Electrochemical device and method capable of continuously preparing covalent functionalized graphene

Abstract

The invention belongs to the technical field of graphene material preparation, and particularly relates to an electrochemical device and method capable of continuously preparing covalent functionalized graphene. According to the method, a continuous flexible graphite paper coiled material or a carbon fiber wire rod is taken as a raw material and is clamped by a mesh belt of a conveying mechanism to be subjected to an electrochemical oxidation reaction through an integrated electrolytic bath, so that graphite paper or carbon fibers are continuously converted into a sheet material or a wire rod formed by functionalized graphene; the functionalized graphene aggregate attached to the surface of the mesh belt is scraped off through a scraper and collected into a stripping groove, a solvent is added, shearing stripping and cleaning are conducted, and then the dispersion liquid of the functionalized graphene is obtained. The device mainly comprises five parts, namely a mesh belt clamping and conveying mechanism, an electrolytic cell, an electrolytic power supply mechanism, a working liquid conveying mechanism and a functionalized graphene collecting and stripping mechanism, automatic continuous preparation of different types of functionalized graphene can be realized through combination of the mechanisms, and the application requirement of efficient industrial production of the functionalized graphene is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of graphene material preparation, and specifically relates to an electrochemical device and method for continuously preparing covalently functionalized graphene (CFG). Background Art

[0002] CFG refers to a two-dimensional graphene-like material in which a large number of non-carbon atoms or organic functional groups are covalently grafted onto or within the carbon plane of graphene. The presence of these functional groups or dopant atoms can endow graphene with a wider range of functionalities, improving its dispersibility in solvents and facilitating its assembly into macroscopic application materials and their effective function. Therefore, CFG is a key material form for graphene applications, and its efficient and controlled preparation holds significant application value.

[0003] The Chinese invention patent application with application number CN202311072987.3, “A universal electrochemical preparation method for covalently functionalized graphene,” proposes a technology that utilizes two-step micro-liquid membrane electrolysis technology to achieve efficient preparation of different types of covalently functionalized graphene. The core of the technology lies in achieving the stable existence of the first-order intercalated graphite electrode through oil sealing technology and by constructing and manipulating the micro-liquid membrane structure for electrolysis. The Chinese invention patent application with application number CN202311202638.9, “A universal electrolytic preparation device for covalently functionalized graphene and its use method,” provides the design and use method of a preparation device for preparing a small amount (single output gram level) of CFG using this technology. Since CFG has important application value in both scientific research and industrial fields, how to use the above-mentioned electrochemical preparation technology to achieve efficient and large-scale preparation of CFG is a key technical problem that needs to be solved urgently. Summary of the Invention

[0004] The purpose of the present invention is to provide an electrochemical device and method for continuously preparing covalently functionalized graphene. The device and method can realize the automatic and continuous preparation of different types of CFG, meeting the application requirements of efficient industrial production of CFG.

[0005] The technical solution of the present invention is:

[0006] An electrochemical device capable of continuously preparing covalently functionalized graphene comprises a mesh belt clamping and conveying mechanism, an electrolytic cell, a CFG collecting and stripping mechanism, a working liquid conveying mechanism, and an electrolytic power supply mechanism. A discharge roller is provided on one side of the mesh belt clamping and conveying mechanism, raw graphite is mounted on the discharge roller, and a discharge roller shield is installed on the discharge roller. A CFG collecting and stripping mechanism is provided on the other side of the mesh belt clamping and conveying mechanism. The mesh belt clamping and conveying mechanism passes through the electrolytic cell. The working liquid conveying mechanism is respectively provided with storage tanks ①, ②, ③, and ④ for providing working liquid 1, working liquid 2, working liquid 3, and working liquid 4 to the electrolytic cell. Storage tanks ①, ②, ③, and ④ are respectively connected to the electrolytic cell via pipelines. A working liquid conveying pump is provided on the pipelines. The raw graphite on the discharge roller passes through the mesh belt clamping and conveying mechanism, the electrolytic cell, and the CFG collecting and stripping mechanism in sequence. The electrolytic cell is powered by the electrolytic power supply mechanism, thereby realizing continuous preparation of CFG.

[0007] The electrochemical device capable of continuously preparing covalently functionalized graphene is characterized in that the mesh belt clamping and conveying mechanism is composed of two groups of conveying mechanisms that are independent of each other, arranged relative to each other up and down, and move in opposite directions. The raw graphite is installed on the discharge roller, and the output end of the raw graphite is relatively provided with a first anode conductive pinch roller and a second anode conductive pinch roller up and down to form a positive electrode conductive roller. The raw graphite is transmitted between the two groups of conveying mechanisms through the first anode conductive pinch roller and the second anode conductive pinch roller, wherein: the first group of conveying mechanisms is composed of a first upper conveyor belt circulating steering roller, a second upper conveyor belt circulating steering roller, a first common steering roller, a second common steering roller and an upper conveyor belt, and the first upper conveyor belt circulating The ring steering roller and the second upper conveyor belt circulation steering roller are respectively the two vertices of the upper bottom of the inverted trapezoid, the first common steering roller and the second common steering roller are respectively the two vertices of the lower bottom of the inverted trapezoid, the upper conveyor belt is sleeved on the first upper conveyor belt circulation steering roller, the second upper conveyor belt circulation steering roller, the first common steering roller and the second common steering roller to form an inverted trapezoid structure, and an upper scraper is arranged on the outer side of the upper conveyor belt corresponding to the first upper conveyor belt circulation steering roller; the second group of conveying mechanisms consists of the first common steering roller, the second common steering roller, the first lower conveyor belt circulation steering roller, the second lower conveyor belt circulation steering roller, the third lower conveyor belt circulation steering roller and the fourth lower conveyor belt circulation steering roller. The lower conveyor belt is composed of a ring steering roller, a fifth lower conveyor belt circulating steering roller and a lower conveyor belt, wherein the first common steering roller, the second common steering roller, the first lower conveyor belt circulating steering roller, the second lower conveyor belt circulating steering roller, the third lower conveyor belt circulating steering roller, the fourth lower conveyor belt circulating steering roller and the fifth lower conveyor belt circulating steering roller are vertices of the heptagon in sequence, and the lower conveyor belt is sequentially sleeved on the first lower conveyor belt circulating steering roller, the second lower conveyor belt circulating steering roller, the third lower conveyor belt circulating steering roller, the fourth lower conveyor belt circulating steering roller and the fifth lower conveyor belt circulating steering roller, and is pressed on the top of the lower conveyor belt through the first common steering roller and the second common steering roller A groove structure is formed on the outside, the first group of conveying mechanisms matches the groove structure, and a lower scraper is set on the outside of the lower conveyor belt corresponding to the second lower conveyor belt circulation steering roller; after the graphite raw material is output through the discharge roller and the first anode conductive pinch roller and the second anode conductive pinch roller, it passes through the upper conveyor belt circulation of the first group of conveying mechanisms and the lower conveyor belt circulation of the second group of conveying mechanisms to form CFG products. The position of the first lower conveyor belt circulation steering roller is higher than that of the second lower conveyor belt circulation steering roller. The CFG product is collected along the slope between the first lower conveyor belt circulation steering roller and the second lower conveyor belt circulation steering roller along the lower conveyor belt and enters the CFG collection and stripping mechanism.

[0008] The electrochemical device capable of continuously preparing covalently functionalized graphene comprises a second upper conveyor belt circulating steering roller and a fifth lower conveyor belt circulating steering roller arranged relative to each other to form a pair of rollers serving as a guide point A, a first common steering roller and a second common steering roller serving as guide point B and guide point C, respectively; a first upper conveyor belt circulating steering roller and a first lower conveyor belt circulating steering roller being arranged relative to each other to form a pair of rollers serving as a guide point D, guide points A and D being the two vertices of the upper base of an inverted trapezoid, and guide points B and C being the two vertices of the lower base of an inverted trapezoid, respectively; the upper conveyor belt and the lower conveyor belt being driven by a motor to perform clockwise and counterclockwise circular motions at the same linear speed, respectively, and forming a clamping area in the area A→B→C→D in which two conveyor belts are parallel to each other.

[0009] The electrochemical device capable of continuously preparing covalently functionalized graphene, when the device starts to operate, the raw graphite is first installed on the unwinding roller, and the unwound graphite paper first passes through the conductive roller clamping area of ​​the first anode conductive roller and the second anode conductive roller to make it conductive with the positive electrode of the power supply, and then is introduced between the rollers of the second upper conveyor belt circulating steering roller and the fifth lower conveyor belt circulating steering roller, and enters the mesh belt clamping area between the upper conveyor belt and the lower conveyor belt, and is driven by the circulating operation of the upper conveyor belt and the lower conveyor belt to form a continuous graphite paper transport and pass through the electrochemical in the electrolytic cell. Chemical reaction zone; when the graphite paper is transported between the rollers of the first upper conveyor belt circulating steering roller and the first lower conveyor belt circulating steering roller, this area of ​​the graphite paper has been converted into graphite oxide; at this time, the graphite oxide sheets will separate from the upper conveyor belt and mainly adhere to the surface of the lower conveyor belt. A small amount of graphite oxide adhering to the upper conveyor belt will be scraped off by the upper scraper and fall on the surface of the lower conveyor belt; the graphite oxide adhering to the lower conveyor belt will be scraped off by the lower scraper when it moves to the second lower conveyor belt circulating steering roller area and collected in the CFG collection and stripping mechanism for subsequent processing.

[0010] The electrochemical device capable of continuously preparing covalently functionalized graphene includes an integrated electrolytic cell comprising: an electrolytic intercalation negative electrode plate, an electrolytic oxidation negative electrode rod, a common steering roller mounting frame, a concentrated sulfuric acid injection pipe, a concentrated sulfuric acid discharge pipe, a functionalized electrolyte injection and discharge pipe, a heavy sealing oil inlet and discharge pipe, an outlet side light sealing oil inlet and discharge pipe, an inlet side light sealing oil inlet and discharge pipe, a concentrated sulfuric acid level pipe, an intercalation reaction zone, an inlet sealed isolation zone, a working liquid isolation zone, an electrochemical oxidation reaction zone, an outlet sealed isolation zone, an inlet hydrogen collection zone, an outlet hydrogen collection zone, a working liquid II, a working liquid IV, a working liquid III, a working liquid I, a hydrogen collection chamber partition, and a hydrogen exhaust port. The specific structure is as follows:

[0011] The inner cavity of the electrolytic cell is a groove-shaped structure with two sides of the horizontal section inclined upward. The upper port on one side of the inner cavity is the electrolytic cell inlet, and the upper port on the other side of the inner cavity is the electrolytic cell outlet. Two common steering roller mounting frames are arranged oppositely at the bottom of the horizontal section of the inner cavity of the electrolytic cell. A first common steering roller is mounted on one common steering roller mounting frame, and a second common steering roller is mounted on the other common steering roller mounting frame.

[0012] The injection procedure of the four working liquids into the electrolytic cell is as follows: (1) when the electrolytic cell is completely empty, first inject working liquid 2 into the electrolytic cell to fill the intercalation reaction zone; (2) inject working liquid 1 into the inlet area of ​​the electrolytic cell to fill the inlet sealed isolation zone; at the same time, inject working liquid 4 into the outlet area of ​​the electrolytic cell to fill the working liquid isolation zone; (3) inject working liquid 3 into the outlet area of ​​the electrolytic cell to fill the electrochemical oxidation reaction zone; (4) inject working liquid 1 into the outlet area of ​​the electrolytic cell to fill the outlet sealed isolation zone;

[0013] The injection ports of different working liquids are all arranged at the contact interface of the two working liquids and are connected to the working liquid delivery pump through pipelines. The pipelines include: a concentrated sulfuric acid injection pipe, a concentrated sulfuric acid discharge pipe, a functionalized electrolyte injection and discharge pipe, a heavy sealing oil inlet and discharge pipe, an outlet side light sealing oil inlet and discharge pipe, and an inlet side light sealing oil inlet and discharge pipe. The concentrated sulfuric acid injection pipe is connected to the top of the intercalation reaction zone, the concentrated sulfuric acid discharge pipe is connected to the bottom of the intercalation reaction zone, the functionalized electrolyte injection and discharge pipe is connected to the electrochemical oxidation reaction zone, the heavy sealing oil inlet and discharge pipe is connected to the working liquid isolation zone, the outlet side light sealing oil inlet and discharge pipe is connected to the outlet sealed isolation zone, and the inlet side light sealing oil inlet and discharge pipe is connected to the inlet sealed isolation zone.

[0014] A concentrated sulfuric acid level tube is provided at the top of the intercalation reaction zone, an inlet hydrogen collection zone is provided at the inlet of the electrolyzer, and an outlet hydrogen collection zone is provided at the outlet area of ​​the electrolyzer to collect hydrogen gas generated during the electrochemical reaction and discharge or recycle it in a centralized manner to avoid safety risks caused by hydrogen escaping into the working environment; the outlet sealed isolation zone and the outlet hydrogen collection zone are surrounded by a vertical hydrogen collection bin partition in the inner cavity of the electrolyzer outlet area and an upwardly inclined tank body top wall of the electrolyzer outlet area; the outlet hydrogen collection zone is located above the outlet sealed isolation zone, and a hydrogen exhaust port is provided on the upwardly inclined tank body top wall of the electrolyzer outlet area; the working liquid 1 in the outlet sealed isolation zone is located on top of the working liquid 3, and the electrolytic oxidation negative electrode rod is inserted into the working liquid 1 in the outlet sealed isolation zone and is located between the working liquid 3;

[0015] After the power is turned on, the graphite paper electrode enters the above-mentioned electrolytic cell under the drive of the mesh belt clamping and conveying mechanism, and passes through the inlet sealed isolation area filled with working liquid 1, the intercalation reaction area filled with working liquid 2, the working liquid isolation area filled with working liquid 4, the electrochemical oxidation reaction area filled with working liquid 3, and finally leaves the electrolytic cell from the outlet; in this process, the raw graphite in the clamping state of the mesh belt clamping structure on the graphite electrode inlet side is first converted into intercalation graphite by the mesh belt clamping structure in the middle stage of the graphite electrode electrolysis reaction , and then converted into graphite oxide at the mesh belt clamping structure on the CFG product outlet side; wherein, the mesh belt clamping structure on the graphite electrode inlet side is for clamping the raw graphite between the upper conveyor belt and the lower conveyor belt, and the mesh belt clamping structure in the intermediate stage of the graphite electrode electrolysis reaction is for clamping the raw graphite between the upper conveyor belt and the lower conveyor belt, and converting it into intercalation graphite in the intercalation reaction zone, and the mesh belt clamping structure on the CFG product outlet side is for clamping the intercalation graphite between the upper conveyor belt and the lower conveyor belt, and converting it into graphite oxide in the electrochemical oxidation reaction zone.

[0016] The electrochemical device capable of continuously preparing covalently functionalized graphene comprises an electrolysis power supply mechanism comprising an electrochemical intercalation power supply, an electrochemical oxidation power supply, and an equipment operation power supply. The electrochemical intercalation power supply and the electrochemical oxidation power supply are both independent low-voltage DC power supplies that regulate output voltage or current and operate for a long time in a constant voltage or constant current mode. The voltage regulation range of the electrochemical intercalation power supply is 0-10V, and the current regulation range is 0-100A; the voltage regulation range of the electrochemical oxidation power supply is 0-20V, and the current regulation range is 0-500A. The equipment operation power supply is a conventional voltage-regulated power supply that provides operating power for various electrical devices in the device.

[0017] The electrochemical device capable of continuously preparing covalently functionalized graphene comprises an electrochemical intercalation power supply and an electrochemical oxidation power supply sharing a common positive electrode and conducting with the raw graphite via a conductive roller to achieve an electrochemical reaction. The electrochemical intercalation power supply and the electrochemical oxidation power supply are both DC constant voltage power supplies. After the positive electrodes of the two power supplies are directly connected, a positive conductive roller formed by a first anode conductive roller and a second anode conductive roller is connected to the raw graphite. The negative electrode of the electrochemical intercalation power supply is connected to the electrolytic intercalation negative electrode plate, and the negative electrode of the electrochemical oxidation power supply is connected to the electrolytic oxidation negative electrode rod. The electrochemical intercalation electrodes are distributed in the electrolytic cell region immersed in the intercalation agent, and the electrochemical oxidation electrodes are distributed in the electrolytic cell region immersed in the functionalized electrolyte.

[0018] To achieve an electrochemical intercalation reaction, two or more electrolytic intercalation negative electrode plates are installed on the inner side of the top wall of the electrolytic cell's intercalation reaction zone. All of the electrolytic intercalation negative electrode plates are electrically connected to the negative electrode of the electrochemical intercalation power supply, forming a conductive circuit consisting of the positive electrode of the electrochemical intercalation power supply - graphite paper - concentrated sulfuric acid - electrolytic intercalation negative electrode plates - the negative electrode of the electrochemical intercalation power supply. In operation, when the raw graphite enters the intercalation reaction zone filled with concentrated sulfuric acid with a clamping mechanism, an electrochemical intercalation reaction begins in the immersed portion, gradually converting the graphite paper into sulfuric acid-intercalated graphite paper. When the intercalated graphite paper leaves the intercalation reaction zone with the clamping mechanism and enters the working liquid isolation zone, the electrochemical intercalation reaction ceases for the intercalated graphite paper immersed in the working liquid.

[0019] In order to achieve electrochemical oxidation reaction, an electrolytic oxidation negative electrode rod is inserted into the electrochemical oxidation reaction zone, and the electrolytic oxidation negative electrode rod is connected to the negative electrode of the electrochemical oxidation power supply, forming a conductive circuit of the electrochemical oxidation power supply positive electrode - graphite paper - intercalated graphite paper - dilute sulfuric acid - electrolytic oxidation negative electrode rod - negative electrode of the electrochemical oxidation power supply; under working conditions, after the intercalated graphite paper enters the electrochemical oxidation reaction zone filled with dilute sulfuric acid with the clamping mechanism, the immersed part begins to undergo electrochemical oxidation reaction, gradually converting the intercalated graphite paper into oxidized graphite paper; when the oxidized graphite paper leaves the electrochemical oxidation reaction zone with the clamping mechanism, the oxidized graphite paper that leaves the reaction zone is the product of this step, which is collected and used for exfoliation to prepare GO.

[0020] The electrochemical device capable of continuously preparing covalently functionalized graphene comprises a CFG collection and stripping mechanism including a scraper, a material collection tank, and a shear disperser. After the raw graphite is converted into graphite oxide through a reaction in the electrolytic cell, it is continuously conveyed to the opening of the material collection tank by a mesh belt clamping conveyor mechanism. The raw graphite is scraped off the surface of the conveyor belt by a scraper and falls into the material collection tank. The scraper is used to scrape the raw graphite from the conveyor belt surface and the graphite falls into the material collection tank. The raw graphite is mixed with pure water in the material collection tank and crushed and stripped by a shear disperser to form a dispersion liquid with a fineness that meets the standard. The dispersion liquid is then discharged from the bottom of the material collection tank. The dispersion liquid is purified by conventional processes to obtain a GO aqueous dispersion product.

[0021] An electrochemical method for continuously preparing covalently functionalized graphene uses continuous flexible graphite paper coils or carbon fiber wires as raw materials. The method performs an electrochemical oxidation reaction in an integrated electrolytic cell while being clamped by a mesh belt clamping and conveying mechanism, continuously converting the graphite paper or carbon fiber into sheets or wires composed of CFG. CFG aggregates attached to the mesh belt surface are scraped off by a scraper and collected in a stripping tank. A solvent is added to shear the stripped product and washed to obtain a CFG dispersion.

[0022] In the electrochemical method for continuously preparing covalently functionalized graphene, at least one side of the upper and lower conveyor belts used in the mesh belt clamping conveyor mechanism must have a large number of holes to facilitate the electrolyte to pass through the holes and combine with the raw graphite to achieve an electrochemical reaction. The porosity of the upper and lower conveyor belts with the hole structure should be no less than 30%. The two sets of conveying mechanisms form a circular motion loop through a roller mechanism to meet the requirements of continuously conveying the raw graphite. The operating linear speed of the circular motion loop is adjustable within an adjustment range of 1 mm / min to 1 m / s.

[0023] The design idea of ​​the present invention is:

[0024] Utilizing the differences in solubility and density between different working liquids, distinct electrochemical reaction zones are created within an electrolytic cell. While maintaining a relatively constant reaction zone, a continuous stream of graphite feedstock, electrically connected to the positive electrode of the electrolytic power source, is conveyed by a mesh belt conveyor mechanism through an inlet at the top side of the electrolytic cell. The feedstock first passes through an oil seal composed of light sealing oil, which isolates the intercalant from air and prevents airborne water and oxygen from affecting its properties. The feedstock then enters the electrochemical intercalation reaction zone composed of liquid intercalant, where the feedstock undergoes an electrochemical intercalation reaction, gradually and continuously converting it into intercalated graphite. The intercalated graphite then passes through a working liquid isolation zone composed of heavy sealing oil, which separates the liquid intercalant from the functionalized electrolyte, preventing fusion between the two. The intercalated graphite remains unreactive during this passage. After this, the intercalated graphite will enter the functionalized reaction zone composed of functional electrolyte, where an electrochemical functionalization reaction will occur, gradually and continuously being converted into CFG. Subsequently, the CFG that has completed the two-step electrochemical reaction leaves the functionalized reaction zone under the drive of the conveying mechanism and leaves the electrolytic cell from the outlet on the other side of the top of the electrolytic cell. The CFG generated in this way is transported by the transmission mechanism to the CFG collection and stripping mechanism, where the CFG product is scraped off by a scraper and collected in a tank. A solvent is added for mechanical stripping, and then after washing and concentration, a CFG dispersion product can be obtained. After drying, a CFG solid product can be obtained.

[0025] The core technology of the above-mentioned preparation process lies in the integrated electrolytic cell, its mesh belt clamping and conveying mechanism, the electrolytic power supply mechanism, and the working liquid delivery mechanism, as well as the coordination between these mechanisms. Its main feature is that the electrolytic cell and the electrolyte within it remain essentially stationary during the preparation process, while the continuous graphite feedstock is continuously converted into CFG under the drive of the delivery mechanism, thereby achieving continuous and automated production of CFG. The innovations of the present invention are mainly reflected in the structural design of the double-opening integrated electrolytic reaction cell, the coordination design of the integrated electrolytic cell and the mesh belt clamping and conveying mechanism, the technical solution of two sets of electrolytic power supplies sharing a graphite anode to form two independent electrochemical reaction systems, and the sealing strategy of using lightweight sealing oil to isolate the intercalant from contact with air and prevent it from absorbing moisture and deteriorating. The basic design of the continuous preparation device provided by the present invention can effectively integrate the above-mentioned innovations to achieve continuous and automated production of CFG. Therefore, it is a major technical improvement in CFG electrochemical preparation technology for industrial production, combining innovation and practicality, and is expected to promote the rapid development of the CFG preparation and application industry.

[0026] The advantages and beneficial effects of the present invention are as follows:

[0027] By using the device and method of the present invention, efficient and continuous preparation of different types of CFG can be achieved, and the product purity is high and the by-products are few. The production process can be automatically controlled, the reaction process does not require human intervention, is simple and easy to use, and the properties of the product are stable, which can meet the application requirements of industrial batch preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1-2 . The overall structural model diagram of the CFG continuous electrolytic preparation device in Example 1. Figure 1 For the front view, Figure 2 This is a three-dimensional view of the back structure model.

[0029] Figure 3-4 .Structural model diagram of the raw material graphite mesh belt clamping and conveying mechanism (excluding the bracket) of the CFG continuous electrolytic preparation device in Example 1. Figure 3 This is the combined diagram of the mesh belt clamping transmission mechanism. Figure 4 For its decomposition diagram.

[0030] Figure 5 .Structural model diagram of the integrated electrolytic cell (excluding the bracket) of the CFG continuous electrolytic preparation device in Example 1.

[0031] Figure 6 .Structural model diagram of the multilayer liquid membrane reaction zone of the CFG continuous electrolysis preparation device in Example 1.

[0032] Figure 7 .Schematic diagram of the power supply connection method of the CFG continuous electrolysis preparation device in Example 1.

[0033] Figure 8 .Schematic diagram of the "V"-shaped integrated electrolytic cell structure used in the CFG continuous electrolytic preparation device in Example 2.

[0034] Figure 9 .Schematic diagram of the "U"-shaped integrated electrolytic cell structure used in the CFG continuous electrolytic preparation device in Example 3.

[0035] Attachment Figure 1-7 The numbers in the figure refer to the following mechanisms: 1-mesh belt clamping and conveying mechanism; 2-electrolytic cell; 3-CFG collecting and stripping mechanism; 4-working liquid conveying mechanism; 5-electrolysis power supply mechanism; 6-first upper conveyor belt circulating steering roller; 7-second upper conveyor belt circulating steering roller; 8-first common steering roller; 9-second common steering roller; 10-first lower conveyor belt circulating steering roller; 11-second lower conveyor belt circulating steering roller; 12-third lower conveyor belt circulating steering roller; 13-Fourth lower conveyor belt circulating steering roller; 14-Fifth lower conveyor belt circulating steering roller; 15-First anode conductive pinch roller; 16-Second anode conductive pinch roller; 17-Unloading roller; 18-Unloading roller guard; 19-Upper conveyor belt; 20-Lower conveyor belt; 21-Upper scraper; 22-Lower scraper; 23-Raw graphite (coil or wire); 24-Electrolytic intercalation negative electrode plate; 25-Electrolytic oxidation negative electrode rod; 26-Common steering roller mounting frame; 27-Concentrated Sulfuric acid injection pipe; 28-concentrated sulfuric acid discharge pipe; 29-functionalized electrolyte injection and discharge pipe; 30-heavy sealing oil inlet and discharge pipe; 31-outlet light sealing oil inlet and discharge pipe; 32-inlet light sealing oil inlet and discharge pipe; 33-concentrated sulfuric acid level pipe (exhaust pipe); 34-graphite electrode inlet side mesh belt clamping structure; 35-graphite electrode electrolysis reaction intermediate stage mesh belt clamping structure; 36-CFG product outlet side mesh belt clamping structure; 37-intercalation reaction zone; 38-inlet Inlet sealing isolation area; 39-working liquid isolation area; 40-electrochemical oxidation reaction area; 41-export sealing isolation area; 42-inlet hydrogen collection area; 43-export hydrogen collection area; 44-working liquid 2; 45-working liquid 4; 46-working liquid 3; 47-working liquid 1; 48-hydrogen collection chamber partition; 49-hydrogen exhaust port; 50-CFG product; 51-power supply for electrochemical intercalation; 52-power supply for electrochemical oxidation; 53-positive electrode conductive roller. DETAILED DESCRIPTION

[0036] In practice, the present invention proposes an electrochemical device and method for the continuous production of CFG. This method uses continuous flexible graphite paper coils or carbon fiber wires as raw materials. Under the grip of a conveyor mesh belt, an integrated electrolytic cell undergoes an electrochemical oxidation reaction, continuously converting the graphite paper or carbon fiber into sheets or wires composed of CFG. CFG aggregates adhering to the mesh belt surface are scraped off by a scraper and collected in a stripping tank. After adding a solvent, shearing, stripping, and cleaning, a CFG dispersion is obtained. The device primarily comprises five components: a mesh belt clamping and conveying mechanism, an electrolytic cell, an electrolytic power supply, a working liquid delivery mechanism, and a CFG collection and stripping mechanism. The combination of these components enables the automated and continuous production of different types of CFG.

[0037] Among them, the raw graphite used for the continuous preparation of CFG includes but is not limited to flexible graphite paper coils, carbon fiber wires, artificial graphite film coils and other graphite materials. Its key feature is that the material form is continuous on a certain scale, such as length; and it has good mechanical strength and flexibility, and can be delivered in a roll-to-roll manner; at the same time, the material must also have good electrical conductivity, and its electrical conductivity must be ≥100S / m.

[0038] A mesh belt clamping conveyor mechanism is composed of two independent conveyor mechanisms. Within a specific conveying range, the two conveyor belts are aligned parallel to each other, with no relative motion between them. Using this conveyor mechanism, raw graphite (coils or wires) is clamped between the two conveyor belts and pulled from one end of the conveying area to the other, thereby transporting the raw graphite.

[0039] A key feature of the mesh belt clamping conveyor mechanism is that at least one side of the upper and lower conveyor belts must have a large number of holes to facilitate the electrolyte's penetration and combination with the raw graphite to achieve an electrochemical reaction. The porosity of the upper and lower conveyor belts with these holes should be no less than 30%. The two conveyor belts can form a circular motion loop through a roller mechanism, ensuring continuous conveyance of the raw graphite. The linear speed of the circular motion loop is adjustable from 1 mm / min to 1 m / s, with a preferred range of 10 mm / min to 200 mm / min.

[0040] The core feature of the electrolytic cell is that the same electrolytic cell has two separate openings. The raw graphite enters the electrolytic cell from one opening (inlet) under the traction of the mesh belt clamping conveyor mechanism and passes through a series of working liquid layers in the electrolytic cell and is sent out of the electrolytic cell from the other opening (outlet). The electrochemical oxidation treatment of the raw graphite is completed to obtain CFG products.

[0041] An important feature of the electrolytic cell is that, except for the inlet and outlet, all other areas of the electrolytic cell are sealed structures that are not in direct contact with the external air environment. In addition, when placed horizontally, the lowest areas of the inlet and outlet are significantly higher than the other sealed structures of the electrolytic cell, to ensure that after the working liquid is added to the electrolytic cell, the internal space of the electrolytic cell can be completely filled with the working liquid, and the working liquid will not overflow the electrolytic cell through the inlet and outlet.

[0042] An important feature of the electrolytic cell is that at least four working liquids are added to the electrolytic cell, including light sealing oil (working liquid one), intercalating agent (working liquid two), functionalized electrolyte (working liquid three) and heavy sealing oil (working liquid four), and these four working liquids can form a stable and mutually immiscible multilayer liquid film structure due to differences in density and solubility; after the raw graphite enters the electrolytic cell under the traction of the mesh belt clamping and conveying mechanism, it can pass through the imported light sealing oil layer, intercalating agent layer, heavy sealing oil layer, functionalized electrolyte layer in sequence, and finally be sent out of the electrolytic cell; in the above process, the raw graphite completes the electrochemical intercalation reaction in the intercalating agent layer, and completes the electrochemical oxidation reaction in the functionalized electrolyte layer to generate CFG.

[0043] The important feature of the electrolytic cell is that the entire electrolytic cell must be made of non-conductive inert materials, including but not limited to polymer materials, glass (including quartz glass, etc.), ceramics, etc. In addition, the electrochemical reaction electrodes must be integrated in the electrolytic cell, including electrodes for electrochemical intercalation and electrodes for electrochemical oxidation; wherein, the electrodes for electrochemical intercalation are mainly distributed in the electrolytic cell area immersed in the intercalation agent, and the electrodes for electrochemical oxidation are mainly distributed in the electrolytic cell area immersed in the functionalized electrolyte; the electrodes for electrochemical intercalation are connected to the positive or negative electrode of the electrochemical intercalation power supply, and the electrodes for electrochemical oxidation are connected to the positive or negative electrode of the electrochemical oxidation power supply. In order to ensure the formation of a multi-layer liquid film structure inside the electrolytic cell and facilitate the regulation of the thickness of different liquid film layers, working liquid inlet / drain ports and working liquid delivery mechanism pipelines must be set in different areas of the electrolytic cell wall; on this basis, different working liquids are injected into the electrolytic cell through a certain working liquid injection procedure to form a multi-layer liquid film structure. Hydrogen collection areas can be set up at the two outlet areas of the electrolyzer to collect the hydrogen gas generated during the electrochemical reaction and discharge or recycle it in a centralized manner to avoid safety risks caused by hydrogen escaping into the working environment.

[0044] The working liquid injection procedure is as follows: (1) when the electrolytic cell is completely empty, first inject the intercalant into the electrolytic cell to the set liquid level; (2) inject a light sealing oil layer into the inlet area to the set liquid level, and at the same time inject a heavy sealing oil layer into the outlet area to the set liquid level; (3) inject the functionalized electrolyte into the outlet area to the set liquid level; (4) inject the light sealing oil into the hydrogen collection area of ​​the outlet area to the set liquid level. When the device of the present invention is in continuous operation, each working liquid will be consumed at a certain rate, so it is necessary to monitor the liquid level changes of each working liquid. When the liquid level drops to or exceeds 5%, the working liquid needs to be replenished in time. When the device of the present invention is stopped for a long time or for maintenance, the working liquid in the electrolytic cell needs to be discharged in sequence. The discharge order is opposite to the injection order, that is, (1) discharge the light sealing oil in the hydrogen collection area of ​​the outlet area; (2) discharge the functionalized electrolyte in the outlet area; (3) discharge the light sealing oil in the inlet area and the heavy sealing oil in the outlet area; (4) discharge the intercalant until the electrolytic cell is completely empty. In order to ensure the effective implementation of the above-mentioned sequential injection procedure, a liquid level monitoring sensor needs to be integrated on the outer wall of the electrolytic cell, and the working liquid delivery mechanism is controlled by the host computer to automatically complete the injection and discharge process of the working liquid.

[0045] The CFG collection and stripping mechanism primarily consists of a scraper, a material collection tank, and a shear disperser. After the raw graphite is converted into CFG through the reaction in the electrolytic cell, it is continuously conveyed to the opening of the material collection tank by a mesh belt clamping conveyor mechanism. The scraper then scrapes the raw graphite from the mesh belt surface and drops it into the material collection tank. It is then mixed with the stripping liquid in the material collection tank and crushed and stripped by the shear disperser, forming a dispersion that meets the fineness requirements and is discharged from the bottom of the material collection tank. After the dispersion is purified using conventional processes, the CFG dispersion product is obtained.

[0046] The working liquid delivery mechanism mainly includes storage tanks for the four working liquids for the electrolytic cell and the stripping liquid in the collection tank, a working liquid delivery pump and a delivery pipeline, which are respectively connected to the corresponding liquid inlets of the electrolytic cell and the collection tank to meet the process requirements of automatic liquid injection, liquid replenishment and liquid discharge of each working liquid in production.

[0047] The electrolysis power supply mechanism primarily consists of three components: the electrochemical intercalation power supply, the electrochemical oxidation power supply, and the equipment operating power supply. Both the electrochemical intercalation power supply and the electrochemical oxidation power supply are independent low-voltage DC power supplies with adjustable output voltage or current, allowing long-term operation in constant voltage or constant current mode. The electrochemical intercalation power supply has a voltage control range of 0-10V and a current control range of 0-100A; the electrochemical oxidation power supply has a voltage control range of 0-20V and a current control range of 0-500A. The equipment operating power supply is a conventional regulated power supply, providing operating power for the device's various electrical components.

[0048] The important feature of the electrolytic power supply mechanism is that the power supply for electrochemical intercalation and the power supply for electrochemical oxidation share a common positive electrode and are connected to the raw graphite coil or wire through a conductive roller to achieve electrochemical reaction.

[0049] The above-mentioned preparation process and the main features of the apparatus required for implementing the preparation will be described in detail below through specific embodiments and drawings.

[0050] Example 1

[0051] In this embodiment, a graphene oxide (GO) dispersion is prepared using a flexible graphite paper roll with good electrical conductivity as a raw material.

[0052] like Figure 1-Figure 2 As shown, the device scheme proposed by the present invention for realizing the preparation process mainly includes five parts, specifically: a mesh belt clamping and conveying mechanism 1, an electrolytic cell 2, a CFG collecting and stripping mechanism 3, a working liquid conveying mechanism 4, and an electrolytic power supply mechanism 5. A discharge roller 17 is set on one side of the mesh belt clamping and conveying mechanism 1, and the raw graphite 23 (coil or wire) is installed on the discharge roller 17. A discharge roller shield 18 is installed on the discharge roller 17. A CFG collecting and stripping mechanism 3 is set on the other side of the mesh belt clamping and conveying mechanism 1. The mesh belt clamping and conveying mechanism 1 is passed through the electrolytic cell. Tank 2, the working liquid delivery mechanism 4 is respectively provided with storage tanks ①, ②, ③, and ④ for providing working liquid 1 47, working liquid 2 44, working liquid 3 46, and working liquid 4 45 to the electrolytic cell 2. Storage tanks ①, ②, ③, and ④ are respectively connected to the electrolytic cell 2 through pipelines, and a working liquid delivery pump is provided on the pipeline. The raw graphite 23 on the discharge roller 17 is sequentially passed through the mesh belt clamping and conveying mechanism 1, the electrolytic cell 2, and the CFG collection and stripping mechanism 3. The electrolytic cell 2 is powered by the electrolysis power supply mechanism 5 to achieve continuous preparation of CFG.

[0053] The raw material graphite used in the preparation process is flexible graphite paper roll, which has a thickness of 0.5mm, a width of 40cm, a single roll length of 50m, and a density of 1.6g / cm 3 , the volume conductivity is 550S / cm.

[0054] In order to achieve electrochemical oxidation of the graphite paper coil to completely convert it into graphite oxide and ultimately into a graphene oxide dispersion product, it is necessary to utilize a mesh belt clamping conveying mechanism 1 to continuously transport it to the electrolytic cell 2 at a linear speed of 5 mm / min to carry out the two-step reaction of electrochemical intercalation and electrochemical oxidation in sequence.

[0055] like Figure 3-Figure 4As shown, the schematic diagram of the structure of the mesh belt clamping and conveying mechanism when it is working, and the schematic diagram of its structural decomposition and working principle. The mesh belt clamping and conveying mechanism is composed of two groups of conveying mechanisms that are independent of each other, arranged relative to each other up and down and move in opposite directions. The raw graphite 23 is installed on the discharge roller 17. The output end of the raw graphite 23 is relatively arranged with the first anode conductive clamping roller 15 and the second anode conductive clamping roller 16 up and down to form a positive conductive roller 53. The raw graphite 23 is transmitted between the two groups of conveying mechanisms through the first anode conductive clamping roller 15 and the second anode conductive clamping roller 16, wherein: the first group of conveying mechanisms is composed of the first upper conveyor belt circulating steering roller 6, the second upper conveyor belt circulating steering roller 7, the first common steering roller 8, the second common steering roller 9 and the upper conveyor belt 19, and the first upper conveyor belt circulating steering roller 6 and the second upper conveyor belt circulating steering roller 7 are respectively The first common steering roller 8 and the second common steering roller 9 are the two vertices of the lower base of the inverted trapezoid, respectively. The upper conveyor belt 19 is sleeved on the first upper conveyor belt circulating steering roller 6, the second upper conveyor belt circulating steering roller 7, the first common steering roller 8, and the second common steering roller 9 to form an inverted trapezoid structure. An upper scraper 21 is arranged on the outer side of the upper conveyor belt 19 corresponding to the first upper conveyor belt circulating steering roller 6; the second group of conveying mechanisms consists of the first common steering roller 8, the second common steering roller 9, the first lower conveyor belt circulating steering roller 10, the second lower conveyor belt circulating steering roller 11, the third lower conveyor belt circulating steering roller 12, the fourth lower conveyor belt circulating steering roller 13, and the fifth lower conveyor belt circulating steering roller 14 and the lower conveyor belt 20, the first common steering roller 8, the second common steering roller 9, the first lower conveyor belt circulating steering roller 10, the second lower conveyor belt circulating steering roller 11, the third lower conveyor belt circulating steering roller 12, the fourth lower conveyor belt circulating steering roller 13, and the fifth lower conveyor belt circulating steering roller 14 are the vertices of the heptagon in sequence, and the lower conveyor belt 20 is sequentially sleeved on the first lower conveyor belt circulating steering roller 10, the second lower conveyor belt circulating steering roller 11, the third lower conveyor belt circulating steering roller 12, the fourth lower conveyor belt circulating steering roller 13, and the fifth lower conveyor belt circulating steering roller 14, and is pressed on the outer side of the top of the lower conveyor belt 20 by the first common steering roller 8 and the second common steering roller 9 to form a groove Structure, the first group of conveying mechanisms matches the groove structure, and a lower scraper plate 22 is set on the outer side of the lower conveyor belt 20 corresponding to the second lower conveyor belt circulation steering roller 11; after the graphite raw material is output through the discharge roller 17 and the first anode conductive clamping roller 15 and the second anode conductive clamping roller 16, it passes through the upper conveyor belt circulation of the first group of conveying mechanisms and the lower conveyor belt circulation of the second group of conveying mechanisms to form a CFG product 50, the position of the first lower conveyor belt circulation steering roller 10 is higher than the second lower conveyor belt circulation steering roller 11, the CFG product 50 is collected along the lower conveyor belt 20 on the inclined surface between the first lower conveyor belt circulation steering roller 10 and the second lower conveyor belt circulation steering roller 11, and enters the CFG collection and stripping mechanism 3.

[0056] The second upper conveyor belt circulating steering roller 7 and the fifth lower conveyor belt circulating steering roller 14 are arranged relative to each other to form a pair of rollers as guide point A, the first common steering roller 8 and the second common steering roller 9 are respectively used as guide point B and guide point C, the first upper conveyor belt circulating steering roller 6 and the first lower conveyor belt circulating steering roller 10 are relatively arranged to form a pair of rollers as guide point D, guide point A and guide point D are respectively the two vertices of the upper base of the inverted trapezoid, and guide point B and guide point C are respectively the two vertices of the lower base of the inverted trapezoid, the upper conveyor belt 19 and the lower conveyor belt 20 are driven by the motor to perform clockwise and counterclockwise circulation motions at the same linear speed, and form a clamping area in the area A→B→C→D where the two conveyor belts are parallel to each other.

[0057] In this embodiment, when the electrochemical device capable of continuously preparing CFG starts to operate, the raw graphite 23 (graphite paper roll) is first installed on the unwinding roller 17, and the unwound graphite paper first passes through the conductive roller clamping area (the first anode conductive clamping roller 15 and the second anode conductive clamping roller 16) to make it conductive with the positive pole of the power supply, and then is introduced between the rollers (the second upper conveyor belt circulating turning roller 7 and the fifth lower conveyor belt circulating turning roller 14), enters the mesh belt clamping area between the upper conveyor belt 19 and the lower conveyor belt 20, and is driven by the circulating operation of the upper conveyor belt 19 and the lower conveyor belt 20 to form a continuous graphite paper transport and pass through the electrochemical reaction zone in the electrolytic cell. When the graphite paper is transported between the pair of rollers (the first upper conveyor belt circulating turning roller 6 and the first lower conveyor belt circulating turning roller 10), this area of ​​the graphite paper has been converted into graphite oxide; at this time, the graphite oxide sheets will separate from the upper conveyor belt 19 and mainly adhere to the surface of the lower conveyor belt 20. A small amount of graphite oxide adhering to the upper conveyor belt 19 can be scraped off by the upper scraper plate 21 and fall on the surface of the lower conveyor belt 20; the graphite oxide attached to the lower conveyor belt 20 will be scraped off by the lower scraper plate 22 when it moves to the area of ​​the second lower conveyor belt circulating turning roller 11 and collected in the CFG collection and stripping mechanism 3 for subsequent processing.

[0058] The upper and lower conveyor belts 19 and 20 of the mesh belt clamping and conveying mechanism are made of polytetrafluoroethylene. The upper conveyor belt 19 is a porous mesh belt with a porosity of 60%, while the lower conveyor belt 20 is a non-porous belt. The inverted trapezoidal edges of the parallel clamping zones A→B→C→D, formed by the reversing rollers, are designed to accommodate the structure and inlet and outlet configurations of the integrated electrolytic cell.

[0059] like Figure 5-Figure 6As shown, the integrated electrolytic cell 2 mainly includes: an electrolytic intercalation negative electrode plate 24, an electrolytic oxidation negative electrode rod 25, a common steering roller mounting frame 26, a concentrated sulfuric acid injection pipe 27, a concentrated sulfuric acid discharge pipe 28, a functionalized electrolyte injection and discharge pipe 29, a heavy sealing oil inlet and discharge pipe 30, an outlet side light sealing oil inlet and discharge pipe 31, an inlet side light sealing oil inlet and discharge pipe 32, a concentrated sulfuric acid level pipe 33 (exhaust pipe), an intercalation reaction zone 37, an inlet sealed isolation zone 38, a working liquid isolation zone 39, an electrochemical oxidation reaction zone 40, an outlet sealed isolation zone 41, an inlet hydrogen collection zone 42, an outlet hydrogen collection zone 43, a working liquid 2 44, a working liquid 45, a working liquid 3 46, a working liquid 1 47, a hydrogen collection bin partition 48, and a hydrogen exhaust port 49. The specific structure is as follows:

[0060] The inner cavity of the electrolytic cell 2 is a groove-shaped structure with upward inclinations on both sides of the horizontal section. The upper port on one side of the inner cavity is the electrolytic cell inlet, and the upper port on one side of the inner cavity is the electrolytic cell outlet; two common steering roller mounting frames 26 are relatively arranged at the bottom of the horizontal section of the inner cavity of the electrolytic cell 2, and the first common steering roller 8 is installed on one common steering roller mounting frame 26, and the second common steering roller 9 is installed on the other common steering roller mounting frame 26.

[0061] The main body of the electrolytic cell 2 is made of polypropylene (PP) plastic. Except for the inlet and outlet, other areas of the electrolytic cell are sealed structures that are not in direct contact with the external air environment. When placed horizontally, the lowest areas of the inlet and outlet are significantly higher than other sealed structures of the electrolytic cell to ensure that after the working liquid is added to the electrolytic cell, the internal space of the electrolytic cell can be completely filled with the working liquid, and the working liquid will not overflow the electrolytic cell through the inlet and outlet.

[0062] In order to complete the two-step electrochemical reaction of electrochemical intercalation and electrochemical oxidation in the same electrolytic cell, it is necessary to use four working liquids in a certain order of addition to construct multiple liquid layer structures in the electrolytic cell. In this embodiment, four working liquids are used, among which: working liquid 47 (light sealing oil), petroleum ether 120 (density 0.82g / cm 3 ); working liquid 244 (intercalant), 98wt% concentrated sulfuric acid (density 1.84g / cm 3 ); Working liquid 3 46 (functionalized electrolyte), using 30wt% dilute sulfuric acid (density 1.11g / cm 3 ); Working liquid 45 (heavy sealing oil), fluorinated liquid DA-310 (density 1.70g / cm 3 ).

[0063] The injection procedure of the above four working liquids into the electrolytic cell is as follows: (1) when the electrolytic cell is completely empty, first inject working liquid 2 44 into the electrolytic cell 2 to fill the intercalation reaction zone 37; (2) inject working liquid 1 47 into the inlet area of ​​the electrolytic cell 2 to fill the inlet sealed isolation zone 38; at the same time, inject working liquid 4 45 into the outlet area of ​​the electrolytic cell 2 to fill the working liquid isolation zone 39; (3) inject working liquid 3 46 into the outlet area of ​​the electrolytic cell 2 to fill the electrochemical oxidation reaction zone 40; (4) inject working liquid 1 47 into the outlet area of ​​the electrolytic cell 2 to fill the outlet sealed isolation zone 41. In order to achieve an ideal working liquid injection effect, the injection ports of different working liquids are all arranged at the contact interface of the two working liquids and are connected to the working liquid delivery pump through pipelines. The pipelines include: a concentrated sulfuric acid injection pipe 27, a concentrated sulfuric acid discharge pipe 28, a functionalized electrolyte injection and discharge pipe 29, a heavy sealing oil inlet and discharge pipe 30, an outlet side light sealing oil inlet and discharge pipe 31, and an inlet side light sealing oil inlet and discharge pipe 32. The concentrated sulfuric acid injection pipe 27 is connected to the top of the intercalation reaction zone 37, the concentrated sulfuric acid discharge pipe 28 is connected to the bottom of the intercalation reaction zone 37, the functionalized electrolyte injection and discharge pipe 29 is connected to the electrochemical oxidation reaction zone 40, the heavy sealing oil inlet and discharge pipe 30 is connected to the working liquid isolation zone 39, the outlet side light sealing oil inlet and discharge pipe 31 is connected to the outlet sealed isolation zone 41, and the inlet side light sealing oil inlet and discharge pipe 32 is connected to the inlet sealed isolation zone 38. In order to facilitate observation of the liquid level of concentrated sulfuric acid and discharge the hydrogen generated on the electrolytic intercalation negative electrode plate 24 during the intercalation reaction, a concentrated sulfuric acid liquid level pipe 33 (exhaust pipe) is provided at the top of the intercalation reaction zone 37; at the same time, an inlet hydrogen collection area 42 can be provided at the inlet of the electrolytic cell 2, and an outlet hydrogen collection area 43 can be provided at the outlet area of ​​the electrolytic cell 2 to collect the hydrogen gas generated during the electrochemical reaction and discharge or recover it in a centralized manner to avoid safety risks caused by hydrogen escaping into the working environment. The outlet sealed isolation area 41 and the outlet hydrogen collection area 43 are surrounded by the vertical hydrogen collection bin partition 48 in the inner cavity of the outlet area of ​​the electrolyzer 2 and the upward inclined top wall of the tank body in the outlet area of ​​the electrolyzer 2. The outlet hydrogen collection area 43 is located above the outlet sealed isolation area 41. A hydrogen exhaust port 49 is provided on the upward inclined top wall of the tank body in the outlet area of ​​the electrolyzer 2. The working liquid one 47 in the outlet sealed isolation area 41 is located on the top of the working liquid three 46. The electrolytic oxidation negative electrode rod 25 is inserted into the working liquid one 47 in the outlet sealed isolation area 41 and is located between the working liquid three 46.

[0064] After power is turned on, the graphite paper electrode enters the electrolytic cell 2, driven by the mesh belt clamping and conveying mechanism. It then passes through the sealed inlet isolation zone 38 (filled with working liquid 1 47), the intercalation reaction zone 37 (filled with working liquid 2 44), the working liquid isolation zone 39 (filled with working liquid 4 45), and the electrochemical oxidation reaction zone 40 (filled with working liquid 3 46), before exiting the electrolytic cell through the outlet. During this process, the raw graphite 23, which is clamped by the mesh belt clamping structure 34 on the graphite electrode inlet side, is first converted into intercalation graphite by the mesh belt clamping structure 35 during the intermediate stage of the graphite electrode electrolysis reaction, and then converted into oxidized graphite by the mesh belt clamping structure 36 on the CFG product outlet side. Among them, the mesh belt clamping structure 34 on the graphite electrode inlet side is used to clamp the raw graphite 23 between the upper conveyor belt 19 and the lower conveyor belt 20, the mesh belt clamping structure 35 in the intermediate stage of the graphite electrode electrolysis reaction is used to clamp the raw graphite 23 between the upper conveyor belt 19 and the lower conveyor belt 20 and convert it into intercalated graphite in the intercalation reaction zone 37, and the mesh belt clamping structure 36 on the CFG product outlet side is used to clamp the intercalated graphite between the upper conveyor belt 19 and the lower conveyor belt 20 and convert it into oxidized graphite in the electrochemical oxidation reaction zone 40 to CFG product 50.

[0065] like Figure 6 As shown, a schematic diagram of the partial structure of the multi-layer liquid film reaction zone on the outlet side of the electrolytic cell 2 is shown. The electrochemical oxidation reaction zone 40 is the key reaction zone for converting the intercalated graphite into graphite oxide. Its liquid film structure is composed of working liquid 2 44 (concentrated sulfuric acid layer), working liquid 4 45 (fluorinated liquid DA-310 layer) and working liquid 3 46 (dilute sulfuric acid layer) from bottom to top. Among them, working liquid 45 (fluorinated liquid DA-310 layer) mainly plays the role of isolating working liquid 2 44 (concentrated sulfuric acid layer) and working liquid 3 46 (dilute sulfuric acid layer), and its thickness is 10 cm; working liquid 3 46 (dilute sulfuric acid layer) is the reaction zone for the electrochemical oxidation reaction, and its thickness is 1 cm.

[0066] In the present invention, an important feature of the circuit connection for electrochemical reaction is that the intercalation circuit and the oxidation circuit share a common positive electrode. Figure 7 As shown in the circuit connection diagram in FIG, the electrochemical intercalation power supply 51 and the electrochemical oxidation power supply 52 are both DC constant voltage power supplies. After the positive electrodes of the two power supplies are directly connected, they are connected to the raw graphite 23 (graphite paper) through the positive electrode conductive roller 53 (a pair of rollers formed by the first anode conductive roller 15 and the second anode conductive roller 16). The negative electrode of the electrochemical intercalation power supply 51 is connected to the electrolytic intercalation negative electrode plate 24, and the negative electrode of the electrochemical oxidation power supply 52 is connected to the electrolytic oxidation negative electrode rod 25. The electrodes for electrochemical intercalation are mainly distributed in the electrolytic cell area immersed in the intercalator, and the electrodes for electrochemical oxidation are mainly distributed in the electrolytic cell area immersed in the functionalized electrolyte.

[0067] To achieve the electrochemical intercalation reaction, two or more electrolytic intercalation negative electrode plates 24 need to be installed on the inner side of the top wall of the electrolytic cell's intercalation reaction zone 37. In this embodiment, the electrolytic intercalation negative electrode plates 24 are made of stainless steel plates, and there are six electrolytic intercalation negative electrode plates 24. All electrolytic intercalation negative electrode plates 24 are electrically connected to the negative electrode of the electrochemical intercalation power supply 51, forming a conductive circuit consisting of the positive electrode of the electrochemical intercalation power supply 51 - graphite paper - concentrated sulfuric acid - electrolytic intercalation negative electrode plates 24 - the negative electrode of the electrochemical intercalation power supply 51. In the working state, the output voltage of the electrochemical intercalation power supply 51 is 1.8V. After the graphite paper enters the intercalation reaction zone 37 filled with concentrated sulfuric acid at a linear speed of 5mm / min along with the clamping mechanism, an electrochemical intercalation reaction begins in the immersed portion, gradually converting the graphite paper into sulfuric acid-intercalated graphite paper. When the intercalated graphite paper leaves the intercalation reaction zone 37 along with the clamping mechanism and enters the working liquid isolation zone 39, the electrochemical intercalation reaction of the intercalated graphite paper immersed in the fluorinated liquid DA-310 stops.

[0068] To achieve the electrochemical oxidation reaction, an electrolytic oxidation negative electrode rod 25 is inserted into the electrochemical oxidation reaction zone 40. In this embodiment, the electrolytic oxidation negative electrode rod 25 is a stainless steel rod, and the number is one. The electrolytic oxidation negative electrode rod 25 is electrically connected to the negative electrode of the electrochemical oxidation power supply 52, forming a conductive circuit: the positive electrode of the electrochemical oxidation power supply 52 - graphite paper - intercalated graphite paper - dilute sulfuric acid - electrolytic oxidation negative electrode rod 25 - the negative electrode of the electrochemical oxidation power supply 52. ​​In the operating state, the output voltage of the electrochemical oxidation power supply 52 is 2.8V. After the intercalated graphite paper enters the electrochemical oxidation reaction zone 40 filled with dilute sulfuric acid at a linear speed of 5mm / min, the immersed portion begins an electrochemical oxidation reaction, gradually converting the intercalated graphite paper into oxidized graphite paper. When the oxidized graphite paper leaves the electrochemical oxidation reaction zone 40 with the clamping mechanism, the oxidized graphite paper that has left the reaction zone is the product of this step and can be collected and used for exfoliation to prepare GO.

[0069] The CFG collection and stripping mechanism 3 primarily comprises a scraper, a material collection tank, and a shear disperser. After the raw graphite is converted into graphite oxide through the reaction in the electrolytic cell 2, it is continuously conveyed by the mesh belt-clamped conveyor mechanism 1 to the opening of the material collection tank. The scraper scrapes the raw graphite from the conveyor belt surface and drops it into the material collection tank. It is then mixed with pure water in the tank and crushed and stripped by the shear disperser to form a dispersion with a satisfactory fineness. The dispersion is then discharged from the bottom of the tank. After purification using conventional processes, the GO aqueous dispersion product is obtained.

[0070] During the above process, the working liquids are primarily delivered via a working liquid delivery mechanism 4, which comprises storage tanks for the four working liquids used in the electrolytic cell and the stripping liquid from the collection tank, a working liquid delivery pump, and delivery pipelines. These storage tanks are connected to the corresponding liquid inlets of the electrolytic cell and the collection tank via the working liquid delivery pump and delivery pipeline, respectively, to meet the process requirements of automatic addition, replenishment, and drainage of the working liquids during production. The power required for electrochemical intercalation and oxidation, as well as for device control and operation, is primarily provided by a power supply system. These two mechanisms are essential components for implementing the technical solution of the present invention and can be assembled using a combination of conventional piping, mechanical, and electrical components.

[0071] Example 2

[0072] In this example, continuous carbon fiber wire with good conductivity is used as raw material to prepare fluorinated graphene dispersion. The diameter of the carbon fiber wire used is 500 μm and the density is 1.8 g / cm 3 , the volume conductivity is 650S / cm.

[0073] The device structure and operation process used in this embodiment are basically the same as those in Example 1, with the main differences being:

[0074] (1) The shapes of the integrated electrolytic cells are different. Figure 8 As shown, the "V"-shaped integrated electrolytic cell used in this embodiment is different from the inverted trapezoidal integrated electrolytic cell ( Figure 5 ) compared to the conventional electrolytic cell, its bottom horizontal length is significantly shortened, and the number of steering axes has been reduced from two to one. The corresponding mesh belt of the clamping mechanism has also been changed to a "V" shape. The reason for the change in the electrolytic cell shape is that the smaller diameter of carbon fiber shortens the intercalation time, thus reducing the space in the intercalation reaction zone. On the other hand, carbon fiber is relatively brittle and is prone to breakage after repeated deflection by the rollers, causing a break in the electrical circuit and affecting production continuity. Therefore, the number of bends needs to be reduced.

[0075] (2) The types of some working fluids are different. The working fluid 47 (light sealing oil) is replaced with petroleum ether 90 (density 0.82g / cm 3 ); Working liquid three (functional electrolyte) was replaced with a 20wt% NaF aqueous solution (density 1.02g / cm 3 ).

[0076] (3) The electrochemical reaction parameters are different. The output voltage of the power supply for electrochemical intercalation is changed to 2.2V, the output voltage of the power supply for electrochemical oxidation is changed to 3.5V, and the linear speed of the carbon fiber wire entering the reaction tank is 15mm / min.

[0077] (4) The composition of the stripping solution is different. The stripping solution is an ethanol aqueous solution with a concentration of 60 wt%.

[0078] Using the above-described reaction apparatus and reaction conditions, the raw carbon fibers are converted into a linear material of fluorinated graphene through a reaction in an electrolytic cell. This material is then continuously transported by a mesh belt clamping conveyor mechanism to the opening of a material collection tank. A scraper scrapes the material from the mesh belt surface and drops it into the collection tank. The material is then mixed with an ethanol / water solution in the tank and pulverized and exfoliated using a shear disperser, forming a dispersion that meets the required fineness. The dispersion is then discharged from the bottom of the tank. Purification of the dispersion using conventional processes yields the fluorinated graphene dispersion product.

[0079] Example 3

[0080] In this example, a flexible graphite paper roll with good conductivity was used as a raw material to prepare a nitrogen-doped graphene dispersion. The properties of the flexible graphite paper raw material used were the same as those in Example 1, specifically a flexible graphite paper roll with a thickness of 0.5 mm, a width of 40 cm, a single roll length of 50 m, and a density of 1.6 g / cm 3 , the volume conductivity is 550S / cm.

[0081] The device structure and operation process used in this embodiment are basically the same as those in Example 1, with the main differences being:

[0082] (1) The shapes of the integrated electrolytic cells are different. Figure 9 As shown, the "U"-shaped integrated electrolytic cell used in this embodiment is different from the inverted trapezoidal integrated electrolytic cell ( Figure 5 ), its bottom horizontal length is shortened to some extent, but the two steering axes are retained. The corresponding mesh belt of the clamping mechanism is also changed to a "U" shape.

[0083] (2) The types of some working fluids are different. The working fluid 47 (light sealing oil) is replaced with petroleum ether 90 (density 0.82g / cm 3 ); Working liquid three (functional electrolyte) was replaced with a 30wt% aqueous solution of ammonium sulfate (density 1.04g / cm 3 ).

[0084] (3) Electrochemical reaction parameters are different. The output voltage of the power supply for electrochemical intercalation is changed to 2.0 V, the output voltage of the power supply for electrochemical oxidation is changed to 3.2 V, and the linear speed of the graphite paper roll entering the reaction tank is 25 mm / min.

[0085] (4) The composition of the stripping solution is different. The stripping solution is an isopropyl alcohol aqueous solution with a concentration of 20 wt%.

[0086] Using the above-described reaction apparatus and reaction conditions, the raw flexible graphite paper is converted into a sheet of nitrogen-doped graphene aggregates through a reaction in an electrolytic cell. This sheet is then continuously conveyed to the opening of a material collection tank by a mesh belt clamping conveyor mechanism. A scraper scrapes the sheet from the mesh belt surface and drops it into the collection tank. The sheet is then mixed with an isopropyl alcohol / water solution in the tank and pulverized and exfoliated using a shear disperser, forming a dispersion of the desired fineness. The dispersion is then discharged from the bottom of the tank. Purification of the dispersion using conventional processes yields a nitrogen-doped graphene dispersion product.

Claims

1. An electrochemical device capable of continuously preparing covalently functionalized graphene, characterized in that: The device includes a mesh belt clamping and conveying mechanism, an electrolytic cell, a CFG collecting and stripping mechanism, a working liquid conveying mechanism, and an electrolytic power supply mechanism. A discharge roller is arranged on one side of the mesh belt clamping and conveying mechanism, raw graphite is installed on the discharge roller, and a discharge roller shield is installed on the discharge roller. A CFG collecting and stripping mechanism is arranged on the other side of the mesh belt clamping and conveying mechanism. The mesh belt clamping and conveying mechanism passes through the electrolytic cell. The working liquid conveying mechanism is respectively provided with storage tanks ①, ②, ③, and ④ for providing working liquid 1, working liquid 2, working liquid 3, and working liquid 4 to the electrolytic cell. Storage tanks ①, ②, ③, and ④ are respectively connected to the electrolytic cell through pipelines. A working liquid conveying pump is provided on the pipeline. The raw graphite on the discharge roller is sequentially passed through the mesh belt clamping and conveying mechanism, the electrolytic cell, and the CFG collecting and stripping mechanism. The electrolytic cell is powered by the electrolytic power supply mechanism to realize continuous preparation of CFG.

2. The electrochemical device for continuously preparing covalently functionalized graphene according to claim 1, characterized in that: The mesh belt clamping conveying mechanism is composed of two groups of independent conveying mechanisms that are arranged relative to each other and move toward each other. The raw graphite is installed on the unwinding roller. The output end of the raw graphite is relatively arranged with a first anode conductive clamping roller and a second anode conductive clamping roller to form a positive conductive roller. The raw graphite is transmitted between the two groups of conveying mechanisms through the first anode conductive clamping roller and the second anode conductive clamping roller. Among them, the first group of conveying mechanisms is composed of a first upper conveyor belt circulating steering roller, a second upper conveyor belt circulating steering roller, a first common steering roller, a second common steering roller and an upper conveyor belt. The first upper conveyor belt circulating steering roller and the second upper conveyor belt circulating steering roller are respectively The first common steering roller and the second common steering roller are respectively the two vertices of the inverted trapezoidal bottom, the upper conveyor belt is sleeved on the first upper conveyor belt circulating steering roller, the second upper conveyor belt circulating steering roller, the first common steering roller, and the second common steering roller to form an inverted trapezoidal structure, and an upper scraper is arranged on the outer side of the upper conveyor belt corresponding to the first upper conveyor belt circulating steering roller; the second group of conveying mechanisms consists of the first common steering roller, the second common steering roller, the first lower conveyor belt circulating steering roller, the second lower conveyor belt circulating steering roller, the third lower conveyor belt circulating steering roller, the fourth lower conveyor belt circulating steering roller, and the fifth lower conveyor belt. The circulating steering roller and the lower conveyor belt are composed of the first common steering roller, the second common steering roller, the first lower conveyor belt circulating steering roller, the second lower conveyor belt circulating steering roller, the third lower conveyor belt circulating steering roller, the fourth lower conveyor belt circulating steering roller and the fifth lower conveyor belt circulating steering roller, which are respectively the vertices of the heptagon. The lower conveyor belt is sequentially sleeved on the first lower conveyor belt circulating steering roller, the second lower conveyor belt circulating steering roller, the third lower conveyor belt circulating steering roller, the fourth lower conveyor belt circulating steering roller and the fifth lower conveyor belt circulating steering roller, and is pressed on the outer side of the top of the lower conveyor belt by the first common steering roller and the second common steering roller to form a groove. Structure, the first group of conveying mechanisms matches the groove structure, and a lower scraper is set on the outer side of the lower conveyor belt corresponding to the second lower conveyor belt circulation steering roller; after the graphite raw material is output through the discharge roller and the first anode conductive pinch roller and the second anode conductive pinch roller, it passes through the upper conveyor belt circulation of the first group of conveying mechanisms and the lower conveyor belt circulation of the second group of conveying mechanisms to form CFG products, the position of the first lower conveyor belt circulation steering roller is higher than the second lower conveyor belt circulation steering roller, the CFG product is collected along the lower conveyor belt at the inclined surface between the first lower conveyor belt circulation steering roller and the second lower conveyor belt circulation steering roller, and enters the CFG collection and stripping mechanism.

3. The electrochemical device for continuously preparing covalently functionalized graphene according to claim 2, characterized in that: The second upper conveyor belt circulating steering roller and the fifth lower conveyor belt circulating steering roller are arranged relative to each other to form a pair of rollers as guide point A, the first common steering roller and the second common steering roller serve as guide point B and guide point C respectively, the first upper conveyor belt circulating steering roller and the first lower conveyor belt circulating steering roller are arranged relative to each other to form a pair of rollers as guide point D, guide point A and guide point D are respectively the two vertices of the upper base of the inverted trapezoid, guide point B and guide point C are respectively the two vertices of the lower base of the inverted trapezoid, the upper conveyor belt and the lower conveyor belt are driven by the motor to perform clockwise and counterclockwise circulation motion at the same linear speed respectively, and form a clamping area in the area A→B→C→D where the two conveyor belts are parallel to each other.

4. The electrochemical device for continuously preparing covalently functionalized graphene according to claim 3, characterized in that: When the device starts to operate, the raw graphite is first installed on the unwinding roller. The unwinding and pulled graphite paper first passes through the conductive roller clamping area of ​​the first anode conductive roller and the second anode conductive roller to make it conductive with the positive pole of the power supply. Then it is introduced between the rollers of the second upper conveyor belt circulation steering roller and the fifth lower conveyor belt circulation steering roller, and enters the mesh belt clamping area between the upper conveyor belt and the lower conveyor belt. Driven by the circulation of the upper and lower conveyor belts, continuous graphite paper transportation is formed and passes through the electrochemical reaction area in the electrolytic cell. When the graphite paper is transported When it reaches the pair of rollers of the first upper conveyor belt circulating steering roller and the first lower conveyor belt circulating steering roller, this area of ​​the graphite paper has been converted into graphite oxide; at this time, the graphite oxide sheets will separate from the upper conveyor belt and mainly adhere to the surface of the lower conveyor belt. A small amount of graphite oxide adhering to the upper conveyor belt will be scraped off by the upper scraper and fall on the surface of the lower conveyor belt; the graphite oxide attached to the lower conveyor belt will be scraped off by the lower scraper when it moves to the second lower conveyor belt circulating steering roller area and collected in the CFG collection and stripping mechanism for subsequent processing.

5. The electrochemical device for continuously preparing covalently functionalized graphene according to claim 1, characterized in that: The integrated electrolytic cell includes: electrolytic intercalation negative electrode plate, electrolytic oxidation negative electrode rod, common steering roller mounting frame, concentrated sulfuric acid injection pipe, concentrated sulfuric acid discharge pipe, functionalized electrolyte injection and discharge pipe, heavy sealing oil inlet and discharge pipe, outlet side light sealing oil inlet and discharge pipe, inlet side light sealing oil inlet and discharge pipe, concentrated sulfuric acid level pipe, intercalation reaction zone, inlet sealed isolation zone, working liquid isolation zone, electrochemical oxidation reaction zone, outlet sealed isolation zone, inlet hydrogen collection zone, outlet hydrogen collection zone, working liquid 2, working liquid 4, working liquid 3, working liquid 1, hydrogen collection chamber partition, hydrogen exhaust port. The specific structure is as follows: The inner cavity of the electrolytic cell is a groove-shaped structure with two sides of the horizontal section inclined upward. The upper port on one side of the inner cavity is the electrolytic cell inlet, and the upper port on the other side of the inner cavity is the electrolytic cell outlet. Two common steering roller mounting frames are arranged oppositely at the bottom of the horizontal section of the inner cavity of the electrolytic cell. A first common steering roller is mounted on one common steering roller mounting frame, and a second common steering roller is mounted on the other common steering roller mounting frame. The injection procedure of the four working liquids into the electrolytic cell is as follows: (1) when the electrolytic cell is completely empty, first inject working liquid 2 into the electrolytic cell to fill the intercalation reaction zone; (2) inject working liquid 1 into the inlet area of ​​the electrolytic cell to fill the inlet sealed isolation zone; at the same time, inject working liquid 4 into the outlet area of ​​the electrolytic cell to fill the working liquid isolation zone; (3) inject working liquid 3 into the outlet area of ​​the electrolytic cell to fill the electrochemical oxidation reaction zone; (4) inject working liquid 1 into the outlet area of ​​the electrolytic cell to fill the outlet sealed isolation zone; The injection ports of different working liquids are all arranged at the contact interface of the two working liquids and are connected to the working liquid delivery pump through pipelines. The pipelines include: a concentrated sulfuric acid injection pipe, a concentrated sulfuric acid discharge pipe, a functionalized electrolyte injection and discharge pipe, a heavy sealing oil inlet and discharge pipe, an outlet side light sealing oil inlet and discharge pipe, and an inlet side light sealing oil inlet and discharge pipe. The concentrated sulfuric acid injection pipe is connected to the top of the intercalation reaction zone, the concentrated sulfuric acid discharge pipe is connected to the bottom of the intercalation reaction zone, the functionalized electrolyte injection and discharge pipe is connected to the electrochemical oxidation reaction zone, the heavy sealing oil inlet and discharge pipe is connected to the working liquid isolation zone, the outlet side light sealing oil inlet and discharge pipe is connected to the outlet sealed isolation zone, and the inlet side light sealing oil inlet and discharge pipe is connected to the inlet sealed isolation zone. A concentrated sulfuric acid level tube is provided at the top of the intercalation reaction zone, an inlet hydrogen collection zone is provided at the inlet of the electrolyzer, and an outlet hydrogen collection zone is provided at the outlet area of ​​the electrolyzer to collect hydrogen gas generated during the electrochemical reaction and discharge or recycle it in a centralized manner to avoid safety risks caused by hydrogen escaping into the working environment; the outlet sealed isolation zone and the outlet hydrogen collection zone are surrounded by a vertical hydrogen collection bin partition in the inner cavity of the electrolyzer outlet area and an upwardly inclined tank body top wall of the electrolyzer outlet area; the outlet hydrogen collection zone is located above the outlet sealed isolation zone, and a hydrogen exhaust port is provided on the upwardly inclined tank body top wall of the electrolyzer outlet area; the working liquid 1 in the outlet sealed isolation zone is located on top of the working liquid 3, and the electrolytic oxidation negative electrode rod is inserted into the working liquid 1 in the outlet sealed isolation zone and is located between the working liquid 3; After the power is turned on, the graphite paper electrode enters the above-mentioned electrolytic cell under the drive of the mesh belt clamping and conveying mechanism, and passes through the inlet sealed isolation area filled with working liquid 1, the intercalation reaction area filled with working liquid 2, the working liquid isolation area filled with working liquid 4, the electrochemical oxidation reaction area filled with working liquid 3, and finally leaves the electrolytic cell from the outlet; in this process, the raw graphite in the clamping state of the mesh belt clamping structure on the graphite electrode inlet side is first converted into intercalation graphite by the mesh belt clamping structure in the middle stage of the graphite electrode electrolysis reaction , and then converted into graphite oxide at the mesh belt clamping structure on the CFG product outlet side; wherein, the mesh belt clamping structure on the graphite electrode inlet side is for clamping the raw graphite between the upper conveyor belt and the lower conveyor belt, and the mesh belt clamping structure in the intermediate stage of the graphite electrode electrolysis reaction is for clamping the raw graphite between the upper conveyor belt and the lower conveyor belt, and converting it into intercalation graphite in the intercalation reaction zone, and the mesh belt clamping structure on the CFG product outlet side is for clamping the intercalation graphite between the upper conveyor belt and the lower conveyor belt, and converting it into graphite oxide in the electrochemical oxidation reaction zone.

6. The electrochemical device for continuously preparing covalently functionalized graphene according to claim 1, characterized in that: The electrolysis power supply mechanism includes three parts: the power supply for electrochemical intercalation, the power supply for electrochemical oxidation, and the power supply for equipment operation. The power supply for electrochemical intercalation and the power supply for electrochemical oxidation are both independent low-voltage DC power supplies that regulate the output voltage or current and operate for a long time in constant voltage or constant current mode; the voltage control range of the power supply for electrochemical intercalation is 0-10V, and the current control range is 0-100A; the voltage control range of the power supply for electrochemical oxidation is 0-20V, and the current control range is 0-500A; the equipment operation power supply is a conventional regulated power supply, which provides operating power for all electrical equipment in the device.

7. The electrochemical device for continuously preparing covalently functionalized graphene according to claim 6, characterized in that: The power supply for electrochemical intercalation and the power supply for electrochemical oxidation share a positive electrode and are connected to the raw graphite through a conductive roller to achieve an electrochemical reaction. The power supply for electrochemical intercalation and the power supply for electrochemical oxidation are both DC constant voltage power supplies. After the positive electrodes of the two power supplies are directly connected, the positive conductive roller formed by the first anode conductive roller and the second anode conductive roller is connected to the raw graphite. The negative electrode of the power supply for electrochemical intercalation is connected to the electrolytic intercalation negative electrode plate, and the negative electrode of the power supply for electrochemical oxidation is connected to the electrolytic oxidation negative electrode rod. The electrodes for electrochemical intercalation are distributed in the electrolytic cell area immersed in the intercalator, and the electrodes for electrochemical oxidation are distributed in the electrolytic cell area immersed in the functionalized electrolyte. To achieve an electrochemical intercalation reaction, two or more electrolytic intercalation negative electrode plates are installed on the inner side of the top wall of the electrolytic cell's intercalation reaction zone. All of the electrolytic intercalation negative electrode plates are electrically connected to the negative electrode of the electrochemical intercalation power supply, forming a conductive circuit consisting of the positive electrode of the electrochemical intercalation power supply - graphite paper - concentrated sulfuric acid - electrolytic intercalation negative electrode plates - the negative electrode of the electrochemical intercalation power supply. In operation, when the raw graphite enters the intercalation reaction zone filled with concentrated sulfuric acid with a clamping mechanism, an electrochemical intercalation reaction begins in the immersed portion, gradually converting the graphite paper into sulfuric acid-intercalated graphite paper. When the intercalated graphite paper leaves the intercalation reaction zone with the clamping mechanism and enters the working liquid isolation zone, the electrochemical intercalation reaction ceases for the intercalated graphite paper immersed in the working liquid. In order to achieve electrochemical oxidation reaction, an electrolytic oxidation negative electrode rod is inserted into the electrochemical oxidation reaction zone, and the electrolytic oxidation negative electrode rod is connected to the negative electrode of the electrochemical oxidation power supply, forming a conductive circuit of the electrochemical oxidation power supply positive electrode - graphite paper - intercalated graphite paper - dilute sulfuric acid - electrolytic oxidation negative electrode rod - negative electrode of the electrochemical oxidation power supply; under working conditions, after the intercalated graphite paper enters the electrochemical oxidation reaction zone filled with dilute sulfuric acid with the clamping mechanism, the immersed part begins to undergo electrochemical oxidation reaction, gradually converting the intercalated graphite paper into oxidized graphite paper; when the oxidized graphite paper leaves the electrochemical oxidation reaction zone with the clamping mechanism, the oxidized graphite paper that leaves the reaction zone is the product of this step, which is collected and used for exfoliation to prepare GO.

8. The electrochemical device for continuously preparing covalently functionalized graphene according to claim 1, characterized in that: The CFG collection and stripping mechanism includes a scraper, a material collection tank, and a shear disperser. After the raw graphite is converted into graphite oxide through the reaction in the electrolytic cell, it is continuously transported to the opening of the material collection tank by a mesh belt clamping conveyor mechanism. The scraper is used to scrape it from the conveyor belt surface and drop it into the material collection tank. It is mixed with pure water in the material collection tank and crushed and stripped by the shear disperser. After forming a dispersion liquid with a fineness that meets the standard, it is discharged from the bottom of the material collection tank. After the dispersion is purified using conventional processes, a GO aqueous dispersion product is obtained.

9. An electrochemical method for continuously preparing covalently functionalized graphene using the apparatus according to any one of claims 1 to 8, characterized in that: This method uses continuous flexible graphite paper coils or carbon fiber wires as raw materials, and conducts electrochemical oxidation reaction through an integrated electrolytic cell under the clamping of a mesh belt clamping and conveying mechanism to continuously convert the graphite paper or carbon fiber into sheets or wires composed of CFG. The CFG aggregates attached to the surface of the mesh belt are scraped off by a scraper and collected in a stripping tank. After adding a solvent, shearing, stripping and cleaning, a CFG dispersion is obtained.

10. The electrochemical method for continuously preparing covalently functionalized graphene according to claim 9, characterized in that: At least one side of the upper conveyor belt and the lower conveyor belt used in the mesh belt clamping conveying mechanism must have a large number of holes to facilitate the electrolyte to pass through the holes and combine with the raw graphite to realize the electrochemical reaction. The porosity of the upper conveyor belt and the lower conveyor belt with a hole structure should be not less than 30%; the two sets of conveying mechanisms form a circular motion loop through the roller mechanism to meet the requirements of continuous transportation of raw graphite; the operating linear speed of the circular motion loop is adjustable, and the adjustment range is 1mm / min~1m / s.

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