Electrochemically induced metal oriented growth method based on gallium-based liquid metal substrate

Abstract

The invention relates to an electrochemical induced metal oriented growth method based on a gallium-based liquid metal substrate, and belongs to the technical field of electrochemical materials. According to the present invention, the dynamic smooth interface and the low lattice mismatch characteristic of the liquid metal are utilized, the reduction kinetics of the metal ions is regulated and controlled through the constant current mode, the high orientation degree growth of the crystal along the specific crystal face (such as Zn (002) and In (111)) is achieved, and the prepared deposited metal dominant crystal face has the high orientation degree. The problems of stress accumulation and dendritic crystals of a traditional solid substrate can be solved, and the method is suitable for green preparation of nanowire arrays and functional coatings; and the process is simple and convenient to operate, easy in control of process parameters and suitable for batch production.

Description

Technical Field

[0001] This invention relates to an electrochemically induced directional growth method for metals based on gallium-based liquid metal substrates, belonging to the field of electrochemical materials technology. Background Technology

[0002] When traditional solid substrates (such as metal foils and silicon wafers) induce electrochemical growth of metals, lattice mismatch leads to interfacial stress accumulation, strong randomness in crystal orientation, and a tendency to generate dendritic defects. Although the technique of inducing high-orientation directional growth of metals by constructing single crystal planes (such as Cu(111) electrodeposition to induce Zn(002) directional growth) can reduce lattice mismatch to achieve high-orientation electrochemical directional growth of metals, it often involves complex process technologies and high manufacturing costs, such as magnetron sputtering, physical vapor deposition, and chemical vapor deposition.

[0003] Liquid metals exhibit long-range disorder and short-range order, with weak interatomic bonding and no stable crystal structure in the liquid state. Therefore, the dynamic adaptive interface of liquid metals can effectively eliminate lattice mismatch, allowing deposited metals to grow oriented along low-energy crystal planes. Simultaneously, the weak interatomic bonding in liquid metals facilitates the diffusion of deposited metal ions on the surface and in the bulk phase, thus suppressing dendrite growth. While mercury-based liquid metals can alleviate stress, their high toxicity and environmental risks limit their application. Existing technologies struggle to achieve a balance between low interfacial stress, high orientation consistency, and environmental friendliness, particularly hindering the controllable growth of micro / nano-scale metal structures. Summary of the Invention

[0004] To address the problems of random metal growth orientation, high interfacial stress, and high toxicity of mercury-based liquid metals caused by lattice mismatch in solid substrates, this invention provides an electrochemically induced metal directional growth method based on gallium-based liquid metal substrates. By utilizing the dynamic smooth interface and low lattice mismatch characteristics of liquid metals, and controlling the reduction kinetics of metal ions through constant current mode, crystals can be grown with high orientation along specific crystal planes (such as Zn(002) and In(111)), resulting in deposited metals with high orientation of dominant crystal planes.

[0005] An electrochemically induced directional growth method for metals based on gallium-based liquid metal substrates, comprising the following steps: (1) A continuous liquid film is formed by covering a conductive substrate with liquid metal as a liquid metal-induced deposition layer; (2) A three-electrode system is constructed by using a liquid metal-induced deposition layer on a conductive substrate as the working electrode, an inert electrode or a target metal electrode as the counter electrode, and an Ag / AgCl electrode or a saturated calomel electrode as the reference electrode. Constant current electrochemical deposition is carried out in the metal salt electrolyte and the working electrode moves dynamically in the metal salt electrolyte. The target metal crystal in the metal salt solution is oriented along a specific crystal plane at the interface of the liquid metal-induced deposition layer / metal salt electrolyte.

[0006] Preferably, the liquid metal in step (1) is Ga or a Ga-based liquid alloy.

[0007] Preferably, the Ga-based liquid alloy is a liquid alloy formed by combining one or more of In, Sn, and Bi with Ga.

[0008] Preferably, the thickness of the liquid metal-induced deposition layer in step (1) is 10 nm to 500 μm.

[0009] Preferably, the metal salt in step (2) is an organic or inorganic salt of the target metal, and the target metal is Zn, In, Sn or Bi.

[0010] Preferably, the metal salt electrolyte in step (2) is an organic electrolyte or an inorganic electrolyte, and the concentration of metal salt in the metal salt electrolyte is 0.1~3 mol / L.

[0011] Preferably, the dynamic moving speed of the working electrode in step (2) is 1~100mm / s.

[0012] Preferably, the temperature for the constant current electrochemical deposition in step (2) is 15~40℃, and the current density is 1~150mA / cm². 2 The time ranges from 1 minute to 10 hours.

[0013] The beneficial effects of the present invention are: (1) In the electrochemical induced metal directional growth method based on gallium-based liquid metal substrate, the dynamic smooth interface of the liquid metal induced layer can effectively eliminate lattice mismatch and interface stress, solve the stress accumulation problem of traditional solid substrates in the electrodeposition process, and induce the orientation degree of the dominant crystal plane of the deposited metal crystal to be ≥95%; (2) The gallium-based liquid metal of the present invention can regulate the initial nucleation behavior of the deposited metal and achieve local electric field and ion flux uniformity during the electrodeposition process; at the same time, the alloying characteristics and fluidity of the gallium-based liquid metal, together with the pulsed electric field, can effectively suppress dendrite formation. (3) The present invention reduces the nucleation energy of the deposited metal on the surface by constructing a continuous liquid metal film layer on the surface of the conductive substrate, making it easier to form a uniform metal deposition layer with high crystal orientation; gallium-based liquid metal is non-toxic, environmentally friendly and recyclable; (4) The method of the present invention has high versatility and can be used for the deposition of metals with eutectic phase with gallium. It can also continuously and on a large scale prepare metal coatings with high crystal orientation, thus meeting industrial needs. Attached Figure Description

[0014] Figure 1 The images show the SEM and EDS images of the Zn(002) deposition layer in Example 1; Figure 2 The image shows the XRD pattern of the Zn(002) deposition layer in Example 1. Figure 3 The images show the SEM and EDS images of the Zn(002) deposition layer in Example 2; Figure 4 The image shows the XRD pattern of the Zn(002) deposition layer in Example 2. Figure 5 Here is a SEM image of the Zn(002) deposition layer in the comparative example; Figure 6 The XRD pattern of the Zn(002) deposition layer in the comparative example; Figure 7 The diagrams show a comparison of the dendrite suppression effects in the comparative example and Example 2. (a) is the comparative example, and (b) is the example. Figure 8 XRD pattern of the In (111) deposition layer in Example 3; Figure 9 XRD pattern of Sn(020) deposition layer in Example 4; Figure 10 The image shows the XRD pattern of the Bi(012) deposition layer in Example 5. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0016] Example 1: An electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate, the specific steps of which are as follows: (1) Liquid gallium metal is uniformly coated onto a conductive substrate (conductive ITO glass) using a blade coating process to form a continuous liquid film as a liquid metal induced deposition layer; the thickness of the liquid metal induced deposition layer is 500 μm; (2) A three-electrode system is constructed using a liquid metal-induced deposition layer on a conductive substrate (conductive ITO glass) as the working electrode, a zinc electrode as the counter electrode, and a saturated calomel electrode as the reference electrode. Constant current electrochemical deposition is performed in a metal salt electrolyte (an aqueous solution containing 1 mol / L ZnSO4, 0.1 mol / L ZnAc, and 0.01 mol / L LCTAB), with the working electrode moving at a speed of 1 mm / s in the electrolyte. The target metal crystal in the metal salt solution is oriented along a specific crystal plane (002) at the interface between the liquid metal-induced deposition layer and the metal salt electrolyte. The constant current electrochemical deposition temperature is 40°C, and the current density is 150 mA / cm². 2 The time is 1 minute; SEM and EDS images of the Zn(002) deposition layer in this embodiment are shown below. Figure 1 SEM showed that the deposited layers were regularly and uniformly arranged, with grains stacked in layers and having a diameter greater than 20 μm. The XRD pattern of the Zn(002) deposition layer in this embodiment is shown below. Figure 2 XRD analysis showed that the orientation degree of Zn(002) crystal plane was 99.2%.

[0017] Example 2: An electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate, the specific steps of which are as follows: (1) A continuous liquid film is formed by uniformly coating liquid metal (gallium indium tin bismuth alloy) onto a conductive substrate (copper foil) using a spraying process as a liquid metal induced deposition layer; the thickness of the liquid metal induced deposition layer is 100 μm; (2) A three-electrode system is constructed using a liquid metal-induced deposition layer on a conductive substrate (copper foil) as the working electrode, a platinum electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode. Constant current electrochemical deposition is performed in a metal salt electrolyte (the electrolyte is an organic solution, the solvent is a 3:1 volume ratio mixture of DMSO (dimethyl sulfoxide) and EMC (methyl ethyl carbonate), and the electrolyte is 1 mol / L zinc acetylacetone (Zn(C5H7O2)2). The working electrode moves dynamically in the metal salt electrolyte at a speed of 25 mm / s. At the interface between the liquid metal-induced deposition layer and the metal salt electrolyte, the target metal crystal in the metal salt solution is oriented along a specific crystal plane (002). The constant current electrochemical deposition temperature is 20 °C, and the current density is 20 mA / cm². 2 The time is 1 hour; SEM and EDS images of the Zn(002) deposition layer in this embodiment are shown below. Figure 3 SEM showed that the deposited layers were regularly and uniformly arranged, with grains stacked in layers and about 10 μm in diameter. The XRD pattern of the Zn(002) deposition layer in this embodiment is shown below. Figure 4XRD analysis showed that the orientation degree of Zn(002) crystal plane was 98.6%.

[0018] Comparative Example: The difference between this comparative example and Example 2 is that the working electrode is zinc foil; The SEM image of the Zn(002) deposition layer in this comparative example is shown below. Figure 5 SEM showed that the Zn deposited on the Cu foil surface grew in layers with different orientations and uneven arrangement. The XRD pattern of the Zn(002) deposition layer in this comparative example is shown below. Figure 6 XRD analysis showed that the Zn deposited on the Cu foil surface was polycrystalline, and the orientation degree of the Zn(002) crystal plane was only 61.1%. The comparison diagram of dendrite suppression effects in Example 2 and the comparative example is shown in the figure. Figure 7 Optical microscopy revealed that zinc deposited on the Cu foil surface grew in the form of coarse dendrites, while zinc deposited on the liquid metal surface was smooth and flat. This was due to the rapid alloying ability of the liquid metal, which effectively eliminated zinc dendrites.

[0019] Example 3: An electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate, the specific steps of which are as follows: (1) A continuous liquid film is formed by electroplating liquid metal (gallium indium alloy) onto a conductive substrate (carbon paper) as a liquid metal induced deposition layer; the thickness of the liquid metal induced deposition layer is 10 nm; (2) A three-electrode system was constructed using a liquid metal-induced deposition layer on a conductive substrate (carbon paper) as the working electrode, a platinum electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode. Constant current electrochemical deposition was performed in a metal salt electrolyte (the electrolyte was an aqueous solution containing 0.5 mol / L InCl3 and 0.01 mol / L HCl), and the working electrode moved dynamically in the metal salt electrolyte at a speed of 50 mm / s. The target metal (In) crystal in the metal salt solution was induced to grow oriented along a specific crystal plane (111) at the interface of the liquid metal-induced deposition layer / metal salt electrolyte. The temperature of the constant current electrochemical deposition was 15 °C, and the current density was 1 mA / cm². 2 The time is 10 hours; The XRD pattern of the In(111) deposition layer in this embodiment is shown below. Figure 8 XRD analysis showed that the orientation degree of the In(111) crystal plane was 95.3%.

[0020] Example 4: An electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate, the specific steps of which are as follows: (1) A continuous liquid film is formed on a conductive substrate (conductive ITO glass) by uniformly coating liquid metal (gallium tin alloy) using a spraying process as a liquid metal induced deposition layer; the thickness of the liquid metal induced deposition layer is 300 μm; (2) A three-electrode system is constructed using a liquid metal-induced deposition layer on a conductive substrate (conductive ITO glass) as the working electrode, a platinum electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode. Constant current electrochemical deposition is performed in a metal salt electrolyte (0.25 mol / L SnCl2, 0.05 mol / L HCl), with the working electrode moving dynamically at a speed of 100 mm / s in the electrolyte. At the interface between the liquid metal-induced deposition layer and the metal salt electrolyte, the target metal (Sn) crystal in the metal salt solution is oriented along a specific crystal plane (020). The constant current electrochemical deposition temperature is 40 °C, and the current density is 100 mA / cm². 2 The time is 5 minutes; The XRD pattern of the Sn(020) deposition layer in this embodiment is shown below. Figure 9 XRD analysis showed that the orientation degree of the Sn(020) crystal plane was 95.6%.

[0021] Example 5: An electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate, the specific steps of which are as follows: (1) A continuous liquid film is formed by uniformly coating liquid metal (gallium bismuth alloy) onto a conductive substrate (copper foil) using a scraping process as a liquid metal induced deposition layer; the thickness of the liquid metal induced deposition layer is 400 μm; (2) A three-electrode system was constructed using a liquid metal-induced deposition layer on a conductive substrate (copper foil) as the working electrode, a platinum electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode. Constant current electrochemical deposition was performed in a metal salt electrolyte (3 mol / L Bi(NO3)3, 0.01 mol / L HNO3), with the working electrode dynamically moving within the electrolyte at a speed of 15 mm / s. At the interface between the liquid metal-induced deposition layer and the metal salt electrolyte, the target metal (Bi) crystal in the metal salt solution was induced to grow oriented along a specific crystal plane (012). The constant current electrochemical deposition temperature was 30 °C, and the current density was 10 mA / cm². 2 The time is 2 hours; The XRD pattern of the Bi(012) deposition layer in this embodiment is shown below. Figure 10 XRD analysis showed that the orientation degree of the Bi(012) crystal plane was 97.2%.

[0022] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for electrochemically induced directional growth of metals based on gallium-based liquid metal substrates, characterized in that, The specific steps are as follows: (1) A continuous liquid film is formed by covering a conductive substrate with liquid metal as a liquid metal-induced deposition layer; (2) A three-electrode system is constructed by using a liquid metal-induced deposition layer on a conductive substrate as the working electrode, an inert electrode or a target metal electrode as the counter electrode, and an Ag / AgCl electrode or a saturated calomel electrode as the reference electrode. Constant current electrochemical deposition is carried out in the metal salt electrolyte and the working electrode moves dynamically in the metal salt electrolyte. The target metal crystal in the metal salt solution is oriented along a specific crystal plane at the interface of the liquid metal-induced deposition layer / metal salt electrolyte.

2. The electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate according to claim 1, characterized in that: Step (1) The liquid metal is Ga or a Ga-based liquid alloy.

3. The electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate according to claim 2, characterized in that: Ga-based liquid alloys are liquid alloys formed by combining one or more of In, Sn, and Bi with Ga.

4. The electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate according to claim 1, characterized in that: Step (1) The thickness of the liquid metal-induced deposition layer is 10 nm to 500 μm.

5. The electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate according to claim 1, characterized in that: Step (2) The metal salt is an organic or inorganic salt of the target metal, and the target metal is Zn, In, Sn or Bi.

6. The electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate according to claim 1, characterized in that: Step (2) The metal salt electrolyte is an organic electrolyte or an inorganic electrolyte, and the concentration of metal salt in the metal salt electrolyte is 0.1~3 mol / L.

7. The electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate according to claim 1, characterized in that: Step (2) The dynamic moving speed of the working electrode is 1~100mm / s.

8. The electrochemically induced directional metal growth method based on a gallium-based liquid metal substrate according to claim 1, characterized in that: Step (2) The temperature for constant current electrochemical deposition is 15~40℃, and the current density is 1~150mA / cm². 2 The time ranges from 1 minute to 10 hours.

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