A nanoparticle graphene / foam metal-based filtering supercapacitor and a preparation method thereof

Abstract

The application relates to the field of laser micro-nano manufacturing technology and discloses a filtering super capacitor based on nanoparticle graphene / foam metal and a preparation method thereof, which comprises the following steps: foam metal with an open structure and liquid cyanate ester monomers are used to prepare a cyanate ester resin / foam metal composite film; a laser processing is performed by using a middle infrared large-size light spot laser beam and a ultraviolet small-size light spot laser beam, in-situ laser-induced nanoparticle graphene growth is performed on the surface of the foam metal, and a nanoparticle graphene / foam metal electrode raw material is prepared; the electrode raw material is cut into an electrode, and a second mask is attached; and a sandwich type filtering super capacitor is prepared. The conductivity of the generated nanoparticle graphene / foam metal film is as high as 909.09 S / cm, the prepared super capacitor still has a good capacitance behavior at a scanning speed of 2500 V / s, the phase angle is as high as -70 degrees at 120 Hz, the surface specific capacitance is 245 mu F / cm 2 and simultaneously has a cutoff frequency of up to 3 kHz and an RC time constant as low as 0.33 ms.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of laser micro-nano manufacturing, and in particular to a filtering supercapacitor based on nanoparticle-shaped graphene / foam metal and a preparation method thereof. BACKGROUND

[0002] With the rapid development of portable intelligent electronic devices towards miniaturization and high integration, although traditional aluminum electrolytic capacitors have long occupied the market of filtering capacitors due to advantages such as high voltage resistance and low cost, the inherent defects of large size and insufficient specific capacitance are increasingly prominent, which seriously restricts the development of device miniaturization and planar integration technology. In comparison, micro supercapacitors have become an ideal choice to replace traditional energy storage devices due to their small size, high power density, fast charging and discharging speed and excellent cycle stability, and have shown broad prospects in the fields of flexible electronics, biomedical treatment and Internet of Things.

[0003] The current laser-processed electrode faces significant technical bottlenecks in the field of filtering applications, and the essence is the two core problems commonly existing in carbon-based supercapacitors: insufficient electrode conductivity and slow ion diffusion kinetics. On the one hand, the laser-induced graphene electrode has poor conductivity due to low crystallinity and disordered structure; on the other hand, the disordered structure also limits the rapid migration of ions. The two factors together significantly reduce the cutoff frequency of the electrode, which cannot meet the stringent requirements of alternating current filtering for fast charging and discharging and high frequency response.

[0004] Therefore, there is an urgent need for a new capacitor preparation method to solve the above technical problems. SUMMARY

[0005] In view of the above defects, the purpose of the present application is to provide a filtering supercapacitor based on nanoparticle-shaped graphene / foam metal and a preparation method thereof, which solves the problems of low yield, high cost and complex process of traditional graphene preparation process, and cannot meet the production requirements of industrialization and large-scale production.

[0006] To achieve this purpose, the application adopts the following technical solutions:

[0007] A preparation method of a filtering supercapacitor based on nanoparticle-shaped graphene / foam metal, comprising the following steps:

[0008] S1, a substrate is attached to a glass substrate, then a foam metal with an open structure is placed on the substrate, and then a flexible ring-shaped first mask with single-sided glue is used to press and attach the outer periphery of the foam metal to realize fixation and sealing, after which liquid cyanate monomer is coated on the foam metal and heated at a constant temperature for curing, to obtain a cyanate resin / foam metal composite film;

[0009] S2. The cyanate ester resin / foam metal composite film obtained in step S1 is irradiated with a mid-infrared large-size laser beam to generate a nanoparticle-shaped graphene / foam metal film; then the nanoparticle-shaped graphene / foam metal film is inverted and the substrate and glass substrate are separated by an ultraviolet small-size laser beam to obtain nanoparticle-shaped graphene / foam metal electrode raw material.

[0010] S3. Cut the nanoparticle-shaped graphene / foam metal electrode raw material obtained in step S2 into electrodes, clean and dry the electrodes, use laser ablation process to pattern the second mask, and attach the second mask to the electrode.

[0011] S4. Take at least two electrodes obtained in step S3, uniformly coat the surface of each electrode with ion gel electrolyte, and then transfer the electrodes to a vacuum chamber for vacuum treatment; after the ion gel electrolyte is transformed into a semi-solid state, align and attach several electrodes, apply pressure, and solidify and shape them at room temperature to obtain a sandwich-type filter supercapacitor.

[0012] Preferably, in step S1, the substrate is made of polyimide or polyethylene terephthalate, and the thickness of the substrate is 0.01 mm to 0.2 mm.

[0013] Preferably, in step S1, the substrate is made of polyimide or polyethylene terephthalate, and the thickness of the substrate is 0.01 mm to 0.2 mm.

[0014] Preferably, in steps S1 and S3, the first mask and the second mask are both made of polyimide or polyethylene terephthalate, and both have a thickness of 20~125μm.

[0015] Preferably, the method further includes pretreating the solid cyanate monomer into a liquid cyanate monomer, placing the solid cyanate in a container, sealing the container, and then immersing the container in a water bath for heating. The water bath heating temperature is 50-70°C, and the time is 20-30 minutes.

[0016] Preferably, the liquid cyanate monomer is added by quantitative dripping in a proportional manner, with the amount of liquid cyanate monomer added per unit area of ​​the foamed metal being 20 mg / cm² to 50 mg / cm². Preferably, in step S1, the heating and curing adopts a stepped heating method, with the heating temperature being 90~230℃ and the time being 7-8 hours.

[0017] Preferably, in step S2, the spot size of the mid-infrared large-size spot laser beam is 200-500 mu m, the scanning adopts a grating S-shaped overlapping path (serpentine scanning), the scanning speed is 80-120 mm / s, the defocusing amount is +2-+4 mm, the scanning pixel step is 800-1200 DPI, and the laser power is 7.5-25 W.

[0018] Preferably, in step S2, the spot size of the ultraviolet small-size spot laser beam is 10-20 mu m, the pulse center wavelength is 355 nm, the pulse width is 5-20 ps, the scanning adopts a grating overlapping line-by-line path from left to right, the scanning speed is 600-1000 mm / s, the focusing is performed, the scanning pitch is 15-25.4 mu m, and the laser power is set to 7.5-16 W.

[0019] A filter supercapacitor is prepared by using the preparation method.

[0020] The technical scheme provided by the application can have the following beneficial effects:

[0021] 1. The selected open-cell structured foam metal is a two-phase composite material composed of a metal matrix skeleton continuous phase and a pore continuous phase. The pore continuous phase of the foam metal has a liquid absorption property, so that the liquid cyanate ester monomer spontaneously penetrates into the pore network of the foam metal under the action of capillary force, and then the cyanate ester monomer is cured to make the cyanate ester monomer polymerize and form a cyanate ester film combined with the metal skeleton, thereby inducing the generation of a nanoparticle graphene / foam metal film on the substrate.

[0022] 2. By inducing the generation of a nanoparticle graphene / foam metal film on the substrate, the metal matrix skeleton continuous phase of the foam metal provides a continuous low-resistance electronic path, and the graphene is combined to reduce the interface resistance, thereby realizing three-dimensional efficient current collection, so that the conductivity of the nanoparticle graphene / foam metal film is as high as 909.09 S / cm, which is 7.8 times that of the graphene film.

[0023] 3. Benefiting from the efficient current collection effect of the metal matrix skeleton continuous phase of the foam metal, the low resistance of the electrode, and the excellent electrode / electrolyte interface contact, the pore continuous phase of the foam metal promotes the diffusion of the electrolyte, the nanoparticle graphene greatly shortens the ion diffusion distance and provides a high accessible surface area, so that the supercapacitor still maintains good capacitance behavior at a scanning rate as high as 2500 V / s.

[0024] 4. The graphene material forms a directional arrangement of through nano-pores or layered channels inside, and the low tortuosity of the graphene structure itself, making the ion migration path close to straight line rather than repeatedly winding, this ordered structure creates low tortuosity ion channels, realizes high-speed ion migration, combined with ultra-low resistance, significantly shortens the charge and discharge relaxation time, so that the supercapacitor prepared based on the material can realize a phase angle of up to-70° at 120Hz, a surface specific capacitance of up to 245μF / cm², while having a cutoff frequency of up to 3kHz, an RC time constant as low as 0.33ms, significantly exceeding the performance upper limit of traditional commercial aluminum electrolytic capacitors, thus effectively supporting harsh high-frequency filtering applications.

[0025] 5. The substrate uses polyimide or polyethylene terephthalate, etc., and the low thermal conductivity helps to maintain a high temperature environment at the irradiation point, and the appropriate thickness can provide sufficient heat capacity to buffer the instantaneous thermal shock, making it an ideal sacrificial layer substrate for laser-induced graphene.

[0026] 6. The first mask and the second mask are made of polyimide PI or polyethylene terephthalate PET film, which has high absorption in the ultraviolet band, good thermal stability (especially PI), excellent mechanical flexibility, chemical stability and mature laser processing suitability, making it an ideal and mainstream choice for flexible mask laser patterning. The polyimide PI or polyethylene terephthalate PET film has hydrophobicity, which significantly reduces the risk of electrolyte penetration short circuit caused by mask thinning or electrode roughness, improves device safety and reliability, and enhances moisture resistance, anti-fouling and electrolyte surface creep suppression ability, improving the environmental stability of the prepared supercapacitor.

[0027] 7. By quantitative dropping of liquid cyanate monomer, uniform and low-defect impregnation is achieved by making full use of the capillary force of the foam metal, and the operation is simple, the cost is low, and it is beneficial to form a good interfacial bond. The scraping step as an auxiliary means effectively promotes the rapid surface distribution of cyanate monomer and improves the effect of capillary penetration.

[0028] 8. A large-size mid-infrared laser beam with low laser scanning speed is used to induce graphene with optimal structure integrity and conductivity.

[0029] 9. The ultraviolet small-size laser beam uses a small-size spot, high peak power, short pulse width, and high laser scanning speed of ultrafast pulse ultraviolet laser, which can realize selective ablation of cyanate resin / foam metal composite film, so that the adhesive layer of the substrate is fully carbonized, and the morphology and electrical properties of the surface layer material are stable when the cyanate resin / foam metal composite film is peeled off from the glass substrate. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Flow chart of the preparation method of one embodiment of the present application.

[0031] Figure 2 Preparation technical scheme principle diagram of the nanoparticle graphene / foam metal film of one embodiment of the present application.

[0032] Figure 3 Explosion schematic diagram of the sandwich type filter supercapacitor prepared in embodiment 1 of the present application.

[0033] Figure 4 Structure schematic diagram of the series array sandwich type filter supercapacitor prepared in embodiment 2 of the present application.

[0034] Figure 5 Surface micro-morphology schematic diagram of the nanoparticle graphene / foam metal film prepared in embodiment 1 of the present application;

[0035] Figure 6 CV curve diagram of the sandwich type filter supercapacitor prepared in embodiment 1 of the present application at a scan speed of 2500V / s;

[0036] Figure 7 CV curve diagram of the series array sandwich type filter supercapacitor prepared in embodiment 2 of the present application at a scan speed of 5000V / s;

[0037] Figure 8 Bode curve diagram of the sandwich type filter supercapacitor prepared in embodiment 2 of the present application;

[0038] Figure 9 Filtering performance comparison diagram of the commercial aluminum electrolytic capacitor and the sandwich type filter supercapacitor prepared in embodiment 1 of the present application;

[0039] Figure 10 Filtering performance comparison diagram of the commercial aluminum electrolytic capacitor and the series array sandwich type filter supercapacitor prepared in embodiment 2 of the present application.

[0040] Figure 11 XRD diagram of the nanoparticle graphene / foam nickel film prepared in embodiment 2 of the present application.

[0041] Figure 12 Raman spectrum diagram of the nanoparticle graphene / foam nickel film prepared in embodiment 2 of the present application.

[0042] Among them: electrode 1, second mask 2, electrolyte 3. DETAILED DESCRIPTION

[0043] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like component have the same or similar designations. The embodiments described below are presented by way of example only and are not intended to limit the present application as defined by the appended claims and their equivalents.

[0044] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, features defined with "first", "second" can explicitly or implicitly include one or more of the features, for distinguishing the description of the features, without order, without light and heavy.

[0045] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0046] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] The embodiments of the present application are described below with reference to the accompanying drawings.

[0048] As shown in Figure 1 and Figure 2 A preparation method of a filtering supercapacitor based on nanoparticle graphene / foam metal, comprising the following steps:

[0049] S1, laminating a substrate on a glass substrate, then placing a foam metal with an open structure on the substrate, then fixing and sealing the outer periphery of the foam metal by pressing and laminating the outer periphery of the foam metal through a flexible annular first mask with single-sided adhesive, then coating liquid cyanate monomer on the foam metal and constant temperature heating and curing to obtain a cyanate resin / foam metal composite film;

[0050] S2, irradiating the cyanate ester resin / foam metal composite film obtained in step S1 by a mid-infrared large-size spot laser beam to generate a nanoparticle graphene / foam metal film; then inverting the nanoparticle graphene / foam metal film and separating the substrate and the glass substrate by a ultraviolet small-size spot laser beam to obtain a nanoparticle graphene / foam metal electrode raw material;

[0051] S3, cutting the nanoparticle graphene / foam metal electrode raw material obtained in step S2 into electrodes, cleaning and drying the electrodes, patterning a second mask by a laser ablation process, and attaching the second mask to the electrodes;

[0052] S4, taking at least two electrodes prepared in step S3, uniformly coating an ion gel electrolyte on the surface of each electrode, then transferring the electrodes to a vacuum chamber for vacuumizing treatment; after the ion gel electrolyte is converted into a semi-cured state, aligning and attaching a plurality of electrodes, applying pressure, and curing and shaping at room temperature to obtain a sandwich type filter supercapacitor.

[0053] By using the above preparation method, the open-cell foam metal selected is a two-phase composite material composed of a metal matrix skeleton continuous phase and a pore continuous phase. The pore continuous phase of the foam metal has a liquid absorption property, so that the liquid cyanate ester monomer spontaneously penetrates into the pore network of the foam metal under the action of capillary force, and then the cyanate ester monomer is cured to make the cyanate ester monomer polymerize and form a cyanate ester film combined with the metal skeleton, thereby inducing the generation of a nanoparticle graphene / foam metal film on the substrate. The electrode size has no inherent process limitation, and the cutting size is completely determined according to the application requirements of the capacitor, such as the electrode size range of a single capacitor: 4 mm × 5 mm to 6 mm × 7 mm; the electrode size range of a series capacitor: 4 mm × 10 mm to 6 mm × 12 mm. The patterning of the second mask is according to the complex pattern required by the use of the final product.

[0054] By using the first mask, it is ensured that the liquid cyanate ester monomer is only infiltrated and cured in the desired foam metal area to form a composite film with clear boundaries. After pressing and attaching the first mask, the contact line between the first mask, the foam metal and the substrate should be a continuous, gap-free, wrinkle-free and bubble-free tight attachment line. Any visible gap or edge lifting means poor sealing. At the same time, check whether the mask is flatly attached as a whole, without local bulging or detachment.

[0055] The conventional method for inducing the formation of graphene film is to use a small-spot CO2 infrared laser (wavelength 10.6 μm). The conventional laser process aims to form a continuous graphene structure, and to form uniformly dispersed nanoparticle graphene on the metal skeleton, a more uniform heat field and specific reaction conditions are required. The highly localized and non-uniform heat field generated by small-spot scanning is difficult to achieve such precise control, and is prone to cause uneven products (partially over-burned into continuous graphene or carbide, and partially unreacted). The preparation method of the present application solves the problem of accurately controlling the formation of uniformly dispersed nanoparticle graphene on the metal skeleton by irradiating the cyanate ester resin / foam metal composite film with a mid-infrared large-size laser beam, and in-situ laser-induced nanoparticle graphene growth on the foam metal surface.

[0056] The conventional method for separating the substrate is to use a small-spot ultraviolet laser, and the laser is incident from the substrate side to accurately act on the interface sacrificial layer to achieve separation by ablation or weakening the interface. However, the ultraviolet laser will be scattered when it penetrates the porous film, and the energy density needs to be increased, which is easy to ablate the surface graphene nanoparticles or melt the metal skeleton. And the laser energy impact causes the brittle foam metal structure to break and the graphene to fall off. The preparation method of the present application uses ultraviolet laser to ablate the adhesive layer at the bottom of the substrate through the glass substrate, which can avoid the damage of the surface functional layer, and the morphology and electrical properties of the surface layer material remain stable.

[0057] By inducing the formation of nanoparticle graphene / foam metal film on the substrate, the continuous phase of the metal matrix skeleton of the foam metal provides a continuous low-resistance electronic path, and the combination of graphene close composite reduces the interface resistance to realize three-dimensional efficient current collection, so that the conductivity of the nanoparticle graphene / foam metal film is as high as 909.09 S / cm, which is 7.8 times that of the graphene film.

[0058] Benefiting from the efficient current collection effect of the continuous phase of the metal matrix skeleton of the foam metal, the low resistance of the electrode, and the excellent electrode / electrolyte interface contact, the continuous phase of the pores of the foam metal promotes the diffusion of the electrolyte, and the nanoparticle graphene greatly shortens the ion diffusion distance and provides a high accessible surface area, so that the supercapacitor still maintains good capacitance behavior at a scan rate as high as 2500 V / s.

[0059] The graphene material forms a directional arrangement of through nano-pores or layered channels inside, and the low tortuosity of the graphene structure itself makes the ion migration path close to straight line instead of repeated detours. This ordered structure creates a low-tortuosity ion channel to realize high-speed ion migration, combined with ultra-low resistance, significantly shortens the charge and discharge relaxation time, so that the supercapacitor prepared based on the material can realize a phase angle of up to-70° and a surface specific capacitance of up to 245 μF / cm² at 120 Hz, while having a cutoff frequency of up to 3 kHz and an RC time constant as low as 0.33 ms, significantly exceeding the performance upper limit of traditional commercial aluminum electrolytic capacitors, thus effectively supporting harsh high-frequency filtering applications.

[0060] Preferably, in step S1, the material of the glass substrate is borosilicate glass or fused quartz, and the thickness of the glass substrate is 1mm-3mm.

[0061] The borosilicate glass or fused quartz has high transmittance in the ultraviolet band, which can maximize the effective utilization rate of laser energy, ensure that the laser can efficiently penetrate the glass substrate, and accurately act on the target layer to achieve controllable peeling of the subsequent mask.

[0062] The thickness of the glass substrate is greater than 1mm, which can ensure its mechanical stability and heat buffering capacity to avoid fragmentation and thermal runaway. The thickness of the glass substrate is less than 3mm, which is convenient for controlling the laser attenuation and thermal stress to ensure the energy transmission efficiency.

[0063] Preferably, in step S1, the material of the substrate is polyimide or polyethylene terephthalate, and the thickness of the substrate is 0.01mm-0.2mm.

[0064] Under the same processing conditions, higher thermal conductivity helps to improve the uniformity and graphitization degree of the final graphene surface, and the type and thickness of the substrate directly affect the thermal conductivity of the composite material. The use of low-thermal-conductivity materials such as polyimide or polyethylene terephthalate can effectively limit the diffusion of laser energy, making it highly localized at the irradiation point, thereby generating an ultra-high temperature of more than 800℃ to meet the graphitization requirements. In addition, the thickness of the substrate has a significant impact on this process. If it is too thin, the heat capacity is insufficient, causing the temperature to rise sharply above the gasification threshold of 500℃, leading to graphene oxidation and shedding. If it is too thick, the thermal resistance increases, causing energy to be absorbed by the deep non-reactive area, resulting in insufficient surface temperature to inhibit the cyanate reaction. Therefore, the combination of low thermal conductivity and moderate thickness is the key to achieving controllable thermal localization. Low thermal conductivity helps to maintain a high-temperature environment at the irradiation point, while the appropriate thickness provides sufficient heat capacity to buffer the instantaneous thermal shock, making it an ideal sacrificial layer substrate for laser-induced graphene.

[0065] Preferably, in step S1, the foam metal is foam nickel or foam copper, and the thickness of the foam metal is 0.1mm-0.3mm.

[0066] The unique catalytic activity of the foamed nickel can significantly improve the efficiency of laser-induced graphene, and can reduce the pyrolysis temperature by about 200℃; while the extremely low resistivity (1.7 μΩ·cm) of foamed copper and its cost advantage are more suitable for large-scale production. When the thickness of the foamed metal is less than 0.1 mm, the strength of the hole wall structure is insufficient, and it is easy to cause tearing mechanical failure under laser thermal stress; when the thickness exceeds 0.3 mm, the multiple scattering of the mid-infrared laser in the metal skeleton leads to energy attenuation, and the deep cyanate ester resin cannot reach the graphene generation threshold temperature, resulting in a decrease in energy utilization.

[0067] Preferably, in the step S1 and the step S3, the material of the first mask and the second mask is polyimide or polyethylene terephthalate, and the thickness is 20-125 μm.

[0068] The first mask and the second mask are made of polyimide PI or polyethylene terephthalate PET film, which has high absorption in the ultraviolet band, good thermal stability (especially PI), excellent mechanical flexibility, chemical stability and mature laser processing suitability, and is the ideal and mainstream choice for flexible mask laser patterning processing. The polyimide PI or polyethylene terephthalate PET film has hydrophobicity, which significantly reduces the risk of electrolyte penetration short circuit caused by mask thinning or electrode roughness, improves the safety and reliability of the device, and enhances the moisture-proof, anti-fouling and electrolyte surface creep suppression ability, and improves the environmental stability of the prepared supercapacitor.

[0069] When the first mask is too thick, it will form a clear step, causing the resin to abnormally climb and thicken at the edge due to surface tension during resin coating; at the same time, the flexibility of the first mask decreases, making it difficult to closely fit the foam metal and the substrate joint, and the risk of poor sealing is high. When the first mask is too thin, it will cause the first mask to lack mechanical strength and be easily scratched or torn by the foam metal, and the glue layer will be difficult to effectively fill the gap due to lack of support, resulting in poor sealing reliability, and the first mask will be wrinkled when it is too thin, making it difficult to operate.

[0070] It is worth mentioning that the thickness of the second mask has a decisive influence on the filter supercapacitor. A thinner second mask can significantly shorten the electrolyte thickness, thereby shortening the ion migration path and reducing the ion resistance, thereby improving the high-frequency response characteristics. However, excessive thinning will sacrifice the mechanical strength, and when the thickness of the second mask is less than 20 μm, short circuit may be caused by electrode roughness. When the thickness of the second mask is greater than 125 μm, it will directly increase the thickness of the electrolyte layer, lengthen the ion migration path and increase the resistance, and seriously degrade the high-frequency response performance, which cannot meet the filtering requirements.

[0071] Preferably, in steps S1 and S3, the first mask and the second mask are both made of polyethylene naphthalate (PEN) with a thickness of 20-125 μm. In another embodiment, the PEN is a better mask material with higher performance but higher cost, which is suitable for applications that are sensitive to cost but require better performance than PET.

[0072] Preferably, the solid cyanate ester monomer is pre-processed into liquid cyanate ester monomer, the solid cyanate ester is placed in a container, the container is sealed, and then the container is immersed in a water bath for heating, the water bath is heated at a temperature of 50-70°C for 20-30 minutes.

[0073] The cyanate ester monomer is solid at room temperature and needs to be liquefied for effective impregnation in the foam metal. The use of a sealed container can inhibit the volatilization of cyanate ester, and immersing in a water bath can further seal the container to ensure the sealing effect. The water bath uniformly transfers heat to the container wall through water convection, and then to the cyanate ester, which can avoid local overheating / overcooling; the specific heat capacity of water is high, and water bath heating can buffer temperature fluctuations through water medium.

[0074] When the water bath temperature is too low, the cyanate ester cannot be completely melted, and the fluidity is insufficient; when the water bath temperature is too high, the cyanate ester viscosity is too low, and the fluidity is too strong during solidification operation, which is easy to contaminate the mold or equipment. When the water bath time is too short, the cyanate ester is not fully preheated, the viscosity is too high, the fluidity is insufficient, and gaps are easily generated during solidification, and micro-bubbles or moisture in the cyanate ester are not easily escaped, which is easy to form pinholes or cavities after solidification; when the water bath time is too long, the cyanate ester will partially crosslink (pre-solidification) during the heating stage, and the viscosity will abnormally increase.

[0075] Preferably, the liquid cyanate ester monomer is added in a proportional and quantitative manner, and the unit area addition amount of the liquid cyanate ester monomer to the foam metal is 20-50 mg / cm².

[0076] The sample with the foam metal fixed thereon is placed on a tray balance, a rubber bulb dropper is used to add the liquid cyanate ester monomer, the dropping speed is controlled to be greater than 2 seconds per drop, and the liquid droplet freely falls (non-spraying state); the dropping height is controlled to be less than 1 cm from the tip of the dropper to the surface of the foam metal to avoid splashing or local accumulation caused by liquid droplet impact; the dropping path is controlled to be a zigzag path at a constant speed during the dropping process to cover the entire effective area. After the dropping is completed, a small spatula is immediately used to gently scrape the surface of the sample, and if the cyanate ester can be seen to overflow slightly and the trace after scraping disappears within 10 seconds, it indicates that the scraping is completed.

[0077] If the addition amount of the liquid cyanate ester monomer is less than 20 mg / cm², the cyanate ester is difficult to completely infiltrate the foam metal pores, which leads to uneven distribution of the laser-induced graphene layer and reduces the charge transfer efficiency;

[0078] If the amount of liquid cyanate monomer added exceeds 50 mg / cm², the excessive cyanate will submerge the foam metal skeleton, preventing it from being effectively exposed to the laser irradiation area, weakening the construction effect of the three-dimensional conductive network, and ultimately affecting the filtering performance.

[0079] By quantitatively adding liquid cyanate monomers, the capillary force of the foamed metal is fully utilized to achieve uniform, low-defect impregnation, which also has the advantages of simple operation, low cost, and good interfacial bonding. The scraping coating step, as an auxiliary method, effectively promotes the rapid surface distribution of cyanate monomers and improves the capillary penetration effect.

[0080] Preferably, in step S1, the heating and curing adopts a stepped heating method, with a heating temperature of 90~230℃ and a time of 7-8 hours.

[0081] By employing a stepped heating method, the resin viscosity is sufficiently reduced in the low-temperature range (90-120℃) to achieve complete filling of the foam metal pores and avoid residual air bubbles. In the medium-temperature range (150-180℃), the heat of reaction is released in stages, with a core-to-surface temperature difference of <5℃, preventing thermal decomposition of the resin. In the high-temperature range (200-240℃), the complete cross-linking of the triazine ring network is promoted. This addresses the problems of: during isothermal curing, the initial high viscosity of the resin cannot be sufficiently reduced at a constant temperature, resulting in insufficient capillary force and difficulty in completely wetting the foam metal; and during uniform heating, the resin exhibits a sudden viscosity drop inflection point at 120–150℃, which is instantly bypassed by uniform heating, losing the opportunity for deep wetting. Furthermore, the resin viscosity increases exponentially after 160℃, and uniform heating lacks a pressure-holding and venting stage, causing the gas escape rate within the pores to lag behind the gelation rate, resulting in a high rate of residual air bubbles.

[0082] Furthermore, if the curing temperature is too high, the high temperature increases the curing reaction rate, and concentrated exothermic reactions lead to localized carbonization of the cyanate ester, releasing toxic gases. Excessive cross-linking caused by high temperatures reduces the free volume of the molecular chains, decreasing impact strength, elongation at break, and significantly increasing product brittleness. If the curing temperature is too low, the cyanate ester will not cure completely, and insufficient molecular kinetic energy will cause cross-linking to stagnate, resulting in residual stickiness on the surface, loss of wear resistance, and long-term reliability degradation. Unreacted monomers will slowly migrate and precipitate, accelerating product aging and contaminating surrounding components. If the curing time is too short, the cyanate ester will appear hardened, but the internal cross-linking degree will be less than 80%. It may pass short-term tests, but its performance will collapse after long-term use. Internal stress concentration in the cyanate ester, and surface curing shrinkage restricting continued internal shrinkage, easily induces spontaneous cracking. If the curing time is too long, the cyanate ester will experience over-curing degradation, molecular chain oxidation, decreased tensile strength, yellowing, and waste of energy and costs. Ineffectively extending the curing time increases costs.

[0083] Preferably, in step S2, the spot size of the mid-infrared large-size spot laser beam is 200-500 μm, the scanning adopts a grating S-shaped overlapping path (serpentine scanning), the scanning speed is 80-120 mm / s, the defocusing amount is +2-+4 mm, the scanning pixel step is 800-1200 DPI, and the laser power is 7.5-25 W.

[0084] The graphene with optimal structural integrity and electrical conductivity can be induced by the parameter combination.

[0085] It is worth mentioning that the cyanate ester resin / foam metal composite film is graphitized by using a mid-infrared large-size spot laser beam and a low laser scanning speed. The cyanate ester material itself has a high absorption rate for infrared wavelength laser. Although the surface layer of the cured cyanate ester material is covered by the foam metal, the three-dimensional interconnected pore network of the foam metal allows the mid-infrared wavelength CO2 laser to partially penetrate the metal skeleton gap and directly act on the internal resin layer. The laser energy forms a localized high-temperature field on the resin surface, and the high thermal conductivity of the foam metal promotes the rapid heat diffusion along the metal skeleton, forming a dynamically balanced temperature gradient. The center region of the spot is instantaneously heated to more than 2000 degrees Celsius due to energy concentration, triggering the intense pyrolysis and graphitization of the resin, and further realizing the in-situ growth of nanoparticle-shaped graphene on the surface of the foam metal. The adjacent pore edges maintain a relatively low temperature due to metal heat dissipation, thereby inhibiting excessive oxidation and stabilizing the graphitization reaction process.

[0086] In a more preferred embodiment, the mid-infrared large-size spot laser beam is provided by a mid-infrared CO2 laser or a visible semiconductor laser. Preferably, the laser power is 16 W, the defocusing amount is +2 mm, the scanning speed is 100 mm / s, and the scanning pixel step is 1000 DPI (i.e., the scanning pitch is 25.4 μm) of the mid-infrared CO2 laser. The prepared supercapacitor has the best performance.

[0087] Preferably, in step S2, the spot size of the ultraviolet small-size spot laser beam is 10-20 μm, the pulse center wavelength is 355 nm, the pulse width is 5-20 ps, the scanning adopts a grating-type overlapping row-by-row path from left to right, the scanning speed is 600-1000 mm / s, the focusing is adopted, the scanning pitch is 15-25.4 μm, and the laser power is set to 7.5-16 W.

[0088] The selective ablation of the cyanate ester resin / foam metal composite film can be realized by the parameter combination, so that the adhesive layer of the substrate is fully carbonized, and the morphology and electrical properties of the surface layer material are stable when the cyanate ester resin / foam metal composite film is peeled off from the glass substrate.

[0089] The ultraviolet small-size spot laser beam adopts a small-size spot, high peak power, short pulse width, and high laser scanning speed of the ultraviolet ultrafast pulse laser, the purpose is to use the characteristics of the instantaneous high peak power of the ultrafast pulse laser to complete the bond breaking before energy diffusion, and avoid the expansion of the heat affected zone; at the same time, the adhesive layer experiences the conversion chain of dehydrogenation, aromatic ring and polycondensation at the instantaneous high temperature (> 1500K), and finally forms a continuous carbon network; and the glass substrate has a high thermal diffusion coefficient, thereby limiting the substrate temperature rise to below 80°C.

[0090] In a more preferred embodiment, the ultraviolet small-size spot laser beam is provided by an ultraviolet ultrafast laser or an ultraviolet nanosecond laser, preferably an ultraviolet picosecond laser with a pulse center wavelength of 355 nm and a pulse width of 10 ps, and the parameters are set as a scanning speed of 800 mm / s, focusing, a scanning interval of 25.4 μm, and a laser power of 10.5 W, and the prepared supercapacitor has the best performance.

[0091] Preferably, in step S3, the edges of the coated ionogel electrolyte are covered on the inner edge of the second mask to form a safety interval, and the width of the safety interval is 0.8 mm-1.2 mm.

[0092] When coating the electrolyte, the electrolyte is in contact with and covers the inner edge of the second mask to ensure complete coverage of the coating area by the electrolyte. At the same time, due to the hydrophobic property of the second mask, the electrolyte will be limited within the coating area under the action of surface tension and will not overflow the coating boundary. A safety interval less than 0.8 mm will result in insufficient sealing strength, and a safety interval greater than 1.2 mm will affect the effective area of the electrode.

[0093] Preferably, in step S3, after the second mask is attached to the electrode, the second mask needs to be repeatedly pressed. In a specific embodiment, the mask is pressed by tweezers or an acrylic rod to make the second mask tightly adhere to the surface of the electrode, prevent electrolyte leakage, and isolate the gas infiltration path to eliminate the risk of short circuit caused by the interface gap.

[0094] Preferably, in step S3, the electrode is cleaned with anhydrous ethanol and deionized water. The cleaned electrode is dried at 50°C-90°C for 10 minutes to 30 minutes.

[0095] Preferably, in step S4, the material of the ionogel electrolyte is PVA / H3PO4, PVA / H2SO4, or PVA / LiCl.

[0096] The polyvinyl alcohol (PVA) based semi-solid gel electrolyte has excellent leakage prevention and solid state characteristics, greatly enhancing safety and packaging convenience; its flexible gel structure has a certain flexibility and elasticity, and can be bent and stretched; and it can provide more stable electrode / electrolyte interface contact.

[0097] Preferably, the vacuum degree of the vacuumizing treatment in step S4 is maintained at -0.9 MPa to -0.7 MPa, and the treatment time is 30 minutes to 50 minutes.

[0098] It is worth mentioning that the key of the vacuumizing treatment is to completely remove the gas molecules in the electrode micropores and the gel electrolyte, ensuring the two to form a close contact without bubbles. Any bubbles remaining in the electrode / electrolyte interface or inside the gel will significantly increase the system resistance and hinder the effective interface transmission of ions, thereby affecting the filtering effect of the device. In specific embodiments, a vacuum drying oven is used for vacuumizing treatment.

[0099] A filtering supercapacitor prepared by using the above preparation method.

[0100] The filtering supercapacitor prepared by the present scheme still maintains good capacitance behavior at a scan rate of up to 2500 V / s, and is suitable for the rapid development of portable intelligent electronic devices towards miniaturization and high integration. Other characteristics refer to Figures 5 to 12 .

[0101] Example 1

[0102] S1, adhere a substrate on a glass substrate, then place a foamed metal with an open hole structure on the substrate, and then fix and seal the outer periphery of the foamed metal by pressing and adhering the outer periphery of the foamed metal through a flexible annular first mask with single-sided adhesive; thereafter, coat a liquid cyanate ester monomer on the foamed metal and heat it at a constant temperature for solidification, to obtain a cyanate ester resin / foamed metal composite film;

[0103] The substrate is a polyimide film with a size of 50 mm x 50 mm and a thickness of 125 μm, which is flatly attached to a glass substrate with a size of 50 mm x 50 mm and a thickness of 2 mm. Then the surface of the sample is cleaned with anhydrous ethanol and washed with deionized water, and after cleaning, it is dried in a vacuum oven at 60°C for 15 min to remove residual solvents and moisture. A piece of foam copper with a size of 33 mm x 33 mm and a thickness of 0.1 mm is placed on the center of the cleaned sample surface, and a first mask of polyimide material with a thickness of 100 μm is used to position and fix and seal the foam copper area, ensuring accurate control of the subsequent operation area. At the same time, the solid cyanate ester monomer is pretreated, and after being placed in a sealed container, it is heated in a 70°C water bath for 30 min, and the solid cyanate ester monomer is converted into a uniform liquid cyanate ester monomer for use. The sample assembly with the fixed foam copper is placed on a balance tray, accurately weighed and slowly added 0.3 g of liquid cyanate ester monomer to the foam copper area. Then use a small stick to scrape the surface, so that the liquid cyanate ester monomer completely covers the foam copper and uniformly impregnates the foam copper pores. Finally, the whole sample is transferred to a preheated heating stage. Set the temperature program so that the sample is heated from the starting temperature of 90°C to 230°C in 8 hours for curing reaction, starting at 90°C for 30 min to fully infiltrate the foam metal pores; then increase to 120°C in 30 min, and keep for 30 min to activate the prepolymerization reaction and start the bubble discharge; continue to increase to 150°C in 30 min, and keep for 30 min to complete the dynamic degassing; then increase to 200°C in 30 min, and keep for 2 hours to control the main crosslinking exothermic peak; then increase to 230°C in 30 min, and keep for 2 hours to strengthen the triazine ring network to ensure complete reaction. After the reaction is completed, the sample is naturally cooled to room temperature on the heating stage, and a cyanate ester resin / foam copper composite film is prepared.

[0104] S2, irradiate the cyanate ester resin / foam metal composite film obtained in step S1 by a mid-infrared large-size spot laser beam to generate a nanoparticle graphene / foam metal film; then invert the nanoparticle graphene / foam metal film, and separate the substrate and the glass substrate by a ultraviolet small-size spot laser beam to obtain a nanoparticle graphene / foam metal electrode raw material;

[0105] The prepared cyanate ester resin / foamed copper composite film is placed on the workbench, and the middle infrared large-size spot laser beam irradiation process adopts a continuous CO2 laser with a rated power of 50 W and a beam diameter of 250 μm (wavelength 10.6 μm). The laser working power is set to 16 W, the defocusing amount is +2 mm, the scanning speed is 100 mm / s, the scanning pixel step is 1000 DPI, and the grating S-shaped overlapping path (serpentine scanning) is used for laser direct writing scanning of the film. The scanning process in-situ grows nano-particle graphene on the foamed metal surface, induces the conversion of the cyanate ester resin / foamed copper composite film into a nano-particle graphene / foamed copper film, and the surface micro-morphology of the nano-particle graphene / foamed metal film is shown in Figure 5 Subsequently, the sample is placed upside down on the workbench, and the ultraviolet small-size spot laser beam irradiation process selects an ultraviolet picosecond pulse laser with a center wavelength of 355 nm, a repetition frequency of 600 Hz, and a pulse width of about 10 ps. The laser scanning adopts a grating overlapping row-by-row path from left to right, the scanning speed is 800 mm / s, the focusing, and the scanning pitch is 25.4 μm, and the laser power is set to 10.5 W, thereby completing the substrate peeling process.

[0106] S3, the nano-particle graphene / foamed metal electrode raw material obtained in step S2 is cut into an electrode, the electrode is cleaned and dried, a laser ablation process is used to pattern the second mask, and the second mask is attached to the electrode;

[0107] The nano-particle graphene / foamed metal electrode raw material is cut into an electrode with a size of 5 mm × 6 mm. Subsequently, the electrode surface is cleaned with anhydrous ethanol and deionized water in sequence, and then dried at 50°C for 15 minutes after cleaning. The second mask is made of polyimide and has a thickness of 40 μm. The laser ablation process uses an ultraviolet picosecond laser with a wavelength of 355 nm, and the laser power is set to 16 W, the focusing, and the scanning speed is 60 mm / s. The second mask is patterned according to the preset pattern. After processing, the polyimide part corresponding to the electrolyte coating area on the second mask is removed using tweezers or a precision knife. Then, the patterned second mask is attached to the electrode. During the attachment process, the inner edge of the second mask should cover the working area of the electrode, and the second mask should be pressed repeatedly by the tweezers to completely remove the air bubbles. This operation aims to ensure the reliability and sealing performance of the packaging structure.

[0108] S4, two electrodes prepared in step S3 are taken, and the ion gel electrolyte is uniformly coated on the surface of each electrode, and then the electrodes are transferred to the vacuum chamber for vacuum treatment. After the ion gel electrolyte is converted into a semi-cured state, a plurality of electrodes are aligned and attached, and pressure is applied. The electrodes are cured and shaped at room temperature to obtain a sandwich type filter supercapacitor.

[0109] The material of the ion gel electrolyte is PVA / H2SO4, and the preparation method is as follows: polyvinyl alcohol, deionized water and H2SO are mixed in a mass ratio of 2.8 g PVA: 26 g H2O: 2.8 g H2SO4, and stirred at 90°C for 2 hours to obtain the ion gel electrolyte. Then, 0.2 mL of ion gel electrolyte is uniformly dropped on the surface of the electrode, and transferred to the vacuum chamber, and after vacuum treatment at-0.8 MPa, the sample is taken out and placed in a constant temperature drying box at 25°C for 12 hours to fully remove the residual moisture.

[0110] As shown in Figure 3 , in this embodiment, two electrodes are respectively provided with one working area coated with electrolyte, and then the working areas of the two electrodes are accurately aligned and attached. After being fixed for 12 hours in the same temperature environment (25°C), a single sandwich type filter supercapacitor is prepared. The prepared supercapacitor has a phase angle of-68.8° at 120Hz, a surface specific capacitance of 102.1 μF / cm² (18 times that of a commercial aluminum electrolytic capacitor), a cutoff frequency of 2373Hz (10 times that of a commercial aluminum electrolytic capacitor), an RC time constant of 0.40ms, and as shown in Figure 6 , the CV curve still maintains a quasi-rectangular shape at a scanning speed of 2500V / s. According to Figure 9 , various complex waveform signals can be filtered through experimental tests, and the output is a nearly straight DC output signal, and the filtering effect is good.

[0111] Example 2

[0112] S1, a substrate is attached on a glass substrate, then a foamed metal with an opening structure is placed on the substrate, and then a flexible annular first mask with single-sided adhesive is used to press and attach the outer periphery of the foamed metal to fix and seal it. Then, liquid cyanate ester monomer is coated on the foamed metal and heated at constant temperature for curing to obtain a cyanate ester resin / foamed metal composite film;

[0113] A 125 pm thick polyimide film was cut into a 50 mm x 50 mm piece and attached flat to a 50 mm x 50 mm glass sheet with a thickness of 2 mm. The sample surface was then cleaned with absolute ethanol and rinsed with deionized water, and after cleaning, dried in a vacuum oven at 60 °C for 15 min to remove residual solvents and moisture. A 33 mm x 33 mm x 0.1 mm piece of nickel foam was placed centrally on the cleaned sample surface, and a 100 pm thick square ring polyimide mask was used to locate the nickel foam area and to perform fixation and sealing to ensure accurate control of the area for subsequent operations. At the same time, the solid cyanate ester monomer was pre-processed by heating it in a 70 °C water bath. After 30 min, the solid cyanate ester monomer was converted to a uniform liquid state for use. The sample assembly with the nickel foam fixed was placed on a balance tray. 0.3 g of the liquid cyanate ester monomer was accurately weighed and slowly added to the nickel foam area. Then a small rod was used to scrape the surface of the monomer to uniformly impregnate and completely cover the nickel foam pores. Finally, the sample-loaded assembly was transferred to a preheated heating stage. The temperature program was set so that the sample was heated from the starting temperature of 90 °C to 230 °C in 8 hours for the curing reaction. Starting at 90 °C for 30 min, the foam metal pores were fully infiltrated; then increasing to 120 °C for 30 min to activate the prepolymerization reaction and initiate bubble discharge; continuing to increase to 150 °C for 30 min, and holding for 30 min to complete the dynamic degassing; then increasing to 200 °C for 2 h to control the main crosslinking exothermic peak; and then increasing to 230 °C for 2 h to strengthen the triazine ring network to ensure complete reaction. After the reaction was completed, the sample was naturally cooled to room temperature on the heating stage to obtain the target product, a cyanate ester resin / nickel foam composite film.

[0114] S2, irradiating the cyanate ester resin / foam metal composite film obtained in step S1 by a mid-infrared large-size spot laser beam to generate a nanoparticle graphene / foam metal film; then inverting the nanoparticle graphene / foam metal film and separating the substrate and glass substrate by a ultraviolet small-size spot laser beam to obtain a nanoparticle graphene / foam metal electrode raw material;

[0115] The prepared cyanate ester resin / foam nickel composite film was placed on the workbench, a continuous CO2 laser with a rated power of 50 W and a light beam diameter of 250 μm (wavelength 10.6 μm) was used, the laser working power was set to 16 W, the defocusing amount was +2 mm, the scanning speed was 100 mm / s, the scanning pixel step was 1000 DPI, and the grating S-shaped overlapping path (serpentine scanning) was used for laser direct writing scanning of the film. The scanning process in-situ grew nano-particle graphene on the foam metal surface, induced the conversion of the cyanate ester resin / foam nickel composite film into a nano-particle graphene / foam nickel film, and the XRD pattern of the nano-particle graphene / foam nickel film is shown in Figure 11 The Raman spectrum of the nano-particle graphene / foam nickel film is shown in Figure 12 Subsequently, the sample was placed upside down on the workbench, a UV picosecond pulsed laser with a center wavelength of 355 nm, a repetition frequency of 600 Hz, and a pulse width of about 10 ps was selected, the laser scanning used a grating overlapping row-by-row path from left to right, the scanning speed was 800 mm / s, the focusing, and the scanning pitch was 25.4 μm, and the laser power was set to 10.5 W, thereby completing the substrate peeling process.

[0116] S3, the nano-particle graphene / foam metal electrode raw material obtained in step S2 was cut into an electrode, the electrode was cleaned and dried, a laser ablation process was used to pattern the second mask, and the second mask was attached to the electrode;

[0117] The nano-particle graphene / foam metal electrode raw material was cut into an electrode with a size of 5 mm × 6 mm. Subsequently, the electrode surface was cleaned with anhydrous ethanol and deionized water in sequence, and then dried at 50°C for 15 minutes after cleaning. The laser ablation process used a UV picosecond laser with a wavelength of 355 nm, the laser power was set to 16 W, the focusing, the scanning speed was 60 mm / s, and the second mask was patterned according to the preset pattern. After processing, the polyimide part corresponding to the electrolyte coating area on the second mask was removed using tweezers or a precision knife. Then, the patterned second mask was attached to the electrode. During the attachment process, it was necessary to ensure that the inner edge of the second mask covered the working area of the electrode, and the second mask was repeatedly pressed by the tweezers to completely remove the air bubbles. This operation aimed to ensure the reliability and sealing of the packaging structure.

[0118] S4, eleven electrodes prepared in step S3 were taken, and the ionic gel electrolyte was uniformly coated on the surface of each electrode, and then the electrodes were transferred to a vacuum chamber for vacuum treatment; after the ionic gel electrolyte was converted into a semi-cured state, a plurality of electrodes were aligned and attached, and pressure was applied, and the electrodes were cured and shaped at room temperature, thereby preparing a sandwich type filter supercapacitor.

[0119] The ionogel electrolyte is made of PVA / H2SO4 and is prepared as follows: Polyvinyl alcohol, deionized water, and H2SO4 are mixed at a mass ratio of 2.8 g PVA : 26 g H2O : 2.8 g H2SO4 and stirred continuously at 90℃ for 2 hours to obtain the ionogel electrolyte. Subsequently, 0.2 mL of the ionogel electrolyte is uniformly drop-coated onto the electrode surface and transferred to a vacuum chamber. After vacuum treatment at -0.8 MPa, the sample is removed and placed in a 25℃ constant temperature drying oven for 12 hours to fully remove residual moisture.

[0120] like Figure 4 As shown, in this embodiment, the two electrodes at the beginning and end each have a working area coated with electrolyte, and the nine electrodes in the middle each have two working areas coated with electrolyte. The electrolyte-coated surface of each electrode is then precisely aligned and bonded to the adjacent electrodes. Each electrode in the middle is staggered from its two adjacent electrodes and arranged in series. After being fixed in a constant temperature environment (25°C) for 12 hours, a sandwich-type filter supercapacitor with a series array is obtained. The supercapacitor produced exhibits a phase angle as high as -70° at 120Hz and a surface capacitance of 245μF / cm² (44 times that of commercial aluminum electrolytic capacitors). Figure 8 As shown, the cutoff frequency is as high as 3020Hz (12 times that of commercial aluminum electrolytic capacitors), and the RC time constant is as low as 0.33ms. The fabricated series array sandwich-type filter supercapacitor has a linear operating voltage extension to 10V, such as... Figure 7 As shown, the CV curve shows no distortion at a scan rate of 5000 V / s. (Reference) Figure 10 In actual filtering tests, the variance coefficient of the output DC signal for complex waveforms such as sine waves and pulse waves is less than 0.00024, indicating good filtering performance.

[0121] Other configurations and operations according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0122] In the description of this specification, references to terms such as "embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0123] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and application of the present application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present application, which is defined by the following claims and their equivalents.

Claims

1. A method for preparing a nanoparticulate graphene / foam metal-based filtering supercapacitor, characterized by, Comprise the following steps: S1, laminating a substrate on a glass substrate, then placing a foamed metal with an opening structure on the substrate, and then realizing fixation and sealing by pressing and laminating the outer periphery of the foamed metal through a flexible annular first mask with single-side glue coating, then coating liquid cyanate ester monomer on the foamed metal and constant temperature heating and curing to obtain a cyanate ester resin / foamed metal composite film; S2, irradiating the cyanate ester resin / foamed metal composite film obtained in step S1 by a middle infrared large size light spot laser beam to generate a nanoparticle graphene / foamed metal film; then inverting the nanoparticle graphene / foamed metal film and separating the substrate and the glass substrate by a ultraviolet small size light spot laser beam to obtain a nanoparticle graphene / foamed metal electrode raw material; S3, cutting the nanoparticle graphene / foamed metal electrode raw material obtained in step S2 into an electrode, cleaning and drying the electrode, patterning processing a second mask by a laser ablation process, and attaching the second mask on the electrode; S4, taking at least two electrodes prepared in step S3, coating an ion gel electrolyte on the surface of each electrode respectively, then transferring the electrodes to a vacuum cavity for vacuumizing treatment; after the ion gel electrolyte is converted into a semi-cured state, aligning and laminating a plurality of electrodes, applying pressure, and curing and shaping at room temperature to prepare a sandwich type filter supercapacitor.

2. The preparation method of the filtering supercapacitor based on nanoparticle graphene / foam metal according to claim 1, characterized in that: In step S1, the substrate is made of polyimide or polyethylene terephthalate, and the thickness of the substrate is 0.01mm-0.2mm.

3. The method for preparing a nanoparticle graphene / foam metal-based filtering supercapacitor according to claim 1, characterized in that: In step S1, the foamed metal is foamed nickel or foamed copper, and the thickness of the foamed metal is 0.1mm-0.3mm.

4. The method for preparing a nanoparticle graphene / foam metal-based filtering supercapacitor according to claim 1, characterized in that: In steps S1 and S3, the first mask and the second mask are both made of polyimide or polyethylene terephthalate, and the thickness of the first mask and the second mask is both 20-125μm.

5. The method for preparing a nanoparticle graphene / foam metal-based filtering supercapacitor according to claim 1, characterized in that: The solid cyanate ester monomer is pre-processed into a liquid cyanate ester monomer, the solid cyanate ester is placed in a container, the container is sealed, and then the container is immersed in a water bath for heating, the temperature of the water bath heating is 50-70℃, and the time is 20-30 minutes.

6. The method of claim 1, wherein the method comprises: The liquid cyanate ester monomer is added in a proportional and quantitative manner, and the unit area addition amount of the liquid cyanate ester monomer relative to the foamed metal is 20mg / cm² to 50mg / cm². ​ 7. The method of claim 1, wherein the method comprises: providing a graphene nanoplatelet dispersion; providing a foam metal; and mixing the graphene nanoplatelet dispersion and the foam metal to form a graphene nanoplatelet / foam metal mixture. In step S1, the heating and curing adopts a stepwise heating mode, the heating temperature is 90-230℃, and the time is 7-8 hours. 8.The method for preparing a nanoparticulate graphene / foam metal-based filtering supercapacitor according to claim 1, characterized in that: In step S2, the spot size of the middle infrared large size light spot laser beam is 200-500μm, the scanning adopts a grating S-shaped overlapping path, the scanning speed is 80-120mm / s, the defocusing amount is +2 to +4mm, the scanning pitch is 21.17-31.75μm, and the laser power is 7.5-25W. 9.The method for preparing a nanoparticulate graphene / foam metal-based filtering supercapacitor according to claim 1, characterized in that: In step S2, the spot size of the ultraviolet small-size spot laser beam is 10-20 μm, the pulse center wavelength is 355 nm, the pulse width is 5-20 ps, the scanning adopts the left-to-right grating type overlapping line-by-line path, the scanning speed is 600-1000 mm / s, the focusing is performed, the scanning interval is 15-25.4 μm, and the laser power is set to 7.5-16 W.

10. A filtered ultracapacitor, characterized by, The preparation method according to any one of claims 1-9.

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