Method for preparing copper-based graphene composite foil by eutectic solvent electrodeposition

Abstract

The application belongs to the technical field of composite materials, and particularly discloses a method for preparing a copper-based graphene composite foil by means of eutectic solvent electrodeposition. The method uses a novel electrolyte composition for direct current electrodeposition, and a eutectic solvent is prepared from choline chloride and ethylene glycol in a certain molar ratio, which replaces deionized water in the traditional electrolyte as a solvent. The graphene is well dispersed in the electrolyte due to the excellent dissolving capacity, strong polarity and proper viscosity of the eutectic solvent. In addition, by adding appropriate additives and reasonably selecting electrodeposition parameters, the copper-based graphene composite material with high strength, high thermal conductivity and low roughness is prepared, which meets the use requirements of the microelectronic and battery industries.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials and specifically discloses a method for preparing copper-based graphene composite foil by electrodeposition of a low eutectic solvent. Background Art

[0002] Copper has high electrical and thermal conductivity as well as good mechanical properties. Therefore, copper prepared by electrodeposition is widely used in fields such as electronics, batteries, printed circuit boards, and aerospace. In terms of electrodeposition technology, electrodeposition using water-based solutions is the most important application technology. Coatings that meet the performance requirements can be prepared by changing the temperature, current density, plate spacing, type and concentration of additives, etc. However, water-based solutions also have some disadvantages, such as the possibility of hydrogen evolution during electrodeposition, the relatively low solubility of certain copper salts in water, sensitivity to temperature changes, and environmental pollution. Low eutectic solvents, on the other hand, have the advantages of high current efficiency, high deposition rate, wider solubility, better temperature stability, and environmental friendliness.

[0003] Graphene, with its exceptionally high strength, electrical and thermal conductivity, is an ideal reinforcement phase. However, the formulation of composite electrolytes using graphene as a reinforcement phase often faces a challenge: graphene easily aggregates in aqueous solutions due to its inherent properties. Surfactants such as polyacrylic acid, sodium lauryl sulfate, and polyvinyl pyrrolidone are commonly added to promote the dispersion of graphene in aqueous solutions. However, these surfactants have limited effectiveness and are difficult to sustain for long-term electrodeposition production. Summary of the Invention

[0004] In order to solve the technical problems pointed out in the background technology, the present invention provides a method for preparing copper-based graphene composite foil by electrodeposition using a low eutectic solvent.

[0005] The preparation method of copper-based graphene-based composite foil comprises the following specific steps:

[0006] (1) Preparation of a low eutectic solvent: The preparation method is as follows: Due to the strong water absorption of choline chloride, choline chloride needs to be placed in a drying oven and then weighed. Then, choline chloride and ethylene glycol are weighed and mixed in a molar ratio of 1:1.5 to 1:2.5, and heated in an oil bath at 60 to 80°C and mechanically stirred until dissolved.

[0007] (2) Preparation of copper chloride solution: Copper chloride dihydrate and gelatin are added to the low eutectic solvent of step (1) at concentrations of 20-50 g / L and 10-50 mg / L, respectively. The mixture is heated in an oil bath at 50° C. and mechanically stirred until dissolved. Deionized water is then added.

[0008] (3) Preparation of copper-based graphene electrodeposition solution: adding graphene to a copper chloride solution at a concentration of 0.05 to 2.0 g / L, first performing ultrasonic dispersion, and then performing high-speed homogenous dispersion to obtain a composite electrolyte for preparing copper-based graphene composite materials.

[0009] (4) Polish the plates with 1000-mesh, 1500-mesh and 2000-mesh sandpaper in sequence, and then place the polished anode and cathode plates in a 10% dilute hydrochloric acid solution for activation for 5 to 10 minutes.

[0010] (5) Using the composite electrolyte prepared in step (3) to perform direct current electrodeposition, the electrodeposition process parameters are: current density of 5 to 60 mA / cm 2 The temperature of the deposition liquid is 20-50°C, the deposition time is 0.5-3h, magnetic stirring is performed during electrodeposition, and the rotation speed is 80-200r / min.

[0011] The composite electrodeposition liquid used in the present invention has a reasonable composition ratio and is recyclable, has a better graphene dispersion effect, and achieves cost savings and environmental protection. The composite foil prepared using the electrodeposition liquid has a smooth surface, a uniform and dense structure, and its surface roughness, mechanical properties and thermal conductivity meet the requirements of the microelectronics and battery industries.

[0012] Beneficial effects of the present invention

[0013] 1. The process of the present invention is simple, and the prepared composite material has fine surface particles, low surface roughness, and excellent mechanical properties and thermal conductivity.

[0014] 2. The present invention provides a new composite deposition liquid formula, which replaces the traditional water-based solvent with a low eutectic solvent. While fully dispersing graphene, it also has the advantages of high conductivity, wide electrochemical window and good thermal stability.

[0015] 3. The sedimentation liquid of the present invention is environmentally friendly, does not require the addition of excessive additives or sulfate, hydrochloric acid, etc., and has low toxicity and is biodegradable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a surface scanning electron microscope image of the composite foil prepared in Example 3.

[0017] Figure 2 This is a three-dimensional image of the surface morphology of the composite foil prepared in Example 3.

[0018] Figure 3 This is a three-dimensional image of the surface morphology of the composite foil prepared in Comparative Example 3.

[0019] Figure 4 3 is a comparison diagram of the composite electrolyte prepared in Example 3 before and after standing for 24 hours.

[0020] Figure 5 3 is a comparison chart of the composite electrolyte prepared in Comparative Example 3 before and after standing for 24 hours. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to the following examples: The following examples are all based on the preparation of 250 mL of an electrodeposition solution of a copper-based graphene composite material as an example.

[0022] Example 1

[0023] The composition ratio of the copper-based graphene electrodeposition solution is: 35 g / L copper chloride dihydrate, 0.8 g / L graphene, 30 ml deionized water, and the balance is choline chloride (ChCl)-ethylene glycol (EG) low eutectic solvent; the additive is: 20 mg / L gelatin.

[0024] The preparation method of ChCl-EG low eutectic solvent is as follows: put ChCl into a drying oven to dry and then weigh it, then weigh EG with a molar ratio of 1:2 to ChCl, heat it in an oil bath at 80°C and stir it mechanically until it dissolves.

[0025] The preparation method of the copper-based graphene electrodeposition solution is as follows: adding copper chloride dihydrate and gelatin to a low eutectic solvent, heating in a 50°C oil bath and mechanically stirring until dissolved, and adding deionized water after complete dissolution; adding graphene to the copper chloride solution, mechanically stirring and then ultrasonically dispersing, and finally performing high-speed homogenous dispersion to obtain a composite electrodeposition solution.

[0026] Pretreatment of the anode and cathode plates: Use metallographic sandpaper to polish the anode and cathode plates to remove surface stains and oxide films, then place the plates in a 10% dilute hydrochloric acid solution for 5 minutes for activation.

[0027] The electrodeposition process parameters are: current density of 10 mA / cm 2 The deposition liquid temperature was 30°C, the deposition time was 2 h, magnetic stirring was performed during electrodeposition, and the rotation speed was 200 r / min.

[0028] The composite deposited layer prepared under these conditions has a relatively uneven macroscopic surface with concave-convex fascia, large particles in the microscopic surface morphology, and general density. The tensile strength of the deposited layer reaches 412±10MPa, the thermal conductivity can reach 475W / m·K, and the surface roughness reaches 1.27μm.

[0029] Example 2

[0030] The composition ratio of the copper-based graphene electrodeposition solution is: 35 g / L of copper chloride dihydrate, 0.8 g / L of graphene, 15 ml of deionized water, and the balance is ChCl-EG low eutectic solvent; the additive is: 20 mg / L of gelatin.

[0031] The preparation method of ChCl-EG deep eutectic solvent is the same as that in Example 1.

[0032] The preparation method of the copper-based graphene electrodeposition solution is the same as that in Example 1.

[0033] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0034] The electrodeposition process parameters are the same as those in Example 1.

[0035] The composite deposited layer prepared under these conditions has a slight fascia on the macroscopic surface, small particles on the microscopic surface morphology, and good density. The tensile strength of the deposited layer reaches 573±10MPa, the thermal conductivity can reach 628W / m·K, and the surface roughness reaches 0.83μm.

[0036] Example 3

[0037] The composition ratio of the copper-based graphene electrodeposition solution is: 35 g / L of copper chloride dihydrate, 0.8 g / L of graphene, and the balance is a ChCl-EG low eutectic solvent; the additive is: 20 mg / L of gelatin.

[0038] The preparation method of ChCl-EG deep eutectic solvent is the same as that in Example 1.

[0039] The preparation method of the copper-based graphene electrodeposition solution is as follows: adding copper chloride dihydrate and gelatin to a ChCl-EG low eutectic solvent, heating in a 50°C oil bath and mechanically stirring until dissolved; adding graphene to the copper chloride solution, mechanically stirring and then ultrasonically dispersing, and finally performing high-speed homogenous dispersion to obtain a composite electrodeposition solution.

[0040] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0041] The electrodeposition process parameters are the same as those in Example 1.

[0042] The composite deposited layer prepared under these conditions has a smooth macroscopic surface, extremely small microscopic surface particles, and good density. The tensile strength of the deposited layer reaches 835±10MPa, the thermal conductivity can reach 797W / m·K, and the surface roughness reaches 0.28μm.

[0043] Example 4

[0044] The composition ratio of the copper-based graphene electrodeposition solution is the same as that of Example 3.

[0045] The preparation method of ChCl-EG low eutectic solvent is as follows: put ChCl into a drying oven to dry and then weigh it, then weigh EG with a molar ratio of 1:1.5 to ChCl, heat it in an oil bath at 80°C and stir it mechanically until it dissolves.

[0046] The preparation method of the copper-based graphene electrodeposition solution is the same as that in Example 3.

[0047] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0048] The electrodeposition process parameters are the same as those in Example 1.

[0049] The composite deposited layer prepared under these conditions has a smooth macroscopic surface, small microscopic surface particles, and good density. The tensile strength of the deposited layer reaches 553±10MPa, the thermal conductivity can reach 642W / m·K, and the surface roughness reaches 0.64μm.

[0050] Example 5

[0051] The composition ratio of the copper-based graphene electrodeposition solution is the same as that of Example 3.

[0052] The preparation method of ChCl-EG low eutectic solvent is as follows: put ChCl into a drying oven to dry and then weigh it, then weigh EG with a molar ratio of 1:2.5 to ChCl, heat it in an oil bath at 80°C and stir it mechanically until it dissolves.

[0053] The preparation method of the copper-based graphene electrodeposition solution is the same as that in Example 3.

[0054] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0055] The electrodeposition process parameters are the same as those in Example 1.

[0056] The composite deposited layer prepared under these conditions has a relatively smooth macroscopic surface, large particles on the microscopic surface, pores, and poor density. The tensile strength of the deposited layer reaches 373±10MPa, the thermal conductivity can reach 489W / m·K, and the surface roughness reaches 1.47μm.

[0057] Example 6

[0058] The composition ratio of the copper-based graphene electrodeposition solution is: 35 g / L of copper chloride dihydrate, 0.4 g / L of graphene, and the balance is a ChCl-EG low eutectic solvent; the additive is: 20 mg / L of gelatin.

[0059] The preparation method of ChCl-EG deep eutectic solvent is the same as that in Example 1.

[0060] The preparation method of the copper-based graphene electrodeposition solution is the same as that in Example 3.

[0061] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0062] The electrodeposition process parameters are the same as those in Example 1.

[0063] The composite deposited layer prepared under these conditions has a smooth macroscopic surface, fine microscopic surface morphology, and good density. The tensile strength of the deposited layer reaches 681±10MPa, the thermal conductivity can reach 764W / m·K, and the surface roughness reaches 0.33μm.

[0064] Example 7

[0065] The composition ratio of the copper-based graphene electrodeposition solution is: 35 g / L of copper chloride dihydrate, 1.2 g / L of graphene, and the balance is a ChCl-EG low eutectic solvent; the additive is: 20 mg / L of gelatin.

[0066] The preparation method of ChCl-EG deep eutectic solvent is the same as that in Example 1.

[0067] The preparation method of the copper-based graphene electrodeposition solution is the same as that in Example 3.

[0068] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0069] The electrodeposition process parameters are the same as those in Example 1.

[0070] The composite deposited layer prepared under these conditions has a relatively rough macroscopic surface with protruding particles, and a microscopic surface with large particles, pores, and poor density. The tensile strength of the deposited layer reaches 337±10MPa, the thermal conductivity can reach 362W / m·K, and the surface roughness reaches 1.86μm.

[0071] Example 8

[0072] The composition ratio of the copper-based graphene electrodeposition solution is the same as that of Example 3.

[0073] The preparation method of ChCl-EG deep eutectic solvent is the same as that in Example 1.

[0074] The preparation method of the copper-based graphene electrodeposition solution is the same as that in Example 3.

[0075] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0076] The electrodeposition process parameters are: current density 5mA / cm 2 The deposition liquid temperature was 30°C, the deposition time was 2 h, magnetic stirring was performed during electrodeposition, and the rotation speed was 200 r / min.

[0077] The composite deposited layer prepared under these conditions has a smooth macroscopic surface, small microscopic surface particles, and good density, but the deposition rate is low and the deposited layer is thin. The tensile strength of the deposited layer reaches 662±10MPa, the thermal conductivity can reach 741W / m·K, and the surface roughness reaches 0.31μm.

[0078] Example 9

[0079] The composition ratio of the copper-based graphene electrodeposition solution is the same as that of Example 3.

[0080] The preparation method of ChCl-EG deep eutectic solvent is the same as that in Example 1.

[0081] The preparation method of the copper-based graphene electrodeposition solution is the same as that in Example 3.

[0082] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0083] The electrodeposition process parameters are: current density of 15 mA / cm 2 The deposition liquid temperature was 30°C, the deposition time was 2 h, magnetic stirring was performed during electrodeposition, and the rotation speed was 200 r / min.

[0084] The macroscopic surface of the composite deposited layer prepared under these conditions is relatively rough with protruding particles, the microscopic surface morphology has large particles, no pores, and general density. The tensile strength of the deposited layer reaches 451±10MPa, the thermal conductivity can reach 537W / m·K, and the surface roughness reaches 1.39μm.

[0085] Comparative Example 1

[0086] The composition ratio of the copper-based graphene electrodeposition solution is: 35 g / L of copper chloride dihydrate, 0.8 g / L of graphene, and the balance is a choline chloride (ChCl)-urea (Urea) low eutectic solvent; the additive is: 20 mg / L of gelatin.

[0087] The preparation method of ChCl-Urea low eutectic solvent is as follows: put ChCl into a drying oven to dry and then weigh it, then weigh Urea with a molar ratio of 1:2 to ChCl, heat it in an 80℃ oil bath and mechanically stir it until it dissolves.

[0088] The preparation method of the copper-based graphene electrodeposition solution is as follows: adding copper chloride dihydrate and gelatin to a ChCl-Urea low eutectic solvent, heating in a 50°C oil bath and mechanically stirring until dissolved; adding graphene to the copper chloride solution, mechanically stirring and then ultrasonically dispersing, and finally performing high-speed homogenous dispersion to obtain a composite electrodeposition solution.

[0089] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0090] The electrodeposition process parameters are the same as those in Example 1.

[0091] The composite deposited layer prepared under these conditions has a rough macroscopic surface with a large number of protruding particles, pores on the microscopic surface, and poor density. The tensile strength of the deposited layer reaches 187±10MPa, the thermal conductivity can reach 281W / m·K, and the surface roughness reaches 3.87μm.

[0092] Comparative Example 2

[0093] The composition ratio of the copper-based graphene electrodeposition solution is: 35 g / L of copper chloride dihydrate, 0.8 g / L of graphene, and the balance is a choline chloride (ChCl)-glycerol (Gly) low eutectic solvent; the additive is: 20 mg / L of gelatin.

[0094] The preparation method of the ChCl-Gly low eutectic solvent is as follows: put ChCl into a drying oven to dry and then weigh it, then weigh Gly at a molar ratio of 1:1.5 to ChCl, heat it in an oil bath at 70°C and mechanically stir it until it dissolves.

[0095] The preparation method of the copper-based graphene electrodeposition solution is as follows: adding copper chloride dihydrate and gelatin to a ChCl-Gly low eutectic solvent, heating in a 50°C oil bath and mechanically stirring until dissolved; adding graphene to the copper chloride solution, mechanically stirring and then ultrasonically dispersing, and finally performing high-speed homogenous dispersion to obtain a composite electrodeposition solution.

[0096] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0097] The electrodeposition process parameters are the same as those in Example 1.

[0098] The composite deposition layer prepared under this condition is not formed but in powder form.

[0099] Comparative Example 3

[0100] The composition ratio of the graphene / copper water-based electrodeposition solution is: 180 g / L copper sulfate pentahydrate, 0.8 g / L graphene, and the balance is deionized water; the additive concentrations are: 20 mg / L gelatin, 0.6 g / L SDS.

[0101] The pretreatment of the anode and cathode plates is the same as in Example 1.

[0102] The preparation method of the graphene / copper water-based electrodeposition solution is as follows: ultrasonically dispersing SDS and a graphene solution, and then performing high-speed homogenous dispersion; adding gelatin to a copper sulfate solution, and mechanically stirring and dissolving; mechanically stirring and mixing the graphene solution and the copper sulfate solution, adjusting the pH value to 1 with sulfuric acid, and then performing ultrasonic dispersion to obtain the graphene / copper water-based electrodeposition solution.

[0103] The electrodeposition process parameters are: temperature 20°C; current density 70 mA / cm 2 The electrodeposition time was 1 hour, and mechanical stirring was performed at a speed of 150 r / min. Under these conditions, the composite deposited layer produced exhibited uniform thickness, a smooth surface, and good density. The tensile strength of the deposited layer reached 421±10 MPa, the thermal conductivity reached 453 W / m·K, and the surface roughness reached 1.75 μm.

[0104] The above-described embodiments are preferred implementations of the present invention, but the present invention is not limited to the above-described implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention are within the scope of protection of the present invention.

Claims

1. A method for preparing a copper-based graphene composite foil by electrodeposition of a deep eutectic solvent, characterized in that: The method steps are as follows: (1) preparing a choline chloride and ethylene glycol eutectic solvent; the molar ratio of choline chloride to ethylene glycol is 1:1.5 to 1:2.5; (2) adding copper chloride dihydrate and gelatin to the low eutectic solvent prepared in step (1), heating in an oil bath, and mechanically stirring until dissolved to obtain a copper chloride solution; (3) fully dispersing the graphene in the copper chloride solution prepared in step (2), and mixing by magnetic stirring to obtain an electrodeposition solution of a copper-based graphene composite material; The prepared copper-based graphene composite material electrodeposition solution has the following composition by mass concentration: 20-50 g / L of copper chloride dihydrate, 10-50 mg / L of gelatin, 0.05-2.0 g / L of graphene, and the balance being a deep eutectic solvent; (4) Use metallographic sandpaper to polish the anode copper plate and cathode titanium plate to remove oil stains and oxide film, and then activate the plates with 10% dilute hydrochloric acid solution for 5 to 10 minutes; (5) Using the electrodeposition solution prepared in step (3) to perform direct current electrodeposition to obtain a copper-based graphene composite foil, the current density during electrodeposition is 5-60 mA / cm 2 .

2. The method for preparing a copper-based graphene composite foil by electrodeposition of a deep eutectic solvent according to claim 1, characterized in that: In step (1), the preparation method of the low eutectic solvent is: mixing choline chloride and ethylene glycol in a molar ratio of 1:1.5 to 1:2.5, heating in an oil bath at 60 to 80° C. and mechanically stirring until dissolved, to obtain a low eutectic solvent.

3. The method for preparing a copper-based graphene composite foil by electrodeposition of a deep eutectic solvent according to claim 1, wherein: In step (5), the electrodeposition parameters are as follows: the electrodeposition time is 0.5 to 3 hours; the temperature of the deposition liquid is 20 to 50° C.; magnetic stirring is performed during the electrodeposition, and the rotation speed is 80 to 200 r / min.

4. The method for preparing a copper-based graphene composite foil by electrodeposition of a deep eutectic solvent according to claim 1, wherein: In step (5), the tensile strength of the prepared copper-based graphene composite foil is: 337~835MPa, the thermal conductivity is: 362~797W / m·K, and the surface roughness is: 0.28~1.86μm.

5. The method for preparing a copper-based graphene composite foil by electrodeposition of a deep eutectic solvent according to claim 1, wherein: In step (5), the prepared copper-based graphene composite foil is used as a heat conduction material.

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