Device and method for preparing graphene

Abstract

The invention relates to a device and method for preparing graphene. The device comprises a graphite roll, an upper support, a movable module, a temperature measuring barrel, a bubbling pipe, an electrolytic bath, a bath frame, a filter box, a diaphragm pump, a manual ball valve, a heat exchanger, an electric ball valve, filter cloth and the like. Graphite sheets to be processed are wound on the graphite reels, the number of the graphite reels is two, the two graphite reels are installed on the two upper supports respectively, and the distance between the two graphite reels is adjusted through the movable module; the graphite roll, the supporting seat, the graphite roller, the driving shaft, the upper bracket and the stepping motor form a group, the group is fixed on the moving module, and the moving module is mounted on the electrolytic bath and can integrally move; the other group is directly fixed on the electrolytic bath; according to the invention, the production quality and consistency of graphene can be improved, the graphite coarse material subjected to electrochemical stripping is timely removed through the combination of bubbling stirring, real-time suction filtration and the heat exchanger, the accurate control of electrolyte components and viscosity is realized, and the production stability and safety are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a device and a method for preparing graphene, and in particular to a device and a method for preparing graphene with improved stability and consistency. BACKGROUND

[0002] Since its discovery in 2004, graphene has attracted much attention as a new type of carbon material. It is a quasi-two-dimensional crystal material composed of sp 2 hybridized carbon atoms with a thickness of only one or a few atomic layers, and has excellent properties such as high light transmittance and electrical conductivity, high specific surface area, high strength, and flexibility, and is expected to be widely used in high-performance nanoelectronic devices, optoelectronic devices, gas sensors, composite materials, field emission materials, and energy storage. At present, there are many methods for preparing graphene, among which the oxidation-reduction method, liquid phase exfoliation method, and mechanical exfoliation method are the main methods, and the electrochemical method has also been widely used in recent years due to its simple preparation process, low energy consumption, low cost, and easy industrialization.

[0003] Chinese Patent No. CN106544690A discloses an electrolytic reaction device for preparing graphene, which comprises an electrolytic tank, a graphite plate, a feeding mechanism, and a graphite paper supporting mechanism. The feeding mechanism comprises a compression roller and a graphite conductive roller connected to the positive terminal of a power source through a carbon brush. The compression roller and the graphite conductive roller are symmetrically arranged above the electrolytic tank. The graphite paper supporting mechanism is fixed above the feeding mechanism. The graphite plate is arranged as a negative electrode in the electrolytic tank.

[0004] Chinese Patent No. CN111470499A relates to a method for preparing graphene, which comprises the following steps: preparing a graphite material into an electrode; preparing an ammonium salt into an electrolyte; first pretreating the electrode under an applied voltage, then adding ammonia water, and performing electrolytic exfoliation of the graphite positive electrode at a certain temperature; and then performing solid-liquid separation and drying of the electrolytic product to obtain graphene of different qualities.

[0005] Chinese Patent No. CN115159515A discloses a device and method for continuously preparing graphene oxide, which comprises a transmission mechanism and an electrolytic tank, including a pre-intercalation electrolytic tank and an exfoliation electrolytic tank, respectively used for pre-intercalation treatment and exfoliation treatment of graphite materials. The pre-intercalation electrolytic tank and the exfoliation electrolytic tank are respectively provided with a pre-intercalation electrode and an exfoliation electrode, which are connected to the negative electrode of a power source. The graphite material is connected to the positive electrode of the power source.

[0006] It can be seen that the device and process for stripping graphene by electrochemical method have become more and more mature, but there is no stable and consistent product on sale in the industry at present. The stability and consistency of production are important evaluation standards for electrochemical graphene at present. It is also one of the important indicators of high-quality graphene that the industry is constantly pursuing.

[0007] At present, the batch production of electrochemical graphene products is difficult, although there are many related patents or papers, but there is no clear product sales in the market. This is mainly because the size of the graphene sheet obtained by the traditional electrochemical stripping method is poor. In the laboratory level preparation process, many preparation conditions and details are not paid attention to, including the consistency of intercalation and stripping conditions, the fine control of power supply conditions, the temperature control of electrolyte and the timely discharge of graphite crude material, etc. At present, there is a lack of a systematic structural design and supporting process to meet the above needs and obtain high-quality graphene products with good consistency. In addition, material accumulation and thermal runaway during continuous production have always been another problem faced by the large-scale preparation of electrochemical graphene. At present, there is no related work to investigate this problem, and the related structural design is also very lacking. SUMMARY

[0008] In view of the above problems, the main purpose of the present application is to provide a device and method for preparing graphene which can improve the stability and consistency of graphene products.

[0009] The present application solves the above technical problems by the following technical scheme: a device for preparing graphene, comprising: a graphite roll, an upper support, a moving module, a temperature measuring barrel, a bubble tube, an electrolytic cell, a tank frame, a filter box, a support frame, a diaphragm pump, a manual ball valve, a heat exchanger, a stepping motor, a support seat, a partition, a graphite roller, a driving shaft, an electric ball valve and filter cloth.

[0010] The graphite sheet roll to be processed is on the graphite roll shaft, which includes two, respectively installed on two upper supports, and the distance between the two graphite rolls is adjusted by the moving module.

[0011] The graphite roll, support seat, graphite roller, driving shaft, upper support and stepping motor form a group, which is fixed on the moving module, and the moving module is installed on the electrolytic cell and can move as a whole; the other group is directly fixed on the electrolytic cell.

[0012] The temperature measuring barrel, bubble tube and partition are placed in the electrolytic cell; the electrolytic cell is placed in the tank frame and supported by the support frame; the electric ball valve connects the electrolytic cell and the filter box; the filter screen is placed inside the filter box and together placed inside the support frame.

[0013] The diaphragm pump draws the reaction liquid filtered by the filter cloth in the filter tank through the manual ball valve and the heat exchanger, and then outputs the reaction liquid to the electrolytic tank to make the electrolyte circulate and cool.

[0014] In the specific embodiment of the present application, the temperature measuring barrel is a temperature measuring barrel with a thermometer arranged therein; and the bubbling pipe is a pipe for introducing gas into the electrolyte in the electrolytic tank at different positions.

[0015] In the specific embodiment of the present application, the partition plate is a partition plate for guiding the graphite paper in the electrolyte and preventing the graphite paper in the positive and negative electrodes from being in contact and short-circuited.

[0016] In the specific embodiment of the present application, the electric ball valve is an on-off valve for controlling the reaction liquid in the electrolytic tank to enter the filter tank; and the filter cloth is a filter cloth for separating the electrolyte in the electrolytic tank from the graphene.

[0017] The method for preparing the graphene comprises a preparation step before the operation of the device, a raw material preparation step for preparing the graphene, an electrolysis process step for preparing the graphene, and a post-treatment step after the electrolysis process.

[0018] In the specific embodiment of the present application, the preparation step before the operation of the device specifically comprises the following:

[0019] Step 1: install the graphite roll with an appropriate length on the two upper supports, check the smoothness of the material conveying, and the graphite paper conveying accuracy of the graphite roll is 1 mm / h and stable;

[0020] Step 2: check the moving module, and determine that the repeated positioning accuracy can reach 0.1 mm;

[0021] Step 3: check the bubbling pipe, which can ensure that the gas flow is controlled between 0-5 m 3 / h;

[0022] Step 4: prepare sufficient electrolyte according to the formula, and the total amount of the electrolyte is slightly less than half of the total volume of the electrolytic tank and the filter tank.

[0023] Step 5: ensure that the heat exchange pump is operating normally, and the normal electrolyte flow is controlled at 15-20 m 3 / h.

[0024] In the specific embodiment of the present application, the raw material preparation step for preparing the graphene specifically comprises:

[0025] The electrolyte formula: 1000 parts by mass of water as a solvent, 100-150 parts by mass of a core electrolyte, 5-10 parts by mass of an antioxidant additive, 20-30 parts by mass of a pH stabilizer, and 10-20 parts by mass of an electrolytic surfactant are added to the solvent, respectively.

[0026] The core electrolyte is one or a combination of sulfuric acid, potassium sulfate, ammonium sulfate, sodium sulfate, potassium persulfate, ammonium persulfate, sodium persulfate, etc.

[0027] The antioxidant auxiliary agent is one or a combination of ascorbic acid, sodium ascorbate, citric acid, sodium citrate, etc.

[0028] The pH stabilizer is a mixed solvent of hydrogen phosphate and dihydrogen phosphate. The specific components are determined according to the pH value during the reaction.

[0029] The electrolytic surfactant is one or a combination of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, dodecyl benzene sulfonic acid, and sodium cetyl sulfate.

[0030] The preparation process of graphene electrolysis is as follows: first, control the electrolyte height in the electrolysis tank, so that the lower end of the graphite roll is immersed in the electrolyte by 10 cm±1 cm; in the subsequent reaction, the feeding motor is controlled to keep the graphite roll at 10 cm±1 cm during the reaction; the electrolyte temperature is controlled at 25-30℃; and the pH value is stabilized at 6-7 by appropriately adjusting the amount of pH stabilizer.

[0031] In the specific embodiment of the present application, the electrolysis process in the preparation process of graphene is divided into four stages and cycles.

[0032] The first stage is the pre-insertion layer of the fixed-end graphite roll: the electrode distance is adjusted to 20-30 cm, the fixed-end graphite roll is used as the positive electrode, the moving-end graphite roll is used as the negative electrode, a voltage of 3-5 V is applied, and the process is continued for 0.5-1 h.

[0033] The second stage is the stripping of the fixed-end graphite roll: the electrode distance is adjusted to 5-10 cm, the fixed-end graphite roll is used as the positive electrode, the moving-end graphite roll is used as the negative electrode, a voltage of 5-10 V is applied, and the process is continued for 1-2 h until the 10 cm±1 cm of the immersed graphite roll is completely reacted; the power supply is stopped, and the feeding motor is started to deliver new 10 cm±1 cm into the liquid surface.

[0034] The third stage is the pre-insertion layer of the moving-end graphite roll: the electrode distance is adjusted to 20-30 cm, the moving-end graphite roll is used as the positive electrode, the moving-end graphite roll is used as the negative electrode, a voltage of 3-5 V is applied, and the process is continued for 0.5-1 h.

[0035] The fourth stage is the stripping of the moving-end graphite roll: the electrode distance is adjusted to 5-10 cm, the moving-end graphite roll is used as the positive electrode, the moving-end graphite roll is used as the negative electrode, a voltage of 5-10 V is applied, and the process is continued for 1-2 h until the 10 cm±1 cm of the immersed graphite roll is completely reacted; the power supply is stopped, and the feeding motor is started to deliver new 10 cm±1 cm into the liquid surface.

[0036] Fifth stage: return to the first stage, repeat.

[0037] In the specific embodiment of the present application, the post-treatment step after the electrolysis process is completed includes: after the crude material of the reaction is cleaned, impurities are removed, and further stripping is performed using ultrasonic, homogenization or stirring to obtain high-quality graphene products.

[0038] The positive progress effect of the present application is that the device and method for preparing graphene provided by the present application have the following advantages compared with common technologies:

[0039] 1. The complete high-purity graphite roll is used as the reaction raw material, and the reaction time is long with single-word feeding. The graphite roll is driven by a high-precision stepping motor combined with a reducer to realize accurate control of the feeding rate at the level of um / s, further improving the reaction accuracy.

[0040] 2. By coupling control of the electrode distance and the power supply parameters, the dynamic balance of long-distance pre-intercalation and short-distance electrolysis is realized, the large piece of graphite is prevented from falling off during electrolysis, and the quality and consistency of the graphene product are further improved.

[0041] 3. By combining bubble stirring, real-time filtration and heat exchanger, the graphite crude material stripped by electrochemistry is timely removed, the electrolyte composition and viscosity are accurately controlled, the side reactions caused by material accumulation near the electrode and insufficient heat dissipation during the reaction process are reduced, and the production stability and safety are further improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a perspective view (line drawing, exploded view) of the overall structure of the present application.

[0043] Figure 2 is a front view of Figure 1 .

[0044] Figure 3 is a perspective view (effect drawing) of the overall structure of the present application.

[0045] Figure 4 is a picture display of graphene prepared by the present application under atomic force microscope (AFM).

[0046] The following is the name corresponding to the label in the present application:

[0047] Graphite roll 1, upper support 2, moving module 3, temperature measuring barrel 4, bubble tube 5, electrolytic cell 6, tank frame 7, filter box 8, support frame 9, diaphragm pump 10, manual ball valve 11, heat exchanger 12, stepping motor 13, support seat 14, partition 15, graphite roller 16, driving shaft 17, electric ball valve 18, filter cloth 19. DETAILED DESCRIPTION

[0048] The preferred embodiments of the present application are described below in detail with reference to the accompanying drawings.

[0049] Figure 1 is a perspective view (line drawing, exploded view) of the overall structure of the present application, Figure 2 is a front view of Figure 1 , Figure 3 is a perspective view (effect drawing) of the overall structure of the present application, as shown in Figures 1-3 , the present application proposes a device for preparing graphene, which comprises: an upper support 2, a moving module 3, a temperature measuring barrel 4, a bubbling pipe 5, an electrolytic cell 6, a tank frame 7, a filter box 8, a support frame 9, a diaphragm pump 10, a manual ball valve 11, a heat exchanger 12, a stepping motor 13, a support seat 14, a partition plate 15, a graphite roll 16, a driving shaft 17, an electric ball valve 18, and filter cloth 19.

[0050] The graphite sheet to be processed is wound on the shaft of the graphite roll 1, and the graphite roll shaft comprises two, which are respectively installed on two upper supports 1, and the distance between the two graphite rolls is adjusted by the moving module 3.

[0051] The graphite roll 1, the support seat 14, the graphite roll 16, the driving shaft 17, the upper support 2, and the stepping motor 13 form a group, which is fixed on the moving module 3, and the moving module 3 is installed on the electrolytic cell 6 and can move as a whole; the other group is directly fixed on the electrolytic cell 6.

[0052] The temperature measuring barrel 4, the bubbling pipe 5, and the partition plate 15 are placed in the electrolytic cell 6; the electrolytic cell 6 is placed in the tank frame 7 and supported by the support frame 9; the electric ball valve 18 connects the electrolytic cell 6 and the filter box 8; the filter cloth 19 is placed inside the filter box 9 and is fixed together inside the support frame.

[0053] The diaphragm pump 10 extracts the reaction liquid filtered by the filter cloth in the filter box through the manual ball valve 11 and the heat exchanger 12, and then outputs it to the electrolytic cell, so that the electrolyte is circulated and cooled.

[0054] The temperature measuring barrel 4 in the present application is a temperature measuring barrel provided with a thermometer inside, the bubbling pipe 5 is a bubbling pipe for introducing gas into the electrolyte in the electrolytic cell at different positions, the partition plate 15 is a partition plate for guiding the graphite paper in the electrolyte and preventing the positive and negative graphite papers from being in contact and short-circuited.

[0055] The electric ball valve 18 is an on-off valve for controlling the reaction liquid in the electrolytic cell to enter the filter box; the filter cloth 19 is a filter cloth for separating the electrolyte in the electrolytic cell from the graphene.

[0056] The upper support 2 in the present application is used to support the graphite roll; the moving module 3 in the present application adjusts the distance between the two graphite papers; the electrolytic cell 6 in the present application carries the electrolyte; and the tank frame 7 in the present application protects the electrolytic cell and supports the graphite roll.

[0057] The diaphragm pump 10 in the application makes the electrolyte in the filter tank 8 into the heat exchanger 12 to cool and deliver to the electrolytic tank 6, the manual ball valve 11 in the application controls the delivery of the solution in the pipeline.

[0058] The heat exchanger 12 in the application cools the electrolyte pumped by the diaphragm pump 10. The stepping motor 13 in the application drives the graphite roll to rotate, so that the graphite sheet material continuously enters the electrolytic tank.

[0059] The support seat 14 in the application supports the graphite roll to make it rotate. The graphite roll 16 in the application is electrified to make the graphite roll charged. The driving shaft in the application connects the stepping motor 13 and clamps the graphite roll sheet material to make it deliver.

[0060] The application provides a method for preparing the above-mentioned graphene, and the method comprises the following steps: a preparation step before running the device, a raw material preparation step for preparing graphene, an electrolysis process step for preparing graphene, and a post-processing step after the electrolysis process is completed.

[0061] The preparation step before running the device specifically comprises the following steps:

[0062] Step 1: Install the graphite roll with an appropriate length on the two upper supports, check the smooth delivery of the material, and the graphite roll delivers the graphite paper with an accuracy of 1 mm / h and stability.

[0063] Step 2: Check the moving module to ensure that the repeated positioning accuracy can reach 0.1 mm.

[0064] Step 3: Check the bubbling pipe to ensure that the gas flow can be controlled between 0-5 m 3 / h.

[0065] Step 4: Prepare sufficient electrolyte according to the formula, and the total amount of electrolyte is slightly less than half of the total volume of the electrolytic tank and the filter tank.

[0066] Step 5: Ensure that the heat exchange pump is running normally, and the normal electrolyte flow is controlled at 15-20 m 3 / h.

[0067] The raw material preparation step for preparing graphene specifically comprises the following steps:

[0068] The electrolyte formula: 1000 parts by mass of water as a solvent, 100-150 parts by mass of core electrolyte, 5-10 parts by mass of antioxidant additive, 20-30 parts by mass of pH stabilizer, and 10-20 parts by mass of electrolytic surfactant are added to the solvent.

[0069] The core electrolyte is one or a combination of several of the following: sulfuric acid, potassium sulfate, ammonium sulfate, sodium sulfate, potassium persulfate, ammonium persulfate, and sodium persulfate.

[0070] The antioxidant aid is one or a combination of ascorbic acid, sodium ascorbate, citric acid, sodium citrate, etc.

[0071] The pH stabilizer is a mixture of hydrogen phosphate and dihydrogen phosphate, and the specific components are determined according to the pH value during the reaction.

[0072] The electrolytic surfactant is one or a combination of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, dodecyl benzene sulfonic acid, and sodium cetyl sulfate.

[0073] The preparation of graphene electrolysis process steps are as follows: first, control the electrolyte height in the electrolytic cell, so that the lower end of the graphite roll is immersed in the electrolyte by 10 cm ± 1 cm, and in the subsequent reaction, the feed motor is controlled to keep the two ends of the graphite roll within 10 cm ± 1 cm during the reaction; the electrolyte temperature is controlled at 25-30℃; the pH value is stabilized at 6-7 by appropriately adjusting the amount of pH stabilizer.

[0074] The electrolysis process in the preparation of graphene electrolysis process is divided into four stages, which are periodically cycled.

[0075] First stage: fixed end graphite roll pre-insertion layer: adjust the electrode distance to 20-30 cm, take the fixed end graphite roll as the positive electrode, and take the moving end graphite roll as the negative electrode, apply a voltage of 3-5 V, and continue for 0.5-1 h.

[0076] Second stage: fixed end graphite roll peeling: adjust the electrode distance to 5-10 cm, take the fixed end graphite roll as the positive electrode, and take the moving end graphite roll as the negative electrode, apply a voltage of 5-10 V; continue for 1-2 h, until the 10 cm ± 1 cm of the immersed graphite roll is completely reacted; stop power supply, and start the feed motor to transport new 10 cm ± 1 cm into the liquid surface.

[0077] Third stage: moving end graphite roll pre-insertion layer: adjust the electrode distance to 20-30 cm, take the moving end graphite roll as the positive electrode, and take the moving end graphite roll as the negative electrode, apply a voltage of 3-5 V, and continue for 0.5-1 h.

[0078] Fourth stage: moving end graphite roll peeling: adjust the electrode distance to 5-10 cm, take the moving end graphite roll as the positive electrode, and take the moving end graphite roll as the negative electrode, apply a voltage of 5-10 V; continue for 1-2 h, until the 10 cm ± 1 cm of the immersed graphite roll is completely reacted; stop power supply, and start the feed motor to transport new 10 cm ± 1 cm into the liquid surface.

[0079] Fifth stage: return to the first stage and repeat.

[0080] The post-treatment step after the electrolysis process is completed includes: after the crude material of the reaction is cleaned, impurities are removed, and high-quality graphene products are obtained by further peeling using ultrasonic, homogenization or stirring.

[0081] The following are some specific examples:

[0082] Example 1

[0083] Take 1000 parts by mass of water as the solvent, add 100 parts by mass of sodium sulfate, 5 parts by mass of ascorbic acid, 10 parts by mass of dodecylbenzenesulfonic acid sodium, and pH stabilizers of hydrogen phosphate and dihydrogen phosphate to the solvent, adjust the pH to 6, and complete the configuration of the electrolyte. The height of the electrolyte in the electrolytic cell is controlled so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, the feeding motor is controlled to keep the graphite roll within this range during the reaction. The temperature of the electrolyte is controlled at 25°C.

[0084] The electrolysis process is divided into four stages, which are cycled.

[0085] First stage: fixed-end graphite roll pre-insertion layer. Adjust the electrode distance to 20 cm, use the fixed-end graphite roll as the positive electrode, and the moving-end graphite roll as the negative electrode, apply a voltage of 3V, and continue for 0.5h.

[0086] Second stage: fixed-end graphite roll peeling. Adjust the electrode distance to 5 cm, use the fixed-end graphite roll as the positive electrode, and the moving-end graphite roll as the negative electrode, apply a voltage of 5V. Continue for 1h until the 10cm of graphite roll immersed is completely reacted. Stop power supply, start the feeding motor to transport new 10cm into the liquid surface.

[0087] Third stage: moving-end graphite roll pre-insertion layer. Adjust the electrode distance to 20 cm, use the fixed-end graphite roll as the positive electrode, and the moving-end graphite roll as the negative electrode, apply a voltage of 3V, and continue for 0.5h. (The parameters in this stage are consistent with those in the first stage)

[0088] Fourth stage: moving-end graphite roll peeling. Adjust the electrode distance to 5 cm, use the fixed-end graphite roll as the positive electrode, and the moving-end graphite roll as the negative electrode, apply a voltage of 5V. Continue for 1h until the 10cm of graphite roll immersed is completely reacted. Stop power supply, start the feeding motor to transport new 10cm into the liquid surface. (The parameters in this stage are consistent with those in the second stage)

[0089] Fifth stage: return to the first stage and repeat.

[0090] Example 2

[0091] Take 1000 parts by mass of water as the solvent, add 150 parts by mass of potassium sulfate, 10 parts by mass of sodium citrate, 20 parts of dodecylbenzenesulfonic acid, and pH stabilizers of hydrogen phosphate and dihydrogen phosphate to the solvent, adjust the pH to 7, and complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll within this range during the reaction. The electrolyte temperature is controlled at 30°C. The electrolysis process is divided into four stages, with a cycle.

[0092] First stage: fixed-end graphite roll pre-insertion layer. Adjust the electrode distance to 30 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 5V for 1h.

[0093] Second stage: fixed-end graphite roll stripping. Adjust the electrode distance to 10 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 10V. Continue for 2h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface.

[0094] Third stage: moving-end graphite roll pre-insertion layer. Adjust the electrode distance to 30 cm, with the moving-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 5V for 1h. (The parameters in this stage are consistent with the first stage)

[0095] Fourth stage: moving-end graphite roll stripping. Adjust the electrode distance to 10 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 10V. Continue for 2h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface. (The parameters in this stage are consistent with the second stage)

[0096] Fifth stage: return to the first stage and repeat.

[0097] After stripping, the crude graphene reaction material is washed to remove impurities, and further stripped using a homogenization method to obtain high-quality graphene products.

[0098] Example Three

[0099] Take 1000 parts by mass of water as the solvent, add 120 parts by mass of ammonium sulfate, 8 parts by mass of sodium ascorbate, 15 parts of sodium lauryl sulfate, add hydrogen phosphate and dihydrogen phosphate pH stabilizers, adjust the pH to 6.5, and complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll within this range during the reaction. The electrolyte temperature is controlled at 27°C. The electrolysis process is divided into four stages, with a cycle.

[0100] First stage: fixed end graphite roll pre-insertion layer. Adjust the electrode distance to 25 cm, with the fixed end graphite roll as the positive electrode and the moving end graphite roll as the negative electrode, apply a voltage of 4V, and continue for 0.7h.

[0101] Second stage: fixed end graphite roll stripping. Adjust the electrode distance to 7 cm, with the fixed end graphite roll as the positive electrode and the moving end graphite roll as the negative electrode, apply a voltage of 7V. Continue for 1.5h until the 10cm of graphite roll immersed is completely reacted. Stop power supply, start the feed motor to transport new 10cm into the liquid surface.

[0102] Third stage: moving end graphite roll pre-insertion layer. Adjust the electrode distance to 25 cm, with the moving end graphite roll as the positive electrode and the moving end graphite roll as the negative electrode, apply a voltage of 4V, and continue for 0.7h. (The parameters in this stage are consistent with the first stage)

[0103] Fourth stage: moving end graphite roll stripping. Adjust the electrode distance to 7 cm, with the fixed end graphite roll as the positive electrode and the moving end graphite roll as the negative electrode, apply a voltage of 7V. Continue for 1.5h until the 10cm of graphite roll immersed is completely reacted. Stop power supply, start the feed motor to transport new 10cm into the liquid surface. (The parameters in this stage are consistent with the second stage)

[0104] Fifth stage: back to the first stage and repeat.

[0105] After stripping, the crude graphene reaction material is washed to remove impurities, and further stripped using stirring to obtain high-quality graphene products.

[0106] Example Four

[0107] Take 1000 parts by mass of water as the solvent, add 130 parts by mass of sulfuric acid, 6 parts by mass of citric acid, 12 parts of sodium dodecyl sulfate, add hydrogen phosphate and dihydrogen phosphate pH stabilizers, adjust the pH to 6.3, and complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll within this range during the reaction. The electrolyte temperature is controlled at 26°C. The electrolysis process is divided into four stages, with a cycle.

[0108] First stage: fixed end graphite roll pre-insertion layer. Adjust the electrode distance to 22 cm, with the fixed end graphite roll as the positive electrode and the moving end graphite roll as the negative electrode, apply a voltage of 3.5V, and continue for 0.6h.

[0109] Second stage: fixed end graphite roll stripping. Adjust the electrode distance to 6 cm, with the fixed end graphite roll as the positive electrode and the moving end graphite roll as the negative electrode, apply a voltage of 6V. Continue for 1.2h until the 10cm of graphite roll immersed is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface.

[0110] Third stage: moving end graphite roll pre-insertion layer. Adjust the electrode distance to 22 cm, with the moving end graphite roll as the positive electrode and the moving end graphite roll as the negative electrode, apply a voltage of 3.5V, and continue for 0.6h. (The parameters in this stage are consistent with the first stage)

[0111] Fourth stage: moving end graphite roll stripping. Adjust the electrode distance to 6 cm, with the fixed end graphite roll as the positive electrode and the moving end graphite roll as the negative electrode, apply a voltage of 6V. Continue for 1.2h until the 10cm of graphite roll immersed is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface. (The parameters in this stage are consistent with the second stage)

[0112] Fifth stage: return to the first stage and repeat.

[0113] After stripping, the crude graphene reaction material is washed to remove impurities, and further stripped using ultrasonic method to obtain high-quality graphene products.

[0114] Example five

[0115] Take 1000 parts by mass of water as the solvent, add 110 parts by mass of potassium persulfate, 7 parts by mass of ascorbic acid, 18 parts of a combination of sodium dodecylbenzenesulfonate and sodium dodecyl sulfate (9 parts each) to the solvent, add hydrogen phosphate and dihydrogen phosphate pH stabilizers, and adjust the pH to 6.7 to complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll within this range during the reaction. The electrolyte temperature is controlled at 28°C. The electrolysis process is divided into four stages, with a cycle.

[0116] First stage: fixed-end graphite roll pre-intercalation. Adjust the electrode distance to 28 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, and apply a voltage of 4.5 V for 0.8 h.

[0117] Second stage: fixed-end graphite roll exfoliation. Adjust the electrode distance to 8 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, and apply a voltage of 8 V. Continue for 1.7 h until the 10 cm of the immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10 cm into the liquid surface.

[0118] Third stage: moving-end graphite roll pre-intercalation. Adjust the electrode distance to 28 cm, with the moving-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, and apply a voltage of 4.5 V for 0.8 h. (The parameters in this stage remain the same as in the first stage)

[0119] Fourth stage: moving-end graphite roll exfoliation. Adjust the electrode distance to 8 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, and apply a voltage of 8 V. Continue for 1.7 h until the 10 cm of the immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10 cm into the liquid surface. (The parameters in this stage remain the same as in the second stage)

[0120] Fifth stage: return to the first stage and repeat.

[0121] After exfoliation, the crude graphene reaction material is washed to remove impurities, and further exfoliated using a homogenization method to obtain high-quality graphene products.

[0122] Example Six

[0123] Take 1000 parts by mass of water as the solvent, add 140 parts by mass of a combination of sodium sulfate and ammonium sulfate (70 parts each), 9 parts by mass of a combination of citric acid and sodium citrate (4.5 parts each), 16 parts of a combination of sodium hexadecyl sulfate and dodecylbenzenesulfonic acid (8 parts each) to the solvent, add hydrogen phosphate and dihydrogen phosphate pH stabilizers, adjust the pH to 6.2, and complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll within this range during the reaction. The electrolyte temperature is controlled at 29°C. The electrolysis process is divided into four stages, with a cycle.

[0124] First stage: fixed-end graphite roll pre-intercalation. Adjust the electrode distance to 23 cm, use the fixed-end graphite roll as the positive electrode, and the moving-end graphite roll as the negative electrode, apply a voltage of 3.8V, and last for 0.65h.

[0125] Second stage: fixed-end graphite roll exfoliation. Adjust the electrode distance to 5.5 cm, use the fixed-end graphite roll as the positive electrode, and the moving-end graphite roll as the negative electrode, apply a voltage of 5.5V. Last for 1.3h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface.

[0126] Third stage: moving-end graphite roll pre-intercalation. Adjust the electrode distance to 23 cm, use the moving-end graphite roll as the positive electrode, and the moving-end graphite roll as the negative electrode, apply a voltage of 3.8V, and last for 0.65h. (The parameters in this stage are consistent with the first stage)

[0127] Fourth stage: moving-end graphite roll exfoliation. Adjust the electrode distance to 5.5 cm, use the fixed-end graphite roll as the positive electrode, and the moving-end graphite roll as the negative electrode, apply a voltage of 5.5V. Last for 1.3h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface. (The parameters in this stage are consistent with the second stage)

[0128] Fifth stage: return to the first stage and repeat.

[0129] After exfoliation, the crude graphene reaction material is washed to remove impurities, and further exfoliated using stirring to obtain high-quality graphene products.

[0130] Example Seven

[0131] Take 1000 parts by mass of water as the solvent, add 105 parts by mass of ammonium persulfate, 10 parts by mass of sodium ascorbate, 13 parts of a combination of sodium dodecyl sulfate and sodium hexadecyl sulfate (6.5 parts each) to the solvent, add hydrogen phosphate and dihydrogen phosphate pH stabilizers, adjust the pH to 6.9, and complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll within this range during the reaction. The electrolyte temperature is controlled at 26.5°C. The electrolysis process is divided into four stages, with a cycle.

[0132] First stage: fixed-end graphite roll pre-insertion layer. Adjust the electrode distance to 27 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 4.2V, and continue for 0.75h.

[0133] Second stage: fixed-end graphite roll stripping. Adjust the electrode distance to 9 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 9V. Continue for 1.8h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface.

[0134] Third stage: moving-end graphite roll pre-insertion layer. Adjust the electrode distance to 27 cm, with the moving-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 4.2V, and continue for 0.75h. (The parameters in this stage are consistent with those in the first stage)

[0135] Fourth stage: moving-end graphite roll stripping. Adjust the electrode distance to 9 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 9V. Continue for 1.8h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface. (The parameters in this stage are consistent with those in the second stage)

[0136] Fifth stage: return to the first stage and repeat.

[0137] After stripping, the crude graphene reaction material is washed to remove impurities, and further stripped using ultrasonic method to obtain high-quality graphene products.

[0138] Example Eight

[0139] Take 1000 parts by mass of water as the solvent, add 125 parts by mass of a combination of potassium sulfate and sulfuric acid (62.5 parts each), 6 parts by mass of sodium citrate, 17 parts of a combination of sodium dodecylbenzenesulfonate and dodecylbenzenesulfonic acid (8.5 parts each) to the solvent, add hydrogen phosphate and dihydrogen phosphate pH stabilizers, and adjust the pH to 6.4 to complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll within this range during the reaction. The electrolyte temperature is controlled at 28.5°C. The electrolysis process is divided into four stages, with a cycle.

[0140] First stage: fixed-end graphite roll pre-insertion layer. Adjust the electrode distance to 21 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, and apply a voltage of 3.3V for 0.55h.

[0141] Second stage: fixed-end graphite roll stripping. Adjust the electrode distance to 5.8 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, and apply a voltage of 5.2V. Continue for 1.1h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface.

[0142] Third stage: moving-end graphite roll pre-insertion layer. Adjust the electrode distance to 21 cm, with the moving-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, and apply a voltage of 3.3V for 0.55h. (The parameters in this stage are consistent with those in the first stage)

[0143] Fourth stage: moving-end graphite roll stripping. Adjust the electrode distance to 5.8 cm, with the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, and apply a voltage of 5.2V. Continue for 1.1h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface. (The parameters in this stage are consistent with those in the second stage)

[0144] Fifth stage: return to the first stage and repeat.

[0145] After stripping, the graphene reaction crude material is washed to remove impurities, and further stripped using a homogenization method to obtain high-quality graphene products.

[0146] Example Nine

[0147] Take 1000 parts by mass of water as the solvent, add 135 parts by mass of sodium persulfate, 8 parts by mass of ascorbic acid and the combination of ascorbic acid and sodium ascorbate (4 parts each), 14 parts of sodium hexadecyl sulfate to the solvent, add hydrogen phosphate and dihydrogen phosphate pH stabilizers, adjust the pH to 6.6, and complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll at both ends within this range during the reaction. The electrolyte temperature is controlled at 27.5°C. The electrolysis process is divided into four stages, with a cycle.

[0148] First stage: fixed end graphite roll pre-intercalation: adjust the electrode distance to 29 cm, use the fixed end graphite roll as the positive electrode, and the moving end graphite roll as the negative electrode, apply a voltage of 4.8V, and last for 0.9h.

[0149] Second stage: fixed end graphite roll exfoliation: adjust the electrode distance to 9.5 cm, use the fixed end graphite roll as the positive electrode, and the moving end graphite roll as the negative electrode, apply a voltage of 9.5V. Last for 1.9h, until the 10cm immersed graphite roll is completely reacted. Stop power supply, start the feed motor to transport new 10cm into the liquid surface.

[0150] Third stage: moving end graphite roll pre-intercalation: adjust the electrode distance to 29 cm, use the moving end graphite roll as the positive electrode, and the moving end graphite roll as the negative electrode, apply a voltage of 4.8V, and last for 0.9h. (The parameters in this stage are consistent with those in the first stage).

[0151] Fourth stage: moving end graphite roll exfoliation: adjust the electrode distance to 9.5 cm, use the fixed end graphite roll as the positive electrode, and the moving end graphite roll as the negative electrode, apply a voltage of 9.5V. Last for 1.9h, until the 10cm immersed graphite roll is completely reacted. Stop power supply, start the feed motor to transport new 10cm into the liquid surface. (The parameters in this stage are consistent with those in the second stage)

[0152] Fifth stage: return to the first stage and repeat.

[0153] After exfoliation, the crude graphene reaction material is washed to remove impurities, and further exfoliated using stirring to obtain high-quality graphene products.

[0154] Example Ten

[0155] Take 1000 parts by mass of water as the solvent, add 115 parts by mass of ammonium sulfate and a combination of ammonium persulfate (57.5 parts each) respectively, 7.5 parts by mass of citric acid, 19 parts of a combination of sodium dodecylbenzenesulfonate, sodium dodecyl sulfate and sodium hexadecyl sulfate (about 6.33 parts each), add hydrogen phosphate and dihydrogen phosphate pH stabilizers, adjust the pH to 6.1, and complete the electrolyte configuration. Control the electrolyte height in the electrolytic cell so that the lower end of the graphite roll is immersed in the electrolyte by about 10 cm ± 1 cm, and during the subsequent reaction, control the feed motor to keep the graphite roll within this range during the reaction. The electrolyte temperature is controlled at 25.5°C. The electrolysis process is divided into four stages, with a cycle.

[0156] First stage: fixed-end graphite roll pre-insertion layer. Adjust the electrode distance to 24 cm, use the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 3.7V, and continue for 0.7h.

[0157] Second stage: fixed-end graphite roll stripping. Adjust the electrode distance to 7.5 cm, use the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 7.5V. Continue for 1.6h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface.

[0158] Third stage: moving-end graphite roll pre-insertion layer. Adjust the electrode distance to 24 cm, use the moving-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 3.7V, and continue for 0.7h (the parameters in this stage remain the same as in the first stage).

[0159] Fourth stage: moving-end graphite roll stripping. Adjust the electrode distance to 7.5 cm, use the fixed-end graphite roll as the positive electrode and the moving-end graphite roll as the negative electrode, apply a voltage of 7.5V. Continue for 1.6h until the 10cm immersed graphite roll is completely reacted. Stop the power supply and start the feed motor to deliver new 10cm into the liquid surface (the parameters in this stage remain the same as in the second stage).

[0160] Fifth stage: return to the first stage and repeat.

[0161] After stripping, the crude graphene reaction material is washed to remove impurities, and further stripped using ultrasonic method to obtain high-quality graphene products.

[0162] The present application can use a high-precision stepper motor to drive the graphite roll through a reducer, realize the accurate control of the feeding rate at the level of um / s, and further improve the reaction accuracy; through the coupling regulation and control of the electrode distance and the power supply parameters, the dynamic balance of long-distance pre-intercalation and short-distance electrolysis is realized, the graphite of large pieces is prevented from falling off during electrolysis, and the quality and consistency of the graphene product are further improved (when the electrode distance is the farthest, the power supply voltage is controlled at 3-5V. When the electrode distance is the closest, a voltage of 5-10V is applied). Through the combination of bubbling stirring, real-time filtration and heat exchanger, the graphite coarse material peeled off by electrochemistry is timely removed, the electrolyte composition and viscosity are accurately controlled, the side reactions caused by material accumulation near the electrode and insufficient heat dissipation in the reaction process are reduced, and the production stability and safety are further improved.

[0163] Figure 4 The picture of graphene prepared by the present application under atomic force microscope (AFM) is shown in the figure. As shown in Figure 4 The atomic force microscope (AFM) picture shows a picture of graphene prepared by the present application, which shows the graphene material prepared by the present application. The graphene presents irregular sheet morphology. The surface of the graphene is relatively flat, only slight undulation and wrinkle appear in the local area, which indicates that the graphene has good flatness and uniformity. The edge of the graphene is relatively clear, which indicates that it has high crystallinity and complete crystal structure. There are some white spots on the surface, which may be impurities or folded parts of the graphene sheet, but the overall structure is still relatively complete.

[0164] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, the above examples and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, which fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A device for preparing graphene, characterized in that: The graphene preparation device includes: a graphite roll, an upper bracket, a mobile module, a temperature measuring barrel, a bubbling tube, an electrolytic cell, a cell frame, a filter box, a support frame, a diaphragm pump, a manual ball valve, a heat exchanger, a stepper motor, a support seat, a partition, a graphite roller, a driving shaft, an electric ball valve, and a filter cloth; The graphite sheet to be processed is rolled on a graphite reel. There are two graphite reels, which are respectively mounted on two upper brackets. A movable module is used to adjust the distance between the two graphite rolls. The graphite roll, support seat, graphite roller, driving shaft, upper bracket and stepper motor form a group. This group is fixed on the mobile module, which is installed on the electrolytic cell and can move as a whole. The other group is directly fixed on the electrolytic cell. The temperature measuring barrel, bubbling tube, and partition are placed in the electrolytic cell; the electrolytic cell is placed in the cell frame and supported by a support frame; the electric ball valve connects the electrolytic cell and the filter box; the filter cloth is placed inside the filter box and fixed together inside the support frame; The diaphragm pump extracts the reaction liquid filtered by the filter cloth in the filter box through the manual ball valve and the heat exchanger, and then outputs it to the electrolytic cell to circulate and cool the electrolyte.

2. The device for preparing graphene according to claim 1, wherein: The temperature measuring barrel is a temperature measuring barrel with a thermometer arranged therein; the bubbling tube is a bubbling tube for introducing gas into different positions of the electrolyte in the electrolytic cell.

3. The device for preparing graphene according to claim 1, wherein: The separator guides the graphite paper in the electrolyte and prevents the positive and negative graphite papers from short-circuiting.

4. The device for preparing graphene according to claim 1, wherein: The electric ball valve is an on-off valve that controls the reaction liquid in the electrolytic cell to enter the filter box; the filter cloth is a filter cloth that separates the electrolyte and graphene in the electrolytic cell.

5. A method for preparing the graphene according to any one of claims 1 to 4, characterized in that: The method for preparing graphene includes: a preparation step before operating the device, a raw material preparation step for preparing graphene, an electrolysis process step for preparing graphene, and a post-processing step after the electrolysis process is completed.

6. The method for preparing graphene according to claim 5, wherein: The preparation steps before running the device include the following: Step 1. Install the graphite roll of appropriate length on the two upper brackets, check that the material is conveyed smoothly without any jams, and that the graphite roll conveys the graphite paper with an accuracy of 1mm / h and is stable; Step 2: Check the moving module to make sure the repeat positioning accuracy can reach 0.1mm; Step 3: Check the bubbler tube to ensure that the gas flow rate is between 0 and 5 m 3 Regulate between / h; Step 4: Prepare sufficient electrolyte according to the formula, with the total amount of electrolyte slightly less than half of the total volume of the electrolytic tank and filter tank; Step 5: Ensure that the heat exchange pump is operating normally and the normal electrolyte flow rate is controlled at 15-20m 3 / h.

7. The method for preparing graphene according to claim 6, wherein: The steps for preparing raw materials for graphene preparation specifically include: Electrolyte formula: 1000 parts by weight of water as solvent, 100-150 parts by weight of core electrolyte, 5-10 parts by weight of antioxidant, 20-30 parts by weight of pH stabilizer, and 10-20 parts by weight of electrolytic surfactant are added to the solvent respectively; The core electrolyte is one or a combination of sulfuric acid, potassium sulfate, ammonium sulfate, sodium sulfate, potassium persulfate, ammonium persulfate, sodium persulfate, etc. The antioxidant auxiliary agent is: ascorbic acid, sodium ascorbate, citric acid, sodium citrate, etc., or a combination thereof; The pH stabilizer is a mixed solvent of hydrogen phosphate and dihydrogen phosphate. The electrolytic surfactant is one or a combination of sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, dodecylbenzenesulfonic acid, and sodium hexadecyl sulfate.

8. The method for preparing graphene according to claim 5, wherein: The specific steps of the graphene electrolysis process are as follows: first, the electrolyte height in the electrolytic cell is controlled so that the lower ends of the graphite rolls at both ends are immersed in the electrolyte by 10cm±1cm. During the subsequent reaction, the feed motor is controlled to control the graphite rolls at both ends to remain within 10cm±1cm during the reaction; the electrolyte temperature is controlled at 25-30℃; and the pH is stabilized between 6 and 7 by appropriately adjusting the amount of pH stabilizer.

9. The method for preparing graphene according to claim 8, wherein: The electrolysis process in the graphene preparation electrolysis process is divided into four stages and cycles: Stage 1: Pre-intercalation of the fixed-end graphite roll: The electrode distance is adjusted to 20-30 cm, the fixed-end graphite roll is used as the positive electrode, and the movable-end graphite roll is used as the negative electrode. A voltage of 3-5 V is applied for 0.5-1 h. Second stage: fixed end graphite roll peeling: adjust the electrode distance to 5-10cm, with the fixed end graphite roll as the positive electrode and the movable end graphite roll as the negative electrode, and apply a voltage of 5-10V; continue for 1-2 hours until the immersed 10cm±1cm graphite roll is completely reacted; stop the power supply, start the feed motor to deliver a new 10cm±1cm into the liquid surface; The third stage: pre-intercalation of the graphite roll at the moving end: the electrode distance is adjusted to 20-30 cm, the graphite roll at the moving end is used as the positive electrode, and the graphite roll at the moving end is used as the negative electrode, and a voltage of 3-5 V is applied for 0.5-1 h; Stage 4: Peeling of the graphite roll at the moving end: The electrode distance is adjusted to 5-10 cm, with the graphite roll at the moving end as the positive electrode and the graphite roll at the moving end as the negative electrode, and a voltage of 5-10 V is applied. This process continues for 1-2 hours until the submerged graphite roll of 10 cm ± 1 cm is completely reacted. The power is then turned off, and the feeding motor is started to deliver a new 10 cm ± 1 cm roll into the liquid surface. Stage 5: Return to stage 1 and repeat.

10. The method for preparing graphene according to claim 5, wherein: The post-processing steps after the electrolysis process are completed include: cleaning the crude material of the reaction to remove impurities, and further exfoliating it using ultrasound, homogenization or stirring to obtain high-quality graphene products.

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