Super capacitor bimetallic oxide electrode and preparation method thereof, and planar miniature super capacitor

Abstract

The invention provides a supercapacitor bimetallic oxide electrode, a preparation method thereof and a planar miniature supercapacitor, and belongs to the technical field of supercapacitors. According to the method, the copper sheet is subjected to etching treatment through wire cut electrical discharge machining to obtain the molybdenum-copper bimetallic oxide material, then the molybdenum-copper bimetallic oxide material is subjected to patterned cutting through wire cut electrical discharge machining, digital control can be achieved, the preparation process is simple, patterning is easy, the preparation process is low in cost and free of pollution, and the method is suitable for industrial production. And the obtained electrode material is excellent in electrochemical performance and good in universality. The result of the embodiment shows that the area specific capacitance of the prepared supercapacitor bimetallic oxide electrode can reach 27.5 mF cm <-2 > at the scanning speed of 5mV s <-1 >, and the supercapacitor bimetallic oxide electrode has excellent electrochemical performance.

Description

Technical Field

[0001] The present invention relates to the technical field of supercapacitors, and in particular to a supercapacitor bimetallic oxide electrode and a preparation method thereof, and a planar micro supercapacitor. Background Art

[0002] Faced with the increasingly severe energy crisis, the whole society is actively seeking strategies to increase revenue and save costs to meet this challenge. Clean energy, such as solar energy, tidal energy and wind energy, provides hope for the sustainable development of energy, but these clean energy sources face a key problem: how to effectively store and utilize these unstable energy outputs. Supercapacitors, with their unique fast charging and discharging and stable cycle characteristics, have become an ideal choice to meet the needs of unstable energy storage. Among supercapacitors, planar interdigitated supercapacitors with interdigitated structure electrodes have attracted much attention due to their advantages such as ultra-thin thickness, small size, easy integration, high power density and long cycle life. However, planar interdigitated supercapacitors currently face two technical challenges: one is the efficient and controllable preparation of high-performance electrode materials, and the other is the high-precision processing of extremely small-sized interdigitated electrodes.

[0003] First, metal oxide electrode materials have become an important choice for supercapacitor electrode materials due to their high specific capacity, rich pseudocapacitive reactions, good structural stability, wide electrochemical window, abundant resources, high cost-effectiveness and environmental friendliness. Compared with single metal oxides, different metal particles of bimetallic oxides can improve electrochemical activity through synergistic effects. At present, the preparation method of metal oxide electrode materials is usually to first prepare a bimetallic composite material and then spray it on the interdigitated electrode current collector. For example, the preparation method of an all-solid-state planar micro-supercapacitor disclosed in Chinese patent CN 201911034372.5. However, this method for preparing a bimetallic composite material is relatively complicated, and a mask plate is required, and the thickness uniformity of the bimetallic composite material on the interdigitated electrode current collector is difficult to ensure.

[0004] Secondly, the current preparation methods for planar micro-supercapacitors include technologies such as photolithography, screen printing, and 3D printing. However, although photolithography can achieve high-precision patterning, its equipment cost is high, maintenance costs are expensive, and the environmental conditions are extremely strict. The preparation process is cumbersome and complicated, a mask plate is required, and the photoresist is very easy to cause pollution. The resolution of screen printing technology is low, which makes it difficult to produce fine patterns, and it is challenging to control the uniform thickness of the printed layer. 3D printing has the advantages of customized manufacturing and design flexibility, but the types of printing materials that can be used for supercapacitor manufacturing are relatively limited, and often cannot meet the high performance requirements of supercapacitors.

[0005] Therefore, there is an urgent need to develop a method for preparing supercapacitor electrodes that is simple to operate, low-cost, green, environmentally friendly, high-precision and widely applicable. Summary of the invention

[0006] The object of the present invention is to provide a supercapacitor bimetallic oxide electrode and a preparation method thereof and a planar micro supercapacitor. The preparation method provided by the present invention is simple to operate, low-cost, green, environmentally friendly, high-precision and widely applicable.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for preparing a bimetallic oxide electrode for a supercapacitor, comprising the following steps:

[0009] (1) etching the outer surface of the copper sheet to obtain a molybdenum-copper bimetallic oxide material; the etching method is electric spark wire cutting, and the working electrode wire of the electric spark wire cutting is a molybdenum wire;

[0010] (2) Patterning the molybdenum-copper bimetallic oxide material obtained in step (1) to obtain a supercapacitor bimetallic oxide electrode; the patterning cutting method is electric spark wire cutting; the processing pattern of the patterning cutting is an interdigitated electrode pattern.

[0011] Preferably, the thickness of the copper sheet in step (1) is 0.2 to 10 mm.

[0012] Preferably, the parameters of the electric spark wire cutting in step (1) include: current of 1 to 5A, pulse width of 1 to 96 μs, working voltage of 60V to 140V, and interval ratio of 2 to 20.

[0013] Preferably, the working fluid of the electric spark wire cutting in step (1) is deionized water.

[0014] Preferably, the diameter of the molybdenum wire in step (1) is 0.05-0.3 mm.

[0015] Preferably, in step (2), the finger width of the interdigitated electrode pattern is 0.4-5 mm.

[0016] Preferably, in step (2), the gap between the interdigitated electrode patterns is 0.1 to 1 mm.

[0017] The present invention also provides a supercapacitor bimetallic oxide electrode prepared by the preparation method described in the above technical solution, wherein the supercapacitor bimetallic oxide electrode is an interdigitated electrode, and the outer surface of the interdigitated electrode includes an in-situ grown molybdenum-copper bimetallic oxide layer.

[0018] The present invention also provides a planar micro supercapacitor, comprising interdigital electrodes and an electrolyte solution; the interdigital electrodes are the supercapacitor bimetallic oxide electrodes described in the above technical solution.

[0019] Preferably, the electrolyte solution is a potassium hydroxide solution, a sodium hydroxide solution or a lithium hydroxide solution.

[0020] The present invention provides a method for preparing a supercapacitor bimetallic oxide electrode, comprising the following steps: etching the outer surface of a copper sheet to obtain a molybdenum-copper bimetallic oxide material; the etching method is electric spark wire cutting, and the working electrode wire of the electric spark wire cutting is a molybdenum wire; patterning the molybdenum-copper bimetallic oxide material to obtain a supercapacitor bimetallic oxide electrode; the patterning cutting method is electric spark wire cutting; and the processing pattern of the patterning cutting is an interdigitated electrode pattern. The present invention uses molybdenum wire as electrode wire, and when the outer surface of the copper sheet is etched by electric spark wire cutting, under the instantaneous high temperature generated by electric spark discharge, molybdenum and the copper surface undergo an instant redox reaction, so that the material is melted or even vaporized, and under the flushing and cooling of the electric spark wire cutting working fluid, a pseudocapacitive active material molybdenum-copper bimetallic oxide is directly formed in situ on the copper sheet substrate without any adhesive, and the molybdenum-copper bimetallic oxide can produce more electronic reactions, improve the conductivity of the electrode material, provide more redox active sites, and thus improve the capacitance and stability of the electrode; and the high temperature condition of the electric spark wire cutting also introduces more oxygen vacancies, and the presence of oxygen vacancies helps to improve the conductivity and ion diffusion rate of the electrode material, thereby enhancing the charge and discharge capacity of the electrode. The present invention performs patterned cutting on the molybdenum-copper bimetallic oxide material, has wide applicability, can accurately control the morphology of the interdigitated electrode according to the pattern, and improves the precision of the interdigitated electrode.

[0021] The present invention uses electric spark wire cutting to etch the copper sheet to form a molybdenum-copper bimetallic oxide material, and then uses electric spark wire cutting to pattern the molybdenum-copper bimetallic oxide material. This method can be controlled digitally, the preparation process is simple, easy to pattern, and the preparation process is low-cost and pollution-free. The obtained electrode material has excellent electrochemical properties and good versatility. The results of the embodiment show that the supercapacitor bimetallic oxide electrode prepared by the present invention has a high electrochemical performance at 5mV s -1 The area specific capacitance can reach 27.5 mF cm at a scan rate of -2 , with excellent electrochemical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a method for preparing a bimetallic oxide electrode for a supercapacitor and assembling a planar micro-supercapacitor according to an embodiment of the present invention;

[0023] Figure 2 This is a SEM image of the supercapacitor bimetallic oxide electrode prepared in Example 1 of the present invention;

[0024] Figure 3 This is an EDS image of the supercapacitor bimetallic oxide electrode prepared in Example 1 of the present invention;

[0025] Figure 4 The XRD pattern of the supercapacitor bimetallic oxide electrode prepared in Example 1 of the present invention;

[0026] Figure 5 CV curves of the planar micro supercapacitor prepared in Example 2 of the present invention at different scan rates;

[0027] Figure 6 CV curves of the planar micro supercapacitor prepared in Example 4 of the present invention at different scan rates;

[0028] Figure 7 CV curves of the planar micro supercapacitor prepared in Example 6 of the present invention at different scan rates;

[0029] Figure 8 The planar micro supercapacitors prepared in Examples 2, 4 and 6 of the present invention are 5 mV s -1 Comparison of area specific capacitance at different scan rates. DETAILED DESCRIPTION

[0030] The present invention provides a method for preparing a bimetallic oxide electrode for a supercapacitor, comprising the following steps:

[0031] (1) etching the outer surface of the copper sheet to obtain a molybdenum-copper bimetallic oxide material; the etching method is electric spark wire cutting, and the working electrode wire of the electric spark wire cutting is a molybdenum wire;

[0032] (2) Patterning the molybdenum-copper bimetallic oxide material obtained in step (1) to obtain a supercapacitor bimetallic oxide electrode; the patterning cutting method is electric spark wire cutting; the processing pattern of the patterning cutting is an interdigitated electrode pattern.

[0033] The present invention performs etching treatment on the outer surface of the copper sheet to obtain a molybdenum-copper bimetallic oxide material.

[0034] In the present invention, the thickness of the copper sheet is preferably 0.2 to 10 mm, more preferably 1 to 5 mm. The copper sheet of the above thickness used in the present invention can react with molybdenum to form a molybdenum-copper bimetallic oxide material with a supporting effect.

[0035] The present invention has no special limitation on the size of the copper sheet, and the size can be selected according to the size of the electrode to be prepared. In an embodiment of the present invention, the copper sheet is a rectangular copper sheet, the width of the copper sheet is 10 mm, and the length of the copper sheet is 30 mm.

[0036] The present invention preferably cleans and dries the copper sheet before etching. The present invention can remove contaminants on the surface of the copper sheet by cleaning and drying. The present invention does not specifically limit the operation method of the cleaning and drying, and conventional cleaning and drying can be used to remove contaminants on the surface of the copper sheet. In an embodiment of the present invention, the cleaning reagent is deionized water, the cleaning times are 2 to 3 times; the drying temperature is 60°C, and the drying time is 20 minutes.

[0037] In the present invention, the etching treatment method is electric spark wire cutting, and the working electrode wire of the electric spark wire cutting is molybdenum wire. The present invention uses electric spark wire cutting and uses molybdenum wire as the working electrode, which can induce the molybdenum wire to undergo an in-situ oxidation reaction on the surface of the copper sheet under high temperature to form nano-level molybdenum-copper bimetallic oxide nanoparticles, introduce bimetallic and oxygen vacancies in the electrode, and the synergistic effect of different metal particles improves the electrochemical activity. The two metals can also provide more valences for redox reactions, increase the active sites and conductivity of the electrode material, and improve the specific capacitance of the electrode and the stability in multiple charge and discharge cycles. In addition, the method abandons the traditional complex and expensive mask and photolithography equipment, greatly simplifies the process of manufacturing electrodes, and provides easy-to-implement pattern design capabilities, reduces the complexity of the manufacturing process, and is suitable for large-scale industrial production of electrode materials.

[0038] In the present invention, the diameter of the molybdenum wire is preferably 0.05 to 0.3 mm, more preferably 0.15 to 0.18 mm. The molybdenum wire of the above diameter is used in the present invention to improve the processing efficiency and the surface quality of the molybdenum-copper bimetallic oxide material.

[0039] In the present invention, the parameters of the electric spark wire cutting preferably include: current of 1 to 5A, pulse width of 1 to 96μs, working voltage of 60V to 100V, and interval ratio of 2 to 20, and more preferably: current of 2 to 3A, pulse width of 24 to 50μs, working voltage of 60 to 100V, and interval ratio of 4 to 10. The present invention is more conducive to forming high-quality molybdenum-copper bimetallic oxide particles on the surface of the copper sheet by controlling the parameters of the electric spark wire cutting to the above range.

[0040] The present invention has no special limitation on the operation method of the electric spark wire cutting. The conventional electric spark wire cutting operation method can be used to form the molybdenum-copper bimetallic oxide material on the outer surface of the copper sheet. In the present invention, the outer surface of the copper sheet includes the upper and lower surfaces and the side surfaces of the copper sheet.

[0041] In an embodiment of the present invention, the operation method of wire electric discharge cutting preferably includes:

[0042] Design and compile CNC Wire EDM programs according to Wire EDM machining parameters;

[0043] Clamp the rectangular copper sheet horizontally on the workbench of the CNC wire-cut EDM machine, making sure it is clamped and fixed without looseness; use molybdenum wire as the cutting wire;

[0044] Retrieving and executing a CNC wire-cutting program, etching the surface of the copper sheet to obtain a first rectangular block;

[0045] The first rectangular block is clamped longitudinally on the workbench of a CNC wire-cut electro-discharge machine to ensure that it is stable and vibration-free; the CNC wire-cut electro-discharge machining program is called up and executed to perform linear electro-discharge etching on the two unoxidized sides of the first rectangular block to evenly form molybdenum-copper bimetallic oxide nanoparticle clusters on the sides to obtain a second rectangular block.

[0046] The present invention performs etching treatment by the above method, so that the outer surface of the copper sheet can be formed with molybdenum-copper bimetallic oxide nanomaterials.

[0047] In the present invention, the working fluid of the electric spark wire cutting is preferably deionized water. The present invention uses deionized water as the working fluid, which is more conducive to forming high-quality molybdenum-copper bimetallic oxide particles on the outer surface of the copper sheet.

[0048] After obtaining the molybdenum-copper bimetallic oxide material, the present invention performs patterned cutting on the molybdenum-copper bimetallic oxide material to obtain a supercapacitor bimetallic oxide electrode.

[0049] In the present invention, the pattern cutting method is electric spark wire cutting. The present invention adopts electric spark wire cutting for pattern cutting, which can realize digital pattern cutting, and then control the morphology of the electrode with high precision. The present invention has no special limitation on the operation method of the electric spark wire cutting, and adopts the conventional electric spark wire cutting method to enable the molybdenum-copper bimetallic oxide material to be cut to form an electrode with the desired morphology.

[0050] In the present invention, the processing pattern of the patterned cutting is an interdigital electrode pattern. The present invention can obtain the interdigital electrodes required for the supercapacitor by patterned cutting of the interdigital electrode pattern.

[0051] In the present invention, the method of wire electric discharge cutting preferably includes: firstly setting a programmed interdigital pattern, and then executing a CNC wire electric discharge cutting machine to programme the interdigital pattern to obtain a supercapacitor bimetallic oxide electrode.

[0052] In an embodiment of the present invention, the patterned cutting method is preferably: the molybdenum-copper bimetallic oxide material is horizontally clamped on the workbench of a CNC wire-cut electric discharge machine, and the clamping is ensured to be fixed and stable, and the programmed interdigitated pattern of the CNC wire-cut electric discharge machine is called and executed, and then the machine is started again to cut into an interdigitated microelectrode structure.

[0053] In the present invention, the finger width of the interdigital electrode pattern is preferably 0.4 to 5 mm, more preferably 1.25 to 3 mm; the gap of the interdigital electrode pattern is preferably 0.1 to 1 mm, more preferably 0.5 to 1 mm. The present invention adopts the interdigital electrode pattern with the above parameters to obtain an interdigital electrode with the above parameter range, and the interdigital electrode is composed of a first electrode and a second electrode.

[0054] In the present invention, the number of pairs of interdigital electrodes is preferably 1 to 5, more preferably 2 to 5. The present invention prepares the interdigital electrodes of the above number to form 1 to 5 pairs of first electrodes and second electrodes, thereby obtaining electrodes with excellent performance.

[0055] The present invention preferably washes and dries the electrode obtained by pattern cutting in sequence to obtain a supercapacitor bimetallic oxide electrode. In an embodiment of the present invention, the cleaning agent is preferably deionized water, the number of cleanings is preferably 2 to 3 times; the drying temperature is preferably 60°C, and the drying time is preferably 20 minutes.

[0056] The method provided by the present invention utilizes electric spark wire cutting to etch a copper sheet to form a molybdenum-copper bimetallic oxide material, and then utilizes electric spark wire cutting to pattern-cut the molybdenum-copper bimetallic oxide material. This method can be controlled digitally, and the preparation process is simple and easy to pattern. The preparation process is low-cost and pollution-free, and the obtained electrode material has excellent electrochemical properties and good versatility.

[0057] The present invention also provides a supercapacitor bimetallic oxide electrode prepared by the preparation method described in the above technical solution.

[0058] In the present invention, the supercapacitor bimetallic oxide electrode is an interdigitated electrode, and the outer surface of the interdigitated electrode includes an in-situ grown molybdenum-copper bimetallic oxide layer.

[0059] The present invention also provides a planar micro supercapacitor, comprising interdigital electrodes and an electrolyte solution; the interdigital electrodes are the supercapacitor bimetallic oxide electrodes described in the above technical solution.

[0060] In the present invention, the electrolyte solution is preferably a potassium hydroxide solution, a sodium hydroxide solution, a lithium hydroxide solution or a potassium hydroxide solution, and more preferably a potassium hydroxide solution. In the present invention, the concentration of the electrolyte solution is preferably 0.1 to 6 mol / L, and more preferably 1 to 5 mol / L. The present invention adopts the above electrolyte solution, which is more conducive to improving the electrochemical performance of the capacitor.

[0061] In the present invention, the method for assembling the planar micro supercapacitor preferably includes: cross-arranging and fixing the interdigitated electrodes, clamping them with acrylic plates, immersing them in an electrolyte solution, and assembling them into a planar micro supercapacitor.

[0062] In the present invention, the fixing method is preferably glue bonding. The present invention has no special limitation on the type of the glue, as long as it can fix the interdigital electrodes.

[0063] The schematic diagram of the preparation method of the supercapacitor bimetallic oxide electrode and the assembled planar micro-supercapacitor provided by the present invention is preferably as follows Figure 1 As shown. Figure 1 It can be seen that the present invention first etches the outer surface of the copper sheet to obtain a molybdenum-copper bimetallic oxide material, then cuts the molybdenum-copper bimetallic oxide material into interdigitated electrodes, wherein the interdigitated electrodes include a first electrode and a second electrode, and finally assembles the interdigitated electrodes into a planar micro supercapacitor.

[0064] The present invention provides a supercapacitor bimetallic oxide electrode that introduces bimetallic and oxygen vacancies, and the synergistic effect of different metal particles improves electrochemical activity. The two metals can also provide more valences for redox reactions, increase the active sites and conductivity of the electrode material, and significantly improve the specific capacitance. At the same time, the nanoscale structural characteristics and uniform element distribution ensure the stability and performance consistency of the electrode material in multiple charge and discharge cycles. Therefore, after being assembled into a planar micro supercapacitor, it has excellent electrochemical performance.

[0065] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] Example 1

[0067] A method for preparing a planar micro-supercapacitor bimetallic oxide electrode, comprising the following steps:

[0068] (1) After cleaning the surface of a copper sheet with a width of 10 mm, a length of 30 mm, and a thickness of 1 mm with deionized water twice, the copper sheet was placed in a 60°C constant temperature drying oven and dried for 20 min to obtain a dry copper sheet;

[0069] Molybdenum wire is used as the working electrode wire, deionized water is used as the working fluid, the working current is set to 2A, the pulse width is 24μs, the working voltage is 60V, the interval ratio is 4, and the diameter of the molybdenum wire is 0.18mm;

[0070] Clamp the dry copper sheet horizontally on the workbench of the CNC wire-cut EDM machine and ensure that it is clamped and fixed without looseness; replace the cutting wire with molybdenum wire and adjust the tightness;

[0071] Retrieving and executing a CNC wire-cutting program to etch the copper sheet to obtain a first rectangular block;

[0072] The first rectangular block is clamped longitudinally on the workbench of the CNC wire-cut electric discharge machine and ensured to be stable and vibration-free; the CNC wire-cut electric discharge machining program is retrieved and executed to perform linear electric discharge etching on the two unoxidized sides of the first rectangular block, and molybdenum-copper bimetallic oxide nanoparticle clusters are uniformly formed on the sides to obtain a second rectangular block, namely, a molybdenum-copper bimetallic oxide material;

[0073] (2) The molybdenum-copper bimetallic oxide material obtained in the step (1) is horizontally clamped on the workbench of a CNC electric spark wire cutting machine and ensured to be fixed and stable; the finger width of the forked-finger type of the processing pattern is drawn to be 1.25 mm and the gap is 0.5 mm; the forked-finger type pattern programmed by the CNC electric spark wire cutting machine is called and executed, and then the machine is started again to perform pattern cutting to obtain a supercapacitor bimetallic oxide electrode; the supercapacitor bimetallic oxide electrode is a pair of forked-finger electrodes, respectively named as the first electrode and the second electrode; the finger width of the first electrode and the second electrode is 1.25 mm, the gap between the first electrode and the second electrode is 0.5 mm, and the number of electrode pairs is 3.

[0074] Example 2

[0075] A planar micro supercapacitor, comprising interdigital electrodes, an electrolyte solution and an acrylic plate; the interdigital electrodes are the supercapacitor bimetallic oxide electrodes of Example 1;

[0076] The preparation method of the planar micro supercapacitor is as follows: the first electrode and the second electrode of the supercapacitor bimetallic oxide electrode prepared in Example 1 are cross-arranged as the positive and negative electrodes of the planar micro supercapacitor, respectively, glue is applied to the ends of the electrodes for fixing, after standing for 15 minutes, they are clamped with acrylic plates, immersed in a 1 mol / L KOH electrolyte solution, and assembled into a planar micro supercapacitor.

[0077] Example 3

[0078] A method for preparing a bimetallic oxide electrode for a supercapacitor, comprising the following steps:

[0079] (1) After cleaning the surface of a copper sheet with a width of 10 mm, a length of 30 mm, and a thickness of 1 mm with deionized water twice, the copper sheet was placed in a 60°C constant temperature drying oven and dried for 20 min to obtain a dry copper sheet;

[0080] Molybdenum wire is used as the working electrode wire, deionized water is used as the working fluid, the working current is set to 2A, the pulse width is 24μs, the working voltage is 80V, the interval ratio is 4, and the diameter of the molybdenum wire is 0.18mm;

[0081] Clamp the dry copper sheet horizontally on the workbench of the CNC wire-cut EDM machine and ensure that it is clamped and fixed without looseness; replace the cutting wire with molybdenum wire and adjust the tightness;

[0082] Retrieving and executing a CNC wire-cutting program, etching clusters on the copper sheet to obtain a first rectangular block;

[0083] The first rectangular block is clamped longitudinally on the workbench of the CNC wire-cut electric discharge machine and ensured to be stable and vibration-free; the CNC wire-cut electric discharge machining program is retrieved and executed to perform linear electric discharge etching on the two unoxidized sides of the first rectangular block, and molybdenum-copper bimetallic oxide nanoparticle clusters are uniformly formed on the sides to obtain a second rectangular block, namely, a molybdenum-copper bimetallic oxide material;

[0084] (2) The molybdenum-copper bimetallic oxide material obtained in the step (1) is horizontally clamped on the workbench of a CNC electric spark wire cutting machine and ensured to be fixed and stable; the finger width of the forked-finger type of the processing pattern is drawn to be 1.25 mm and the gap is 0.5 mm; the forked-finger type pattern programmed by the CNC electric spark wire cutting machine is called and executed, and then the machine is started again to perform pattern cutting to obtain a supercapacitor bimetallic oxide electrode; the supercapacitor bimetallic oxide electrode is a pair of forked-finger electrodes, respectively named as the first electrode and the second electrode; the finger width of the first electrode and the second electrode is 1.25 mm, the gap between the first electrode and the second electrode is 0.5 mm, and the number of electrode pairs is 3.

[0085] Example 4

[0086] A planar micro supercapacitor, comprising interdigital electrodes, an electrolyte solution and an acrylic plate; the interdigital electrodes are the supercapacitor bimetallic oxide electrodes of Example 3;

[0087] The preparation method of the planar micro supercapacitor device is the same as that of Example 2.

[0088] Example 5

[0089] A method for preparing a bimetallic oxide electrode for a supercapacitor, comprising the following steps:

[0090] (1) After cleaning the surface of a copper sheet with a width of 10 mm, a length of 30 mm, and a thickness of 1 mm with deionized water twice, the copper sheet was placed in a 60°C constant temperature drying oven and dried for 20 min to obtain a dry copper sheet;

[0091] Molybdenum wire is used as the working electrode wire, deionized water is used as the working fluid, the working current is set to 2A, the pulse width is 24μs, the working voltage is 100V, the interval ratio is 4, and the diameter of the molybdenum wire is 0.18mm;

[0092] Clamp the dry copper sheet horizontally on the workbench of the CNC wire-cut EDM machine and ensure that it is clamped and fixed without looseness; replace the cutting wire with molybdenum wire and adjust the tightness;

[0093] Retrieving and executing a CNC wire-cutting program, etching clusters on the copper sheet to obtain a first rectangular block;

[0094] The first rectangular block is clamped longitudinally on the workbench of the CNC wire-cut electric discharge machine and ensured to be stable and vibration-free; the CNC wire-cut electric discharge machining program is retrieved and executed to perform linear electric discharge etching on the two unoxidized sides of the first rectangular block, and molybdenum-copper bimetallic oxide nanoparticle clusters are uniformly formed on the sides to obtain a second rectangular block, namely, a molybdenum-copper bimetallic oxide material;

[0095] (2) The molybdenum-copper bimetallic oxide material obtained in the step (1) is horizontally clamped on the workbench of a CNC electric spark wire cutting machine and ensured to be fixed and stable; the finger width of the forked-finger type of the processing pattern is drawn to be 1.25 mm and the gap is 0.5 mm; the forked-finger type pattern programmed by the CNC electric spark wire cutting machine is called and executed, and then the machine is started again to perform pattern cutting to obtain a supercapacitor bimetallic oxide electrode; the supercapacitor bimetallic oxide electrode is a pair of forked-finger electrodes, respectively named as the first electrode and the second electrode; the finger width of the first electrode and the second electrode is 1.25 mm, the gap between the first electrode and the second electrode is 0.5 mm, and the number of electrode pairs is 3.

[0096] Example 6

[0097] A planar micro supercapacitor, comprising interdigital electrodes, an electrolyte solution and an acrylic plate; the interdigital electrodes are the supercapacitor bimetallic oxide electrodes of Example 5;

[0098] The preparation method of the planar micro supercapacitor is the same as that of Example 2.

[0099] Test Example 1

[0100] The SEM image of the supercapacitor bimetallic oxide electrode prepared in Example 1 is as follows: Figure 2As shown. Figure 2 It can be seen that uniform nanoscale oxide particle clusters can be observed on the electrode surface. This morphology allows ions to quickly enter the material and increase the charge and discharge rate when the energy storage reaction occurs. In addition, the electrode surface is rough and there is no large amount of agglomeration, which can ensure that as much molybdenum-copper bimetallic oxide as possible participates in the energy storage reaction while increasing the specific surface area. This structure provides a large number of active sites for redox reactions and effectively reduces the transmission path of ions, which is more conducive to the penetration of electrolytes and significantly improves the electrochemical performance of the electrode.

[0101] The EDS image of the supercapacitor bimetallic oxide electrode prepared in Example 1 is as follows: Figure 3 As shown. Figure 3 It can be seen that the elements on the surface of the supercapacitor bimetallic oxide electrode prepared in Example 1 are evenly distributed, and there are three elements of molybdenum (Mo), copper (Cu) and oxygen (O). This shows that the EDM wire cutting etching process achieves uniform fusion of molybdenum wire and copper metal sheet elements during the processing, ensuring the consistency and stability of the material. In addition, both metal oxides participate in the redox reaction, which can reduce the charge transfer impedance of the electrochemical supercapacitor.

[0102] The XRD pattern of the supercapacitor bimetallic oxide electrode prepared in Example 1 is as follows: Figure 4 As shown. Figure 4 It can be seen that the bimetallic oxide MoCuO on the surface of the electrode prepared by the present invention x , the main components are Cu, Cu 2 O、MoO 2 Cu as a current collector provides good mechanical properties, ensuring the mechanical strength and stability of the electrode material. MoCuO x As active materials, MoCuO x The synergistic effect of the ions and oxygen vacancies can further enhance the ion transport efficiency and charge storage capacity.

[0103] Test Example 2

[0104] The CV curves of the planar micro supercapacitor prepared in Example 2 at different scan rates are shown in Figure 2. Figure 5 As shown, the CV curves of the planar micro supercapacitor prepared in Example 4 at different scan rates are as follows Figure 6 As shown; the CV curves of the planar micro supercapacitor prepared in Example 6 at different scan rates are shown Figure 7 As shown. Figures 5 to 7 It can be seen that the CV curves at different scan rates show ideal capacitance behavior close to a rectangle. The results show that the electrode prepared in Example 1 has a capacitance of 5 mV s -1The area specific capacitance can reach 27.5 mF cm at a scan rate of -2 .

[0105] The planar micro supercapacitors prepared in Example 2, Example 4 and Example 6 were -1 The comparison of area specific capacitance at the scan rate is shown in the figure below. Figure 8 As shown. Figure 8 It can be seen that the area specific capacitance of the supercapacitor bimetallic oxide electrode prepared in Example 1 is 27.5 mF cm -2 The area specific capacitance of the supercapacitor bimetallic oxide electrode prepared in Example 2 is 20 mF cm -2 The area specific capacitance of the supercapacitor bimetallic oxide electrode prepared in Example 3 is 15 mF cm -2 The results show that the best capacitance performance can be obtained when the processing voltage is 60V.

[0106] The present invention uses electric spark wire cutting numerical control technology to perform precision machining on copper sheets, uses the principle of discharge etching to form molybdenum-copper bimetallic oxide on the surface of the copper sheet, and can accurately control the electrode morphology. The preparation method has the advantages of simple operation, strong patterning ability, high cost-effectiveness, and no environmental pollution, and is suitable for industrial large-scale production. The planar micro-supercapacitor electrode prepared by this method exhibits significant advantages such as high specific capacitance, excellent cycle stability, fast charge and discharge performance, and green environmental protection.

[0107] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a bimetallic oxide electrode for a supercapacitor, comprising the following steps: (1) etching the outer surface of the copper sheet to obtain a molybdenum-copper bimetallic oxide material; the etching method is electric spark wire cutting, and the working electrode wire of the electric spark wire cutting is a molybdenum wire; (2) Patterning the molybdenum-copper bimetallic oxide material obtained in step (1) to obtain a supercapacitor bimetallic oxide electrode; the patterning cutting method is electric spark wire cutting; the processing pattern of the patterning cutting is an interdigitated electrode pattern.

2. The preparation method according to claim 1, characterized in that: The thickness of the copper sheet in step (1) is 0.2 to 10 mm.

3. The preparation method according to claim 1, characterized in that: The parameters of the electric spark wire cutting in step (1) include: current of 1 to 5A, pulse width of 1 to 96 μs, working voltage of 60V to 140V, and interval ratio of 2 to 20.

4. The preparation method according to claim 1, characterized in that: The working fluid of the electric spark wire cutting in step (1) is deionized water.

5. The preparation method according to claim 1, characterized in that: The diameter of the molybdenum wire in step (1) is 0.05-0.3 mm.

6. The preparation method according to claim 1, characterized in that: In the step (2), the finger width of the interdigitated electrode pattern is 0.4 to 5 mm.

7. The preparation method according to claim 1 or 6, characterized in that: In the step (2), the gap between the interdigitated electrode patterns is 0.1 to 1 mm.

8. A supercapacitor bimetallic oxide electrode prepared by the preparation method according to any one of claims 1 to 7, wherein the supercapacitor bimetallic oxide electrode is an interdigitated electrode, and the outer surface of the interdigitated electrode comprises an in-situ grown molybdenum-copper bimetallic oxide layer.

9. A planar micro supercapacitor comprising interdigital electrodes and an electrolyte solution; the interdigital electrodes are the supercapacitor bimetallic oxide electrodes according to claim 8.

10. The planar micro-supercapacitor according to claim 9, characterized in that: The electrolyte solution is a potassium hydroxide solution, a sodium hydroxide solution or a lithium hydroxide solution.

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