A metal@RGO composite material, its preparation process and application

Abstract

This invention belongs to the field of new materials and discloses a preparation process for co-depositing metal@RGO composite materials under the action of an electric field, comprising the following steps: Step 1: Adding an electroplating solution containing graphene oxide and a soluble metal salt to an electrolytic cell for electroplating deposition and intermittently collecting the deposits; the metal ions in the soluble metal salt can be reduced under the action of an electric field; Step 2: Cleaning and pulverizing the deposits; Step 3: Calcining the pulverized product from Step 2 under a reducing atmosphere to obtain a metal@RGO composite material composed of elemental metal and graphene. This process uses electrochemical deposition combined with a suitable pulverization method and the reduction of graphene oxide to obtain friction materials that meet the requirements. Furthermore, this invention also provides related applications of this material.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new materials, in particular to a metal-RGO composite material, a preparation process thereof and an application thereof. BACKGROUND

[0002] Friction material is an important supporting material in high-end equipment such as wind power generation, agricultural machinery, high-speed trains, airplanes and military vehicles, which plays a role in transmission, braking, parking and other functions in friction transmission devices and braking devices and other components, and is of great significance to the safe, reliable and stable operation of machinery and equipment. Among them, copper-based friction material is widely used in the field of brake pads of high-end equipment such as wind power generation, high-speed trains and airplanes due to its high stability of friction coefficient, good anti-bonding and anti-sticking performance, and good corrosion resistance.

[0003] The copper-based friction material components usually include a copper matrix, a friction-reducing phase and a reinforcing phase (wear-resistant phase). According to the requirements of the application friction environment, the friction-reducing phase and the reinforcing phase in the copper-based friction material not only play a role in reducing friction resistance, but also play a role in improving the strength of the matrix, so selecting appropriate friction-reducing phase and reinforcing phase plays a key role in the copper-based friction material. Among many friction-reducing phases and wear-resistant phases, graphene has attracted widespread attention due to its high strength and Young's modulus and super-high thermal conductivity. Through particle strengthening principle, copper / graphene composite material has high stability, corrosion resistance, toughness and mechanical strength, which also makes graphene widely used in the field of friction materials, especially attracting the attention of many material researchers.

[0004] Most of the existing methods use chemical deposition method for preparation, such as the patent application with the title of a graphene reinforced copper alloy composite material and a preparation method thereof, with the publication number CN118703816A. The preparation process of the patent is complex, and a large amount of chemical additives need to be used to avoid the agglomeration of graphene and to improve the wear resistance and friction reduction of the matrix. Overall, the patent implementation process is not conducive to large-scale production and has high production cost.

[0005] The preparation of graphene / copper alloy can also use electrochemical method, such as the patent application with the title of a preparation method of copper-based-graphene composite material, with the publication number CN116623244A, which is prepared by electrochemical method. The main purpose is to prepare copper alloy-based graphene composite material with excellent conductivity, thermal conductivity and wear resistance. However, in the production of friction materials, this method has some limitations, such as it cannot prepare the required friction products, and it can only get a plating layer with acceptable wear resistance.

[0006] Therefore, there are still many application problems to be solved between the preparation of copper / RGO and the preparation of friction materials. SUMMARY

[0007] The application aims to provide a preparation process of metal@RGO composite material, which adopts electrochemical deposition method, combines with suitable crushing method and reduces graphene oxide, so that the required friction material can be obtained.

[0008] Meanwhile, the application also discloses the composite material prepared based on the method.

[0009] To achieve the above-mentioned purpose, the application provides the following technical scheme.

[0010] A preparation process of metal@RGO composite material co-deposited under the action of electric field, comprising the following steps.

[0011] Step 1: electroplating liquid containing graphene oxide and soluble metal salt is added into an electrolytic cell for electroplating deposition, and the deposit is collected intermittently; the metal ions in the soluble metal salt can be reduced under the action of electric field;

[0012] Step 2: the deposit is cleaned and crushed;

[0013] Step 3: the product crushed in step 2 is calcined in a reducing atmosphere to obtain metal@RGO composite material composed of metal element and graphene.

[0014] The core innovation points of the application are two.

[0015] 1. The metal@RGO composite material is obtained by adopting electrochemical deposition method and reduction method;

[0016] Compared with the traditional chemical deposition method, the metal element particle size obtained by the electrochemical deposition method is nanoscale, and the structure of the composite material is that the metal element coats the graphene; the traditional chemical deposition method adopts metal powder, and the metal powder or the metal powder and the graphene can only be coated or cross-coated, and the coating form of all particles is not consistent, which leads to the weakening of the wear resistance of the material.

[0017] 2. The deposit is collected intermittently during electroplating deposition and crushed, so that the crushing difficulty is reduced, and the coating integrity is prevented from being damaged and easily oxidized due to excessive crushing for pursuing too small particle size and uniform particle size.

[0018] Through the above two improvements, the obtained composite material has the advantages of complete structure, small particle size and controllable material quality, and the performance of the wear-resistant material prepared by the composite material can be obviously improved.

[0019] Preferably, the length of the crushing in step 2 is 30-45s, and the rotating speed of the rotor during the crushing is 30000-40000rpm; in step 1, the collection time interval of the deposits is not more than 15min, preferably, the collection time interval of the deposits is 5-10min.

[0020] The friction material has certain requirements for the particlularity of the composite material, so the composite material must be crushed, but if the crushing time is too short or the crushing speed is too slow, the particle size requirement cannot be met, and if the crushing time is too long or the crushing speed is too fast, the graphene and copper element will be accelerated to oxidize;

[0021] In the preparation of the deposits, the deposits on the electrode are removed in a timely manner, and the deposits are in a relatively loose state, so that the subsequent crushing process can maintain a relatively loose state, so that the crushed product can be crushed into a particle size meeting the requirements in a short time, and the oxidation degree is reduced.

[0022] In the above preparation process, the concentration of graphene oxide in the electroplating solution is 1-5g / L, and the concentration of the soluble metal salt is 20-100g / L.

[0023] The D50 flake diameter of the graphene oxide is 0.5-1 microns, the metal ions in the soluble metal salt are copper ions and / or silver ions, and the particle size specification of the product after step 2 crushing is 1-5 microns.

[0024] In production, the flake diameter of graphene oxide is controlled by the following process:

[0025] After the graphene oxide is crushed, it is placed in a grinding machine, and zirconium oxide beads are used for grinding; the flake diameter is controlled by controlling the grinding time; the D50 flake diameter is continuously sampled and analyzed; and the material is discharged when the requirement is met. The particle size of the zirconium oxide beads can be selected in the range of 0.5 to 1.5 microns.

[0026] In the above preparation process, the electrode plate in the electrolytic cell is composed of an inert cathode plate and an inert anode plate; the inert cathode plate and the inert anode plate are arranged horizontally; the inert cathode plate is located below the inert anode plate; and the inert cathode plate is provided with a scraper for scraping the deposits deposited on the inert cathode plate.

[0027] In the production process, the electrode plate can be arranged vertically or horizontally, and more preferably horizontally; through the horizontal arrangement, the uniform adhesion of copper precipitation on the electrode surface based on the self-weight of the reduced copper particles can be realized, and the influence of different adhesion degrees on the uniformity of electroplating can be avoided.

[0028] In the preparation process, the electrolytic cell is provided with at least one flow channel structure which is a Tesla valve structure or a flow channel similar to the Tesla valve structure; the electrolytic cell has a liquid inlet and a liquid outlet at two ends; the liquid inlet and the liquid outlet are connected to realize the circulation of the liquid in the electrolytic cell by a pump; the liquid inlet is used for inputting the electroplating solution into the inlet of the flow channel; the electroplating solution discharged from the outlet of the flow channel is discharged through the liquid outlet; the flow channel is composed of a main flow channel and a secondary flow channel, most of the electroplating solution flows through the main flow channel, and a small part of the electroplating solution flows through the secondary flow channel; the inert cathode plate and the inert anode plate are arranged in the secondary flow channel.

[0029] The flow channel is composed of a plurality of first flow guide plates, second flow guide plates and third flow guide plates; the second flow guide plates and the third flow guide plates constitute the secondary flow channel; the first flow guide plates are located on one side of the second flow guide plates and the third flow guide plates; the first flow guide plates and the second flow guide plates and the first flow guide plates and the third flow guide plates constitute the main flow channel.

[0030] In order to further improve the uniformity of coating, the flow channel with the Tesla valve structure or the flow channel similar to the Tesla valve structure is adopted, most of the electroplating solution flows through the main flow channel, a small part of the electroplating solution flows through the secondary flow channel, the flow rate of the liquid in the secondary flow channel is lower than that in the main flow channel, and the cathode plate and the anode plate are arranged in the secondary flow channel, so that the uniform coating and assembly of the graphene and the copper element are more facilitated.

[0031] In the preparation process, in step 1, the electroplating deposition process parameters are as follows: the voltage range is 3.5-4.5 V, the current range is 15-35 A, and the electroplating time is 30-60 min.

[0032] In step 3, the process parameters of the reduction are as follows: the product after crushing in step 2 is heated from room temperature to 200-400 DEG C at a speed of 4-6 DEG C / min, and kept at this temperature for 30-60 min; then the temperature is increased to 700-900 DEG C at a speed of 8-12 DEG C / min, and then kept at this temperature for 1-2 h; finally, the product is naturally cooled to room temperature. The reduction atmosphere is a reducing gas or a mixed gas of a reducing gas and an inert protective gas, the reducing gas at least includes one of H2, CO and CH4, and the inert protective gas at least includes one of Ar and N2, and the volume ratio of the two gases is 4:6.

[0033] Meanwhile, the application also discloses a metal@RGO composite material prepared by using the preparation process.

[0034] In the composite material, the metal@RGO composite material is a metal@RGO composite material composed of copper and graphene.

[0035] Furthermore, the application also discloses a use of the composite material for preparing the friction material.

[0036] Finally, the application also discloses a friction material containing the composite material.

[0037] Compared with the prior art, the application has the following beneficial effects:

[0038] The metal@RGO composite material is obtained by electrochemical deposition and reduction, and the deposits are collected and crushed in an intermittent manner during the electroplating deposition, so that the crushing difficulty is reduced, and the coating integrity is not damaged and the material is not easily oxidized due to excessive crushing for pursuing too small particle size and uniform particle size. Through the above two improvements, the obtained composite material has the advantages of complete structure, small particle size and controllable material quality, and the performance of the wear-resistant material prepared by the composite material can be obviously improved. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a top view of the electrolytic cell of the device embodiment;

[0040] Figure 2 is a front view of the electrolytic cell of the device embodiment;

[0041] Figure 3 is a front view of the cooperation of the scraper and the cathode plate of the device embodiment;

[0042] Figure 4 is a top view of the electrolytic cell used in embodiment 13. DETAILED DESCRIPTION

[0043] The technical solutions of the application will be described in detail below with reference to the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0044] The structure of the electrolytic cell used in the application is shown in the device embodiment.

[0045] Device embodiment

[0046] Reference Figures 1 to 3 An electrolytic cell, which is internally provided with two flow channels, i.e., a Tesla valve structure or a flow channel 1 similar to the Tesla valve structure; the electrolytic cell is provided with a liquid inlet 2 and a liquid outlet 3 at two ends; the liquid inlet 2 and the liquid outlet 3 realize the circulation of the liquid in the electrolytic cell through a pump 4; the electroplating liquid in the electrolytic cell is in a flowing state at all times; the liquid inlet 2 is used for inputting the electroplating liquid to the inlet of the flow channel 1; the electroplating liquid discharged from the outlet of the flow channel 1 is discharged through the liquid outlet 3.

[0047] The flow channel 1 is composed of a main flow channel 5 and a secondary flow channel 6, most of the liquid in the electroplating solution flows through the main flow channel 5, and a small part of the liquid in the electroplating solution flows through the secondary flow channel 6; the cathode plate 10 and the anode plate 11 in the fluid are arranged in the secondary flow channel 6.

[0048] In order to further improve the uniformity of coating, we use a flow channel 1 with a Tesla valve structure or similar to the Tesla valve structure, most of the liquid flows through the main flow channel 5, and a small part of the liquid flows through the secondary flow channel 6, the flow rate of the liquid in the secondary flow channel 6 is lower than that of the main flow channel 5, and the cathode plate 10 and the anode plate 11 are in the secondary flow channel 6, which is more conducive to the uniform coating and assembly of graphene oxide and elemental copper.

[0049] More specifically, the flow channel 1 is composed of a plurality of first flow guide plates 7, second flow guide plates 8 and third flow guide plates 9; the second flow guide plates 8 and the third flow guide plates 9 constitute the secondary flow channel 6; the first flow guide plates 7 are located on one side of the second flow guide plates 8 and the third flow guide plates 9; the first flow guide plates 7 and the second flow guide plates 8, and the first flow guide plates 7 and the third flow guide plates 9 constitute the main flow channel 5.

[0050] The first flow guide plate 7 is arranged in the form of fishbone, and there is also fluid flowing between the two rows of first flow guide plates 7, so the comprehensive Figure 1 It can be seen that the fluid flow form of the present application is generally divided into the flow based on the flow channel 1 of the Tesla valve structure and the fluid flow between the two rows of first flow guide plates 7; among the two flow forms, part of the liquid enters between the two rows of first flow guide plates 7 from the flow channel 1 of the Tesla valve structure, and part of the liquid enters the flow channel 1 of the Tesla valve structure from between the two rows of first flow guide plates 7; but the overall flow mode is still dominated by the flow channel 1 of the Tesla valve structure;

[0051] The present application has a plurality of cathode plates 10 and anode plates 11;

[0052] The cathode plate 10 and the anode plate 11 are both inert plates, specifically titanium alloy plates with ruthenium-iridium alloy plating; the cathode plate 10 and the anode plate 11 are arranged horizontally, the cathode plate 10 is below, and the anode plate 11 is above;

[0053] A scraper 12 is provided beside the cathode plate 10, which is connected to an external shaft by a sealing connection, and the shaft is driven by an additional driving module to periodically scrape the deposits on the cathode plate 10 obtained by the electrochemical deposition method; the deposits can be filtered and removed before entering the circulating pump 4, and then sent to the subsequent cleaning, drying and crushing processes. More preferably, a buffer tank 13 is provided outside the electrolytic tank, and the plating solution flows out of the electrolytic tank and enters the buffer tank 13, and then flows back to the electrolytic tank. By controlling the material concentration in the buffer tank 13 to be within an acceptable concentration range, the stability of the production operation is ensured. If the buffer tank 13 is provided, the filter is not provided, and the particles plated to a suitable thickness are settled by the natural sedimentation in the buffer tank. The graphene without plating or the graphene oxide with insufficient plating is suspended in the upper layer of the solution and is circulated back to the electrolytic tank for further electroplating treatment.

[0054] More specifically, in the following examples, the electrolytic tank of the present application used has the following specific parameters (in actual application, the relevant parameters can be adjusted according to the production scale and other factors, and the actual protection scope is not limited to the following specific structural parameters):

[0055] Electrolytic tank: length: 56 cm; width: 45 cm; height: 16 cm;

[0056] First flow guide plate 7: 9 cm;

[0057] Second flow guide plate 8: 5 cm

[0058] Third flow guide plate 9: 16 cm

[0059] The distance between the second flow guide plate 8 and the third flow guide plate 9 is 5 cm

[0060] The distance between the anode and the cathode is 3-4 cm

[0061] The volume of the electrolytic tank containing the plating solution is 30000 cm 3 ;

[0062] The circulating amount of the pump 4 during operation is 8-12 L / h.

[0063] Example 1

[0064] Example: Co-deposition preparation of Cu@GO composite material

[0065] S1: Preparation of CuSO4 solution: weigh part of copper sulfate pentahydrate crystal powder, add deionized water, ultrasonic stirring for 2-5 h, add a small amount of dilute sulfuric acid, and keep the pH at 3.0-3.5. Prepare CuSO4 solution and store at room temperature;

[0066] S2: Preparation of GO dispersion liquid: a certain amount of GO was weighed and added to deionized water, and ultrasonic treatment was performed for 4h to form a uniform and stable GO dispersion liquid; the D50 flake diameter of the flaky GO was 1 micron;

[0067] S3: Preparation of electroplating reaction solution: the above GO dispersion liquid and CuSO4 solution were added to deionized water, stirred uniformly and ultrasonically dispersed, and a uniformly mixed electroplating solution was obtained, which was then poured into an electrolytic cell; the mass concentration of GO in the electroplating solution was 2g / L and the mass concentration of CuSO4 was 50g / L; the ultrasonic time was 1h; the ultrasonic power was 200w; and the ultrasonic frequency was 10000Hz;

[0068] S4: Preparation of GO@Cu composite material: the feed pump of the electrolytic cell (such as the equipment embodiment) was started and lasted for 45min.

[0069] The electroplating electrode of the electrolytic cell was connected to the positive and negative electrodes of an external power source, and the voltage, current and electroplating time of the electrode were changed (voltage: 4.2V, current: 21A, electroplating time: 45min) to synthesize the GO@Cu composite material. During the electroplating process, the temperature of the electrolytic cell was controlled at 35℃, and every 10 minutes, the GO@Cu coating layer deposited on the surface of the negative electrode was hung to the solution by a scraper, and then the electroplating experiment was continued;

[0070] S5: Impurity removal: after electroplating, the solution obtained after electroplating was allowed to stand and precipitate to remove the supernatant, and deionized water was repeatedly used for multiple times of precipitation and washing to mainly wash away Cu 2+ 、SO4 2- attached to the surface of the GO@Cu composite material, and then vacuum drying treatment was performed to obtain a GO@Cu composite powder. The vacuum drying temperature was 90℃, and the drying time was controlled at 20h.

[0071] S6: GO@Cu powder crushing: the dried GO@Cu co-deposition powder was treated by a pulverizer for 35s, and after the treatment, the powder was sieved by a 2500-mesh screen, and the particle size of the crushed powder was less than 5 microns; the material of the pulverizer was 304 stainless steel, the model was BF-3, and the rotating speed was 35000rpm.

[0072] S7: Preparation of RGO@Cu: the GO@Cu powder was calcined in a reducing gas, specifically a H2-N2 gas mixture (volume ratio 6:4), and the GO@Cu powder was heated from room temperature to 300℃ at a speed of 5℃ / min and kept at this temperature for 30min; then the temperature was quickly raised to 800℃ (10℃ / min), and then heat annealing was performed at this temperature for 2h; finally, the powder was naturally cooled to room temperature to obtain an RGO@Cu composite material.

[0073] Example 2

[0074] Generally the same as Example 1, except that:

[0075] The concentration of graphene oxide in the electroplating solution was 1 g / L, the concentration of CuSO4 was 20 g / L, and the graphene oxide D50 particle size was 800 nm.

[0076] Example 3

[0077] Generally the same as Example 1, except that:

[0078] The concentration of graphene oxide in the electroplating solution was 5 g / L, the concentration of CuSO4 was 100 g / L, and the graphene oxide D50 particle size was 500 nm.

[0079] Example 4

[0080] Generally the same as Example 1, except that:

[0081] The concentration of graphene oxide in the electroplating solution was 1 g / L, the concentration of CuSO4 was 100 g / L.

[0082] Example 5

[0083] Generally the same as Example 1, except that:

[0084] The concentration of graphene oxide in the electroplating solution was 5 g / L, the concentration of CuSO4 was 20 g / L.

[0085] Example 6

[0086] Generally the same as Example 1, except that:

[0087] The concentration of graphene oxide in the electroplating solution was 0.5 g / L, the concentration of CuSO4 was 50 g / L.

[0088] Example 7

[0089] The concentration of graphene oxide in the electroplating solution was 0.1 g / L, the concentration of CuSO4 was 50 g / L.

[0090] Example 8

[0091] The concentration of graphene oxide in the electroplating solution was 2 g / L, the concentration of CuSO4 was 150 g / L.

[0092] Example 9

[0093] The concentration of graphene oxide in the electroplating solution was 2 g / L, the concentration of CuSO4 was 10 g / L.

[0094] Example 10

[0095] Generally the same as Example 1, except that:

[0096] The scraper was used every 15 min; the pulverization time was extended to 45 s at a speed of 35,000 rpm;

[0097] The plating process was: voltage: 3.5 V, current: 15 A, plating time: 60 min.

[0098] The reduction calcination step was:

[0099] Heating from room temperature to 400°C at a rate of 4°C / min and maintaining at this temperature for 30 min; then heating to 900°C at a rate of 8°C / min and then maintaining at this temperature for 1 h; finally, natural cooling to room temperature.

[0100] Example 11

[0101] Generally the same as Example 1, except that:

[0102] The scraper was used every 5 min; the pulverization time was 30 s at a speed of 35,000 rpm;

[0103] The plating process was: voltage: 4.5 V, current: 35 A, plating time: 30 min.

[0104] The reduction step was:

[0105] Heating from room temperature to 200°C at a rate of 6°C / min and maintaining at this temperature for 60 min; then heating to 800°C at a rate of 12°C / min and then maintaining at this temperature for 2 h.

[0106] Example 12

[0107] Generally the same as Example 1, except that steps S4 and S6 were different:

[0108] In S4, the scraper was used every 20 min;

[0109] In S6, the time was extended to 55 s to achieve the synchronous particle size and yield requirements, while the speed remained unchanged.

[0110] Example 13

[0111] Generally the same as Example 1, except that:

[0112] The cathode plate and anode plate were arranged in the main flow channel, and reference was made to Figure 4 .

[0113] Example 14

[0114] Generally the same as Example 1, except that:

[0115] The cathode plate and the anode plate are arranged in a vertical manner in the sub-flow channel, the plate spacing is the same as that in Example 1, and a scraper is arranged on the cathode plate to scrape off the deposited material at the same time interval.

[0116] Sample preparation

[0117] The powder of the above examples is respectively prepared into corresponding metal samples by using an SPS sintering furnace (process, 1000 degrees, 40 megapascals), and after the end, the surface thereof is polished by using 1000-mesh sandpaper, and eddy current conductivity instrument is used for testing;

[0118] Friction performance detection:

[0119] A pin-on-disk tester is used to prepare pin-shaped samples (sample size 4x4x15mm, sliding speed 100rpm, wear radius 10mm, load 15N, load material stainless steel, test time 30min), and the samples are slid on a rotating disk, which is suitable for small-sized materials. After the test, the samples are cleaned by using an ultrasonic cleaning machine for 2-5min, the wear amount is obtained according to the mass change of the front and rear samples, and the volume wear rate formula is used for calculation.

[0120]

[0121] In the formula:

[0122] ρ——actual density of the sample, g / cm 3 ;

[0123] V m ——volume wear rate, mm 3 / N.m;

[0124] Δ m ——mass loss before and after wear, g

[0125] N——experimental load, kg;

[0126] S——sliding distance, m;

[0127] ρ V ——density of the worn material, g / cm;

[0128] The detection results are as shown in Table 1.

[0129] Table 1 detection result table

[0130]

[0131]

[0132] Result analysis:

[0133] 1. As seen from Example 1 to Example 5, the concentration of copper sulfate and the conductivity have a positive correlation, which may be due to the fact that the increase of the concentration of copper sulfate leads to the increase of the conductivity of the whole electroplating system, the copper layer is accelerated to deposit on the surface of graphene, and a relatively complete plating layer modification process on the surface of graphene can be completed when the graphene powder stays between the electrode plates; the friction coefficient and the wear rate are not much related to the concentration of graphene oxide and copper sulfate, but it should be noted that there is a certain correlation between the wear rate and the concentration of copper sulfate, and when the concentration of copper sulfate reaches 100 g / L, the wear rate increases, which may be due to the fact that the higher conductivity can thicken the plating layer on the surface of graphene, which not only directly changes the wear rate, but also affects the reducibility of the internal graphene oxide.

[0134] 2. As seen from Example 1, Example 6 to Example 9, when the concentration of graphene oxide is too low, the wear is further increased, which may be due to the increase of the plating layer thickness, because the lower concentration of graphene can increase the plating layer thickness of a single graphene sheet, thereby affecting the wear rate and the reducibility of graphene oxide.

[0135] When the concentration of copper sulfate is too high or too low, the comprehensive performance will be reduced, especially when the concentration of copper sulfate is too low, the coating thickness is low, which may form a ceramic precursor before sintering, resulting in the reduction of the overall strength after sintering and affecting the comprehensive performance.

[0136] 3. As seen from Example 1, Example 10, Example 11 and Example 12, it is a relatively key operation to scrape the composite material into the solution at a suitable frequency, which is related to the subsequent crushing, and when too much is deposited, the particles will be bonded and other phenomena will occur, which will increase the difficulty of subsequent crushing, and excessive crushing will damage the integrity of the particles, ultimately leading to the deterioration of the overall performance.

[0137] 4. As seen from Example 1, Example 13 and Example 14, the electrolytic cell of the application has a positive effect on the electroplating process, and the position of the electrode plate is relatively critical, which determines the flow rate of graphene at the position of the electrode plate, thereby affecting the uniformity and integrity of the electroplating layer; in addition, the arrangement of the electrode plate is also relatively important, and in the present application, the horizontal arrangement of the electrode plate and the small flow rate can make the graphene regularly settle in the solution, improve the uniformity of the coating, and improve the comprehensive performance.

Claims

1. A process for the preparation of metal@RGO composite by co-deposition under the action of an electric field, characterized in that, The method comprises the following steps: Step 1: adding an electroplating solution containing graphene oxide and a soluble metal salt into an electrolytic cell for electroplating deposition and intermittently collecting the deposits; metal ions in the soluble metal salt are reduced under the action of an electric field; Step 2: washing and crushing the deposits; Step 3: calcining the crushed product in a reducing atmosphere to obtain a metal@RGO composite material composed of a metal element and graphene; The electrode plates in the electrolytic cell are composed of an inert cathode plate and an inert anode plate; the inert cathode plate and the inert anode plate are horizontally arranged; the inert cathode plate is located below the inert anode plate; the inert cathode plate is provided with a scraper for scraping off the deposits deposited on the inert cathode plate; The electrolytic cell is provided with at least one flow channel structure which is a Tesla valve structure or a flow channel similar to the Tesla valve structure; the two ends of the electrolytic cell are a liquid inlet and a liquid outlet; the liquid in the electrolytic cell is circulated by a pump; the liquid inlet is used for inputting the electroplating solution into the inlet of the flow channel; the electroplating solution discharged from the outlet of the flow channel is discharged through the liquid outlet; The flow channel is composed of a main flow channel and a secondary flow channel; most of the liquid in the electroplating solution flows through the main flow channel, and a small part of the liquid in the electroplating solution flows through the secondary flow channel; the inert cathode plate and the inert anode plate are arranged in the secondary flow channel; The flow channel is composed of a plurality of first flow guide plates, second flow guide plates and third flow guide plates; the second flow guide plates and the third flow guide plates constitute the secondary flow channel; the first flow guide plates are located on one side of the second flow guide plates and the third flow guide plates; the first flow guide plates and the second flow guide plates and the first flow guide plates and the third flow guide plates constitute the main flow channel.

2. The manufacturing process of claim 1, wherein, The crushing time of step 2 is 30-45 s, and the rotating speed of the rotor during crushing is 30000-40000 rpm; in step 1, the collection time interval of the deposits is not more than 15 min.

3. The manufacturing process of claim 2, wherein, The collection time interval of the deposits is 5-10 min.

4. The manufacturing process of claim 1, wherein, The concentration of graphene oxide in the electroplating solution is 1-5 g / L, and the concentration of the soluble metal salt is 20-100 g / L; The D50 flake diameter of the graphene oxide is 0.5-1 micron; the metal ions in the soluble metal salt are copper ions and / or silver ions; the particle size of the crushed product of step 2 is less than 5 microns.

5. The manufacturing process of claim 1, wherein, In step 1, the electroplating deposition process parameters are: the voltage range is 3.5-4.5 V, the current range is 15-35 A, and the electroplating time is 30-60 min; In step 3, the reduction calcination process parameters are: the crushed product of step 2 is heated from room temperature to 200-400℃ at a speed of 4-6℃ / min, and kept at this temperature for 30-60 min; then heated to 700-900℃ at a speed of 8-12℃ / min, and then kept at this temperature for 1-2 h; finally, naturally cooled to room temperature.

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