Electrochemical preparation of large-area graphene

Abstract

The application discloses an electrochemical preparation method of large-size graphene, which comprises the following steps: under the protection of inert gas, a three-electrode system is adopted, the potential in an electrolyte is increased from the lowest potential of ion intercalation to the highest potential of ion intercalation, a graphite intercalation compound is prepared, then the graphite intercalation compound is peeled off by constant potential electrolysis at an ion decomposition potential, and finally the large-size graphene is prepared. The graphene prepared by the method has a size of 10 microns, low oxidation degree and few defects, and can be applied to MOS devices.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electrochemical preparation of graphene, and particularly relates to an electrochemical preparation method of large-diameter graphene. BACKGROUND

[0002] Graphene is a two-dimensional carbon nanomaterial, which has attracted close attention in the fields of energy storage, sensors, photocatalysis and flexible electronic devices due to its extremely high carrier mobility and thermal conductivity, outstanding mechanical strength and light transmittance and extremely large theoretical specific surface area. Among them, as the basis for industrial application of graphene, how to prepare high-quality graphene in an environmentally friendly, efficient and low-cost manner has been widely studied by people.

[0003] Among the numerous preparation methods of graphene, the electrochemical method has been widely concerned as a low-cost and efficient graphene preparation method. However, due to the fact that the electrochemical cathode method preparation process often involves ultrasonic assistance, and is restricted by the source sheet diameter of raw material graphite, the prepared graphene generally has a small diameter, generally 2-3 μm; on the other hand, although the electrochemical anode method can avoid ultrasonic, the oxidation reaction of anode graphite will occur, resulting in more defects in the product graphene. Smaller diameter and more defects restrict the application range of graphene, for example, it is difficult to use in MOS devices such as sensors. SUMMARY

[0004] In view of the problem of small diameter of graphene prepared by the electrochemical cathode method, the purpose of the present application is to provide an electrochemical preparation method of high-quality large-diameter graphene.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] An electrochemical preparation method of large-diameter graphene, comprising the following steps:

[0007] Under the protection of inert gas, using a three-electrode system, the potential in the electrolyte is increased from the lowest ion intercalation potential to the highest ion intercalation potential to prepare a graphite intercalation compound, and then a constant potential electrolysis is carried out at the ion decomposition potential to exfoliate the graphite intercalation compound and prepare large-diameter graphene.

[0008] Further, the three-electrode system comprises one or more of natural flake graphite electrode, highly oriented pyrolytic graphite, graphite foil and graphite rod as the working electrode, platinum electrode as the counter electrode, and silver wire as the reference electrode.

[0009] Further, the concentration of the electrolyte is 0.1 mol / L.

[0010] Further, the potential is less than 100 μV s -1The rate of the potential will be raised from the lowest ion intercalation potential to the highest ion intercalation potential.

[0011] Further, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are determined by cyclic voltammetry.

[0012] Further, the electrolyte is prepared by the following process: one or more of the following after water removal: tetramethylammonium hydrogen sulfate, tetraethylammonium hydrogen sulfate, tetrapropylammonium hydrogen sulfate, tetrabutylammonium hydrogen sulfate and tetrapentylammonium hydrogen sulfate is added to one or more of the following after water removal: propylene carbonate, N-N-dimethylformamide, N-methylpyrrolidone, acetone and tetramethyl sulfoxide, and mixed uniformly to obtain the electrolyte.

[0013] Further, for TBA + and acetone solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.0V, -2.5V and -4.0V, respectively; for TBA + and NMP solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5V, -2.5V and -4.0V, respectively; for TBA + and DMF solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5V, -2.5V and -4.5V, respectively; for TBA + and DMSO solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5V, -3.0V and -4.5V, respectively; for TMA + and PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.0V, -2.5V and -4.0V, respectively; for TEA + and PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5V, -3.0V and -4.0V, respectively; for TPA + and PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5V, -3.0V and -4.5V, respectively; for TPeA + and PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.0V, -2.5V and -4.0V, respectively.

[0014] Further, the flake diameter of the graphene is 10 microns.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] The present application adopts an electrochemical two-step method to prepare graphene. In the electrolysis process, the cathode graphite will undergo a reduction reaction, which inhibits the generation of oxygen-containing functional groups on the surface of the graphite, improves the C / O of the product graphene, and reduces the defects of the product graphene. After the graphite intercalation compound is prepared in the first step of electrolysis, constant potential electrolysis is carried out at the ion decomposition potential, so that the ions intercalated between the graphite layers and the solvent molecules co-intercalated are decomposed. When the particles are decomposed, the volume is further expanded, accompanied by the generation of gas, so that the van der Waals force between the graphite layers is further weakened, and the graphite intercalation compound is peeled off into large-diameter graphene. Since the intercalation rate of the ions between the graphite layers is improved, the ultrasonic step is eliminated, and therefore graphene with few defects and large flake diameter can be prepared. Compared with the conventional electrochemical cathode preparation of graphene, the graphene prepared by the method can increase the flake diameter by more than 5 times, and can be applied to MOS devices

[0017] Further, the potential in the first step of electrolysis is slowly changed at a rate of less than 100 μV / s, so that the ions are continuously intercalated between the graphite layers to prepare the graphite intercalation compound.

[0018] Further, the water removal operation of the electrolyte solvent and solute and the subsequent gas protection during storage and reaction inhibit the influence of water on the product during electrolysis, which can avoid the adsorption of a layer of hydrogen atoms on the surface of the graphite due to the reduction of hydrogen ions at the cathode, hinder the intercalation of ions between the graphite layers, and further cause insufficient intercalation of ions, so that the prepared graphene has a large thickness.

[0019] Further, the ion intercalation potential and ion decomposition potential are determined by cyclic voltammetry, and then the potential is slowly increased for electrolysis within the ion intercalation potential range, so that the cations are continuously intercalated between the graphite layers, and the slowly changing potential overcomes the repulsion of the ions already intercalated between the graphite layers to the subsequent ions, thereby improving the intercalation rate of the ions between the graphite layers.

[0020] Further, the synergistic effect of the water removal operation, gas protection and slowly changing potential electrolysis in the present application improves the intercalation rate of the ions between the graphite layers, so that the graphite intercalation compound can be peeled off into graphene only by constant potential electrolysis. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is an optical microscope photo of Example 1 of the present application; wherein (a) is single-layer graphene with a flake diameter of 10 μm, (b) is double-layer graphene with a flake diameter of 10 μm, (c) is 3-5 layer graphene with a flake diameter of 10 μm, and (d) is 5-10 layer graphene with a flake diameter of 10 μm.

[0022] Figure 2 It is an X-ray photoelectron spectrogram of Example 1 of the present application;

[0023] Figure 3 It is a Raman spectrum of Example 1 of the present application;

[0024] Figure 4 The schematic diagram of the present application. DETAILED DESCRIPTION

[0025] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments, and are not intended to limit the scope to be disclosed by the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed by the present application. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the scope to be protected by the present application.

[0026] The electrochemical preparation method of the large flake graphene of the present application comprises the following steps:

[0027] Under the protection of gas, the large flake graphene is prepared by the electrochemical two-step method in a three-electrode system, using one or more of natural flake graphite electrode, highly oriented pyrolytic graphite and graphite foil and graphite rod as the working electrode, platinum electrode as the counter electrode and silver wire as the reference electrode.

[0028] In the electrolyte, the potential is slowly increased from the lowest ion intercalation potential to the highest ion intercalation potential at a rate of less than 100 muV s -1 to obtain the graphite intercalation compound, and then the graphite intercalation compound is peeled off to obtain the large flake graphene at the ion decomposition potential under constant potential electrolysis.

[0029] The electrolyte comprises a solute and a solvent; the solute is one or more of dehydrated tetramethylammonium hydrogen sulfate, tetraethylammonium hydrogen sulfate, tetrapropylammonium hydrogen sulfate, tetrabutylammonium hydrogen sulfate and tetraamylammonium hydrogen sulfate.

[0030] The solvent is one or more of dehydrated propylene carbonate, N-N-dimethylformamide, N-methylpyrrolidone, acetone and tetramethyl sulfoxide.

[0031] The solute and the solvent need to be dehydrated before being prepared, and after being prepared, they are stored in an argon atmosphere, and the electrolytic cell needs to be protected by nitrogen, argon or other inert gas during electrolysis.

[0032] The preparation method of the electrolyte is as follows: the solute is dried in a vacuum oven at 120°C for 24 hours, the molecular sieve is dried for 24 hours, the electrolyte is prepared in a glove box, 0.1 mol of the solute is added to 1 L of the solvent, and the mixture is uniformly mixed.

[0033] The natural flake graphite electrode is prepared by coating natural flake graphite in a 100-mesh 304 stainless steel mesh and pressing for 3 minutes under a pressure of 25 MPa.

[0034] The ion intercalation potential and the electrolyte decomposition potential are determined by cyclic voltammetry, and are used as the electrolysis potentials of the two-step electrolysis method. + For TBA and acetone solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.0 V, -2.5 V and -4.0 V, respectively. + For TBA and NMP solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5 V, -2.5 V and -4.0 V, respectively. + For TBA and DMF solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5 V, -2.5 V and -4.5 V, respectively. + For TMA and DMSO solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5 V, -3.0 V and -4.5 V, respectively. + For TEA and PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.0 V, -2.5 V and -4.0 V, respectively. + For TPA and PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5 V, -3.0 V and -4.0 V, respectively. + For TPeA and PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.5 V, -3.0 V and -4.5 V, respectively. + For TPeA and PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are -1.0 V, -2.5 V and -4.0 V, respectively. The above potentials are hydrogen standard electrode potentials.

[0035] The prepared electrolyte is added to a reaction container under nitrogen protection, a Pt electrode is used as a counter electrode, an Ag electrode is used as a reference electrode, and a natural flake graphite electrode is used as a working electrode. The potential range of ion intercalation between graphite layers and the decomposition potential of ions between graphite layers are measured by cyclic voltammetry on an electrochemical workstation. After obtaining the above-mentioned potentials, in the first step of electrolysis, the potential is slowly changed at a rate lower than 100 μV / s in the ion intercalation potential range, so as to realize effective ion intercalation and prepare an ion fully intercalated graphite intercalation compound; in the second step of electrolysis, the potential is constant at the ion decomposition potential, so as to decompose the ions and co-intercalated solvent molecules between the graphite layers, and further make the graphite exfoliate to produce graphene.

[0036] Referring to Figure 4 The principle of the present application is that: in the electrolysis process, the cathode graphite will undergo a reduction reaction, which inhibits the generation of oxygen-containing functional groups on the surface of the graphite, improves the C / O of the product graphene, and reduces the defects of the product graphene; the water removal operation of the electrolyte solvent and solute and the subsequent storage and gas protection during the reaction inhibit the influence of water participating in the electrolysis reaction on the product, which can avoid the hydrogen atom layer adsorbed on the surface of the graphite due to the reduction of hydrogen ions at the cathode, hinder the ion intercalation between the graphite layers, and further cause insufficient ion intercalation, so that the prepared graphene is thick; the ion intercalation potential and the ion decomposition potential are determined by cyclic voltammetry, and then the potential is electrolyzed at a slow increasing rate in the ion intercalation potential range, so as to drive the cations to continuously intercalate between the graphite layers, and the slowly changing potential overcomes the repulsion of the ions intercalated between the graphite layers to the subsequent ions, thereby improving the ion intercalation rate between the graphite layers; after the graphite intercalation compound is prepared in the first step of electrolysis, constant potential electrolysis is carried out at the ion decomposition potential, so as to decompose the ions intercalated between the graphite layers and the co-intercalated solvent molecules, and the particles further expand in volume when decomposed, accompanied by the generation of gas, so as to further weaken the van der Waals force between the graphite layers, and the graphite intercalation compound is exfoliated into graphene.

[0037] Example 1

[0038] The graphene is prepared according to the following electrode, electrolyte and electrolysis potential: the electrode is a natural flake graphite electrode, the electrolyte is 0.1 mol / L TBA + / DMF, the lowest ion intercalation potential, the highest ion intercalation potential and the electrolyte decomposition potential are-1.5 V, -2.5 V and-4.5 V, respectively

[0039] After water removal, the tetrabutylammonium hydrogen sulfate is added to the water-removed N-N-dimethylformamide and uniformly mixed to obtain an electrolyte of 0.1 mol / L.

[0040] Under nitrogen protection, the natural flake graphite electrode is used as a working electrode, the platinum electrode is used as a counter electrode, and the silver wire is used as a reference electrode, and the cyclic voltammetry is carried out at a rate lower than 100 μV / s -1The potential is raised from the ion intercalation minimum potential to the ion intercalation maximum potential at a rate of less than 100 μV s-1 to produce graphite intercalation compounds, and then the graphite intercalation compounds are exfoliated by constant potential electrolysis at the ion decomposition potential to produce large-diameter graphene.

[0041] Example 2

[0042] The graphene is prepared according to the following electrode, electrolyte and electrolysis potential: the electrode is a natural flake graphite electrode, the electrolyte is 0.1 mol / L TBA + / NMP, the ion intercalation minimum potential, the ion intercalation maximum potential and the electrolyte decomposition potential are -1.5 V, -2.5 V and -4.5 V respectively.

[0043] The dehydrated tetrabutylammonium hydrogen sulfate is added into the dehydrated N-methylpyrrolidone to obtain the electrolyte of 0.1 mol / L after mixing uniformly.

[0044] Under nitrogen protection, the natural flake graphite electrode is used as the working electrode, the platinum electrode is used as the counter electrode, the silver wire is used as the reference electrode, the potential is raised from the ion intercalation minimum potential to the ion intercalation maximum potential at a rate of less than 100 μV s -1 -1 to produce graphite intercalation compounds, and then the graphite intercalation compounds are exfoliated by constant potential electrolysis at the ion decomposition potential to produce large-diameter graphene.

[0045] Example 3

[0046] The graphene is prepared according to the following electrode, electrolyte and electrolysis potential: the electrode is a natural flake graphite electrode, the electrolyte is 0.1 mol / L TBA + / DMSO, the ion intercalation minimum potential, the ion intercalation maximum potential and the electrolyte decomposition potential are -1.5 V, 3.0 V and -4.5 V respectively.

[0047] The dehydrated tetrabutylammonium hydrogen sulfate is added into the dehydrated tetramethyl sulfoxide to obtain the electrolyte of 0.1 mol / L after mixing uniformly.

[0048] Under nitrogen protection, the natural flake graphite electrode is used as the working electrode, the platinum electrode is used as the counter electrode, the silver wire is used as the reference electrode, the potential is raised from the ion intercalation minimum potential to the ion intercalation maximum potential at a rate of less than 100 μV s -1 -1 to produce graphite intercalation compounds, and then the graphite intercalation compounds are exfoliated by constant potential electrolysis at the ion decomposition potential to produce large-diameter graphene.

[0049] Example 4

[0050] The graphene is prepared according to the following electrode, electrolyte and electrolysis potential: the electrode is a natural flake graphite electrode, the electrolyte is 0.1 mol / L TMA + / PC, the ion intercalation minimum potential, the ion intercalation maximum potential and the electrolyte decomposition potential are -1.0V, -2.5V and -4.0V respectively.

[0051] After the water is removed, the tetraethylammonium hydrogen sulfate is added to the propylene carbonate after the water is removed, and is mixed uniformly to obtain 0.1 mol / L electrolyte.

[0052] Under the protection of nitrogen, the natural flake graphite electrode is used as the working electrode, the platinum electrode is used as the counter electrode, the silver wire is used as the reference electrode, the potential is increased from the ion intercalation minimum potential to the ion intercalation maximum potential at a rate of less than 100 μV s -1 , the graphite intercalation compound is prepared, then the graphite intercalation compound is exfoliated at the ion decomposition potential, and the large piece diameter graphene is prepared.

[0053] Example 5

[0054] The graphene is prepared according to the following electrode, electrolyte and electrolysis potential: the electrode is the natural flake graphite electrode, the electrolyte is 0.1 mol / L TEA + / PC, the ion intercalation minimum potential, the ion intercalation maximum potential and the electrolyte decomposition potential are -1.5V, -3.0V and -4.0V respectively.

[0055] After the water is removed, the tetraethylammonium hydrogen sulfate is added to the propylene carbonate after the water is removed, and is mixed uniformly to obtain 0.1 mol / L electrolyte.

[0056] Under the protection of nitrogen, the natural flake graphite electrode is used as the working electrode, the platinum electrode is used as the counter electrode, the silver wire is used as the reference electrode, the potential is increased from the ion intercalation minimum potential to the ion intercalation maximum potential at a rate of less than 100 μV s -1 , the graphite intercalation compound is prepared, then the graphite intercalation compound is exfoliated at the ion decomposition potential, and the large piece diameter graphene is prepared.

[0057] Example 6

[0058] The graphene is prepared according to the following electrode, electrolyte and electrolysis potential: the electrode is the natural flake graphite electrode, the electrolyte is 0.1 mol / L TPA + / PC, the ion intercalation minimum potential, the ion intercalation maximum potential and the electrolyte decomposition potential are -1.5V, -3.0V and -4.5V respectively.

[0059] After the water is removed, the tetraethylammonium hydrogen sulfate is added to the propylene carbonate after the water is removed, and is mixed uniformly to obtain 0.1 mol / L electrolyte.

[0060] Under the protection of nitrogen, the natural flake graphite electrode is used as the working electrode, the platinum electrode is used as the counter electrode, the silver wire is used as the reference electrode, the potential is increased from the ion intercalation minimum potential to the ion intercalation maximum potential at a rate of less than 100 μV s-1 The rate of the potential will raise the potential from the lowest intercalation potential to the highest intercalation potential, and graphite intercalation compound is prepared, and then the graphite intercalation compound is exfoliated by constant potential electrolysis at the ion decomposition potential, and large flake graphene is prepared.

[0061] Comparative Example 1

[0062] The graphene is prepared by the following electrode, electrolyte and electrolysis potential: the electrode is a natural flake graphite electrode, the electrolyte is 0.1 mol / L TBA + / PC, and the electrolysis potential is 5V constant voltage.

[0063] The non-water-removed tetrabutylammonium hydrogen sulfate is added into the non-water-removed propylene carbonate, and mixed uniformly to obtain the electrolyte of 0.1 mol / L.

[0064] The graphite intercalation compound is prepared by 5V constant voltage electrolysis for 20 minutes in an air atmosphere with the natural flake graphite electrode as the working electrode and the carbon cloth as the counter electrode, and the graphene is prepared by exfoliating the graphite intercalation compound by ultrasonic for 20 minutes.

[0065] Comparative Example 2

[0066] The graphene is prepared by the following electrode, electrolyte and electrolysis potential: the electrode is a natural flake graphite electrode, the electrolyte is 0.1 mol / L TMA + / NMP, and the electrolysis potential is 5V constant voltage.

[0067] The non-water-removed tetramethylammonium hydrogen sulfate is added into the non-water-removed propylene carbonate, and mixed uniformly to obtain the electrolyte of 0.1 mol / L.

[0068] The graphite intercalation compound is prepared by 5V constant voltage electrolysis for 20 minutes in an air atmosphere with the natural flake graphite electrode as the working electrode and the carbon cloth as the counter electrode, and the graphene is prepared by exfoliating the graphite intercalation compound by ultrasonic for 20 minutes.

[0069] The graphene is prepared by the above parameters, and the graphene in the above examples and comparative examples is diluted to prepare the Langmuir-Blodgett film, and then the flake diameter of the product is observed under an optical microscope, the defect density I D / I G of the product is characterized by Raman spectrum, and the oxidation degree C / O of the product is characterized by X-ray photoelectron spectroscopy, and the comparison results are shown in the following table 1.

[0070] Table 1: Comprehensive comparison of product performance of graphene prepared by electrochemical cathodic exfoliation in different electrolytes and electrolysis modes

[0071]

[0072]

[0073] The electrolyte was sampled, dried, observed under a lens, characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, etc. Figure 1 As can be seen from (a), (b), (c) and (d), the size of the product graphene can reach 10 μm, which is much larger than the size of conventional electrochemical cathode graphene.

[0074] As can be seen from (a), (b), (c) and (d), the size of the product graphene can reach 10 μm, which is much larger than the size of conventional electrochemical cathode graphene. Figure 2 As can be seen, the C / O of the product graphene is 26.5, indicating that the degree of oxidation of the graphite is very low, and the purity of the graphene is high.

[0075] As can be seen, the C / O of the product graphene is 26.5, indicating that the degree of oxidation of the graphite is very low, and the purity of the graphene is high. Figure 3 As can be seen, the I D / I G of the product graphene is 0.111, indicating that the defect density of the graphene is low and the quality is high.

[0076] As can be seen, the I D / I G of the product graphene is 0.111, indicating that the defect density of the graphene is low and the quality is high. Figure 4 As can be seen, the voltage is applied in the electrolytic cell, and the anions and cations will migrate to the anode and cathode respectively under the driving of the electric field, and the cations will be embedded into the interlayer of the cathode graphite to form an intercalation compound.

Claims

1. An electrochemical preparation method for large-diameter graphene, characterized in that, Includes the following steps: Under inert gas protection, using a three-electrode system, in the electrolyte, at a voltage below 100 μV s -1 The potential was increased from the lowest to the highest ion intercalation potential at a certain rate to prepare a graphite intercalation compound. Then, constant-potential electrolysis was performed at the ion decomposition potential to exfoliate the graphite intercalation compound, yielding large-diameter graphene sheets with a diameter of 10 μm and a C / O ratio of 26.

5. D / I G It is 0.111; The minimum ion intercalation potential, the maximum ion intercalation potential, and the electrolyte decomposition potential were determined by cyclic voltammetry, with graphite as the cathode. The three-electrode system includes: one or more of natural flake graphite electrodes, highly oriented pyrolytic graphite, graphite foil and graphite rod as working electrodes, a platinum electrode as counter electrode, and a silver wire as reference electrode. The electrolyte is prepared by the following process: adding one or more of the following after dehydration: tetramethylammonium bisulfate, tetraethylammonium bisulfate, tetrapropylammonium bisulfate, tetrabutylammonium bisulfate and tetrapentylammonium bisulfate, to one or more of the following after dehydration: propylene carbonate, N,N-dimethylformamide, N-methylpyrrolidone, acetone and tetramethyl sulfoxide, and mixing evenly to obtain the electrolyte. For TBA + In acetone solvent, the lowest ion intercalation potential, the highest ion intercalation potential, and the electrolyte decomposition potential are -1.0V, -2.5V, and -4.0V, respectively; for TBA + For NMP solvent, the lowest ion intercalation potential, the highest ion intercalation potential, and the electrolyte decomposition potential are -1.5V, -2.5V, and -4.0V, respectively; for TBA + For DMF solvent, the lowest ion intercalation potential, the highest ion intercalation potential, and the electrolyte decomposition potential are -1.5V, -2.5V, and -4.5V, respectively; for TBA... + For DMSO solvent, the lowest ion intercalation potential, the highest ion intercalation potential, and the electrolyte decomposition potential are -1.5V, -3.0V, and -4.5V, respectively; for TMA... + For PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential, and the electrolyte decomposition potential are -1.0V, -2.5V, and -4.0V, respectively; for TEA... + For PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential, and the electrolyte decomposition potential are -1.5V, -3.0V, and -4.0V, respectively; for TPA... + For PC solvent, the lowest ion intercalation potential, the highest ion intercalation potential, and the electrolyte decomposition potential are -1.5V, -3.0V, and -4.5V, respectively; for TPeA + The lowest ion intercalation potential, the highest ion intercalation potential, and the electrolyte decomposition potential of the PC solvent are -1.0V, -2.5V, and -4.0V, respectively.

2. The electrochemical preparation method for large-diameter graphene according to claim 1, characterized in that, The concentration of the electrolyte is 0.1 mol / L.

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