Electrolysis device and method for preparing graphene through electrochemical stripping

Abstract

The invention discloses an electrolysis device for preparing graphene through electrochemical stripping and a corresponding electrolysis method.The device comprises an electrolyte circulating system and at least one group of paired electrode part assemblies, and the electrode part assemblies are connected with a power source; the electrolyte circulating system comprises a head tank, a circulating pump, an electrolytic tank, a first valve and a second valve, the convenience of electrochemical stripping of graphene by a user is improved, and the device has the advantages of being reasonable in design, easy to operate, environmentally friendly, low in cost, high in preparation efficiency, high in expandability and the like. Meanwhile, the electrochemical stripping method has a wide market application prospect in the aspect of electrochemical stripping of graphene.

Description

Technical Field

[0001] The present application relates to an electrolysis device and method for preparing graphene by electrochemical exfoliation, belonging to the field of electrochemistry. Background Art

[0002] Graphene has been widely studied and applied due to its excellent physical and chemical properties. Its industrial application is inseparable from the development of preparation technology. The wide range of application scenarios has also continuously increased the requirements for the process of mass preparation of graphene. Traditional graphene preparation methods are difficult to meet the needs of many application scenarios. Therefore, the research and development of environmentally friendly, large-scale, high-quality, and low-cost graphene preparation methods is particularly important.

[0003] Electrochemical preparation of graphene is a method of exfoliating graphene in an electrolyte with an external power source. Compared with other graphene preparation methods, the electrochemical method can obtain larger graphene with good conductivity and is not prone to other defects. It has the advantages of easy operation, easy large-scale preparation, and scalability, and has great development prospects.

[0004] However, in the electrochemical exfoliation technology for preparing graphene, since the graphite electrode is a consumable electrode, during the exfoliation process, it is necessary to control the electrode lifting and lowering so that the graphite always maintains a small area of ​​contact with the electrolyte. This requires a complete set of electrode lifting systems, which increases the design and manufacturing costs of the equipment. In addition, the electrochemical exfoliation of graphene requires controlling the lifting and lowering of the graphite paper according to the exfoliation situation so that it is in contact with the electrolyte, which can easily cause the thick graphite flakes that have not been completely exfoliated to fall off, resulting in exfoliation failure. Summary of the invention

[0005] According to one aspect of the present application, an electrolysis device for electrochemical batch preparation of graphene is provided, which improves the convenience of users in electrochemically exfoliating graphene, and has the advantages of reasonable design, simple operation, environmental protection, low cost, high preparation efficiency, strong scalability, etc. At the same time, it has broad market application prospects in electrochemical exfoliation of graphene.

[0006] The present application provides an electrolysis device for preparing graphene by electrochemical exfoliation, comprising an electrolyte circulation system and at least one set of paired electrode components, wherein the electrode components are connected to a power source;

[0007] The electrolyte circulation system comprises a high-level tank, a circulation pump and an electrolytic tank;

[0008] The first connecting pipe and the second connecting pipe respectively connect the header tank and the electrolytic tank to form a loop;

[0009] The first connecting pipe is provided with a first valve;

[0010] The second connecting pipe is provided with a circulation pump and a second valve;

[0011] The electrolyte flows to the high-level tank through the second connecting pipe, the second valve, and the circulating pump, and then flows back to the electrolytic tank through the first connecting pipe and the first valve, forming a circulation path;

[0012] The electrode assembly comprises a base, a clamp and an electrode part, wherein the base fixes the clamp to the electrolytic cell, and the electrode part is clamped and fixed by the clamp and inserted into the electrolyte, and the clamp is made of copper material;

[0013] The clamp can be easily adjusted on the base to make the stripping process more controllable.

[0014] Each set of paired electrode components are placed facing each other, with one electrode component serving as a cathode electrode and the other electrode component serving as an anode electrode;

[0015] One of the cathode electrode and the anode electrode is a graphite electrode.

[0016] The electrolyte flows to the high-level tank through the second connecting pipe, the second valve, and the circulating pump, and then flows back to the electrolytic tank through the first connecting pipe and the first valve, forming a circulating passage.

[0017] Optionally, a first base is provided at the bottom of the high-level tank, and a second base is provided at the bottom of the electrolytic tank;

[0018] Preferably, the height of the first base is greater than the height of the second base;

[0019] Preferably, the first base and the high-position tank are integrally formed;

[0020] The second base is integrally formed with the electrolytic cell.

[0021] Optionally, the electrode assembly is connected to a power source via an output cable;

[0022] Preferably, two sets of paired electrode components are provided;

[0023] Preferably, the base is a conductive base.

[0024] Optionally, the other of the cathode electrode and the anode electrode is a stainless steel electrode plate. Both the graphite electrode and the stainless steel electrode plate can be used as the cathode electrode or the anode electrode. The stainless steel electrode plate as an inert electrode can ensure the peeling of high-quality graphene while having lower cost compared with the platinum electrode commonly used in the prior art.

[0025] Optionally, the power supply is a pulse power supply dedicated for electrolysis;

[0026] Preferably, the power supply is provided with an insulating power base.

[0027] Optionally, the circulation pump is an acid-resistant circulation pump;

[0028] Preferably, the circulation pump is equipped with an insulating circulation pump base.

[0029] Optionally, the top of the high-level trough is equipped with a high-level trough cover, and the high-level trough cover has a handle.

[0030] Optionally, the first connecting pipe connects the lower part of the side wall of the high-level tank with the upper part of the side wall of the electrolytic tank;

[0031] The second connecting pipe connects the lower part of the side wall of the electrolytic tank with the upper part of the side wall of the high-level tank;

[0032] Preferably, among the four connection ports between the first connection pipe, the second connection pipe, the header tank and the electrolytic tank, only the connection port between the second connection pipe and the header tank is higher than the electrolyte level, and the other three connection ports are all below the electrolyte level;

[0033] Preferably, a filtering device is also provided on the second connecting pipe, and the filtering device can filter out the peeled graphite microsheets.

[0034] According to another aspect of the present application, a method for preparing graphene according to the above electrolysis device is provided, comprising the following steps:

[0035] S1: Assembling and fixing the clamp and the electrode part, and then connecting them to the base fixed on the electrolytic cell to form an electrode part assembly;

[0036] The electrode portion serving as the cathode electrode and the electrode portion serving as the anode electrode are placed facing each other;

[0037] S2: injecting electrolyte into the high-level tank, opening the first valve to allow the electrolyte to flow into the electrolytic tank, and when the electrolyte level is about to soak the bottom of the electrode part, closing the first valve and continuing to inject an appropriate amount of electrolyte into the high-level tank;

[0038] S3: setting the voltage of the power supply, opening the power supply and the first valve, allowing the electrolyte to flow from the high-level tank into the electrolytic tank to submerge the bottom of the electrode part, and starting stripping;

[0039] S4: After the stripping is completed, the second valve and the circulation pump are opened to form a circulating liquid flow, and the height of the electrolyte in the electrolytic cell is adjusted to prepare for the next round of stripping.

[0040] Optionally, the stripping speed is controlled by adjusting the voltage of the power supply;

[0041] Preferably, the height of the electrolyte level in the electrolytic cell is controlled by adjusting the first valve;

[0042] Preferably, the circulating liquid flow is controlled by adjusting the second valve.

[0043] The working principle of the electrolysis device for preparing graphene by electrochemical exfoliation provided in this application is specifically described as follows:

[0044] Setting the voltage of the power supply, starting the device, adjusting the first valve to control the flow rate and flow velocity of the electrolyte, adjusting the depth of the graphite electrode part in the electrolytic cell immersed in the liquid surface, so as to stably peel it, and after the peeling is completed, adjusting the second valve and opening the circulation pump to make the electrolyte in the electrolytic cell stably flow to the high-level tank, so as to adjust the height of the electrolyte in the electrolytic cell for the next round of peeling;

[0045] When the stripping speed is slow, increasing the voltage of the power supply;

[0046] When the stripping is unstable, the electrolyte flow rate is reduced by adjusting the first valve, so that the stripping is restored to a stable state.

[0047] The beneficial effects of this application include:

[0048] The present application provides an electrolytic device for preparing graphene by electrochemical exfoliation. Through the electrolyte circulation system, the exfoliation process is controlled to proceed continuously and stably during the reaction, and can be recycled multiple times, which effectively reduces the large-scale shedding of graphite electrodes during the exfoliation process and improves the exfoliation efficiency. At the same time, it also makes the electrochemical exfoliation of graphene more convenient. It has the advantages of reasonable design, simple operation, environmental protection, low cost, high preparation efficiency, strong scalability, etc., and has broad market application prospects in the electrochemical exfoliation of graphene. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic structural diagram of an implementation method of the present application.

[0050] List of parts and reference numerals:

[0051] 1. High-level tank; 2. Electrolytic cell; 3. Power supply; 4. Base; 5. Clamp; 6. Electrode part; 7. Output cable; 8. Circulation pump; 9. First base; 10. First connecting pipe; 11. First valve; 12. Second connecting pipe; 13. Second valve; 14. Second base. DETAILED DESCRIPTION

[0052] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0053] According to one embodiment of the present application, an electrolysis device for preparing graphene by electrochemical exfoliation is provided, comprising an electrolyte circulation system and two sets of paired electrode parts 6 components, wherein the electrode parts 6 components are connected to a power supply 3 via an output cable 7, and the power supply 3 is a pulse power supply 3 dedicated for electrolysis and is equipped with an insulating power supply 3 base;

[0054] The electrolyte circulation system comprises an elevated tank 1, a circulation pump 8 and an electrolytic tank 2, wherein an integrally formed first base 9 is provided at the bottom of the elevated tank 1, and an integrally formed second base 14 is provided at the bottom of the electrolytic tank 2, wherein the height of the first base 9 is greater than the height of the second base 14;

[0055] The first connecting pipe 10 and the second connecting pipe 12 respectively connect the header tank 1 and the electrolytic tank 2 to form a loop;

[0056] Specifically, the first connecting pipe 10 connects the lower part of the side wall of the high-level tank 1 with the upper part of the side wall of the electrolytic tank 2;

[0057] The second connecting pipe 12 connects the lower part of the side wall of the electrolytic tank 2 with the upper part of the side wall of the high-level tank 1;

[0058] Among the four connection ports between the first connection pipe 10, the second connection pipe 12, the header tank 1 and the electrolytic tank 2, only the connection port between the second connection pipe 12 and the header tank 1 is higher than the electrolyte level, and the other three connection ports are all below the electrolyte level;

[0059] The first connecting pipe 10 is provided with a first valve 11;

[0060] The second connecting pipe 12 is provided with a circulation pump 8 and a second valve 13, wherein the circulation pump 8 is an acid-resistant circulation pump 8 and is provided with an insulating circulation pump 8 base;

[0061] The electrolyte flows to the high-level tank 1 through the second connecting pipe 12, the second valve 13, and the circulating pump 8, and then flows back to the electrolytic tank 2 through the first connecting pipe 10 and the first valve 11, forming a circulation path;

[0062] The electrode part 6 assembly includes a base 4, a clamp 5 and an electrode part 6, wherein the base 4 is a conductive base 4, and the base 4 fixes the clamp 5 to the electrolytic cell 2, and the electrode part 6 is clamped and fixed by the clamp 5 and inserted into the electrolyte, and the clamp 5 is made of copper material;

[0063] The position of the clamp 5 on the base 4 can be easily adjusted to make the stripping process more controllable.

[0064] Each set of paired electrode parts 6 components are placed facing each other, with one electrode part 6 serving as a cathode electrode and the other electrode part 6 serving as an anode electrode;

[0065] One of the cathode electrode and the anode electrode is a graphite electrode, and the other is a stainless steel electrode plate. Both the graphite electrode and the stainless steel electrode plate can be used as cathode electrodes or anode electrodes. The stainless steel electrode plate is used as an inert electrode. While ensuring that high-quality graphene can be peeled off, it has lower cost compared with the platinum electrode commonly used in the prior art.

[0066] The electrolyte flows to the high-level tank 1 through the second connecting pipe 12, the second valve 13, and the circulation pump 8, and then flows back to the electrolytic tank 2 through the first connecting pipe 10 and the first valve 11, forming a circulation path.

[0067] In addition, the present application also provides a method for preparing graphene according to the above electrolysis device, comprising the following steps:

[0068] S1: Assemble and fix the clamp 5 and the electrode part 6 and then connect them to the base 4 fixed on the electrolytic cell 2 to form an electrode part 6 assembly;

[0069] The electrode portion 6 serving as the cathode electrode and the electrode portion 6 serving as the anode electrode are placed facing each other.

[0070] S2: inject the electrolyte into the high-level tank 1, open the first valve 11, and allow the electrolyte to flow into the electrolytic tank 2. When the electrolyte level is about to soak the bottom of the electrode part 6, close the first valve 11 and continue to inject an appropriate amount of electrolyte into the high-level tank 1.

[0071] S3: setting the voltage of the power source 3, opening the power source 3 and the first valve 11, allowing the electrolyte to flow from the high-level tank 1 into the electrolytic tank 2 to submerge the bottom of the electrode part 6, and starting the stripping.

[0072] S4: After the stripping is completed, the second valve 13 and the circulation pump 8 are opened to form a circulating liquid flow, and the height of the electrolyte in the electrolytic cell 2 is adjusted to prepare for the next round of stripping.

[0073] The stripping speed is controlled by adjusting the voltage of the power supply 3 .

[0074] The height of the electrolyte level in the electrolytic cell 2 is controlled by adjusting the first valve 11 .

[0075] The circulating liquid flow is controlled by adjusting the second valve 13 .

[0076] The working principle of the electrolysis device for preparing graphene by electrochemical exfoliation provided in this application is specifically described as follows:

[0077] The voltage of the power supply 3 is set, the device is started, the first valve 11 is adjusted to control the flow rate and flow velocity of the electrolyte, and the depth of the graphite electrode part 6 in the electrolytic cell 2 immersed in the liquid surface is adjusted so that it can be stably peeled. After the peeling is completed, the second valve 13 is adjusted and the circulation pump 8 is turned on to make the electrolyte in the electrolytic cell 2 flow stably into the high-level tank 1, so as to adjust the height of the electrolyte in the electrolytic cell 2 for the next round of peeling;

[0078] When the stripping speed is slow, increasing the voltage of the power supply 3;

[0079] When the stripping is unstable, the electrolyte flow rate is reduced by adjusting the first valve 11 so that the stripping can be restored to a stable state.

[0080] The above description is only a partial embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the above disclosed technical content to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An electrolysis device for preparing graphene by electrochemical exfoliation, characterized in that: It includes an electrolyte circulation system and at least one set of paired electrode components, wherein the electrode components are connected to a power source; The electrolyte circulation system comprises an elevated tank, a circulation pump and an electrolytic tank; The first connecting pipe and the second connecting pipe respectively connect the header tank and the electrolytic tank to form a loop; The first connecting pipe is provided with a first valve; The second connecting pipe is provided with a circulation pump and a second valve; The electrolyte flows to the high-level tank through the second connecting pipe, the second valve, and the circulating pump, and then flows back to the electrolytic tank through the first connecting pipe and the first valve, forming a circulation path; The electrode assembly comprises a base, a clamp and an electrode part, wherein the base fixes the clamp to the electrolytic cell, and the electrode part is clamped and fixed by the clamp and inserted into the electrolyte; Each set of paired electrode components are placed facing each other, with one electrode component serving as a cathode electrode and the other electrode component serving as an anode electrode; One of the cathode electrode and the anode electrode is a graphite electrode.

2. The electrolysis device for preparing graphene by electrochemical exfoliation according to claim 1, characterized in that: A first base is provided at the bottom of the high-level tank, and a second base is provided at the bottom of the electrolytic tank; Preferably, the height of the first base is greater than the height of the second base; Preferably, the first base and the high-position tank are integrally formed; The second base is integrally formed with the electrolytic cell.

3. The electrolysis device for preparing graphene by electrochemical exfoliation according to claim 1, characterized in that: The electrode assembly is connected to a power source via an output cable; Preferably, two sets of paired electrode components are provided; Preferably, the base is a conductive base.

4. The electrolysis device for preparing graphene by electrochemical exfoliation according to claim 1, characterized in that: The other of the cathode electrode and the anode electrode is a stainless steel electrode plate.

5. The electrolysis device for preparing graphene by electrochemical exfoliation according to claim 1, characterized in that: The power supply is a pulse power supply dedicated for electrolysis; Preferably, the power supply is provided with an insulating power base.

6. The electrolysis device for preparing graphene by electrochemical exfoliation according to claim 1, characterized in that: The circulating pump is an acid-resistant circulating pump; Preferably, the circulation pump is equipped with an insulating circulation pump base.

7. The electrolysis device for preparing graphene by electrochemical exfoliation according to claim 1, characterized in that: The top of the high-position trough is equipped with a high-position trough cover, and the high-position trough cover is provided with a handle.

8. The electrolysis device for preparing graphene by electrochemical exfoliation according to claim 1, characterized in that: The first connecting pipe connects the lower part of the side wall of the high-level tank with the upper part of the side wall of the electrolytic tank; The second connecting pipe connects the lower part of the side wall of the electrolytic tank with the upper part of the side wall of the high-level tank; Preferably, among the four connection ports between the first connection pipe, the second connection pipe, the header tank and the electrolytic tank, only the connection port between the second connection pipe and the header tank is higher than the electrolyte level, and the other three connection ports are all below the electrolyte level; Preferably, a filtering device is also provided on the second connecting pipe.

9. The method for preparing graphene using an electrolysis device according to any one of claims 1 to 8, characterized in that: The steps include: S1: Assembling and fixing the clamp and the electrode part, and then connecting them to the base fixed on the electrolytic cell to form an electrode part assembly; The electrode portion serving as the cathode electrode and the electrode portion serving as the anode electrode are placed facing each other; S2: injecting electrolyte into the high-level tank, opening the first valve to allow the electrolyte to flow into the electrolytic tank, and when the electrolyte level is about to soak the bottom of the electrode part, closing the first valve and continuing to inject an appropriate amount of electrolyte into the high-level tank; S3: setting the voltage of the power supply, opening the power supply and the first valve, allowing the electrolyte to flow from the high-level tank into the electrolytic tank to submerge the bottom of the electrode part, and starting stripping; S4: After the stripping is completed, the second valve and the circulation pump are opened to form a circulating liquid flow, and the height of the electrolyte in the electrolytic cell is adjusted to prepare for the next round of stripping.

10. The method according to claim 9, characterized in that Controlling the stripping speed by adjusting the voltage of the power supply; Preferably, the height of the electrolyte level in the electrolytic cell is controlled by adjusting the first valve; Preferably, the circulating liquid flow is controlled by adjusting the second valve.

Images