CN115312326A - Method for preparing supercapacitor electrode material based on camellia peel - Google Patents
Method for preparing supercapacitor electrode material based on camellia peel Download PDFInfo
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- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
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- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
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- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
- H01G11/86—Processes for the manufacture of hybrid or EDL capacitors, or components thereof specially adapted for electrodes
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- Y02E60/13—Energy storage using capacitors
Abstract
A method for preparing a supercapacitor electrode material based on camellia peel comprises the following steps: s1, washing, drying and crushing camellia peel to obtain a camellia peel block; s2, carbonizing the camellia peel blocks at a target temperature under an inert atmosphere to obtain a high-temperature carbonized material; s3, uniformly mixing the carbonized material and the alkaline activator in an ethanol-water mixed solvent according to a preset mass ratio, and drying; s4, calcining the dried sample in an inert atmosphere; s5, soaking the calcined sample in an acid solution, washing the calcined sample to be neutral by using distilled water, and drying the washed sample to obtain the camellia peel-based biomass charcoal material; and S6, uniformly mixing the biochar material with a conductive agent and an adhesive, drying and tabletting to obtain the camellia peel-based supercapacitor electrode material. The invention uses the camellia peel waste as the raw material, the material cost is low, the obtained carbon material has rich pore channel structure and high specific surface area, and the prepared electrode material has higher specific capacitance, good conductivity and reversibility.
Description
Technical Field
The invention belongs to the technical field of electrode material preparation, and particularly relates to a method for preparing a supercapacitor electrode material based on camellia peel.
Background
The super capacitor is a novel energy storage device integrating the advantages of a lithium battery and a traditional capacitor, and has long cycle life. The heteroatom doping can cause the increase of the material pseudo capacitance and improve the capacitance performance of the material. Many biomasses also contain rich impurity elements, and can be used for directly preparing heteroatom-doped porous carbon materials, so that the method becomes a new research hotspot in the field, and the porous biomass carbon materials are paid more and more attention due to good capacitance performance and cycle performance, so that the method has great research value.
In order to solve the problems of great environmental pollution and resource waste caused by peel wastes, a plurality of reports of manufacturing a supercapacitor electrode material by using peel exist in the prior art, the problems can be solved, and the problems of low capacitance performance and high manufacturing cost of a supercapacitor can also be solved, for example, patent application number CN202010056398.6 discloses a preparation method of the supercapacitor electrode material based on orange peel biomass charcoal, which comprises the following steps: (1) pretreatment; (2) carbonizing; and (3) activating: taking the carbon powder in the step (2), uniformly mixing the carbon powder with KOH in water, performing ultrasonic treatment for 1h, drying in an oven, centrifuging to obtain a precipitate, drying the precipitate for the first time, placing the precipitate in a tubular furnace heated to 600-900 ℃, performing heat preservation, and performing secondary drying and activation; and (4) purifying and drying to obtain the electrode material.
Although the preparation method can effectively utilize the orange peels, the specific capacitance of the electrode material prepared by the method is lower than 240F/g, and the specific capacitance prepared by the method is low and cannot meet the requirement of high specific capacitance; in addition, the electrode material is made of orange peel instead of camellia peel, and the problems of resource waste and environmental pollution caused by camellia peel waste cannot be solved.
Therefore, how to prepare the electrode material of the supercapacitor by using camellia peel waste as a raw material to solve the defects of high price, low specific capacitance, poor conductivity and the like of the existing carbon-based electrode material is a problem to be solved urgently.
Disclosure of Invention
The invention aims to provide a method for preparing a supercapacitor electrode material based on camellia peel, which aims to solve the problems of high price, low specific capacitance, poor conductivity and the like of the existing carbon-based electrode material.
The technical scheme of the invention is as follows: a method for preparing an electrode material of a supercapacitor based on camellia peels comprises the following steps:
s1, washing, drying and crushing camellia peel to obtain a camellia peel block;
s2, carbonizing the camellia peel blocks at a target temperature under an inert atmosphere to obtain a high-temperature carbonized material;
s3, uniformly mixing the high-temperature carbonized material and the alkaline activator in an ethanol-water mixed solvent according to a preset mass ratio, and then drying;
s4, calcining the dried sample in an inert atmosphere;
s5, soaking the calcined sample in an acid solution, washing the calcined sample to be neutral by using distilled water, and drying the washed sample to obtain the camellia peel-based biomass charcoal material;
and S6, uniformly mixing the biochar material with a conductive agent and an adhesive, drying and tabletting to obtain the camellia peel-based supercapacitor electrode material.
According to the invention, camellia peel is used as a raw material, compared with camellia husks and other peel and shell biomass, the camellia peel contains a large amount of polysaccharide, lignin and the like which can be used as raw materials for producing active carbon, the content of the polysaccharide, the lignin and the like is more than 10% than that of the husk, and the camellia peel is soft relative to the husk, so that the camellia peel has a special microstructure and is richer in pore structure after high-temperature calcination; in addition, the camellia peel contains more trace elements (such as N, S and O), and the trace elements can be doped in situ in the high-temperature carbonization process, so that the conductivity of the electrode material can be increased, the surface wettability of the material is improved, and the performance of the capacitor is improved.
The preparation method of the electrode material provided by the invention is characterized in that the camellia peel block obtained by pretreatment is carbonized, organic impurities such as pectin and the like in the camellia peel can be effectively removed, and a large amount of CO can be generated in the carbonization process of the organic impurities 2 CO and other gases, so that the material forms a porous structure with the aperture larger than 50nm, the specific surface area of the whole material is lower, and the specific capacitance is further lower; in order to further solve the problems of low specific surface area and low specific capacitance of the material, the high-temperature carbonized material and the alkaline activator are uniformly mixed in the ethanol-water mixed solvent and then are calcined at high temperature, so that pores can be further formed to form more micropores and mesoporous structures, and the improvement of the specific capacitance of the material is facilitated; then adopting the method of acid soaking and distilled water washing to wash off many impurities generated after calcination and neutralize the alkaline activating agent, so that the produced micropores can not be blocked, and the specific capacitance of the material is further improved. According to the preparation method, through mutual cooperation among the steps, the preparation of the supercapacitor electrode material which is low in material cost, low in high specific capacitance and high in conductivity is realized, the pore diameter of the prepared camellia peel-based biomass charcoal material is distributed in the range of 0.1-10 nm and mainly below 2nm, and the camellia peel-based biomass charcoal material is provided with more micropores which are beneficial to permeation and transfer of electrolyte ions, so that the capacitance performance of the supercapacitor electrode material is improved.
In general, the specific capacitance of the carbon material for preparing the supercapacitor increases with the increase of the specific surface area of the carbon material, the electrode material prepared by the existing preparation method has many closed pores or narrow micropores although the electrode material has larger specific surface area, and the closed pores and the narrow micropores (generally the pore diameter is below 0.1 nm) do not contribute to the transfer of electrolyte ions, so when the prepared material has large specific surface area, the large amount of closed pores or narrow micropores existAlso resulting in a lower specific capacitance. In the step 3, a mixed solution of ethanol and water is used as a solvent, and due to the doping of microelements in the camellia fruit peel and oxygen-containing functional groups on the surface in the carbonization process of the step 2), the surface of the prepared high-temperature carbonization material is hydrophobic, so that the alkaline activator (such as KOH) cannot fully enter the pore structure of the high-temperature carbonization material when the subsequent alkaline activator and water are used as solvents to be mixed, and the next pore-forming process is influenced. Therefore, the ethanol and the water are adopted as the solvent to be fully mixed with the alkaline activator in the step 3), so that the alkaline activator can be effectively promoted to be dispersed and enter pores of the high-temperature carbonized material to further react with the carbon to form a porous structure; in addition, alkali metal ions of basic activators (e.g. K) + ) The material prepared by the method has more micropores, and the pore diameter is mainly distributed below 2nm, so that the material is favorable for permeation and transfer of electrolyte ions, and further the capacitance performance of the super capacitor is improved. In addition, when the pore diameter of the carbon material is less than 1nm, charge storage in the pores will result in high capacitance. Therefore, the pore structure and pore distribution prepared by the method have higher specific capacitance performance.
Further, the size of the camellia peel block in the step S1 is 0.01 to 2 cm. If the size of the block is larger than 2cm, insufficient carbonization of the center of the block can be caused; if the size is less than 0.01cm, the yield of the carbon material is lowered.
Further, in the step S2, the carbonization temperature of the camellia peel block is 500 to 700 ℃, and the carbonization time is 2 to 8 hours. If the carbonization temperature is less than 500 ℃ or the carbonization time is less than 2 hours, insufficient carbonization can be caused; carbonization temperatures >700 ℃ or carbonization times >8 h will reduce the content of heteroatoms in the carbon material.
Further, the inert atmosphere used in steps S2 and S4 is any one of nitrogen, helium, neon, argon, krypton, and xenon. .
Further, the alkaline activator in step S3 is KOH, naOH, ca (OH) 2 Any one of them.
Further, the mass ratio of the carbonized material to the activator in the step S3 is 0.5 to 5:1, with the increase of the proportion of the activating agent, the specific surface area of the carbon material is increased and then gradually unchanged, but the addition of excessive activating agent can cause difficulty in subsequent drying and cleaning processes and extremely pollute the environment; the volume ratio of ethanol to water in the mixed solvent is 0.1 to 10:1, as the boiling point of the ethanol is lower than that of the water, the more the proportion of the ethanol in the mixed solvent is, the shorter the subsequent volatilization drying time is, and the preparation efficiency can be improved.
Further, the calcining temperature in the step S4 is 900 to 1000 ℃, and the calcining time is 0.5 to 8 hours. The calcination temperature is less than 900 ℃ or the calcination time is less than 0.5 h, so that the activation is insufficient, and the specific surface area and the graphitization degree of the carbon material are reduced; calcination temperatures >1000 ℃ or calcination times >8 h can result in collapse of the pore structure in the carbon material, which in turn reduces the specific surface area of the carbon material.
Preferably, the calcination temperature is 950 ℃.
Further, in the step S5, the acid solution is H 2 SO 4 、H 3 PO 4 、HCl、HNO 3 Any one of them.
Further, in the step S5, the concentration of the acid solution is 0.1 to 3M; the soaking time of the material is 5 to 100 min. Too high concentration of the acid solution can cause too violent reaction, and too high concentration or too long soaking time can also damage the skeleton structure of the biomass charcoal material and reduce the specific surface area of the biomass charcoal material. Too low a concentration of the acidic solution or too short a soaking time may result in insufficient cleaning of the carbon material and residual alkali metal ions.
Further, in the steps S1, S3 and S5, the drying temperature is 50-80 ℃, and the drying time is 12-36h.
Further, in step S6, the conductive agent is acetylene black, the adhesive is polytetrafluoroethylene emulsion, and a mixing ratio of the camellia peel-based biochar material to the acetylene black and the polytetrafluoroethylene emulsion is 8:1:1.
further, the pore diameter of the camellia peel-based biomass charcoal material is 0.1nm-10nm.
The method for preparing the supercapacitor electrode material based on the camellia peel has the beneficial effects that:
(1) The electrode material takes the waste camellia peel generated in the production process of camellia oil as the raw material, the raw material has rich sources, stable composition and structure and low price, changes waste into valuable, and the porous charcoal electrode material is prepared by a method with simple process and strong repeatability, so that the preparation cost of the electrode material can be reduced, the pollution to the environment caused by the camellia peel used as fuel or simply burnt can be avoided, and the resource utilization rate of the camellia peel can be effectively improved; the supercapacitor electrode material prepared by taking the camellia peel as the raw material has the advantages of high specific capacitance, good conductivity and good cycling stability, and has great application value;
(2) The preparation process is simple, the steps of raw material treatment, carbonization, alkali activation, drying, calcination, acid leaching and the like are sequentially adopted, and the prepared camellia peel-based biomass carbon material has more micropores or mesoporous structures, the pore diameter is distributed between 0.1nm and 10nm and is mainly distributed below 2nm through mutual cooperation of the steps, the micropores are beneficial to permeation and transmission of electrolyte ions, so that the specific capacitance of an electrode material prepared by further adopting the camellia peel-based biomass carbon material is up to 360F/g, the capacitance performance of the electrode material of the supercapacitor is effectively improved, and the preparation of the electrode material of the supercapacitor, which is low in material cost, high in specific capacitance and high in conductivity, is realized.
Drawings
FIG. 1 is a scanning electron microscope image of the camellia peel-based biochar material prepared in example 1;
FIG. 2 is a pore size distribution diagram of the camellia peel-based biomass charcoal material prepared in example 1;
FIG. 3 is a nitrogen adsorption and desorption graph of the camellia peel-based biomass charcoal material prepared in example 1 of the present invention;
FIG. 4 is a cyclic voltammetry curve of the camellia peel-based supercapacitor electrode material prepared in example 1 at different sweep rates;
FIG. 5 is a charging and discharging curve of the camellia peel-based supercapacitor electrode material prepared in example 1 at different current densities;
FIG. 6 is a specific surface area diagram of the camellia peel-based supercapacitor electrode material obtained at different calcination temperatures.
Detailed description of the preferred embodiment
The following further describes the embodiments of the present invention in detail. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
Example 1
A method for preparing an electrode material of a supercapacitor based on camellia peels comprises the following steps:
1) Washing, drying and crushing 10 g of washed and dried camellia peel to obtain a camellia peel block body with the size of 1 cm;
2) Heating the camellia peel block to 500 ℃ in argon atmosphere, carbonizing, keeping for 2h, cooling to room temperature, and grinding the obtained high-temperature carbonized material into powder for later use;
3) Uniformly mixing 1g of powdery high-temperature carbonized material and 2g of KOH (the mass ratio is 1;
4) Keeping the dried sample calcined for 2 hours at the temperature of 950 ℃ in a nitrogen atmosphere;
5) Soaking the calcined sample in 1M HCl for 20 min, washing with distilled water to neutrality, and drying at 70 ℃ to obtain the camellia peel-based biomass charcoal material;
6) Mixing the camellia peel-based biomass carbon material with acetylene black and polytetrafluoroethylene emulsion according to the mixing ratio of 8:1:1, drying in a 70 ℃ oven after uniformly mixing, and tabletting to obtain the camellia peel-based supercapacitor electrode material.
The microstructure, the pore size distribution, the nitrogen adsorption and desorption curve and the specific surface area of the camellia peel-based biomass charcoal material prepared in the example 1 are measured, and then the electrochemical performance of the camellia peel-based supercapacitor electrode material is tested in a three-electrode system, wherein the measuring method comprises the following steps of: an Ag/AgCl electrode and a platinum sheet electrode are respectively used as a reference electrode and a counter electrode, 6 mol L -1 The KOH solution of (a) serves as an electrolyte solution in the electrochemical test. The cyclic voltammetry curve is carried out in a potential range of-1 to 0V, and the sweep rate is 5 mV s -1 To 100 mV s -1 . The constant current charge and discharge experiment is carried out in a potential range of-1 to 0V, and the charge and discharge current is from 0.1A g -1 To 20 ag -1 . The specific capacitance of the sample is calculated according to a constant current charging and discharging curve, and the calculation formula is as follows:C=I∆t/m∆Vwherein the content of the first and second substances,C (F g -1 ) Is the specific capacitance of the capacitor, and,I(A) Is current of charge and dischargeV (V) is discharge timetA potential within(s) changes, andm (g) Is the mass of active material on the electrode. (J. Power Sources, 2011, 196: 5756-5760））。
The BET specific surface area of the camellia peel-based biomass charcoal material prepared in the embodiment is 2100 m 2 And the microstructure, the pore size distribution and the electrochemical performance test results of the camellia peel-based supercapacitor electrode material are shown in figures 1-5.
As can be seen from FIG. 1, the camellia peel-based biomass charcoal material prepared by the invention is in an irregular block shape; as can be seen from FIG. 2, the pore size of the prepared camellia peel-based biomass charcoal material is distributed at 0.3-1.6 nm, mainly at 0.4 nm; as can be seen from FIG. 3, the nitrogen adsorption-desorption curve of the camellia peel-based biomass charcoal material shows a tendency of rapidly rising at the initial stage and then gradually stabilizing, which is a typical nitrogen elution-adsorption curve of a microporous material, and shows that the camellia peel-based biomass charcoal material manufactured by the method has more microporous structures, can effectively promote the permeation and transfer of electrolyte ions, and further improves the capacitance performance of a supercapacitor.
As can be seen from fig. 4, the cyclic voltammetry curves of the electrode material at different sweep rates all have a rectangular-like shape, which is a typical characteristic of the electric double layer supercapacitor, and shows that the electrode material prepared by the method of the present invention has the characteristics of the electric double layer supercapacitor; as can be seen from FIG. 5, when the voltage range is controlled to be-1 to 0V, the charge and discharge curves of the electrode material all present symmetrical triangles, which shows that the material has good charge and discharge performance.
The specific capacitance of the electrode material of the supercapacitor prepared in example 1 under different current densities is tested, and the specific measurement method is shown in the reference (J. PowerSources2011, 196: 5756-5760), the result shows that the specific capacitance is 360F/g when the current density is 1A/g; when the current density is 10A/g, the specific capacitance is 330F/g, which is 91.7 percent of the specific capacitance when the current density is 1A/g, and the high specific capacitance and the excellent rate performance are shown. After 1000 times of cyclic discharge, the specific capacitance of the material can still be maintained at 94-98%, which shows that the material has good reversibility.
Example 2
A method for preparing a supercapacitor electrode material based on camellia peel comprises the following steps:
1) Washing, drying and crushing 10 g of washed and dried camellia peel to obtain camellia peel blocks with the size of 0.2 cm;
2) Heating the camellia peel block under nitrogen atmosphere to 600 ℃ for carbonization, keeping for 4h, cooling to room temperature, and grinding the obtained high-temperature carbonized material into powder for later use;
3) Uniformly mixing 2g of a powdery high-temperature carbonized material with 1g of KOH (the mass ratio is 2;
4) Keeping the dried sample calcined for 3 hours at the temperature of 1000 ℃ in the nitrogen atmosphere;
5) Soaking the calcined sample in 1M HCl for 20 min, washing the sample to be neutral by distilled water, and drying the sample at 70 ℃ to obtain the camellia peel-based biomass charcoal material;
6) Mixing the camellia peel-based biomass carbon material with acetylene black and polytetrafluoroethylene emulsion according to the mixing ratio of 8:1:1, drying in a 70 ℃ oven after uniformly mixing, and tabletting to obtain the camellia peel-based supercapacitor electrode material.
The pore structure of the camellia peel-based biomass charcoal material prepared by the embodiment contains a large number of micropores, mesopores and a small number of microporesMacro pores with pore diameter mainly distributed at 0.3-3 nm and mainly concentrated at 0.4 nm, BET specific surface area of 1800 m 2 (ii) in terms of/g. Specific capacitance of the prepared electrode material of the super capacitor under different current densities is tested, and the result shows that the specific capacitance is 322F/g when the current density is 1A/g; when the current density is 10A/g, the specific capacitance is 291F/g, which is 90.4% of the specific capacitance when the current density is 1A/g, and the high specific capacitance and the excellent rate capability are shown. After 1000 times of cyclic discharge, the specific capacitance of the material can still be kept at 93-96%.
Comparative example 1
This comparative example differs from example 1 in that: step 3) taking 1g of powdery high-temperature carbonized material and 2g of KOH (the mass ratio is 1.
Comparative example 2
This comparative example differs from example 1 in that: step 3) 1g of powdery high-temperature carbonized material and 2g of KOH (the mass ratio is 1.
Comparative example 3
This comparative example differs from example 1 in that: and step 5) washing the calcined sample with distilled water to be neutral, and drying at 70 ℃ to prepare the camellia peel-based biomass charcoal material, wherein the other steps are the same as those in the example 1.
Comparative example 4
This comparative example differs from example 1 in that: step 2 is not included, 1g of camellia peel blocks and 2g of KOH (mass ratio of 1.
Comparative example 5
The comparative example differs from example 1 in that: adding an acid washing step between the steps 2) and 3), and specifically comprising the following steps: and (3) soaking the carbonized sample in 1M HCl for 20 min, washing the sample to be neutral by distilled water, and drying the sample at 70 ℃.
The specific surface area of the camellia peel-based biomass charcoal material prepared in the comparison ratio of 1-5 and the specific capacitance of the camellia peel-based supercapacitor electrode material are measured, and the results are shown in the following table:
TABLE 1 determination of the specific surface area of the camellia peel-based biochar material prepared in example 1 and comparative examples 1-5 and the specific capacitance of the camellia peel-based supercapacitor electrode material
As can be seen from table 1, when the solvent used in alkali activation is simply ethanol or water (corresponding to comparative example 1 and comparative example 2, respectively), the specific surface area of the camellia peel-based biomass charcoal material and the specific capacitance of the camellia peel-based supercapacitor electrode material further prepared using the carbon material are significantly reduced, compared to example 1, because: because the camellia peel contains a large amount of trace elements, the trace elements can realize in-situ doping when high-temperature carbonization is carried out in the step 2), and oxygen-containing functional groups exist on the surface of the high-temperature carbon material, so that the surface of the high-temperature carbon material presents hydrophobicity, a subsequent alkaline activator is prevented from entering the pore structure of the high-temperature carbon material, further reaction of the alkaline activator and carbon in the pores is prevented, the next pore-forming process is influenced, and the specific surface area and the pore volume of the material are reduced;
the method adopts ethanol-water as a solvent to be fully mixed with the solvent during alkali activation, so that the specific surface area of the obtained camellia peel-based biomass charcoal material is 2100 m 2 Per g, pore volume 0.7cm 3 In each case higher than when ethanol was used alone (comparative example 1, specific surface area 460 m 2 Per g, pore volume 0.28 cm 3 In g) and water alone (comparative example 2, specific surface area 780 m 2 Per g, pore volume 0.36 cm 3 /g) for the reasons: ethanol and water are adopted as solvents to be fully mixed with the activating agent, so that the alkaline activating agent can be effectively promoted to enter the pore structure of the high-temperature carbon material, and the alkaline activating agent is further reacted with carbon in the pores to formA porous structure is formed, in addition, alkali metal ions (such as K < + >) can also be intercalated into the partially crystallized carbon material, so that the carbon material is expanded, more porous structures are further obtained, and the specific capacitance of the electrode material is further improved;
when carbonization is not performed in the preparation method of the electrode material (corresponding to comparative example 4) and acid soaking is not performed after calcination (corresponding to comparative example 3), the specific surface area of the camellia peel-based biomass charcoal material is also remarkably reduced, so that the specific capacitance of the camellia peel-based supercapacitor electrode material prepared from the camellia peel-based biomass charcoal material is reduced; when the specific surface area of the carbon material obtained by adding the acid soaking and washing steps after carbonization and the specific capacitance of the electrode material are not significantly different from those of the embodiment 1, the preparation steps of the electrode material can be simplified by omitting the steps, and the preparation efficiency of the electrode material is improved. In conclusion, the operation steps for preparing the electrode material are mutually cooperated and jointly acted, so that the prepared camellia peel-based biomass carbon material has high specific surface area, and the electrode material prepared by adopting the carbon material has electrical characteristics of high specific capacitance.
Examples of the experiments
The method of example 1 is adopted in the invention, and the specific surface area of the camellia peel-based biomass charcoal material prepared by calcining at different calcining temperatures (800 ℃, 850 ℃, 900 ℃, 950 ℃, 1000 ℃ and 1050 ℃) in the step 4) is measured, and the result is shown in fig. 6.
As can be seen from fig. 6, the specific area of the camellia peel-based biomass charcoal material tends to increase and decrease with the increase of temperature, and the specific area is maximized at a temperature of 950 ℃. When the temperature is lower than 900 ℃, the specific surface area of the carbon material is lower than 1600 m 2 A/g, probably because the lower temperature leads to insufficient activation, resulting in a lower specific surface area; when the temperature is 900-1000 ℃, the specific surface area of the carbon material is higher than 1600 m 2 At this temperature, pore structure formation is promoted, and due to the polysaccharide in the camellia peel, the charcoal has high crystallinity at high temperature, and is beneficial to alkali metal ions (such as K) + Etc.) into the hole structureFurther reacting with carbon to form pores, thereby obtaining larger specific surface area; however, due to the increase of the temperature, the pore structure in the carbon material can collapse, and when the temperature exceeds 1000 ℃, the pore structure in the carbon material collapses seriously, so that the specific surface area is reduced. Therefore, the temperature is selected to be 900-1000 ℃, so that the formation of a pore structure can be effectively promoted, the collapse degree of the pore structure can be reduced, the specific surface area of the carbon material is increased, the specific capacitance of the electrode material further manufactured by adopting the carbon material can be improved, and the electrical characteristics of the electrode material are improved. In conclusion, the camellia peel waste is used as the raw material, and the steps of high-temperature carbonization, alkali activation, calcination, acid washing and the like are cooperated with one another to prepare the supercapacitor electrode material with high added value and high electrical property, so that the cost of large-scale production of the supercapacitor electrode material is reduced, and the problem of environmental pollution caused by the camellia peel waste in a traditional treatment mode is solved. Each step of the preparation method of the supercapacitor electrode material is complementary and none is available, the camellia peel-based biomass carbon material prepared by the synergistic preparation method has rich pore structure and higher specific surface area, and the electrode material prepared by further adopting the camellia peel-based biomass carbon material has higher specific capacitance, good conductivity and reversibility.
Claims (10)
1. A method for preparing a supercapacitor electrode material based on camellia peel is characterized by comprising the following steps:
s1, washing, drying and crushing camellia peel to obtain a camellia peel block;
s2, carbonizing the camellia peel blocks at a target temperature under an inert atmosphere to obtain a high-temperature carbonized material;
s3, uniformly mixing the high-temperature carbonized material and the alkaline activator in an ethanol-water mixed solvent according to a preset mass ratio, and then drying;
s4, calcining the dried sample in an inert atmosphere;
s5, soaking the calcined sample in an acid solution, washing the calcined sample to be neutral by using distilled water, and drying the washed sample to obtain the camellia peel-based biomass charcoal material;
s6, uniformly mixing the camellia peel-based biochar material with a conductive agent and an adhesive, drying and tabletting to obtain the camellia peel-based supercapacitor electrode material.
2. The method for preparing the electrode material of the supercapacitor based on the camellia peel as claimed in claim 1, wherein in the step S1, the size of a block of the camellia peel is 0.01 to 2 cm.
3. The method for preparing the electrode material of the supercapacitor based on the camellia peel as claimed in claim 1, wherein in the step S2, the carbonization temperature of the camellia peel block is 500-700 ℃, and the carbonization time is 2-8 h.
4. The method for preparing the electrode material of the supercapacitor based on the camellia peel as claimed in claim 1, wherein in the step S2 and the step S4, the inert atmosphere is any one of nitrogen, helium, neon, argon, krypton and xenon.
5. The method for preparing the electrode material of the supercapacitor based on the camellia peel as claimed in claim 1, wherein in the step S3, the alkaline activator is KOH, naOH, ca (OH) 2 At least one of (1).
6. The method for preparing the electrode material of the supercapacitor based on the camellia peel as claimed in claim 1, wherein the mass ratio of the high-temperature carbonized material to the alkaline activator is 0.5-5: 1, the volume ratio of ethanol to water in the ethanol-water mixed solvent is 0.1 to 10:1.
7. the method for preparing the electrode material of the supercapacitor based on the camellia peel as the claim 1, wherein in the step S4, the calcining temperature of the sample is 900-1000 ℃, and the calcining time is 0.5-8 h.
8. The method for preparing the electrode material of the supercapacitor based on camellia peel as claimed in claim 1, wherein in the step S5, the acidic solution is H 2 SO 4 、H 3 PO 4 、HCl、HNO 3 The concentration of the acidic solution is 0.1 to 3M; the soaking time is 5 to 100 min.
9. The method for preparing the electrode material of the supercapacitor based on camellia peel as claimed in claim 1, wherein in step S6, the conductive agent is acetylene black, the adhesive is polytetrafluoroethylene emulsion, and the mixing ratio of the camellia peel-based biochar material to the acetylene black and the polytetrafluoroethylene emulsion is 8:1:1.
10. the method for preparing the supercapacitor electrode material based on camellia oleifera abel peels as claimed in any one of claims 1 to 9, wherein the pore size of the camellia oleifera abel peel-based biomass charcoal material is 0.1nm to 10nm.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014072497A (en) * | 2012-10-01 | 2014-04-21 | Almedio Inc | Active carbon for capacitor electrode material, process of manufacturing the same, electrode for capacitor, and capacitor |
| CN107973286A (en) * | 2017-11-20 | 2018-05-01 | 福州大学 | A kind of preparation method and application of baobab scytoblastema multiporous biological matter Carbon Materials |
| US10090117B1 (en) * | 2018-01-16 | 2018-10-02 | King Saud University | Method of making a porous nano-carbon electrode from biomass |
| CN111180220A (en) * | 2020-01-18 | 2020-05-19 | 温州大学 | Preparation method of supercapacitor electrode material based on citrus peel biomass charcoal |
| CN113353932A (en) * | 2021-07-09 | 2021-09-07 | 重庆大学 | Hierarchical pore charcoal electrocatalyst prepared from pitaya peel and preparation method and application thereof |
-
2022
- 2022-04-20 CN CN202210413709.9A patent/CN115312326A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014072497A (en) * | 2012-10-01 | 2014-04-21 | Almedio Inc | Active carbon for capacitor electrode material, process of manufacturing the same, electrode for capacitor, and capacitor |
| CN107973286A (en) * | 2017-11-20 | 2018-05-01 | 福州大学 | A kind of preparation method and application of baobab scytoblastema multiporous biological matter Carbon Materials |
| US10090117B1 (en) * | 2018-01-16 | 2018-10-02 | King Saud University | Method of making a porous nano-carbon electrode from biomass |
| CN111180220A (en) * | 2020-01-18 | 2020-05-19 | 温州大学 | Preparation method of supercapacitor electrode material based on citrus peel biomass charcoal |
| CN113353932A (en) * | 2021-07-09 | 2021-09-07 | 重庆大学 | Hierarchical pore charcoal electrocatalyst prepared from pitaya peel and preparation method and application thereof |
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