Preparation method and device of graphene metal composite material

Abstract

The invention provides a preparation method and device of a graphene metal composite material. The preparation method comprises the steps that a metal raw material is prefabricated into metal liquid or metal powder or metal powder coated with a carbon source; a prefabricated metal raw material is sprayed to the first reaction area, and metal powder with the solid metal powder surface is prepared; the metal powder with the solid surface is put into a second reaction area, the metal powder is heated until part or all of the surface of the metal powder is in a liquid state, graphene is deposited on the surface of the metal powder, and a graphene metal compound is obtained; wherein the temperature of the second reaction zone is higher than that of the first reaction zone; the graphene metal compound is put into a cooling area to be cooled, and the graphene metal composite material is obtained; wherein the temperature of the cooling zone is lower than that of the first reaction zone. The invention aims to solve the technical defects of small graphene coating area and low quality in the graphene metal composite material obtained in the prior art.

Description

Technical Field

[0001] The present application relates to the technical field of graphene conductive material preparation, and in particular to a method and device for preparing a graphene metal composite material. Background Art

[0002] Graphene has excellent electrical conductivity, thermal conductivity and mechanical properties, so it is added to metal materials to form graphene metal composite materials to enhance the electrical, mechanical, corrosion resistance, oxidation resistance and other properties of metal materials. In the prior art, the composite of graphene and metal materials mainly includes physical mixing and CVD process.

[0003] The physical mixing process mainly includes the following steps: a large amount of graphene is prepared by mechanical exfoliation, oxidation-reduction method and other processes, and then it is directly added to the metal substrate as the second phase, and mixed by ultrasound, stirring, ball milling and other methods to obtain the graphene metal matrix composite material. Although this process is very efficient and low in cost, the second phase materials such as graphene will agglomerate in the metal substrate and the dispersion uniformity is poor; and the graphene used in this process is of low quality and poor performance, so the final graphene metal matrix composite material does not have excellent performance.

[0004] The process of in-situ growth of graphene based on CVD is to directly grow graphene in-situ on the surface of the metal substrate through the CVD process. Although the quality of graphene obtained by this process is significantly improved compared with the physical mixing valve, the efficiency is not high, and the coverage area of ​​the graphene is small and the quality is not high.

[0005] In summary, the graphene metal composite material obtained by the prior art has the technical deficiencies of small graphene coating area and low quality. Summary of the invention

[0006] The present application provides a method and device for preparing a graphene metal composite material, aiming to solve the technical deficiencies of small graphene coating area and low quality in the graphene metal composite material obtained in the prior art.

[0007] On the one hand, the present application provides a method for preparing a graphene metal powder material, the preparation method comprising:

[0008] Prefabricate the metal raw material into metal liquid or metal powder or metal powder coated with a carbon source;

[0009] Spraying the prefabricated metal raw material into the first reaction zone to prepare a metal powder having a solid surface;

[0010] The metal powder with a solid surface is placed in a second reaction zone, the metal powder with a solid surface is heated until part or all of the surface is liquid, and graphene is deposited on the surface of the metal powder with a part or all of the surface being liquid to obtain a graphene-metal composite; wherein the temperature of the second reaction zone is greater than the temperature of the first reaction zone;

[0011] The graphene metal composite is placed in a cooling zone for cooling to obtain a graphene metal composite material; wherein the temperature of the cooling zone is lower than the temperature of the first reaction zone.

[0012] Optionally, the temperature of the first reaction zone is lower than the melting temperature of the metal raw material;

[0013] Prefabricate the raw materials into a molten metal liquid;

[0014] Spraying molten metal liquid into the first reaction zone;

[0015] The metal powder stays in the first reaction zone for 10-60 seconds and is cooled to form a metal powder with a solid surface.

[0016] Optionally, the metal powder with a solid surface stays in the second reaction zone for 2-20 minutes, so that the surface of the metal powder with a solid surface is slightly melted to be in a liquid state.

[0017] Optionally, a gaseous carbon source is introduced into the second reaction zone;

[0018] The graphene is deposited on the metal powder whose surface is in liquid state to obtain the graphene-metal composite.

[0019] Optionally, the temperature of the first reaction zone is 800-1000°C, and the temperature of the second reaction zone is 1080-1150°C.

[0020] Optionally, the temperature of the first reaction zone is lower than the melting temperature of the metal raw material;

[0021] Prefabricating the metal raw material into a molten metal liquid;

[0022] Spraying molten metal liquid into the first reaction zone;

[0023] The molten metal liquid sprayed into the first reaction zone stays in the first reaction zone for 0.5 to 5 seconds to cool down and becomes a metal powder with a solid surface and a liquid interior.

[0024] Optionally, the radius ratio of the solid outer wall to the internal liquid of the metal powder with a solid surface and a liquid interior is 1:1 to 10:1.

[0025] Optionally, the metal powder obtained in the first reaction zone is fed to a second reaction zone; the second reaction zone comprises: a first graphene deposition zone, a second graphene deposition zone and a third graphene layer deposition zone;

[0026] introducing the gaseous carbon source into the first graphene deposition zone and the third graphene deposition zone of the second reaction zone;

[0027] The metal powder with a solid surface and a liquid interior stays in the first graphene deposition area for 3-10 minutes to obtain a first intermediate graphene metal composite;

[0028] When the first intermediate graphene metal composite moves in the second graphene deposition area, the outer wall is punctured, and the liquid metal inside flows out and is coated on the outer wall of the first intermediate graphene metal composite, thereby obtaining a coated second intermediate graphene metal composite;

[0029] The second intermediate graphene metal composite stays in the third graphene deposition zone for 3 to 5 minutes, and graphene is deposited on the surface of the second intermediate graphene metal composite; and the metal powder in the second intermediate graphene metal composite is in the second graphene deposition zone, and the empty shell formed by the outflowing liquid metal is filled due to the liquefaction of the metal to obtain the graphene metal composite.

[0030] Optionally, the temperature of the first reaction zone is 800-1000°C, the temperature of the first graphene deposition zone is 1000-1060°C, the temperature of the second graphene deposition zone is 1080-1120°C, and the temperature of the third graphene deposition zone is 1080-1200°C.

[0031] Optionally, before the metal powder with a solid surface is placed in the second reaction zone, the metal powder with a solid surface is heated until part or all of the surface is liquid, and graphene is deposited on the surface of the metal powder with a liquid surface, to obtain the graphene-metal composite, the preparation method includes:

[0032] Putting the metal powder with a solid surface and a liquid interior into the mixing area;

[0033] In the mixing zone, the metal powder with a solid surface and a liquid interior is mixed with an anti-sintering agent to obtain a prefabricated mixture.

[0034] Optionally, a gaseous carbon source is introduced into the second reaction zone; the gaseous carbon source obtains graphene in the second reaction zone;

[0035] The residence time of the prefabricated mixture in the second reaction zone is 3-20 minutes, and the metal powder with a solid surface and a liquid interior is melted into a liquid state to combine with the graphene to obtain the graphene-metal composite.

[0036] Optionally, the temperature of the first reaction zone is 800-1000 degrees Celsius, and the temperature of the second reaction zone is 1080-1200 degrees Celsius; and / or

[0037] The anti-sintering agent is one or more of magnesium oxide, aluminum oxide or graphite; and / or,

[0038] The particle size of the anti-sintering agent is 0.1 to 15 microns; and / or,

[0039] The mass ratio of the semi-solid metal powder to the anti-sintering agent is 1:1 to 5:1.

[0040] Optionally, the gaseous carbon source includes alkane gas, hydrogen and inert gas; or the gaseous carbon source includes a carbon atom-containing gas obtained after pretreatment.

[0041] Optionally, the alkane gas is methane, and the inert gas is nitrogen and / or argon;

[0042] The amount of methane introduced is 5 to 50 sccm, the amount of hydrogen introduced is 5 to 500 sccm, and the amount of nitrogen and / or argon introduced is 0 to 1000 sccm.

[0043] Optionally, the raw material further comprises a solid carbon source and / or a liquid carbon source; the solid carbon source comprises polystyrene; the liquid carbon source comprises PMMA;

[0044] Prefabrication of raw materials into metal powder coated with carbon source includes:

[0045] mixing the solid carbon source with metal powder; and / or,

[0046] The metal powder is immersed in the liquid carbon source.

[0047] Optionally, the graphene metal composite enters the cooling zone so that the graphene metal composite is cooled, and obtaining the graphene metal composite material comprises:

[0048] The graphene metal composite material first enters the air cooling zone and then enters the water cooling zone to obtain the graphene metal composite material; the temperature of the air cooling zone is 400-500 degrees Celsius.

[0049] The present application also proposes a preparation device for a graphene metal composite material, which is used to prepare the graphene metal composite material. The preparation device comprises:

[0050] A reaction cylinder, wherein the reaction cylinder defines a feeding port and a first reaction zone, a second reaction zone and a cooling zone which are sequentially connected to the feeding port; wherein the temperature of the first reaction zone is greater than the temperature of the cooling zone and less than the second temperature of the second reaction zone;

[0051] A feeding assembly, the feeding assembly is arranged corresponding to the feeding port, and is configured to spray metal liquid or metal powder or metal powder coated with a carbon source into the first reaction zone through the feeding port;

[0052] A carbon source conveying component is configured to be connected to the second reaction zone to inject the carbon source into the second reaction zone or to inject the carbon source into the feeding component to form the metal powder coated with the carbon source.

[0053] Optionally, the first reaction zone is provided with a first conveying structure for guiding the metal liquid or metal powder or metal powder coated with a carbon source to move toward the second reaction zone;

[0054] The second reaction zone is provided with a second conveying structure, and the first conveying structure is connected to the second conveying structure, and is used to guide the metal powder with a solid surface to move toward the cooling zone.

[0055] Optionally, the first conveying structure includes a first track; the second conveying structure includes a second track, the second track is connected to the first track; the angle between the first track and the horizontal direction is 15-50°, and the angle between the second track and the horizontal direction is 10-70°; and / or

[0056] The first track and the second track are provided with protrusions and / or grooves; and / or;

[0057] The first track is a spiral track or a slope track, and the second track is a spiral track.

[0058] Optionally, the second reaction zone includes a first graphene deposition zone, a second graphene deposition zone and a third graphene deposition zone; the second graphene deposition zone is arranged between the first graphene deposition zone and the cooling zone; the third graphene deposition zone is arranged between the second graphene deposition zone and the cooling zone;

[0059] The second track includes a first conveying section, a second conveying section and a third conveying section which are connected in sequence; the first conveying section is arranged in the first graphene deposition area; the second conveying section is arranged on the second graphene deposition area, and a pointed protrusion is arranged on the second conveying section; the third conveying section is arranged on the third graphene deposition area.

[0060] Optionally, the first track is a slope track; and / or

[0061] The angle between the second conveying section and the horizontal direction is 40-70°, the angle between the first conveying section and the horizontal direction is 10-40°, and the angle between the third conveying section and the horizontal direction is 10-30°.

[0062] Optionally, the preparation device is further provided with a mixing zone located between the first reaction zone and the second reaction zone; a platform is further provided in the second reaction zone; and the second conveying structure is arranged between the mixing zone and the platform.

[0063] Optionally, the feeding assembly includes a crucible, and a nozzle is provided on the crucible for spraying metal liquid or metal powder or metal powder coated with a carbon source.

[0064] Optionally, the feeding assembly further comprises a mixing tank configured as a mixing cavity having a discharge port; the mixing tank is connected to the carbon source conveying device to mix the solid and / or liquid carbon source with the metal powder in the mixing cavity to form the metal powder coated with the carbon source;

[0065] The mixing tank comprises a baffle, and the baffle is used to open or close the discharge port; the crucible is arranged corresponding to the discharge port to receive the metal powder coated with the carbon source.

[0066] Optionally, the carbon source delivery assembly includes an air pipe, which is configured to be connected to the second reaction zone for delivering a gaseous carbon source to the second reaction zone; wherein the gaseous carbon source includes alkane gas, hydrogen and inert gas; or the gaseous carbon source includes a carbon atom-containing gas obtained after pretreatment.

[0067] In the technical solution of the embodiment of the present application, the metal raw material is heat-treated by spraying metal liquid or metal powder or metal powder coated with a carbon source into the first reaction zone to make it a metal powder with a solid surface; then the metal powder with a solid surface is placed in the second reaction zone to further heat the metal powder, heat the metal powder until part or all of the surface is liquid, and deposit graphene on the surface of the metal powder to obtain a graphene metal composite; then the graphene metal composite is further cooled to obtain a graphene metal composite material. In the technical solution of the embodiment of the present application, the metal powder is combined with graphene when at least part of the surface or the whole surface is liquid, which increases the graphene deposition time of the metal droplets, is conducive to forming a graphene layer with a large coating area, and improves the quality of the graphene metal composite material.

[0068] Furthermore, in the technical solution of the embodiment of the present application, the metal powder moves along the first conveying structure and the second conveying structure in the preparation device to polish the surface of the metal powder while controlling the residence time of the metal material in the first reaction zone and the second reaction zone to reserve sufficient growth time for obtaining a graphene layer with a large coating area. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0070] Figure 1 It is a schematic diagram of a process for preparing a graphene metal composite material provided in an embodiment of the present application;

[0071] Figure 2 1 is a first structural schematic diagram of a device for preparing a graphene metal composite material provided in an embodiment of the present application;

[0072] Figure 3 is a second structural schematic diagram of a device for preparing a graphene metal composite material provided in an embodiment of the present application;

[0073] Figure 4 It is a schematic structural diagram of the second conveying section in the second structure of the device for preparing the graphene metal composite material provided in the embodiment of the present application;

[0074] Figure 5 1 is a first structural schematic diagram of a device for preparing a graphene metal composite material provided in an embodiment of the present application;

[0075] Figure 6 This is an electron microscope image of a graphene metal composite material obtained by using the preparation method of the graphene metal composite material provided in the examples of the present application.

[0076] Reference numerals list

[0077] 1 First reaction zone 24 The third conveying section 2 Second reaction zone 100 Crucible 3 Cooling Zone 110 nozzle 4 Mixing area 200 Mixing tank 5 platform 231 Pointed protrusion 11 First Track 2a First graphene deposition area 21 Second Track 2b Second graphene deposition area 22 First conveying section 2c The third graphene deposition area 23 Second conveying section DETAILED DESCRIPTION

[0078] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0079] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0080] In this application, the word "exemplary" is used to mean "serving as an example, illustration, or illustration." Any embodiment described in this application as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any person skilled in the art to implement and use the invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the invention can be implemented without using these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in this application.

[0081] Graphene metal composite materials are usually prepared with two processes, one is to adopt physical mixing method, and the other is based on CVD process. The former is mainly to prepare a large amount of graphene by mechanical stripping method, redox method and other processes, and then directly add it to the metal substrate as the second phase, and mix it with methods such as ultrasound, stirring, ball milling to obtain graphene metal matrix composite materials. In this preparation process, the second phase materials such as graphene have agglomeration phenomenon in the metal substrate, and the uniformity of dispersion is poor, so the final graphene metal matrix composite material performance is not excellent enough. The graphene coating area obtained by the latter is small, and the powder uniformity is not high, and the quality of the graphene metal composite material obtained is still relatively low.

[0082] To this end, an embodiment of the present application provides a method for preparing a graphene metal composite material, by depositing graphene when the metal material is at least partially in liquid state to obtain a high-quality and large-area graphene coating layer, thereby improving the quality of the graphene metal composite material.

[0083] Specifically, the present application proposes a method for preparing a graphene metal composite material, and uses a graphene metal composite material preparation device to produce a graphene metal composite material, such as Figure 1 As shown. Figure 2 As shown, the preparation device has a chamber, and the chamber is divided into a first reaction zone 1, a second reaction zone 2 and a cooling zone 3. The temperature of the first reaction zone 1 is lower than the temperature of the second reaction zone 2, and the temperature of the cooling zone 3 is lower than the temperature of the first reaction zone 1.

[0084] like Figure 1 As shown, the preparation method comprises:

[0085] S100, prefabricating the metal raw material into metal liquid or metal powder or metal powder coated with a carbon source;

[0086] S200, spraying the prefabricated metal raw material into the first reaction zone to prepare a metal powder having a solid surface;

[0087] S300, placing the metal powder with a solid surface into a second reaction zone, heating the metal powder until a part or all of the surface is liquid, and depositing graphene on the surface of the metal powder to obtain a graphene-metal composite; wherein the temperature of the second reaction zone is greater than the temperature of the first reaction zone;

[0088] S400, placing the graphene-metal composite into a cooling zone for cooling to obtain a graphene-metal composite material; wherein the temperature of the cooling zone is lower than the temperature of the first reaction zone.

[0089] In the technical solution of the embodiment of the present application, the metal raw material is heat-treated by spraying metal liquid or metal powder or metal powder coated with a carbon source into the first reaction zone 1, so that the metal raw material is in a solid metal powder surface; then the metal powder with a solid surface is placed in the second reaction zone 2 to further heat the metal material, heat the metal powder until part or all of the surface is liquid, and deposit graphene on the surface of the metal powder to obtain a graphene metal composite; then the graphene metal composite is further cooled to obtain a graphene metal composite material. In the technical solution of the embodiment of the present application, the metal powder is combined with graphene when at least part of the surface or the entire surface is liquid, which increases the graphene deposition time of the metal droplets, is conducive to the formation of a graphene layer with a large coating area, and improves the quality of the graphene metal composite material.

[0090] It should be noted that the temperature of the first reaction zone 1 and the temperature of the second reaction zone 2 are set corresponding to the metal raw materials. The metal raw materials are metal materials that can deposit graphene, such as copper, copper alloys, nickel, nickel alloys and other metal materials. The setting of the temperature of the first reaction zone 1 can respectively make the surface of the metal raw materials solid, such as the metal material is soft or semi-solid. The temperature of the second reaction zone 2 makes the metal material with a solid surface appear to be liquid or part of the surface is liquid. The temperature of the cooling zone 3 is usually a temperature that can make the metal material re-solidify. Furthermore, a heating device is provided on the periphery of the refrigeration device, and the heating device sets the corresponding temperature through a temperature control controller so that the first reaction zone 1, the second reaction zone 2 and the cooling zone 3 have different temperatures respectively.

[0091] Furthermore, in some embodiments, the metal material can be put into the first reaction zone 1 in the form of metal powder, and then the metal powder in the first reaction zone 1 is in a soft state or semi-solid state due to the high temperature. For example, after the metal material is made into powder, the metal powder is evenly put into the first reaction zone 1 through a screen; in other embodiments, the metal material can be pre-treated into a molten state, and then sprayed into the first reaction zone 1 through the nozzle 110. In this case, the temperature of the first reaction zone 1 is set to be lower than the melting point of the metal material, and the temperature of the metal material decreases to present a soft state or a semi-solid metal powder. For example, Figure 2 , 4 As shown in Figures 5 and 6, in the embodiment, a mixing tank 200 is provided on the top of the crucible 110. The mixing tank 200 has a baffle. By opening the baffle, the metal material in the mixing tank 200 is put into the crucible. The mixing tank 200 may contain a block of metal material or a powdered metal material. The metal material is melted by the crucible 100, and the melted metal material is sprayed toward the first reaction zone 1 through the nozzle 110. In this embodiment, the size of the nozzle 110 can be adjusted according to the process requirements and product requirements.

[0092] Further, it should be noted that the carbon source of graphene can be a gaseous carbon source, a solid carbon source or a liquid carbon source. For example, when a gaseous carbon source is used, the gaseous carbon source is injected into the second reaction zone 2 through the carbon source delivery assembly 300, and the gaseous carbon source decomposes under the high temperature environment of the second reaction zone 2 to contain carbon atoms. Alternatively, the raw materials may contain not only metal materials but also solid carbon sources or liquid carbon sources; the carbon source delivery component 300 delivers the solid carbon source to the mixing chamber of the mixing tank; the solid carbon source may be pre-made into a powder, such as polystyrene, and mixed evenly with the powdered metal material in the mixing tank, and then put into the crucible after the baffle is opened, and then sprayed into the first reaction zone through the nozzle on the crucible; alternatively, the carbon source delivery component 300 delivers the liquid carbon source to the mixing chamber of the mixing tank, so that the powdered metal material is immersed in the liquid carbon source (such as PMMA) for a period of time, and then put into the crucible after the baffle is opened, and then sprayed into the first reaction zone through the nozzle on the crucible; the crucible may not be heated at this time.

[0093] In some embodiments, the gaseous carbon source generally contains alkane gas, such as methane, ethane, etc., or it can be a gas containing carbon atoms obtained by a pretreatment device. The pretreatment device contains a catalyst for catalytically cracking the alkane carbon source gas to obtain a gas containing carbon atoms. The catalyst can be a metal such as copper and nickel, or a non-metallic material such as sodium chloride and potassium chloride. In addition, the gaseous carbon source generally contains hydrogen and an inert gas. The inert gas generally includes nitrogen or argon.

[0094] Further, the cooling zone 3 includes an air cooling zone and a water cooling zone; the temperature of the air cooling zone is 400-500 degrees Celsius. The graphene metal composite enters the cooling zone 3 so that the graphene metal composite is cooled, and the graphene metal composite material is obtained, including: the graphene metal composite first enters the air cooling zone, and then enters the water cooling zone to obtain the graphene metal composite material. In the air cooling zone, the graphene metal composite is gradually cooled to 400-500 degrees by gas phase cooling, and the cooled graphene metal composite enters the water cooling at the bottom of the device to be cooled again to room temperature. First, it is gradually cooled by air to prevent the surface morphology of the metal powder from changing due to severe water cooling, thereby effectively improving the quality of the graphene metal material. In an embodiment, the air cooling zone is usually injected with an inert gas, usually nitrogen.

[0095] In some embodiments, the first reaction zone 1, the second reaction zone 2 and the cooling zone 3 are arranged in sequence along the direction of gravity. In the technical solution of the embodiment of the present application, after the metal material is put into the preparation device, it passes through the first reaction zone 1, the second reaction zone 2 and the cooling zone 3 in sequence under the action of gravity. The metal raw material moves toward the second reaction zone in the first reaction zone, and in the process of movement, it is the soft metal powder or the semi-solid metal powder; the soft metal powder or the semi-solid metal powder moves toward the cooling zone in the second reaction zone, and part of the surface or the whole surface presents a liquid state on at least one section of the movement path. In an embodiment, a first conveying structure is arranged in the first reaction zone 1; the metal raw material moves toward the second reaction zone 2 on the first conveying structure, and in the process of movement, it presents the soft metal powder or the semi-solid metal powder. A second conveying structure is arranged in the second reaction zone 2: the soft metal powder or the semi-solid metal powder moves toward the cooling zone 3 on the second conveying structure, and presents a liquid state on at least one section of the movement path. In the technical solution of the embodiment of the present application, the metal material moves along the first conveying structure and the second conveying structure in the preparation device to polish the surface of the metal material. At the same time, the residence time of the metal material in the first reaction zone 1 and the second reaction zone 2 can be controlled to reserve sufficient growth time for obtaining a graphene layer with a large coating area.

[0096] In the above embodiments, the soft metal powder or semi-solid metal powder moves on the second conveying structure toward the cooling zone 3 and is in liquid state on at least a section of the movement path. It can be understood as follows: 1. During the movement, the metal powder slightly melts on the surface in the second reaction zone 2 due to the increase in temperature; 2. During the movement, the semi-solid metal powder is punctured in a certain space in the second reaction zone 2 due to the outer wall being punctured, and the liquid metal inside flows out; 3. The metal powder is completely melted.

[0097] For example, both the first conveying structure and the second conveying mechanism can be set as a spiral track (or a reciprocating ramp track). The surface quality of the metal material and the residence time in different reaction zones can be controlled by setting the roughness, slope and length of the spiral track (or the length of the reciprocating ramp track). For another example, both the first conveying structure and the second conveying mechanism can be set as a conveying track, and the conveying speed of the conveying track can be controlled and the roughness of the conveying track can be set to control the surface quality of the metal material and the residence time in different reaction zones.

[0098] Furthermore, in an embodiment, the pressure environment in the preparation device may be a vacuum environment. For example, the preparation device further includes a vacuum pump for evacuating the environment so that the preparation device is in a vacuum state.

[0099] Example 1

[0100] Combination Figure 2 As shown, in the technical solution of Example 1, the metal material is put into the preparation device in a molten state. In this embodiment, the first conveying structure includes a first track 11; the second conveying structure includes a second track 21; the temperature of the first reaction zone 1 is lower than the melting temperature of the metal raw material.

[0101] The raw materials are prefabricated into a molten metal liquid. In the embodiment, a crucible 100 is pre-arranged on the top of the preparation device. The crucible 100 melts the metal raw materials to obtain molten metal raw materials.

[0102] The step of spraying the prefabricated metal raw material into the first reaction zone to prepare a soft metal powder or a semi-solid metal powder comprises:

[0103] The molten metal material is sprayed into the first reaction zone 1; the metal material is sprayed into the first reaction zone 1 through the nozzle 110; it should be noted that the nozzle 110 is configured to be replaceable so as to be adjusted according to product and process requirements.

[0104] The molten metal material sprayed into the first reaction zone 1 stays in the first reaction zone 1 for 10-60 seconds to cool down and becomes a metal powder with a solid surface. The solid metal powder is in a soft state and moves on the first track 11 toward the second reaction zone 2;

[0105] The ejected metal material is a small droplet. It should be noted that when the molten metal material is ejected, the metal material is a small metal droplet. Since the temperature of the first reaction zone 1 is lower than the melting temperature of the metal raw material, the small droplets gradually solidify into a metal powder with a solid surface, that is, a metal powder in a soft state. After the metal material stays in the first reaction zone 1 for 10-60s, it gradually becomes a metal powder in a soft state, and when it moves on the first track 11, it contacts the first track 11, thereby regularizing the morphology of the metal powder and surface treating the surface of the metal powder, providing favorable conditions for the deposition of graphene. For example, the first reaction zone 1 is arranged near the nozzle 110, and the nozzle 110 ejects the metal liquid. The first reaction zone 1 is cooled by the air supply pipe (in the embodiment, nitrogen is usually introduced), atomized to form a metal powder, and moves along the first track 11 set in the first reaction zone 1. The first track 11 is spirally spiraled along the tube wall, that is, the first track 11 is a spiral track. The metal powder moves downward along the first track 11. Normally, the first track 11 is at an angle of 15-50 degrees to the horizontal direction, the length of the first track 11 is 50-200 cm, and the residence time on the first track 11 is 10-60 seconds. The surface of the first track 11 has a first roughness, and the first roughness can be achieved by providing a bump on the surface or a groove on the track surface. If the metal material is copper, the temperature of this zone is 800-1000 degrees Celsius (copper is in a soft state after cooling, and its surface has a certain roughness after rolling on the first track 11). In some specific embodiments, the soft metal powder stays in the first reaction zone 1 for 30 seconds.

[0106] The metal powder with a solid surface is placed in a second reaction zone, the metal powder is heated until a part or all of the surface is liquid, and graphene is deposited on the surface of the metal powder to obtain a graphene-metal composite. The method of obtaining the graphene-metal composite includes:

[0107] The metal powder with a solid surface stays in the second reaction zone for 2-20 minutes, so that the surface of the metal powder with a solid surface is slightly melted to be in a liquid state.

[0108] In the embodiment, the soft metal powder sliding out of the first track 11 enters the second track 21, moves along the second track 21 toward the cooling zone 3, and stays in the second reaction zone 2 for 2-20 minutes to be heated, so that the surface of the soft metal powder is slightly melted to be in a liquid state, so as to combine with the graphene to obtain a graphene metal composite. The electron microscope image of the graphene metal composite is as follows: Figure 6 shown.

[0109] In practice, the first track 11 and the second track 21 are connected. After the soft metal powder slides out of the first reaction zone 1, it enters the second track 21 and continues to move along the second track 21 toward the cooling zone 3. Generally speaking, the second track 21 is also a spiral track that spirals along the tube wall. Due to the increase in the temperature of the second reaction zone 2, the surface of the soft metal powder is slightly melted and presents a liquid state during the movement, and the slightly melted surface forms a more uniform surface, so that the coverage rate of graphene is greater and the deposition quality is better. The angle between the second track 21 and the horizontal direction is 10-40 degrees, the length of the second track 21 is 300-900cm, and the metal powder stays on the second track 21 for 2-20min, so that there is sufficient time for graphene deposition. Taking copper as an example, the temperature of the second reaction zone 2 is 1080-1150℃.

[0110] In some embodiments, the step of placing the metal powder having a solid surface into the second reaction zone, heating the metal powder until a part or all of the surface is liquid, and depositing graphene on the surface of the metal powder to obtain the graphene-metal composite further comprises:

[0111] A gaseous carbon source is introduced into the second reaction zone 2; the gaseous carbon source obtains graphene in the second reaction zone 2; the graphene is deposited on the metal powder whose surface is in liquid state to obtain the graphene metal composite. In some embodiments, the gaseous carbon source includes alkane gas, hydrogen and inert gas; or the gaseous carbon source includes a gas containing carbon atoms obtained after pretreatment. In some embodiments, the alkane gas is methane, and the inert gas is nitrogen and / or argon; wherein the amount of methane introduced is 5 to 50 sccm, the amount of hydrogen introduced is 5 to 500 sccm, and the amount of nitrogen and / or argon introduced is 0 to 1000 sccm. In an embodiment, a gas injection pipeline is correspondingly provided in the second reaction zone 2, and hydrogen, inert gas and gaseous carbon source are injected respectively.

[0112] The first track 11 has a first roughness and the second track 21 has a second roughness. The first roughness and the second roughness are specifically set according to the required product requirements, and the two can be the same or different.

[0113] Taking copper as an example, in a specific real-time process, first, copper of any form is placed in a top-mounted crucible 100, and a heating device is arranged around the crucible 100 to heat the crucible 100 so that the copper is in a molten state. The liquid copper is sprayed into the first reaction zone 1 in the chamber through the nozzle 110. The first reaction zone 1 is adjacent to the nozzle 110, and the temperature of the zone is controlled to be 850°C. The nozzle 110 sprays out the liquid metal, which is cooled through the gas supply pipeline in the zone and atomized to form metal powder, which moves along the first track 11. The first track 11 is spirally spiraled along the tube wall, and the surface of the first track 11 has a first roughness. The roughness can be increased by providing a protrusion on the surface. The first track 11 is at a certain angle of 20 degrees to the horizontal direction, the length of the first track 11 is 150 cm, and the residence time in the first track 11 is 30 seconds. The metal powder enters the second reaction zone 2, the temperature of the reaction zone is 1080-1150 degrees Celsius, the metal surface is slightly melted, and the slightly melted surface forms a more uniform surface, so that the quality of graphene is better. The second track 21 has a second roughness, and the angle between the track and the horizontal direction is set to 25 degrees. The length of the second track 21 is 450cm; the residence time in the second track 21 is 5min. The particle size of the metal powder formed is about 1um. The methane intake in the second reaction zone 2 is 6sccm, the hydrogen intake is 10sccm, and the nitrogen or argon intake is 30sccm. After the graphene layer is deposited by the reaction in the second reaction zone 2, the graphene copper-based composite enters the cooling zone 3, and the graphene copper-based composite is cooled by gas input through the air supply pipeline in the cooling zone 3, and cooled to 400 degrees. After cooling in the cooling zone 3, the graphene copper-based composite enters the water cooling pool and is further cooled to obtain a graphene copper-based composite material.

[0114] In the technical solution of Example 1, the obtained graphene metal material not only has a large coating area and high quality, but also does not require the use of an anti-sintering agent, which can reduce the pre- and post-processing steps, reduce costs, and improve efficiency; at the same time, during the production process, the appearance and product form of the obtained product are taken into account.

[0115] Example 2

[0116] Combination Figure 3 and Figure 4 As shown, Example 2 is different from Example 1 in that the state of the metal material after passing through the first reaction zone 1 is semi-solid, that is, the surface is solid and the inside is liquid, rather than soft. Compared with Example 1, the residence time of the molten metal liquid in the first reaction zone 1 is shortened to 0.5 seconds to 1 second, and the metal liquid does not have time to completely solidify in the first reaction zone 1, but forms a semi-solid state with a solid outer wall and a liquid inside. Normally, the radius ratio of the solid outer wall to the liquid inner core of the semi-solid metal powder is between 10:1 and 1:1. Specifically,

[0117] In some embodiments, the first conveying structure includes a first track 11;

[0118] The raw material is prefabricated into a molten metal liquid. The temperature of the first reaction zone 1 is lower than the melting temperature of the metal raw material. The molten metal material is sprayed into the first reaction zone 1. The processing process of the above stages can refer to Example 1.

[0119] After the metal material is melted, the molten metal liquid sprayed into the first reaction zone 1 stays in the first reaction zone 1 for 0.5 to 1 second to cool down and becomes a metal powder with a solid surface and a liquid inside. In an embodiment, the semi-solid metal powder moves toward the second reaction zone 2 on the first track 11. Specifically, since the residence time in the first reaction zone 1 becomes shorter, the inside of the metal powder does not have time to become liquid, and becomes a semi-solid metal powder. The first track 11 is usually a slope track with a large slope so that the semi-solid metal powder can quickly pass through the first reaction zone 1.

[0120] The method steps for depositing graphene in the second reaction zone 2 with semi-solid metal powder are different from those in Example 1 in terms of the movement structure and mode of the metal powder. The specific method steps refer to the following examples. As in Example 1, the carbon source of the deposited graphene also comes from the gaseous carbon source injected into the second reaction zone 2. In some embodiments, the gaseous carbon source includes alkane gas, hydrogen and inert gas; or the gaseous carbon source includes a gas containing carbon atoms obtained after pretreatment. In some embodiments, the alkane gas is methane, and the inert gas is nitrogen and / or argon; wherein the amount of methane introduced is 5 to 50 sccm, the amount of hydrogen introduced is 5 to 500 sccm, and the amount of nitrogen and / or argon introduced is 0 to 1000 sccm; however, the input stage and position of the gaseous carbon source are also different, and refer to the following examples for details.

[0121] In some embodiments, the second reaction zone 2 includes a first graphene deposition zone 2a; the second conveying structure includes a first conveying section 22, and the first conveying section 22 is disposed in the first graphene deposition zone 2a;

[0122] The method of placing the metal powder with a solid surface into a second reaction zone, heating the metal powder until a part or all of the surface is liquid, and depositing graphene on the surface of the metal powder to obtain a graphene-metal composite comprises:

[0123] The gaseous carbon source is introduced into the first graphene deposition area 2a; the gaseous carbon source obtains graphene in the first graphene deposition area 2a;

[0124] The metal powder with a solid surface and a liquid interior stays in the first graphene deposition area for 3-10 minutes, and the graphene is deposited on the surface of the metal powder with a solid surface and a liquid interior to obtain a first intermediate graphene metal composite. Specifically, the semi-solid metal powder moves toward the cooling area 3 on the first conveying section 22 and stays in the first graphene deposition area 2a for 3-10 minutes, and the graphene is deposited on the surface of the semi-solid metal powder to obtain a first intermediate graphene metal composite.

[0125] The semi-solid metal powder stays in the first graphene deposition area 2a for 3-10 minutes, and the carbon atoms decomposed from the gaseous carbon source or the carbon atoms pre-treated in the gaseous carbon source are pre-deposited on the surface of the semi-solid metal powder, and graphene is deposited on the semi-solid metal powder to obtain a first intermediate graphene metal composite. The metal powder moves on the first conveying section 22, and its surface is more uniform, so that the coverage rate of graphene is greater and the deposition quality is better. In some embodiments, the first intermediate graphene metal composite can be cooled to obtain a graphene metal composite material.

[0126] Furthermore, in some other embodiments, the first intermediate graphene metal composite can be further processed to improve the coverage of graphene. The second reaction zone 2 further includes a second graphene deposition zone 2b, which is disposed between the first graphene deposition zone 2a and the cooling zone 3; the second conveying structure includes a second conveying section 23, which is disposed on the second graphene deposition zone 2b, and a pointed protrusion 231 is disposed on the second conveying section 23;

[0127] The method of placing the metal powder with a solid surface into the second reaction zone, heating the metal powder until a part or all of the surface is liquid, and depositing graphene on the surface of the metal powder to obtain the graphene-metal composite further comprises:

[0128] When the first intermediate graphene metal composite moves in the second graphene deposition zone of the second reaction zone, its outer wall is punctured, so that the liquid metal inside it flows out and coats the outer wall of the first intermediate graphene metal composite, thereby obtaining a coated second intermediate graphene metal composite.

[0129] Specifically, the first intermediate graphene metal composite that slides out of the first graphene deposition area 2a enters the second graphene deposition area 2b, and moves toward the cooling area 3 on the second conveying section 23; during the movement, the outer wall of the first intermediate graphene metal composite is punctured by the pointed protrusion 231, and the liquid metal inside the first intermediate graphene metal composite flows out and is coated on the outer wall of the first intermediate graphene metal composite, thereby obtaining a coated second intermediate graphene metal composite.

[0130] In this embodiment, the pointed protrusion 231 is perpendicular to the surface of the second conveying section 23, and the maximum length of the pointed protrusion 231 is 30-40% of the particle size of the powder (the maximum length of the pointed protrusion 231 is related to the particle size of the powder, the larger the particle size, the longer the protrusion length; and it is greater than the solid thickness of the outer part of the semi-solid metal powder). During the movement along the second conveying section 23, the solid outer wall of the metal powder deposited with graphene is punctured by the protrusion, and the liquid metal inside the powder flows out as the metal powder slides along the second conveying section 23, partially coating the metal outer wall, and coating the deposited graphene layer into the metal powder, thereby obtaining a second intermediate graphene metal composite.

[0131] Compared with the technical solution of Example 1, the liquid metal of Example 2 comes from the interior of the semi-solid metal. After the liquid metal is retained, it is at least partially wrapped on the outer wall thereof, thereby encapsulating the deposited graphene layer into the metal powder.

[0132] The second intermediate graphene metal composite obtained above can also be cooled to obtain a graphene metal composite material, but the interior of the graphene metal composite material is hollow, and graphene is not deposited on part of its surface. Therefore, in some other embodiments, in order to ensure that the interior of the graphene metal composite material is solid and graphene is deposited on the surface,

[0133] In some embodiments, the second reaction zone 2 further includes a third graphene deposition zone 2c; the second conveying structure further includes a third conveying section 24, and the third conveying section 24 is disposed on the third graphene deposition zone 2c; the third graphene deposition zone 2c is disposed between the second graphene deposition zone 2b and the cooling zone 3;

[0134] The metal powder with a solid surface is placed in the second reaction zone, the metal powder is heated until part or all of the surface is liquid, and graphene is deposited on the surface of the metal powder to obtain a graphene-metal composite; and further comprising:

[0135] Introducing a gaseous carbon source into the third graphene deposition area 2c;

[0136] The second intermediate graphene metal composite stays in the third graphene deposition zone for 3 to 5 minutes, and graphene is deposited on the surface of the second intermediate graphene metal composite; and the metal powder in the second intermediate graphene metal composite is in the third graphene deposition zone, and the empty shell formed by the outflowing liquid metal is filled due to the liquefaction of the metal to obtain the graphene metal composite.

[0137] Specifically, the second intermediate graphene metal composite that slides out of the second graphene deposition zone 2b enters the third graphene deposition zone 2c and moves toward the cooling zone 3 on the third conveying section 24; the second intermediate graphene metal composite stays in the third graphene deposition zone 2c for 3 to 5 minutes, and during the movement, graphene is deposited on the surface of the second intermediate graphene metal composite; and the metal powder in the second intermediate graphene metal composite is in the third graphene deposition zone 2c, and the empty shell formed by the outflowing liquid metal is filled due to the liquefaction of the metal to obtain the graphene metal composite.

[0138] In this embodiment, since the second intermediate graphene metal composite has a liquid surface on the outside, carbon atoms are further deposited on the surface to form a graphene layer, so the obtained graphene metal composite can present a multi-layer sandwich structure. In order to obtain a solid graphene metal composite, the temperature of the third graphene deposition area 2c can be further increased, so that the metal material is further melted and has a certain fluidity to fill its hollow part, so that after cooling, the hollow shell formed by the outflow of liquid metal is filled due to the liquefaction of the metal to obtain a solid graphene metal composite.

[0139] The obtained graphene metal composite material is obtained after cooling.

[0140] In the above embodiments, in some embodiments, the temperature of the first reaction zone 1 is 800-1000°C, the temperature of the first graphene deposition zone 2a is 1000-1060°C, the temperature of the second graphene deposition zone 2b is 1080-1120°C, and the temperature of the third graphene deposition zone 2c is 1080-1200°C; and / or the first conveying section 22, the second conveying section 23 and the third conveying section 24 are spiral tracks; and / or the angle of the second conveying section 23 with the horizontal direction is 40-70°, the angle of the first conveying section 22 with the horizontal direction is 10-40°, and the angle of the third conveying section 24 with the horizontal direction is 10-30°.

[0141] A specific implementation process of the above embodiment is as follows: first, a metal material of any form is placed in a top-mounted crucible 100, and a heating device is arranged around the crucible 100 to heat the crucible 100 so that the metal material is in a molten state. Liquid metal is sprayed into the chamber through a nozzle 110, and the chamber includes different temperatures and reaction zones. The sprayed metal droplets first pass through the first reaction zone 1, and the temperature of the first reaction zone 1 is 800 degrees. The residence time in the first reaction zone 1 is 1 second, forming a semi-solid metal powder with a metal solid surface and a metal liquid inside (wherein the radius ratio of the metal solid surface to the liquid inner core is 5:1), and the semi-solid metal powder enters the first track 11.

[0142] The semi-solid metal powder enters the first graphene deposition area 2a, the temperature of the first graphene deposition area 2a is 1000 degrees, the flow rate of the protective gas nitrogen or argon is 50sccm, the flow rate of the hydrogen is 50sccm, and the flow rate of the methane is 10sccm. Stay in the first graphene deposition area 2a for 8 minutes, and set the angle of the first conveying section 22 to the horizontal direction to be 15 degrees, and the length of the first conveying section 22 is 300cm; in the first graphene deposition area 2a, a graphene layer is deposited on the semi-solid metal powder to obtain a first intermediate graphene metal composite.

[0143] The first intermediate graphene metal composite enters the second graphene deposition zone 2b. The surface of the second conveying section 23 of the second reaction sub-zone is provided with a pointed protrusion 231 perpendicular to the track surface. The maximum length of the protrusion is 33% of the powder particle size. The angle between the second conveying section 23 and the horizontal plane is greater than the angle between the first conveying section 22 of the first graphene deposition zone 2a and the horizontal plane. The angle between the surface of the second conveying section 23 and the horizontal plane is 40 degrees (the spiral track in this embodiment can be calculated by considering the spiral descent of about 50 cm in diameter). The soft solid metal on the outer wall of the powder is punctured by the protrusion, and the liquid metal inside the powder flows out as the powder slides along the track, partially coating the outer wall of the metal, and coating the deposited graphene layer into the metal powder to obtain the second intermediate graphene metal composite. The temperature of the second graphene deposition zone 2b is 1100 degrees.

[0144] The second intermediate graphene metal composite enters the third graphene deposition area 2c along the track, and the angle between the third conveying section 24 and the horizontal plane is 55 degrees. A new graphene layer is formed on the exposed surface of the metal powder. The metal powder stays in the third graphene deposition area 2c for 3 minutes, and the temperature of the third reaction zone is 1150 degrees Celsius. The metal powder is melted in the fourth reaction zone, and the empty shell formed by the outflow of liquid metal is re-formed into a solid powder during the movement along the track. In the fourth reaction zone, the length of the third conveying section 24 is about 150cm, and the angle with the horizontal direction is 10 degrees. The obtained graphene metal composite. The obtained graphene metal composite is cooled in the cooling zone 3 to obtain a graphene metal material.

[0145] In the technical solution of Example 2, the obtained graphene metal material has a larger coating area and high quality, and does not require the use of anti-sintering agents, which can reduce the pre- and post-processing steps, reduce costs, and improve efficiency; at the same time, during the production process, the appearance and product form of the obtained product are taken into account.

[0146] Example 3

[0147] Combination Figure 5 As shown, compared with Example 1, the residence time of the molten metal powder in the first reaction zone 1 in Example 3 is shortened to 1 second to 5 seconds, and the metal powder does not have time to completely solidify in the first reaction zone 1, and forms a semi-solid state with a solid outer wall and a liquid inner core. Generally, the radius ratio of the solid outer wall to the liquid inner core of the semi-solid metal body is between 10:1 and 1:1. The difference between Example 3 and Example 2 is that an anti-sintering agent is used in Example 3.

[0148] In some embodiments, the first conveying structure includes a first track 11; the prefabricated raw material includes:

[0149] The metal raw material is prefabricated into a molten state; wherein the temperature of the first reaction zone 1 is lower than the melting temperature of the metal raw material; the prefabricated raw material is placed into the first reaction zone 1 so that the metal material in the prefabricated raw material is a soft metal powder, comprising: spraying a molten metal liquid into the first reaction zone 1. The above steps may correspond to the method steps of Embodiment 1 and Embodiment 2.

[0150] The difference is that the preparation device is further provided with a mixing zone 44 located between the first reaction zone 1 and the second reaction zone 2. The metal material sprayed into the first reaction zone 1 moves toward the mixing zone 44 on the first track 11, and stays in the first reaction zone 1 for 1s-5s, so that the molten metal material is cooled in the first reaction zone 1 to obtain the semi-solid metal powder. Compared with Example 2, the time of staying in the first reaction zone 1 is prolonged, and compared with Example 1, the time of staying in the first reaction zone 1 is shortened.

[0151] The metal powder with a solid surface is placed in a second reaction zone, the metal powder is heated until part or all of the surface is liquid, and graphene is deposited on the surface of the metal powder to obtain a graphene-metal composite. The preparation method includes:

[0152] The metal powder with a solid surface and a liquid interior is placed into the mixing area 4;

[0153] In the mixing zone 4, the metal powder with a solid surface and a liquid interior is mixed with an anti-sintering agent to obtain a prefabricated mixture.

[0154] Specifically, the semi-solid metal powder sliding out of the first track 11 enters the mixing zone 44; in the mixing zone 44, the semi-solid metal powder is mixed with the anti-sintering agent to obtain a prefabricated mixture. In the embodiment, a mixing zone 44 is provided between the first reaction zone 1 and the second reaction zone 2. The anti-sintering agent is transported into the mixing zone 44, and the solid metal powder is mixed with the anti-sintering agent.

[0155] In some embodiments, the second conveying structure further includes a second track 21, and the second track 21 is disposed in the second reaction zone 2; a platform 5 is further disposed in the second reaction zone 2, and the platform 5 is located between the second track 21 and the cooling zone 3 in the direction of gravity;

[0156] The step of placing the metal powder with a solid surface into the second reaction zone, heating the metal powder until a part or all of the surface is liquid, and depositing graphene on the surface of the metal powder to obtain the graphene-metal composite comprises:

[0157] A gaseous carbon source is introduced into the second reaction zone 2; the gaseous carbon source obtains graphene in the second reaction zone 2;

[0158] The residence time of the prefabricated mixture in the second reaction zone is 3-20 minutes, and the metal powder with a solid surface and a liquid interior is melted into a liquid state to combine with the graphene to obtain the graphene-metal composite.

[0159] Specifically, the prefabricated mixture moves on the second track 21 toward the platform 5;

[0160] The residence time of the prefabricated mixture in the second reaction zone 2 is 3-20 minutes, and when the semi-solid metal powder moves on the platform 5 and on the second track 21, the semi-solid metal powder melts into a liquid state to combine with the graphene to obtain the graphene-metal composite.

[0161] In this embodiment, during the movement, the semi-solid metal powder is melted and graphene can also be deposited; on the platform 5, sufficient growth time is reserved for the semi-solid graphene to increase the graphene coverage area. The metal powder is semi-solid, so that it can be quickly melted in the second reaction zone 2 and graphene is deposited in the liquid state, and the deposition time is 3-20 minutes.

[0162] In some embodiments, the temperature of the first reaction zone 1 is 800-1000°C, and the temperature of the second reaction zone 2 is 1080-1200°C; and / or the anti-sintering agent is one or more of magnesium oxide, aluminum oxide or graphite; and / or the particle size of the anti-sintering agent is 0.1 to 15 microns; and / or the mass ratio of the semi-solid metal powder to the anti-sintering agent is 1:1 to 5:1. Compared with the process using the anti-sintering agent in the prior art, the amount of the anti-sintering agent used in this embodiment is reduced.

[0163] Similar to the above-mentioned embodiments 1 and 2, the gaseous carbon source includes an alkane gas, hydrogen and an inert gas; or the gaseous carbon source includes a carbon atom-containing gas obtained after pretreatment. In some embodiments, the alkane gas is methane, and the inert gas is nitrogen and / or argon; wherein the amount of methane introduced is 5 to 50 sccm, the amount of hydrogen introduced is 5 to 500 sccm, and the amount of nitrogen and / or argon introduced is 0 to 1000 sccm.

[0164] Example 4

[0165] The difference between Example 4 and Example 1, Example 2 and Example 3 is that the metal material is put into the preparation device in a solid form. In some embodiments, the prefabricated raw material includes: preparing the metal material into a metal powder. In this embodiment, the raw material may contain only metal material or may contain a carbon source. In the solution containing only metal material, the source of graphene is gaseous paralysis injected into the second reaction zone 2;

[0166] Example 5

[0167] The difference between Example 5 and Example 1, Example 2 and Example 3 is that the carbon source is put into the preparation device together with the powdered metal material. In some embodiments, the raw material also includes a solid carbon source and / or a liquid carbon source; the prefabricated raw material also includes: mixing the solid carbon source with the metal powder; and / or immersing the metal powder in the liquid carbon source. The solid carbon source can be pre-made into a powder, mixed evenly with the powdered metal material, and then put into the preparation device; or the powdered metal material is immersed in the liquid carbon source for a period of time and then put into the preparation device. In the embodiment, a mixing device is added to the front end of the crucible 100, and the metal powder and the solid carbon source (such as polystyrene, etc.) are mixed evenly by ultrasonic, ball milling and other mixing methods. At this time, the crucible 100 does not need to be heated, and the metal powder wrapped with the solid carbon source only needs to be sprinkled into the preparation device. Or the metal powder is immersed in the PMMA solution, a layer of PMMA film is wrapped on the surface of the metal powder as a carbon source, and then it is sprayed into the preparation device.

[0168] Example 6

[0169] Embodiment 6 provides a preparation device of the method using all or part of the technical solutions in any one of the above embodiments.

[0170] In an embodiment, the preparation device comprises a reaction cylinder, wherein the reaction cylinder defines a feeding port and a first reaction zone, a second reaction zone and a cooling zone which are sequentially connected to the feeding port; wherein the temperature of the first reaction zone is greater than the temperature of the cooling zone and less than the second temperature of the second reaction zone;

[0171] A feeding assembly, the feeding assembly is arranged corresponding to the feeding port, and is configured to spray metal liquid or metal powder or metal powder coated with a carbon source into the first reaction zone through the feeding port;

[0172] The carbon source delivery component 300 is configured to be connected to the second reaction zone to inject the carbon source into the second reaction zone or to inject the carbon source into the feeding component to form the metal powder coated with the carbon source.

[0173] In an embodiment, the first reaction zone is configured to have a first temperature, and is used to prepare a metal powder having a solid surface from a metal liquid or a metal powder or a metal powder coated with a carbon source;

[0174] The second reaction zone has a second temperature, and is used to prepare the metal powder with a solid surface into a metal powder with a partial surface or a whole surface in a liquid state, and to deposit graphene on the surface of the metal powder with a partial surface or a whole surface in a liquid state, so as to obtain the graphene metal composite material;

[0175] The first temperature is lower than the second temperature, and the third temperature is lower than the second temperature.

[0176] Specifically, the first reaction zone 1 is configured to have a first temperature, and the metal material entering the first reaction zone 1 is a soft metal powder or a semi-solid metal powder; the semi-solid metal powder is solid on the outside and liquid on the inside;

[0177] The second reaction zone 2 has a second temperature; the soft or semi-solid metal powder after passing through the first reaction zone 1 is at least partially melted in the second reaction zone 2, and combined with graphene in the second reaction zone 2 to obtain a graphene-metal composite; wherein the graphene is derived from the carbon source of the raw material or from the carbon source introduced into the second reaction zone 2;

[0178] The cooling zone 3 has a third temperature; the graphene metal composite is cooled in the cooling zone 3 to obtain the graphene metal composite material;

[0179] The first temperature is lower than the second temperature, and the third temperature is lower than the second temperature.

[0180] In the technical solution of the embodiment of the present application, in the preparation device, since the first reaction zone 1 has a first temperature, the metal material is put into the first reaction zone 1 to heat-treat the metal material so that it is a metal powder in a soft state or a semi-solid metal powder; then, since the second reaction zone 2 has a second temperature, the metal powder in a soft state or a semi-solid metal powder is put into the second reaction zone 2 to further heat the metal material so that the metal powder in a soft state or a semi-solid state is combined with graphene when at least part of it is in a liquid state to obtain a graphene metal composite; then, further, the cooling zone 3 has a third temperature, and the graphene metal composite is cooled to obtain a graphene metal composite material. In the technical solution of the embodiment of the present application, the metal powder in a soft state or a semi-solid state is combined with graphene when at least part of it is in a liquid state, which increases the graphene deposition time of the metal droplets, is conducive to forming a graphene layer with a large coating area, and improves the quality of the graphene metal composite material.

[0181] It should be noted that the first temperature of the first reaction zone 1 and the second temperature of the second reaction zone 2 are set corresponding to the metal material. The metal material is a metal material that can deposit graphene, such as copper, copper alloy, nickel, nickel alloy and other metal materials. The setting of the first temperature of the first reaction zone 1 and the second temperature of the second reaction zone 2 can respectively make the metal raw material soft or semi-solid. The third temperature of the cooling zone 3 is a temperature that can re-solidify the metal material. Furthermore, a heating device is provided on the periphery of the refrigeration device, and the heating device sets the corresponding temperature through a temperature control controller, so that the first reaction zone 1, the second reaction zone 2 and the cooling zone 3 have different temperatures respectively.

[0182] In some embodiments, the first reaction zone 1 is provided with a first conveying structure, and the metal raw material is in a soft metal powder or a semi-solid metal powder during the movement along the first conveying structure toward the second reaction zone 2; and / or,

[0183] The second reaction zone 2 is provided with a second conveying structure: the soft metal powder or semi-solid metal powder is in a liquid state in at least one section of the path along which it moves in the second conveying structure.

[0184] In the technical solution of the embodiment of the present application, the metal material moves along the first conveying structure and the second conveying structure in the preparation device to polish the surface of the metal material. At the same time, the residence time of the metal material in the first reaction zone 1 and the second reaction zone 2 can be controlled to reserve sufficient growth time for obtaining a graphene layer with a large coating area.

[0185] In the above embodiments, the soft metal powder or semi-solid metal powder moves on the second conveying structure toward the cooling zone 3 and is in liquid state on at least a section of the movement path. It can be understood as follows: 1. During the movement, the metal powder slightly melts on the surface in the second reaction zone 2 due to the increase in temperature; 2. During the movement, the semi-solid metal powder is punctured in a certain space in the second reaction zone 2 due to the outer wall being punctured, and the liquid metal inside flows out; 3. The metal powder is completely melted.

[0186] For example, both the first conveying structure and the second conveying mechanism can be set as a spiral track (or a reciprocating ramp track). The surface quality of the metal material and the residence time in different reaction zones can be controlled by setting the roughness, slope and length of the spiral track (or the length of the reciprocating ramp track). For another example, both the first conveying structure and the second conveying mechanism can be set as a conveying track, and the conveying speed of the conveying track can be controlled and the roughness of the conveying track can be set to control the surface quality of the metal material and the residence time in different reaction zones.

[0187] Corresponding to Example 2, the first conveying structure includes a first track; the second conveying structure includes a second track; the angle between the first track and the horizontal direction is 15-50 degrees, and the angle between the second track and the horizontal direction is 10-70 degrees; and / or the first track has a first roughness and the second track has a second roughness; and / or the first track is a spiral track and the second track is a spiral track.

[0188] Corresponding to Example 3, the second reaction zone includes a first graphene deposition zone, a second graphene deposition zone and a third graphene deposition zone; the second graphene deposition zone is arranged between the first graphene deposition zone and the cooling zone; the third graphene deposition zone is arranged between the second graphene deposition zone and the cooling zone; the second conveying structure includes a first conveying section, the first conveying section is arranged in the first graphene deposition zone; the second conveying structure includes a second conveying section, the second conveying section is arranged on the second graphene deposition zone, and the second conveying section is provided with a pointed protrusion; the second conveying structure also includes a third conveying section, the third conveying section is arranged on the third graphene deposition zone. The third track is a ramp track, the first conveying section, the second conveying section and the third conveying section are spiral tracks; and / or the angle between the second conveying section and the horizontal direction is 40-70°, the angle between the first conveying section and the horizontal direction is 10-40°, and the angle between the third conveying section and the horizontal direction is 10-30°.

[0189] Corresponding to Example 4, the preparation device is further provided with a mixing zone 4 located between the first reaction zone and the second reaction zone; a platform 5 is further provided in the second reaction zone, and the platform 5 is located between the second conveying structure and the cooling zone in the direction of gravity. A second conveying structure, i.e., a second track, is provided between the mixing zone 4 and the platform 5.

[0190] Furthermore, in some embodiments, the metal material can be put into the first reaction zone 1 in the form of metal powder, and then the metal powder in the first reaction zone 1 is in a soft state or semi-solid state due to the high temperature. For example, after the metal material is made into powder, the metal powder is evenly put into the first reaction zone 1 through a screen; in other embodiments, the metal material can be pre-treated into a molten state, and then sprayed into the first reaction zone 1 through the nozzle 110. In this case, the temperature of the first reaction zone 1 is set to be lower than the melting point of the metal material, and the temperature of the metal material decreases to present a soft state or a semi-solid metal powder. For example, Figure 2 , 4 As shown in Figures 1 and 5, in the embodiment, a mixing tank 200 is provided on the top of the crucible 200. The mixing tank 200 has a baffle. By opening the baffle, the metal material in the mixing tank 200 is put into the crucible. The mixing tank 200 may contain a block of metal material or a powdered metal material. The metal material is melted by the crucible 100, and the melted metal material is sprayed toward the first reaction zone 1 through the nozzle 110. In this embodiment, the size of the nozzle 110 can be adjusted according to the process requirements and product requirements.

[0191] In the embodiment, the feeding assembly includes a crucible 200, and a nozzle 110 is provided on the crucible for spraying metal liquid or metal powder or metal powder coated with a carbon source.

[0192] In an embodiment, the feeding assembly also includes a mixing tank 300, which is configured as a mixing chamber with a discharge port; the mixing tank is connected to the carbon source conveying device to mix the solid and / or liquid carbon source with the metal powder in the mixing chamber to form the metal powder coated with the carbon source; the mixing tank includes a baffle, which is used to open or close the discharge port; the crucible is arranged corresponding to the discharge port to receive the metal powder coated with the carbon source. The raw materials may contain not only metal materials but also solid carbon sources or liquid carbon sources; the carbon source delivery component 300 delivers the solid carbon source to the mixing chamber of the mixing tank; the solid carbon source may be pre-made into a powder, such as polystyrene, and mixed evenly with the powdered metal material in the mixing tank, and then put into the crucible after the baffle is opened, and then sprayed into the first reaction zone through the nozzle on the crucible; or the carbon source delivery component 300 delivers the liquid carbon source to the mixing chamber of the mixing tank, so that the powdered metal material is immersed in the liquid carbon source (such as PMMA) for a period of time, and then put into the crucible after the baffle is opened, and then sprayed into the first reaction zone through the nozzle on the crucible; the crucible may not be heated at this time.

[0193] In the embodiment, the carbon source delivery assembly includes a gas pipe, which is configured to be connected to the second reaction zone to deliver a gaseous carbon source to the second reaction zone; wherein the gaseous carbon source includes alkane gas, hydrogen and inert gas; or the gaseous carbon source includes a gas containing carbon atoms obtained after pretreatment. For example, when a gaseous carbon source is used, the gaseous carbon source is injected into the second reaction zone 2 through the carbon source delivery assembly 300, and the gaseous carbon source decomposes to contain carbon atoms under the high temperature environment of the second reaction zone 2.

[0194] In some embodiments, the gaseous carbon source generally contains alkane gas, such as methane, ethane, etc., or it can be a gas containing carbon atoms obtained by a pretreatment device. The pretreatment device contains a catalyst for catalytically cracking the alkane carbon source gas to obtain a gas containing carbon atoms. The catalyst can be a metal such as copper and nickel, or a non-metallic material such as sodium chloride and potassium chloride. In addition, the gaseous carbon source generally contains hydrogen and an inert gas. The inert gas generally includes nitrogen or argon.

[0195] The above is a detailed introduction to the preparation method and device of a graphene metal composite material provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for preparing a graphene metal powder material, characterized in that: The preparation method comprises: Prefabricate the metal raw material into metal liquid or metal powder or metal powder coated with a carbon source; Spraying the prefabricated metal raw material into the first reaction zone to prepare a metal powder having a solid surface; The metal powder with a solid surface is placed in a second reaction zone, the metal powder with a solid surface is heated until part or all of the surface is liquid, and graphene is deposited on the surface of the metal powder with a part or all of the surface being liquid to obtain a graphene-metal composite; wherein the temperature of the second reaction zone is greater than the temperature of the first reaction zone; The graphene metal composite is placed in a cooling zone for cooling to obtain a graphene metal composite material; wherein the temperature of the cooling zone is lower than the temperature of the first reaction zone.

2. The preparation method according to claim 1, characterized in that The temperature of the first reaction zone is lower than the melting temperature of the metal raw material; Prefabricating the metal raw material into a molten metal liquid; Spraying molten metal liquid into the first reaction zone; The metal powder stays in the first reaction zone for 10-60 seconds and is cooled to form a metal powder with a solid surface.

3. The preparation method according to claim 2, characterized in that: The metal powder with a solid surface stays in the second reaction zone for 2-20 minutes, so that the surface of the metal powder with a solid surface is slightly melted to a liquid state.

4. The preparation method according to claim 3, characterized in that: introducing a gaseous carbon source into the second reaction zone; Graphene is deposited on the surface of liquid metal powder to obtain a graphene-metal composite.

5. The preparation method according to claim 3 or 4, characterized in that: The temperature of the first reaction zone is 800-1000°C, and the temperature of the second reaction zone is 1080-1150°C.

6. The preparation method according to claim 1, characterized in that: The temperature of the first reaction zone is lower than the melting temperature of the metal raw material; Prefabricating the metal raw material into a molten metal liquid; Spraying molten metal liquid into the first reaction zone; The molten metal liquid sprayed into the first reaction zone stays in the first reaction zone for 0.5 to 5 seconds to obtain a metal powder with a solid surface and a liquid interior.

7. The preparation method according to claim 6, characterized in that: The ratio of the thickness of the solid outer wall of the metal powder with a solid surface and a liquid inner part to the radius of the liquid inner core is 1:1 to 10:

1.

8. The preparation method according to claim 6, characterized in that: The metal powder obtained in the first reaction zone is put into the second reaction zone; the second reaction zone includes: a first graphene deposition zone, a second graphene deposition zone and a third graphene layer deposition zone; introducing the gaseous carbon source into the first graphene deposition zone and the third graphene deposition zone of the second reaction zone; The metal powder with a solid surface and a liquid interior stays in the first graphene deposition area for 3-10 minutes to obtain a first intermediate graphene metal composite; When the first intermediate graphene metal composite moves in the second graphene deposition area, the outer wall is punctured, and the liquid metal inside flows out and is coated on the outer wall of the first intermediate graphene metal composite, thereby obtaining a coated second intermediate graphene metal composite; The second intermediate graphene metal composite stays in the third graphene deposition zone for 3 to 5 minutes, and graphene is deposited on the surface of the second intermediate graphene metal composite; and the metal powder in the second intermediate graphene metal composite is in the second graphene deposition zone, and the empty shell formed by the outflowing liquid metal is filled due to the liquefaction of the metal to obtain the graphene metal composite.

9. The preparation method according to claim 8, characterized in that: The temperature of the first reaction zone is 800-1000°C, the temperature of the first graphene deposition zone is 1000-1060°C, the temperature of the second graphene deposition zone is 1080-1120°C, and the temperature of the third graphene deposition zone is 1080-1200°C.

10. The preparation method according to claim 6 or 7, characterized in that: Before placing the metal powder with a solid surface into a second reaction zone, heating the metal powder with a solid surface until part or all of the surface is liquid, and depositing graphene on the surface of the metal powder with a liquid surface, to obtain a graphene-metal composite, the preparation method comprises: Putting the metal powder with a solid surface and a liquid interior into the mixing area; In the mixing zone, the metal powder with a solid surface and a liquid interior is mixed with an anti-sintering agent to obtain a prefabricated mixture.

11. The preparation method according to claim 10, characterized in that: A gaseous carbon source is introduced into the second reaction zone; the gaseous carbon source obtains graphene in the second reaction zone; The residence time of the prefabricated mixture in the second reaction zone is 3-20 minutes, and the metal powder with a solid surface and a liquid interior is melted into a liquid state to combine with the graphene to obtain the graphene-metal composite.

12. The preparation method according to claim 11, characterized in that: The temperature of the first reaction zone is 800-1000 degrees Celsius, and the temperature of the second reaction zone is 1080-1200 degrees Celsius; and / or The anti-sintering agent is one or more of magnesium oxide, aluminum oxide or graphite; and / or, The particle size of the anti-sintering agent is 0.1 to 15 microns; and / or, The mass ratio of the metal powder with a solid surface and a liquid interior to the anti-sintering agent is 1:1 to 5:

1.

13. The preparation method according to claim 8, 9, 11 or 12, characterized in that: The gaseous carbon source includes alkane gas, hydrogen and inert gas; or the gaseous carbon source includes a carbon atom-containing gas obtained after pretreatment.

14. The preparation method according to claim 13, characterized in that: The alkane gas is methane, and the inert gas is nitrogen and / or argon; The amount of methane introduced is 5 to 50 sccm, the amount of hydrogen introduced is 5 to 500 sccm, and the amount of nitrogen and / or argon introduced is 0 to 1000 sccm.

15. The preparation method according to claim 1, characterized in that: The raw materials further include a solid carbon source and / or a liquid carbon source; the solid carbon source includes polystyrene; the liquid carbon source includes PMMA; Prefabrication of raw materials into metal powder coated with carbon source includes: mixing the solid carbon source with metal powder; and / or, The metal powder is immersed in the liquid carbon source.

16. The preparation method according to claim 1, characterized in that: The graphene metal composite enters the cooling zone so that the graphene metal composite is cooled, and obtaining the graphene metal composite material comprises: The graphene metal composite material first enters the air cooling zone and then enters the water cooling zone to obtain the graphene metal composite material; the temperature of the air cooling zone is 400-500 degrees Celsius.

17. A graphene metal composite material preparation device, used for preparing a graphene metal composite material, characterized in that: The preparation device comprises: A reaction cylinder, wherein the reaction cylinder defines a feeding port and a first reaction zone, a second reaction zone and a cooling zone which are sequentially connected to the feeding port; wherein the temperature of the first reaction zone is greater than the temperature of the cooling zone and less than the second temperature of the second reaction zone; A feeding assembly, the feeding assembly is arranged corresponding to the feeding port, and is configured to spray metal liquid or metal powder or metal powder coated with a carbon source into the first reaction zone through the feeding port; A carbon source conveying component is configured to be connected to the second reaction zone to inject the carbon source into the second reaction zone or to inject the carbon source into the feeding component to form the metal powder coated with the carbon source.

18. The preparation device according to claim 17, characterized in that: The first reaction zone is provided with a first conveying structure for guiding the metal liquid or metal powder or metal powder coated with a carbon source to move toward the second reaction zone; The second reaction zone is provided with a second conveying structure, and the first conveying structure is connected to the second conveying structure, and is used to guide the metal powder with a solid surface to move toward the cooling zone.

19. The preparation device according to claim 18, characterized in that: The first conveying structure includes a first track; the second conveying structure includes a second track, and the second track is connected to the first track; the angle between the first track and the horizontal direction is 15-50°, and the angle between the second track and the horizontal direction is 10-70°; and / or The first track and the second track are provided with protrusions and / or grooves; and / or; The first track is a spiral track or a slope track, and the second track is a spiral track.

20. The preparation device according to claim 19, characterized in that: The second reaction zone includes a first graphene deposition zone, a second graphene deposition zone and a third graphene deposition zone; the second graphene deposition zone is arranged between the first graphene deposition zone and the cooling zone; the third graphene deposition zone is arranged between the second graphene deposition zone and the cooling zone; The second track includes a first conveying section, a second conveying section and a third conveying section which are connected in sequence; the first conveying section is arranged in the first graphene deposition area; the second conveying section is arranged on the second graphene deposition area, and a pointed protrusion is arranged on the second conveying section; the third conveying section is arranged on the third graphene deposition area.

21. The preparation device according to claim 20, characterized in that: The first track is a slope track; and / or The angle between the second conveying section and the horizontal direction is 40-70°, the angle between the first conveying section and the horizontal direction is 10-40°, and the angle between the third conveying section and the horizontal direction is 10-30°.

22. The preparation device according to claim 18, characterized in that: The preparation device is also provided with a mixing zone located between the first reaction zone and the second reaction zone; and a platform is also provided in the second reaction zone; The second conveying structure is disposed between the mixing zone and the platform.

23. The preparation device according to claim 17, characterized in that: The feeding assembly comprises a crucible, on which a nozzle is arranged for spraying metal liquid or metal powder or metal powder coated with a carbon source.

24. The preparation device according to claim 23, characterized in that: The feeding assembly further includes a mixing tank configured as a mixing cavity having a discharge port; the mixing tank is connected to the carbon source conveying device to mix the solid and / or liquid carbon source with the metal powder in the mixing cavity to form the metal powder coated with the carbon source; The mixing tank comprises a baffle, and the baffle is used to open or close the discharge port; the crucible is arranged corresponding to the discharge port to receive the metal powder coated with the carbon source.

25. The preparation device according to claim 17, characterized in that: The carbon source delivery component includes a gas pipe, which is configured to be connected to the second reaction zone for delivering a gaseous carbon source to the second reaction zone; wherein the gaseous carbon source includes alkane gas, hydrogen and inert gas; or the gaseous carbon source includes a carbon atom-containing gas obtained after pretreatment.

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