone (NMP), drying the mixture for 12 hours in a vacuum drying oven at the relative vacuum degree of-0.1 MPa and the temperature of 110 ℃, and obtaining the high-performance fluorinated peanut shell hard carbon electrode material.

10. A high performance fluorinated peanut shell hard carbon electrode material prepared by the method of preparing a high performance fluorinated peanut shell hard carbon electrode material according to any one of claims 1 to 9.

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