Method for preparing high response micro supercapacitor based on high conductive graphene

Abstract

The application relates to a preparation method of a high-response micro super capacitor based on high-conductivity graphene, and the method comprises the following steps: S1, preparing a cyanate ester film on a surface-modified substrate; S2, irradiating the cyanate ester film by a large-size light spot laser beam to induce the cyanate ester film to form a high-conductivity graphene film with a sintered nanoparticle-like morphology; performing engraving on the high-conductivity graphene film by a small-size light spot laser beam to obtain a high-resolution interdigital electrode; S3, pasting copper foils on two ends of each capacitor by using conductive silver paste; designing a corresponding mask pattern, and reserving specific spaces at detection hole positions and electrolyte coating areas of the mask pattern; and S4, performing cleaning, drying and vacuumizing treatment on the high-resolution interdigital electrode to obtain the high-response micro super capacitor. The graphene film with high conductivity is prepared, and then the high-response micro super capacitor is manufactured, and the manufacturing cost is low.

Description

Technical Field

[0001] This invention belongs to the field of laser micro-nano manufacturing, specifically relating to a method for preparing a high-response micro supercapacitor based on highly conductive graphene. Background Technology

[0002] With the rapid development of electronic products and devices, various portable smart devices have been widely used. Traditional capacitors, due to their excessively large size, cannot fully meet the development needs of increasingly miniaturized and highly integrated electronic devices. Therefore, miniature energy storage devices such as micro supercapacitors have become a research hotspot in the scientific field.

[0003] Miniature supercapacitors (MSCs) possess advantages such as small size, long lifespan, high power density, fast charge / discharge, and excellent cycle stability, making them promising candidates for applications in electronics, energy storage, biomedicine, and thermal management. For a long time, aluminum electrolytic capacitors (AECs) have been considered the preferred choice for filtering capacitors due to their high voltage resistance, low cost, and capacitance values ​​far exceeding those of ceramic capacitors. However, AECs still suffer from inherent drawbacks such as large size and insufficient specific capacitance, severely hindering the development of miniaturized, planarized, and integrated devices. Therefore, there is an urgent need for a method that can stably fabricate capacitors with higher capacitance values ​​than AECs and can be planarized to replace them.

[0004] Compared to AECs, supercapacitors overcome the limitations of large size and low capacitance, making them an attractive alternative. However, the complex electrode material structure of traditional supercapacitors leads to slow ion diffusion and increases electronic and ionic resistance, limiting their charge-discharge frequencies to no more than 1 Hz and hindering their application in high-frequency alternating current (AC) filtering. Therefore, exploring innovative supercapacitor electrode materials is crucial for improving supercapacitor performance and expanding their application range.

[0005] Therefore, the present invention provides a method for preparing a high-response micro supercapacitor based on highly conductive graphene to solve the above-mentioned technical problems. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a method for preparing a high-response micro supercapacitor based on highly conductive graphene. This method is low in cost, highly efficient, and can be used for large-scale production.

[0007] This invention provides a method for fabricating a high-response micro supercapacitor based on highly conductive graphene, the method comprising the following steps:

[0008] Step S1: Provide a substrate and perform surface modification on the substrate; prepare a cyanate film on the surface-modified substrate;

[0009] Step S2: Irradiate the cyanate film with a large-size laser beam to induce the cyanate film to form a sintered nanoparticle-like highly conductive graphene film; then etch the highly conductive graphene film with a small-size laser beam to obtain a high-resolution interdigitated electrode.

[0010] Step S3: Apply copper foil to both ends of each capacitor using conductive silver paste; design the corresponding mask pattern and reserve specific spaces in the detection hole position and electrolyte coating area of ​​the mask pattern; then perform surface patterning processing on the flexible mask and attach the mask to the capacitor. During the attachment process, it is necessary to ensure that the electrolyte coating interface and the detection hole in the electrode area are completely exposed to the mask opening area.

[0011] Step S4: Clean and dry the high-resolution interdigitated electrode; uniformly coat the dried high-resolution interdigitated electrode with gel electrolyte, and place the high-resolution interdigitated electrode coated with gel electrolyte in a vacuum chamber for vacuum treatment to obtain a high-response micro supercapacitor.

[0012] Preferably, the surface modification in step S1 is performed by X-ray irradiation, where an array of microstructure patterns with a size of less than 100 μm is processed on the substrate surface using an ultraviolet laser.

[0013] Preferably, the ultraviolet laser has a wavelength of 355nm, a pulse frequency of 600Hz, and a pulse duration of 10ps; the scanning direction of the ultraviolet laser is progressive from left to right and from top to bottom, the scanning interval is 50μm-100μm, the scanning speed is 600mm / s-1200mm / s, and the power is 50%-70% of the peak power of 17.5W.

[0014] Preferably, the substrate is selected from any one of glass, quartz, silicon, and flexible substrate, and the thickness of the substrate is 0.01mm-0.2mm.

[0015] Preferably, the preparation of a cyanate film on the surface-modified substrate in step S1 specifically includes:

[0016] Step S11: Provide cyanate monomer and heat the cyanate monomer in a water bath to obtain liquid cyanate monomer;

[0017] Step S12: The liquid cyanate monomer is uniformly coated onto the surface of the surface-modified substrate.

[0018] Step S13: Perform a high-temperature thermosetting treatment on the substrate coated with the liquid cyanate monomer to convert the liquid cyanate monomer into a cyanate film and cure it on the substrate.

[0019] Preferably, in step S11, the water bath heating temperature is 50℃-70℃, and the heating time is 20min-30min; in step S12, the coating method of the liquid cyanate monomer is drop coating and weighing method; in step S13, the high temperature heat curing treatment temperature is 25℃-250℃, and the treatment time is 5h-6h.

[0020] Preferably, the large-spot laser beam is emitted by a mid-infrared CO2 laser or a visible light semiconductor laser, and the spot size of the large-spot laser beam is 200μm-500μm; the scanning method of the mid-infrared CO2 laser or the visible light semiconductor laser is a left-to-right grating overlapping progressive scan, with a scanning speed of 60mm / s-200mm / s, a defocusing amount between +1 and +5mm, and a scanning pixel step size of 800 dots / inch (DPI)-1200 dots / inch (DPI); and the product of the spot size of the large-spot laser beam and the scanning spacing is between 5000μm. 2 -8000μm 2 .

[0021] Preferably, the small-sized laser beam is emitted by an ultraviolet ultrafast laser or an ultraviolet nanolaser, and the spot size of the small-sized laser beam is less than 20 μm; the ultraviolet ultrafast laser or ultraviolet nanolaser adopts an alternating laser beam movement path, with a scanning speed between 600 mm / s and 1500 mm / s, a scanning interval of less than 8 μm, a scanning number of not less than 2, and a power of 80%-95% of the peak power of 17.5 W.

[0022] Preferably, in step S3, during the flexible mask selection stage, a superhydrophobic polyimide or polyethylene terephthalate film is used, and its thickness window should be set to 25-80 μm.

[0023] Preferably, in step S3, the mask pattern design establishes a critical dimension compensation mechanism:

[0024] The geometric design of the electrode functional area should follow a process allowance of 0.2mm for single-sided expansion in the X / Y direction.

[0025] Compared with related technologies, the present invention provides a method for preparing a high-response micro supercapacitor based on highly conductive graphene, comprising the following steps: providing a substrate and modifying its surface; preparing a cyanate film on the substrate; irradiating the cyanate film with a large-spot laser beam to induce the cyanate film to form a highly conductive graphene film with a sintered nanoparticle morphology; engraving the highly conductive graphene film with a small-spot laser beam to obtain a high-resolution interdigitated electrode; attaching a copper foil using conductive silver paste, and then attaching a patterned flexible mask; cleaning and drying the high-resolution interdigitated electrode, then uniformly coating the dried high-resolution interdigitated electrode with a gel electrolyte, and performing a vacuum treatment to obtain a high-response micro supercapacitor. The above preparation method enables the induced formation of highly conductive graphene films with sintered nanoparticle morphology on any substrate. If the substrate is a polymer substrate, the resistivity of the graphene film is as low as 1.7 Ω / square (equivalent to a conductivity of approximately 122.5 S / cm); if the substrate is a metal substrate, the resistivity of the graphene film is as low as 1.6 Ω / square (equivalent to a conductivity >130 S / cm). Utilizing the optimized design of interdigitated electrodes, their interleaved charge storage characteristics achieve efficient AC-DC filtering. Furthermore, the high-response micro supercapacitor fabricated using the highly conductive graphene film can achieve a maximum scanning speed of 1000 V / s. Flexible mask encapsulation combines high-precision patterning capabilities with high integration advantages, allowing the integration of multiple independent electrodes within a miniaturized area. This supports performance testing of single / multi-electrode and series systems via an electrochemical workstation. The synergistic effect of the superhydrophobic encapsulation layer and vacuum processing ensures long-term stable encapsulation of the highly active electrolyte within complex microstructures. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart of a method for preparing a high-response micro supercapacitor based on highly conductive graphene according to the present invention.

[0027] Figure 2 This is a schematic diagram of the process for preparing a cyanate film on the surface-modified substrate in step S1.

[0028] Figure 3 This is a schematic diagram illustrating the fabrication technique of the high-response micro supercapacitor in Example 1.

[0029] Figure 4 These are microscope images of the substrates after surface modification in Examples 1 and 2;

[0030] Figure 5 This is a comparison chart of the resistance of highly conductive graphene films obtained in Examples 1 and 2 under the same parameters;

[0031] Figure 6This is a schematic diagram of the high-resolution interdigitated electrode engraving patterns prepared in Examples 1 and 2;

[0032] Figure 7 These are schematic diagrams of the high-resolution interdigitated electrode packages prepared in Examples 1 and 2;

[0033] Figure 8 These are schematic diagrams of the surface microstructure of the highly conductive graphene film described in Examples 1 and 2;

[0034] Figure 9 This is the CV curve of the high-response micro supercapacitor prepared in Example 1 at a scan rate of 50V / s;

[0035] Figure 10 This is the CV curve of the high-response micro supercapacitor prepared in Example 2 at a scan rate of 50V / s;

[0036] Figure 11 This is the CV curve of the high-response micro supercapacitor prepared in Example 2 at a scan rate of 1000V / s;

[0037] Figure 12 This is a graph showing the filtering performance of the high-response micro supercapacitor prepared in Example 2. Detailed Implementation

[0038] This invention provides a method for preparing a high-response micro supercapacitor based on highly conductive graphene, aiming to solve the problems of low yield, high cost, and complex process of traditional graphene preparation processes, which cannot meet the requirements of industrialization and large-scale production.

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please also refer to the appendix. Figure 1-2 This invention provides a method for fabricating a high-response micro supercapacitor based on highly conductive graphene, comprising the following steps:

[0041] S1, a substrate is provided, and the surface of the substrate is modified; a cyanate film is prepared on the surface-modified substrate.

[0042] In this embodiment, the surface modification is performed using X-ray irradiation. An array of microstructure patterns with individual dimensions less than 100 μm is fabricated on the substrate surface using an ultraviolet laser to improve the wettability of the substrate surface. The ultraviolet laser wavelength is 355 nm, the pulse frequency is 600 Hz, and the pulse duration is 10 ps. The scanning direction of the ultraviolet laser is progressive from left to right and from top to bottom, with a scanning spacing of 50 μm-100 μm, a scanning speed of 600 mm / s-1200 mm / s, and a power of 50%-70% of the peak power of 17.5 W. Specifically, this method utilizes laser surface microstructuring technology, specifically leveraging the high energy peak intensity and nonlinear absorption characteristics of laser light, and a picosecond laser pulse width (1 ps = 10 μm). -12 The time is much shorter than the electronic lattice relaxation time of the processed material (10). -10 ~10 -12 Before the lattice is heated, electrons absorb photon energy. Therefore, during the processing, electrons and the lattice are in a non-equilibrium state, which inhibits heat diffusion. This greatly reduces the heat-affected zone, reduces the thickness of the recast layer, and reduces surface microcracks, ultimately achieving high-precision and high-quality processing of the material and preparing a surface hydrophilic microstructure.

[0043] Specifically, the substrate is selected from any one of glass, quartz, silicon, and flexible substrates, such as polyimide film / paper, titanium foil, nickel foil, copper foil, non-woven carbon cloth, etc., and the thickness of the substrate is 0.01mm-0.2mm. It should be noted that the type and thickness of the substrate were determined through extensive experiments, because the type and thickness of the substrate ultimately affect the thermal conductivity of the composite material. Under the same processing conditions, the composite material has better thermal conductivity, resulting in higher uniformity and graphitization of the final graphene surface. At the same time, the thickness should not be too thick or too thin. If it is too thick, most of the laser energy will be absorbed by other parts of the material and not absorbed by the cyanate ester. If the thermally conductive layer is too thin, the resin will absorb energy exceeding the vaporization temperature, resulting in excessive oxidation and shedding of the graphene.

[0044] In this embodiment, step S1, which involves preparing a cyanate film on the surface-modified substrate, specifically includes: step S11, providing a cyanate monomer and heating the cyanate monomer in a water bath to obtain a liquid cyanate monomer; step S12, uniformly coating the liquid cyanate monomer onto the surface of the surface-modified substrate; and step S13, subjecting the substrate coated with the liquid cyanate monomer to a high-temperature thermosetting treatment to convert the liquid cyanate monomer into a cyanate film and cure it on the substrate. Furthermore, cyanate monomers are solid at room temperature, but can be obtained as liquid cyanate monomers with good flowability by water bath heating, which facilitates subsequent substrate coating. Therefore, the water bath heating temperature in step S11 is set to 50℃-70℃, and the heating time is 20min-30min. The coating method of the liquid cyanate monomer in step S12 is drop coating and weighing method. The final film thickness is determined by controlling the amount of drop added by weighing method. The temperature conditions of the high-temperature thermal curing treatment in step S13 are 25℃-250℃, and the treatment time is 5h-6h. After natural cooling to room temperature, a cyanate film with uniform surface thickness can be obtained.

[0045] S2, the cyanate ester film is irradiated with a large-spot laser beam to induce the formation of a sintered nanoparticle-like highly conductive graphene film. A small-spot laser beam is then used to etch the highly conductive graphene film, resulting in a high-resolution interdigitated electrode. The main differences between the large and small-spot laser beams lie in their coverage area, energy density, treatment speed, and applicable scenarios. The large-spot laser covers a larger area, allowing for the treatment of more vitiligo areas in a single irradiation, making it suitable for treating large areas of vitiligo and shortening treatment time. The small-spot laser covers a smaller area but has a higher energy density, making it suitable for treating small, localized vitiligo areas, or for edge and detail treatment when dealing with large areas of vitiligo.

[0046] In this embodiment, the large-spot laser beam is emitted by a mid-infrared CO2 laser or a visible light semiconductor laser, and the spot size of the large-spot laser beam is 200μm-500μm. During laser induction, the laser scanning method of the mid-infrared CO2 laser or the visible light semiconductor laser is a left-to-right grating overlap progressive scan, with a scanning speed of 60mm / s-200mm / s, a defocusing amount between +1 and +5mm, and a scanning pixel step size of 800 dots / inch (DPI)-1200 dots / inch (DPI). Furthermore, the product of the spot size of the large-spot laser beam and the scanning spacing must be between 5000μm. 2 -8000μm 2In addition, for mid-infrared CO2 lasers, the best processing effect is achieved by using a mid-infrared CO2 laser with a laser power greater than 16W, a defocusing amount of -2mm, a scanning speed of 100mm / s, and a scanning pixel step size of 1000DPI (25.4μm spacing).

[0047] It is worth mentioning that cyanate esters can be graphitized by using a large-size laser beam and a low laser scanning speed. The principle is that cyanate ester materials themselves have a high absorption rate for infrared laser wavelengths, and the substrate material with high thermal and electrical conductivity can quickly convert the absorbed laser energy into heat energy. In a high-temperature and high-pressure environment, the lattice of the cyanate ester polymer begins to undergo pyrolysis, eventually releasing some C, O, N and other atoms in the form of gas. The remaining C atoms begin to self-heal, forming a stable six-ring (benzene ring) structure. The rings are interconnected, eventually graphitizing.

[0048] The small-spot laser beam is emitted by an ultraviolet ultrafast laser or an ultraviolet nanolaser, and the spot size of the small-spot laser beam is less than 20 μm. During laser engraving, especially in the process of ablation of extremely small sizes, the ultraviolet ultrafast laser or ultraviolet nanolaser adopts an alternating laser beam movement path, with a scanning speed between 600 mm / s and 1500 mm / s, a scanning interval of less than 8 μm, a scanning number of no less than 2, and a power of 80%-95% of the peak power of 17.5 W. Preferably, an ultraviolet picosecond laser with a pulse center wavelength of 355 nm and a pulse width of 10 ps is used, with parameters set to a scanning speed of 600 mm / s to 800 mm / s, a scanning interval of 4 μm, a scanning number of 3, and a laser power of 15-16 W, which yields the best processing results.

[0049] Furthermore, an ultrafast pulsed ultraviolet laser with a small spot size, high peak power, short pulse width, and high laser scanning speed is used. The purpose is to take advantage of the instantaneous high peak power of the ultrafast pulsed laser to rapidly heat up, vaporize, sublimate, and cool the processed area, while leaving a pattern of high-resolution interdigitated electrodes on the unprocessed area.

[0050] It is worth mentioning that the interdigitated electrode design significantly enhances the AC-DC filtering characteristics of supercapacitors, mainly due to the optimization of charge transport and distribution by its special geometry. The interdigitated structure effectively shortens the ion diffusion path, reduces the equivalent series resistance, and improves the capacitor's rapid charge and discharge capability. Furthermore, this design increases the specific surface area of ​​the electrodes, enhancing the double-layer capacitance, enabling it to maintain excellent energy storage and release performance even under high-frequency conditions.

[0051] Step S3: Apply copper foil to both ends of each capacitor using conductive silver paste; design the corresponding mask pattern and reserve specific spaces in the detection hole position and electrolyte coating area of ​​the mask pattern; then perform surface patterning processing on the flexible mask and attach the mask to the capacitor. During the attachment process, it is necessary to ensure that the electrolyte coating interface and the detection hole in the electrode area are completely exposed to the mask opening area.

[0052] In this embodiment, the flexible mask is a polyimide (PI) film or a polyethylene terephthalate (PET) film, and the thickness of the encapsulation film is 25μm-80μm. The surface patterning of the flexible mask is best performed using an ultraviolet ultrafast laser or an ultraviolet nanolaser, preferably with a laser power of 8.5W-9.5W, focusing, and a scanning speed of 60-80mm / s, which yields the best processing results.

[0053] Furthermore, in the flexible mask attachment process in step S3, tweezers or acrylic rods are used to apply pressure to the mask surface multiple times, and tape is used to implement airtight sealing in the edge area to ensure that gas infiltration is prevented. This also ensures that the flexible mask and the surface of the micro supercapacitor form a seamless bond, thereby avoiding the risk of short circuit caused by electrolyte infiltration through the interface gap.

[0054] It is worth mentioning that the detection holes distributed around the electrode array have multifunctional measurement characteristics: they support selective detection of single or multiple electrode units. During measurement, the test probe only needs to be inserted vertically into the detection hole so that its tip makes reliable contact with the substrate conductive layer to obtain accurate capacitance characteristic parameters in real time.

[0055] Step S4: Clean and dry the high-resolution interdigitated electrode; uniformly coat the dried high-resolution interdigitated electrode with gel electrolyte, and place the high-resolution interdigitated electrode coated with gel electrolyte in a vacuum chamber for vacuum treatment to obtain a high-response micro supercapacitor.

[0056] Furthermore, in step S4, the solvent used to clean the high-resolution interdigitated electrode after the lead-out pin is anhydrous ethanol and deionized water; the temperature for drying the cleaned high-resolution interdigitated electrode is 50℃-90℃, and the drying time is 10min-30min; the gel electrolyte is any one of PVA / H3PO4 gel electrolyte, PVA / H2SO4 gel electrolyte, and PVA / LiCl gel electrolyte; the vacuum degree of the vacuum treatment is -0.9MPa to -0.7MPa; the vacuum treatment time is 20min-40min; the purpose of maintaining the vacuum for a certain period of time is to remove the voids in the high-resolution interdigitated electrode itself and the gas molecules in the gel electrolyte, so that the gel electrolyte and the high-resolution interdigitated electrode can make full contact. In addition, in this embodiment, the vacuum treatment is carried out in a vacuum chamber, which is a vacuum drying oven.

[0057] Please also refer to the appendix. Figures 3-12 To further illustrate the present invention, two specific embodiments are provided.

[0058] Example 1

[0059] 1. A PI substrate is provided, and the surface of the PI substrate is modified; a cyanate film is prepared on the surface-modified PI substrate.

[0060] In this embodiment, a 125 μm thick Kapton PI film was cut into 50 mm × 50 mm segments, flatly attached to a glass slide, then cleaned with anhydrous ethanol, rinsed with deionized water, and dried in a 50°C vacuum oven for 15 min. Next, the sample was placed in the center of a worktable, and by importing a CAD pattern and setting laser parameters, it was processed using a picosecond ultraviolet laser with a pulse center wavelength of 355 nm, a pulse duration of ~10 ps with a basic repetition frequency of 600 Hz, a scanning distance of 50 μm, a laser power of 60% of the peak power of 17.5 W, and a scanning speed of 600 mm / s. This improved the wettability of the PI substrate surface, placing the sample at the position with the smallest laser spot size and the most concentrated energy along the z-axis. Solid cyanate monomers were pre-placed in a 70°C water bath for 30 min to obtain liquid cyanate monomers. Place the PI substrate on a balance and slowly drop 0.5g of liquid cyanate monomer onto the processing area on the surface of the PI substrate. Then, use a small stick to spread it evenly on the surface. Transfer it to a heating stage, set the temperature and heating time, and raise the temperature of the heating stage from 25℃ to 250℃ within 5 hours. After natural cooling, a cyanate film cured on the PI substrate can be obtained.

[0061] 2. The cyanate film is irradiated with a large-spot laser beam to induce the formation of a highly conductive graphene film with a sintered nanoparticle morphology; the highly conductive graphene film is then etched with a small-spot laser beam to obtain a high-resolution interdigitated electrode.

[0062] In this embodiment, a cyanate film on a PI substrate is placed on a worktable, and a continuous CO2 laser (10.6 μm) with a rated power of 50 W and a beam diameter of ~250 μm is used to laser-induce graphene on the cyanate film. During the laser induction process, the cyanate film is scanned by direct laser writing with a defocusing amount of -2 mm. The laser scanning method is a left-to-right grating overlap line-by-line scanning, with a laser power of 16 W, a scanning speed of 100 mm / s, and a scanning pixel step size of 1000 DPI, thereby transforming the cyanate film into a highly conductive graphene film. The obtained highly conductive graphene film was then placed on the worktable, and the CAD pattern was imported into the control center. A picosecond ultraviolet laser with a pulse center wavelength of 355nm, a pulse duration of ~10ps with a basic repetition of 600Hz was used. The laser scanning mode was from left to right and from top to bottom. The laser power was 90% of the peak power of 17.5W, the scanning speed was 600mm / s, the scanning gap was 4μm, and the number of scans was 3 times to etch a high-resolution interdigitated electrode pattern.

[0063] 3. Use conductive silver paste to attach copper foil to both ends of each capacitor; design the corresponding mask pattern and reserve specific spaces in the detection hole position and electrolyte coating area; then perform surface patterning processing on the flexible mask and attach the mask to the capacitor. During the attachment process, it is necessary to ensure that the electrolyte coating interface of the electrode area and the detection hole are completely exposed to the mask opening area.

[0064] Copper foil was applied to the contact surfaces between each capacitor and to the input and output terminals of the entire series capacitor array using conductive silver paste. Then, a 50μm thick PI film was used for encapsulation. The PI tape was then patterned with high precision using a 355nm ultraviolet picosecond laser at a laser power of 9.0W and a scanning speed of 60mm / s, following a pre-set flexible mask pattern. After processing, tweezers or precision tools were used to precisely remove the electrodes and detection holes that needed to be exposed from the mask. During the bonding process, it was ensured that the electrolyte-coated electrodes were completely exposed, while all detection holes were covered by the flexible mask. Tweezers or acrylic rods were then used to repeatedly press and eliminate interface air bubbles, and the mask was secured with tape around its edges to ensure the reliability and sealing of the encapsulation structure.

[0065] 4. Clean and dry the high-resolution interdigitated electrode; uniformly coat the dried high-resolution interdigitated electrode with gel electrolyte, and place the high-resolution interdigitated electrode coated with gel electrolyte in a vacuum chamber for vacuum treatment to obtain a high-response micro supercapacitor.

[0066] In this embodiment, the high-resolution interdigitated electrode was cleaned with anhydrous ethanol and deionized water, and dried at 50°C for 15 min. Polyvinyl alcohol (PVA, AH-26, SCR) was mixed with deionized water and H2SO4 (95%, Sigma-Aldrich) (1 g PVA / 10 ml H2O / 1 g H2SO4) at 85°C for approximately 1 h to prepare a PVA / H2SO4 ion gel electrolyte. Finally, -0.20 mL of the ion gel electrolyte was dripped into the gap between the high-resolution interdigitated electrode, and the chamber was placed in a vacuum chamber maintaining a vacuum of ~0.8 MPa for 30 min to remove gas molecules from the gaps in the high-resolution interdigitated electrode and the gel electrolyte. After removal, the chamber was placed overnight in a constant-temperature desiccator (25°C) to remove excess moisture, resulting in a micro supercapacitor.

[0067] Example 2

[0068] 1. A metal substrate is provided, and the surface of the metal substrate is modified; a cyanate film is prepared on the surface-modified metal substrate.

[0069] In this embodiment, the metal substrate material is titanium foil. A 0.03mm thick titanium foil is cut into 50mm × 50mm segments, flatly attached to a glass slide, then cleaned with anhydrous ethanol, rinsed with deionized water, and dried in a 50℃ vacuum oven for 15 minutes. Next, the sample is placed in the center of the worktable. A CAD pattern is imported, and laser parameters are set. A picosecond ultraviolet laser with a pulse center wavelength of 355nm, a pulse duration of ~10ps with a basic repetition rate of 600Hz is used. The scanning direction is from left to right and from top to bottom, with a scanning interval of 50μm, a laser power of 17.5W (60% of the peak power), and a scanning speed of 600mm / s. This improves the wettability of the titanium foil surface, placing the sample at the position with the smallest laser spot size and the most concentrated energy along the z-axis. Solid cyanate monomer is pre-placed in a 70℃ water bath for 30 minutes to obtain liquid cyanate monomer. Place the metal substrate on a balance and slowly drop 0.5g of liquid cyanate monomer onto the processing area on the surface of the metal substrate. Then, use a small stick to spread it evenly on the surface. Transfer it to a heating stage, set the temperature and heating time, and raise the temperature of the heating stage from 25°C to 250°C within 5 hours. After natural cooling, a cyanate film cured on the metal substrate will be obtained.

[0070] 2. The cyanate film is irradiated with a large-size laser beam to induce the formation of a highly conductive graphene film with a sintered nanoparticle morphology; the highly conductive graphene film is then etched with a small-size laser beam to obtain a high-resolution interdigitated electrode array.

[0071] In this embodiment, a cyanate film on a metal substrate is placed on a worktable. A continuous CO2 laser (10.6 μm) with a maximum power of 50 W and a beam diameter of ~250 μm is used to cut the cyanate film for laser-induced graphene. During the laser induction process, the cyanate film is scanned by direct laser writing with a defocusing amount of +2 mm. The laser scanning method is a left-to-right grating overlap line-by-line scanning, with a laser power of 16 W, a scanning speed of 100 mm / s, and a scanning pixel step size of 1000 DPI, thereby transforming the cyanate film into a highly conductive graphene film. The obtained highly conductive graphene film was then placed on the worktable, and the CAD pattern was imported into the control center. A picosecond ultraviolet laser with a pulse center wavelength of 355nm, a pulse duration of ~10ps with a basic repetition of 600Hz was used. The laser scanning mode was from left to right and from top to bottom. The laser power was 90% of the peak power of 17.5W, the scanning speed was 600mm / s, the scanning gap was 4μm, and the number of scans was 3 times to etch a high-resolution interdigitated electrode pattern.

[0072] 3. Use conductive silver paste to attach copper foil to both ends of each capacitor; design the corresponding mask pattern and reserve specific spaces in the detection hole position and electrolyte coating area; then perform surface patterning processing on the flexible mask and attach the mask to the capacitor. During the attachment process, it is necessary to ensure that the electrolyte coating interface of the electrode area and the detection hole are completely exposed to the mask opening area.

[0073] Copper foil was applied to the contact surfaces between each capacitor and to the input and output terminals of the entire series capacitor array using conductive silver paste. Then, a 50μm thick PI film was used for encapsulation. The PI tape was then patterned with high precision using a 355nm ultraviolet picosecond laser at a laser power of 9.0W and a scanning speed of 60mm / s, following a pre-set flexible mask pattern. After processing, tweezers or precision tools were used to precisely remove the electrodes and detection holes that needed to be exposed from the mask. During the bonding process, it was ensured that the electrolyte-coated electrodes were completely exposed, while all detection holes were covered by the flexible mask. Tweezers or acrylic rods were then used to repeatedly press and eliminate interface air bubbles, and the mask was secured with tape around its edges to ensure the reliability and sealing of the encapsulation structure.

[0074] 4. Clean and dry the high-resolution interdigitated electrode; uniformly coat the dried high-resolution interdigitated electrode with gel electrolyte, and place the high-resolution interdigitated electrode coated with gel electrolyte in a vacuum chamber for vacuum treatment to obtain a high-response micro supercapacitor.

[0075] In this embodiment, the high-resolution interdigitated electrode was cleaned with anhydrous ethanol and deionized water, and dried at 50°C for 15 min. Polyvinyl alcohol (PVA, AH-26, SCR) was mixed with deionized water and H2SO4 (98%, Sigma-Aldrich (1g PVA / 10ml H2O / 1g H2SO4)) at 85°C for approximately 1 h to prepare a PVA / H2SO4 ion gel electrolyte. Finally, -0.20 mL of the ion gel electrolyte was dripped into the gap between the high-resolution interdigitated electrode, and the chamber was placed in a vacuum chamber maintaining a vacuum of ~-0.8 MPa for 30 min. Gas molecules were extracted from the gaps in the high-resolution interdigitated electrode itself and from the gel electrolyte. After removal, the chamber was placed overnight in a constant-temperature desiccator (25°C) to remove excess moisture, resulting in a micro supercapacitor.

[0076] Compared with related technologies, the present invention provides a method for preparing a high-response micro supercapacitor based on highly conductive graphene, comprising the following steps: providing a substrate and modifying its surface; preparing a cyanate film on the substrate; irradiating the cyanate film with a large-spot laser beam to induce the cyanate film to form a sintered nanoparticle-like highly conductive graphene film, and engraving the highly conductive graphene film with a small-spot laser beam to obtain a high-resolution interdigitated electrode; attaching copper foil with conductive silver paste, and then attaching a patterned flexible mask; cleaning and drying the high-resolution interdigitated electrode, then uniformly coating the dried high-resolution interdigitated electrode with gel electrolyte, and performing vacuum treatment to obtain a high-response micro supercapacitor. The above preparation method enables the induced formation of highly conductive graphene films with sintered nanoparticle morphology on any substrate. If the substrate is a polymer substrate, the sheet resistance of the graphene film is as low as 1.7 Ω / square; if the substrate is a metal substrate, the sheet resistance is as low as 1.6 Ω / square. Utilizing the optimized design of interdigitated electrodes, their interleaved charge storage characteristics achieve efficient AC-DC filtering. Furthermore, the high-response micro-supercapacitor fabricated using the highly conductive graphene film can achieve a maximum scan speed of 1000 V / s. Flexible mask encapsulation combines high-precision patterning capabilities with high integration advantages, allowing the integration of multiple independent electrodes within a miniaturized area. This supports performance testing of single / multi-electrode and series systems via an electrochemical workstation. The superhydrophobic encapsulation layer and vacuum processing work synergistically to ensure long-term stable encapsulation of the highly active electrolyte within complex microstructures.

[0077] It should be noted that the above-described embodiments should be understood as illustrative, not as limiting the scope of protection of this invention. The scope of protection of this invention is defined by the claims. For those skilled in the art, some non-essential improvements and adjustments made to this invention without departing from the essence and scope of this invention still fall within the scope of protection of this invention.

Claims

1. A method for fabricating a high-response micro supercapacitor based on highly conductive graphene, characterized in that, The method includes the following steps: Step S1: Provide a substrate and perform surface modification on the substrate; prepare a cyanate film on the surface-modified substrate; Step S2: Irradiate the cyanate film with a large-size laser beam to induce the cyanate film to form a sintered nanoparticle-like highly conductive graphene film; then etch the highly conductive graphene film with a small-size laser beam to obtain a high-resolution interdigitated electrode. Step S3: Apply copper foil to both ends of each capacitor using conductive silver paste; design the corresponding mask pattern and reserve specific spaces in the detection hole position and electrolyte coating area of ​​the mask pattern; then perform surface patterning processing on the flexible mask and attach the mask to the capacitor. During the attachment process, it is necessary to ensure that the electrolyte coating interface and the detection hole in the electrode area are completely exposed to the mask opening area. Step S4: Clean and dry the high-resolution interdigitated electrode; uniformly coat the dried high-resolution interdigitated electrode with gel electrolyte, and place the high-resolution interdigitated electrode coated with gel electrolyte in a vacuum chamber for vacuum treatment to obtain a high-response micro supercapacitor.

2. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 1, characterized in that, In step S1, the surface modification is performed by X-ray irradiation, where an array of microstructure patterns with a size of less than 100 μm is processed on the substrate surface using an ultraviolet laser.

3. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 2, characterized in that, The ultraviolet laser has a wavelength of 355nm, a pulse frequency of 600Hz, and a pulse duration of 10ps. The scanning direction of the ultraviolet laser is from left to right and from top to bottom, with a scanning spacing of 50μm-100μm, a scanning speed of 600mm / s-1200mm / s, and a power of 50%-70% of the peak power of 17.5W.

4. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 1, characterized in that, The substrate is selected from any one of glass, quartz, silicon, and flexible substrate, and the thickness of the substrate is 0.01mm-0.2mm.

5. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 1, characterized in that, The step S1, which involves preparing a cyanate film on the surface-modified substrate, specifically includes: Step S11: Provide cyanate monomer and heat the cyanate monomer in a water bath to obtain liquid cyanate monomer; Step S12: The liquid cyanate monomer is uniformly coated onto the surface of the surface-modified substrate. Step S13: Perform a high-temperature thermosetting treatment on the substrate coated with the liquid cyanate monomer to convert the liquid cyanate monomer into a cyanate film and cure it on the substrate.

6. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 5, characterized in that, In step S11, the water bath heating temperature is 50℃-70℃, and the heating time is 20min-30min; in step S12, the coating method of the liquid cyanate monomer is drop coating and weighing method; in step S13, the high temperature heat curing treatment temperature is 25℃-250℃, and the treatment time is 5h-6h.

7. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 1, characterized in that, The large-spot laser beam is emitted by a mid-infrared CO2 laser or a visible light semiconductor laser, and the spot size of the large-spot laser beam is 200μm-500μm. The scanning method of the mid-infrared CO2 laser or the visible light semiconductor laser is a left-to-right grating overlap progressive scan, with a scanning speed of 60mm / s-200mm / s, a defocusing amount between +1 and +5mm, and a scanning pixel step size of 800 dots / inch (DPI)-1200 dots / inch (DPI). Furthermore, the product of the spot size of the large-spot laser beam and the scanning spacing must be between 5000μm. 2 -8000μm 2 .

8. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 1, characterized in that, The small-sized laser beam is emitted by an ultraviolet ultrafast laser or an ultraviolet nanolaser, and the spot size of the small-sized laser beam is less than 20 μm. The ultraviolet ultrafast laser or ultraviolet nanolaser adopts an alternating laser beam movement path, with a scanning speed between 600 mm / s and 1500 mm / s, a scanning interval of less than 8 μm, a scanning number of no less than 2, and a power of 80%-95% of the peak power of 17.5 W.

9. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 1, characterized in that, In step S3, during the flexible mask selection stage, a superhydrophobic polyimide or polyethylene terephthalate film is used, and its thickness window should preferably be set to 25-80 μm.

10. The method for preparing a high-response micro supercapacitor based on highly conductive graphene according to claim 1, characterized in that, In step S3, the mask pattern design establishes a critical dimension compensation mechanism. The geometric design of the electrode functional area should follow a process allowance of 0.2mm for single-sided expansion in the X / Y direction.

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