CN109950050A - A preparation method of supercapacitor electrode material based on carbonized melamine foam@Bi2O3 nanosheets - Google Patents

Abstract

A preparation method of supercapacitor electrode material based on carbonized melamine foam@Bi ₂ O ₃ nanosheets disclosed in the present invention includes the following steps: (1) hydrothermally reacting water-soluble bismuth salt with carbonized melamine foam; (2) cleaning ( _{3) under an inert atmosphere, annealing the intermediate product to obtain the carbonized melamine foam@Bi 2 O 3} ^nanosheet _{supercapacitor electrode} ^material , In the present invention, Bi ₂ O ₃ nanosheets are grown in situ on carbonized melamine foam by a simple solvothermal method to form a three-dimensional core-sheath structure. The electrode material has good electrical conductivity and high specific surface area, which is beneficial to electrolytes storage, shorten the diffusion path of electrolyte ions, increase the contact area between the electrolyte and the material, thereby improving the capacitance, and avoid the use of binders and conductive additives when constructing capacitors, and the obtained materials can be made into flexible electrodes, The preparation method is simple, environmentally friendly and low in cost.

Description

A supercapacitor electrode based on carbonized melamine foam@Bi2O3 nanosheets material preparation method

technical field

The invention relates to the technical field of electrode materials, in particular to a preparation method of a supercapacitor electrode material based _on carbonized melamine foam@ _Bi2O3 nanosheets.

Background technique

With the rapid development of modern technology, new concept electronic products such as highly integrated, lightweight, portable, wearable, and implantable are constantly emerging. With the advent of smart electronic products, it is urgent to develop micro-nano energy storage devices that are highly compatible with them to solve power problems. As an emerging energy storage device, supercapacitors have attracted widespread attention due to their ability to bridge the gap between batteries and traditional capacitors. To meet the huge demand for practical applications, it is imperative to develop a supercapacitor with high energy density and high operating voltage while maintaining high power density and long cycle life. Supercapacitors are mainly composed of current collectors, electrodes, electrolytes and separators, and electrode materials are generally considered to be the most critical parts of supercapacitors. Among many electrode materials, porous carbon materials are widely used due to their high specific surface area, abundant pore structure, high electrical conductivity, low cost, and stable physicochemical properties. Melamine Foam (MF) has a three-dimensional structure with regular pores and high nitrogen content. Through high-temperature carbonization, three-dimensional nitrogen-doped porous carbon foams can be obtained. Even after carbonization, the pore structure can still maintain good mechanical properties and can be used as an ideal carrier for the synthesis of supercapacitor electrode materials.

Carbon materials usually have relatively low capacitance. In the prior art, heteroatoms are often doped to improve capacitance, such as patent CN201810212762.6, but their electrochemical stability, redox reversibility, and cycle stability are poor.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a preparation method based _on carbonized melamine foam@ _Bi2O3 nanosheet supercapacitor electrode material, which has good conductivity, stable electrochemical performance, high capacitance and simple preparation method.

The technical solution solved by the present invention is to provide a method for preparing a supercapacitor electrode material based on carbonized melamine foam@Bi ₂ O ₃ nanosheets, which is characterized by comprising the following steps: (1) dispersing the bismuth-containing compound solution that has been uniformly dispersed Hydrothermal reaction with carbonized melamine foam; (2) The cleaning agent removes residual solvent and Bi ³⁺ , NO ^3- to obtain an intermediate product; (3) In an inert atmosphere, annealing the intermediate product to obtain a carbonized melamine foam@ Bi ₂ O ₃ nanosheet supercapacitor electrode material.

Preferably, the bismuth-containing compound is bismuth nitrate pentahydrate.

Preferably, the total volume of the carbonized melamine foam is 13.0×2.5×2.5 cm ³ , and the reaction volume is 1×1×0.2 cm ³ .

Preferably, the hydrothermal reaction temperature is 140-170 °C, and the reaction time is 4-9 h.

Preferably, the annealing treatment conditions are: an annealing temperature of 200-400 °C, an annealing time of 1-3 h, and a heating rate of 2 °C/min.

Preferably, the inert gas is argon.

Preferably, the cleaning agent is one or more of water, nitric acid, acetic acid, glycerol, and acetone.

Preferably, the mass of the bismuth nitrate pentahydrate is 0.97-2.0 g.

Bi ₂ O ₃ is considered to be an important transition metal oxide due to its harmlessness, low toxicity, wide band gap, good oxide ionic conductivity and suitable negative working window, and it has a high theoretical specific capacity over 1300 Fg ^-1 , has the advantages of high electrochemical stability, high redox reversibility and high cycle stability, so it is selected as the hybrid atom _{of carbonized} melamine foam. connected to each other to form channels in the _{Bi2O3 sheath} , these channels constitute open spaces, which are beneficial to store the electrolyte, shorten the diffusion path of the electrolyte ions, increase the contact area of the electrolyte and the material, and improve the capacitance. The reaction mechanism is shown in the attached diagram. Figure 8, in the process: the melamine foam is carbonized into a N-doped three-dimensional porous carbon foam. Due to the presence of N element, the carbonized melamine foam undergoes a simple hydrothermal reaction to uniformly anchor the bismuth oxide nanosheets on the carbonized melamine foam. On the three-dimensional framework, the bismuth oxide nanosheets and the N-doped three-dimensional carbon foam framework synergistically form a three-dimensional interconnected conductive network structure, which realizes fast electron/ion transport.

The supercapacitor carbonized melamine foam@Bi ₂ O ₃ electrode material produced by the present invention exhibits good electrochemical performance. The reasons are: (1) The carbonized melamine foam has good chemical stability, rich porous structure, open pores, Due to the advantages of large specific surface area and good electrical conductivity, it is very suitable as an ideal carrier for transition metal oxides. Due to the large porosity of carbonized melamine foam, the three-dimensional porous framework has good electron transfer ability. (2) The _three -dimensional core-sheath structure of carbonized melamine foam@ _Bi2O3 nanosheets synthesized by solvothermal method is beneficial to store electrolyte, shorten the diffusion path of electrolyte ions, and increase the contact area between electrolyte and material, thereby improving capacitance.

In step (2), a cleaning agent is used to remove unreacted Bi ³⁺ , NO ₃ ^- , and ethanol and ethylene glycol solvents attached to the product in the solution, so as to avoid the influence on subsequent calcination. After cleaning and drying, an intermediate solution is obtained. product.

The carbonized melamine foam@ _Bi2O3 nanosheet _- based supercapacitor electrode material prepared in this scheme provides a fast channel for electron transport, and the porous structure provides a good mass transfer channel for reactants and products, and is conducive to active sites and reactions The material is in full contact, the material has a high structural abundance and a large specific surface area, so it has good electrical conductivity, which is conducive to the storage of the electrolyte, shortens the diffusion path of the electrolyte ions, and increases the contact area between the electrolyte and the material, thereby improving the capacitance.

Compared with the prior art, the present invention grows Bi ₂ O ₃ nanosheets on carbonized melamine foam in situ by a simple solvothermal method to form a three-dimensional core-sheath structure, and the electrode material has good electrical conductivity and high The specific surface area is good for the storage of the electrolyte, shortens the diffusion path of the electrolyte ions, increases the contact area between the electrolyte and the material, thereby improving the capacitance, and avoids the use of binders and conductive additives when building capacitors. It can be made into a flexible electrode, and the preparation method is simple, environmentally friendly and low in cost.

Description of drawings

Fig. 1 is the SEM image of the electrode material of CF prepared in Example 1;

2 is a SEM image of the CF@Bi ₂ O ₃ electrode material prepared in Example 1;

3 is a TEM image of the CF@Bi ₂ O ₃ electrode material prepared in Example 1;

4 is the XRD pattern of the CF@Bi ₂ O ₃ electrode material prepared in Example 1;

5 is a Raman diagram of the CF@Bi ₂ O ₃ electrode material prepared in Example 1;

6 is the cyclic voltammogram of the CF@Bi ₂ O ₃ and CF electrode materials prepared in Example 1;

7 is a charge-discharge curve diagram of CF@Bi ₂ O ₃ and CF electrode materials prepared in Example 1;

Figure 8 is a schematic diagram of the mechanism of in _- situ growth of _Bi2O3 nanosheets on carbonized melamine foam.

Detailed ways

The following are specific embodiments of the present invention to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

Example 1

(1) The melamine foam sample (13.0×2.5×2.5 cm ³ ) was loaded on a quartz boat and placed in a tube furnace. Before pyrolysis, the samples were bubbled with argon at room temperature for 10-30 min, and the argon flow rate was 1000 standard cubic centimeters per minute, and the air inside was exhausted. The melamine foam was pyrolyzed at 600-800 ℃ for 1-2 h, and the heating rate was 5-10 ℃/min, reaching the highest temperature. After pyrolysis, the sample temperature slowly returned to room temperature. The entire heating and cooling process was carried out under continuous argon at 500-1000 standard cubic centimeters/min.

(2) Dissolve 0.97 g of bismuth nitrate pentahydrate in a mixed solution of ethanol and ethylene glycol, stir and dissolve to obtain a dispersion.

(3) Cut out a small piece of the carbonized melamine foam obtained in step (1) and put it into a polytetrafluoroethylene hydrothermal reactor, and pour the uniform dispersion obtained in step (2) into it to carry out a hydrothermal reaction . The hydrothermal reaction temperature was 160 °C and the reaction time was 5 h.

(4) After cooling the sample in step (3) to room temperature, take it out and rinse it with deionized water and ethanol several times to remove ionic residues, and dry.

(5) Put the dried sample in step (4) into a tube furnace, and anneal it in an argon atmosphere to obtain an electrode material for growing Bi ₂ O ₃ nanosheets with carbonized melamine foam as the base.

Example 2

(1) The melamine foam sample (13.0×2.5×2.5 cm ³ ) was loaded on a quartz boat and placed in a tube furnace. Before pyrolysis, the samples were bubbled with argon at room temperature for 10-30 min, and the argon flow rate was 1000 standard cubic centimeters per minute, and the air inside was exhausted. The melamine foam was pyrolyzed at 600-800 ℃ for 1-2 h, and the heating rate was 5-10 ℃/min, reaching the highest temperature. After pyrolysis, the sample temperature slowly rose to 25-40 ℃. The entire heating and cooling process was carried out under continuous argon at 500-1000 standard cubic centimeters/min.

(2) Dissolve 1.455 g of bismuth nitrate pentahydrate in a mixed solution of ethanol and ethylene glycol, stir and dissolve to obtain a dispersion.

(3) Cut out a small piece of the carbonized melamine foam obtained in step (1) and put it into a polytetrafluoroethylene hydrothermal reactor, and pour the uniform dispersion obtained in step (2) into it to carry out a hydrothermal reaction . The hydrothermal reaction temperature was 160 °C and the reaction time was 5 h. .

(4) After cooling the sample in step (3) to room temperature, take it out and rinse it with deionized water and ethanol several times to remove ionic residues, and dry.

(5) Putting the dried sample in step (4) into a tube furnace, and annealing in an argon atmosphere to obtain an electrode material for growing Bi ₂ O ₃ nanosheets with melamine foam as the base.

Example 3

(1) The melamine foam sample (13.0×2.5×2.5 cm ³ ) was loaded on a quartz boat and placed in a tube furnace. Before pyrolysis, the samples were bubbled with argon at room temperature for 10-30 min, and the argon flow rate was 1000 standard cubic centimeters per minute, and the air inside was exhausted. The melamine foam was pyrolyzed at 600-800 ℃ for 1-2 h, and the heating rate was 5-10 ℃/min, reaching the highest temperature. After pyrolysis, the sample temperature slowly rose to 25-40 ℃. The entire heating and cooling process was carried out under continuous argon at 500-1000 standard cubic centimeters/min.

(2) Dissolve 1.94 g of bismuth nitrate pentahydrate in a mixed solution of ethanol and ethylene glycol, stir and dissolve to obtain a dispersion.

(3) Cut out a small piece of the carbonized melamine foam obtained in step (1) and put it into a polytetrafluoroethylene hydrothermal reactor, and pour the uniform dispersion obtained in step (2) into it to carry out a hydrothermal reaction . The hydrothermal reaction temperature was 160 °C and the reaction time was 5 h.

(4) After cooling the sample in step (3) to room temperature, take it out and rinse it with deionized water and ethanol several times to remove ionic residues, and dry.

(5) Put the dried sample in step (4) into a tube furnace, and anneal it in an argon atmosphere to obtain an electrode material for growing Bi ₂ O ₃ nanosheets with carbonized melamine foam as the base.

Example 4

(1) The melamine foam sample (13.0×2.5×2.5 cm ³ ) was loaded on a quartz boat and placed in a tube furnace. Before pyrolysis, the samples were bubbled with argon at room temperature for 10-30 min, and the argon flow rate was 1000 standard cubic centimeters per minute, and the air inside was exhausted. The melamine foam was pyrolyzed at 600-800 ℃ for 1-2 h, and the heating rate was 5-10 ℃/min, reaching the highest temperature. After pyrolysis, the sample temperature slowly rose to 25-40 ℃. The entire heating and cooling process was carried out under continuous argon at 500-1000 standard cubic centimeters/min.

(2) Dissolve 0.97 g of bismuth nitrate pentahydrate in a mixed solution of ethanol and ethylene glycol, stir and dissolve to obtain a dispersion.

(3) Cut out a small piece of the carbonized melamine foam obtained in step (1) and put it into a polytetrafluoroethylene hydrothermal reactor, and pour the uniform dispersion obtained in step (2) into it to carry out a hydrothermal reaction . The hydrothermal reaction temperature was 160 °C and the reaction time was 7 h.

(4) After cooling the sample in step (3) to room temperature, take it out and rinse it with deionized water and ethanol several times to remove ionic residues, and dry.

(5) Put the dried sample in step (4) into a tube furnace, and anneal it in an argon atmosphere to obtain an electrode material for growing Bi ₂ O ₃ nanosheets with carbonized melamine foam as the base.

Example 5

(1) The melamine foam sample (13.0×2.5×2.5 cm ³ ) was loaded on a quartz boat and placed in a tube furnace. Before pyrolysis, the samples were bubbled with argon at room temperature for 10-30 min, and the argon flow rate was 1000 standard cubic centimeters per minute, and the air inside was exhausted. The melamine foam was pyrolyzed at 600-800 ℃ for 1-2 h, and the heating rate was 5-10 ℃/min, reaching the highest temperature. After pyrolysis, the sample temperature slowly rose to 25-40 ℃. The entire heating and cooling process was carried out under continuous argon at 500-1000 standard cubic centimeters/min.

(2) Dissolve 0.97 g of bismuth nitrate pentahydrate in a mixed solution of ethanol and ethylene glycol, stir and dissolve to obtain a dispersion.

(3) Cut out a small piece of the carbonized melamine foam obtained in step (1) and put it into a polytetrafluoroethylene hydrothermal reactor, and pour the uniform dispersion obtained in step (2) into it to carry out a hydrothermal reaction . The hydrothermal reaction temperature was 160 °C and the reaction time was 9 h.

(4) After cooling the sample in step (3) to room temperature, take it out and rinse it with deionized water and ethanol several times to remove ionic residues, and dry.

(5) Put the dried sample in step (4) into a tube furnace, and anneal it in an argon atmosphere to obtain an electrode material for growing Bi ₂ O ₃ nanosheets with carbonized melamine foam as the base.

Example 6

(1) The melamine foam sample (13.0×2.5×2.5 cm ³ ) was loaded on a quartz boat and placed in a tube furnace. Before pyrolysis, the samples were bubbled with argon at room temperature for 10-30 min, and the argon flow rate was 1000 standard cubic centimeters per minute, and the air inside was exhausted. The melamine foam was pyrolyzed at 900 ℃ for 1-2 h, and the heating rate was 5-10 ℃/min, reaching the highest temperature. After pyrolysis, the sample temperature slowly rose to 25-40 ℃. The entire heating and cooling process was carried out under continuous argon at 500-1000 standard cubic centimeters/min.

(2) Dissolve 0.97 g of bismuth nitrate pentahydrate in a mixed solution of ethanol and ethylene glycol, stir and dissolve to obtain a dispersion.

(3) Cut out a small piece of the carbonized melamine foam obtained in step (1) and put it into a polytetrafluoroethylene hydrothermal reactor, and pour the uniform dispersion obtained in step (2) into it to carry out a hydrothermal reaction . The hydrothermal reaction temperature was 170 °C and the reaction time was 5 h.

(4) After cooling the sample in step (3) to room temperature, take it out and rinse it with deionized water and ethanol several times to remove ionic residues, and dry.

(5) Put the dried sample in step (4) into a tube furnace, and anneal it in an argon atmosphere to obtain an electrode material for growing Bi ₂ O ₃ nanosheets with carbonized melamine foam as the base.

Example 7

(1) The melamine foam sample (13.0×2.5×2.5 cm ³ ) was loaded on a quartz boat and placed in a tube furnace. Before pyrolysis, the samples were bubbled with argon at room temperature for 10-30 min, and the argon flow rate was 1000 standard cubic centimeters per minute, and the air inside was exhausted. The melamine foam was pyrolyzed at 900 ℃ for 1-2 h, and the heating rate was 5-10 ℃/min, reaching the highest temperature. After pyrolysis, the sample temperature slowly rose to 25-40 ℃. The entire heating and cooling process was carried out under continuous argon at 500-1000 standard cubic centimeters/min.

(2) Dissolve 0.97 g of bismuth nitrate pentahydrate in a mixed solution of ethanol and ethylene glycol, stir and dissolve to obtain a dispersion.

(3) Cut out a small piece of the carbonized melamine foam obtained in step (1) and put it into a polytetrafluoroethylene hydrothermal reactor, and pour the uniform dispersion obtained in step (2) into it to carry out a hydrothermal reaction . The hydrothermal reaction temperature was 170 °C and the reaction time was 7 h.

(4) After cooling the sample in step (3) to room temperature, take it out and rinse it with deionized water and ethanol several times to remove ionic residues, and dry.

(5) Put the dried sample in step (4) into a tube furnace, and anneal it in an argon atmosphere to obtain an electrode material for growing Bi ₂ O ₃ nanosheets with carbonized melamine foam as the base.

Electrochemical performance testing and characterization of the electrode materials prepared above:

Fig. 1 is the micro-morphology of the carbonized melamine foam material prepared in Example 1. It can be seen from the figure that the carbonized melamine foam has a three-dimensional interconnected network structure, and the surface is smooth and flat. This interconnected structure is conducive to the migration of electrolytes, and also has It is favorable for the uniform growth of Bi ₂ O ₃ nanosheets on the carbonized melamine foam skeleton.

It can be seen from Figure 2 and Figure 3 that the bismuth nitrate in Example 1 is decomposed into Bi ₂ O ₃ nanosheets and uniformly grown on the carbonized melamine foam skeleton after a simple solvothermal treatment, and assembled to form a porous structure without obvious stacking and overlapping.

The phase of CF@Bi ₂ O ₃ was determined by X-ray diffraction (XRD) method, and the results are shown in Fig. 4 . Except for one diffraction peak from CF, there are four diffraction peaks at 2θ values of 28°, 32.4°, 46.5°, 55.1°, corresponding to (111), (200), (220) and ( 311) crystal planes, these values can well point to the cubic phase of CF@Bi ₂ O ₃ (JCPDS, No. 27-0052).

The Raman spectrum of CF@Bi ₂ O ₃ is shown in Figure 5. From Figure 4, it can be observed that in addition to the D and G peaks generated by CF, there is a characteristic peak of Bi ₂ O ₃ at 305 cm ^-1 . Both Figures 4 and ₅ can demonstrate the existence of pure _Bi2O3 in CF.

Electrochemical tests were carried out in a three-electrode system, the working electrode was carbonized melamine foam and carbonized melamine foam@Bi ₂ O ₃ , the reference electrode was mercury/mercury oxide electrode, the counter electrode was platinum wire, and the electrolyte was 1 M KOH solution , the capacitance properties of the samples were tested by cyclic voltammetry and galvanostatic charge-discharge methods.

It can be seen from Fig. 6 that the carbonized melamine foam and carbonized melamine foam@Bi ₂ O ₃ prepared in Example 1 were used as the working electrode, respectively, in 1 M KOH electrolyte as the working electrode of the three-electrode system. The cyclic voltammetry test was carried out . Panel A shows the cyclic voltammetry curves _of carbonized melamine foam@ _Bi2O3 at different scan rates. Between the -0.95 to 0 v potential window, a series of well-defined characteristic redox peaks for _{Bi2O3 were} observed, following the Faraday reaction equation as follows:

,

As the scan rate increases, the carbonized melamine foam@ _{Bi2O3 electrode} exhibits good capacitive behavior and high rate performance, and the CV curves are well maintained. In addition, the current response increases with the increase of the scan rate, and at a scan rate of 80 mv/s, an obvious redox peak can also be observed, and the shift is small, showing better stability. Panel B is the cyclic voltammetry curves of carbonized melamine foam and carbonized melamine foam@ _Bi2O3 electrode _over a potential window of -0.95 to 0 v with a scan rate of 5 mv/s. The curve has a distinct pseudocapacitive feature with a pair of well-defined redox peaks, indicating that the capacitive characteristic is controlled by the Faradaic redox reaction, which is very different from the CV curve of carbonized melamine foam. It is shown that the current density of the carbonized melamine foam@ _Bi2O3 electrode is much higher _than that of the original carbonized melamine foam, indicating that the capacitance of the composite electrode is mainly derived from the pseudocapacitive material _{of Bi2O3} .

It can be seen from Fig. 7 that the carbonized melamine foam and carbonized melamine foam@Bi ₂ O ₃ prepared in Example 1 are used as the working electrode, respectively, in 1 M KOH electrolyte as the working electrode of the three-electrode system. test. Figure 5A shows the galvanostatic charge _- discharge curves of carbonized melamine foam@ _Bi2O3 electrodes at different current densities. The charge-discharge curve plateaus are in good agreement with the redox peaks in the CV curve. When the current density was 1 mA/cm ² -10 mA/cm ² , the areal capacitance decreased from 951.3 to 434.7 mF/cm ² . Panel B is the galvanostatic charge-discharge curves of carbonized melamine foam and carbonized melamine foam@Bi ₂ O ₃ electrodes over a potential window of −0.95 to 0 v with a current density of 1 mA/cm ² . It can be seen from the figure that the capacitance of the carbonized melamine foam@ _Bi2O3 electrode is much higher _than that of the pristine carbonized melamine foam.

The supercapacitor carbonized melamine foam@Bi ₂ O ₃ electrode material produced by the present invention exhibits good electrochemical performance. The reasons are: (1) The carbonized melamine foam has good chemical stability, rich porous structure, open pores, Due to the advantages of large specific surface area and good electrical conductivity, it is very suitable as an ideal carrier for transition metal oxides. Due to the large porosity of carbonized melamine foam, the three-dimensional porous framework has good electron transfer ability. (2) The _three -dimensional core-sheath structure of carbonized melamine foam@ _Bi2O3 nanosheets synthesized by solvothermal method is beneficial to store electrolyte, shorten the diffusion path of electrolyte ions, and increase the contact area between electrolyte and material, thereby improving capacitance.

Everything not covered above is applicable to the prior art. The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention pertains can make various modifications or additions to the described specific embodiments or substitute in similar manners, but will not deviate from the spirit of the present invention or go beyond the definitions of the appended claims range.

Claims (8)

1. one kind is based on carbonization melamine foamed plastic@Bi₂O₃The preparation method of nanometer sheet electrode material for super capacitor, feature It is, comprising the following steps: (1) water-soluble bismuth salt and carbonization melamine foamed plastic are subjected to hydro-thermal reaction；(2) cleaning agent removes Remaining solvent and Bi³⁺、NO₃ ^-, obtain intermediate product；(3) under an inert atmosphere, the intermediate product is made annealing treatment to get carbonization Melamine foamed plastic@Bi₂O₃Nanometer sheet electrode material for super capacitor.

2. according to claim 1 a kind of based on carbonization melamine foamed plastic@Bi₂O₃Nanometer sheet electrode of super capacitor material The preparation method of material, which is characterized in that the bismuth-containing compound is five water bismuth nitrates.

3. according to claim 1 a kind of based on carbonization melamine foamed plastic@Bi₂O₃Nanometer sheet electrode of super capacitor material The preparation method of material, which is characterized in that the carbonization melamine foamed plastic total volume is 13.0 × 2.5 × 2.5 cm³, reactant Product is 1 × 1 × 0.2 cm³。

4. according to claim 1 a kind of based on carbonization melamine foamed plastic@Bi₂O₃Nanometer sheet electrode of super capacitor material The preparation method of material, which is characterized in that the hydrothermal temperature is 140-170 DEG C, and the reaction time is 4-9 h.

5. according to claim 1 a kind of based on carbonization melamine foamed plastic@Bi₂O₃Nanometer sheet electrode of super capacitor material The preparation method of material, which is characterized in that the annealing condition are as follows: 200-400 DEG C of annealing temperature, annealing time 1-3 h, 2 DEG C/min of heating rate.

6. according to claim 1 a kind of based on carbonization melamine foamed plastic@Bi₂O₃Nanometer sheet electrode of super capacitor material The preparation method of material, which is characterized in that the inert gas is one of argon gas, neon, nitrogen or at least two kinds.

7. according to claim 1 a kind of based on carbonization melamine foamed plastic@Bi₂O₃Nanometer sheet electrode of super capacitor material The preparation method of material, which is characterized in that the cleaning agent is one or more of water, nitric acid, acetic acid, glycerol, acetone.

8. according to claim 1 a kind of based on carbonization melamine foamed plastic@Bi₂O₃Nanometer sheet electrode of super capacitor material The preparation method of material, which is characterized in that the quality of the five water bismuth nitrate is 0.97-2.0 g.