Device for in-situ preparation of graphene coating on surface of graphite current collector and application

Abstract

The invention provides a device for in-situ preparation of a graphene coating on the surface of a graphite current collector and application, relates to the technical field of functional coating preparation, and particularly relates to the device for in-situ preparation of the graphene coating on the surface of the graphite current collector, a use method of the device and a preparation method of the graphene coating. The device comprises a rack, a two-dimensional motion track arranged on the rack, a working electrode module connected with the two-dimensional motion track through a working electrode module fixing seat, and a conductive base fixed on the rack and used for fixing a graphite current collector, and the working electrode module comprises an air nozzle, a working electrode, a power interface and an air source interface. The working face of the device is very flexible, the rotatable working electrode is combined with the movable two-dimensional motion track to achieve the synergistic effect, the motion dimensions of the working electrode are diversified, and continuous preparation of the graphene coating on the three-dimensional curved surface can be achieved.

Description

Technical Field

[0001] The present application belongs to the technical field of functional coating preparation, and particularly relates to a device for in-situ preparing a graphene coating on the surface of a graphite current collector and a method for preparing a graphene coating using the device. Background Art

[0002] Graphene is a two-dimensional layered material with only one or a few layers of carbon atoms thick, which exhibits excellent electrical conductivity, thermal conductivity, chemical stability and light transmittance. Therefore, graphene coatings have great application potential in the fields of corrosion protection, light and sound elimination, transparent conductivity, and electrode performance enhancement.

[0003] The preparation of traditional graphene coatings generally includes the steps of graphene preparation, slurry preparation and spray curing. Among them, the preparation methods of graphene mainly include chemical vapor deposition and chemical oxidation-reduction methods. On the one hand, the chemical vapor deposition method requires high-temperature equipment and involves flammable and explosive gases, which leads to a long preparation cycle and high cost of graphene; on the other hand, the chemical oxidation-reduction method requires the use of concentrated sulfuric acid, potassium permanganate, hydrazine hydrate, sodium borohydride and other dangerous chemicals, and the environmental cost of waste liquid treatment is extremely high. In addition, the subsequent graphene slurry preparation steps and the spray curing steps of the graphene coating require a large amount of solvents and additives. The process is cumbersome and the prepared coating has many graphene defect sites, poor conductivity, dense arrangement, and a small effective area.

[0004] In summary, there is an urgent need for an efficient, convenient and low-cost device for preparing graphene coatings to achieve stable, fast and efficient preparation of graphene-based electrodes. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a device and application for in-situ preparation of a graphene coating on the surface of a graphite current collector, and to solve a series of problems raised in the above background technology through the following technical solutions.

[0006] In a first aspect, a device for in-situ preparation of a graphene coating on the surface of a graphite current collector is provided, comprising a frame, a two-dimensional motion track arranged on the frame, a working electrode module connected to the two-dimensional motion track via a working electrode module fixing seat, and a conductive base fixed on the frame for fixing the graphite current collector, the working electrode module comprising a gas nozzle interface fixed thereon, gas outlets distributed inside thereof and an electrode clamp fixed at the center position thereof, a working electrode and a gas nozzle, a pulse power supply interface, and a gas source interface.

[0007] In some specific embodiments, the two-dimensional motion track includes an X-axis sliding module and a Y-axis sliding module.

[0008] In some specific embodiments, the working electrode includes a conductive body and a discharge tip, the discharge tip is in the shape of a needle, a tube or a sheet, and the number of the discharge tip is one or more.

[0009] In some specific embodiments, the working electrode module fixing seat includes a spacing adjustment knob, a working electrode rotation motor, a working electrode fixing anchor point, a sliding table and a fixed table located below the sliding table. The sliding table and the fixed table are movably connected by a dovetail mortise and tenon structure, and the spacing adjustment knob is used to adjust the distance between the sliding table and the fixed table.

[0010] In some specific embodiments, the device further comprises a pulse power supply, a gas source, a gas flow controller, and a motor controller.

[0011] In a second aspect, a method for using a device for in-situ preparing a graphene coating on a graphite current collector surface is provided, including equipment connection and debugging steps:

[0012] The working electrode module is mounted on the two-dimensional motion track through a working electrode module fixing seat;

[0013] placing a graphite current collector on a conductive base;

[0014] Connect the two electrodes of the pulse power supply to the pulse power supply interface of the working electrode module and the conductive base respectively;

[0015] Connect the gas source and the gas flow controller to the gas source interface of the working electrode module, supply gas to the gas outlet, and gather it around the working electrode through the gas nozzle to form a specified gas atmosphere;

[0016] Adjust the spacing adjustment knob of the working electrode module fixing seat so that the spacing between the working electrode and the graphite current collector is less than 10 mm;

[0017] Turn on the power of the rack and connect the motor controller, operate the X-axis sliding module and the Y-axis sliding module to move the working electrode to the positioning point, turn on the pulse power supply, and prepare the graphene layer.

[0018] In some specific embodiments, the method for using the device includes the step of preparing a graphene layer: after confirming that the working electrode has moved to the positioning point, turning on the power supply, setting the output voltage and pulse frequency, so that a stable arc is formed between the working electrode and the graphite current collector, and the graphite on the surface of the current collector forms a graphene coating under the action of the arc.

[0019] In some specific embodiments, the graphite current collector is a pure graphite product or a composite current collector with a graphite coating.

[0020] Beneficial effects of this application:

[0021] (1) The present application relates to a device for in-situ preparation of a graphene coating on the surface of a graphite current collector, which mainly consists of a two-dimensionally movable track frame, a conductive base for fixing the graphite current collector, a working electrode module fixed on the track, a working electrode module and a pulse power supply, a gas source, a gas flow controller and a motor controller. The device has a very flexible working surface, and adopts a rotatable working electrode combined with a movable two-dimensional motion track to achieve a variety of movement dimensions of the working electrode, which can realize continuous preparation of graphene coating on a three-dimensional curved surface.

[0022] (2) The present application relates to a method for using a device for in-situ preparation of a graphene coating on the surface of a graphite current collector, wherein a motor controller is connected to a frame and a working electrode module fixing seat respectively; a gas source and a gas flow controller are connected to the gas source interface of the working electrode module, the gas source is turned on and the gas flow rate is regulated by the gas flow controller; the two poles of a pulse power supply are connected to the working electrode module and the conductive base respectively; the spacing adjustment knob on the working electrode module fixing seat is turned to adjust the distance between the electrode and the base; the pulse power supply is turned on and parameters are set to form a stable arc between the working electrode and the current collector, and the position, movement speed and direction of the pulse arc are controlled by the motor controller to control the movement of the X and Y sliding modules and the working electrode rotation motor, thereby quickly and stably preparing a high-quality graphene layer in situ on the surface of the current collector. The device has a high degree of integration and semi-automatic control, and can achieve precise positioning of the graphene coating formation position, and the shape of the graphene coating is flexible and controllable.

[0023] (3) The present application relates to a method for preparing a graphene coating in situ on the surface of a graphite current collector. The device described in the present invention uses a pulsed electric arc to act on the graphite on the surface of the current collector to convert it into one or a few layers of graphene. By adjusting the voltage and frequency of the pulsed electric arc and controlling the movement of the electric arc, a graphene coating of a specific shape and thickness can be formed in situ at a designated position of the graphite current collector or a composite current collector having a graphite coating. Different atmospheres can be created in the arc working area by changing the gas source. For example: using argon as the gas source can reduce the oxidation of graphene and improve the yield and purity; using fluorine / argon mixed gas as the gas source can prepare fluorine-doped graphene. This method provides a simple, efficient and convenient method for the preparation of graphene coatings, greatly improving the preparation efficiency of graphene-based electrodes and other related products, and reducing the production costs of related industries.

[0024] (4) The present application relates to a graphene coating. The device of the present application can be used to prepare a graphene coating in situ on a graphite current collector or a composite current collector with a graphite coating, and finally obtain a graphene electrode. The obtained graphene electrode can be applied to the field of energy storage, and can effectively improve the specific capacity and cycle stability. Compared with the traditional method, the in-situ graphene electrode prepared by the device of the present application does not require a high temperature environment and toxic chemicals, making the operation safer, more convenient, energy-saving and environmentally friendly, reducing labor requirements and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings.

[0026] Figure 1 A schematic diagram of the overall structure of a device for in-situ preparation of a graphene coating on the surface of a graphite current collector provided in the present application;

[0027] Figure 2 A schematic diagram of module connections of a device for in-situ preparation of a graphene coating on a graphite current collector surface provided in the present application;

[0028] Figure 3 A schematic diagram of the structure of a working electrode module of a device for in-situ preparation of a graphene coating on a graphite current collector surface provided in the present application;

[0029] Figure 4 Provided for this application Figure 3 A is an enlarged schematic diagram;

[0030] Figure 5 A schematic structural diagram of a working electrode module fixing seat of a device for in-situ preparation of a graphene coating on a graphite current collector surface provided in the present application;

[0031] Figure 6 A photograph of a graphene coating prepared in situ on the surface of a graphite current collector using the device described in the present application;

[0032] Figure 7 Schematic diagram (1) and partial magnified diagram (2) of the scanning electron microscope (SEM) results of the graphene coating prepared in this application;

[0033] Figure 8 This is the Raman spectrum (Raman) of the graphene coating prepared in this application.

[0034] In the figure: 10, frame; 20, X-axis sliding module; 30, working electrode module fixing seat; 31, spacing adjustment knob; 32, working electrode rotating motor; 33, working electrode fixing anchor point; 34, sliding table; 35, fixed table; 40, Y-axis sliding module; 50, working electrode module; 51, gas nozzle interface; 52, gas outlet; 53, electrode fixture; 54, working electrode; 54-1, conductive body; 54-2 discharge tip; 55, gas nozzle; 56, pulse power supply interface; 57, gas source interface; 60, conductive base; 70, pulse power supply; 80, gas source; 81, gas flow controller; 90, motor controller. DETAILED DESCRIPTION

[0035] In order to make the technical means, creative features, objectives and effects achieved by this application easy to understand, this application is further explained below in conjunction with specific implementation methods and drawings.

[0036] It should be noted that: when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a centered component; when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centered component at the same time; when a component is considered to be "set on" another component, it may be directly set on the other component or there may be a centered component at the same time. The terms "vertical", "horizontal", "left", "right", "head", "tail" and similar expressions used in this application are for illustrative purposes only. The term "and / or" used in this application includes any and all combinations of one or more related listed items. The terms "first", "second", "third", etc. used in this application are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those generally understood by technicians in the technical field of this application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0037] Example 1

[0038] This embodiment provides a device for in-situ preparation of a graphene coating on the surface of a graphite current collector, such as Figures 1 to 5As shown, it includes a frame 10, a two-dimensional motion track arranged on the frame 10, a working electrode module 50 connected to the two-dimensional motion track through a working electrode module fixing seat 30, a conductive base 60 fixed on the frame 10 for fixing a graphite current collector, a pulse power supply 70, a gas source 80, a gas flow controller 81, and a motor controller 90; the two-dimensional motion track includes an X-axis sliding module 20 and a Y-axis sliding module 40; the working electrode module fixing seat 30 includes a spacing adjustment knob 31 for adjusting the spacing between the working electrode and the graphite current collector, a working electrode rotating motor 32, a working electrode fixing anchor point 33, and a sliding table 34. A fixed table 35 is located below the sliding table 34. The spacing adjustment knob 31 is used to adjust the relative distance between the sliding table 34 and the fixed table 35. The sliding table 34 and the fixed table 35 are movably connected through a dovetail mortise and tenon structure 36. The working electrode module 50 includes a gas nozzle interface 51 fixed on the working electrode module 50, an air outlet 52 distributed inside the working electrode module 50 and an electrode fixture 53 fixed at the center position of the working electrode module 50, a working electrode 54 and a gas nozzle 55, a pulse power supply interface 56, and a gas source interface 57. The working electrode 54 includes a conductive body 54-1 and a discharge tip 54-2.

[0039] Specifically, the shape of the discharge tip 54-2 may include but is not limited to needle-shaped, tubular or sheet-shaped, and the number of the discharge tip 54-2 may be one or more. In this embodiment, the discharge tip 54-2 of the working electrode 54 is shaped as five needles arranged in a cross, and is located at one end of the conductive body 54-1.

[0040] The pulse power supply 70 involved in this embodiment adopts a structure well known to those skilled in the art, and can output adjustable pulse voltage amplitude and frequency.

[0041] The gas flow controller 81 involved in this embodiment adopts a structure well known to those skilled in the art and is not particularly limited.

[0042] Example 2

[0043] This embodiment provides a method for using the device described in the above embodiment. The method is completed by using the device for in-situ preparing a graphene coating on the surface of a graphite current collector in the above embodiment. The specific steps include:

[0044] S1. Equipment connection and debugging

[0045] The working electrode module 50 is mounted on the X-axis sliding module 20 of the two-dimensional motion track through the working electrode module fixing seat 30;

[0046] Place the graphene current collector on the conductive base 60 and fix it as tightly and flatly as possible to ensure good current conductivity; wherein the graphite current collector can be a pure graphite product or a composite current collector with a graphite coating;

[0047] Connect one electrode of the pulse power supply 70 to the pulse power supply interface 56 of the working electrode module 50, and connect the other electrode of the pulse power supply 70 to the conductive base 60;

[0048] Connect the gas source 80 and the gas flow controller 81 to the gas source interface 54 of the working electrode module 50, supply gas to the gas outlet 52, and gather around the working electrode 54 through the gas nozzle 55 to form a specified gas atmosphere;

[0049] Rotate the spacing adjustment knob 31 to adjust the translation distance of the sliding table 34 on the fixed table 35 so that the spacing between the working electrode 52 and the graphite current collector is less than 10 mm;

[0050] The rack 10 is powered on and connected to the motor controller 90, the X-axis sliding module 20 and the Y-axis sliding module 40 are controlled to move the working electrode 52 to the positioning point, and the pulse power supply 70 is turned on to prepare the graphene coating;

[0051] S2. Preparation of graphene coating

[0052] Adjust the gas flow controller 81 so that the gas is ejected from the gas nozzle 55 and forms a stable atmosphere between the electrode and the current collector;

[0053] After confirming that the working electrode 54 has moved to the positioning point, the pulse power supply 70 is turned on, and the output pulse voltage amplitude and frequency are set so that a stable arc is formed between the working electrode 54 and the graphite current collector;

[0054] The motor controller 90 controls the motors to work together, so that the working electrode 54 moves the arc at a set speed and path. When sweeping across the graphite current collector, the graphite on the surface of the graphite current collector expands and transforms into graphene in situ. The continuous graphene eventually forms a porous graphene coating.

[0055] Example 3

[0056] The present embodiment provides a graphene coating, which is prepared by using the device shown in the embodiment and completed by the method of using the device provided in Example 2. The obtained graphene coating has a thickness of 200 μm. The specific operation steps are: the gas source 80 is argon gas, the flow rate is set to 100 mL / min, the distance between the working electrode 54 and the current collector is adjusted to 5 mm, and after confirming that the working electrode 54 has moved to the positioning point, the pulse power supply 70 is turned on, the output voltage is set to 10 kV, and the pulse frequency is set to 500 Hz, so that a stable arc is formed between the working electrode 54 and the graphite current collector; when the arc sweeps across the graphite current collector at a speed of 60 mm / min, the volume of graphite on the surface of the graphite current collector expands and is converted into a graphene coating in situ at the specified position.

[0057] Embodiment 4-12

[0058] Examples 4-12 provide graphene coatings of different thicknesses, and the specific preparation method is the same as that of Example 3, except that the parameters such as voltage, current, and arc movement speed are different during the preparation process. In Example 4-12, graphene coatings of different thicknesses are prepared in situ by changing the voltage, frequency, and electrode movement speed applied to both ends of the conductor, and the specific parameters are shown in Table 1.

[0059] Table 1 Specific parameters of the embodiment

[0060]

[0061] Test Example 1

[0062] The appearance of the graphene coating prepared in Example 3 was photographed and recorded. Figure 6 As shown, the in-situ prepared graphene coating is uniform, precisely positioned, and has diverse shapes.

[0063] Test Example 2

[0064] The graphene coating prepared in Example 7 was observed using a scanning electron microscope (SEM) to observe its internal structure. Figure 7 As shown in (1), the in situ prepared graphene coating exhibits a porous structure under a scanning electron microscope. Figure 7 (2) is a partial enlarged view, where a few layers of graphene can be seen. It can be seen that the device and preparation method used in this application can effectively realize the in-situ preparation of graphene coatings. In addition, by adjusting the loading voltage and frequency, and the moving speed of the working electrode, graphene coatings of different thicknesses can also be prepared.

[0065] Test Example 3

[0066] Raman spectroscopy was used to observe the number of layers in the graphene prepared in Example 11. Figure 8 As shown, the Raman spectrum shows a well-defined G peak (1630 cm -1 ) and 2D peak (2785cm -1 ), compared with graphite, the 2D peak and G peak height ratio of graphene coating (I 2D / I G ) value is significantly increased, which indicates that the graphite sheet structure is transformed into a mixture of single-layer and multi-layer graphene under the action of the arc.

[0067] The above description is a detailed description, basic principles and beneficial effects of the preferred feasible embodiments of the present application, but the embodiments are not intended to limit the scope of the patent application of the present application. Without departing from the spirit or basic features of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work based on the embodiments in the present application belong to the scope of protection of the present application, and all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present application. Although this specification is described in accordance with the implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should take the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A device for in-situ preparation of a graphene coating on the surface of a graphite current collector, characterized in that: The invention comprises a frame (10), a two-dimensional motion track arranged on the frame (10), a working electrode module (50) connected to the two-dimensional motion track via a working electrode module fixing seat (30), and a conductive base (60) fixed on the frame (10) for fixing a graphite current collector, wherein the working electrode module (50) comprises a gas nozzle interface (51) fixed thereon, gas outlets (52) distributed inside the working electrode module and an electrode fixture (53) fixed at the center of the circle, a working electrode (54) and a gas nozzle (55), a pulse power supply interface (56), and a gas source interface (57).

2. The device according to claim 1, characterized in that The two-dimensional motion track comprises an X-axis sliding module (20) and a Y-axis sliding module (40).

3. The device according to claim 1, characterized in that The working electrode (54) comprises a conductive body (54-1) and a discharge tip (54-2). The discharge tip (54-2) is in the shape of a needle, a tube or a sheet. The number of the discharge tip (54-2) is one or more.

4. The device according to claim 1 or 2, characterized in that: The working electrode module fixing seat (30) comprises a spacing adjustment knob (31), a working electrode rotating motor (32), a working electrode fixing anchor point (33), a sliding platform (34) and a fixing platform (35) located below the sliding platform (34); the sliding platform (34) and the fixing platform (35) are movably connected via a dovetail mortise and tenon structure (36); and the spacing adjustment knob (31) is used to adjust the distance between the sliding platform (34) and the fixing platform (35).

5. The device according to claim 4, characterized in that It also includes a pulse power supply (70), a gas source (80), a gas flow controller (81), and a motor controller (90).

6. A method for using the device according to any one of claims 1 to 5, characterized in that: Including equipment connection and debugging steps: The working electrode module (50) is mounted on a two-dimensional motion track via a working electrode module fixing seat (30); Placing a graphite current collector on a conductive base (60); Connecting two electrodes of a pulse power supply (70) to the pulse power supply interface (56) of the working electrode module (50) and the conductive base (60) respectively; Connecting a gas source (80) and a gas flow controller (81) to the gas source interface (54) of the working electrode module (50), supplying gas to the gas outlet (52), and converging the gas through the gas nozzle (55) around the working electrode (54) to form a specified gas atmosphere; Adjusting the spacing adjustment knob (31) of the working electrode module fixing seat (30) so that the spacing between the working electrode (52) and the graphite current collector is less than 10 mm; The power supply of the frame (10) is turned on and the motor controller (90) is connected, the X-axis sliding module (20) and the Y-axis sliding module (40) are controlled to move the working electrode (52) to the positioning point, and the pulse power supply (70) is turned on to prepare the graphene layer.

7. The method of use according to claim 6, characterized in that: The method comprises the steps of preparing a graphene layer: after confirming that the working electrode (54) moves to a positioning point, turning on a power source, setting an output voltage and a pulse frequency, so that a stable arc is formed between the working electrode (54) and the graphite current collector, and a graphene coating is formed on the surface of the current collector under the action of the arc.

8. The method of use according to claim 7, characterized in that: The graphite current collector is a pure graphite product or a composite current collector with a graphite coating.

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